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29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
30 * $FreeBSD: src/sys/netinet/ip_output.c,v 1.99.2.37 2003/04/15 06:44:45 silby Exp $
31 * $DragonFly: src/sys/netinet/ip_output.c,v 1.26 2005/02/11 22:25:57 joerg Exp $
38 #include "opt_ipdivert.h"
39 #include "opt_ipfilter.h"
40 #include "opt_ipsec.h"
41 #include "opt_random_ip_id.h"
42 #include "opt_mbuf_stress_test.h"
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/malloc.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
53 #include <sys/sysctl.h>
54 #include <sys/in_cksum.h>
57 #include <net/netisr.h>
59 #include <net/route.h>
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #include <netinet/in_pcb.h>
65 #include <netinet/in_var.h>
66 #include <netinet/ip_var.h>
68 static MALLOC_DEFINE(M_IPMOPTS, "ip_moptions", "internet multicast options");
71 #include <netinet6/ipsec.h>
72 #include <netproto/key/key.h>
74 #include <netproto/key/key_debug.h>
76 #define KEYDEBUG(lev,arg)
81 #include <netproto/ipsec/ipsec.h>
82 #include <netproto/ipsec/xform.h>
83 #include <netproto/ipsec/key.h>
86 #include <net/ipfw/ip_fw.h>
87 #include <net/dummynet/ip_dummynet.h>
89 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\
90 x, (ntohl(a.s_addr)>>24)&0xFF,\
91 (ntohl(a.s_addr)>>16)&0xFF,\
92 (ntohl(a.s_addr)>>8)&0xFF,\
93 (ntohl(a.s_addr))&0xFF, y);
97 #ifdef MBUF_STRESS_TEST
98 int mbuf_frag_size = 0;
99 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
100 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
103 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
104 static struct ifnet *ip_multicast_if(struct in_addr *, int *);
105 static void ip_mloopback
106 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
107 static int ip_getmoptions
108 (struct sockopt *, struct ip_moptions *);
109 static int ip_pcbopts(int, struct mbuf **, struct mbuf *);
110 static int ip_setmoptions
111 (struct sockopt *, struct ip_moptions **);
113 int ip_optcopy(struct ip *, struct ip *);
116 extern struct protosw inetsw[];
119 * IP output. The packet in mbuf chain m contains a skeletal IP
120 * header (with len, off, ttl, proto, tos, src, dst).
121 * The mbuf chain containing the packet will be freed.
122 * The mbuf opt, if present, will not be freed.
125 ip_output(struct mbuf *m0, struct mbuf *opt, struct route *ro,
126 int flags, struct ip_moptions *imo, struct inpcb *inp)
129 struct ifnet *ifp = NULL; /* keep compiler happy */
131 int hlen = sizeof(struct ip);
132 int len, off, error = 0;
133 struct sockaddr_in *dst = NULL; /* keep compiler happy */
134 struct in_ifaddr *ia = NULL;
135 int isbroadcast, sw_csum;
136 struct in_addr pkt_dst;
137 struct route iproute;
139 struct secpolicy *sp = NULL;
140 struct socket *so = inp ? inp->inp_socket : NULL;
144 struct secpolicy *sp = NULL;
145 struct tdb_ident *tdbi;
147 #endif /* FAST_IPSEC */
148 struct ip_fw_args args;
149 int src_was_INADDR_ANY = 0; /* as the name says... */
153 args.next_hop = NULL;
154 args.divert_rule = 0; /* divert cookie */
156 /* Grab info from MT_TAG mbufs prepended to the chain. */
157 while (m0 != NULL && m0->m_type == MT_TAG) {
158 switch(m0->_m_tag_id) {
159 case PACKET_TAG_DUMMYNET:
161 * the packet was already tagged, so part of the
162 * processing was already done, and we need to go down.
163 * Get parameters from the header.
165 args.rule = ((struct dn_pkt *)m0)->rule;
167 ro = &((struct dn_pkt *)m0)->ro;
169 dst = ((struct dn_pkt *)m0)->dn_dst ;
170 ifp = ((struct dn_pkt *)m0)->ifp ;
171 flags = ((struct dn_pkt *)m0)->flags ;
173 case PACKET_TAG_DIVERT:
174 args.divert_rule = (int)m0->m_data & 0xffff;
176 case PACKET_TAG_IPFORWARD:
177 args.next_hop = (struct sockaddr_in *)m0->m_data;
180 printf("ip_output: unrecognised MT_TAG tag %d\n",
187 KASSERT(m != NULL && (m->m_flags & M_PKTHDR), ("ip_output: no HDR"));
191 bzero(ro, sizeof *ro);
194 if (args.rule != NULL) { /* dummynet already saw us */
195 ip = mtod(m, struct ip *);
196 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
198 ia = ifatoia(ro->ro_rt->rt_ifa);
204 m = ip_insertoptions(m, opt, &len);
208 ip = mtod(m, struct ip *);
209 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
214 if (!(flags & (IP_FORWARDING|IP_RAWOUTPUT))) {
215 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
218 ip->ip_id = ip_randomid();
220 ip->ip_id = htons(ip_id++);
222 ipstat.ips_localout++;
224 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
227 dst = (struct sockaddr_in *)&ro->ro_dst;
229 * If there is a cached route,
230 * check that it is to the same destination
231 * and is still up. If not, free it and try again.
232 * The address family should also be checked in case of sharing the
236 (!(ro->ro_rt->rt_flags & RTF_UP) ||
237 dst->sin_family != AF_INET ||
238 dst->sin_addr.s_addr != pkt_dst.s_addr)) {
240 ro->ro_rt = (struct rtentry *)NULL;
242 if (ro->ro_rt == NULL) {
243 bzero(dst, sizeof *dst);
244 dst->sin_family = AF_INET;
245 dst->sin_len = sizeof *dst;
246 dst->sin_addr = pkt_dst;
249 * If routing to interface only,
250 * short circuit routing lookup.
252 if (flags & IP_ROUTETOIF) {
253 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
254 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
255 ipstat.ips_noroute++;
261 isbroadcast = in_broadcast(dst->sin_addr, ifp);
262 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
263 imo != NULL && imo->imo_multicast_ifp != NULL) {
265 * Bypass the normal routing lookup for multicast
266 * packets if the interface is specified.
268 ifp = imo->imo_multicast_ifp;
270 isbroadcast = 0; /* fool gcc */
273 * If this is the case, we probably don't want to allocate
274 * a protocol-cloned route since we didn't get one from the
275 * ULP. This lets TCP do its thing, while not burdening
276 * forwarding or ICMP with the overhead of cloning a route.
277 * Of course, we still want to do any cloning requested by
278 * the link layer, as this is probably required in all cases
279 * for correct operation (as it is for ARP).
281 if (ro->ro_rt == NULL)
282 rtalloc_ign(ro, RTF_PRCLONING);
283 if (ro->ro_rt == NULL) {
284 ipstat.ips_noroute++;
285 error = EHOSTUNREACH;
288 ia = ifatoia(ro->ro_rt->rt_ifa);
289 ifp = ro->ro_rt->rt_ifp;
291 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
292 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
293 if (ro->ro_rt->rt_flags & RTF_HOST)
294 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
296 isbroadcast = in_broadcast(dst->sin_addr, ifp);
298 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
299 struct in_multi *inm;
301 m->m_flags |= M_MCAST;
303 * IP destination address is multicast. Make sure "dst"
304 * still points to the address in "ro". (It may have been
305 * changed to point to a gateway address, above.)
307 dst = (struct sockaddr_in *)&ro->ro_dst;
309 * See if the caller provided any multicast options
312 ip->ip_ttl = imo->imo_multicast_ttl;
313 if (imo->imo_multicast_vif != -1)
316 ip_mcast_src(imo->imo_multicast_vif) :
319 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
321 * Confirm that the outgoing interface supports multicast.
323 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
324 if (!(ifp->if_flags & IFF_MULTICAST)) {
325 ipstat.ips_noroute++;
331 * If source address not specified yet, use address
332 * of outgoing interface.
334 if (ip->ip_src.s_addr == INADDR_ANY) {
335 /* Interface may have no addresses. */
337 ip->ip_src = IA_SIN(ia)->sin_addr;
340 IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
342 (imo == NULL || imo->imo_multicast_loop)) {
344 * If we belong to the destination multicast group
345 * on the outgoing interface, and the caller did not
346 * forbid loopback, loop back a copy.
348 ip_mloopback(ifp, m, dst, hlen);
352 * If we are acting as a multicast router, perform
353 * multicast forwarding as if the packet had just
354 * arrived on the interface to which we are about
355 * to send. The multicast forwarding function
356 * recursively calls this function, using the
357 * IP_FORWARDING flag to prevent infinite recursion.
359 * Multicasts that are looped back by ip_mloopback(),
360 * above, will be forwarded by the ip_input() routine,
363 if (ip_mrouter && !(flags & IP_FORWARDING)) {
365 * If rsvp daemon is not running, do not
366 * set ip_moptions. This ensures that the packet
367 * is multicast and not just sent down one link
368 * as prescribed by rsvpd.
373 ip_mforward(ip, ifp, m, imo) != 0) {
381 * Multicasts with a time-to-live of zero may be looped-
382 * back, above, but must not be transmitted on a network.
383 * Also, multicasts addressed to the loopback interface
384 * are not sent -- the above call to ip_mloopback() will
385 * loop back a copy if this host actually belongs to the
386 * destination group on the loopback interface.
388 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
397 * If the source address is not specified yet, use the address
398 * of the outoing interface. In case, keep note we did that, so
399 * if the the firewall changes the next-hop causing the output
400 * interface to change, we can fix that.
402 if (ip->ip_src.s_addr == INADDR_ANY) {
403 /* Interface may have no addresses. */
405 ip->ip_src = IA_SIN(ia)->sin_addr;
406 src_was_INADDR_ANY = 1;
412 * Disable packet drop hack.
413 * Packetdrop should be done by queueing.
417 * Verify that we have any chance at all of being able to queue
418 * the packet or packet fragments
420 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
421 ifp->if_snd.ifq_maxlen) {
423 ipstat.ips_odropped++;
429 * Look for broadcast address and
430 * verify user is allowed to send
434 if (!(ifp->if_flags & IFF_BROADCAST)) {
435 error = EADDRNOTAVAIL;
438 if (!(flags & IP_ALLOWBROADCAST)) {
442 /* don't allow broadcast messages to be fragmented */
443 if (ip->ip_len > ifp->if_mtu) {
447 m->m_flags |= M_BCAST;
449 m->m_flags &= ~M_BCAST;
454 /* get SP for this packet */
456 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
458 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
461 ipsecstat.out_inval++;
468 switch (sp->policy) {
469 case IPSEC_POLICY_DISCARD:
471 * This packet is just discarded.
473 ipsecstat.out_polvio++;
476 case IPSEC_POLICY_BYPASS:
477 case IPSEC_POLICY_NONE:
478 /* no need to do IPsec. */
481 case IPSEC_POLICY_IPSEC:
482 if (sp->req == NULL) {
483 /* acquire a policy */
484 error = key_spdacquire(sp);
489 case IPSEC_POLICY_ENTRUST:
491 printf("ip_output: Invalid policy found. %d\n", sp->policy);
494 struct ipsec_output_state state;
495 bzero(&state, sizeof state);
497 if (flags & IP_ROUTETOIF) {
499 bzero(&iproute, sizeof iproute);
502 state.dst = (struct sockaddr *)dst;
508 * delayed checksums are not currently compatible with IPsec
510 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
512 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
515 ip->ip_len = htons(ip->ip_len);
516 ip->ip_off = htons(ip->ip_off);
518 error = ipsec4_output(&state, sp, flags);
521 if (flags & IP_ROUTETOIF) {
523 * if we have tunnel mode SA, we may need to ignore
526 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
527 flags &= ~IP_ROUTETOIF;
532 dst = (struct sockaddr_in *)state.dst;
534 /* mbuf is already reclaimed in ipsec4_output. */
544 printf("ip4_output (ipsec): error code %d\n", error);
547 /* don't show these error codes to the user */
555 /* be sure to update variables that are affected by ipsec4_output() */
556 ip = mtod(m, struct ip *);
558 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
560 hlen = ip->ip_hl << 2;
562 if (ro->ro_rt == NULL) {
563 if (!(flags & IP_ROUTETOIF)) {
565 "can't update route after IPsec processing\n");
566 error = EHOSTUNREACH; /*XXX*/
570 ia = ifatoia(ro->ro_rt->rt_ifa);
571 ifp = ro->ro_rt->rt_ifp;
574 /* make it flipped, again. */
575 ip->ip_len = ntohs(ip->ip_len);
576 ip->ip_off = ntohs(ip->ip_off);
581 * Check the security policy (SP) for the packet and, if
582 * required, do IPsec-related processing. There are two
583 * cases here; the first time a packet is sent through
584 * it will be untagged and handled by ipsec4_checkpolicy.
585 * If the packet is resubmitted to ip_output (e.g. after
586 * AH, ESP, etc. processing), there will be a tag to bypass
587 * the lookup and related policy checking.
589 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
592 tdbi = (struct tdb_ident *)(mtag + 1);
593 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
595 error = -EINVAL; /* force silent drop */
596 m_tag_delete(m, mtag);
598 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
602 * There are four return cases:
603 * sp != NULL apply IPsec policy
604 * sp == NULL, error == 0 no IPsec handling needed
605 * sp == NULL, error == -EINVAL discard packet w/o error
606 * sp == NULL, error != 0 discard packet, report error
609 /* Loop detection, check if ipsec processing already done */
610 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
611 for (mtag = m_tag_first(m); mtag != NULL;
612 mtag = m_tag_next(m, mtag)) {
613 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
615 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
616 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
619 * Check if policy has an SA associated with it.
620 * This can happen when an SP has yet to acquire
621 * an SA; e.g. on first reference. If it occurs,
622 * then we let ipsec4_process_packet do its thing.
624 if (sp->req->sav == NULL)
626 tdbi = (struct tdb_ident *)(mtag + 1);
627 if (tdbi->spi == sp->req->sav->spi &&
628 tdbi->proto == sp->req->sav->sah->saidx.proto &&
629 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
630 sizeof(union sockaddr_union)) == 0) {
632 * No IPsec processing is needed, free
635 * NB: null pointer to avoid free at
638 KEY_FREESP(&sp), sp = NULL;
645 * Do delayed checksums now because we send before
646 * this is done in the normal processing path.
648 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
650 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
653 ip->ip_len = htons(ip->ip_len);
654 ip->ip_off = htons(ip->ip_off);
656 /* NB: callee frees mbuf */
657 error = ipsec4_process_packet(m, sp->req, flags, 0);
659 * Preserve KAME behaviour: ENOENT can be returned
660 * when an SA acquire is in progress. Don't propagate
661 * this to user-level; it confuses applications.
663 * XXX this will go away when the SADB is redone.
674 * Hack: -EINVAL is used to signal that a packet
675 * should be silently discarded. This is typically
676 * because we asked key management for an SA and
677 * it was delayed (e.g. kicked up to IKE).
679 if (error == -EINVAL)
683 /* No IPsec processing for this packet. */
687 * If deferred crypto processing is needed, check that
688 * the interface supports it.
690 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
691 if (mtag != NULL && !(ifp->if_capenable & IFCAP_IPSEC)) {
692 /* notify IPsec to do its own crypto */
693 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
694 error = EHOSTUNREACH;
700 #endif /* FAST_IPSEC */
703 * - Xlate: translate packet's addr/port (NAT).
704 * - Firewall: deny/allow/etc.
705 * - Wrap: fake packet's addr/port <unimpl.>
706 * - Encapsulate: put it in another IP and send out. <unimp.>
710 * Run through list of hooks for output packets.
712 if (pfil_has_hooks(&inet_pfil_hook)) {
713 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
714 if (error != 0 || m == NULL)
716 ip = mtod(m, struct ip *);
720 * Check with the firewall...
721 * but not if we are already being fwd'd from a firewall.
723 if (fw_enable && IPFW_LOADED && !args.next_hop) {
724 struct sockaddr_in *old = dst;
729 off = ip_fw_chk_ptr(&args);
734 * On return we must do the following:
735 * m == NULL -> drop the pkt (old interface, deprecated)
736 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface)
737 * 1<=off<= 0xffff -> DIVERT
738 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe
739 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet
740 * dst != old -> IPFIREWALL_FORWARD
741 * off==0, dst==old -> accept
742 * If some of the above modules are not compiled in, then
743 * we should't have to check the corresponding condition
744 * (because the ipfw control socket should not accept
745 * unsupported rules), but better play safe and drop
746 * packets in case of doubt.
748 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) {
754 ip = mtod(m, struct ip *);
755 if (off == 0 && dst == old) /* common case */
757 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG)) {
759 * pass the pkt to dummynet. Need to include
760 * pipe number, m, ifp, ro, dst because these are
761 * not recomputed in the next pass.
762 * All other parameters have been already used and
763 * so they are not needed anymore.
764 * XXX note: if the ifp or ro entry are deleted
765 * while a pkt is in dummynet, we are in trouble!
771 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT,
776 if (off != 0 && !(off & IP_FW_PORT_DYNT_FLAG)) {
777 struct mbuf *clone = NULL;
779 /* Clone packet if we're doing a 'tee' */
780 if ((off & IP_FW_PORT_TEE_FLAG))
781 clone = m_dup(m, MB_DONTWAIT);
785 * delayed checksums are not currently compatible
786 * with divert sockets.
788 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
790 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
793 /* Restore packet header fields to original values */
794 ip->ip_len = htons(ip->ip_len);
795 ip->ip_off = htons(ip->ip_off);
797 /* Deliver packet to divert input routine */
798 divert_packet(m, 0, off & 0xffff, args.divert_rule);
800 /* If 'tee', continue with original packet */
803 ip = mtod(m, struct ip *);
810 /* IPFIREWALL_FORWARD */
812 * Check dst to make sure it is directly reachable on the
813 * interface we previously thought it was.
814 * If it isn't (which may be likely in some situations) we have
815 * to re-route it (ie, find a route for the next-hop and the
816 * associated interface) and set them here. This is nested
817 * forwarding which in most cases is undesirable, except where
818 * such control is nigh impossible. So we do it here.
821 if (off == 0 && old != dst) { /* FORWARD, dst has changed */
824 * XXX To improve readability, this block should be
825 * changed into a function call as below:
827 error = ip_ipforward(&m, &dst, &ifp);
830 if (m == NULL) /* ip_input consumed the mbuf */
833 struct in_ifaddr *ia;
836 * XXX sro_fwd below is static, and a pointer
837 * to it gets passed to routines downstream.
838 * This could have surprisingly bad results in
839 * practice, because its content is overwritten
840 * by subsequent packets.
842 /* There must be a better way to do this next line... */
843 static struct route sro_fwd;
844 struct route *ro_fwd = &sro_fwd;
847 print_ip("IPFIREWALL_FORWARD: New dst ip: ",
848 dst->sin_addr, "\n");
852 * We need to figure out if we have been forwarded
853 * to a local socket. If so, then we should somehow
854 * "loop back" to ip_input, and get directed to the
855 * PCB as if we had received this packet. This is
856 * because it may be dificult to identify the packets
857 * you want to forward until they are being output
858 * and have selected an interface. (e.g. locally
859 * initiated packets) If we used the loopback inteface,
860 * we would not be able to control what happens
861 * as the packet runs through ip_input() as
862 * it is done through a ISR.
864 LIST_FOREACH(ia, INADDR_HASH(dst->sin_addr.s_addr),
867 * If the addr to forward to is one
868 * of ours, we pretend to
869 * be the destination for this packet.
871 if (IA_SIN(ia)->sin_addr.s_addr ==
872 dst->sin_addr.s_addr)
875 if (ia != NULL) { /* tell ip_input "dont filter" */
878 tag.mh_type = MT_TAG;
879 tag.mh_flags = PACKET_TAG_IPFORWARD;
880 tag.mh_data = (caddr_t)args.next_hop;
883 if (m->m_pkthdr.rcvif == NULL)
884 m->m_pkthdr.rcvif = ifunit("lo0");
885 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
886 m->m_pkthdr.csum_flags |=
887 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
888 m0->m_pkthdr.csum_data = 0xffff;
890 m->m_pkthdr.csum_flags |=
891 CSUM_IP_CHECKED | CSUM_IP_VALID;
892 ip->ip_len = htons(ip->ip_len);
893 ip->ip_off = htons(ip->ip_off);
894 ip_input((struct mbuf *)&tag);
897 /* Some of the logic for this was nicked from above.
899 * This rewrites the cached route in a local PCB.
900 * Is this what we want to do?
902 bcopy(dst, &ro_fwd->ro_dst, sizeof *dst);
903 ro_fwd->ro_rt = NULL;
905 rtalloc_ign(ro_fwd, RTF_PRCLONING);
906 if (ro_fwd->ro_rt == NULL) {
907 ipstat.ips_noroute++;
908 error = EHOSTUNREACH;
912 ia = ifatoia(ro_fwd->ro_rt->rt_ifa);
913 ifp = ro_fwd->ro_rt->rt_ifp;
914 ro_fwd->ro_rt->rt_use++;
915 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
916 dst = (struct sockaddr_in *)
917 ro_fwd->ro_rt->rt_gateway;
918 if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
920 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
922 isbroadcast = in_broadcast(dst->sin_addr, ifp);
923 if (ro->ro_rt != NULL)
925 ro->ro_rt = ro_fwd->ro_rt;
926 dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
928 #endif /* ... block to be put into a function */
930 * If we added a default src ip earlier,
931 * which would have been gotten from the-then
932 * interface, do it again, from the new one.
934 if (src_was_INADDR_ANY)
935 ip->ip_src = IA_SIN(ia)->sin_addr;
940 * if we get here, none of the above matches, and
941 * we have to drop the pkt
944 error = EACCES; /* not sure this is the right error msg */
949 /* 127/8 must not appear on wire - RFC1122. */
950 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
951 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
952 if (!(ifp->if_flags & IFF_LOOPBACK)) {
953 ipstat.ips_badaddr++;
954 error = EADDRNOTAVAIL;
959 m->m_pkthdr.csum_flags |= CSUM_IP;
960 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
961 if (sw_csum & CSUM_DELAY_DATA) {
963 sw_csum &= ~CSUM_DELAY_DATA;
965 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
968 * If small enough for interface, or the interface will take
969 * care of the fragmentation for us, can just send directly.
971 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) &&
972 !(ip->ip_off & IP_DF))) {
973 ip->ip_len = htons(ip->ip_len);
974 ip->ip_off = htons(ip->ip_off);
976 if (sw_csum & CSUM_DELAY_IP) {
977 if (ip->ip_vhl == IP_VHL_BORING) {
978 ip->ip_sum = in_cksum_hdr(ip);
980 ip->ip_sum = in_cksum(m, hlen);
984 /* Record statistics for this interface address. */
985 if (!(flags & IP_FORWARDING) && ia) {
986 ia->ia_ifa.if_opackets++;
987 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
991 /* clean ipsec history once it goes out of the node */
995 #ifdef MBUF_STRESS_TEST
996 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
997 struct mbuf *m1, *m2;
1000 tmp = length = m->m_pkthdr.len;
1002 while ((length -= mbuf_frag_size) >= 1) {
1003 m1 = m_split(m, length, MB_DONTWAIT);
1006 m1->m_flags &= ~M_PKTHDR;
1008 while (m2->m_next != NULL)
1012 m->m_pkthdr.len = tmp;
1015 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst,
1020 if (ip->ip_off & IP_DF) {
1023 * This case can happen if the user changed the MTU
1024 * of an interface after enabling IP on it. Because
1025 * most netifs don't keep track of routes pointing to
1026 * them, there is no way for one to update all its
1027 * routes when the MTU is changed.
1029 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) &&
1030 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
1031 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
1032 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
1034 ipstat.ips_cantfrag++;
1039 * Too large for interface; fragment if possible. If successful,
1040 * on return, m will point to a list of packets to be sent.
1042 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum);
1047 m->m_nextpkt = NULL;
1049 /* clean ipsec history once it goes out of the node */
1053 /* Record statistics for this interface address. */
1055 ia->ia_ifa.if_opackets++;
1056 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1058 error = (*ifp->if_output)(ifp, m,
1059 (struct sockaddr *)dst,
1066 ipstat.ips_fragmented++;
1069 if (ro == &iproute && ro->ro_rt != NULL) {
1075 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1076 printf("DP ip_output call free SP:%p\n", sp));
1091 * Create a chain of fragments which fit the given mtu. m_frag points to the
1092 * mbuf to be fragmented; on return it points to the chain with the fragments.
1093 * Return 0 if no error. If error, m_frag may contain a partially built
1094 * chain of fragments that should be freed by the caller.
1096 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1097 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1100 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1101 u_long if_hwassist_flags, int sw_csum)
1104 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1105 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
1107 struct mbuf *m0 = *m_frag; /* the original packet */
1109 struct mbuf **mnext;
1112 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
1113 ipstat.ips_cantfrag++;
1118 * Must be able to put at least 8 bytes per fragment.
1124 * If the interface will not calculate checksums on
1125 * fragmented packets, then do it here.
1127 if ((m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) &&
1128 !(if_hwassist_flags & CSUM_IP_FRAGS)) {
1129 in_delayed_cksum(m0);
1130 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1133 if (len > PAGE_SIZE) {
1135 * Fragment large datagrams such that each segment
1136 * contains a multiple of PAGE_SIZE amount of data,
1137 * plus headers. This enables a receiver to perform
1138 * page-flipping zero-copy optimizations.
1140 * XXX When does this help given that sender and receiver
1141 * could have different page sizes, and also mtu could
1142 * be less than the receiver's page size ?
1147 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1151 * firstlen (off - hlen) must be aligned on an
1155 goto smart_frag_failure;
1156 off = ((off - hlen) & ~7) + hlen;
1157 newlen = (~PAGE_MASK) & mtu;
1158 if ((newlen + sizeof(struct ip)) > mtu) {
1159 /* we failed, go back the default */
1170 firstlen = off - hlen;
1171 mnext = &m0->m_nextpkt; /* pointer to next packet */
1174 * Loop through length of segment after first fragment,
1175 * make new header and copy data of each part and link onto chain.
1176 * Here, m0 is the original packet, m is the fragment being created.
1177 * The fragments are linked off the m_nextpkt of the original
1178 * packet, which after processing serves as the first fragment.
1180 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1181 struct ip *mhip; /* ip header on the fragment */
1183 int mhlen = sizeof(struct ip);
1185 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1188 ipstat.ips_odropped++;
1191 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1193 * In the first mbuf, leave room for the link header, then
1194 * copy the original IP header including options. The payload
1195 * goes into an additional mbuf chain returned by m_copy().
1197 m->m_data += max_linkhdr;
1198 mhip = mtod(m, struct ip *);
1200 if (hlen > sizeof(struct ip)) {
1201 mhlen = ip_optcopy(ip, mhip) + sizeof(struct ip);
1202 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1205 /* XXX do we need to add ip->ip_off below ? */
1206 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1207 if (off + len >= ip->ip_len) { /* last fragment */
1208 len = ip->ip_len - off;
1209 m->m_flags |= M_LASTFRAG;
1211 mhip->ip_off |= IP_MF;
1212 mhip->ip_len = htons((u_short)(len + mhlen));
1213 m->m_next = m_copy(m0, off, len);
1214 if (m->m_next == NULL) { /* copy failed */
1216 error = ENOBUFS; /* ??? */
1217 ipstat.ips_odropped++;
1220 m->m_pkthdr.len = mhlen + len;
1221 m->m_pkthdr.rcvif = (struct ifnet *)NULL;
1222 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1223 mhip->ip_off = htons(mhip->ip_off);
1225 if (sw_csum & CSUM_DELAY_IP)
1226 mhip->ip_sum = in_cksum(m, mhlen);
1228 mnext = &m->m_nextpkt;
1230 ipstat.ips_ofragments += nfrags;
1232 /* set first marker for fragment chain */
1233 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1234 m0->m_pkthdr.csum_data = nfrags;
1237 * Update first fragment by trimming what's been copied out
1238 * and updating header.
1240 m_adj(m0, hlen + firstlen - ip->ip_len);
1241 m0->m_pkthdr.len = hlen + firstlen;
1242 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1243 ip->ip_off |= IP_MF;
1244 ip->ip_off = htons(ip->ip_off);
1246 if (sw_csum & CSUM_DELAY_IP)
1247 ip->ip_sum = in_cksum(m0, hlen);
1255 in_delayed_cksum(struct mbuf *m)
1258 u_short csum, offset;
1260 ip = mtod(m, struct ip *);
1261 offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1262 csum = in_cksum_skip(m, ip->ip_len, offset);
1263 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1265 offset += m->m_pkthdr.csum_data; /* checksum offset */
1267 if (offset + sizeof(u_short) > m->m_len) {
1268 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
1269 m->m_len, offset, ip->ip_p);
1272 * this shouldn't happen, but if it does, the
1273 * correct behavior may be to insert the checksum
1274 * in the existing chain instead of rearranging it.
1276 m = m_pullup(m, offset + sizeof(u_short));
1278 *(u_short *)(m->m_data + offset) = csum;
1282 * Insert IP options into preformed packet.
1283 * Adjust IP destination as required for IP source routing,
1284 * as indicated by a non-zero in_addr at the start of the options.
1286 * XXX This routine assumes that the packet has no options in place.
1288 static struct mbuf *
1289 ip_insertoptions(struct mbuf *m, struct mbuf *opt, int *phlen)
1291 struct ipoption *p = mtod(opt, struct ipoption *);
1293 struct ip *ip = mtod(m, struct ip *);
1296 optlen = opt->m_len - sizeof p->ipopt_dst;
1297 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1299 return (m); /* XXX should fail */
1301 if (p->ipopt_dst.s_addr)
1302 ip->ip_dst = p->ipopt_dst;
1303 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1304 MGETHDR(n, MB_DONTWAIT, MT_HEADER);
1309 n->m_pkthdr.rcvif = (struct ifnet *)NULL;
1310 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1311 m->m_len -= sizeof(struct ip);
1312 m->m_data += sizeof(struct ip);
1315 m->m_len = optlen + sizeof(struct ip);
1316 m->m_data += max_linkhdr;
1317 memcpy(mtod(m, void *), ip, sizeof(struct ip));
1319 m->m_data -= optlen;
1321 m->m_pkthdr.len += optlen;
1322 ovbcopy(ip, mtod(m, caddr_t), sizeof(struct ip));
1324 ip = mtod(m, struct ip *);
1325 bcopy(p->ipopt_list, ip + 1, optlen);
1326 *phlen = sizeof(struct ip) + optlen;
1327 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1328 ip->ip_len += optlen;
1333 * Copy options from ip to jp,
1334 * omitting those not copied during fragmentation.
1337 ip_optcopy(struct ip *ip, struct ip *jp)
1340 int opt, optlen, cnt;
1342 cp = (u_char *)(ip + 1);
1343 dp = (u_char *)(jp + 1);
1344 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
1345 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1347 if (opt == IPOPT_EOL)
1349 if (opt == IPOPT_NOP) {
1350 /* Preserve for IP mcast tunnel's LSRR alignment. */
1356 KASSERT(cnt >= IPOPT_OLEN + sizeof *cp,
1357 ("ip_optcopy: malformed ipv4 option"));
1358 optlen = cp[IPOPT_OLEN];
1359 KASSERT(optlen >= IPOPT_OLEN + sizeof *cp && optlen <= cnt,
1360 ("ip_optcopy: malformed ipv4 option"));
1362 /* bogus lengths should have been caught by ip_dooptions */
1365 if (IPOPT_COPIED(opt)) {
1366 bcopy(cp, dp, optlen);
1370 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1376 * IP socket option processing.
1379 ip_ctloutput(struct socket *so, struct sockopt *sopt)
1381 struct inpcb *inp = so->so_pcb;
1385 if (sopt->sopt_level != IPPROTO_IP) {
1389 switch (sopt->sopt_dir) {
1391 switch (sopt->sopt_name) {
1398 if (sopt->sopt_valsize > MLEN) {
1402 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1407 m->m_len = sopt->sopt_valsize;
1408 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1411 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options,
1418 case IP_RECVRETOPTS:
1419 case IP_RECVDSTADDR:
1422 error = sooptcopyin(sopt, &optval, sizeof optval,
1427 switch (sopt->sopt_name) {
1429 inp->inp_ip_tos = optval;
1433 inp->inp_ip_ttl = optval;
1435 #define OPTSET(bit) \
1437 inp->inp_flags |= bit; \
1439 inp->inp_flags &= ~bit;
1442 OPTSET(INP_RECVOPTS);
1445 case IP_RECVRETOPTS:
1446 OPTSET(INP_RECVRETOPTS);
1449 case IP_RECVDSTADDR:
1450 OPTSET(INP_RECVDSTADDR);
1464 case IP_MULTICAST_IF:
1465 case IP_MULTICAST_VIF:
1466 case IP_MULTICAST_TTL:
1467 case IP_MULTICAST_LOOP:
1468 case IP_ADD_MEMBERSHIP:
1469 case IP_DROP_MEMBERSHIP:
1470 error = ip_setmoptions(sopt, &inp->inp_moptions);
1474 error = sooptcopyin(sopt, &optval, sizeof optval,
1480 case IP_PORTRANGE_DEFAULT:
1481 inp->inp_flags &= ~(INP_LOWPORT);
1482 inp->inp_flags &= ~(INP_HIGHPORT);
1485 case IP_PORTRANGE_HIGH:
1486 inp->inp_flags &= ~(INP_LOWPORT);
1487 inp->inp_flags |= INP_HIGHPORT;
1490 case IP_PORTRANGE_LOW:
1491 inp->inp_flags &= ~(INP_HIGHPORT);
1492 inp->inp_flags |= INP_LOWPORT;
1501 #if defined(IPSEC) || defined(FAST_IPSEC)
1502 case IP_IPSEC_POLICY:
1510 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1512 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1514 priv = (sopt->sopt_td != NULL &&
1515 suser(sopt->sopt_td) != 0) ? 0 : 1;
1516 req = mtod(m, caddr_t);
1518 optname = sopt->sopt_name;
1519 error = ipsec4_set_policy(inp, optname, req, len, priv);
1526 error = ENOPROTOOPT;
1532 switch (sopt->sopt_name) {
1535 if (inp->inp_options)
1536 error = sooptcopyout(sopt,
1537 mtod(inp->inp_options,
1539 inp->inp_options->m_len);
1541 sopt->sopt_valsize = 0;
1547 case IP_RECVRETOPTS:
1548 case IP_RECVDSTADDR:
1552 switch (sopt->sopt_name) {
1555 optval = inp->inp_ip_tos;
1559 optval = inp->inp_ip_ttl;
1562 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1565 optval = OPTBIT(INP_RECVOPTS);
1568 case IP_RECVRETOPTS:
1569 optval = OPTBIT(INP_RECVRETOPTS);
1572 case IP_RECVDSTADDR:
1573 optval = OPTBIT(INP_RECVDSTADDR);
1577 optval = OPTBIT(INP_RECVIF);
1581 if (inp->inp_flags & INP_HIGHPORT)
1582 optval = IP_PORTRANGE_HIGH;
1583 else if (inp->inp_flags & INP_LOWPORT)
1584 optval = IP_PORTRANGE_LOW;
1590 optval = OPTBIT(INP_FAITH);
1593 error = sooptcopyout(sopt, &optval, sizeof optval);
1596 case IP_MULTICAST_IF:
1597 case IP_MULTICAST_VIF:
1598 case IP_MULTICAST_TTL:
1599 case IP_MULTICAST_LOOP:
1600 case IP_ADD_MEMBERSHIP:
1601 case IP_DROP_MEMBERSHIP:
1602 error = ip_getmoptions(sopt, inp->inp_moptions);
1605 #if defined(IPSEC) || defined(FAST_IPSEC)
1606 case IP_IPSEC_POLICY:
1608 struct mbuf *m = NULL;
1613 req = mtod(m, caddr_t);
1616 error = ipsec4_get_policy(so->so_pcb, req, len, &m);
1618 error = soopt_mcopyout(sopt, m); /* XXX */
1626 error = ENOPROTOOPT;
1635 * Set up IP options in pcb for insertion in output packets.
1636 * Store in mbuf with pointer in pcbopt, adding pseudo-option
1637 * with destination address if source routed.
1640 ip_pcbopts(int optname, struct mbuf **pcbopt, struct mbuf *m)
1646 /* turn off any old options */
1650 if (m == NULL || m->m_len == 0) {
1652 * Only turning off any previous options.
1659 if (m->m_len % sizeof(int32_t))
1662 * IP first-hop destination address will be stored before
1663 * actual options; move other options back
1664 * and clear it when none present.
1666 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1669 m->m_len += sizeof(struct in_addr);
1670 cp = mtod(m, u_char *) + sizeof(struct in_addr);
1671 ovbcopy(mtod(m, caddr_t), cp, cnt);
1672 bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1674 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1675 opt = cp[IPOPT_OPTVAL];
1676 if (opt == IPOPT_EOL)
1678 if (opt == IPOPT_NOP)
1681 if (cnt < IPOPT_OLEN + sizeof *cp)
1683 optlen = cp[IPOPT_OLEN];
1684 if (optlen < IPOPT_OLEN + sizeof *cp || optlen > cnt)
1695 * user process specifies route as:
1697 * D must be our final destination (but we can't
1698 * check that since we may not have connected yet).
1699 * A is first hop destination, which doesn't appear in
1700 * actual IP option, but is stored before the options.
1702 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1704 m->m_len -= sizeof(struct in_addr);
1705 cnt -= sizeof(struct in_addr);
1706 optlen -= sizeof(struct in_addr);
1707 cp[IPOPT_OLEN] = optlen;
1709 * Move first hop before start of options.
1711 bcopy(&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1712 sizeof(struct in_addr));
1714 * Then copy rest of options back
1715 * to close up the deleted entry.
1717 ovbcopy(&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr),
1718 &cp[IPOPT_OFFSET+1],
1719 cnt - (IPOPT_MINOFF - 1));
1723 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1735 * The whole multicast option thing needs to be re-thought.
1736 * Several of these options are equally applicable to non-multicast
1737 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1738 * standard option (IP_TTL).
1742 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1744 static struct ifnet *
1745 ip_multicast_if(struct in_addr *a, int *ifindexp)
1752 if (ntohl(a->s_addr) >> 24 == 0) {
1753 ifindex = ntohl(a->s_addr) & 0xffffff;
1754 if (ifindex < 0 || if_index < ifindex)
1756 ifp = ifindex2ifnet[ifindex];
1758 *ifindexp = ifindex;
1760 INADDR_TO_IFP(*a, ifp);
1766 * Set the IP multicast options in response to user setsockopt().
1769 ip_setmoptions(struct sockopt *sopt, struct ip_moptions **imop)
1773 struct in_addr addr;
1774 struct ip_mreq mreq;
1776 struct ip_moptions *imo = *imop;
1777 struct sockaddr_in *dst;
1783 * No multicast option buffer attached to the pcb;
1784 * allocate one and initialize to default values.
1786 imo = malloc(sizeof *imo, M_IPMOPTS, M_WAITOK);
1791 imo->imo_multicast_ifp = NULL;
1792 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1793 imo->imo_multicast_vif = -1;
1794 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1795 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1796 imo->imo_num_memberships = 0;
1799 switch (sopt->sopt_name) {
1800 /* store an index number for the vif you wanna use in the send */
1801 case IP_MULTICAST_VIF:
1802 if (legal_vif_num == 0) {
1806 error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
1809 if (!legal_vif_num(i) && (i != -1)) {
1813 imo->imo_multicast_vif = i;
1816 case IP_MULTICAST_IF:
1818 * Select the interface for outgoing multicast packets.
1820 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
1824 * INADDR_ANY is used to remove a previous selection.
1825 * When no interface is selected, a default one is
1826 * chosen every time a multicast packet is sent.
1828 if (addr.s_addr == INADDR_ANY) {
1829 imo->imo_multicast_ifp = NULL;
1833 * The selected interface is identified by its local
1834 * IP address. Find the interface and confirm that
1835 * it supports multicasting.
1838 ifp = ip_multicast_if(&addr, &ifindex);
1839 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1841 error = EADDRNOTAVAIL;
1844 imo->imo_multicast_ifp = ifp;
1846 imo->imo_multicast_addr = addr;
1848 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1852 case IP_MULTICAST_TTL:
1854 * Set the IP time-to-live for outgoing multicast packets.
1855 * The original multicast API required a char argument,
1856 * which is inconsistent with the rest of the socket API.
1857 * We allow either a char or an int.
1859 if (sopt->sopt_valsize == 1) {
1861 error = sooptcopyin(sopt, &ttl, 1, 1);
1864 imo->imo_multicast_ttl = ttl;
1867 error = sooptcopyin(sopt, &ttl, sizeof ttl, sizeof ttl);
1873 imo->imo_multicast_ttl = ttl;
1877 case IP_MULTICAST_LOOP:
1879 * Set the loopback flag for outgoing multicast packets.
1880 * Must be zero or one. The original multicast API required a
1881 * char argument, which is inconsistent with the rest
1882 * of the socket API. We allow either a char or an int.
1884 if (sopt->sopt_valsize == 1) {
1887 error = sooptcopyin(sopt, &loop, 1, 1);
1890 imo->imo_multicast_loop = !!loop;
1894 error = sooptcopyin(sopt, &loop, sizeof loop,
1898 imo->imo_multicast_loop = !!loop;
1902 case IP_ADD_MEMBERSHIP:
1904 * Add a multicast group membership.
1905 * Group must be a valid IP multicast address.
1907 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1911 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1917 * If no interface address was provided, use the interface of
1918 * the route to the given multicast address.
1920 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1923 bzero(&ro, sizeof ro);
1924 dst = (struct sockaddr_in *)&ro.ro_dst;
1925 dst->sin_len = sizeof *dst;
1926 dst->sin_family = AF_INET;
1927 dst->sin_addr = mreq.imr_multiaddr;
1929 if (ro.ro_rt == NULL) {
1930 error = EADDRNOTAVAIL;
1934 --ro.ro_rt->rt_refcnt;
1935 ifp = ro.ro_rt->rt_ifp;
1938 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1942 * See if we found an interface, and confirm that it
1943 * supports multicast.
1945 if (ifp == NULL || !(ifp->if_flags & IFF_MULTICAST)) {
1946 error = EADDRNOTAVAIL;
1951 * See if the membership already exists or if all the
1952 * membership slots are full.
1954 for (i = 0; i < imo->imo_num_memberships; ++i) {
1955 if (imo->imo_membership[i]->inm_ifp == ifp &&
1956 imo->imo_membership[i]->inm_addr.s_addr
1957 == mreq.imr_multiaddr.s_addr)
1960 if (i < imo->imo_num_memberships) {
1965 if (i == IP_MAX_MEMBERSHIPS) {
1966 error = ETOOMANYREFS;
1971 * Everything looks good; add a new record to the multicast
1972 * address list for the given interface.
1974 if ((imo->imo_membership[i] =
1975 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
1980 ++imo->imo_num_memberships;
1984 case IP_DROP_MEMBERSHIP:
1986 * Drop a multicast group membership.
1987 * Group must be a valid IP multicast address.
1989 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1993 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
2000 * If an interface address was specified, get a pointer
2001 * to its ifnet structure.
2003 if (mreq.imr_interface.s_addr == INADDR_ANY)
2006 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
2008 error = EADDRNOTAVAIL;
2014 * Find the membership in the membership array.
2016 for (i = 0; i < imo->imo_num_memberships; ++i) {
2018 imo->imo_membership[i]->inm_ifp == ifp) &&
2019 imo->imo_membership[i]->inm_addr.s_addr ==
2020 mreq.imr_multiaddr.s_addr)
2023 if (i == imo->imo_num_memberships) {
2024 error = EADDRNOTAVAIL;
2029 * Give up the multicast address record to which the
2030 * membership points.
2032 in_delmulti(imo->imo_membership[i]);
2034 * Remove the gap in the membership array.
2036 for (++i; i < imo->imo_num_memberships; ++i)
2037 imo->imo_membership[i-1] = imo->imo_membership[i];
2038 --imo->imo_num_memberships;
2048 * If all options have default values, no need to keep the mbuf.
2050 if (imo->imo_multicast_ifp == NULL &&
2051 imo->imo_multicast_vif == -1 &&
2052 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
2053 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
2054 imo->imo_num_memberships == 0) {
2055 free(*imop, M_IPMOPTS);
2063 * Return the IP multicast options in response to user getsockopt().
2066 ip_getmoptions(struct sockopt *sopt, struct ip_moptions *imo)
2068 struct in_addr addr;
2069 struct in_ifaddr *ia;
2074 switch (sopt->sopt_name) {
2075 case IP_MULTICAST_VIF:
2077 optval = imo->imo_multicast_vif;
2080 error = sooptcopyout(sopt, &optval, sizeof optval);
2083 case IP_MULTICAST_IF:
2084 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2085 addr.s_addr = INADDR_ANY;
2086 else if (imo->imo_multicast_addr.s_addr) {
2087 /* return the value user has set */
2088 addr = imo->imo_multicast_addr;
2090 IFP_TO_IA(imo->imo_multicast_ifp, ia);
2091 addr.s_addr = (ia == NULL) ? INADDR_ANY
2092 : IA_SIN(ia)->sin_addr.s_addr;
2094 error = sooptcopyout(sopt, &addr, sizeof addr);
2097 case IP_MULTICAST_TTL:
2099 optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2101 optval = coptval = imo->imo_multicast_ttl;
2102 if (sopt->sopt_valsize == 1)
2103 error = sooptcopyout(sopt, &coptval, 1);
2105 error = sooptcopyout(sopt, &optval, sizeof optval);
2108 case IP_MULTICAST_LOOP:
2110 optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2112 optval = coptval = imo->imo_multicast_loop;
2113 if (sopt->sopt_valsize == 1)
2114 error = sooptcopyout(sopt, &coptval, 1);
2116 error = sooptcopyout(sopt, &optval, sizeof optval);
2120 error = ENOPROTOOPT;
2127 * Discard the IP multicast options.
2130 ip_freemoptions(struct ip_moptions *imo)
2135 for (i = 0; i < imo->imo_num_memberships; ++i)
2136 in_delmulti(imo->imo_membership[i]);
2137 free(imo, M_IPMOPTS);
2142 * Routine called from ip_output() to loop back a copy of an IP multicast
2143 * packet to the input queue of a specified interface. Note that this
2144 * calls the output routine of the loopback "driver", but with an interface
2145 * pointer that might NOT be a loopback interface -- evil, but easier than
2146 * replicating that code here.
2149 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
2155 copym = m_copypacket(m, MB_DONTWAIT);
2156 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2157 copym = m_pullup(copym, hlen);
2158 if (copym != NULL) {
2160 * if the checksum hasn't been computed, mark it as valid
2162 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2163 in_delayed_cksum(copym);
2164 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
2165 copym->m_pkthdr.csum_flags |=
2166 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2167 copym->m_pkthdr.csum_data = 0xffff;
2170 * We don't bother to fragment if the IP length is greater
2171 * than the interface's MTU. Can this possibly matter?
2173 ip = mtod(copym, struct ip *);
2174 ip->ip_len = htons(ip->ip_len);
2175 ip->ip_off = htons(ip->ip_off);
2177 if (ip->ip_vhl == IP_VHL_BORING) {
2178 ip->ip_sum = in_cksum_hdr(ip);
2180 ip->ip_sum = in_cksum(copym, hlen);
2184 * It's not clear whether there are any lingering
2185 * reentrancy problems in other areas which might
2186 * be exposed by using ip_input directly (in
2187 * particular, everything which modifies the packet
2188 * in-place). Yet another option is using the
2189 * protosw directly to deliver the looped back
2190 * packet. For the moment, we'll err on the side
2191 * of safety by using if_simloop().
2194 if (dst->sin_family != AF_INET) {
2195 printf("ip_mloopback: bad address family %d\n",
2197 dst->sin_family = AF_INET;
2202 copym->m_pkthdr.rcvif = ifp;
2205 if_simloop(ifp, copym, dst->sin_family, 0);