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Minor code reordering and documentation adjustments.
[dragonfly.git] / sys / netinet / ip_output.c
blob9278ffa853fd8d0c1a007dc8c7d0a09281d35550
1 /*
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
30 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $
31 * $DragonFly: src/sys/netinet/ip_output.c,v 1.41 2008/01/06 16:55:52 swildner Exp $
32 */
33
34 #define _IP_VHL
35
36 #include "opt_ipfw.h"
37 #include "opt_ipdn.h"
38 #include "opt_ipdivert.h"
39 #include "opt_ipfilter.h"
40 #include "opt_ipsec.h"
41 #include "opt_mbuf_stress_test.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/protosw.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/proc.h>
52 #include <sys/sysctl.h>
53 #include <sys/thread2.h>
54 #include <sys/in_cksum.h>
55
56 #include <net/if.h>
57 #include <net/netisr.h>
58 #include <net/pfil.h>
59 #include <net/route.h>
60
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #include <netinet/in_pcb.h>
65 #include <netinet/in_var.h>
66 #include <netinet/ip_var.h>
67
68 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
69
70 #ifdef IPSEC
71 #include <netinet6/ipsec.h>
72 #include <netproto/key/key.h>
73 #ifdef IPSEC_DEBUG
74 #include <netproto/key/key_debug.h>
75 #else
76 #define KEYDEBUG(lev,arg)
77 #endif
78 #endif /*IPSEC*/
79
80 #ifdef FAST_IPSEC
81 #include <netproto/ipsec/ipsec.h>
82 #include <netproto/ipsec/xform.h>
83 #include <netproto/ipsec/key.h>
84 #endif /*FAST_IPSEC*/
85
86 #include <net/ipfw/ip_fw.h>
87 #include <net/dummynet/ip_dummynet.h>
88
89 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\
90 x, (ntohl(a.s_addr)>>24)&0xFF,\
91 (ntohl(a.s_addr)>>16)&0xFF,\
92 (ntohl(a.s_addr)>>8)&0xFF,\
93 (ntohl(a.s_addr))&0xFF, y);
94
95 u_short ip_id;
96
97 #ifdef MBUF_STRESS_TEST
98 int mbuf_frag_size = 0;
99 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
100 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
101 #endif
102
103 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
104 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
105 static void ip_mloopback
106 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
107 static int ip_getmoptions
108 (struct sockopt *, struct ip_moptions *);
109 static int ip_pcbopts(int, struct mbuf **, struct mbuf *);
110 static int ip_setmoptions
111 (struct sockopt *, struct ip_moptions **);
112
113 int ip_optcopy(struct ip *, struct ip *);
114
115
116 extern struct protosw inetsw[];
117
118 /*
119 * IP output. The packet in mbuf chain m contains a skeletal IP
120 * header (with len, off, ttl, proto, tos, src, dst).
121 * The mbuf chain containing the packet will be freed.
122 * The mbuf opt, if present, will not be freed.
123 */
124 int
125 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
126 int flags, struct ip_moptions *imo, struct inpcb *inp)
127 {
128 struct ip *ip;
129 struct ifnet *ifp = NULL; /* keep compiler happy */
130 struct mbuf *m;
131 int hlen = sizeof(struct ip);
132 int len, off, error = 0;
133 struct sockaddr_in *dst = NULL; /* keep compiler happy */
134 struct in_ifaddr *ia = NULL;
135 int isbroadcast, sw_csum;
136 struct in_addr pkt_dst;
137 struct route iproute;
138 struct m_tag *dn_mtag = NULL;
139 #ifdef IPSEC
140 struct secpolicy *sp = NULL;
141 struct socket *so = inp ? inp->inp_socket : NULL;
142 #endif
143 #ifdef FAST_IPSEC
144 struct m_tag *mtag;
145 struct secpolicy *sp = NULL;
146 struct tdb_ident *tdbi;
147 #endif /* FAST_IPSEC */
148 struct ip_fw_args args;
149 int src_was_INADDR_ANY = 0; /* as the name says... */
150
151 args.eh = NULL;
152 args.rule = NULL;
153 args.next_hop = NULL;
154
155 /* Grab info from MT_TAG mbufs prepended to the chain. */
156 while (m0 != NULL && m0->m_type == MT_TAG) {
157 switch(m0->_m_tag_id) {
158 case PACKET_TAG_IPFORWARD:
159 args.next_hop = (struct sockaddr_in *)m0->m_data;
160 break;
161 default:
162 kprintf("ip_output: unrecognised MT_TAG tag %d\n",
163 m0->_m_tag_id);
164 break;
165 }
166 m0 = m0->m_next;
167 }
168 m = m0;
169 M_ASSERTPKTHDR(m);
170
171 /* Extract info from dummynet tag */
172 dn_mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
173 if (dn_mtag != NULL) {
174 struct dn_pkt *dn_pkt = m_tag_data(dn_mtag);
175
176 /*
177 * The packet was already tagged, so part of the
178 * processing was already done, and we need to go down.
179 * Get parameters from the tag.
180 */
181 args.rule = dn_pkt->dn_priv;
182 opt = NULL;
183 ro = &dn_pkt->ro;
184 imo = NULL;
185 dst = dn_pkt->dn_dst;
186 ifp = dn_pkt->ifp;
187 flags = dn_pkt->flags;
188
189 /*
190 * Don't delete the dummynet tag here, just unlink it,
191 * since some local variables (like 'ro' and 'dst') are
192 * still referencing certain parts of it.
193 * The dummynet tag will be freed at the end of the
194 * output process.
195 */
196 m_tag_unlink(m, dn_mtag);
197 }
198
199 if (ro == NULL) {
200 ro = &iproute;
201 bzero(ro, sizeof *ro);
202 }
203
204 if (args.rule != NULL) { /* dummynet already saw us */
205 ip = mtod(m, struct ip *);
206 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
207 if (ro->ro_rt)
208 ia = ifatoia(ro->ro_rt->rt_ifa);
209 goto sendit;
210 }
211
212 if (opt) {
213 len = 0;
214 m = ip_insertoptions(m, opt, &len);
215 if (len != 0)
216 hlen = len;
217 }
218 ip = mtod(m, struct ip *);
219 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
220
221 /*
222 * Fill in IP header.
223 */
224 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) {
225 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
226 ip->ip_off &= IP_DF;
227 ip->ip_id = ip_newid();
228 ipstat.ips_localout++;
229 } else {
230 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
231 }
232
233 dst = (struct sockaddr_in *)&ro->ro_dst;
234 /*
235 * If there is a cached route,
236 * check that it is to the same destination
237 * and is still up. If not, free it and try again.
238 * The address family should also be checked in case of sharing the
239 * cache with IPv6.
240 */
241 if (ro->ro_rt &&
242 (!(ro->ro_rt->rt_flags & RTF_UP) ||
243 dst->sin_family != AF_INET ||
244 dst->sin_addr.s_addr != pkt_dst.s_addr)) {
245 rtfree(ro->ro_rt);
246 ro->ro_rt = (struct rtentry *)NULL;
247 }
248 if (ro->ro_rt == NULL) {
249 bzero(dst, sizeof *dst);
250 dst->sin_family = AF_INET;
251 dst->sin_len = sizeof *dst;
252 dst->sin_addr = pkt_dst;
253 }
254 /*
255 * If routing to interface only,
256 * short circuit routing lookup.
257 */
258 if (flags & IP_ROUTETOIF) {
259 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
260 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
261 ipstat.ips_noroute++;
262 error = ENETUNREACH;
263 goto bad;
264 }
265 ifp = ia->ia_ifp;
266 ip->ip_ttl = 1;
267 isbroadcast = in_broadcast(dst->sin_addr, ifp);
268 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
269 imo != NULL && imo->imo_multicast_ifp != NULL) {
270 /*
271 * Bypass the normal routing lookup for multicast
272 * packets if the interface is specified.
273 */
274 ifp = imo->imo_multicast_ifp;
275 IFP_TO_IA(ifp, ia);
276 isbroadcast = 0; /* fool gcc */
277 } else {
278 /*
279 * If this is the case, we probably don't want to allocate
280 * a protocol-cloned route since we didn't get one from the
281 * ULP. This lets TCP do its thing, while not burdening
282 * forwarding or ICMP with the overhead of cloning a route.
283 * Of course, we still want to do any cloning requested by
284 * the link layer, as this is probably required in all cases
285 * for correct operation (as it is for ARP).
286 */
287 if (ro->ro_rt == NULL)
288 rtalloc_ign(ro, RTF_PRCLONING);
289 if (ro->ro_rt == NULL) {
290 ipstat.ips_noroute++;
291 error = EHOSTUNREACH;
292 goto bad;
293 }
294 ia = ifatoia(ro->ro_rt->rt_ifa);
295 ifp = ro->ro_rt->rt_ifp;
296 ro->ro_rt->rt_use++;
297 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
298 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
299 if (ro->ro_rt->rt_flags & RTF_HOST)
300 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
301 else
302 isbroadcast = in_broadcast(dst->sin_addr, ifp);
303 }
304 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
305 struct in_multi *inm;
306
307 m->m_flags |= M_MCAST;
308 /*
309 * IP destination address is multicast. Make sure "dst"
310 * still points to the address in "ro". (It may have been
311 * changed to point to a gateway address, above.)
312 */
313 dst = (struct sockaddr_in *)&ro->ro_dst;
314 /*
315 * See if the caller provided any multicast options
316 */
317 if (imo != NULL) {
318 ip->ip_ttl = imo->imo_multicast_ttl;
319 if (imo->imo_multicast_vif != -1)
320 ip->ip_src.s_addr =
321 ip_mcast_src ?
322 ip_mcast_src(imo->imo_multicast_vif) :
323 INADDR_ANY;
324 } else
325 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
326 /*
327 * Confirm that the outgoing interface supports multicast.
328 */
329 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
330 if (!(ifp->if_flags & IFF_MULTICAST)) {
331 ipstat.ips_noroute++;
332 error = ENETUNREACH;
333 goto bad;
334 }
335 }
336 /*
337 * If source address not specified yet, use address
338 * of outgoing interface.
339 */
340 if (ip->ip_src.s_addr == INADDR_ANY) {
341 /* Interface may have no addresses. */
342 if (ia != NULL)
343 ip->ip_src = IA_SIN(ia)->sin_addr;
344 }
345
346 IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
347 if (inm != NULL &&
348 (imo == NULL || imo->imo_multicast_loop)) {
349 /*
350 * If we belong to the destination multicast group
351 * on the outgoing interface, and the caller did not
352 * forbid loopback, loop back a copy.
353 */
354 ip_mloopback(ifp, m, dst, hlen);
355 }
356 else {
357 /*
358 * If we are acting as a multicast router, perform
359 * multicast forwarding as if the packet had just
360 * arrived on the interface to which we are about
361 * to send. The multicast forwarding function
362 * recursively calls this function, using the
363 * IP_FORWARDING flag to prevent infinite recursion.
364 *
365 * Multicasts that are looped back by ip_mloopback(),
366 * above, will be forwarded by the ip_input() routine,
367 * if necessary.
368 */
369 if (ip_mrouter && !(flags & IP_FORWARDING)) {
370 /*
371 * If rsvp daemon is not running, do not
372 * set ip_moptions. This ensures that the packet
373 * is multicast and not just sent down one link
374 * as prescribed by rsvpd.
375 */
376 if (!rsvp_on)
377 imo = NULL;
378 if (ip_mforward &&
379 ip_mforward(ip, ifp, m, imo) != 0) {
380 m_freem(m);
381 goto done;
382 }
383 }
384 }
385
386 /*
387 * Multicasts with a time-to-live of zero may be looped-
388 * back, above, but must not be transmitted on a network.
389 * Also, multicasts addressed to the loopback interface
390 * are not sent -- the above call to ip_mloopback() will
391 * loop back a copy if this host actually belongs to the
392 * destination group on the loopback interface.
393 */
394 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
395 m_freem(m);
396 goto done;
397 }
398
399 goto sendit;
400 }
401 #ifndef notdef
402 /*
403 * If the source address is not specified yet, use the address
404 * of the outoing interface. In case, keep note we did that, so
405 * if the the firewall changes the next-hop causing the output
406 * interface to change, we can fix that.
407 */
408 if (ip->ip_src.s_addr == INADDR_ANY) {
409 /* Interface may have no addresses. */
410 if (ia != NULL) {
411 ip->ip_src = IA_SIN(ia)->sin_addr;
412 src_was_INADDR_ANY = 1;
413 }
414 }
415 #endif /* notdef */
416 #ifdef ALTQ
417 /*
418 * Disable packet drop hack.
419 * Packetdrop should be done by queueing.
420 */
421 #else /* !ALTQ */
422 /*
423 * Verify that we have any chance at all of being able to queue
424 * the packet or packet fragments
425 */
426 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
427 ifp->if_snd.ifq_maxlen) {
428 error = ENOBUFS;
429 ipstat.ips_odropped++;
430 goto bad;
431 }
432 #endif /* !ALTQ */
433
434 /*
435 * Look for broadcast address and
436 * verify user is allowed to send
437 * such a packet.
438 */
439 if (isbroadcast) {
440 if (!(ifp->if_flags & IFF_BROADCAST)) {
441 error = EADDRNOTAVAIL;
442 goto bad;
443 }
444 if (!(flags & IP_ALLOWBROADCAST)) {
445 error = EACCES;
446 goto bad;
447 }
448 /* don't allow broadcast messages to be fragmented */
449 if (ip->ip_len > ifp->if_mtu) {
450 error = EMSGSIZE;
451 goto bad;
452 }
453 m->m_flags |= M_BCAST;
454 } else {
455 m->m_flags &= ~M_BCAST;
456 }
457
458 sendit:
459 #ifdef IPSEC
460 /* get SP for this packet */
461 if (so == NULL)
462 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
463 else
464 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
465
466 if (sp == NULL) {
467 ipsecstat.out_inval++;
468 goto bad;
469 }
470
471 error = 0;
472
473 /* check policy */
474 switch (sp->policy) {
475 case IPSEC_POLICY_DISCARD:
476 /*
477 * This packet is just discarded.
478 */
479 ipsecstat.out_polvio++;
480 goto bad;
481
482 case IPSEC_POLICY_BYPASS:
483 case IPSEC_POLICY_NONE:
484 /* no need to do IPsec. */
485 goto skip_ipsec;
486
487 case IPSEC_POLICY_IPSEC:
488 if (sp->req == NULL) {
489 /* acquire a policy */
490 error = key_spdacquire(sp);
491 goto bad;
492 }
493 break;
494
495 case IPSEC_POLICY_ENTRUST:
496 default:
497 kprintf("ip_output: Invalid policy found. %d\n", sp->policy);
498 }
499 {
500 struct ipsec_output_state state;
501 bzero(&state, sizeof state);
502 state.m = m;
503 if (flags & IP_ROUTETOIF) {
504 state.ro = &iproute;
505 bzero(&iproute, sizeof iproute);
506 } else
507 state.ro = ro;
508 state.dst = (struct sockaddr *)dst;
509
510 ip->ip_sum = 0;
511
512 /*
513 * XXX
514 * delayed checksums are not currently compatible with IPsec
515 */
516 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
517 in_delayed_cksum(m);
518 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
519 }
520
521 ip->ip_len = htons(ip->ip_len);
522 ip->ip_off = htons(ip->ip_off);
523
524 error = ipsec4_output(&state, sp, flags);
525
526 m = state.m;
527 if (flags & IP_ROUTETOIF) {
528 /*
529 * if we have tunnel mode SA, we may need to ignore
530 * IP_ROUTETOIF.
531 */
532 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
533 flags &= ~IP_ROUTETOIF;
534 ro = state.ro;
535 }
536 } else
537 ro = state.ro;
538 dst = (struct sockaddr_in *)state.dst;
539 if (error) {
540 /* mbuf is already reclaimed in ipsec4_output. */
541 m0 = NULL;
542 switch (error) {
543 case EHOSTUNREACH:
544 case ENETUNREACH:
545 case EMSGSIZE:
546 case ENOBUFS:
547 case ENOMEM:
548 break;
549 default:
550 kprintf("ip4_output (ipsec): error code %d\n", error);
551 /*fall through*/
552 case ENOENT:
553 /* don't show these error codes to the user */
554 error = 0;
555 break;
556 }
557 goto bad;
558 }
559 }
560
561 /* be sure to update variables that are affected by ipsec4_output() */
562 ip = mtod(m, struct ip *);
563 #ifdef _IP_VHL
564 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
565 #else
566 hlen = ip->ip_hl << 2;
567 #endif
568 if (ro->ro_rt == NULL) {
569 if (!(flags & IP_ROUTETOIF)) {
570 kprintf("ip_output: "
571 "can't update route after IPsec processing\n");
572 error = EHOSTUNREACH; /*XXX*/
573 goto bad;
574 }
575 } else {
576 ia = ifatoia(ro->ro_rt->rt_ifa);
577 ifp = ro->ro_rt->rt_ifp;
578 }
579
580 /* make it flipped, again. */
581 ip->ip_len = ntohs(ip->ip_len);
582 ip->ip_off = ntohs(ip->ip_off);
583 skip_ipsec:
584 #endif /*IPSEC*/
585 #ifdef FAST_IPSEC
586 /*
587 * Check the security policy (SP) for the packet and, if
588 * required, do IPsec-related processing. There are two
589 * cases here; the first time a packet is sent through
590 * it will be untagged and handled by ipsec4_checkpolicy.
591 * If the packet is resubmitted to ip_output (e.g. after
592 * AH, ESP, etc. processing), there will be a tag to bypass
593 * the lookup and related policy checking.
594 */
595 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
596 crit_enter();
597 if (mtag != NULL) {
598 tdbi = (struct tdb_ident *)m_tag_data(mtag);
599 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
600 if (sp == NULL)
601 error = -EINVAL; /* force silent drop */
602 m_tag_delete(m, mtag);
603 } else {
604 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
605 &error, inp);
606 }
607 /*
608 * There are four return cases:
609 * sp != NULL apply IPsec policy
610 * sp == NULL, error == 0 no IPsec handling needed
611 * sp == NULL, error == -EINVAL discard packet w/o error
612 * sp == NULL, error != 0 discard packet, report error
613 */
614 if (sp != NULL) {
615 /* Loop detection, check if ipsec processing already done */
616 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
617 for (mtag = m_tag_first(m); mtag != NULL;
618 mtag = m_tag_next(m, mtag)) {
619 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
620 continue;
621 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
622 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
623 continue;
624 /*
625 * Check if policy has an SA associated with it.
626 * This can happen when an SP has yet to acquire
627 * an SA; e.g. on first reference. If it occurs,
628 * then we let ipsec4_process_packet do its thing.
629 */
630 if (sp->req->sav == NULL)
631 break;
632 tdbi = (struct tdb_ident *)m_tag_data(mtag);
633 if (tdbi->spi == sp->req->sav->spi &&
634 tdbi->proto == sp->req->sav->sah->saidx.proto &&
635 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
636 sizeof(union sockaddr_union)) == 0) {
637 /*
638 * No IPsec processing is needed, free
639 * reference to SP.
640 *
641 * NB: null pointer to avoid free at
642 * done: below.
643 */
644 KEY_FREESP(&sp), sp = NULL;
645 crit_exit();
646 goto spd_done;
647 }
648 }
649
650 /*
651 * Do delayed checksums now because we send before
652 * this is done in the normal processing path.
653 */
654 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
655 in_delayed_cksum(m);
656 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
657 }
658
659 ip->ip_len = htons(ip->ip_len);
660 ip->ip_off = htons(ip->ip_off);
661
662 /* NB: callee frees mbuf */
663 error = ipsec4_process_packet(m, sp->req, flags, 0);
664 /*
665 * Preserve KAME behaviour: ENOENT can be returned
666 * when an SA acquire is in progress. Don't propagate
667 * this to user-level; it confuses applications.
668 *
669 * XXX this will go away when the SADB is redone.
670 */
671 if (error == ENOENT)
672 error = 0;
673 crit_exit();
674 goto done;
675 } else {
676 crit_exit();
677
678 if (error != 0) {
679 /*
680 * Hack: -EINVAL is used to signal that a packet
681 * should be silently discarded. This is typically
682 * because we asked key management for an SA and
683 * it was delayed (e.g. kicked up to IKE).
684 */
685 if (error == -EINVAL)
686 error = 0;
687 goto bad;
688 } else {
689 /* No IPsec processing for this packet. */
690 }
691 #ifdef notyet
692 /*
693 * If deferred crypto processing is needed, check that
694 * the interface supports it.
695 */
696 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
697 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) {
698 /* notify IPsec to do its own crypto */
699 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag));
700 error = EHOSTUNREACH;
701 goto bad;
702 }
703 #endif
704 }
705 spd_done:
706 #endif /* FAST_IPSEC */
707 /*
708 * IpHack's section.
709 * - Xlate: translate packet's addr/port (NAT).
710 * - Firewall: deny/allow/etc.
711 * - Wrap: fake packet's addr/port <unimpl.>
712 * - Encapsulate: put it in another IP and send out. <unimp.>
713 */
714
715 /*
716 * Run through list of hooks for output packets.
717 */
718 if (pfil_has_hooks(&inet_pfil_hook)) {
719 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
720 if (error != 0 || m == NULL)
721 goto done;
722 ip = mtod(m, struct ip *);
723 }
724
725 /*
726 * Check with the firewall...
727 * but not if we are already being fwd'd from a firewall.
728 */
729 if (fw_enable && IPFW_LOADED && !args.next_hop) {
730 struct sockaddr_in *old = dst;
731
732 args.m = m;
733 args.next_hop = dst;
734 args.oif = ifp;
735 off = ip_fw_chk_ptr(&args);
736 m = args.m;
737 dst = args.next_hop;
738
739 /*
740 * On return we must do the following:
741 * m == NULL -> drop the pkt (old interface, deprecated)
742 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface)
743 * 1<=off<= 0xffff -> DIVERT
744 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe
745 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet
746 * dst != old -> IPFIREWALL_FORWARD
747 * off==0, dst==old -> accept
748 * If some of the above modules are not compiled in, then
749 * we should't have to check the corresponding condition
750 * (because the ipfw control socket should not accept
751 * unsupported rules), but better play safe and drop
752 * packets in case of doubt.
753 */
754 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) {
755 if (m)
756 m_freem(m);
757 error = EACCES;
758 goto done;
759 }
760 ip = mtod(m, struct ip *);
761 if (off == 0 && dst == old) /* common case */
762 goto pass;
763 if (off & IP_FW_PORT_DYNT_FLAG) {
764 /*
765 * pass the pkt to dummynet. Need to include
766 * pipe number, m, ifp, ro, dst because these are
767 * not recomputed in the next pass.
768 * All other parameters have been already used and
769 * so they are not needed anymore.
770 * XXX note: if the ifp or ro entry are deleted
771 * while a pkt is in dummynet, we are in trouble!
772 */
773 args.ro = ro;
774 args.dst = dst;
775 args.flags = flags;
776
777 error = 0;
778 ip_fw_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT, &args);
779 goto done;
780 }
781 #ifdef IPDIVERT
782 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) {
783 struct mbuf *clone = NULL;
784
785 /* Clone packet if we're doing a 'tee' */
786 if ((off & IP_FW_PORT_TEE_FLAG))
787 clone = m_dup(m, MB_DONTWAIT);
788
789 /*
790 * XXX
791 * delayed checksums are not currently compatible
792 * with divert sockets.
793 */
794 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
795 in_delayed_cksum(m);
796 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
797 }
798
799 /* Restore packet header fields to original values */
800 ip->ip_len = htons(ip->ip_len);
801 ip->ip_off = htons(ip->ip_off);
802
803 /* Deliver packet to divert input routine */
804 divert_packet(m, 0, off & 0xffff);
805
806 /* If 'tee', continue with original packet */
807 if (clone != NULL) {
808 m = clone;
809 ip = mtod(m, struct ip *);
810 goto pass;
811 }
812 goto done;
813 }
814 #endif
815
816 /* IPFIREWALL_FORWARD */
817 /*
818 * Check dst to make sure it is directly reachable on the
819 * interface we previously thought it was.
820 * If it isn't (which may be likely in some situations) we have
821 * to re-route it (ie, find a route for the next-hop and the
822 * associated interface) and set them here. This is nested
823 * forwarding which in most cases is undesirable, except where
824 * such control is nigh impossible. So we do it here.
825 * And I'm babbling.
826 */
827 if (off == 0 && old != dst) { /* FORWARD, dst has changed */
828 #if 0
829 /*
830 * XXX To improve readability, this block should be
831 * changed into a function call as below:
832 */
833 error = ip_ipforward(&m, &dst, &ifp);
834 if (error)
835 goto bad;
836 if (m == NULL) /* ip_input consumed the mbuf */
837 goto done;
838 #else
839 struct in_ifaddr *ia;
840
841 /*
842 * XXX sro_fwd below is static, and a pointer
843 * to it gets passed to routines downstream.
844 * This could have surprisingly bad results in
845 * practice, because its content is overwritten
846 * by subsequent packets.
847 */
848 /* There must be a better way to do this next line... */
849 static struct route sro_fwd;
850 struct route *ro_fwd = &sro_fwd;
851
852 #if 0
853 print_ip("IPFIREWALL_FORWARD: New dst ip: ",
854 dst->sin_addr, "\n");
855 #endif
856
857 /*
858 * We need to figure out if we have been forwarded
859 * to a local socket. If so, then we should somehow
860 * "loop back" to ip_input, and get directed to the
861 * PCB as if we had received this packet. This is
862 * because it may be dificult to identify the packets
863 * you want to forward until they are being output
864 * and have selected an interface. (e.g. locally
865 * initiated packets) If we used the loopback inteface,
866 * we would not be able to control what happens
867 * as the packet runs through ip_input() as
868 * it is done through a ISR.
869 */
870 LIST_FOREACH(ia, INADDR_HASH(dst->sin_addr.s_addr),
871 ia_hash) {
872 /*
873 * If the addr to forward to is one
874 * of ours, we pretend to
875 * be the destination for this packet.
876 */
877 if (IA_SIN(ia)->sin_addr.s_addr ==
878 dst->sin_addr.s_addr)
879 break;
880 }
881 if (ia != NULL) { /* tell ip_input "dont filter" */
882 struct m_hdr tag;
883
884 tag.mh_type = MT_TAG;
885 tag.mh_flags = PACKET_TAG_IPFORWARD;
886 tag.mh_data = (caddr_t)args.next_hop;
887 tag.mh_next = m;
888
889 if (m->m_pkthdr.rcvif == NULL)
890 m->m_pkthdr.rcvif = ifunit("lo0");
891 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
892 m->m_pkthdr.csum_flags |=
893 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
894 m->m_pkthdr.csum_data = 0xffff;
895 }
896 m->m_pkthdr.csum_flags |=
897 CSUM_IP_CHECKED | CSUM_IP_VALID;
898 ip->ip_len = htons(ip->ip_len);
899 ip->ip_off = htons(ip->ip_off);
900 ip_input((struct mbuf *)&tag);
901 goto done;
902 }
903 /* Some of the logic for this was nicked from above.
904 *
905 * This rewrites the cached route in a local PCB.
906 * Is this what we want to do?
907 */
908 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst);
909 ro_fwd->ro_rt = NULL;
910
911 rtalloc_ign(ro_fwd, RTF_PRCLONING);
912 if (ro_fwd->ro_rt == NULL) {
913 ipstat.ips_noroute++;
914 error = EHOSTUNREACH;
915 goto bad;
916 }
917
918 ia = ifatoia(ro_fwd->ro_rt->rt_ifa);
919 ifp = ro_fwd->ro_rt->rt_ifp;
920 ro_fwd->ro_rt->rt_use++;
921 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
922 dst = (struct sockaddr_in *)
923 ro_fwd->ro_rt->rt_gateway;
924 if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
925 isbroadcast =
926 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
927 else
928 isbroadcast = in_broadcast(dst->sin_addr, ifp);
929 if (ro->ro_rt != NULL)
930 rtfree(ro->ro_rt);
931 ro->ro_rt = ro_fwd->ro_rt;
932 dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
933
934 #endif /* ... block to be put into a function */
935 /*
936 * If we added a default src ip earlier,
937 * which would have been gotten from the-then
938 * interface, do it again, from the new one.
939 */
940 if (src_was_INADDR_ANY)
941 ip->ip_src = IA_SIN(ia)->sin_addr;
942 goto pass ;
943 }
944
945 /*
946 * if we get here, none of the above matches, and
947 * we have to drop the pkt
948 */
949 m_freem(m);
950 error = EACCES; /* not sure this is the right error msg */
951 goto done;
952 }
953
954 pass:
955 /* 127/8 must not appear on wire - RFC1122. */
956 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
957 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
958 if (!(ifp->if_flags & IFF_LOOPBACK)) {
959 ipstat.ips_badaddr++;
960 error = EADDRNOTAVAIL;
961 goto bad;
962 }
963 }
964
965 m->m_pkthdr.csum_flags |= CSUM_IP;
966 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
967 if (sw_csum & CSUM_DELAY_DATA) {
968 in_delayed_cksum(m);
969 sw_csum &= ~CSUM_DELAY_DATA;
970 }
971 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
972
973 /*
974 * If small enough for interface, or the interface will take
975 * care of the fragmentation for us, can just send directly.
976 */
977 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) &&
978 !(ip->ip_off & IP_DF))) {
979 ip->ip_len = htons(ip->ip_len);
980 ip->ip_off = htons(ip->ip_off);
981 ip->ip_sum = 0;
982 if (sw_csum & CSUM_DELAY_IP) {
983 if (ip->ip_vhl == IP_VHL_BORING) {
984 ip->ip_sum = in_cksum_hdr(ip);
985 } else {
986 ip->ip_sum = in_cksum(m, hlen);
987 }
988 }
989
990 /* Record statistics for this interface address. */
991 if (!(flags & IP_FORWARDING) && ia) {
992 ia->ia_ifa.if_opackets++;
993 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
994 }
995
996 #ifdef IPSEC
997 /* clean ipsec history once it goes out of the node */
998 ipsec_delaux(m);
999 #endif
1000
1001 #ifdef MBUF_STRESS_TEST
1002 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
1003 struct mbuf *m1, *m2;
1004 int length, tmp;
1005
1006 tmp = length = m->m_pkthdr.len;
1007
1008 while ((length -= mbuf_frag_size) >= 1) {
1009 m1 = m_split(m, length, MB_DONTWAIT);
1010 if (m1 == NULL)
1011 break;
1012 m2 = m;
1013 while (m2->m_next != NULL)
1014 m2 = m2->m_next;
1015 m2->m_next = m1;
1016 }
1017 m->m_pkthdr.len = tmp;
1018 }
1019 #endif
1020 lwkt_serialize_enter(ifp->if_serializer);
1021 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst,
1022 ro->ro_rt);
1023 lwkt_serialize_exit(ifp->if_serializer);
1024 goto done;
1025 }
1026
1027 if (ip->ip_off & IP_DF) {
1028 error = EMSGSIZE;
1029 /*
1030 * This case can happen if the user changed the MTU
1031 * of an interface after enabling IP on it. Because
1032 * most netifs don't keep track of routes pointing to
1033 * them, there is no way for one to update all its
1034 * routes when the MTU is changed.
1035 */
1036 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) &&
1037 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
1038 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
1039 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
1040 }
1041 ipstat.ips_cantfrag++;
1042 goto bad;
1043 }
1044
1045 /*
1046 * Too large for interface; fragment if possible. If successful,
1047 * on return, m will point to a list of packets to be sent.
1048 */
1049 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum);
1050 if (error)
1051 goto bad;
1052 for (; m; m = m0) {
1053 m0 = m->m_nextpkt;
1054 m->m_nextpkt = NULL;
1055 #ifdef IPSEC
1056 /* clean ipsec history once it goes out of the node */
1057 ipsec_delaux(m);
1058 #endif
1059 if (error == 0) {
1060 /* Record statistics for this interface address. */
1061 if (ia != NULL) {
1062 ia->ia_ifa.if_opackets++;
1063 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1064 }
1065 lwkt_serialize_enter(ifp->if_serializer);
1066 error = (*ifp->if_output)(ifp, m,
1067 (struct sockaddr *)dst,
1068 ro->ro_rt);
1069 lwkt_serialize_exit(ifp->if_serializer);
1070 } else {
1071 m_freem(m);
1072 }
1073 }
1074
1075 if (error == 0)
1076 ipstat.ips_fragmented++;
1077
1078 done:
1079 if (ro == &iproute && ro->ro_rt != NULL) {
1080 RTFREE(ro->ro_rt);
1081 ro->ro_rt = NULL;
1082 }
1083 #ifdef IPSEC
1084 if (sp != NULL) {
1085 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1086 kprintf("DP ip_output call free SP:%p\n", sp));
1087 key_freesp(sp);
1088 }
1089 #endif
1090 #ifdef FAST_IPSEC
1091 if (sp != NULL)
1092 KEY_FREESP(&sp);
1093 #endif
1094 if (dn_mtag != NULL)
1095 m_tag_free(dn_mtag);
1096
1097 return (error);
1098 bad:
1099 m_freem(m);
1100 goto done;
1101 }
1102
1103 /*
1104 * Create a chain of fragments which fit the given mtu. m_frag points to the
1105 * mbuf to be fragmented; on return it points to the chain with the fragments.
1106 * Return 0 if no error. If error, m_frag may contain a partially built
1107 * chain of fragments that should be freed by the caller.
1108 *
1109 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1110 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1111 */
1112 int
1113 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1114 u_long if_hwassist_flags, int sw_csum)
1115 {
1116 int error = 0;
1117 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1118 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
1119 int off;
1120 struct mbuf *m0 = *m_frag; /* the original packet */
1121 int firstlen;
1122 struct mbuf **mnext;
1123 int nfrags;
1124
1125 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
1126 ipstat.ips_cantfrag++;
1127 return EMSGSIZE;
1128 }
1129
1130 /*
1131 * Must be able to put at least 8 bytes per fragment.
1132 */
1133 if (len < 8)
1134 return EMSGSIZE;
1135
1136 /*
1137 * If the interface will not calculate checksums on
1138 * fragmented packets, then do it here.
1139 */
1140 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) &&
1141 !(if_hwassist_flags & CSUM_IP_FRAGS)) {
1142 in_delayed_cksum(m0);
1143 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1144 }
1145
1146 if (len > PAGE_SIZE) {
1147 /*
1148 * Fragment large datagrams such that each segment
1149 * contains a multiple of PAGE_SIZE amount of data,
1150 * plus headers. This enables a receiver to perform
1151 * page-flipping zero-copy optimizations.
1152 *
1153 * XXX When does this help given that sender and receiver
1154 * could have different page sizes, and also mtu could
1155 * be less than the receiver's page size ?
1156 */
1157 int newlen;
1158 struct mbuf *m;
1159
1160 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1161 off += m->m_len;
1162
1163 /*
1164 * firstlen (off - hlen) must be aligned on an
1165 * 8-byte boundary
1166 */
1167 if (off < hlen)
1168 goto smart_frag_failure;
1169 off = ((off - hlen) & ~7) + hlen;
1170 newlen = (~PAGE_MASK) & mtu;
1171 if ((newlen + sizeof(struct ip)) > mtu) {
1172 /* we failed, go back the default */
1173 smart_frag_failure:
1174 newlen = len;
1175 off = hlen + len;
1176 }
1177 len = newlen;
1178
1179 } else {
1180 off = hlen + len;
1181 }
1182
1183 firstlen = off - hlen;
1184 mnext = &m0->m_nextpkt; /* pointer to next packet */
1185
1186 /*
1187 * Loop through length of segment after first fragment,
1188 * make new header and copy data of each part and link onto chain.
1189 * Here, m0 is the original packet, m is the fragment being created.
1190 * The fragments are linked off the m_nextpkt of the original
1191 * packet, which after processing serves as the first fragment.
1192 */
1193 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1194 struct ip *mhip; /* ip header on the fragment */
1195 struct mbuf *m;
1196 int mhlen = sizeof(struct ip);
1197
1198 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1199 if (m == NULL) {
1200 error = ENOBUFS;
1201 ipstat.ips_odropped++;
1202 goto done;
1203 }
1204 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1205 /*
1206 * In the first mbuf, leave room for the link header, then
1207 * copy the original IP header including options. The payload
1208 * goes into an additional mbuf chain returned by m_copy().
1209 */
1210 m->m_data += max_linkhdr;
1211 mhip = mtod(m, struct ip *);
1212 *mhip = *ip;
1213 if (hlen > sizeof(struct ip)) {
1214 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip);
1215 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1216 }
1217 m->m_len = mhlen;
1218 /* XXX do we need to add ip->ip_off below ? */
1219 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1220 if (off + len >= ip->ip_len) { /* last fragment */
1221 len = ip->ip_len - off;
1222 m->m_flags |= M_LASTFRAG;
1223 } else
1224 mhip->ip_off |= IP_MF;
1225 mhip->ip_len = htons((u_short)(len + mhlen));
1226 m->m_next = m_copy(m0, off, len);
1227 if (m->m_next == NULL) { /* copy failed */
1228 m_free(m);
1229 error = ENOBUFS; /* ??? */
1230 ipstat.ips_odropped++;
1231 goto done;
1232 }
1233 m->m_pkthdr.len = mhlen + len;
1234 m->m_pkthdr.rcvif = (struct ifnet *)NULL;
1235 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1236 mhip->ip_off = htons(mhip->ip_off);
1237 mhip->ip_sum = 0;
1238 if (sw_csum & CSUM_DELAY_IP)
1239 mhip->ip_sum = in_cksum(m, mhlen);
1240 *mnext = m;
1241 mnext = &m->m_nextpkt;
1242 }
1243 ipstat.ips_ofragments += nfrags;
1244
1245 /* set first marker for fragment chain */
1246 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1247 m0->m_pkthdr.csum_data = nfrags;
1248
1249 /*
1250 * Update first fragment by trimming what's been copied out
1251 * and updating header.
1252 */
1253 m_adj(m0, hlen + firstlen - ip->ip_len);
1254 m0->m_pkthdr.len = hlen + firstlen;
1255 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1256 ip->ip_off |= IP_MF;
1257 ip->ip_off = htons(ip->ip_off);
1258 ip->ip_sum = 0;
1259 if (sw_csum & CSUM_DELAY_IP)
1260 ip->ip_sum = in_cksum(m0, hlen);
1261
1262 done:
1263 *m_frag = m0;
1264 return error;
1265 }
1266
1267 void
1268 in_delayed_cksum(struct mbuf *m)
1269 {
1270 struct ip *ip;
1271 u_short csum, offset;
1272
1273 ip = mtod(m, struct ip *);
1274 offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1275 csum = in_cksum_skip(m, ip->ip_len, offset);
1276 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1277 csum = 0xffff;
1278 offset += m->m_pkthdr.csum_data; /* checksum offset */
1279
1280 if (offset + sizeof(u_short) > m->m_len) {
1281 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n",
1282 m->m_len, offset, ip->ip_p);
1283 /*
1284 * XXX
1285 * this shouldn't happen, but if it does, the
1286 * correct behavior may be to insert the checksum
1287 * in the existing chain instead of rearranging it.
1288 */
1289 m = m_pullup(m, offset + sizeof(u_short));
1290 }
1291 *(u_short *)(m->m_data + offset) = csum;
1292 }
1293
1294 /*
1295 * Insert IP options into preformed packet.
1296 * Adjust IP destination as required for IP source routing,
1297 * as indicated by a non-zero in_addr at the start of the options.
1298 *
1299 * XXX This routine assumes that the packet has no options in place.
1300 */
1301 static struct mbuf *
1302 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen)
1303 {
1304 struct ipoption *p = mtod(opt, struct ipoption *);
1305 struct mbuf *n;
1306 struct ip *ip = mtod(m, struct ip *);
1307 unsigned optlen;
1308
1309 optlen = opt->m_len - sizeof p->ipopt_dst;
1310 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1311 *phlen = 0;
1312 return (m); /* XXX should fail */
1313 }
1314 if (p->ipopt_dst.s_addr)
1315 ip->ip_dst = p->ipopt_dst;
1316 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1317 MGETHDR(n, MB_DONTWAIT, MT_HEADER);
1318 if (n == NULL) {
1319 *phlen = 0;
1320 return (m);
1321 }
1322 n->m_pkthdr.rcvif = (struct ifnet *)NULL;
1323 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1324 m->m_len -= sizeof(struct ip);
1325 m->m_data += sizeof(struct ip);
1326 n->m_next = m;
1327 m = n;
1328 m->m_len = optlen + sizeof(struct ip);
1329 m->m_data += max_linkhdr;
1330 memcpy(mtod(m, void *), ip, sizeof(struct ip));
1331 } else {
1332 m->m_data -= optlen;
1333 m->m_len += optlen;
1334 m->m_pkthdr.len += optlen;
1335 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
1336 }
1337 ip = mtod(m, struct ip *);
1338 bcopy(p->ipopt_list, ip + 1, optlen);
1339 *phlen = sizeof(struct ip) + optlen;
1340 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1341 ip->ip_len += optlen;
1342 return (m);
1343 }
1344
1345 /*
1346 * Copy options from ip to jp,
1347 * omitting those not copied during fragmentation.
1348 */
1349 int
1350 ip_optcopy(struct ip *ip, struct ip *jp)
1351 {
1352 u_char *cp, *dp;
1353 int opt, optlen, cnt;
1354
1355 cp = (u_char *)(ip + 1);
1356 dp = (u_char *)(jp + 1);
1357 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1358 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1359 opt = cp[0];
1360 if (opt == IPOPT_EOL)
1361 break;
1362 if (opt == IPOPT_NOP) {
1363 /* Preserve for IP mcast tunnel's LSRR alignment. */
1364 *dp++ = IPOPT_NOP;
1365 optlen = 1;
1366 continue;
1367 }
1368
1369 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp,
1370 ("ip_optcopy: malformed ipv4 option"));
1371 optlen = cp[IPOPT_OLEN];
1372 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt,
1373 ("ip_optcopy: malformed ipv4 option"));
1374
1375 /* bogus lengths should have been caught by ip_dooptions */
1376 if (optlen > cnt)
1377 optlen = cnt;
1378 if (IPOPT_COPIED(opt)) {
1379 bcopy(cp, dp, optlen);
1380 dp += optlen;
1381 }
1382 }
1383 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1384 *dp++ = IPOPT_EOL;
1385 return (optlen);
1386 }
1387
1388 /*
1389 * IP socket option processing.
1390 */
1391 int
1392 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1393 {
1394 struct inpcb *inp = so->so_pcb;
1395 int error, optval;
1396
1397 error = optval = 0;
1398 if (sopt->sopt_level != IPPROTO_IP) {
1399 return (EINVAL);
1400 }
1401
1402 switch (sopt->sopt_dir) {
1403 case SOPT_SET:
1404 switch (sopt->sopt_name) {
1405 case IP_OPTIONS:
1406 #ifdef notyet
1407 case IP_RETOPTS:
1408 #endif
1409 {
1410 struct mbuf *m;
1411 if (sopt->sopt_valsize > MLEN) {
1412 error = EMSGSIZE;
1413 break;
1414 }
1415 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1416 if (m == NULL) {
1417 error = ENOBUFS;
1418 break;
1419 }
1420 m->m_len = sopt->sopt_valsize;
1421 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1422 m->m_len);
1423
1424 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options,
1425 m));
1426 }
1427
1428 case IP_TOS:
1429 case IP_TTL:
1430 case IP_MINTTL:
1431 case IP_RECVOPTS:
1432 case IP_RECVRETOPTS:
1433 case IP_RECVDSTADDR:
1434 case IP_RECVIF:
1435 case IP_RECVTTL:
1436 case IP_FAITH:
1437 error = sooptcopyin(sopt, &optval, sizeof optval,
1438 sizeof optval);
1439 if (error)
1440 break;
1441
1442 switch (sopt->sopt_name) {
1443 case IP_TOS:
1444 inp->inp_ip_tos = optval;
1445 break;
1446
1447 case IP_TTL:
1448 inp->inp_ip_ttl = optval;
1449 break;
1450 case IP_MINTTL:
1451 if (optval > 0 && optval <= MAXTTL)
1452 inp->inp_ip_minttl = optval;
1453 else
1454 error = EINVAL;
1455 break;
1456 #define OPTSET(bit) \
1457 if (optval) \
1458 inp->inp_flags |= bit; \
1459 else \
1460 inp->inp_flags &= ~bit;
1461
1462 case IP_RECVOPTS:
1463 OPTSET(INP_RECVOPTS);
1464 break;
1465
1466 case IP_RECVRETOPTS:
1467 OPTSET(INP_RECVRETOPTS);
1468 break;
1469
1470 case IP_RECVDSTADDR:
1471 OPTSET(INP_RECVDSTADDR);
1472 break;
1473
1474 case IP_RECVIF:
1475 OPTSET(INP_RECVIF);
1476 break;
1477
1478 case IP_RECVTTL:
1479 OPTSET(INP_RECVTTL);
1480 break;
1481
1482 case IP_FAITH:
1483 OPTSET(INP_FAITH);
1484 break;
1485 }
1486 break;
1487 #undef OPTSET
1488
1489 case IP_MULTICAST_IF:
1490 case IP_MULTICAST_VIF:
1491 case IP_MULTICAST_TTL:
1492 case IP_MULTICAST_LOOP:
1493 case IP_ADD_MEMBERSHIP:
1494 case IP_DROP_MEMBERSHIP:
1495 error = ip_setmoptions(sopt, &inp->inp_moptions);
1496 break;
1497
1498 case IP_PORTRANGE:
1499 error = sooptcopyin(sopt, &optval, sizeof optval,
1500 sizeof optval);
1501 if (error)
1502 break;
1503
1504 switch (optval) {
1505 case IP_PORTRANGE_DEFAULT:
1506 inp->inp_flags &= ~(INP_LOWPORT);
1507 inp->inp_flags &= ~(INP_HIGHPORT);
1508 break;
1509
1510 case IP_PORTRANGE_HIGH:
1511 inp->inp_flags &= ~(INP_LOWPORT);
1512 inp->inp_flags |= INP_HIGHPORT;
1513 break;
1514
1515 case IP_PORTRANGE_LOW:
1516 inp->inp_flags &= ~(INP_HIGHPORT);
1517 inp->inp_flags |= INP_LOWPORT;
1518 break;
1519
1520 default:
1521 error = EINVAL;
1522 break;
1523 }
1524 break;
1525
1526 #if defined(IPSEC) || defined(FAST_IPSEC)
1527 case IP_IPSEC_POLICY:
1528 {
1529 caddr_t req;
1530 size_t len = 0;
1531 int priv;
1532 struct mbuf *m;
1533 int optname;
1534
1535 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1536 break;
1537 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1538 break;
1539 priv = (sopt->sopt_td != NULL &&
1540 suser(sopt->sopt_td) != 0) ? 0 : 1;
1541 req = mtod(m, caddr_t);
1542 len = m->m_len;
1543 optname = sopt->sopt_name;
1544 error = ipsec4_set_policy(inp, optname, req, len, priv);
1545 m_freem(m);
1546 break;
1547 }
1548 #endif /*IPSEC*/
1549
1550 default:
1551 error = ENOPROTOOPT;
1552 break;
1553 }
1554 break;
1555
1556 case SOPT_GET:
1557 switch (sopt->sopt_name) {
1558 case IP_OPTIONS:
1559 case IP_RETOPTS:
1560 if (inp->inp_options)
1561 error = sooptcopyout(sopt,
1562 mtod(inp->inp_options,
1563 char *),
1564 inp->inp_options->m_len);
1565 else
1566 sopt->sopt_valsize = 0;
1567 break;
1568
1569 case IP_TOS:
1570 case IP_TTL:
1571 case IP_MINTTL:
1572 case IP_RECVOPTS:
1573 case IP_RECVRETOPTS:
1574 case IP_RECVDSTADDR:
1575 case IP_RECVTTL:
1576 case IP_RECVIF:
1577 case IP_PORTRANGE:
1578 case IP_FAITH:
1579 switch (sopt->sopt_name) {
1580
1581 case IP_TOS:
1582 optval = inp->inp_ip_tos;
1583 break;
1584
1585 case IP_TTL:
1586 optval = inp->inp_ip_ttl;
1587 break;
1588 case IP_MINTTL:
1589 optval = inp->inp_ip_minttl;
1590 break;
1591
1592 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1593
1594 case IP_RECVOPTS:
1595 optval = OPTBIT(INP_RECVOPTS);
1596 break;
1597
1598 case IP_RECVRETOPTS:
1599 optval = OPTBIT(INP_RECVRETOPTS);
1600 break;
1601
1602 case IP_RECVDSTADDR:
1603 optval = OPTBIT(INP_RECVDSTADDR);
1604 break;
1605
1606 case IP_RECVTTL:
1607 optval = OPTBIT(INP_RECVTTL);
1608 break;
1609
1610 case IP_RECVIF:
1611 optval = OPTBIT(INP_RECVIF);
1612 break;
1613
1614 case IP_PORTRANGE:
1615 if (inp->inp_flags & INP_HIGHPORT)
1616 optval = IP_PORTRANGE_HIGH;
1617 else if (inp->inp_flags & INP_LOWPORT)
1618 optval = IP_PORTRANGE_LOW;
1619 else
1620 optval = 0;
1621 break;
1622
1623 case IP_FAITH:
1624 optval = OPTBIT(INP_FAITH);
1625 break;
1626 }
1627 error = sooptcopyout(sopt, &optval, sizeof optval);
1628 break;
1629
1630 case IP_MULTICAST_IF:
1631 case IP_MULTICAST_VIF:
1632 case IP_MULTICAST_TTL:
1633 case IP_MULTICAST_LOOP:
1634 case IP_ADD_MEMBERSHIP:
1635 case IP_DROP_MEMBERSHIP:
1636 error = ip_getmoptions(sopt, inp->inp_moptions);
1637 break;
1638
1639 #if defined(IPSEC) || defined(FAST_IPSEC)
1640 case IP_IPSEC_POLICY:
1641 {
1642 struct mbuf *m = NULL;
1643 caddr_t req = NULL;
1644 size_t len = 0;
1645
1646 if (m != NULL) {
1647 req = mtod(m, caddr_t);
1648 len = m->m_len;
1649 }
1650 error = ipsec4_get_policy(so->so_pcb, req, len, &m);
1651 if (error == 0)
1652 error = soopt_mcopyout(sopt, m); /* XXX */
1653 if (error == 0)
1654 m_freem(m);
1655 break;
1656 }
1657 #endif /*IPSEC*/
1658
1659 default:
1660 error = ENOPROTOOPT;
1661 break;
1662 }
1663 break;
1664 }
1665 return (error);
1666 }
1667
1668 /*
1669 * Set up IP options in pcb for insertion in output packets.
1670 * Store in mbuf with pointer in pcbopt, adding pseudo-option
1671 * with destination address if source routed.
1672 */
1673 static int
1674 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m)
1675 {
1676 int cnt, optlen;
1677 u_char *cp;
1678 u_char opt;
1679
1680 /* turn off any old options */
1681 if (*pcbopt)
1682 m_free(*pcbopt);
1683 *pcbopt = 0;
1684 if (m == NULL || m->m_len == 0) {
1685 /*
1686 * Only turning off any previous options.
1687 */
1688 if (m != NULL)
1689 m_free(m);
1690 return (0);
1691 }
1692
1693 if (m->m_len % sizeof(int32_t))
1694 goto bad;
1695 /*
1696 * IP first-hop destination address will be stored before
1697 * actual options; move other options back
1698 * and clear it when none present.
1699 */
1700 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1701 goto bad;
1702 cnt = m->m_len;
1703 m->m_len += sizeof(struct in_addr);
1704 cp = mtod(m, u_char *) + sizeof(struct in_addr);
1705 ovbcopy(mtod(m, caddr_t), cp, cnt);
1706 bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1707
1708 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1709 opt = cp[IPOPT_OPTVAL];
1710 if (opt == IPOPT_EOL)
1711 break;
1712 if (opt == IPOPT_NOP)
1713 optlen = 1;
1714 else {
1715 if (cnt < IPOPT_OLEN + sizeof *cp)
1716 goto bad;
1717 optlen = cp[IPOPT_OLEN];
1718 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt)
1719 goto bad;
1720 }
1721 switch (opt) {
1722
1723 default:
1724 break;
1725
1726 case IPOPT_LSRR:
1727 case IPOPT_SSRR:
1728 /*
1729 * user process specifies route as:
1730 * ->A->B->C->D
1731 * D must be our final destination (but we can't
1732 * check that since we may not have connected yet).
1733 * A is first hop destination, which doesn't appear in
1734 * actual IP option, but is stored before the options.
1735 */
1736 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1737 goto bad;
1738 m->m_len -= sizeof(struct in_addr);
1739 cnt -= sizeof(struct in_addr);
1740 optlen -= sizeof(struct in_addr);
1741 cp[IPOPT_OLEN] = optlen;
1742 /*
1743 * Move first hop before start of options.
1744 */
1745 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1746 sizeof(struct in_addr));
1747 /*
1748 * Then copy rest of options back
1749 * to close up the deleted entry.
1750 */
1751 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr),
1752 &cp[IPOPT_OFFSET+1],
1753 cnt - (IPOPT_MINOFF - 1));
1754 break;
1755 }
1756 }
1757 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1758 goto bad;
1759 *pcbopt = m;
1760 return (0);
1761
1762 bad:
1763 m_free(m);
1764 return (EINVAL);
1765 }
1766
1767 /*
1768 * XXX
1769 * The whole multicast option thing needs to be re-thought.
1770 * Several of these options are equally applicable to non-multicast
1771 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1772 * standard option (IP_TTL).
1773 */
1774
1775 /*
1776 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1777 */
1778 static struct ifnet *
1779 ip_multicast_if(struct in_addr *a, int *ifindexp)
1780 {
1781 int ifindex;
1782 struct ifnet *ifp;
1783
1784 if (ifindexp)
1785 *ifindexp = 0;
1786 if (ntohl(a->s_addr) >> 24 == 0) {
1787 ifindex = ntohl(a->s_addr) & 0xffffff;
1788 if (ifindex < 0 || if_index < ifindex)
1789 return NULL;
1790 ifp = ifindex2ifnet[ifindex];
1791 if (ifindexp)
1792 *ifindexp = ifindex;
1793 } else {
1794 INADDR_TO_IFP(*a, ifp);
1795 }
1796 return ifp;
1797 }
1798
1799 /*
1800 * Set the IP multicast options in response to user setsockopt().
1801 */
1802 static int
1803 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop)
1804 {
1805 int error = 0;
1806 int i;
1807 struct in_addr addr;
1808 struct ip_mreq mreq;
1809 struct ifnet *ifp;
1810 struct ip_moptions *imo = *imop;
1811 int ifindex;
1812
1813 if (imo == NULL) {
1814 /*
1815 * No multicast option buffer attached to the pcb;
1816 * allocate one and initialize to default values.
1817 */
1818 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK);
1819
1820 *imop = imo;
1821 imo->imo_multicast_ifp = NULL;
1822 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1823 imo->imo_multicast_vif = -1;
1824 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1825 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1826 imo->imo_num_memberships = 0;
1827 }
1828
1829 switch (sopt->sopt_name) {
1830 /* store an index number for the vif you wanna use in the send */
1831 case IP_MULTICAST_VIF:
1832 if (legal_vif_num == 0) {
1833 error = EOPNOTSUPP;
1834 break;
1835 }
1836 error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
1837 if (error)
1838 break;
1839 if (!legal_vif_num(i) && (i != -1)) {
1840 error = EINVAL;
1841 break;
1842 }
1843 imo->imo_multicast_vif = i;
1844 break;
1845
1846 case IP_MULTICAST_IF:
1847 /*
1848 * Select the interface for outgoing multicast packets.
1849 */
1850 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
1851 if (error)
1852 break;
1853 /*
1854 * INADDR_ANY is used to remove a previous selection.
1855 * When no interface is selected, a default one is
1856 * chosen every time a multicast packet is sent.
1857 */
1858 if (addr.s_addr == INADDR_ANY) {
1859 imo->imo_multicast_ifp = NULL;
1860 break;
1861 }
1862 /*
1863 * The selected interface is identified by its local
1864 * IP address. Find the interface and confirm that
1865 * it supports multicasting.
1866 */
1867 crit_enter();
1868 ifp = ip_multicast_if(&addr, &ifindex);
1869 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1870 crit_exit();
1871 error = EADDRNOTAVAIL;
1872 break;
1873 }
1874 imo->imo_multicast_ifp = ifp;
1875 if (ifindex)
1876 imo->imo_multicast_addr = addr;
1877 else
1878 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1879 crit_exit();
1880 break;
1881
1882 case IP_MULTICAST_TTL:
1883 /*
1884 * Set the IP time-to-live for outgoing multicast packets.
1885 * The original multicast API required a char argument,
1886 * which is inconsistent with the rest of the socket API.
1887 * We allow either a char or an int.
1888 */
1889 if (sopt->sopt_valsize == 1) {
1890 u_char ttl;
1891 error = sooptcopyin(sopt, &ttl, 1, 1);
1892 if (error)
1893 break;
1894 imo->imo_multicast_ttl = ttl;
1895 } else {
1896 u_int ttl;
1897 error = sooptcopyin(sopt, &ttl, sizeof ttl, sizeof ttl);
1898 if (error)
1899 break;
1900 if (ttl > 255)
1901 error = EINVAL;
1902 else
1903 imo->imo_multicast_ttl = ttl;
1904 }
1905 break;
1906
1907 case IP_MULTICAST_LOOP:
1908 /*
1909 * Set the loopback flag for outgoing multicast packets.
1910 * Must be zero or one. The original multicast API required a
1911 * char argument, which is inconsistent with the rest
1912 * of the socket API. We allow either a char or an int.
1913 */
1914 if (sopt->sopt_valsize == 1) {
1915 u_char loop;
1916
1917 error = sooptcopyin(sopt, &loop, 1, 1);
1918 if (error)
1919 break;
1920 imo->imo_multicast_loop = !!loop;
1921 } else {
1922 u_int loop;
1923
1924 error = sooptcopyin(sopt, &loop, sizeof loop,
1925 sizeof loop);
1926 if (error)
1927 break;
1928 imo->imo_multicast_loop = !!loop;
1929 }
1930 break;
1931
1932 case IP_ADD_MEMBERSHIP:
1933 /*
1934 * Add a multicast group membership.
1935 * Group must be a valid IP multicast address.
1936 */
1937 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1938 if (error)
1939 break;
1940
1941 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1942 error = EINVAL;
1943 break;
1944 }
1945 crit_enter();
1946 /*
1947 * If no interface address was provided, use the interface of
1948 * the route to the given multicast address.
1949 */
1950 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1951 struct sockaddr_in dst;
1952 struct rtentry *rt;
1953
1954 bzero(&dst, sizeof(struct sockaddr_in));
1955 dst.sin_len = sizeof(struct sockaddr_in);
1956 dst.sin_family = AF_INET;
1957 dst.sin_addr = mreq.imr_multiaddr;
1958 rt = rtlookup((struct sockaddr *)&dst);
1959 if (rt == NULL) {
1960 error = EADDRNOTAVAIL;
1961 crit_exit();
1962 break;
1963 }
1964 --rt->rt_refcnt;
1965 ifp = rt->rt_ifp;
1966 } else {
1967 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1968 }
1969
1970 /*
1971 * See if we found an interface, and confirm that it
1972 * supports multicast.
1973 */
1974 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1975 error = EADDRNOTAVAIL;
1976 crit_exit();
1977 break;
1978 }
1979 /*
1980 * See if the membership already exists or if all the
1981 * membership slots are full.
1982 */
1983 for (i = 0; i < imo->imo_num_memberships; ++i) {
1984 if (imo->imo_membership[i]->inm_ifp == ifp &&
1985 imo->imo_membership[i]->inm_addr.s_addr
1986 == mreq.imr_multiaddr.s_addr)
1987 break;
1988 }
1989 if (i < imo->imo_num_memberships) {
1990 error = EADDRINUSE;
1991 crit_exit();
1992 break;
1993 }
1994 if (i == IP_MAX_MEMBERSHIPS) {
1995 error = ETOOMANYREFS;
1996 crit_exit();
1997 break;
1998 }
1999 /*
2000 * Everything looks good; add a new record to the multicast
2001 * address list for the given interface.
2002 */
2003 if ((imo->imo_membership[i] =
2004 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
2005 error = ENOBUFS;
2006 crit_exit();
2007 break;
2008 }
2009 ++imo->imo_num_memberships;
2010 crit_exit();
2011 break;
2012
2013 case IP_DROP_MEMBERSHIP:
2014 /*
2015 * Drop a multicast group membership.
2016 * Group must be a valid IP multicast address.
2017 */
2018 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
2019 if (error)
2020 break;
2021
2022 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
2023 error = EINVAL;
2024 break;
2025 }
2026
2027 crit_enter();
2028 /*
2029 * If an interface address was specified, get a pointer
2030 * to its ifnet structure.
2031 */
2032 if (mreq.imr_interface.s_addr == INADDR_ANY)
2033 ifp = NULL;
2034 else {
2035 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
2036 if (ifp == NULL) {
2037 error = EADDRNOTAVAIL;
2038 crit_exit();
2039 break;
2040 }
2041 }
2042 /*
2043 * Find the membership in the membership array.
2044 */
2045 for (i = 0; i < imo->imo_num_memberships; ++i) {
2046 if ((ifp == NULL ||
2047 imo->imo_membership[i]->inm_ifp == ifp) &&
2048 imo->imo_membership[i]->inm_addr.s_addr ==
2049 mreq.imr_multiaddr.s_addr)
2050 break;
2051 }
2052 if (i == imo->imo_num_memberships) {
2053 error = EADDRNOTAVAIL;
2054 crit_exit();
2055 break;
2056 }
2057 /*
2058 * Give up the multicast address record to which the
2059 * membership points.
2060 */
2061 in_delmulti(imo->imo_membership[i]);
2062 /*
2063 * Remove the gap in the membership array.
2064 */
2065 for (++i; i < imo->imo_num_memberships; ++i)
2066 imo->imo_membership[i-1] = imo->imo_membership[i];
2067 --imo->imo_num_memberships;
2068 crit_exit();
2069 break;
2070
2071 default:
2072 error = EOPNOTSUPP;
2073 break;
2074 }
2075
2076 /*
2077 * If all options have default values, no need to keep the mbuf.
2078 */
2079 if (imo->imo_multicast_ifp == NULL &&
2080 imo->imo_multicast_vif == -1 &&
2081 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
2082 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
2083 imo->imo_num_memberships == 0) {
2084 kfree(*imop, M_IPMOPTS);
2085 *imop = NULL;
2086 }
2087
2088 return (error);
2089 }
2090
2091 /*
2092 * Return the IP multicast options in response to user getsockopt().
2093 */
2094 static int
2095 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo)
2096 {
2097 struct in_addr addr;
2098 struct in_ifaddr *ia;
2099 int error, optval;
2100 u_char coptval;
2101
2102 error = 0;
2103 switch (sopt->sopt_name) {
2104 case IP_MULTICAST_VIF:
2105 if (imo != NULL)
2106 optval = imo->imo_multicast_vif;
2107 else
2108 optval = -1;
2109 error = sooptcopyout(sopt, &optval, sizeof optval);
2110 break;
2111
2112 case IP_MULTICAST_IF:
2113 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2114 addr.s_addr = INADDR_ANY;
2115 else if (imo->imo_multicast_addr.s_addr) {
2116 /* return the value user has set */
2117 addr = imo->imo_multicast_addr;
2118 } else {
2119 IFP_TO_IA(imo->imo_multicast_ifp, ia);
2120 addr.s_addr = (ia == NULL) ? INADDR_ANY
2121 : IA_SIN(ia)->sin_addr.s_addr;
2122 }
2123 error = sooptcopyout(sopt, &addr, sizeof addr);
2124 break;
2125
2126 case IP_MULTICAST_TTL:
2127 if (imo == NULL)
2128 optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2129 else
2130 optval = coptval = imo->imo_multicast_ttl;
2131 if (sopt->sopt_valsize == 1)
2132 error = sooptcopyout(sopt, &coptval, 1);
2133 else
2134 error = sooptcopyout(sopt, &optval, sizeof optval);
2135 break;
2136
2137 case IP_MULTICAST_LOOP:
2138 if (imo == NULL)
2139 optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2140 else
2141 optval = coptval = imo->imo_multicast_loop;
2142 if (sopt->sopt_valsize == 1)
2143 error = sooptcopyout(sopt, &coptval, 1);
2144 else
2145 error = sooptcopyout(sopt, &optval, sizeof optval);
2146 break;
2147
2148 default:
2149 error = ENOPROTOOPT;
2150 break;
2151 }
2152 return (error);
2153 }
2154
2155 /*
2156 * Discard the IP multicast options.
2157 */
2158 void
2159 ip_freemoptions(struct ip_moptions *imo)
2160 {
2161 int i;
2162
2163 if (imo != NULL) {
2164 for (i = 0; i < imo->imo_num_memberships; ++i)
2165 in_delmulti(imo->imo_membership[i]);
2166 kfree(imo, M_IPMOPTS);
2167 }
2168 }
2169
2170 /*
2171 * Routine called from ip_output() to loop back a copy of an IP multicast
2172 * packet to the input queue of a specified interface. Note that this
2173 * calls the output routine of the loopback "driver", but with an interface
2174 * pointer that might NOT be a loopback interface -- evil, but easier than
2175 * replicating that code here.
2176 */
2177 static void
2178 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
2179 int hlen)
2180 {
2181 struct ip *ip;
2182 struct mbuf *copym;
2183
2184 copym = m_copypacket(m, MB_DONTWAIT);
2185 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2186 copym = m_pullup(copym, hlen);
2187 if (copym != NULL) {
2188 /*
2189 * if the checksum hasn't been computed, mark it as valid
2190 */
2191 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2192 in_delayed_cksum(copym);
2193 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
2194 copym->m_pkthdr.csum_flags |=
2195 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2196 copym->m_pkthdr.csum_data = 0xffff;
2197 }
2198 /*
2199 * We don't bother to fragment if the IP length is greater
2200 * than the interface's MTU. Can this possibly matter?
2201 */
2202 ip = mtod(copym, struct ip *);
2203 ip->ip_len = htons(ip->ip_len);
2204 ip->ip_off = htons(ip->ip_off);
2205 ip->ip_sum = 0;
2206 if (ip->ip_vhl == IP_VHL_BORING) {
2207 ip->ip_sum = in_cksum_hdr(ip);
2208 } else {
2209 ip->ip_sum = in_cksum(copym, hlen);
2210 }
2211 /*
2212 * NB:
2213 * It's not clear whether there are any lingering
2214 * reentrancy problems in other areas which might
2215 * be exposed by using ip_input directly (in
2216 * particular, everything which modifies the packet
2217 * in-place). Yet another option is using the
2218 * protosw directly to deliver the looped back
2219 * packet. For the moment, we'll err on the side
2220 * of safety by using if_simloop().
2221 */
2222 #if 1 /* XXX */
2223 if (dst->sin_family != AF_INET) {
2224 kprintf("ip_mloopback: bad address family %d\n",
2225 dst->sin_family);
2226 dst->sin_family = AF_INET;
2227 }
2228 #endif
2229
2230 #ifdef notdef
2231 copym->m_pkthdr.rcvif = ifp;
2232 ip_input(copym);
2233 #else
2234 if_simloop(ifp, copym, dst->sin_family, 0);
2235 #endif
2236 }
2237 }
DragonFly BSD