xref: /freebsd/sys/netpfil/ipfilter/netinet/ip_proxy.c (revision 29363fb446372cb3f10bc98664e9767c53fbb457)
1 
2 /*
3  * Copyright (C) 2012 by Darren Reed.
4  *
5  * See the IPFILTER.LICENCE file for details on licencing.
6  */
7 #if defined(KERNEL) || defined(_KERNEL)
8 # undef KERNEL
9 # undef _KERNEL
10 # define        KERNEL	1
11 # define        _KERNEL	1
12 #endif
13 #include <sys/errno.h>
14 #include <sys/types.h>
15 #include <sys/param.h>
16 #include <sys/time.h>
17 #include <sys/file.h>
18 # include <sys/fcntl.h>
19 #if !defined(_KERNEL) && !defined(__KERNEL__)
20 # include <stdio.h>
21 # include <string.h>
22 # include <stdlib.h>
23 # include <ctype.h>
24 # define _KERNEL
25 # include <sys/uio.h>
26 # undef _KERNEL
27 #endif
28 # include <sys/protosw.h>
29 #include <sys/socket.h>
30 #if defined(_KERNEL)
31 #ifdef __FreeBSD__
32 #  include <sys/ctype.h>
33 # endif
34 # include <sys/systm.h>
35 # if !defined(__SVR4)
36 #  include <sys/mbuf.h>
37 # endif
38 #endif
39 #if defined(_KERNEL) && defined(__FreeBSD__)
40 # include <sys/filio.h>
41 # include <sys/fcntl.h>
42 #else
43 # include <sys/ioctl.h>
44 #endif
45 #if defined(__SVR4)
46 # include <sys/byteorder.h>
47 # ifdef _KERNEL
48 #  include <sys/dditypes.h>
49 # endif
50 # include <sys/stream.h>
51 # include <sys/kmem.h>
52 #endif
53 #ifdef __FreeBSD__
54 # include <sys/queue.h>
55 #endif
56 #include <net/if.h>
57 #if defined(__FreeBSD__) && defined(_KERNEL)
58 #include <net/vnet.h>
59 #else
60 #define CURVNET_SET(arg)
61 #define CURVNET_RESTORE()
62 #define	VNET_DEFINE(_t, _v)	_t _v
63 #define	VNET_DECLARE(_t, _v)	extern _t _v
64 #define	VNET(arg)	arg
65 #endif
66 #ifdef sun
67 # include <net/af.h>
68 #endif
69 #include <netinet/in.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/ip.h>
72 # include <netinet/ip_var.h>
73 #include <netinet/tcp.h>
74 #include <netinet/udp.h>
75 #include <netinet/ip_icmp.h>
76 #include "netinet/ip_compat.h"
77 #include <netinet/tcpip.h>
78 #include "netinet/ip_fil.h"
79 #include "netinet/ip_nat.h"
80 #include "netinet/ip_state.h"
81 #include "netinet/ip_proxy.h"
82 #if defined(__FreeBSD__)
83 # include <sys/malloc.h>
84 #endif
85 
86 /* END OF INCLUDES */
87 
88 #include "netinet/ip_ftp_pxy.c"
89 #include "netinet/ip_tftp_pxy.c"
90 #include "netinet/ip_rcmd_pxy.c"
91 #include "netinet/ip_pptp_pxy.c"
92 #if defined(_KERNEL)
93 # include "netinet/ip_irc_pxy.c"
94 # include "netinet/ip_raudio_pxy.c"
95 # include "netinet/ip_netbios_pxy.c"
96 #endif
97 #include "netinet/ip_ipsec_pxy.c"
98 #include "netinet/ip_rpcb_pxy.c"
99 
100 
101 #define	AP_SESS_SIZE	53
102 
103 static int ipf_proxy_fixseqack(fr_info_t *, ip_t *, ap_session_t *, int );
104 static aproxy_t *ipf_proxy_create_clone(ipf_main_softc_t *, aproxy_t *);
105 
106 typedef struct ipf_proxy_softc_s {
107 	int		ips_proxy_debug;
108 	int		ips_proxy_session_size;
109 	ap_session_t	**ips_sess_tab;
110 	ap_session_t	*ips_sess_list;
111 	aproxy_t	*ips_proxies;
112 	int		ips_init_run;
113 	ipftuneable_t	*ipf_proxy_tune;
114 } ipf_proxy_softc_t;
115 
116 static ipftuneable_t ipf_proxy_tuneables[] = {
117 	{ { (void *)offsetof(ipf_proxy_softc_t, ips_proxy_debug) },
118 		"proxy_debug",	0,	0x1f,
119 		stsizeof(ipf_proxy_softc_t, ips_proxy_debug),
120 		0,	NULL,	NULL },
121 	{ { NULL },		NULL,			0,	0,
122 		0,
123 		0,	NULL,	NULL}
124 };
125 
126 static	aproxy_t	*ap_proxylist = NULL;
127 static	aproxy_t	ips_proxies[] = {
128 #ifdef	IPF_FTP_PROXY
129 	{ NULL, NULL, "ftp", (char)IPPROTO_TCP, 0, 0, 0,
130 	  ipf_p_ftp_main_load, ipf_p_ftp_main_unload,
131 	  ipf_p_ftp_soft_create, ipf_p_ftp_soft_destroy,
132 	  NULL, NULL,
133 	  ipf_p_ftp_new, ipf_p_ftp_del, ipf_p_ftp_in, ipf_p_ftp_out, NULL,
134 	  NULL, NULL, NULL, NULL },
135 #endif
136 #ifdef	IPF_TFTP_PROXY
137 	{ NULL, NULL, "tftp", (char)IPPROTO_UDP, 0, 0, 0,
138 	  ipf_p_tftp_main_load, ipf_p_tftp_main_unload,
139 	  ipf_p_tftp_soft_create, ipf_p_tftp_soft_destroy,
140 	  NULL, NULL,
141 	  ipf_p_tftp_new, ipf_p_tftp_del,
142 	  ipf_p_tftp_in, ipf_p_tftp_out, NULL,
143 	  NULL, NULL, NULL, NULL },
144 #endif
145 #ifdef	IPF_IRC_PROXY
146 	{ NULL, NULL, "irc", (char)IPPROTO_TCP, 0, 0, 0,
147 	  ipf_p_irc_main_load, ipf_p_irc_main_unload,
148 	  NULL, NULL,
149 	  NULL, NULL,
150 	  ipf_p_irc_new, NULL, NULL, ipf_p_irc_out, NULL,
151 	  NULL, NULL, NULL, NULL },
152 #endif
153 #ifdef	IPF_RCMD_PROXY
154 	{ NULL, NULL, "rcmd", (char)IPPROTO_TCP, 0, 0, 0,
155 	  ipf_p_rcmd_main_load, ipf_p_rcmd_main_unload,
156 	  NULL, NULL,
157 	  NULL, NULL,
158 	  ipf_p_rcmd_new, ipf_p_rcmd_del,
159 	  ipf_p_rcmd_in, ipf_p_rcmd_out, NULL,
160 	  NULL, NULL, NULL, NULL },
161 #endif
162 #ifdef	IPF_RAUDIO_PROXY
163 	{ NULL, NULL, "raudio", (char)IPPROTO_TCP, 0, 0, 0,
164 	  ipf_p_raudio_main_load, ipf_p_raudio_main_unload,
165 	  NULL, NULL,
166 	  NULL, NULL,
167 	  ipf_p_raudio_new, NULL, ipf_p_raudio_in, ipf_p_raudio_out, NULL,
168 	  NULL, NULL, NULL, NULL },
169 #endif
170 #ifdef	IPF_MSNRPC_PROXY
171 	{ NULL, NULL, "msnrpc", (char)IPPROTO_TCP, 0, 0, 0,
172 	  ipf_p_msnrpc_init, ipf_p_msnrpc_fini,
173 	  NULL, NULL,
174 	  NULL, NULL,
175 	  ipf_p_msnrpc_new, NULL, ipf_p_msnrpc_in, ipf_p_msnrpc_out, NULL,
176 	  NULL, NULL, NULL, NULL },
177 #endif
178 #ifdef	IPF_NETBIOS_PROXY
179 	{ NULL, NULL, "netbios", (char)IPPROTO_UDP, 0, 0, 0,
180 	  ipf_p_netbios_main_load, ipf_p_netbios_main_unload,
181 	  NULL, NULL,
182 	  NULL, NULL,
183 	  NULL, NULL, NULL, ipf_p_netbios_out, NULL,
184 	  NULL, NULL, NULL, NULL },
185 #endif
186 #ifdef	IPF_IPSEC_PROXY
187 	{ NULL, NULL, "ipsec", (char)IPPROTO_UDP, 0, 0, 0,
188 	  NULL, NULL,
189 	  ipf_p_ipsec_soft_create, ipf_p_ipsec_soft_destroy,
190 	  ipf_p_ipsec_soft_init, ipf_p_ipsec_soft_fini,
191 	  ipf_p_ipsec_new, ipf_p_ipsec_del,
192 	  ipf_p_ipsec_inout, ipf_p_ipsec_inout, ipf_p_ipsec_match,
193 	  NULL, NULL, NULL, NULL },
194 #endif
195 #ifdef	IPF_DNS_PROXY
196 	{ NULL, NULL, "dns", (char)IPPROTO_UDP, 0, 0, 0,
197 	  NULL, NULL,
198 	  ipf_p_dns_soft_create, ipf_p_dns_soft_destroy,
199 	  NULL, NULL,
200 	  ipf_p_dns_new, ipf_p_ipsec_del,
201 	  ipf_p_dns_inout, ipf_p_dns_inout, ipf_p_dns_match,
202 	  ipf_p_dns_ctl, NULL, NULL, NULL },
203 #endif
204 #ifdef	IPF_PPTP_PROXY
205 	{ NULL, NULL, "pptp", (char)IPPROTO_TCP, 0, 0, 0,
206 	  ipf_p_pptp_main_load, ipf_p_pptp_main_unload,
207 	  NULL, NULL,
208 	  NULL, NULL,
209 	  ipf_p_pptp_new, ipf_p_pptp_del,
210 	  ipf_p_pptp_inout, ipf_p_pptp_inout, NULL,
211 	  NULL, NULL, NULL, NULL },
212 #endif
213 #ifdef	IPF_RPCB_PROXY
214 # ifndef _KERNEL
215 	{ NULL, NULL, "rpcbt", (char)IPPROTO_TCP, 0, 0, 0,
216 	  NULL, NULL,
217 	  NULL, NULL,
218 	  NULL, NULL,
219 	  ipf_p_rpcb_new, ipf_p_rpcb_del,
220 	  ipf_p_rpcb_in, ipf_p_rpcb_out, NULL,
221 	  NULL, NULL, NULL, NULL },
222 # endif
223 	{ NULL, NULL, "rpcbu", (char)IPPROTO_UDP, 0, 0, 0,
224 	  ipf_p_rpcb_main_load, ipf_p_rpcb_main_unload,
225 	  NULL, NULL,
226 	  NULL, NULL,
227 	  ipf_p_rpcb_new, ipf_p_rpcb_del,
228 	  ipf_p_rpcb_in, ipf_p_rpcb_out, NULL,
229 	  NULL, NULL, NULL, NULL },
230 #endif
231 	{ NULL, NULL, "", '\0', 0, 0, 0,
232 	  NULL, NULL,
233 	  NULL, NULL,
234 	  NULL, NULL,
235 	  NULL, NULL,
236 	  NULL, NULL, NULL,
237 	  NULL, NULL, NULL, NULL }
238 };
239 
240 
241 /* ------------------------------------------------------------------------ */
242 /* Function:    ipf_proxy_main_load                                         */
243 /* Returns:     int    - 0 == success, else failure.                        */
244 /* Parameters:  Nil                                                         */
245 /*                                                                          */
246 /* Initialise hook for kernel application proxies.                          */
247 /* Call the initialise routine for all the compiled in kernel proxies.      */
248 /* ------------------------------------------------------------------------ */
249 int
ipf_proxy_main_load(void)250 ipf_proxy_main_load(void)
251 {
252 	aproxy_t *ap;
253 
254 	for (ap = ips_proxies; ap->apr_p; ap++) {
255 		if (ap->apr_load != NULL)
256 			(*ap->apr_load)();
257 	}
258 	return (0);
259 }
260 
261 
262 /* ------------------------------------------------------------------------ */
263 /* Function:    ipf_proxy_main_unload                                       */
264 /* Returns:     int - 0 == success, else failure.                           */
265 /* Parameters:  Nil                                                         */
266 /*                                                                          */
267 /* Unload hook for kernel application proxies.                              */
268 /* Call the finialise routine for all the compiled in kernel proxies.       */
269 /* ------------------------------------------------------------------------ */
270 int
ipf_proxy_main_unload(void)271 ipf_proxy_main_unload(void)
272 {
273 	aproxy_t *ap;
274 
275 	for (ap = ips_proxies; ap->apr_p; ap++)
276 		if (ap->apr_unload != NULL)
277 			(*ap->apr_unload)();
278 	for (ap = ap_proxylist; ap; ap = ap->apr_next)
279 		if (ap->apr_unload != NULL)
280 			(*ap->apr_unload)();
281 
282 	return (0);
283 }
284 
285 
286 /* ------------------------------------------------------------------------ */
287 /* Function:    ipf_proxy_soft_create                                       */
288 /* Returns:     void *   -                                                  */
289 /* Parameters:  softc(I) - pointer to soft context main structure           */
290 /*                                                                          */
291 /* Build the structure to hold all of the run time data to support proxies. */
292 /* ------------------------------------------------------------------------ */
293 void *
ipf_proxy_soft_create(ipf_main_softc_t * softc)294 ipf_proxy_soft_create(ipf_main_softc_t *softc)
295 {
296 	ipf_proxy_softc_t *softp;
297 	aproxy_t *last;
298 	aproxy_t *apn;
299 	aproxy_t *ap;
300 
301 	KMALLOC(softp, ipf_proxy_softc_t *);
302 	if (softp == NULL)
303 		return (softp);
304 
305 	bzero((char *)softp, sizeof(*softp));
306 
307 #if defined(_KERNEL)
308 	softp->ips_proxy_debug = 0;
309 #else
310 	softp->ips_proxy_debug = 2;
311 #endif
312 	softp->ips_proxy_session_size = AP_SESS_SIZE;
313 
314 	softp->ipf_proxy_tune = ipf_tune_array_copy(softp,
315 						    sizeof(ipf_proxy_tuneables),
316 						    ipf_proxy_tuneables);
317 	if (softp->ipf_proxy_tune == NULL) {
318 		ipf_proxy_soft_destroy(softc, softp);
319 		return (NULL);
320 	}
321 	if (ipf_tune_array_link(softc, softp->ipf_proxy_tune) == -1) {
322 		ipf_proxy_soft_destroy(softc, softp);
323 		return (NULL);
324 	}
325 
326 	last = NULL;
327 	for (ap = ips_proxies; ap->apr_p; ap++) {
328 		apn = ipf_proxy_create_clone(softc, ap);
329 		if (apn == NULL)
330 			goto failed;
331 		if (last != NULL)
332 			last->apr_next = apn;
333 		else
334 			softp->ips_proxies = apn;
335 		last = apn;
336 	}
337 	for (ap = ips_proxies; ap != NULL; ap = ap->apr_next) {
338 		apn = ipf_proxy_create_clone(softc, ap);
339 		if (apn == NULL)
340 			goto failed;
341 		if (last != NULL)
342 			last->apr_next = apn;
343 		else
344 			softp->ips_proxies = apn;
345 		last = apn;
346 	}
347 
348 	return (softp);
349 failed:
350 	ipf_proxy_soft_destroy(softc, softp);
351 	return (NULL);
352 }
353 
354 
355 /* ------------------------------------------------------------------------ */
356 /* Function:    ipf_proxy_soft_create                                       */
357 /* Returns:     void *   -                                                  */
358 /* Parameters:  softc(I) - pointer to soft context main structure           */
359 /*              orig(I)  - pointer to proxy definition to copy              */
360 /*                                                                          */
361 /* This function clones a proxy definition given by orig and returns a      */
362 /* a pointer to that copy.                                                  */
363 /* ------------------------------------------------------------------------ */
364 static aproxy_t *
ipf_proxy_create_clone(ipf_main_softc_t * softc,aproxy_t * orig)365 ipf_proxy_create_clone(ipf_main_softc_t *softc, aproxy_t *orig)
366 {
367 	aproxy_t *apn;
368 
369 	KMALLOC(apn, aproxy_t *);
370 	if (apn == NULL)
371 		return (NULL);
372 
373 	bcopy((char *)orig, (char *)apn, sizeof(*apn));
374 	apn->apr_next = NULL;
375 	apn->apr_soft = NULL;
376 
377 	if (apn->apr_create != NULL) {
378 		apn->apr_soft = (*apn->apr_create)(softc);
379 		if (apn->apr_soft == NULL) {
380 			KFREE(apn);
381 			return (NULL);
382 		}
383 	}
384 
385 	apn->apr_parent = orig;
386 	orig->apr_clones++;
387 
388 	return (apn);
389 }
390 
391 
392 /* ------------------------------------------------------------------------ */
393 /* Function:    ipf_proxy_soft_create                                       */
394 /* Returns:     int      - 0 == success, else failure.                      */
395 /* Parameters:  softc(I) - pointer to soft context main structure           */
396 /*              arg(I)   - pointer to proxy contect data                    */
397 /*                                                                          */
398 /* Initialise the proxy context and walk through each of the proxies and    */
399 /* call its initialisation function. This allows for proxies to do any      */
400 /* local setup prior to actual use.                                         */
401 /* ------------------------------------------------------------------------ */
402 int
ipf_proxy_soft_init(ipf_main_softc_t * softc,void * arg)403 ipf_proxy_soft_init(ipf_main_softc_t *softc, void *arg)
404 {
405 	ipf_proxy_softc_t *softp;
406 	aproxy_t *ap;
407 	u_int size;
408 	int err;
409 
410 	softp = arg;
411 	size = softp->ips_proxy_session_size * sizeof(ap_session_t *);
412 
413 	KMALLOCS(softp->ips_sess_tab, ap_session_t **, size);
414 
415 	if (softp->ips_sess_tab == NULL)
416 		return (-1);
417 
418 	bzero(softp->ips_sess_tab, size);
419 
420 	for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) {
421 		if (ap->apr_init != NULL) {
422 			err = (*ap->apr_init)(softc, ap->apr_soft);
423 			if (err != 0)
424 				return (-2);
425 		}
426 	}
427 	softp->ips_init_run = 1;
428 
429 	return (0);
430 }
431 
432 
433 /* ------------------------------------------------------------------------ */
434 /* Function:    ipf_proxy_soft_create                                       */
435 /* Returns:     int      - 0 == success, else failure.                      */
436 /* Parameters:  softc(I) - pointer to soft context main structure           */
437 /*              arg(I)   - pointer to proxy contect data                    */
438 /*                                                                          */
439 /* This function should always succeed. It is responsible for ensuring that */
440 /* the proxy context can be safely called when ipf_proxy_soft_destroy is    */
441 /* called and suring all of the proxies have similarly been instructed.     */
442 /* ------------------------------------------------------------------------ */
443 int
ipf_proxy_soft_fini(ipf_main_softc_t * softc,void * arg)444 ipf_proxy_soft_fini(ipf_main_softc_t *softc, void *arg)
445 {
446 	ipf_proxy_softc_t *softp = arg;
447 	aproxy_t *ap;
448 
449 	for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next) {
450 		if (ap->apr_fini != NULL) {
451 			(*ap->apr_fini)(softc, ap->apr_soft);
452 		}
453 	}
454 
455 	if (softp->ips_sess_tab != NULL) {
456 		KFREES(softp->ips_sess_tab,
457 		       softp->ips_proxy_session_size * sizeof(ap_session_t *));
458 		softp->ips_sess_tab = NULL;
459 	}
460 	softp->ips_init_run = 0;
461 
462 	return (0);
463 }
464 
465 
466 /* ------------------------------------------------------------------------ */
467 /* Function:    ipf_proxy_soft_destroy                                      */
468 /* Returns:     Nil                                                         */
469 /* Parameters:  softc(I) - pointer to soft context main structure           */
470 /*              arg(I)   - pointer to proxy contect data                    */
471 /*                                                                          */
472 /* Free up all of the local data structures allocated during creation.      */
473 /* ------------------------------------------------------------------------ */
474 void
ipf_proxy_soft_destroy(ipf_main_softc_t * softc,void * arg)475 ipf_proxy_soft_destroy(ipf_main_softc_t *softc, void *arg)
476 {
477 	ipf_proxy_softc_t *softp = arg;
478 	aproxy_t *ap;
479 
480 	while ((ap = softp->ips_proxies) != NULL) {
481 		softp->ips_proxies = ap->apr_next;
482 		if (ap->apr_destroy != NULL)
483 			(*ap->apr_destroy)(softc, ap->apr_soft);
484 		ap->apr_parent->apr_clones--;
485 		KFREE(ap);
486 	}
487 
488 	if (softp->ipf_proxy_tune != NULL) {
489 		ipf_tune_array_unlink(softc, softp->ipf_proxy_tune);
490 		KFREES(softp->ipf_proxy_tune, sizeof(ipf_proxy_tuneables));
491 		softp->ipf_proxy_tune = NULL;
492 	}
493 
494 	KFREE(softp);
495 }
496 
497 
498 /* ------------------------------------------------------------------------ */
499 /* Function:    ipf_proxy_flush                                             */
500 /* Returns:     Nil                                                         */
501 /* Parameters:  arg(I)   - pointer to proxy contect data                    */
502 /*              how(I)   - indicates the type of flush operation            */
503 /*                                                                          */
504 /* Walk through all of the proxies and pass on the flush command as either  */
505 /* a flush or a clear.                                                      */
506 /* ------------------------------------------------------------------------ */
507 void
ipf_proxy_flush(void * arg,int how)508 ipf_proxy_flush(void *arg, int how)
509 {
510 	ipf_proxy_softc_t *softp = arg;
511 	aproxy_t *ap;
512 
513 	switch (how)
514 	{
515 	case 0 :
516 		for (ap = softp->ips_proxies; ap; ap = ap->apr_next)
517 			if (ap->apr_flush != NULL)
518 				(*ap->apr_flush)(ap, how);
519 		break;
520 	case 1 :
521 		for (ap = softp->ips_proxies; ap; ap = ap->apr_next)
522 			if (ap->apr_clear != NULL)
523 				(*ap->apr_clear)(ap);
524 		break;
525 	default :
526 		break;
527 	}
528 }
529 
530 
531 /* ------------------------------------------------------------------------ */
532 /* Function:    ipf_proxy_add                                               */
533 /* Returns:     int   - 0 == success, else failure.                         */
534 /* Parameters:  ap(I) - pointer to proxy structure                          */
535 /*                                                                          */
536 /* Dynamically add a new kernel proxy.  Ensure that it is unique in the     */
537 /* collection compiled in and dynamically added.                            */
538 /* ------------------------------------------------------------------------ */
539 int
ipf_proxy_add(void * arg,aproxy_t * ap)540 ipf_proxy_add(void *arg, aproxy_t *ap)
541 {
542 	ipf_proxy_softc_t *softp = arg;
543 
544 	aproxy_t *a;
545 
546 	for (a = ips_proxies; a->apr_p; a++)
547 		if ((a->apr_p == ap->apr_p) &&
548 		    !strncmp(a->apr_label, ap->apr_label,
549 			     sizeof(ap->apr_label))) {
550 			if (softp->ips_proxy_debug & 0x01)
551 				printf("ipf_proxy_add: %s/%d present (B)\n",
552 				       a->apr_label, a->apr_p);
553 			return (-1);
554 		}
555 
556 	for (a = ap_proxylist; (a != NULL); a = a->apr_next)
557 		if ((a->apr_p == ap->apr_p) &&
558 		    !strncmp(a->apr_label, ap->apr_label,
559 			     sizeof(ap->apr_label))) {
560 			if (softp->ips_proxy_debug & 0x01)
561 				printf("ipf_proxy_add: %s/%d present (D)\n",
562 				       a->apr_label, a->apr_p);
563 			return (-1);
564 		}
565 	ap->apr_next = ap_proxylist;
566 	ap_proxylist = ap;
567 	if (ap->apr_load != NULL)
568 		(*ap->apr_load)();
569 	return (0);
570 }
571 
572 
573 /* ------------------------------------------------------------------------ */
574 /* Function:    ipf_proxy_ctl                                               */
575 /* Returns:     int    - 0 == success, else error                           */
576 /* Parameters:  softc(I) - pointer to soft context main structure           */
577 /*              arg(I)   - pointer to proxy context                         */
578 /*              ctl(I)   - pointer to proxy control structure               */
579 /*                                                                          */
580 /* Check to see if the proxy this control request has come through for      */
581 /* exists, and if it does and it has a control function then invoke that    */
582 /* control function.                                                        */
583 /* ------------------------------------------------------------------------ */
584 int
ipf_proxy_ctl(ipf_main_softc_t * softc,void * arg,ap_ctl_t * ctl)585 ipf_proxy_ctl(ipf_main_softc_t *softc, void *arg, ap_ctl_t *ctl)
586 {
587 	ipf_proxy_softc_t *softp = arg;
588 	aproxy_t *a;
589 	int error;
590 
591 	a = ipf_proxy_lookup(arg, ctl->apc_p, ctl->apc_label);
592 	if (a == NULL) {
593 		if (softp->ips_proxy_debug & 0x01)
594 			printf("ipf_proxy_ctl: can't find %s/%d\n",
595 				ctl->apc_label, ctl->apc_p);
596 		IPFERROR(80001);
597 		error = ESRCH;
598 	} else if (a->apr_ctl == NULL) {
599 		if (softp->ips_proxy_debug & 0x01)
600 			printf("ipf_proxy_ctl: no ctl function for %s/%d\n",
601 				ctl->apc_label, ctl->apc_p);
602 		IPFERROR(80002);
603 		error = ENXIO;
604 	} else {
605 		error = (*a->apr_ctl)(softc, a->apr_soft, ctl);
606 		if ((error != 0) && (softp->ips_proxy_debug & 0x02))
607 			printf("ipf_proxy_ctl: %s/%d ctl error %d\n",
608 				a->apr_label, a->apr_p, error);
609 	}
610 	return (error);
611 }
612 
613 
614 /* ------------------------------------------------------------------------ */
615 /* Function:    ipf_proxy_del                                               */
616 /* Returns:     int   - 0 == success, else failure.                         */
617 /* Parameters:  ap(I) - pointer to proxy structure                          */
618 /*                                                                          */
619 /* Delete a proxy that has been added dynamically from those available.     */
620 /* If it is in use, return 1 (do not destroy NOW), not in use 0 or -1       */
621 /* if it cannot be matched.                                                 */
622 /* ------------------------------------------------------------------------ */
623 int
ipf_proxy_del(aproxy_t * ap)624 ipf_proxy_del(aproxy_t *ap)
625 {
626 	aproxy_t *a, **app;
627 
628 	for (app = &ap_proxylist; ((a = *app) != NULL); app = &a->apr_next) {
629 		if (a == ap) {
630 			a->apr_flags |= APR_DELETE;
631 			if (ap->apr_ref == 0 && ap->apr_clones == 0) {
632 				*app = a->apr_next;
633 				return (0);
634 			}
635 			return (1);
636 		}
637 	}
638 
639 	return (-1);
640 }
641 
642 
643 /* ------------------------------------------------------------------------ */
644 /* Function:    ipf_proxy_ok                                                */
645 /* Returns:     int    - 1 == good match else not.                          */
646 /* Parameters:  fin(I) - pointer to packet information                      */
647 /*              tcp(I) - pointer to TCP/UDP header                          */
648 /*              nat(I) - pointer to current NAT session                     */
649 /*                                                                          */
650 /* This function extends the NAT matching to ensure that a packet that has  */
651 /* arrived matches the proxy information attached to the NAT rule. Notably, */
652 /* if the proxy is scheduled to be deleted then packets will not match the  */
653 /* rule even if the rule is still active.                                   */
654 /* ------------------------------------------------------------------------ */
655 int
ipf_proxy_ok(fr_info_t * fin,tcphdr_t * tcp,ipnat_t * np)656 ipf_proxy_ok(fr_info_t *fin, tcphdr_t *tcp, ipnat_t *np)
657 {
658 	aproxy_t *apr = np->in_apr;
659 	u_short dport = np->in_odport;
660 
661 	if ((apr == NULL) || (apr->apr_flags & APR_DELETE) ||
662 	    (fin->fin_p != apr->apr_p))
663 		return (0);
664 	if ((tcp == NULL) && dport)
665 		return (0);
666 	return (1);
667 }
668 
669 
670 /* ------------------------------------------------------------------------ */
671 /* Function:    ipf_proxy_ioctl                                             */
672 /* Returns:     int    - 0 == success, else error                           */
673 /* Parameters:  softc(I) - pointer to soft context main structure           */
674 /*              data(I)  - pointer to ioctl data                            */
675 /*              cmd(I)   - ioctl command                                    */
676 /*              mode(I)  - mode bits for device                             */
677 /*              ctx(I)   - pointer to context information                   */
678 /*                                                                          */
679 /* ------------------------------------------------------------------------ */
680 int
ipf_proxy_ioctl(ipf_main_softc_t * softc,caddr_t data,ioctlcmd_t cmd,int mode,void * ctx)681 ipf_proxy_ioctl(ipf_main_softc_t *softc, caddr_t data, ioctlcmd_t cmd,
682 	int mode, void *ctx)
683 {
684 	ap_ctl_t ctl;
685 	caddr_t ptr;
686 	int error;
687 
688 	mode = mode;	/* LINT */
689 
690 	switch (cmd)
691 	{
692 	case SIOCPROXY :
693 		error = ipf_inobj(softc, data, NULL, &ctl, IPFOBJ_PROXYCTL);
694 		if (error != 0) {
695 			return (error);
696 		}
697 		ptr = NULL;
698 
699 		if (ctl.apc_dsize > 0) {
700 			KMALLOCS(ptr, caddr_t, ctl.apc_dsize);
701 			if (ptr == NULL) {
702 				IPFERROR(80003);
703 				error = ENOMEM;
704 			} else {
705 				error = copyinptr(softc, ctl.apc_data, ptr,
706 						  ctl.apc_dsize);
707 				if (error == 0)
708 					ctl.apc_data = ptr;
709 			}
710 		} else {
711 			ctl.apc_data = NULL;
712 			error = 0;
713 		}
714 
715 		if (error == 0)
716 			error = ipf_proxy_ctl(softc, softc->ipf_proxy_soft,
717 					      &ctl);
718 
719 		if ((error != 0) && (ptr != NULL)) {
720 			KFREES(ptr, ctl.apc_dsize);
721 		}
722 		break;
723 
724 	default :
725 		IPFERROR(80004);
726 		error = EINVAL;
727 	}
728 	return (error);
729 }
730 
731 
732 /* ------------------------------------------------------------------------ */
733 /* Function:    ipf_proxy_match                                             */
734 /* Returns:     int    - 0 == success, else error                           */
735 /* Parameters:  fin(I) - pointer to packet information                      */
736 /*              nat(I) - pointer to current NAT session                     */
737 /*                                                                          */
738 /* If a proxy has a match function, call that to do extended packet         */
739 /* matching. Whilst other parts of the NAT code are rather lenient when it  */
740 /* comes to the quality of the packet that it will transform, the proxy     */
741 /* matching is not because they need to work with data, not just headers.   */
742 /* ------------------------------------------------------------------------ */
743 int
ipf_proxy_match(fr_info_t * fin,nat_t * nat)744 ipf_proxy_match(fr_info_t *fin, nat_t *nat)
745 {
746 	ipf_main_softc_t *softc = fin->fin_main_soft;
747 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
748 	aproxy_t *apr;
749 	ipnat_t *ipn;
750 	int result;
751 
752 	ipn = nat->nat_ptr;
753 	if (softp->ips_proxy_debug & 0x04)
754 		printf("ipf_proxy_match(%lx,%lx) aps %lx ptr %lx\n",
755 			(u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
756 			(u_long)ipn);
757 
758 	if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
759 		if (softp->ips_proxy_debug & 0x08)
760 			printf("ipf_proxy_match: flx 0x%x (BAD|SHORT)\n",
761 				fin->fin_flx);
762 		return (-1);
763 	}
764 
765 	apr = ipn->in_apr;
766 	if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
767 		if (softp->ips_proxy_debug & 0x08)
768 			printf("ipf_proxy_match:apr %lx apr_flags 0x%x\n",
769 				(u_long)apr, apr ? apr->apr_flags : 0);
770 		return (-1);
771 	}
772 
773 	if (apr->apr_match != NULL) {
774 		result = (*apr->apr_match)(fin, nat->nat_aps, nat);
775 		if (result != 0) {
776 			if (softp->ips_proxy_debug & 0x08)
777 				printf("ipf_proxy_match: result %d\n", result);
778 			return (-1);
779 		}
780 	}
781 	return (0);
782 }
783 
784 
785 /* ------------------------------------------------------------------------ */
786 /* Function:    ipf_proxy_new                                               */
787 /* Returns:     int    - 0 == success, else error                           */
788 /* Parameters:  fin(I) - pointer to packet information                      */
789 /*              nat(I) - pointer to current NAT session                     */
790 /*                                                                          */
791 /* Allocate a new application proxy structure and fill it in with the       */
792 /* relevant details.  call the init function once complete, prior to        */
793 /* returning.                                                               */
794 /* ------------------------------------------------------------------------ */
795 int
ipf_proxy_new(fr_info_t * fin,nat_t * nat)796 ipf_proxy_new(fr_info_t *fin, nat_t *nat)
797 {
798 	ipf_main_softc_t *softc = fin->fin_main_soft;
799 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
800 	register ap_session_t *aps;
801 	aproxy_t *apr;
802 
803 	if (softp->ips_proxy_debug & 0x04)
804 		printf("ipf_proxy_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);
805 
806 	if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
807 		if (softp->ips_proxy_debug & 0x08)
808 			printf("ipf_proxy_new: nat_ptr %lx nat_aps %lx\n",
809 				(u_long)nat->nat_ptr, (u_long)nat->nat_aps);
810 		return (-1);
811 	}
812 
813 	apr = nat->nat_ptr->in_apr;
814 
815 	if ((apr->apr_flags & APR_DELETE) ||
816 	    (fin->fin_p != apr->apr_p)) {
817 		if (softp->ips_proxy_debug & 0x08)
818 			printf("ipf_proxy_new: apr_flags 0x%x p %d/%d\n",
819 				apr->apr_flags, fin->fin_p, apr->apr_p);
820 		return (-1);
821 	}
822 
823 	KMALLOC(aps, ap_session_t *);
824 	if (!aps) {
825 		if (softp->ips_proxy_debug & 0x08)
826 			printf("ipf_proxy_new: malloc failed (%lu)\n",
827 				(u_long)sizeof(ap_session_t));
828 		return (-1);
829 	}
830 
831 	bzero((char *)aps, sizeof(*aps));
832 	aps->aps_data = NULL;
833 	aps->aps_apr = apr;
834 	aps->aps_psiz = 0;
835 	if (apr->apr_new != NULL)
836 		if ((*apr->apr_new)(apr->apr_soft, fin, aps, nat) == -1) {
837 			if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
838 				KFREES(aps->aps_data, aps->aps_psiz);
839 			}
840 			KFREE(aps);
841 			if (softp->ips_proxy_debug & 0x08)
842 				printf("ipf_proxy_new: new(%lx) failed\n",
843 					(u_long)apr->apr_new);
844 			return (-1);
845 		}
846 	aps->aps_nat = nat;
847 	aps->aps_next = softp->ips_sess_list;
848 	softp->ips_sess_list = aps;
849 	nat->nat_aps = aps;
850 
851 	return (0);
852 }
853 
854 
855 /* ------------------------------------------------------------------------ */
856 /* Function:    ipf_proxy_check                                             */
857 /* Returns:     int - -1 == error, 1 == success                             */
858 /* Parameters:  fin(I) - pointer to packet information                      */
859 /*              nat(I) - pointer to current NAT session                     */
860 /*                                                                          */
861 /* Check to see if a packet should be passed through an active proxy        */
862 /* routine if one has been setup for it.  We don't need to check the        */
863 /* checksum here if IPFILTER_CKSUM is defined because if it is, a failed    */
864 /* check causes FI_BAD to be set.                                           */
865 /* ------------------------------------------------------------------------ */
866 int
ipf_proxy_check(fr_info_t * fin,nat_t * nat)867 ipf_proxy_check(fr_info_t *fin, nat_t *nat)
868 {
869 	ipf_main_softc_t *softc = fin->fin_main_soft;
870 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
871 #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
872 	mb_t *m;
873 #endif
874 	tcphdr_t *tcp = NULL;
875 	udphdr_t *udp = NULL;
876 	ap_session_t *aps;
877 	aproxy_t *apr;
878 	short adjlen;
879 	int dosum;
880 	ip_t *ip;
881 	short rv;
882 	int err;
883 #if !defined(_KERNEL) || SOLARIS || defined(__FreeBSD__)
884 	u_32_t s1, s2, sd;
885 #endif
886 
887 	if (fin->fin_flx & FI_BAD) {
888 		if (softp->ips_proxy_debug & 0x08)
889 			printf("ipf_proxy_check: flx 0x%x (BAD)\n",
890 			       fin->fin_flx);
891 		return (-1);
892 	}
893 
894 #ifndef IPFILTER_CKSUM
895 	if ((fin->fin_out == 0) && (ipf_checkl4sum(fin) == -1)) {
896 		if (softp->ips_proxy_debug & 0x08)
897 			printf("ipf_proxy_check: l4 checksum failure %d\n",
898 				fin->fin_p);
899 		if (fin->fin_p == IPPROTO_TCP)
900 			softc->ipf_stats[fin->fin_out].fr_tcpbad++;
901 		return (-1);
902 	}
903 #endif
904 
905 	aps = nat->nat_aps;
906 	if (aps != NULL) {
907 		/*
908 		 * If there is data in this packet to be proxied then try and
909 		 * get it all into the one buffer, else drop it.
910 		 */
911 #if SOLARIS || defined(HAVE_M_PULLDOWN)
912 		if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
913 			if (ipf_coalesce(fin) == -1) {
914 				if (softp->ips_proxy_debug & 0x08)
915 					printf("ipf_proxy_check: %s %x\n",
916 					       "coalesce failed", fin->fin_flx);
917 				return (-1);
918 			}
919 #endif
920 		ip = fin->fin_ip;
921 		if (fin->fin_cksum > FI_CK_SUMOK)
922 			dosum = 0;
923 		else
924 			dosum = 1;
925 
926 		switch (fin->fin_p)
927 		{
928 		case IPPROTO_TCP :
929 			tcp = (tcphdr_t *)fin->fin_dp;
930 #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
931 			m = fin->fin_qfm;
932 			if (dohwcksum && (m->b_ick_flag == ICK_VALID))
933 				dosum = 0;
934 #endif
935 			break;
936 		case IPPROTO_UDP :
937 			udp = (udphdr_t *)fin->fin_dp;
938 			break;
939 		default :
940 			break;
941 		}
942 
943 		apr = aps->aps_apr;
944 		err = 0;
945 		if (fin->fin_out != 0) {
946 			if (apr->apr_outpkt != NULL)
947 				err = (*apr->apr_outpkt)(apr->apr_soft, fin,
948 							 aps, nat);
949 		} else {
950 			if (apr->apr_inpkt != NULL)
951 				err = (*apr->apr_inpkt)(apr->apr_soft, fin,
952 							aps, nat);
953 		}
954 
955 		rv = APR_EXIT(err);
956 		if (((softp->ips_proxy_debug & 0x08) && (rv != 0)) ||
957 		    (softp->ips_proxy_debug & 0x04))
958 			printf("ipf_proxy_check: out %d err %x rv %d\n",
959 				fin->fin_out, err, rv);
960 		if (rv == 1)
961 			return (-1);
962 
963 		if (rv == 2) {
964 			ipf_proxy_deref(apr);
965 			nat->nat_aps = NULL;
966 			return (-1);
967 		}
968 
969 		/*
970 		 * If err != 0 then the data size of the packet has changed
971 		 * so we need to recalculate the header checksums for the
972 		 * packet.
973 		 */
974 		adjlen = APR_INC(err);
975 #if !defined(_KERNEL) || SOLARIS || defined(__FreeBSD__)
976 		s1 = LONG_SUM(fin->fin_plen - adjlen);
977 		s2 = LONG_SUM(fin->fin_plen);
978 		CALC_SUMD(s1, s2, sd);
979 		if ((err != 0) && (fin->fin_cksum < FI_CK_L4PART) &&
980 		    fin->fin_v == 4)
981 			ipf_fix_outcksum(0, &ip->ip_sum, sd, 0);
982 #endif
983 		if (fin->fin_flx & FI_DOCKSUM)
984 			dosum = 1;
985 
986 		/*
987 		 * For TCP packets, we may need to adjust the sequence and
988 		 * acknowledgement numbers to reflect changes in size of the
989 		 * data stream.
990 		 *
991 		 * For both TCP and UDP, recalculate the layer 4 checksum,
992 		 * regardless, as we can't tell (here) if data has been
993 		 * changed or not.
994 		 */
995 		if (tcp != NULL) {
996 			err = ipf_proxy_fixseqack(fin, ip, aps, adjlen);
997 			if (fin->fin_cksum == FI_CK_L4PART) {
998 				u_short sum = ntohs(tcp->th_sum);
999 				sum += adjlen;
1000 				tcp->th_sum = htons(sum);
1001 			} else if (fin->fin_cksum < FI_CK_L4PART) {
1002 				tcp->th_sum = fr_cksum(fin, ip,
1003 						       IPPROTO_TCP, tcp);
1004 			}
1005 		} else if ((udp != NULL) && (udp->uh_sum != 0)) {
1006 			if (fin->fin_cksum == FI_CK_L4PART) {
1007 				u_short sum = ntohs(udp->uh_sum);
1008 				sum += adjlen;
1009 				udp->uh_sum = htons(sum);
1010 			} else if (dosum) {
1011 				udp->uh_sum = fr_cksum(fin, ip,
1012 						       IPPROTO_UDP, udp);
1013 			}
1014 		}
1015 		aps->aps_bytes += fin->fin_plen;
1016 		aps->aps_pkts++;
1017 	}
1018 	return (1);
1019 }
1020 
1021 
1022 /* ------------------------------------------------------------------------ */
1023 /* Function:    ipf_proxy_lookup                                            */
1024 /* Returns:     int - -1 == error, 0 == success                             */
1025 /* Parameters:  arg(I)  - pointer to proxy context information              */
1026 /*              pr(I)   - protocol number for proxy                         */
1027 /*              name(I) - proxy name                                        */
1028 /*                                                                          */
1029 /* Search for a proxy by the protocol being used and by its name.           */
1030 /* ------------------------------------------------------------------------ */
1031 aproxy_t *
ipf_proxy_lookup(void * arg,u_int pr,char * name)1032 ipf_proxy_lookup(void *arg, u_int pr, char *name)
1033 {
1034 	ipf_proxy_softc_t *softp = arg;
1035 	aproxy_t *ap;
1036 
1037 	if (softp->ips_proxy_debug & 0x04)
1038 		printf("ipf_proxy_lookup(%d,%s)\n", pr, name);
1039 
1040 	for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next)
1041 		if ((ap->apr_p == pr) &&
1042 		    !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
1043 			ap->apr_ref++;
1044 			return (ap);
1045 		}
1046 
1047 	if (softp->ips_proxy_debug & 0x08)
1048 		printf("ipf_proxy_lookup: failed for %d/%s\n", pr, name);
1049 	return (NULL);
1050 }
1051 
1052 
1053 /* ------------------------------------------------------------------------ */
1054 /* Function:    ipf_proxy_deref                                             */
1055 /* Returns:     Nil                                                         */
1056 /* Parameters:  ap(I) - pointer to proxy structure                          */
1057 /*                                                                          */
1058 /* Drop the reference counter associated with the proxy.                    */
1059 /* ------------------------------------------------------------------------ */
1060 void
ipf_proxy_deref(aproxy_t * ap)1061 ipf_proxy_deref(aproxy_t *ap)
1062 {
1063 	ap->apr_ref--;
1064 }
1065 
1066 
1067 /* ------------------------------------------------------------------------ */
1068 /* Function:    ipf_proxy_free                                              */
1069 /* Returns:     Nil                                                         */
1070 /* Parameters:  softc(I) - pointer to soft context main structure           */
1071 /*              aps(I)   - pointer to current proxy session                 */
1072 /* Locks Held:  ipf_nat_new, ipf_nat(W)                                     */
1073 /*                                                                          */
1074 /* Free up proxy session information allocated to be used with a NAT        */
1075 /* session.                                                                 */
1076 /* ------------------------------------------------------------------------ */
1077 void
ipf_proxy_free(ipf_main_softc_t * softc,ap_session_t * aps)1078 ipf_proxy_free(ipf_main_softc_t *softc, ap_session_t *aps)
1079 {
1080 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
1081 	ap_session_t *a, **ap;
1082 	aproxy_t *apr;
1083 
1084 	if (!aps)
1085 		return;
1086 
1087 	for (ap = &softp->ips_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
1088 		if (a == aps) {
1089 			*ap = a->aps_next;
1090 			break;
1091 		}
1092 
1093 	apr = aps->aps_apr;
1094 	if ((apr != NULL) && (apr->apr_del != NULL))
1095 		(*apr->apr_del)(softc, aps);
1096 
1097 	if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
1098 		KFREES(aps->aps_data, aps->aps_psiz);
1099 	KFREE(aps);
1100 }
1101 
1102 
1103 /* ------------------------------------------------------------------------ */
1104 /* Function:    ipf_proxy_fixseqack                                         */
1105 /* Returns:     int    - 2 if TCP ack/seq is changed, else 0                */
1106 /* Parameters:  fin(I) - pointer to packet information                      */
1107 /*              ip(I)  - pointer to IP header                               */
1108 /*              nat(I) - pointer to current NAT session                     */
1109 /*              inc(I) - delta to apply to TCP sequence numbering           */
1110 /*                                                                          */
1111 /* Adjust the TCP sequence/acknowledge numbers in the TCP header based on   */
1112 /* whether or not the new header is past the point at which an adjustment   */
1113 /* occurred. This might happen because of (say) an FTP string being changed */
1114 /* and the new string being a different length to the old.                  */
1115 /* ------------------------------------------------------------------------ */
1116 static int
ipf_proxy_fixseqack(fr_info_t * fin,ip_t * ip,ap_session_t * aps,int inc)1117 ipf_proxy_fixseqack(fr_info_t *fin, ip_t *ip, ap_session_t *aps, int inc)
1118 {
1119 	ipf_main_softc_t *softc = fin->fin_main_soft;
1120 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
1121 	int sel, ch = 0, out, nlen;
1122 	u_32_t seq1, seq2;
1123 	tcphdr_t *tcp;
1124 	short inc2;
1125 
1126 	tcp = (tcphdr_t *)fin->fin_dp;
1127 	out = fin->fin_out;
1128 	/*
1129 	 * ip_len has already been adjusted by 'inc'.
1130 	 */
1131 	nlen = fin->fin_dlen;
1132 	nlen -= (TCP_OFF(tcp) << 2);
1133 
1134 	inc2 = inc;
1135 	inc = (int)inc2;
1136 
1137 	if (out != 0) {
1138 		seq1 = (u_32_t)ntohl(tcp->th_seq);
1139 		sel = aps->aps_sel[out];
1140 
1141 		/* switch to other set ? */
1142 		if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
1143 		    (seq1 > aps->aps_seqmin[!sel])) {
1144 			if (softp->ips_proxy_debug & 0x10)
1145 				printf("proxy out switch set seq %d -> %d %x > %x\n",
1146 					sel, !sel, seq1,
1147 					aps->aps_seqmin[!sel]);
1148 			sel = aps->aps_sel[out] = !sel;
1149 		}
1150 
1151 		if (aps->aps_seqoff[sel]) {
1152 			seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
1153 			if (seq1 > seq2) {
1154 				seq2 = aps->aps_seqoff[sel];
1155 				seq1 += seq2;
1156 				tcp->th_seq = htonl(seq1);
1157 				ch = 1;
1158 			}
1159 		}
1160 
1161 		if (inc && (seq1 > aps->aps_seqmin[!sel])) {
1162 			aps->aps_seqmin[sel] = seq1 + nlen - 1;
1163 			aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
1164 			if (softp->ips_proxy_debug & 0x10)
1165 				printf("proxy seq set %d at %x to %d + %d\n",
1166 					sel, aps->aps_seqmin[sel],
1167 					aps->aps_seqoff[sel], inc);
1168 		}
1169 
1170 		/***/
1171 
1172 		seq1 = ntohl(tcp->th_ack);
1173 		sel = aps->aps_sel[1 - out];
1174 
1175 		/* switch to other set ? */
1176 		if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
1177 		    (seq1 > aps->aps_ackmin[!sel])) {
1178 			if (softp->ips_proxy_debug & 0x10)
1179 				printf("proxy out switch set ack %d -> %d %x > %x\n",
1180 					sel, !sel, seq1,
1181 					aps->aps_ackmin[!sel]);
1182 			sel = aps->aps_sel[1 - out] = !sel;
1183 		}
1184 
1185 		if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
1186 			seq2 = aps->aps_ackoff[sel];
1187 			tcp->th_ack = htonl(seq1 - seq2);
1188 			ch = 1;
1189 		}
1190 	} else {
1191 		seq1 = ntohl(tcp->th_seq);
1192 		sel = aps->aps_sel[out];
1193 
1194 		/* switch to other set ? */
1195 		if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
1196 		    (seq1 > aps->aps_ackmin[!sel])) {
1197 			if (softp->ips_proxy_debug & 0x10)
1198 				printf("proxy in switch set ack %d -> %d %x > %x\n",
1199 					sel, !sel, seq1, aps->aps_ackmin[!sel]);
1200 			sel = aps->aps_sel[out] = !sel;
1201 		}
1202 
1203 		if (aps->aps_ackoff[sel]) {
1204 			seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
1205 			if (seq1 > seq2) {
1206 				seq2 = aps->aps_ackoff[sel];
1207 				seq1 += seq2;
1208 				tcp->th_seq = htonl(seq1);
1209 				ch = 1;
1210 			}
1211 		}
1212 
1213 		if (inc && (seq1 > aps->aps_ackmin[!sel])) {
1214 			aps->aps_ackmin[!sel] = seq1 + nlen - 1;
1215 			aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;
1216 
1217 			if (softp->ips_proxy_debug & 0x10)
1218 				printf("proxy ack set %d at %x to %d + %d\n",
1219 					!sel, aps->aps_seqmin[!sel],
1220 					aps->aps_seqoff[sel], inc);
1221 		}
1222 
1223 		/***/
1224 
1225 		seq1 = ntohl(tcp->th_ack);
1226 		sel = aps->aps_sel[1 - out];
1227 
1228 		/* switch to other set ? */
1229 		if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
1230 		    (seq1 > aps->aps_seqmin[!sel])) {
1231 			if (softp->ips_proxy_debug & 0x10)
1232 				printf("proxy in switch set seq %d -> %d %x > %x\n",
1233 					sel, !sel, seq1, aps->aps_seqmin[!sel]);
1234 			sel = aps->aps_sel[1 - out] = !sel;
1235 		}
1236 
1237 		if (aps->aps_seqoff[sel] != 0) {
1238 			if (softp->ips_proxy_debug & 0x10)
1239 				printf("sel %d seqoff %d seq1 %x seqmin %x\n",
1240 					sel, aps->aps_seqoff[sel], seq1,
1241 					aps->aps_seqmin[sel]);
1242 			if (seq1 > aps->aps_seqmin[sel]) {
1243 				seq2 = aps->aps_seqoff[sel];
1244 				tcp->th_ack = htonl(seq1 - seq2);
1245 				ch = 1;
1246 			}
1247 		}
1248 	}
1249 
1250 	if (softp->ips_proxy_debug & 0x10)
1251 		printf("ipf_proxy_fixseqack: seq %u ack %u\n",
1252 			(u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack));
1253 	return (ch ? 2 : 0);
1254 }
1255 
1256 
1257 /* ------------------------------------------------------------------------ */
1258 /* Function:    ipf_proxy_rule_rev                                          */
1259 /* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
1260 /* Parameters:  nat(I) - pointer to NAT session to create rule from         */
1261 /*                                                                          */
1262 /* This function creates a NAT rule that is based upon the reverse packet   */
1263 /* flow associated with this NAT session. Thus if this NAT session was      */
1264 /* created with a map rule then this function will create a rdr rule.       */
1265 /* Only address fields and network interfaces are assigned in this function */
1266 /* and the address fields are formed such that an exact is required. If the */
1267 /* original rule had a netmask, that is not replicated here not is it       */
1268 /* desired. The ultimate goal here is to create a NAT rule to support a NAT */
1269 /* session being created that does not have a user configured rule. The     */
1270 /* classic example is supporting the FTP proxy, where a data channel needs  */
1271 /* to be setup, based on the addresses used for the control connection. In  */
1272 /* that case, this function is used to handle creating NAT rules to support */
1273 /* data connections with the PORT and EPRT commands.                        */
1274 /* ------------------------------------------------------------------------ */
1275 ipnat_t *
ipf_proxy_rule_rev(nat_t * nat)1276 ipf_proxy_rule_rev(nat_t *nat)
1277 {
1278 	ipnat_t *old;
1279 	ipnat_t *ipn;
1280 	int size;
1281 
1282 	old = nat->nat_ptr;
1283 	size = old->in_size;
1284 
1285 	KMALLOCS(ipn, ipnat_t *, size);
1286 	if (ipn == NULL)
1287 		return (NULL);
1288 
1289 	bzero((char *)ipn, size);
1290 
1291 	ipn->in_use = 1;
1292 	ipn->in_hits = 1;
1293 	ipn->in_ippip = 1;
1294 	ipn->in_apr = NULL;
1295 	ipn->in_size = size;
1296 	ipn->in_pr[0] = old->in_pr[1];
1297 	ipn->in_pr[1] = old->in_pr[0];
1298 	ipn->in_v[0] = old->in_v[1];
1299 	ipn->in_v[1] = old->in_v[0];
1300 	ipn->in_ifps[0] = old->in_ifps[1];
1301 	ipn->in_ifps[1] = old->in_ifps[0];
1302 	ipn->in_flags = (old->in_flags | IPN_PROXYRULE);
1303 
1304 	ipn->in_nsrcip6 = nat->nat_odst6;
1305 	ipn->in_osrcip6 = nat->nat_ndst6;
1306 
1307 	if ((old->in_redir & NAT_REDIRECT) != 0) {
1308 		ipn->in_redir = NAT_MAP;
1309 		if (ipn->in_v[0] == 4) {
1310 			ipn->in_snip = ntohl(nat->nat_odstaddr);
1311 			ipn->in_dnip = ntohl(nat->nat_nsrcaddr);
1312 #ifdef USE_INET6
1313 		} else {
1314 			ipn->in_snip6 = nat->nat_odst6;
1315 			ipn->in_dnip6 = nat->nat_nsrc6;
1316 #endif
1317 		}
1318 		ipn->in_ndstip6 = nat->nat_nsrc6;
1319 		ipn->in_odstip6 = nat->nat_osrc6;
1320 	} else {
1321 		ipn->in_redir = NAT_REDIRECT;
1322 		if (ipn->in_v[0] == 4) {
1323 			ipn->in_snip = ntohl(nat->nat_odstaddr);
1324 			ipn->in_dnip = ntohl(nat->nat_osrcaddr);
1325 #ifdef USE_INET6
1326 		} else {
1327 			ipn->in_snip6 = nat->nat_odst6;
1328 			ipn->in_dnip6 = nat->nat_osrc6;
1329 #endif
1330 		}
1331 		ipn->in_ndstip6 = nat->nat_osrc6;
1332 		ipn->in_odstip6 = nat->nat_nsrc6;
1333 	}
1334 
1335 	IP6_SETONES(&ipn->in_osrcmsk6);
1336 	IP6_SETONES(&ipn->in_nsrcmsk6);
1337 	IP6_SETONES(&ipn->in_odstmsk6);
1338 	IP6_SETONES(&ipn->in_ndstmsk6);
1339 
1340 	ipn->in_namelen = old->in_namelen;
1341 	ipn->in_ifnames[0] = old->in_ifnames[1];
1342 	ipn->in_ifnames[1] = old->in_ifnames[0];
1343 	bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
1344 	MUTEX_INIT(&ipn->in_lock, "ipnat rev rule lock");
1345 
1346 	return (ipn);
1347 }
1348 
1349 
1350 /* ------------------------------------------------------------------------ */
1351 /* Function:    ipf_proxy_rule_fwd                                          */
1352 /* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
1353 /* Parameters:  nat(I) - pointer to NAT session to create rule from         */
1354 /*                                                                          */
1355 /* The purpose and rationale of this function is much the same as the above */
1356 /* function, ipf_proxy_rule_rev, except that a rule is created that matches */
1357 /* the same direction as that of the existing NAT session. Thus if this NAT */
1358 /* session was created with a map rule then this function will also create  */
1359 /* a data structure to represent a map rule. Whereas ipf_proxy_rule_rev is  */
1360 /* used to support PORT/EPRT, this function supports PASV/EPSV.             */
1361 /* ------------------------------------------------------------------------ */
1362 ipnat_t *
ipf_proxy_rule_fwd(nat_t * nat)1363 ipf_proxy_rule_fwd(nat_t *nat)
1364 {
1365 	ipnat_t *old;
1366 	ipnat_t *ipn;
1367 	int size;
1368 
1369 	old = nat->nat_ptr;
1370 	size = old->in_size;
1371 
1372 	KMALLOCS(ipn, ipnat_t *, size);
1373 	if (ipn == NULL)
1374 		return (NULL);
1375 
1376 	bzero((char *)ipn, size);
1377 
1378 	ipn->in_use = 1;
1379 	ipn->in_hits = 1;
1380 	ipn->in_ippip = 1;
1381 	ipn->in_apr = NULL;
1382 	ipn->in_size = size;
1383 	ipn->in_pr[0] = old->in_pr[0];
1384 	ipn->in_pr[1] = old->in_pr[1];
1385 	ipn->in_v[0] = old->in_v[0];
1386 	ipn->in_v[1] = old->in_v[1];
1387 	ipn->in_ifps[0] = nat->nat_ifps[0];
1388 	ipn->in_ifps[1] = nat->nat_ifps[1];
1389 	ipn->in_flags = (old->in_flags | IPN_PROXYRULE);
1390 
1391 	ipn->in_nsrcip6 = nat->nat_nsrc6;
1392 	ipn->in_osrcip6 = nat->nat_osrc6;
1393 	ipn->in_ndstip6 = nat->nat_ndst6;
1394 	ipn->in_odstip6 = nat->nat_odst6;
1395 	ipn->in_redir = old->in_redir;
1396 
1397 	if (ipn->in_v[0] == 4) {
1398 		ipn->in_snip = ntohl(nat->nat_nsrcaddr);
1399 		ipn->in_dnip = ntohl(nat->nat_ndstaddr);
1400 #ifdef USE_INET6
1401 	} else {
1402 		ipn->in_snip6 = nat->nat_nsrc6;
1403 		ipn->in_dnip6 = nat->nat_ndst6;
1404 #endif
1405 	}
1406 
1407 	IP6_SETONES(&ipn->in_osrcmsk6);
1408 	IP6_SETONES(&ipn->in_nsrcmsk6);
1409 	IP6_SETONES(&ipn->in_odstmsk6);
1410 	IP6_SETONES(&ipn->in_ndstmsk6);
1411 
1412 	ipn->in_namelen = old->in_namelen;
1413 	ipn->in_ifnames[0] = old->in_ifnames[0];
1414 	ipn->in_ifnames[1] = old->in_ifnames[1];
1415 	bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
1416 	MUTEX_INIT(&ipn->in_lock, "ipnat fwd rule lock");
1417 
1418 	return (ipn);
1419 }
1420