2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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15 * This product includes software developed by the University of
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
34 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $
35 * $DragonFly: src/sys/netinet/ip_output.c,v 1.11 2004/03/06 01:58:55 hsu Exp $
42 #include "opt_ipdivert.h"
43 #include "opt_ipfilter.h"
44 #include "opt_ipsec.h"
45 #include "opt_pfil_hooks.h"
46 #include "opt_random_ip_id.h"
47 #include "opt_mbuf_stress_test.h"
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/malloc.h>
54 #include <sys/protosw.h>
55 #include <sys/socket.h>
56 #include <sys/socketvar.h>
58 #include <sys/sysctl.h>
59 #include <sys/in_cksum.h>
62 #include <net/netisr.h>
66 #include <net/route.h>
68 #include <netinet/in.h>
69 #include <netinet/in_systm.h>
70 #include <netinet/ip.h>
71 #include <netinet/in_pcb.h>
72 #include <netinet/in_var.h>
73 #include <netinet/ip_var.h>
75 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
78 #include <netinet6/ipsec.h>
79 #include <netproto/key/key.h>
81 #include <netproto/key/key_debug.h>
83 #define KEYDEBUG(lev,arg)
88 #include <netipsec/ipsec.h>
89 #include <netipsec/xform.h>
90 #include <netipsec/key.h>
93 #include <net/ipfw/ip_fw.h>
94 #include <net/dummynet/ip_dummynet.h>
96 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\
97 x, (ntohl(a.s_addr)>>24)&0xFF,\
98 (ntohl(a.s_addr)>>16)&0xFF,\
99 (ntohl(a.s_addr)>>8)&0xFF,\
100 (ntohl(a.s_addr))&0xFF, y);
104 #ifdef MBUF_STRESS_TEST
105 int mbuf_frag_size = 0;
106 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
107 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
110 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
111 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
112 static void ip_mloopback
113 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
114 static int ip_getmoptions
115 (struct sockopt *, struct ip_moptions *);
116 static int ip_pcbopts(int, struct mbuf **, struct mbuf *);
117 static int ip_setmoptions
118 (struct sockopt *, struct ip_moptions **);
120 int ip_optcopy(struct ip *, struct ip *);
121 extern int (*fr_checkp) (struct ip *, int, struct ifnet *, int, struct mbuf **);
124 extern struct protosw inetsw[];
127 * IP output. The packet in mbuf chain m contains a skeletal IP
128 * header (with len, off, ttl, proto, tos, src, dst).
129 * The mbuf chain containing the packet will be freed.
130 * The mbuf opt, if present, will not be freed.
133 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
134 int flags, struct ip_moptions *imo, struct inpcb *inp)
137 struct ifnet *ifp = NULL; /* keep compiler happy */
139 int hlen = sizeof (struct ip);
140 int len, off, error = 0;
141 struct sockaddr_in *dst = NULL; /* keep compiler happy */
142 struct in_ifaddr *ia = NULL;
143 int isbroadcast, sw_csum;
144 struct in_addr pkt_dst;
146 struct route iproute;
147 struct secpolicy *sp = NULL;
148 struct socket *so = inp ? inp->inp_socket : NULL;
151 struct route iproute;
153 struct secpolicy *sp = NULL;
154 struct tdb_ident *tdbi;
156 #endif /* FAST_IPSEC */
157 struct ip_fw_args args;
158 int src_was_INADDR_ANY = 0; /* as the name says... */
162 args.next_hop = NULL;
163 args.divert_rule = 0; /* divert cookie */
165 /* Grab info from MT_TAG mbufs prepended to the chain. */
166 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) {
167 switch(m0->_m_tag_id) {
169 printf("ip_output: unrecognised MT_TAG tag %d\n",
173 case PACKET_TAG_DUMMYNET:
175 * the packet was already tagged, so part of the
176 * processing was already done, and we need to go down.
177 * Get parameters from the header.
179 args.rule = ((struct dn_pkt *)m0)->rule;
181 ro = & ( ((struct dn_pkt *)m0)->ro ) ;
183 dst = ((struct dn_pkt *)m0)->dn_dst ;
184 ifp = ((struct dn_pkt *)m0)->ifp ;
185 flags = ((struct dn_pkt *)m0)->flags ;
188 case PACKET_TAG_DIVERT:
189 args.divert_rule = (int)m0->m_data & 0xffff;
192 case PACKET_TAG_IPFORWARD:
193 args.next_hop = (struct sockaddr_in *)m0->m_data;
199 KASSERT(!m || (m->m_flags & M_PKTHDR) != 0, ("ip_output: no HDR"));
201 KASSERT(ro != NULL, ("ip_output: no route, proto %d",
202 mtod(m, struct ip *)->ip_p));
205 if (args.rule != NULL) { /* dummynet already saw us */
206 ip = mtod(m, struct ip *);
207 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
209 ia = ifatoia(ro->ro_rt->rt_ifa);
215 m = ip_insertoptions(m, opt, &len);
219 ip = mtod(m, struct ip *);
220 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
225 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
226 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
229 ip->ip_id = ip_randomid();
231 ip->ip_id = htons(ip_id++);
233 ipstat.ips_localout++;
235 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
241 bzero(ro, sizeof (*ro));
243 #endif /* FAST_IPSEC */
244 dst = (struct sockaddr_in *)&ro->ro_dst;
246 * If there is a cached route,
247 * check that it is to the same destination
248 * and is still up. If not, free it and try again.
249 * The address family should also be checked in case of sharing the
252 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
253 dst->sin_family != AF_INET ||
254 dst->sin_addr.s_addr != pkt_dst.s_addr)) {
256 ro->ro_rt = (struct rtentry *)0;
258 if (ro->ro_rt == 0) {
259 bzero(dst, sizeof(*dst));
260 dst->sin_family = AF_INET;
261 dst->sin_len = sizeof(*dst);
262 dst->sin_addr = pkt_dst;
265 * If routing to interface only,
266 * short circuit routing lookup.
268 if (flags & IP_ROUTETOIF) {
269 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 &&
270 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) {
271 ipstat.ips_noroute++;
277 isbroadcast = in_broadcast(dst->sin_addr, ifp);
278 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
279 imo != NULL && imo->imo_multicast_ifp != NULL) {
281 * Bypass the normal routing lookup for multicast
282 * packets if the interface is specified.
284 ifp = imo->imo_multicast_ifp;
286 isbroadcast = 0; /* fool gcc */
289 * If this is the case, we probably don't want to allocate
290 * a protocol-cloned route since we didn't get one from the
291 * ULP. This lets TCP do its thing, while not burdening
292 * forwarding or ICMP with the overhead of cloning a route.
293 * Of course, we still want to do any cloning requested by
294 * the link layer, as this is probably required in all cases
295 * for correct operation (as it is for ARP).
298 rtalloc_ign(ro, RTF_PRCLONING);
299 if (ro->ro_rt == 0) {
300 ipstat.ips_noroute++;
301 error = EHOSTUNREACH;
304 ia = ifatoia(ro->ro_rt->rt_ifa);
305 ifp = ro->ro_rt->rt_ifp;
307 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
308 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
309 if (ro->ro_rt->rt_flags & RTF_HOST)
310 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
312 isbroadcast = in_broadcast(dst->sin_addr, ifp);
314 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
315 struct in_multi *inm;
317 m->m_flags |= M_MCAST;
319 * IP destination address is multicast. Make sure "dst"
320 * still points to the address in "ro". (It may have been
321 * changed to point to a gateway address, above.)
323 dst = (struct sockaddr_in *)&ro->ro_dst;
325 * See if the caller provided any multicast options
328 ip->ip_ttl = imo->imo_multicast_ttl;
329 if (imo->imo_multicast_vif != -1)
332 ip_mcast_src(imo->imo_multicast_vif) :
335 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
337 * Confirm that the outgoing interface supports multicast.
339 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
340 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
341 ipstat.ips_noroute++;
347 * If source address not specified yet, use address
348 * of outgoing interface.
350 if (ip->ip_src.s_addr == INADDR_ANY) {
351 /* Interface may have no addresses. */
353 ip->ip_src = IA_SIN(ia)->sin_addr;
356 if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
359 * delayed checksums are not currently
360 * compatible with IP multicast routing
362 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
364 m->m_pkthdr.csum_flags &=
368 IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
370 (imo == NULL || imo->imo_multicast_loop)) {
372 * If we belong to the destination multicast group
373 * on the outgoing interface, and the caller did not
374 * forbid loopback, loop back a copy.
376 ip_mloopback(ifp, m, dst, hlen);
380 * If we are acting as a multicast router, perform
381 * multicast forwarding as if the packet had just
382 * arrived on the interface to which we are about
383 * to send. The multicast forwarding function
384 * recursively calls this function, using the
385 * IP_FORWARDING flag to prevent infinite recursion.
387 * Multicasts that are looped back by ip_mloopback(),
388 * above, will be forwarded by the ip_input() routine,
391 if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
393 * If rsvp daemon is not running, do not
394 * set ip_moptions. This ensures that the packet
395 * is multicast and not just sent down one link
396 * as prescribed by rsvpd.
401 ip_mforward(ip, ifp, m, imo) != 0) {
409 * Multicasts with a time-to-live of zero may be looped-
410 * back, above, but must not be transmitted on a network.
411 * Also, multicasts addressed to the loopback interface
412 * are not sent -- the above call to ip_mloopback() will
413 * loop back a copy if this host actually belongs to the
414 * destination group on the loopback interface.
416 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
425 * If the source address is not specified yet, use the address
426 * of the outoing interface. In case, keep note we did that, so
427 * if the the firewall changes the next-hop causing the output
428 * interface to change, we can fix that.
430 if (ip->ip_src.s_addr == INADDR_ANY) {
431 /* Interface may have no addresses. */
433 ip->ip_src = IA_SIN(ia)->sin_addr;
434 src_was_INADDR_ANY = 1;
439 * Verify that we have any chance at all of being able to queue
440 * the packet or packet fragments
442 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
443 ifp->if_snd.ifq_maxlen) {
445 ipstat.ips_odropped++;
450 * Look for broadcast address and
451 * verify user is allowed to send
455 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
456 error = EADDRNOTAVAIL;
459 if ((flags & IP_ALLOWBROADCAST) == 0) {
463 /* don't allow broadcast messages to be fragmented */
464 if (ip->ip_len > ifp->if_mtu) {
468 m->m_flags |= M_BCAST;
470 m->m_flags &= ~M_BCAST;
475 /* get SP for this packet */
477 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
479 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
482 ipsecstat.out_inval++;
489 switch (sp->policy) {
490 case IPSEC_POLICY_DISCARD:
492 * This packet is just discarded.
494 ipsecstat.out_polvio++;
497 case IPSEC_POLICY_BYPASS:
498 case IPSEC_POLICY_NONE:
499 /* no need to do IPsec. */
502 case IPSEC_POLICY_IPSEC:
503 if (sp->req == NULL) {
504 /* acquire a policy */
505 error = key_spdacquire(sp);
510 case IPSEC_POLICY_ENTRUST:
512 printf("ip_output: Invalid policy found. %d\n", sp->policy);
515 struct ipsec_output_state state;
516 bzero(&state, sizeof(state));
518 if (flags & IP_ROUTETOIF) {
520 bzero(&iproute, sizeof(iproute));
523 state.dst = (struct sockaddr *)dst;
529 * delayed checksums are not currently compatible with IPsec
531 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
533 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
536 ip->ip_len = htons(ip->ip_len);
537 ip->ip_off = htons(ip->ip_off);
539 error = ipsec4_output(&state, sp, flags);
542 if (flags & IP_ROUTETOIF) {
544 * if we have tunnel mode SA, we may need to ignore
547 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
548 flags &= ~IP_ROUTETOIF;
553 dst = (struct sockaddr_in *)state.dst;
555 /* mbuf is already reclaimed in ipsec4_output. */
565 printf("ip4_output (ipsec): error code %d\n", error);
568 /* don't show these error codes to the user */
576 /* be sure to update variables that are affected by ipsec4_output() */
577 ip = mtod(m, struct ip *);
579 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
581 hlen = ip->ip_hl << 2;
583 if (ro->ro_rt == NULL) {
584 if ((flags & IP_ROUTETOIF) == 0) {
586 "can't update route after IPsec processing\n");
587 error = EHOSTUNREACH; /*XXX*/
591 ia = ifatoia(ro->ro_rt->rt_ifa);
592 ifp = ro->ro_rt->rt_ifp;
595 /* make it flipped, again. */
596 ip->ip_len = ntohs(ip->ip_len);
597 ip->ip_off = ntohs(ip->ip_off);
602 * Check the security policy (SP) for the packet and, if
603 * required, do IPsec-related processing. There are two
604 * cases here; the first time a packet is sent through
605 * it will be untagged and handled by ipsec4_checkpolicy.
606 * If the packet is resubmitted to ip_output (e.g. after
607 * AH, ESP, etc. processing), there will be a tag to bypass
608 * the lookup and related policy checking.
610 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
613 tdbi = (struct tdb_ident *)(mtag + 1);
614 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
616 error = -EINVAL; /* force silent drop */
617 m_tag_delete(m, mtag);
619 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
623 * There are four return cases:
624 * sp != NULL apply IPsec policy
625 * sp == NULL, error == 0 no IPsec handling needed
626 * sp == NULL, error == -EINVAL discard packet w/o error
627 * sp == NULL, error != 0 discard packet, report error
630 /* Loop detection, check if ipsec processing already done */
631 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
632 for (mtag = m_tag_first(m); mtag != NULL;
633 mtag = m_tag_next(m, mtag)) {
634 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
636 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
637 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
640 * Check if policy has an SA associated with it.
641 * This can happen when an SP has yet to acquire
642 * an SA; e.g. on first reference. If it occurs,
643 * then we let ipsec4_process_packet do its thing.
645 if (sp->req->sav == NULL)
647 tdbi = (struct tdb_ident *)(mtag + 1);
648 if (tdbi->spi == sp->req->sav->spi &&
649 tdbi->proto == sp->req->sav->sah->saidx.proto &&
650 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
651 sizeof (union sockaddr_union)) == 0) {
653 * No IPsec processing is needed, free
656 * NB: null pointer to avoid free at
659 KEY_FREESP(&sp), sp = NULL;
666 * Do delayed checksums now because we send before
667 * this is done in the normal processing path.
669 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
671 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
674 ip->ip_len = htons(ip->ip_len);
675 ip->ip_off = htons(ip->ip_off);
677 /* NB: callee frees mbuf */
678 error = ipsec4_process_packet(m, sp->req, flags, 0);
680 * Preserve KAME behaviour: ENOENT can be returned
681 * when an SA acquire is in progress. Don't propagate
682 * this to user-level; it confuses applications.
684 * XXX this will go away when the SADB is redone.
695 * Hack: -EINVAL is used to signal that a packet
696 * should be silently discarded. This is typically
697 * because we asked key management for an SA and
698 * it was delayed (e.g. kicked up to IKE).
700 if (error == -EINVAL)
704 /* No IPsec processing for this packet. */
708 * If deferred crypto processing is needed, check that
709 * the interface supports it.
711 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
712 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) {
713 /* notify IPsec to do its own crypto */
714 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
715 error = EHOSTUNREACH;
721 #endif /* FAST_IPSEC */
724 * - Xlate: translate packet's addr/port (NAT).
725 * - Firewall: deny/allow/etc.
726 * - Wrap: fake packet's addr/port <unimpl.>
727 * - Encapsulate: put it in another IP and send out. <unimp.>
731 * Run through list of hooks for output packets.
733 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
734 if (error != 0 || m == NULL)
736 ip = mtod(m, struct ip *);
737 #endif /* PFIL_HOOKS */
740 * Check with the firewall...
741 * but not if we are already being fwd'd from a firewall.
743 if (fw_enable && IPFW_LOADED && !args.next_hop) {
744 struct sockaddr_in *old = dst;
749 off = ip_fw_chk_ptr(&args);
754 * On return we must do the following:
755 * m == NULL -> drop the pkt (old interface, deprecated)
756 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface)
757 * 1<=off<= 0xffff -> DIVERT
758 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe
759 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet
760 * dst != old -> IPFIREWALL_FORWARD
761 * off==0, dst==old -> accept
762 * If some of the above modules are not compiled in, then
763 * we should't have to check the corresponding condition
764 * (because the ipfw control socket should not accept
765 * unsupported rules), but better play safe and drop
766 * packets in case of doubt.
768 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) {
774 ip = mtod(m, struct ip *);
775 if (off == 0 && dst == old) /* common case */
777 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) {
779 * pass the pkt to dummynet. Need to include
780 * pipe number, m, ifp, ro, dst because these are
781 * not recomputed in the next pass.
782 * All other parameters have been already used and
783 * so they are not needed anymore.
784 * XXX note: if the ifp or ro entry are deleted
785 * while a pkt is in dummynet, we are in trouble!
791 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT,
796 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) {
797 struct mbuf *clone = NULL;
799 /* Clone packet if we're doing a 'tee' */
800 if ((off & IP_FW_PORT_TEE_FLAG) != 0)
801 clone = m_dup(m, M_DONTWAIT);
805 * delayed checksums are not currently compatible
806 * with divert sockets.
808 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
810 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
813 /* Restore packet header fields to original values */
814 ip->ip_len = htons(ip->ip_len);
815 ip->ip_off = htons(ip->ip_off);
817 /* Deliver packet to divert input routine */
818 divert_packet(m, 0, off & 0xffff, args.divert_rule);
820 /* If 'tee', continue with original packet */
823 ip = mtod(m, struct ip *);
830 /* IPFIREWALL_FORWARD */
832 * Check dst to make sure it is directly reachable on the
833 * interface we previously thought it was.
834 * If it isn't (which may be likely in some situations) we have
835 * to re-route it (ie, find a route for the next-hop and the
836 * associated interface) and set them here. This is nested
837 * forwarding which in most cases is undesirable, except where
838 * such control is nigh impossible. So we do it here.
841 if (off == 0 && old != dst) { /* FORWARD, dst has changed */
844 * XXX To improve readability, this block should be
845 * changed into a function call as below:
847 error = ip_ipforward(&m, &dst, &ifp);
850 if (m == NULL) /* ip_input consumed the mbuf */
853 struct in_ifaddr *ia;
856 * XXX sro_fwd below is static, and a pointer
857 * to it gets passed to routines downstream.
858 * This could have surprisingly bad results in
859 * practice, because its content is overwritten
860 * by subsequent packets.
862 /* There must be a better way to do this next line... */
863 static struct route sro_fwd;
864 struct route *ro_fwd = &sro_fwd;
867 print_ip("IPFIREWALL_FORWARD: New dst ip: ",
868 dst->sin_addr, "\n");
872 * We need to figure out if we have been forwarded
873 * to a local socket. If so, then we should somehow
874 * "loop back" to ip_input, and get directed to the
875 * PCB as if we had received this packet. This is
876 * because it may be dificult to identify the packets
877 * you want to forward until they are being output
878 * and have selected an interface. (e.g. locally
879 * initiated packets) If we used the loopback inteface,
880 * we would not be able to control what happens
881 * as the packet runs through ip_input() as
882 * it is done through a ISR.
885 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) {
887 * If the addr to forward to is one
888 * of ours, we pretend to
889 * be the destination for this packet.
891 if (IA_SIN(ia)->sin_addr.s_addr ==
892 dst->sin_addr.s_addr)
895 if (ia) { /* tell ip_input "dont filter" */
897 struct netmsg_packet msg;
899 tag.mh_type = MT_TAG;
900 tag.mh_flags = PACKET_TAG_IPFORWARD;
901 tag.mh_data = (caddr_t)args.next_hop;
904 if (m->m_pkthdr.rcvif == NULL)
905 m->m_pkthdr.rcvif = ifunit("lo0");
906 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
907 m->m_pkthdr.csum_flags |=
908 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
909 m0->m_pkthdr.csum_data = 0xffff;
911 m->m_pkthdr.csum_flags |=
912 CSUM_IP_CHECKED | CSUM_IP_VALID;
913 ip->ip_len = htons(ip->ip_len);
914 ip->ip_off = htons(ip->ip_off);
915 msg.nm_packet = (struct mbuf *)&tag;
916 ip_input((struct netmsg *)&msg);
919 /* Some of the logic for this was
922 * This rewrites the cached route in a local PCB.
923 * Is this what we want to do?
925 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst));
928 rtalloc_ign(ro_fwd, RTF_PRCLONING);
930 if (ro_fwd->ro_rt == 0) {
931 ipstat.ips_noroute++;
932 error = EHOSTUNREACH;
936 ia = ifatoia(ro_fwd->ro_rt->rt_ifa);
937 ifp = ro_fwd->ro_rt->rt_ifp;
938 ro_fwd->ro_rt->rt_use++;
939 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
940 dst = (struct sockaddr_in *)
941 ro_fwd->ro_rt->rt_gateway;
942 if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
944 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
946 isbroadcast = in_broadcast(dst->sin_addr, ifp);
949 ro->ro_rt = ro_fwd->ro_rt;
950 dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
952 #endif /* ... block to be put into a function */
954 * If we added a default src ip earlier,
955 * which would have been gotten from the-then
956 * interface, do it again, from the new one.
958 if (src_was_INADDR_ANY)
959 ip->ip_src = IA_SIN(ia)->sin_addr;
964 * if we get here, none of the above matches, and
965 * we have to drop the pkt
968 error = EACCES; /* not sure this is the right error msg */
973 /* 127/8 must not appear on wire - RFC1122. */
974 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
975 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
976 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
977 ipstat.ips_badaddr++;
978 error = EADDRNOTAVAIL;
983 m->m_pkthdr.csum_flags |= CSUM_IP;
984 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
985 if (sw_csum & CSUM_DELAY_DATA) {
987 sw_csum &= ~CSUM_DELAY_DATA;
989 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
992 * If small enough for interface, or the interface will take
993 * care of the fragmentation for us, can just send directly.
995 if (ip->ip_len <= ifp->if_mtu || ifp->if_hwassist & CSUM_FRAGMENT) {
996 ip->ip_len = htons(ip->ip_len);
997 ip->ip_off = htons(ip->ip_off);
999 if (sw_csum & CSUM_DELAY_IP) {
1000 if (ip->ip_vhl == IP_VHL_BORING) {
1001 ip->ip_sum = in_cksum_hdr(ip);
1003 ip->ip_sum = in_cksum(m, hlen);
1007 /* Record statistics for this interface address. */
1008 if (!(flags & IP_FORWARDING) && ia) {
1009 ia->ia_ifa.if_opackets++;
1010 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1014 /* clean ipsec history once it goes out of the node */
1018 #ifdef MBUF_STRESS_TEST
1019 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
1020 struct mbuf *m1, *m2;
1023 tmp = length = m->m_pkthdr.len;
1025 while ((length -= mbuf_frag_size) >= 1) {
1026 m1 = m_split(m, length, M_DONTWAIT);
1029 m1->m_flags &= ~M_PKTHDR;
1031 while (m2->m_next != NULL)
1035 m->m_pkthdr.len = tmp;
1038 error = (*ifp->if_output)(ifp, m,
1039 (struct sockaddr *)dst, ro->ro_rt);
1043 if (ip->ip_off & IP_DF) {
1046 * This case can happen if the user changed the MTU
1047 * of an interface after enabling IP on it. Because
1048 * most netifs don't keep track of routes pointing to
1049 * them, there is no way for one to update all its
1050 * routes when the MTU is changed.
1052 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) &&
1053 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
1054 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
1055 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
1057 ipstat.ips_cantfrag++;
1062 * Too large for interface; fragment if possible. If successful,
1063 * on return, m will point to a list of packets to be sent.
1065 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum);
1072 /* clean ipsec history once it goes out of the node */
1076 /* Record statistics for this interface address. */
1078 ia->ia_ifa.if_opackets++;
1079 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1082 error = (*ifp->if_output)(ifp, m,
1083 (struct sockaddr *)dst, ro->ro_rt);
1089 ipstat.ips_fragmented++;
1093 if (ro == &iproute && ro->ro_rt) {
1098 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1099 printf("DP ip_output call free SP:%p\n", sp));
1104 if (ro == &iproute && ro->ro_rt) {
1118 * Create a chain of fragments which fit the given mtu. m_frag points to the
1119 * mbuf to be fragmented; on return it points to the chain with the fragments.
1120 * Return 0 if no error. If error, m_frag may contain a partially built
1121 * chain of fragments that should be freed by the caller.
1123 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1124 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1127 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1128 u_long if_hwassist_flags, int sw_csum)
1131 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1132 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
1134 struct mbuf *m0 = *m_frag; /* the original packet */
1136 struct mbuf **mnext;
1139 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
1140 ipstat.ips_cantfrag++;
1145 * Must be able to put at least 8 bytes per fragment.
1151 * If the interface will not calculate checksums on
1152 * fragmented packets, then do it here.
1154 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA &&
1155 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
1156 in_delayed_cksum(m0);
1157 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1160 if (len > PAGE_SIZE) {
1162 * Fragment large datagrams such that each segment
1163 * contains a multiple of PAGE_SIZE amount of data,
1164 * plus headers. This enables a receiver to perform
1165 * page-flipping zero-copy optimizations.
1167 * XXX When does this help given that sender and receiver
1168 * could have different page sizes, and also mtu could
1169 * be less than the receiver's page size ?
1174 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1178 * firstlen (off - hlen) must be aligned on an
1182 goto smart_frag_failure;
1183 off = ((off - hlen) & ~7) + hlen;
1184 newlen = (~PAGE_MASK) & mtu;
1185 if ((newlen + sizeof (struct ip)) > mtu) {
1186 /* we failed, go back the default */
1197 firstlen = off - hlen;
1198 mnext = &m0->m_nextpkt; /* pointer to next packet */
1201 * Loop through length of segment after first fragment,
1202 * make new header and copy data of each part and link onto chain.
1203 * Here, m0 is the original packet, m is the fragment being created.
1204 * The fragments are linked off the m_nextpkt of the original
1205 * packet, which after processing serves as the first fragment.
1207 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1208 struct ip *mhip; /* ip header on the fragment */
1210 int mhlen = sizeof (struct ip);
1212 MGETHDR(m, M_DONTWAIT, MT_HEADER);
1215 ipstat.ips_odropped++;
1218 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1220 * In the first mbuf, leave room for the link header, then
1221 * copy the original IP header including options. The payload
1222 * goes into an additional mbuf chain returned by m_copy().
1224 m->m_data += max_linkhdr;
1225 mhip = mtod(m, struct ip *);
1227 if (hlen > sizeof (struct ip)) {
1228 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
1229 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1232 /* XXX do we need to add ip->ip_off below ? */
1233 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1234 if (off + len >= ip->ip_len) { /* last fragment */
1235 len = ip->ip_len - off;
1236 m->m_flags |= M_LASTFRAG;
1238 mhip->ip_off |= IP_MF;
1239 mhip->ip_len = htons((u_short)(len + mhlen));
1240 m->m_next = m_copy(m0, off, len);
1241 if (m->m_next == 0) { /* copy failed */
1243 error = ENOBUFS; /* ??? */
1244 ipstat.ips_odropped++;
1247 m->m_pkthdr.len = mhlen + len;
1248 m->m_pkthdr.rcvif = (struct ifnet *)0;
1249 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1250 mhip->ip_off = htons(mhip->ip_off);
1252 if (sw_csum & CSUM_DELAY_IP)
1253 mhip->ip_sum = in_cksum(m, mhlen);
1255 mnext = &m->m_nextpkt;
1257 ipstat.ips_ofragments += nfrags;
1259 /* set first marker for fragment chain */
1260 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1261 m0->m_pkthdr.csum_data = nfrags;
1264 * Update first fragment by trimming what's been copied out
1265 * and updating header.
1267 m_adj(m0, hlen + firstlen - ip->ip_len);
1268 m0->m_pkthdr.len = hlen + firstlen;
1269 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1270 ip->ip_off |= IP_MF;
1271 ip->ip_off = htons(ip->ip_off);
1273 if (sw_csum & CSUM_DELAY_IP)
1274 ip->ip_sum = in_cksum(m0, hlen);
1282 in_delayed_cksum(struct mbuf *m)
1285 u_short csum, offset;
1287 ip = mtod(m, struct ip *);
1288 offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1289 csum = in_cksum_skip(m, ip->ip_len, offset);
1290 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1292 offset += m->m_pkthdr.csum_data; /* checksum offset */
1294 if (offset + sizeof(u_short) > m->m_len) {
1295 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
1296 m->m_len, offset, ip->ip_p);
1299 * this shouldn't happen, but if it does, the
1300 * correct behavior may be to insert the checksum
1301 * in the existing chain instead of rearranging it.
1303 m = m_pullup(m, offset + sizeof(u_short));
1305 *(u_short *)(m->m_data + offset) = csum;
1309 * Insert IP options into preformed packet.
1310 * Adjust IP destination as required for IP source routing,
1311 * as indicated by a non-zero in_addr at the start of the options.
1313 * XXX This routine assumes that the packet has no options in place.
1315 static struct mbuf *
1316 ip_insertoptions(m, opt, phlen)
1321 struct ipoption *p = mtod(opt, struct ipoption *);
1323 struct ip *ip = mtod(m, struct ip *);
1326 optlen = opt->m_len - sizeof(p->ipopt_dst);
1327 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1329 return (m); /* XXX should fail */
1331 if (p->ipopt_dst.s_addr)
1332 ip->ip_dst = p->ipopt_dst;
1333 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1334 MGETHDR(n, M_DONTWAIT, MT_HEADER);
1339 n->m_pkthdr.rcvif = (struct ifnet *)0;
1340 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1341 m->m_len -= sizeof(struct ip);
1342 m->m_data += sizeof(struct ip);
1345 m->m_len = optlen + sizeof(struct ip);
1346 m->m_data += max_linkhdr;
1347 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip));
1349 m->m_data -= optlen;
1351 m->m_pkthdr.len += optlen;
1352 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
1354 ip = mtod(m, struct ip *);
1355 bcopy(p->ipopt_list, ip + 1, optlen);
1356 *phlen = sizeof(struct ip) + optlen;
1357 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1358 ip->ip_len += optlen;
1363 * Copy options from ip to jp,
1364 * omitting those not copied during fragmentation.
1371 int opt, optlen, cnt;
1373 cp = (u_char *)(ip + 1);
1374 dp = (u_char *)(jp + 1);
1375 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
1376 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1378 if (opt == IPOPT_EOL)
1380 if (opt == IPOPT_NOP) {
1381 /* Preserve for IP mcast tunnel's LSRR alignment. */
1387 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp),
1388 ("ip_optcopy: malformed ipv4 option"));
1389 optlen = cp[IPOPT_OLEN];
1390 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt,
1391 ("ip_optcopy: malformed ipv4 option"));
1393 /* bogus lengths should have been caught by ip_dooptions */
1396 if (IPOPT_COPIED(opt)) {
1397 bcopy(cp, dp, optlen);
1401 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1407 * IP socket option processing.
1410 ip_ctloutput(so, sopt)
1412 struct sockopt *sopt;
1414 struct inpcb *inp = sotoinpcb(so);
1418 if (sopt->sopt_level != IPPROTO_IP) {
1422 switch (sopt->sopt_dir) {
1424 switch (sopt->sopt_name) {
1431 if (sopt->sopt_valsize > MLEN) {
1435 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_HEADER);
1440 m->m_len = sopt->sopt_valsize;
1441 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1444 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options,
1451 case IP_RECVRETOPTS:
1452 case IP_RECVDSTADDR:
1455 error = sooptcopyin(sopt, &optval, sizeof optval,
1460 switch (sopt->sopt_name) {
1462 inp->inp_ip_tos = optval;
1466 inp->inp_ip_ttl = optval;
1468 #define OPTSET(bit) \
1470 inp->inp_flags |= bit; \
1472 inp->inp_flags &= ~bit;
1475 OPTSET(INP_RECVOPTS);
1478 case IP_RECVRETOPTS:
1479 OPTSET(INP_RECVRETOPTS);
1482 case IP_RECVDSTADDR:
1483 OPTSET(INP_RECVDSTADDR);
1497 case IP_MULTICAST_IF:
1498 case IP_MULTICAST_VIF:
1499 case IP_MULTICAST_TTL:
1500 case IP_MULTICAST_LOOP:
1501 case IP_ADD_MEMBERSHIP:
1502 case IP_DROP_MEMBERSHIP:
1503 error = ip_setmoptions(sopt, &inp->inp_moptions);
1507 error = sooptcopyin(sopt, &optval, sizeof optval,
1513 case IP_PORTRANGE_DEFAULT:
1514 inp->inp_flags &= ~(INP_LOWPORT);
1515 inp->inp_flags &= ~(INP_HIGHPORT);
1518 case IP_PORTRANGE_HIGH:
1519 inp->inp_flags &= ~(INP_LOWPORT);
1520 inp->inp_flags |= INP_HIGHPORT;
1523 case IP_PORTRANGE_LOW:
1524 inp->inp_flags &= ~(INP_HIGHPORT);
1525 inp->inp_flags |= INP_LOWPORT;
1534 #if defined(IPSEC) || defined(FAST_IPSEC)
1535 case IP_IPSEC_POLICY:
1543 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1545 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1547 priv = (sopt->sopt_td != NULL &&
1548 suser(sopt->sopt_td) != 0) ? 0 : 1;
1549 req = mtod(m, caddr_t);
1551 optname = sopt->sopt_name;
1552 error = ipsec4_set_policy(inp, optname, req, len, priv);
1559 error = ENOPROTOOPT;
1565 switch (sopt->sopt_name) {
1568 if (inp->inp_options)
1569 error = sooptcopyout(sopt,
1570 mtod(inp->inp_options,
1572 inp->inp_options->m_len);
1574 sopt->sopt_valsize = 0;
1580 case IP_RECVRETOPTS:
1581 case IP_RECVDSTADDR:
1585 switch (sopt->sopt_name) {
1588 optval = inp->inp_ip_tos;
1592 optval = inp->inp_ip_ttl;
1595 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1598 optval = OPTBIT(INP_RECVOPTS);
1601 case IP_RECVRETOPTS:
1602 optval = OPTBIT(INP_RECVRETOPTS);
1605 case IP_RECVDSTADDR:
1606 optval = OPTBIT(INP_RECVDSTADDR);
1610 optval = OPTBIT(INP_RECVIF);
1614 if (inp->inp_flags & INP_HIGHPORT)
1615 optval = IP_PORTRANGE_HIGH;
1616 else if (inp->inp_flags & INP_LOWPORT)
1617 optval = IP_PORTRANGE_LOW;
1623 optval = OPTBIT(INP_FAITH);
1626 error = sooptcopyout(sopt, &optval, sizeof optval);
1629 case IP_MULTICAST_IF:
1630 case IP_MULTICAST_VIF:
1631 case IP_MULTICAST_TTL:
1632 case IP_MULTICAST_LOOP:
1633 case IP_ADD_MEMBERSHIP:
1634 case IP_DROP_MEMBERSHIP:
1635 error = ip_getmoptions(sopt, inp->inp_moptions);
1638 #if defined(IPSEC) || defined(FAST_IPSEC)
1639 case IP_IPSEC_POLICY:
1641 struct mbuf *m = NULL;
1646 req = mtod(m, caddr_t);
1649 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m);
1651 error = soopt_mcopyout(sopt, m); /* XXX */
1659 error = ENOPROTOOPT;
1668 * Set up IP options in pcb for insertion in output packets.
1669 * Store in mbuf with pointer in pcbopt, adding pseudo-option
1670 * with destination address if source routed.
1673 ip_pcbopts(optname, pcbopt, m)
1675 struct mbuf **pcbopt;
1682 /* turn off any old options */
1684 (void)m_free(*pcbopt);
1686 if (m == (struct mbuf *)0 || m->m_len == 0) {
1688 * Only turning off any previous options.
1695 if (m->m_len % sizeof(int32_t))
1698 * IP first-hop destination address will be stored before
1699 * actual options; move other options back
1700 * and clear it when none present.
1702 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1705 m->m_len += sizeof(struct in_addr);
1706 cp = mtod(m, u_char *) + sizeof(struct in_addr);
1707 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt);
1708 bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1710 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1711 opt = cp[IPOPT_OPTVAL];
1712 if (opt == IPOPT_EOL)
1714 if (opt == IPOPT_NOP)
1717 if (cnt < IPOPT_OLEN + sizeof(*cp))
1719 optlen = cp[IPOPT_OLEN];
1720 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt)
1731 * user process specifies route as:
1733 * D must be our final destination (but we can't
1734 * check that since we may not have connected yet).
1735 * A is first hop destination, which doesn't appear in
1736 * actual IP option, but is stored before the options.
1738 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1740 m->m_len -= sizeof(struct in_addr);
1741 cnt -= sizeof(struct in_addr);
1742 optlen -= sizeof(struct in_addr);
1743 cp[IPOPT_OLEN] = optlen;
1745 * Move first hop before start of options.
1747 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1748 sizeof(struct in_addr));
1750 * Then copy rest of options back
1751 * to close up the deleted entry.
1753 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] +
1754 sizeof(struct in_addr)),
1755 (caddr_t)&cp[IPOPT_OFFSET+1],
1756 (unsigned)cnt + sizeof(struct in_addr));
1760 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1772 * The whole multicast option thing needs to be re-thought.
1773 * Several of these options are equally applicable to non-multicast
1774 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1775 * standard option (IP_TTL).
1779 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1781 static struct ifnet *
1782 ip_multicast_if(a, ifindexp)
1791 if (ntohl(a->s_addr) >> 24 == 0) {
1792 ifindex = ntohl(a->s_addr) & 0xffffff;
1793 if (ifindex < 0 || if_index < ifindex)
1795 ifp = ifindex2ifnet[ifindex];
1797 *ifindexp = ifindex;
1799 INADDR_TO_IFP(*a, ifp);
1805 * Set the IP multicast options in response to user setsockopt().
1808 ip_setmoptions(sopt, imop)
1809 struct sockopt *sopt;
1810 struct ip_moptions **imop;
1814 struct in_addr addr;
1815 struct ip_mreq mreq;
1817 struct ip_moptions *imo = *imop;
1819 struct sockaddr_in *dst;
1825 * No multicast option buffer attached to the pcb;
1826 * allocate one and initialize to default values.
1828 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS,
1834 imo->imo_multicast_ifp = NULL;
1835 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1836 imo->imo_multicast_vif = -1;
1837 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1838 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1839 imo->imo_num_memberships = 0;
1842 switch (sopt->sopt_name) {
1843 /* store an index number for the vif you wanna use in the send */
1844 case IP_MULTICAST_VIF:
1845 if (legal_vif_num == 0) {
1849 error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
1852 if (!legal_vif_num(i) && (i != -1)) {
1856 imo->imo_multicast_vif = i;
1859 case IP_MULTICAST_IF:
1861 * Select the interface for outgoing multicast packets.
1863 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
1867 * INADDR_ANY is used to remove a previous selection.
1868 * When no interface is selected, a default one is
1869 * chosen every time a multicast packet is sent.
1871 if (addr.s_addr == INADDR_ANY) {
1872 imo->imo_multicast_ifp = NULL;
1876 * The selected interface is identified by its local
1877 * IP address. Find the interface and confirm that
1878 * it supports multicasting.
1881 ifp = ip_multicast_if(&addr, &ifindex);
1882 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1884 error = EADDRNOTAVAIL;
1887 imo->imo_multicast_ifp = ifp;
1889 imo->imo_multicast_addr = addr;
1891 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1895 case IP_MULTICAST_TTL:
1897 * Set the IP time-to-live for outgoing multicast packets.
1898 * The original multicast API required a char argument,
1899 * which is inconsistent with the rest of the socket API.
1900 * We allow either a char or an int.
1902 if (sopt->sopt_valsize == 1) {
1904 error = sooptcopyin(sopt, &ttl, 1, 1);
1907 imo->imo_multicast_ttl = ttl;
1910 error = sooptcopyin(sopt, &ttl, sizeof ttl,
1917 imo->imo_multicast_ttl = ttl;
1921 case IP_MULTICAST_LOOP:
1923 * Set the loopback flag for outgoing multicast packets.
1924 * Must be zero or one. The original multicast API required a
1925 * char argument, which is inconsistent with the rest
1926 * of the socket API. We allow either a char or an int.
1928 if (sopt->sopt_valsize == 1) {
1930 error = sooptcopyin(sopt, &loop, 1, 1);
1933 imo->imo_multicast_loop = !!loop;
1936 error = sooptcopyin(sopt, &loop, sizeof loop,
1940 imo->imo_multicast_loop = !!loop;
1944 case IP_ADD_MEMBERSHIP:
1946 * Add a multicast group membership.
1947 * Group must be a valid IP multicast address.
1949 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1953 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1959 * If no interface address was provided, use the interface of
1960 * the route to the given multicast address.
1962 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1963 bzero((caddr_t)&ro, sizeof(ro));
1964 dst = (struct sockaddr_in *)&ro.ro_dst;
1965 dst->sin_len = sizeof(*dst);
1966 dst->sin_family = AF_INET;
1967 dst->sin_addr = mreq.imr_multiaddr;
1969 if (ro.ro_rt == NULL) {
1970 error = EADDRNOTAVAIL;
1974 ifp = ro.ro_rt->rt_ifp;
1978 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1982 * See if we found an interface, and confirm that it
1983 * supports multicast.
1985 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1986 error = EADDRNOTAVAIL;
1991 * See if the membership already exists or if all the
1992 * membership slots are full.
1994 for (i = 0; i < imo->imo_num_memberships; ++i) {
1995 if (imo->imo_membership[i]->inm_ifp == ifp &&
1996 imo->imo_membership[i]->inm_addr.s_addr
1997 == mreq.imr_multiaddr.s_addr)
2000 if (i < imo->imo_num_memberships) {
2005 if (i == IP_MAX_MEMBERSHIPS) {
2006 error = ETOOMANYREFS;
2011 * Everything looks good; add a new record to the multicast
2012 * address list for the given interface.
2014 if ((imo->imo_membership[i] =
2015 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
2020 ++imo->imo_num_memberships;
2024 case IP_DROP_MEMBERSHIP:
2026 * Drop a multicast group membership.
2027 * Group must be a valid IP multicast address.
2029 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
2033 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
2040 * If an interface address was specified, get a pointer
2041 * to its ifnet structure.
2043 if (mreq.imr_interface.s_addr == INADDR_ANY)
2046 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
2048 error = EADDRNOTAVAIL;
2054 * Find the membership in the membership array.
2056 for (i = 0; i < imo->imo_num_memberships; ++i) {
2058 imo->imo_membership[i]->inm_ifp == ifp) &&
2059 imo->imo_membership[i]->inm_addr.s_addr ==
2060 mreq.imr_multiaddr.s_addr)
2063 if (i == imo->imo_num_memberships) {
2064 error = EADDRNOTAVAIL;
2069 * Give up the multicast address record to which the
2070 * membership points.
2072 in_delmulti(imo->imo_membership[i]);
2074 * Remove the gap in the membership array.
2076 for (++i; i < imo->imo_num_memberships; ++i)
2077 imo->imo_membership[i-1] = imo->imo_membership[i];
2078 --imo->imo_num_memberships;
2088 * If all options have default values, no need to keep the mbuf.
2090 if (imo->imo_multicast_ifp == NULL &&
2091 imo->imo_multicast_vif == -1 &&
2092 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
2093 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
2094 imo->imo_num_memberships == 0) {
2095 free(*imop, M_IPMOPTS);
2103 * Return the IP multicast options in response to user getsockopt().
2106 ip_getmoptions(sopt, imo)
2107 struct sockopt *sopt;
2108 struct ip_moptions *imo;
2110 struct in_addr addr;
2111 struct in_ifaddr *ia;
2116 switch (sopt->sopt_name) {
2117 case IP_MULTICAST_VIF:
2119 optval = imo->imo_multicast_vif;
2122 error = sooptcopyout(sopt, &optval, sizeof optval);
2125 case IP_MULTICAST_IF:
2126 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2127 addr.s_addr = INADDR_ANY;
2128 else if (imo->imo_multicast_addr.s_addr) {
2129 /* return the value user has set */
2130 addr = imo->imo_multicast_addr;
2132 IFP_TO_IA(imo->imo_multicast_ifp, ia);
2133 addr.s_addr = (ia == NULL) ? INADDR_ANY
2134 : IA_SIN(ia)->sin_addr.s_addr;
2136 error = sooptcopyout(sopt, &addr, sizeof addr);
2139 case IP_MULTICAST_TTL:
2141 optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2143 optval = coptval = imo->imo_multicast_ttl;
2144 if (sopt->sopt_valsize == 1)
2145 error = sooptcopyout(sopt, &coptval, 1);
2147 error = sooptcopyout(sopt, &optval, sizeof optval);
2150 case IP_MULTICAST_LOOP:
2152 optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2154 optval = coptval = imo->imo_multicast_loop;
2155 if (sopt->sopt_valsize == 1)
2156 error = sooptcopyout(sopt, &coptval, 1);
2158 error = sooptcopyout(sopt, &optval, sizeof optval);
2162 error = ENOPROTOOPT;
2169 * Discard the IP multicast options.
2172 ip_freemoptions(imo)
2173 struct ip_moptions *imo;
2178 for (i = 0; i < imo->imo_num_memberships; ++i)
2179 in_delmulti(imo->imo_membership[i]);
2180 free(imo, M_IPMOPTS);
2185 * Routine called from ip_output() to loop back a copy of an IP multicast
2186 * packet to the input queue of a specified interface. Note that this
2187 * calls the output routine of the loopback "driver", but with an interface
2188 * pointer that might NOT be a loopback interface -- evil, but easier than
2189 * replicating that code here.
2192 ip_mloopback(ifp, m, dst, hlen)
2195 struct sockaddr_in *dst;
2201 copym = m_copy(m, 0, M_COPYALL);
2202 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2203 copym = m_pullup(copym, hlen);
2204 if (copym != NULL) {
2206 * We don't bother to fragment if the IP length is greater
2207 * than the interface's MTU. Can this possibly matter?
2209 ip = mtod(copym, struct ip *);
2210 ip->ip_len = htons(ip->ip_len);
2211 ip->ip_off = htons(ip->ip_off);
2213 if (ip->ip_vhl == IP_VHL_BORING) {
2214 ip->ip_sum = in_cksum_hdr(ip);
2216 ip->ip_sum = in_cksum(copym, hlen);
2220 * It's not clear whether there are any lingering
2221 * reentrancy problems in other areas which might
2222 * be exposed by using ip_input directly (in
2223 * particular, everything which modifies the packet
2224 * in-place). Yet another option is using the
2225 * protosw directly to deliver the looped back
2226 * packet. For the moment, we'll err on the side
2227 * of safety by using if_simloop().
2230 if (dst->sin_family != AF_INET) {
2231 printf("ip_mloopback: bad address family %d\n",
2233 dst->sin_family = AF_INET;
2238 copym->m_pkthdr.rcvif = ifp;
2241 /* if the checksum hasn't been computed, mark it as valid */
2242 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2243 copym->m_pkthdr.csum_flags |=
2244 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2245 copym->m_pkthdr.csum_data = 0xffff;
2247 if_simloop(ifp, copym, dst->sin_family, 0);