sys/contrib/ipfilter/netinet/ip_proxy.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 #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 #else
  53 # include <sys/ioctl.h>
  54 #endif
  55 #if defined(__SVR4) || defined(__svr4__)
  56 # include <sys/byteorder.h>
  57 # ifdef _KERNEL
  58 #  include <sys/dditypes.h>
  59 # endif
  60 # include <sys/stream.h>
  61 # include <sys/kmem.h>
  62 #endif
  63 #if __FreeBSD_version >= 300000
  64 # include <sys/queue.h>
  65 #endif
  66 #include <net/if.h>
  67 #if defined(__FreeBSD_version) && (__FreeBSD_version >= 800000) && defined(_KERNEL)
  68 #include <net/vnet.h>
  69 #else
  70 #define CURVNET_SET(arg)
  71 #define CURVNET_RESTORE()
  72 #define VNET_DEFINE(_t, _v)     _t _v
  73 #define VNET_DECLARE(_t, _v)    extern _t _v
  74 #define VNET(arg)       arg
  75 #endif
  76 #ifdef sun
  77 # include <net/af.h>
  78 #endif
  79 #include <netinet/in.h>
  80 #include <netinet/in_systm.h>
  81 #include <netinet/ip.h>
  82 #ifndef linux
  83 # include <netinet/ip_var.h>
  84 #endif
  85 #include <netinet/tcp.h>
  86 #include <netinet/udp.h>
  87 #include <netinet/ip_icmp.h>
  88 #include "netinet/ip_compat.h"
  89 #include <netinet/tcpip.h>
  90 #include "netinet/ip_fil.h"
  91 #include "netinet/ip_nat.h"
  92 #include "netinet/ip_state.h"
  93 #include "netinet/ip_proxy.h"
  94 #if (__FreeBSD_version >= 300000)
  95 # include <sys/malloc.h>
  96 #endif
  97
  98 /* END OF INCLUDES */
  99
 100 #include "netinet/ip_ftp_pxy.c"
 101 #include "netinet/ip_tftp_pxy.c"
 102 #include "netinet/ip_rcmd_pxy.c"
 103 #include "netinet/ip_pptp_pxy.c"
 104 #if defined(_KERNEL)
 105 # include "netinet/ip_irc_pxy.c"
 106 # include "netinet/ip_raudio_pxy.c"
 107 # include "netinet/ip_netbios_pxy.c"
 108 #endif
 109 #include "netinet/ip_ipsec_pxy.c"
 110 #include "netinet/ip_rpcb_pxy.c"
 111
 112 #if !defined(lint)
 113 static const char rcsid[] = "@(#)$Id$";
 114 #endif
 115
 116 #define AP_SESS_SIZE    53
 117
 118 static int ipf_proxy_fixseqack __P((fr_info_t *, ip_t *, ap_session_t *, int ));
 119 static aproxy_t *ipf_proxy_create_clone __P((ipf_main_softc_t *, aproxy_t *));
 120
 121 typedef struct ipf_proxy_softc_s {
 122         int             ips_proxy_debug;
 123         int             ips_proxy_session_size;
 124         ap_session_t    **ips_sess_tab;
 125         ap_session_t    *ips_sess_list;
 126         aproxy_t        *ips_proxies;
 127         int             ips_init_run;
 128         ipftuneable_t   *ipf_proxy_tune;
 129 } ipf_proxy_softc_t;
 130
 131 static ipftuneable_t ipf_proxy_tuneables[] = {
 132         { { (void *)offsetof(ipf_proxy_softc_t, ips_proxy_debug) },
 133                 "proxy_debug",  0,      0x1f,
 134                 stsizeof(ipf_proxy_softc_t, ips_proxy_debug),
 135                 0,      NULL,   NULL },
 136         { { NULL },             NULL,                   0,      0,
 137                 0,
 138                 0,      NULL,   NULL}
 139 };
 140
 141 static  aproxy_t        *ap_proxylist = NULL;
 142 static  aproxy_t        ips_proxies[] = {
 143 #ifdef  IPF_FTP_PROXY
 144         { NULL, NULL, "ftp", (char)IPPROTO_TCP, 0, 0, 0,
 145           ipf_p_ftp_main_load, ipf_p_ftp_main_unload,
 146           ipf_p_ftp_soft_create, ipf_p_ftp_soft_destroy,
 147           NULL, NULL,
 148           ipf_p_ftp_new, ipf_p_ftp_del, ipf_p_ftp_in, ipf_p_ftp_out, NULL,
 149           NULL, NULL, NULL, NULL },
 150 #endif
 151 #ifdef  IPF_TFTP_PROXY
 152         { NULL, NULL, "tftp", (char)IPPROTO_UDP, 0, 0, 0,
 153           ipf_p_tftp_main_load, ipf_p_tftp_main_unload,
 154           ipf_p_tftp_soft_create, ipf_p_tftp_soft_destroy,
 155           NULL, NULL,
 156           ipf_p_tftp_new, ipf_p_tftp_del,
 157           ipf_p_tftp_in, ipf_p_tftp_out, NULL,
 158           NULL, NULL, NULL, NULL },
 159 #endif
 160 #ifdef  IPF_IRC_PROXY
 161         { NULL, NULL, "irc", (char)IPPROTO_TCP, 0, 0, 0,
 162           ipf_p_irc_main_load, ipf_p_irc_main_unload,
 163           NULL, NULL,
 164           NULL, NULL,
 165           ipf_p_irc_new, NULL, NULL, ipf_p_irc_out, NULL,
 166           NULL, NULL, NULL, NULL },
 167 #endif
 168 #ifdef  IPF_RCMD_PROXY
 169         { NULL, NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, 0,
 170           ipf_p_rcmd_main_load, ipf_p_rcmd_main_unload,
 171           NULL, NULL,
 172           NULL, NULL,
 173           ipf_p_rcmd_new, ipf_p_rcmd_del,
 174           ipf_p_rcmd_in, ipf_p_rcmd_out, NULL,
 175           NULL, NULL, NULL, NULL },
 176 #endif
 177 #ifdef  IPF_RAUDIO_PROXY
 178         { NULL, NULL, "raudio", (char)IPPROTO_TCP, 0, 0, 0,
 179           ipf_p_raudio_main_load, ipf_p_raudio_main_unload,
 180           NULL, NULL,
 181           NULL, NULL,
 182           ipf_p_raudio_new, NULL, ipf_p_raudio_in, ipf_p_raudio_out, NULL,
 183           NULL, NULL, NULL, NULL },
 184 #endif
 185 #ifdef  IPF_MSNRPC_PROXY
 186         { NULL, NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, 0,
 187           ipf_p_msnrpc_init, ipf_p_msnrpc_fini,
 188           NULL, NULL,
 189           NULL, NULL,
 190           ipf_p_msnrpc_new, NULL, ipf_p_msnrpc_in, ipf_p_msnrpc_out, NULL,
 191           NULL, NULL, NULL, NULL },
 192 #endif
 193 #ifdef  IPF_NETBIOS_PROXY
 194         { NULL, NULL, "netbios", (char)IPPROTO_UDP, 0, 0, 0,
 195           ipf_p_netbios_main_load, ipf_p_netbios_main_unload,
 196           NULL, NULL,
 197           NULL, NULL,
 198           NULL, NULL, NULL, ipf_p_netbios_out, NULL,
 199           NULL, NULL, NULL, NULL },
 200 #endif
 201 #ifdef  IPF_IPSEC_PROXY
 202         { NULL, NULL, "ipsec", (char)IPPROTO_UDP, 0, 0, 0,
 203           NULL, NULL,
 204           ipf_p_ipsec_soft_create, ipf_p_ipsec_soft_destroy,
 205           ipf_p_ipsec_soft_init, ipf_p_ipsec_soft_fini,
 206           ipf_p_ipsec_new, ipf_p_ipsec_del,
 207           ipf_p_ipsec_inout, ipf_p_ipsec_inout, ipf_p_ipsec_match,
 208           NULL, NULL, NULL, NULL },
 209 #endif
 210 #ifdef  IPF_DNS_PROXY
 211         { NULL, NULL, "dns", (char)IPPROTO_UDP, 0, 0, 0,
 212           NULL, NULL,
 213           ipf_p_dns_soft_create, ipf_p_dns_soft_destroy,
 214           NULL, NULL,
 215           ipf_p_dns_new, ipf_p_ipsec_del,
 216           ipf_p_dns_inout, ipf_p_dns_inout, ipf_p_dns_match,
 217           ipf_p_dns_ctl, NULL, NULL, NULL },
 218 #endif
 219 #ifdef  IPF_PPTP_PROXY
 220         { NULL, NULL, "pptp", (char)IPPROTO_TCP, 0, 0, 0,
 221           ipf_p_pptp_main_load, ipf_p_pptp_main_unload,
 222           NULL, NULL,
 223           NULL, NULL,
 224           ipf_p_pptp_new, ipf_p_pptp_del,
 225           ipf_p_pptp_inout, ipf_p_pptp_inout, NULL,
 226           NULL, NULL, NULL, NULL },
 227 #endif
 228 #ifdef  IPF_RPCB_PROXY
 229 # ifndef _KERNEL
 230         { NULL, NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0, 0,
 231           NULL, NULL,
 232           NULL, NULL,
 233           NULL, NULL,
 234           ipf_p_rpcb_new, ipf_p_rpcb_del,
 235           ipf_p_rpcb_in, ipf_p_rpcb_out, NULL,
 236           NULL, NULL, NULL, NULL },
 237 # endif
 238         { NULL, NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0, 0,
 239           ipf_p_rpcb_main_load, ipf_p_rpcb_main_unload,
 240           NULL, NULL,
 241           NULL, NULL,
 242           ipf_p_rpcb_new, ipf_p_rpcb_del,
 243           ipf_p_rpcb_in, ipf_p_rpcb_out, NULL,
 244           NULL, NULL, NULL, NULL },
 245 #endif
 246         { NULL, NULL, "", '\0', 0, 0, 0,
 247           NULL, NULL,
 248           NULL, NULL,
 249           NULL, NULL,
 250           NULL, NULL,
 251           NULL, NULL, NULL,
 252           NULL, NULL, NULL, NULL }
 253 };
 254
 255
 256 /* ------------------------------------------------------------------------ */
 257 /* Function:    ipf_proxy_main_load                                         */
 258 /* Returns:     int    - 0 == success, else failure.                        */
 259 /* Parameters:  Nil                                                         */
 260 /*                                                                          */
 261 /* Initialise hook for kernel application proxies.                          */
 262 /* Call the initialise routine for all the compiled in kernel proxies.      */
 263 /* ------------------------------------------------------------------------ */
 264 int
 265 ipf_proxy_main_load()
 266 {
 267         aproxy_t *ap;
 268
 269         for (ap = ips_proxies; ap->apr_p; ap++) {
 270                 if (ap->apr_load != NULL)
 271                         (*ap->apr_load)();
 272         }
 273         return 0;
 274 }
 275
 276
 277 /* ------------------------------------------------------------------------ */
 278 /* Function:    ipf_proxy_main_unload                                       */
 279 /* Returns:     int - 0 == success, else failure.                           */
 280 /* Parameters:  Nil                                                         */
 281 /*                                                                          */
 282 /* Unload hook for kernel application proxies.                              */
 283 /* Call the finialise routine for all the compiled in kernel proxies.       */
 284 /* ------------------------------------------------------------------------ */
 285 int
 286 ipf_proxy_main_unload()
 287 {
 288         aproxy_t *ap;
 289
 290         for (ap = ips_proxies; ap->apr_p; ap++)
 291                 if (ap->apr_unload != NULL)
 292                         (*ap->apr_unload)();
 293         for (ap = ap_proxylist; ap; ap = ap->apr_next)
 294                 if (ap->apr_unload != NULL)
 295                         (*ap->apr_unload)();
 296
 297         return 0;
 298 }
 299
 300
 301 /* ------------------------------------------------------------------------ */
 302 /* Function:    ipf_proxy_soft_create                                       */
 303 /* Returns:     void *   -                                                  */
 304 /* Parameters:  softc(I) - pointer to soft context main structure           */
 305 /*                                                                          */
 306 /* Build the structure to hold all of the run time data to support proxies. */
 307 /* ------------------------------------------------------------------------ */
 308 void *
 309 ipf_proxy_soft_create(softc)
 310         ipf_main_softc_t *softc;
 311 {
 312         ipf_proxy_softc_t *softp;
 313         aproxy_t *last;
 314         aproxy_t *apn;
 315         aproxy_t *ap;
 316
 317         KMALLOC(softp, ipf_proxy_softc_t *);
 318         if (softp == NULL)
 319                 return softp;
 320
 321         bzero((char *)softp, sizeof(*softp));
 322
 323 #if defined(_KERNEL)
 324         softp->ips_proxy_debug = 0;
 325 #else
 326         softp->ips_proxy_debug = 2;
 327 #endif
 328         softp->ips_proxy_session_size = AP_SESS_SIZE;
 329
 330         softp->ipf_proxy_tune = ipf_tune_array_copy(softp,
 331                                                     sizeof(ipf_proxy_tuneables),
 332                                                     ipf_proxy_tuneables);
 333         if (softp->ipf_proxy_tune == NULL) {
 334                 ipf_proxy_soft_destroy(softc, softp);
 335                 return NULL;
 336         }
 337         if (ipf_tune_array_link(softc, softp->ipf_proxy_tune) == -1) {
 338                 ipf_proxy_soft_destroy(softc, softp);
 339                 return NULL;
 340         }
 341
 342         last = NULL;
 343         for (ap = ips_proxies; ap->apr_p; ap++) {
 344                 apn = ipf_proxy_create_clone(softc, ap);
 345                 if (apn == NULL)
 346                         goto failed;
 347                 if (last != NULL)
 348                         last->apr_next = apn;
 349                 else
 350                         softp->ips_proxies = apn;
 351                 last = apn;
 352         }
 353         for (ap = ips_proxies; ap != NULL; ap = ap->apr_next) {
 354                 apn = ipf_proxy_create_clone(softc, ap);
 355                 if (apn == NULL)
 356                         goto failed;
 357                 if (last != NULL)
 358                         last->apr_next = apn;
 359                 else
 360                         softp->ips_proxies = apn;
 361                 last = apn;
 362         }
 363
 364         return softp;
 365 failed:
 366         ipf_proxy_soft_destroy(softc, softp);
 367         return NULL;
 368 }
 369
 370
 371 /* ------------------------------------------------------------------------ */
 372 /* Function:    ipf_proxy_soft_create                                       */
 373 /* Returns:     void *   -                                                  */
 374 /* Parameters:  softc(I) - pointer to soft context main structure           */
 375 /*              orig(I)  - pointer to proxy definition to copy              */
 376 /*                                                                          */
 377 /* This function clones a proxy definition given by orig and returns a      */
 378 /* a pointer to that copy.                                                  */
 379 /* ------------------------------------------------------------------------ */
 380 static aproxy_t *
 381 ipf_proxy_create_clone(softc, orig)
 382         ipf_main_softc_t *softc;
 383         aproxy_t *orig;
 384 {
 385         aproxy_t *apn;
 386
 387         KMALLOC(apn, aproxy_t *);
 388         if (apn == NULL)
 389                 return NULL;
 390
 391         bcopy((char *)orig, (char *)apn, sizeof(*apn));
 392         apn->apr_next = NULL;
 393         apn->apr_soft = NULL;
 394
 395         if (apn->apr_create != NULL) {
 396                 apn->apr_soft = (*apn->apr_create)(softc);
 397                 if (apn->apr_soft == NULL) {
 398                         KFREE(apn);
 399                         return NULL;
 400                 }
 401         }
 402
 403         apn->apr_parent = orig;
 404         orig->apr_clones++;
 405
 406         return apn;
 407 }
 408
 409
 410 /* ------------------------------------------------------------------------ */
 411 /* Function:    ipf_proxy_soft_create                                       */
 412 /* Returns:     int      - 0 == success, else failure.                      */
 413 /* Parameters:  softc(I) - pointer to soft context main structure           */
 414 /*              arg(I)   - pointer to proxy contect data                    */
 415 /*                                                                          */
 416 /* Initialise the proxy context and walk through each of the proxies and    */
 417 /* call its initialisation function. This allows for proxies to do any      */
 418 /* local setup prior to actual use.                                         */
 419 /* ------------------------------------------------------------------------ */
 420 int
 421 ipf_proxy_soft_init(softc, arg)
 422         ipf_main_softc_t *softc;
 423         void *arg;
 424 {
 425         ipf_proxy_softc_t *softp;
 426         aproxy_t *ap;
 427         u_int size;
 428         int err;
 429
 430         softp = arg;
 431         size = softp->ips_proxy_session_size * sizeof(ap_session_t *);
 432
 433         KMALLOCS(softp->ips_sess_tab, ap_session_t **, size);
 434
 435         if (softp->ips_sess_tab == NULL)
 436                 return -1;
 437
 438         bzero(softp->ips_sess_tab, size);
 439
 440         for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) {
 441                 if (ap->apr_init != NULL) {
 442                         err = (*ap->apr_init)(softc, ap->apr_soft);
 443                         if (err != 0)
 444                                 return -2;
 445                 }
 446         }
 447         softp->ips_init_run = 1;
 448
 449         return 0;
 450 }
 451
 452
 453 /* ------------------------------------------------------------------------ */
 454 /* Function:    ipf_proxy_soft_create                                       */
 455 /* Returns:     int      - 0 == success, else failure.                      */
 456 /* Parameters:  softc(I) - pointer to soft context main structure           */
 457 /*              arg(I)   - pointer to proxy contect data                    */
 458 /*                                                                          */
 459 /* This function should always succeed. It is responsible for ensuring that */
 460 /* the proxy context can be safely called when ipf_proxy_soft_destroy is    */
 461 /* called and suring all of the proxies have similarly been instructed.     */
 462 /* ------------------------------------------------------------------------ */
 463 int
 464 ipf_proxy_soft_fini(softc, arg)
 465         ipf_main_softc_t *softc;
 466         void *arg;
 467 {
 468         ipf_proxy_softc_t *softp = arg;
 469         aproxy_t *ap;
 470
 471         for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) {
 472                 if (ap->apr_fini != NULL) {
 473                         (*ap->apr_fini)(softc, ap->apr_soft);
 474                 }
 475         }
 476
 477         if (softp->ips_sess_tab != NULL) {
 478                 KFREES(softp->ips_sess_tab,
 479                        softp->ips_proxy_session_size * sizeof(ap_session_t *));
 480                 softp->ips_sess_tab = NULL;
 481         }
 482         softp->ips_init_run = 0;
 483
 484         return 0;
 485 }
 486
 487
 488 /* ------------------------------------------------------------------------ */
 489 /* Function:    ipf_proxy_soft_destroy                                      */
 490 /* Returns:     Nil                                                         */
 491 /* Parameters:  softc(I) - pointer to soft context main structure           */
 492 /*              arg(I)   - pointer to proxy contect data                    */
 493 /*                                                                          */
 494 /* Free up all of the local data structures allocated during creation.      */
 495 /* ------------------------------------------------------------------------ */
 496 void
 497 ipf_proxy_soft_destroy(softc, arg)
 498         ipf_main_softc_t *softc;
 499         void *arg;
 500 {
 501         ipf_proxy_softc_t *softp = arg;
 502         aproxy_t *ap;
 503
 504         while ((ap = softp->ips_proxies) != NULL) {
 505                 softp->ips_proxies = ap->apr_next;
 506                 if (ap->apr_destroy != NULL)
 507                         (*ap->apr_destroy)(softc, ap->apr_soft);
 508                 ap->apr_parent->apr_clones--;
 509                 KFREE(ap);
 510         }
 511
 512         if (softp->ipf_proxy_tune != NULL) {
 513                 ipf_tune_array_unlink(softc, softp->ipf_proxy_tune);
 514                 KFREES(softp->ipf_proxy_tune, sizeof(ipf_proxy_tuneables));
 515                 softp->ipf_proxy_tune = NULL;
 516         }
 517
 518         KFREE(softp);
 519 }
 520
 521
 522 /* ------------------------------------------------------------------------ */
 523 /* Function:    ipf_proxy_flush                                             */
 524 /* Returns:     Nil                                                         */
 525 /* Parameters:  arg(I)   - pointer to proxy contect data                    */
 526 /*              how(I)   - indicates the type of flush operation            */
 527 /*                                                                          */
 528 /* Walk through all of the proxies and pass on the flush command as either  */
 529 /* a flush or a clear.                                                      */
 530 /* ------------------------------------------------------------------------ */
 531 void
 532 ipf_proxy_flush(arg, how)
 533         void *arg;
 534         int how;
 535 {
 536         ipf_proxy_softc_t *softp = arg;
 537         aproxy_t *ap;
 538
 539         switch (how)
 540         {
 541         case 0 :
 542                 for (ap = softp->ips_proxies; ap; ap = ap->apr_next)
 543                         if (ap->apr_flush != NULL)
 544                                 (*ap->apr_flush)(ap, how);
 545                 break;
 546         case 1 :
 547                 for (ap = softp->ips_proxies; ap; ap = ap->apr_next)
 548                         if (ap->apr_clear != NULL)
 549                                 (*ap->apr_clear)(ap);
 550                 break;
 551         default :
 552                 break;
 553         }
 554 }
 555
 556
 557 /* ------------------------------------------------------------------------ */
 558 /* Function:    ipf_proxy_add                                               */
 559 /* Returns:     int   - 0 == success, else failure.                         */
 560 /* Parameters:  ap(I) - pointer to proxy structure                          */
 561 /*                                                                          */
 562 /* Dynamically add a new kernel proxy.  Ensure that it is unique in the     */
 563 /* collection compiled in and dynamically added.                            */
 564 /* ------------------------------------------------------------------------ */
 565 int
 566 ipf_proxy_add(arg, ap)
 567         void *arg;
 568         aproxy_t *ap;
 569 {
 570         ipf_proxy_softc_t *softp = arg;
 571
 572         aproxy_t *a;
 573
 574         for (a = ips_proxies; a->apr_p; a++)
 575                 if ((a->apr_p == ap->apr_p) &&
 576                     !strncmp(a->apr_label, ap->apr_label,
 577                              sizeof(ap->apr_label))) {
 578                         if (softp->ips_proxy_debug & 0x01)
 579                                 printf("ipf_proxy_add: %s/%d present (B)\n",
 580                                        a->apr_label, a->apr_p);
 581                         return -1;
 582                 }
 583
 584         for (a = ap_proxylist; (a != NULL); a = a->apr_next)
 585                 if ((a->apr_p == ap->apr_p) &&
 586                     !strncmp(a->apr_label, ap->apr_label,
 587                              sizeof(ap->apr_label))) {
 588                         if (softp->ips_proxy_debug & 0x01)
 589                                 printf("ipf_proxy_add: %s/%d present (D)\n",
 590                                        a->apr_label, a->apr_p);
 591                         return -1;
 592                 }
 593         ap->apr_next = ap_proxylist;
 594         ap_proxylist = ap;
 595         if (ap->apr_load != NULL)
 596                 (*ap->apr_load)();
 597         return 0;
 598 }
 599
 600
 601 /* ------------------------------------------------------------------------ */
 602 /* Function:    ipf_proxy_ctl                                               */
 603 /* Returns:     int    - 0 == success, else error                           */
 604 /* Parameters:  softc(I) - pointer to soft context main structure           */
 605 /*              arg(I)   - pointer to proxy context                         */
 606 /*              ctl(I)   - pointer to proxy control structure               */
 607 /*                                                                          */
 608 /* Check to see if the proxy this control request has come through for      */
 609 /* exists, and if it does and it has a control function then invoke that    */
 610 /* control function.                                                        */
 611 /* ------------------------------------------------------------------------ */
 612 int
 613 ipf_proxy_ctl(softc, arg, ctl)
 614         ipf_main_softc_t *softc;
 615         void *arg;
 616         ap_ctl_t *ctl;
 617 {
 618         ipf_proxy_softc_t *softp = arg;
 619         aproxy_t *a;
 620         int error;
 621
 622         a = ipf_proxy_lookup(arg, ctl->apc_p, ctl->apc_label);
 623         if (a == NULL) {
 624                 if (softp->ips_proxy_debug & 0x01)
 625                         printf("ipf_proxy_ctl: can't find %s/%d\n",
 626                                 ctl->apc_label, ctl->apc_p);
 627                 IPFERROR(80001);
 628                 error = ESRCH;
 629         } else if (a->apr_ctl == NULL) {
 630                 if (softp->ips_proxy_debug & 0x01)
 631                         printf("ipf_proxy_ctl: no ctl function for %s/%d\n",
 632                                 ctl->apc_label, ctl->apc_p);
 633                 IPFERROR(80002);
 634                 error = ENXIO;
 635         } else {
 636                 error = (*a->apr_ctl)(softc, a->apr_soft, ctl);
 637                 if ((error != 0) && (softp->ips_proxy_debug & 0x02))
 638                         printf("ipf_proxy_ctl: %s/%d ctl error %d\n",
 639                                 a->apr_label, a->apr_p, error);
 640         }
 641         return error;
 642 }
 643
 644
 645 /* ------------------------------------------------------------------------ */
 646 /* Function:    ipf_proxy_del                                               */
 647 /* Returns:     int   - 0 == success, else failure.                         */
 648 /* Parameters:  ap(I) - pointer to proxy structure                          */
 649 /*                                                                          */
 650 /* Delete a proxy that has been added dynamically from those available.     */
 651 /* If it is in use, return 1 (do not destroy NOW), not in use 0 or -1       */
 652 /* if it cannot be matched.                                                 */
 653 /* ------------------------------------------------------------------------ */
 654 int
 655 ipf_proxy_del(ap)
 656         aproxy_t *ap;
 657 {
 658         aproxy_t *a, **app;
 659
 660         for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next) {
 661                 if (a == ap) {
 662                         a->apr_flags |= APR_DELETE;
 663                         if (ap->apr_ref == 0 && ap->apr_clones == 0) {
 664                                 *app = a->apr_next;
 665                                 return 0;
 666                         }
 667                         return 1;
 668                 }
 669         }
 670
 671         return -1;
 672 }
 673
 674
 675 /* ------------------------------------------------------------------------ */
 676 /* Function:    ipf_proxy_ok                                                */
 677 /* Returns:     int    - 1 == good match else not.                          */
 678 /* Parameters:  fin(I) - pointer to packet information                      */
 679 /*              tcp(I) - pointer to TCP/UDP header                          */
 680 /*              nat(I) - pointer to current NAT session                     */
 681 /*                                                                          */
 682 /* This function extends the NAT matching to ensure that a packet that has  */
 683 /* arrived matches the proxy information attached to the NAT rule. Notably, */
 684 /* if the proxy is scheduled to be deleted then packets will not match the  */
 685 /* rule even if the rule is still active.                                   */
 686 /* ------------------------------------------------------------------------ */
 687 int
 688 ipf_proxy_ok(fin, tcp, np)
 689         fr_info_t *fin;
 690         tcphdr_t *tcp;
 691         ipnat_t *np;
 692 {
 693         aproxy_t *apr = np->in_apr;
 694         u_short dport = np->in_odport;
 695
 696         if ((apr == NULL) || (apr->apr_flags & APR_DELETE) ||
 697             (fin->fin_p != apr->apr_p))
 698                 return 0;
 699         if ((tcp == NULL) && dport)
 700                 return 0;
 701         return 1;
 702 }
 703
 704
 705 /* ------------------------------------------------------------------------ */
 706 /* Function:    ipf_proxy_ioctl                                             */
 707 /* Returns:     int    - 0 == success, else error                           */
 708 /* Parameters:  softc(I) - pointer to soft context main structure           */
 709 /*              data(I)  - pointer to ioctl data                            */
 710 /*              cmd(I)   - ioctl command                                    */
 711 /*              mode(I)  - mode bits for device                             */
 712 /*              ctx(I)   - pointer to context information                   */
 713 /*                                                                          */
 714 /* ------------------------------------------------------------------------ */
 715 int
 716 ipf_proxy_ioctl(softc, data, cmd, mode, ctx)
 717         ipf_main_softc_t *softc;
 718         caddr_t data;
 719         ioctlcmd_t cmd;
 720         int mode;
 721         void *ctx;
 722 {
 723         ap_ctl_t ctl;
 724         caddr_t ptr;
 725         int error;
 726
 727         mode = mode;    /* LINT */
 728
 729         switch (cmd)
 730         {
 731         case SIOCPROXY :
 732                 error = ipf_inobj(softc, data, NULL, &ctl, IPFOBJ_PROXYCTL);
 733                 if (error != 0) {
 734                         return error;
 735                 }
 736                 ptr = NULL;
 737
 738                 if (ctl.apc_dsize > 0) {
 739                         KMALLOCS(ptr, caddr_t, ctl.apc_dsize);
 740                         if (ptr == NULL) {
 741                                 IPFERROR(80003);
 742                                 error = ENOMEM;
 743                         } else {
 744                                 error = copyinptr(softc, ctl.apc_data, ptr,
 745                                                   ctl.apc_dsize);
 746                                 if (error == 0)
 747                                         ctl.apc_data = ptr;
 748                         }
 749                 } else {
 750                         ctl.apc_data = NULL;
 751                         error = 0;
 752                 }
 753
 754                 if (error == 0)
 755                         error = ipf_proxy_ctl(softc, softc->ipf_proxy_soft,
 756                                               &ctl);
 757
 758                 if ((error != 0) && (ptr != NULL)) {
 759                         KFREES(ptr, ctl.apc_dsize);
 760                 }
 761                 break;
 762
 763         default :
 764                 IPFERROR(80004);
 765                 error = EINVAL;
 766         }
 767         return error;
 768 }
 769
 770
 771 /* ------------------------------------------------------------------------ */
 772 /* Function:    ipf_proxy_match                                             */
 773 /* Returns:     int    - 0 == success, else error                           */
 774 /* Parameters:  fin(I) - pointer to packet information                      */
 775 /*              nat(I) - pointer to current NAT session                     */
 776 /*                                                                          */
 777 /* If a proxy has a match function, call that to do extended packet         */
 778 /* matching. Whilst other parts of the NAT code are rather lenient when it  */
 779 /* comes to the quality of the packet that it will transform, the proxy     */
 780 /* matching is not because they need to work with data, not just headers.   */
 781 /* ------------------------------------------------------------------------ */
 782 int
 783 ipf_proxy_match(fin, nat)
 784         fr_info_t *fin;
 785         nat_t *nat;
 786 {
 787         ipf_main_softc_t *softc = fin->fin_main_soft;
 788         ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
 789         aproxy_t *apr;
 790         ipnat_t *ipn;
 791         int result;
 792
 793         ipn = nat->nat_ptr;
 794         if (softp->ips_proxy_debug & 0x04)
 795                 printf("ipf_proxy_match(%lx,%lx) aps %lx ptr %lx\n",
 796                         (u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
 797                         (u_long)ipn);
 798
 799         if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
 800                 if (softp->ips_proxy_debug & 0x08)
 801                         printf("ipf_proxy_match: flx 0x%x (BAD|SHORT)\n",
 802                                 fin->fin_flx);
 803                 return -1;
 804         }
 805
 806         apr = ipn->in_apr;
 807         if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
 808                 if (softp->ips_proxy_debug & 0x08)
 809                         printf("ipf_proxy_match:apr %lx apr_flags 0x%x\n",
 810                                 (u_long)apr, apr ? apr->apr_flags : 0);
 811                 return -1;
 812         }
 813
 814         if (apr->apr_match != NULL) {
 815                 result = (*apr->apr_match)(fin, nat->nat_aps, nat);
 816                 if (result != 0) {
 817                         if (softp->ips_proxy_debug & 0x08)
 818                                 printf("ipf_proxy_match: result %d\n", result);
 819                         return -1;
 820                 }
 821         }
 822         return 0;
 823 }
 824
 825
 826 /* ------------------------------------------------------------------------ */
 827 /* Function:    ipf_proxy_new                                               */
 828 /* Returns:     int    - 0 == success, else error                           */
 829 /* Parameters:  fin(I) - pointer to packet information                      */
 830 /*              nat(I) - pointer to current NAT session                     */
 831 /*                                                                          */
 832 /* Allocate a new application proxy structure and fill it in with the       */
 833 /* relevant details.  call the init function once complete, prior to        */
 834 /* returning.                                                               */
 835 /* ------------------------------------------------------------------------ */
 836 int
 837 ipf_proxy_new(fin, nat)
 838         fr_info_t *fin;
 839         nat_t *nat;
 840 {
 841         ipf_main_softc_t *softc = fin->fin_main_soft;
 842         ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
 843         register ap_session_t *aps;
 844         aproxy_t *apr;
 845
 846         if (softp->ips_proxy_debug & 0x04)
 847                 printf("ipf_proxy_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);
 848
 849         if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
 850                 if (softp->ips_proxy_debug & 0x08)
 851                         printf("ipf_proxy_new: nat_ptr %lx nat_aps %lx\n",
 852                                 (u_long)nat->nat_ptr, (u_long)nat->nat_aps);
 853                 return -1;
 854         }
 855
 856         apr = nat->nat_ptr->in_apr;
 857
 858         if ((apr->apr_flags & APR_DELETE) ||
 859             (fin->fin_p != apr->apr_p)) {
 860                 if (softp->ips_proxy_debug & 0x08)
 861                         printf("ipf_proxy_new: apr_flags 0x%x p %d/%d\n",
 862                                 apr->apr_flags, fin->fin_p, apr->apr_p);
 863                 return -1;
 864         }
 865
 866         KMALLOC(aps, ap_session_t *);
 867         if (!aps) {
 868                 if (softp->ips_proxy_debug & 0x08)
 869                         printf("ipf_proxy_new: malloc failed (%lu)\n",
 870                                 (u_long)sizeof(ap_session_t));
 871                 return -1;
 872         }
 873
 874         bzero((char *)aps, sizeof(*aps));
 875         aps->aps_data = NULL;
 876         aps->aps_apr = apr;
 877         aps->aps_psiz = 0;
 878         if (apr->apr_new != NULL)
 879                 if ((*apr->apr_new)(apr->apr_soft, fin, aps, nat) == -1) {
 880                         if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
 881                                 KFREES(aps->aps_data, aps->aps_psiz);
 882                         }
 883                         KFREE(aps);
 884                         if (softp->ips_proxy_debug & 0x08)
 885                                 printf("ipf_proxy_new: new(%lx) failed\n",
 886                                         (u_long)apr->apr_new);
 887                         return -1;
 888                 }
 889         aps->aps_nat = nat;
 890         aps->aps_next = softp->ips_sess_list;
 891         softp->ips_sess_list = aps;
 892         nat->nat_aps = aps;
 893
 894         return 0;
 895 }
 896
 897
 898 /* ------------------------------------------------------------------------ */
 899 /* Function:    ipf_proxy_check                                             */
 900 /* Returns:     int - -1 == error, 0 == success                             */
 901 /* Parameters:  fin(I) - pointer to packet information                      */
 902 /*              nat(I) - pointer to current NAT session                     */
 903 /*                                                                          */
 904 /* Check to see if a packet should be passed through an active proxy        */
 905 /* routine if one has been setup for it.  We don't need to check the        */
 906 /* checksum here if IPFILTER_CKSUM is defined because if it is, a failed    */
 907 /* check causes FI_BAD to be set.                                           */
 908 /* ------------------------------------------------------------------------ */
 909 int
 910 ipf_proxy_check(fin, nat)
 911         fr_info_t *fin;
 912         nat_t *nat;
 913 {
 914         ipf_main_softc_t *softc = fin->fin_main_soft;
 915         ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
 916 #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
 917         mb_t *m;
 918 #endif
 919         tcphdr_t *tcp = NULL;
 920         udphdr_t *udp = NULL;
 921         ap_session_t *aps;
 922         aproxy_t *apr;
 923         short adjlen;
 924         int dosum;
 925         ip_t *ip;
 926         short rv;
 927         int err;
 928 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
 929         u_32_t s1, s2, sd;
 930 #endif
 931
 932         if (fin->fin_flx & FI_BAD) {
 933                 if (softp->ips_proxy_debug & 0x08)
 934                         printf("ipf_proxy_check: flx 0x%x (BAD)\n",
 935                                fin->fin_flx);
 936                 return -1;
 937         }
 938
 939 #ifndef IPFILTER_CKSUM
 940         if ((fin->fin_out == 0) && (ipf_checkl4sum(fin) == -1)) {
 941                 if (softp->ips_proxy_debug & 0x08)
 942                         printf("ipf_proxy_check: l4 checksum failure %d\n",
 943                                 fin->fin_p);
 944                 if (fin->fin_p == IPPROTO_TCP)
 945                         softc->ipf_stats[fin->fin_out].fr_tcpbad++;
 946                 return -1;
 947         }
 948 #endif
 949
 950         aps = nat->nat_aps;
 951         if (aps != NULL) {
 952                 /*
 953                  * If there is data in this packet to be proxied then try and
 954                  * get it all into the one buffer, else drop it.
 955                  */
 956 #if defined(MENTAT) || defined(HAVE_M_PULLDOWN)
 957                 if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
 958                         if (ipf_coalesce(fin) == -1) {
 959                                 if (softp->ips_proxy_debug & 0x08)
 960                                         printf("ipf_proxy_check: %s %x\n",
 961                                                "coalesce failed", fin->fin_flx);
 962                                 return -1;
 963                         }
 964 #endif
 965                 ip = fin->fin_ip;
 966                 if (fin->fin_cksum > FI_CK_SUMOK)
 967                         dosum = 0;
 968                 else
 969                         dosum = 1;
 970
 971                 switch (fin->fin_p)
 972                 {
 973                 case IPPROTO_TCP :
 974                         tcp = (tcphdr_t *)fin->fin_dp;
 975 #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
 976                         m = fin->fin_qfm;
 977                         if (dohwcksum && (m->b_ick_flag == ICK_VALID))
 978                                 dosum = 0;
 979 #endif
 980                         break;
 981                 case IPPROTO_UDP :
 982                         udp = (udphdr_t *)fin->fin_dp;
 983                         break;
 984                 default :
 985                         break;
 986                 }
 987
 988                 apr = aps->aps_apr;
 989                 err = 0;
 990                 if (fin->fin_out != 0) {
 991                         if (apr->apr_outpkt != NULL)
 992                                 err = (*apr->apr_outpkt)(apr->apr_soft, fin,
 993                                                          aps, nat);
 994                 } else {
 995                         if (apr->apr_inpkt != NULL)
 996                                 err = (*apr->apr_inpkt)(apr->apr_soft, fin,
 997                                                         aps, nat);
 998                 }
 999
1000                 rv = APR_EXIT(err);
1001                 if (((softp->ips_proxy_debug & 0x08) && (rv != 0)) ||
1002                     (softp->ips_proxy_debug & 0x04))
1003                         printf("ipf_proxy_check: out %d err %x rv %d\n",
1004                                 fin->fin_out, err, rv);
1005                 if (rv == 1)
1006                         return -1;
1007
1008                 if (rv == 2) {
1009                         ipf_proxy_deref(apr);
1010                         nat->nat_aps = NULL;
1011                         return -1;
1012                 }
1013
1014                 /*
1015                  * If err != 0 then the data size of the packet has changed
1016                  * so we need to recalculate the header checksums for the
1017                  * packet.
1018                  */
1019                 adjlen = APR_INC(err);
1020 #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
1021                 s1 = LONG_SUM(fin->fin_plen - adjlen);
1022                 s2 = LONG_SUM(fin->fin_plen);
1023                 CALC_SUMD(s1, s2, sd);
1024                 if ((err != 0) && (fin->fin_cksum < FI_CK_L4PART) &&
1025                     fin->fin_v == 4)
1026                         ipf_fix_outcksum(0, &ip->ip_sum, sd, 0);
1027 #endif
1028                 if (fin->fin_flx & FI_DOCKSUM)
1029                         dosum = 1;
1030
1031                 /*
1032                  * For TCP packets, we may need to adjust the sequence and
1033                  * acknowledgement numbers to reflect changes in size of the
1034                  * data stream.
1035                  *
1036                  * For both TCP and UDP, recalculate the layer 4 checksum,
1037                  * regardless, as we can't tell (here) if data has been
1038                  * changed or not.
1039                  */
1040                 if (tcp != NULL) {
1041                         err = ipf_proxy_fixseqack(fin, ip, aps, adjlen);
1042                         if (fin->fin_cksum == FI_CK_L4PART) {
1043                                 u_short sum = ntohs(tcp->th_sum);
1044                                 sum += adjlen;
1045                                 tcp->th_sum = htons(sum);
1046                         } else if (fin->fin_cksum < FI_CK_L4PART) {
1047                                 tcp->th_sum = fr_cksum(fin, ip,
1048                                                        IPPROTO_TCP, tcp);
1049                         }
1050                 } else if ((udp != NULL) && (udp->uh_sum != 0)) {
1051                         if (fin->fin_cksum == FI_CK_L4PART) {
1052                                 u_short sum = ntohs(udp->uh_sum);
1053                                 sum += adjlen;
1054                                 udp->uh_sum = htons(sum);
1055                         } else if (dosum) {
1056                                 udp->uh_sum = fr_cksum(fin, ip,
1057                                                        IPPROTO_UDP, udp);
1058                         }
1059                 }
1060                 aps->aps_bytes += fin->fin_plen;
1061                 aps->aps_pkts++;
1062                 return 1;
1063         }
1064         return 0;
1065 }
1066
1067
1068 /* ------------------------------------------------------------------------ */
1069 /* Function:    ipf_proxy_lookup                                            */
1070 /* Returns:     int - -1 == error, 0 == success                             */
1071 /* Parameters:  arg(I)  - pointer to proxy context information              */
1072 /*              pr(I)   - protocol number for proxy                         */
1073 /*              name(I) - proxy name                                        */
1074 /*                                                                          */
1075 /* Search for an proxy by the protocol it is being used with and its name.  */
1076 /* ------------------------------------------------------------------------ */
1077 aproxy_t *
1078 ipf_proxy_lookup(arg, pr, name)
1079         void *arg;
1080         u_int pr;
1081         char *name;
1082 {
1083         ipf_proxy_softc_t *softp = arg;
1084         aproxy_t *ap;
1085
1086         if (softp->ips_proxy_debug & 0x04)
1087                 printf("ipf_proxy_lookup(%d,%s)\n", pr, name);
1088
1089         for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next)
1090                 if ((ap->apr_p == pr) &&
1091                     !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
1092                         ap->apr_ref++;
1093                         return ap;
1094                 }
1095
1096         if (softp->ips_proxy_debug & 0x08)
1097                 printf("ipf_proxy_lookup: failed for %d/%s\n", pr, name);
1098         return NULL;
1099 }
1100
1101
1102 /* ------------------------------------------------------------------------ */
1103 /* Function:    ipf_proxy_deref                                             */
1104 /* Returns:     Nil                                                         */
1105 /* Parameters:  ap(I) - pointer to proxy structure                          */
1106 /*                                                                          */
1107 /* Drop the reference counter associated with the proxy.                    */
1108 /* ------------------------------------------------------------------------ */
1109 void
1110 ipf_proxy_deref(ap)
1111         aproxy_t *ap;
1112 {
1113         ap->apr_ref--;
1114 }
1115
1116
1117 /* ------------------------------------------------------------------------ */
1118 /* Function:    ipf_proxy_free                                              */
1119 /* Returns:     Nil                                                         */
1120 /* Parameters:  softc(I) - pointer to soft context main structure           */
1121 /*              aps(I)   - pointer to current proxy session                 */
1122 /* Locks Held:  ipf_nat_new, ipf_nat(W)                                     */
1123 /*                                                                          */
1124 /* Free up proxy session information allocated to be used with a NAT        */
1125 /* session.                                                                 */
1126 /* ------------------------------------------------------------------------ */
1127 void
1128 ipf_proxy_free(softc, aps)
1129         ipf_main_softc_t *softc;
1130         ap_session_t *aps;
1131 {
1132         ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
1133         ap_session_t *a, **ap;
1134         aproxy_t *apr;
1135
1136         if (!aps)
1137                 return;
1138
1139         for (ap = &softp->ips_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
1140                 if (a == aps) {
1141                         *ap = a->aps_next;
1142                         break;
1143                 }
1144
1145         apr = aps->aps_apr;
1146         if ((apr != NULL) && (apr->apr_del != NULL))
1147                 (*apr->apr_del)(softc, aps);
1148
1149         if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
1150                 KFREES(aps->aps_data, aps->aps_psiz);
1151         KFREE(aps);
1152 }
1153
1154
1155 /* ------------------------------------------------------------------------ */
1156 /* Function:    ipf_proxy_fixseqack                                         */
1157 /* Returns:     int    - 2 if TCP ack/seq is changed, else 0                */
1158 /* Parameters:  fin(I) - pointer to packet information                      */
1159 /*              ip(I)  - pointer to IP header                               */
1160 /*              nat(I) - pointer to current NAT session                     */
1161 /*              inc(I) - delta to apply to TCP sequence numbering           */
1162 /*                                                                          */
1163 /* Adjust the TCP sequence/acknowledge numbers in the TCP header based on   */
1164 /* whether or not the new header is past the point at which an adjustment   */
1165 /* occurred. This might happen because of (say) an FTP string being changed */
1166 /* and the new string being a different length to the old.                  */
1167 /* ------------------------------------------------------------------------ */
1168 static int
1169 ipf_proxy_fixseqack(fin, ip, aps, inc)
1170         fr_info_t *fin;
1171         ip_t *ip;
1172         ap_session_t *aps;
1173         int inc;
1174 {
1175         ipf_main_softc_t *softc = fin->fin_main_soft;
1176         ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
1177         int sel, ch = 0, out, nlen;
1178         u_32_t seq1, seq2;
1179         tcphdr_t *tcp;
1180         short inc2;
1181
1182         tcp = (tcphdr_t *)fin->fin_dp;
1183         out = fin->fin_out;
1184         /*
1185          * ip_len has already been adjusted by 'inc'.
1186          */
1187         nlen = fin->fin_dlen;
1188         nlen -= (TCP_OFF(tcp) << 2);
1189
1190         inc2 = inc;
1191         inc = (int)inc2;
1192
1193         if (out != 0) {
1194                 seq1 = (u_32_t)ntohl(tcp->th_seq);
1195                 sel = aps->aps_sel[out];
1196
1197                 /* switch to other set ? */
1198                 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
1199                     (seq1 > aps->aps_seqmin[!sel])) {
1200                         if (softp->ips_proxy_debug & 0x10)
1201                                 printf("proxy out switch set seq %d -> %d %x > %x\n",
1202                                         sel, !sel, seq1,
1203                                         aps->aps_seqmin[!sel]);
1204                         sel = aps->aps_sel[out] = !sel;
1205                 }
1206
1207                 if (aps->aps_seqoff[sel]) {
1208                         seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
1209                         if (seq1 > seq2) {
1210                                 seq2 = aps->aps_seqoff[sel];
1211                                 seq1 += seq2;
1212                                 tcp->th_seq = htonl(seq1);
1213                                 ch = 1;
1214                         }
1215                 }
1216
1217                 if (inc && (seq1 > aps->aps_seqmin[!sel])) {
1218                         aps->aps_seqmin[sel] = seq1 + nlen - 1;
1219                         aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
1220                         if (softp->ips_proxy_debug & 0x10)
1221                                 printf("proxy seq set %d at %x to %d + %d\n",
1222                                         sel, aps->aps_seqmin[sel],
1223                                         aps->aps_seqoff[sel], inc);
1224                 }
1225
1226                 /***/
1227
1228                 seq1 = ntohl(tcp->th_ack);
1229                 sel = aps->aps_sel[1 - out];
1230
1231                 /* switch to other set ? */
1232                 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
1233                     (seq1 > aps->aps_ackmin[!sel])) {
1234                         if (softp->ips_proxy_debug & 0x10)
1235                                 printf("proxy out switch set ack %d -> %d %x > %x\n",
1236                                         sel, !sel, seq1,
1237                                         aps->aps_ackmin[!sel]);
1238                         sel = aps->aps_sel[1 - out] = !sel;
1239                 }
1240
1241                 if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
1242                         seq2 = aps->aps_ackoff[sel];
1243                         tcp->th_ack = htonl(seq1 - seq2);
1244                         ch = 1;
1245                 }
1246         } else {
1247                 seq1 = ntohl(tcp->th_seq);
1248                 sel = aps->aps_sel[out];
1249
1250                 /* switch to other set ? */
1251                 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
1252                     (seq1 > aps->aps_ackmin[!sel])) {
1253                         if (softp->ips_proxy_debug & 0x10)
1254                                 printf("proxy in switch set ack %d -> %d %x > %x\n",
1255                                         sel, !sel, seq1, aps->aps_ackmin[!sel]);
1256                         sel = aps->aps_sel[out] = !sel;
1257                 }
1258
1259                 if (aps->aps_ackoff[sel]) {
1260                         seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
1261                         if (seq1 > seq2) {
1262                                 seq2 = aps->aps_ackoff[sel];
1263                                 seq1 += seq2;
1264                                 tcp->th_seq = htonl(seq1);
1265                                 ch = 1;
1266                         }
1267                 }
1268
1269                 if (inc && (seq1 > aps->aps_ackmin[!sel])) {
1270                         aps->aps_ackmin[!sel] = seq1 + nlen - 1;
1271                         aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;
1272
1273                         if (softp->ips_proxy_debug & 0x10)
1274                                 printf("proxy ack set %d at %x to %d + %d\n",
1275                                         !sel, aps->aps_seqmin[!sel],
1276                                         aps->aps_seqoff[sel], inc);
1277                 }
1278
1279                 /***/
1280
1281                 seq1 = ntohl(tcp->th_ack);
1282                 sel = aps->aps_sel[1 - out];
1283
1284                 /* switch to other set ? */
1285                 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
1286                     (seq1 > aps->aps_seqmin[!sel])) {
1287                         if (softp->ips_proxy_debug & 0x10)
1288                                 printf("proxy in switch set seq %d -> %d %x > %x\n",
1289                                         sel, !sel, seq1, aps->aps_seqmin[!sel]);
1290                         sel = aps->aps_sel[1 - out] = !sel;
1291                 }
1292
1293                 if (aps->aps_seqoff[sel] != 0) {
1294                         if (softp->ips_proxy_debug & 0x10)
1295                                 printf("sel %d seqoff %d seq1 %x seqmin %x\n",
1296                                         sel, aps->aps_seqoff[sel], seq1,
1297                                         aps->aps_seqmin[sel]);
1298                         if (seq1 > aps->aps_seqmin[sel]) {
1299                                 seq2 = aps->aps_seqoff[sel];
1300                                 tcp->th_ack = htonl(seq1 - seq2);
1301                                 ch = 1;
1302                         }
1303                 }
1304         }
1305
1306         if (softp->ips_proxy_debug & 0x10)
1307                 printf("ipf_proxy_fixseqack: seq %u ack %u\n",
1308                         (u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack));
1309         return ch ? 2 : 0;
1310 }
1311
1312
1313 /* ------------------------------------------------------------------------ */
1314 /* Function:    ipf_proxy_rule_rev                                          */
1315 /* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
1316 /* Parameters:  nat(I) - pointer to NAT session to create rule from         */
1317 /*                                                                          */
1318 /* This function creates a NAT rule that is based upon the reverse packet   */
1319 /* flow associated with this NAT session. Thus if this NAT session was      */
1320 /* created with a map rule then this function will create a rdr rule.       */
1321 /* Only address fields and network interfaces are assigned in this function */
1322 /* and the address fields are formed such that an exact is required. If the */
1323 /* original rule had a netmask, that is not replicated here not is it       */
1324 /* desired. The ultimate goal here is to create a NAT rule to support a NAT */
1325 /* session being created that does not have a user configured rule. The     */
1326 /* classic example is supporting the FTP proxy, where a data channel needs  */
1327 /* to be setup, based on the addresses used for the control connection. In  */
1328 /* that case, this function is used to handle creating NAT rules to support */
1329 /* data connections with the PORT and EPRT commands.                        */
1330 /* ------------------------------------------------------------------------ */
1331 ipnat_t *
1332 ipf_proxy_rule_rev(nat)
1333         nat_t *nat;
1334 {
1335         ipnat_t *old;
1336         ipnat_t *ipn;
1337         int size;
1338
1339         old = nat->nat_ptr;
1340         size = old->in_size;
1341
1342         KMALLOCS(ipn, ipnat_t *, size);
1343         if (ipn == NULL)
1344                 return NULL;
1345
1346         bzero((char *)ipn, size);
1347
1348         ipn->in_use = 1;
1349         ipn->in_hits = 1;
1350         ipn->in_ippip = 1;
1351         ipn->in_apr = NULL;
1352         ipn->in_size = size;
1353         ipn->in_pr[0] = old->in_pr[1];
1354         ipn->in_pr[1] = old->in_pr[0];
1355         ipn->in_v[0] = old->in_v[1];
1356         ipn->in_v[1] = old->in_v[0];
1357         ipn->in_ifps[0] = old->in_ifps[1];
1358         ipn->in_ifps[1] = old->in_ifps[0];
1359         ipn->in_flags = (old->in_flags | IPN_PROXYRULE);
1360
1361         ipn->in_nsrcip6 = nat->nat_odst6;
1362         ipn->in_osrcip6 = nat->nat_ndst6;
1363
1364         if ((old->in_redir & NAT_REDIRECT) != 0) {
1365                 ipn->in_redir = NAT_MAP;
1366                 if (ipn->in_v[0] == 4) {
1367                         ipn->in_snip = ntohl(nat->nat_odstaddr);
1368                         ipn->in_dnip = ntohl(nat->nat_nsrcaddr);
1369                 } else {
1370 #ifdef USE_INET6
1371                         ipn->in_snip6 = nat->nat_odst6;
1372                         ipn->in_dnip6 = nat->nat_nsrc6;
1373 #endif
1374                 }
1375                 ipn->in_ndstip6 = nat->nat_nsrc6;
1376                 ipn->in_odstip6 = nat->nat_osrc6;
1377         } else {
1378                 ipn->in_redir = NAT_REDIRECT;
1379                 if (ipn->in_v[0] == 4) {
1380                         ipn->in_snip = ntohl(nat->nat_odstaddr);
1381                         ipn->in_dnip = ntohl(nat->nat_osrcaddr);
1382                 } else {
1383 #ifdef USE_INET6
1384                         ipn->in_snip6 = nat->nat_odst6;
1385                         ipn->in_dnip6 = nat->nat_osrc6;
1386 #endif
1387                 }
1388                 ipn->in_ndstip6 = nat->nat_osrc6;
1389                 ipn->in_odstip6 = nat->nat_nsrc6;
1390         }
1391
1392         IP6_SETONES(&ipn->in_osrcmsk6);
1393         IP6_SETONES(&ipn->in_nsrcmsk6);
1394         IP6_SETONES(&ipn->in_odstmsk6);
1395         IP6_SETONES(&ipn->in_ndstmsk6);
1396
1397         ipn->in_namelen = old->in_namelen;
1398         ipn->in_ifnames[0] = old->in_ifnames[1];
1399         ipn->in_ifnames[1] = old->in_ifnames[0];
1400         bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
1401         MUTEX_INIT(&ipn->in_lock, "ipnat rev rule lock");
1402
1403         return ipn;
1404 }
1405
1406
1407 /* ------------------------------------------------------------------------ */
1408 /* Function:    ipf_proxy_rule_fwd                                          */
1409 /* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
1410 /* Parameters:  nat(I) - pointer to NAT session to create rule from         */
1411 /*                                                                          */
1412 /* The purpose and rationale of this function is much the same as the above */
1413 /* function, ipf_proxy_rule_rev, except that a rule is created that matches */
1414 /* the same direction as that of the existing NAT session. Thus if this NAT */
1415 /* session was created with a map rule then this function will also create  */
1416 /* a data structure to represent a map rule. Whereas ipf_proxy_rule_rev is  */
1417 /* used to support PORT/EPRT, this function supports PASV/EPSV.             */
1418 /* ------------------------------------------------------------------------ */
1419 ipnat_t *
1420 ipf_proxy_rule_fwd(nat)
1421         nat_t *nat;
1422 {
1423         ipnat_t *old;
1424         ipnat_t *ipn;
1425         int size;
1426
1427         old = nat->nat_ptr;
1428         size = old->in_size;
1429
1430         KMALLOCS(ipn, ipnat_t *, size);
1431         if (ipn == NULL)
1432                 return NULL;
1433
1434         bzero((char *)ipn, size);
1435
1436         ipn->in_use = 1;
1437         ipn->in_hits = 1;
1438         ipn->in_ippip = 1;
1439         ipn->in_apr = NULL;
1440         ipn->in_size = size;
1441         ipn->in_pr[0] = old->in_pr[0];
1442         ipn->in_pr[1] = old->in_pr[1];
1443         ipn->in_v[0] = old->in_v[0];
1444         ipn->in_v[1] = old->in_v[1];
1445         ipn->in_ifps[0] = nat->nat_ifps[0];
1446         ipn->in_ifps[1] = nat->nat_ifps[1];
1447         ipn->in_flags = (old->in_flags | IPN_PROXYRULE);
1448
1449         ipn->in_nsrcip6 = nat->nat_nsrc6;
1450         ipn->in_osrcip6 = nat->nat_osrc6;
1451         ipn->in_ndstip6 = nat->nat_ndst6;
1452         ipn->in_odstip6 = nat->nat_odst6;
1453         ipn->in_redir = old->in_redir;
1454
1455         if (ipn->in_v[0] == 4) {
1456                 ipn->in_snip = ntohl(nat->nat_nsrcaddr);
1457                 ipn->in_dnip = ntohl(nat->nat_ndstaddr);
1458         } else {
1459 #ifdef USE_INET6
1460                 ipn->in_snip6 = nat->nat_nsrc6;
1461                 ipn->in_dnip6 = nat->nat_ndst6;
1462 #endif
1463         }
1464
1465         IP6_SETONES(&ipn->in_osrcmsk6);
1466         IP6_SETONES(&ipn->in_nsrcmsk6);
1467         IP6_SETONES(&ipn->in_odstmsk6);
1468         IP6_SETONES(&ipn->in_ndstmsk6);
1469
1470         ipn->in_namelen = old->in_namelen;
1471         ipn->in_ifnames[0] = old->in_ifnames[0];
1472         ipn->in_ifnames[1] = old->in_ifnames[1];
1473         bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
1474         MUTEX_INIT(&ipn->in_lock, "ipnat fwd rule lock");
1475
1476         return ipn;
1477 }