ip_rcmd_pxy.c revision 1.2.4.3
1 1.2.4.3 yamt /* $NetBSD: ip_rcmd_pxy.c,v 1.2.4.3 2012/10/30 17:22:20 yamt Exp $ */ 2 1.2.4.2 yamt 3 1.2.4.2 yamt /* 4 1.2.4.3 yamt * Copyright (C) 2012 by Darren Reed. 5 1.2.4.2 yamt * 6 1.2.4.2 yamt * See the IPFILTER.LICENCE file for details on licencing. 7 1.2.4.2 yamt * 8 1.2.4.3 yamt * Id: ip_rcmd_pxy.c,v 1.1.1.2 2012/07/22 13:45:33 darrenr Exp 9 1.2.4.2 yamt * 10 1.2.4.2 yamt * Simple RCMD transparent proxy for in-kernel use. For use with the NAT 11 1.2.4.2 yamt * code. 12 1.2.4.2 yamt */ 13 1.2.4.2 yamt 14 1.2.4.2 yamt #include <sys/cdefs.h> 15 1.2.4.3 yamt __KERNEL_RCSID(1, "$NetBSD: ip_rcmd_pxy.c,v 1.2.4.3 2012/10/30 17:22:20 yamt Exp $"); 16 1.2.4.2 yamt 17 1.2.4.2 yamt #define IPF_RCMD_PROXY 18 1.2.4.2 yamt 19 1.2.4.3 yamt typedef struct rcmdinfo { 20 1.2.4.3 yamt u_32_t rcmd_port; /* Port number seen */ 21 1.2.4.3 yamt u_32_t rcmd_portseq; /* Sequence number where port is first seen */ 22 1.2.4.3 yamt ipnat_t *rcmd_rule; /* Template rule for back connection */ 23 1.2.4.3 yamt } rcmdinfo_t; 24 1.2.4.3 yamt 25 1.2.4.2 yamt void ipf_p_rcmd_main_load(void); 26 1.2.4.2 yamt void ipf_p_rcmd_main_unload(void); 27 1.2.4.2 yamt 28 1.2.4.2 yamt int ipf_p_rcmd_init(void); 29 1.2.4.2 yamt void ipf_p_rcmd_fini(void); 30 1.2.4.2 yamt void ipf_p_rcmd_del(ipf_main_softc_t *, ap_session_t *); 31 1.2.4.2 yamt int ipf_p_rcmd_new(void *, fr_info_t *, ap_session_t *, nat_t *); 32 1.2.4.2 yamt int ipf_p_rcmd_out(void *, fr_info_t *, ap_session_t *, nat_t *); 33 1.2.4.2 yamt int ipf_p_rcmd_in(void *, fr_info_t *, ap_session_t *, nat_t *); 34 1.2.4.2 yamt u_short ipf_rcmd_atoi(char *); 35 1.2.4.2 yamt int ipf_p_rcmd_portmsg(fr_info_t *, ap_session_t *, nat_t *); 36 1.2.4.2 yamt 37 1.2.4.2 yamt static frentry_t rcmdfr; 38 1.2.4.2 yamt 39 1.2.4.2 yamt static int rcmd_proxy_init = 0; 40 1.2.4.2 yamt 41 1.2.4.2 yamt 42 1.2.4.2 yamt /* 43 1.2.4.2 yamt * RCMD application proxy initialization. 44 1.2.4.2 yamt */ 45 1.2.4.2 yamt void 46 1.2.4.2 yamt ipf_p_rcmd_main_load(void) 47 1.2.4.2 yamt { 48 1.2.4.2 yamt bzero((char *)&rcmdfr, sizeof(rcmdfr)); 49 1.2.4.2 yamt rcmdfr.fr_ref = 1; 50 1.2.4.2 yamt rcmdfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; 51 1.2.4.2 yamt MUTEX_INIT(&rcmdfr.fr_lock, "RCMD proxy rule lock"); 52 1.2.4.2 yamt rcmd_proxy_init = 1; 53 1.2.4.2 yamt } 54 1.2.4.2 yamt 55 1.2.4.2 yamt 56 1.2.4.2 yamt void 57 1.2.4.2 yamt ipf_p_rcmd_main_unload(void) 58 1.2.4.2 yamt { 59 1.2.4.2 yamt if (rcmd_proxy_init == 1) { 60 1.2.4.2 yamt MUTEX_DESTROY(&rcmdfr.fr_lock); 61 1.2.4.2 yamt rcmd_proxy_init = 0; 62 1.2.4.2 yamt } 63 1.2.4.2 yamt } 64 1.2.4.2 yamt 65 1.2.4.2 yamt 66 1.2.4.2 yamt /* 67 1.2.4.2 yamt * Setup for a new RCMD proxy. 68 1.2.4.2 yamt */ 69 1.2.4.2 yamt int 70 1.2.4.2 yamt ipf_p_rcmd_new(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) 71 1.2.4.2 yamt { 72 1.2.4.2 yamt tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp; 73 1.2.4.2 yamt rcmdinfo_t *rc; 74 1.2.4.2 yamt ipnat_t *ipn; 75 1.2.4.3 yamt ipnat_t *np; 76 1.2.4.3 yamt int size; 77 1.2.4.2 yamt 78 1.2.4.2 yamt fin = fin; /* LINT */ 79 1.2.4.2 yamt 80 1.2.4.3 yamt np = nat->nat_ptr; 81 1.2.4.3 yamt size = np->in_size; 82 1.2.4.3 yamt KMALLOC(rc, rcmdinfo_t *); 83 1.2.4.2 yamt if (rc == NULL) { 84 1.2.4.2 yamt printf("ipf_p_rcmd_new:KMALLOCS(%zu) failed\n", sizeof(*rc)); 85 1.2.4.2 yamt return -1; 86 1.2.4.2 yamt } 87 1.2.4.3 yamt aps->aps_sport = tcp->th_sport; 88 1.2.4.3 yamt aps->aps_dport = tcp->th_dport; 89 1.2.4.3 yamt 90 1.2.4.3 yamt ipn = ipf_proxy_rule_rev(nat); 91 1.2.4.3 yamt if (ipn == NULL) { 92 1.2.4.3 yamt KFREE(rc); 93 1.2.4.3 yamt return -1; 94 1.2.4.3 yamt } 95 1.2.4.2 yamt 96 1.2.4.2 yamt aps->aps_data = rc; 97 1.2.4.3 yamt aps->aps_psiz = sizeof(*rc); 98 1.2.4.2 yamt bzero((char *)rc, sizeof(*rc)); 99 1.2.4.2 yamt 100 1.2.4.3 yamt rc->rcmd_rule = ipn; 101 1.2.4.2 yamt 102 1.2.4.2 yamt return 0; 103 1.2.4.2 yamt } 104 1.2.4.2 yamt 105 1.2.4.2 yamt 106 1.2.4.2 yamt void 107 1.2.4.2 yamt ipf_p_rcmd_del(ipf_main_softc_t *softc, ap_session_t *aps) 108 1.2.4.2 yamt { 109 1.2.4.2 yamt rcmdinfo_t *rci; 110 1.2.4.2 yamt 111 1.2.4.2 yamt rci = aps->aps_data; 112 1.2.4.2 yamt if (rci != NULL) { 113 1.2.4.3 yamt rci->rcmd_rule->in_flags |= IPN_DELETE; 114 1.2.4.3 yamt ipf_nat_rule_deref(softc, &rci->rcmd_rule); 115 1.2.4.2 yamt } 116 1.2.4.2 yamt } 117 1.2.4.2 yamt 118 1.2.4.2 yamt 119 1.2.4.2 yamt /* 120 1.2.4.2 yamt * ipf_rcmd_atoi - implement a simple version of atoi 121 1.2.4.2 yamt */ 122 1.2.4.2 yamt u_short 123 1.2.4.2 yamt ipf_rcmd_atoi(char *ptr) 124 1.2.4.2 yamt { 125 1.2.4.2 yamt char *s = ptr, c; 126 1.2.4.2 yamt u_short i = 0; 127 1.2.4.2 yamt 128 1.2.4.2 yamt while (((c = *s++) != '\0') && ISDIGIT(c)) { 129 1.2.4.2 yamt i *= 10; 130 1.2.4.2 yamt i += c - '0'; 131 1.2.4.2 yamt } 132 1.2.4.2 yamt return i; 133 1.2.4.2 yamt } 134 1.2.4.2 yamt 135 1.2.4.2 yamt 136 1.2.4.2 yamt int 137 1.2.4.2 yamt ipf_p_rcmd_portmsg(fr_info_t *fin, ap_session_t *aps, nat_t *nat) 138 1.2.4.2 yamt { 139 1.2.4.2 yamt tcphdr_t *tcp, tcph, *tcp2 = &tcph; 140 1.2.4.2 yamt int off, dlen, nflags, direction; 141 1.2.4.2 yamt ipf_main_softc_t *softc; 142 1.2.4.3 yamt ipf_nat_softc_t *softn; 143 1.2.4.2 yamt char portbuf[8], *s; 144 1.2.4.2 yamt rcmdinfo_t *rc; 145 1.2.4.2 yamt fr_info_t fi; 146 1.2.4.2 yamt u_short sp; 147 1.2.4.2 yamt nat_t *nat2; 148 1.2.4.3 yamt #ifdef USE_INET6 149 1.2.4.3 yamt ip6_t *ip6; 150 1.2.4.3 yamt #endif 151 1.2.4.3 yamt int tcpsz; 152 1.2.4.3 yamt int slen = 0; 153 1.2.4.2 yamt ip_t *ip; 154 1.2.4.2 yamt mb_t *m; 155 1.2.4.2 yamt 156 1.2.4.2 yamt tcp = (tcphdr_t *)fin->fin_dp; 157 1.2.4.2 yamt 158 1.2.4.2 yamt m = fin->fin_m; 159 1.2.4.2 yamt ip = fin->fin_ip; 160 1.2.4.3 yamt tcpsz = TCP_OFF(tcp) << 2; 161 1.2.4.3 yamt #ifdef USE_INET6 162 1.2.4.3 yamt ip6 = (ip6_t *)fin->fin_ip; 163 1.2.4.2 yamt #endif 164 1.2.4.3 yamt softc = fin->fin_main_soft; 165 1.2.4.3 yamt softn = softc->ipf_nat_soft; 166 1.2.4.3 yamt off = (char *)tcp - (char *)ip + tcpsz + fin->fin_ipoff; 167 1.2.4.3 yamt 168 1.2.4.3 yamt dlen = fin->fin_dlen - tcpsz; 169 1.2.4.2 yamt if (dlen <= 0) 170 1.2.4.2 yamt return 0; 171 1.2.4.2 yamt 172 1.2.4.2 yamt rc = (rcmdinfo_t *)aps->aps_data; 173 1.2.4.2 yamt if ((rc->rcmd_portseq != 0) && 174 1.2.4.2 yamt (tcp->th_seq != rc->rcmd_portseq)) 175 1.2.4.2 yamt return 0; 176 1.2.4.2 yamt 177 1.2.4.2 yamt bzero(portbuf, sizeof(portbuf)); 178 1.2.4.2 yamt COPYDATA(m, off, MIN(sizeof(portbuf), dlen), portbuf); 179 1.2.4.2 yamt 180 1.2.4.2 yamt portbuf[sizeof(portbuf) - 1] = '\0'; 181 1.2.4.2 yamt s = portbuf; 182 1.2.4.2 yamt sp = ipf_rcmd_atoi(s); 183 1.2.4.2 yamt if (sp == 0) { 184 1.2.4.2 yamt #ifdef IP_RCMD_PROXY_DEBUG 185 1.2.4.2 yamt printf("ipf_p_rcmd_portmsg:sp == 0 dlen %d [%s]\n", 186 1.2.4.2 yamt dlen, portbuf); 187 1.2.4.2 yamt #endif 188 1.2.4.2 yamt return 0; 189 1.2.4.2 yamt } 190 1.2.4.2 yamt 191 1.2.4.2 yamt if (rc->rcmd_port != 0 && sp != rc->rcmd_port) { 192 1.2.4.2 yamt #ifdef IP_RCMD_PROXY_DEBUG 193 1.2.4.2 yamt printf("ipf_p_rcmd_portmsg:sp(%d) != rcmd_port(%d)\n", 194 1.2.4.2 yamt sp, rc->rcmd_port); 195 1.2.4.2 yamt #endif 196 1.2.4.2 yamt return 0; 197 1.2.4.2 yamt } 198 1.2.4.2 yamt 199 1.2.4.2 yamt rc->rcmd_port = sp; 200 1.2.4.2 yamt rc->rcmd_portseq = tcp->th_seq; 201 1.2.4.2 yamt 202 1.2.4.2 yamt /* 203 1.2.4.2 yamt * Initialise the packet info structure so we can search the NAT 204 1.2.4.2 yamt * table to see if there already is soemthing present that matches 205 1.2.4.2 yamt * up with what we want to add. 206 1.2.4.2 yamt */ 207 1.2.4.2 yamt bcopy((char *)fin, (char *)&fi, sizeof(fi)); 208 1.2.4.2 yamt fi.fin_flx |= FI_IGNORE; 209 1.2.4.2 yamt fi.fin_data[0] = 0; 210 1.2.4.2 yamt fi.fin_data[1] = sp; 211 1.2.4.3 yamt fi.fin_src6 = nat->nat_ndst6; 212 1.2.4.3 yamt fi.fin_dst6 = nat->nat_nsrc6; 213 1.2.4.2 yamt 214 1.2.4.3 yamt if (nat->nat_v[0] == 6) { 215 1.2.4.3 yamt #ifdef USE_INET6 216 1.2.4.3 yamt if (nat->nat_dir == NAT_OUTBOUND) { 217 1.2.4.3 yamt nat2 = ipf_nat6_outlookup(&fi, NAT_SEARCH|IPN_TCP, 218 1.2.4.3 yamt nat->nat_pr[1], 219 1.2.4.3 yamt &nat->nat_osrc6.in6, 220 1.2.4.3 yamt &nat->nat_odst6.in6); 221 1.2.4.3 yamt } else { 222 1.2.4.3 yamt nat2 = ipf_nat6_inlookup(&fi, NAT_SEARCH|IPN_TCP, 223 1.2.4.3 yamt nat->nat_pr[0], 224 1.2.4.3 yamt &nat->nat_osrc6.in6, 225 1.2.4.3 yamt &nat->nat_odst6.in6); 226 1.2.4.3 yamt } 227 1.2.4.3 yamt #else 228 1.2.4.3 yamt nat2 = (void *)-1; 229 1.2.4.3 yamt #endif 230 1.2.4.2 yamt } else { 231 1.2.4.3 yamt if (nat->nat_dir == NAT_OUTBOUND) { 232 1.2.4.3 yamt nat2 = ipf_nat_outlookup(&fi, NAT_SEARCH|IPN_TCP, 233 1.2.4.3 yamt nat->nat_pr[1], 234 1.2.4.3 yamt nat->nat_osrcip, 235 1.2.4.3 yamt nat->nat_odstip); 236 1.2.4.3 yamt } else { 237 1.2.4.3 yamt nat2 = ipf_nat_inlookup(&fi, NAT_SEARCH|IPN_TCP, 238 1.2.4.3 yamt nat->nat_pr[0], 239 1.2.4.3 yamt nat->nat_osrcip, 240 1.2.4.3 yamt nat->nat_odstip); 241 1.2.4.3 yamt } 242 1.2.4.2 yamt } 243 1.2.4.3 yamt if (nat2 != NULL) 244 1.2.4.3 yamt return APR_ERR(1); 245 1.2.4.2 yamt 246 1.2.4.3 yamt /* 247 1.2.4.3 yamt * Add skeleton NAT entry for connection which will come 248 1.2.4.3 yamt * back the other way. 249 1.2.4.3 yamt */ 250 1.2.4.2 yamt 251 1.2.4.3 yamt if (nat->nat_v[0] == 6) { 252 1.2.4.3 yamt #ifdef USE_INET6 253 1.2.4.3 yamt slen = ip6->ip6_plen; 254 1.2.4.3 yamt ip6->ip6_plen = htons(sizeof(*tcp)); 255 1.2.4.3 yamt #endif 256 1.2.4.3 yamt } else { 257 1.2.4.2 yamt slen = ip->ip_len; 258 1.2.4.2 yamt ip->ip_len = htons(fin->fin_hlen + sizeof(*tcp)); 259 1.2.4.3 yamt } 260 1.2.4.2 yamt 261 1.2.4.3 yamt /* 262 1.2.4.3 yamt * Fill out the fake TCP header with a few fields that ipfilter 263 1.2.4.3 yamt * considers to be important. 264 1.2.4.3 yamt */ 265 1.2.4.3 yamt bzero((char *)tcp2, sizeof(*tcp2)); 266 1.2.4.3 yamt tcp2->th_win = htons(8192); 267 1.2.4.3 yamt TCP_OFF_A(tcp2, 5); 268 1.2.4.3 yamt tcp2->th_flags = TH_SYN; 269 1.2.4.3 yamt 270 1.2.4.3 yamt fi.fin_dp = (char *)tcp2; 271 1.2.4.3 yamt fi.fin_fr = &rcmdfr; 272 1.2.4.3 yamt fi.fin_dlen = sizeof(*tcp2); 273 1.2.4.3 yamt fi.fin_plen = fi.fin_hlen + sizeof(*tcp2); 274 1.2.4.3 yamt fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE; 275 1.2.4.2 yamt 276 1.2.4.3 yamt if (nat->nat_dir == NAT_OUTBOUND) { 277 1.2.4.3 yamt fi.fin_out = 0; 278 1.2.4.3 yamt direction = NAT_INBOUND; 279 1.2.4.3 yamt } else { 280 1.2.4.3 yamt fi.fin_out = 1; 281 1.2.4.3 yamt direction = NAT_OUTBOUND; 282 1.2.4.3 yamt } 283 1.2.4.3 yamt nflags = SI_W_SPORT|NAT_SLAVE|IPN_TCP; 284 1.2.4.2 yamt 285 1.2.4.3 yamt MUTEX_ENTER(&softn->ipf_nat_new); 286 1.2.4.3 yamt if (fin->fin_v == 4) 287 1.2.4.3 yamt nat2 = ipf_nat_add(&fi, rc->rcmd_rule, NULL, nflags, 288 1.2.4.2 yamt direction); 289 1.2.4.3 yamt #ifdef USE_INET6 290 1.2.4.3 yamt else 291 1.2.4.3 yamt nat2 = ipf_nat6_add(&fi, rc->rcmd_rule, NULL, nflags, 292 1.2.4.3 yamt direction); 293 1.2.4.3 yamt #endif 294 1.2.4.3 yamt MUTEX_EXIT(&softn->ipf_nat_new); 295 1.2.4.2 yamt 296 1.2.4.3 yamt if (nat2 != NULL) { 297 1.2.4.3 yamt (void) ipf_nat_proto(&fi, nat2, IPN_TCP); 298 1.2.4.3 yamt MUTEX_ENTER(&nat2->nat_lock); 299 1.2.4.3 yamt ipf_nat_update(&fi, nat2); 300 1.2.4.3 yamt MUTEX_EXIT(&nat2->nat_lock); 301 1.2.4.3 yamt fi.fin_ifp = NULL; 302 1.2.4.3 yamt if (nat2->nat_dir == NAT_INBOUND) 303 1.2.4.3 yamt fi.fin_dst6 = nat->nat_osrc6; 304 1.2.4.3 yamt (void) ipf_state_add(softc, &fi, NULL, SI_W_SPORT); 305 1.2.4.3 yamt } 306 1.2.4.3 yamt if (nat->nat_v[0] == 6) { 307 1.2.4.3 yamt #ifdef USE_INET6 308 1.2.4.3 yamt ip6->ip6_plen = slen; 309 1.2.4.3 yamt #endif 310 1.2.4.3 yamt } else { 311 1.2.4.2 yamt ip->ip_len = slen; 312 1.2.4.2 yamt } 313 1.2.4.3 yamt if (nat2 == NULL) 314 1.2.4.3 yamt return APR_ERR(1); 315 1.2.4.2 yamt return 0; 316 1.2.4.2 yamt } 317 1.2.4.2 yamt 318 1.2.4.2 yamt 319 1.2.4.2 yamt int 320 1.2.4.2 yamt ipf_p_rcmd_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) 321 1.2.4.2 yamt { 322 1.2.4.2 yamt if (nat->nat_dir == NAT_OUTBOUND) 323 1.2.4.2 yamt return ipf_p_rcmd_portmsg(fin, aps, nat); 324 1.2.4.2 yamt return 0; 325 1.2.4.2 yamt } 326 1.2.4.2 yamt 327 1.2.4.2 yamt 328 1.2.4.2 yamt int 329 1.2.4.2 yamt ipf_p_rcmd_in(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) 330 1.2.4.2 yamt { 331 1.2.4.2 yamt if (nat->nat_dir == NAT_INBOUND) 332 1.2.4.2 yamt return ipf_p_rcmd_portmsg(fin, aps, nat); 333 1.2.4.2 yamt return 0; 334 1.2.4.2 yamt } 335
Indexes created Tue Oct 28 12:10:06 GMT 2025