1/* $FreeBSD: head/sys/contrib/ipfilter/netinet/ip_proxy.c 145522 2005-04-25 18:43:14Z darrenr $ */
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#include <sys/fcntl.h>
20#if !defined(_KERNEL) && !defined(__KERNEL__)
21# include <stdio.h>
22# include <string.h>
23# include <stdlib.h>
24# include <ctype.h>
25# define _KERNEL
26# ifdef __OpenBSD__
27struct file;
28# endif
29# include <sys/uio.h>
30# undef _KERNEL
31#endif
32#if !defined(linux)
33# include <sys/protosw.h>
34#endif
35#include <sys/socket.h>
36#if defined(_KERNEL)
37# if !defined(__NetBSD__) && !defined(sun) && !defined(__osf__) && \
38 !defined(__OpenBSD__) && !defined(__hpux) && !defined(__sgi)
39# include <sys/ctype.h>
40# endif
41# include <sys/systm.h>
42# if !defined(__SVR4) && !defined(__svr4__)
43# include <sys/mbuf.h>
44# endif
45#endif
46#if defined(_KERNEL) && (__FreeBSD_version >= 220000)
47# include <sys/filio.h>
48# include <sys/fcntl.h>
49# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM)
50# include "opt_ipfilter.h"
51# endif
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__ > 2
64# include <sys/queue.h>
65#endif
66#include <net/if.h>
67#ifdef sun
68# include <net/af.h>
69#endif
70#include <net/route.h>
71#include <netinet/in.h>
72#include <netinet/in_systm.h>
73#include <netinet/ip.h>
74#ifndef linux
75# include <netinet/ip_var.h>
76#endif
77#include <netinet/tcp.h>
78#include <netinet/udp.h>
79#include <netinet/ip_icmp.h>
80#include "netinet/ip_compat.h"
81#include <netinet/tcpip.h>
82#include "netinet/ip_fil.h"
83#include "netinet/ip_nat.h"
84#include "netinet/ip_state.h"
85#include "netinet/ip_proxy.h"
86#if (__FreeBSD_version >= 300000)
87# include <sys/malloc.h>
88#endif
89
90#include "netinet/ip_ftp_pxy.c"
91#include "netinet/ip_rcmd_pxy.c"
92# include "netinet/ip_pptp_pxy.c"
93#if defined(_KERNEL)
94# include "netinet/ip_irc_pxy.c"
95# include "netinet/ip_raudio_pxy.c"
96# include "netinet/ip_h323_pxy.c"
97# ifdef IPFILTER_PRO
98# include "netinet/ip_msnrpc_pxy.c"
99# endif
100# include "netinet/ip_netbios_pxy.c"
101#endif
102#include "netinet/ip_ipsec_pxy.c"
103#include "netinet/ip_rpcb_pxy.c"
104
105/* END OF INCLUDES */
106
107#if !defined(lint)
108static const char rcsid[] = "@(#)Id: ip_proxy.c,v 2.62.2.12 2005/03/03 14:28:24 darrenr Exp";
109#endif
110
111static int appr_fixseqack __P((fr_info_t *, ip_t *, ap_session_t *, int ));
112
113#define AP_SESS_SIZE 53
114
115#if defined(_KERNEL)
116int ipf_proxy_debug = 0;
117#else
118int ipf_proxy_debug = 2;
119#endif
120ap_session_t *ap_sess_tab[AP_SESS_SIZE];
121ap_session_t *ap_sess_list = NULL;
122aproxy_t *ap_proxylist = NULL;
123aproxy_t ap_proxies[] = {
124#ifdef IPF_FTP_PROXY
125 { NULL, "ftp", (char)IPPROTO_TCP, 0, 0, ippr_ftp_init, ippr_ftp_fini,
126 ippr_ftp_new, NULL, ippr_ftp_in, ippr_ftp_out, NULL },
127#endif
128#ifdef IPF_IRC_PROXY
129 { NULL, "irc", (char)IPPROTO_TCP, 0, 0, ippr_irc_init, ippr_irc_fini,
130 ippr_irc_new, NULL, NULL, ippr_irc_out, NULL, NULL },
131#endif
132#ifdef IPF_RCMD_PROXY
133 { NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, ippr_rcmd_init, ippr_rcmd_fini,
134 ippr_rcmd_new, NULL, ippr_rcmd_in, ippr_rcmd_out, NULL, NULL },
135#endif
136#ifdef IPF_RAUDIO_PROXY
137 { NULL, "raudio", (char)IPPROTO_TCP, 0, 0, ippr_raudio_init, ippr_raudio_fini,
138 ippr_raudio_new, NULL, ippr_raudio_in, ippr_raudio_out, NULL, NULL },
139#endif
140#ifdef IPF_MSNRPC_PROXY
141 { NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, ippr_msnrpc_init, ippr_msnrpc_fini,
142 ippr_msnrpc_new, NULL, ippr_msnrpc_in, ippr_msnrpc_out, NULL, NULL },
143#endif
144#ifdef IPF_NETBIOS_PROXY
145 { NULL, "netbios", (char)IPPROTO_UDP, 0, 0, ippr_netbios_init, ippr_netbios_fini,
146 NULL, NULL, NULL, ippr_netbios_out, NULL, NULL },
147#endif
148#ifdef IPF_IPSEC_PROXY
149 { NULL, "ipsec", (char)IPPROTO_UDP, 0, 0,
150 ippr_ipsec_init, ippr_ipsec_fini, ippr_ipsec_new, ippr_ipsec_del,
151 ippr_ipsec_inout, ippr_ipsec_inout, ippr_ipsec_match, NULL },
152#endif
153#ifdef IPF_PPTP_PROXY
154 { NULL, "pptp", (char)IPPROTO_TCP, 0, 0,
155 ippr_pptp_init, ippr_pptp_fini, ippr_pptp_new, ippr_pptp_del,
156 ippr_pptp_inout, ippr_pptp_inout, NULL, NULL },
157#endif
158#ifdef IPF_H323_PROXY
159 { NULL, "h323", (char)IPPROTO_TCP, 0, 0, ippr_h323_init, ippr_h323_fini,
160 ippr_h323_new, ippr_h323_del, ippr_h323_in, NULL, NULL },
161 { NULL, "h245", (char)IPPROTO_TCP, 0, 0, NULL, NULL,
162 ippr_h245_new, NULL, NULL, ippr_h245_out, NULL },
163#endif
164#ifdef IPF_RPCB_PROXY
165# if 0
166 { NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0,
167 ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del,
168 ippr_rpcb_in, ippr_rpcb_out, NULL, NULL },
169# endif
170 { NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0,
171 ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del,
172 ippr_rpcb_in, ippr_rpcb_out, NULL, NULL },
173#endif
174 { NULL, "", '\0', 0, 0, NULL, NULL, NULL, NULL }
175};
176
177/*
178 * Dynamically add a new kernel proxy. Ensure that it is unique in the
179 * collection compiled in and dynamically added.
180 */
181int appr_add(ap)
182aproxy_t *ap;
183{
184 aproxy_t *a;
185
186 for (a = ap_proxies; a->apr_p; a++)
187 if ((a->apr_p == ap->apr_p) &&
188 !strncmp(a->apr_label, ap->apr_label,
189 sizeof(ap->apr_label))) {
190 if (ipf_proxy_debug > 1)
191 printf("appr_add: %s/%d already present (B)\n",
192 a->apr_label, a->apr_p);
193 return -1;
194 }
195
196 for (a = ap_proxylist; a->apr_p; a = a->apr_next)
197 if ((a->apr_p == ap->apr_p) &&
198 !strncmp(a->apr_label, ap->apr_label,
199 sizeof(ap->apr_label))) {
200 if (ipf_proxy_debug > 1)
201 printf("appr_add: %s/%d already present (D)\n",
202 a->apr_label, a->apr_p);
203 return -1;
204 }
205 ap->apr_next = ap_proxylist;
206 ap_proxylist = ap;
207 if (ap->apr_init != NULL)
208 return (*ap->apr_init)();
209 return 0;
210}
211
212
213/*
214 * Check to see if the proxy this control request has come through for
215 * exists, and if it does and it has a control function then invoke that
216 * control function.
217 */
218int appr_ctl(ctl)
219ap_ctl_t *ctl;
220{
221 aproxy_t *a;
222 int error;
223
224 a = appr_lookup(ctl->apc_p, ctl->apc_label);
225 if (a == NULL) {
226 if (ipf_proxy_debug > 1)
227 printf("appr_ctl: can't find %s/%d\n",
228 ctl->apc_label, ctl->apc_p);
229 error = ESRCH;
230 } else if (a->apr_ctl == NULL) {
231 if (ipf_proxy_debug > 1)
232 printf("appr_ctl: no ctl function for %s/%d\n",
233 ctl->apc_label, ctl->apc_p);
234 error = ENXIO;
235 } else {
236 error = (*a->apr_ctl)(a, ctl);
237 if ((error != 0) && (ipf_proxy_debug > 1))
238 printf("appr_ctl: %s/%d ctl error %d\n",
239 a->apr_label, a->apr_p, error);
240 }
241 return error;
242}
243
244
245/*
246 * Delete a proxy that has been added dynamically from those available.
247 * If it is in use, return 1 (do not destroy NOW), not in use 0 or -1
248 * if it cannot be matched.
249 */
250int appr_del(ap)
251aproxy_t *ap;
252{
253 aproxy_t *a, **app;
254
255 for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next)
256 if (a == ap) {
257 a->apr_flags |= APR_DELETE;
258 *app = a->apr_next;
259 if (ap->apr_ref != 0) {
260 if (ipf_proxy_debug > 2)
261 printf("appr_del: orphaning %s/%d\n",
262 ap->apr_label, ap->apr_p);
263 return 1;
264 }
265 return 0;
266 }
267 if (ipf_proxy_debug > 1)
268 printf("appr_del: proxy %lx not found\n", (u_long)ap);
269 return -1;
270}
271
272
273/*
274 * Return 1 if the packet is a good match against a proxy, else 0.
275 */
276int appr_ok(fin, tcp, nat)
277fr_info_t *fin;
278tcphdr_t *tcp;
279ipnat_t *nat;
280{
281 aproxy_t *apr = nat->in_apr;
282 u_short dport = nat->in_dport;
283
284 if ((apr == NULL) || (apr->apr_flags & APR_DELETE) ||
285 (fin->fin_p != apr->apr_p))
286 return 0;
287 if ((tcp == NULL) && dport)
288 return 0;
289 return 1;
290}
291
292
293int appr_ioctl(data, cmd, mode)
294caddr_t data;
295ioctlcmd_t cmd;
296int mode;
297{
298 ap_ctl_t ctl;
299 caddr_t ptr;
300 int error;
301
302 mode = mode; /* LINT */
303
304 switch (cmd)
305 {
306 case SIOCPROXY :
307 BCOPYIN(data, &ctl, sizeof(ctl));
308 ptr = NULL;
309
310 if (ctl.apc_dsize > 0) {
311 KMALLOCS(ptr, caddr_t, ctl.apc_dsize);
312 if (ptr == NULL)
313 error = ENOMEM;
314 else {
315 error = copyinptr(ctl.apc_data, ptr,
316 ctl.apc_dsize);
317 if (error == 0)
318 ctl.apc_data = ptr;
319 }
320 } else {
321 ctl.apc_data = NULL;
322 error = 0;
323 }
324
325 if (error == 0)
326 error = appr_ctl(&ctl);
327
328 if ((ctl.apc_dsize > 0) && (ptr != NULL) &&
329 (ctl.apc_data == ptr)) {
330 KFREES(ptr, ctl.apc_dsize);
331 }
332 break;
333
334 default :
335 error = EINVAL;
336 }
337 return error;
338}
339
340
341/*
342 * If a proxy has a match function, call that to do extended packet
343 * matching.
344 */
345int appr_match(fin, nat)
346fr_info_t *fin;
347nat_t *nat;
348{
349 aproxy_t *apr;
350 ipnat_t *ipn;
351 int result;
352
353 ipn = nat->nat_ptr;
354 if (ipf_proxy_debug > 8)
355 printf("appr_match(%lx,%lx) aps %lx ptr %lx\n",
356 (u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
357 (u_long)ipn);
358
359 if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
360 if (ipf_proxy_debug > 0)
361 printf("appr_match: flx 0x%x (BAD|SHORT)\n",
362 fin->fin_flx);
363 return -1;
364 }
365
366 apr = ipn->in_apr;
367 if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
368 if (ipf_proxy_debug > 0)
369 printf("appr_match:apr %lx apr_flags 0x%x\n",
370 (u_long)apr, apr ? apr->apr_flags : 0);
371 return -1;
372 }
373
374 if (apr->apr_match != NULL) {
375 result = (*apr->apr_match)(fin, nat->nat_aps, nat);
376 if (result != 0) {
377 if (ipf_proxy_debug > 4)
378 printf("appr_match: result %d\n", result);
379 return -1;
380 }
381 }
382 return 0;
383}
384
385
386/*
387 * Allocate a new application proxy structure and fill it in with the
388 * relevant details. call the init function once complete, prior to
389 * returning.
390 */
391int appr_new(fin, nat)
392fr_info_t *fin;
393nat_t *nat;
394{
395 register ap_session_t *aps;
396 aproxy_t *apr;
397
398 if (ipf_proxy_debug > 8)
399 printf("appr_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);
400
401 if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
402 if (ipf_proxy_debug > 0)
403 printf("appr_new: nat_ptr %lx nat_aps %lx\n",
404 (u_long)nat->nat_ptr, (u_long)nat->nat_aps);
405 return -1;
406 }
407
408 apr = nat->nat_ptr->in_apr;
409
410 if ((apr->apr_flags & APR_DELETE) ||
411 (fin->fin_p != apr->apr_p)) {
412 if (ipf_proxy_debug > 2)
413 printf("appr_new: apr_flags 0x%x p %d/%d\n",
414 apr->apr_flags, fin->fin_p, apr->apr_p);
415 return -1;
416 }
417
418 KMALLOC(aps, ap_session_t *);
419 if (!aps) {
420 if (ipf_proxy_debug > 0)
421 printf("appr_new: malloc failed (%lu)\n",
422 (u_long)sizeof(ap_session_t));
423 return -1;
424 }
425
426 bzero((char *)aps, sizeof(*aps));
427 aps->aps_p = fin->fin_p;
428 aps->aps_data = NULL;
429 aps->aps_apr = apr;
430 aps->aps_psiz = 0;
431 if (apr->apr_new != NULL)
432 if ((*apr->apr_new)(fin, aps, nat) == -1) {
433 if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
434 KFREES(aps->aps_data, aps->aps_psiz);
435 }
436 KFREE(aps);
437 if (ipf_proxy_debug > 2)
438 printf("appr_new: new(%lx) failed\n",
439 (u_long)apr->apr_new);
440 return -1;
441 }
442 aps->aps_nat = nat;
443 aps->aps_next = ap_sess_list;
444 ap_sess_list = aps;
445 nat->nat_aps = aps;
446
447 return 0;
448}
449
450
451/*
452 * Check to see if a packet should be passed through an active proxy routine
453 * if one has been setup for it. We don't need to check the checksum here if
454 * IPFILTER_CKSUM is defined because if it is, a failed check causes FI_BAD
455 * to be set.
456 */
457int appr_check(fin, nat)
458fr_info_t *fin;
459nat_t *nat;
460{
461#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
462# if defined(ICK_VALID)
463 mb_t *m;
464# endif
465 int dosum = 1;
466#endif
467 tcphdr_t *tcp = NULL;
468 udphdr_t *udp = NULL;
469 ap_session_t *aps;
470 aproxy_t *apr;
471 ip_t *ip;
472 short rv;
473 int err;
474#if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
475 u_32_t s1, s2, sd;
476#endif
477
478 if (fin->fin_flx & FI_BAD) {
479 if (ipf_proxy_debug > 0)
480 printf("appr_check: flx 0x%x (BAD)\n", fin->fin_flx);
481 return -1;
482 }
483
484#ifndef IPFILTER_CKSUM
485 if ((fin->fin_out == 0) && (fr_checkl4sum(fin) == -1)) {
486 if (ipf_proxy_debug > 0)
487 printf("appr_check: l4 checksum failure %d\n",
488 fin->fin_p);
489 if (fin->fin_p == IPPROTO_TCP)
490 frstats[fin->fin_out].fr_tcpbad++;
491 return -1;
492 }
493#endif
494
495 aps = nat->nat_aps;
496 if ((aps != NULL) && (aps->aps_p == fin->fin_p)) {
497 /*
498 * If there is data in this packet to be proxied then try and
499 * get it all into the one buffer, else drop it.
500 */
501#if defined(MENTAT) || defined(HAVE_M_PULLDOWN)
502 if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
503 if (fr_coalesce(fin) == -1) {
504 if (ipf_proxy_debug > 0)
505 printf("appr_check: fr_coalesce failed %x\n", fin->fin_flx);
506 return -1;
507 }
508#endif
509 ip = fin->fin_ip;
510
511 switch (fin->fin_p)
512 {
513 case IPPROTO_TCP :
514 tcp = (tcphdr_t *)fin->fin_dp;
515
516#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_VALID)
517 m = fin->fin_qfm;
518 if (dohwcksum && (m->b_ick_flag == ICK_VALID))
519 dosum = 0;
520#endif
521 /*
522 * Don't bother the proxy with these...or in fact,
523 * should we free up proxy stuff when seen?
524 */
525 if ((fin->fin_tcpf & TH_RST) != 0)
526 break;
527 /*FALLTHROUGH*/
528 case IPPROTO_UDP :
529 udp = (udphdr_t *)fin->fin_dp;
530 break;
531 default :
532 break;
533 }
534
535 apr = aps->aps_apr;
536 err = 0;
537 if (fin->fin_out != 0) {
538 if (apr->apr_outpkt != NULL)
539 err = (*apr->apr_outpkt)(fin, aps, nat);
540 } else {
541 if (apr->apr_inpkt != NULL)
542 err = (*apr->apr_inpkt)(fin, aps, nat);
543 }
544
545 rv = APR_EXIT(err);
546 if (((ipf_proxy_debug > 0) && (rv != 0)) ||
547 (ipf_proxy_debug > 8))
548 printf("appr_check: out %d err %x rv %d\n",
549 fin->fin_out, err, rv);
550 if (rv == 1)
551 return -1;
552
553 if (rv == 2) {
554 appr_free(apr);
555 nat->nat_aps = NULL;
556 return -1;
557 }
558
559 /*
560 * If err != 0 then the data size of the packet has changed
561 * so we need to recalculate the header checksums for the
562 * packet.
563 */
564#if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
565 if (err != 0) {
566 short adjlen = err & 0xffff;
567
568 s1 = LONG_SUM(ip->ip_len - adjlen);
569 s2 = LONG_SUM(ip->ip_len);
570 CALC_SUMD(s1, s2, sd);
571 fix_outcksum(fin, &ip->ip_sum, sd);
572 }
573#endif
574
575 /*
576 * For TCP packets, we may need to adjust the sequence and
577 * acknowledgement numbers to reflect changes in size of the
578 * data stream.
579 *
580 * For both TCP and UDP, recalculate the layer 4 checksum,
581 * regardless, as we can't tell (here) if data has been
582 * changed or not.
583 */
584 if (tcp != NULL) {
585 err = appr_fixseqack(fin, ip, aps, APR_INC(err));
586#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
587 if (dosum)
588 tcp->th_sum = fr_cksum(fin->fin_qfm, ip,
589 IPPROTO_TCP, tcp);
590#else
591 tcp->th_sum = fr_cksum(fin->fin_m, ip,
592 IPPROTO_TCP, tcp);
593#endif
594 } else if ((udp != NULL) && (udp->uh_sum != 0)) {
595#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
596 if (dosum)
597 udp->uh_sum = fr_cksum(fin->fin_qfm, ip,
598 IPPROTO_UDP, udp);
599#else
600 udp->uh_sum = fr_cksum(fin->fin_m, ip,
601 IPPROTO_UDP, udp);
602#endif
603 }
604 aps->aps_bytes += fin->fin_plen;
605 aps->aps_pkts++;
606 return 1;
607 }
608 return 0;
609}
610
611
612/*
613 * Search for an proxy by the protocol it is being used with and its name.
614 */
615aproxy_t *appr_lookup(pr, name)
616u_int pr;
617char *name;
618{
619 aproxy_t *ap;
620
621 if (ipf_proxy_debug > 8)
622 printf("appr_lookup(%d,%s)\n", pr, name);
623
624 for (ap = ap_proxies; ap->apr_p; ap++)
625 if ((ap->apr_p == pr) &&
626 !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
627 ap->apr_ref++;
628 return ap;
629 }
630
631 for (ap = ap_proxylist; ap; ap = ap->apr_next)
632 if ((ap->apr_p == pr) &&
633 !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
634 ap->apr_ref++;
635 return ap;
636 }
637 if (ipf_proxy_debug > 2)
638 printf("appr_lookup: failed for %d/%s\n", pr, name);
639 return NULL;
640}
641
642
643void appr_free(ap)
644aproxy_t *ap;
645{
646 ap->apr_ref--;
647}
648
649
650void aps_free(aps)
651ap_session_t *aps;
652{
653 ap_session_t *a, **ap;
654 aproxy_t *apr;
655
656 if (!aps)
657 return;
658
659 for (ap = &ap_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
660 if (a == aps) {
661 *ap = a->aps_next;
662 break;
663 }
664
665 apr = aps->aps_apr;
666 if ((apr != NULL) && (apr->apr_del != NULL))
667 (*apr->apr_del)(aps);
668
669 if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
670 KFREES(aps->aps_data, aps->aps_psiz);
671 KFREE(aps);
672}
673
674
675/*
676 * returns 2 if ack or seq number in TCP header is changed, returns 0 otherwise
677 */
678static int appr_fixseqack(fin, ip, aps, inc)
679fr_info_t *fin;
680ip_t *ip;
681ap_session_t *aps;
682int inc;
683{
684 int sel, ch = 0, out, nlen;
685 u_32_t seq1, seq2;
686 tcphdr_t *tcp;
687 short inc2;
688
689 tcp = (tcphdr_t *)fin->fin_dp;
690 out = fin->fin_out;
691 /*
692 * ip_len has already been adjusted by 'inc'.
693 */
694 nlen = ip->ip_len;
695 nlen -= (IP_HL(ip) << 2) + (TCP_OFF(tcp) << 2);
696
697 inc2 = inc;
698 inc = (int)inc2;
699
700 if (out != 0) {
701 seq1 = (u_32_t)ntohl(tcp->th_seq);
702 sel = aps->aps_sel[out];
703
704 /* switch to other set ? */
705 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
706 (seq1 > aps->aps_seqmin[!sel])) {
707 if (ipf_proxy_debug > 7)
708 printf("proxy out switch set seq %d -> %d %x > %x\n",
709 sel, !sel, seq1,
710 aps->aps_seqmin[!sel]);
711 sel = aps->aps_sel[out] = !sel;
712 }
713
714 if (aps->aps_seqoff[sel]) {
715 seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
716 if (seq1 > seq2) {
717 seq2 = aps->aps_seqoff[sel];
718 seq1 += seq2;
719 tcp->th_seq = htonl(seq1);
720 ch = 1;
721 }
722 }
723
724 if (inc && (seq1 > aps->aps_seqmin[!sel])) {
725 aps->aps_seqmin[sel] = seq1 + nlen - 1;
726 aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
727 if (ipf_proxy_debug > 7)
728 printf("proxy seq set %d at %x to %d + %d\n",
729 sel, aps->aps_seqmin[sel],
730 aps->aps_seqoff[sel], inc);
731 }
732
733 /***/
734
735 seq1 = ntohl(tcp->th_ack);
736 sel = aps->aps_sel[1 - out];
737
738 /* switch to other set ? */
739 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
740 (seq1 > aps->aps_ackmin[!sel])) {
741 if (ipf_proxy_debug > 7)
742 printf("proxy out switch set ack %d -> %d %x > %x\n",
743 sel, !sel, seq1,
744 aps->aps_ackmin[!sel]);
745 sel = aps->aps_sel[1 - out] = !sel;
746 }
747
748 if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
749 seq2 = aps->aps_ackoff[sel];
750 tcp->th_ack = htonl(seq1 - seq2);
751 ch = 1;
752 }
753 } else {
754 seq1 = ntohl(tcp->th_seq);
755 sel = aps->aps_sel[out];
756
757 /* switch to other set ? */
758 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
759 (seq1 > aps->aps_ackmin[!sel])) {
760 if (ipf_proxy_debug > 7)
761 printf("proxy in switch set ack %d -> %d %x > %x\n",
762 sel, !sel, seq1, aps->aps_ackmin[!sel]);
763 sel = aps->aps_sel[out] = !sel;
764 }
765
766 if (aps->aps_ackoff[sel]) {
767 seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
768 if (seq1 > seq2) {
769 seq2 = aps->aps_ackoff[sel];
770 seq1 += seq2;
771 tcp->th_seq = htonl(seq1);
772 ch = 1;
773 }
774 }
775
776 if (inc && (seq1 > aps->aps_ackmin[!sel])) {
777 aps->aps_ackmin[!sel] = seq1 + nlen - 1;
778 aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;
779
780 if (ipf_proxy_debug > 7)
781 printf("proxy ack set %d at %x to %d + %d\n",
782 !sel, aps->aps_seqmin[!sel],
783 aps->aps_seqoff[sel], inc);
784 }
785
786 /***/
787
788 seq1 = ntohl(tcp->th_ack);
789 sel = aps->aps_sel[1 - out];
790
791 /* switch to other set ? */
792 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
793 (seq1 > aps->aps_seqmin[!sel])) {
794 if (ipf_proxy_debug > 7)
795 printf("proxy in switch set seq %d -> %d %x > %x\n",
796 sel, !sel, seq1, aps->aps_seqmin[!sel]);
797 sel = aps->aps_sel[1 - out] = !sel;
798 }
799
800 if (aps->aps_seqoff[sel] != 0) {
801 if (ipf_proxy_debug > 7)
802 printf("sel %d seqoff %d seq1 %x seqmin %x\n",
803 sel, aps->aps_seqoff[sel], seq1,
804 aps->aps_seqmin[sel]);
805 if (seq1 > aps->aps_seqmin[sel]) {
806 seq2 = aps->aps_seqoff[sel];
807 tcp->th_ack = htonl(seq1 - seq2);
808 ch = 1;
809 }
810 }
811 }
812
813 if (ipf_proxy_debug > 8)
814 printf("appr_fixseqack: seq %x ack %x\n",
815 ntohl(tcp->th_seq), ntohl(tcp->th_ack));
816 return ch ? 2 : 0;
817}
818
819
820/*
821 * Initialise hook for kernel application proxies.
822 * Call the initialise routine for all the compiled in kernel proxies.
823 */
824int appr_init()
825{
826 aproxy_t *ap;
827 int err = 0;
828
829 for (ap = ap_proxies; ap->apr_p; ap++) {
830 if (ap->apr_init != NULL) {
831 err = (*ap->apr_init)();
832 if (err != 0)
833 break;
834 }
835 }
836 return err;
837}
838
839
840/*
841 * Unload hook for kernel application proxies.
842 * Call the finialise routine for all the compiled in kernel proxies.
843 */
844void appr_unload()
845{
846 aproxy_t *ap;
847
848 for (ap = ap_proxies; ap->apr_p; ap++)
849 if (ap->apr_fini != NULL)
850 (*ap->apr_fini)();
851 for (ap = ap_proxylist; ap; ap = ap->apr_next)
852 if (ap->apr_fini != NULL)
853 (*ap->apr_fini)();
854}
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#include <sys/fcntl.h>
20#if !defined(_KERNEL) && !defined(__KERNEL__)
21# include <stdio.h>
22# include <string.h>
23# include <stdlib.h>
24# include <ctype.h>
25# define _KERNEL
26# ifdef __OpenBSD__
27struct file;
28# endif
29# include <sys/uio.h>
30# undef _KERNEL
31#endif
32#if !defined(linux)
33# include <sys/protosw.h>
34#endif
35#include <sys/socket.h>
36#if defined(_KERNEL)
37# if !defined(__NetBSD__) && !defined(sun) && !defined(__osf__) && \
38 !defined(__OpenBSD__) && !defined(__hpux) && !defined(__sgi)
39# include <sys/ctype.h>
40# endif
41# include <sys/systm.h>
42# if !defined(__SVR4) && !defined(__svr4__)
43# include <sys/mbuf.h>
44# endif
45#endif
46#if defined(_KERNEL) && (__FreeBSD_version >= 220000)
47# include <sys/filio.h>
48# include <sys/fcntl.h>
49# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM)
50# include "opt_ipfilter.h"
51# endif
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__ > 2
64# include <sys/queue.h>
65#endif
66#include <net/if.h>
67#ifdef sun
68# include <net/af.h>
69#endif
70#include <net/route.h>
71#include <netinet/in.h>
72#include <netinet/in_systm.h>
73#include <netinet/ip.h>
74#ifndef linux
75# include <netinet/ip_var.h>
76#endif
77#include <netinet/tcp.h>
78#include <netinet/udp.h>
79#include <netinet/ip_icmp.h>
80#include "netinet/ip_compat.h"
81#include <netinet/tcpip.h>
82#include "netinet/ip_fil.h"
83#include "netinet/ip_nat.h"
84#include "netinet/ip_state.h"
85#include "netinet/ip_proxy.h"
86#if (__FreeBSD_version >= 300000)
87# include <sys/malloc.h>
88#endif
89
90#include "netinet/ip_ftp_pxy.c"
91#include "netinet/ip_rcmd_pxy.c"
92# include "netinet/ip_pptp_pxy.c"
93#if defined(_KERNEL)
94# include "netinet/ip_irc_pxy.c"
95# include "netinet/ip_raudio_pxy.c"
96# include "netinet/ip_h323_pxy.c"
97# ifdef IPFILTER_PRO
98# include "netinet/ip_msnrpc_pxy.c"
99# endif
100# include "netinet/ip_netbios_pxy.c"
101#endif
102#include "netinet/ip_ipsec_pxy.c"
103#include "netinet/ip_rpcb_pxy.c"
104
105/* END OF INCLUDES */
106
107#if !defined(lint)
108static const char rcsid[] = "@(#)Id: ip_proxy.c,v 2.62.2.12 2005/03/03 14:28:24 darrenr Exp";
109#endif
110
111static int appr_fixseqack __P((fr_info_t *, ip_t *, ap_session_t *, int ));
112
113#define AP_SESS_SIZE 53
114
115#if defined(_KERNEL)
116int ipf_proxy_debug = 0;
117#else
118int ipf_proxy_debug = 2;
119#endif
120ap_session_t *ap_sess_tab[AP_SESS_SIZE];
121ap_session_t *ap_sess_list = NULL;
122aproxy_t *ap_proxylist = NULL;
123aproxy_t ap_proxies[] = {
124#ifdef IPF_FTP_PROXY
125 { NULL, "ftp", (char)IPPROTO_TCP, 0, 0, ippr_ftp_init, ippr_ftp_fini,
126 ippr_ftp_new, NULL, ippr_ftp_in, ippr_ftp_out, NULL },
127#endif
128#ifdef IPF_IRC_PROXY
129 { NULL, "irc", (char)IPPROTO_TCP, 0, 0, ippr_irc_init, ippr_irc_fini,
130 ippr_irc_new, NULL, NULL, ippr_irc_out, NULL, NULL },
131#endif
132#ifdef IPF_RCMD_PROXY
133 { NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, ippr_rcmd_init, ippr_rcmd_fini,
134 ippr_rcmd_new, NULL, ippr_rcmd_in, ippr_rcmd_out, NULL, NULL },
135#endif
136#ifdef IPF_RAUDIO_PROXY
137 { NULL, "raudio", (char)IPPROTO_TCP, 0, 0, ippr_raudio_init, ippr_raudio_fini,
138 ippr_raudio_new, NULL, ippr_raudio_in, ippr_raudio_out, NULL, NULL },
139#endif
140#ifdef IPF_MSNRPC_PROXY
141 { NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, ippr_msnrpc_init, ippr_msnrpc_fini,
142 ippr_msnrpc_new, NULL, ippr_msnrpc_in, ippr_msnrpc_out, NULL, NULL },
143#endif
144#ifdef IPF_NETBIOS_PROXY
145 { NULL, "netbios", (char)IPPROTO_UDP, 0, 0, ippr_netbios_init, ippr_netbios_fini,
146 NULL, NULL, NULL, ippr_netbios_out, NULL, NULL },
147#endif
148#ifdef IPF_IPSEC_PROXY
149 { NULL, "ipsec", (char)IPPROTO_UDP, 0, 0,
150 ippr_ipsec_init, ippr_ipsec_fini, ippr_ipsec_new, ippr_ipsec_del,
151 ippr_ipsec_inout, ippr_ipsec_inout, ippr_ipsec_match, NULL },
152#endif
153#ifdef IPF_PPTP_PROXY
154 { NULL, "pptp", (char)IPPROTO_TCP, 0, 0,
155 ippr_pptp_init, ippr_pptp_fini, ippr_pptp_new, ippr_pptp_del,
156 ippr_pptp_inout, ippr_pptp_inout, NULL, NULL },
157#endif
158#ifdef IPF_H323_PROXY
159 { NULL, "h323", (char)IPPROTO_TCP, 0, 0, ippr_h323_init, ippr_h323_fini,
160 ippr_h323_new, ippr_h323_del, ippr_h323_in, NULL, NULL },
161 { NULL, "h245", (char)IPPROTO_TCP, 0, 0, NULL, NULL,
162 ippr_h245_new, NULL, NULL, ippr_h245_out, NULL },
163#endif
164#ifdef IPF_RPCB_PROXY
165# if 0
166 { NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0,
167 ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del,
168 ippr_rpcb_in, ippr_rpcb_out, NULL, NULL },
169# endif
170 { NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0,
171 ippr_rpcb_init, ippr_rpcb_fini, ippr_rpcb_new, ippr_rpcb_del,
172 ippr_rpcb_in, ippr_rpcb_out, NULL, NULL },
173#endif
174 { NULL, "", '\0', 0, 0, NULL, NULL, NULL, NULL }
175};
176
177/*
178 * Dynamically add a new kernel proxy. Ensure that it is unique in the
179 * collection compiled in and dynamically added.
180 */
181int appr_add(ap)
182aproxy_t *ap;
183{
184 aproxy_t *a;
185
186 for (a = ap_proxies; a->apr_p; a++)
187 if ((a->apr_p == ap->apr_p) &&
188 !strncmp(a->apr_label, ap->apr_label,
189 sizeof(ap->apr_label))) {
190 if (ipf_proxy_debug > 1)
191 printf("appr_add: %s/%d already present (B)\n",
192 a->apr_label, a->apr_p);
193 return -1;
194 }
195
196 for (a = ap_proxylist; a->apr_p; a = a->apr_next)
197 if ((a->apr_p == ap->apr_p) &&
198 !strncmp(a->apr_label, ap->apr_label,
199 sizeof(ap->apr_label))) {
200 if (ipf_proxy_debug > 1)
201 printf("appr_add: %s/%d already present (D)\n",
202 a->apr_label, a->apr_p);
203 return -1;
204 }
205 ap->apr_next = ap_proxylist;
206 ap_proxylist = ap;
207 if (ap->apr_init != NULL)
208 return (*ap->apr_init)();
209 return 0;
210}
211
212
213/*
214 * Check to see if the proxy this control request has come through for
215 * exists, and if it does and it has a control function then invoke that
216 * control function.
217 */
218int appr_ctl(ctl)
219ap_ctl_t *ctl;
220{
221 aproxy_t *a;
222 int error;
223
224 a = appr_lookup(ctl->apc_p, ctl->apc_label);
225 if (a == NULL) {
226 if (ipf_proxy_debug > 1)
227 printf("appr_ctl: can't find %s/%d\n",
228 ctl->apc_label, ctl->apc_p);
229 error = ESRCH;
230 } else if (a->apr_ctl == NULL) {
231 if (ipf_proxy_debug > 1)
232 printf("appr_ctl: no ctl function for %s/%d\n",
233 ctl->apc_label, ctl->apc_p);
234 error = ENXIO;
235 } else {
236 error = (*a->apr_ctl)(a, ctl);
237 if ((error != 0) && (ipf_proxy_debug > 1))
238 printf("appr_ctl: %s/%d ctl error %d\n",
239 a->apr_label, a->apr_p, error);
240 }
241 return error;
242}
243
244
245/*
246 * Delete a proxy that has been added dynamically from those available.
247 * If it is in use, return 1 (do not destroy NOW), not in use 0 or -1
248 * if it cannot be matched.
249 */
250int appr_del(ap)
251aproxy_t *ap;
252{
253 aproxy_t *a, **app;
254
255 for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next)
256 if (a == ap) {
257 a->apr_flags |= APR_DELETE;
258 *app = a->apr_next;
259 if (ap->apr_ref != 0) {
260 if (ipf_proxy_debug > 2)
261 printf("appr_del: orphaning %s/%d\n",
262 ap->apr_label, ap->apr_p);
263 return 1;
264 }
265 return 0;
266 }
267 if (ipf_proxy_debug > 1)
268 printf("appr_del: proxy %lx not found\n", (u_long)ap);
269 return -1;
270}
271
272
273/*
274 * Return 1 if the packet is a good match against a proxy, else 0.
275 */
276int appr_ok(fin, tcp, nat)
277fr_info_t *fin;
278tcphdr_t *tcp;
279ipnat_t *nat;
280{
281 aproxy_t *apr = nat->in_apr;
282 u_short dport = nat->in_dport;
283
284 if ((apr == NULL) || (apr->apr_flags & APR_DELETE) ||
285 (fin->fin_p != apr->apr_p))
286 return 0;
287 if ((tcp == NULL) && dport)
288 return 0;
289 return 1;
290}
291
292
293int appr_ioctl(data, cmd, mode)
294caddr_t data;
295ioctlcmd_t cmd;
296int mode;
297{
298 ap_ctl_t ctl;
299 caddr_t ptr;
300 int error;
301
302 mode = mode; /* LINT */
303
304 switch (cmd)
305 {
306 case SIOCPROXY :
307 BCOPYIN(data, &ctl, sizeof(ctl));
308 ptr = NULL;
309
310 if (ctl.apc_dsize > 0) {
311 KMALLOCS(ptr, caddr_t, ctl.apc_dsize);
312 if (ptr == NULL)
313 error = ENOMEM;
314 else {
315 error = copyinptr(ctl.apc_data, ptr,
316 ctl.apc_dsize);
317 if (error == 0)
318 ctl.apc_data = ptr;
319 }
320 } else {
321 ctl.apc_data = NULL;
322 error = 0;
323 }
324
325 if (error == 0)
326 error = appr_ctl(&ctl);
327
328 if ((ctl.apc_dsize > 0) && (ptr != NULL) &&
329 (ctl.apc_data == ptr)) {
330 KFREES(ptr, ctl.apc_dsize);
331 }
332 break;
333
334 default :
335 error = EINVAL;
336 }
337 return error;
338}
339
340
341/*
342 * If a proxy has a match function, call that to do extended packet
343 * matching.
344 */
345int appr_match(fin, nat)
346fr_info_t *fin;
347nat_t *nat;
348{
349 aproxy_t *apr;
350 ipnat_t *ipn;
351 int result;
352
353 ipn = nat->nat_ptr;
354 if (ipf_proxy_debug > 8)
355 printf("appr_match(%lx,%lx) aps %lx ptr %lx\n",
356 (u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
357 (u_long)ipn);
358
359 if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
360 if (ipf_proxy_debug > 0)
361 printf("appr_match: flx 0x%x (BAD|SHORT)\n",
362 fin->fin_flx);
363 return -1;
364 }
365
366 apr = ipn->in_apr;
367 if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
368 if (ipf_proxy_debug > 0)
369 printf("appr_match:apr %lx apr_flags 0x%x\n",
370 (u_long)apr, apr ? apr->apr_flags : 0);
371 return -1;
372 }
373
374 if (apr->apr_match != NULL) {
375 result = (*apr->apr_match)(fin, nat->nat_aps, nat);
376 if (result != 0) {
377 if (ipf_proxy_debug > 4)
378 printf("appr_match: result %d\n", result);
379 return -1;
380 }
381 }
382 return 0;
383}
384
385
386/*
387 * Allocate a new application proxy structure and fill it in with the
388 * relevant details. call the init function once complete, prior to
389 * returning.
390 */
391int appr_new(fin, nat)
392fr_info_t *fin;
393nat_t *nat;
394{
395 register ap_session_t *aps;
396 aproxy_t *apr;
397
398 if (ipf_proxy_debug > 8)
399 printf("appr_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);
400
401 if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
402 if (ipf_proxy_debug > 0)
403 printf("appr_new: nat_ptr %lx nat_aps %lx\n",
404 (u_long)nat->nat_ptr, (u_long)nat->nat_aps);
405 return -1;
406 }
407
408 apr = nat->nat_ptr->in_apr;
409
410 if ((apr->apr_flags & APR_DELETE) ||
411 (fin->fin_p != apr->apr_p)) {
412 if (ipf_proxy_debug > 2)
413 printf("appr_new: apr_flags 0x%x p %d/%d\n",
414 apr->apr_flags, fin->fin_p, apr->apr_p);
415 return -1;
416 }
417
418 KMALLOC(aps, ap_session_t *);
419 if (!aps) {
420 if (ipf_proxy_debug > 0)
421 printf("appr_new: malloc failed (%lu)\n",
422 (u_long)sizeof(ap_session_t));
423 return -1;
424 }
425
426 bzero((char *)aps, sizeof(*aps));
427 aps->aps_p = fin->fin_p;
428 aps->aps_data = NULL;
429 aps->aps_apr = apr;
430 aps->aps_psiz = 0;
431 if (apr->apr_new != NULL)
432 if ((*apr->apr_new)(fin, aps, nat) == -1) {
433 if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
434 KFREES(aps->aps_data, aps->aps_psiz);
435 }
436 KFREE(aps);
437 if (ipf_proxy_debug > 2)
438 printf("appr_new: new(%lx) failed\n",
439 (u_long)apr->apr_new);
440 return -1;
441 }
442 aps->aps_nat = nat;
443 aps->aps_next = ap_sess_list;
444 ap_sess_list = aps;
445 nat->nat_aps = aps;
446
447 return 0;
448}
449
450
451/*
452 * Check to see if a packet should be passed through an active proxy routine
453 * if one has been setup for it. We don't need to check the checksum here if
454 * IPFILTER_CKSUM is defined because if it is, a failed check causes FI_BAD
455 * to be set.
456 */
457int appr_check(fin, nat)
458fr_info_t *fin;
459nat_t *nat;
460{
461#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
462# if defined(ICK_VALID)
463 mb_t *m;
464# endif
465 int dosum = 1;
466#endif
467 tcphdr_t *tcp = NULL;
468 udphdr_t *udp = NULL;
469 ap_session_t *aps;
470 aproxy_t *apr;
471 ip_t *ip;
472 short rv;
473 int err;
474#if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
475 u_32_t s1, s2, sd;
476#endif
477
478 if (fin->fin_flx & FI_BAD) {
479 if (ipf_proxy_debug > 0)
480 printf("appr_check: flx 0x%x (BAD)\n", fin->fin_flx);
481 return -1;
482 }
483
484#ifndef IPFILTER_CKSUM
485 if ((fin->fin_out == 0) && (fr_checkl4sum(fin) == -1)) {
486 if (ipf_proxy_debug > 0)
487 printf("appr_check: l4 checksum failure %d\n",
488 fin->fin_p);
489 if (fin->fin_p == IPPROTO_TCP)
490 frstats[fin->fin_out].fr_tcpbad++;
491 return -1;
492 }
493#endif
494
495 aps = nat->nat_aps;
496 if ((aps != NULL) && (aps->aps_p == fin->fin_p)) {
497 /*
498 * If there is data in this packet to be proxied then try and
499 * get it all into the one buffer, else drop it.
500 */
501#if defined(MENTAT) || defined(HAVE_M_PULLDOWN)
502 if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
503 if (fr_coalesce(fin) == -1) {
504 if (ipf_proxy_debug > 0)
505 printf("appr_check: fr_coalesce failed %x\n", fin->fin_flx);
506 return -1;
507 }
508#endif
509 ip = fin->fin_ip;
510
511 switch (fin->fin_p)
512 {
513 case IPPROTO_TCP :
514 tcp = (tcphdr_t *)fin->fin_dp;
515
516#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_VALID)
517 m = fin->fin_qfm;
518 if (dohwcksum && (m->b_ick_flag == ICK_VALID))
519 dosum = 0;
520#endif
521 /*
522 * Don't bother the proxy with these...or in fact,
523 * should we free up proxy stuff when seen?
524 */
525 if ((fin->fin_tcpf & TH_RST) != 0)
526 break;
527 /*FALLTHROUGH*/
528 case IPPROTO_UDP :
529 udp = (udphdr_t *)fin->fin_dp;
530 break;
531 default :
532 break;
533 }
534
535 apr = aps->aps_apr;
536 err = 0;
537 if (fin->fin_out != 0) {
538 if (apr->apr_outpkt != NULL)
539 err = (*apr->apr_outpkt)(fin, aps, nat);
540 } else {
541 if (apr->apr_inpkt != NULL)
542 err = (*apr->apr_inpkt)(fin, aps, nat);
543 }
544
545 rv = APR_EXIT(err);
546 if (((ipf_proxy_debug > 0) && (rv != 0)) ||
547 (ipf_proxy_debug > 8))
548 printf("appr_check: out %d err %x rv %d\n",
549 fin->fin_out, err, rv);
550 if (rv == 1)
551 return -1;
552
553 if (rv == 2) {
554 appr_free(apr);
555 nat->nat_aps = NULL;
556 return -1;
557 }
558
559 /*
560 * If err != 0 then the data size of the packet has changed
561 * so we need to recalculate the header checksums for the
562 * packet.
563 */
564#if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi)
565 if (err != 0) {
566 short adjlen = err & 0xffff;
567
568 s1 = LONG_SUM(ip->ip_len - adjlen);
569 s2 = LONG_SUM(ip->ip_len);
570 CALC_SUMD(s1, s2, sd);
571 fix_outcksum(fin, &ip->ip_sum, sd);
572 }
573#endif
574
575 /*
576 * For TCP packets, we may need to adjust the sequence and
577 * acknowledgement numbers to reflect changes in size of the
578 * data stream.
579 *
580 * For both TCP and UDP, recalculate the layer 4 checksum,
581 * regardless, as we can't tell (here) if data has been
582 * changed or not.
583 */
584 if (tcp != NULL) {
585 err = appr_fixseqack(fin, ip, aps, APR_INC(err));
586#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
587 if (dosum)
588 tcp->th_sum = fr_cksum(fin->fin_qfm, ip,
589 IPPROTO_TCP, tcp);
590#else
591 tcp->th_sum = fr_cksum(fin->fin_m, ip,
592 IPPROTO_TCP, tcp);
593#endif
594 } else if ((udp != NULL) && (udp->uh_sum != 0)) {
595#if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6)
596 if (dosum)
597 udp->uh_sum = fr_cksum(fin->fin_qfm, ip,
598 IPPROTO_UDP, udp);
599#else
600 udp->uh_sum = fr_cksum(fin->fin_m, ip,
601 IPPROTO_UDP, udp);
602#endif
603 }
604 aps->aps_bytes += fin->fin_plen;
605 aps->aps_pkts++;
606 return 1;
607 }
608 return 0;
609}
610
611
612/*
613 * Search for an proxy by the protocol it is being used with and its name.
614 */
615aproxy_t *appr_lookup(pr, name)
616u_int pr;
617char *name;
618{
619 aproxy_t *ap;
620
621 if (ipf_proxy_debug > 8)
622 printf("appr_lookup(%d,%s)\n", pr, name);
623
624 for (ap = ap_proxies; ap->apr_p; ap++)
625 if ((ap->apr_p == pr) &&
626 !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
627 ap->apr_ref++;
628 return ap;
629 }
630
631 for (ap = ap_proxylist; ap; ap = ap->apr_next)
632 if ((ap->apr_p == pr) &&
633 !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
634 ap->apr_ref++;
635 return ap;
636 }
637 if (ipf_proxy_debug > 2)
638 printf("appr_lookup: failed for %d/%s\n", pr, name);
639 return NULL;
640}
641
642
643void appr_free(ap)
644aproxy_t *ap;
645{
646 ap->apr_ref--;
647}
648
649
650void aps_free(aps)
651ap_session_t *aps;
652{
653 ap_session_t *a, **ap;
654 aproxy_t *apr;
655
656 if (!aps)
657 return;
658
659 for (ap = &ap_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
660 if (a == aps) {
661 *ap = a->aps_next;
662 break;
663 }
664
665 apr = aps->aps_apr;
666 if ((apr != NULL) && (apr->apr_del != NULL))
667 (*apr->apr_del)(aps);
668
669 if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
670 KFREES(aps->aps_data, aps->aps_psiz);
671 KFREE(aps);
672}
673
674
675/*
676 * returns 2 if ack or seq number in TCP header is changed, returns 0 otherwise
677 */
678static int appr_fixseqack(fin, ip, aps, inc)
679fr_info_t *fin;
680ip_t *ip;
681ap_session_t *aps;
682int inc;
683{
684 int sel, ch = 0, out, nlen;
685 u_32_t seq1, seq2;
686 tcphdr_t *tcp;
687 short inc2;
688
689 tcp = (tcphdr_t *)fin->fin_dp;
690 out = fin->fin_out;
691 /*
692 * ip_len has already been adjusted by 'inc'.
693 */
694 nlen = ip->ip_len;
695 nlen -= (IP_HL(ip) << 2) + (TCP_OFF(tcp) << 2);
696
697 inc2 = inc;
698 inc = (int)inc2;
699
700 if (out != 0) {
701 seq1 = (u_32_t)ntohl(tcp->th_seq);
702 sel = aps->aps_sel[out];
703
704 /* switch to other set ? */
705 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
706 (seq1 > aps->aps_seqmin[!sel])) {
707 if (ipf_proxy_debug > 7)
708 printf("proxy out switch set seq %d -> %d %x > %x\n",
709 sel, !sel, seq1,
710 aps->aps_seqmin[!sel]);
711 sel = aps->aps_sel[out] = !sel;
712 }
713
714 if (aps->aps_seqoff[sel]) {
715 seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
716 if (seq1 > seq2) {
717 seq2 = aps->aps_seqoff[sel];
718 seq1 += seq2;
719 tcp->th_seq = htonl(seq1);
720 ch = 1;
721 }
722 }
723
724 if (inc && (seq1 > aps->aps_seqmin[!sel])) {
725 aps->aps_seqmin[sel] = seq1 + nlen - 1;
726 aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
727 if (ipf_proxy_debug > 7)
728 printf("proxy seq set %d at %x to %d + %d\n",
729 sel, aps->aps_seqmin[sel],
730 aps->aps_seqoff[sel], inc);
731 }
732
733 /***/
734
735 seq1 = ntohl(tcp->th_ack);
736 sel = aps->aps_sel[1 - out];
737
738 /* switch to other set ? */
739 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
740 (seq1 > aps->aps_ackmin[!sel])) {
741 if (ipf_proxy_debug > 7)
742 printf("proxy out switch set ack %d -> %d %x > %x\n",
743 sel, !sel, seq1,
744 aps->aps_ackmin[!sel]);
745 sel = aps->aps_sel[1 - out] = !sel;
746 }
747
748 if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
749 seq2 = aps->aps_ackoff[sel];
750 tcp->th_ack = htonl(seq1 - seq2);
751 ch = 1;
752 }
753 } else {
754 seq1 = ntohl(tcp->th_seq);
755 sel = aps->aps_sel[out];
756
757 /* switch to other set ? */
758 if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
759 (seq1 > aps->aps_ackmin[!sel])) {
760 if (ipf_proxy_debug > 7)
761 printf("proxy in switch set ack %d -> %d %x > %x\n",
762 sel, !sel, seq1, aps->aps_ackmin[!sel]);
763 sel = aps->aps_sel[out] = !sel;
764 }
765
766 if (aps->aps_ackoff[sel]) {
767 seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
768 if (seq1 > seq2) {
769 seq2 = aps->aps_ackoff[sel];
770 seq1 += seq2;
771 tcp->th_seq = htonl(seq1);
772 ch = 1;
773 }
774 }
775
776 if (inc && (seq1 > aps->aps_ackmin[!sel])) {
777 aps->aps_ackmin[!sel] = seq1 + nlen - 1;
778 aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;
779
780 if (ipf_proxy_debug > 7)
781 printf("proxy ack set %d at %x to %d + %d\n",
782 !sel, aps->aps_seqmin[!sel],
783 aps->aps_seqoff[sel], inc);
784 }
785
786 /***/
787
788 seq1 = ntohl(tcp->th_ack);
789 sel = aps->aps_sel[1 - out];
790
791 /* switch to other set ? */
792 if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
793 (seq1 > aps->aps_seqmin[!sel])) {
794 if (ipf_proxy_debug > 7)
795 printf("proxy in switch set seq %d -> %d %x > %x\n",
796 sel, !sel, seq1, aps->aps_seqmin[!sel]);
797 sel = aps->aps_sel[1 - out] = !sel;
798 }
799
800 if (aps->aps_seqoff[sel] != 0) {
801 if (ipf_proxy_debug > 7)
802 printf("sel %d seqoff %d seq1 %x seqmin %x\n",
803 sel, aps->aps_seqoff[sel], seq1,
804 aps->aps_seqmin[sel]);
805 if (seq1 > aps->aps_seqmin[sel]) {
806 seq2 = aps->aps_seqoff[sel];
807 tcp->th_ack = htonl(seq1 - seq2);
808 ch = 1;
809 }
810 }
811 }
812
813 if (ipf_proxy_debug > 8)
814 printf("appr_fixseqack: seq %x ack %x\n",
815 ntohl(tcp->th_seq), ntohl(tcp->th_ack));
816 return ch ? 2 : 0;
817}
818
819
820/*
821 * Initialise hook for kernel application proxies.
822 * Call the initialise routine for all the compiled in kernel proxies.
823 */
824int appr_init()
825{
826 aproxy_t *ap;
827 int err = 0;
828
829 for (ap = ap_proxies; ap->apr_p; ap++) {
830 if (ap->apr_init != NULL) {
831 err = (*ap->apr_init)();
832 if (err != 0)
833 break;
834 }
835 }
836 return err;
837}
838
839
840/*
841 * Unload hook for kernel application proxies.
842 * Call the finialise routine for all the compiled in kernel proxies.
843 */
844void appr_unload()
845{
846 aproxy_t *ap;
847
848 for (ap = ap_proxies; ap->apr_p; ap++)
849 if (ap->apr_fini != NULL)
850 (*ap->apr_fini)();
851 for (ap = ap_proxylist; ap; ap = ap->apr_next)
852 if (ap->apr_fini != NULL)
853 (*ap->apr_fini)();
854}