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tcp: Don't assume power of 2 netisrs.
[dragonfly.git] / sys / netinet / ip_output.c
blob00d8717144b833109c1a7fb2a319dd463ff7eb16
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 */
32
33 #define _IP_VHL
34
35 #include "opt_ipdn.h"
36 #include "opt_ipdivert.h"
37 #include "opt_ipsec.h"
38 #include "opt_mbuf_stress_test.h"
39 #include "opt_mpls.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/protosw.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/proc.h>
50 #include <sys/priv.h>
51 #include <sys/sysctl.h>
52 #include <sys/in_cksum.h>
53 #include <sys/lock.h>
54
55 #include <sys/thread2.h>
56 #include <sys/mplock2.h>
57 #include <sys/msgport2.h>
58
59 #include <net/if.h>
60 #include <net/netisr.h>
61 #include <net/pfil.h>
62 #include <net/route.h>
63
64 #include <netinet/in.h>
65 #include <netinet/in_systm.h>
66 #include <netinet/ip.h>
67 #include <netinet/in_pcb.h>
68 #include <netinet/in_var.h>
69 #include <netinet/ip_var.h>
70
71 #include <netproto/mpls/mpls_var.h>
72
73 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
74
75 #ifdef IPSEC
76 #include <netinet6/ipsec.h>
77 #include <netproto/key/key.h>
78 #ifdef IPSEC_DEBUG
79 #include <netproto/key/key_debug.h>
80 #else
81 #define KEYDEBUG(lev,arg)
82 #endif
83 #endif /*IPSEC*/
84
85 #ifdef FAST_IPSEC
86 #include <netproto/ipsec/ipsec.h>
87 #include <netproto/ipsec/xform.h>
88 #include <netproto/ipsec/key.h>
89 #endif /*FAST_IPSEC*/
90
91 #include <net/ipfw/ip_fw.h>
92 #include <net/dummynet/ip_dummynet.h>
93
94 #define print_ip(x, a, y) kprintf("%s %d.%d.%d.%d%s",\
95 x, (ntohl(a.s_addr)>>24)&0xFF,\
96 (ntohl(a.s_addr)>>16)&0xFF,\
97 (ntohl(a.s_addr)>>8)&0xFF,\
98 (ntohl(a.s_addr))&0xFF, y);
99
100 u_short ip_id;
101
102 #ifdef MBUF_STRESS_TEST
103 int mbuf_frag_size = 0;
104 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
105 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
106 #endif
107
108 static int ip_do_rfc6864 = 1;
109 SYSCTL_INT(_net_inet_ip, OID_AUTO, rfc6864, CTLFLAG_RW, &ip_do_rfc6864, 0,
110 "Don't generate IP ID for DF IP datagrams");
111
112 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
113 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
114 static void ip_mloopback
115 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
116 static int ip_getmoptions
117 (struct sockopt *, struct ip_moptions *);
118 static int ip_pcbopts(int, struct mbuf **, struct mbuf *);
119 static int ip_setmoptions
120 (struct sockopt *, struct ip_moptions **);
121
122 int ip_optcopy(struct ip *, struct ip *);
123
124 extern struct protosw inetsw[];
125
126 static int
127 ip_localforward(struct mbuf *m, const struct sockaddr_in *dst, int hlen)
128 {
129 struct in_ifaddr_container *iac;
130
131 /*
132 * We need to figure out if we have been forwarded to a local
133 * socket. If so, then we should somehow "loop back" to
134 * ip_input(), and get directed to the PCB as if we had received
135 * this packet. This is because it may be difficult to identify
136 * the packets you want to forward until they are being output
137 * and have selected an interface (e.g. locally initiated
138 * packets). If we used the loopback inteface, we would not be
139 * able to control what happens as the packet runs through
140 * ip_input() as it is done through a ISR.
141 */
142 LIST_FOREACH(iac, INADDR_HASH(dst->sin_addr.s_addr), ia_hash) {
143 /*
144 * If the addr to forward to is one of ours, we pretend
145 * to be the destination for this packet.
146 */
147 if (IA_SIN(iac->ia)->sin_addr.s_addr == dst->sin_addr.s_addr)
148 break;
149 }
150 if (iac != NULL) {
151 struct ip *ip;
152
153 if (m->m_pkthdr.rcvif == NULL)
154 m->m_pkthdr.rcvif = ifunit_netisr("lo0");
155 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
156 m->m_pkthdr.csum_flags |= CSUM_DATA_VALID |
157 CSUM_PSEUDO_HDR;
158 m->m_pkthdr.csum_data = 0xffff;
159 }
160 m->m_pkthdr.csum_flags |= CSUM_IP_CHECKED | CSUM_IP_VALID;
161
162 /*
163 * Make sure that the IP header is in one mbuf,
164 * required by ip_input
165 */
166 if (m->m_len < hlen) {
167 m = m_pullup(m, hlen);
168 if (m == NULL) {
169 /* The packet was freed; we are done */
170 return 1;
171 }
172 }
173 ip = mtod(m, struct ip *);
174
175 ip->ip_len = htons(ip->ip_len);
176 ip->ip_off = htons(ip->ip_off);
177 ip_input(m);
178
179 return 1; /* The packet gets forwarded locally */
180 }
181 return 0;
182 }
183
184 /*
185 * IP output. The packet in mbuf chain m contains a skeletal IP
186 * header (with len, off, ttl, proto, tos, src, dst).
187 * The mbuf chain containing the packet will be freed.
188 * The mbuf opt, if present, will not be freed.
189 */
190 int
191 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
192 int flags, struct ip_moptions *imo, struct inpcb *inp)
193 {
194 struct ip *ip;
195 struct ifnet *ifp = NULL; /* keep compiler happy */
196 struct mbuf *m;
197 int hlen = sizeof(struct ip);
198 int len, error = 0;
199 struct sockaddr_in *dst = NULL; /* keep compiler happy */
200 struct in_ifaddr *ia = NULL;
201 int isbroadcast, sw_csum;
202 struct in_addr pkt_dst;
203 struct route iproute;
204 struct m_tag *mtag;
205 #ifdef IPSEC
206 struct secpolicy *sp = NULL;
207 struct socket *so = inp ? inp->inp_socket : NULL;
208 #endif
209 #ifdef FAST_IPSEC
210 struct secpolicy *sp = NULL;
211 struct tdb_ident *tdbi;
212 #endif /* FAST_IPSEC */
213 struct sockaddr_in *next_hop = NULL;
214 int src_was_INADDR_ANY = 0; /* as the name says... */
215
216 m = m0;
217 M_ASSERTPKTHDR(m);
218
219 if (ro == NULL) {
220 ro = &iproute;
221 bzero(ro, sizeof *ro);
222 } else if (ro->ro_rt != NULL && ro->ro_rt->rt_cpuid != mycpuid) {
223 if (flags & IP_DEBUGROUTE) {
224 panic("ip_output: rt rt_cpuid %d accessed on cpu %d\n",
225 ro->ro_rt->rt_cpuid, mycpuid);
226 }
227
228 /*
229 * XXX
230 * If the cached rtentry's owner CPU is not the current CPU,
231 * then don't touch the cached rtentry (remote free is too
232 * expensive in this context); just relocate the route.
233 */
234 ro = &iproute;
235 bzero(ro, sizeof *ro);
236 }
237
238 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
239 /* Next hop */
240 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
241 KKASSERT(mtag != NULL);
242 next_hop = m_tag_data(mtag);
243 }
244
245 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
246 struct dn_pkt *dn_pkt;
247
248 /* Extract info from dummynet tag */
249 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
250 KKASSERT(mtag != NULL);
251 dn_pkt = m_tag_data(mtag);
252
253 /*
254 * The packet was already tagged, so part of the
255 * processing was already done, and we need to go down.
256 * Get the calculated parameters from the tag.
257 */
258 ifp = dn_pkt->ifp;
259
260 KKASSERT(ro == &iproute);
261 *ro = dn_pkt->ro; /* structure copy */
262 KKASSERT(ro->ro_rt == NULL || ro->ro_rt->rt_cpuid == mycpuid);
263
264 dst = dn_pkt->dn_dst;
265 if (dst == (struct sockaddr_in *)&(dn_pkt->ro.ro_dst)) {
266 /* If 'dst' points into dummynet tag, adjust it */
267 dst = (struct sockaddr_in *)&(ro->ro_dst);
268 }
269
270 ip = mtod(m, struct ip *);
271 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
272 if (ro->ro_rt)
273 ia = ifatoia(ro->ro_rt->rt_ifa);
274 goto sendit;
275 }
276
277 if (opt) {
278 len = 0;
279 m = ip_insertoptions(m, opt, &len);
280 if (len != 0)
281 hlen = len;
282 }
283 ip = mtod(m, struct ip *);
284
285 /*
286 * Fill in IP header.
287 */
288 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) {
289 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
290 ip->ip_off &= IP_DF;
291 if (ip_do_rfc6864 && (ip->ip_off & IP_DF))
292 ip->ip_id = 0;
293 else
294 ip->ip_id = ip_newid();
295 ipstat.ips_localout++;
296 } else {
297 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
298 }
299
300 reroute:
301 pkt_dst = next_hop ? next_hop->sin_addr : ip->ip_dst;
302
303 dst = (struct sockaddr_in *)&ro->ro_dst;
304 /*
305 * If there is a cached route,
306 * check that it is to the same destination
307 * and is still up. If not, free it and try again.
308 * The address family should also be checked in case of sharing the
309 * cache with IPv6.
310 */
311 if (ro->ro_rt &&
312 (!(ro->ro_rt->rt_flags & RTF_UP) ||
313 dst->sin_family != AF_INET ||
314 dst->sin_addr.s_addr != pkt_dst.s_addr)) {
315 rtfree(ro->ro_rt);
316 ro->ro_rt = NULL;
317 }
318 if (ro->ro_rt == NULL) {
319 bzero(dst, sizeof *dst);
320 dst->sin_family = AF_INET;
321 dst->sin_len = sizeof *dst;
322 dst->sin_addr = pkt_dst;
323 }
324 /*
325 * If routing to interface only,
326 * short circuit routing lookup.
327 */
328 if (flags & IP_ROUTETOIF) {
329 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
330 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
331 ipstat.ips_noroute++;
332 error = ENETUNREACH;
333 goto bad;
334 }
335 ifp = ia->ia_ifp;
336 ip->ip_ttl = 1;
337 isbroadcast = in_broadcast(dst->sin_addr, ifp);
338 } else if (IN_MULTICAST(ntohl(pkt_dst.s_addr)) &&
339 imo != NULL && imo->imo_multicast_ifp != NULL) {
340 /*
341 * Bypass the normal routing lookup for multicast
342 * packets if the interface is specified.
343 */
344 ifp = imo->imo_multicast_ifp;
345 ia = IFP_TO_IA(ifp);
346 isbroadcast = 0; /* fool gcc */
347 } else {
348 /*
349 * If this is the case, we probably don't want to allocate
350 * a protocol-cloned route since we didn't get one from the
351 * ULP. This lets TCP do its thing, while not burdening
352 * forwarding or ICMP with the overhead of cloning a route.
353 * Of course, we still want to do any cloning requested by
354 * the link layer, as this is probably required in all cases
355 * for correct operation (as it is for ARP).
356 */
357 if (ro->ro_rt == NULL)
358 rtalloc_ign(ro, RTF_PRCLONING);
359 if (ro->ro_rt == NULL) {
360 ipstat.ips_noroute++;
361 error = EHOSTUNREACH;
362 goto bad;
363 }
364 ia = ifatoia(ro->ro_rt->rt_ifa);
365 ifp = ro->ro_rt->rt_ifp;
366 ro->ro_rt->rt_use++;
367 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
368 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
369 if (ro->ro_rt->rt_flags & RTF_HOST)
370 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
371 else
372 isbroadcast = in_broadcast(dst->sin_addr, ifp);
373 }
374 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
375 m->m_flags |= M_MCAST;
376 /*
377 * IP destination address is multicast. Make sure "dst"
378 * still points to the address in "ro". (It may have been
379 * changed to point to a gateway address, above.)
380 */
381 dst = (struct sockaddr_in *)&ro->ro_dst;
382 /*
383 * See if the caller provided any multicast options
384 */
385 if (imo != NULL) {
386 ip->ip_ttl = imo->imo_multicast_ttl;
387 if (imo->imo_multicast_vif != -1) {
388 ip->ip_src.s_addr =
389 ip_mcast_src ?
390 ip_mcast_src(imo->imo_multicast_vif) :
391 INADDR_ANY;
392 }
393 } else {
394 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
395 }
396 /*
397 * Confirm that the outgoing interface supports multicast.
398 */
399 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
400 if (!(ifp->if_flags & IFF_MULTICAST)) {
401 ipstat.ips_noroute++;
402 error = ENETUNREACH;
403 goto bad;
404 }
405 }
406 /*
407 * If source address not specified yet, use address of the
408 * outgoing interface. In case, keep note we did that, so
409 * if the the firewall changes the next-hop causing the
410 * output interface to change, we can fix that.
411 */
412 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) {
413 /* Interface may have no addresses. */
414 if (ia != NULL) {
415 ip->ip_src = IA_SIN(ia)->sin_addr;
416 src_was_INADDR_ANY = 1;
417 }
418 }
419
420 if (ip->ip_src.s_addr != INADDR_ANY) {
421 struct in_multi *inm;
422
423 inm = IN_LOOKUP_MULTI(&pkt_dst, ifp);
424 if (inm != NULL &&
425 (imo == NULL || imo->imo_multicast_loop)) {
426 /*
427 * If we belong to the destination multicast
428 * group on the outgoing interface, and the
429 * caller did not forbid loopback, loop back
430 * a copy.
431 */
432 ip_mloopback(ifp, m, dst, hlen);
433 } else {
434 /*
435 * If we are acting as a multicast router,
436 * perform multicast forwarding as if the
437 * packet had just arrived on the interface
438 * to which we are about to send. The
439 * multicast forwarding function recursively
440 * calls this function, using the IP_FORWARDING
441 * flag to prevent infinite recursion.
442 *
443 * Multicasts that are looped back by
444 * ip_mloopback(), above, will be forwarded by
445 * the ip_input() routine, if necessary.
446 */
447 if (ip_mrouter && !(flags & IP_FORWARDING)) {
448 /*
449 * If rsvp daemon is not running, do
450 * not set ip_moptions. This ensures
451 * that the packet is multicast and
452 * not just sent down one link as
453 * prescribed by rsvpd.
454 */
455 if (!rsvp_on)
456 imo = NULL;
457 if (ip_mforward) {
458 get_mplock();
459 if (ip_mforward(ip, ifp,
460 m, imo) != 0) {
461 m_freem(m);
462 rel_mplock();
463 goto done;
464 }
465 rel_mplock();
466 }
467 }
468 }
469 }
470
471 /*
472 * Multicasts with a time-to-live of zero may be looped-
473 * back, above, but must not be transmitted on a network.
474 * Also, multicasts addressed to the loopback interface
475 * are not sent -- the above call to ip_mloopback() will
476 * loop back a copy if this host actually belongs to the
477 * destination group on the loopback interface.
478 */
479 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
480 m_freem(m);
481 goto done;
482 }
483
484 goto sendit;
485 } else {
486 m->m_flags &= ~M_MCAST;
487 }
488
489 /*
490 * If the source address is not specified yet, use the address
491 * of the outgoing interface. In case, keep note we did that,
492 * so if the the firewall changes the next-hop causing the output
493 * interface to change, we can fix that.
494 */
495 if (ip->ip_src.s_addr == INADDR_ANY || src_was_INADDR_ANY) {
496 /* Interface may have no addresses. */
497 if (ia != NULL) {
498 ip->ip_src = IA_SIN(ia)->sin_addr;
499 src_was_INADDR_ANY = 1;
500 }
501 }
502
503 /*
504 * Look for broadcast address and
505 * verify user is allowed to send
506 * such a packet.
507 */
508 if (isbroadcast) {
509 if (!(ifp->if_flags & IFF_BROADCAST)) {
510 error = EADDRNOTAVAIL;
511 goto bad;
512 }
513 if (!(flags & IP_ALLOWBROADCAST)) {
514 error = EACCES;
515 goto bad;
516 }
517 /* don't allow broadcast messages to be fragmented */
518 if (ip->ip_len > ifp->if_mtu) {
519 error = EMSGSIZE;
520 goto bad;
521 }
522 m->m_flags |= M_BCAST;
523 } else {
524 m->m_flags &= ~M_BCAST;
525 }
526
527 sendit:
528 #ifdef IPSEC
529 /* get SP for this packet */
530 if (so == NULL)
531 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
532 else
533 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
534
535 if (sp == NULL) {
536 ipsecstat.out_inval++;
537 goto bad;
538 }
539
540 error = 0;
541
542 /* check policy */
543 switch (sp->policy) {
544 case IPSEC_POLICY_DISCARD:
545 /*
546 * This packet is just discarded.
547 */
548 ipsecstat.out_polvio++;
549 goto bad;
550
551 case IPSEC_POLICY_BYPASS:
552 case IPSEC_POLICY_NONE:
553 case IPSEC_POLICY_TCP:
554 /* no need to do IPsec. */
555 goto skip_ipsec;
556
557 case IPSEC_POLICY_IPSEC:
558 if (sp->req == NULL) {
559 /* acquire a policy */
560 error = key_spdacquire(sp);
561 goto bad;
562 }
563 break;
564
565 case IPSEC_POLICY_ENTRUST:
566 default:
567 kprintf("ip_output: Invalid policy found. %d\n", sp->policy);
568 }
569 {
570 struct ipsec_output_state state;
571 bzero(&state, sizeof state);
572 state.m = m;
573 if (flags & IP_ROUTETOIF) {
574 state.ro = &iproute;
575 bzero(&iproute, sizeof iproute);
576 } else
577 state.ro = ro;
578 state.dst = (struct sockaddr *)dst;
579
580 ip->ip_sum = 0;
581
582 /*
583 * XXX
584 * delayed checksums are not currently compatible with IPsec
585 */
586 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
587 in_delayed_cksum(m);
588 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
589 }
590
591 ip->ip_len = htons(ip->ip_len);
592 ip->ip_off = htons(ip->ip_off);
593
594 error = ipsec4_output(&state, sp, flags);
595
596 m = state.m;
597 if (flags & IP_ROUTETOIF) {
598 /*
599 * if we have tunnel mode SA, we may need to ignore
600 * IP_ROUTETOIF.
601 */
602 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
603 flags &= ~IP_ROUTETOIF;
604 ro = state.ro;
605 }
606 } else
607 ro = state.ro;
608 dst = (struct sockaddr_in *)state.dst;
609 if (error) {
610 /* mbuf is already reclaimed in ipsec4_output. */
611 m0 = NULL;
612 switch (error) {
613 case EHOSTUNREACH:
614 case ENETUNREACH:
615 case EMSGSIZE:
616 case ENOBUFS:
617 case ENOMEM:
618 break;
619 default:
620 kprintf("ip4_output (ipsec): error code %d\n", error);
621 /*fall through*/
622 case ENOENT:
623 /* don't show these error codes to the user */
624 error = 0;
625 break;
626 }
627 goto bad;
628 }
629 }
630
631 /* be sure to update variables that are affected by ipsec4_output() */
632 ip = mtod(m, struct ip *);
633 #ifdef _IP_VHL
634 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
635 #else
636 hlen = ip->ip_hl << 2;
637 #endif
638 if (ro->ro_rt == NULL) {
639 if (!(flags & IP_ROUTETOIF)) {
640 kprintf("ip_output: "
641 "can't update route after IPsec processing\n");
642 error = EHOSTUNREACH; /*XXX*/
643 goto bad;
644 }
645 } else {
646 ia = ifatoia(ro->ro_rt->rt_ifa);
647 ifp = ro->ro_rt->rt_ifp;
648 }
649
650 /* make it flipped, again. */
651 ip->ip_len = ntohs(ip->ip_len);
652 ip->ip_off = ntohs(ip->ip_off);
653 skip_ipsec:
654 #endif /*IPSEC*/
655 #ifdef FAST_IPSEC
656 /*
657 * Check the security policy (SP) for the packet and, if
658 * required, do IPsec-related processing. There are two
659 * cases here; the first time a packet is sent through
660 * it will be untagged and handled by ipsec4_checkpolicy.
661 * If the packet is resubmitted to ip_output (e.g. after
662 * AH, ESP, etc. processing), there will be a tag to bypass
663 * the lookup and related policy checking.
664 */
665 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
666 crit_enter();
667 if (mtag != NULL) {
668 tdbi = (struct tdb_ident *)m_tag_data(mtag);
669 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
670 if (sp == NULL)
671 error = -EINVAL; /* force silent drop */
672 m_tag_delete(m, mtag);
673 } else {
674 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
675 &error, inp);
676 }
677 /*
678 * There are four return cases:
679 * sp != NULL apply IPsec policy
680 * sp == NULL, error == 0 no IPsec handling needed
681 * sp == NULL, error == -EINVAL discard packet w/o error
682 * sp == NULL, error != 0 discard packet, report error
683 */
684 if (sp != NULL) {
685 /* Loop detection, check if ipsec processing already done */
686 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
687 for (mtag = m_tag_first(m); mtag != NULL;
688 mtag = m_tag_next(m, mtag)) {
689 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
690 continue;
691 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
692 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
693 continue;
694 /*
695 * Check if policy has an SA associated with it.
696 * This can happen when an SP has yet to acquire
697 * an SA; e.g. on first reference. If it occurs,
698 * then we let ipsec4_process_packet do its thing.
699 */
700 if (sp->req->sav == NULL)
701 break;
702 tdbi = (struct tdb_ident *)m_tag_data(mtag);
703 if (tdbi->spi == sp->req->sav->spi &&
704 tdbi->proto == sp->req->sav->sah->saidx.proto &&
705 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
706 sizeof(union sockaddr_union)) == 0) {
707 /*
708 * No IPsec processing is needed, free
709 * reference to SP.
710 *
711 * NB: null pointer to avoid free at
712 * done: below.
713 */
714 KEY_FREESP(&sp), sp = NULL;
715 crit_exit();
716 goto spd_done;
717 }
718 }
719
720 /*
721 * Do delayed checksums now because we send before
722 * this is done in the normal processing path.
723 */
724 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
725 in_delayed_cksum(m);
726 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
727 }
728
729 ip->ip_len = htons(ip->ip_len);
730 ip->ip_off = htons(ip->ip_off);
731
732 /* NB: callee frees mbuf */
733 error = ipsec4_process_packet(m, sp->req, flags, 0);
734 /*
735 * Preserve KAME behaviour: ENOENT can be returned
736 * when an SA acquire is in progress. Don't propagate
737 * this to user-level; it confuses applications.
738 *
739 * XXX this will go away when the SADB is redone.
740 */
741 if (error == ENOENT)
742 error = 0;
743 crit_exit();
744 goto done;
745 } else {
746 crit_exit();
747
748 if (error != 0) {
749 /*
750 * Hack: -EINVAL is used to signal that a packet
751 * should be silently discarded. This is typically
752 * because we asked key management for an SA and
753 * it was delayed (e.g. kicked up to IKE).
754 */
755 if (error == -EINVAL)
756 error = 0;
757 goto bad;
758 } else {
759 /* No IPsec processing for this packet. */
760 }
761 #ifdef notyet
762 /*
763 * If deferred crypto processing is needed, check that
764 * the interface supports it.
765 */
766 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
767 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) {
768 /* notify IPsec to do its own crypto */
769 ipsp_skipcrypto_unmark((struct tdb_ident *)m_tag_data(mtag));
770 error = EHOSTUNREACH;
771 goto bad;
772 }
773 #endif
774 }
775 spd_done:
776 #endif /* FAST_IPSEC */
777
778 /* We are already being fwd'd from a firewall. */
779 if (next_hop != NULL)
780 goto pass;
781
782 /* No pfil hooks */
783 if (!pfil_has_hooks(&inet_pfil_hook)) {
784 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
785 /*
786 * Strip dummynet tags from stranded packets
787 */
788 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
789 KKASSERT(mtag != NULL);
790 m_tag_delete(m, mtag);
791 m->m_pkthdr.fw_flags &= ~DUMMYNET_MBUF_TAGGED;
792 }
793 goto pass;
794 }
795
796 /*
797 * IpHack's section.
798 * - Xlate: translate packet's addr/port (NAT).
799 * - Firewall: deny/allow/etc.
800 * - Wrap: fake packet's addr/port <unimpl.>
801 * - Encapsulate: put it in another IP and send out. <unimp.>
802 */
803
804 /*
805 * Run through list of hooks for output packets.
806 */
807 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
808 if (error != 0 || m == NULL)
809 goto done;
810 ip = mtod(m, struct ip *);
811
812 if (m->m_pkthdr.fw_flags & IPFORWARD_MBUF_TAGGED) {
813 /*
814 * Check dst to make sure it is directly reachable on the
815 * interface we previously thought it was.
816 * If it isn't (which may be likely in some situations) we have
817 * to re-route it (ie, find a route for the next-hop and the
818 * associated interface) and set them here. This is nested
819 * forwarding which in most cases is undesirable, except where
820 * such control is nigh impossible. So we do it here.
821 * And I'm babbling.
822 */
823 mtag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
824 KKASSERT(mtag != NULL);
825 next_hop = m_tag_data(mtag);
826
827 /*
828 * Try local forwarding first
829 */
830 if (ip_localforward(m, next_hop, hlen))
831 goto done;
832
833 /*
834 * Relocate the route based on next_hop.
835 * If the current route is inp's cache, keep it untouched.
836 */
837 if (ro == &iproute && ro->ro_rt != NULL) {
838 RTFREE(ro->ro_rt);
839 ro->ro_rt = NULL;
840 }
841 ro = &iproute;
842 bzero(ro, sizeof *ro);
843
844 /*
845 * Forwarding to broadcast address is not allowed.
846 * XXX Should we follow IP_ROUTETOIF?
847 */
848 flags &= ~(IP_ALLOWBROADCAST | IP_ROUTETOIF);
849
850 /* We are doing forwarding now */
851 flags |= IP_FORWARDING;
852
853 goto reroute;
854 }
855
856 if (m->m_pkthdr.fw_flags & DUMMYNET_MBUF_TAGGED) {
857 struct dn_pkt *dn_pkt;
858
859 mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
860 KKASSERT(mtag != NULL);
861 dn_pkt = m_tag_data(mtag);
862
863 /*
864 * Under certain cases it is not possible to recalculate
865 * 'ro' and 'dst', let alone 'flags', so just save them in
866 * dummynet tag and avoid the possible wrong reculcalation
867 * when we come back to ip_output() again.
868 *
869 * All other parameters have been already used and so they
870 * are not needed anymore.
871 * XXX if the ifp is deleted while a pkt is in dummynet,
872 * we are in trouble! (TODO use ifnet_detach_event)
873 *
874 * We need to copy *ro because for ICMP pkts (and maybe
875 * others) the caller passed a pointer into the stack;
876 * dst might also be a pointer into *ro so it needs to
877 * be updated.
878 */
879 dn_pkt->ro = *ro;
880 if (ro->ro_rt)
881 ro->ro_rt->rt_refcnt++;
882 if (dst == (struct sockaddr_in *)&ro->ro_dst) {
883 /* 'dst' points into 'ro' */
884 dst = (struct sockaddr_in *)&(dn_pkt->ro.ro_dst);
885 }
886 dn_pkt->dn_dst = dst;
887 dn_pkt->flags = flags;
888
889 ip_dn_queue(m);
890 goto done;
891 }
892 pass:
893 /* 127/8 must not appear on wire - RFC1122. */
894 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
895 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
896 if (!(ifp->if_flags & IFF_LOOPBACK)) {
897 ipstat.ips_badaddr++;
898 error = EADDRNOTAVAIL;
899 goto bad;
900 }
901 }
902 if (ip->ip_src.s_addr == INADDR_ANY ||
903 IN_MULTICAST(ntohl(ip->ip_src.s_addr))) {
904 ipstat.ips_badaddr++;
905 error = EADDRNOTAVAIL;
906 goto bad;
907 }
908
909 if ((m->m_pkthdr.csum_flags & CSUM_TSO) == 0) {
910 m->m_pkthdr.csum_flags |= CSUM_IP;
911 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
912 if (sw_csum & CSUM_DELAY_DATA) {
913 in_delayed_cksum(m);
914 sw_csum &= ~CSUM_DELAY_DATA;
915 }
916 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
917 } else {
918 sw_csum = 0;
919 }
920 m->m_pkthdr.csum_iphlen = hlen;
921
922 /*
923 * If small enough for interface, or the interface will take
924 * care of the fragmentation or segmentation for us, can just
925 * send directly.
926 */
927 if (ip->ip_len <= ifp->if_mtu ||
928 ((ifp->if_hwassist & CSUM_FRAGMENT) && !(ip->ip_off & IP_DF)) ||
929 (m->m_pkthdr.csum_flags & CSUM_TSO)) {
930 ip->ip_len = htons(ip->ip_len);
931 ip->ip_off = htons(ip->ip_off);
932 ip->ip_sum = 0;
933 if (sw_csum & CSUM_DELAY_IP) {
934 if (ip->ip_vhl == IP_VHL_BORING)
935 ip->ip_sum = in_cksum_hdr(ip);
936 else
937 ip->ip_sum = in_cksum(m, hlen);
938 }
939
940 /* Record statistics for this interface address. */
941 if (!(flags & IP_FORWARDING) && ia) {
942 IFA_STAT_INC(&ia->ia_ifa, opackets, 1);
943 IFA_STAT_INC(&ia->ia_ifa, obytes, m->m_pkthdr.len);
944 }
945
946 #ifdef IPSEC
947 /* clean ipsec history once it goes out of the node */
948 ipsec_delaux(m);
949 #endif
950
951 #ifdef MBUF_STRESS_TEST
952 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
953 struct mbuf *m1, *m2;
954 int length, tmp;
955
956 tmp = length = m->m_pkthdr.len;
957
958 while ((length -= mbuf_frag_size) >= 1) {
959 m1 = m_split(m, length, M_NOWAIT);
960 if (m1 == NULL)
961 break;
962 m2 = m;
963 while (m2->m_next != NULL)
964 m2 = m2->m_next;
965 m2->m_next = m1;
966 }
967 m->m_pkthdr.len = tmp;
968 }
969 #endif
970
971 #ifdef MPLS
972 if (!mpls_output_process(m, ro->ro_rt))
973 goto done;
974 #endif
975 error = ifp->if_output(ifp, m, (struct sockaddr *)dst,
976 ro->ro_rt);
977 goto done;
978 }
979
980 if (ip->ip_off & IP_DF) {
981 error = EMSGSIZE;
982 /*
983 * This case can happen if the user changed the MTU
984 * of an interface after enabling IP on it. Because
985 * most netifs don't keep track of routes pointing to
986 * them, there is no way for one to update all its
987 * routes when the MTU is changed.
988 */
989 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) &&
990 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
991 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
992 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
993 }
994 ipstat.ips_cantfrag++;
995 goto bad;
996 }
997
998 /*
999 * Too large for interface; fragment if possible. If successful,
1000 * on return, m will point to a list of packets to be sent.
1001 */
1002 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum);
1003 if (error)
1004 goto bad;
1005 for (; m; m = m0) {
1006 m0 = m->m_nextpkt;
1007 m->m_nextpkt = NULL;
1008 #ifdef IPSEC
1009 /* clean ipsec history once it goes out of the node */
1010 ipsec_delaux(m);
1011 #endif
1012 if (error == 0) {
1013 /* Record statistics for this interface address. */
1014 if (ia != NULL) {
1015 IFA_STAT_INC(&ia->ia_ifa, opackets, 1);
1016 IFA_STAT_INC(&ia->ia_ifa, obytes,
1017 m->m_pkthdr.len);
1018 }
1019 #ifdef MPLS
1020 if (!mpls_output_process(m, ro->ro_rt))
1021 continue;
1022 #endif
1023 error = ifp->if_output(ifp, m, (struct sockaddr *)dst,
1024 ro->ro_rt);
1025 } else {
1026 m_freem(m);
1027 }
1028 }
1029
1030 if (error == 0)
1031 ipstat.ips_fragmented++;
1032
1033 done:
1034 if (ro == &iproute && ro->ro_rt != NULL) {
1035 RTFREE(ro->ro_rt);
1036 ro->ro_rt = NULL;
1037 }
1038 #ifdef IPSEC
1039 if (sp != NULL) {
1040 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1041 kprintf("DP ip_output call free SP:%p\n", sp));
1042 key_freesp(sp);
1043 }
1044 #endif
1045 #ifdef FAST_IPSEC
1046 if (sp != NULL)
1047 KEY_FREESP(&sp);
1048 #endif
1049 return (error);
1050 bad:
1051 m_freem(m);
1052 goto done;
1053 }
1054
1055 /*
1056 * Create a chain of fragments which fit the given mtu. m_frag points to the
1057 * mbuf to be fragmented; on return it points to the chain with the fragments.
1058 * Return 0 if no error. If error, m_frag may contain a partially built
1059 * chain of fragments that should be freed by the caller.
1060 *
1061 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1062 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1063 */
1064 int
1065 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1066 u_long if_hwassist_flags, int sw_csum)
1067 {
1068 int error = 0;
1069 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1070 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
1071 int off;
1072 struct mbuf *m0 = *m_frag; /* the original packet */
1073 int firstlen;
1074 struct mbuf **mnext;
1075 int nfrags;
1076
1077 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
1078 ipstat.ips_cantfrag++;
1079 return EMSGSIZE;
1080 }
1081
1082 /*
1083 * Must be able to put at least 8 bytes per fragment.
1084 */
1085 if (len < 8)
1086 return EMSGSIZE;
1087
1088 /*
1089 * If the interface will not calculate checksums on
1090 * fragmented packets, then do it here.
1091 */
1092 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) &&
1093 !(if_hwassist_flags & CSUM_IP_FRAGS)) {
1094 in_delayed_cksum(m0);
1095 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1096 }
1097
1098 if (len > PAGE_SIZE) {
1099 /*
1100 * Fragment large datagrams such that each segment
1101 * contains a multiple of PAGE_SIZE amount of data,
1102 * plus headers. This enables a receiver to perform
1103 * page-flipping zero-copy optimizations.
1104 *
1105 * XXX When does this help given that sender and receiver
1106 * could have different page sizes, and also mtu could
1107 * be less than the receiver's page size ?
1108 */
1109 int newlen;
1110 struct mbuf *m;
1111
1112 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1113 off += m->m_len;
1114
1115 /*
1116 * firstlen (off - hlen) must be aligned on an
1117 * 8-byte boundary
1118 */
1119 if (off < hlen)
1120 goto smart_frag_failure;
1121 off = ((off - hlen) & ~7) + hlen;
1122 newlen = (~PAGE_MASK) & mtu;
1123 if ((newlen + sizeof(struct ip)) > mtu) {
1124 /* we failed, go back the default */
1125 smart_frag_failure:
1126 newlen = len;
1127 off = hlen + len;
1128 }
1129 len = newlen;
1130
1131 } else {
1132 off = hlen + len;
1133 }
1134
1135 firstlen = off - hlen;
1136 mnext = &m0->m_nextpkt; /* pointer to next packet */
1137
1138 /*
1139 * Loop through length of segment after first fragment,
1140 * make new header and copy data of each part and link onto chain.
1141 * Here, m0 is the original packet, m is the fragment being created.
1142 * The fragments are linked off the m_nextpkt of the original
1143 * packet, which after processing serves as the first fragment.
1144 */
1145 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1146 struct ip *mhip; /* ip header on the fragment */
1147 struct mbuf *m;
1148 int mhlen = sizeof(struct ip);
1149
1150 MGETHDR(m, M_NOWAIT, MT_HEADER);
1151 if (m == NULL) {
1152 error = ENOBUFS;
1153 ipstat.ips_odropped++;
1154 goto done;
1155 }
1156 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1157 /*
1158 * In the first mbuf, leave room for the link header, then
1159 * copy the original IP header including options. The payload
1160 * goes into an additional mbuf chain returned by m_copy().
1161 */
1162 m->m_data += max_linkhdr;
1163 mhip = mtod(m, struct ip *);
1164 *mhip = *ip;
1165 if (hlen > sizeof(struct ip)) {
1166 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip);
1167 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1168 }
1169 m->m_len = mhlen;
1170 /* XXX do we need to add ip->ip_off below ? */
1171 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1172 if (off + len >= ip->ip_len) { /* last fragment */
1173 len = ip->ip_len - off;
1174 m->m_flags |= M_LASTFRAG;
1175 } else
1176 mhip->ip_off |= IP_MF;
1177 mhip->ip_len = htons((u_short)(len + mhlen));
1178 m->m_next = m_copy(m0, off, len);
1179 if (m->m_next == NULL) { /* copy failed */
1180 m_free(m);
1181 error = ENOBUFS; /* ??? */
1182 ipstat.ips_odropped++;
1183 goto done;
1184 }
1185 m->m_pkthdr.len = mhlen + len;
1186 m->m_pkthdr.rcvif = NULL;
1187 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1188 m->m_pkthdr.csum_iphlen = mhlen;
1189 mhip->ip_off = htons(mhip->ip_off);
1190 mhip->ip_sum = 0;
1191 if (sw_csum & CSUM_DELAY_IP)
1192 mhip->ip_sum = in_cksum(m, mhlen);
1193 *mnext = m;
1194 mnext = &m->m_nextpkt;
1195 }
1196 ipstat.ips_ofragments += nfrags;
1197
1198 /* set first marker for fragment chain */
1199 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1200 m0->m_pkthdr.csum_data = nfrags;
1201
1202 /*
1203 * Update first fragment by trimming what's been copied out
1204 * and updating header.
1205 */
1206 m_adj(m0, hlen + firstlen - ip->ip_len);
1207 m0->m_pkthdr.len = hlen + firstlen;
1208 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1209 ip->ip_off |= IP_MF;
1210 ip->ip_off = htons(ip->ip_off);
1211 ip->ip_sum = 0;
1212 if (sw_csum & CSUM_DELAY_IP)
1213 ip->ip_sum = in_cksum(m0, hlen);
1214
1215 done:
1216 *m_frag = m0;
1217 return error;
1218 }
1219
1220 void
1221 in_delayed_cksum(struct mbuf *m)
1222 {
1223 struct ip *ip;
1224 u_short csum, offset;
1225
1226 ip = mtod(m, struct ip *);
1227 offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1228 csum = in_cksum_skip(m, ip->ip_len, offset);
1229 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1230 csum = 0xffff;
1231 offset += m->m_pkthdr.csum_data; /* checksum offset */
1232
1233 if (offset + sizeof(u_short) > m->m_len) {
1234 kprintf("delayed m_pullup, m->len: %d off: %d p: %d\n",
1235 m->m_len, offset, ip->ip_p);
1236 /*
1237 * XXX
1238 * this shouldn't happen, but if it does, the
1239 * correct behavior may be to insert the checksum
1240 * in the existing chain instead of rearranging it.
1241 */
1242 m = m_pullup(m, offset + sizeof(u_short));
1243 }
1244 *(u_short *)(m->m_data + offset) = csum;
1245 }
1246
1247 /*
1248 * Insert IP options into preformed packet.
1249 * Adjust IP destination as required for IP source routing,
1250 * as indicated by a non-zero in_addr at the start of the options.
1251 *
1252 * XXX This routine assumes that the packet has no options in place.
1253 */
1254 static struct mbuf *
1255 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen)
1256 {
1257 struct ipoption *p = mtod(opt, struct ipoption *);
1258 struct mbuf *n;
1259 struct ip *ip = mtod(m, struct ip *);
1260 unsigned optlen;
1261
1262 optlen = opt->m_len - sizeof p->ipopt_dst;
1263 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1264 *phlen = 0;
1265 return (m); /* XXX should fail */
1266 }
1267 if (p->ipopt_dst.s_addr)
1268 ip->ip_dst = p->ipopt_dst;
1269 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1270 MGETHDR(n, M_NOWAIT, MT_HEADER);
1271 if (n == NULL) {
1272 *phlen = 0;
1273 return (m);
1274 }
1275 n->m_pkthdr.rcvif = NULL;
1276 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1277 m->m_len -= sizeof(struct ip);
1278 m->m_data += sizeof(struct ip);
1279 n->m_next = m;
1280 m = n;
1281 m->m_len = optlen + sizeof(struct ip);
1282 m->m_data += max_linkhdr;
1283 memcpy(mtod(m, void *), ip, sizeof(struct ip));
1284 } else {
1285 m->m_data -= optlen;
1286 m->m_len += optlen;
1287 m->m_pkthdr.len += optlen;
1288 bcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
1289 }
1290 ip = mtod(m, struct ip *);
1291 bcopy(p->ipopt_list, ip + 1, optlen);
1292 *phlen = sizeof(struct ip) + optlen;
1293 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1294 ip->ip_len += optlen;
1295 return (m);
1296 }
1297
1298 /*
1299 * Copy options from ip to jp,
1300 * omitting those not copied during fragmentation.
1301 */
1302 int
1303 ip_optcopy(struct ip *ip, struct ip *jp)
1304 {
1305 u_char *cp, *dp;
1306 int opt, optlen, cnt;
1307
1308 cp = (u_char *)(ip + 1);
1309 dp = (u_char *)(jp + 1);
1310 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1311 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1312 opt = cp[0];
1313 if (opt == IPOPT_EOL)
1314 break;
1315 if (opt == IPOPT_NOP) {
1316 /* Preserve for IP mcast tunnel's LSRR alignment. */
1317 *dp++ = IPOPT_NOP;
1318 optlen = 1;
1319 continue;
1320 }
1321
1322 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp,
1323 ("ip_optcopy: malformed ipv4 option"));
1324 optlen = cp[IPOPT_OLEN];
1325 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt,
1326 ("ip_optcopy: malformed ipv4 option"));
1327
1328 /* bogus lengths should have been caught by ip_dooptions */
1329 if (optlen > cnt)
1330 optlen = cnt;
1331 if (IPOPT_COPIED(opt)) {
1332 bcopy(cp, dp, optlen);
1333 dp += optlen;
1334 }
1335 }
1336 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1337 *dp++ = IPOPT_EOL;
1338 return (optlen);
1339 }
1340
1341 /*
1342 * IP socket option processing.
1343 */
1344 void
1345 ip_ctloutput(netmsg_t msg)
1346 {
1347 struct socket *so = msg->base.nm_so;
1348 struct sockopt *sopt = msg->ctloutput.nm_sopt;
1349 struct inpcb *inp = so->so_pcb;
1350 int error, optval;
1351
1352 error = optval = 0;
1353
1354 /* Get socket's owner cpuid hint */
1355 if (sopt->sopt_level == SOL_SOCKET &&
1356 sopt->sopt_dir == SOPT_GET &&
1357 sopt->sopt_name == SO_CPUHINT) {
1358 optval = mycpuid;
1359 soopt_from_kbuf(sopt, &optval, sizeof(optval));
1360 goto done;
1361 }
1362
1363 if (sopt->sopt_level != IPPROTO_IP) {
1364 error = EINVAL;
1365 goto done;
1366 }
1367
1368 switch (sopt->sopt_name) {
1369 case IP_MULTICAST_IF:
1370 case IP_MULTICAST_VIF:
1371 case IP_MULTICAST_TTL:
1372 case IP_MULTICAST_LOOP:
1373 case IP_ADD_MEMBERSHIP:
1374 case IP_DROP_MEMBERSHIP:
1375 /*
1376 * Handle multicast options in netisr0
1377 */
1378 if (&curthread->td_msgport != netisr_cpuport(0)) {
1379 /* NOTE: so_port MUST NOT be checked in netisr0 */
1380 msg->lmsg.ms_flags |= MSGF_IGNSOPORT;
1381 lwkt_forwardmsg(netisr_cpuport(0), &msg->lmsg);
1382 return;
1383 }
1384 break;
1385 }
1386
1387 switch (sopt->sopt_dir) {
1388 case SOPT_SET:
1389 switch (sopt->sopt_name) {
1390 case IP_OPTIONS:
1391 #ifdef notyet
1392 case IP_RETOPTS:
1393 #endif
1394 {
1395 struct mbuf *m;
1396 if (sopt->sopt_valsize > MLEN) {
1397 error = EMSGSIZE;
1398 break;
1399 }
1400 MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_HEADER);
1401 if (m == NULL) {
1402 error = ENOBUFS;
1403 break;
1404 }
1405 m->m_len = sopt->sopt_valsize;
1406 error = soopt_to_kbuf(sopt, mtod(m, void *), m->m_len,
1407 m->m_len);
1408 error = ip_pcbopts(sopt->sopt_name,
1409 &inp->inp_options, m);
1410 goto done;
1411 }
1412
1413 case IP_TOS:
1414 case IP_TTL:
1415 case IP_MINTTL:
1416 case IP_RECVOPTS:
1417 case IP_RECVRETOPTS:
1418 case IP_RECVDSTADDR:
1419 case IP_RECVIF:
1420 case IP_RECVTTL:
1421 case IP_FAITH:
1422 error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1423 sizeof optval);
1424 if (error)
1425 break;
1426 switch (sopt->sopt_name) {
1427 case IP_TOS:
1428 inp->inp_ip_tos = optval;
1429 break;
1430
1431 case IP_TTL:
1432 inp->inp_ip_ttl = optval;
1433 break;
1434 case IP_MINTTL:
1435 if (optval >= 0 && optval <= MAXTTL)
1436 inp->inp_ip_minttl = optval;
1437 else
1438 error = EINVAL;
1439 break;
1440 #define OPTSET(bit) \
1441 if (optval) \
1442 inp->inp_flags |= bit; \
1443 else \
1444 inp->inp_flags &= ~bit;
1445
1446 case IP_RECVOPTS:
1447 OPTSET(INP_RECVOPTS);
1448 break;
1449
1450 case IP_RECVRETOPTS:
1451 OPTSET(INP_RECVRETOPTS);
1452 break;
1453
1454 case IP_RECVDSTADDR:
1455 OPTSET(INP_RECVDSTADDR);
1456 break;
1457
1458 case IP_RECVIF:
1459 OPTSET(INP_RECVIF);
1460 break;
1461
1462 case IP_RECVTTL:
1463 OPTSET(INP_RECVTTL);
1464 break;
1465
1466 case IP_FAITH:
1467 OPTSET(INP_FAITH);
1468 break;
1469 }
1470 break;
1471 #undef OPTSET
1472
1473 case IP_MULTICAST_IF:
1474 case IP_MULTICAST_VIF:
1475 case IP_MULTICAST_TTL:
1476 case IP_MULTICAST_LOOP:
1477 case IP_ADD_MEMBERSHIP:
1478 case IP_DROP_MEMBERSHIP:
1479 error = ip_setmoptions(sopt, &inp->inp_moptions);
1480 break;
1481
1482 case IP_PORTRANGE:
1483 error = soopt_to_kbuf(sopt, &optval, sizeof optval,
1484 sizeof optval);
1485 if (error)
1486 break;
1487
1488 switch (optval) {
1489 case IP_PORTRANGE_DEFAULT:
1490 inp->inp_flags &= ~(INP_LOWPORT);
1491 inp->inp_flags &= ~(INP_HIGHPORT);
1492 break;
1493
1494 case IP_PORTRANGE_HIGH:
1495 inp->inp_flags &= ~(INP_LOWPORT);
1496 inp->inp_flags |= INP_HIGHPORT;
1497 break;
1498
1499 case IP_PORTRANGE_LOW:
1500 inp->inp_flags &= ~(INP_HIGHPORT);
1501 inp->inp_flags |= INP_LOWPORT;
1502 break;
1503
1504 default:
1505 error = EINVAL;
1506 break;
1507 }
1508 break;
1509
1510 #if defined(IPSEC) || defined(FAST_IPSEC)
1511 case IP_IPSEC_POLICY:
1512 {
1513 caddr_t req;
1514 size_t len = 0;
1515 int priv;
1516 struct mbuf *m;
1517 int optname;
1518
1519 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1520 break;
1521 soopt_to_mbuf(sopt, m);
1522 priv = (sopt->sopt_td != NULL &&
1523 priv_check(sopt->sopt_td, PRIV_ROOT) != 0) ? 0 : 1;
1524 req = mtod(m, caddr_t);
1525 len = m->m_len;
1526 optname = sopt->sopt_name;
1527 error = ipsec4_set_policy(inp, optname, req, len, priv);
1528 m_freem(m);
1529 break;
1530 }
1531 #endif /*IPSEC*/
1532
1533 default:
1534 error = ENOPROTOOPT;
1535 break;
1536 }
1537 break;
1538
1539 case SOPT_GET:
1540 switch (sopt->sopt_name) {
1541 case IP_OPTIONS:
1542 case IP_RETOPTS:
1543 if (inp->inp_options)
1544 soopt_from_kbuf(sopt, mtod(inp->inp_options,
1545 char *),
1546 inp->inp_options->m_len);
1547 else
1548 sopt->sopt_valsize = 0;
1549 break;
1550
1551 case IP_TOS:
1552 case IP_TTL:
1553 case IP_MINTTL:
1554 case IP_RECVOPTS:
1555 case IP_RECVRETOPTS:
1556 case IP_RECVDSTADDR:
1557 case IP_RECVTTL:
1558 case IP_RECVIF:
1559 case IP_PORTRANGE:
1560 case IP_FAITH:
1561 switch (sopt->sopt_name) {
1562
1563 case IP_TOS:
1564 optval = inp->inp_ip_tos;
1565 break;
1566
1567 case IP_TTL:
1568 optval = inp->inp_ip_ttl;
1569 break;
1570 case IP_MINTTL:
1571 optval = inp->inp_ip_minttl;
1572 break;
1573
1574 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1575
1576 case IP_RECVOPTS:
1577 optval = OPTBIT(INP_RECVOPTS);
1578 break;
1579
1580 case IP_RECVRETOPTS:
1581 optval = OPTBIT(INP_RECVRETOPTS);
1582 break;
1583
1584 case IP_RECVDSTADDR:
1585 optval = OPTBIT(INP_RECVDSTADDR);
1586 break;
1587
1588 case IP_RECVTTL:
1589 optval = OPTBIT(INP_RECVTTL);
1590 break;
1591
1592 case IP_RECVIF:
1593 optval = OPTBIT(INP_RECVIF);
1594 break;
1595
1596 case IP_PORTRANGE:
1597 if (inp->inp_flags & INP_HIGHPORT)
1598 optval = IP_PORTRANGE_HIGH;
1599 else if (inp->inp_flags & INP_LOWPORT)
1600 optval = IP_PORTRANGE_LOW;
1601 else
1602 optval = 0;
1603 break;
1604
1605 case IP_FAITH:
1606 optval = OPTBIT(INP_FAITH);
1607 break;
1608 }
1609 soopt_from_kbuf(sopt, &optval, sizeof optval);
1610 break;
1611
1612 case IP_MULTICAST_IF:
1613 case IP_MULTICAST_VIF:
1614 case IP_MULTICAST_TTL:
1615 case IP_MULTICAST_LOOP:
1616 case IP_ADD_MEMBERSHIP:
1617 case IP_DROP_MEMBERSHIP:
1618 error = ip_getmoptions(sopt, inp->inp_moptions);
1619 break;
1620
1621 #if defined(IPSEC) || defined(FAST_IPSEC)
1622 case IP_IPSEC_POLICY:
1623 {
1624 struct mbuf *m = NULL;
1625 caddr_t req = NULL;
1626 size_t len = 0;
1627
1628 if (m != NULL) {
1629 req = mtod(m, caddr_t);
1630 len = m->m_len;
1631 }
1632 error = ipsec4_get_policy(so->so_pcb, req, len, &m);
1633 if (error == 0)
1634 error = soopt_from_mbuf(sopt, m); /* XXX */
1635 if (error == 0)
1636 m_freem(m);
1637 break;
1638 }
1639 #endif /*IPSEC*/
1640
1641 default:
1642 error = ENOPROTOOPT;
1643 break;
1644 }
1645 break;
1646 }
1647 done:
1648 lwkt_replymsg(&msg->lmsg, error);
1649 }
1650
1651 /*
1652 * Set up IP options in pcb for insertion in output packets.
1653 * Store in mbuf with pointer in pcbopt, adding pseudo-option
1654 * with destination address if source routed.
1655 */
1656 static int
1657 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m)
1658 {
1659 int cnt, optlen;
1660 u_char *cp;
1661 u_char opt;
1662
1663 /* turn off any old options */
1664 if (*pcbopt)
1665 m_free(*pcbopt);
1666 *pcbopt = NULL;
1667 if (m == NULL || m->m_len == 0) {
1668 /*
1669 * Only turning off any previous options.
1670 */
1671 if (m != NULL)
1672 m_free(m);
1673 return (0);
1674 }
1675
1676 if (m->m_len % sizeof(int32_t))
1677 goto bad;
1678 /*
1679 * IP first-hop destination address will be stored before
1680 * actual options; move other options back
1681 * and clear it when none present.
1682 */
1683 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1684 goto bad;
1685 cnt = m->m_len;
1686 m->m_len += sizeof(struct in_addr);
1687 cp = mtod(m, u_char *) + sizeof(struct in_addr);
1688 bcopy(mtod(m, caddr_t), cp, cnt);
1689 bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1690
1691 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1692 opt = cp[IPOPT_OPTVAL];
1693 if (opt == IPOPT_EOL)
1694 break;
1695 if (opt == IPOPT_NOP)
1696 optlen = 1;
1697 else {
1698 if (cnt < IPOPT_OLEN + sizeof *cp)
1699 goto bad;
1700 optlen = cp[IPOPT_OLEN];
1701 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt)
1702 goto bad;
1703 }
1704 switch (opt) {
1705
1706 default:
1707 break;
1708
1709 case IPOPT_LSRR:
1710 case IPOPT_SSRR:
1711 /*
1712 * user process specifies route as:
1713 * ->A->B->C->D
1714 * D must be our final destination (but we can't
1715 * check that since we may not have connected yet).
1716 * A is first hop destination, which doesn't appear in
1717 * actual IP option, but is stored before the options.
1718 */
1719 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1720 goto bad;
1721 m->m_len -= sizeof(struct in_addr);
1722 cnt -= sizeof(struct in_addr);
1723 optlen -= sizeof(struct in_addr);
1724 cp[IPOPT_OLEN] = optlen;
1725 /*
1726 * Move first hop before start of options.
1727 */
1728 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1729 sizeof(struct in_addr));
1730 /*
1731 * Then copy rest of options back
1732 * to close up the deleted entry.
1733 */
1734 bcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr),
1735 &cp[IPOPT_OFFSET+1],
1736 cnt - (IPOPT_MINOFF - 1));
1737 break;
1738 }
1739 }
1740 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1741 goto bad;
1742 *pcbopt = m;
1743 return (0);
1744
1745 bad:
1746 m_free(m);
1747 return (EINVAL);
1748 }
1749
1750 /*
1751 * XXX
1752 * The whole multicast option thing needs to be re-thought.
1753 * Several of these options are equally applicable to non-multicast
1754 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1755 * standard option (IP_TTL).
1756 */
1757
1758 /*
1759 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1760 */
1761 static struct ifnet *
1762 ip_multicast_if(struct in_addr *a, int *ifindexp)
1763 {
1764 int ifindex;
1765 struct ifnet *ifp;
1766
1767 if (ifindexp)
1768 *ifindexp = 0;
1769 if (ntohl(a->s_addr) >> 24 == 0) {
1770 ifindex = ntohl(a->s_addr) & 0xffffff;
1771 if (ifindex < 0 || if_index < ifindex)
1772 return NULL;
1773 ifp = ifindex2ifnet[ifindex];
1774 if (ifindexp)
1775 *ifindexp = ifindex;
1776 } else {
1777 ifp = INADDR_TO_IFP(a);
1778 }
1779 return ifp;
1780 }
1781
1782 /*
1783 * Set the IP multicast options in response to user setsockopt().
1784 */
1785 static int
1786 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop)
1787 {
1788 int error = 0;
1789 int i;
1790 struct in_addr addr;
1791 struct ip_mreq mreq;
1792 struct ifnet *ifp;
1793 struct ip_moptions *imo = *imop;
1794 int ifindex;
1795
1796 if (imo == NULL) {
1797 /*
1798 * No multicast option buffer attached to the pcb;
1799 * allocate one and initialize to default values.
1800 */
1801 imo = kmalloc(sizeof *imo, M_IPMOPTS, M_WAITOK);
1802
1803 imo->imo_multicast_ifp = NULL;
1804 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1805 imo->imo_multicast_vif = -1;
1806 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1807 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1808 imo->imo_num_memberships = 0;
1809 /* Assign imo to imop after all fields are setup */
1810 cpu_sfence();
1811 *imop = imo;
1812 }
1813 switch (sopt->sopt_name) {
1814 /* store an index number for the vif you wanna use in the send */
1815 case IP_MULTICAST_VIF:
1816 if (legal_vif_num == 0) {
1817 error = EOPNOTSUPP;
1818 break;
1819 }
1820 error = soopt_to_kbuf(sopt, &i, sizeof i, sizeof i);
1821 if (error)
1822 break;
1823 if (!legal_vif_num(i) && (i != -1)) {
1824 error = EINVAL;
1825 break;
1826 }
1827 imo->imo_multicast_vif = i;
1828 break;
1829
1830 case IP_MULTICAST_IF:
1831 /*
1832 * Select the interface for outgoing multicast packets.
1833 */
1834 error = soopt_to_kbuf(sopt, &addr, sizeof addr, sizeof addr);
1835 if (error)
1836 break;
1837
1838 /*
1839 * INADDR_ANY is used to remove a previous selection.
1840 * When no interface is selected, a default one is
1841 * chosen every time a multicast packet is sent.
1842 */
1843 if (addr.s_addr == INADDR_ANY) {
1844 imo->imo_multicast_ifp = NULL;
1845 break;
1846 }
1847 /*
1848 * The selected interface is identified by its local
1849 * IP address. Find the interface and confirm that
1850 * it supports multicasting.
1851 */
1852 crit_enter();
1853 ifp = ip_multicast_if(&addr, &ifindex);
1854 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1855 crit_exit();
1856 error = EADDRNOTAVAIL;
1857 break;
1858 }
1859 imo->imo_multicast_ifp = ifp;
1860 if (ifindex)
1861 imo->imo_multicast_addr = addr;
1862 else
1863 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1864 crit_exit();
1865 break;
1866
1867 case IP_MULTICAST_TTL:
1868 /*
1869 * Set the IP time-to-live for outgoing multicast packets.
1870 * The original multicast API required a char argument,
1871 * which is inconsistent with the rest of the socket API.
1872 * We allow either a char or an int.
1873 */
1874 if (sopt->sopt_valsize == 1) {
1875 u_char ttl;
1876 error = soopt_to_kbuf(sopt, &ttl, 1, 1);
1877 if (error)
1878 break;
1879 imo->imo_multicast_ttl = ttl;
1880 } else {
1881 u_int ttl;
1882 error = soopt_to_kbuf(sopt, &ttl, sizeof ttl, sizeof ttl);
1883 if (error)
1884 break;
1885 if (ttl > 255)
1886 error = EINVAL;
1887 else
1888 imo->imo_multicast_ttl = ttl;
1889 }
1890 break;
1891
1892 case IP_MULTICAST_LOOP:
1893 /*
1894 * Set the loopback flag for outgoing multicast packets.
1895 * Must be zero or one. The original multicast API required a
1896 * char argument, which is inconsistent with the rest
1897 * of the socket API. We allow either a char or an int.
1898 */
1899 if (sopt->sopt_valsize == 1) {
1900 u_char loop;
1901
1902 error = soopt_to_kbuf(sopt, &loop, 1, 1);
1903 if (error)
1904 break;
1905 imo->imo_multicast_loop = !!loop;
1906 } else {
1907 u_int loop;
1908
1909 error = soopt_to_kbuf(sopt, &loop, sizeof loop,
1910 sizeof loop);
1911 if (error)
1912 break;
1913 imo->imo_multicast_loop = !!loop;
1914 }
1915 break;
1916
1917 case IP_ADD_MEMBERSHIP:
1918 /*
1919 * Add a multicast group membership.
1920 * Group must be a valid IP multicast address.
1921 */
1922 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq);
1923 if (error)
1924 break;
1925
1926 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1927 error = EINVAL;
1928 break;
1929 }
1930 crit_enter();
1931 /*
1932 * If no interface address was provided, use the interface of
1933 * the route to the given multicast address.
1934 */
1935 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1936 struct sockaddr_in dst;
1937 struct rtentry *rt;
1938
1939 bzero(&dst, sizeof(struct sockaddr_in));
1940 dst.sin_len = sizeof(struct sockaddr_in);
1941 dst.sin_family = AF_INET;
1942 dst.sin_addr = mreq.imr_multiaddr;
1943 rt = rtlookup((struct sockaddr *)&dst);
1944 if (rt == NULL) {
1945 error = EADDRNOTAVAIL;
1946 crit_exit();
1947 break;
1948 }
1949 --rt->rt_refcnt;
1950 ifp = rt->rt_ifp;
1951 } else {
1952 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1953 }
1954
1955 /*
1956 * See if we found an interface, and confirm that it
1957 * supports multicast.
1958 */
1959 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1960 error = EADDRNOTAVAIL;
1961 crit_exit();
1962 break;
1963 }
1964 /*
1965 * See if the membership already exists or if all the
1966 * membership slots are full.
1967 */
1968 for (i = 0; i < imo->imo_num_memberships; ++i) {
1969 if (imo->imo_membership[i]->inm_ifp == ifp &&
1970 imo->imo_membership[i]->inm_addr.s_addr
1971 == mreq.imr_multiaddr.s_addr)
1972 break;
1973 }
1974 if (i < imo->imo_num_memberships) {
1975 error = EADDRINUSE;
1976 crit_exit();
1977 break;
1978 }
1979 if (i == IP_MAX_MEMBERSHIPS) {
1980 error = ETOOMANYREFS;
1981 crit_exit();
1982 break;
1983 }
1984 /*
1985 * Everything looks good; add a new record to the multicast
1986 * address list for the given interface.
1987 */
1988 if ((imo->imo_membership[i] =
1989 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
1990 error = ENOBUFS;
1991 crit_exit();
1992 break;
1993 }
1994 ++imo->imo_num_memberships;
1995 crit_exit();
1996 break;
1997
1998 case IP_DROP_MEMBERSHIP:
1999 /*
2000 * Drop a multicast group membership.
2001 * Group must be a valid IP multicast address.
2002 */
2003 error = soopt_to_kbuf(sopt, &mreq, sizeof mreq, sizeof mreq);
2004 if (error)
2005 break;
2006
2007 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
2008 error = EINVAL;
2009 break;
2010 }
2011
2012 crit_enter();
2013 /*
2014 * If an interface address was specified, get a pointer
2015 * to its ifnet structure.
2016 */
2017 if (mreq.imr_interface.s_addr == INADDR_ANY)
2018 ifp = NULL;
2019 else {
2020 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
2021 if (ifp == NULL) {
2022 error = EADDRNOTAVAIL;
2023 crit_exit();
2024 break;
2025 }
2026 }
2027 /*
2028 * Find the membership in the membership array.
2029 */
2030 for (i = 0; i < imo->imo_num_memberships; ++i) {
2031 if ((ifp == NULL ||
2032 imo->imo_membership[i]->inm_ifp == ifp) &&
2033 imo->imo_membership[i]->inm_addr.s_addr ==
2034 mreq.imr_multiaddr.s_addr)
2035 break;
2036 }
2037 if (i == imo->imo_num_memberships) {
2038 error = EADDRNOTAVAIL;
2039 crit_exit();
2040 break;
2041 }
2042 /*
2043 * Give up the multicast address record to which the
2044 * membership points.
2045 */
2046 in_delmulti(imo->imo_membership[i]);
2047 /*
2048 * Remove the gap in the membership array.
2049 */
2050 for (++i; i < imo->imo_num_memberships; ++i)
2051 imo->imo_membership[i-1] = imo->imo_membership[i];
2052 --imo->imo_num_memberships;
2053 crit_exit();
2054 break;
2055
2056 default:
2057 error = EOPNOTSUPP;
2058 break;
2059 }
2060
2061 return (error);
2062 }
2063
2064 /*
2065 * Return the IP multicast options in response to user getsockopt().
2066 */
2067 static int
2068 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo)
2069 {
2070 struct in_addr addr;
2071 struct in_ifaddr *ia;
2072 int error, optval;
2073 u_char coptval;
2074
2075 error = 0;
2076 switch (sopt->sopt_name) {
2077 case IP_MULTICAST_VIF:
2078 if (imo != NULL)
2079 optval = imo->imo_multicast_vif;
2080 else
2081 optval = -1;
2082 soopt_from_kbuf(sopt, &optval, sizeof optval);
2083 break;
2084
2085 case IP_MULTICAST_IF:
2086 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2087 addr.s_addr = INADDR_ANY;
2088 else if (imo->imo_multicast_addr.s_addr) {
2089 /* return the value user has set */
2090 addr = imo->imo_multicast_addr;
2091 } else {
2092 ia = IFP_TO_IA(imo->imo_multicast_ifp);
2093 addr.s_addr = (ia == NULL) ? INADDR_ANY
2094 : IA_SIN(ia)->sin_addr.s_addr;
2095 }
2096 soopt_from_kbuf(sopt, &addr, sizeof addr);
2097 break;
2098
2099 case IP_MULTICAST_TTL:
2100 if (imo == NULL)
2101 optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2102 else
2103 optval = coptval = imo->imo_multicast_ttl;
2104 if (sopt->sopt_valsize == 1)
2105 soopt_from_kbuf(sopt, &coptval, 1);
2106 else
2107 soopt_from_kbuf(sopt, &optval, sizeof optval);
2108 break;
2109
2110 case IP_MULTICAST_LOOP:
2111 if (imo == NULL)
2112 optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2113 else
2114 optval = coptval = imo->imo_multicast_loop;
2115 if (sopt->sopt_valsize == 1)
2116 soopt_from_kbuf(sopt, &coptval, 1);
2117 else
2118 soopt_from_kbuf(sopt, &optval, sizeof optval);
2119 break;
2120
2121 default:
2122 error = ENOPROTOOPT;
2123 break;
2124 }
2125 return (error);
2126 }
2127
2128 /*
2129 * Discard the IP multicast options.
2130 */
2131 void
2132 ip_freemoptions(struct ip_moptions *imo)
2133 {
2134 int i;
2135
2136 if (imo != NULL) {
2137 for (i = 0; i < imo->imo_num_memberships; ++i)
2138 in_delmulti(imo->imo_membership[i]);
2139 kfree(imo, M_IPMOPTS);
2140 }
2141 }
2142
2143 /*
2144 * Routine called from ip_output() to loop back a copy of an IP multicast
2145 * packet to the input queue of a specified interface. Note that this
2146 * calls the output routine of the loopback "driver", but with an interface
2147 * pointer that might NOT be a loopback interface -- evil, but easier than
2148 * replicating that code here.
2149 */
2150 static void
2151 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
2152 int hlen)
2153 {
2154 struct ip *ip;
2155 struct mbuf *copym;
2156
2157 copym = m_copypacket(m, M_NOWAIT);
2158 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2159 copym = m_pullup(copym, hlen);
2160 if (copym != NULL) {
2161 /*
2162 * if the checksum hasn't been computed, mark it as valid
2163 */
2164 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2165 in_delayed_cksum(copym);
2166 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
2167 copym->m_pkthdr.csum_flags |=
2168 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2169 copym->m_pkthdr.csum_data = 0xffff;
2170 }
2171 /*
2172 * We don't bother to fragment if the IP length is greater
2173 * than the interface's MTU. Can this possibly matter?
2174 */
2175 ip = mtod(copym, struct ip *);
2176 ip->ip_len = htons(ip->ip_len);
2177 ip->ip_off = htons(ip->ip_off);
2178 ip->ip_sum = 0;
2179 if (ip->ip_vhl == IP_VHL_BORING) {
2180 ip->ip_sum = in_cksum_hdr(ip);
2181 } else {
2182 ip->ip_sum = in_cksum(copym, hlen);
2183 }
2184 /*
2185 * NB:
2186 * It's not clear whether there are any lingering
2187 * reentrancy problems in other areas which might
2188 * be exposed by using ip_input directly (in
2189 * particular, everything which modifies the packet
2190 * in-place). Yet another option is using the
2191 * protosw directly to deliver the looped back
2192 * packet. For the moment, we'll err on the side
2193 * of safety by using if_simloop().
2194 */
2195 #if 1 /* XXX */
2196 if (dst->sin_family != AF_INET) {
2197 kprintf("ip_mloopback: bad address family %d\n",
2198 dst->sin_family);
2199 dst->sin_family = AF_INET;
2200 }
2201 #endif
2202 if_simloop(ifp, copym, dst->sin_family, 0);
2203 }
2204 }
DragonFly BSD