1/* $OpenBSD: control.c,v 1.28 2023/03/08 04:43:14 guenther Exp $ */ 2 3/* 4 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19#include <sys/types.h> 20#include <sys/stat.h> 21#include <sys/socket.h> 22#include <sys/un.h> 23#include <errno.h> 24#include <fcntl.h> 25#include <stdlib.h> 26#include <string.h> 27#include <unistd.h> 28 29#include "ripd.h" 30#include "rip.h" 31#include "ripe.h" 32#include "log.h" 33#include "control.h" 34 35TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 36 37#define CONTROL_BACKLOG 5 38 39struct ctl_conn *control_connbyfd(int); 40struct ctl_conn *control_connbypid(pid_t); 41void control_close(int); 42 43struct { 44 struct event ev; 45 struct event evt; 46 int fd; 47} control_state; 48 49int 50control_init(char *path) 51{ 52 struct sockaddr_un sun; 53 int fd; 54 mode_t old_umask; 55 56 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 57 0)) == -1) { 58 log_warn("control_init: socket"); 59 return (-1); 60 } 61 62 bzero(&sun, sizeof(sun)); 63 sun.sun_family = AF_UNIX; 64 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 65 66 if (unlink(path) == -1) 67 if (errno != ENOENT) { 68 log_warn("control_init: unlink %s", path); 69 close(fd); 70 return (-1); 71 } 72 73 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 74 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 75 log_warn("control_init: bind: %s", path); 76 close(fd); 77 umask(old_umask); 78 return (-1); 79 } 80 umask(old_umask); 81 82 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 83 log_warn("control_init: chmod"); 84 close(fd); 85 (void)unlink(path); 86 return (-1); 87 } 88 89 control_state.fd = fd; 90 91 return (0); 92} 93 94int 95control_listen(void) 96{ 97 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 98 log_warn("control_listen: listen"); 99 return (-1); 100 } 101 102 event_set(&control_state.ev, control_state.fd, EV_READ, 103 control_accept, NULL); 104 event_add(&control_state.ev, NULL); 105 evtimer_set(&control_state.evt, control_accept, NULL); 106 107 return (0); 108} 109 110void 111control_accept(int listenfd, short event, void *bula) 112{ 113 int connfd; 114 socklen_t len; 115 struct sockaddr_un sun; 116 struct ctl_conn *c; 117 118 event_add(&control_state.ev, NULL); 119 if ((event & EV_TIMEOUT)) 120 return; 121 122 len = sizeof(sun); 123 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 124 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 125 /* 126 * Pause accept if we are out of file descriptors, or 127 * libevent will haunt us here too. 128 */ 129 if (errno == ENFILE || errno == EMFILE) { 130 struct timeval evtpause = { 1, 0 }; 131 132 event_del(&control_state.ev); 133 evtimer_add(&control_state.evt, &evtpause); 134 } else if (errno != EWOULDBLOCK && errno != EINTR && 135 errno != ECONNABORTED) 136 log_warn("control_accept: accept"); 137 return; 138 } 139 140 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 141 log_warn("control_accept"); 142 close(connfd); 143 return; 144 } 145 146 imsg_init(&c->iev.ibuf, connfd); 147 c->iev.handler = control_dispatch_imsg; 148 c->iev.events = EV_READ; 149 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 150 c->iev.handler, &c->iev); 151 event_add(&c->iev.ev, NULL); 152 153 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 154} 155 156struct ctl_conn * 157control_connbyfd(int fd) 158{ 159 struct ctl_conn *c; 160 161 TAILQ_FOREACH(c, &ctl_conns, entry) { 162 if (c->iev.ibuf.fd == fd) 163 break; 164 } 165 166 return (c); 167} 168 169struct ctl_conn * 170control_connbypid(pid_t pid) 171{ 172 struct ctl_conn *c; 173 174 TAILQ_FOREACH(c, &ctl_conns, entry) { 175 if (c->iev.ibuf.pid == pid) 176 break; 177 } 178 179 return (c); 180} 181 182void 183control_close(int fd) 184{ 185 struct ctl_conn *c; 186 187 if ((c = control_connbyfd(fd)) == NULL) { 188 log_warn("control_close: fd %d: not found", fd); 189 return; 190 } 191 192 msgbuf_clear(&c->iev.ibuf.w); 193 TAILQ_REMOVE(&ctl_conns, c, entry); 194 195 event_del(&c->iev.ev); 196 close(c->iev.ibuf.fd); 197 198 /* Some file descriptors are available again. */ 199 if (evtimer_pending(&control_state.evt, NULL)) { 200 evtimer_del(&control_state.evt); 201 event_add(&control_state.ev, NULL); 202 } 203 204 free(c); 205} 206 207void 208control_dispatch_imsg(int fd, short event, void *bula) 209{ 210 struct ctl_conn *c; 211 struct imsg imsg; 212 ssize_t n; 213 unsigned int ifidx; 214 int verbose; 215 216 if ((c = control_connbyfd(fd)) == NULL) { 217 log_warn("control_dispatch_imsg: fd %d: not found", fd); 218 return; 219 } 220 221 if (event & EV_READ) { 222 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 223 n == 0) { 224 control_close(fd); 225 return; 226 } 227 } 228 if (event & EV_WRITE) { 229 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 230 control_close(fd); 231 return; 232 } 233 } 234 235 for (;;) { 236 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 237 control_close(fd); 238 return; 239 } 240 241 if (n == 0) 242 break; 243 244 switch (imsg.hdr.type) { 245 case IMSG_CTL_SHOW_INTERFACE: 246 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(ifidx)) 247 return; 248 249 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 250 ripe_iface_ctl(c, ifidx); 251 imsg_compose(&c->iev.ibuf, IMSG_CTL_END, 0, 0, 252 -1, NULL, 0); 253 254 break; 255 case IMSG_CTL_SHOW_RIB: 256 c->iev.ibuf.pid = imsg.hdr.pid; 257 ripe_imsg_compose_rde(imsg.hdr.type, 0, 258 imsg.hdr.pid, imsg.data, imsg.hdr.len - 259 IMSG_HEADER_SIZE); 260 break; 261 case IMSG_CTL_SHOW_NBR: 262 ripe_nbr_ctl(c); 263 break; 264 case IMSG_CTL_KROUTE_ADDR: 265 case IMSG_CTL_KROUTE: 266 case IMSG_CTL_IFINFO: 267 c->iev.ibuf.pid = imsg.hdr.pid; 268 ripe_imsg_compose_parent(imsg.hdr.type, 269 imsg.hdr.pid, imsg.data, 270 imsg.hdr.len - IMSG_HEADER_SIZE); 271 break; 272 case IMSG_CTL_FIB_COUPLE: 273 case IMSG_CTL_FIB_DECOUPLE: 274 case IMSG_CTL_RELOAD: 275 c->iev.ibuf.pid = imsg.hdr.pid; 276 ripe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 277 break; 278 case IMSG_CTL_LOG_VERBOSE: 279 if (imsg.hdr.len != IMSG_HEADER_SIZE + 280 sizeof(verbose)) 281 break; 282 283 /* forward to other processes */ 284 ripe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 285 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 286 ripe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 287 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 288 289 memcpy(&verbose, imsg.data, sizeof(verbose)); 290 log_verbose(verbose); 291 break; 292 default: 293 log_debug("control_dispatch_imsg: " 294 "error handling imsg %d", imsg.hdr.type); 295 break; 296 } 297 imsg_free(&imsg); 298 } 299 300 imsg_event_add(&c->iev); 301} 302 303int 304control_imsg_relay(struct imsg *imsg) 305{ 306 struct ctl_conn *c; 307 308 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 309 return (0); 310 311 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 312 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 313} 314