2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 #include "opt_ipsec.h"
37 #include "opt_kdtrace.h"
38 #include "opt_mbuf_stress_test.h"
39 #include "opt_mpath.h"
40 #include "opt_route.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
50 #include <sys/protosw.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/ucred.h>
58 #include <net/if_llatbl.h>
59 #include <net/netisr.h>
61 #include <net/route.h>
62 #include <net/flowtable.h>
64 #include <net/radix_mpath.h>
68 #include <netinet/in.h>
69 #include <netinet/in_kdtrace.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/ip.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/in_var.h>
74 #include <netinet/ip_var.h>
75 #include <netinet/ip_options.h>
77 #include <netinet/sctp.h>
78 #include <netinet/sctp_crc32.h>
82 #include <netinet/ip_ipsec.h>
83 #include <netipsec/ipsec.h>
86 #include <machine/in_cksum.h>
88 #include <security/mac/mac_framework.h>
90 VNET_DEFINE(u_short, ip_id);
92 #ifdef MBUF_STRESS_TEST
93 static int mbuf_frag_size = 0;
94 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
95 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
98 static void ip_mloopback
99 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
102 extern int in_mcast_loop;
103 extern struct protosw inetsw[];
106 * IP output. The packet in mbuf chain m contains a skeletal IP
107 * header (with len, off, ttl, proto, tos, src, dst).
108 * The mbuf chain containing the packet will be freed.
109 * The mbuf opt, if present, will not be freed.
110 * If route ro is present and has ro_rt initialized, route lookup would be
111 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
112 * then result of route lookup is stored in ro->ro_rt.
114 * In the IP forwarding case, the packet will arrive with options already
115 * inserted, so must have a NULL opt pointer.
118 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
119 struct ip_moptions *imo, struct inpcb *inp)
122 struct ifnet *ifp = NULL; /* keep compiler happy */
124 int hlen = sizeof (struct ip);
126 int n; /* scratchpad */
128 struct sockaddr_in *dst;
129 const struct sockaddr_in *gw;
130 struct in_ifaddr *ia;
132 uint16_t ip_len, ip_off;
133 struct route iproute;
134 struct rtentry *rte; /* cache for ro->ro_rt */
136 struct m_tag *fwd_tag = NULL;
138 int no_route_but_check_spd = 0;
143 INP_LOCK_ASSERT(inp);
144 M_SETFIB(m, inp->inp_inc.inc_fibnum);
145 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
146 m->m_pkthdr.flowid = inp->inp_flowid;
147 m->m_flags |= M_FLOWID;
153 bzero(ro, sizeof (*ro));
157 if (ro->ro_rt == NULL) {
161 * The flow table returns route entries valid for up to 30
162 * seconds; we rely on the remainder of ip_output() taking no
163 * longer than that long for the stability of ro_rt. The
164 * flow ID assignment must have happened before this point.
166 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
168 flow_to_route(fle, ro);
174 m = ip_insertoptions(m, opt, &len);
176 hlen = len; /* ip->ip_hl is updated above */
178 ip = mtod(m, struct ip *);
179 ip_len = ntohs(ip->ip_len);
180 ip_off = ntohs(ip->ip_off);
183 * Fill in IP header. If we are not allowing fragmentation,
184 * then the ip_id field is meaningless, but we don't set it
185 * to zero. Doing so causes various problems when devices along
186 * the path (routers, load balancers, firewalls, etc.) illegally
187 * disable DF on our packet. Note that a 16-bit counter
188 * will wrap around in less than 10 seconds at 100 Mbit/s on a
189 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
190 * for Counting NATted Hosts", Proc. IMW'02, available at
191 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
193 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
194 ip->ip_v = IPVERSION;
195 ip->ip_hl = hlen >> 2;
196 ip->ip_id = ip_newid();
197 IPSTAT_INC(ips_localout);
199 /* Header already set, fetch hlen from there */
200 hlen = ip->ip_hl << 2;
203 gw = dst = (struct sockaddr_in *)&ro->ro_dst;
207 * If there is a cached route,
208 * check that it is to the same destination
209 * and is still up. If not, free it and try again.
210 * The address family should also be checked in case of sharing the
214 if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
215 rte->rt_ifp == NULL ||
216 !RT_LINK_IS_UP(rte->rt_ifp) ||
217 dst->sin_family != AF_INET ||
218 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
223 if (rte == NULL && fwd_tag == NULL) {
224 bzero(dst, sizeof(*dst));
225 dst->sin_family = AF_INET;
226 dst->sin_len = sizeof(*dst);
227 dst->sin_addr = ip->ip_dst;
230 * If routing to interface only, short circuit routing lookup.
231 * The use of an all-ones broadcast address implies this; an
232 * interface is specified by the broadcast address of an interface,
233 * or the destination address of a ptp interface.
235 if (flags & IP_SENDONES) {
236 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
237 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
238 IPSTAT_INC(ips_noroute);
242 ip->ip_dst.s_addr = INADDR_BROADCAST;
243 dst->sin_addr = ip->ip_dst;
247 } else if (flags & IP_ROUTETOIF) {
248 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
249 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
250 IPSTAT_INC(ips_noroute);
256 isbroadcast = in_broadcast(dst->sin_addr, ifp);
257 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
258 imo != NULL && imo->imo_multicast_ifp != NULL) {
260 * Bypass the normal routing lookup for multicast
261 * packets if the interface is specified.
263 ifp = imo->imo_multicast_ifp;
265 isbroadcast = 0; /* fool gcc */
268 * We want to do any cloning requested by the link layer,
269 * as this is probably required in all cases for correct
270 * operation (as it is for ARP).
274 rtalloc_mpath_fib(ro,
275 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
276 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
278 in_rtalloc_ign(ro, 0,
279 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
284 rte->rt_ifp == NULL ||
285 !RT_LINK_IS_UP(rte->rt_ifp)) {
288 * There is no route for this packet, but it is
289 * possible that a matching SPD entry exists.
291 no_route_but_check_spd = 1;
292 mtu = 0; /* Silence GCC warning. */
295 IPSTAT_INC(ips_noroute);
296 error = EHOSTUNREACH;
299 ia = ifatoia(rte->rt_ifa);
300 ifa_ref(&ia->ia_ifa);
302 rte->rt_rmx.rmx_pksent++;
303 if (rte->rt_flags & RTF_GATEWAY)
304 gw = (struct sockaddr_in *)rte->rt_gateway;
305 if (rte->rt_flags & RTF_HOST)
306 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
308 isbroadcast = in_broadcast(gw->sin_addr, ifp);
311 * Calculate MTU. If we have a route that is up, use that,
312 * otherwise use the interface's MTU.
314 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
316 * This case can happen if the user changed the MTU
317 * of an interface after enabling IP on it. Because
318 * most netifs don't keep track of routes pointing to
319 * them, there is no way for one to update all its
320 * routes when the MTU is changed.
322 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
323 rte->rt_rmx.rmx_mtu = ifp->if_mtu;
324 mtu = rte->rt_rmx.rmx_mtu;
328 /* Catch a possible divide by zero later. */
329 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
330 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
331 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
332 m->m_flags |= M_MCAST;
334 * IP destination address is multicast. Make sure "gw"
335 * still points to the address in "ro". (It may have been
336 * changed to point to a gateway address, above.)
340 * See if the caller provided any multicast options
343 ip->ip_ttl = imo->imo_multicast_ttl;
344 if (imo->imo_multicast_vif != -1)
347 ip_mcast_src(imo->imo_multicast_vif) :
350 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
352 * Confirm that the outgoing interface supports multicast.
354 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
355 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
356 IPSTAT_INC(ips_noroute);
362 * If source address not specified yet, use address
363 * of outgoing interface.
365 if (ip->ip_src.s_addr == INADDR_ANY) {
366 /* Interface may have no addresses. */
368 ip->ip_src = IA_SIN(ia)->sin_addr;
371 if ((imo == NULL && in_mcast_loop) ||
372 (imo && imo->imo_multicast_loop)) {
374 * Loop back multicast datagram if not expressly
375 * forbidden to do so, even if we are not a member
376 * of the group; ip_input() will filter it later,
377 * thus deferring a hash lookup and mutex acquisition
378 * at the expense of a cheap copy using m_copym().
380 ip_mloopback(ifp, m, dst, hlen);
383 * If we are acting as a multicast router, perform
384 * multicast forwarding as if the packet had just
385 * arrived on the interface to which we are about
386 * to send. The multicast forwarding function
387 * recursively calls this function, using the
388 * IP_FORWARDING flag to prevent infinite recursion.
390 * Multicasts that are looped back by ip_mloopback(),
391 * above, will be forwarded by the ip_input() routine,
394 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
396 * If rsvp daemon is not running, do not
397 * set ip_moptions. This ensures that the packet
398 * is multicast and not just sent down one link
399 * as prescribed by rsvpd.
404 ip_mforward(ip, ifp, m, imo) != 0) {
412 * Multicasts with a time-to-live of zero may be looped-
413 * back, above, but must not be transmitted on a network.
414 * Also, multicasts addressed to the loopback interface
415 * are not sent -- the above call to ip_mloopback() will
416 * loop back a copy. ip_input() will drop the copy if
417 * this host does not belong to the destination group on
418 * the loopback interface.
420 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
429 * If the source address is not specified yet, use the address
430 * of the outoing interface.
432 if (ip->ip_src.s_addr == INADDR_ANY) {
433 /* Interface may have no addresses. */
435 ip->ip_src = IA_SIN(ia)->sin_addr;
440 * Verify that we have any chance at all of being able to queue the
441 * packet or packet fragments, unless ALTQ is enabled on the given
442 * interface in which case packetdrop should be done by queueing.
444 n = ip_len / mtu + 1; /* how many fragments ? */
447 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
449 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
451 IPSTAT_INC(ips_odropped);
452 ifp->if_snd.ifq_drops += n;
457 * Look for broadcast address and
458 * verify user is allowed to send
462 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
463 error = EADDRNOTAVAIL;
466 if ((flags & IP_ALLOWBROADCAST) == 0) {
470 /* don't allow broadcast messages to be fragmented */
475 m->m_flags |= M_BCAST;
477 m->m_flags &= ~M_BCAST;
482 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
489 break; /* Continue with packet processing. */
492 * Check if there was a route for this packet; return error if not.
494 if (no_route_but_check_spd) {
495 IPSTAT_INC(ips_noroute);
496 error = EHOSTUNREACH;
499 /* Update variables that are affected by ipsec4_output(). */
500 ip = mtod(m, struct ip *);
501 hlen = ip->ip_hl << 2;
504 /* Jump over all PFIL processing if hooks are not active. */
505 if (!PFIL_HOOKED(&V_inet_pfil_hook))
508 /* Run through list of hooks for output packets. */
509 odst.s_addr = ip->ip_dst.s_addr;
510 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
511 if (error != 0 || m == NULL)
514 ip = mtod(m, struct ip *);
516 /* See if destination IP address was changed by packet filter. */
517 if (odst.s_addr != ip->ip_dst.s_addr) {
518 m->m_flags |= M_SKIP_FIREWALL;
519 /* If destination is now ourself drop to ip_input(). */
520 if (in_localip(ip->ip_dst)) {
521 m->m_flags |= M_FASTFWD_OURS;
522 if (m->m_pkthdr.rcvif == NULL)
523 m->m_pkthdr.rcvif = V_loif;
524 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
525 m->m_pkthdr.csum_flags |=
526 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
527 m->m_pkthdr.csum_data = 0xffff;
529 m->m_pkthdr.csum_flags |=
530 CSUM_IP_CHECKED | CSUM_IP_VALID;
532 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
533 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
535 error = netisr_queue(NETISR_IP, m);
539 ifa_free(&ia->ia_ifa);
540 goto again; /* Redo the routing table lookup. */
544 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
545 if (m->m_flags & M_FASTFWD_OURS) {
546 if (m->m_pkthdr.rcvif == NULL)
547 m->m_pkthdr.rcvif = V_loif;
548 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
549 m->m_pkthdr.csum_flags |=
550 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
551 m->m_pkthdr.csum_data = 0xffff;
554 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
555 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
557 m->m_pkthdr.csum_flags |=
558 CSUM_IP_CHECKED | CSUM_IP_VALID;
560 error = netisr_queue(NETISR_IP, m);
563 /* Or forward to some other address? */
564 if ((m->m_flags & M_IP_NEXTHOP) &&
565 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
566 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
567 m->m_flags |= M_SKIP_FIREWALL;
568 m->m_flags &= ~M_IP_NEXTHOP;
569 m_tag_delete(m, fwd_tag);
571 ifa_free(&ia->ia_ifa);
576 /* 127/8 must not appear on wire - RFC1122. */
577 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
578 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
579 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
580 IPSTAT_INC(ips_badaddr);
581 error = EADDRNOTAVAIL;
586 m->m_pkthdr.csum_flags |= CSUM_IP;
587 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
589 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
592 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
593 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
594 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
599 * If small enough for interface, or the interface will take
600 * care of the fragmentation for us, we can just send directly.
603 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
604 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
606 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
607 ip->ip_sum = in_cksum(m, hlen);
608 m->m_pkthdr.csum_flags &= ~CSUM_IP;
612 * Record statistics for this interface address.
613 * With CSUM_TSO the byte/packet count will be slightly
614 * incorrect because we count the IP+TCP headers only
615 * once instead of for every generated packet.
617 if (!(flags & IP_FORWARDING) && ia) {
618 if (m->m_pkthdr.csum_flags & CSUM_TSO)
619 ia->ia_ifa.if_opackets +=
620 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
622 ia->ia_ifa.if_opackets++;
623 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
625 #ifdef MBUF_STRESS_TEST
626 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
627 m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
630 * Reset layer specific mbuf flags
631 * to avoid confusing lower layers.
634 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
635 error = (*ifp->if_output)(ifp, m,
636 (const struct sockaddr *)gw, ro);
640 /* Balk when DF bit is set or the interface didn't support TSO. */
641 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
643 IPSTAT_INC(ips_cantfrag);
648 * Too large for interface; fragment if possible. If successful,
649 * on return, m will point to a list of packets to be sent.
651 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
658 /* Record statistics for this interface address. */
660 ia->ia_ifa.if_opackets++;
661 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
664 * Reset layer specific mbuf flags
665 * to avoid confusing upper layers.
669 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
670 error = (*ifp->if_output)(ifp, m,
671 (const struct sockaddr *)gw, ro);
677 IPSTAT_INC(ips_fragmented);
683 ifa_free(&ia->ia_ifa);
691 * Create a chain of fragments which fit the given mtu. m_frag points to the
692 * mbuf to be fragmented; on return it points to the chain with the fragments.
693 * Return 0 if no error. If error, m_frag may contain a partially built
694 * chain of fragments that should be freed by the caller.
696 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
699 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
700 u_long if_hwassist_flags)
703 int hlen = ip->ip_hl << 2;
704 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
706 struct mbuf *m0 = *m_frag; /* the original packet */
710 uint16_t ip_len, ip_off;
712 ip_len = ntohs(ip->ip_len);
713 ip_off = ntohs(ip->ip_off);
715 if (ip_off & IP_DF) { /* Fragmentation not allowed */
716 IPSTAT_INC(ips_cantfrag);
721 * Must be able to put at least 8 bytes per fragment.
727 * If the interface will not calculate checksums on
728 * fragmented packets, then do it here.
730 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
731 in_delayed_cksum(m0);
732 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
735 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
736 sctp_delayed_cksum(m0, hlen);
737 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
740 if (len > PAGE_SIZE) {
742 * Fragment large datagrams such that each segment
743 * contains a multiple of PAGE_SIZE amount of data,
744 * plus headers. This enables a receiver to perform
745 * page-flipping zero-copy optimizations.
747 * XXX When does this help given that sender and receiver
748 * could have different page sizes, and also mtu could
749 * be less than the receiver's page size ?
754 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
758 * firstlen (off - hlen) must be aligned on an
762 goto smart_frag_failure;
763 off = ((off - hlen) & ~7) + hlen;
764 newlen = (~PAGE_MASK) & mtu;
765 if ((newlen + sizeof (struct ip)) > mtu) {
766 /* we failed, go back the default */
777 firstlen = off - hlen;
778 mnext = &m0->m_nextpkt; /* pointer to next packet */
781 * Loop through length of segment after first fragment,
782 * make new header and copy data of each part and link onto chain.
783 * Here, m0 is the original packet, m is the fragment being created.
784 * The fragments are linked off the m_nextpkt of the original
785 * packet, which after processing serves as the first fragment.
787 for (nfrags = 1; off < ip_len; off += len, nfrags++) {
788 struct ip *mhip; /* ip header on the fragment */
790 int mhlen = sizeof (struct ip);
792 m = m_gethdr(M_NOWAIT, MT_DATA);
795 IPSTAT_INC(ips_odropped);
798 m->m_flags |= (m0->m_flags & M_MCAST);
800 * In the first mbuf, leave room for the link header, then
801 * copy the original IP header including options. The payload
802 * goes into an additional mbuf chain returned by m_copym().
804 m->m_data += max_linkhdr;
805 mhip = mtod(m, struct ip *);
807 if (hlen > sizeof (struct ip)) {
808 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
809 mhip->ip_v = IPVERSION;
810 mhip->ip_hl = mhlen >> 2;
813 /* XXX do we need to add ip_off below ? */
814 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
815 if (off + len >= ip_len)
818 mhip->ip_off |= IP_MF;
819 mhip->ip_len = htons((u_short)(len + mhlen));
820 m->m_next = m_copym(m0, off, len, M_NOWAIT);
821 if (m->m_next == NULL) { /* copy failed */
823 error = ENOBUFS; /* ??? */
824 IPSTAT_INC(ips_odropped);
827 m->m_pkthdr.len = mhlen + len;
828 m->m_pkthdr.rcvif = NULL;
830 mac_netinet_fragment(m0, m);
832 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
833 mhip->ip_off = htons(mhip->ip_off);
835 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
836 mhip->ip_sum = in_cksum(m, mhlen);
837 m->m_pkthdr.csum_flags &= ~CSUM_IP;
840 mnext = &m->m_nextpkt;
842 IPSTAT_ADD(ips_ofragments, nfrags);
845 * Update first fragment by trimming what's been copied out
846 * and updating header.
848 m_adj(m0, hlen + firstlen - ip_len);
849 m0->m_pkthdr.len = hlen + firstlen;
850 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
851 ip->ip_off = htons(ip_off | IP_MF);
853 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
854 ip->ip_sum = in_cksum(m0, hlen);
855 m0->m_pkthdr.csum_flags &= ~CSUM_IP;
864 in_delayed_cksum(struct mbuf *m)
867 uint16_t csum, offset, ip_len;
869 ip = mtod(m, struct ip *);
870 offset = ip->ip_hl << 2 ;
871 ip_len = ntohs(ip->ip_len);
872 csum = in_cksum_skip(m, ip_len, offset);
873 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
875 offset += m->m_pkthdr.csum_data; /* checksum offset */
877 if (offset + sizeof(u_short) > m->m_len) {
878 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
879 m->m_len, offset, ip->ip_p);
882 * this shouldn't happen, but if it does, the
883 * correct behavior may be to insert the checksum
884 * in the appropriate next mbuf in the chain.
888 *(u_short *)(m->m_data + offset) = csum;
892 * IP socket option processing.
895 ip_ctloutput(struct socket *so, struct sockopt *sopt)
897 struct inpcb *inp = sotoinpcb(so);
901 if (sopt->sopt_level != IPPROTO_IP) {
904 if (sopt->sopt_level == SOL_SOCKET &&
905 sopt->sopt_dir == SOPT_SET) {
906 switch (sopt->sopt_name) {
909 if ((so->so_options & SO_REUSEADDR) != 0)
910 inp->inp_flags2 |= INP_REUSEADDR;
912 inp->inp_flags2 &= ~INP_REUSEADDR;
918 if ((so->so_options & SO_REUSEPORT) != 0)
919 inp->inp_flags2 |= INP_REUSEPORT;
921 inp->inp_flags2 &= ~INP_REUSEPORT;
927 inp->inp_inc.inc_fibnum = so->so_fibnum;
938 switch (sopt->sopt_dir) {
940 switch (sopt->sopt_name) {
947 if (sopt->sopt_valsize > MLEN) {
951 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
956 m->m_len = sopt->sopt_valsize;
957 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
964 error = ip_pcbopts(inp, sopt->sopt_name, m);
970 if (sopt->sopt_td != NULL) {
971 error = priv_check(sopt->sopt_td,
972 PRIV_NETINET_BINDANY);
989 error = sooptcopyin(sopt, &optval, sizeof optval,
994 switch (sopt->sopt_name) {
996 inp->inp_ip_tos = optval;
1000 inp->inp_ip_ttl = optval;
1004 if (optval >= 0 && optval <= MAXTTL)
1005 inp->inp_ip_minttl = optval;
1010 #define OPTSET(bit) do { \
1013 inp->inp_flags |= bit; \
1015 inp->inp_flags &= ~bit; \
1020 OPTSET(INP_RECVOPTS);
1023 case IP_RECVRETOPTS:
1024 OPTSET(INP_RECVRETOPTS);
1027 case IP_RECVDSTADDR:
1028 OPTSET(INP_RECVDSTADDR);
1032 OPTSET(INP_RECVTTL);
1044 OPTSET(INP_ONESBCAST);
1047 OPTSET(INP_DONTFRAG);
1050 OPTSET(INP_BINDANY);
1053 OPTSET(INP_RECVTOS);
1060 * Multicast socket options are processed by the in_mcast
1063 case IP_MULTICAST_IF:
1064 case IP_MULTICAST_VIF:
1065 case IP_MULTICAST_TTL:
1066 case IP_MULTICAST_LOOP:
1067 case IP_ADD_MEMBERSHIP:
1068 case IP_DROP_MEMBERSHIP:
1069 case IP_ADD_SOURCE_MEMBERSHIP:
1070 case IP_DROP_SOURCE_MEMBERSHIP:
1071 case IP_BLOCK_SOURCE:
1072 case IP_UNBLOCK_SOURCE:
1074 case MCAST_JOIN_GROUP:
1075 case MCAST_LEAVE_GROUP:
1076 case MCAST_JOIN_SOURCE_GROUP:
1077 case MCAST_LEAVE_SOURCE_GROUP:
1078 case MCAST_BLOCK_SOURCE:
1079 case MCAST_UNBLOCK_SOURCE:
1080 error = inp_setmoptions(inp, sopt);
1084 error = sooptcopyin(sopt, &optval, sizeof optval,
1091 case IP_PORTRANGE_DEFAULT:
1092 inp->inp_flags &= ~(INP_LOWPORT);
1093 inp->inp_flags &= ~(INP_HIGHPORT);
1096 case IP_PORTRANGE_HIGH:
1097 inp->inp_flags &= ~(INP_LOWPORT);
1098 inp->inp_flags |= INP_HIGHPORT;
1101 case IP_PORTRANGE_LOW:
1102 inp->inp_flags &= ~(INP_HIGHPORT);
1103 inp->inp_flags |= INP_LOWPORT;
1114 case IP_IPSEC_POLICY:
1119 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1121 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1123 req = mtod(m, caddr_t);
1124 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1125 m->m_len, (sopt->sopt_td != NULL) ?
1126 sopt->sopt_td->td_ucred : NULL);
1133 error = ENOPROTOOPT;
1139 switch (sopt->sopt_name) {
1142 if (inp->inp_options)
1143 error = sooptcopyout(sopt,
1144 mtod(inp->inp_options,
1146 inp->inp_options->m_len);
1148 sopt->sopt_valsize = 0;
1155 case IP_RECVRETOPTS:
1156 case IP_RECVDSTADDR:
1165 switch (sopt->sopt_name) {
1168 optval = inp->inp_ip_tos;
1172 optval = inp->inp_ip_ttl;
1176 optval = inp->inp_ip_minttl;
1179 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1182 optval = OPTBIT(INP_RECVOPTS);
1185 case IP_RECVRETOPTS:
1186 optval = OPTBIT(INP_RECVRETOPTS);
1189 case IP_RECVDSTADDR:
1190 optval = OPTBIT(INP_RECVDSTADDR);
1194 optval = OPTBIT(INP_RECVTTL);
1198 optval = OPTBIT(INP_RECVIF);
1202 if (inp->inp_flags & INP_HIGHPORT)
1203 optval = IP_PORTRANGE_HIGH;
1204 else if (inp->inp_flags & INP_LOWPORT)
1205 optval = IP_PORTRANGE_LOW;
1211 optval = OPTBIT(INP_FAITH);
1215 optval = OPTBIT(INP_ONESBCAST);
1218 optval = OPTBIT(INP_DONTFRAG);
1221 optval = OPTBIT(INP_BINDANY);
1224 optval = OPTBIT(INP_RECVTOS);
1227 error = sooptcopyout(sopt, &optval, sizeof optval);
1231 * Multicast socket options are processed by the in_mcast
1234 case IP_MULTICAST_IF:
1235 case IP_MULTICAST_VIF:
1236 case IP_MULTICAST_TTL:
1237 case IP_MULTICAST_LOOP:
1239 error = inp_getmoptions(inp, sopt);
1243 case IP_IPSEC_POLICY:
1245 struct mbuf *m = NULL;
1250 req = mtod(m, caddr_t);
1253 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1255 error = soopt_mcopyout(sopt, m); /* XXX */
1263 error = ENOPROTOOPT;
1272 * Routine called from ip_output() to loop back a copy of an IP multicast
1273 * packet to the input queue of a specified interface. Note that this
1274 * calls the output routine of the loopback "driver", but with an interface
1275 * pointer that might NOT be a loopback interface -- evil, but easier than
1276 * replicating that code here.
1279 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1282 register struct ip *ip;
1286 * Make a deep copy of the packet because we're going to
1287 * modify the pack in order to generate checksums.
1289 copym = m_dup(m, M_NOWAIT);
1290 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1291 copym = m_pullup(copym, hlen);
1292 if (copym != NULL) {
1293 /* If needed, compute the checksum and mark it as valid. */
1294 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1295 in_delayed_cksum(copym);
1296 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1297 copym->m_pkthdr.csum_flags |=
1298 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1299 copym->m_pkthdr.csum_data = 0xffff;
1302 * We don't bother to fragment if the IP length is greater
1303 * than the interface's MTU. Can this possibly matter?
1305 ip = mtod(copym, struct ip *);
1307 ip->ip_sum = in_cksum(copym, hlen);
1309 if (dst->sin_family != AF_INET) {
1310 printf("ip_mloopback: bad address family %d\n",
1312 dst->sin_family = AF_INET;
1315 if_simloop(ifp, copym, dst->sin_family, 0);