sys/dist/ipf/netinet/ip_proxy.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 1997-2003 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  */
   8 #if defined(KERNEL) || defined(_KERNEL)
   9 # undef KERNEL
  10 # undef _KERNEL
  11 # define        KERNEL  1
  12 # define        _KERNEL 1
  13 #endif
  14 #include <sys/errno.h>
  15 #include <sys/types.h>
  16 #include <sys/param.h>
  17 #include <sys/time.h>
  18 #include <sys/file.h>
  19 #if !defined(AIX)
  20 # include <sys/fcntl.h>
  21 #endif
  22 #if !defined(_KERNEL) && !defined(__KERNEL__)
  23 # include <stdio.h>
  24 # include <string.h>
  25 # include <stdlib.h>
  26 # include <ctype.h>
  27 # define _KERNEL
  28 # ifdef __OpenBSD__
  29 struct file;
  30 # endif
  31 # include <sys/uio.h>
  32 # undef _KERNEL
  33 #endif
  34 #if !defined(linux)
  35 # include <sys/protosw.h>
  36 #endif
  37 #include <sys/socket.h>
  38 #if defined(_KERNEL)
  39 # if !defined(__NetBSD__) && !defined(sun) && !defined(__osf__) && \
  40      !defined(__OpenBSD__) && !defined(__hpux) && !defined(__sgi) && \
  41      !defined(AIX)
  42 #  include <sys/ctype.h>
  43 # endif
  44 # include <sys/systm.h>
  45 # if !defined(__SVR4) && !defined(__svr4__)
  46 #  include <sys/mbuf.h>
  47 # endif
  48 #endif
  49 #if defined(_KERNEL) && (__FreeBSD_version >= 220000)
  50 # include <sys/filio.h>
  51 # include <sys/fcntl.h>
  52 # if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM)
  53 #  include "opt_ipfilter.h"
  54 # endif
  55 #else
  56 # include <sys/ioctl.h>
  57 #endif
  58 #if defined(__SVR4) || defined(__svr4__)
  59 # include <sys/byteorder.h>
  60 # ifdef _KERNEL
  61 #  include <sys/dditypes.h>
  62 # endif
  63 # include <sys/stream.h>
  64 # include <sys/kmem.h>
  65 #endif
  66 #if __FreeBSD__ > 2
  67 # include <sys/queue.h>
  68 #endif
  69 #include <net/if.h>
  70 #ifdef sun
  71 # include <net/af.h>
  72 #endif
  73 #include <netinet/in.h>
  74 #include <netinet/in_systm.h>
  75 #include <netinet/ip.h>
  76 #ifndef linux
  77 # include <netinet/ip_var.h>
  78 #endif
  79 #include <netinet/tcp.h>
  80 #include <netinet/udp.h>
  81 #include <netinet/ip_icmp.h>
  82 #include "netinet/ip_compat.h"
  83 #include <netinet/tcpip.h>
  84 #include "netinet/ip_fil.h"
  85 #include "netinet/ip_nat.h"
  86 #include "netinet/ip_state.h"
  87 #include "netinet/ip_proxy.h"
  88 #if (__FreeBSD_version >= 300000)
  89 # include <sys/malloc.h>
  90 #endif
  91
  92 /* END OF INCLUDES */
  93
  94 #include "netinet/ip_ftp_pxy.c"
  95 #include "netinet/ip_rcmd_pxy.c"
  96 # include "netinet/ip_pptp_pxy.c"
  97 #if defined(_KERNEL)
  98 # include "netinet/ip_irc_pxy.c"
  99 # include "netinet/ip_raudio_pxy.c"
 100 # include "netinet/ip_h323_pxy.c"
 101 # include "netinet/ip_netbios_pxy.c"
 102 #endif
 103 #include "netinet/ip_ipsec_pxy.c"
 104 #include "netinet/ip_rpcb_pxy.c"
 105
 106 #if !defined(lint)
 107 #if defined(__NetBSD__)
 108 #include <sys/cdefs.h>
 109 __KERNEL_RCSID(0, "$NetBSD$");
 110 #else
 111 static const char rcsid[] = "@(#)Id: ip_proxy.c,v 2.62.2.23 2009/07/22 01:41:14 darrenr Exp";
 112 #endif
 113 #endif
 114
 115 #ifdef INET
 116 static int appr_fixseqack __P((fr_info_t *, ip_t *, ap_session_t *, int ));
 117 #endif
 118
 119 #define AP_SESS_SIZE    53
 120
 121 #if defined(_KERNEL)
 122 int             ipf_proxy_debug = 0;
 123 #else
 124 int             ipf_proxy_debug = 2;
 125 #endif
 126 ap_session_t    *ap_sess_tab[AP_SESS_SIZE];
 127 ap_session_t    *ap_sess_list = NULL;
 128 aproxy_t        *ap_proxylist = NULL;
 129 aproxy_t        ap_proxies[] = {
 130 #ifdef  IPF_FTP_PROXY
 131         { NULL, "ftp", (char)IPPROTO_TCP, 0, 0, ippr_ftp_init, ippr_ftp_fini,
 132           ippr_ftp_new, NULL, ippr_ftp_in, ippr_ftp_out, NULL, NULL },
 133 #endif
 134 #ifdef  IPF_IRC_PROXY
 135         { NULL, "irc", (char)IPPROTO_TCP, 0, 0, ippr_irc_init, ippr_irc_fini,
 136           ippr_irc_new, NULL, NULL, ippr_irc_out, NULL, NULL },
 137 #endif
 138 #ifdef  IPF_RCMD_PROXY
 139         { NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, ippr_rcmd_init, ippr_rcmd_fini,
 140           ippr_rcmd_new, NULL, ippr_rcmd_in, ippr_rcmd_out, NULL, NULL },
 141 #endif
 142 #ifdef  IPF_RAUDIO_PROXY
 143         { NULL, "raudio", (char)IPPROTO_TCP, 0, 0, ippr_raudio_init, ippr_raudio_fini,
 144           ippr_raudio_new, NULL, ippr_raudio_in, ippr_raudio_out, NULL, NULL },
 145 #endif
 146 #ifdef  IPF_MSNRPC_PROXY
 147         { NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, ippr_msnrpc_init, ippr_msnrpc_fini,
 148           ippr_msnrpc_new, NULL, ippr_msnrpc_in, ippr_msnrpc_out, NULL, NULL },
 149 #endif
 150 #ifdef  IPF_NETBIOS_PROXY
 151         { NULL, "netbios", (char)IPPROTO_UDP, 0, 0, ippr_netbios_init, ippr_netbios_fini,
 152           NULL, NULL, NULL, ippr_netbios_out, NULL, NULL },
 153 #endif
 154 #ifdef  IPF_IPSEC_PROXY
 155         { NULL, "ipsec", (char)IPPROTO_UDP, 0, 0,
 156           ippr_ipsec_init, ippr_ipsec_fini, ippr_ipsec_new, ippr_ipsec_del,
 157           ippr_ipsec_inout, ippr_ipsec_inout, ippr_ipsec_match, NULL },
 158 #endif
 159 #ifdef  IPF_PPTP_PROXY
 160         { NULL, "pptp", (char)IPPROTO_TCP, 0, 0,
 161           ippr_pptp_init, ippr_pptp_fini, ippr_pptp_new, ippr_pptp_del,
 162           ippr_pptp_inout, ippr_pptp_inout, NULL, NULL },
 163 #endif
 164 #ifdef  IPF_H323_PROXY
 165         { NULL, "h323", (char)IPPROTO_TCP, 0, 0, ippr_h323_init, ippr_h323_fini,
 166           ippr_h323_new, ippr_h323_del, ippr_h323_in, NULL, NULL, NULL },
 167         { NULL, "h245", (char)IPPROTO_TCP, 0, 0, NULL, NULL,
 168           ippr_h245_new, NULL, NULL, ippr_h245_out, NULL, NULL },
 169 #endif
 170 #ifdef  IPF_RPCB_PROXY
 171 # if 0
 172         { NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0,
 173           ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del,
 174           ippr_rpcb_in, ippr_rpcb_out, NULL, NULL },
 175 # endif
 176         { NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0,
 177           ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del,
 178           ippr_rpcb_in, ippr_rpcb_out, NULL, NULL },
 179 #endif
 180         { NULL, "", '\0', 0, 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
 181 };
 182
 183 /*
 184  * Dynamically add a new kernel proxy.  Ensure that it is unique in the
 185  * collection compiled in and dynamically added.
 186  */
 187 int appr_add(ap)
 188 aproxy_t *ap;
 189 {
 190         aproxy_t *a;
 191
 192         for (a = ap_proxies; a->apr_p; a++)
 193                 if ((a->apr_p == ap->apr_p) &&
 194                     !strncmp(a->apr_label, ap->apr_label,
 195                              sizeof(ap->apr_label))) {
 196                         if (ipf_proxy_debug > 1)
 197                                 printf("appr_add: %s/%d already present (B)\n",
 198                                        a->apr_label, a->apr_p);
 199                         return -1;
 200                 }
 201
 202         for (a = ap_proxylist; (a != NULL); a = a->apr_next)
 203                 if ((a->apr_p == ap->apr_p) &&
 204                     !strncmp(a->apr_label, ap->apr_label,
 205                              sizeof(ap->apr_label))) {
 206                         if (ipf_proxy_debug > 1)
 207                                 printf("appr_add: %s/%d already present (D)\n",
 208                                        a->apr_label, a->apr_p);
 209                         return -1;
 210                 }
 211         ap->apr_next = ap_proxylist;
 212         ap_proxylist = ap;
 213         if (ap->apr_init != NULL)
 214                 return (*ap->apr_init)();
 215         return 0;
 216 }
 217
 218
 219 /*
 220  * Check to see if the proxy this control request has come through for
 221  * exists, and if it does and it has a control function then invoke that
 222  * control function.
 223  */
 224 int appr_ctl(ctl)
 225 ap_ctl_t *ctl;
 226 {
 227         aproxy_t *a;
 228         int error;
 229
 230         a = appr_lookup(ctl->apc_p, ctl->apc_label);
 231         if (a == NULL) {
 232                 if (ipf_proxy_debug > 1)
 233                         printf("appr_ctl: can't find %s/%d\n",
 234                                 ctl->apc_label, ctl->apc_p);
 235                 error = ESRCH;
 236         } else if (a->apr_ctl == NULL) {
 237                 if (ipf_proxy_debug > 1)
 238                         printf("appr_ctl: no ctl function for %s/%d\n",
 239                                 ctl->apc_label, ctl->apc_p);
 240                 error = ENXIO;
 241         } else {
 242                 error = (*a->apr_ctl)(a, ctl);
 243                 if ((error != 0) && (ipf_proxy_debug > 1))
 244                         printf("appr_ctl: %s/%d ctl error %d\n",
 245                                 a->apr_label, a->apr_p, error);
 246         }
 247         return error;
 248 }
 249
 250
 251 /*
 252  * Delete a proxy that has been added dynamically from those available.
 253  * If it is in use, return 1 (do not destroy NOW), not in use 0 or -1
 254  * if it cannot be matched.
 255  */
 256 int appr_del(ap)
 257 aproxy_t *ap;
 258 {
 259         aproxy_t *a, **app;
 260
 261         for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next)
 262                 if (a == ap) {
 263                         a->apr_flags |= APR_DELETE;
 264                         *app = a->apr_next;
 265                         if (ap->apr_ref != 0) {
 266                                 if (ipf_proxy_debug > 2)
 267                                         printf("appr_del: orphaning %s/%d\n",
 268                                                 ap->apr_label, ap->apr_p);
 269                                 return 1;
 270                         }
 271                         return 0;
 272                 }
 273         if (ipf_proxy_debug > 1)
 274                 printf("appr_del: proxy %lx not found\n", (u_long)ap);
 275         return -1;
 276 }
 277
 278
 279 /*
 280  * Return 1 if the packet is a good match against a proxy, else 0.
 281  */
 282 int appr_ok(fin, tcp, nat)
 283 fr_info_t *fin;
 284 tcphdr_t *tcp;
 285 ipnat_t *nat;
 286 {
 287         aproxy_t *apr = nat->in_apr;
 288         u_short dport = nat->in_dport;
 289
 290         if ((apr == NULL) || (apr->apr_flags & APR_DELETE) ||
 291             (fin->fin_p != apr->apr_p))
 292                 return 0;
 293         if ((tcp == NULL) && dport)
 294                 return 0;
 295         return 1;
 296 }
 297
 298
 299 int appr_ioctl(data, cmd, mode, ctx)
 300 void * data;
 301 ioctlcmd_t cmd;
 302 int mode;
 303 void *ctx;
 304 {
 305         ap_ctl_t ctl;
 306         void *ptr;
 307         int error;
 308
 309         mode = mode;    /* LINT */
 310
 311         switch (cmd)
 312         {
 313         case SIOCPROXY :
 314                 error = BCOPYIN(data, &ctl, sizeof(ctl));
 315                 if (error != 0)
 316                         return EFAULT;
 317                 ptr = NULL;
 318
 319                 if (ctl.apc_dsize > 0) {
 320                         KMALLOCS(ptr, void *, ctl.apc_dsize);
 321                         if (ptr == NULL)
 322                                 error = ENOMEM;
 323                         else {
 324                                 error = copyinptr(ctl.apc_data, ptr,
 325                                                   ctl.apc_dsize);
 326                                 if (error == 0)
 327                                         ctl.apc_data = ptr;
 328                         }
 329                 } else {
 330                         ctl.apc_data = NULL;
 331                         error = 0;
 332                 }
 333
 334                 if (error == 0)
 335                         error = appr_ctl(&ctl);
 336
 337                 if (ptr != NULL) {
 338                         KFREES(ptr, ctl.apc_dsize);
 339                 }
 340                 break;
 341
 342         default :
 343                 error = EINVAL;
 344         }
 345         return error;
 346 }
 347
 348
 349 /*
 350  * If a proxy has a match function, call that to do extended packet
 351  * matching.
 352  */
 353 int appr_match(fin, nat)
 354 fr_info_t *fin;
 355 nat_t *nat;
 356 {
 357         aproxy_t *apr;
 358         ipnat_t *ipn;
 359         int result;
 360
 361         ipn = nat->nat_ptr;
 362         if (ipf_proxy_debug > 8)
 363                 printf("appr_match(%lx,%lx) aps %lx ptr %lx\n",
 364                         (u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
 365                         (u_long)ipn);
 366
 367         if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
 368                 if (ipf_proxy_debug > 0)
 369                         printf("appr_match: flx 0x%x (BAD|SHORT)\n",
 370                                 fin->fin_flx);
 371                 return -1;
 372         }
 373
 374         apr = ipn->in_apr;
 375         if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
 376                 if (ipf_proxy_debug > 0)
 377                         printf("appr_match:apr %lx apr_flags 0x%x\n",
 378                                 (u_long)apr, apr ? apr->apr_flags : 0);
 379                 return -1;
 380         }
 381
 382         if (apr->apr_match != NULL) {
 383                 result = (*apr->apr_match)(fin, nat->nat_aps, nat);
 384                 if (result != 0) {
 385                         if (ipf_proxy_debug > 4)
 386                                 printf("appr_match: result %d\n", result);
 387                         return -1;
 388                 }
 389         }
 390         return 0;
 391 }
 392
 393
 394 /*
 395  * Allocate a new application proxy structure and fill it in with the
 396  * relevant details.  call the init function once complete, prior to
 397  * returning.
 398  */
 399 int appr_new(fin, nat)
 400 fr_info_t *fin;
 401 nat_t *nat;
 402 {
 403         register ap_session_t *aps;
 404         aproxy_t *apr;
 405
 406         if (ipf_proxy_debug > 8)
 407                 printf("appr_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);
 408
 409         if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
 410                 if (ipf_proxy_debug > 0)
 411                         printf("appr_new: nat_ptr %lx nat_aps %lx\n",
 412                                 (u_long)nat->nat_ptr, (u_long)nat->nat_aps);
 413                 return -1;
 414         }
 415
 416         apr = nat->nat_ptr->in_apr;
 417
 418         if ((apr->apr_flags & APR_DELETE) ||
 419             (fin->fin_p != apr->apr_p)) {
 420                 if (ipf_proxy_debug > 2)
 421                         printf("appr_new: apr_flags 0x%x p %d/%d\n",
 422                                 apr->apr_flags, fin->fin_p, apr->apr_p);
 423                 return -1;
 424         }
 425
 426         KMALLOC(aps, ap_session_t *);
 427         if (!aps) {
 428                 if (ipf_proxy_debug > 0)
 429                         printf("appr_new: malloc failed (%lu)\n",
 430                                 (u_long)sizeof(ap_session_t));
 431                 return -1;
 432         }
 433
 434         bzero((char *)aps, sizeof(*aps));
 435         aps->aps_p = fin->fin_p;
 436         aps->aps_data = NULL;
 437         aps->aps_apr = apr;
 438         aps->aps_psiz = 0;
 439         if (apr->apr_new != NULL)
 440                 if ((*apr->apr_new)(fin, aps, nat) == -1) {
 441                         if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
 442                                 KFREES(aps->aps_data, aps->aps_psiz);
 443                         }
 444                         KFREE(aps);
 445                         if (ipf_proxy_debug > 2)
 446                                 printf("appr_new: new(%lx) failed\n",
 447                                         (u_long)apr->apr_new);
 448                         return -1;
 449                 }
 450         aps->aps_nat = nat;
 451         aps->aps_next = ap_sess_list;
 452         ap_sess_list = aps;
 453         nat->nat_aps = aps;
 454
 455         return 0;
 456 }
 457
 458
 459 /*
 460  * Check to see if a packet should be passed through an active proxy routine
 461  * if one has been setup for it.  We don't need to check the checksum here if
 462  * IPFILTER_CKSUM is defined because if it is, a failed check causes FI_BAD
 463  * to be set.
 464  */
 465 int appr_check(fin, nat)
 466 fr_info_t *fin;
 467 nat_t *nat;
 468 {
 469 #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
 470 # if defined(ICK_VALID)
 471         mb_t *m;
 472 # endif
 473         int dosum = 1;
 474 #endif
 475         tcphdr_t *tcp = NULL;
 476         udphdr_t *udp = NULL;
 477         ap_session_t *aps;
 478         aproxy_t *apr;
 479         ip_t *ip;
 480         short rv;
 481         int err;
 482 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
 483         u_32_t s1, s2, sd;
 484 #endif
 485
 486         if (fin->fin_flx & FI_BAD) {
 487                 if (ipf_proxy_debug > 0)
 488                         printf("appr_check: flx 0x%x (BAD)\n", fin->fin_flx);
 489                 return -1;
 490         }
 491
 492 #ifndef IPFILTER_CKSUM
 493         if ((fin->fin_out == 0) && (fr_checkl4sum(fin) == -1)) {
 494                 if (ipf_proxy_debug > 0)
 495                         printf("appr_check: l4 checksum failure %d\n",
 496                                 fin->fin_p);
 497                 if (fin->fin_p == IPPROTO_TCP)
 498                         frstats[fin->fin_out].fr_tcpbad++;
 499                 return -1;
 500         }
 501 #endif
 502
 503         aps = nat->nat_aps;
 504         if ((aps != NULL) && (aps->aps_p == fin->fin_p)) {
 505                 /*
 506                  * If there is data in this packet to be proxied then try and
 507                  * get it all into the one buffer, else drop it.
 508                  */
 509 #if defined(MENTAT) || defined(HAVE_M_PULLDOWN)
 510                 if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
 511                         if (fr_coalesce(fin) == -1) {
 512                                 if (ipf_proxy_debug > 0)
 513                                         printf("appr_check: fr_coalesce failed %x\n", fin->fin_flx);
 514                                 return -1;
 515                         }
 516 #endif
 517                 ip = fin->fin_ip;
 518
 519                 switch (fin->fin_p)
 520                 {
 521                 case IPPROTO_TCP :
 522                         tcp = (tcphdr_t *)fin->fin_dp;
 523
 524 #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_VALID)
 525                         m = fin->fin_qfm;
 526                         if (dohwcksum && (m->b_ick_flag == ICK_VALID))
 527                                 dosum = 0;
 528 #endif
 529                         /*
 530                          * Don't bother the proxy with these...or in fact,
 531                          * should we free up proxy stuff when seen?
 532                          */
 533                         if ((fin->fin_tcpf & TH_RST) != 0)
 534                                 break;
 535                         /*FALLTHROUGH*/
 536                 case IPPROTO_UDP :
 537                         udp = (udphdr_t *)fin->fin_dp;
 538                         break;
 539                 default :
 540                         break;
 541                 }
 542
 543                 apr = aps->aps_apr;
 544                 err = 0;
 545                 if (fin->fin_out != 0) {
 546                         if (apr->apr_outpkt != NULL)
 547                                 err = (*apr->apr_outpkt)(fin, aps, nat);
 548                 } else {
 549                         if (apr->apr_inpkt != NULL)
 550                                 err = (*apr->apr_inpkt)(fin, aps, nat);
 551                 }
 552
 553                 rv = APR_EXIT(err);
 554                 if (((ipf_proxy_debug > 0) && (rv != 0)) ||
 555                     (ipf_proxy_debug > 8))
 556                         printf("appr_check: out %d err %x rv %d\n",
 557                                 fin->fin_out, err, rv);
 558                 if (rv == 1)
 559                         return -1;
 560
 561                 if (rv == 2) {
 562                         appr_free(apr);
 563                         nat->nat_aps = NULL;
 564                         return -1;
 565                 }
 566
 567                 /*
 568                  * If err != 0 then the data size of the packet has changed
 569                  * so we need to recalculate the header checksums for the
 570                  * packet.
 571                  */
 572 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
 573                 if (err != 0) {
 574                         short adjlen = err & 0xffff;
 575
 576                         s1 = LONG_SUM(fin->fin_plen - adjlen);
 577                         s2 = LONG_SUM(fin->fin_plen);
 578                         CALC_SUMD(s1, s2, sd);
 579                         fix_outcksum(fin, &ip->ip_sum, sd);
 580                 }
 581 #endif
 582
 583 #ifdef INET
 584                 /*
 585                  * For TCP packets, we may need to adjust the sequence and
 586                  * acknowledgement numbers to reflect changes in size of the
 587                  * data stream.
 588                  *
 589                  * For both TCP and UDP, recalculate the layer 4 checksum,
 590                  * regardless, as we can't tell (here) if data has been
 591                  * changed or not.
 592                  */
 593                 if (tcp != NULL) {
 594                         err = appr_fixseqack(fin, ip, aps, APR_INC(err));
 595 #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
 596                         if (dosum)
 597                                 tcp->th_sum = fr_cksum(fin->fin_qfm, ip,
 598                                                        IPPROTO_TCP, tcp,
 599                                                        fin->fin_plen);
 600 #else
 601                         tcp->th_sum = fr_cksum(fin->fin_m, ip,
 602                                                IPPROTO_TCP, tcp,
 603                                                fin->fin_plen);
 604 #endif
 605                 } else if ((udp != NULL) && (udp->uh_sum != 0)) {
 606 #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
 607                         if (dosum)
 608                                 udp->uh_sum = fr_cksum(fin->fin_qfm, ip,
 609                                                        IPPROTO_UDP, udp,
 610                                                        fin->fin_plen);
 611 #else
 612                         udp->uh_sum = fr_cksum(fin->fin_m, ip,
 613                                                IPPROTO_UDP, udp,
 614                                                fin->fin_plen);
 615 #endif
 616                 }
 617 #endif
 618                 aps->aps_bytes += fin->fin_plen;
 619                 aps->aps_pkts++;
 620                 return 1;
 621         }
 622         return 0;
 623 }
 624
 625
 626 /*
 627  * Search for an proxy by the protocol it is being used with and its name.
 628  */
 629 aproxy_t *appr_lookup(pr, name)
 630 u_int pr;
 631 char *name;
 632 {
 633         aproxy_t *ap;
 634
 635         if (ipf_proxy_debug > 8)
 636                 printf("appr_lookup(%d,%s)\n", pr, name);
 637
 638         for (ap = ap_proxies; ap->apr_p; ap++)
 639                 if ((ap->apr_p == pr) &&
 640                     !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
 641                         ap->apr_ref++;
 642                         return ap;
 643                 }
 644
 645         for (ap = ap_proxylist; ap; ap = ap->apr_next)
 646                 if ((ap->apr_p == pr) &&
 647                     !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
 648                         ap->apr_ref++;
 649                         return ap;
 650                 }
 651         if (ipf_proxy_debug > 2)
 652                 printf("appr_lookup: failed for %d/%s\n", pr, name);
 653         return NULL;
 654 }
 655
 656
 657 void appr_free(ap)
 658 aproxy_t *ap;
 659 {
 660         ap->apr_ref--;
 661 }
 662
 663
 664 void aps_free(aps)
 665 ap_session_t *aps;
 666 {
 667         ap_session_t *a, **ap;
 668         aproxy_t *apr;
 669
 670         if (!aps)
 671                 return;
 672
 673         for (ap = &ap_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
 674                 if (a == aps) {
 675                         *ap = a->aps_next;
 676                         break;
 677                 }
 678
 679         apr = aps->aps_apr;
 680         if ((apr != NULL) && (apr->apr_del != NULL))
 681                 (*apr->apr_del)(aps);
 682
 683         if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
 684                 KFREES(aps->aps_data, aps->aps_psiz);
 685         KFREE(aps);
 686 }
 687
 688
 689 #ifdef INET
 690 /*
 691  * returns 2 if ack or seq number in TCP header is changed, returns 0 otherwise
 692  */
 693 static int appr_fixseqack(fin, ip, aps, inc)
 694 fr_info_t *fin;
 695 ip_t *ip;
 696 ap_session_t *aps;
 697 int inc;
 698 {
 699         int sel, ch = 0, out, nlen;
 700         u_32_t seq1, seq2;
 701         tcphdr_t *tcp;
 702         short inc2;
 703
 704         tcp = (tcphdr_t *)fin->fin_dp;
 705         out = fin->fin_out;
 706         /*
 707          * fin->fin_plen has already been adjusted by 'inc'.
 708          */
 709         nlen = fin->fin_plen;
 710         nlen -= (IP_HL(ip) << 2) + (TCP_OFF(tcp) << 2);
 711
 712         inc2 = inc;
 713         inc = (int)inc2;
 714
 715         if (out != 0) {
 716                 seq1 = (u_32_t)ntohl(tcp->th_seq);
 717                 sel = aps->aps_sel[out];
 718
 719                 /* switch to other set ? */
 720                 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
 721                     (seq1 > aps->aps_seqmin[!sel])) {
 722                         if (ipf_proxy_debug > 7)
 723                                 printf("proxy out switch set seq %d -> %d %x > %x\n",
 724                                         sel, !sel, seq1,
 725                                         aps->aps_seqmin[!sel]);
 726                         sel = aps->aps_sel[out] = !sel;
 727                 }
 728
 729                 if (aps->aps_seqoff[sel]) {
 730                         seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
 731                         if (seq1 > seq2) {
 732                                 seq2 = aps->aps_seqoff[sel];
 733                                 seq1 += seq2;
 734                                 tcp->th_seq = htonl(seq1);
 735                                 ch = 1;
 736                         }
 737                 }
 738
 739                 if (inc && (seq1 > aps->aps_seqmin[!sel])) {
 740                         aps->aps_seqmin[sel] = seq1 + nlen - 1;
 741                         aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
 742                         if (ipf_proxy_debug > 7)
 743                                 printf("proxy seq set %d at %x to %d + %d\n",
 744                                         sel, aps->aps_seqmin[sel],
 745                                         aps->aps_seqoff[sel], inc);
 746                 }
 747
 748                 /***/
 749
 750                 seq1 = ntohl(tcp->th_ack);
 751                 sel = aps->aps_sel[1 - out];
 752
 753                 /* switch to other set ? */
 754                 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
 755                     (seq1 > aps->aps_ackmin[!sel])) {
 756                         if (ipf_proxy_debug > 7)
 757                                 printf("proxy out switch set ack %d -> %d %x > %x\n",
 758                                         sel, !sel, seq1,
 759                                         aps->aps_ackmin[!sel]);
 760                         sel = aps->aps_sel[1 - out] = !sel;
 761                 }
 762
 763                 if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
 764                         seq2 = aps->aps_ackoff[sel];
 765                         tcp->th_ack = htonl(seq1 - seq2);
 766                         ch = 1;
 767                 }
 768         } else {
 769                 seq1 = ntohl(tcp->th_seq);
 770                 sel = aps->aps_sel[out];
 771
 772                 /* switch to other set ? */
 773                 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
 774                     (seq1 > aps->aps_ackmin[!sel])) {
 775                         if (ipf_proxy_debug > 7)
 776                                 printf("proxy in switch set ack %d -> %d %x > %x\n",
 777                                         sel, !sel, seq1, aps->aps_ackmin[!sel]);
 778                         sel = aps->aps_sel[out] = !sel;
 779                 }
 780
 781                 if (aps->aps_ackoff[sel]) {
 782                         seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
 783                         if (seq1 > seq2) {
 784                                 seq2 = aps->aps_ackoff[sel];
 785                                 seq1 += seq2;
 786                                 tcp->th_seq = htonl(seq1);
 787                                 ch = 1;
 788                         }
 789                 }
 790
 791                 if (inc && (seq1 > aps->aps_ackmin[!sel])) {
 792                         aps->aps_ackmin[!sel] = seq1 + nlen - 1;
 793                         aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;
 794
 795                         if (ipf_proxy_debug > 7)
 796                                 printf("proxy ack set %d at %x to %d + %d\n",
 797                                         !sel, aps->aps_seqmin[!sel],
 798                                         aps->aps_seqoff[sel], inc);
 799                 }
 800
 801                 /***/
 802
 803                 seq1 = ntohl(tcp->th_ack);
 804                 sel = aps->aps_sel[1 - out];
 805
 806                 /* switch to other set ? */
 807                 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
 808                     (seq1 > aps->aps_seqmin[!sel])) {
 809                         if (ipf_proxy_debug > 7)
 810                                 printf("proxy in switch set seq %d -> %d %x > %x\n",
 811                                         sel, !sel, seq1, aps->aps_seqmin[!sel]);
 812                         sel = aps->aps_sel[1 - out] = !sel;
 813                 }
 814
 815                 if (aps->aps_seqoff[sel] != 0) {
 816                         if (ipf_proxy_debug > 7)
 817                                 printf("sel %d seqoff %d seq1 %x seqmin %x\n",
 818                                         sel, aps->aps_seqoff[sel], seq1,
 819                                         aps->aps_seqmin[sel]);
 820                         if (seq1 > aps->aps_seqmin[sel]) {
 821                                 seq2 = aps->aps_seqoff[sel];
 822                                 tcp->th_ack = htonl(seq1 - seq2);
 823                                 ch = 1;
 824                         }
 825                 }
 826         }
 827
 828         if (ipf_proxy_debug > 8)
 829                 printf("appr_fixseqack: seq %x ack %x\n",
 830                         (u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack));
 831         return ch ? 2 : 0;
 832 }
 833 #endif
 834
 835
 836 /*
 837  * Initialise hook for kernel application proxies.
 838  * Call the initialise routine for all the compiled in kernel proxies.
 839  */
 840 int appr_init()
 841 {
 842         aproxy_t *ap;
 843         int err = 0;
 844
 845         for (ap = ap_proxies; ap->apr_p; ap++) {
 846                 if (ap->apr_init != NULL) {
 847                         err = (*ap->apr_init)();
 848                         if (err != 0)
 849                                 break;
 850                 }
 851         }
 852         return err;
 853 }
 854
 855
 856 /*
 857  * Unload hook for kernel application proxies.
 858  * Call the finialise routine for all the compiled in kernel proxies.
 859  */
 860 void appr_unload()
 861 {
 862         aproxy_t *ap;
 863
 864         for (ap = ap_proxies; ap->apr_p; ap++)
 865                 if (ap->apr_fini != NULL)
 866                         (*ap->apr_fini)();
 867         for (ap = ap_proxylist; ap; ap = ap->apr_next)
 868                 if (ap->apr_fini != NULL)
 869                         (*ap->apr_fini)();
 870 }