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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 1.20 2004/08/26 21:21:46 dillon 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 <netipsec/ipsec.h>
82 #include <netipsec/xform.h>
83 #include <netipsec/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;
138 struct route iproute;
139 struct secpolicy *sp = NULL;
140 struct socket *so = inp ? inp->inp_socket : NULL;
143 struct route iproute;
145 struct secpolicy *sp = NULL;
146 struct tdb_ident *tdbi;
148 #endif /* FAST_IPSEC */
149 struct ip_fw_args args;
150 int src_was_INADDR_ANY = 0; /* as the name says... */
154 args.next_hop = NULL;
155 args.divert_rule = 0; /* divert cookie */
157 /* Grab info from MT_TAG mbufs prepended to the chain. */
158 for (; m0 && m0->m_type == MT_TAG; m0 = m0->m_next) {
159 switch(m0->_m_tag_id) {
161 printf("ip_output: unrecognised MT_TAG tag %d\n",
165 case PACKET_TAG_DUMMYNET:
167 * the packet was already tagged, so part of the
168 * processing was already done, and we need to go down.
169 * Get parameters from the header.
171 args.rule = ((struct dn_pkt *)m0)->rule;
173 ro = & ( ((struct dn_pkt *)m0)->ro ) ;
175 dst = ((struct dn_pkt *)m0)->dn_dst ;
176 ifp = ((struct dn_pkt *)m0)->ifp ;
177 flags = ((struct dn_pkt *)m0)->flags ;
180 case PACKET_TAG_DIVERT:
181 args.divert_rule = (int)m0->m_data & 0xffff;
184 case PACKET_TAG_IPFORWARD:
185 args.next_hop = (struct sockaddr_in *)m0->m_data;
191 KASSERT(!m || (m->m_flags & M_PKTHDR) != 0, ("ip_output: no HDR"));
193 KASSERT(ro != NULL, ("ip_output: no route, proto %d",
194 mtod(m, struct ip *)->ip_p));
197 if (args.rule != NULL) { /* dummynet already saw us */
198 ip = mtod(m, struct ip *);
199 hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
201 ia = ifatoia(ro->ro_rt->rt_ifa);
207 m = ip_insertoptions(m, opt, &len);
211 ip = mtod(m, struct ip *);
212 pkt_dst = args.next_hop ? args.next_hop->sin_addr : ip->ip_dst;
217 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
218 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, hlen >> 2);
221 ip->ip_id = ip_randomid();
223 ip->ip_id = htons(ip_id++);
225 ipstat.ips_localout++;
227 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
233 bzero(ro, sizeof (*ro));
235 #endif /* FAST_IPSEC */
236 dst = (struct sockaddr_in *)&ro->ro_dst;
238 * If there is a cached route,
239 * check that it is to the same destination
240 * and is still up. If not, free it and try again.
241 * The address family should also be checked in case of sharing the
244 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
245 dst->sin_family != AF_INET ||
246 dst->sin_addr.s_addr != pkt_dst.s_addr)) {
248 ro->ro_rt = (struct rtentry *)0;
250 if (ro->ro_rt == 0) {
251 bzero(dst, sizeof(*dst));
252 dst->sin_family = AF_INET;
253 dst->sin_len = sizeof(*dst);
254 dst->sin_addr = pkt_dst;
257 * If routing to interface only,
258 * short circuit routing lookup.
260 if (flags & IP_ROUTETOIF) {
261 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == 0 &&
262 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == 0) {
263 ipstat.ips_noroute++;
269 isbroadcast = in_broadcast(dst->sin_addr, ifp);
270 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
271 imo != NULL && imo->imo_multicast_ifp != NULL) {
273 * Bypass the normal routing lookup for multicast
274 * packets if the interface is specified.
276 ifp = imo->imo_multicast_ifp;
278 isbroadcast = 0; /* fool gcc */
281 * If this is the case, we probably don't want to allocate
282 * a protocol-cloned route since we didn't get one from the
283 * ULP. This lets TCP do its thing, while not burdening
284 * forwarding or ICMP with the overhead of cloning a route.
285 * Of course, we still want to do any cloning requested by
286 * the link layer, as this is probably required in all cases
287 * for correct operation (as it is for ARP).
290 rtalloc_ign(ro, RTF_PRCLONING);
291 if (ro->ro_rt == 0) {
292 ipstat.ips_noroute++;
293 error = EHOSTUNREACH;
296 ia = ifatoia(ro->ro_rt->rt_ifa);
297 ifp = ro->ro_rt->rt_ifp;
299 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
300 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
301 if (ro->ro_rt->rt_flags & RTF_HOST)
302 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
304 isbroadcast = in_broadcast(dst->sin_addr, ifp);
306 if (IN_MULTICAST(ntohl(pkt_dst.s_addr))) {
307 struct in_multi *inm;
309 m->m_flags |= M_MCAST;
311 * IP destination address is multicast. Make sure "dst"
312 * still points to the address in "ro". (It may have been
313 * changed to point to a gateway address, above.)
315 dst = (struct sockaddr_in *)&ro->ro_dst;
317 * See if the caller provided any multicast options
320 ip->ip_ttl = imo->imo_multicast_ttl;
321 if (imo->imo_multicast_vif != -1)
324 ip_mcast_src(imo->imo_multicast_vif) :
327 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
329 * Confirm that the outgoing interface supports multicast.
331 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
332 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
333 ipstat.ips_noroute++;
339 * If source address not specified yet, use address
340 * of outgoing interface.
342 if (ip->ip_src.s_addr == INADDR_ANY) {
343 /* Interface may have no addresses. */
345 ip->ip_src = IA_SIN(ia)->sin_addr;
348 IN_LOOKUP_MULTI(pkt_dst, ifp, inm);
350 (imo == NULL || imo->imo_multicast_loop)) {
352 * If we belong to the destination multicast group
353 * on the outgoing interface, and the caller did not
354 * forbid loopback, loop back a copy.
356 ip_mloopback(ifp, m, dst, hlen);
360 * If we are acting as a multicast router, perform
361 * multicast forwarding as if the packet had just
362 * arrived on the interface to which we are about
363 * to send. The multicast forwarding function
364 * recursively calls this function, using the
365 * IP_FORWARDING flag to prevent infinite recursion.
367 * Multicasts that are looped back by ip_mloopback(),
368 * above, will be forwarded by the ip_input() routine,
371 if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
373 * If rsvp daemon is not running, do not
374 * set ip_moptions. This ensures that the packet
375 * is multicast and not just sent down one link
376 * as prescribed by rsvpd.
381 ip_mforward(ip, ifp, m, imo) != 0) {
389 * Multicasts with a time-to-live of zero may be looped-
390 * back, above, but must not be transmitted on a network.
391 * Also, multicasts addressed to the loopback interface
392 * are not sent -- the above call to ip_mloopback() will
393 * loop back a copy if this host actually belongs to the
394 * destination group on the loopback interface.
396 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
405 * If the source address is not specified yet, use the address
406 * of the outoing interface. In case, keep note we did that, so
407 * if the the firewall changes the next-hop causing the output
408 * interface to change, we can fix that.
410 if (ip->ip_src.s_addr == INADDR_ANY) {
411 /* Interface may have no addresses. */
413 ip->ip_src = IA_SIN(ia)->sin_addr;
414 src_was_INADDR_ANY = 1;
419 * Verify that we have any chance at all of being able to queue
420 * the packet or packet fragments
422 if ((ifp->if_snd.ifq_len + ip->ip_len / ifp->if_mtu + 1) >=
423 ifp->if_snd.ifq_maxlen) {
425 ipstat.ips_odropped++;
430 * Look for broadcast address and
431 * verify user is allowed to send
435 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
436 error = EADDRNOTAVAIL;
439 if ((flags & IP_ALLOWBROADCAST) == 0) {
443 /* don't allow broadcast messages to be fragmented */
444 if (ip->ip_len > ifp->if_mtu) {
448 m->m_flags |= M_BCAST;
450 m->m_flags &= ~M_BCAST;
455 /* get SP for this packet */
457 sp = ipsec4_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, flags, &error);
459 sp = ipsec4_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);
462 ipsecstat.out_inval++;
469 switch (sp->policy) {
470 case IPSEC_POLICY_DISCARD:
472 * This packet is just discarded.
474 ipsecstat.out_polvio++;
477 case IPSEC_POLICY_BYPASS:
478 case IPSEC_POLICY_NONE:
479 /* no need to do IPsec. */
482 case IPSEC_POLICY_IPSEC:
483 if (sp->req == NULL) {
484 /* acquire a policy */
485 error = key_spdacquire(sp);
490 case IPSEC_POLICY_ENTRUST:
492 printf("ip_output: Invalid policy found. %d\n", sp->policy);
495 struct ipsec_output_state state;
496 bzero(&state, sizeof(state));
498 if (flags & IP_ROUTETOIF) {
500 bzero(&iproute, sizeof(iproute));
503 state.dst = (struct sockaddr *)dst;
509 * delayed checksums are not currently compatible with IPsec
511 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
513 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
516 ip->ip_len = htons(ip->ip_len);
517 ip->ip_off = htons(ip->ip_off);
519 error = ipsec4_output(&state, sp, flags);
522 if (flags & IP_ROUTETOIF) {
524 * if we have tunnel mode SA, we may need to ignore
527 if (state.ro != &iproute || state.ro->ro_rt != NULL) {
528 flags &= ~IP_ROUTETOIF;
533 dst = (struct sockaddr_in *)state.dst;
535 /* mbuf is already reclaimed in ipsec4_output. */
545 printf("ip4_output (ipsec): error code %d\n", error);
548 /* don't show these error codes to the user */
556 /* be sure to update variables that are affected by ipsec4_output() */
557 ip = mtod(m, struct ip *);
559 hlen = IP_VHL_HL(ip->ip_vhl) << 2;
561 hlen = ip->ip_hl << 2;
563 if (ro->ro_rt == NULL) {
564 if ((flags & IP_ROUTETOIF) == 0) {
566 "can't update route after IPsec processing\n");
567 error = EHOSTUNREACH; /*XXX*/
571 ia = ifatoia(ro->ro_rt->rt_ifa);
572 ifp = ro->ro_rt->rt_ifp;
575 /* make it flipped, again. */
576 ip->ip_len = ntohs(ip->ip_len);
577 ip->ip_off = ntohs(ip->ip_off);
582 * Check the security policy (SP) for the packet and, if
583 * required, do IPsec-related processing. There are two
584 * cases here; the first time a packet is sent through
585 * it will be untagged and handled by ipsec4_checkpolicy.
586 * If the packet is resubmitted to ip_output (e.g. after
587 * AH, ESP, etc. processing), there will be a tag to bypass
588 * the lookup and related policy checking.
590 mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
593 tdbi = (struct tdb_ident *)(mtag + 1);
594 sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
596 error = -EINVAL; /* force silent drop */
597 m_tag_delete(m, mtag);
599 sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND, flags,
603 * There are four return cases:
604 * sp != NULL apply IPsec policy
605 * sp == NULL, error == 0 no IPsec handling needed
606 * sp == NULL, error == -EINVAL discard packet w/o error
607 * sp == NULL, error != 0 discard packet, report error
610 /* Loop detection, check if ipsec processing already done */
611 KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
612 for (mtag = m_tag_first(m); mtag != NULL;
613 mtag = m_tag_next(m, mtag)) {
614 if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
616 if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
617 mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
620 * Check if policy has an SA associated with it.
621 * This can happen when an SP has yet to acquire
622 * an SA; e.g. on first reference. If it occurs,
623 * then we let ipsec4_process_packet do its thing.
625 if (sp->req->sav == NULL)
627 tdbi = (struct tdb_ident *)(mtag + 1);
628 if (tdbi->spi == sp->req->sav->spi &&
629 tdbi->proto == sp->req->sav->sah->saidx.proto &&
630 bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
631 sizeof (union sockaddr_union)) == 0) {
633 * No IPsec processing is needed, free
636 * NB: null pointer to avoid free at
639 KEY_FREESP(&sp), sp = NULL;
646 * Do delayed checksums now because we send before
647 * this is done in the normal processing path.
649 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
651 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
654 ip->ip_len = htons(ip->ip_len);
655 ip->ip_off = htons(ip->ip_off);
657 /* NB: callee frees mbuf */
658 error = ipsec4_process_packet(m, sp->req, flags, 0);
660 * Preserve KAME behaviour: ENOENT can be returned
661 * when an SA acquire is in progress. Don't propagate
662 * this to user-level; it confuses applications.
664 * XXX this will go away when the SADB is redone.
675 * Hack: -EINVAL is used to signal that a packet
676 * should be silently discarded. This is typically
677 * because we asked key management for an SA and
678 * it was delayed (e.g. kicked up to IKE).
680 if (error == -EINVAL)
684 /* No IPsec processing for this packet. */
688 * If deferred crypto processing is needed, check that
689 * the interface supports it.
691 mtag = m_tag_find(m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
692 if (mtag != NULL && (ifp->if_capenable & IFCAP_IPSEC) == 0) {
693 /* notify IPsec to do its own crypto */
694 ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
695 error = EHOSTUNREACH;
701 #endif /* FAST_IPSEC */
704 * - Xlate: translate packet's addr/port (NAT).
705 * - Firewall: deny/allow/etc.
706 * - Wrap: fake packet's addr/port <unimpl.>
707 * - Encapsulate: put it in another IP and send out. <unimp.>
711 * Run through list of hooks for output packets.
713 if (pfil_has_hooks(&inet_pfil_hook)) {
714 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT);
715 if (error != 0 || m == NULL)
717 ip = mtod(m, struct ip *);
721 * Check with the firewall...
722 * but not if we are already being fwd'd from a firewall.
724 if (fw_enable && IPFW_LOADED && !args.next_hop) {
725 struct sockaddr_in *old = dst;
730 off = ip_fw_chk_ptr(&args);
735 * On return we must do the following:
736 * m == NULL -> drop the pkt (old interface, deprecated)
737 * (off & IP_FW_PORT_DENY_FLAG) -> drop the pkt (new interface)
738 * 1<=off<= 0xffff -> DIVERT
739 * (off & IP_FW_PORT_DYNT_FLAG) -> send to a DUMMYNET pipe
740 * (off & IP_FW_PORT_TEE_FLAG) -> TEE the packet
741 * dst != old -> IPFIREWALL_FORWARD
742 * off==0, dst==old -> accept
743 * If some of the above modules are not compiled in, then
744 * we should't have to check the corresponding condition
745 * (because the ipfw control socket should not accept
746 * unsupported rules), but better play safe and drop
747 * packets in case of doubt.
749 if ( (off & IP_FW_PORT_DENY_FLAG) || m == NULL) {
755 ip = mtod(m, struct ip *);
756 if (off == 0 && dst == old) /* common case */
758 if (DUMMYNET_LOADED && (off & IP_FW_PORT_DYNT_FLAG) != 0) {
760 * pass the pkt to dummynet. Need to include
761 * pipe number, m, ifp, ro, dst because these are
762 * not recomputed in the next pass.
763 * All other parameters have been already used and
764 * so they are not needed anymore.
765 * XXX note: if the ifp or ro entry are deleted
766 * while a pkt is in dummynet, we are in trouble!
772 error = ip_dn_io_ptr(m, off & 0xffff, DN_TO_IP_OUT,
777 if (off != 0 && (off & IP_FW_PORT_DYNT_FLAG) == 0) {
778 struct mbuf *clone = NULL;
780 /* Clone packet if we're doing a 'tee' */
781 if ((off & IP_FW_PORT_TEE_FLAG) != 0)
782 clone = m_dup(m, MB_DONTWAIT);
786 * delayed checksums are not currently compatible
787 * with divert sockets.
789 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
791 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
794 /* Restore packet header fields to original values */
795 ip->ip_len = htons(ip->ip_len);
796 ip->ip_off = htons(ip->ip_off);
798 /* Deliver packet to divert input routine */
799 divert_packet(m, 0, off & 0xffff, args.divert_rule);
801 /* If 'tee', continue with original packet */
804 ip = mtod(m, struct ip *);
811 /* IPFIREWALL_FORWARD */
813 * Check dst to make sure it is directly reachable on the
814 * interface we previously thought it was.
815 * If it isn't (which may be likely in some situations) we have
816 * to re-route it (ie, find a route for the next-hop and the
817 * associated interface) and set them here. This is nested
818 * forwarding which in most cases is undesirable, except where
819 * such control is nigh impossible. So we do it here.
822 if (off == 0 && old != dst) { /* FORWARD, dst has changed */
825 * XXX To improve readability, this block should be
826 * changed into a function call as below:
828 error = ip_ipforward(&m, &dst, &ifp);
831 if (m == NULL) /* ip_input consumed the mbuf */
834 struct in_ifaddr *ia;
837 * XXX sro_fwd below is static, and a pointer
838 * to it gets passed to routines downstream.
839 * This could have surprisingly bad results in
840 * practice, because its content is overwritten
841 * by subsequent packets.
843 /* There must be a better way to do this next line... */
844 static struct route sro_fwd;
845 struct route *ro_fwd = &sro_fwd;
848 print_ip("IPFIREWALL_FORWARD: New dst ip: ",
849 dst->sin_addr, "\n");
853 * We need to figure out if we have been forwarded
854 * to a local socket. If so, then we should somehow
855 * "loop back" to ip_input, and get directed to the
856 * PCB as if we had received this packet. This is
857 * because it may be dificult to identify the packets
858 * you want to forward until they are being output
859 * and have selected an interface. (e.g. locally
860 * initiated packets) If we used the loopback inteface,
861 * we would not be able to control what happens
862 * as the packet runs through ip_input() as
863 * it is done through a ISR.
866 INADDR_HASH(dst->sin_addr.s_addr), ia_hash) {
868 * If the addr to forward to is one
869 * of ours, we pretend to
870 * be the destination for this packet.
872 if (IA_SIN(ia)->sin_addr.s_addr ==
873 dst->sin_addr.s_addr)
876 if (ia) { /* tell ip_input "dont filter" */
879 tag.mh_type = MT_TAG;
880 tag.mh_flags = PACKET_TAG_IPFORWARD;
881 tag.mh_data = (caddr_t)args.next_hop;
884 if (m->m_pkthdr.rcvif == NULL)
885 m->m_pkthdr.rcvif = ifunit("lo0");
886 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
887 m->m_pkthdr.csum_flags |=
888 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
889 m0->m_pkthdr.csum_data = 0xffff;
891 m->m_pkthdr.csum_flags |=
892 CSUM_IP_CHECKED | CSUM_IP_VALID;
893 ip->ip_len = htons(ip->ip_len);
894 ip->ip_off = htons(ip->ip_off);
895 ip_input((struct mbuf *)&tag);
898 /* Some of the logic for this was
901 * This rewrites the cached route in a local PCB.
902 * Is this what we want to do?
904 bcopy(dst, &ro_fwd->ro_dst, sizeof(*dst));
907 rtalloc_ign(ro_fwd, RTF_PRCLONING);
909 if (ro_fwd->ro_rt == 0) {
910 ipstat.ips_noroute++;
911 error = EHOSTUNREACH;
915 ia = ifatoia(ro_fwd->ro_rt->rt_ifa);
916 ifp = ro_fwd->ro_rt->rt_ifp;
917 ro_fwd->ro_rt->rt_use++;
918 if (ro_fwd->ro_rt->rt_flags & RTF_GATEWAY)
919 dst = (struct sockaddr_in *)
920 ro_fwd->ro_rt->rt_gateway;
921 if (ro_fwd->ro_rt->rt_flags & RTF_HOST)
923 (ro_fwd->ro_rt->rt_flags & RTF_BROADCAST);
925 isbroadcast = in_broadcast(dst->sin_addr, ifp);
928 ro->ro_rt = ro_fwd->ro_rt;
929 dst = (struct sockaddr_in *)&ro_fwd->ro_dst;
931 #endif /* ... block to be put into a function */
933 * If we added a default src ip earlier,
934 * which would have been gotten from the-then
935 * interface, do it again, from the new one.
937 if (src_was_INADDR_ANY)
938 ip->ip_src = IA_SIN(ia)->sin_addr;
943 * if we get here, none of the above matches, and
944 * we have to drop the pkt
947 error = EACCES; /* not sure this is the right error msg */
952 /* 127/8 must not appear on wire - RFC1122. */
953 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
954 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
955 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
956 ipstat.ips_badaddr++;
957 error = EADDRNOTAVAIL;
962 m->m_pkthdr.csum_flags |= CSUM_IP;
963 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
964 if (sw_csum & CSUM_DELAY_DATA) {
966 sw_csum &= ~CSUM_DELAY_DATA;
968 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
971 * If small enough for interface, or the interface will take
972 * care of the fragmentation for us, can just send directly.
974 if (ip->ip_len <= ifp->if_mtu || ((ifp->if_hwassist & CSUM_FRAGMENT) &&
975 (ip->ip_off & IP_DF) == 0)) {
976 ip->ip_len = htons(ip->ip_len);
977 ip->ip_off = htons(ip->ip_off);
979 if (sw_csum & CSUM_DELAY_IP) {
980 if (ip->ip_vhl == IP_VHL_BORING) {
981 ip->ip_sum = in_cksum_hdr(ip);
983 ip->ip_sum = in_cksum(m, hlen);
987 /* Record statistics for this interface address. */
988 if (!(flags & IP_FORWARDING) && ia) {
989 ia->ia_ifa.if_opackets++;
990 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
994 /* clean ipsec history once it goes out of the node */
998 #ifdef MBUF_STRESS_TEST
999 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size) {
1000 struct mbuf *m1, *m2;
1003 tmp = length = m->m_pkthdr.len;
1005 while ((length -= mbuf_frag_size) >= 1) {
1006 m1 = m_split(m, length, MB_DONTWAIT);
1009 m1->m_flags &= ~M_PKTHDR;
1011 while (m2->m_next != NULL)
1015 m->m_pkthdr.len = tmp;
1018 error = (*ifp->if_output)(ifp, m,
1019 (struct sockaddr *)dst, ro->ro_rt);
1023 if (ip->ip_off & IP_DF) {
1026 * This case can happen if the user changed the MTU
1027 * of an interface after enabling IP on it. Because
1028 * most netifs don't keep track of routes pointing to
1029 * them, there is no way for one to update all its
1030 * routes when the MTU is changed.
1032 if ((ro->ro_rt->rt_flags & (RTF_UP | RTF_HOST)) &&
1033 !(ro->ro_rt->rt_rmx.rmx_locks & RTV_MTU) &&
1034 (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)) {
1035 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
1037 ipstat.ips_cantfrag++;
1042 * Too large for interface; fragment if possible. If successful,
1043 * on return, m will point to a list of packets to be sent.
1045 error = ip_fragment(ip, &m, ifp->if_mtu, ifp->if_hwassist, sw_csum);
1052 /* clean ipsec history once it goes out of the node */
1056 /* Record statistics for this interface address. */
1058 ia->ia_ifa.if_opackets++;
1059 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
1062 error = (*ifp->if_output)(ifp, m,
1063 (struct sockaddr *)dst, ro->ro_rt);
1069 ipstat.ips_fragmented++;
1073 if (ro == &iproute && ro->ro_rt) {
1078 KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
1079 printf("DP ip_output call free SP:%p\n", sp));
1084 if (ro == &iproute && ro->ro_rt) {
1098 * Create a chain of fragments which fit the given mtu. m_frag points to the
1099 * mbuf to be fragmented; on return it points to the chain with the fragments.
1100 * Return 0 if no error. If error, m_frag may contain a partially built
1101 * chain of fragments that should be freed by the caller.
1103 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
1104 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
1107 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
1108 u_long if_hwassist_flags, int sw_csum)
1111 int hlen = IP_VHL_HL(ip->ip_vhl) << 2;
1112 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
1114 struct mbuf *m0 = *m_frag; /* the original packet */
1116 struct mbuf **mnext;
1119 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
1120 ipstat.ips_cantfrag++;
1125 * Must be able to put at least 8 bytes per fragment.
1131 * If the interface will not calculate checksums on
1132 * fragmented packets, then do it here.
1134 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA &&
1135 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
1136 in_delayed_cksum(m0);
1137 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1140 if (len > PAGE_SIZE) {
1142 * Fragment large datagrams such that each segment
1143 * contains a multiple of PAGE_SIZE amount of data,
1144 * plus headers. This enables a receiver to perform
1145 * page-flipping zero-copy optimizations.
1147 * XXX When does this help given that sender and receiver
1148 * could have different page sizes, and also mtu could
1149 * be less than the receiver's page size ?
1154 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
1158 * firstlen (off - hlen) must be aligned on an
1162 goto smart_frag_failure;
1163 off = ((off - hlen) & ~7) + hlen;
1164 newlen = (~PAGE_MASK) & mtu;
1165 if ((newlen + sizeof (struct ip)) > mtu) {
1166 /* we failed, go back the default */
1177 firstlen = off - hlen;
1178 mnext = &m0->m_nextpkt; /* pointer to next packet */
1181 * Loop through length of segment after first fragment,
1182 * make new header and copy data of each part and link onto chain.
1183 * Here, m0 is the original packet, m is the fragment being created.
1184 * The fragments are linked off the m_nextpkt of the original
1185 * packet, which after processing serves as the first fragment.
1187 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
1188 struct ip *mhip; /* ip header on the fragment */
1190 int mhlen = sizeof (struct ip);
1192 MGETHDR(m, MB_DONTWAIT, MT_HEADER);
1195 ipstat.ips_odropped++;
1198 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
1200 * In the first mbuf, leave room for the link header, then
1201 * copy the original IP header including options. The payload
1202 * goes into an additional mbuf chain returned by m_copy().
1204 m->m_data += max_linkhdr;
1205 mhip = mtod(m, struct ip *);
1207 if (hlen > sizeof (struct ip)) {
1208 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
1209 mhip->ip_vhl = IP_MAKE_VHL(IPVERSION, mhlen >> 2);
1212 /* XXX do we need to add ip->ip_off below ? */
1213 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
1214 if (off + len >= ip->ip_len) { /* last fragment */
1215 len = ip->ip_len - off;
1216 m->m_flags |= M_LASTFRAG;
1218 mhip->ip_off |= IP_MF;
1219 mhip->ip_len = htons((u_short)(len + mhlen));
1220 m->m_next = m_copy(m0, off, len);
1221 if (m->m_next == 0) { /* copy failed */
1223 error = ENOBUFS; /* ??? */
1224 ipstat.ips_odropped++;
1227 m->m_pkthdr.len = mhlen + len;
1228 m->m_pkthdr.rcvif = (struct ifnet *)0;
1229 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
1230 mhip->ip_off = htons(mhip->ip_off);
1232 if (sw_csum & CSUM_DELAY_IP)
1233 mhip->ip_sum = in_cksum(m, mhlen);
1235 mnext = &m->m_nextpkt;
1237 ipstat.ips_ofragments += nfrags;
1239 /* set first marker for fragment chain */
1240 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
1241 m0->m_pkthdr.csum_data = nfrags;
1244 * Update first fragment by trimming what's been copied out
1245 * and updating header.
1247 m_adj(m0, hlen + firstlen - ip->ip_len);
1248 m0->m_pkthdr.len = hlen + firstlen;
1249 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
1250 ip->ip_off |= IP_MF;
1251 ip->ip_off = htons(ip->ip_off);
1253 if (sw_csum & CSUM_DELAY_IP)
1254 ip->ip_sum = in_cksum(m0, hlen);
1262 in_delayed_cksum(struct mbuf *m)
1265 u_short csum, offset;
1267 ip = mtod(m, struct ip *);
1268 offset = IP_VHL_HL(ip->ip_vhl) << 2 ;
1269 csum = in_cksum_skip(m, ip->ip_len, offset);
1270 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
1272 offset += m->m_pkthdr.csum_data; /* checksum offset */
1274 if (offset + sizeof(u_short) > m->m_len) {
1275 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
1276 m->m_len, offset, ip->ip_p);
1279 * this shouldn't happen, but if it does, the
1280 * correct behavior may be to insert the checksum
1281 * in the existing chain instead of rearranging it.
1283 m = m_pullup(m, offset + sizeof(u_short));
1285 *(u_short *)(m->m_data + offset) = csum;
1289 * Insert IP options into preformed packet.
1290 * Adjust IP destination as required for IP source routing,
1291 * as indicated by a non-zero in_addr at the start of the options.
1293 * XXX This routine assumes that the packet has no options in place.
1295 static struct mbuf *
1296 ip_insertoptions(m, opt, phlen)
1301 struct ipoption *p = mtod(opt, struct ipoption *);
1303 struct ip *ip = mtod(m, struct ip *);
1306 optlen = opt->m_len - sizeof(p->ipopt_dst);
1307 if (optlen + (u_short)ip->ip_len > IP_MAXPACKET) {
1309 return (m); /* XXX should fail */
1311 if (p->ipopt_dst.s_addr)
1312 ip->ip_dst = p->ipopt_dst;
1313 if (m->m_flags & M_EXT || m->m_data - optlen < m->m_pktdat) {
1314 MGETHDR(n, MB_DONTWAIT, MT_HEADER);
1319 n->m_pkthdr.rcvif = (struct ifnet *)0;
1320 n->m_pkthdr.len = m->m_pkthdr.len + optlen;
1321 m->m_len -= sizeof(struct ip);
1322 m->m_data += sizeof(struct ip);
1325 m->m_len = optlen + sizeof(struct ip);
1326 m->m_data += max_linkhdr;
1327 (void)memcpy(mtod(m, void *), ip, sizeof(struct ip));
1329 m->m_data -= optlen;
1331 m->m_pkthdr.len += optlen;
1332 ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
1334 ip = mtod(m, struct ip *);
1335 bcopy(p->ipopt_list, ip + 1, optlen);
1336 *phlen = sizeof(struct ip) + optlen;
1337 ip->ip_vhl = IP_MAKE_VHL(IPVERSION, *phlen >> 2);
1338 ip->ip_len += optlen;
1343 * Copy options from ip to jp,
1344 * omitting those not copied during fragmentation.
1351 int opt, optlen, cnt;
1353 cp = (u_char *)(ip + 1);
1354 dp = (u_char *)(jp + 1);
1355 cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
1356 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1358 if (opt == IPOPT_EOL)
1360 if (opt == IPOPT_NOP) {
1361 /* Preserve for IP mcast tunnel's LSRR alignment. */
1367 KASSERT(cnt >= IPOPT_OLEN + sizeof(*cp),
1368 ("ip_optcopy: malformed ipv4 option"));
1369 optlen = cp[IPOPT_OLEN];
1370 KASSERT(optlen >= IPOPT_OLEN + sizeof(*cp) && optlen <= cnt,
1371 ("ip_optcopy: malformed ipv4 option"));
1373 /* bogus lengths should have been caught by ip_dooptions */
1376 if (IPOPT_COPIED(opt)) {
1377 bcopy(cp, dp, optlen);
1381 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++)
1387 * IP socket option processing.
1390 ip_ctloutput(so, sopt)
1392 struct sockopt *sopt;
1394 struct inpcb *inp = sotoinpcb(so);
1398 if (sopt->sopt_level != IPPROTO_IP) {
1402 switch (sopt->sopt_dir) {
1404 switch (sopt->sopt_name) {
1411 if (sopt->sopt_valsize > MLEN) {
1415 MGET(m, sopt->sopt_td ? MB_WAIT : MB_DONTWAIT, MT_HEADER);
1420 m->m_len = sopt->sopt_valsize;
1421 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
1424 return (ip_pcbopts(sopt->sopt_name, &inp->inp_options,
1431 case IP_RECVRETOPTS:
1432 case IP_RECVDSTADDR:
1435 error = sooptcopyin(sopt, &optval, sizeof optval,
1440 switch (sopt->sopt_name) {
1442 inp->inp_ip_tos = optval;
1446 inp->inp_ip_ttl = optval;
1448 #define OPTSET(bit) \
1450 inp->inp_flags |= bit; \
1452 inp->inp_flags &= ~bit;
1455 OPTSET(INP_RECVOPTS);
1458 case IP_RECVRETOPTS:
1459 OPTSET(INP_RECVRETOPTS);
1462 case IP_RECVDSTADDR:
1463 OPTSET(INP_RECVDSTADDR);
1477 case IP_MULTICAST_IF:
1478 case IP_MULTICAST_VIF:
1479 case IP_MULTICAST_TTL:
1480 case IP_MULTICAST_LOOP:
1481 case IP_ADD_MEMBERSHIP:
1482 case IP_DROP_MEMBERSHIP:
1483 error = ip_setmoptions(sopt, &inp->inp_moptions);
1487 error = sooptcopyin(sopt, &optval, sizeof optval,
1493 case IP_PORTRANGE_DEFAULT:
1494 inp->inp_flags &= ~(INP_LOWPORT);
1495 inp->inp_flags &= ~(INP_HIGHPORT);
1498 case IP_PORTRANGE_HIGH:
1499 inp->inp_flags &= ~(INP_LOWPORT);
1500 inp->inp_flags |= INP_HIGHPORT;
1503 case IP_PORTRANGE_LOW:
1504 inp->inp_flags &= ~(INP_HIGHPORT);
1505 inp->inp_flags |= INP_LOWPORT;
1514 #if defined(IPSEC) || defined(FAST_IPSEC)
1515 case IP_IPSEC_POLICY:
1523 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1525 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1527 priv = (sopt->sopt_td != NULL &&
1528 suser(sopt->sopt_td) != 0) ? 0 : 1;
1529 req = mtod(m, caddr_t);
1531 optname = sopt->sopt_name;
1532 error = ipsec4_set_policy(inp, optname, req, len, priv);
1539 error = ENOPROTOOPT;
1545 switch (sopt->sopt_name) {
1548 if (inp->inp_options)
1549 error = sooptcopyout(sopt,
1550 mtod(inp->inp_options,
1552 inp->inp_options->m_len);
1554 sopt->sopt_valsize = 0;
1560 case IP_RECVRETOPTS:
1561 case IP_RECVDSTADDR:
1565 switch (sopt->sopt_name) {
1568 optval = inp->inp_ip_tos;
1572 optval = inp->inp_ip_ttl;
1575 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1578 optval = OPTBIT(INP_RECVOPTS);
1581 case IP_RECVRETOPTS:
1582 optval = OPTBIT(INP_RECVRETOPTS);
1585 case IP_RECVDSTADDR:
1586 optval = OPTBIT(INP_RECVDSTADDR);
1590 optval = OPTBIT(INP_RECVIF);
1594 if (inp->inp_flags & INP_HIGHPORT)
1595 optval = IP_PORTRANGE_HIGH;
1596 else if (inp->inp_flags & INP_LOWPORT)
1597 optval = IP_PORTRANGE_LOW;
1603 optval = OPTBIT(INP_FAITH);
1606 error = sooptcopyout(sopt, &optval, sizeof optval);
1609 case IP_MULTICAST_IF:
1610 case IP_MULTICAST_VIF:
1611 case IP_MULTICAST_TTL:
1612 case IP_MULTICAST_LOOP:
1613 case IP_ADD_MEMBERSHIP:
1614 case IP_DROP_MEMBERSHIP:
1615 error = ip_getmoptions(sopt, inp->inp_moptions);
1618 #if defined(IPSEC) || defined(FAST_IPSEC)
1619 case IP_IPSEC_POLICY:
1621 struct mbuf *m = NULL;
1626 req = mtod(m, caddr_t);
1629 error = ipsec4_get_policy(sotoinpcb(so), req, len, &m);
1631 error = soopt_mcopyout(sopt, m); /* XXX */
1639 error = ENOPROTOOPT;
1648 * Set up IP options in pcb for insertion in output packets.
1649 * Store in mbuf with pointer in pcbopt, adding pseudo-option
1650 * with destination address if source routed.
1653 ip_pcbopts(optname, pcbopt, m)
1655 struct mbuf **pcbopt;
1662 /* turn off any old options */
1664 (void)m_free(*pcbopt);
1666 if (m == (struct mbuf *)0 || m->m_len == 0) {
1668 * Only turning off any previous options.
1675 if (m->m_len % sizeof(int32_t))
1678 * IP first-hop destination address will be stored before
1679 * actual options; move other options back
1680 * and clear it when none present.
1682 if (m->m_data + m->m_len + sizeof(struct in_addr) >= &m->m_dat[MLEN])
1685 m->m_len += sizeof(struct in_addr);
1686 cp = mtod(m, u_char *) + sizeof(struct in_addr);
1687 ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt);
1688 bzero(mtod(m, caddr_t), sizeof(struct in_addr));
1690 for (; cnt > 0; cnt -= optlen, cp += optlen) {
1691 opt = cp[IPOPT_OPTVAL];
1692 if (opt == IPOPT_EOL)
1694 if (opt == IPOPT_NOP)
1697 if (cnt < IPOPT_OLEN + sizeof(*cp))
1699 optlen = cp[IPOPT_OLEN];
1700 if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt)
1711 * user process specifies route as:
1713 * D must be our final destination (but we can't
1714 * check that since we may not have connected yet).
1715 * A is first hop destination, which doesn't appear in
1716 * actual IP option, but is stored before the options.
1718 if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
1720 m->m_len -= sizeof(struct in_addr);
1721 cnt -= sizeof(struct in_addr);
1722 optlen -= sizeof(struct in_addr);
1723 cp[IPOPT_OLEN] = optlen;
1725 * Move first hop before start of options.
1727 bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
1728 sizeof(struct in_addr));
1730 * Then copy rest of options back
1731 * to close up the deleted entry.
1733 ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] +
1734 sizeof(struct in_addr)),
1735 &cp[IPOPT_OFFSET+1],
1736 (unsigned)cnt - (IPOPT_MINOFF - 1));
1740 if (m->m_len > MAX_IPOPTLEN + sizeof(struct in_addr))
1752 * The whole multicast option thing needs to be re-thought.
1753 * Several of these options are equally applicable to non-multicast
1754 * transmission, and one (IP_MULTICAST_TTL) totally duplicates a
1755 * standard option (IP_TTL).
1759 * following RFC1724 section 3.3, 0.0.0.0/8 is interpreted as interface index.
1761 static struct ifnet *
1762 ip_multicast_if(a, ifindexp)
1771 if (ntohl(a->s_addr) >> 24 == 0) {
1772 ifindex = ntohl(a->s_addr) & 0xffffff;
1773 if (ifindex < 0 || if_index < ifindex)
1775 ifp = ifindex2ifnet[ifindex];
1777 *ifindexp = ifindex;
1779 INADDR_TO_IFP(*a, ifp);
1785 * Set the IP multicast options in response to user setsockopt().
1788 ip_setmoptions(sopt, imop)
1789 struct sockopt *sopt;
1790 struct ip_moptions **imop;
1794 struct in_addr addr;
1795 struct ip_mreq mreq;
1797 struct ip_moptions *imo = *imop;
1799 struct sockaddr_in *dst;
1805 * No multicast option buffer attached to the pcb;
1806 * allocate one and initialize to default values.
1808 imo = (struct ip_moptions*)malloc(sizeof(*imo), M_IPMOPTS,
1814 imo->imo_multicast_ifp = NULL;
1815 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1816 imo->imo_multicast_vif = -1;
1817 imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
1818 imo->imo_multicast_loop = IP_DEFAULT_MULTICAST_LOOP;
1819 imo->imo_num_memberships = 0;
1822 switch (sopt->sopt_name) {
1823 /* store an index number for the vif you wanna use in the send */
1824 case IP_MULTICAST_VIF:
1825 if (legal_vif_num == 0) {
1829 error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
1832 if (!legal_vif_num(i) && (i != -1)) {
1836 imo->imo_multicast_vif = i;
1839 case IP_MULTICAST_IF:
1841 * Select the interface for outgoing multicast packets.
1843 error = sooptcopyin(sopt, &addr, sizeof addr, sizeof addr);
1847 * INADDR_ANY is used to remove a previous selection.
1848 * When no interface is selected, a default one is
1849 * chosen every time a multicast packet is sent.
1851 if (addr.s_addr == INADDR_ANY) {
1852 imo->imo_multicast_ifp = NULL;
1856 * The selected interface is identified by its local
1857 * IP address. Find the interface and confirm that
1858 * it supports multicasting.
1861 ifp = ip_multicast_if(&addr, &ifindex);
1862 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1864 error = EADDRNOTAVAIL;
1867 imo->imo_multicast_ifp = ifp;
1869 imo->imo_multicast_addr = addr;
1871 imo->imo_multicast_addr.s_addr = INADDR_ANY;
1875 case IP_MULTICAST_TTL:
1877 * Set the IP time-to-live for outgoing multicast packets.
1878 * The original multicast API required a char argument,
1879 * which is inconsistent with the rest of the socket API.
1880 * We allow either a char or an int.
1882 if (sopt->sopt_valsize == 1) {
1884 error = sooptcopyin(sopt, &ttl, 1, 1);
1887 imo->imo_multicast_ttl = ttl;
1890 error = sooptcopyin(sopt, &ttl, sizeof ttl,
1897 imo->imo_multicast_ttl = ttl;
1901 case IP_MULTICAST_LOOP:
1903 * Set the loopback flag for outgoing multicast packets.
1904 * Must be zero or one. The original multicast API required a
1905 * char argument, which is inconsistent with the rest
1906 * of the socket API. We allow either a char or an int.
1908 if (sopt->sopt_valsize == 1) {
1910 error = sooptcopyin(sopt, &loop, 1, 1);
1913 imo->imo_multicast_loop = !!loop;
1916 error = sooptcopyin(sopt, &loop, sizeof loop,
1920 imo->imo_multicast_loop = !!loop;
1924 case IP_ADD_MEMBERSHIP:
1926 * Add a multicast group membership.
1927 * Group must be a valid IP multicast address.
1929 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
1933 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
1939 * If no interface address was provided, use the interface of
1940 * the route to the given multicast address.
1942 if (mreq.imr_interface.s_addr == INADDR_ANY) {
1943 bzero((caddr_t)&ro, sizeof(ro));
1944 dst = (struct sockaddr_in *)&ro.ro_dst;
1945 dst->sin_len = sizeof(*dst);
1946 dst->sin_family = AF_INET;
1947 dst->sin_addr = mreq.imr_multiaddr;
1949 if (ro.ro_rt == NULL) {
1950 error = EADDRNOTAVAIL;
1954 ifp = ro.ro_rt->rt_ifp;
1958 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
1962 * See if we found an interface, and confirm that it
1963 * supports multicast.
1965 if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
1966 error = EADDRNOTAVAIL;
1971 * See if the membership already exists or if all the
1972 * membership slots are full.
1974 for (i = 0; i < imo->imo_num_memberships; ++i) {
1975 if (imo->imo_membership[i]->inm_ifp == ifp &&
1976 imo->imo_membership[i]->inm_addr.s_addr
1977 == mreq.imr_multiaddr.s_addr)
1980 if (i < imo->imo_num_memberships) {
1985 if (i == IP_MAX_MEMBERSHIPS) {
1986 error = ETOOMANYREFS;
1991 * Everything looks good; add a new record to the multicast
1992 * address list for the given interface.
1994 if ((imo->imo_membership[i] =
1995 in_addmulti(&mreq.imr_multiaddr, ifp)) == NULL) {
2000 ++imo->imo_num_memberships;
2004 case IP_DROP_MEMBERSHIP:
2006 * Drop a multicast group membership.
2007 * Group must be a valid IP multicast address.
2009 error = sooptcopyin(sopt, &mreq, sizeof mreq, sizeof mreq);
2013 if (!IN_MULTICAST(ntohl(mreq.imr_multiaddr.s_addr))) {
2020 * If an interface address was specified, get a pointer
2021 * to its ifnet structure.
2023 if (mreq.imr_interface.s_addr == INADDR_ANY)
2026 ifp = ip_multicast_if(&mreq.imr_interface, NULL);
2028 error = EADDRNOTAVAIL;
2034 * Find the membership in the membership array.
2036 for (i = 0; i < imo->imo_num_memberships; ++i) {
2038 imo->imo_membership[i]->inm_ifp == ifp) &&
2039 imo->imo_membership[i]->inm_addr.s_addr ==
2040 mreq.imr_multiaddr.s_addr)
2043 if (i == imo->imo_num_memberships) {
2044 error = EADDRNOTAVAIL;
2049 * Give up the multicast address record to which the
2050 * membership points.
2052 in_delmulti(imo->imo_membership[i]);
2054 * Remove the gap in the membership array.
2056 for (++i; i < imo->imo_num_memberships; ++i)
2057 imo->imo_membership[i-1] = imo->imo_membership[i];
2058 --imo->imo_num_memberships;
2068 * If all options have default values, no need to keep the mbuf.
2070 if (imo->imo_multicast_ifp == NULL &&
2071 imo->imo_multicast_vif == -1 &&
2072 imo->imo_multicast_ttl == IP_DEFAULT_MULTICAST_TTL &&
2073 imo->imo_multicast_loop == IP_DEFAULT_MULTICAST_LOOP &&
2074 imo->imo_num_memberships == 0) {
2075 free(*imop, M_IPMOPTS);
2083 * Return the IP multicast options in response to user getsockopt().
2086 ip_getmoptions(sopt, imo)
2087 struct sockopt *sopt;
2088 struct ip_moptions *imo;
2090 struct in_addr addr;
2091 struct in_ifaddr *ia;
2096 switch (sopt->sopt_name) {
2097 case IP_MULTICAST_VIF:
2099 optval = imo->imo_multicast_vif;
2102 error = sooptcopyout(sopt, &optval, sizeof optval);
2105 case IP_MULTICAST_IF:
2106 if (imo == NULL || imo->imo_multicast_ifp == NULL)
2107 addr.s_addr = INADDR_ANY;
2108 else if (imo->imo_multicast_addr.s_addr) {
2109 /* return the value user has set */
2110 addr = imo->imo_multicast_addr;
2112 IFP_TO_IA(imo->imo_multicast_ifp, ia);
2113 addr.s_addr = (ia == NULL) ? INADDR_ANY
2114 : IA_SIN(ia)->sin_addr.s_addr;
2116 error = sooptcopyout(sopt, &addr, sizeof addr);
2119 case IP_MULTICAST_TTL:
2121 optval = coptval = IP_DEFAULT_MULTICAST_TTL;
2123 optval = coptval = imo->imo_multicast_ttl;
2124 if (sopt->sopt_valsize == 1)
2125 error = sooptcopyout(sopt, &coptval, 1);
2127 error = sooptcopyout(sopt, &optval, sizeof optval);
2130 case IP_MULTICAST_LOOP:
2132 optval = coptval = IP_DEFAULT_MULTICAST_LOOP;
2134 optval = coptval = imo->imo_multicast_loop;
2135 if (sopt->sopt_valsize == 1)
2136 error = sooptcopyout(sopt, &coptval, 1);
2138 error = sooptcopyout(sopt, &optval, sizeof optval);
2142 error = ENOPROTOOPT;
2149 * Discard the IP multicast options.
2152 ip_freemoptions(imo)
2153 struct ip_moptions *imo;
2158 for (i = 0; i < imo->imo_num_memberships; ++i)
2159 in_delmulti(imo->imo_membership[i]);
2160 free(imo, M_IPMOPTS);
2165 * Routine called from ip_output() to loop back a copy of an IP multicast
2166 * packet to the input queue of a specified interface. Note that this
2167 * calls the output routine of the loopback "driver", but with an interface
2168 * pointer that might NOT be a loopback interface -- evil, but easier than
2169 * replicating that code here.
2172 ip_mloopback(ifp, m, dst, hlen)
2175 struct sockaddr_in *dst;
2181 copym = m_copy(m, 0, M_COPYALL);
2182 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
2183 copym = m_pullup(copym, hlen);
2184 if (copym != NULL) {
2186 * if the checksum hasn't been computed, mark it as valid
2188 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
2189 in_delayed_cksum(copym);
2190 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
2191 copym->m_pkthdr.csum_flags |=
2192 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
2193 copym->m_pkthdr.csum_data = 0xffff;
2196 * We don't bother to fragment if the IP length is greater
2197 * than the interface's MTU. Can this possibly matter?
2199 ip = mtod(copym, struct ip *);
2200 ip->ip_len = htons(ip->ip_len);
2201 ip->ip_off = htons(ip->ip_off);
2203 if (ip->ip_vhl == IP_VHL_BORING) {
2204 ip->ip_sum = in_cksum_hdr(ip);
2206 ip->ip_sum = in_cksum(copym, hlen);
2210 * It's not clear whether there are any lingering
2211 * reentrancy problems in other areas which might
2212 * be exposed by using ip_input directly (in
2213 * particular, everything which modifies the packet
2214 * in-place). Yet another option is using the
2215 * protosw directly to deliver the looped back
2216 * packet. For the moment, we'll err on the side
2217 * of safety by using if_simloop().
2220 if (dst->sin_family != AF_INET) {
2221 printf("ip_mloopback: bad address family %d\n",
2223 dst->sin_family = AF_INET;
2228 copym->m_pkthdr.rcvif = ifp;
2231 if_simloop(ifp, copym, dst->sin_family, 0);