1
2 /*
3 * Copyright (C) 2012 by Darren Reed.
4 *
5 * See the IPFILTER.LICENCE file for details on licencing.
6 */
7 #if !defined(lint)
8 static const char sccsid[] = "@(#)ip_fil.c 2.41 6/5/96 (C) 1993-2000 Darren Reed";
9 static const char rcsid[] = "@(#)$Id$";
10 #endif
11
12 #if defined(KERNEL) || defined(_KERNEL)
13 # undef KERNEL
14 # undef _KERNEL
15 # define KERNEL 1
16 # define _KERNEL 1
17 #endif
18 #if defined(__FreeBSD__) && \
19 !defined(KLD_MODULE) && !defined(IPFILTER_LKM)
20 # include "opt_inet6.h"
21 #endif
22 #include <sys/param.h>
23 #include <sys/eventhandler.h>
24 #include <sys/conf.h>
25 #include <sys/errno.h>
26 #include <sys/types.h>
27 #include <sys/file.h>
28 #include <sys/fcntl.h>
29 #include <sys/filio.h>
30 #include <sys/time.h>
31 #include <sys/systm.h>
32 #include <sys/dirent.h>
33 #if defined(__FreeBSD__)
34 # include <sys/jail.h>
35 #endif
36 #include <sys/malloc.h>
37 #include <sys/mbuf.h>
38 #include <sys/sockopt.h>
39 #include <sys/socket.h>
40 #include <sys/selinfo.h>
41 #include <net/if.h>
42 #include <net/if_var.h>
43 #include <net/netisr.h>
44 #include <net/route.h>
45 #include <net/route/nhop.h>
46 #include <netinet/in.h>
47 #include <netinet/in_fib.h>
48 #include <netinet/in_pcb.h>
49 #include <netinet/in_var.h>
50 #include <netinet/in_systm.h>
51 #include <netinet/ip.h>
52 #include <netinet/ip_var.h>
53 #include <netinet/tcp.h>
54 #include <netinet/tcp_var.h>
55 #include <net/vnet.h>
56 #include <netinet/udp.h>
57 #include <netinet/tcpip.h>
58 #include <netinet/ip_icmp.h>
59 #include "netinet/ip_compat.h"
60 #ifdef USE_INET6
61 # include <netinet/icmp6.h>
62 #endif
63 #include "netinet/ip_fil.h"
64 #include "netinet/ip_nat.h"
65 #include "netinet/ip_frag.h"
66 #include "netinet/ip_state.h"
67 #include "netinet/ip_proxy.h"
68 #include "netinet/ip_auth.h"
69 #include "netinet/ip_sync.h"
70 #include "netinet/ip_lookup.h"
71 #include "netinet/ip_dstlist.h"
72 #ifdef IPFILTER_SCAN
73 # include "netinet/ip_scan.h"
74 #endif
75 #include "netinet/ip_pool.h"
76 #include <sys/malloc.h>
77 #include <sys/kernel.h>
78 #ifdef CSUM_DATA_VALID
79 # include <machine/in_cksum.h>
80 #endif
81 extern int ip_optcopy(struct ip *, struct ip *);
82
83 #ifdef IPFILTER_M_IPFILTER
84 MALLOC_DEFINE(M_IPFILTER, "ipfilter", "IP Filter packet filter data structures");
85 #endif
86
87
88 static int ipf_send_ip(fr_info_t *, mb_t *);
89 static void ipf_timer_func(void *arg);
90
91 VNET_DEFINE(ipf_main_softc_t, ipfmain) = {
92 .ipf_running = -2,
93 };
94 #define V_ipfmain VNET(ipfmain)
95
96 #include <sys/conf.h>
97 #include <net/pfil.h>
98
99 VNET_DEFINE_STATIC(eventhandler_tag, ipf_arrivetag);
100 VNET_DEFINE_STATIC(eventhandler_tag, ipf_departtag);
101 #define V_ipf_arrivetag VNET(ipf_arrivetag)
102 #define V_ipf_departtag VNET(ipf_departtag)
103 #if 0
104 /*
105 * Disable the "cloner" event handler; we are getting interface
106 * events before the firewall is fully initiallized and also no vnet
107 * information thus leading to uninitialised memory accesses.
108 * In addition it is unclear why we need it in first place.
109 * If it turns out to be needed, well need a dedicated event handler
110 * for it to deal with the ifc and the correct vnet.
111 */
112 VNET_DEFINE_STATIC(eventhandler_tag, ipf_clonetag);
113 #define V_ipf_clonetag VNET(ipf_clonetag)
114 #endif
115
116 static void ipf_ifevent(void *arg, struct ifnet *ifp);
117
ipf_ifevent(void * arg,struct ifnet * ifp)118 static void ipf_ifevent(void *arg, struct ifnet *ifp)
119 {
120
121 CURVNET_SET(ifp->if_vnet);
122 if (V_ipfmain.ipf_running > 0)
123 ipf_sync(&V_ipfmain, NULL);
124 CURVNET_RESTORE();
125 }
126
127
128
129 static pfil_return_t
ipf_check_wrapper(struct mbuf ** mp,struct ifnet * ifp,int flags,void * ruleset __unused,struct inpcb * inp)130 ipf_check_wrapper(struct mbuf **mp, struct ifnet *ifp, int flags,
131 void *ruleset __unused, struct inpcb *inp)
132 {
133 struct ip *ip = mtod(*mp, struct ip *);
134 pfil_return_t rv;
135
136 CURVNET_SET(ifp->if_vnet);
137 rv = ipf_check(&V_ipfmain, ip, ip->ip_hl << 2, ifp,
138 !!(flags & PFIL_OUT), mp);
139 CURVNET_RESTORE();
140 return (rv == 0 ? PFIL_PASS : PFIL_DROPPED);
141 }
142
143 #ifdef USE_INET6
144 static pfil_return_t
ipf_check_wrapper6(struct mbuf ** mp,struct ifnet * ifp,int flags,void * ruleset __unused,struct inpcb * inp)145 ipf_check_wrapper6(struct mbuf **mp, struct ifnet *ifp, int flags,
146 void *ruleset __unused, struct inpcb *inp)
147 {
148 pfil_return_t rv;
149
150 CURVNET_SET(ifp->if_vnet);
151 rv = ipf_check(&V_ipfmain, mtod(*mp, struct ip *),
152 sizeof(struct ip6_hdr), ifp, !!(flags & PFIL_OUT), mp);
153 CURVNET_RESTORE();
154
155 return (rv == 0 ? PFIL_PASS : PFIL_DROPPED);
156 }
157 # endif
158 #if defined(IPFILTER_LKM)
ipf_identify(char * s)159 int ipf_identify(char *s)
160 {
161 if (strcmp(s, "ipl") == 0)
162 return (1);
163 return (0);
164 }
165 #endif /* IPFILTER_LKM */
166
167
168 static void
ipf_timer_func(void * arg)169 ipf_timer_func(void *arg)
170 {
171 ipf_main_softc_t *softc = arg;
172 SPL_INT(s);
173
174 SPL_NET(s);
175 READ_ENTER(&softc->ipf_global);
176
177 if (softc->ipf_running > 0)
178 ipf_slowtimer(softc);
179
180 if (softc->ipf_running == -1 || softc->ipf_running == 1) {
181 #if 0
182 softc->ipf_slow_ch = timeout(ipf_timer_func, softc, hz/2);
183 #endif
184 callout_init(&softc->ipf_slow_ch, 1);
185 callout_reset(&softc->ipf_slow_ch,
186 (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
187 ipf_timer_func, softc);
188 }
189 RWLOCK_EXIT(&softc->ipf_global);
190 SPL_X(s);
191 }
192
193
194 int
ipfattach(ipf_main_softc_t * softc)195 ipfattach(ipf_main_softc_t *softc)
196 {
197 #ifdef USE_SPL
198 int s;
199 #endif
200
201 SPL_NET(s);
202 if (softc->ipf_running > 0) {
203 SPL_X(s);
204 return (EBUSY);
205 }
206
207 if (ipf_init_all(softc) < 0) {
208 SPL_X(s);
209 return (EIO);
210 }
211
212
213 bzero((char *)V_ipfmain.ipf_selwait, sizeof(V_ipfmain.ipf_selwait));
214 softc->ipf_running = 1;
215
216 if (softc->ipf_control_forwarding & 1)
217 V_ipforwarding = 1;
218
219 SPL_X(s);
220 #if 0
221 softc->ipf_slow_ch = timeout(ipf_timer_func, softc,
222 (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT);
223 #endif
224 callout_init(&softc->ipf_slow_ch, 1);
225 callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT,
226 ipf_timer_func, softc);
227 return (0);
228 }
229
230
231 /*
232 * Disable the filter by removing the hooks from the IP input/output
233 * stream.
234 */
235 int
ipfdetach(ipf_main_softc_t * softc)236 ipfdetach(ipf_main_softc_t *softc)
237 {
238 #ifdef USE_SPL
239 int s;
240 #endif
241
242 if (softc->ipf_control_forwarding & 2)
243 V_ipforwarding = 0;
244
245 SPL_NET(s);
246
247 #if 0
248 if (softc->ipf_slow_ch.callout != NULL)
249 untimeout(ipf_timer_func, softc, softc->ipf_slow_ch);
250 bzero(&softc->ipf_slow, sizeof(softc->ipf_slow));
251 #endif
252 callout_drain(&softc->ipf_slow_ch);
253
254 ipf_fini_all(softc);
255
256 softc->ipf_running = -2;
257
258 SPL_X(s);
259
260 return (0);
261 }
262
263
264 /*
265 * Filter ioctl interface.
266 */
267 int
ipfioctl(struct cdev * dev,ioctlcmd_t cmd,caddr_t data,int mode,struct thread * p)268 ipfioctl(struct cdev *dev, ioctlcmd_t cmd, caddr_t data,
269 int mode, struct thread *p)
270 #define p_cred td_ucred
271 #define p_uid td_ucred->cr_ruid
272 {
273 int error = 0, unit = 0;
274 SPL_INT(s);
275
276 CURVNET_SET(TD_TO_VNET(p));
277 if (securelevel_ge(p->p_cred, 3) && (mode & FWRITE))
278 {
279 V_ipfmain.ipf_interror = 130001;
280 CURVNET_RESTORE();
281 return (EPERM);
282 }
283
284 if (jailed_without_vnet(p->p_cred)) {
285 V_ipfmain.ipf_interror = 130018;
286 CURVNET_RESTORE();
287 return (EOPNOTSUPP);
288 }
289
290 unit = GET_MINOR(dev);
291 if ((IPL_LOGMAX < unit) || (unit < 0)) {
292 V_ipfmain.ipf_interror = 130002;
293 CURVNET_RESTORE();
294 return (ENXIO);
295 }
296
297 if (V_ipfmain.ipf_running <= 0) {
298 if (unit != IPL_LOGIPF && cmd != SIOCIPFINTERROR) {
299 V_ipfmain.ipf_interror = 130003;
300 CURVNET_RESTORE();
301 return (EIO);
302 }
303 if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET &&
304 cmd != SIOCIPFSET && cmd != SIOCFRENB &&
305 cmd != SIOCGETFS && cmd != SIOCGETFF &&
306 cmd != SIOCIPFINTERROR) {
307 V_ipfmain.ipf_interror = 130004;
308 CURVNET_RESTORE();
309 return (EIO);
310 }
311 }
312
313 SPL_NET(s);
314
315 error = ipf_ioctlswitch(&V_ipfmain, unit, data, cmd, mode, p->p_uid, p);
316 CURVNET_RESTORE();
317 if (error != -1) {
318 SPL_X(s);
319 return (error);
320 }
321
322 SPL_X(s);
323
324 return (error);
325 }
326
327
328 /*
329 * ipf_send_reset - this could conceivably be a call to tcp_respond(), but that
330 * requires a large amount of setting up and isn't any more efficient.
331 */
332 int
ipf_send_reset(fr_info_t * fin)333 ipf_send_reset(fr_info_t *fin)
334 {
335 struct tcphdr *tcp, *tcp2;
336 int tlen = 0, hlen;
337 struct mbuf *m;
338 #ifdef USE_INET6
339 ip6_t *ip6;
340 #endif
341 ip_t *ip;
342
343 tcp = fin->fin_dp;
344 if (tcp->th_flags & TH_RST)
345 return (-1); /* feedback loop */
346
347 if (ipf_checkl4sum(fin) == -1)
348 return (-1);
349
350 tlen = fin->fin_dlen - (TCP_OFF(tcp) << 2) +
351 ((tcp->th_flags & TH_SYN) ? 1 : 0) +
352 ((tcp->th_flags & TH_FIN) ? 1 : 0);
353
354 #ifdef USE_INET6
355 hlen = (fin->fin_v == 6) ? sizeof(ip6_t) : sizeof(ip_t);
356 #else
357 hlen = sizeof(ip_t);
358 #endif
359 #ifdef MGETHDR
360 MGETHDR(m, M_NOWAIT, MT_HEADER);
361 #else
362 MGET(m, M_NOWAIT, MT_HEADER);
363 #endif
364 if (m == NULL)
365 return (-1);
366 if (sizeof(*tcp2) + hlen > MLEN) {
367 if (!(MCLGET(m, M_NOWAIT))) {
368 FREE_MB_T(m);
369 return (-1);
370 }
371 }
372
373 m->m_len = sizeof(*tcp2) + hlen;
374 m->m_data += max_linkhdr;
375 m->m_pkthdr.len = m->m_len;
376 m->m_pkthdr.rcvif = (struct ifnet *)0;
377 ip = mtod(m, struct ip *);
378 bzero((char *)ip, hlen);
379 #ifdef USE_INET6
380 ip6 = (ip6_t *)ip;
381 #endif
382 tcp2 = (struct tcphdr *)((char *)ip + hlen);
383 tcp2->th_sport = tcp->th_dport;
384 tcp2->th_dport = tcp->th_sport;
385
386 if (tcp->th_flags & TH_ACK) {
387 tcp2->th_seq = tcp->th_ack;
388 tcp2->th_flags = TH_RST;
389 tcp2->th_ack = 0;
390 } else {
391 tcp2->th_seq = 0;
392 tcp2->th_ack = ntohl(tcp->th_seq);
393 tcp2->th_ack += tlen;
394 tcp2->th_ack = htonl(tcp2->th_ack);
395 tcp2->th_flags = TH_RST|TH_ACK;
396 }
397 TCP_X2_A(tcp2, 0);
398 TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2);
399 tcp2->th_win = tcp->th_win;
400 tcp2->th_sum = 0;
401 tcp2->th_urp = 0;
402
403 #ifdef USE_INET6
404 if (fin->fin_v == 6) {
405 ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow;
406 ip6->ip6_plen = htons(sizeof(struct tcphdr));
407 ip6->ip6_nxt = IPPROTO_TCP;
408 ip6->ip6_hlim = 0;
409 ip6->ip6_src = fin->fin_dst6.in6;
410 ip6->ip6_dst = fin->fin_src6.in6;
411 tcp2->th_sum = in6_cksum(m, IPPROTO_TCP,
412 sizeof(*ip6), sizeof(*tcp2));
413 return (ipf_send_ip(fin, m));
414 }
415 #endif
416 ip->ip_p = IPPROTO_TCP;
417 ip->ip_len = htons(sizeof(struct tcphdr));
418 ip->ip_src.s_addr = fin->fin_daddr;
419 ip->ip_dst.s_addr = fin->fin_saddr;
420 tcp2->th_sum = in_cksum(m, hlen + sizeof(*tcp2));
421 ip->ip_len = htons(hlen + sizeof(*tcp2));
422 return (ipf_send_ip(fin, m));
423 }
424
425
426 /*
427 * ip_len must be in network byte order when called.
428 */
429 static int
ipf_send_ip(fr_info_t * fin,mb_t * m)430 ipf_send_ip(fr_info_t *fin, mb_t *m)
431 {
432 fr_info_t fnew;
433 ip_t *ip, *oip;
434 int hlen;
435
436 ip = mtod(m, ip_t *);
437 bzero((char *)&fnew, sizeof(fnew));
438 fnew.fin_main_soft = fin->fin_main_soft;
439
440 IP_V_A(ip, fin->fin_v);
441 switch (fin->fin_v)
442 {
443 case 4 :
444 oip = fin->fin_ip;
445 hlen = sizeof(*oip);
446 fnew.fin_v = 4;
447 fnew.fin_p = ip->ip_p;
448 fnew.fin_plen = ntohs(ip->ip_len);
449 IP_HL_A(ip, sizeof(*oip) >> 2);
450 ip->ip_tos = oip->ip_tos;
451 ip->ip_id = fin->fin_ip->ip_id;
452 ip->ip_off = htons(V_path_mtu_discovery ? IP_DF : 0);
453 ip->ip_ttl = V_ip_defttl;
454 ip->ip_sum = 0;
455 break;
456 #ifdef USE_INET6
457 case 6 :
458 {
459 ip6_t *ip6 = (ip6_t *)ip;
460
461 ip6->ip6_vfc = 0x60;
462 ip6->ip6_hlim = IPDEFTTL;
463
464 hlen = sizeof(*ip6);
465 fnew.fin_p = ip6->ip6_nxt;
466 fnew.fin_v = 6;
467 fnew.fin_plen = ntohs(ip6->ip6_plen) + hlen;
468 break;
469 }
470 #endif
471 default :
472 return (EINVAL);
473 }
474 #ifdef IPSEC_SUPPORT
475 m->m_pkthdr.rcvif = NULL;
476 #endif
477
478 fnew.fin_ifp = fin->fin_ifp;
479 fnew.fin_flx = FI_NOCKSUM;
480 fnew.fin_m = m;
481 fnew.fin_ip = ip;
482 fnew.fin_mp = &m;
483 fnew.fin_hlen = hlen;
484 fnew.fin_dp = (char *)ip + hlen;
485 (void) ipf_makefrip(hlen, ip, &fnew);
486
487 return (ipf_fastroute(m, &m, &fnew, NULL));
488 }
489
490
491 int
ipf_send_icmp_err(int type,fr_info_t * fin,int dst)492 ipf_send_icmp_err(int type, fr_info_t *fin, int dst)
493 {
494 int err, hlen, xtra, iclen, ohlen, avail, code;
495 struct in_addr dst4;
496 struct icmp *icmp;
497 struct mbuf *m;
498 i6addr_t dst6;
499 void *ifp;
500 #ifdef USE_INET6
501 ip6_t *ip6;
502 #endif
503 ip_t *ip, *ip2;
504
505 if ((type < 0) || (type >= ICMP_MAXTYPE))
506 return (-1);
507
508 code = fin->fin_icode;
509 #ifdef USE_INET6
510 /* See NetBSD ip_fil_netbsd.c r1.4: */
511 if ((code < 0) || (code >= sizeof(icmptoicmp6unreach)/sizeof(int)))
512 return (-1);
513 #endif
514
515 if (ipf_checkl4sum(fin) == -1)
516 return (-1);
517 #ifdef MGETHDR
518 MGETHDR(m, M_NOWAIT, MT_HEADER);
519 #else
520 MGET(m, M_NOWAIT, MT_HEADER);
521 #endif
522 if (m == NULL)
523 return (-1);
524 avail = MHLEN;
525
526 xtra = 0;
527 hlen = 0;
528 ohlen = 0;
529 dst4.s_addr = 0;
530 ifp = fin->fin_ifp;
531 if (fin->fin_v == 4) {
532 if ((fin->fin_p == IPPROTO_ICMP) && !(fin->fin_flx & FI_SHORT))
533 switch (ntohs(fin->fin_data[0]) >> 8)
534 {
535 case ICMP_ECHO :
536 case ICMP_TSTAMP :
537 case ICMP_IREQ :
538 case ICMP_MASKREQ :
539 break;
540 default :
541 FREE_MB_T(m);
542 return (0);
543 }
544
545 if (dst == 0) {
546 if (ipf_ifpaddr(&V_ipfmain, 4, FRI_NORMAL, ifp,
547 &dst6, NULL) == -1) {
548 FREE_MB_T(m);
549 return (-1);
550 }
551 dst4 = dst6.in4;
552 } else
553 dst4.s_addr = fin->fin_daddr;
554
555 hlen = sizeof(ip_t);
556 ohlen = fin->fin_hlen;
557 iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen;
558 if (fin->fin_hlen < fin->fin_plen)
559 xtra = MIN(fin->fin_dlen, 8);
560 else
561 xtra = 0;
562 }
563
564 #ifdef USE_INET6
565 else if (fin->fin_v == 6) {
566 hlen = sizeof(ip6_t);
567 ohlen = sizeof(ip6_t);
568 iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen;
569 type = icmptoicmp6types[type];
570 if (type == ICMP6_DST_UNREACH)
571 code = icmptoicmp6unreach[code];
572
573 if (iclen + max_linkhdr + fin->fin_plen > avail) {
574 if (!(MCLGET(m, M_NOWAIT))) {
575 FREE_MB_T(m);
576 return (-1);
577 }
578 avail = MCLBYTES;
579 }
580 xtra = MIN(fin->fin_plen, avail - iclen - max_linkhdr);
581 xtra = MIN(xtra, IPV6_MMTU - iclen);
582 if (dst == 0) {
583 if (ipf_ifpaddr(&V_ipfmain, 6, FRI_NORMAL, ifp,
584 &dst6, NULL) == -1) {
585 FREE_MB_T(m);
586 return (-1);
587 }
588 } else
589 dst6 = fin->fin_dst6;
590 }
591 #endif
592 else {
593 FREE_MB_T(m);
594 return (-1);
595 }
596
597 avail -= (max_linkhdr + iclen);
598 if (avail < 0) {
599 FREE_MB_T(m);
600 return (-1);
601 }
602 if (xtra > avail)
603 xtra = avail;
604 iclen += xtra;
605 m->m_data += max_linkhdr;
606 m->m_pkthdr.rcvif = (struct ifnet *)0;
607 m->m_pkthdr.len = iclen;
608 m->m_len = iclen;
609 ip = mtod(m, ip_t *);
610 icmp = (struct icmp *)((char *)ip + hlen);
611 ip2 = (ip_t *)&icmp->icmp_ip;
612
613 icmp->icmp_type = type;
614 icmp->icmp_code = fin->fin_icode;
615 icmp->icmp_cksum = 0;
616 #ifdef icmp_nextmtu
617 if (type == ICMP_UNREACH && fin->fin_icode == ICMP_UNREACH_NEEDFRAG) {
618 if (fin->fin_mtu != 0) {
619 icmp->icmp_nextmtu = htons(fin->fin_mtu);
620
621 } else if (ifp != NULL) {
622 icmp->icmp_nextmtu = htons(GETIFMTU_4(ifp));
623
624 } else { /* make up a number... */
625 icmp->icmp_nextmtu = htons(fin->fin_plen - 20);
626 }
627 }
628 #endif
629
630 bcopy((char *)fin->fin_ip, (char *)ip2, ohlen);
631
632 #ifdef USE_INET6
633 ip6 = (ip6_t *)ip;
634 if (fin->fin_v == 6) {
635 ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow;
636 ip6->ip6_plen = htons(iclen - hlen);
637 ip6->ip6_nxt = IPPROTO_ICMPV6;
638 ip6->ip6_hlim = 0;
639 ip6->ip6_src = dst6.in6;
640 ip6->ip6_dst = fin->fin_src6.in6;
641 if (xtra > 0)
642 bcopy((char *)fin->fin_ip + ohlen,
643 (char *)&icmp->icmp_ip + ohlen, xtra);
644 icmp->icmp_cksum = in6_cksum(m, IPPROTO_ICMPV6,
645 sizeof(*ip6), iclen - hlen);
646 } else
647 #endif
648 {
649 ip->ip_p = IPPROTO_ICMP;
650 ip->ip_src.s_addr = dst4.s_addr;
651 ip->ip_dst.s_addr = fin->fin_saddr;
652
653 if (xtra > 0)
654 bcopy((char *)fin->fin_ip + ohlen,
655 (char *)&icmp->icmp_ip + ohlen, xtra);
656 icmp->icmp_cksum = ipf_cksum((u_short *)icmp,
657 sizeof(*icmp) + 8);
658 ip->ip_len = htons(iclen);
659 ip->ip_p = IPPROTO_ICMP;
660 }
661 err = ipf_send_ip(fin, m);
662 return (err);
663 }
664
665
666
667
668 /*
669 * m0 - pointer to mbuf where the IP packet starts
670 * mpp - pointer to the mbuf pointer that is the start of the mbuf chain
671 */
672 int
ipf_fastroute(mb_t * m0,mb_t ** mpp,fr_info_t * fin,frdest_t * fdp)673 ipf_fastroute(mb_t *m0, mb_t **mpp, fr_info_t *fin, frdest_t *fdp)
674 {
675 register struct ip *ip, *mhip;
676 register struct mbuf *m = *mpp;
677 int len, off, error = 0, hlen, code;
678 struct ifnet *ifp, *sifp;
679 struct route ro;
680 struct sockaddr_in *dst;
681 const struct sockaddr *gw;
682 struct nhop_object *nh;
683 u_long fibnum = 0;
684 u_short ip_off;
685 frdest_t node;
686 frentry_t *fr;
687
688 #ifdef M_WRITABLE
689 /*
690 * HOT FIX/KLUDGE:
691 *
692 * If the mbuf we're about to send is not writable (because of
693 * a cluster reference, for example) we'll need to make a copy
694 * of it since this routine modifies the contents.
695 *
696 * If you have non-crappy network hardware that can transmit data
697 * from the mbuf, rather than making a copy, this is gonna be a
698 * problem.
699 */
700 if (M_WRITABLE(m) == 0) {
701 m0 = m_dup(m, M_NOWAIT);
702 if (m0 != NULL) {
703 FREE_MB_T(m);
704 m = m0;
705 *mpp = m;
706 } else {
707 error = ENOBUFS;
708 FREE_MB_T(m);
709 goto done;
710 }
711 }
712 #endif
713
714 #ifdef USE_INET6
715 if (fin->fin_v == 6) {
716 /*
717 * currently "to <if>" and "to <if>:ip#" are not supported
718 * for IPv6
719 */
720 return (ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL));
721 }
722 #endif
723
724 hlen = fin->fin_hlen;
725 ip = mtod(m0, struct ip *);
726 ifp = NULL;
727
728 /*
729 * Route packet.
730 */
731 bzero(&ro, sizeof (ro));
732 dst = (struct sockaddr_in *)&ro.ro_dst;
733 dst->sin_family = AF_INET;
734 dst->sin_addr = ip->ip_dst;
735 dst->sin_len = sizeof(dst);
736 gw = (const struct sockaddr *)dst;
737
738 fr = fin->fin_fr;
739 if ((fr != NULL) && !(fr->fr_flags & FR_KEEPSTATE) && (fdp != NULL) &&
740 (fdp->fd_type == FRD_DSTLIST)) {
741 if (ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &node) == 0)
742 fdp = &node;
743 }
744
745 if (fdp != NULL)
746 ifp = fdp->fd_ptr;
747 else
748 ifp = fin->fin_ifp;
749
750 if ((ifp == NULL) && ((fr == NULL) || !(fr->fr_flags & FR_FASTROUTE))) {
751 error = -2;
752 goto bad;
753 }
754
755 if ((fdp != NULL) && (fdp->fd_ip.s_addr != 0))
756 dst->sin_addr = fdp->fd_ip;
757
758 fibnum = M_GETFIB(m0);
759 NET_EPOCH_ASSERT();
760 nh = fib4_lookup(fibnum, dst->sin_addr, 0, NHR_NONE, 0);
761 if (nh == NULL) {
762 if (in_localaddr(ip->ip_dst))
763 error = EHOSTUNREACH;
764 else
765 error = ENETUNREACH;
766 goto bad;
767 }
768
769 if (ifp == NULL)
770 ifp = nh->nh_ifp;
771 if (nh->nh_flags & NHF_GATEWAY) {
772 gw = &nh->gw_sa;
773 ro.ro_flags |= RT_HAS_GW;
774 }
775
776 /*
777 * For input packets which are being "fastrouted", they won't
778 * go back through output filtering and miss their chance to get
779 * NAT'd and counted. Duplicated packets aren't considered to be
780 * part of the normal packet stream, so do not NAT them or pass
781 * them through stateful checking, etc.
782 */
783 if ((fdp != &fr->fr_dif) && (fin->fin_out == 0)) {
784 sifp = fin->fin_ifp;
785 fin->fin_ifp = ifp;
786 fin->fin_out = 1;
787 (void) ipf_acctpkt(fin, NULL);
788 fin->fin_fr = NULL;
789 if (!fr || !(fr->fr_flags & FR_RETMASK)) {
790 u_32_t pass;
791
792 (void) ipf_state_check(fin, &pass);
793 }
794
795 switch (ipf_nat_checkout(fin, NULL))
796 {
797 case 0 :
798 break;
799 case 1 :
800 ip->ip_sum = 0;
801 break;
802 case -1 :
803 error = -1;
804 goto bad;
805 break;
806 }
807
808 fin->fin_ifp = sifp;
809 fin->fin_out = 0;
810 } else
811 ip->ip_sum = 0;
812 /*
813 * If small enough for interface, can just send directly.
814 */
815 if (ntohs(ip->ip_len) <= ifp->if_mtu) {
816 if (!ip->ip_sum)
817 ip->ip_sum = in_cksum(m, hlen);
818 error = (*ifp->if_output)(ifp, m, gw, &ro);
819 goto done;
820 }
821 /*
822 * Too large for interface; fragment if possible.
823 * Must be able to put at least 8 bytes per fragment.
824 */
825 ip_off = ntohs(ip->ip_off);
826 if (ip_off & IP_DF) {
827 error = EMSGSIZE;
828 goto bad;
829 }
830 len = (ifp->if_mtu - hlen) &~ 7;
831 if (len < 8) {
832 error = EMSGSIZE;
833 goto bad;
834 }
835
836 {
837 int mhlen, firstlen = len;
838 struct mbuf **mnext = &m->m_act;
839
840 /*
841 * Loop through length of segment after first fragment,
842 * make new header and copy data of each part and link onto chain.
843 */
844 m0 = m;
845 mhlen = sizeof (struct ip);
846 for (off = hlen + len; off < ntohs(ip->ip_len); off += len) {
847 #ifdef MGETHDR
848 MGETHDR(m, M_NOWAIT, MT_HEADER);
849 #else
850 MGET(m, M_NOWAIT, MT_HEADER);
851 #endif
852 if (m == NULL) {
853 m = m0;
854 error = ENOBUFS;
855 goto bad;
856 }
857 m->m_data += max_linkhdr;
858 mhip = mtod(m, struct ip *);
859 bcopy((char *)ip, (char *)mhip, sizeof(*ip));
860 if (hlen > sizeof (struct ip)) {
861 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
862 IP_HL_A(mhip, mhlen >> 2);
863 }
864 m->m_len = mhlen;
865 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
866 if (off + len >= ntohs(ip->ip_len))
867 len = ntohs(ip->ip_len) - off;
868 else
869 mhip->ip_off |= IP_MF;
870 mhip->ip_len = htons((u_short)(len + mhlen));
871 *mnext = m;
872 m->m_next = m_copym(m0, off, len, M_NOWAIT);
873 if (m->m_next == 0) {
874 error = ENOBUFS; /* ??? */
875 goto sendorfree;
876 }
877 m->m_pkthdr.len = mhlen + len;
878 m->m_pkthdr.rcvif = NULL;
879 mhip->ip_off = htons((u_short)mhip->ip_off);
880 mhip->ip_sum = 0;
881 mhip->ip_sum = in_cksum(m, mhlen);
882 mnext = &m->m_act;
883 }
884 /*
885 * Update first fragment by trimming what's been copied out
886 * and updating header, then send each fragment (in order).
887 */
888 m_adj(m0, hlen + firstlen - ip->ip_len);
889 ip->ip_len = htons((u_short)(hlen + firstlen));
890 ip->ip_off = htons((u_short)IP_MF);
891 ip->ip_sum = 0;
892 ip->ip_sum = in_cksum(m0, hlen);
893 sendorfree:
894 for (m = m0; m; m = m0) {
895 m0 = m->m_act;
896 m->m_act = 0;
897 if (error == 0)
898 error = (*ifp->if_output)(ifp, m, gw, &ro);
899 else
900 FREE_MB_T(m);
901 }
902 }
903 done:
904 if (!error)
905 V_ipfmain.ipf_frouteok[0]++;
906 else
907 V_ipfmain.ipf_frouteok[1]++;
908
909 return (0);
910 bad:
911 if (error == EMSGSIZE) {
912 sifp = fin->fin_ifp;
913 code = fin->fin_icode;
914 fin->fin_icode = ICMP_UNREACH_NEEDFRAG;
915 fin->fin_ifp = ifp;
916 (void) ipf_send_icmp_err(ICMP_UNREACH, fin, 1);
917 fin->fin_ifp = sifp;
918 fin->fin_icode = code;
919 }
920 FREE_MB_T(m);
921 goto done;
922 }
923
924
925 int
ipf_verifysrc(fr_info_t * fin)926 ipf_verifysrc(fr_info_t *fin)
927 {
928 struct nhop_object *nh;
929
930 NET_EPOCH_ASSERT();
931 nh = fib4_lookup(RT_DEFAULT_FIB, fin->fin_src, 0, NHR_NONE, 0);
932 if (nh == NULL)
933 return (0);
934 return (fin->fin_ifp == nh->nh_ifp);
935 }
936
937
938 /*
939 * return the first IP Address associated with an interface
940 */
941 int
ipf_ifpaddr(ipf_main_softc_t * softc,int v,int atype,void * ifptr,i6addr_t * inp,i6addr_t * inpmask)942 ipf_ifpaddr(ipf_main_softc_t *softc, int v, int atype, void *ifptr,
943 i6addr_t *inp, i6addr_t *inpmask)
944 {
945 #ifdef USE_INET6
946 struct in6_addr *ia6 = NULL;
947 #endif
948 struct sockaddr *sock, *mask;
949 struct sockaddr_in *sin;
950 struct ifaddr *ifa;
951 struct ifnet *ifp;
952
953 if ((ifptr == NULL) || (ifptr == (void *)-1))
954 return (-1);
955
956 sin = NULL;
957 ifp = ifptr;
958
959 if (v == 4)
960 inp->in4.s_addr = 0;
961 #ifdef USE_INET6
962 else if (v == 6)
963 bzero((char *)inp, sizeof(*inp));
964 #endif
965 ifa = CK_STAILQ_FIRST(&ifp->if_addrhead);
966
967 sock = ifa->ifa_addr;
968 while (sock != NULL && ifa != NULL) {
969 sin = (struct sockaddr_in *)sock;
970 if ((v == 4) && (sin->sin_family == AF_INET))
971 break;
972 #ifdef USE_INET6
973 if ((v == 6) && (sin->sin_family == AF_INET6)) {
974 ia6 = &((struct sockaddr_in6 *)sin)->sin6_addr;
975 if (!IN6_IS_ADDR_LINKLOCAL(ia6) &&
976 !IN6_IS_ADDR_LOOPBACK(ia6))
977 break;
978 }
979 #endif
980 ifa = CK_STAILQ_NEXT(ifa, ifa_link);
981 if (ifa != NULL)
982 sock = ifa->ifa_addr;
983 }
984
985 if (ifa == NULL || sin == NULL)
986 return (-1);
987
988 mask = ifa->ifa_netmask;
989 if (atype == FRI_BROADCAST)
990 sock = ifa->ifa_broadaddr;
991 else if (atype == FRI_PEERADDR)
992 sock = ifa->ifa_dstaddr;
993
994 if (sock == NULL)
995 return (-1);
996
997 #ifdef USE_INET6
998 if (v == 6) {
999 return (ipf_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock,
1000 (struct sockaddr_in6 *)mask,
1001 inp, inpmask));
1002 }
1003 #endif
1004 return (ipf_ifpfillv4addr(atype, (struct sockaddr_in *)sock,
1005 (struct sockaddr_in *)mask,
1006 &inp->in4, &inpmask->in4));
1007 }
1008
1009
1010 u_32_t
ipf_newisn(fr_info_t * fin)1011 ipf_newisn(fr_info_t *fin)
1012 {
1013 u_32_t newiss;
1014 newiss = arc4random();
1015 return (newiss);
1016 }
1017
1018
1019 int
ipf_checkv4sum(fr_info_t * fin)1020 ipf_checkv4sum(fr_info_t *fin)
1021 {
1022 #ifdef CSUM_DATA_VALID
1023 int manual = 0;
1024 u_short sum;
1025 ip_t *ip;
1026 mb_t *m;
1027
1028 if ((fin->fin_flx & FI_NOCKSUM) != 0)
1029 return (0);
1030
1031 if ((fin->fin_flx & FI_SHORT) != 0)
1032 return (1);
1033
1034 if (fin->fin_cksum != FI_CK_NEEDED)
1035 return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1;
1036
1037 m = fin->fin_m;
1038 if (m == NULL) {
1039 manual = 1;
1040 goto skipauto;
1041 }
1042 ip = fin->fin_ip;
1043
1044 if ((m->m_pkthdr.csum_flags & (CSUM_IP_CHECKED|CSUM_IP_VALID)) ==
1045 CSUM_IP_CHECKED) {
1046 fin->fin_cksum = FI_CK_BAD;
1047 fin->fin_flx |= FI_BAD;
1048 DT2(ipf_fi_bad_checkv4sum_csum_ip_checked, fr_info_t *, fin, u_int, m->m_pkthdr.csum_flags & (CSUM_IP_CHECKED|CSUM_IP_VALID));
1049 return (-1);
1050 }
1051 if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
1052 /* Depending on the driver, UDP may have zero checksum */
1053 if (fin->fin_p == IPPROTO_UDP && (fin->fin_flx &
1054 (FI_FRAG|FI_SHORT|FI_BAD)) == 0) {
1055 udphdr_t *udp = fin->fin_dp;
1056 if (udp->uh_sum == 0) {
1057 /*
1058 * we're good no matter what the hardware
1059 * checksum flags and csum_data say (handling
1060 * of csum_data for zero UDP checksum is not
1061 * consistent across all drivers)
1062 */
1063 fin->fin_cksum = 1;
1064 return (0);
1065 }
1066 }
1067
1068 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
1069 sum = m->m_pkthdr.csum_data;
1070 else
1071 sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
1072 htonl(m->m_pkthdr.csum_data +
1073 fin->fin_dlen + fin->fin_p));
1074 sum ^= 0xffff;
1075 if (sum != 0) {
1076 fin->fin_cksum = FI_CK_BAD;
1077 fin->fin_flx |= FI_BAD;
1078 DT2(ipf_fi_bad_checkv4sum_sum, fr_info_t *, fin, u_int, sum);
1079 } else {
1080 fin->fin_cksum = FI_CK_SUMOK;
1081 return (0);
1082 }
1083 } else {
1084 if (m->m_pkthdr.csum_flags == CSUM_DELAY_DATA) {
1085 fin->fin_cksum = FI_CK_L4FULL;
1086 return (0);
1087 } else if (m->m_pkthdr.csum_flags == CSUM_TCP ||
1088 m->m_pkthdr.csum_flags == CSUM_UDP ||
1089 m->m_pkthdr.csum_flags == CSUM_IP) {
1090 fin->fin_cksum = FI_CK_L4PART;
1091 return (0);
1092 } else {
1093 manual = 1;
1094 }
1095 }
1096 skipauto:
1097 if (manual != 0) {
1098 if (ipf_checkl4sum(fin) == -1) {
1099 fin->fin_flx |= FI_BAD;
1100 DT2(ipf_fi_bad_checkv4sum_manual, fr_info_t *, fin, u_int, manual);
1101 return (-1);
1102 }
1103 }
1104 #else
1105 if (ipf_checkl4sum(fin) == -1) {
1106 fin->fin_flx |= FI_BAD;
1107 DT2(ipf_fi_bad_checkv4sum_checkl4sum, fr_info_t *, fin, u_int, -1);
1108 return (-1);
1109 }
1110 #endif
1111 return (0);
1112 }
1113
1114
1115 #ifdef USE_INET6
1116 int
ipf_checkv6sum(fr_info_t * fin)1117 ipf_checkv6sum(fr_info_t *fin)
1118 {
1119 if ((fin->fin_flx & FI_NOCKSUM) != 0) {
1120 DT(ipf_checkv6sum_fi_nocksum);
1121 return (0);
1122 }
1123
1124 if ((fin->fin_flx & FI_SHORT) != 0) {
1125 DT(ipf_checkv6sum_fi_short);
1126 return (1);
1127 }
1128
1129 if (fin->fin_cksum != FI_CK_NEEDED) {
1130 DT(ipf_checkv6sum_fi_ck_needed);
1131 return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1;
1132 }
1133
1134 if (ipf_checkl4sum(fin) == -1) {
1135 fin->fin_flx |= FI_BAD;
1136 DT2(ipf_fi_bad_checkv6sum_checkl4sum, fr_info_t *, fin, u_int, -1);
1137 return (-1);
1138 }
1139 return (0);
1140 }
1141 #endif /* USE_INET6 */
1142
1143
1144 size_t
mbufchainlen(struct mbuf * m0)1145 mbufchainlen(struct mbuf *m0)
1146 {
1147 size_t len;
1148
1149 if ((m0->m_flags & M_PKTHDR) != 0) {
1150 len = m0->m_pkthdr.len;
1151 } else {
1152 struct mbuf *m;
1153
1154 for (m = m0, len = 0; m != NULL; m = m->m_next)
1155 len += m->m_len;
1156 }
1157 return (len);
1158 }
1159
1160
1161 /* ------------------------------------------------------------------------ */
1162 /* Function: ipf_pullup */
1163 /* Returns: NULL == pullup failed, else pointer to protocol header */
1164 /* Parameters: xmin(I)- pointer to buffer where data packet starts */
1165 /* fin(I) - pointer to packet information */
1166 /* len(I) - number of bytes to pullup */
1167 /* */
1168 /* Attempt to move at least len bytes (from the start of the buffer) into a */
1169 /* single buffer for ease of access. Operating system native functions are */
1170 /* used to manage buffers - if necessary. If the entire packet ends up in */
1171 /* a single buffer, set the FI_COALESCE flag even though ipf_coalesce() has */
1172 /* not been called. Both fin_ip and fin_dp are updated before exiting _IF_ */
1173 /* and ONLY if the pullup succeeds. */
1174 /* */
1175 /* We assume that 'xmin' is a pointer to a buffer that is part of the chain */
1176 /* of buffers that starts at *fin->fin_mp. */
1177 /* ------------------------------------------------------------------------ */
1178 ip_t *
ipf_pullup(mb_t * xmin,fr_info_t * fin,int len)1179 ipf_pullup(mb_t *xmin, fr_info_t *fin, int len)
1180 {
1181 int dpoff, ipoff;
1182 mb_t *m = xmin;
1183 ip_t *ip;
1184
1185 if (m == NULL)
1186 return (NULL);
1187
1188 ip = fin->fin_ip;
1189 if ((fin->fin_flx & FI_COALESCE) != 0)
1190 return (ip);
1191
1192 ipoff = fin->fin_ipoff;
1193 if (fin->fin_dp != NULL)
1194 dpoff = (char *)fin->fin_dp - (char *)ip;
1195 else
1196 dpoff = 0;
1197
1198 if (M_LEN(m) < len) {
1199 mb_t *n = *fin->fin_mp;
1200 /*
1201 * Assume that M_PKTHDR is set and just work with what is left
1202 * rather than check..
1203 * Should not make any real difference, anyway.
1204 */
1205 if (m != n) {
1206 /*
1207 * Record the mbuf that points to the mbuf that we're
1208 * about to go to work on so that we can update the
1209 * m_next appropriately later.
1210 */
1211 for (; n->m_next != m; n = n->m_next)
1212 ;
1213 } else {
1214 n = NULL;
1215 }
1216
1217 #ifdef MHLEN
1218 if (len > MHLEN)
1219 #else
1220 if (len > MLEN)
1221 #endif
1222 {
1223 #ifdef HAVE_M_PULLDOWN
1224 if (m_pulldown(m, 0, len, NULL) == NULL)
1225 m = NULL;
1226 #else
1227 FREE_MB_T(*fin->fin_mp);
1228 m = NULL;
1229 n = NULL;
1230 #endif
1231 } else
1232 {
1233
1234 m = m_pullup(m, len);
1235 }
1236 if (n != NULL)
1237 n->m_next = m;
1238 if (m == NULL) {
1239 /*
1240 * When n is non-NULL, it indicates that m pointed to
1241 * a sub-chain (tail) of the mbuf and that the head
1242 * of this chain has not yet been free'd.
1243 */
1244 if (n != NULL) {
1245 FREE_MB_T(*fin->fin_mp);
1246 }
1247
1248 *fin->fin_mp = NULL;
1249 fin->fin_m = NULL;
1250 return (NULL);
1251 }
1252
1253 if (n == NULL)
1254 *fin->fin_mp = m;
1255
1256 while (M_LEN(m) == 0) {
1257 m = m->m_next;
1258 }
1259 fin->fin_m = m;
1260 ip = MTOD(m, ip_t *) + ipoff;
1261
1262 fin->fin_ip = ip;
1263 if (fin->fin_dp != NULL)
1264 fin->fin_dp = (char *)fin->fin_ip + dpoff;
1265 if (fin->fin_fraghdr != NULL)
1266 fin->fin_fraghdr = (char *)ip +
1267 ((char *)fin->fin_fraghdr -
1268 (char *)fin->fin_ip);
1269 }
1270
1271 if (len == fin->fin_plen)
1272 fin->fin_flx |= FI_COALESCE;
1273 return (ip);
1274 }
1275
1276
1277 int
ipf_inject(fr_info_t * fin,mb_t * m)1278 ipf_inject(fr_info_t *fin, mb_t *m)
1279 {
1280 struct epoch_tracker et;
1281 int error = 0;
1282
1283 NET_EPOCH_ENTER(et);
1284 if (fin->fin_out == 0) {
1285 netisr_dispatch(NETISR_IP, m);
1286 } else {
1287 fin->fin_ip->ip_len = ntohs(fin->fin_ip->ip_len);
1288 fin->fin_ip->ip_off = ntohs(fin->fin_ip->ip_off);
1289 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL);
1290 }
1291 NET_EPOCH_EXIT(et);
1292
1293 return (error);
1294 }
1295
1296 VNET_DEFINE_STATIC(pfil_hook_t, ipf_inet_hook);
1297 VNET_DEFINE_STATIC(pfil_hook_t, ipf_inet6_hook);
1298 #define V_ipf_inet_hook VNET(ipf_inet_hook)
1299 #define V_ipf_inet6_hook VNET(ipf_inet6_hook)
1300
ipf_pfil_unhook(void)1301 int ipf_pfil_unhook(void) {
1302
1303 pfil_remove_hook(V_ipf_inet_hook);
1304
1305 #ifdef USE_INET6
1306 pfil_remove_hook(V_ipf_inet6_hook);
1307 #endif
1308
1309 return (0);
1310 }
1311
ipf_pfil_hook(void)1312 int ipf_pfil_hook(void) {
1313 int error, error6;
1314
1315 struct pfil_hook_args pha = {
1316 .pa_version = PFIL_VERSION,
1317 .pa_flags = PFIL_IN | PFIL_OUT,
1318 .pa_modname = "ipfilter",
1319 .pa_rulname = "default-ip4",
1320 .pa_mbuf_chk = ipf_check_wrapper,
1321 .pa_type = PFIL_TYPE_IP4,
1322 };
1323 V_ipf_inet_hook = pfil_add_hook(&pha);
1324
1325 #ifdef USE_INET6
1326 pha.pa_rulname = "default-ip6";
1327 pha.pa_mbuf_chk = ipf_check_wrapper6;
1328 pha.pa_type = PFIL_TYPE_IP6;
1329 V_ipf_inet6_hook = pfil_add_hook(&pha);
1330 #endif
1331
1332 struct pfil_link_args pla = {
1333 .pa_version = PFIL_VERSION,
1334 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR,
1335 .pa_head = V_inet_pfil_head,
1336 .pa_hook = V_ipf_inet_hook,
1337 };
1338 error = pfil_link(&pla);
1339
1340 error6 = 0;
1341 #ifdef USE_INET6
1342 pla.pa_head = V_inet6_pfil_head;
1343 pla.pa_hook = V_ipf_inet6_hook;
1344 error6 = pfil_link(&pla);
1345 #endif
1346
1347 if (error || error6)
1348 error = ENODEV;
1349 else
1350 error = 0;
1351
1352 return (error);
1353 }
1354
1355 void
ipf_event_reg(void)1356 ipf_event_reg(void)
1357 {
1358 V_ipf_arrivetag = EVENTHANDLER_REGISTER(ifnet_arrival_event, \
1359 ipf_ifevent, NULL, \
1360 EVENTHANDLER_PRI_ANY);
1361 V_ipf_departtag = EVENTHANDLER_REGISTER(ifnet_departure_event, \
1362 ipf_ifevent, NULL, \
1363 EVENTHANDLER_PRI_ANY);
1364 #if 0
1365 V_ipf_clonetag = EVENTHANDLER_REGISTER(if_clone_event, ipf_ifevent, \
1366 NULL, EVENTHANDLER_PRI_ANY);
1367 #endif
1368 }
1369
1370 void
ipf_event_dereg(void)1371 ipf_event_dereg(void)
1372 {
1373 if (V_ipf_arrivetag != NULL) {
1374 EVENTHANDLER_DEREGISTER(ifnet_arrival_event, V_ipf_arrivetag);
1375 }
1376 if (V_ipf_departtag != NULL) {
1377 EVENTHANDLER_DEREGISTER(ifnet_departure_event, V_ipf_departtag);
1378 }
1379 #if 0
1380 if (V_ipf_clonetag != NULL) {
1381 EVENTHANDLER_DEREGISTER(if_clone_event, V_ipf_clonetag);
1382 }
1383 #endif
1384 }
1385
1386
1387 u_32_t
ipf_random(void)1388 ipf_random(void)
1389 {
1390 return (arc4random());
1391 }
1392
1393
1394 u_int
ipf_pcksum(fr_info_t * fin,int hlen,u_int sum)1395 ipf_pcksum(fr_info_t *fin, int hlen, u_int sum)
1396 {
1397 struct mbuf *m;
1398 u_int sum2;
1399 int off;
1400
1401 m = fin->fin_m;
1402 off = (char *)fin->fin_dp - (char *)fin->fin_ip;
1403 m->m_data += hlen;
1404 m->m_len -= hlen;
1405 sum2 = in_cksum(fin->fin_m, fin->fin_plen - off);
1406 m->m_len += hlen;
1407 m->m_data -= hlen;
1408
1409 /*
1410 * Both sum and sum2 are partial sums, so combine them together.
1411 */
1412 sum += ~sum2 & 0xffff;
1413 while (sum > 0xffff)
1414 sum = (sum & 0xffff) + (sum >> 16);
1415 sum2 = ~sum & 0xffff;
1416 return (sum2);
1417 }
1418
1419 #ifdef USE_INET6
1420 u_int
ipf_pcksum6(struct mbuf * m,ip6_t * ip6,u_int32_t off,u_int32_t len)1421 ipf_pcksum6(struct mbuf *m, ip6_t *ip6, u_int32_t off, u_int32_t len)
1422 {
1423 #ifdef _KERNEL
1424 int sum;
1425
1426 if (m->m_len < sizeof(struct ip6_hdr)) {
1427 return (0xffff);
1428 }
1429
1430 sum = in6_cksum(m, ip6->ip6_nxt, off, len);
1431 return (sum);
1432 #else
1433 u_short *sp;
1434 u_int sum;
1435
1436 sp = (u_short *)&ip6->ip6_src;
1437 sum = *sp++; /* ip6_src */
1438 sum += *sp++;
1439 sum += *sp++;
1440 sum += *sp++;
1441 sum += *sp++;
1442 sum += *sp++;
1443 sum += *sp++;
1444 sum += *sp++;
1445 sum += *sp++; /* ip6_dst */
1446 sum += *sp++;
1447 sum += *sp++;
1448 sum += *sp++;
1449 sum += *sp++;
1450 sum += *sp++;
1451 sum += *sp++;
1452 sum += *sp++;
1453 return (ipf_pcksum(fin, off, sum));
1454 #endif
1455 }
1456 #endif
1457
1458 void
ipf_fbsd_kenv_get(ipf_main_softc_t * softc)1459 ipf_fbsd_kenv_get(ipf_main_softc_t *softc)
1460 {
1461 TUNABLE_INT_FETCH("net.inet.ipf.large_nat",
1462 &softc->ipf_large_nat);
1463 }
1464