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Save 'ipfw forward' information in mtag, use m_pkthdr.fw_flags to indicate
[dragonfly/netmp.git] / sys / netinet / ip_output.c
blobcab77a7fd1edfc56b529b7cdca2cc47c848f86b0
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 1.49 2008/08/22 09:14:16 sephe 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 #include "opt_mpls.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/proc.h>
53 #include <sys/sysctl.h>
54 #include <sys/thread2.h>
55 #include <sys/in_cksum.h>
56
57 #include <net/if.h>
58 #include <net/netisr.h>
59 #include <net/pfil.h>
60 #include <net/route.h>
61
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #include <netinet/in_pcb.h>
66 #include <netinet/in_var.h>
67 #include <netinet/ip_var.h>
68
69 #include <netproto/mpls/mpls_var.h>
70
71 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
72
73 #ifdef IPSEC
74 #include <netinet6/ipsec.h>
75 #include <netproto/key/key.h>
76 #ifdef IPSEC_DEBUG
77 #include <netproto/key/key_debug.h>
78 #else
79 #define KEYDEBUG(lev,arg)
80 #endif
81 #endif /*IPSEC*/
82
83 #ifdef FAST_IPSEC
84 #include <netproto/ipsec/ipsec.h>
85 #include <netproto/ipsec/xform.h>
86 #include <netproto/ipsec/key.h>
87 #endif /*FAST_IPSEC*/
88
89 #include <net/ipfw/ip_fw.h>
90 #include <net/dummynet/ip_dummynet.h>
91
92 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\
93 x, (ntohl(a.s_addr)>>24)&0xFF,\
94 (ntohl(a.s_addr)>>16)&0xFF,\
95 (ntohl(a.s_addr)>>8)&0xFF,\
96 (ntohl(a.s_addr))&0xFF, y);
97
98 u_short ip_id;
99
100 #ifdef MBUF_STRESS_TEST
101 int mbuf_frag_size = 0;
102 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
103 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
104 #endif
105
106 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
107 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
108 static void ip_mloopback
109 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
110 static int ip_getmoptions
111 (struct sockopt *, struct ip_moptions *);
112 static int ip_pcbopts(int, struct mbuf **, struct mbuf *);
113 static int ip_setmoptions
114 (struct sockopt *, struct ip_moptions **);
115
116 int ip_optcopy(struct ip *, struct ip *);
117
118
119 extern struct protosw inetsw[];
120
121 /*
122 * IP output. The packet in mbuf chain m contains a skeletal IP
123 * header (with len, off, ttl, proto, tos, src, dst).
124 * The mbuf chain containing the packet will be freed.
125 * The mbuf opt, if present, will not be freed.
126 */
127 int
128 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
129 int flags, struct ip_moptions *imo, struct inpcb *inp)
130 {
131 struct ip *ip;
132 struct ifnet *ifp = NULL; /* keep compiler happy */
133 struct mbuf *m;
134 int hlen = sizeof(struct ip);
135 int len, off, error = 0;
136 struct sockaddr_in *dst = NULL; /* keep compiler happy */
137 struct in_ifaddr *ia = NULL;
138 int isbroadcast, sw_csum;
139 struct in_addr pkt_dst;
140 struct route iproute;
141 struct m_tag *dn_mtag, *mtag;
142 #ifdef IPSEC
143 struct secpolicy *sp = NULL;
144 struct socket *so = inp ? inp->inp_socket : NULL;
145 #endif
146 #ifdef FAST_IPSEC
147 struct secpolicy *sp = NULL;
148 struct tdb_ident *tdbi;
149 #endif /* FAST_IPSEC */
150 struct ip_fw_args args;
151 struct sockaddr_in *next_hop = NULL;
152 int src_was_INADDR_ANY = 0; /* as the name says... */
153
154 args.eh = NULL;
155 args.rule = NULL;
156
157 m = m0;
158 M_ASSERTPKTHDR(m);
159
160 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
161 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
162 KKASSERT(mtag != NULL);
163 next_hop = m_tag_data(mtag);
164 }
165
166 /* Extract info from dummynet tag */
167 dn_mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
168 if (dn_mtag != NULL) {
169 struct dn_pkt *dn_pkt = m_tag_data(dn_mtag);
170
171 /*
172 * The packet was already tagged, so part of the
173 * processing was already done, and we need to go down.
174 * Get parameters from the tag.
175 */
176 args.rule = dn_pkt->dn_priv;
177 opt = NULL;
178 ro = &dn_pkt->ro;
179 imo = NULL;
180 dst = dn_pkt->dn_dst;
181 ifp = dn_pkt->ifp;
182 flags = dn_pkt->flags;
183
184 /*
185 * Don't delete the dummynet tag here, just unlink it,
186 * since some local variables (like 'ro' and 'dst') are
187 * still referencing certain parts of it.
188 * The dummynet tag will be freed at the end of the
189 * output process.
190 */
191 m_tag_unlink(m, dn_mtag);
192 }
193
194 if (ro == NULL) {
195 ro = &iproute;
196 bzero(ro, sizeof *ro);
197 }
198
199 if (args.rule != NULL) { /* dummynet already saw us */
200 ip = mtod(m, struct ip *);
201 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
202 if (ro->ro_rt)
203 ia = ifatoia(ro->ro_rt->rt_ifa);
204 goto sendit;
205 }
206
207 if (opt) {
208 len = 0;
209 m = ip_insertoptions(m, opt, &len);
210 if (len != 0)
211 hlen = len;
212 }
213 ip = mtod(m, struct ip *);
214 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
215
216 /*
217 * Fill in IP header.
218 */
219 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) {
220 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
221 ip->ip_off &= IP_DF;
222 ip->ip_id = ip_newid();
223 ipstat.ips_localout++;
224 } else {
225 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
226 }
227
228 dst = (struct sockaddr_in *)&ro->ro_dst;
229 /*
230 * If there is a cached route,
231 * check that it is to the same destination
232 * and is still up. If not, free it and try again.
233 * The address family should also be checked in case of sharing the
234 * cache with IPv6.
235 */
236 if (ro->ro_rt &&
237 (!(ro->ro_rt->rt_flags & RTF_UP) ||
238 dst->sin_family != AF_INET ||
239 dst->sin_addr.s_addr != pkt_dst.s_addr)) {
240 rtfree(ro->ro_rt);
241 ro->ro_rt = (struct rtentry *)NULL;
242 }
243 if (ro->ro_rt == NULL) {
244 bzero(dst, sizeof *dst);
245 dst->sin_family = AF_INET;
246 dst->sin_len = sizeof *dst;
247 dst->sin_addr = pkt_dst;
248 }
249 /*
250 * If routing to interface only,
251 * short circuit routing lookup.
252 */
253 if (flags & IP_ROUTETOIF) {
254 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
255 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
256 ipstat.ips_noroute++;
257 error = ENETUNREACH;
258 goto bad;
259 }
260 ifp = ia->ia_ifp;
261 ip->ip_ttl = 1;
262 isbroadcast = in_broadcast(dst->sin_addr, ifp);
263 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
264 imo != NULL && imo->imo_multicast_ifp != NULL) {
265 /*
266 * Bypass the normal routing lookup for multicast
267 * packets if the interface is specified.
268 */
269 ifp = imo->imo_multicast_ifp;
270 ia = IFP_TO_IA(ifp);
271 isbroadcast = 0; /* fool gcc */
272 } else {
273 /*
274 * If this is the case, we probably don't want to allocate
275 * a protocol-cloned route since we didn't get one from the
276 * ULP. This lets TCP do its thing, while not burdening
277 * forwarding or ICMP with the overhead of cloning a route.
278 * Of course, we still want to do any cloning requested by
279 * the link layer, as this is probably required in all cases
280 * for correct operation (as it is for ARP).
281 */
282 if (ro->ro_rt == NULL)
283 rtalloc_ign(ro, RTF_PRCLONING);
284 if (ro->ro_rt == NULL) {
285 ipstat.ips_noroute++;
286 error = EHOSTUNREACH;
287 goto bad;
288 }
289 ia = ifatoia(ro->ro_rt->rt_ifa);
290 ifp = ro->ro_rt->rt_ifp;
291 ro->ro_rt->rt_use++;
292 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
293 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
294 if (ro->ro_rt->rt_flags & RTF_HOST)
295 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
296 else
297 isbroadcast = in_broadcast(dst->sin_addr, ifp);
298 }
299 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
300 struct in_multi *inm;
301
302 m->m_flags |= M_MCAST;
303 /*
304 * IP destination address is multicast. Make sure "dst"
305 * still points to the address in "ro". (It may have been
306 * changed to point to a gateway address, above.)
307 */
308 dst = (struct sockaddr_in *)&ro->ro_dst;
309 /*
310 * See if the caller provided any multicast options
311 */
312 if (imo != NULL) {
313 ip->ip_ttl = imo->imo_multicast_ttl;
314 if (imo->imo_multicast_vif != -1)
315 ip->ip_src.s_addr =
316 ip_mcast_src ?
317 ip_mcast_src(imo->imo_multicast_vif) :
318 INADDR_ANY;
319 } else
320 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
321 /*
322 * Confirm that the outgoing interface supports multicast.
323 */
324 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
325 if (!(ifp->if_flags & IFF_MULTICAST)) {
326 ipstat.ips_noroute++;
327 error = ENETUNREACH;
328 goto bad;
329 }
330 }
331 /*
332 * If source address not specified yet, use address
333 * of outgoing interface.
334 */
335 if (ip->ip_src.s_addr == INADDR_ANY) {
336 /* Interface may have no addresses. */
337 if (ia != NULL)
338 ip->ip_src = IA_SIN(ia)->sin_addr;
339 }
340
341 IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
342 if (inm != NULL &&
343 (imo == NULL || imo->imo_multicast_loop)) {
344 /*
345 * If we belong to the destination multicast group
346 * on the outgoing interface, and the caller did not
347 * forbid loopback, loop back a copy.
348 */
349 ip_mloopback(ifp, m, dst, hlen);
350 }
351 else {
352 /*
353 * If we are acting as a multicast router, perform
354 * multicast forwarding as if the packet had just
355 * arrived on the interface to which we are about
356 * to send. The multicast forwarding function
357 * recursively calls this function, using the
358 * IP_FORWARDING flag to prevent infinite recursion.
359 *
360 * Multicasts that are looped back by ip_mloopback(),
361 * above, will be forwarded by the ip_input() routine,
362 * if necessary.
363 */
364 if (ip_mrouter && !(flags & IP_FORWARDING)) {
365 /*
366 * If rsvp daemon is not running, do not
367 * set ip_moptions. This ensures that the packet
368 * is multicast and not just sent down one link
369 * as prescribed by rsvpd.
370 */
371 if (!rsvp_on)
372 imo = NULL;
373 if (ip_mforward &&
374 ip_mforward(ip, ifp, m, imo) != 0) {
375 m_freem(m);
376 goto done;
377 }
378 }
379 }
380
381 /*
382 * Multicasts with a time-to-live of zero may be looped-
383 * back, above, but must not be transmitted on a network.
384 * Also, multicasts addressed to the loopback interface
385 * are not sent -- the above call to ip_mloopback() will
386 * loop back a copy if this host actually belongs to the
387 * destination group on the loopback interface.
388 */
389 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
390 m_freem(m);
391 goto done;
392 }
393
394 goto sendit;
395 }
396 #ifndef notdef
397 /*
398 * If the source address is not specified yet, use the address
399 * of the outoing interface. In case, keep note we did that, so
400 * if the the firewall changes the next-hop causing the output
401 * interface to change, we can fix that.
402 */
403 if (ip->ip_src.s_addr == INADDR_ANY) {
404 /* Interface may have no addresses. */
405 if (ia != NULL) {
406 ip->ip_src = IA_SIN(ia)->sin_addr;
407 src_was_INADDR_ANY = 1;
408 }
409 }
410 #endif /* notdef */
411 #ifdef ALTQ
412 /*
413 * Disable packet drop hack.
414 * Packetdrop should be done by queueing.
415 */
416 #else /* !ALTQ */
417 /*
418 * Verify that we have any chance at all of being able to queue
419 * the packet or packet fragments
420 */
421 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
422 ifp->if_snd.ifq_maxlen) {
423 error = ENOBUFS;
424 ipstat.ips_odropped++;
425 goto bad;
426 }
427 #endif /* !ALTQ */
428
429 /*
430 * Look for broadcast address and
431 * verify user is allowed to send
432 * such a packet.
433 */
434 if (isbroadcast) {
435 if (!(ifp->if_flags & IFF_BROADCAST)) {
436 error = EADDRNOTAVAIL;
437 goto bad;
438 }
439 if (!(flags & IP_ALLOWBROADCAST)) {
440 error = EACCES;
441 goto bad;
442 }
443 /* don't allow broadcast messages to be fragmented */
444 if (ip->ip_len > ifp->if_mtu) {
445 error = EMSGSIZE;
446 goto bad;
447 }
448 m->m_flags |= M_BCAST;
449 } else {
450 m->m_flags &= ~M_BCAST;
451 }
452
453 sendit:
454 #ifdef IPSEC
455 /* get SP for this packet */
456 if (so == NULL)
457 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
458 else
459 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
460
461 if (sp == NULL) {
462 ipsecstat.out_inval++;
463 goto bad;
464 }
465
466 error = 0;
467
468 /* check policy */
469 switch (sp->policy) {
470 case IPSEC_POLICY_DISCARD:
471 /*
472 * This packet is just discarded.
473 */
474 ipsecstat.out_polvio++;
475 goto bad;
476
477 case IPSEC_POLICY_BYPASS:
478 case IPSEC_POLICY_NONE:
479 /* no need to do IPsec. */
480 goto skip_ipsec;
481
482 case IPSEC_POLICY_IPSEC:
483 if (sp->req == NULL) {
484 /* acquire a policy */
485 error = key_spdacquire(sp);
486 goto bad;
487 }
488 break;
489
490 case IPSEC_POLICY_ENTRUST:
491 default:
492 kprintf("ip_output: Invalid policy found. %d\n", sp->policy);
493 }
494 {
495 struct ipsec_output_state state;
496 bzero(&state, sizeof state);
497 state.m = m;
498 if (flags & IP_ROUTETOIF) {
499 state.ro = &iproute;
500 bzero(&iproute, sizeof iproute);
501 } else
502 state.ro = ro;
503 state.dst = (struct sockaddr *)dst;
504
505 ip->ip_sum = 0;
506
507 /*
508 * XXX
509 * delayed checksums are not currently compatible with IPsec
510 */
511 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
512 in_delayed_cksum(m);
513 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
514 }
515
516 ip->ip_len = htons(ip->ip_len);
517 ip->ip_off = htons(ip->ip_off);
518
519 error = ipsec4_output(&state, sp, flags);
520
521 m = state.m;
522 if (flags & IP_ROUTETOIF) {
523 /*
524 * if we have tunnel mode SA, we may need to ignore
525 * IP_ROUTETOIF.
526 */
527 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
528 flags &= ~IP_ROUTETOIF;
529 ro = state.ro;
530 }
531 } else
532 ro = state.ro;
533 dst = (struct sockaddr_in *)state.dst;
534 if (error) {
535 /* mbuf is already reclaimed in ipsec4_output. */
536 m0 = NULL;
537 switch (error) {
538 case EHOSTUNREACH:
539 case ENETUNREACH:
540 case EMSGSIZE:
541 case ENOBUFS:
542 case ENOMEM:
543 break;
544 default:
545 kprintf("ip4_output (ipsec): error code %d\n", error);
546 /*fall through*/
547 case ENOENT:
548 /* don't show these error codes to the user */
549 error = 0;
550 break;
551 }
552 goto bad;
553 }
554 }
555
556 /* be sure to update variables that are affected by ipsec4_output() */
557 ip = mtod(m, struct ip *);
558 #ifdef _IP_VHL
559 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
560 #else
561 hlen = ip->ip_hl << 2;
562 #endif
563 if (ro->ro_rt == NULL) {
564 if (!(flags & IP_ROUTETOIF)) {
565 kprintf("ip_output: "
566 "can't update route after IPsec processing\n");
567 error = EHOSTUNREACH; /*XXX*/
568 goto bad;
569 }
570 } else {
571 ia = ifatoia(ro->ro_rt->rt_ifa);
572 ifp = ro->ro_rt->rt_ifp;
573 }
574
575 /* make it flipped, again. */
576 ip->ip_len = ntohs(ip->ip_len);
577 ip->ip_off = ntohs(ip->ip_off);
578 skip_ipsec:
579 #endif /*IPSEC*/
580 #ifdef FAST_IPSEC
581 /*
582 * Check the security policy (SP) for the packet and, if
583 * required, do IPsec-related processing. There are two
584 * cases here; the first time a packet is sent through
585 * it will be untagged and handled by ipsec4_checkpolicy.
586 * If the packet is resubmitted to ip_output (e.g. after
587 * AH, ESP, etc. processing), there will be a tag to bypass
588 * the lookup and related policy checking.
589 */
590 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
591 crit_enter();
592 if (mtag != NULL) {
593 tdbi = (struct tdb_ident *)m_tag_data(mtag);
594 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
595 if (sp == NULL)
596 error = -EINVAL; /* force silent drop */
597 m_tag_delete(m, mtag);
598 } else {
599 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
600 &error, inp);
601 }
602 /*
603 * There are four return cases:
604 * sp != NULL apply IPsec policy
605 * sp == NULL, error == 0 no IPsec handling needed
606 * sp == NULL, error == -EINVAL discard packet w/o error
607 * sp == NULL, error != 0 discard packet, report error
608 */
609 if (sp != NULL) {
610 /* Loop detection, check if ipsec processing already done */
611 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
612 for (mtag = m_tag_first(m); mtag != NULL;
613 mtag = m_tag_next(m, mtag)) {
614 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
615 continue;
616 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
617 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
618 continue;
619 /*
620 * Check if policy has an SA associated with it.
621 * This can happen when an SP has yet to acquire
622 * an SA; e.g. on first reference. If it occurs,
623 * then we let ipsec4_process_packet do its thing.
624 */
625 if (sp->req->sav == NULL)
626 break;
627 tdbi = (struct tdb_ident *)m_tag_data(mtag);
628 if (tdbi->spi == sp->req->sav->spi &&
629 tdbi->proto == sp->req->sav->sah->saidx.proto &&
630 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
631 sizeof(union sockaddr_union)) == 0) {
632 /*
633 * No IPsec processing is needed, free
634 * reference to SP.
635 *
636 * NB: null pointer to avoid free at
637 * done: below.
638 */
639 KEY_FREESP(&sp), sp = NULL;
640 crit_exit();
641 goto spd_done;
642 }
643 }
644
645 /*
646 * Do delayed checksums now because we send before
647 * this is done in the normal processing path.
648 */
649 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
650 in_delayed_cksum(m);
651 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
652 }
653
654 ip->ip_len = htons(ip->ip_len);
655 ip->ip_off = htons(ip->ip_off);
656
657 /* NB: callee frees mbuf */
658 error = ipsec4_process_packet(m, sp->req, flags, 0);
659 /*
660 * Preserve KAME behaviour: ENOENT can be returned
661 * when an SA acquire is in progress. Don't propagate
662 * this to user-level; it confuses applications.
663 *
664 * XXX this will go away when the SADB is redone.
665 */
666 if (error == ENOENT)
667 error = 0;
668 crit_exit();
669 goto done;
670 } else {
671 crit_exit();
672
673 if (error != 0) {
674 /*
675 * Hack: -EINVAL is used to signal that a packet
676 * should be silently discarded. This is typically
677 * because we asked key management for an SA and
678 * it was delayed (e.g. kicked up to IKE).
679 */
680 if (error == -EINVAL)
681 error = 0;
682 goto bad;
683 } else {
684 /* No IPsec processing for this packet. */
685 }
686 #ifdef notyet
687 /*
688 * If deferred crypto processing is needed, check that
689 * the interface supports it.
690 */
691 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
692 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) {
693 /* notify IPsec to do its own crypto */
694 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag));
695 error = EHOSTUNREACH;
696 goto bad;
697 }
698 #endif
699 }
700 spd_done:
701 #endif /* FAST_IPSEC */
702 /*
703 * IpHack's section.
704 * - Xlate: translate packet's addr/port (NAT).
705 * - Firewall: deny/allow/etc.
706 * - Wrap: fake packet's addr/port <unimpl.>
707 * - Encapsulate: put it in another IP and send out. <unimp.>
708 */
709
710 /*
711 * Run through list of hooks for output packets.
712 */
713 if (pfil_has_hooks(&inet_pfil_hook)) {
714 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
715 if (error != 0 || m == NULL)
716 goto done;
717 ip = mtod(m, struct ip *);
718 }
719
720 /*
721 * Check with the firewall...
722 * but not if we are already being fwd'd from a firewall.
723 */
724 if (fw_enable && IPFW_LOADED && !next_hop) {
725 struct sockaddr_in *old = dst;
726
727 args.m = m;
728 args.oif = ifp;
729 off = ip_fw_chk_ptr(&args);
730 m = args.m;
731
732 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
733 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
734 KKASSERT(mtag != NULL);
735 next_hop = m_tag_data(mtag);
736 dst = next_hop;
737 }
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 struct in_ifaddr_container *iac;
841
842 /*
843 * XXX sro_fwd below is static, and a pointer
844 * to it gets passed to routines downstream.
845 * This could have surprisingly bad results in
846 * practice, because its content is overwritten
847 * by subsequent packets.
848 */
849 /* There must be a better way to do this next line... */
850 static struct route sro_fwd;
851 struct route *ro_fwd = &sro_fwd;
852
853 #if 0
854 print_ip("IPFIREWALL_FORWARD: New dst ip: ",
855 dst->sin_addr, "\n");
856 #endif
857
858 /*
859 * We need to figure out if we have been forwarded
860 * to a local socket. If so, then we should somehow
861 * "loop back" to ip_input, and get directed to the
862 * PCB as if we had received this packet. This is
863 * because it may be dificult to identify the packets
864 * you want to forward until they are being output
865 * and have selected an interface. (e.g. locally
866 * initiated packets) If we used the loopback inteface,
867 * we would not be able to control what happens
868 * as the packet runs through ip_input() as
869 * it is done through a ISR.
870 */
871 ia = NULL;
872 LIST_FOREACH(iac, INADDR_HASH(dst->sin_addr.s_addr),
873 ia_hash) {
874 /*
875 * If the addr to forward to is one
876 * of ours, we pretend to
877 * be the destination for this packet.
878 */
879 if (IA_SIN(iac->ia)->sin_addr.s_addr ==
880 dst->sin_addr.s_addr) {
881 ia = iac->ia;
882 break;
883 }
884 }
885 if (ia != NULL) { /* tell ip_input "dont filter" */
886 if (m->m_pkthdr.rcvif == NULL)
887 m->m_pkthdr.rcvif = ifunit("lo0");
888 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
889 m->m_pkthdr.csum_flags |=
890 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
891 m->m_pkthdr.csum_data = 0xffff;
892 }
893 m->m_pkthdr.csum_flags |=
894 CSUM_IP_CHECKED | CSUM_IP_VALID;
895 ip->ip_len = htons(ip->ip_len);
896 ip->ip_off = htons(ip->ip_off);
897 ip_input(m);
898 goto done;
899 }
900 /* Some of the logic for this was nicked from above.
901 *
902 * This rewrites the cached route in a local PCB.
903 * Is this what we want to do?
904 */
905 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst);
906 ro_fwd->ro_rt = NULL;
907
908 rtalloc_ign(ro_fwd, RTF_PRCLONING);
909 if (ro_fwd->ro_rt == NULL) {
910 ipstat.ips_noroute++;
911 error = EHOSTUNREACH;
912 goto bad;
913 }
914
915 ia = ifatoia(ro_fwd->ro_rt->rt_ifa);
916 ifp = ro_fwd->ro_rt->rt_ifp;
917 ro_fwd->ro_rt->rt_use++;
918 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
919 dst = (struct sockaddr_in *)
920 ro_fwd->ro_rt->rt_gateway;
921 if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
922 isbroadcast =
923 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
924 else
925 isbroadcast = in_broadcast(dst->sin_addr, ifp);
926 if (ro->ro_rt != NULL)
927 rtfree(ro->ro_rt);
928 ro->ro_rt = ro_fwd->ro_rt;
929 dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
930
931 #endif /* ... block to be put into a function */
932 /*
933 * If we added a default src ip earlier,
934 * which would have been gotten from the-then
935 * interface, do it again, from the new one.
936 */
937 if (src_was_INADDR_ANY)
938 ip->ip_src = IA_SIN(ia)->sin_addr;
939 goto pass ;
940 }
941
942 /*
943 * if we get here, none of the above matches, and
944 * we have to drop the pkt
945 */
946 m_freem(m);
947 error = EACCES; /* not sure this is the right error msg */
948 goto done;
949 }
950
951 pass:
952 /* 127/8 must not appear on wire - RFC1122. */
953 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
954 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
955 if (!(ifp->if_flags & IFF_LOOPBACK)) {
956 ipstat.ips_badaddr++;
957 error = EADDRNOTAVAIL;
958 goto bad;
959 }
960 }
961
962 m->m_pkthdr.csum_flags |= CSUM_IP;
963 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
964 if (sw_csum & CSUM_DELAY_DATA) {
965 in_delayed_cksum(m);
966 sw_csum &= ~CSUM_DELAY_DATA;
967 }
968 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
969
970 /*
971 * If small enough for interface, or the interface will take
972 * care of the fragmentation for us, can just send directly.
973 */
974 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) &&
975 !(ip->ip_off & IP_DF))) {
976 ip->ip_len = htons(ip->ip_len);
977 ip->ip_off = htons(ip->ip_off);
978 ip->ip_sum = 0;
979 if (sw_csum & CSUM_DELAY_IP) {
980 if (ip->ip_vhl == IP_VHL_BORING) {
981 ip->ip_sum = in_cksum_hdr(ip);
982 } else {
983 ip->ip_sum = in_cksum(m, hlen);
984 }
985 }
986
987 /* Record statistics for this interface address. */
988 if (!(flags & IP_FORWARDING) && ia) {
989 ia->ia_ifa.if_opackets++;
990 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
991 }
992
993 #ifdef IPSEC
994 /* clean ipsec history once it goes out of the node */
995 ipsec_delaux(m);
996 #endif
997
998 #ifdef MBUF_STRESS_TEST
999 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
1000 struct mbuf *m1, *m2;
1001 int length, tmp;
1002
1003 tmp = length = m->m_pkthdr.len;
1004
1005 while ((length -= mbuf_frag_size) >= 1) {
1006 m1 = m_split(m, length, MB_DONTWAIT);
1007 if (m1 == NULL)
1008 break;
1009 m2 = m;
1010 while (m2->m_next != NULL)
1011 m2 = m2->m_next;
1012 m2->m_next = m1;
1013 }
1014 m->m_pkthdr.len = tmp;
1015 }
1016 #endif
1017
1018 #ifdef MPLS
1019 if (!mpls_output_process(m, ro->ro_rt))
1020 goto done;
1021 #endif
1022 error = ifp->if_output(ifp, m, (struct sockaddr *)dst,
1023 ro->ro_rt);
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 #ifdef MPLS
1066 if (!mpls_output_process(m, ro->ro_rt))
1067 continue;
1068 #endif
1069 error = ifp->if_output(ifp, m, (struct sockaddr *)dst,
1070 ro->ro_rt);
1071 } else {
1072 m_freem(m);
1073 }
1074 }
1075
1076 if (error == 0)
1077 ipstat.ips_fragmented++;
1078
1079 done:
1080 if (ro == &iproute && ro->ro_rt != NULL) {
1081 RTFREE(ro->ro_rt);
1082 ro->ro_rt = NULL;
1083 }
1084 #ifdef IPSEC
1085 if (sp != NULL) {
1086 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1087 kprintf("DP ip_output call free SP:%p\n", sp));
1088 key_freesp(sp);
1089 }
1090 #endif
1091 #ifdef FAST_IPSEC
1092 if (sp != NULL)
1093 KEY_FREESP(&sp);
1094 #endif
1095 if (dn_mtag != NULL)
1096 m_tag_free(dn_mtag);
1097
1098 return (error);
1099 bad:
1100 m_freem(m);
1101 goto done;
1102 }
1103
1104 /*
1105 * Create a chain of fragments which fit the given mtu. m_frag points to the
1106 * mbuf to be fragmented; on return it points to the chain with the fragments.
1107 * Return 0 if no error. If error, m_frag may contain a partially built
1108 * chain of fragments that should be freed by the caller.
1109 *
1110 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1111 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1112 */
1113 int
1114 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1115 u_long if_hwassist_flags, int sw_csum)
1116 {
1117 int error = 0;
1118 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1119 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
1120 int off;
1121 struct mbuf *m0 = *m_frag; /* the original packet */
1122 int firstlen;
1123 struct mbuf **mnext;
1124 int nfrags;
1125
1126 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
1127 ipstat.ips_cantfrag++;
1128 return EMSGSIZE;
1129 }
1130
1131 /*
1132 * Must be able to put at least 8 bytes per fragment.
1133 */
1134 if (len < 8)
1135 return EMSGSIZE;
1136
1137 /*
1138 * If the interface will not calculate checksums on
1139 * fragmented packets, then do it here.
1140 */
1141 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) &&
1142 !(if_hwassist_flags & CSUM_IP_FRAGS)) {
1143 in_delayed_cksum(m0);
1144 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1145 }
1146
1147 if (len > PAGE_SIZE) {
1148 /*
1149 * Fragment large datagrams such that each segment
1150 * contains a multiple of PAGE_SIZE amount of data,
1151 * plus headers. This enables a receiver to perform
1152 * page-flipping zero-copy optimizations.
1153 *
1154 * XXX When does this help given that sender and receiver
1155 * could have different page sizes, and also mtu could
1156 * be less than the receiver's page size ?
1157 */
1158 int newlen;
1159 struct mbuf *m;
1160
1161 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1162 off += m->m_len;
1163
1164 /*
1165 * firstlen (off - hlen) must be aligned on an
1166 * 8-byte boundary
1167 */
1168 if (off < hlen)
1169 goto smart_frag_failure;
1170 off = ((off - hlen) & ~7) + hlen;
1171 newlen = (~PAGE_MASK) & mtu;
1172 if ((newlen + sizeof(struct ip)) > mtu) {
1173 /* we failed, go back the default */
1174 smart_frag_failure:
1175 newlen = len;
1176 off = hlen + len;
1177 }
1178 len = newlen;
1179
1180 } else {
1181 off = hlen + len;
1182 }
1183
1184 firstlen = off - hlen;
1185 mnext = &m0->m_nextpkt; /* pointer to next packet */
1186
1187 /*
1188 * Loop through length of segment after first fragment,
1189 * make new header and copy data of each part and link onto chain.
1190 * Here, m0 is the original packet, m is the fragment being created.
1191 * The fragments are linked off the m_nextpkt of the original
1192 * packet, which after processing serves as the first fragment.
1193 */
1194 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1195 struct ip *mhip; /* ip header on the fragment */
1196 struct mbuf *m;
1197 int mhlen = sizeof(struct ip);
1198
1199 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1200 if (m == NULL) {
1201 error = ENOBUFS;
1202 ipstat.ips_odropped++;
1203 goto done;
1204 }
1205 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1206 /*
1207 * In the first mbuf, leave room for the link header, then
1208 * copy the original IP header including options. The payload
1209 * goes into an additional mbuf chain returned by m_copy().
1210 */
1211 m->m_data += max_linkhdr;
1212 mhip = mtod(m, struct ip *);
1213 *mhip = *ip;
1214 if (hlen > sizeof(struct ip)) {
1215 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip);
1216 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1217 }
1218 m->m_len = mhlen;
1219 /* XXX do we need to add ip->ip_off below ? */
1220 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1221 if (off + len >= ip->ip_len) { /* last fragment */
1222 len = ip->ip_len - off;
1223 m->m_flags |= M_LASTFRAG;
1224 } else
1225 mhip->ip_off |= IP_MF;
1226 mhip->ip_len = htons((u_short)(len + mhlen));
1227 m->m_next = m_copy(m0, off, len);
1228 if (m->m_next == NULL) { /* copy failed */
1229 m_free(m);
1230 error = ENOBUFS; /* ??? */
1231 ipstat.ips_odropped++;
1232 goto done;
1233 }
1234 m->m_pkthdr.len = mhlen + len;
1235 m->m_pkthdr.rcvif = (struct ifnet *)NULL;
1236 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1237 mhip->ip_off = htons(mhip->ip_off);
1238 mhip->ip_sum = 0;
1239 if (sw_csum & CSUM_DELAY_IP)
1240 mhip->ip_sum = in_cksum(m, mhlen);
1241 *mnext = m;
1242 mnext = &m->m_nextpkt;
1243 }
1244 ipstat.ips_ofragments += nfrags;
1245
1246 /* set first marker for fragment chain */
1247 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1248 m0->m_pkthdr.csum_data = nfrags;
1249
1250 /*
1251 * Update first fragment by trimming what's been copied out
1252 * and updating header.
1253 */
1254 m_adj(m0, hlen + firstlen - ip->ip_len);
1255 m0->m_pkthdr.len = hlen + firstlen;
1256 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1257 ip->ip_off |= IP_MF;
1258 ip->ip_off = htons(ip->ip_off);
1259 ip->ip_sum = 0;
1260 if (sw_csum & CSUM_DELAY_IP)
1261 ip->ip_sum = in_cksum(m0, hlen);
1262
1263 done:
1264 *m_frag = m0;
1265 return error;
1266 }
1267
1268 void
1269 in_delayed_cksum(struct mbuf *m)
1270 {
1271 struct ip *ip;
1272 u_short csum, offset;
1273
1274 ip = mtod(m, struct ip *);
1275 offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1276 csum = in_cksum_skip(m, ip->ip_len, offset);
1277 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1278 csum = 0xffff;
1279 offset += m->m_pkthdr.csum_data; /* checksum offset */
1280
1281 if (offset + sizeof(u_short) > m->m_len) {
1282 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n",
1283 m->m_len, offset, ip->ip_p);
1284 /*
1285 * XXX
1286 * this shouldn't happen, but if it does, the
1287 * correct behavior may be to insert the checksum
1288 * in the existing chain instead of rearranging it.
1289 */
1290 m = m_pullup(m, offset + sizeof(u_short));
1291 }
1292 *(u_short *)(m->m_data + offset) = csum;
1293 }
1294
1295 /*
1296 * Insert IP options into preformed packet.
1297 * Adjust IP destination as required for IP source routing,
1298 * as indicated by a non-zero in_addr at the start of the options.
1299 *
1300 * XXX This routine assumes that the packet has no options in place.
1301 */
1302 static struct mbuf *
1303 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen)
1304 {
1305 struct ipoption *p = mtod(opt, struct ipoption *);
1306 struct mbuf *n;
1307 struct ip *ip = mtod(m, struct ip *);
1308 unsigned optlen;
1309
1310 optlen = opt->m_len - sizeof p->ipopt_dst;
1311 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1312 *phlen = 0;
1313 return (m); /* XXX should fail */
1314 }
1315 if (p->ipopt_dst.s_addr)
1316 ip->ip_dst = p->ipopt_dst;
1317 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1318 MGETHDR(n, MB_DONTWAIT, MT_HEADER);
1319 if (n == NULL) {
1320 *phlen = 0;
1321 return (m);
1322 }
1323 n->m_pkthdr.rcvif = (struct ifnet *)NULL;
1324 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1325 m->m_len -= sizeof(struct ip);
1326 m->m_data += sizeof(struct ip);
1327 n->m_next = m;
1328 m = n;
1329 m->m_len = optlen + sizeof(struct ip);
1330 m->m_data += max_linkhdr;
1331 memcpy(mtod(m, void *), ip, sizeof(struct ip));
1332 } else {
1333 m->m_data -= optlen;
1334 m->m_len += optlen;
1335 m->m_pkthdr.len += optlen;
1336 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
1337 }
1338 ip = mtod(m, struct ip *);
1339 bcopy(p->ipopt_list, ip + 1, optlen);
1340 *phlen = sizeof(struct ip) + optlen;
1341 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1342 ip->ip_len += optlen;
1343 return (m);
1344 }
1345
1346 /*
1347 * Copy options from ip to jp,
1348 * omitting those not copied during fragmentation.
1349 */
1350 int
1351 ip_optcopy(struct ip *ip, struct ip *jp)
1352 {
1353 u_char *cp, *dp;
1354 int opt, optlen, cnt;
1355
1356 cp = (u_char *)(ip + 1);
1357 dp = (u_char *)(jp + 1);
1358 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1359 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1360 opt = cp[0];
1361 if (opt == IPOPT_EOL)
1362 break;
1363 if (opt == IPOPT_NOP) {
1364 /* Preserve for IP mcast tunnel's LSRR alignment. */
1365 *dp++ = IPOPT_NOP;
1366 optlen = 1;
1367 continue;
1368 }
1369
1370 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp,
1371 ("ip_optcopy: malformed ipv4 option"));
1372 optlen = cp[IPOPT_OLEN];
1373 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt,
1374 ("ip_optcopy: malformed ipv4 option"));
1375
1376 /* bogus lengths should have been caught by ip_dooptions */
1377 if (optlen > cnt)
1378 optlen = cnt;
1379 if (IPOPT_COPIED(opt)) {
1380 bcopy(cp, dp, optlen);
1381 dp += optlen;
1382 }
1383 }
1384 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1385 *dp++ = IPOPT_EOL;
1386 return (optlen);
1387 }
1388
1389 /*
1390 * IP socket option processing.
1391 */
1392 int
1393 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1394 {
1395 struct inpcb *inp = so->so_pcb;
1396 int error, optval;
1397
1398 error = optval = 0;
1399 if (sopt->sopt_level != IPPROTO_IP) {
1400 return (EINVAL);
1401 }
1402
1403 switch (sopt->sopt_dir) {
1404 case SOPT_SET:
1405 switch (sopt->sopt_name) {
1406 case IP_OPTIONS:
1407 #ifdef notyet
1408 case IP_RETOPTS:
1409 #endif
1410 {
1411 struct mbuf *m;
1412 if (sopt->sopt_valsize > MLEN) {
1413 error = EMSGSIZE;
1414 break;
1415 }
1416 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1417 if (m == NULL) {
1418 error = ENOBUFS;
1419 break;
1420 }
1421 m->m_len = sopt->sopt_valsize;
1422 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len,
1423 m->m_len);
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 = soopt_to_kbuf(sopt, &optval, sizeof optval,
1438 sizeof optval);
1439 if (error)
1440 break;
1441 switch (sopt->sopt_name) {
1442 case IP_TOS:
1443 inp->inp_ip_tos = optval;
1444 break;
1445
1446 case IP_TTL:
1447 inp->inp_ip_ttl = optval;
1448 break;
1449 case IP_MINTTL:
1450 if (optval > 0 && optval <= MAXTTL)
1451 inp->inp_ip_minttl = optval;
1452 else
1453 error = EINVAL;
1454 break;
1455 #define OPTSET(bit) \
1456 if (optval) \
1457 inp->inp_flags |= bit; \
1458 else \
1459 inp->inp_flags &= ~bit;
1460
1461 case IP_RECVOPTS:
1462 OPTSET(INP_RECVOPTS);
1463 break;
1464
1465 case IP_RECVRETOPTS:
1466 OPTSET(INP_RECVRETOPTS);
1467 break;
1468
1469 case IP_RECVDSTADDR:
1470 OPTSET(INP_RECVDSTADDR);
1471 break;
1472
1473 case IP_RECVIF:
1474 OPTSET(INP_RECVIF);
1475 break;
1476
1477 case IP_RECVTTL:
1478 OPTSET(INP_RECVTTL);
1479 break;
1480
1481 case IP_FAITH:
1482 OPTSET(INP_FAITH);
1483 break;
1484 }
1485 break;
1486 #undef OPTSET
1487
1488 case IP_MULTICAST_IF:
1489 case IP_MULTICAST_VIF:
1490 case IP_MULTICAST_TTL:
1491 case IP_MULTICAST_LOOP:
1492 case IP_ADD_MEMBERSHIP:
1493 case IP_DROP_MEMBERSHIP:
1494 error = ip_setmoptions(sopt, &inp->inp_moptions);
1495 break;
1496
1497 case IP_PORTRANGE:
1498 error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1499 sizeof optval);
1500 if (error)
1501 break;
1502
1503 switch (optval) {
1504 case IP_PORTRANGE_DEFAULT:
1505 inp->inp_flags &= ~(INP_LOWPORT);
1506 inp->inp_flags &= ~(INP_HIGHPORT);
1507 break;
1508
1509 case IP_PORTRANGE_HIGH:
1510 inp->inp_flags &= ~(INP_LOWPORT);
1511 inp->inp_flags |= INP_HIGHPORT;
1512 break;
1513
1514 case IP_PORTRANGE_LOW:
1515 inp->inp_flags &= ~(INP_HIGHPORT);
1516 inp->inp_flags |= INP_LOWPORT;
1517 break;
1518
1519 default:
1520 error = EINVAL;
1521 break;
1522 }
1523 break;
1524
1525 #if defined(IPSEC) || defined(FAST_IPSEC)
1526 case IP_IPSEC_POLICY:
1527 {
1528 caddr_t req;
1529 size_t len = 0;
1530 int priv;
1531 struct mbuf *m;
1532 int optname;
1533
1534 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1535 break;
1536 soopt_to_mbuf(sopt, m);
1537 priv = (sopt->sopt_td != NULL &&
1538 suser(sopt->sopt_td) != 0) ? 0 : 1;
1539 req = mtod(m, caddr_t);
1540 len = m->m_len;
1541 optname = sopt->sopt_name;
1542 error = ipsec4_set_policy(inp, optname, req, len, priv);
1543 m_freem(m);
1544 break;
1545 }
1546 #endif /*IPSEC*/
1547
1548 default:
1549 error = ENOPROTOOPT;
1550 break;
1551 }
1552 break;
1553
1554 case SOPT_GET:
1555 switch (sopt->sopt_name) {
1556 case IP_OPTIONS:
1557 case IP_RETOPTS:
1558 if (inp->inp_options)
1559 soopt_from_kbuf(sopt, mtod(inp->inp_options,
1560 char *),
1561 inp->inp_options->m_len);
1562 else
1563 sopt->sopt_valsize = 0;
1564 break;
1565
1566 case IP_TOS:
1567 case IP_TTL:
1568 case IP_MINTTL:
1569 case IP_RECVOPTS:
1570 case IP_RECVRETOPTS:
1571 case IP_RECVDSTADDR:
1572 case IP_RECVTTL:
1573 case IP_RECVIF:
1574 case IP_PORTRANGE:
1575 case IP_FAITH:
1576 switch (sopt->sopt_name) {
1577
1578 case IP_TOS:
1579 optval = inp->inp_ip_tos;
1580 break;
1581
1582 case IP_TTL:
1583 optval = inp->inp_ip_ttl;
1584 break;
1585 case IP_MINTTL:
1586 optval = inp->inp_ip_minttl;
1587 break;
1588
1589 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1590
1591 case IP_RECVOPTS:
1592 optval = OPTBIT(INP_RECVOPTS);
1593 break;
1594
1595 case IP_RECVRETOPTS:
1596 optval = OPTBIT(INP_RECVRETOPTS);
1597 break;
1598
1599 case IP_RECVDSTADDR:
1600 optval = OPTBIT(INP_RECVDSTADDR);
1601 break;
1602
1603 case IP_RECVTTL:
1604 optval = OPTBIT(INP_RECVTTL);
1605 break;
1606
1607 case IP_RECVIF:
1608 optval = OPTBIT(INP_RECVIF);
1609 break;
1610
1611 case IP_PORTRANGE:
1612 if (inp->inp_flags & INP_HIGHPORT)
1613 optval = IP_PORTRANGE_HIGH;
1614 else if (inp->inp_flags & INP_LOWPORT)
1615 optval = IP_PORTRANGE_LOW;
1616 else
1617 optval = 0;
1618 break;
1619
1620 case IP_FAITH:
1621 optval = OPTBIT(INP_FAITH);
1622 break;
1623 }
1624 soopt_from_kbuf(sopt, &optval, sizeof optval);
1625 break;
1626
1627 case IP_MULTICAST_IF:
1628 case IP_MULTICAST_VIF:
1629 case IP_MULTICAST_TTL:
1630 case IP_MULTICAST_LOOP:
1631 case IP_ADD_MEMBERSHIP:
1632 case IP_DROP_MEMBERSHIP:
1633 error = ip_getmoptions(sopt, inp->inp_moptions);
1634 break;
1635
1636 #if defined(IPSEC) || defined(FAST_IPSEC)
1637 case IP_IPSEC_POLICY:
1638 {
1639 struct mbuf *m = NULL;
1640 caddr_t req = NULL;
1641 size_t len = 0;
1642
1643 if (m != NULL) {
1644 req = mtod(m, caddr_t);
1645 len = m->m_len;
1646 }
1647 error = ipsec4_get_policy(so->so_pcb, req, len, &m);
1648 if (error == 0)
1649 error = soopt_from_mbuf(sopt, m); /* XXX */
1650 if (error == 0)
1651 m_freem(m);
1652 break;
1653 }
1654 #endif /*IPSEC*/
1655
1656 default:
1657 error = ENOPROTOOPT;
1658 break;
1659 }
1660 break;
1661 }
1662 return (error);
1663 }
1664
1665 /*
1666 * Set up IP options in pcb for insertion in output packets.
1667 * Store in mbuf with pointer in pcbopt, adding pseudo-option
1668 * with destination address if source routed.
1669 */
1670 static int
1671 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m)
1672 {
1673 int cnt, optlen;
1674 u_char *cp;
1675 u_char opt;
1676
1677 /* turn off any old options */
1678 if (*pcbopt)
1679 m_free(*pcbopt);
1680 *pcbopt = 0;
1681 if (m == NULL || m->m_len == 0) {
1682 /*
1683 * Only turning off any previous options.
1684 */
1685 if (m != NULL)
1686 m_free(m);
1687 return (0);
1688 }
1689
1690 if (m->m_len % sizeof(int32_t))
1691 goto bad;
1692 /*
1693 * IP first-hop destination address will be stored before
1694 * actual options; move other options back
1695 * and clear it when none present.
1696 */
1697 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1698 goto bad;
1699 cnt = m->m_len;
1700 m->m_len += sizeof(struct in_addr);
1701 cp = mtod(m, u_char *) + sizeof(struct in_addr);
1702 ovbcopy(mtod(m, caddr_t), cp, cnt);
1703 bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1704
1705 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1706 opt = cp[IPOPT_OPTVAL];
1707 if (opt == IPOPT_EOL)
1708 break;
1709 if (opt == IPOPT_NOP)
1710 optlen = 1;
1711 else {
1712 if (cnt < IPOPT_OLEN + sizeof *cp)
1713 goto bad;
1714 optlen = cp[IPOPT_OLEN];
1715 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt)
1716 goto bad;
1717 }
1718 switch (opt) {
1719
1720 default:
1721 break;
1722
1723 case IPOPT_LSRR:
1724 case IPOPT_SSRR:
1725 /*
1726 * user process specifies route as:
1727 * ->A->B->C->D
1728 * D must be our final destination (but we can't
1729 * check that since we may not have connected yet).
1730 * A is first hop destination, which doesn't appear in
1731 * actual IP option, but is stored before the options.
1732 */
1733 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1734 goto bad;
1735 m->m_len -= sizeof(struct in_addr);
1736 cnt -= sizeof(struct in_addr);
1737 optlen -= sizeof(struct in_addr);
1738 cp[IPOPT_OLEN] = optlen;
1739 /*
1740 * Move first hop before start of options.
1741 */
1742 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1743 sizeof(struct in_addr));
1744 /*
1745 * Then copy rest of options back
1746 * to close up the deleted entry.
1747 */
1748 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr),
1749 &cp[IPOPT_OFFSET+1],
1750 cnt - (IPOPT_MINOFF - 1));
1751 break;
1752 }
1753 }
1754 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1755 goto bad;
1756 *pcbopt = m;
1757 return (0);
1758
1759 bad:
1760 m_free(m);
1761 return (EINVAL);
1762 }
1763
1764 /*
1765 * XXX
1766 * The whole multicast option thing needs to be re-thought.
1767 * Several of these options are equally applicable to non-multicast
1768 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1769 * standard option (IP_TTL).
1770 */
1771
1772 /*
1773 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1774 */
1775 static struct ifnet *
1776 ip_multicast_if(struct in_addr *a, int *ifindexp)
1777 {
1778 int ifindex;
1779 struct ifnet *ifp;
1780
1781 if (ifindexp)
1782 *ifindexp = 0;
1783 if (ntohl(a->s_addr) >> 24 == 0) {
1784 ifindex = ntohl(a->s_addr) & 0xffffff;
1785 if (ifindex < 0 || if_index < ifindex)
1786 return NULL;
1787 ifp = ifindex2ifnet[ifindex];
1788 if (ifindexp)
1789 *ifindexp = ifindex;
1790 } else {
1791 ifp = INADDR_TO_IFP(a);
1792 }
1793 return ifp;
1794 }
1795
1796 /*
1797 * Set the IP multicast options in response to user setsockopt().
1798 */
1799 static int
1800 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop)
1801 {
1802 int error = 0;
1803 int i;
1804 struct in_addr addr;
1805 struct ip_mreq mreq;
1806 struct ifnet *ifp;
1807 struct ip_moptions *imo = *imop;
1808 int ifindex;
1809
1810 if (imo == NULL) {
1811 /*
1812 * No multicast option buffer attached to the pcb;
1813 * allocate one and initialize to default values.
1814 */
1815 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK);
1816
1817 *imop = imo;
1818 imo->imo_multicast_ifp = NULL;
1819 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1820 imo->imo_multicast_vif = -1;
1821 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1822 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1823 imo->imo_num_memberships = 0;
1824 }
1825 switch (sopt->sopt_name) {
1826 /* store an index number for the vif you wanna use in the send */
1827 case IP_MULTICAST_VIF:
1828 if (legal_vif_num == 0) {
1829 error = EOPNOTSUPP;
1830 break;
1831 }
1832 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i);
1833 if (error)
1834 break;
1835 if (!legal_vif_num(i) && (i != -1)) {
1836 error = EINVAL;
1837 break;
1838 }
1839 imo->imo_multicast_vif = i;
1840 break;
1841
1842 case IP_MULTICAST_IF:
1843 /*
1844 * Select the interface for outgoing multicast packets.
1845 */
1846 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr);
1847 if (error)
1848 break;
1849
1850 /*
1851 * INADDR_ANY is used to remove a previous selection.
1852 * When no interface is selected, a default one is
1853 * chosen every time a multicast packet is sent.
1854 */
1855 if (addr.s_addr == INADDR_ANY) {
1856 imo->imo_multicast_ifp = NULL;
1857 break;
1858 }
1859 /*
1860 * The selected interface is identified by its local
1861 * IP address. Find the interface and confirm that
1862 * it supports multicasting.
1863 */
1864 crit_enter();
1865 ifp = ip_multicast_if(&addr, &ifindex);
1866 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1867 crit_exit();
1868 error = EADDRNOTAVAIL;
1869 break;
1870 }
1871 imo->imo_multicast_ifp = ifp;
1872 if (ifindex)
1873 imo->imo_multicast_addr = addr;
1874 else
1875 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1876 crit_exit();
1877 break;
1878
1879 case IP_MULTICAST_TTL:
1880 /*
1881 * Set the IP time-to-live for outgoing multicast packets.
1882 * The original multicast API required a char argument,
1883 * which is inconsistent with the rest of the socket API.
1884 * We allow either a char or an int.
1885 */
1886 if (sopt->sopt_valsize == 1) {
1887 u_char ttl;
1888 error = soopt_to_kbuf(sopt, &ttl, 1, 1);
1889 if (error)
1890 break;
1891 imo->imo_multicast_ttl = ttl;
1892 } else {
1893 u_int ttl;
1894 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl);
1895 if (error)
1896 break;
1897 if (ttl > 255)
1898 error = EINVAL;
1899 else
1900 imo->imo_multicast_ttl = ttl;
1901 }
1902 break;
1903
1904 case IP_MULTICAST_LOOP:
1905 /*
1906 * Set the loopback flag for outgoing multicast packets.
1907 * Must be zero or one. The original multicast API required a
1908 * char argument, which is inconsistent with the rest
1909 * of the socket API. We allow either a char or an int.
1910 */
1911 if (sopt->sopt_valsize == 1) {
1912 u_char loop;
1913
1914 error = soopt_to_kbuf(sopt, &loop, 1, 1);
1915 if (error)
1916 break;
1917 imo->imo_multicast_loop = !!loop;
1918 } else {
1919 u_int loop;
1920
1921 error = soopt_to_kbuf(sopt, &loop, sizeof loop,
1922 sizeof loop);
1923 if (error)
1924 break;
1925 imo->imo_multicast_loop = !!loop;
1926 }
1927 break;
1928
1929 case IP_ADD_MEMBERSHIP:
1930 /*
1931 * Add a multicast group membership.
1932 * Group must be a valid IP multicast address.
1933 */
1934 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq);
1935 if (error)
1936 break;
1937
1938 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1939 error = EINVAL;
1940 break;
1941 }
1942 crit_enter();
1943 /*
1944 * If no interface address was provided, use the interface of
1945 * the route to the given multicast address.
1946 */
1947 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1948 struct sockaddr_in dst;
1949 struct rtentry *rt;
1950
1951 bzero(&dst, sizeof(struct sockaddr_in));
1952 dst.sin_len = sizeof(struct sockaddr_in);
1953 dst.sin_family = AF_INET;
1954 dst.sin_addr = mreq.imr_multiaddr;
1955 rt = rtlookup((struct sockaddr *)&dst);
1956 if (rt == NULL) {
1957 error = EADDRNOTAVAIL;
1958 crit_exit();
1959 break;
1960 }
1961 --rt->rt_refcnt;
1962 ifp = rt->rt_ifp;
1963 } else {
1964 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1965 }
1966
1967 /*
1968 * See if we found an interface, and confirm that it
1969 * supports multicast.
1970 */
1971 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1972 error = EADDRNOTAVAIL;
1973 crit_exit();
1974 break;
1975 }
1976 /*
1977 * See if the membership already exists or if all the
1978 * membership slots are full.
1979 */
1980 for (i = 0; i < imo->imo_num_memberships; ++i) {
1981 if (imo->imo_membership[i]->inm_ifp == ifp &&
1982 imo->imo_membership[i]->inm_addr.s_addr
1983 == mreq.imr_multiaddr.s_addr)
1984 break;
1985 }
1986 if (i < imo->imo_num_memberships) {
1987 error = EADDRINUSE;
1988 crit_exit();
1989 break;
1990 }
1991 if (i == IP_MAX_MEMBERSHIPS) {
1992 error = ETOOMANYREFS;
1993 crit_exit();
1994 break;
1995 }
1996 /*
1997 * Everything looks good; add a new record to the multicast
1998 * address list for the given interface.
1999 */
2000 if ((imo->imo_membership[i] =
2001 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
2002 error = ENOBUFS;
2003 crit_exit();
2004 break;
2005 }
2006 ++imo->imo_num_memberships;
2007 crit_exit();
2008 break;
2009
2010 case IP_DROP_MEMBERSHIP:
2011 /*
2012 * Drop a multicast group membership.
2013 * Group must be a valid IP multicast address.
2014 */
2015 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq);
2016 if (error)
2017 break;
2018
2019 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
2020 error = EINVAL;
2021 break;
2022 }
2023
2024 crit_enter();
2025 /*
2026 * If an interface address was specified, get a pointer
2027 * to its ifnet structure.
2028 */
2029 if (mreq.imr_interface.s_addr == INADDR_ANY)
2030 ifp = NULL;
2031 else {
2032 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
2033 if (ifp == NULL) {
2034 error = EADDRNOTAVAIL;
2035 crit_exit();
2036 break;
2037 }
2038 }
2039 /*
2040 * Find the membership in the membership array.
2041 */
2042 for (i = 0; i < imo->imo_num_memberships; ++i) {
2043 if ((ifp == NULL ||
2044 imo->imo_membership[i]->inm_ifp == ifp) &&
2045 imo->imo_membership[i]->inm_addr.s_addr ==
2046 mreq.imr_multiaddr.s_addr)
2047 break;
2048 }
2049 if (i == imo->imo_num_memberships) {
2050 error = EADDRNOTAVAIL;
2051 crit_exit();
2052 break;
2053 }
2054 /*
2055 * Give up the multicast address record to which the
2056 * membership points.
2057 */
2058 in_delmulti(imo->imo_membership[i]);
2059 /*
2060 * Remove the gap in the membership array.
2061 */
2062 for (++i; i < imo->imo_num_memberships; ++i)
2063 imo->imo_membership[i-1] = imo->imo_membership[i];
2064 --imo->imo_num_memberships;
2065 crit_exit();
2066 break;
2067
2068 default:
2069 error = EOPNOTSUPP;
2070 break;
2071 }
2072
2073 /*
2074 * If all options have default values, no need to keep the mbuf.
2075 */
2076 if (imo->imo_multicast_ifp == NULL &&
2077 imo->imo_multicast_vif == -1 &&
2078 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
2079 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
2080 imo->imo_num_memberships == 0) {
2081 kfree(*imop, M_IPMOPTS);
2082 *imop = NULL;
2083 }
2084
2085 return (error);
2086 }
2087
2088 /*
2089 * Return the IP multicast options in response to user getsockopt().
2090 */
2091 static int
2092 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo)
2093 {
2094 struct in_addr addr;
2095 struct in_ifaddr *ia;
2096 int error, optval;
2097 u_char coptval;
2098
2099 error = 0;
2100 switch (sopt->sopt_name) {
2101 case IP_MULTICAST_VIF:
2102 if (imo != NULL)
2103 optval = imo->imo_multicast_vif;
2104 else
2105 optval = -1;
2106 soopt_from_kbuf(sopt, &optval, sizeof optval);
2107 break;
2108
2109 case IP_MULTICAST_IF:
2110 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2111 addr.s_addr = INADDR_ANY;
2112 else if (imo->imo_multicast_addr.s_addr) {
2113 /* return the value user has set */
2114 addr = imo->imo_multicast_addr;
2115 } else {
2116 ia = IFP_TO_IA(imo->imo_multicast_ifp);
2117 addr.s_addr = (ia == NULL) ? INADDR_ANY
2118 : IA_SIN(ia)->sin_addr.s_addr;
2119 }
2120 soopt_from_kbuf(sopt, &addr, sizeof addr);
2121 break;
2122
2123 case IP_MULTICAST_TTL:
2124 if (imo == NULL)
2125 optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2126 else
2127 optval = coptval = imo->imo_multicast_ttl;
2128 if (sopt->sopt_valsize == 1)
2129 soopt_from_kbuf(sopt, &coptval, 1);
2130 else
2131 soopt_from_kbuf(sopt, &optval, sizeof optval);
2132 break;
2133
2134 case IP_MULTICAST_LOOP:
2135 if (imo == NULL)
2136 optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2137 else
2138 optval = coptval = imo->imo_multicast_loop;
2139 if (sopt->sopt_valsize == 1)
2140 soopt_from_kbuf(sopt, &coptval, 1);
2141 else
2142 soopt_from_kbuf(sopt, &optval, sizeof optval);
2143 break;
2144
2145 default:
2146 error = ENOPROTOOPT;
2147 break;
2148 }
2149 return (error);
2150 }
2151
2152 /*
2153 * Discard the IP multicast options.
2154 */
2155 void
2156 ip_freemoptions(struct ip_moptions *imo)
2157 {
2158 int i;
2159
2160 if (imo != NULL) {
2161 for (i = 0; i < imo->imo_num_memberships; ++i)
2162 in_delmulti(imo->imo_membership[i]);
2163 kfree(imo, M_IPMOPTS);
2164 }
2165 }
2166
2167 /*
2168 * Routine called from ip_output() to loop back a copy of an IP multicast
2169 * packet to the input queue of a specified interface. Note that this
2170 * calls the output routine of the loopback "driver", but with an interface
2171 * pointer that might NOT be a loopback interface -- evil, but easier than
2172 * replicating that code here.
2173 */
2174 static void
2175 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
2176 int hlen)
2177 {
2178 struct ip *ip;
2179 struct mbuf *copym;
2180
2181 copym = m_copypacket(m, MB_DONTWAIT);
2182 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2183 copym = m_pullup(copym, hlen);
2184 if (copym != NULL) {
2185 /*
2186 * if the checksum hasn't been computed, mark it as valid
2187 */
2188 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2189 in_delayed_cksum(copym);
2190 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
2191 copym->m_pkthdr.csum_flags |=
2192 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2193 copym->m_pkthdr.csum_data = 0xffff;
2194 }
2195 /*
2196 * We don't bother to fragment if the IP length is greater
2197 * than the interface's MTU. Can this possibly matter?
2198 */
2199 ip = mtod(copym, struct ip *);
2200 ip->ip_len = htons(ip->ip_len);
2201 ip->ip_off = htons(ip->ip_off);
2202 ip->ip_sum = 0;
2203 if (ip->ip_vhl == IP_VHL_BORING) {
2204 ip->ip_sum = in_cksum_hdr(ip);
2205 } else {
2206 ip->ip_sum = in_cksum(copym, hlen);
2207 }
2208 /*
2209 * NB:
2210 * It's not clear whether there are any lingering
2211 * reentrancy problems in other areas which might
2212 * be exposed by using ip_input directly (in
2213 * particular, everything which modifies the packet
2214 * in-place). Yet another option is using the
2215 * protosw directly to deliver the looped back
2216 * packet. For the moment, we'll err on the side
2217 * of safety by using if_simloop().
2218 */
2219 #if 1 /* XXX */
2220 if (dst->sin_family != AF_INET) {
2221 kprintf("ip_mloopback: bad address family %d\n",
2222 dst->sin_family);
2223 dst->sin_family = AF_INET;
2224 }
2225 #endif
2226
2227 #ifdef notdef
2228 copym->m_pkthdr.rcvif = ifp;
2229 ip_input(copym);
2230 #else
2231 if_simloop(ifp, copym, dst->sin_family, 0);
2232 #endif
2233 }
2234 }
MP support for (parts of) the network stack