contrib/ipfilter/lib/ipft_tx.c

   1 /*      $FreeBSD$       */
   2
   3 /*
   4  * Copyright (C) 2012 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  * $Id$
   9  */
  10 #if !defined(lint)
  11 static const char sccsid[] = "@(#)ipft_tx.c     1.7 6/5/96 (C) 1993 Darren Reed";
  12 static const char rcsid[] = "@(#)$Id$";
  13 #endif
  14
  15 #include <ctype.h>
  16
  17 #include "ipf.h"
  18 #include "ipt.h"
  19
  20 extern  int     opts;
  21
  22 static  char    *tx_proto = "";
  23
  24 static  int     text_open __P((char *)), text_close __P((void));
  25 static  int     text_readip __P((mb_t *, char **, int *));
  26 static  int     parseline __P((char *, ip_t *, char **, int *));
  27
  28 static  char    myflagset[] = "FSRPAUEC";
  29 static  u_char  myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
  30                                 TH_ACK, TH_URG, TH_ECN, TH_CWR };
  31
  32 struct  ipread  iptext = { text_open, text_close, text_readip, R_DO_CKSUM };
  33 static  FILE    *tfp = NULL;
  34 static  int     tfd = -1;
  35
  36 static  u_32_t  tx_hostnum __P((char *, int *));
  37 static  u_short tx_portnum __P((char *));
  38
  39 #ifdef USE_INET6
  40 int parseipv6 __P((char **, ip6_t *, char **, int *));
  41 #endif
  42
  43 /*
  44  * returns an ip address as a long var as a result of either a DNS lookup or
  45  * straight inet_addr() call
  46  */
  47 static  u_32_t  tx_hostnum(host, resolved)
  48         char    *host;
  49         int     *resolved;
  50 {
  51         i6addr_t        ipa;
  52
  53         *resolved = 0;
  54         if (!strcasecmp("any", host))
  55                 return 0L;
  56         if (ISDIGIT(*host))
  57                 return inet_addr(host);
  58
  59         if (gethost(AF_INET, host, &ipa) == -1) {
  60                 *resolved = -1;
  61                 fprintf(stderr, "can't resolve hostname: %s\n", host);
  62                 return 0;
  63         }
  64         return ipa.in4.s_addr;
  65 }
  66
  67
  68 /*
  69  * find the port number given by the name, either from getservbyname() or
  70  * straight atoi()
  71  */
  72 static  u_short tx_portnum(name)
  73         char    *name;
  74 {
  75         struct  servent *sp;
  76
  77         if (ISDIGIT(*name))
  78                 return (u_short)atoi(name);
  79         sp = getservbyname(name, tx_proto);
  80         if (sp)
  81                 return ntohs(sp->s_port);
  82         (void) fprintf(stderr, "unknown service \"%s\".\n", name);
  83         return 0;
  84 }
  85
  86
  87 static  int     text_open(fname)
  88         char    *fname;
  89 {
  90         if (tfp && tfd != -1) {
  91                 rewind(tfp);
  92                 return tfd;
  93         }
  94
  95         if (!strcmp(fname, "-")) {
  96                 tfd = 0;
  97                 tfp = stdin;
  98         } else {
  99                 tfd = open(fname, O_RDONLY);
 100                 if (tfd != -1)
 101                         tfp = fdopen(tfd, "r");
 102         }
 103         return tfd;
 104 }
 105
 106
 107 static  int     text_close()
 108 {
 109         int     cfd = tfd;
 110
 111         tfd = -1;
 112         return close(cfd);
 113 }
 114
 115
 116 static  int     text_readip(mb, ifn, dir)
 117         mb_t    *mb;
 118         char    **ifn;
 119         int     *dir;
 120 {
 121         register char *s;
 122         char    line[513];
 123         ip_t    *ip;
 124         char    *buf;
 125         int     cnt;
 126
 127         buf = (char *)mb->mb_buf;
 128         cnt = sizeof(mb->mb_buf);
 129
 130         *ifn = NULL;
 131         while (fgets(line, sizeof(line)-1, tfp)) {
 132                 if ((s = strchr(line, '\n')))
 133                         *s = '\0';
 134                 if ((s = strchr(line, '\r')))
 135                         *s = '\0';
 136                 if ((s = strchr(line, '#')))
 137                         *s = '\0';
 138                 if (!*line)
 139                         continue;
 140                 if ((opts & OPT_DEBUG) != 0)
 141                         printf("input: %s\n", line);
 142                 *ifn = NULL;
 143                 *dir = 0;
 144                 if (!parseline(line, (ip_t *)buf, ifn, dir)) {
 145                         ip = (ip_t *)buf;
 146                         if (IP_V(ip) == 6) {
 147 #ifdef USE_INET6
 148                                 mb->mb_len = ntohs(((ip6_t *)ip)->ip6_plen) +
 149                                        sizeof(ip6_t);
 150 #else
 151                                 mb->mb_len = 0;
 152 #endif
 153                         } else {
 154                                 mb->mb_len = ntohs(ip->ip_len);
 155                         }
 156                         return mb->mb_len;
 157                 }
 158         }
 159         if (feof(tfp))
 160                 return 0;
 161         return -1;
 162 }
 163
 164 static  int     parseline(line, ip, ifn, out)
 165         char    *line;
 166         ip_t    *ip;
 167         char    **ifn;
 168         int     *out;
 169 {
 170         tcphdr_t        th, *tcp = &th;
 171         struct  icmp    icmp, *ic = &icmp;
 172         char    *cps[20], **cpp, c, ipopts[68];
 173         int     i, r;
 174
 175         if (*ifn)
 176                 free(*ifn);
 177         bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
 178         bzero((char *)tcp, sizeof(*tcp));
 179         bzero((char *)ic, sizeof(*ic));
 180         bzero(ipopts, sizeof(ipopts));
 181         IP_HL_A(ip, sizeof(*ip) >> 2);
 182         IP_V_A(ip, IPVERSION);
 183         ip->ip_ttl = 63;
 184         for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
 185                 cps[++i] = strtok(NULL, " \b\t\r\n");
 186
 187         cpp = cps;
 188         if (!*cpp)
 189                 return 1;
 190
 191         c = **cpp;
 192         if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) {
 193                 fprintf(stderr, "bad direction \"%s\"\n", *cpp);
 194                 return 1;
 195         }
 196
 197 #ifdef USE_INET6
 198         if (!strcasecmp(*cpp, "out6") || !strcasecmp(*cpp, "in6")) {
 199                 return parseipv6(cpp, (ip6_t *)ip, ifn, out);
 200         }
 201 #endif
 202
 203         *out = (TOLOWER(c) == 'o') ? 1 : 0;
 204         cpp++;
 205         if (!*cpp)
 206                 return 1;
 207
 208         if (!strcasecmp(*cpp, "on")) {
 209                 cpp++;
 210                 if (!*cpp)
 211                         return 1;
 212                 *ifn = strdup(*cpp++);
 213                 if (!*cpp)
 214                         return 1;
 215         }
 216
 217         c = **cpp;
 218         ip->ip_len = sizeof(ip_t);
 219         if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
 220             !strcasecmp(*cpp, "icmp")) {
 221                 if (c == 't') {
 222                         ip->ip_p = IPPROTO_TCP;
 223                         ip->ip_len += sizeof(struct tcphdr);
 224                         tx_proto = "tcp";
 225                 } else if (c == 'u') {
 226                         ip->ip_p = IPPROTO_UDP;
 227                         ip->ip_len += sizeof(struct udphdr);
 228                         tx_proto = "udp";
 229                 } else {
 230                         ip->ip_p = IPPROTO_ICMP;
 231                         ip->ip_len += ICMPERR_IPICMPHLEN;
 232                         tx_proto = "icmp";
 233                 }
 234                 cpp++;
 235         } else if (ISDIGIT(**cpp) && !index(*cpp, '.')) {
 236                 ip->ip_p = atoi(*cpp);
 237                 cpp++;
 238         } else
 239                 ip->ip_p = IPPROTO_IP;
 240
 241         if (!*cpp)
 242                 return 1;
 243         if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
 244                 char    *last;
 245
 246                 last = strchr(*cpp, ',');
 247                 if (!last) {
 248                         fprintf(stderr, "tcp/udp with no source port\n");
 249                         return 1;
 250                 }
 251                 *last++ = '\0';
 252                 tcp->th_sport = htons(tx_portnum(last));
 253                 if (ip->ip_p == IPPROTO_TCP) {
 254                         tcp->th_win = htons(4096);
 255                         TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
 256                 }
 257         }
 258         ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
 259         cpp++;
 260         if (!*cpp)
 261                 return 1;
 262
 263         if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
 264                 char    *last;
 265
 266                 last = strchr(*cpp, ',');
 267                 if (!last) {
 268                         fprintf(stderr, "tcp/udp with no destination port\n");
 269                         return 1;
 270                 }
 271                 *last++ = '\0';
 272                 tcp->th_dport = htons(tx_portnum(last));
 273         }
 274         ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
 275         cpp++;
 276         if (ip->ip_p == IPPROTO_TCP) {
 277                 if (*cpp != NULL) {
 278                         char    *s, *t;
 279
 280                         tcp->th_flags = 0;
 281                         for (s = *cpp; *s; s++)
 282                                 if ((t  = strchr(myflagset, *s)))
 283                                         tcp->th_flags |= myflags[t-myflagset];
 284                         if (tcp->th_flags)
 285                                 cpp++;
 286                 }
 287
 288                 if (tcp->th_flags & TH_URG)
 289                         tcp->th_urp = htons(1);
 290
 291                 if (*cpp && !strncasecmp(*cpp, "seq=", 4)) {
 292                         tcp->th_seq = htonl(atoi(*cpp + 4));
 293                         cpp++;
 294                 }
 295
 296                 if (*cpp && !strncasecmp(*cpp, "ack=", 4)) {
 297                         tcp->th_ack = htonl(atoi(*cpp + 4));
 298                         cpp++;
 299                 }
 300         } else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
 301                 char    *t;
 302
 303                 t = strchr(*cpp, ',');
 304                 if (t != NULL)
 305                         *t = '\0';
 306
 307                 ic->icmp_type = geticmptype(AF_INET, *cpp);
 308                 if (t != NULL)
 309                         ic->icmp_code = atoi(t + 1);
 310                 cpp++;
 311
 312                 if (ic->icmp_type == ICMP_ECHO ||
 313                     ic->icmp_type == ICMP_ECHOREPLY)
 314                         ic->icmp_id = htons(getpid());
 315                 if (t != NULL)
 316                         *t = ',';
 317         }
 318
 319         if (*cpp && !strcasecmp(*cpp, "opt")) {
 320                 u_long  olen;
 321
 322                 cpp++;
 323                 olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2);
 324                 if (olen) {
 325                         bcopy(ipopts, (char *)(ip + 1), olen);
 326                         IP_HL_A(ip, IP_HL(ip) + (olen >> 2));
 327                         ip->ip_len += olen;
 328                 }
 329         }
 330         if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
 331                 bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2),
 332                         sizeof(*tcp));
 333         else if (ip->ip_p == IPPROTO_ICMP)
 334                 bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2),
 335                         sizeof(*ic));
 336         ip->ip_len = htons(ip->ip_len);
 337         return 0;
 338 }
 339
 340
 341 #ifdef USE_INET6
 342 int parseipv6(cpp, ip6, ifn, out)
 343         char **cpp;
 344         ip6_t *ip6;
 345         char **ifn;
 346         int *out;
 347 {
 348         tcphdr_t th, *tcp = &th;
 349         struct icmp6_hdr icmp, *ic6 = &icmp;
 350
 351         bzero((char *)ip6, MAX(sizeof(*tcp), sizeof(*ic6)) + sizeof(*ip6));
 352         bzero((char *)tcp, sizeof(*tcp));
 353         bzero((char *)ic6, sizeof(*ic6));
 354         ip6->ip6_vfc = 0x60;
 355
 356         *out = (**cpp == 'o') ? 1 : 0;
 357         cpp++;
 358         if (!*cpp)
 359                 return 1;
 360
 361         if (!strcasecmp(*cpp, "on")) {
 362                 cpp++;
 363                 if (!*cpp)
 364                         return 1;
 365                 *ifn = strdup(*cpp++);
 366                 if (!*cpp)
 367                         return 1;
 368         }
 369
 370         if (!strcasecmp(*cpp, "tcp")) {
 371                 ip6->ip6_nxt = IPPROTO_TCP;
 372                 tx_proto = "tcp";
 373                 cpp++;
 374         } else if (!strcasecmp(*cpp, "udp")) {
 375                 ip6->ip6_nxt = IPPROTO_UDP;
 376                 tx_proto = "udp";
 377                 cpp++;
 378         } else if (!strcasecmp(*cpp, "icmpv6")) {
 379                 ip6->ip6_nxt = IPPROTO_ICMPV6;
 380                 tx_proto = "icmpv6";
 381                 cpp++;
 382         } else if (ISDIGIT(**cpp) && !index(*cpp, ':')) {
 383                 ip6->ip6_nxt = atoi(*cpp);
 384                 cpp++;
 385         } else
 386                 ip6->ip6_nxt = IPPROTO_IPV6;
 387
 388         if (!*cpp)
 389                 return 1;
 390
 391         switch (ip6->ip6_nxt)
 392         {
 393         case IPPROTO_TCP :
 394                 ip6->ip6_plen = sizeof(struct tcphdr);
 395                 break;
 396         case IPPROTO_UDP :
 397                 ip6->ip6_plen = sizeof(struct udphdr);
 398                 break;
 399         case IPPROTO_ICMPV6 :
 400                 ip6->ip6_plen = ICMP6ERR_IPICMPHLEN;
 401                 break;
 402         default :
 403                 break;
 404         }
 405
 406         if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
 407                 char *last;
 408
 409                 last = strchr(*cpp, ',');
 410                 if (!last) {
 411                         fprintf(stderr, "tcp/udp with no source port\n");
 412                         return 1;
 413                 }
 414                 *last++ = '\0';
 415                 tcp->th_sport = htons(tx_portnum(last));
 416                 if (ip6->ip6_nxt == IPPROTO_TCP) {
 417                         tcp->th_win = htons(4096);
 418                         TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
 419                 }
 420         }
 421
 422         if (inet_pton(AF_INET6, *cpp, &ip6->ip6_src) != 1) {
 423                 fprintf(stderr, "cannot parse source address '%s'\n", *cpp);
 424                 return 1;
 425         }
 426
 427         cpp++;
 428         if (!*cpp)
 429                 return 1;
 430
 431         if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
 432                 char *last;
 433
 434                 last = strchr(*cpp, ',');
 435                 if (!last) {
 436                         fprintf(stderr, "tcp/udp with no destination port\n");
 437                         return 1;
 438                 }
 439                 *last++ = '\0';
 440                 tcp->th_dport = htons(tx_portnum(last));
 441         }
 442
 443         if (inet_pton(AF_INET6, *cpp, &ip6->ip6_dst) != 1) {
 444                 fprintf(stderr, "cannot parse destination address '%s'\n",
 445                         *cpp);
 446                 return 1;
 447         }
 448
 449         cpp++;
 450         if (ip6->ip6_nxt == IPPROTO_TCP) {
 451                 if (*cpp != NULL) {
 452                         char *s, *t;
 453
 454                         tcp->th_flags = 0;
 455                         for (s = *cpp; *s; s++)
 456                                 if ((t  = strchr(myflagset, *s)))
 457                                         tcp->th_flags |= myflags[t-myflagset];
 458                         if (tcp->th_flags)
 459                                 cpp++;
 460                 }
 461
 462                 if (tcp->th_flags & TH_URG)
 463                         tcp->th_urp = htons(1);
 464
 465                 if (*cpp && !strncasecmp(*cpp, "seq=", 4)) {
 466                         tcp->th_seq = htonl(atoi(*cpp + 4));
 467                         cpp++;
 468                 }
 469
 470                 if (*cpp && !strncasecmp(*cpp, "ack=", 4)) {
 471                         tcp->th_ack = htonl(atoi(*cpp + 4));
 472                         cpp++;
 473                 }
 474         } else if (*cpp && ip6->ip6_nxt == IPPROTO_ICMPV6) {
 475                 char *t;
 476
 477                 t = strchr(*cpp, ',');
 478                 if (t != NULL)
 479                         *t = '\0';
 480
 481                 ic6->icmp6_type = geticmptype(AF_INET6, *cpp);
 482                 if (t != NULL)
 483                         ic6->icmp6_code = atoi(t + 1);
 484
 485                 if (ic6->icmp6_type == ICMP6_ECHO_REQUEST ||
 486                     ic6->icmp6_type == ICMP6_ECHO_REPLY)
 487                         ic6->icmp6_id = htons(getpid());
 488
 489                 if (t != NULL)
 490                         *t = ',';
 491         }
 492
 493         if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
 494                 bcopy((char *)tcp, (char *)ip6 + sizeof(*ip6),
 495                         sizeof(*tcp));
 496         } else if (ip6->ip6_nxt == IPPROTO_ICMPV6) {
 497                 bcopy((char *)ic6, (char *)ip6 + sizeof(*ip6),
 498                         sizeof(*ic6));
 499         }
 500
 501         /*
 502          * Because a length of 0 == jumbo gram...
 503          */
 504         if (ip6->ip6_plen == 0) {
 505                 ip6->ip6_plen++;
 506         }
 507         ip6->ip6_plen = htons(ip6->ip6_plen);
 508         return 0;
 509 }
 510 #endif