1/* $FreeBSD: head/sys/contrib/ipfilter/netinet/ip_rcmd_pxy.c 145522 2005-04-25 18:43:14Z darrenr $ */ 2 |
3/* |
4 * Copyright (C) 1998-2003 by Darren Reed 5 * 6 * See the IPFILTER.LICENCE file for details on licencing. 7 * 8 * Id: ip_rcmd_pxy.c,v 1.41.2.4 2005/02/04 10:22:55 darrenr Exp 9 * |
10 * Simple RCMD transparent proxy for in-kernel use. For use with the NAT 11 * code. |
12 * $FreeBSD: head/sys/contrib/ipfilter/netinet/ip_rcmd_pxy.c 145522 2005-04-25 18:43:14Z darrenr $ |
13 */ |
14 |
15#define IPF_RCMD_PROXY 16 17 18int ippr_rcmd_init __P((void)); |
19void ippr_rcmd_fini __P((void)); 20int ippr_rcmd_new __P((fr_info_t *, ap_session_t *, nat_t *)); 21int ippr_rcmd_out __P((fr_info_t *, ap_session_t *, nat_t *)); 22int ippr_rcmd_in __P((fr_info_t *, ap_session_t *, nat_t *)); |
23u_short ipf_rcmd_atoi __P((char *)); |
24int ippr_rcmd_portmsg __P((fr_info_t *, ap_session_t *, nat_t *)); |
25 26static frentry_t rcmdfr; 27 |
28int rcmd_proxy_init = 0; |
29 |
30 |
31/* 32 * RCMD application proxy initialization. 33 */ 34int ippr_rcmd_init() 35{ 36 bzero((char *)&rcmdfr, sizeof(rcmdfr)); 37 rcmdfr.fr_ref = 1; 38 rcmdfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; |
39 MUTEX_INIT(&rcmdfr.fr_lock, "RCMD proxy rule lock"); 40 rcmd_proxy_init = 1; 41 |
42 return 0; 43} 44 45 |
46void ippr_rcmd_fini() 47{ 48 if (rcmd_proxy_init == 1) { 49 MUTEX_DESTROY(&rcmdfr.fr_lock); 50 rcmd_proxy_init = 0; 51 } 52} 53 54 |
55/* 56 * Setup for a new RCMD proxy. 57 */ |
58int ippr_rcmd_new(fin, aps, nat) |
59fr_info_t *fin; |
60ap_session_t *aps; 61nat_t *nat; 62{ 63 tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp; 64 |
65 fin = fin; /* LINT */ 66 nat = nat; /* LINT */ 67 |
68 aps->aps_psiz = sizeof(u_32_t); 69 KMALLOCS(aps->aps_data, u_32_t *, sizeof(u_32_t)); |
70 if (aps->aps_data == NULL) { 71#ifdef IP_RCMD_PROXY_DEBUG 72 printf("ippr_rcmd_new:KMALLOCS(%d) failed\n", sizeof(u_32_t)); 73#endif |
74 return -1; |
75 } |
76 *(u_32_t *)aps->aps_data = 0; 77 aps->aps_sport = tcp->th_sport; 78 aps->aps_dport = tcp->th_dport; 79 return 0; 80} 81 82 83/* 84 * ipf_rcmd_atoi - implement a simple version of atoi 85 */ 86u_short ipf_rcmd_atoi(ptr) 87char *ptr; 88{ 89 register char *s = ptr, c; 90 register u_short i = 0; 91 |
92 while (((c = *s++) != '\0') && ISDIGIT(c)) { |
93 i *= 10; 94 i += c - '0'; 95 } 96 return i; 97} 98 99 |
100int ippr_rcmd_portmsg(fin, aps, nat) |
101fr_info_t *fin; |
102ap_session_t *aps; 103nat_t *nat; 104{ |
105 tcphdr_t *tcp, tcph, *tcp2 = &tcph; |
106 struct in_addr swip, swip2; 107 int off, dlen, nflags; 108 char portbuf[8], *s; |
109 fr_info_t fi; 110 u_short sp; |
111 nat_t *nat2; 112 ip_t *ip; |
113 mb_t *m; 114 115 tcp = (tcphdr_t *)fin->fin_dp; 116 117 if (tcp->th_flags & TH_SYN) { 118 *(u_32_t *)aps->aps_data = htonl(ntohl(tcp->th_seq) + 1); 119 return 0; 120 } 121 122 if ((*(u_32_t *)aps->aps_data != 0) && 123 (tcp->th_seq != *(u_32_t *)aps->aps_data)) 124 return 0; 125 |
126 m = fin->fin_m; 127 ip = fin->fin_ip; 128 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
129 |
130#ifdef __sgi 131 dlen = fin->fin_plen - off; |
132#else |
133 dlen = MSGDSIZE(m) - off; |
134#endif |
135 if (dlen <= 0) 136 return 0; |
137 |
138 bzero(portbuf, sizeof(portbuf)); 139 COPYDATA(m, off, MIN(sizeof(portbuf), dlen), portbuf); 140 |
141 portbuf[sizeof(portbuf) - 1] = '\0'; 142 s = portbuf; 143 sp = ipf_rcmd_atoi(s); |
144 if (sp == 0) { 145#ifdef IP_RCMD_PROXY_DEBUG 146 printf("ippr_rcmd_portmsg:sp == 0 dlen %d [%s]\n", 147 dlen, portbuf); 148#endif |
149 return 0; |
150 } |
151 152 /* 153 * Add skeleton NAT entry for connection which will come back the 154 * other way. 155 */ 156 bcopy((char *)fin, (char *)&fi, sizeof(fi)); |
157 fi.fin_flx |= FI_IGNORE; |
158 fi.fin_data[0] = sp; |
159 fi.fin_data[1] = 0; 160 if (nat->nat_dir == NAT_OUTBOUND) 161 nat2 = nat_outlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p, 162 nat->nat_inip, nat->nat_oip); 163 else 164 nat2 = nat_inlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p, 165 nat->nat_inip, nat->nat_oip); 166 if (nat2 == NULL) { |
167 int slen; 168 169 slen = ip->ip_len; 170 ip->ip_len = fin->fin_hlen + sizeof(*tcp); 171 bzero((char *)tcp2, sizeof(*tcp2)); 172 tcp2->th_win = htons(8192); 173 tcp2->th_sport = htons(sp); 174 tcp2->th_dport = 0; /* XXX - don't specify remote port */ |
175 TCP_OFF_A(tcp2, 5); |
176 tcp2->th_flags = TH_SYN; |
177 fi.fin_dp = (char *)tcp2; |
178 fi.fin_fr = &rcmdfr; |
179 fi.fin_dlen = sizeof(*tcp2); |
180 fi.fin_plen = fi.fin_hlen + sizeof(*tcp2); 181 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE; 182 nflags = NAT_SLAVE|IPN_TCP|SI_W_DPORT; 183 |
184 swip = ip->ip_src; |
185 swip2 = ip->ip_dst; 186 187 if (nat->nat_dir == NAT_OUTBOUND) { 188 fi.fin_fi.fi_saddr = nat->nat_inip.s_addr; 189 ip->ip_src = nat->nat_inip; 190 } else { 191 fi.fin_fi.fi_saddr = nat->nat_oip.s_addr; 192 ip->ip_src = nat->nat_oip; 193 nflags |= NAT_NOTRULEPORT; |
194 } |
195 196 nat2 = nat_new(&fi, nat->nat_ptr, NULL, nflags, nat->nat_dir); 197 198 if (nat2 != NULL) { 199 (void) nat_proto(&fi, nat2, IPN_TCP); 200 nat_update(&fi, nat2, nat2->nat_ptr); 201 fi.fin_ifp = NULL; 202 if (nat->nat_dir == NAT_INBOUND) { 203 fi.fin_fi.fi_daddr = nat->nat_inip.s_addr; 204 ip->ip_dst = nat->nat_inip; 205 } 206 (void) fr_addstate(&fi, &nat2->nat_state, SI_W_DPORT); 207 if (fi.fin_state != NULL) 208 fr_statederef(&fi, (ipstate_t **)&fi.fin_state); 209 } |
210 ip->ip_len = slen; 211 ip->ip_src = swip; |
212 ip->ip_dst = swip2; |
213 } 214 return 0; 215} 216 217 |
218int ippr_rcmd_out(fin, aps, nat) |
219fr_info_t *fin; |
220ap_session_t *aps; 221nat_t *nat; 222{ |
223 if (nat->nat_dir == NAT_OUTBOUND) 224 return ippr_rcmd_portmsg(fin, aps, nat); 225 return 0; |
226} |
227 228 229int ippr_rcmd_in(fin, aps, nat) 230fr_info_t *fin; 231ap_session_t *aps; 232nat_t *nat; 233{ 234 if (nat->nat_dir == NAT_INBOUND) 235 return ippr_rcmd_portmsg(fin, aps, nat); 236 return 0; 237} |