1 2 /* 3 * Copyright (C) 2012 by Darren Reed. 4 * 5 * See the IPFILTER.LICENCE file for details on licencing. 6 * 7 * $Id$ 8 */ 9 10 #include <ctype.h> 11 12 #include "ipf.h" 13 #include "ipt.h" 14 15 extern int opts; 16 17 static char *tx_proto = ""; 18 19 static int text_open(char *), text_close(void); 20 static int text_readip(mb_t *, char **, int *); 21 static int parseline(char *, ip_t *, char **, int *); 22 23 static char myflagset[] = "FSRPAUEC"; 24 static u_char myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH, 25 TH_ACK, TH_URG, TH_ECN, TH_CWR }; 26 27 struct ipread iptext = { text_open, text_close, text_readip, R_DO_CKSUM }; 28 static FILE *tfp = NULL; 29 static int tfd = -1; 30 31 static u_32_t tx_hostnum(char *, int *); 32 static u_short tx_portnum(char *); 33 34 #ifdef USE_INET6 35 int parseipv6(char **, ip6_t *, char **, int *); 36 #endif 37 38 /* 39 * returns an ip address as a long var as a result of either a DNS lookup or 40 * straight inet_addr() call 41 */ 42 static u_32_t 43 tx_hostnum(char *host, int *resolved) 44 { 45 i6addr_t ipa; 46 47 *resolved = 0; 48 if (!strcasecmp("any", host)) 49 return (0L); 50 if (ISDIGIT(*host)) 51 return (inet_addr(host)); 52 53 if (gethost(AF_INET, host, &ipa) == -1) { 54 *resolved = -1; 55 fprintf(stderr, "can't resolve hostname: %s\n", host); 56 return (0); 57 } 58 return (ipa.in4.s_addr); 59 } 60 61 62 /* 63 * find the port number given by the name, either from getservbyname() or 64 * straight atoi() 65 */ 66 static u_short 67 tx_portnum(char *name) 68 { 69 struct servent *sp; 70 71 if (ISDIGIT(*name)) 72 return (u_short)atoi(name); 73 sp = getservbyname(name, tx_proto); 74 if (sp) 75 return (ntohs(sp->s_port)); 76 (void) fprintf(stderr, "unknown service \"%s\".\n", name); 77 return (0); 78 } 79 80 81 static int 82 text_open(char *fname) 83 { 84 if (tfp && tfd != -1) { 85 rewind(tfp); 86 return (tfd); 87 } 88 89 if (!strcmp(fname, "-")) { 90 tfd = 0; 91 tfp = stdin; 92 } else { 93 tfd = open(fname, O_RDONLY); 94 if (tfd != -1) 95 tfp = fdopen(tfd, "r"); 96 } 97 return (tfd); 98 } 99 100 101 static int 102 text_close(void) 103 { 104 int cfd = tfd; 105 106 tfd = -1; 107 return (close(cfd)); 108 } 109 110 111 static int 112 text_readip(mb_t *mb, char **ifn, int *dir) 113 { 114 register char *s; 115 char line[513]; 116 ip_t *ip; 117 char *buf; 118 119 buf = (char *)mb->mb_buf; 120 121 *ifn = NULL; 122 while (fgets(line, sizeof(line)-1, tfp)) { 123 if ((s = strchr(line, '\n'))) 124 *s = '\0'; 125 if ((s = strchr(line, '\r'))) 126 *s = '\0'; 127 if ((s = strchr(line, '#'))) 128 *s = '\0'; 129 if (!*line) 130 continue; 131 if ((opts & OPT_DEBUG) != 0) 132 printf("input: %s\n", line); 133 *ifn = NULL; 134 *dir = 0; 135 if (!parseline(line, (ip_t *)buf, ifn, dir)) { 136 ip = (ip_t *)buf; 137 if (IP_V(ip) == 6) { 138 #ifdef USE_INET6 139 mb->mb_len = ntohs(((ip6_t *)ip)->ip6_plen) + 140 sizeof(ip6_t); 141 #else 142 mb->mb_len = 0; 143 #endif 144 } else { 145 mb->mb_len = ntohs(ip->ip_len); 146 } 147 return (mb->mb_len); 148 } 149 } 150 if (feof(tfp)) 151 return (0); 152 return (-1); 153 } 154 155 static int 156 parseline(char *line, ip_t *ip, char **ifn, int *out) 157 { 158 tcphdr_t th, *tcp = &th; 159 struct icmp icmp, *ic = &icmp; 160 char *cps[20], **cpp, c, ipopts[68]; 161 int i, r; 162 163 if (*ifn) 164 free(*ifn); 165 bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip)); 166 bzero((char *)tcp, sizeof(*tcp)); 167 bzero((char *)ic, sizeof(*ic)); 168 bzero(ipopts, sizeof(ipopts)); 169 IP_HL_A(ip, sizeof(*ip) >> 2); 170 IP_V_A(ip, IPVERSION); 171 ip->ip_ttl = 63; 172 for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; ) 173 cps[++i] = strtok(NULL, " \b\t\r\n"); 174 175 cpp = cps; 176 if (!*cpp) 177 return (1); 178 179 c = **cpp; 180 if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) { 181 fprintf(stderr, "bad direction \"%s\"\n", *cpp); 182 return (1); 183 } 184 185 #ifdef USE_INET6 186 if (!strcasecmp(*cpp, "out6") || !strcasecmp(*cpp, "in6")) { 187 return (parseipv6(cpp, (ip6_t *)ip, ifn, out)); 188 } 189 #endif 190 191 *out = (TOLOWER(c) == 'o') ? 1 : 0; 192 cpp++; 193 if (!*cpp) 194 return (1); 195 196 if (!strcasecmp(*cpp, "on")) { 197 cpp++; 198 if (!*cpp) 199 return (1); 200 *ifn = strdup(*cpp++); 201 if (!*cpp) 202 return (1); 203 } 204 205 c = **cpp; 206 ip->ip_len = sizeof(ip_t); 207 if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") || 208 !strcasecmp(*cpp, "icmp")) { 209 if (c == 't') { 210 ip->ip_p = IPPROTO_TCP; 211 ip->ip_len += sizeof(struct tcphdr); 212 tx_proto = "tcp"; 213 } else if (c == 'u') { 214 ip->ip_p = IPPROTO_UDP; 215 ip->ip_len += sizeof(struct udphdr); 216 tx_proto = "udp"; 217 } else { 218 ip->ip_p = IPPROTO_ICMP; 219 ip->ip_len += ICMPERR_IPICMPHLEN; 220 tx_proto = "icmp"; 221 } 222 cpp++; 223 } else if (ISDIGIT(**cpp) && !index(*cpp, '.')) { 224 ip->ip_p = atoi(*cpp); 225 cpp++; 226 } else 227 ip->ip_p = IPPROTO_IP; 228 229 if (!*cpp) 230 return (1); 231 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) { 232 char *last; 233 234 last = strchr(*cpp, ','); 235 if (!last) { 236 fprintf(stderr, "tcp/udp with no source port\n"); 237 return (1); 238 } 239 *last++ = '\0'; 240 tcp->th_sport = htons(tx_portnum(last)); 241 if (ip->ip_p == IPPROTO_TCP) { 242 tcp->th_win = htons(4096); 243 TCP_OFF_A(tcp, sizeof(*tcp) >> 2); 244 } 245 } 246 ip->ip_src.s_addr = tx_hostnum(*cpp, &r); 247 cpp++; 248 if (!*cpp) 249 return (1); 250 251 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) { 252 char *last; 253 254 last = strchr(*cpp, ','); 255 if (!last) { 256 fprintf(stderr, "tcp/udp with no destination port\n"); 257 return (1); 258 } 259 *last++ = '\0'; 260 tcp->th_dport = htons(tx_portnum(last)); 261 } 262 ip->ip_dst.s_addr = tx_hostnum(*cpp, &r); 263 cpp++; 264 if (ip->ip_p == IPPROTO_TCP) { 265 if (*cpp != NULL) { 266 char *s, *t; 267 268 tcp->th_flags = 0; 269 for (s = *cpp; *s; s++) 270 if ((t = strchr(myflagset, *s))) 271 tcp->th_flags |= myflags[t-myflagset]; 272 if (tcp->th_flags) 273 cpp++; 274 } 275 276 if (tcp->th_flags & TH_URG) 277 tcp->th_urp = htons(1); 278 279 if (*cpp && !strncasecmp(*cpp, "seq=", 4)) { 280 tcp->th_seq = htonl(atoi(*cpp + 4)); 281 cpp++; 282 } 283 284 if (*cpp && !strncasecmp(*cpp, "ack=", 4)) { 285 tcp->th_ack = htonl(atoi(*cpp + 4)); 286 cpp++; 287 } 288 } else if (*cpp && ip->ip_p == IPPROTO_ICMP) { 289 char *t; 290 291 t = strchr(*cpp, ','); 292 if (t != NULL) 293 *t = '\0'; 294 295 ic->icmp_type = geticmptype(AF_INET, *cpp); 296 if (t != NULL) 297 ic->icmp_code = atoi(t + 1); 298 cpp++; 299 300 if (ic->icmp_type == ICMP_ECHO || 301 ic->icmp_type == ICMP_ECHOREPLY) 302 ic->icmp_id = htons(getpid()); 303 if (t != NULL) 304 *t = ','; 305 } 306 307 if (*cpp && !strcasecmp(*cpp, "opt")) { 308 u_long olen; 309 310 cpp++; 311 olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2); 312 if (olen) { 313 bcopy(ipopts, (char *)(ip + 1), olen); 314 IP_HL_A(ip, IP_HL(ip) + (olen >> 2)); 315 ip->ip_len += olen; 316 } 317 } 318 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) 319 bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2), 320 sizeof(*tcp)); 321 else if (ip->ip_p == IPPROTO_ICMP) 322 bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2), 323 sizeof(*ic)); 324 ip->ip_len = htons(ip->ip_len); 325 return (0); 326 } 327 328 329 #ifdef USE_INET6 330 int 331 parseipv6(char **cpp, ip6_t *ip6, char **ifn, int *out) 332 { 333 tcphdr_t th, *tcp = &th; 334 struct icmp6_hdr icmp, *ic6 = &icmp; 335 336 bzero((char *)ip6, MAX(sizeof(*tcp), sizeof(*ic6)) + sizeof(*ip6)); 337 bzero((char *)tcp, sizeof(*tcp)); 338 bzero((char *)ic6, sizeof(*ic6)); 339 ip6->ip6_vfc = 0x60; 340 341 *out = (**cpp == 'o') ? 1 : 0; 342 cpp++; 343 if (!*cpp) 344 return (1); 345 346 if (!strcasecmp(*cpp, "on")) { 347 cpp++; 348 if (!*cpp) 349 return (1); 350 *ifn = strdup(*cpp++); 351 if (!*cpp) 352 return (1); 353 } 354 355 if (!strcasecmp(*cpp, "tcp")) { 356 ip6->ip6_nxt = IPPROTO_TCP; 357 tx_proto = "tcp"; 358 cpp++; 359 } else if (!strcasecmp(*cpp, "udp")) { 360 ip6->ip6_nxt = IPPROTO_UDP; 361 tx_proto = "udp"; 362 cpp++; 363 } else if (!strcasecmp(*cpp, "icmpv6")) { 364 ip6->ip6_nxt = IPPROTO_ICMPV6; 365 tx_proto = "icmpv6"; 366 cpp++; 367 } else if (ISDIGIT(**cpp) && !index(*cpp, ':')) { 368 ip6->ip6_nxt = atoi(*cpp); 369 cpp++; 370 } else 371 ip6->ip6_nxt = IPPROTO_IPV6; 372 373 if (!*cpp) 374 return (1); 375 376 switch (ip6->ip6_nxt) 377 { 378 case IPPROTO_TCP : 379 ip6->ip6_plen = sizeof(struct tcphdr); 380 break; 381 case IPPROTO_UDP : 382 ip6->ip6_plen = sizeof(struct udphdr); 383 break; 384 case IPPROTO_ICMPV6 : 385 ip6->ip6_plen = ICMP6ERR_IPICMPHLEN; 386 break; 387 default : 388 break; 389 } 390 391 if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) { 392 char *last; 393 394 last = strchr(*cpp, ','); 395 if (!last) { 396 fprintf(stderr, "tcp/udp with no source port\n"); 397 return (1); 398 } 399 *last++ = '\0'; 400 tcp->th_sport = htons(tx_portnum(last)); 401 if (ip6->ip6_nxt == IPPROTO_TCP) { 402 tcp->th_win = htons(4096); 403 TCP_OFF_A(tcp, sizeof(*tcp) >> 2); 404 } 405 } 406 407 if (inet_pton(AF_INET6, *cpp, &ip6->ip6_src) != 1) { 408 fprintf(stderr, "cannot parse source address '%s'\n", *cpp); 409 return (1); 410 } 411 412 cpp++; 413 if (!*cpp) 414 return (1); 415 416 if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) { 417 char *last; 418 419 last = strchr(*cpp, ','); 420 if (!last) { 421 fprintf(stderr, "tcp/udp with no destination port\n"); 422 return (1); 423 } 424 *last++ = '\0'; 425 tcp->th_dport = htons(tx_portnum(last)); 426 } 427 428 if (inet_pton(AF_INET6, *cpp, &ip6->ip6_dst) != 1) { 429 fprintf(stderr, "cannot parse destination address '%s'\n", 430 *cpp); 431 return (1); 432 } 433 434 cpp++; 435 if (ip6->ip6_nxt == IPPROTO_TCP) { 436 if (*cpp != NULL) { 437 char *s, *t; 438 439 tcp->th_flags = 0; 440 for (s = *cpp; *s; s++) 441 if ((t = strchr(myflagset, *s))) 442 tcp->th_flags |= myflags[t-myflagset]; 443 if (tcp->th_flags) 444 cpp++; 445 } 446 447 if (tcp->th_flags & TH_URG) 448 tcp->th_urp = htons(1); 449 450 if (*cpp && !strncasecmp(*cpp, "seq=", 4)) { 451 tcp->th_seq = htonl(atoi(*cpp + 4)); 452 cpp++; 453 } 454 455 if (*cpp && !strncasecmp(*cpp, "ack=", 4)) { 456 tcp->th_ack = htonl(atoi(*cpp + 4)); 457 cpp++; 458 } 459 } else if (*cpp && ip6->ip6_nxt == IPPROTO_ICMPV6) { 460 char *t; 461 462 t = strchr(*cpp, ','); 463 if (t != NULL) 464 *t = '\0'; 465 466 ic6->icmp6_type = geticmptype(AF_INET6, *cpp); 467 if (t != NULL) 468 ic6->icmp6_code = atoi(t + 1); 469 470 if (ic6->icmp6_type == ICMP6_ECHO_REQUEST || 471 ic6->icmp6_type == ICMP6_ECHO_REPLY) 472 ic6->icmp6_id = htons(getpid()); 473 474 if (t != NULL) 475 *t = ','; 476 } 477 478 if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) { 479 bcopy((char *)tcp, (char *)ip6 + sizeof(*ip6), 480 sizeof(*tcp)); 481 } else if (ip6->ip6_nxt == IPPROTO_ICMPV6) { 482 bcopy((char *)ic6, (char *)ip6 + sizeof(*ip6), 483 sizeof(*ic6)); 484 } 485 486 /* 487 * Because a length of 0 == jumbo gram... 488 */ 489 if (ip6->ip6_plen == 0) { 490 ip6->ip6_plen++; 491 } 492 ip6->ip6_plen = htons(ip6->ip6_plen); 493 return (0); 494 } 495 #endif 496