xref: /freebsd/sys/netpfil/ipfilter/netinet/ip_proxy.c (revision 79d23845179a534f533185763cb92032202729a7)
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 __unused,void * ctx)681 ipf_proxy_ioctl(ipf_main_softc_t *softc, caddr_t data, ioctlcmd_t cmd,
682 	int mode __unused, void *ctx)
683 {
684 	ap_ctl_t ctl;
685 	caddr_t ptr;
686 	int error;
687 
688 	switch (cmd)
689 	{
690 	case SIOCPROXY :
691 		error = ipf_inobj(softc, data, NULL, &ctl, IPFOBJ_PROXYCTL);
692 		if (error != 0) {
693 			return (error);
694 		}
695 		ptr = NULL;
696 
697 		if (ctl.apc_dsize > 0) {
698 			KMALLOCS(ptr, caddr_t, ctl.apc_dsize);
699 			if (ptr == NULL) {
700 				IPFERROR(80003);
701 				error = ENOMEM;
702 			} else {
703 				error = copyinptr(softc, ctl.apc_data, ptr,
704 						  ctl.apc_dsize);
705 				if (error == 0)
706 					ctl.apc_data = ptr;
707 			}
708 		} else {
709 			ctl.apc_data = NULL;
710 			error = 0;
711 		}
712 
713 		if (error == 0)
714 			error = ipf_proxy_ctl(softc, softc->ipf_proxy_soft,
715 					      &ctl);
716 
717 		if ((error != 0) && (ptr != NULL)) {
718 			KFREES(ptr, ctl.apc_dsize);
719 		}
720 		break;
721 
722 	default :
723 		IPFERROR(80004);
724 		error = EINVAL;
725 	}
726 	return (error);
727 }
728 
729 
730 /* ------------------------------------------------------------------------ */
731 /* Function:    ipf_proxy_match                                             */
732 /* Returns:     int    - 0 == success, else error                           */
733 /* Parameters:  fin(I) - pointer to packet information                      */
734 /*              nat(I) - pointer to current NAT session                     */
735 /*                                                                          */
736 /* If a proxy has a match function, call that to do extended packet         */
737 /* matching. Whilst other parts of the NAT code are rather lenient when it  */
738 /* comes to the quality of the packet that it will transform, the proxy     */
739 /* matching is not because they need to work with data, not just headers.   */
740 /* ------------------------------------------------------------------------ */
741 int
ipf_proxy_match(fr_info_t * fin,nat_t * nat)742 ipf_proxy_match(fr_info_t *fin, nat_t *nat)
743 {
744 	ipf_main_softc_t *softc = fin->fin_main_soft;
745 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
746 	aproxy_t *apr;
747 	ipnat_t *ipn;
748 	int result;
749 
750 	ipn = nat->nat_ptr;
751 	if (softp->ips_proxy_debug & 0x04)
752 		printf("ipf_proxy_match(%lx,%lx) aps %lx ptr %lx\n",
753 			(u_long)fin, (u_long)nat, (u_long)nat->nat_aps,
754 			(u_long)ipn);
755 
756 	if ((fin->fin_flx & (FI_SHORT|FI_BAD)) != 0) {
757 		if (softp->ips_proxy_debug & 0x08)
758 			printf("ipf_proxy_match: flx 0x%x (BAD|SHORT)\n",
759 				fin->fin_flx);
760 		return (-1);
761 	}
762 
763 	apr = ipn->in_apr;
764 	if ((apr == NULL) || (apr->apr_flags & APR_DELETE)) {
765 		if (softp->ips_proxy_debug & 0x08)
766 			printf("ipf_proxy_match:apr %lx apr_flags 0x%x\n",
767 				(u_long)apr, apr ? apr->apr_flags : 0);
768 		return (-1);
769 	}
770 
771 	if (apr->apr_match != NULL) {
772 		result = (*apr->apr_match)(fin, nat->nat_aps, nat);
773 		if (result != 0) {
774 			if (softp->ips_proxy_debug & 0x08)
775 				printf("ipf_proxy_match: result %d\n", result);
776 			return (-1);
777 		}
778 	}
779 	return (0);
780 }
781 
782 
783 /* ------------------------------------------------------------------------ */
784 /* Function:    ipf_proxy_new                                               */
785 /* Returns:     int    - 0 == success, else error                           */
786 /* Parameters:  fin(I) - pointer to packet information                      */
787 /*              nat(I) - pointer to current NAT session                     */
788 /*                                                                          */
789 /* Allocate a new application proxy structure and fill it in with the       */
790 /* relevant details.  call the init function once complete, prior to        */
791 /* returning.                                                               */
792 /* ------------------------------------------------------------------------ */
793 int
ipf_proxy_new(fr_info_t * fin,nat_t * nat)794 ipf_proxy_new(fr_info_t *fin, nat_t *nat)
795 {
796 	ipf_main_softc_t *softc = fin->fin_main_soft;
797 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
798 	register ap_session_t *aps;
799 	aproxy_t *apr;
800 
801 	if (softp->ips_proxy_debug & 0x04)
802 		printf("ipf_proxy_new(%lx,%lx) \n", (u_long)fin, (u_long)nat);
803 
804 	if ((nat->nat_ptr == NULL) || (nat->nat_aps != NULL)) {
805 		if (softp->ips_proxy_debug & 0x08)
806 			printf("ipf_proxy_new: nat_ptr %lx nat_aps %lx\n",
807 				(u_long)nat->nat_ptr, (u_long)nat->nat_aps);
808 		return (-1);
809 	}
810 
811 	apr = nat->nat_ptr->in_apr;
812 
813 	if ((apr->apr_flags & APR_DELETE) ||
814 	    (fin->fin_p != apr->apr_p)) {
815 		if (softp->ips_proxy_debug & 0x08)
816 			printf("ipf_proxy_new: apr_flags 0x%x p %d/%d\n",
817 				apr->apr_flags, fin->fin_p, apr->apr_p);
818 		return (-1);
819 	}
820 
821 	KMALLOC(aps, ap_session_t *);
822 	if (!aps) {
823 		if (softp->ips_proxy_debug & 0x08)
824 			printf("ipf_proxy_new: malloc failed (%lu)\n",
825 				(u_long)sizeof(ap_session_t));
826 		return (-1);
827 	}
828 
829 	bzero((char *)aps, sizeof(*aps));
830 	aps->aps_data = NULL;
831 	aps->aps_apr = apr;
832 	aps->aps_psiz = 0;
833 	if (apr->apr_new != NULL)
834 		if ((*apr->apr_new)(apr->apr_soft, fin, aps, nat) == -1) {
835 			if ((aps->aps_data != NULL) && (aps->aps_psiz != 0)) {
836 				KFREES(aps->aps_data, aps->aps_psiz);
837 			}
838 			KFREE(aps);
839 			if (softp->ips_proxy_debug & 0x08)
840 				printf("ipf_proxy_new: new(%lx) failed\n",
841 					(u_long)apr->apr_new);
842 			return (-1);
843 		}
844 	aps->aps_nat = nat;
845 	aps->aps_next = softp->ips_sess_list;
846 	softp->ips_sess_list = aps;
847 	nat->nat_aps = aps;
848 
849 	return (0);
850 }
851 
852 
853 /* ------------------------------------------------------------------------ */
854 /* Function:    ipf_proxy_check                                             */
855 /* Returns:     int - -1 == error, 1 == success                             */
856 /* Parameters:  fin(I) - pointer to packet information                      */
857 /*              nat(I) - pointer to current NAT session                     */
858 /*                                                                          */
859 /* Check to see if a packet should be passed through an active proxy        */
860 /* routine if one has been setup for it.  We don't need to check the        */
861 /* checksum here if IPFILTER_CKSUM is defined because if it is, a failed    */
862 /* check causes FI_BAD to be set.                                           */
863 /* ------------------------------------------------------------------------ */
864 int
ipf_proxy_check(fr_info_t * fin,nat_t * nat)865 ipf_proxy_check(fr_info_t *fin, nat_t *nat)
866 {
867 	ipf_main_softc_t *softc = fin->fin_main_soft;
868 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
869 #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
870 	mb_t *m;
871 #endif
872 	tcphdr_t *tcp = NULL;
873 	udphdr_t *udp = NULL;
874 	ap_session_t *aps;
875 	aproxy_t *apr;
876 	short adjlen;
877 	int dosum;
878 	ip_t *ip;
879 	short rv;
880 	int err;
881 #if !defined(_KERNEL) || SOLARIS || defined(__FreeBSD__)
882 	u_32_t s1, s2, sd;
883 #endif
884 
885 	if (fin->fin_flx & FI_BAD) {
886 		if (softp->ips_proxy_debug & 0x08)
887 			printf("ipf_proxy_check: flx 0x%x (BAD)\n",
888 			       fin->fin_flx);
889 		return (-1);
890 	}
891 
892 #ifndef IPFILTER_CKSUM
893 	if ((fin->fin_out == 0) && (ipf_checkl4sum(fin) == -1)) {
894 		if (softp->ips_proxy_debug & 0x08)
895 			printf("ipf_proxy_check: l4 checksum failure %d\n",
896 				fin->fin_p);
897 		if (fin->fin_p == IPPROTO_TCP)
898 			softc->ipf_stats[fin->fin_out].fr_tcpbad++;
899 		return (-1);
900 	}
901 #endif
902 
903 	aps = nat->nat_aps;
904 	if (aps != NULL) {
905 		/*
906 		 * If there is data in this packet to be proxied then try and
907 		 * get it all into the one buffer, else drop it.
908 		 */
909 #if SOLARIS || defined(HAVE_M_PULLDOWN)
910 		if ((fin->fin_dlen > 0) && !(fin->fin_flx & FI_COALESCE))
911 			if (ipf_coalesce(fin) == -1) {
912 				if (softp->ips_proxy_debug & 0x08)
913 					printf("ipf_proxy_check: %s %x\n",
914 					       "coalesce failed", fin->fin_flx);
915 				return (-1);
916 			}
917 #endif
918 		ip = fin->fin_ip;
919 		if (fin->fin_cksum > FI_CK_SUMOK)
920 			dosum = 0;
921 		else
922 			dosum = 1;
923 
924 		switch (fin->fin_p)
925 		{
926 		case IPPROTO_TCP :
927 			tcp = (tcphdr_t *)fin->fin_dp;
928 #if SOLARIS && defined(_KERNEL) && defined(ICK_VALID)
929 			m = fin->fin_qfm;
930 			if (dohwcksum && (m->b_ick_flag == ICK_VALID))
931 				dosum = 0;
932 #endif
933 			break;
934 		case IPPROTO_UDP :
935 			udp = (udphdr_t *)fin->fin_dp;
936 			break;
937 		default :
938 			break;
939 		}
940 
941 		apr = aps->aps_apr;
942 		err = 0;
943 		if (fin->fin_out != 0) {
944 			if (apr->apr_outpkt != NULL)
945 				err = (*apr->apr_outpkt)(apr->apr_soft, fin,
946 							 aps, nat);
947 		} else {
948 			if (apr->apr_inpkt != NULL)
949 				err = (*apr->apr_inpkt)(apr->apr_soft, fin,
950 							aps, nat);
951 		}
952 
953 		rv = APR_EXIT(err);
954 		if (((softp->ips_proxy_debug & 0x08) && (rv != 0)) ||
955 		    (softp->ips_proxy_debug & 0x04))
956 			printf("ipf_proxy_check: out %d err %x rv %d\n",
957 				fin->fin_out, err, rv);
958 		if (rv == 1)
959 			return (-1);
960 
961 		if (rv == 2) {
962 			ipf_proxy_deref(apr);
963 			nat->nat_aps = NULL;
964 			return (-1);
965 		}
966 
967 		/*
968 		 * If err != 0 then the data size of the packet has changed
969 		 * so we need to recalculate the header checksums for the
970 		 * packet.
971 		 */
972 		adjlen = APR_INC(err);
973 #if !defined(_KERNEL) || SOLARIS || defined(__FreeBSD__)
974 		s1 = LONG_SUM(fin->fin_plen - adjlen);
975 		s2 = LONG_SUM(fin->fin_plen);
976 		CALC_SUMD(s1, s2, sd);
977 		if ((err != 0) && (fin->fin_cksum < FI_CK_L4PART) &&
978 		    fin->fin_v == 4)
979 			ipf_fix_outcksum(0, &ip->ip_sum, sd, 0);
980 #endif
981 		if (fin->fin_flx & FI_DOCKSUM)
982 			dosum = 1;
983 
984 		/*
985 		 * For TCP packets, we may need to adjust the sequence and
986 		 * acknowledgement numbers to reflect changes in size of the
987 		 * data stream.
988 		 *
989 		 * For both TCP and UDP, recalculate the layer 4 checksum,
990 		 * regardless, as we can't tell (here) if data has been
991 		 * changed or not.
992 		 */
993 		if (tcp != NULL) {
994 			err = ipf_proxy_fixseqack(fin, ip, aps, adjlen);
995 			if (fin->fin_cksum == FI_CK_L4PART) {
996 				u_short sum = ntohs(tcp->th_sum);
997 				sum += adjlen;
998 				tcp->th_sum = htons(sum);
999 			} else if (fin->fin_cksum < FI_CK_L4PART) {
1000 				tcp->th_sum = fr_cksum(fin, ip,
1001 						       IPPROTO_TCP, tcp);
1002 			}
1003 		} else if ((udp != NULL) && (udp->uh_sum != 0)) {
1004 			if (fin->fin_cksum == FI_CK_L4PART) {
1005 				u_short sum = ntohs(udp->uh_sum);
1006 				sum += adjlen;
1007 				udp->uh_sum = htons(sum);
1008 			} else if (dosum) {
1009 				udp->uh_sum = fr_cksum(fin, ip,
1010 						       IPPROTO_UDP, udp);
1011 			}
1012 		}
1013 		aps->aps_bytes += fin->fin_plen;
1014 		aps->aps_pkts++;
1015 	}
1016 	return (1);
1017 }
1018 
1019 
1020 /* ------------------------------------------------------------------------ */
1021 /* Function:    ipf_proxy_lookup                                            */
1022 /* Returns:     int - -1 == error, 0 == success                             */
1023 /* Parameters:  arg(I)  - pointer to proxy context information              */
1024 /*              pr(I)   - protocol number for proxy                         */
1025 /*              name(I) - proxy name                                        */
1026 /*                                                                          */
1027 /* Search for a proxy by the protocol being used and by its name.           */
1028 /* ------------------------------------------------------------------------ */
1029 aproxy_t *
ipf_proxy_lookup(void * arg,u_int pr,char * name)1030 ipf_proxy_lookup(void *arg, u_int pr, char *name)
1031 {
1032 	ipf_proxy_softc_t *softp = arg;
1033 	aproxy_t *ap;
1034 
1035 	if (softp->ips_proxy_debug & 0x04)
1036 		printf("ipf_proxy_lookup(%d,%s)\n", pr, name);
1037 
1038 	for (ap = softp->ips_proxies; ap != NULL; ap = ap->apr_next)
1039 		if ((ap->apr_p == pr) &&
1040 		    !strncmp(name, ap->apr_label, sizeof(ap->apr_label))) {
1041 			ap->apr_ref++;
1042 			return (ap);
1043 		}
1044 
1045 	if (softp->ips_proxy_debug & 0x08)
1046 		printf("ipf_proxy_lookup: failed for %d/%s\n", pr, name);
1047 	return (NULL);
1048 }
1049 
1050 
1051 /* ------------------------------------------------------------------------ */
1052 /* Function:    ipf_proxy_deref                                             */
1053 /* Returns:     Nil                                                         */
1054 /* Parameters:  ap(I) - pointer to proxy structure                          */
1055 /*                                                                          */
1056 /* Drop the reference counter associated with the proxy.                    */
1057 /* ------------------------------------------------------------------------ */
1058 void
ipf_proxy_deref(aproxy_t * ap)1059 ipf_proxy_deref(aproxy_t *ap)
1060 {
1061 	ap->apr_ref--;
1062 }
1063 
1064 
1065 /* ------------------------------------------------------------------------ */
1066 /* Function:    ipf_proxy_free                                              */
1067 /* Returns:     Nil                                                         */
1068 /* Parameters:  softc(I) - pointer to soft context main structure           */
1069 /*              aps(I)   - pointer to current proxy session                 */
1070 /* Locks Held:  ipf_nat_new, ipf_nat(W)                                     */
1071 /*                                                                          */
1072 /* Free up proxy session information allocated to be used with a NAT        */
1073 /* session.                                                                 */
1074 /* ------------------------------------------------------------------------ */
1075 void
ipf_proxy_free(ipf_main_softc_t * softc,ap_session_t * aps)1076 ipf_proxy_free(ipf_main_softc_t *softc, ap_session_t *aps)
1077 {
1078 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
1079 	ap_session_t *a, **ap;
1080 	aproxy_t *apr;
1081 
1082 	if (!aps)
1083 		return;
1084 
1085 	for (ap = &softp->ips_sess_list; ((a = *ap) != NULL); ap = &a->aps_next)
1086 		if (a == aps) {
1087 			*ap = a->aps_next;
1088 			break;
1089 		}
1090 
1091 	apr = aps->aps_apr;
1092 	if ((apr != NULL) && (apr->apr_del != NULL))
1093 		(*apr->apr_del)(softc, aps);
1094 
1095 	if ((aps->aps_data != NULL) && (aps->aps_psiz != 0))
1096 		KFREES(aps->aps_data, aps->aps_psiz);
1097 	KFREE(aps);
1098 }
1099 
1100 
1101 /* ------------------------------------------------------------------------ */
1102 /* Function:    ipf_proxy_fixseqack                                         */
1103 /* Returns:     int    - 2 if TCP ack/seq is changed, else 0                */
1104 /* Parameters:  fin(I) - pointer to packet information                      */
1105 /*              ip(I)  - pointer to IP header                               */
1106 /*              nat(I) - pointer to current NAT session                     */
1107 /*              inc(I) - delta to apply to TCP sequence numbering           */
1108 /*                                                                          */
1109 /* Adjust the TCP sequence/acknowledge numbers in the TCP header based on   */
1110 /* whether or not the new header is past the point at which an adjustment   */
1111 /* occurred. This might happen because of (say) an FTP string being changed */
1112 /* and the new string being a different length to the old.                  */
1113 /* ------------------------------------------------------------------------ */
1114 static int
ipf_proxy_fixseqack(fr_info_t * fin,ip_t * ip,ap_session_t * aps,int inc)1115 ipf_proxy_fixseqack(fr_info_t *fin, ip_t *ip, ap_session_t *aps, int inc)
1116 {
1117 	ipf_main_softc_t *softc = fin->fin_main_soft;
1118 	ipf_proxy_softc_t *softp = softc->ipf_proxy_soft;
1119 	int sel, ch = 0, out, nlen;
1120 	u_32_t seq1, seq2;
1121 	tcphdr_t *tcp;
1122 	short inc2;
1123 
1124 	tcp = (tcphdr_t *)fin->fin_dp;
1125 	out = fin->fin_out;
1126 	/*
1127 	 * ip_len has already been adjusted by 'inc'.
1128 	 */
1129 	nlen = fin->fin_dlen;
1130 	nlen -= (TCP_OFF(tcp) << 2);
1131 
1132 	inc2 = inc;
1133 	inc = (int)inc2;
1134 
1135 	if (out != 0) {
1136 		seq1 = (u_32_t)ntohl(tcp->th_seq);
1137 		sel = aps->aps_sel[out];
1138 
1139 		/* switch to other set ? */
1140 		if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
1141 		    (seq1 > aps->aps_seqmin[!sel])) {
1142 			if (softp->ips_proxy_debug & 0x10)
1143 				printf("proxy out switch set seq %d -> %d %x > %x\n",
1144 					sel, !sel, seq1,
1145 					aps->aps_seqmin[!sel]);
1146 			sel = aps->aps_sel[out] = !sel;
1147 		}
1148 
1149 		if (aps->aps_seqoff[sel]) {
1150 			seq2 = aps->aps_seqmin[sel] - aps->aps_seqoff[sel];
1151 			if (seq1 > seq2) {
1152 				seq2 = aps->aps_seqoff[sel];
1153 				seq1 += seq2;
1154 				tcp->th_seq = htonl(seq1);
1155 				ch = 1;
1156 			}
1157 		}
1158 
1159 		if (inc && (seq1 > aps->aps_seqmin[!sel])) {
1160 			aps->aps_seqmin[sel] = seq1 + nlen - 1;
1161 			aps->aps_seqoff[sel] = aps->aps_seqoff[sel] + inc;
1162 			if (softp->ips_proxy_debug & 0x10)
1163 				printf("proxy seq set %d at %x to %d + %d\n",
1164 					sel, aps->aps_seqmin[sel],
1165 					aps->aps_seqoff[sel], inc);
1166 		}
1167 
1168 		/***/
1169 
1170 		seq1 = ntohl(tcp->th_ack);
1171 		sel = aps->aps_sel[1 - out];
1172 
1173 		/* switch to other set ? */
1174 		if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
1175 		    (seq1 > aps->aps_ackmin[!sel])) {
1176 			if (softp->ips_proxy_debug & 0x10)
1177 				printf("proxy out switch set ack %d -> %d %x > %x\n",
1178 					sel, !sel, seq1,
1179 					aps->aps_ackmin[!sel]);
1180 			sel = aps->aps_sel[1 - out] = !sel;
1181 		}
1182 
1183 		if (aps->aps_ackoff[sel] && (seq1 > aps->aps_ackmin[sel])) {
1184 			seq2 = aps->aps_ackoff[sel];
1185 			tcp->th_ack = htonl(seq1 - seq2);
1186 			ch = 1;
1187 		}
1188 	} else {
1189 		seq1 = ntohl(tcp->th_seq);
1190 		sel = aps->aps_sel[out];
1191 
1192 		/* switch to other set ? */
1193 		if ((aps->aps_ackmin[!sel] > aps->aps_ackmin[sel]) &&
1194 		    (seq1 > aps->aps_ackmin[!sel])) {
1195 			if (softp->ips_proxy_debug & 0x10)
1196 				printf("proxy in switch set ack %d -> %d %x > %x\n",
1197 					sel, !sel, seq1, aps->aps_ackmin[!sel]);
1198 			sel = aps->aps_sel[out] = !sel;
1199 		}
1200 
1201 		if (aps->aps_ackoff[sel]) {
1202 			seq2 = aps->aps_ackmin[sel] - aps->aps_ackoff[sel];
1203 			if (seq1 > seq2) {
1204 				seq2 = aps->aps_ackoff[sel];
1205 				seq1 += seq2;
1206 				tcp->th_seq = htonl(seq1);
1207 				ch = 1;
1208 			}
1209 		}
1210 
1211 		if (inc && (seq1 > aps->aps_ackmin[!sel])) {
1212 			aps->aps_ackmin[!sel] = seq1 + nlen - 1;
1213 			aps->aps_ackoff[!sel] = aps->aps_ackoff[sel] + inc;
1214 
1215 			if (softp->ips_proxy_debug & 0x10)
1216 				printf("proxy ack set %d at %x to %d + %d\n",
1217 					!sel, aps->aps_seqmin[!sel],
1218 					aps->aps_seqoff[sel], inc);
1219 		}
1220 
1221 		/***/
1222 
1223 		seq1 = ntohl(tcp->th_ack);
1224 		sel = aps->aps_sel[1 - out];
1225 
1226 		/* switch to other set ? */
1227 		if ((aps->aps_seqmin[!sel] > aps->aps_seqmin[sel]) &&
1228 		    (seq1 > aps->aps_seqmin[!sel])) {
1229 			if (softp->ips_proxy_debug & 0x10)
1230 				printf("proxy in switch set seq %d -> %d %x > %x\n",
1231 					sel, !sel, seq1, aps->aps_seqmin[!sel]);
1232 			sel = aps->aps_sel[1 - out] = !sel;
1233 		}
1234 
1235 		if (aps->aps_seqoff[sel] != 0) {
1236 			if (softp->ips_proxy_debug & 0x10)
1237 				printf("sel %d seqoff %d seq1 %x seqmin %x\n",
1238 					sel, aps->aps_seqoff[sel], seq1,
1239 					aps->aps_seqmin[sel]);
1240 			if (seq1 > aps->aps_seqmin[sel]) {
1241 				seq2 = aps->aps_seqoff[sel];
1242 				tcp->th_ack = htonl(seq1 - seq2);
1243 				ch = 1;
1244 			}
1245 		}
1246 	}
1247 
1248 	if (softp->ips_proxy_debug & 0x10)
1249 		printf("ipf_proxy_fixseqack: seq %u ack %u\n",
1250 			(u_32_t)ntohl(tcp->th_seq), (u_32_t)ntohl(tcp->th_ack));
1251 	return (ch ? 2 : 0);
1252 }
1253 
1254 
1255 /* ------------------------------------------------------------------------ */
1256 /* Function:    ipf_proxy_rule_rev                                          */
1257 /* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
1258 /* Parameters:  nat(I) - pointer to NAT session to create rule from         */
1259 /*                                                                          */
1260 /* This function creates a NAT rule that is based upon the reverse packet   */
1261 /* flow associated with this NAT session. Thus if this NAT session was      */
1262 /* created with a map rule then this function will create a rdr rule.       */
1263 /* Only address fields and network interfaces are assigned in this function */
1264 /* and the address fields are formed such that an exact is required. If the */
1265 /* original rule had a netmask, that is not replicated here not is it       */
1266 /* desired. The ultimate goal here is to create a NAT rule to support a NAT */
1267 /* session being created that does not have a user configured rule. The     */
1268 /* classic example is supporting the FTP proxy, where a data channel needs  */
1269 /* to be setup, based on the addresses used for the control connection. In  */
1270 /* that case, this function is used to handle creating NAT rules to support */
1271 /* data connections with the PORT and EPRT commands.                        */
1272 /* ------------------------------------------------------------------------ */
1273 ipnat_t *
ipf_proxy_rule_rev(nat_t * nat)1274 ipf_proxy_rule_rev(nat_t *nat)
1275 {
1276 	ipnat_t *old;
1277 	ipnat_t *ipn;
1278 	int size;
1279 
1280 	old = nat->nat_ptr;
1281 	size = old->in_size;
1282 
1283 	KMALLOCS(ipn, ipnat_t *, size);
1284 	if (ipn == NULL)
1285 		return (NULL);
1286 
1287 	bzero((char *)ipn, size);
1288 
1289 	ipn->in_use = 1;
1290 	ipn->in_hits = 1;
1291 	ipn->in_ippip = 1;
1292 	ipn->in_apr = NULL;
1293 	ipn->in_size = size;
1294 	ipn->in_pr[0] = old->in_pr[1];
1295 	ipn->in_pr[1] = old->in_pr[0];
1296 	ipn->in_v[0] = old->in_v[1];
1297 	ipn->in_v[1] = old->in_v[0];
1298 	ipn->in_ifps[0] = old->in_ifps[1];
1299 	ipn->in_ifps[1] = old->in_ifps[0];
1300 	ipn->in_flags = (old->in_flags | IPN_PROXYRULE);
1301 
1302 	ipn->in_nsrcip6 = nat->nat_odst6;
1303 	ipn->in_osrcip6 = nat->nat_ndst6;
1304 
1305 	if ((old->in_redir & NAT_REDIRECT) != 0) {
1306 		ipn->in_redir = NAT_MAP;
1307 		if (ipn->in_v[0] == 4) {
1308 			ipn->in_snip = ntohl(nat->nat_odstaddr);
1309 			ipn->in_dnip = ntohl(nat->nat_nsrcaddr);
1310 #ifdef USE_INET6
1311 		} else {
1312 			ipn->in_snip6 = nat->nat_odst6;
1313 			ipn->in_dnip6 = nat->nat_nsrc6;
1314 #endif
1315 		}
1316 		ipn->in_ndstip6 = nat->nat_nsrc6;
1317 		ipn->in_odstip6 = nat->nat_osrc6;
1318 	} else {
1319 		ipn->in_redir = NAT_REDIRECT;
1320 		if (ipn->in_v[0] == 4) {
1321 			ipn->in_snip = ntohl(nat->nat_odstaddr);
1322 			ipn->in_dnip = ntohl(nat->nat_osrcaddr);
1323 #ifdef USE_INET6
1324 		} else {
1325 			ipn->in_snip6 = nat->nat_odst6;
1326 			ipn->in_dnip6 = nat->nat_osrc6;
1327 #endif
1328 		}
1329 		ipn->in_ndstip6 = nat->nat_osrc6;
1330 		ipn->in_odstip6 = nat->nat_nsrc6;
1331 	}
1332 
1333 	IP6_SETONES(&ipn->in_osrcmsk6);
1334 	IP6_SETONES(&ipn->in_nsrcmsk6);
1335 	IP6_SETONES(&ipn->in_odstmsk6);
1336 	IP6_SETONES(&ipn->in_ndstmsk6);
1337 
1338 	ipn->in_namelen = old->in_namelen;
1339 	ipn->in_ifnames[0] = old->in_ifnames[1];
1340 	ipn->in_ifnames[1] = old->in_ifnames[0];
1341 	bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
1342 	MUTEX_INIT(&ipn->in_lock, "ipnat rev rule lock");
1343 
1344 	return (ipn);
1345 }
1346 
1347 
1348 /* ------------------------------------------------------------------------ */
1349 /* Function:    ipf_proxy_rule_fwd                                          */
1350 /* Returns:     ipnat_t * - NULL = failure, else pointer to new rule        */
1351 /* Parameters:  nat(I) - pointer to NAT session to create rule from         */
1352 /*                                                                          */
1353 /* The purpose and rationale of this function is much the same as the above */
1354 /* function, ipf_proxy_rule_rev, except that a rule is created that matches */
1355 /* the same direction as that of the existing NAT session. Thus if this NAT */
1356 /* session was created with a map rule then this function will also create  */
1357 /* a data structure to represent a map rule. Whereas ipf_proxy_rule_rev is  */
1358 /* used to support PORT/EPRT, this function supports PASV/EPSV.             */
1359 /* ------------------------------------------------------------------------ */
1360 ipnat_t *
ipf_proxy_rule_fwd(nat_t * nat)1361 ipf_proxy_rule_fwd(nat_t *nat)
1362 {
1363 	ipnat_t *old;
1364 	ipnat_t *ipn;
1365 	int size;
1366 
1367 	old = nat->nat_ptr;
1368 	size = old->in_size;
1369 
1370 	KMALLOCS(ipn, ipnat_t *, size);
1371 	if (ipn == NULL)
1372 		return (NULL);
1373 
1374 	bzero((char *)ipn, size);
1375 
1376 	ipn->in_use = 1;
1377 	ipn->in_hits = 1;
1378 	ipn->in_ippip = 1;
1379 	ipn->in_apr = NULL;
1380 	ipn->in_size = size;
1381 	ipn->in_pr[0] = old->in_pr[0];
1382 	ipn->in_pr[1] = old->in_pr[1];
1383 	ipn->in_v[0] = old->in_v[0];
1384 	ipn->in_v[1] = old->in_v[1];
1385 	ipn->in_ifps[0] = nat->nat_ifps[0];
1386 	ipn->in_ifps[1] = nat->nat_ifps[1];
1387 	ipn->in_flags = (old->in_flags | IPN_PROXYRULE);
1388 
1389 	ipn->in_nsrcip6 = nat->nat_nsrc6;
1390 	ipn->in_osrcip6 = nat->nat_osrc6;
1391 	ipn->in_ndstip6 = nat->nat_ndst6;
1392 	ipn->in_odstip6 = nat->nat_odst6;
1393 	ipn->in_redir = old->in_redir;
1394 
1395 	if (ipn->in_v[0] == 4) {
1396 		ipn->in_snip = ntohl(nat->nat_nsrcaddr);
1397 		ipn->in_dnip = ntohl(nat->nat_ndstaddr);
1398 #ifdef USE_INET6
1399 	} else {
1400 		ipn->in_snip6 = nat->nat_nsrc6;
1401 		ipn->in_dnip6 = nat->nat_ndst6;
1402 #endif
1403 	}
1404 
1405 	IP6_SETONES(&ipn->in_osrcmsk6);
1406 	IP6_SETONES(&ipn->in_nsrcmsk6);
1407 	IP6_SETONES(&ipn->in_odstmsk6);
1408 	IP6_SETONES(&ipn->in_ndstmsk6);
1409 
1410 	ipn->in_namelen = old->in_namelen;
1411 	ipn->in_ifnames[0] = old->in_ifnames[0];
1412 	ipn->in_ifnames[1] = old->in_ifnames[1];
1413 	bcopy(old->in_names, ipn->in_names, ipn->in_namelen);
1414 	MUTEX_INIT(&ipn->in_lock, "ipnat fwd rule lock");
1415 
1416 	return (ipn);
1417 }
1418