715 cc->cb = cb;
716 cc->abandon_cb = abandon_cb;
717 cc->ctx = ctx;
718 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
719}
720
721void
722channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
723{
724 Channel *c = channel_lookup(id);
725
726 if (c == NULL) {
727 logit("channel_register_open_confirm: %d: bad id", id);
728 return;
729 }
730 c->open_confirm = fn;
731 c->open_confirm_ctx = ctx;
732}
733
734void
735channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
736{
737 Channel *c = channel_by_id(id);
738
739 if (c == NULL) {
740 logit("channel_register_cleanup: %d: bad id", id);
741 return;
742 }
743 c->detach_user = fn;
744 c->detach_close = do_close;
745}
746
747void
748channel_cancel_cleanup(int id)
749{
750 Channel *c = channel_by_id(id);
751
752 if (c == NULL) {
753 logit("channel_cancel_cleanup: %d: bad id", id);
754 return;
755 }
756 c->detach_user = NULL;
757 c->detach_close = 0;
758}
759
760void
761channel_register_filter(int id, channel_infilter_fn *ifn,
762 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
763{
764 Channel *c = channel_lookup(id);
765
766 if (c == NULL) {
767 logit("channel_register_filter: %d: bad id", id);
768 return;
769 }
770 c->input_filter = ifn;
771 c->output_filter = ofn;
772 c->filter_ctx = ctx;
773 c->filter_cleanup = cfn;
774}
775
776void
777channel_set_fds(int id, int rfd, int wfd, int efd,
778 int extusage, int nonblock, int is_tty, u_int window_max)
779{
780 Channel *c = channel_lookup(id);
781
782 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
783 fatal("channel_activate for non-larval channel %d.", id);
784 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
785 c->type = SSH_CHANNEL_OPEN;
786 c->local_window = c->local_window_max = window_max;
787 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
788 packet_put_int(c->remote_id);
789 packet_put_int(c->local_window);
790 packet_send();
791}
792
793/*
794 * 'channel_pre*' are called just before select() to add any bits relevant to
795 * channels in the select bitmasks.
796 */
797/*
798 * 'channel_post*': perform any appropriate operations for channels which
799 * have events pending.
800 */
801typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
802chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
803chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
804
805/* ARGSUSED */
806static void
807channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
808{
809 FD_SET(c->sock, readset);
810}
811
812/* ARGSUSED */
813static void
814channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
815{
816 debug3("channel %d: waiting for connection", c->self);
817 FD_SET(c->sock, writeset);
818}
819
820static void
821channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
822{
823 if (buffer_len(&c->input) < packet_get_maxsize())
824 FD_SET(c->sock, readset);
825 if (buffer_len(&c->output) > 0)
826 FD_SET(c->sock, writeset);
827}
828
829static u_int
830channel_tcpwinsz(void)
831{
832 u_int32_t tcpwinsz;
833 socklen_t optsz;
834 int ret, sd;
835 u_int maxlen;
836
837 /* If we are not on a socket return 128KB. */
838 if (!packet_connection_is_on_socket())
839 return (128 * 1024);
840
841 tcpwinsz = 0;
842 optsz = sizeof(tcpwinsz);
843 sd = packet_get_connection_in();
844 ret = getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
845
846 /* Return no more than the maximum buffer size. */
847 maxlen = buffer_get_max_len();
848 if ((ret == 0) && tcpwinsz > maxlen)
849 tcpwinsz = maxlen;
850 /* In case getsockopt() failed return a minimum. */
851 if (tcpwinsz == 0)
852 tcpwinsz = CHAN_TCP_WINDOW_DEFAULT;
853 debug2("tcpwinsz: %d for connection: %d", tcpwinsz, sd);
854 return (tcpwinsz);
855}
856
857static void
858channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
859{
860 u_int limit;
861
862 /* Check buffer limits. */
863 if (!c->tcpwinsz || c->dynamic_window > 0)
864 c->tcpwinsz = channel_tcpwinsz();
865
866 limit = MIN(compat20 ? c->remote_window : packet_get_maxsize(),
867 2 * c->tcpwinsz);
868
869 if (c->istate == CHAN_INPUT_OPEN &&
870 limit > 0 &&
871 buffer_len(&c->input) < limit &&
872 buffer_check_alloc(&c->input, CHAN_RBUF))
873 FD_SET(c->rfd, readset);
874 if (c->ostate == CHAN_OUTPUT_OPEN ||
875 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
876 if (buffer_len(&c->output) > 0) {
877 FD_SET(c->wfd, writeset);
878 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
879 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
880 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
881 c->self, c->efd, buffer_len(&c->extended));
882 else
883 chan_obuf_empty(c);
884 }
885 }
886 /** XXX check close conditions, too */
887 if (compat20 && c->efd != -1 &&
888 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
889 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
890 buffer_len(&c->extended) > 0)
891 FD_SET(c->efd, writeset);
892 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
893 (c->extended_usage == CHAN_EXTENDED_READ ||
894 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
895 buffer_len(&c->extended) < c->remote_window)
896 FD_SET(c->efd, readset);
897 }
898 /* XXX: What about efd? races? */
899}
900
901/* ARGSUSED */
902static void
903channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
904{
905 if (buffer_len(&c->input) == 0) {
906 packet_start(SSH_MSG_CHANNEL_CLOSE);
907 packet_put_int(c->remote_id);
908 packet_send();
909 c->type = SSH_CHANNEL_CLOSED;
910 debug2("channel %d: closing after input drain.", c->self);
911 }
912}
913
914/* ARGSUSED */
915static void
916channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
917{
918 if (buffer_len(&c->output) == 0)
919 chan_mark_dead(c);
920 else
921 FD_SET(c->sock, writeset);
922}
923
924/*
925 * This is a special state for X11 authentication spoofing. An opened X11
926 * connection (when authentication spoofing is being done) remains in this
927 * state until the first packet has been completely read. The authentication
928 * data in that packet is then substituted by the real data if it matches the
929 * fake data, and the channel is put into normal mode.
930 * XXX All this happens at the client side.
931 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
932 */
933static int
934x11_open_helper(Buffer *b)
935{
936 u_char *ucp;
937 u_int proto_len, data_len;
938
939 /* Check if the fixed size part of the packet is in buffer. */
940 if (buffer_len(b) < 12)
941 return 0;
942
943 /* Parse the lengths of variable-length fields. */
944 ucp = buffer_ptr(b);
945 if (ucp[0] == 0x42) { /* Byte order MSB first. */
946 proto_len = 256 * ucp[6] + ucp[7];
947 data_len = 256 * ucp[8] + ucp[9];
948 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
949 proto_len = ucp[6] + 256 * ucp[7];
950 data_len = ucp[8] + 256 * ucp[9];
951 } else {
952 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
953 ucp[0]);
954 return -1;
955 }
956
957 /* Check if the whole packet is in buffer. */
958 if (buffer_len(b) <
959 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
960 return 0;
961
962 /* Check if authentication protocol matches. */
963 if (proto_len != strlen(x11_saved_proto) ||
964 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
965 debug2("X11 connection uses different authentication protocol.");
966 return -1;
967 }
968 /* Check if authentication data matches our fake data. */
969 if (data_len != x11_fake_data_len ||
970 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
971 x11_fake_data, x11_fake_data_len) != 0) {
972 debug2("X11 auth data does not match fake data.");
973 return -1;
974 }
975 /* Check fake data length */
976 if (x11_fake_data_len != x11_saved_data_len) {
977 error("X11 fake_data_len %d != saved_data_len %d",
978 x11_fake_data_len, x11_saved_data_len);
979 return -1;
980 }
981 /*
982 * Received authentication protocol and data match
983 * our fake data. Substitute the fake data with real
984 * data.
985 */
986 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
987 x11_saved_data, x11_saved_data_len);
988 return 1;
989}
990
991static void
992channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
993{
994 int ret = x11_open_helper(&c->output);
995
996 if (ret == 1) {
997 /* Start normal processing for the channel. */
998 c->type = SSH_CHANNEL_OPEN;
999 channel_pre_open_13(c, readset, writeset);
1000 } else if (ret == -1) {
1001 /*
1002 * We have received an X11 connection that has bad
1003 * authentication information.
1004 */
1005 logit("X11 connection rejected because of wrong authentication.");
1006 buffer_clear(&c->input);
1007 buffer_clear(&c->output);
1008 channel_close_fd(&c->sock);
1009 c->sock = -1;
1010 c->type = SSH_CHANNEL_CLOSED;
1011 packet_start(SSH_MSG_CHANNEL_CLOSE);
1012 packet_put_int(c->remote_id);
1013 packet_send();
1014 }
1015}
1016
1017static void
1018channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1019{
1020 int ret = x11_open_helper(&c->output);
1021
1022 /* c->force_drain = 1; */
1023
1024 if (ret == 1) {
1025 c->type = SSH_CHANNEL_OPEN;
1026 channel_pre_open(c, readset, writeset);
1027 } else if (ret == -1) {
1028 logit("X11 connection rejected because of wrong authentication.");
1029 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1030 chan_read_failed(c);
1031 buffer_clear(&c->input);
1032 chan_ibuf_empty(c);
1033 buffer_clear(&c->output);
1034 /* for proto v1, the peer will send an IEOF */
1035 if (compat20)
1036 chan_write_failed(c);
1037 else
1038 c->type = SSH_CHANNEL_OPEN;
1039 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1040 }
1041}
1042
1043static void
1044channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1045{
1046 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1047 buffer_check_alloc(&c->input, CHAN_RBUF))
1048 FD_SET(c->rfd, readset);
1049 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1050 /* clear buffer immediately (discard any partial packet) */
1051 buffer_clear(&c->input);
1052 chan_ibuf_empty(c);
1053 /* Start output drain. XXX just kill chan? */
1054 chan_rcvd_oclose(c);
1055 }
1056 if (c->ostate == CHAN_OUTPUT_OPEN ||
1057 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1058 if (buffer_len(&c->output) > 0)
1059 FD_SET(c->wfd, writeset);
1060 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1061 chan_obuf_empty(c);
1062 }
1063}
1064
1065/* try to decode a socks4 header */
1066/* ARGSUSED */
1067static int
1068channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1069{
1070 char *p, *host;
1071 u_int len, have, i, found, need;
1072 char username[256];
1073 struct {
1074 u_int8_t version;
1075 u_int8_t command;
1076 u_int16_t dest_port;
1077 struct in_addr dest_addr;
1078 } s4_req, s4_rsp;
1079
1080 debug2("channel %d: decode socks4", c->self);
1081
1082 have = buffer_len(&c->input);
1083 len = sizeof(s4_req);
1084 if (have < len)
1085 return 0;
1086 p = buffer_ptr(&c->input);
1087
1088 need = 1;
1089 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1090 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1091 debug2("channel %d: socks4a request", c->self);
1092 /* ... and needs an extra string (the hostname) */
1093 need = 2;
1094 }
1095 /* Check for terminating NUL on the string(s) */
1096 for (found = 0, i = len; i < have; i++) {
1097 if (p[i] == '\0') {
1098 found++;
1099 if (found == need)
1100 break;
1101 }
1102 if (i > 1024) {
1103 /* the peer is probably sending garbage */
1104 debug("channel %d: decode socks4: too long",
1105 c->self);
1106 return -1;
1107 }
1108 }
1109 if (found < need)
1110 return 0;
1111 buffer_get(&c->input, (char *)&s4_req.version, 1);
1112 buffer_get(&c->input, (char *)&s4_req.command, 1);
1113 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1114 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1115 have = buffer_len(&c->input);
1116 p = buffer_ptr(&c->input);
1117 len = strlen(p);
1118 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1119 len++; /* trailing '\0' */
1120 if (len > have)
1121 fatal("channel %d: decode socks4: len %d > have %d",
1122 c->self, len, have);
1123 strlcpy(username, p, sizeof(username));
1124 buffer_consume(&c->input, len);
1125
1126 free(c->path);
1127 c->path = NULL;
1128 if (need == 1) { /* SOCKS4: one string */
1129 host = inet_ntoa(s4_req.dest_addr);
1130 c->path = xstrdup(host);
1131 } else { /* SOCKS4A: two strings */
1132 have = buffer_len(&c->input);
1133 p = buffer_ptr(&c->input);
1134 len = strlen(p);
1135 debug2("channel %d: decode socks4a: host %s/%d",
1136 c->self, p, len);
1137 len++; /* trailing '\0' */
1138 if (len > have)
1139 fatal("channel %d: decode socks4a: len %d > have %d",
1140 c->self, len, have);
1141 if (len > NI_MAXHOST) {
1142 error("channel %d: hostname \"%.100s\" too long",
1143 c->self, p);
1144 return -1;
1145 }
1146 c->path = xstrdup(p);
1147 buffer_consume(&c->input, len);
1148 }
1149 c->host_port = ntohs(s4_req.dest_port);
1150
1151 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1152 c->self, c->path, c->host_port, s4_req.command);
1153
1154 if (s4_req.command != 1) {
1155 debug("channel %d: cannot handle: %s cn %d",
1156 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1157 return -1;
1158 }
1159 s4_rsp.version = 0; /* vn: 0 for reply */
1160 s4_rsp.command = 90; /* cd: req granted */
1161 s4_rsp.dest_port = 0; /* ignored */
1162 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1163 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1164 return 1;
1165}
1166
1167/* try to decode a socks5 header */
1168#define SSH_SOCKS5_AUTHDONE 0x1000
1169#define SSH_SOCKS5_NOAUTH 0x00
1170#define SSH_SOCKS5_IPV4 0x01
1171#define SSH_SOCKS5_DOMAIN 0x03
1172#define SSH_SOCKS5_IPV6 0x04
1173#define SSH_SOCKS5_CONNECT 0x01
1174#define SSH_SOCKS5_SUCCESS 0x00
1175
1176/* ARGSUSED */
1177static int
1178channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1179{
1180 struct {
1181 u_int8_t version;
1182 u_int8_t command;
1183 u_int8_t reserved;
1184 u_int8_t atyp;
1185 } s5_req, s5_rsp;
1186 u_int16_t dest_port;
1187 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1188 u_char *p;
1189 u_int have, need, i, found, nmethods, addrlen, af;
1190
1191 debug2("channel %d: decode socks5", c->self);
1192 p = buffer_ptr(&c->input);
1193 if (p[0] != 0x05)
1194 return -1;
1195 have = buffer_len(&c->input);
1196 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1197 /* format: ver | nmethods | methods */
1198 if (have < 2)
1199 return 0;
1200 nmethods = p[1];
1201 if (have < nmethods + 2)
1202 return 0;
1203 /* look for method: "NO AUTHENTICATION REQUIRED" */
1204 for (found = 0, i = 2; i < nmethods + 2; i++) {
1205 if (p[i] == SSH_SOCKS5_NOAUTH) {
1206 found = 1;
1207 break;
1208 }
1209 }
1210 if (!found) {
1211 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1212 c->self);
1213 return -1;
1214 }
1215 buffer_consume(&c->input, nmethods + 2);
1216 buffer_put_char(&c->output, 0x05); /* version */
1217 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1218 FD_SET(c->sock, writeset);
1219 c->flags |= SSH_SOCKS5_AUTHDONE;
1220 debug2("channel %d: socks5 auth done", c->self);
1221 return 0; /* need more */
1222 }
1223 debug2("channel %d: socks5 post auth", c->self);
1224 if (have < sizeof(s5_req)+1)
1225 return 0; /* need more */
1226 memcpy(&s5_req, p, sizeof(s5_req));
1227 if (s5_req.version != 0x05 ||
1228 s5_req.command != SSH_SOCKS5_CONNECT ||
1229 s5_req.reserved != 0x00) {
1230 debug2("channel %d: only socks5 connect supported", c->self);
1231 return -1;
1232 }
1233 switch (s5_req.atyp){
1234 case SSH_SOCKS5_IPV4:
1235 addrlen = 4;
1236 af = AF_INET;
1237 break;
1238 case SSH_SOCKS5_DOMAIN:
1239 addrlen = p[sizeof(s5_req)];
1240 af = -1;
1241 break;
1242 case SSH_SOCKS5_IPV6:
1243 addrlen = 16;
1244 af = AF_INET6;
1245 break;
1246 default:
1247 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1248 return -1;
1249 }
1250 need = sizeof(s5_req) + addrlen + 2;
1251 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1252 need++;
1253 if (have < need)
1254 return 0;
1255 buffer_consume(&c->input, sizeof(s5_req));
1256 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1257 buffer_consume(&c->input, 1); /* host string length */
1258 buffer_get(&c->input, &dest_addr, addrlen);
1259 buffer_get(&c->input, (char *)&dest_port, 2);
1260 dest_addr[addrlen] = '\0';
1261 free(c->path);
1262 c->path = NULL;
1263 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1264 if (addrlen >= NI_MAXHOST) {
1265 error("channel %d: dynamic request: socks5 hostname "
1266 "\"%.100s\" too long", c->self, dest_addr);
1267 return -1;
1268 }
1269 c->path = xstrdup(dest_addr);
1270 } else {
1271 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1272 return -1;
1273 c->path = xstrdup(ntop);
1274 }
1275 c->host_port = ntohs(dest_port);
1276
1277 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1278 c->self, c->path, c->host_port, s5_req.command);
1279
1280 s5_rsp.version = 0x05;
1281 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1282 s5_rsp.reserved = 0; /* ignored */
1283 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1284 dest_port = 0; /* ignored */
1285
1286 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1287 buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
1288 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1289 return 1;
1290}
1291
1292Channel *
1293channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1294 int in, int out)
1295{
1296 Channel *c;
1297
1298 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1299 port_to_connect);
1300
1301 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1302 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1303 0, "stdio-forward", /*nonblock*/0);
1304
1305 c->path = xstrdup(host_to_connect);
1306 c->host_port = port_to_connect;
1307 c->listening_port = 0;
1308 c->force_drain = 1;
1309
1310 channel_register_fds(c, in, out, -1, 0, 1, 0);
1311 port_open_helper(c, "direct-tcpip");
1312
1313 return c;
1314}
1315
1316/* dynamic port forwarding */
1317static void
1318channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1319{
1320 u_char *p;
1321 u_int have;
1322 int ret;
1323
1324 have = buffer_len(&c->input);
1325 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1326 /* buffer_dump(&c->input); */
1327 /* check if the fixed size part of the packet is in buffer. */
1328 if (have < 3) {
1329 /* need more */
1330 FD_SET(c->sock, readset);
1331 return;
1332 }
1333 /* try to guess the protocol */
1334 p = buffer_ptr(&c->input);
1335 switch (p[0]) {
1336 case 0x04:
1337 ret = channel_decode_socks4(c, readset, writeset);
1338 break;
1339 case 0x05:
1340 ret = channel_decode_socks5(c, readset, writeset);
1341 break;
1342 default:
1343 ret = -1;
1344 break;
1345 }
1346 if (ret < 0) {
1347 chan_mark_dead(c);
1348 } else if (ret == 0) {
1349 debug2("channel %d: pre_dynamic: need more", c->self);
1350 /* need more */
1351 FD_SET(c->sock, readset);
1352 } else {
1353 /* switch to the next state */
1354 c->type = SSH_CHANNEL_OPENING;
1355 port_open_helper(c, "direct-tcpip");
1356 }
1357}
1358
1359/* This is our fake X11 server socket. */
1360/* ARGSUSED */
1361static void
1362channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1363{
1364 Channel *nc;
1365 struct sockaddr_storage addr;
1366 int newsock, oerrno;
1367 socklen_t addrlen;
1368 char buf[16384], *remote_ipaddr;
1369 int remote_port;
1370
1371 if (FD_ISSET(c->sock, readset)) {
1372 debug("X11 connection requested.");
1373 addrlen = sizeof(addr);
1374 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1375 if (c->single_connection) {
1376 oerrno = errno;
1377 debug2("single_connection: closing X11 listener.");
1378 channel_close_fd(&c->sock);
1379 chan_mark_dead(c);
1380 errno = oerrno;
1381 }
1382 if (newsock < 0) {
1383 if (errno != EINTR && errno != EWOULDBLOCK &&
1384 errno != ECONNABORTED)
1385 error("accept: %.100s", strerror(errno));
1386 if (errno == EMFILE || errno == ENFILE)
1387 c->notbefore = monotime() + 1;
1388 return;
1389 }
1390 set_nodelay(newsock);
1391 remote_ipaddr = get_peer_ipaddr(newsock);
1392 remote_port = get_peer_port(newsock);
1393 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1394 remote_ipaddr, remote_port);
1395
1396 nc = channel_new("accepted x11 socket",
1397 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1398 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1399 if (compat20) {
1400 packet_start(SSH2_MSG_CHANNEL_OPEN);
1401 packet_put_cstring("x11");
1402 packet_put_int(nc->self);
1403 packet_put_int(nc->local_window_max);
1404 packet_put_int(nc->local_maxpacket);
1405 /* originator ipaddr and port */
1406 packet_put_cstring(remote_ipaddr);
1407 if (datafellows & SSH_BUG_X11FWD) {
1408 debug2("ssh2 x11 bug compat mode");
1409 } else {
1410 packet_put_int(remote_port);
1411 }
1412 packet_send();
1413 } else {
1414 packet_start(SSH_SMSG_X11_OPEN);
1415 packet_put_int(nc->self);
1416 if (packet_get_protocol_flags() &
1417 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1418 packet_put_cstring(buf);
1419 packet_send();
1420 }
1421 free(remote_ipaddr);
1422 }
1423}
1424
1425static void
1426port_open_helper(Channel *c, char *rtype)
1427{
1428 int direct;
1429 char buf[1024];
1430 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1431 int remote_port = get_peer_port(c->sock);
1432
1433 if (remote_port == -1) {
1434 /* Fake addr/port to appease peers that validate it (Tectia) */
1435 free(remote_ipaddr);
1436 remote_ipaddr = xstrdup("127.0.0.1");
1437 remote_port = 65535;
1438 }
1439
1440 direct = (strcmp(rtype, "direct-tcpip") == 0);
1441
1442 snprintf(buf, sizeof buf,
1443 "%s: listening port %d for %.100s port %d, "
1444 "connect from %.200s port %d",
1445 rtype, c->listening_port, c->path, c->host_port,
1446 remote_ipaddr, remote_port);
1447
1448 free(c->remote_name);
1449 c->remote_name = xstrdup(buf);
1450
1451 if (compat20) {
1452 packet_start(SSH2_MSG_CHANNEL_OPEN);
1453 packet_put_cstring(rtype);
1454 packet_put_int(c->self);
1455 packet_put_int(c->local_window_max);
1456 packet_put_int(c->local_maxpacket);
1457 if (direct) {
1458 /* target host, port */
1459 packet_put_cstring(c->path);
1460 packet_put_int(c->host_port);
1461 } else {
1462 /* listen address, port */
1463 packet_put_cstring(c->path);
1464 packet_put_int(c->listening_port);
1465 }
1466 /* originator host and port */
1467 packet_put_cstring(remote_ipaddr);
1468 packet_put_int((u_int)remote_port);
1469 packet_send();
1470 } else {
1471 packet_start(SSH_MSG_PORT_OPEN);
1472 packet_put_int(c->self);
1473 packet_put_cstring(c->path);
1474 packet_put_int(c->host_port);
1475 if (packet_get_protocol_flags() &
1476 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1477 packet_put_cstring(c->remote_name);
1478 packet_send();
1479 }
1480 free(remote_ipaddr);
1481}
1482
1483static void
1484channel_set_reuseaddr(int fd)
1485{
1486 int on = 1;
1487
1488 /*
1489 * Set socket options.
1490 * Allow local port reuse in TIME_WAIT.
1491 */
1492 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1493 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1494}
1495
1496/*
1497 * This socket is listening for connections to a forwarded TCP/IP port.
1498 */
1499/* ARGSUSED */
1500static void
1501channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1502{
1503 Channel *nc;
1504 struct sockaddr_storage addr;
1505 int newsock, nextstate;
1506 socklen_t addrlen;
1507 char *rtype;
1508
1509 if (FD_ISSET(c->sock, readset)) {
1510 debug("Connection to port %d forwarding "
1511 "to %.100s port %d requested.",
1512 c->listening_port, c->path, c->host_port);
1513
1514 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1515 nextstate = SSH_CHANNEL_OPENING;
1516 rtype = "forwarded-tcpip";
1517 } else {
1518 if (c->host_port == 0) {
1519 nextstate = SSH_CHANNEL_DYNAMIC;
1520 rtype = "dynamic-tcpip";
1521 } else {
1522 nextstate = SSH_CHANNEL_OPENING;
1523 rtype = "direct-tcpip";
1524 }
1525 }
1526
1527 addrlen = sizeof(addr);
1528 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1529 if (newsock < 0) {
1530 if (errno != EINTR && errno != EWOULDBLOCK &&
1531 errno != ECONNABORTED)
1532 error("accept: %.100s", strerror(errno));
1533 if (errno == EMFILE || errno == ENFILE)
1534 c->notbefore = monotime() + 1;
1535 return;
1536 }
1537 set_nodelay(newsock);
1538 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1539 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1540 nc->listening_port = c->listening_port;
1541 nc->host_port = c->host_port;
1542 if (c->path != NULL)
1543 nc->path = xstrdup(c->path);
1544
1545 if (nextstate != SSH_CHANNEL_DYNAMIC)
1546 port_open_helper(nc, rtype);
1547 }
1548}
1549
1550/*
1551 * This is the authentication agent socket listening for connections from
1552 * clients.
1553 */
1554/* ARGSUSED */
1555static void
1556channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1557{
1558 Channel *nc;
1559 int newsock;
1560 struct sockaddr_storage addr;
1561 socklen_t addrlen;
1562
1563 if (FD_ISSET(c->sock, readset)) {
1564 addrlen = sizeof(addr);
1565 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1566 if (newsock < 0) {
1567 error("accept from auth socket: %.100s",
1568 strerror(errno));
1569 if (errno == EMFILE || errno == ENFILE)
1570 c->notbefore = monotime() + 1;
1571 return;
1572 }
1573 nc = channel_new("accepted auth socket",
1574 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1575 c->local_window_max, c->local_maxpacket,
1576 0, "accepted auth socket", 1);
1577 if (compat20) {
1578 packet_start(SSH2_MSG_CHANNEL_OPEN);
1579 packet_put_cstring("auth-agent@openssh.com");
1580 packet_put_int(nc->self);
1581 packet_put_int(c->local_window_max);
1582 packet_put_int(c->local_maxpacket);
1583 } else {
1584 packet_start(SSH_SMSG_AGENT_OPEN);
1585 packet_put_int(nc->self);
1586 }
1587 packet_send();
1588 }
1589}
1590
1591/* ARGSUSED */
1592static void
1593channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1594{
1595 int err = 0, sock;
1596 socklen_t sz = sizeof(err);
1597
1598 if (FD_ISSET(c->sock, writeset)) {
1599 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1600 err = errno;
1601 error("getsockopt SO_ERROR failed");
1602 }
1603 if (err == 0) {
1604 debug("channel %d: connected to %s port %d",
1605 c->self, c->connect_ctx.host, c->connect_ctx.port);
1606 channel_connect_ctx_free(&c->connect_ctx);
1607 c->type = SSH_CHANNEL_OPEN;
1608 if (compat20) {
1609 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1610 packet_put_int(c->remote_id);
1611 packet_put_int(c->self);
1612 packet_put_int(c->local_window);
1613 packet_put_int(c->local_maxpacket);
1614 } else {
1615 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1616 packet_put_int(c->remote_id);
1617 packet_put_int(c->self);
1618 }
1619 } else {
1620 debug("channel %d: connection failed: %s",
1621 c->self, strerror(err));
1622 /* Try next address, if any */
1623 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1624 close(c->sock);
1625 c->sock = c->rfd = c->wfd = sock;
1626 channel_max_fd = channel_find_maxfd();
1627 return;
1628 }
1629 /* Exhausted all addresses */
1630 error("connect_to %.100s port %d: failed.",
1631 c->connect_ctx.host, c->connect_ctx.port);
1632 channel_connect_ctx_free(&c->connect_ctx);
1633 if (compat20) {
1634 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1635 packet_put_int(c->remote_id);
1636 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1637 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1638 packet_put_cstring(strerror(err));
1639 packet_put_cstring("");
1640 }
1641 } else {
1642 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1643 packet_put_int(c->remote_id);
1644 }
1645 chan_mark_dead(c);
1646 }
1647 packet_send();
1648 }
1649}
1650
1651/* ARGSUSED */
1652static int
1653channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1654{
1655 char buf[CHAN_RBUF];
1656 int len, force;
1657
1658 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1659 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1660 errno = 0;
1661 len = read(c->rfd, buf, sizeof(buf));
1662 if (len < 0 && (errno == EINTR ||
1663 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1664 return 1;
1665#ifndef PTY_ZEROREAD
1666 if (len <= 0) {
1667#else
1668 if ((!c->isatty && len <= 0) ||
1669 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1670#endif
1671 debug2("channel %d: read<=0 rfd %d len %d",
1672 c->self, c->rfd, len);
1673 if (c->type != SSH_CHANNEL_OPEN) {
1674 debug2("channel %d: not open", c->self);
1675 chan_mark_dead(c);
1676 return -1;
1677 } else if (compat13) {
1678 buffer_clear(&c->output);
1679 c->type = SSH_CHANNEL_INPUT_DRAINING;
1680 debug2("channel %d: input draining.", c->self);
1681 } else {
1682 chan_read_failed(c);
1683 }
1684 return -1;
1685 }
1686 if (c->input_filter != NULL) {
1687 if (c->input_filter(c, buf, len) == -1) {
1688 debug2("channel %d: filter stops", c->self);
1689 chan_read_failed(c);
1690 }
1691 } else if (c->datagram) {
1692 buffer_put_string(&c->input, buf, len);
1693 } else {
1694 buffer_append(&c->input, buf, len);
1695 }
1696 }
1697 return 1;
1698}
1699
1700/* ARGSUSED */
1701static int
1702channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1703{
1704 struct termios tio;
1705 u_char *data = NULL, *buf;
1706 u_int dlen, olen = 0;
1707 int len;
1708
1709 /* Send buffered output data to the socket. */
1710 if (c->wfd != -1 &&
1711 FD_ISSET(c->wfd, writeset) &&
1712 buffer_len(&c->output) > 0) {
1713 olen = buffer_len(&c->output);
1714 if (c->output_filter != NULL) {
1715 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1716 debug2("channel %d: filter stops", c->self);
1717 if (c->type != SSH_CHANNEL_OPEN)
1718 chan_mark_dead(c);
1719 else
1720 chan_write_failed(c);
1721 return -1;
1722 }
1723 } else if (c->datagram) {
1724 buf = data = buffer_get_string(&c->output, &dlen);
1725 } else {
1726 buf = data = buffer_ptr(&c->output);
1727 dlen = buffer_len(&c->output);
1728 }
1729
1730 if (c->datagram) {
1731 /* ignore truncated writes, datagrams might get lost */
1732 len = write(c->wfd, buf, dlen);
1733 free(data);
1734 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1735 errno == EWOULDBLOCK))
1736 return 1;
1737 if (len <= 0) {
1738 if (c->type != SSH_CHANNEL_OPEN)
1739 chan_mark_dead(c);
1740 else
1741 chan_write_failed(c);
1742 return -1;
1743 }
1744 goto out;
1745 }
1746#ifdef _AIX
1747 /* XXX: Later AIX versions can't push as much data to tty */
1748 if (compat20 && c->wfd_isatty)
1749 dlen = MIN(dlen, 8*1024);
1750#endif
1751
1752 len = write(c->wfd, buf, dlen);
1753 if (len < 0 &&
1754 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1755 return 1;
1756 if (len <= 0) {
1757 if (c->type != SSH_CHANNEL_OPEN) {
1758 debug2("channel %d: not open", c->self);
1759 chan_mark_dead(c);
1760 return -1;
1761 } else if (compat13) {
1762 buffer_clear(&c->output);
1763 debug2("channel %d: input draining.", c->self);
1764 c->type = SSH_CHANNEL_INPUT_DRAINING;
1765 } else {
1766 chan_write_failed(c);
1767 }
1768 return -1;
1769 }
1770#ifndef BROKEN_TCGETATTR_ICANON
1771 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1772 if (tcgetattr(c->wfd, &tio) == 0 &&
1773 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1774 /*
1775 * Simulate echo to reduce the impact of
1776 * traffic analysis. We need to match the
1777 * size of a SSH2_MSG_CHANNEL_DATA message
1778 * (4 byte channel id + buf)
1779 */
1780 packet_send_ignore(4 + len);
1781 packet_send();
1782 }
1783 }
1784#endif
1785 buffer_consume(&c->output, len);
1786 }
1787 out:
1788 if (compat20 && olen > 0)
1789 c->local_consumed += olen - buffer_len(&c->output);
1790 return 1;
1791}
1792
1793static int
1794channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1795{
1796 char buf[CHAN_RBUF];
1797 int len;
1798
1799/** XXX handle drain efd, too */
1800 if (c->efd != -1) {
1801 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1802 FD_ISSET(c->efd, writeset) &&
1803 buffer_len(&c->extended) > 0) {
1804 len = write(c->efd, buffer_ptr(&c->extended),
1805 buffer_len(&c->extended));
1806 debug2("channel %d: written %d to efd %d",
1807 c->self, len, c->efd);
1808 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1809 errno == EWOULDBLOCK))
1810 return 1;
1811 if (len <= 0) {
1812 debug2("channel %d: closing write-efd %d",
1813 c->self, c->efd);
1814 channel_close_fd(&c->efd);
1815 } else {
1816 buffer_consume(&c->extended, len);
1817 c->local_consumed += len;
1818 }
1819 } else if (c->efd != -1 &&
1820 (c->extended_usage == CHAN_EXTENDED_READ ||
1821 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1822 (c->detach_close || FD_ISSET(c->efd, readset))) {
1823 len = read(c->efd, buf, sizeof(buf));
1824 debug2("channel %d: read %d from efd %d",
1825 c->self, len, c->efd);
1826 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1827 errno == EWOULDBLOCK) && !c->detach_close)))
1828 return 1;
1829 if (len <= 0) {
1830 debug2("channel %d: closing read-efd %d",
1831 c->self, c->efd);
1832 channel_close_fd(&c->efd);
1833 } else {
1834 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1835 debug3("channel %d: discard efd",
1836 c->self);
1837 } else
1838 buffer_append(&c->extended, buf, len);
1839 }
1840 }
1841 }
1842 return 1;
1843}
1844
1845static int
1846channel_check_window(Channel *c)
1847{
1848 if (c->type == SSH_CHANNEL_OPEN &&
1849 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1850 ((c->local_window_max - c->local_window >
1851 c->local_maxpacket*3) ||
1852 c->local_window < c->local_window_max/2) &&
1853 c->local_consumed > 0) {
1854 u_int addition = 0;
1855
1856 /* Adjust max window size if we are in a dynamic environment. */
1857 if (c->dynamic_window && c->tcpwinsz > c->local_window_max) {
1858 /*
1859 * Grow the window somewhat aggressively to maintain
1860 * pressure.
1861 */
1862 addition = 1.5 * (c->tcpwinsz - c->local_window_max);
1863 c->local_window_max += addition;
1864 }
1865 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1866 packet_put_int(c->remote_id);
1867 packet_put_int(c->local_consumed + addition);
1868 packet_send();
1869 debug2("channel %d: window %d sent adjust %d",
1870 c->self, c->local_window,
1871 c->local_consumed);
1872 c->local_window += c->local_consumed + addition;
1873 c->local_consumed = 0;
1874 }
1875 return 1;
1876}
1877
1878static void
1879channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1880{
1881 channel_handle_rfd(c, readset, writeset);
1882 channel_handle_wfd(c, readset, writeset);
1883 if (!compat20)
1884 return;
1885 channel_handle_efd(c, readset, writeset);
1886 channel_check_window(c);
1887}
1888
1889static u_int
1890read_mux(Channel *c, u_int need)
1891{
1892 char buf[CHAN_RBUF];
1893 int len;
1894 u_int rlen;
1895
1896 if (buffer_len(&c->input) < need) {
1897 rlen = need - buffer_len(&c->input);
1898 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1899 if (len <= 0) {
1900 if (errno != EINTR && errno != EAGAIN) {
1901 debug2("channel %d: ctl read<=0 rfd %d len %d",
1902 c->self, c->rfd, len);
1903 chan_read_failed(c);
1904 return 0;
1905 }
1906 } else
1907 buffer_append(&c->input, buf, len);
1908 }
1909 return buffer_len(&c->input);
1910}
1911
1912static void
1913channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1914{
1915 u_int need;
1916 ssize_t len;
1917
1918 if (!compat20)
1919 fatal("%s: entered with !compat20", __func__);
1920
1921 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1922 (c->istate == CHAN_INPUT_OPEN ||
1923 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1924 /*
1925 * Don't not read past the precise end of packets to
1926 * avoid disrupting fd passing.
1927 */
1928 if (read_mux(c, 4) < 4) /* read header */
1929 return;
1930 need = get_u32(buffer_ptr(&c->input));
1931#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1932 if (need > CHANNEL_MUX_MAX_PACKET) {
1933 debug2("channel %d: packet too big %u > %u",
1934 c->self, CHANNEL_MUX_MAX_PACKET, need);
1935 chan_rcvd_oclose(c);
1936 return;
1937 }
1938 if (read_mux(c, need + 4) < need + 4) /* read body */
1939 return;
1940 if (c->mux_rcb(c) != 0) {
1941 debug("channel %d: mux_rcb failed", c->self);
1942 chan_mark_dead(c);
1943 return;
1944 }
1945 }
1946
1947 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1948 buffer_len(&c->output) > 0) {
1949 len = write(c->wfd, buffer_ptr(&c->output),
1950 buffer_len(&c->output));
1951 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1952 return;
1953 if (len <= 0) {
1954 chan_mark_dead(c);
1955 return;
1956 }
1957 buffer_consume(&c->output, len);
1958 }
1959}
1960
1961static void
1962channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1963{
1964 Channel *nc;
1965 struct sockaddr_storage addr;
1966 socklen_t addrlen;
1967 int newsock;
1968 uid_t euid;
1969 gid_t egid;
1970
1971 if (!FD_ISSET(c->sock, readset))
1972 return;
1973
1974 debug("multiplexing control connection");
1975
1976 /*
1977 * Accept connection on control socket
1978 */
1979 memset(&addr, 0, sizeof(addr));
1980 addrlen = sizeof(addr);
1981 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1982 &addrlen)) == -1) {
1983 error("%s accept: %s", __func__, strerror(errno));
1984 if (errno == EMFILE || errno == ENFILE)
1985 c->notbefore = monotime() + 1;
1986 return;
1987 }
1988
1989 if (getpeereid(newsock, &euid, &egid) < 0) {
1990 error("%s getpeereid failed: %s", __func__,
1991 strerror(errno));
1992 close(newsock);
1993 return;
1994 }
1995 if ((euid != 0) && (getuid() != euid)) {
1996 error("multiplex uid mismatch: peer euid %u != uid %u",
1997 (u_int)euid, (u_int)getuid());
1998 close(newsock);
1999 return;
2000 }
2001 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
2002 newsock, newsock, -1, c->local_window_max,
2003 c->local_maxpacket, 0, "mux-control", 1);
2004 nc->mux_rcb = c->mux_rcb;
2005 debug3("%s: new mux channel %d fd %d", __func__,
2006 nc->self, nc->sock);
2007 /* establish state */
2008 nc->mux_rcb(nc);
2009 /* mux state transitions must not elicit protocol messages */
2010 nc->flags |= CHAN_LOCAL;
2011}
2012
2013/* ARGSUSED */
2014static void
2015channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
2016{
2017 int len;
2018
2019 /* Send buffered output data to the socket. */
2020 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
2021 len = write(c->sock, buffer_ptr(&c->output),
2022 buffer_len(&c->output));
2023 if (len <= 0)
2024 buffer_clear(&c->output);
2025 else
2026 buffer_consume(&c->output, len);
2027 }
2028}
2029
2030static void
2031channel_handler_init_20(void)
2032{
2033 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2034 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2035 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2036 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2037 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2038 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2039 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2040 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2041 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2042 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2043
2044 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2045 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2046 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2047 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2048 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2049 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2050 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2051 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2052 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2053}
2054
2055static void
2056channel_handler_init_13(void)
2057{
2058 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2059 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2060 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2061 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2062 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2063 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2064 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2065 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2066 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2067
2068 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2069 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2070 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2071 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2072 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2073 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2074 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2075}
2076
2077static void
2078channel_handler_init_15(void)
2079{
2080 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2081 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2082 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2083 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2084 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2085 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2086 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2087
2088 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2089 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2090 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2091 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2092 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2093 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2094}
2095
2096static void
2097channel_handler_init(void)
2098{
2099 int i;
2100
2101 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2102 channel_pre[i] = NULL;
2103 channel_post[i] = NULL;
2104 }
2105 if (compat20)
2106 channel_handler_init_20();
2107 else if (compat13)
2108 channel_handler_init_13();
2109 else
2110 channel_handler_init_15();
2111}
2112
2113/* gc dead channels */
2114static void
2115channel_garbage_collect(Channel *c)
2116{
2117 if (c == NULL)
2118 return;
2119 if (c->detach_user != NULL) {
2120 if (!chan_is_dead(c, c->detach_close))
2121 return;
2122 debug2("channel %d: gc: notify user", c->self);
2123 c->detach_user(c->self, NULL);
2124 /* if we still have a callback */
2125 if (c->detach_user != NULL)
2126 return;
2127 debug2("channel %d: gc: user detached", c->self);
2128 }
2129 if (!chan_is_dead(c, 1))
2130 return;
2131 debug2("channel %d: garbage collecting", c->self);
2132 channel_free(c);
2133}
2134
2135static void
2136channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2137 time_t *unpause_secs)
2138{
2139 static int did_init = 0;
2140 u_int i, oalloc;
2141 Channel *c;
2142 time_t now;
2143
2144 if (!did_init) {
2145 channel_handler_init();
2146 did_init = 1;
2147 }
2148 now = monotime();
2149 if (unpause_secs != NULL)
2150 *unpause_secs = 0;
2151 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2152 c = channels[i];
2153 if (c == NULL)
2154 continue;
2155 if (c->delayed) {
2156 if (ftab == channel_pre)
2157 c->delayed = 0;
2158 else
2159 continue;
2160 }
2161 if (ftab[c->type] != NULL) {
2162 /*
2163 * Run handlers that are not paused.
2164 */
2165 if (c->notbefore <= now)
2166 (*ftab[c->type])(c, readset, writeset);
2167 else if (unpause_secs != NULL) {
2168 /*
2169 * Collect the time that the earliest
2170 * channel comes off pause.
2171 */
2172 debug3("%s: chan %d: skip for %d more seconds",
2173 __func__, c->self,
2174 (int)(c->notbefore - now));
2175 if (*unpause_secs == 0 ||
2176 (c->notbefore - now) < *unpause_secs)
2177 *unpause_secs = c->notbefore - now;
2178 }
2179 }
2180 channel_garbage_collect(c);
2181 }
2182 if (unpause_secs != NULL && *unpause_secs != 0)
2183 debug3("%s: first channel unpauses in %d seconds",
2184 __func__, (int)*unpause_secs);
2185}
2186
2187/*
2188 * Allocate/update select bitmasks and add any bits relevant to channels in
2189 * select bitmasks.
2190 */
2191void
2192channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2193 u_int *nallocp, time_t *minwait_secs, int rekeying)
2194{
2195 u_int n, sz, nfdset;
2196
2197 n = MAX(*maxfdp, channel_max_fd);
2198
2199 nfdset = howmany(n+1, NFDBITS);
2200 /* Explicitly test here, because xrealloc isn't always called */
2201 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2202 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2203 sz = nfdset * sizeof(fd_mask);
2204
2205 /* perhaps check sz < nalloc/2 and shrink? */
2206 if (*readsetp == NULL || sz > *nallocp) {
2207 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2208 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2209 *nallocp = sz;
2210 }
2211 *maxfdp = n;
2212 memset(*readsetp, 0, sz);
2213 memset(*writesetp, 0, sz);
2214
2215 if (!rekeying)
2216 channel_handler(channel_pre, *readsetp, *writesetp,
2217 minwait_secs);
2218}
2219
2220/*
2221 * After select, perform any appropriate operations for channels which have
2222 * events pending.
2223 */
2224void
2225channel_after_select(fd_set *readset, fd_set *writeset)
2226{
2227 channel_handler(channel_post, readset, writeset, NULL);
2228}
2229
2230
2231/* If there is data to send to the connection, enqueue some of it now. */
2232void
2233channel_output_poll(void)
2234{
2235 Channel *c;
2236 u_int i, len;
2237
2238 for (i = 0; i < channels_alloc; i++) {
2239 c = channels[i];
2240 if (c == NULL)
2241 continue;
2242
2243 /*
2244 * We are only interested in channels that can have buffered
2245 * incoming data.
2246 */
2247 if (compat13) {
2248 if (c->type != SSH_CHANNEL_OPEN &&
2249 c->type != SSH_CHANNEL_INPUT_DRAINING)
2250 continue;
2251 } else {
2252 if (c->type != SSH_CHANNEL_OPEN)
2253 continue;
2254 }
2255 if (compat20 &&
2256 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2257 /* XXX is this true? */
2258 debug3("channel %d: will not send data after close", c->self);
2259 continue;
2260 }
2261
2262 /* Get the amount of buffered data for this channel. */
2263 if ((c->istate == CHAN_INPUT_OPEN ||
2264 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2265 (len = buffer_len(&c->input)) > 0) {
2266 if (c->datagram) {
2267 if (len > 0) {
2268 u_char *data;
2269 u_int dlen;
2270
2271 data = buffer_get_string(&c->input,
2272 &dlen);
2273 if (dlen > c->remote_window ||
2274 dlen > c->remote_maxpacket) {
2275 debug("channel %d: datagram "
2276 "too big for channel",
2277 c->self);
2278 free(data);
2279 continue;
2280 }
2281 packet_start(SSH2_MSG_CHANNEL_DATA);
2282 packet_put_int(c->remote_id);
2283 packet_put_string(data, dlen);
2284 packet_send();
2285 c->remote_window -= dlen + 4;
2286 free(data);
2287 }
2288 continue;
2289 }
2290 /*
2291 * Send some data for the other side over the secure
2292 * connection.
2293 */
2294 if (compat20) {
2295 if (len > c->remote_window)
2296 len = c->remote_window;
2297 if (len > c->remote_maxpacket)
2298 len = c->remote_maxpacket;
2299 } else {
2300 if (packet_is_interactive()) {
2301 if (len > 1024)
2302 len = 512;
2303 } else {
2304 /* Keep the packets at reasonable size. */
2305 if (len > packet_get_maxsize()/2)
2306 len = packet_get_maxsize()/2;
2307 }
2308 }
2309 if (len > 0) {
2310 packet_start(compat20 ?
2311 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2312 packet_put_int(c->remote_id);
2313 packet_put_string(buffer_ptr(&c->input), len);
2314 packet_send();
2315 buffer_consume(&c->input, len);
2316 c->remote_window -= len;
2317 }
2318 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2319 if (compat13)
2320 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2321 /*
2322 * input-buffer is empty and read-socket shutdown:
2323 * tell peer, that we will not send more data: send IEOF.
2324 * hack for extended data: delay EOF if EFD still in use.
2325 */
2326 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2327 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2328 c->self, c->efd, buffer_len(&c->extended));
2329 else
2330 chan_ibuf_empty(c);
2331 }
2332 /* Send extended data, i.e. stderr */
2333 if (compat20 &&
2334 !(c->flags & CHAN_EOF_SENT) &&
2335 c->remote_window > 0 &&
2336 (len = buffer_len(&c->extended)) > 0 &&
2337 c->extended_usage == CHAN_EXTENDED_READ) {
2338 debug2("channel %d: rwin %u elen %u euse %d",
2339 c->self, c->remote_window, buffer_len(&c->extended),
2340 c->extended_usage);
2341 if (len > c->remote_window)
2342 len = c->remote_window;
2343 if (len > c->remote_maxpacket)
2344 len = c->remote_maxpacket;
2345 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2346 packet_put_int(c->remote_id);
2347 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2348 packet_put_string(buffer_ptr(&c->extended), len);
2349 packet_send();
2350 buffer_consume(&c->extended, len);
2351 c->remote_window -= len;
2352 debug2("channel %d: sent ext data %d", c->self, len);
2353 }
2354 }
2355}
2356
2357
2358/* -- protocol input */
2359
2360/* ARGSUSED */
2361void
2362channel_input_data(int type, u_int32_t seq, void *ctxt)
2363{
2364 int id;
2365 char *data;
2366 u_int data_len, win_len;
2367 Channel *c;
2368
2369 /* Get the channel number and verify it. */
2370 id = packet_get_int();
2371 c = channel_lookup(id);
2372 if (c == NULL)
2373 packet_disconnect("Received data for nonexistent channel %d.", id);
2374
2375 /* Ignore any data for non-open channels (might happen on close) */
2376 if (c->type != SSH_CHANNEL_OPEN &&
2377 c->type != SSH_CHANNEL_X11_OPEN)
2378 return;
2379
2380 /* Get the data. */
2381 data = packet_get_string_ptr(&data_len);
2382 win_len = data_len;
2383 if (c->datagram)
2384 win_len += 4; /* string length header */
2385
2386 /*
2387 * Ignore data for protocol > 1.3 if output end is no longer open.
2388 * For protocol 2 the sending side is reducing its window as it sends
2389 * data, so we must 'fake' consumption of the data in order to ensure
2390 * that window updates are sent back. Otherwise the connection might
2391 * deadlock.
2392 */
2393 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2394 if (compat20) {
2395 c->local_window -= win_len;
2396 c->local_consumed += win_len;
2397 }
2398 return;
2399 }
2400
2401 if (compat20) {
2402 if (win_len > c->local_maxpacket) {
2403 logit("channel %d: rcvd big packet %d, maxpack %d",
2404 c->self, win_len, c->local_maxpacket);
2405 }
2406 if (win_len > c->local_window) {
2407 logit("channel %d: rcvd too much data %d, win %d",
2408 c->self, win_len, c->local_window);
2409 return;
2410 }
2411 c->local_window -= win_len;
2412 }
2413 if (c->datagram)
2414 buffer_put_string(&c->output, data, data_len);
2415 else
2416 buffer_append(&c->output, data, data_len);
2417 packet_check_eom();
2418}
2419
2420/* ARGSUSED */
2421void
2422channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2423{
2424 int id;
2425 char *data;
2426 u_int data_len, tcode;
2427 Channel *c;
2428
2429 /* Get the channel number and verify it. */
2430 id = packet_get_int();
2431 c = channel_lookup(id);
2432
2433 if (c == NULL)
2434 packet_disconnect("Received extended_data for bad channel %d.", id);
2435 if (c->type != SSH_CHANNEL_OPEN) {
2436 logit("channel %d: ext data for non open", id);
2437 return;
2438 }
2439 if (c->flags & CHAN_EOF_RCVD) {
2440 if (datafellows & SSH_BUG_EXTEOF)
2441 debug("channel %d: accepting ext data after eof", id);
2442 else
2443 packet_disconnect("Received extended_data after EOF "
2444 "on channel %d.", id);
2445 }
2446 tcode = packet_get_int();
2447 if (c->efd == -1 ||
2448 c->extended_usage != CHAN_EXTENDED_WRITE ||
2449 tcode != SSH2_EXTENDED_DATA_STDERR) {
2450 logit("channel %d: bad ext data", c->self);
2451 return;
2452 }
2453 data = packet_get_string(&data_len);
2454 packet_check_eom();
2455 if (data_len > c->local_window) {
2456 logit("channel %d: rcvd too much extended_data %d, win %d",
2457 c->self, data_len, c->local_window);
2458 free(data);
2459 return;
2460 }
2461 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2462 c->local_window -= data_len;
2463 buffer_append(&c->extended, data, data_len);
2464 free(data);
2465}
2466
2467/* ARGSUSED */
2468void
2469channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2470{
2471 int id;
2472 Channel *c;
2473
2474 id = packet_get_int();
2475 packet_check_eom();
2476 c = channel_lookup(id);
2477 if (c == NULL)
2478 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2479 chan_rcvd_ieof(c);
2480
2481 /* XXX force input close */
2482 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2483 debug("channel %d: FORCE input drain", c->self);
2484 c->istate = CHAN_INPUT_WAIT_DRAIN;
2485 if (buffer_len(&c->input) == 0)
2486 chan_ibuf_empty(c);
2487 }
2488
2489}
2490
2491/* ARGSUSED */
2492void
2493channel_input_close(int type, u_int32_t seq, void *ctxt)
2494{
2495 int id;
2496 Channel *c;
2497
2498 id = packet_get_int();
2499 packet_check_eom();
2500 c = channel_lookup(id);
2501 if (c == NULL)
2502 packet_disconnect("Received close for nonexistent channel %d.", id);
2503
2504 /*
2505 * Send a confirmation that we have closed the channel and no more
2506 * data is coming for it.
2507 */
2508 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2509 packet_put_int(c->remote_id);
2510 packet_send();
2511
2512 /*
2513 * If the channel is in closed state, we have sent a close request,
2514 * and the other side will eventually respond with a confirmation.
2515 * Thus, we cannot free the channel here, because then there would be
2516 * no-one to receive the confirmation. The channel gets freed when
2517 * the confirmation arrives.
2518 */
2519 if (c->type != SSH_CHANNEL_CLOSED) {
2520 /*
2521 * Not a closed channel - mark it as draining, which will
2522 * cause it to be freed later.
2523 */
2524 buffer_clear(&c->input);
2525 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2526 }
2527}
2528
2529/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2530/* ARGSUSED */
2531void
2532channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2533{
2534 int id = packet_get_int();
2535 Channel *c = channel_lookup(id);
2536
2537 packet_check_eom();
2538 if (c == NULL)
2539 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2540 chan_rcvd_oclose(c);
2541}
2542
2543/* ARGSUSED */
2544void
2545channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2546{
2547 int id = packet_get_int();
2548 Channel *c = channel_lookup(id);
2549
2550 packet_check_eom();
2551 if (c == NULL)
2552 packet_disconnect("Received close confirmation for "
2553 "out-of-range channel %d.", id);
2554 if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
2555 packet_disconnect("Received close confirmation for "
2556 "non-closed channel %d (type %d).", id, c->type);
2557 channel_free(c);
2558}
2559
2560/* ARGSUSED */
2561void
2562channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2563{
2564 int id, remote_id;
2565 Channel *c;
2566
2567 id = packet_get_int();
2568 c = channel_lookup(id);
2569
2570 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2571 packet_disconnect("Received open confirmation for "
2572 "non-opening channel %d.", id);
2573 remote_id = packet_get_int();
2574 /* Record the remote channel number and mark that the channel is now open. */
2575 c->remote_id = remote_id;
2576 c->type = SSH_CHANNEL_OPEN;
2577
2578 if (compat20) {
2579 c->remote_window = packet_get_int();
2580 c->remote_maxpacket = packet_get_int();
2581 if (c->open_confirm) {
2582 debug2("callback start");
2583 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2584 debug2("callback done");
2585 }
2586 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2587 c->remote_window, c->remote_maxpacket);
2588 }
2589 packet_check_eom();
2590}
2591
2592static char *
2593reason2txt(int reason)
2594{
2595 switch (reason) {
2596 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2597 return "administratively prohibited";
2598 case SSH2_OPEN_CONNECT_FAILED:
2599 return "connect failed";
2600 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2601 return "unknown channel type";
2602 case SSH2_OPEN_RESOURCE_SHORTAGE:
2603 return "resource shortage";
2604 }
2605 return "unknown reason";
2606}
2607
2608/* ARGSUSED */
2609void
2610channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2611{
2612 int id, reason;
2613 char *msg = NULL, *lang = NULL;
2614 Channel *c;
2615
2616 id = packet_get_int();
2617 c = channel_lookup(id);
2618
2619 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2620 packet_disconnect("Received open failure for "
2621 "non-opening channel %d.", id);
2622 if (compat20) {
2623 reason = packet_get_int();
2624 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2625 msg = packet_get_string(NULL);
2626 lang = packet_get_string(NULL);
2627 }
2628 logit("channel %d: open failed: %s%s%s", id,
2629 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2630 free(msg);
2631 free(lang);
2632 if (c->open_confirm) {
2633 debug2("callback start");
2634 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2635 debug2("callback done");
2636 }
2637 }
2638 packet_check_eom();
2639 /* Schedule the channel for cleanup/deletion. */
2640 chan_mark_dead(c);
2641}
2642
2643/* ARGSUSED */
2644void
2645channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2646{
2647 Channel *c;
2648 int id;
2649 u_int adjust;
2650
2651 if (!compat20)
2652 return;
2653
2654 /* Get the channel number and verify it. */
2655 id = packet_get_int();
2656 c = channel_lookup(id);
2657
2658 if (c == NULL) {
2659 logit("Received window adjust for non-open channel %d.", id);
2660 return;
2661 }
2662 adjust = packet_get_int();
2663 packet_check_eom();
2664 debug2("channel %d: rcvd adjust %u", id, adjust);
2665 c->remote_window += adjust;
2666}
2667
2668/* ARGSUSED */
2669void
2670channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2671{
2672 Channel *c = NULL;
2673 u_short host_port;
2674 char *host, *originator_string;
2675 int remote_id;
2676
2677 remote_id = packet_get_int();
2678 host = packet_get_string(NULL);
2679 host_port = packet_get_int();
2680
2681 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2682 originator_string = packet_get_string(NULL);
2683 } else {
2684 originator_string = xstrdup("unknown (remote did not supply name)");
2685 }
2686 packet_check_eom();
2687 c = channel_connect_to(host, host_port,
2688 "connected socket", originator_string);
2689 free(originator_string);
2690 free(host);
2691 if (c == NULL) {
2692 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2693 packet_put_int(remote_id);
2694 packet_send();
2695 } else
2696 c->remote_id = remote_id;
2697}
2698
2699/* ARGSUSED */
2700void
2701channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2702{
2703 Channel *c;
2704 struct channel_confirm *cc;
2705 int id;
2706
2707 /* Reset keepalive timeout */
2708 packet_set_alive_timeouts(0);
2709
2710 id = packet_get_int();
2711 packet_check_eom();
2712
2713 debug2("channel_input_status_confirm: type %d id %d", type, id);
2714
2715 if ((c = channel_lookup(id)) == NULL) {
2716 logit("channel_input_status_confirm: %d: unknown", id);
2717 return;
2718 }
2719 ;
2720 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2721 return;
2722 cc->cb(type, c, cc->ctx);
2723 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2724 bzero(cc, sizeof(*cc));
2725 free(cc);
2726}
2727
2728/* -- tcp forwarding */
2729
2730void
2731channel_set_af(int af)
2732{
2733 IPv4or6 = af;
2734}
2735
2736void
2737channel_set_hpn(int disabled, u_int buf_size)
2738{
2739 hpn_disabled = disabled;
2740 buffer_size = buf_size;
2741 debug("HPN Disabled: %d, HPN Buffer Size: %d",
2742 hpn_disabled, buffer_size);
2743}
2744
2745/*
2746 * Determine whether or not a port forward listens to loopback, the
2747 * specified address or wildcard. On the client, a specified bind
2748 * address will always override gateway_ports. On the server, a
2749 * gateway_ports of 1 (``yes'') will override the client's specification
2750 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2751 * will bind to whatever address the client asked for.
2752 *
2753 * Special-case listen_addrs are:
2754 *
2755 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2756 * "" (empty string), "*" -> wildcard v4/v6
2757 * "localhost" -> loopback v4/v6
2758 */
2759static const char *
2760channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2761 int is_client, int gateway_ports)
2762{
2763 const char *addr = NULL;
2764 int wildcard = 0;
2765
2766 if (listen_addr == NULL) {
2767 /* No address specified: default to gateway_ports setting */
2768 if (gateway_ports)
2769 wildcard = 1;
2770 } else if (gateway_ports || is_client) {
2771 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2772 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2773 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2774 (!is_client && gateway_ports == 1))
2775 wildcard = 1;
2776 else if (strcmp(listen_addr, "localhost") != 0)
2777 addr = listen_addr;
2778 }
2779 if (wildcardp != NULL)
2780 *wildcardp = wildcard;
2781 return addr;
2782}
2783
2784static int
2785channel_setup_fwd_listener(int type, const char *listen_addr,
2786 u_short listen_port, int *allocated_listen_port,
2787 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2788{
2789 Channel *c;
2790 int sock, r, success = 0, wildcard = 0, is_client;
2791 struct addrinfo hints, *ai, *aitop;
2792 const char *host, *addr;
2793 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2794 in_port_t *lport_p;
2795
2796 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2797 listen_addr : host_to_connect;
2798 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2799
2800 if (host == NULL) {
2801 error("No forward host name.");
2802 return 0;
2803 }
2804 if (strlen(host) >= NI_MAXHOST) {
2805 error("Forward host name too long.");
2806 return 0;
2807 }
2808
2809 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2810 addr = channel_fwd_bind_addr(listen_addr, &wildcard,
2811 is_client, gateway_ports);
2812 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2813 type, wildcard, (addr == NULL) ? "NULL" : addr);
2814
2815 /*
2816 * getaddrinfo returns a loopback address if the hostname is
2817 * set to NULL and hints.ai_flags is not AI_PASSIVE
2818 */
2819 memset(&hints, 0, sizeof(hints));
2820 hints.ai_family = IPv4or6;
2821 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2822 hints.ai_socktype = SOCK_STREAM;
2823 snprintf(strport, sizeof strport, "%d", listen_port);
2824 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2825 if (addr == NULL) {
2826 /* This really shouldn't happen */
2827 packet_disconnect("getaddrinfo: fatal error: %s",
2828 ssh_gai_strerror(r));
2829 } else {
2830 error("channel_setup_fwd_listener: "
2831 "getaddrinfo(%.64s): %s", addr,
2832 ssh_gai_strerror(r));
2833 }
2834 return 0;
2835 }
2836 if (allocated_listen_port != NULL)
2837 *allocated_listen_port = 0;
2838 for (ai = aitop; ai; ai = ai->ai_next) {
2839 switch (ai->ai_family) {
2840 case AF_INET:
2841 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2842 sin_port;
2843 break;
2844 case AF_INET6:
2845 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2846 sin6_port;
2847 break;
2848 default:
2849 continue;
2850 }
2851 /*
2852 * If allocating a port for -R forwards, then use the
2853 * same port for all address families.
2854 */
2855 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2856 allocated_listen_port != NULL && *allocated_listen_port > 0)
2857 *lport_p = htons(*allocated_listen_port);
2858
2859 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2860 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2861 error("channel_setup_fwd_listener: getnameinfo failed");
2862 continue;
2863 }
2864 /* Create a port to listen for the host. */
2865 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2866 if (sock < 0) {
2867 /* this is no error since kernel may not support ipv6 */
2868 verbose("socket: %.100s", strerror(errno));
2869 continue;
2870 }
2871
2872 channel_set_reuseaddr(sock);
2873 if (ai->ai_family == AF_INET6)
2874 sock_set_v6only(sock);
2875
2876 debug("Local forwarding listening on %s port %s.",
2877 ntop, strport);
2878
2879 /* Bind the socket to the address. */
2880 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2881 /* address can be in use ipv6 address is already bound */
2882 if (!ai->ai_next)
2883 error("bind: %.100s", strerror(errno));
2884 else
2885 verbose("bind: %.100s", strerror(errno));
2886
2887 close(sock);
2888 continue;
2889 }
2890 /* Start listening for connections on the socket. */
2891 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2892 error("listen: %.100s", strerror(errno));
2893 close(sock);
2894 continue;
2895 }
2896
2897 /*
2898 * listen_port == 0 requests a dynamically allocated port -
2899 * record what we got.
2900 */
2901 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2902 allocated_listen_port != NULL &&
2903 *allocated_listen_port == 0) {
2904 *allocated_listen_port = get_sock_port(sock, 1);
2905 debug("Allocated listen port %d",
2906 *allocated_listen_port);
2907 }
2908
2909 /*
2910 * Allocate a channel number for the socket. Explicitly test
2911 * for hpn disabled option. If true use smaller window size.
2912 */
2913 if (hpn_disabled)
2914 c = channel_new("port listener", type, sock, sock, -1,
2915 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2916 0, "port listener", 1);
2917 else
2918 c = channel_new("port listener", type, sock, sock, -1,
2919 buffer_size, CHAN_TCP_PACKET_DEFAULT,
2920 0, "port listener", 1);
2921 c->path = xstrdup(host);
2922 c->host_port = port_to_connect;
2923 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
2924 if (listen_port == 0 && allocated_listen_port != NULL &&
2925 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2926 c->listening_port = *allocated_listen_port;
2927 else
2928 c->listening_port = listen_port;
2929 success = 1;
2930 }
2931 if (success == 0)
2932 error("channel_setup_fwd_listener: cannot listen to port: %d",
2933 listen_port);
2934 freeaddrinfo(aitop);
2935 return success;
2936}
2937
2938int
2939channel_cancel_rport_listener(const char *host, u_short port)
2940{
2941 u_int i;
2942 int found = 0;
2943
2944 for (i = 0; i < channels_alloc; i++) {
2945 Channel *c = channels[i];
2946 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
2947 continue;
2948 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
2949 debug2("%s: close channel %d", __func__, i);
2950 channel_free(c);
2951 found = 1;
2952 }
2953 }
2954
2955 return (found);
2956}
2957
2958int
2959channel_cancel_lport_listener(const char *lhost, u_short lport,
2960 int cport, int gateway_ports)
2961{
2962 u_int i;
2963 int found = 0;
2964 const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports);
2965
2966 for (i = 0; i < channels_alloc; i++) {
2967 Channel *c = channels[i];
2968 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
2969 continue;
2970 if (c->listening_port != lport)
2971 continue;
2972 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
2973 /* skip dynamic forwardings */
2974 if (c->host_port == 0)
2975 continue;
2976 } else {
2977 if (c->host_port != cport)
2978 continue;
2979 }
2980 if ((c->listening_addr == NULL && addr != NULL) ||
2981 (c->listening_addr != NULL && addr == NULL))
2982 continue;
2983 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
2984 debug2("%s: close channel %d", __func__, i);
2985 channel_free(c);
2986 found = 1;
2987 }
2988 }
2989
2990 return (found);
2991}
2992
2993/* protocol local port fwd, used by ssh (and sshd in v1) */
2994int
2995channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2996 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2997{
2998 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2999 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
3000 gateway_ports);
3001}
3002
3003/* protocol v2 remote port fwd, used by sshd */
3004int
3005channel_setup_remote_fwd_listener(const char *listen_address,
3006 u_short listen_port, int *allocated_listen_port, int gateway_ports)
3007{
3008 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
3009 listen_address, listen_port, allocated_listen_port,
3010 NULL, 0, gateway_ports);
3011}
3012
3013/*
3014 * Translate the requested rfwd listen host to something usable for
3015 * this server.
3016 */
3017static const char *
3018channel_rfwd_bind_host(const char *listen_host)
3019{
3020 if (listen_host == NULL) {
3021 if (datafellows & SSH_BUG_RFWD_ADDR)
3022 return "127.0.0.1";
3023 else
3024 return "localhost";
3025 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3026 if (datafellows & SSH_BUG_RFWD_ADDR)
3027 return "0.0.0.0";
3028 else
3029 return "";
3030 } else
3031 return listen_host;
3032}
3033
3034/*
3035 * Initiate forwarding of connections to port "port" on remote host through
3036 * the secure channel to host:port from local side.
3037 * Returns handle (index) for updating the dynamic listen port with
3038 * channel_update_permitted_opens().
3039 */
3040int
3041channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
3042 const char *host_to_connect, u_short port_to_connect)
3043{
3044 int type, success = 0, idx = -1;
3045
3046 /* Send the forward request to the remote side. */
3047 if (compat20) {
3048 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3049 packet_put_cstring("tcpip-forward");
3050 packet_put_char(1); /* boolean: want reply */
3051 packet_put_cstring(channel_rfwd_bind_host(listen_host));
3052 packet_put_int(listen_port);
3053 packet_send();
3054 packet_write_wait();
3055 /* Assume that server accepts the request */
3056 success = 1;
3057 } else {
3058 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
3059 packet_put_int(listen_port);
3060 packet_put_cstring(host_to_connect);
3061 packet_put_int(port_to_connect);
3062 packet_send();
3063 packet_write_wait();
3064
3065 /* Wait for response from the remote side. */
3066 type = packet_read();
3067 switch (type) {
3068 case SSH_SMSG_SUCCESS:
3069 success = 1;
3070 break;
3071 case SSH_SMSG_FAILURE:
3072 break;
3073 default:
3074 /* Unknown packet */
3075 packet_disconnect("Protocol error for port forward request:"
3076 "received packet type %d.", type);
3077 }
3078 }
3079 if (success) {
3080 /* Record that connection to this host/port is permitted. */
3081 permitted_opens = xrealloc(permitted_opens,
3082 num_permitted_opens + 1, sizeof(*permitted_opens));
3083 idx = num_permitted_opens++;
3084 permitted_opens[idx].host_to_connect = xstrdup(host_to_connect);
3085 permitted_opens[idx].port_to_connect = port_to_connect;
3086 permitted_opens[idx].listen_port = listen_port;
3087 }
3088 return (idx);
3089}
3090
3091/*
3092 * Request cancellation of remote forwarding of connection host:port from
3093 * local side.
3094 */
3095int
3096channel_request_rforward_cancel(const char *host, u_short port)
3097{
3098 int i;
3099
3100 if (!compat20)
3101 return -1;
3102
3103 for (i = 0; i < num_permitted_opens; i++) {
3104 if (permitted_opens[i].host_to_connect != NULL &&
3105 permitted_opens[i].listen_port == port)
3106 break;
3107 }
3108 if (i >= num_permitted_opens) {
3109 debug("%s: requested forward not found", __func__);
3110 return -1;
3111 }
3112 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3113 packet_put_cstring("cancel-tcpip-forward");
3114 packet_put_char(0);
3115 packet_put_cstring(channel_rfwd_bind_host(host));
3116 packet_put_int(port);
3117 packet_send();
3118
3119 permitted_opens[i].listen_port = 0;
3120 permitted_opens[i].port_to_connect = 0;
3121 free(permitted_opens[i].host_to_connect);
3122 permitted_opens[i].host_to_connect = NULL;
3123
3124 return 0;
3125}
3126
3127/*
3128 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3129 * listening for the port, and sends back a success reply (or disconnect
3130 * message if there was an error).
3131 */
3132int
3133channel_input_port_forward_request(int is_root, int gateway_ports)
3134{
3135 u_short port, host_port;
3136 int success = 0;
3137 char *hostname;
3138
3139 /* Get arguments from the packet. */
3140 port = packet_get_int();
3141 hostname = packet_get_string(NULL);
3142 host_port = packet_get_int();
3143
3144#ifndef HAVE_CYGWIN
3145 /*
3146 * Check that an unprivileged user is not trying to forward a
3147 * privileged port.
3148 */
3149 if (port < IPPORT_RESERVED && !is_root)
3150 packet_disconnect(
3151 "Requested forwarding of port %d but user is not root.",
3152 port);
3153 if (host_port == 0)
3154 packet_disconnect("Dynamic forwarding denied.");
3155#endif
3156
3157 /* Initiate forwarding */
3158 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3159 host_port, gateway_ports);
3160
3161 /* Free the argument string. */
3162 free(hostname);
3163
3164 return (success ? 0 : -1);
3165}
3166
3167/*
3168 * Permits opening to any host/port if permitted_opens[] is empty. This is
3169 * usually called by the server, because the user could connect to any port
3170 * anyway, and the server has no way to know but to trust the client anyway.
3171 */
3172void
3173channel_permit_all_opens(void)
3174{
3175 if (num_permitted_opens == 0)
3176 all_opens_permitted = 1;
3177}
3178
3179void
3180channel_add_permitted_opens(char *host, int port)
3181{
3182 debug("allow port forwarding to host %s port %d", host, port);
3183
3184 permitted_opens = xrealloc(permitted_opens,
3185 num_permitted_opens + 1, sizeof(*permitted_opens));
3186 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3187 permitted_opens[num_permitted_opens].port_to_connect = port;
3188 num_permitted_opens++;
3189
3190 all_opens_permitted = 0;
3191}
3192
3193/*
3194 * Update the listen port for a dynamic remote forward, after
3195 * the actual 'newport' has been allocated. If 'newport' < 0 is
3196 * passed then they entry will be invalidated.
3197 */
3198void
3199channel_update_permitted_opens(int idx, int newport)
3200{
3201 if (idx < 0 || idx >= num_permitted_opens) {
3202 debug("channel_update_permitted_opens: index out of range:"
3203 " %d num_permitted_opens %d", idx, num_permitted_opens);
3204 return;
3205 }
3206 debug("%s allowed port %d for forwarding to host %s port %d",
3207 newport > 0 ? "Updating" : "Removing",
3208 newport,
3209 permitted_opens[idx].host_to_connect,
3210 permitted_opens[idx].port_to_connect);
3211 if (newport >= 0) {
3212 permitted_opens[idx].listen_port =
3213 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3214 } else {
3215 permitted_opens[idx].listen_port = 0;
3216 permitted_opens[idx].port_to_connect = 0;
3217 free(permitted_opens[idx].host_to_connect);
3218 permitted_opens[idx].host_to_connect = NULL;
3219 }
3220}
3221
3222int
3223channel_add_adm_permitted_opens(char *host, int port)
3224{
3225 debug("config allows port forwarding to host %s port %d", host, port);
3226
3227 permitted_adm_opens = xrealloc(permitted_adm_opens,
3228 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3229 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3230 = xstrdup(host);
3231 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3232 return ++num_adm_permitted_opens;
3233}
3234
3235void
3236channel_disable_adm_local_opens(void)
3237{
3238 channel_clear_adm_permitted_opens();
3239 permitted_adm_opens = xmalloc(sizeof(*permitted_adm_opens));
3240 permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3241 num_adm_permitted_opens = 1;
3242}
3243
3244void
3245channel_clear_permitted_opens(void)
3246{
3247 int i;
3248
3249 for (i = 0; i < num_permitted_opens; i++)
3250 free(permitted_opens[i].host_to_connect);
3251 free(permitted_opens);
3252 permitted_opens = NULL;
3253 num_permitted_opens = 0;
3254}
3255
3256void
3257channel_clear_adm_permitted_opens(void)
3258{
3259 int i;
3260
3261 for (i = 0; i < num_adm_permitted_opens; i++)
3262 free(permitted_adm_opens[i].host_to_connect);
3263 free(permitted_adm_opens);
3264 permitted_adm_opens = NULL;
3265 num_adm_permitted_opens = 0;
3266}
3267
3268void
3269channel_print_adm_permitted_opens(void)
3270{
3271 int i;
3272
3273 printf("permitopen");
3274 if (num_adm_permitted_opens == 0) {
3275 printf(" any\n");
3276 return;
3277 }
3278 for (i = 0; i < num_adm_permitted_opens; i++)
3279 if (permitted_adm_opens[i].host_to_connect == NULL)
3280 printf(" none");
3281 else
3282 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3283 permitted_adm_opens[i].port_to_connect);
3284 printf("\n");
3285}
3286
3287/* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3288int
3289permitopen_port(const char *p)
3290{
3291 int port;
3292
3293 if (strcmp(p, "*") == 0)
3294 return FWD_PERMIT_ANY_PORT;
3295 if ((port = a2port(p)) > 0)
3296 return port;
3297 return -1;
3298}
3299
3300static int
3301port_match(u_short allowedport, u_short requestedport)
3302{
3303 if (allowedport == FWD_PERMIT_ANY_PORT ||
3304 allowedport == requestedport)
3305 return 1;
3306 return 0;
3307}
3308
3309/* Try to start non-blocking connect to next host in cctx list */
3310static int
3311connect_next(struct channel_connect *cctx)
3312{
3313 int sock, saved_errno;
3314 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3315
3316 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3317 if (cctx->ai->ai_family != AF_INET &&
3318 cctx->ai->ai_family != AF_INET6)
3319 continue;
3320 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3321 ntop, sizeof(ntop), strport, sizeof(strport),
3322 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3323 error("connect_next: getnameinfo failed");
3324 continue;
3325 }
3326 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3327 cctx->ai->ai_protocol)) == -1) {
3328 if (cctx->ai->ai_next == NULL)
3329 error("socket: %.100s", strerror(errno));
3330 else
3331 verbose("socket: %.100s", strerror(errno));
3332 continue;
3333 }
3334 if (set_nonblock(sock) == -1)
3335 fatal("%s: set_nonblock(%d)", __func__, sock);
3336 if (connect(sock, cctx->ai->ai_addr,
3337 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3338 debug("connect_next: host %.100s ([%.100s]:%s): "
3339 "%.100s", cctx->host, ntop, strport,
3340 strerror(errno));
3341 saved_errno = errno;
3342 close(sock);
3343 errno = saved_errno;
3344 continue; /* fail -- try next */
3345 }
3346 debug("connect_next: host %.100s ([%.100s]:%s) "
3347 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3348 cctx->ai = cctx->ai->ai_next;
3349 set_nodelay(sock);
3350 return sock;
3351 }
3352 return -1;
3353}
3354
3355static void
3356channel_connect_ctx_free(struct channel_connect *cctx)
3357{
3358 free(cctx->host);
3359 if (cctx->aitop)
3360 freeaddrinfo(cctx->aitop);
3361 bzero(cctx, sizeof(*cctx));
3362 cctx->host = NULL;
3363 cctx->ai = cctx->aitop = NULL;
3364}
3365
3366/* Return CONNECTING channel to remote host, port */
3367static Channel *
3368connect_to(const char *host, u_short port, char *ctype, char *rname)
3369{
3370 struct addrinfo hints;
3371 int gaierr;
3372 int sock = -1;
3373 char strport[NI_MAXSERV];
3374 struct channel_connect cctx;
3375 Channel *c;
3376
3377 memset(&cctx, 0, sizeof(cctx));
3378 memset(&hints, 0, sizeof(hints));
3379 hints.ai_family = IPv4or6;
3380 hints.ai_socktype = SOCK_STREAM;
3381 snprintf(strport, sizeof strport, "%d", port);
3382 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3383 error("connect_to %.100s: unknown host (%s)", host,
3384 ssh_gai_strerror(gaierr));
3385 return NULL;
3386 }
3387
3388 cctx.host = xstrdup(host);
3389 cctx.port = port;
3390 cctx.ai = cctx.aitop;
3391
3392 if ((sock = connect_next(&cctx)) == -1) {
3393 error("connect to %.100s port %d failed: %s",
3394 host, port, strerror(errno));
3395 channel_connect_ctx_free(&cctx);
3396 return NULL;
3397 }
3398 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3399 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3400 c->connect_ctx = cctx;
3401 return c;
3402}
3403
3404Channel *
3405channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3406{
3407 int i;
3408
3409 for (i = 0; i < num_permitted_opens; i++) {
3410 if (permitted_opens[i].host_to_connect != NULL &&
3411 port_match(permitted_opens[i].listen_port, listen_port)) {
3412 return connect_to(
3413 permitted_opens[i].host_to_connect,
3414 permitted_opens[i].port_to_connect, ctype, rname);
3415 }
3416 }
3417 error("WARNING: Server requests forwarding for unknown listen_port %d",
3418 listen_port);
3419 return NULL;
3420}
3421
3422/* Check if connecting to that port is permitted and connect. */
3423Channel *
3424channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3425{
3426 int i, permit, permit_adm = 1;
3427
3428 permit = all_opens_permitted;
3429 if (!permit) {
3430 for (i = 0; i < num_permitted_opens; i++)
3431 if (permitted_opens[i].host_to_connect != NULL &&
3432 port_match(permitted_opens[i].port_to_connect, port) &&
3433 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3434 permit = 1;
3435 }
3436
3437 if (num_adm_permitted_opens > 0) {
3438 permit_adm = 0;
3439 for (i = 0; i < num_adm_permitted_opens; i++)
3440 if (permitted_adm_opens[i].host_to_connect != NULL &&
3441 port_match(permitted_adm_opens[i].port_to_connect, port) &&
3442 strcmp(permitted_adm_opens[i].host_to_connect, host)
3443 == 0)
3444 permit_adm = 1;
3445 }
3446
3447 if (!permit || !permit_adm) {
3448 logit("Received request to connect to host %.100s port %d, "
3449 "but the request was denied.", host, port);
3450 return NULL;
3451 }
3452 return connect_to(host, port, ctype, rname);
3453}
3454
3455void
3456channel_send_window_changes(void)
3457{
3458 u_int i;
3459 struct winsize ws;
3460
3461 for (i = 0; i < channels_alloc; i++) {
3462 if (channels[i] == NULL || !channels[i]->client_tty ||
3463 channels[i]->type != SSH_CHANNEL_OPEN)
3464 continue;
3465 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3466 continue;
3467 channel_request_start(i, "window-change", 0);
3468 packet_put_int((u_int)ws.ws_col);
3469 packet_put_int((u_int)ws.ws_row);
3470 packet_put_int((u_int)ws.ws_xpixel);
3471 packet_put_int((u_int)ws.ws_ypixel);
3472 packet_send();
3473 }
3474}
3475
3476/* -- X11 forwarding */
3477
3478/*
3479 * Creates an internet domain socket for listening for X11 connections.
3480 * Returns 0 and a suitable display number for the DISPLAY variable
3481 * stored in display_numberp , or -1 if an error occurs.
3482 */
3483int
3484x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3485 int single_connection, u_int *display_numberp, int **chanids)
3486{
3487 Channel *nc = NULL;
3488 int display_number, sock;
3489 u_short port;
3490 struct addrinfo hints, *ai, *aitop;
3491 char strport[NI_MAXSERV];
3492 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3493
3494 if (chanids == NULL)
3495 return -1;
3496
3497 for (display_number = x11_display_offset;
3498 display_number < MAX_DISPLAYS;
3499 display_number++) {
3500 port = 6000 + display_number;
3501 memset(&hints, 0, sizeof(hints));
3502 hints.ai_family = IPv4or6;
3503 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3504 hints.ai_socktype = SOCK_STREAM;
3505 snprintf(strport, sizeof strport, "%d", port);
3506 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3507 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3508 return -1;
3509 }
3510 for (ai = aitop; ai; ai = ai->ai_next) {
3511 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3512 continue;
3513 sock = socket(ai->ai_family, ai->ai_socktype,
3514 ai->ai_protocol);
3515 if (sock < 0) {
3516 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3517#ifdef EPFNOSUPPORT
3518 && (errno != EPFNOSUPPORT)
3519#endif
3520 ) {
3521 error("socket: %.100s", strerror(errno));
3522 freeaddrinfo(aitop);
3523 return -1;
3524 } else {
3525 debug("x11_create_display_inet: Socket family %d not supported",
3526 ai->ai_family);
3527 continue;
3528 }
3529 }
3530 if (ai->ai_family == AF_INET6)
3531 sock_set_v6only(sock);
3532 if (x11_use_localhost)
3533 channel_set_reuseaddr(sock);
3534 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3535 debug2("bind port %d: %.100s", port, strerror(errno));
3536 close(sock);
3537
3538 for (n = 0; n < num_socks; n++) {
3539 close(socks[n]);
3540 }
3541 num_socks = 0;
3542 break;
3543 }
3544 socks[num_socks++] = sock;
3545 if (num_socks == NUM_SOCKS)
3546 break;
3547 }
3548 freeaddrinfo(aitop);
3549 if (num_socks > 0)
3550 break;
3551 }
3552 if (display_number >= MAX_DISPLAYS) {
3553 error("Failed to allocate internet-domain X11 display socket.");
3554 return -1;
3555 }
3556 /* Start listening for connections on the socket. */
3557 for (n = 0; n < num_socks; n++) {
3558 sock = socks[n];
3559 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3560 error("listen: %.100s", strerror(errno));
3561 close(sock);
3562 return -1;
3563 }
3564 }
3565
3566 /* Allocate a channel for each socket. */
3567 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3568 for (n = 0; n < num_socks; n++) {
3569 sock = socks[n];
3570 if (hpn_disabled)
3571 nc = channel_new("x11 listener",
3572 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3573 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3574 0, "X11 inet listener", 1);
3575 else
3576 nc = channel_new("x11 listener",
3577 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3578 buffer_size, CHAN_X11_PACKET_DEFAULT,
3579 0, "X11 inet listener", 1);
3580 nc->single_connection = single_connection;
3581 (*chanids)[n] = nc->self;
3582 }
3583 (*chanids)[n] = -1;
3584
3585 /* Return the display number for the DISPLAY environment variable. */
3586 *display_numberp = display_number;
3587 return (0);
3588}
3589
3590static int
3591connect_local_xsocket_path(const char *pathname)
3592{
3593 int sock;
3594 struct sockaddr_un addr;
3595
3596 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3597 if (sock < 0)
3598 error("socket: %.100s", strerror(errno));
3599 memset(&addr, 0, sizeof(addr));
3600 addr.sun_family = AF_UNIX;
3601 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3602 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3603 return sock;
3604 close(sock);
3605 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3606 return -1;
3607}
3608
3609static int
3610connect_local_xsocket(u_int dnr)
3611{
3612 char buf[1024];
3613 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3614 return connect_local_xsocket_path(buf);
3615}
3616
3617int
3618x11_connect_display(void)
3619{
3620 u_int display_number;
3621 const char *display;
3622 char buf[1024], *cp;
3623 struct addrinfo hints, *ai, *aitop;
3624 char strport[NI_MAXSERV];
3625 int gaierr, sock = 0;
3626
3627 /* Try to open a socket for the local X server. */
3628 display = getenv("DISPLAY");
3629 if (!display) {
3630 error("DISPLAY not set.");
3631 return -1;
3632 }
3633 /*
3634 * Now we decode the value of the DISPLAY variable and make a
3635 * connection to the real X server.
3636 */
3637
3638 /* Check if the display is from launchd. */
3639#ifdef __APPLE__
3640 if (strncmp(display, "/tmp/launch", 11) == 0) {
3641 sock = connect_local_xsocket_path(display);
3642 if (sock < 0)
3643 return -1;
3644
3645 /* OK, we now have a connection to the display. */
3646 return sock;
3647 }
3648#endif
3649 /*
3650 * Check if it is a unix domain socket. Unix domain displays are in
3651 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3652 */
3653 if (strncmp(display, "unix:", 5) == 0 ||
3654 display[0] == ':') {
3655 /* Connect to the unix domain socket. */
3656 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3657 error("Could not parse display number from DISPLAY: %.100s",
3658 display);
3659 return -1;
3660 }
3661 /* Create a socket. */
3662 sock = connect_local_xsocket(display_number);
3663 if (sock < 0)
3664 return -1;
3665
3666 /* OK, we now have a connection to the display. */
3667 return sock;
3668 }
3669 /*
3670 * Connect to an inet socket. The DISPLAY value is supposedly
3671 * hostname:d[.s], where hostname may also be numeric IP address.
3672 */
3673 strlcpy(buf, display, sizeof(buf));
3674 cp = strchr(buf, ':');
3675 if (!cp) {
3676 error("Could not find ':' in DISPLAY: %.100s", display);
3677 return -1;
3678 }
3679 *cp = 0;
3680 /* buf now contains the host name. But first we parse the display number. */
3681 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3682 error("Could not parse display number from DISPLAY: %.100s",
3683 display);
3684 return -1;
3685 }
3686
3687 /* Look up the host address */
3688 memset(&hints, 0, sizeof(hints));
3689 hints.ai_family = IPv4or6;
3690 hints.ai_socktype = SOCK_STREAM;
3691 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3692 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3693 error("%.100s: unknown host. (%s)", buf,
3694 ssh_gai_strerror(gaierr));
3695 return -1;
3696 }
3697 for (ai = aitop; ai; ai = ai->ai_next) {
3698 /* Create a socket. */
3699 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3700 if (sock < 0) {
3701 debug2("socket: %.100s", strerror(errno));
3702 continue;
3703 }
3704 /* Connect it to the display. */
3705 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3706 debug2("connect %.100s port %u: %.100s", buf,
3707 6000 + display_number, strerror(errno));
3708 close(sock);
3709 continue;
3710 }
3711 /* Success */
3712 break;
3713 }
3714 freeaddrinfo(aitop);
3715 if (!ai) {
3716 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3717 strerror(errno));
3718 return -1;
3719 }
3720 set_nodelay(sock);
3721 return sock;
3722}
3723
3724/*
3725 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3726 * the remote channel number. We should do whatever we want, and respond
3727 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3728 */
3729
3730/* ARGSUSED */
3731void
3732x11_input_open(int type, u_int32_t seq, void *ctxt)
3733{
3734 Channel *c = NULL;
3735 int remote_id, sock = 0;
3736 char *remote_host;
3737
3738 debug("Received X11 open request.");
3739
3740 remote_id = packet_get_int();
3741
3742 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3743 remote_host = packet_get_string(NULL);
3744 } else {
3745 remote_host = xstrdup("unknown (remote did not supply name)");
3746 }
3747 packet_check_eom();
3748
3749 /* Obtain a connection to the real X display. */
3750 sock = x11_connect_display();
3751 if (sock != -1) {
3752 /* Allocate a channel for this connection. */
3753 c = channel_new("connected x11 socket",
3754 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3755 remote_host, 1);
3756 c->remote_id = remote_id;
3757 c->force_drain = 1;
3758 }
3759 free(remote_host);
3760 if (c == NULL) {
3761 /* Send refusal to the remote host. */
3762 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3763 packet_put_int(remote_id);
3764 } else {
3765 /* Send a confirmation to the remote host. */
3766 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3767 packet_put_int(remote_id);
3768 packet_put_int(c->self);
3769 }
3770 packet_send();
3771}
3772
3773/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3774/* ARGSUSED */
3775void
3776deny_input_open(int type, u_int32_t seq, void *ctxt)
3777{
3778 int rchan = packet_get_int();
3779
3780 switch (type) {
3781 case SSH_SMSG_AGENT_OPEN:
3782 error("Warning: ssh server tried agent forwarding.");
3783 break;
3784 case SSH_SMSG_X11_OPEN:
3785 error("Warning: ssh server tried X11 forwarding.");
3786 break;
3787 default:
3788 error("deny_input_open: type %d", type);
3789 break;
3790 }
3791 error("Warning: this is probably a break-in attempt by a malicious server.");
3792 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3793 packet_put_int(rchan);
3794 packet_send();
3795}
3796
3797/*
3798 * Requests forwarding of X11 connections, generates fake authentication
3799 * data, and enables authentication spoofing.
3800 * This should be called in the client only.
3801 */
3802void
3803x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3804 const char *proto, const char *data, int want_reply)
3805{
3806 u_int data_len = (u_int) strlen(data) / 2;
3807 u_int i, value;
3808 char *new_data;
3809 int screen_number;
3810 const char *cp;
3811 u_int32_t rnd = 0;
3812
3813 if (x11_saved_display == NULL)
3814 x11_saved_display = xstrdup(disp);
3815 else if (strcmp(disp, x11_saved_display) != 0) {
3816 error("x11_request_forwarding_with_spoofing: different "
3817 "$DISPLAY already forwarded");
3818 return;
3819 }
3820
3821 cp = strchr(disp, ':');
3822 if (cp)
3823 cp = strchr(cp, '.');
3824 if (cp)
3825 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3826 else
3827 screen_number = 0;
3828
3829 if (x11_saved_proto == NULL) {
3830 /* Save protocol name. */
3831 x11_saved_proto = xstrdup(proto);
3832 /*
3833 * Extract real authentication data and generate fake data
3834 * of the same length.
3835 */
3836 x11_saved_data = xmalloc(data_len);
3837 x11_fake_data = xmalloc(data_len);
3838 for (i = 0; i < data_len; i++) {
3839 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3840 fatal("x11_request_forwarding: bad "
3841 "authentication data: %.100s", data);
3842 if (i % 4 == 0)
3843 rnd = arc4random();
3844 x11_saved_data[i] = value;
3845 x11_fake_data[i] = rnd & 0xff;
3846 rnd >>= 8;
3847 }
3848 x11_saved_data_len = data_len;
3849 x11_fake_data_len = data_len;
3850 }
3851
3852 /* Convert the fake data into hex. */
3853 new_data = tohex(x11_fake_data, data_len);
3854
3855 /* Send the request packet. */
3856 if (compat20) {
3857 channel_request_start(client_session_id, "x11-req", want_reply);
3858 packet_put_char(0); /* XXX bool single connection */
3859 } else {
3860 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3861 }
3862 packet_put_cstring(proto);
3863 packet_put_cstring(new_data);
3864 packet_put_int(screen_number);
3865 packet_send();
3866 packet_write_wait();
3867 free(new_data);
3868}
3869
3870
3871/* -- agent forwarding */
3872
3873/* Sends a message to the server to request authentication fd forwarding. */
3874
3875void
3876auth_request_forwarding(void)
3877{
3878 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3879 packet_send();
3880 packet_write_wait();
3881}
| 715 cc->cb = cb;
716 cc->abandon_cb = abandon_cb;
717 cc->ctx = ctx;
718 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
719}
720
721void
722channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
723{
724 Channel *c = channel_lookup(id);
725
726 if (c == NULL) {
727 logit("channel_register_open_confirm: %d: bad id", id);
728 return;
729 }
730 c->open_confirm = fn;
731 c->open_confirm_ctx = ctx;
732}
733
734void
735channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
736{
737 Channel *c = channel_by_id(id);
738
739 if (c == NULL) {
740 logit("channel_register_cleanup: %d: bad id", id);
741 return;
742 }
743 c->detach_user = fn;
744 c->detach_close = do_close;
745}
746
747void
748channel_cancel_cleanup(int id)
749{
750 Channel *c = channel_by_id(id);
751
752 if (c == NULL) {
753 logit("channel_cancel_cleanup: %d: bad id", id);
754 return;
755 }
756 c->detach_user = NULL;
757 c->detach_close = 0;
758}
759
760void
761channel_register_filter(int id, channel_infilter_fn *ifn,
762 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
763{
764 Channel *c = channel_lookup(id);
765
766 if (c == NULL) {
767 logit("channel_register_filter: %d: bad id", id);
768 return;
769 }
770 c->input_filter = ifn;
771 c->output_filter = ofn;
772 c->filter_ctx = ctx;
773 c->filter_cleanup = cfn;
774}
775
776void
777channel_set_fds(int id, int rfd, int wfd, int efd,
778 int extusage, int nonblock, int is_tty, u_int window_max)
779{
780 Channel *c = channel_lookup(id);
781
782 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
783 fatal("channel_activate for non-larval channel %d.", id);
784 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
785 c->type = SSH_CHANNEL_OPEN;
786 c->local_window = c->local_window_max = window_max;
787 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
788 packet_put_int(c->remote_id);
789 packet_put_int(c->local_window);
790 packet_send();
791}
792
793/*
794 * 'channel_pre*' are called just before select() to add any bits relevant to
795 * channels in the select bitmasks.
796 */
797/*
798 * 'channel_post*': perform any appropriate operations for channels which
799 * have events pending.
800 */
801typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
802chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
803chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
804
805/* ARGSUSED */
806static void
807channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
808{
809 FD_SET(c->sock, readset);
810}
811
812/* ARGSUSED */
813static void
814channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
815{
816 debug3("channel %d: waiting for connection", c->self);
817 FD_SET(c->sock, writeset);
818}
819
820static void
821channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
822{
823 if (buffer_len(&c->input) < packet_get_maxsize())
824 FD_SET(c->sock, readset);
825 if (buffer_len(&c->output) > 0)
826 FD_SET(c->sock, writeset);
827}
828
829static u_int
830channel_tcpwinsz(void)
831{
832 u_int32_t tcpwinsz;
833 socklen_t optsz;
834 int ret, sd;
835 u_int maxlen;
836
837 /* If we are not on a socket return 128KB. */
838 if (!packet_connection_is_on_socket())
839 return (128 * 1024);
840
841 tcpwinsz = 0;
842 optsz = sizeof(tcpwinsz);
843 sd = packet_get_connection_in();
844 ret = getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
845
846 /* Return no more than the maximum buffer size. */
847 maxlen = buffer_get_max_len();
848 if ((ret == 0) && tcpwinsz > maxlen)
849 tcpwinsz = maxlen;
850 /* In case getsockopt() failed return a minimum. */
851 if (tcpwinsz == 0)
852 tcpwinsz = CHAN_TCP_WINDOW_DEFAULT;
853 debug2("tcpwinsz: %d for connection: %d", tcpwinsz, sd);
854 return (tcpwinsz);
855}
856
857static void
858channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
859{
860 u_int limit;
861
862 /* Check buffer limits. */
863 if (!c->tcpwinsz || c->dynamic_window > 0)
864 c->tcpwinsz = channel_tcpwinsz();
865
866 limit = MIN(compat20 ? c->remote_window : packet_get_maxsize(),
867 2 * c->tcpwinsz);
868
869 if (c->istate == CHAN_INPUT_OPEN &&
870 limit > 0 &&
871 buffer_len(&c->input) < limit &&
872 buffer_check_alloc(&c->input, CHAN_RBUF))
873 FD_SET(c->rfd, readset);
874 if (c->ostate == CHAN_OUTPUT_OPEN ||
875 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
876 if (buffer_len(&c->output) > 0) {
877 FD_SET(c->wfd, writeset);
878 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
879 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
880 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
881 c->self, c->efd, buffer_len(&c->extended));
882 else
883 chan_obuf_empty(c);
884 }
885 }
886 /** XXX check close conditions, too */
887 if (compat20 && c->efd != -1 &&
888 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
889 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
890 buffer_len(&c->extended) > 0)
891 FD_SET(c->efd, writeset);
892 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
893 (c->extended_usage == CHAN_EXTENDED_READ ||
894 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
895 buffer_len(&c->extended) < c->remote_window)
896 FD_SET(c->efd, readset);
897 }
898 /* XXX: What about efd? races? */
899}
900
901/* ARGSUSED */
902static void
903channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
904{
905 if (buffer_len(&c->input) == 0) {
906 packet_start(SSH_MSG_CHANNEL_CLOSE);
907 packet_put_int(c->remote_id);
908 packet_send();
909 c->type = SSH_CHANNEL_CLOSED;
910 debug2("channel %d: closing after input drain.", c->self);
911 }
912}
913
914/* ARGSUSED */
915static void
916channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
917{
918 if (buffer_len(&c->output) == 0)
919 chan_mark_dead(c);
920 else
921 FD_SET(c->sock, writeset);
922}
923
924/*
925 * This is a special state for X11 authentication spoofing. An opened X11
926 * connection (when authentication spoofing is being done) remains in this
927 * state until the first packet has been completely read. The authentication
928 * data in that packet is then substituted by the real data if it matches the
929 * fake data, and the channel is put into normal mode.
930 * XXX All this happens at the client side.
931 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
932 */
933static int
934x11_open_helper(Buffer *b)
935{
936 u_char *ucp;
937 u_int proto_len, data_len;
938
939 /* Check if the fixed size part of the packet is in buffer. */
940 if (buffer_len(b) < 12)
941 return 0;
942
943 /* Parse the lengths of variable-length fields. */
944 ucp = buffer_ptr(b);
945 if (ucp[0] == 0x42) { /* Byte order MSB first. */
946 proto_len = 256 * ucp[6] + ucp[7];
947 data_len = 256 * ucp[8] + ucp[9];
948 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
949 proto_len = ucp[6] + 256 * ucp[7];
950 data_len = ucp[8] + 256 * ucp[9];
951 } else {
952 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
953 ucp[0]);
954 return -1;
955 }
956
957 /* Check if the whole packet is in buffer. */
958 if (buffer_len(b) <
959 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
960 return 0;
961
962 /* Check if authentication protocol matches. */
963 if (proto_len != strlen(x11_saved_proto) ||
964 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
965 debug2("X11 connection uses different authentication protocol.");
966 return -1;
967 }
968 /* Check if authentication data matches our fake data. */
969 if (data_len != x11_fake_data_len ||
970 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
971 x11_fake_data, x11_fake_data_len) != 0) {
972 debug2("X11 auth data does not match fake data.");
973 return -1;
974 }
975 /* Check fake data length */
976 if (x11_fake_data_len != x11_saved_data_len) {
977 error("X11 fake_data_len %d != saved_data_len %d",
978 x11_fake_data_len, x11_saved_data_len);
979 return -1;
980 }
981 /*
982 * Received authentication protocol and data match
983 * our fake data. Substitute the fake data with real
984 * data.
985 */
986 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
987 x11_saved_data, x11_saved_data_len);
988 return 1;
989}
990
991static void
992channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
993{
994 int ret = x11_open_helper(&c->output);
995
996 if (ret == 1) {
997 /* Start normal processing for the channel. */
998 c->type = SSH_CHANNEL_OPEN;
999 channel_pre_open_13(c, readset, writeset);
1000 } else if (ret == -1) {
1001 /*
1002 * We have received an X11 connection that has bad
1003 * authentication information.
1004 */
1005 logit("X11 connection rejected because of wrong authentication.");
1006 buffer_clear(&c->input);
1007 buffer_clear(&c->output);
1008 channel_close_fd(&c->sock);
1009 c->sock = -1;
1010 c->type = SSH_CHANNEL_CLOSED;
1011 packet_start(SSH_MSG_CHANNEL_CLOSE);
1012 packet_put_int(c->remote_id);
1013 packet_send();
1014 }
1015}
1016
1017static void
1018channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1019{
1020 int ret = x11_open_helper(&c->output);
1021
1022 /* c->force_drain = 1; */
1023
1024 if (ret == 1) {
1025 c->type = SSH_CHANNEL_OPEN;
1026 channel_pre_open(c, readset, writeset);
1027 } else if (ret == -1) {
1028 logit("X11 connection rejected because of wrong authentication.");
1029 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1030 chan_read_failed(c);
1031 buffer_clear(&c->input);
1032 chan_ibuf_empty(c);
1033 buffer_clear(&c->output);
1034 /* for proto v1, the peer will send an IEOF */
1035 if (compat20)
1036 chan_write_failed(c);
1037 else
1038 c->type = SSH_CHANNEL_OPEN;
1039 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1040 }
1041}
1042
1043static void
1044channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1045{
1046 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1047 buffer_check_alloc(&c->input, CHAN_RBUF))
1048 FD_SET(c->rfd, readset);
1049 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1050 /* clear buffer immediately (discard any partial packet) */
1051 buffer_clear(&c->input);
1052 chan_ibuf_empty(c);
1053 /* Start output drain. XXX just kill chan? */
1054 chan_rcvd_oclose(c);
1055 }
1056 if (c->ostate == CHAN_OUTPUT_OPEN ||
1057 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1058 if (buffer_len(&c->output) > 0)
1059 FD_SET(c->wfd, writeset);
1060 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1061 chan_obuf_empty(c);
1062 }
1063}
1064
1065/* try to decode a socks4 header */
1066/* ARGSUSED */
1067static int
1068channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1069{
1070 char *p, *host;
1071 u_int len, have, i, found, need;
1072 char username[256];
1073 struct {
1074 u_int8_t version;
1075 u_int8_t command;
1076 u_int16_t dest_port;
1077 struct in_addr dest_addr;
1078 } s4_req, s4_rsp;
1079
1080 debug2("channel %d: decode socks4", c->self);
1081
1082 have = buffer_len(&c->input);
1083 len = sizeof(s4_req);
1084 if (have < len)
1085 return 0;
1086 p = buffer_ptr(&c->input);
1087
1088 need = 1;
1089 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1090 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1091 debug2("channel %d: socks4a request", c->self);
1092 /* ... and needs an extra string (the hostname) */
1093 need = 2;
1094 }
1095 /* Check for terminating NUL on the string(s) */
1096 for (found = 0, i = len; i < have; i++) {
1097 if (p[i] == '\0') {
1098 found++;
1099 if (found == need)
1100 break;
1101 }
1102 if (i > 1024) {
1103 /* the peer is probably sending garbage */
1104 debug("channel %d: decode socks4: too long",
1105 c->self);
1106 return -1;
1107 }
1108 }
1109 if (found < need)
1110 return 0;
1111 buffer_get(&c->input, (char *)&s4_req.version, 1);
1112 buffer_get(&c->input, (char *)&s4_req.command, 1);
1113 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1114 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1115 have = buffer_len(&c->input);
1116 p = buffer_ptr(&c->input);
1117 len = strlen(p);
1118 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1119 len++; /* trailing '\0' */
1120 if (len > have)
1121 fatal("channel %d: decode socks4: len %d > have %d",
1122 c->self, len, have);
1123 strlcpy(username, p, sizeof(username));
1124 buffer_consume(&c->input, len);
1125
1126 free(c->path);
1127 c->path = NULL;
1128 if (need == 1) { /* SOCKS4: one string */
1129 host = inet_ntoa(s4_req.dest_addr);
1130 c->path = xstrdup(host);
1131 } else { /* SOCKS4A: two strings */
1132 have = buffer_len(&c->input);
1133 p = buffer_ptr(&c->input);
1134 len = strlen(p);
1135 debug2("channel %d: decode socks4a: host %s/%d",
1136 c->self, p, len);
1137 len++; /* trailing '\0' */
1138 if (len > have)
1139 fatal("channel %d: decode socks4a: len %d > have %d",
1140 c->self, len, have);
1141 if (len > NI_MAXHOST) {
1142 error("channel %d: hostname \"%.100s\" too long",
1143 c->self, p);
1144 return -1;
1145 }
1146 c->path = xstrdup(p);
1147 buffer_consume(&c->input, len);
1148 }
1149 c->host_port = ntohs(s4_req.dest_port);
1150
1151 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1152 c->self, c->path, c->host_port, s4_req.command);
1153
1154 if (s4_req.command != 1) {
1155 debug("channel %d: cannot handle: %s cn %d",
1156 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1157 return -1;
1158 }
1159 s4_rsp.version = 0; /* vn: 0 for reply */
1160 s4_rsp.command = 90; /* cd: req granted */
1161 s4_rsp.dest_port = 0; /* ignored */
1162 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1163 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1164 return 1;
1165}
1166
1167/* try to decode a socks5 header */
1168#define SSH_SOCKS5_AUTHDONE 0x1000
1169#define SSH_SOCKS5_NOAUTH 0x00
1170#define SSH_SOCKS5_IPV4 0x01
1171#define SSH_SOCKS5_DOMAIN 0x03
1172#define SSH_SOCKS5_IPV6 0x04
1173#define SSH_SOCKS5_CONNECT 0x01
1174#define SSH_SOCKS5_SUCCESS 0x00
1175
1176/* ARGSUSED */
1177static int
1178channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1179{
1180 struct {
1181 u_int8_t version;
1182 u_int8_t command;
1183 u_int8_t reserved;
1184 u_int8_t atyp;
1185 } s5_req, s5_rsp;
1186 u_int16_t dest_port;
1187 char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1188 u_char *p;
1189 u_int have, need, i, found, nmethods, addrlen, af;
1190
1191 debug2("channel %d: decode socks5", c->self);
1192 p = buffer_ptr(&c->input);
1193 if (p[0] != 0x05)
1194 return -1;
1195 have = buffer_len(&c->input);
1196 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1197 /* format: ver | nmethods | methods */
1198 if (have < 2)
1199 return 0;
1200 nmethods = p[1];
1201 if (have < nmethods + 2)
1202 return 0;
1203 /* look for method: "NO AUTHENTICATION REQUIRED" */
1204 for (found = 0, i = 2; i < nmethods + 2; i++) {
1205 if (p[i] == SSH_SOCKS5_NOAUTH) {
1206 found = 1;
1207 break;
1208 }
1209 }
1210 if (!found) {
1211 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1212 c->self);
1213 return -1;
1214 }
1215 buffer_consume(&c->input, nmethods + 2);
1216 buffer_put_char(&c->output, 0x05); /* version */
1217 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1218 FD_SET(c->sock, writeset);
1219 c->flags |= SSH_SOCKS5_AUTHDONE;
1220 debug2("channel %d: socks5 auth done", c->self);
1221 return 0; /* need more */
1222 }
1223 debug2("channel %d: socks5 post auth", c->self);
1224 if (have < sizeof(s5_req)+1)
1225 return 0; /* need more */
1226 memcpy(&s5_req, p, sizeof(s5_req));
1227 if (s5_req.version != 0x05 ||
1228 s5_req.command != SSH_SOCKS5_CONNECT ||
1229 s5_req.reserved != 0x00) {
1230 debug2("channel %d: only socks5 connect supported", c->self);
1231 return -1;
1232 }
1233 switch (s5_req.atyp){
1234 case SSH_SOCKS5_IPV4:
1235 addrlen = 4;
1236 af = AF_INET;
1237 break;
1238 case SSH_SOCKS5_DOMAIN:
1239 addrlen = p[sizeof(s5_req)];
1240 af = -1;
1241 break;
1242 case SSH_SOCKS5_IPV6:
1243 addrlen = 16;
1244 af = AF_INET6;
1245 break;
1246 default:
1247 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1248 return -1;
1249 }
1250 need = sizeof(s5_req) + addrlen + 2;
1251 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1252 need++;
1253 if (have < need)
1254 return 0;
1255 buffer_consume(&c->input, sizeof(s5_req));
1256 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1257 buffer_consume(&c->input, 1); /* host string length */
1258 buffer_get(&c->input, &dest_addr, addrlen);
1259 buffer_get(&c->input, (char *)&dest_port, 2);
1260 dest_addr[addrlen] = '\0';
1261 free(c->path);
1262 c->path = NULL;
1263 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1264 if (addrlen >= NI_MAXHOST) {
1265 error("channel %d: dynamic request: socks5 hostname "
1266 "\"%.100s\" too long", c->self, dest_addr);
1267 return -1;
1268 }
1269 c->path = xstrdup(dest_addr);
1270 } else {
1271 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1272 return -1;
1273 c->path = xstrdup(ntop);
1274 }
1275 c->host_port = ntohs(dest_port);
1276
1277 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1278 c->self, c->path, c->host_port, s5_req.command);
1279
1280 s5_rsp.version = 0x05;
1281 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1282 s5_rsp.reserved = 0; /* ignored */
1283 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1284 dest_port = 0; /* ignored */
1285
1286 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1287 buffer_put_int(&c->output, ntohl(INADDR_ANY)); /* bind address */
1288 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1289 return 1;
1290}
1291
1292Channel *
1293channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1294 int in, int out)
1295{
1296 Channel *c;
1297
1298 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1299 port_to_connect);
1300
1301 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1302 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1303 0, "stdio-forward", /*nonblock*/0);
1304
1305 c->path = xstrdup(host_to_connect);
1306 c->host_port = port_to_connect;
1307 c->listening_port = 0;
1308 c->force_drain = 1;
1309
1310 channel_register_fds(c, in, out, -1, 0, 1, 0);
1311 port_open_helper(c, "direct-tcpip");
1312
1313 return c;
1314}
1315
1316/* dynamic port forwarding */
1317static void
1318channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1319{
1320 u_char *p;
1321 u_int have;
1322 int ret;
1323
1324 have = buffer_len(&c->input);
1325 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1326 /* buffer_dump(&c->input); */
1327 /* check if the fixed size part of the packet is in buffer. */
1328 if (have < 3) {
1329 /* need more */
1330 FD_SET(c->sock, readset);
1331 return;
1332 }
1333 /* try to guess the protocol */
1334 p = buffer_ptr(&c->input);
1335 switch (p[0]) {
1336 case 0x04:
1337 ret = channel_decode_socks4(c, readset, writeset);
1338 break;
1339 case 0x05:
1340 ret = channel_decode_socks5(c, readset, writeset);
1341 break;
1342 default:
1343 ret = -1;
1344 break;
1345 }
1346 if (ret < 0) {
1347 chan_mark_dead(c);
1348 } else if (ret == 0) {
1349 debug2("channel %d: pre_dynamic: need more", c->self);
1350 /* need more */
1351 FD_SET(c->sock, readset);
1352 } else {
1353 /* switch to the next state */
1354 c->type = SSH_CHANNEL_OPENING;
1355 port_open_helper(c, "direct-tcpip");
1356 }
1357}
1358
1359/* This is our fake X11 server socket. */
1360/* ARGSUSED */
1361static void
1362channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1363{
1364 Channel *nc;
1365 struct sockaddr_storage addr;
1366 int newsock, oerrno;
1367 socklen_t addrlen;
1368 char buf[16384], *remote_ipaddr;
1369 int remote_port;
1370
1371 if (FD_ISSET(c->sock, readset)) {
1372 debug("X11 connection requested.");
1373 addrlen = sizeof(addr);
1374 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1375 if (c->single_connection) {
1376 oerrno = errno;
1377 debug2("single_connection: closing X11 listener.");
1378 channel_close_fd(&c->sock);
1379 chan_mark_dead(c);
1380 errno = oerrno;
1381 }
1382 if (newsock < 0) {
1383 if (errno != EINTR && errno != EWOULDBLOCK &&
1384 errno != ECONNABORTED)
1385 error("accept: %.100s", strerror(errno));
1386 if (errno == EMFILE || errno == ENFILE)
1387 c->notbefore = monotime() + 1;
1388 return;
1389 }
1390 set_nodelay(newsock);
1391 remote_ipaddr = get_peer_ipaddr(newsock);
1392 remote_port = get_peer_port(newsock);
1393 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1394 remote_ipaddr, remote_port);
1395
1396 nc = channel_new("accepted x11 socket",
1397 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1398 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1399 if (compat20) {
1400 packet_start(SSH2_MSG_CHANNEL_OPEN);
1401 packet_put_cstring("x11");
1402 packet_put_int(nc->self);
1403 packet_put_int(nc->local_window_max);
1404 packet_put_int(nc->local_maxpacket);
1405 /* originator ipaddr and port */
1406 packet_put_cstring(remote_ipaddr);
1407 if (datafellows & SSH_BUG_X11FWD) {
1408 debug2("ssh2 x11 bug compat mode");
1409 } else {
1410 packet_put_int(remote_port);
1411 }
1412 packet_send();
1413 } else {
1414 packet_start(SSH_SMSG_X11_OPEN);
1415 packet_put_int(nc->self);
1416 if (packet_get_protocol_flags() &
1417 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1418 packet_put_cstring(buf);
1419 packet_send();
1420 }
1421 free(remote_ipaddr);
1422 }
1423}
1424
1425static void
1426port_open_helper(Channel *c, char *rtype)
1427{
1428 int direct;
1429 char buf[1024];
1430 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1431 int remote_port = get_peer_port(c->sock);
1432
1433 if (remote_port == -1) {
1434 /* Fake addr/port to appease peers that validate it (Tectia) */
1435 free(remote_ipaddr);
1436 remote_ipaddr = xstrdup("127.0.0.1");
1437 remote_port = 65535;
1438 }
1439
1440 direct = (strcmp(rtype, "direct-tcpip") == 0);
1441
1442 snprintf(buf, sizeof buf,
1443 "%s: listening port %d for %.100s port %d, "
1444 "connect from %.200s port %d",
1445 rtype, c->listening_port, c->path, c->host_port,
1446 remote_ipaddr, remote_port);
1447
1448 free(c->remote_name);
1449 c->remote_name = xstrdup(buf);
1450
1451 if (compat20) {
1452 packet_start(SSH2_MSG_CHANNEL_OPEN);
1453 packet_put_cstring(rtype);
1454 packet_put_int(c->self);
1455 packet_put_int(c->local_window_max);
1456 packet_put_int(c->local_maxpacket);
1457 if (direct) {
1458 /* target host, port */
1459 packet_put_cstring(c->path);
1460 packet_put_int(c->host_port);
1461 } else {
1462 /* listen address, port */
1463 packet_put_cstring(c->path);
1464 packet_put_int(c->listening_port);
1465 }
1466 /* originator host and port */
1467 packet_put_cstring(remote_ipaddr);
1468 packet_put_int((u_int)remote_port);
1469 packet_send();
1470 } else {
1471 packet_start(SSH_MSG_PORT_OPEN);
1472 packet_put_int(c->self);
1473 packet_put_cstring(c->path);
1474 packet_put_int(c->host_port);
1475 if (packet_get_protocol_flags() &
1476 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1477 packet_put_cstring(c->remote_name);
1478 packet_send();
1479 }
1480 free(remote_ipaddr);
1481}
1482
1483static void
1484channel_set_reuseaddr(int fd)
1485{
1486 int on = 1;
1487
1488 /*
1489 * Set socket options.
1490 * Allow local port reuse in TIME_WAIT.
1491 */
1492 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1493 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1494}
1495
1496/*
1497 * This socket is listening for connections to a forwarded TCP/IP port.
1498 */
1499/* ARGSUSED */
1500static void
1501channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1502{
1503 Channel *nc;
1504 struct sockaddr_storage addr;
1505 int newsock, nextstate;
1506 socklen_t addrlen;
1507 char *rtype;
1508
1509 if (FD_ISSET(c->sock, readset)) {
1510 debug("Connection to port %d forwarding "
1511 "to %.100s port %d requested.",
1512 c->listening_port, c->path, c->host_port);
1513
1514 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1515 nextstate = SSH_CHANNEL_OPENING;
1516 rtype = "forwarded-tcpip";
1517 } else {
1518 if (c->host_port == 0) {
1519 nextstate = SSH_CHANNEL_DYNAMIC;
1520 rtype = "dynamic-tcpip";
1521 } else {
1522 nextstate = SSH_CHANNEL_OPENING;
1523 rtype = "direct-tcpip";
1524 }
1525 }
1526
1527 addrlen = sizeof(addr);
1528 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1529 if (newsock < 0) {
1530 if (errno != EINTR && errno != EWOULDBLOCK &&
1531 errno != ECONNABORTED)
1532 error("accept: %.100s", strerror(errno));
1533 if (errno == EMFILE || errno == ENFILE)
1534 c->notbefore = monotime() + 1;
1535 return;
1536 }
1537 set_nodelay(newsock);
1538 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1539 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1540 nc->listening_port = c->listening_port;
1541 nc->host_port = c->host_port;
1542 if (c->path != NULL)
1543 nc->path = xstrdup(c->path);
1544
1545 if (nextstate != SSH_CHANNEL_DYNAMIC)
1546 port_open_helper(nc, rtype);
1547 }
1548}
1549
1550/*
1551 * This is the authentication agent socket listening for connections from
1552 * clients.
1553 */
1554/* ARGSUSED */
1555static void
1556channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1557{
1558 Channel *nc;
1559 int newsock;
1560 struct sockaddr_storage addr;
1561 socklen_t addrlen;
1562
1563 if (FD_ISSET(c->sock, readset)) {
1564 addrlen = sizeof(addr);
1565 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1566 if (newsock < 0) {
1567 error("accept from auth socket: %.100s",
1568 strerror(errno));
1569 if (errno == EMFILE || errno == ENFILE)
1570 c->notbefore = monotime() + 1;
1571 return;
1572 }
1573 nc = channel_new("accepted auth socket",
1574 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1575 c->local_window_max, c->local_maxpacket,
1576 0, "accepted auth socket", 1);
1577 if (compat20) {
1578 packet_start(SSH2_MSG_CHANNEL_OPEN);
1579 packet_put_cstring("auth-agent@openssh.com");
1580 packet_put_int(nc->self);
1581 packet_put_int(c->local_window_max);
1582 packet_put_int(c->local_maxpacket);
1583 } else {
1584 packet_start(SSH_SMSG_AGENT_OPEN);
1585 packet_put_int(nc->self);
1586 }
1587 packet_send();
1588 }
1589}
1590
1591/* ARGSUSED */
1592static void
1593channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1594{
1595 int err = 0, sock;
1596 socklen_t sz = sizeof(err);
1597
1598 if (FD_ISSET(c->sock, writeset)) {
1599 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1600 err = errno;
1601 error("getsockopt SO_ERROR failed");
1602 }
1603 if (err == 0) {
1604 debug("channel %d: connected to %s port %d",
1605 c->self, c->connect_ctx.host, c->connect_ctx.port);
1606 channel_connect_ctx_free(&c->connect_ctx);
1607 c->type = SSH_CHANNEL_OPEN;
1608 if (compat20) {
1609 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1610 packet_put_int(c->remote_id);
1611 packet_put_int(c->self);
1612 packet_put_int(c->local_window);
1613 packet_put_int(c->local_maxpacket);
1614 } else {
1615 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1616 packet_put_int(c->remote_id);
1617 packet_put_int(c->self);
1618 }
1619 } else {
1620 debug("channel %d: connection failed: %s",
1621 c->self, strerror(err));
1622 /* Try next address, if any */
1623 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1624 close(c->sock);
1625 c->sock = c->rfd = c->wfd = sock;
1626 channel_max_fd = channel_find_maxfd();
1627 return;
1628 }
1629 /* Exhausted all addresses */
1630 error("connect_to %.100s port %d: failed.",
1631 c->connect_ctx.host, c->connect_ctx.port);
1632 channel_connect_ctx_free(&c->connect_ctx);
1633 if (compat20) {
1634 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1635 packet_put_int(c->remote_id);
1636 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1637 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1638 packet_put_cstring(strerror(err));
1639 packet_put_cstring("");
1640 }
1641 } else {
1642 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1643 packet_put_int(c->remote_id);
1644 }
1645 chan_mark_dead(c);
1646 }
1647 packet_send();
1648 }
1649}
1650
1651/* ARGSUSED */
1652static int
1653channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1654{
1655 char buf[CHAN_RBUF];
1656 int len, force;
1657
1658 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1659 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1660 errno = 0;
1661 len = read(c->rfd, buf, sizeof(buf));
1662 if (len < 0 && (errno == EINTR ||
1663 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1664 return 1;
1665#ifndef PTY_ZEROREAD
1666 if (len <= 0) {
1667#else
1668 if ((!c->isatty && len <= 0) ||
1669 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1670#endif
1671 debug2("channel %d: read<=0 rfd %d len %d",
1672 c->self, c->rfd, len);
1673 if (c->type != SSH_CHANNEL_OPEN) {
1674 debug2("channel %d: not open", c->self);
1675 chan_mark_dead(c);
1676 return -1;
1677 } else if (compat13) {
1678 buffer_clear(&c->output);
1679 c->type = SSH_CHANNEL_INPUT_DRAINING;
1680 debug2("channel %d: input draining.", c->self);
1681 } else {
1682 chan_read_failed(c);
1683 }
1684 return -1;
1685 }
1686 if (c->input_filter != NULL) {
1687 if (c->input_filter(c, buf, len) == -1) {
1688 debug2("channel %d: filter stops", c->self);
1689 chan_read_failed(c);
1690 }
1691 } else if (c->datagram) {
1692 buffer_put_string(&c->input, buf, len);
1693 } else {
1694 buffer_append(&c->input, buf, len);
1695 }
1696 }
1697 return 1;
1698}
1699
1700/* ARGSUSED */
1701static int
1702channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1703{
1704 struct termios tio;
1705 u_char *data = NULL, *buf;
1706 u_int dlen, olen = 0;
1707 int len;
1708
1709 /* Send buffered output data to the socket. */
1710 if (c->wfd != -1 &&
1711 FD_ISSET(c->wfd, writeset) &&
1712 buffer_len(&c->output) > 0) {
1713 olen = buffer_len(&c->output);
1714 if (c->output_filter != NULL) {
1715 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1716 debug2("channel %d: filter stops", c->self);
1717 if (c->type != SSH_CHANNEL_OPEN)
1718 chan_mark_dead(c);
1719 else
1720 chan_write_failed(c);
1721 return -1;
1722 }
1723 } else if (c->datagram) {
1724 buf = data = buffer_get_string(&c->output, &dlen);
1725 } else {
1726 buf = data = buffer_ptr(&c->output);
1727 dlen = buffer_len(&c->output);
1728 }
1729
1730 if (c->datagram) {
1731 /* ignore truncated writes, datagrams might get lost */
1732 len = write(c->wfd, buf, dlen);
1733 free(data);
1734 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1735 errno == EWOULDBLOCK))
1736 return 1;
1737 if (len <= 0) {
1738 if (c->type != SSH_CHANNEL_OPEN)
1739 chan_mark_dead(c);
1740 else
1741 chan_write_failed(c);
1742 return -1;
1743 }
1744 goto out;
1745 }
1746#ifdef _AIX
1747 /* XXX: Later AIX versions can't push as much data to tty */
1748 if (compat20 && c->wfd_isatty)
1749 dlen = MIN(dlen, 8*1024);
1750#endif
1751
1752 len = write(c->wfd, buf, dlen);
1753 if (len < 0 &&
1754 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1755 return 1;
1756 if (len <= 0) {
1757 if (c->type != SSH_CHANNEL_OPEN) {
1758 debug2("channel %d: not open", c->self);
1759 chan_mark_dead(c);
1760 return -1;
1761 } else if (compat13) {
1762 buffer_clear(&c->output);
1763 debug2("channel %d: input draining.", c->self);
1764 c->type = SSH_CHANNEL_INPUT_DRAINING;
1765 } else {
1766 chan_write_failed(c);
1767 }
1768 return -1;
1769 }
1770#ifndef BROKEN_TCGETATTR_ICANON
1771 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1772 if (tcgetattr(c->wfd, &tio) == 0 &&
1773 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1774 /*
1775 * Simulate echo to reduce the impact of
1776 * traffic analysis. We need to match the
1777 * size of a SSH2_MSG_CHANNEL_DATA message
1778 * (4 byte channel id + buf)
1779 */
1780 packet_send_ignore(4 + len);
1781 packet_send();
1782 }
1783 }
1784#endif
1785 buffer_consume(&c->output, len);
1786 }
1787 out:
1788 if (compat20 && olen > 0)
1789 c->local_consumed += olen - buffer_len(&c->output);
1790 return 1;
1791}
1792
1793static int
1794channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1795{
1796 char buf[CHAN_RBUF];
1797 int len;
1798
1799/** XXX handle drain efd, too */
1800 if (c->efd != -1) {
1801 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1802 FD_ISSET(c->efd, writeset) &&
1803 buffer_len(&c->extended) > 0) {
1804 len = write(c->efd, buffer_ptr(&c->extended),
1805 buffer_len(&c->extended));
1806 debug2("channel %d: written %d to efd %d",
1807 c->self, len, c->efd);
1808 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1809 errno == EWOULDBLOCK))
1810 return 1;
1811 if (len <= 0) {
1812 debug2("channel %d: closing write-efd %d",
1813 c->self, c->efd);
1814 channel_close_fd(&c->efd);
1815 } else {
1816 buffer_consume(&c->extended, len);
1817 c->local_consumed += len;
1818 }
1819 } else if (c->efd != -1 &&
1820 (c->extended_usage == CHAN_EXTENDED_READ ||
1821 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1822 (c->detach_close || FD_ISSET(c->efd, readset))) {
1823 len = read(c->efd, buf, sizeof(buf));
1824 debug2("channel %d: read %d from efd %d",
1825 c->self, len, c->efd);
1826 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1827 errno == EWOULDBLOCK) && !c->detach_close)))
1828 return 1;
1829 if (len <= 0) {
1830 debug2("channel %d: closing read-efd %d",
1831 c->self, c->efd);
1832 channel_close_fd(&c->efd);
1833 } else {
1834 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1835 debug3("channel %d: discard efd",
1836 c->self);
1837 } else
1838 buffer_append(&c->extended, buf, len);
1839 }
1840 }
1841 }
1842 return 1;
1843}
1844
1845static int
1846channel_check_window(Channel *c)
1847{
1848 if (c->type == SSH_CHANNEL_OPEN &&
1849 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1850 ((c->local_window_max - c->local_window >
1851 c->local_maxpacket*3) ||
1852 c->local_window < c->local_window_max/2) &&
1853 c->local_consumed > 0) {
1854 u_int addition = 0;
1855
1856 /* Adjust max window size if we are in a dynamic environment. */
1857 if (c->dynamic_window && c->tcpwinsz > c->local_window_max) {
1858 /*
1859 * Grow the window somewhat aggressively to maintain
1860 * pressure.
1861 */
1862 addition = 1.5 * (c->tcpwinsz - c->local_window_max);
1863 c->local_window_max += addition;
1864 }
1865 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1866 packet_put_int(c->remote_id);
1867 packet_put_int(c->local_consumed + addition);
1868 packet_send();
1869 debug2("channel %d: window %d sent adjust %d",
1870 c->self, c->local_window,
1871 c->local_consumed);
1872 c->local_window += c->local_consumed + addition;
1873 c->local_consumed = 0;
1874 }
1875 return 1;
1876}
1877
1878static void
1879channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1880{
1881 channel_handle_rfd(c, readset, writeset);
1882 channel_handle_wfd(c, readset, writeset);
1883 if (!compat20)
1884 return;
1885 channel_handle_efd(c, readset, writeset);
1886 channel_check_window(c);
1887}
1888
1889static u_int
1890read_mux(Channel *c, u_int need)
1891{
1892 char buf[CHAN_RBUF];
1893 int len;
1894 u_int rlen;
1895
1896 if (buffer_len(&c->input) < need) {
1897 rlen = need - buffer_len(&c->input);
1898 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1899 if (len <= 0) {
1900 if (errno != EINTR && errno != EAGAIN) {
1901 debug2("channel %d: ctl read<=0 rfd %d len %d",
1902 c->self, c->rfd, len);
1903 chan_read_failed(c);
1904 return 0;
1905 }
1906 } else
1907 buffer_append(&c->input, buf, len);
1908 }
1909 return buffer_len(&c->input);
1910}
1911
1912static void
1913channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1914{
1915 u_int need;
1916 ssize_t len;
1917
1918 if (!compat20)
1919 fatal("%s: entered with !compat20", __func__);
1920
1921 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1922 (c->istate == CHAN_INPUT_OPEN ||
1923 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1924 /*
1925 * Don't not read past the precise end of packets to
1926 * avoid disrupting fd passing.
1927 */
1928 if (read_mux(c, 4) < 4) /* read header */
1929 return;
1930 need = get_u32(buffer_ptr(&c->input));
1931#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1932 if (need > CHANNEL_MUX_MAX_PACKET) {
1933 debug2("channel %d: packet too big %u > %u",
1934 c->self, CHANNEL_MUX_MAX_PACKET, need);
1935 chan_rcvd_oclose(c);
1936 return;
1937 }
1938 if (read_mux(c, need + 4) < need + 4) /* read body */
1939 return;
1940 if (c->mux_rcb(c) != 0) {
1941 debug("channel %d: mux_rcb failed", c->self);
1942 chan_mark_dead(c);
1943 return;
1944 }
1945 }
1946
1947 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1948 buffer_len(&c->output) > 0) {
1949 len = write(c->wfd, buffer_ptr(&c->output),
1950 buffer_len(&c->output));
1951 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1952 return;
1953 if (len <= 0) {
1954 chan_mark_dead(c);
1955 return;
1956 }
1957 buffer_consume(&c->output, len);
1958 }
1959}
1960
1961static void
1962channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1963{
1964 Channel *nc;
1965 struct sockaddr_storage addr;
1966 socklen_t addrlen;
1967 int newsock;
1968 uid_t euid;
1969 gid_t egid;
1970
1971 if (!FD_ISSET(c->sock, readset))
1972 return;
1973
1974 debug("multiplexing control connection");
1975
1976 /*
1977 * Accept connection on control socket
1978 */
1979 memset(&addr, 0, sizeof(addr));
1980 addrlen = sizeof(addr);
1981 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1982 &addrlen)) == -1) {
1983 error("%s accept: %s", __func__, strerror(errno));
1984 if (errno == EMFILE || errno == ENFILE)
1985 c->notbefore = monotime() + 1;
1986 return;
1987 }
1988
1989 if (getpeereid(newsock, &euid, &egid) < 0) {
1990 error("%s getpeereid failed: %s", __func__,
1991 strerror(errno));
1992 close(newsock);
1993 return;
1994 }
1995 if ((euid != 0) && (getuid() != euid)) {
1996 error("multiplex uid mismatch: peer euid %u != uid %u",
1997 (u_int)euid, (u_int)getuid());
1998 close(newsock);
1999 return;
2000 }
2001 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
2002 newsock, newsock, -1, c->local_window_max,
2003 c->local_maxpacket, 0, "mux-control", 1);
2004 nc->mux_rcb = c->mux_rcb;
2005 debug3("%s: new mux channel %d fd %d", __func__,
2006 nc->self, nc->sock);
2007 /* establish state */
2008 nc->mux_rcb(nc);
2009 /* mux state transitions must not elicit protocol messages */
2010 nc->flags |= CHAN_LOCAL;
2011}
2012
2013/* ARGSUSED */
2014static void
2015channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
2016{
2017 int len;
2018
2019 /* Send buffered output data to the socket. */
2020 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
2021 len = write(c->sock, buffer_ptr(&c->output),
2022 buffer_len(&c->output));
2023 if (len <= 0)
2024 buffer_clear(&c->output);
2025 else
2026 buffer_consume(&c->output, len);
2027 }
2028}
2029
2030static void
2031channel_handler_init_20(void)
2032{
2033 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2034 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2035 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2036 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2037 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2038 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2039 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2040 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2041 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2042 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2043
2044 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2045 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2046 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2047 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2048 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2049 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2050 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2051 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2052 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2053}
2054
2055static void
2056channel_handler_init_13(void)
2057{
2058 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2059 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2060 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2061 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2062 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2063 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2064 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2065 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2066 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2067
2068 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2069 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2070 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2071 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2072 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2073 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2074 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2075}
2076
2077static void
2078channel_handler_init_15(void)
2079{
2080 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2081 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2082 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2083 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2084 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2085 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2086 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2087
2088 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2089 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2090 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2091 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2092 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2093 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2094}
2095
2096static void
2097channel_handler_init(void)
2098{
2099 int i;
2100
2101 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2102 channel_pre[i] = NULL;
2103 channel_post[i] = NULL;
2104 }
2105 if (compat20)
2106 channel_handler_init_20();
2107 else if (compat13)
2108 channel_handler_init_13();
2109 else
2110 channel_handler_init_15();
2111}
2112
2113/* gc dead channels */
2114static void
2115channel_garbage_collect(Channel *c)
2116{
2117 if (c == NULL)
2118 return;
2119 if (c->detach_user != NULL) {
2120 if (!chan_is_dead(c, c->detach_close))
2121 return;
2122 debug2("channel %d: gc: notify user", c->self);
2123 c->detach_user(c->self, NULL);
2124 /* if we still have a callback */
2125 if (c->detach_user != NULL)
2126 return;
2127 debug2("channel %d: gc: user detached", c->self);
2128 }
2129 if (!chan_is_dead(c, 1))
2130 return;
2131 debug2("channel %d: garbage collecting", c->self);
2132 channel_free(c);
2133}
2134
2135static void
2136channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset,
2137 time_t *unpause_secs)
2138{
2139 static int did_init = 0;
2140 u_int i, oalloc;
2141 Channel *c;
2142 time_t now;
2143
2144 if (!did_init) {
2145 channel_handler_init();
2146 did_init = 1;
2147 }
2148 now = monotime();
2149 if (unpause_secs != NULL)
2150 *unpause_secs = 0;
2151 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2152 c = channels[i];
2153 if (c == NULL)
2154 continue;
2155 if (c->delayed) {
2156 if (ftab == channel_pre)
2157 c->delayed = 0;
2158 else
2159 continue;
2160 }
2161 if (ftab[c->type] != NULL) {
2162 /*
2163 * Run handlers that are not paused.
2164 */
2165 if (c->notbefore <= now)
2166 (*ftab[c->type])(c, readset, writeset);
2167 else if (unpause_secs != NULL) {
2168 /*
2169 * Collect the time that the earliest
2170 * channel comes off pause.
2171 */
2172 debug3("%s: chan %d: skip for %d more seconds",
2173 __func__, c->self,
2174 (int)(c->notbefore - now));
2175 if (*unpause_secs == 0 ||
2176 (c->notbefore - now) < *unpause_secs)
2177 *unpause_secs = c->notbefore - now;
2178 }
2179 }
2180 channel_garbage_collect(c);
2181 }
2182 if (unpause_secs != NULL && *unpause_secs != 0)
2183 debug3("%s: first channel unpauses in %d seconds",
2184 __func__, (int)*unpause_secs);
2185}
2186
2187/*
2188 * Allocate/update select bitmasks and add any bits relevant to channels in
2189 * select bitmasks.
2190 */
2191void
2192channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2193 u_int *nallocp, time_t *minwait_secs, int rekeying)
2194{
2195 u_int n, sz, nfdset;
2196
2197 n = MAX(*maxfdp, channel_max_fd);
2198
2199 nfdset = howmany(n+1, NFDBITS);
2200 /* Explicitly test here, because xrealloc isn't always called */
2201 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2202 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2203 sz = nfdset * sizeof(fd_mask);
2204
2205 /* perhaps check sz < nalloc/2 and shrink? */
2206 if (*readsetp == NULL || sz > *nallocp) {
2207 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2208 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2209 *nallocp = sz;
2210 }
2211 *maxfdp = n;
2212 memset(*readsetp, 0, sz);
2213 memset(*writesetp, 0, sz);
2214
2215 if (!rekeying)
2216 channel_handler(channel_pre, *readsetp, *writesetp,
2217 minwait_secs);
2218}
2219
2220/*
2221 * After select, perform any appropriate operations for channels which have
2222 * events pending.
2223 */
2224void
2225channel_after_select(fd_set *readset, fd_set *writeset)
2226{
2227 channel_handler(channel_post, readset, writeset, NULL);
2228}
2229
2230
2231/* If there is data to send to the connection, enqueue some of it now. */
2232void
2233channel_output_poll(void)
2234{
2235 Channel *c;
2236 u_int i, len;
2237
2238 for (i = 0; i < channels_alloc; i++) {
2239 c = channels[i];
2240 if (c == NULL)
2241 continue;
2242
2243 /*
2244 * We are only interested in channels that can have buffered
2245 * incoming data.
2246 */
2247 if (compat13) {
2248 if (c->type != SSH_CHANNEL_OPEN &&
2249 c->type != SSH_CHANNEL_INPUT_DRAINING)
2250 continue;
2251 } else {
2252 if (c->type != SSH_CHANNEL_OPEN)
2253 continue;
2254 }
2255 if (compat20 &&
2256 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2257 /* XXX is this true? */
2258 debug3("channel %d: will not send data after close", c->self);
2259 continue;
2260 }
2261
2262 /* Get the amount of buffered data for this channel. */
2263 if ((c->istate == CHAN_INPUT_OPEN ||
2264 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2265 (len = buffer_len(&c->input)) > 0) {
2266 if (c->datagram) {
2267 if (len > 0) {
2268 u_char *data;
2269 u_int dlen;
2270
2271 data = buffer_get_string(&c->input,
2272 &dlen);
2273 if (dlen > c->remote_window ||
2274 dlen > c->remote_maxpacket) {
2275 debug("channel %d: datagram "
2276 "too big for channel",
2277 c->self);
2278 free(data);
2279 continue;
2280 }
2281 packet_start(SSH2_MSG_CHANNEL_DATA);
2282 packet_put_int(c->remote_id);
2283 packet_put_string(data, dlen);
2284 packet_send();
2285 c->remote_window -= dlen + 4;
2286 free(data);
2287 }
2288 continue;
2289 }
2290 /*
2291 * Send some data for the other side over the secure
2292 * connection.
2293 */
2294 if (compat20) {
2295 if (len > c->remote_window)
2296 len = c->remote_window;
2297 if (len > c->remote_maxpacket)
2298 len = c->remote_maxpacket;
2299 } else {
2300 if (packet_is_interactive()) {
2301 if (len > 1024)
2302 len = 512;
2303 } else {
2304 /* Keep the packets at reasonable size. */
2305 if (len > packet_get_maxsize()/2)
2306 len = packet_get_maxsize()/2;
2307 }
2308 }
2309 if (len > 0) {
2310 packet_start(compat20 ?
2311 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2312 packet_put_int(c->remote_id);
2313 packet_put_string(buffer_ptr(&c->input), len);
2314 packet_send();
2315 buffer_consume(&c->input, len);
2316 c->remote_window -= len;
2317 }
2318 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2319 if (compat13)
2320 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2321 /*
2322 * input-buffer is empty and read-socket shutdown:
2323 * tell peer, that we will not send more data: send IEOF.
2324 * hack for extended data: delay EOF if EFD still in use.
2325 */
2326 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2327 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2328 c->self, c->efd, buffer_len(&c->extended));
2329 else
2330 chan_ibuf_empty(c);
2331 }
2332 /* Send extended data, i.e. stderr */
2333 if (compat20 &&
2334 !(c->flags & CHAN_EOF_SENT) &&
2335 c->remote_window > 0 &&
2336 (len = buffer_len(&c->extended)) > 0 &&
2337 c->extended_usage == CHAN_EXTENDED_READ) {
2338 debug2("channel %d: rwin %u elen %u euse %d",
2339 c->self, c->remote_window, buffer_len(&c->extended),
2340 c->extended_usage);
2341 if (len > c->remote_window)
2342 len = c->remote_window;
2343 if (len > c->remote_maxpacket)
2344 len = c->remote_maxpacket;
2345 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2346 packet_put_int(c->remote_id);
2347 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2348 packet_put_string(buffer_ptr(&c->extended), len);
2349 packet_send();
2350 buffer_consume(&c->extended, len);
2351 c->remote_window -= len;
2352 debug2("channel %d: sent ext data %d", c->self, len);
2353 }
2354 }
2355}
2356
2357
2358/* -- protocol input */
2359
2360/* ARGSUSED */
2361void
2362channel_input_data(int type, u_int32_t seq, void *ctxt)
2363{
2364 int id;
2365 char *data;
2366 u_int data_len, win_len;
2367 Channel *c;
2368
2369 /* Get the channel number and verify it. */
2370 id = packet_get_int();
2371 c = channel_lookup(id);
2372 if (c == NULL)
2373 packet_disconnect("Received data for nonexistent channel %d.", id);
2374
2375 /* Ignore any data for non-open channels (might happen on close) */
2376 if (c->type != SSH_CHANNEL_OPEN &&
2377 c->type != SSH_CHANNEL_X11_OPEN)
2378 return;
2379
2380 /* Get the data. */
2381 data = packet_get_string_ptr(&data_len);
2382 win_len = data_len;
2383 if (c->datagram)
2384 win_len += 4; /* string length header */
2385
2386 /*
2387 * Ignore data for protocol > 1.3 if output end is no longer open.
2388 * For protocol 2 the sending side is reducing its window as it sends
2389 * data, so we must 'fake' consumption of the data in order to ensure
2390 * that window updates are sent back. Otherwise the connection might
2391 * deadlock.
2392 */
2393 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2394 if (compat20) {
2395 c->local_window -= win_len;
2396 c->local_consumed += win_len;
2397 }
2398 return;
2399 }
2400
2401 if (compat20) {
2402 if (win_len > c->local_maxpacket) {
2403 logit("channel %d: rcvd big packet %d, maxpack %d",
2404 c->self, win_len, c->local_maxpacket);
2405 }
2406 if (win_len > c->local_window) {
2407 logit("channel %d: rcvd too much data %d, win %d",
2408 c->self, win_len, c->local_window);
2409 return;
2410 }
2411 c->local_window -= win_len;
2412 }
2413 if (c->datagram)
2414 buffer_put_string(&c->output, data, data_len);
2415 else
2416 buffer_append(&c->output, data, data_len);
2417 packet_check_eom();
2418}
2419
2420/* ARGSUSED */
2421void
2422channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2423{
2424 int id;
2425 char *data;
2426 u_int data_len, tcode;
2427 Channel *c;
2428
2429 /* Get the channel number and verify it. */
2430 id = packet_get_int();
2431 c = channel_lookup(id);
2432
2433 if (c == NULL)
2434 packet_disconnect("Received extended_data for bad channel %d.", id);
2435 if (c->type != SSH_CHANNEL_OPEN) {
2436 logit("channel %d: ext data for non open", id);
2437 return;
2438 }
2439 if (c->flags & CHAN_EOF_RCVD) {
2440 if (datafellows & SSH_BUG_EXTEOF)
2441 debug("channel %d: accepting ext data after eof", id);
2442 else
2443 packet_disconnect("Received extended_data after EOF "
2444 "on channel %d.", id);
2445 }
2446 tcode = packet_get_int();
2447 if (c->efd == -1 ||
2448 c->extended_usage != CHAN_EXTENDED_WRITE ||
2449 tcode != SSH2_EXTENDED_DATA_STDERR) {
2450 logit("channel %d: bad ext data", c->self);
2451 return;
2452 }
2453 data = packet_get_string(&data_len);
2454 packet_check_eom();
2455 if (data_len > c->local_window) {
2456 logit("channel %d: rcvd too much extended_data %d, win %d",
2457 c->self, data_len, c->local_window);
2458 free(data);
2459 return;
2460 }
2461 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2462 c->local_window -= data_len;
2463 buffer_append(&c->extended, data, data_len);
2464 free(data);
2465}
2466
2467/* ARGSUSED */
2468void
2469channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2470{
2471 int id;
2472 Channel *c;
2473
2474 id = packet_get_int();
2475 packet_check_eom();
2476 c = channel_lookup(id);
2477 if (c == NULL)
2478 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2479 chan_rcvd_ieof(c);
2480
2481 /* XXX force input close */
2482 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2483 debug("channel %d: FORCE input drain", c->self);
2484 c->istate = CHAN_INPUT_WAIT_DRAIN;
2485 if (buffer_len(&c->input) == 0)
2486 chan_ibuf_empty(c);
2487 }
2488
2489}
2490
2491/* ARGSUSED */
2492void
2493channel_input_close(int type, u_int32_t seq, void *ctxt)
2494{
2495 int id;
2496 Channel *c;
2497
2498 id = packet_get_int();
2499 packet_check_eom();
2500 c = channel_lookup(id);
2501 if (c == NULL)
2502 packet_disconnect("Received close for nonexistent channel %d.", id);
2503
2504 /*
2505 * Send a confirmation that we have closed the channel and no more
2506 * data is coming for it.
2507 */
2508 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2509 packet_put_int(c->remote_id);
2510 packet_send();
2511
2512 /*
2513 * If the channel is in closed state, we have sent a close request,
2514 * and the other side will eventually respond with a confirmation.
2515 * Thus, we cannot free the channel here, because then there would be
2516 * no-one to receive the confirmation. The channel gets freed when
2517 * the confirmation arrives.
2518 */
2519 if (c->type != SSH_CHANNEL_CLOSED) {
2520 /*
2521 * Not a closed channel - mark it as draining, which will
2522 * cause it to be freed later.
2523 */
2524 buffer_clear(&c->input);
2525 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2526 }
2527}
2528
2529/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2530/* ARGSUSED */
2531void
2532channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2533{
2534 int id = packet_get_int();
2535 Channel *c = channel_lookup(id);
2536
2537 packet_check_eom();
2538 if (c == NULL)
2539 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2540 chan_rcvd_oclose(c);
2541}
2542
2543/* ARGSUSED */
2544void
2545channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2546{
2547 int id = packet_get_int();
2548 Channel *c = channel_lookup(id);
2549
2550 packet_check_eom();
2551 if (c == NULL)
2552 packet_disconnect("Received close confirmation for "
2553 "out-of-range channel %d.", id);
2554 if (c->type != SSH_CHANNEL_CLOSED && c->type != SSH_CHANNEL_ABANDONED)
2555 packet_disconnect("Received close confirmation for "
2556 "non-closed channel %d (type %d).", id, c->type);
2557 channel_free(c);
2558}
2559
2560/* ARGSUSED */
2561void
2562channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2563{
2564 int id, remote_id;
2565 Channel *c;
2566
2567 id = packet_get_int();
2568 c = channel_lookup(id);
2569
2570 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2571 packet_disconnect("Received open confirmation for "
2572 "non-opening channel %d.", id);
2573 remote_id = packet_get_int();
2574 /* Record the remote channel number and mark that the channel is now open. */
2575 c->remote_id = remote_id;
2576 c->type = SSH_CHANNEL_OPEN;
2577
2578 if (compat20) {
2579 c->remote_window = packet_get_int();
2580 c->remote_maxpacket = packet_get_int();
2581 if (c->open_confirm) {
2582 debug2("callback start");
2583 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2584 debug2("callback done");
2585 }
2586 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2587 c->remote_window, c->remote_maxpacket);
2588 }
2589 packet_check_eom();
2590}
2591
2592static char *
2593reason2txt(int reason)
2594{
2595 switch (reason) {
2596 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2597 return "administratively prohibited";
2598 case SSH2_OPEN_CONNECT_FAILED:
2599 return "connect failed";
2600 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2601 return "unknown channel type";
2602 case SSH2_OPEN_RESOURCE_SHORTAGE:
2603 return "resource shortage";
2604 }
2605 return "unknown reason";
2606}
2607
2608/* ARGSUSED */
2609void
2610channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2611{
2612 int id, reason;
2613 char *msg = NULL, *lang = NULL;
2614 Channel *c;
2615
2616 id = packet_get_int();
2617 c = channel_lookup(id);
2618
2619 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2620 packet_disconnect("Received open failure for "
2621 "non-opening channel %d.", id);
2622 if (compat20) {
2623 reason = packet_get_int();
2624 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2625 msg = packet_get_string(NULL);
2626 lang = packet_get_string(NULL);
2627 }
2628 logit("channel %d: open failed: %s%s%s", id,
2629 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2630 free(msg);
2631 free(lang);
2632 if (c->open_confirm) {
2633 debug2("callback start");
2634 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2635 debug2("callback done");
2636 }
2637 }
2638 packet_check_eom();
2639 /* Schedule the channel for cleanup/deletion. */
2640 chan_mark_dead(c);
2641}
2642
2643/* ARGSUSED */
2644void
2645channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2646{
2647 Channel *c;
2648 int id;
2649 u_int adjust;
2650
2651 if (!compat20)
2652 return;
2653
2654 /* Get the channel number and verify it. */
2655 id = packet_get_int();
2656 c = channel_lookup(id);
2657
2658 if (c == NULL) {
2659 logit("Received window adjust for non-open channel %d.", id);
2660 return;
2661 }
2662 adjust = packet_get_int();
2663 packet_check_eom();
2664 debug2("channel %d: rcvd adjust %u", id, adjust);
2665 c->remote_window += adjust;
2666}
2667
2668/* ARGSUSED */
2669void
2670channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2671{
2672 Channel *c = NULL;
2673 u_short host_port;
2674 char *host, *originator_string;
2675 int remote_id;
2676
2677 remote_id = packet_get_int();
2678 host = packet_get_string(NULL);
2679 host_port = packet_get_int();
2680
2681 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2682 originator_string = packet_get_string(NULL);
2683 } else {
2684 originator_string = xstrdup("unknown (remote did not supply name)");
2685 }
2686 packet_check_eom();
2687 c = channel_connect_to(host, host_port,
2688 "connected socket", originator_string);
2689 free(originator_string);
2690 free(host);
2691 if (c == NULL) {
2692 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2693 packet_put_int(remote_id);
2694 packet_send();
2695 } else
2696 c->remote_id = remote_id;
2697}
2698
2699/* ARGSUSED */
2700void
2701channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2702{
2703 Channel *c;
2704 struct channel_confirm *cc;
2705 int id;
2706
2707 /* Reset keepalive timeout */
2708 packet_set_alive_timeouts(0);
2709
2710 id = packet_get_int();
2711 packet_check_eom();
2712
2713 debug2("channel_input_status_confirm: type %d id %d", type, id);
2714
2715 if ((c = channel_lookup(id)) == NULL) {
2716 logit("channel_input_status_confirm: %d: unknown", id);
2717 return;
2718 }
2719 ;
2720 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2721 return;
2722 cc->cb(type, c, cc->ctx);
2723 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2724 bzero(cc, sizeof(*cc));
2725 free(cc);
2726}
2727
2728/* -- tcp forwarding */
2729
2730void
2731channel_set_af(int af)
2732{
2733 IPv4or6 = af;
2734}
2735
2736void
2737channel_set_hpn(int disabled, u_int buf_size)
2738{
2739 hpn_disabled = disabled;
2740 buffer_size = buf_size;
2741 debug("HPN Disabled: %d, HPN Buffer Size: %d",
2742 hpn_disabled, buffer_size);
2743}
2744
2745/*
2746 * Determine whether or not a port forward listens to loopback, the
2747 * specified address or wildcard. On the client, a specified bind
2748 * address will always override gateway_ports. On the server, a
2749 * gateway_ports of 1 (``yes'') will override the client's specification
2750 * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2751 * will bind to whatever address the client asked for.
2752 *
2753 * Special-case listen_addrs are:
2754 *
2755 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2756 * "" (empty string), "*" -> wildcard v4/v6
2757 * "localhost" -> loopback v4/v6
2758 */
2759static const char *
2760channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2761 int is_client, int gateway_ports)
2762{
2763 const char *addr = NULL;
2764 int wildcard = 0;
2765
2766 if (listen_addr == NULL) {
2767 /* No address specified: default to gateway_ports setting */
2768 if (gateway_ports)
2769 wildcard = 1;
2770 } else if (gateway_ports || is_client) {
2771 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2772 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2773 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2774 (!is_client && gateway_ports == 1))
2775 wildcard = 1;
2776 else if (strcmp(listen_addr, "localhost") != 0)
2777 addr = listen_addr;
2778 }
2779 if (wildcardp != NULL)
2780 *wildcardp = wildcard;
2781 return addr;
2782}
2783
2784static int
2785channel_setup_fwd_listener(int type, const char *listen_addr,
2786 u_short listen_port, int *allocated_listen_port,
2787 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2788{
2789 Channel *c;
2790 int sock, r, success = 0, wildcard = 0, is_client;
2791 struct addrinfo hints, *ai, *aitop;
2792 const char *host, *addr;
2793 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2794 in_port_t *lport_p;
2795
2796 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2797 listen_addr : host_to_connect;
2798 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2799
2800 if (host == NULL) {
2801 error("No forward host name.");
2802 return 0;
2803 }
2804 if (strlen(host) >= NI_MAXHOST) {
2805 error("Forward host name too long.");
2806 return 0;
2807 }
2808
2809 /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2810 addr = channel_fwd_bind_addr(listen_addr, &wildcard,
2811 is_client, gateway_ports);
2812 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2813 type, wildcard, (addr == NULL) ? "NULL" : addr);
2814
2815 /*
2816 * getaddrinfo returns a loopback address if the hostname is
2817 * set to NULL and hints.ai_flags is not AI_PASSIVE
2818 */
2819 memset(&hints, 0, sizeof(hints));
2820 hints.ai_family = IPv4or6;
2821 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2822 hints.ai_socktype = SOCK_STREAM;
2823 snprintf(strport, sizeof strport, "%d", listen_port);
2824 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2825 if (addr == NULL) {
2826 /* This really shouldn't happen */
2827 packet_disconnect("getaddrinfo: fatal error: %s",
2828 ssh_gai_strerror(r));
2829 } else {
2830 error("channel_setup_fwd_listener: "
2831 "getaddrinfo(%.64s): %s", addr,
2832 ssh_gai_strerror(r));
2833 }
2834 return 0;
2835 }
2836 if (allocated_listen_port != NULL)
2837 *allocated_listen_port = 0;
2838 for (ai = aitop; ai; ai = ai->ai_next) {
2839 switch (ai->ai_family) {
2840 case AF_INET:
2841 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2842 sin_port;
2843 break;
2844 case AF_INET6:
2845 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2846 sin6_port;
2847 break;
2848 default:
2849 continue;
2850 }
2851 /*
2852 * If allocating a port for -R forwards, then use the
2853 * same port for all address families.
2854 */
2855 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2856 allocated_listen_port != NULL && *allocated_listen_port > 0)
2857 *lport_p = htons(*allocated_listen_port);
2858
2859 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2860 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2861 error("channel_setup_fwd_listener: getnameinfo failed");
2862 continue;
2863 }
2864 /* Create a port to listen for the host. */
2865 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2866 if (sock < 0) {
2867 /* this is no error since kernel may not support ipv6 */
2868 verbose("socket: %.100s", strerror(errno));
2869 continue;
2870 }
2871
2872 channel_set_reuseaddr(sock);
2873 if (ai->ai_family == AF_INET6)
2874 sock_set_v6only(sock);
2875
2876 debug("Local forwarding listening on %s port %s.",
2877 ntop, strport);
2878
2879 /* Bind the socket to the address. */
2880 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2881 /* address can be in use ipv6 address is already bound */
2882 if (!ai->ai_next)
2883 error("bind: %.100s", strerror(errno));
2884 else
2885 verbose("bind: %.100s", strerror(errno));
2886
2887 close(sock);
2888 continue;
2889 }
2890 /* Start listening for connections on the socket. */
2891 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2892 error("listen: %.100s", strerror(errno));
2893 close(sock);
2894 continue;
2895 }
2896
2897 /*
2898 * listen_port == 0 requests a dynamically allocated port -
2899 * record what we got.
2900 */
2901 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2902 allocated_listen_port != NULL &&
2903 *allocated_listen_port == 0) {
2904 *allocated_listen_port = get_sock_port(sock, 1);
2905 debug("Allocated listen port %d",
2906 *allocated_listen_port);
2907 }
2908
2909 /*
2910 * Allocate a channel number for the socket. Explicitly test
2911 * for hpn disabled option. If true use smaller window size.
2912 */
2913 if (hpn_disabled)
2914 c = channel_new("port listener", type, sock, sock, -1,
2915 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2916 0, "port listener", 1);
2917 else
2918 c = channel_new("port listener", type, sock, sock, -1,
2919 buffer_size, CHAN_TCP_PACKET_DEFAULT,
2920 0, "port listener", 1);
2921 c->path = xstrdup(host);
2922 c->host_port = port_to_connect;
2923 c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
2924 if (listen_port == 0 && allocated_listen_port != NULL &&
2925 !(datafellows & SSH_BUG_DYNAMIC_RPORT))
2926 c->listening_port = *allocated_listen_port;
2927 else
2928 c->listening_port = listen_port;
2929 success = 1;
2930 }
2931 if (success == 0)
2932 error("channel_setup_fwd_listener: cannot listen to port: %d",
2933 listen_port);
2934 freeaddrinfo(aitop);
2935 return success;
2936}
2937
2938int
2939channel_cancel_rport_listener(const char *host, u_short port)
2940{
2941 u_int i;
2942 int found = 0;
2943
2944 for (i = 0; i < channels_alloc; i++) {
2945 Channel *c = channels[i];
2946 if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
2947 continue;
2948 if (strcmp(c->path, host) == 0 && c->listening_port == port) {
2949 debug2("%s: close channel %d", __func__, i);
2950 channel_free(c);
2951 found = 1;
2952 }
2953 }
2954
2955 return (found);
2956}
2957
2958int
2959channel_cancel_lport_listener(const char *lhost, u_short lport,
2960 int cport, int gateway_ports)
2961{
2962 u_int i;
2963 int found = 0;
2964 const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports);
2965
2966 for (i = 0; i < channels_alloc; i++) {
2967 Channel *c = channels[i];
2968 if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
2969 continue;
2970 if (c->listening_port != lport)
2971 continue;
2972 if (cport == CHANNEL_CANCEL_PORT_STATIC) {
2973 /* skip dynamic forwardings */
2974 if (c->host_port == 0)
2975 continue;
2976 } else {
2977 if (c->host_port != cport)
2978 continue;
2979 }
2980 if ((c->listening_addr == NULL && addr != NULL) ||
2981 (c->listening_addr != NULL && addr == NULL))
2982 continue;
2983 if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
2984 debug2("%s: close channel %d", __func__, i);
2985 channel_free(c);
2986 found = 1;
2987 }
2988 }
2989
2990 return (found);
2991}
2992
2993/* protocol local port fwd, used by ssh (and sshd in v1) */
2994int
2995channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2996 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2997{
2998 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2999 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
3000 gateway_ports);
3001}
3002
3003/* protocol v2 remote port fwd, used by sshd */
3004int
3005channel_setup_remote_fwd_listener(const char *listen_address,
3006 u_short listen_port, int *allocated_listen_port, int gateway_ports)
3007{
3008 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
3009 listen_address, listen_port, allocated_listen_port,
3010 NULL, 0, gateway_ports);
3011}
3012
3013/*
3014 * Translate the requested rfwd listen host to something usable for
3015 * this server.
3016 */
3017static const char *
3018channel_rfwd_bind_host(const char *listen_host)
3019{
3020 if (listen_host == NULL) {
3021 if (datafellows & SSH_BUG_RFWD_ADDR)
3022 return "127.0.0.1";
3023 else
3024 return "localhost";
3025 } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3026 if (datafellows & SSH_BUG_RFWD_ADDR)
3027 return "0.0.0.0";
3028 else
3029 return "";
3030 } else
3031 return listen_host;
3032}
3033
3034/*
3035 * Initiate forwarding of connections to port "port" on remote host through
3036 * the secure channel to host:port from local side.
3037 * Returns handle (index) for updating the dynamic listen port with
3038 * channel_update_permitted_opens().
3039 */
3040int
3041channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
3042 const char *host_to_connect, u_short port_to_connect)
3043{
3044 int type, success = 0, idx = -1;
3045
3046 /* Send the forward request to the remote side. */
3047 if (compat20) {
3048 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3049 packet_put_cstring("tcpip-forward");
3050 packet_put_char(1); /* boolean: want reply */
3051 packet_put_cstring(channel_rfwd_bind_host(listen_host));
3052 packet_put_int(listen_port);
3053 packet_send();
3054 packet_write_wait();
3055 /* Assume that server accepts the request */
3056 success = 1;
3057 } else {
3058 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
3059 packet_put_int(listen_port);
3060 packet_put_cstring(host_to_connect);
3061 packet_put_int(port_to_connect);
3062 packet_send();
3063 packet_write_wait();
3064
3065 /* Wait for response from the remote side. */
3066 type = packet_read();
3067 switch (type) {
3068 case SSH_SMSG_SUCCESS:
3069 success = 1;
3070 break;
3071 case SSH_SMSG_FAILURE:
3072 break;
3073 default:
3074 /* Unknown packet */
3075 packet_disconnect("Protocol error for port forward request:"
3076 "received packet type %d.", type);
3077 }
3078 }
3079 if (success) {
3080 /* Record that connection to this host/port is permitted. */
3081 permitted_opens = xrealloc(permitted_opens,
3082 num_permitted_opens + 1, sizeof(*permitted_opens));
3083 idx = num_permitted_opens++;
3084 permitted_opens[idx].host_to_connect = xstrdup(host_to_connect);
3085 permitted_opens[idx].port_to_connect = port_to_connect;
3086 permitted_opens[idx].listen_port = listen_port;
3087 }
3088 return (idx);
3089}
3090
3091/*
3092 * Request cancellation of remote forwarding of connection host:port from
3093 * local side.
3094 */
3095int
3096channel_request_rforward_cancel(const char *host, u_short port)
3097{
3098 int i;
3099
3100 if (!compat20)
3101 return -1;
3102
3103 for (i = 0; i < num_permitted_opens; i++) {
3104 if (permitted_opens[i].host_to_connect != NULL &&
3105 permitted_opens[i].listen_port == port)
3106 break;
3107 }
3108 if (i >= num_permitted_opens) {
3109 debug("%s: requested forward not found", __func__);
3110 return -1;
3111 }
3112 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3113 packet_put_cstring("cancel-tcpip-forward");
3114 packet_put_char(0);
3115 packet_put_cstring(channel_rfwd_bind_host(host));
3116 packet_put_int(port);
3117 packet_send();
3118
3119 permitted_opens[i].listen_port = 0;
3120 permitted_opens[i].port_to_connect = 0;
3121 free(permitted_opens[i].host_to_connect);
3122 permitted_opens[i].host_to_connect = NULL;
3123
3124 return 0;
3125}
3126
3127/*
3128 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3129 * listening for the port, and sends back a success reply (or disconnect
3130 * message if there was an error).
3131 */
3132int
3133channel_input_port_forward_request(int is_root, int gateway_ports)
3134{
3135 u_short port, host_port;
3136 int success = 0;
3137 char *hostname;
3138
3139 /* Get arguments from the packet. */
3140 port = packet_get_int();
3141 hostname = packet_get_string(NULL);
3142 host_port = packet_get_int();
3143
3144#ifndef HAVE_CYGWIN
3145 /*
3146 * Check that an unprivileged user is not trying to forward a
3147 * privileged port.
3148 */
3149 if (port < IPPORT_RESERVED && !is_root)
3150 packet_disconnect(
3151 "Requested forwarding of port %d but user is not root.",
3152 port);
3153 if (host_port == 0)
3154 packet_disconnect("Dynamic forwarding denied.");
3155#endif
3156
3157 /* Initiate forwarding */
3158 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3159 host_port, gateway_ports);
3160
3161 /* Free the argument string. */
3162 free(hostname);
3163
3164 return (success ? 0 : -1);
3165}
3166
3167/*
3168 * Permits opening to any host/port if permitted_opens[] is empty. This is
3169 * usually called by the server, because the user could connect to any port
3170 * anyway, and the server has no way to know but to trust the client anyway.
3171 */
3172void
3173channel_permit_all_opens(void)
3174{
3175 if (num_permitted_opens == 0)
3176 all_opens_permitted = 1;
3177}
3178
3179void
3180channel_add_permitted_opens(char *host, int port)
3181{
3182 debug("allow port forwarding to host %s port %d", host, port);
3183
3184 permitted_opens = xrealloc(permitted_opens,
3185 num_permitted_opens + 1, sizeof(*permitted_opens));
3186 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3187 permitted_opens[num_permitted_opens].port_to_connect = port;
3188 num_permitted_opens++;
3189
3190 all_opens_permitted = 0;
3191}
3192
3193/*
3194 * Update the listen port for a dynamic remote forward, after
3195 * the actual 'newport' has been allocated. If 'newport' < 0 is
3196 * passed then they entry will be invalidated.
3197 */
3198void
3199channel_update_permitted_opens(int idx, int newport)
3200{
3201 if (idx < 0 || idx >= num_permitted_opens) {
3202 debug("channel_update_permitted_opens: index out of range:"
3203 " %d num_permitted_opens %d", idx, num_permitted_opens);
3204 return;
3205 }
3206 debug("%s allowed port %d for forwarding to host %s port %d",
3207 newport > 0 ? "Updating" : "Removing",
3208 newport,
3209 permitted_opens[idx].host_to_connect,
3210 permitted_opens[idx].port_to_connect);
3211 if (newport >= 0) {
3212 permitted_opens[idx].listen_port =
3213 (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3214 } else {
3215 permitted_opens[idx].listen_port = 0;
3216 permitted_opens[idx].port_to_connect = 0;
3217 free(permitted_opens[idx].host_to_connect);
3218 permitted_opens[idx].host_to_connect = NULL;
3219 }
3220}
3221
3222int
3223channel_add_adm_permitted_opens(char *host, int port)
3224{
3225 debug("config allows port forwarding to host %s port %d", host, port);
3226
3227 permitted_adm_opens = xrealloc(permitted_adm_opens,
3228 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3229 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3230 = xstrdup(host);
3231 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3232 return ++num_adm_permitted_opens;
3233}
3234
3235void
3236channel_disable_adm_local_opens(void)
3237{
3238 channel_clear_adm_permitted_opens();
3239 permitted_adm_opens = xmalloc(sizeof(*permitted_adm_opens));
3240 permitted_adm_opens[num_adm_permitted_opens].host_to_connect = NULL;
3241 num_adm_permitted_opens = 1;
3242}
3243
3244void
3245channel_clear_permitted_opens(void)
3246{
3247 int i;
3248
3249 for (i = 0; i < num_permitted_opens; i++)
3250 free(permitted_opens[i].host_to_connect);
3251 free(permitted_opens);
3252 permitted_opens = NULL;
3253 num_permitted_opens = 0;
3254}
3255
3256void
3257channel_clear_adm_permitted_opens(void)
3258{
3259 int i;
3260
3261 for (i = 0; i < num_adm_permitted_opens; i++)
3262 free(permitted_adm_opens[i].host_to_connect);
3263 free(permitted_adm_opens);
3264 permitted_adm_opens = NULL;
3265 num_adm_permitted_opens = 0;
3266}
3267
3268void
3269channel_print_adm_permitted_opens(void)
3270{
3271 int i;
3272
3273 printf("permitopen");
3274 if (num_adm_permitted_opens == 0) {
3275 printf(" any\n");
3276 return;
3277 }
3278 for (i = 0; i < num_adm_permitted_opens; i++)
3279 if (permitted_adm_opens[i].host_to_connect == NULL)
3280 printf(" none");
3281 else
3282 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3283 permitted_adm_opens[i].port_to_connect);
3284 printf("\n");
3285}
3286
3287/* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3288int
3289permitopen_port(const char *p)
3290{
3291 int port;
3292
3293 if (strcmp(p, "*") == 0)
3294 return FWD_PERMIT_ANY_PORT;
3295 if ((port = a2port(p)) > 0)
3296 return port;
3297 return -1;
3298}
3299
3300static int
3301port_match(u_short allowedport, u_short requestedport)
3302{
3303 if (allowedport == FWD_PERMIT_ANY_PORT ||
3304 allowedport == requestedport)
3305 return 1;
3306 return 0;
3307}
3308
3309/* Try to start non-blocking connect to next host in cctx list */
3310static int
3311connect_next(struct channel_connect *cctx)
3312{
3313 int sock, saved_errno;
3314 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3315
3316 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3317 if (cctx->ai->ai_family != AF_INET &&
3318 cctx->ai->ai_family != AF_INET6)
3319 continue;
3320 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3321 ntop, sizeof(ntop), strport, sizeof(strport),
3322 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3323 error("connect_next: getnameinfo failed");
3324 continue;
3325 }
3326 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3327 cctx->ai->ai_protocol)) == -1) {
3328 if (cctx->ai->ai_next == NULL)
3329 error("socket: %.100s", strerror(errno));
3330 else
3331 verbose("socket: %.100s", strerror(errno));
3332 continue;
3333 }
3334 if (set_nonblock(sock) == -1)
3335 fatal("%s: set_nonblock(%d)", __func__, sock);
3336 if (connect(sock, cctx->ai->ai_addr,
3337 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3338 debug("connect_next: host %.100s ([%.100s]:%s): "
3339 "%.100s", cctx->host, ntop, strport,
3340 strerror(errno));
3341 saved_errno = errno;
3342 close(sock);
3343 errno = saved_errno;
3344 continue; /* fail -- try next */
3345 }
3346 debug("connect_next: host %.100s ([%.100s]:%s) "
3347 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3348 cctx->ai = cctx->ai->ai_next;
3349 set_nodelay(sock);
3350 return sock;
3351 }
3352 return -1;
3353}
3354
3355static void
3356channel_connect_ctx_free(struct channel_connect *cctx)
3357{
3358 free(cctx->host);
3359 if (cctx->aitop)
3360 freeaddrinfo(cctx->aitop);
3361 bzero(cctx, sizeof(*cctx));
3362 cctx->host = NULL;
3363 cctx->ai = cctx->aitop = NULL;
3364}
3365
3366/* Return CONNECTING channel to remote host, port */
3367static Channel *
3368connect_to(const char *host, u_short port, char *ctype, char *rname)
3369{
3370 struct addrinfo hints;
3371 int gaierr;
3372 int sock = -1;
3373 char strport[NI_MAXSERV];
3374 struct channel_connect cctx;
3375 Channel *c;
3376
3377 memset(&cctx, 0, sizeof(cctx));
3378 memset(&hints, 0, sizeof(hints));
3379 hints.ai_family = IPv4or6;
3380 hints.ai_socktype = SOCK_STREAM;
3381 snprintf(strport, sizeof strport, "%d", port);
3382 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3383 error("connect_to %.100s: unknown host (%s)", host,
3384 ssh_gai_strerror(gaierr));
3385 return NULL;
3386 }
3387
3388 cctx.host = xstrdup(host);
3389 cctx.port = port;
3390 cctx.ai = cctx.aitop;
3391
3392 if ((sock = connect_next(&cctx)) == -1) {
3393 error("connect to %.100s port %d failed: %s",
3394 host, port, strerror(errno));
3395 channel_connect_ctx_free(&cctx);
3396 return NULL;
3397 }
3398 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3399 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3400 c->connect_ctx = cctx;
3401 return c;
3402}
3403
3404Channel *
3405channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3406{
3407 int i;
3408
3409 for (i = 0; i < num_permitted_opens; i++) {
3410 if (permitted_opens[i].host_to_connect != NULL &&
3411 port_match(permitted_opens[i].listen_port, listen_port)) {
3412 return connect_to(
3413 permitted_opens[i].host_to_connect,
3414 permitted_opens[i].port_to_connect, ctype, rname);
3415 }
3416 }
3417 error("WARNING: Server requests forwarding for unknown listen_port %d",
3418 listen_port);
3419 return NULL;
3420}
3421
3422/* Check if connecting to that port is permitted and connect. */
3423Channel *
3424channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3425{
3426 int i, permit, permit_adm = 1;
3427
3428 permit = all_opens_permitted;
3429 if (!permit) {
3430 for (i = 0; i < num_permitted_opens; i++)
3431 if (permitted_opens[i].host_to_connect != NULL &&
3432 port_match(permitted_opens[i].port_to_connect, port) &&
3433 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3434 permit = 1;
3435 }
3436
3437 if (num_adm_permitted_opens > 0) {
3438 permit_adm = 0;
3439 for (i = 0; i < num_adm_permitted_opens; i++)
3440 if (permitted_adm_opens[i].host_to_connect != NULL &&
3441 port_match(permitted_adm_opens[i].port_to_connect, port) &&
3442 strcmp(permitted_adm_opens[i].host_to_connect, host)
3443 == 0)
3444 permit_adm = 1;
3445 }
3446
3447 if (!permit || !permit_adm) {
3448 logit("Received request to connect to host %.100s port %d, "
3449 "but the request was denied.", host, port);
3450 return NULL;
3451 }
3452 return connect_to(host, port, ctype, rname);
3453}
3454
3455void
3456channel_send_window_changes(void)
3457{
3458 u_int i;
3459 struct winsize ws;
3460
3461 for (i = 0; i < channels_alloc; i++) {
3462 if (channels[i] == NULL || !channels[i]->client_tty ||
3463 channels[i]->type != SSH_CHANNEL_OPEN)
3464 continue;
3465 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3466 continue;
3467 channel_request_start(i, "window-change", 0);
3468 packet_put_int((u_int)ws.ws_col);
3469 packet_put_int((u_int)ws.ws_row);
3470 packet_put_int((u_int)ws.ws_xpixel);
3471 packet_put_int((u_int)ws.ws_ypixel);
3472 packet_send();
3473 }
3474}
3475
3476/* -- X11 forwarding */
3477
3478/*
3479 * Creates an internet domain socket for listening for X11 connections.
3480 * Returns 0 and a suitable display number for the DISPLAY variable
3481 * stored in display_numberp , or -1 if an error occurs.
3482 */
3483int
3484x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3485 int single_connection, u_int *display_numberp, int **chanids)
3486{
3487 Channel *nc = NULL;
3488 int display_number, sock;
3489 u_short port;
3490 struct addrinfo hints, *ai, *aitop;
3491 char strport[NI_MAXSERV];
3492 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3493
3494 if (chanids == NULL)
3495 return -1;
3496
3497 for (display_number = x11_display_offset;
3498 display_number < MAX_DISPLAYS;
3499 display_number++) {
3500 port = 6000 + display_number;
3501 memset(&hints, 0, sizeof(hints));
3502 hints.ai_family = IPv4or6;
3503 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3504 hints.ai_socktype = SOCK_STREAM;
3505 snprintf(strport, sizeof strport, "%d", port);
3506 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3507 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3508 return -1;
3509 }
3510 for (ai = aitop; ai; ai = ai->ai_next) {
3511 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3512 continue;
3513 sock = socket(ai->ai_family, ai->ai_socktype,
3514 ai->ai_protocol);
3515 if (sock < 0) {
3516 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3517#ifdef EPFNOSUPPORT
3518 && (errno != EPFNOSUPPORT)
3519#endif
3520 ) {
3521 error("socket: %.100s", strerror(errno));
3522 freeaddrinfo(aitop);
3523 return -1;
3524 } else {
3525 debug("x11_create_display_inet: Socket family %d not supported",
3526 ai->ai_family);
3527 continue;
3528 }
3529 }
3530 if (ai->ai_family == AF_INET6)
3531 sock_set_v6only(sock);
3532 if (x11_use_localhost)
3533 channel_set_reuseaddr(sock);
3534 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3535 debug2("bind port %d: %.100s", port, strerror(errno));
3536 close(sock);
3537
3538 for (n = 0; n < num_socks; n++) {
3539 close(socks[n]);
3540 }
3541 num_socks = 0;
3542 break;
3543 }
3544 socks[num_socks++] = sock;
3545 if (num_socks == NUM_SOCKS)
3546 break;
3547 }
3548 freeaddrinfo(aitop);
3549 if (num_socks > 0)
3550 break;
3551 }
3552 if (display_number >= MAX_DISPLAYS) {
3553 error("Failed to allocate internet-domain X11 display socket.");
3554 return -1;
3555 }
3556 /* Start listening for connections on the socket. */
3557 for (n = 0; n < num_socks; n++) {
3558 sock = socks[n];
3559 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3560 error("listen: %.100s", strerror(errno));
3561 close(sock);
3562 return -1;
3563 }
3564 }
3565
3566 /* Allocate a channel for each socket. */
3567 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3568 for (n = 0; n < num_socks; n++) {
3569 sock = socks[n];
3570 if (hpn_disabled)
3571 nc = channel_new("x11 listener",
3572 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3573 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3574 0, "X11 inet listener", 1);
3575 else
3576 nc = channel_new("x11 listener",
3577 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3578 buffer_size, CHAN_X11_PACKET_DEFAULT,
3579 0, "X11 inet listener", 1);
3580 nc->single_connection = single_connection;
3581 (*chanids)[n] = nc->self;
3582 }
3583 (*chanids)[n] = -1;
3584
3585 /* Return the display number for the DISPLAY environment variable. */
3586 *display_numberp = display_number;
3587 return (0);
3588}
3589
3590static int
3591connect_local_xsocket_path(const char *pathname)
3592{
3593 int sock;
3594 struct sockaddr_un addr;
3595
3596 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3597 if (sock < 0)
3598 error("socket: %.100s", strerror(errno));
3599 memset(&addr, 0, sizeof(addr));
3600 addr.sun_family = AF_UNIX;
3601 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3602 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3603 return sock;
3604 close(sock);
3605 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3606 return -1;
3607}
3608
3609static int
3610connect_local_xsocket(u_int dnr)
3611{
3612 char buf[1024];
3613 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3614 return connect_local_xsocket_path(buf);
3615}
3616
3617int
3618x11_connect_display(void)
3619{
3620 u_int display_number;
3621 const char *display;
3622 char buf[1024], *cp;
3623 struct addrinfo hints, *ai, *aitop;
3624 char strport[NI_MAXSERV];
3625 int gaierr, sock = 0;
3626
3627 /* Try to open a socket for the local X server. */
3628 display = getenv("DISPLAY");
3629 if (!display) {
3630 error("DISPLAY not set.");
3631 return -1;
3632 }
3633 /*
3634 * Now we decode the value of the DISPLAY variable and make a
3635 * connection to the real X server.
3636 */
3637
3638 /* Check if the display is from launchd. */
3639#ifdef __APPLE__
3640 if (strncmp(display, "/tmp/launch", 11) == 0) {
3641 sock = connect_local_xsocket_path(display);
3642 if (sock < 0)
3643 return -1;
3644
3645 /* OK, we now have a connection to the display. */
3646 return sock;
3647 }
3648#endif
3649 /*
3650 * Check if it is a unix domain socket. Unix domain displays are in
3651 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3652 */
3653 if (strncmp(display, "unix:", 5) == 0 ||
3654 display[0] == ':') {
3655 /* Connect to the unix domain socket. */
3656 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3657 error("Could not parse display number from DISPLAY: %.100s",
3658 display);
3659 return -1;
3660 }
3661 /* Create a socket. */
3662 sock = connect_local_xsocket(display_number);
3663 if (sock < 0)
3664 return -1;
3665
3666 /* OK, we now have a connection to the display. */
3667 return sock;
3668 }
3669 /*
3670 * Connect to an inet socket. The DISPLAY value is supposedly
3671 * hostname:d[.s], where hostname may also be numeric IP address.
3672 */
3673 strlcpy(buf, display, sizeof(buf));
3674 cp = strchr(buf, ':');
3675 if (!cp) {
3676 error("Could not find ':' in DISPLAY: %.100s", display);
3677 return -1;
3678 }
3679 *cp = 0;
3680 /* buf now contains the host name. But first we parse the display number. */
3681 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3682 error("Could not parse display number from DISPLAY: %.100s",
3683 display);
3684 return -1;
3685 }
3686
3687 /* Look up the host address */
3688 memset(&hints, 0, sizeof(hints));
3689 hints.ai_family = IPv4or6;
3690 hints.ai_socktype = SOCK_STREAM;
3691 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3692 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3693 error("%.100s: unknown host. (%s)", buf,
3694 ssh_gai_strerror(gaierr));
3695 return -1;
3696 }
3697 for (ai = aitop; ai; ai = ai->ai_next) {
3698 /* Create a socket. */
3699 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3700 if (sock < 0) {
3701 debug2("socket: %.100s", strerror(errno));
3702 continue;
3703 }
3704 /* Connect it to the display. */
3705 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3706 debug2("connect %.100s port %u: %.100s", buf,
3707 6000 + display_number, strerror(errno));
3708 close(sock);
3709 continue;
3710 }
3711 /* Success */
3712 break;
3713 }
3714 freeaddrinfo(aitop);
3715 if (!ai) {
3716 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3717 strerror(errno));
3718 return -1;
3719 }
3720 set_nodelay(sock);
3721 return sock;
3722}
3723
3724/*
3725 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3726 * the remote channel number. We should do whatever we want, and respond
3727 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3728 */
3729
3730/* ARGSUSED */
3731void
3732x11_input_open(int type, u_int32_t seq, void *ctxt)
3733{
3734 Channel *c = NULL;
3735 int remote_id, sock = 0;
3736 char *remote_host;
3737
3738 debug("Received X11 open request.");
3739
3740 remote_id = packet_get_int();
3741
3742 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3743 remote_host = packet_get_string(NULL);
3744 } else {
3745 remote_host = xstrdup("unknown (remote did not supply name)");
3746 }
3747 packet_check_eom();
3748
3749 /* Obtain a connection to the real X display. */
3750 sock = x11_connect_display();
3751 if (sock != -1) {
3752 /* Allocate a channel for this connection. */
3753 c = channel_new("connected x11 socket",
3754 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3755 remote_host, 1);
3756 c->remote_id = remote_id;
3757 c->force_drain = 1;
3758 }
3759 free(remote_host);
3760 if (c == NULL) {
3761 /* Send refusal to the remote host. */
3762 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3763 packet_put_int(remote_id);
3764 } else {
3765 /* Send a confirmation to the remote host. */
3766 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3767 packet_put_int(remote_id);
3768 packet_put_int(c->self);
3769 }
3770 packet_send();
3771}
3772
3773/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3774/* ARGSUSED */
3775void
3776deny_input_open(int type, u_int32_t seq, void *ctxt)
3777{
3778 int rchan = packet_get_int();
3779
3780 switch (type) {
3781 case SSH_SMSG_AGENT_OPEN:
3782 error("Warning: ssh server tried agent forwarding.");
3783 break;
3784 case SSH_SMSG_X11_OPEN:
3785 error("Warning: ssh server tried X11 forwarding.");
3786 break;
3787 default:
3788 error("deny_input_open: type %d", type);
3789 break;
3790 }
3791 error("Warning: this is probably a break-in attempt by a malicious server.");
3792 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3793 packet_put_int(rchan);
3794 packet_send();
3795}
3796
3797/*
3798 * Requests forwarding of X11 connections, generates fake authentication
3799 * data, and enables authentication spoofing.
3800 * This should be called in the client only.
3801 */
3802void
3803x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3804 const char *proto, const char *data, int want_reply)
3805{
3806 u_int data_len = (u_int) strlen(data) / 2;
3807 u_int i, value;
3808 char *new_data;
3809 int screen_number;
3810 const char *cp;
3811 u_int32_t rnd = 0;
3812
3813 if (x11_saved_display == NULL)
3814 x11_saved_display = xstrdup(disp);
3815 else if (strcmp(disp, x11_saved_display) != 0) {
3816 error("x11_request_forwarding_with_spoofing: different "
3817 "$DISPLAY already forwarded");
3818 return;
3819 }
3820
3821 cp = strchr(disp, ':');
3822 if (cp)
3823 cp = strchr(cp, '.');
3824 if (cp)
3825 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3826 else
3827 screen_number = 0;
3828
3829 if (x11_saved_proto == NULL) {
3830 /* Save protocol name. */
3831 x11_saved_proto = xstrdup(proto);
3832 /*
3833 * Extract real authentication data and generate fake data
3834 * of the same length.
3835 */
3836 x11_saved_data = xmalloc(data_len);
3837 x11_fake_data = xmalloc(data_len);
3838 for (i = 0; i < data_len; i++) {
3839 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3840 fatal("x11_request_forwarding: bad "
3841 "authentication data: %.100s", data);
3842 if (i % 4 == 0)
3843 rnd = arc4random();
3844 x11_saved_data[i] = value;
3845 x11_fake_data[i] = rnd & 0xff;
3846 rnd >>= 8;
3847 }
3848 x11_saved_data_len = data_len;
3849 x11_fake_data_len = data_len;
3850 }
3851
3852 /* Convert the fake data into hex. */
3853 new_data = tohex(x11_fake_data, data_len);
3854
3855 /* Send the request packet. */
3856 if (compat20) {
3857 channel_request_start(client_session_id, "x11-req", want_reply);
3858 packet_put_char(0); /* XXX bool single connection */
3859 } else {
3860 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3861 }
3862 packet_put_cstring(proto);
3863 packet_put_cstring(new_data);
3864 packet_put_int(screen_number);
3865 packet_send();
3866 packet_write_wait();
3867 free(new_data);
3868}
3869
3870
3871/* -- agent forwarding */
3872
3873/* Sends a message to the server to request authentication fd forwarding. */
3874
3875void
3876auth_request_forwarding(void)
3877{
3878 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3879 packet_send();
3880 packet_write_wait();
3881}
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