2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
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.
10 * 2. Redistributions in binary form must reproduce the above copyright
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12 * documentation and/or other materials provided with the distribution.
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
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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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_route.h"
38 #include "opt_mbuf_stress_test.h"
39 #include "opt_mpath.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/sysctl.h>
53 #include <sys/ucred.h>
56 #include <net/if_llatbl.h>
57 #include <net/netisr.h>
59 #include <net/route.h>
60 #include <net/flowtable.h>
62 #include <net/radix_mpath.h>
66 #include <netinet/in.h>
67 #include <netinet/in_systm.h>
68 #include <netinet/ip.h>
69 #include <netinet/in_pcb.h>
70 #include <netinet/in_var.h>
71 #include <netinet/ip_var.h>
72 #include <netinet/ip_options.h>
74 #include <netinet/sctp.h>
75 #include <netinet/sctp_crc32.h>
79 #include <netinet/ip_ipsec.h>
80 #include <netipsec/ipsec.h>
83 #include <machine/in_cksum.h>
85 #include <security/mac/mac_framework.h>
87 VNET_DEFINE(u_short, ip_id);
89 #ifdef MBUF_STRESS_TEST
90 static int mbuf_frag_size = 0;
91 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
92 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
95 static void ip_mloopback
96 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
99 extern int in_mcast_loop;
100 extern struct protosw inetsw[];
103 * IP output. The packet in mbuf chain m contains a skeletal IP
104 * header (with len, off, ttl, proto, tos, src, dst).
105 * The mbuf chain containing the packet will be freed.
106 * The mbuf opt, if present, will not be freed.
107 * If route ro is present and has ro_rt initialized, route lookup would be
108 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
109 * then result of route lookup is stored in ro->ro_rt.
111 * In the IP forwarding case, the packet will arrive with options already
112 * inserted, so must have a NULL opt pointer.
115 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
116 struct ip_moptions *imo, struct inpcb *inp)
119 struct ifnet *ifp = NULL; /* keep compiler happy */
121 int hlen = sizeof (struct ip);
123 int n; /* scratchpad */
125 struct sockaddr_in *dst;
126 struct in_ifaddr *ia;
128 uint16_t ip_len, ip_off;
129 struct route iproute;
130 struct rtentry *rte; /* cache for ro->ro_rt */
132 struct m_tag *fwd_tag = NULL;
134 int no_route_but_check_spd = 0;
139 INP_LOCK_ASSERT(inp);
140 M_SETFIB(m, inp->inp_inc.inc_fibnum);
141 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
142 m->m_pkthdr.flowid = inp->inp_flowid;
143 m->m_flags |= M_FLOWID;
149 bzero(ro, sizeof (*ro));
153 if (ro->ro_rt == NULL) {
157 * The flow table returns route entries valid for up to 30
158 * seconds; we rely on the remainder of ip_output() taking no
159 * longer than that long for the stability of ro_rt. The
160 * flow ID assignment must have happened before this point.
162 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
164 flow_to_route(fle, ro);
170 m = ip_insertoptions(m, opt, &len);
172 hlen = len; /* ip->ip_hl is updated above */
174 ip = mtod(m, struct ip *);
175 ip_len = ntohs(ip->ip_len);
176 ip_off = ntohs(ip->ip_off);
179 * Fill in IP header. If we are not allowing fragmentation,
180 * then the ip_id field is meaningless, but we don't set it
181 * to zero. Doing so causes various problems when devices along
182 * the path (routers, load balancers, firewalls, etc.) illegally
183 * disable DF on our packet. Note that a 16-bit counter
184 * will wrap around in less than 10 seconds at 100 Mbit/s on a
185 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
186 * for Counting NATted Hosts", Proc. IMW'02, available at
187 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
189 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
190 ip->ip_v = IPVERSION;
191 ip->ip_hl = hlen >> 2;
192 ip->ip_id = ip_newid();
193 IPSTAT_INC(ips_localout);
195 /* Header already set, fetch hlen from there */
196 hlen = ip->ip_hl << 2;
199 dst = (struct sockaddr_in *)&ro->ro_dst;
203 * If there is a cached route,
204 * check that it is to the same destination
205 * and is still up. If not, free it and try again.
206 * The address family should also be checked in case of sharing the
210 if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
211 rte->rt_ifp == NULL ||
212 !RT_LINK_IS_UP(rte->rt_ifp) ||
213 dst->sin_family != AF_INET ||
214 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
219 if (rte == NULL && fwd_tag == NULL) {
220 bzero(dst, sizeof(*dst));
221 dst->sin_family = AF_INET;
222 dst->sin_len = sizeof(*dst);
223 dst->sin_addr = ip->ip_dst;
226 * If routing to interface only, short circuit routing lookup.
227 * The use of an all-ones broadcast address implies this; an
228 * interface is specified by the broadcast address of an interface,
229 * or the destination address of a ptp interface.
231 if (flags & IP_SENDONES) {
232 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
233 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
234 IPSTAT_INC(ips_noroute);
238 ip->ip_dst.s_addr = INADDR_BROADCAST;
239 dst->sin_addr = ip->ip_dst;
243 } else if (flags & IP_ROUTETOIF) {
244 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
245 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
246 IPSTAT_INC(ips_noroute);
252 isbroadcast = in_broadcast(dst->sin_addr, ifp);
253 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
254 imo != NULL && imo->imo_multicast_ifp != NULL) {
256 * Bypass the normal routing lookup for multicast
257 * packets if the interface is specified.
259 ifp = imo->imo_multicast_ifp;
261 isbroadcast = 0; /* fool gcc */
264 * We want to do any cloning requested by the link layer,
265 * as this is probably required in all cases for correct
266 * operation (as it is for ARP).
270 rtalloc_mpath_fib(ro,
271 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
272 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
274 in_rtalloc_ign(ro, 0,
275 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
280 rte->rt_ifp == NULL ||
281 !RT_LINK_IS_UP(rte->rt_ifp)) {
284 * There is no route for this packet, but it is
285 * possible that a matching SPD entry exists.
287 no_route_but_check_spd = 1;
288 mtu = 0; /* Silence GCC warning. */
291 IPSTAT_INC(ips_noroute);
292 error = EHOSTUNREACH;
295 ia = ifatoia(rte->rt_ifa);
296 ifa_ref(&ia->ia_ifa);
298 rte->rt_rmx.rmx_pksent++;
299 if (rte->rt_flags & RTF_GATEWAY)
300 dst = (struct sockaddr_in *)rte->rt_gateway;
301 if (rte->rt_flags & RTF_HOST)
302 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
304 isbroadcast = in_broadcast(dst->sin_addr, ifp);
307 * Calculate MTU. If we have a route that is up, use that,
308 * otherwise use the interface's MTU.
310 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
312 * This case can happen if the user changed the MTU
313 * of an interface after enabling IP on it. Because
314 * most netifs don't keep track of routes pointing to
315 * them, there is no way for one to update all its
316 * routes when the MTU is changed.
318 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
319 rte->rt_rmx.rmx_mtu = ifp->if_mtu;
320 mtu = rte->rt_rmx.rmx_mtu;
324 /* Catch a possible divide by zero later. */
325 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
326 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
327 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
328 m->m_flags |= M_MCAST;
330 * IP destination address is multicast. Make sure "dst"
331 * still points to the address in "ro". (It may have been
332 * changed to point to a gateway address, above.)
334 dst = (struct sockaddr_in *)&ro->ro_dst;
336 * See if the caller provided any multicast options
339 ip->ip_ttl = imo->imo_multicast_ttl;
340 if (imo->imo_multicast_vif != -1)
343 ip_mcast_src(imo->imo_multicast_vif) :
346 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
348 * Confirm that the outgoing interface supports multicast.
350 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
351 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
352 IPSTAT_INC(ips_noroute);
358 * If source address not specified yet, use address
359 * of outgoing interface.
361 if (ip->ip_src.s_addr == INADDR_ANY) {
362 /* Interface may have no addresses. */
364 ip->ip_src = IA_SIN(ia)->sin_addr;
367 if ((imo == NULL && in_mcast_loop) ||
368 (imo && imo->imo_multicast_loop)) {
370 * Loop back multicast datagram if not expressly
371 * forbidden to do so, even if we are not a member
372 * of the group; ip_input() will filter it later,
373 * thus deferring a hash lookup and mutex acquisition
374 * at the expense of a cheap copy using m_copym().
376 ip_mloopback(ifp, m, dst, hlen);
379 * If we are acting as a multicast router, perform
380 * multicast forwarding as if the packet had just
381 * arrived on the interface to which we are about
382 * to send. The multicast forwarding function
383 * recursively calls this function, using the
384 * IP_FORWARDING flag to prevent infinite recursion.
386 * Multicasts that are looped back by ip_mloopback(),
387 * above, will be forwarded by the ip_input() routine,
390 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
392 * If rsvp daemon is not running, do not
393 * set ip_moptions. This ensures that the packet
394 * is multicast and not just sent down one link
395 * as prescribed by rsvpd.
400 ip_mforward(ip, ifp, m, imo) != 0) {
408 * Multicasts with a time-to-live of zero may be looped-
409 * back, above, but must not be transmitted on a network.
410 * Also, multicasts addressed to the loopback interface
411 * are not sent -- the above call to ip_mloopback() will
412 * loop back a copy. ip_input() will drop the copy if
413 * this host does not belong to the destination group on
414 * the loopback interface.
416 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
425 * If the source address is not specified yet, use the address
426 * of the outoing interface.
428 if (ip->ip_src.s_addr == INADDR_ANY) {
429 /* Interface may have no addresses. */
431 ip->ip_src = IA_SIN(ia)->sin_addr;
436 * Verify that we have any chance at all of being able to queue the
437 * packet or packet fragments, unless ALTQ is enabled on the given
438 * interface in which case packetdrop should be done by queueing.
440 n = ip_len / mtu + 1; /* how many fragments ? */
443 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
445 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
447 IPSTAT_INC(ips_odropped);
448 ifp->if_snd.ifq_drops += n;
453 * Look for broadcast address and
454 * verify user is allowed to send
458 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
459 error = EADDRNOTAVAIL;
462 if ((flags & IP_ALLOWBROADCAST) == 0) {
466 /* don't allow broadcast messages to be fragmented */
471 m->m_flags |= M_BCAST;
473 m->m_flags &= ~M_BCAST;
478 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
485 break; /* Continue with packet processing. */
488 * Check if there was a route for this packet; return error if not.
490 if (no_route_but_check_spd) {
491 IPSTAT_INC(ips_noroute);
492 error = EHOSTUNREACH;
495 /* Update variables that are affected by ipsec4_output(). */
496 ip = mtod(m, struct ip *);
497 hlen = ip->ip_hl << 2;
500 /* Jump over all PFIL processing if hooks are not active. */
501 if (!PFIL_HOOKED(&V_inet_pfil_hook))
504 /* Run through list of hooks for output packets. */
505 odst.s_addr = ip->ip_dst.s_addr;
506 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
507 if (error != 0 || m == NULL)
510 ip = mtod(m, struct ip *);
512 /* See if destination IP address was changed by packet filter. */
513 if (odst.s_addr != ip->ip_dst.s_addr) {
514 m->m_flags |= M_SKIP_FIREWALL;
515 /* If destination is now ourself drop to ip_input(). */
516 if (in_localip(ip->ip_dst)) {
517 m->m_flags |= M_FASTFWD_OURS;
518 if (m->m_pkthdr.rcvif == NULL)
519 m->m_pkthdr.rcvif = V_loif;
520 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
521 m->m_pkthdr.csum_flags |=
522 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
523 m->m_pkthdr.csum_data = 0xffff;
525 m->m_pkthdr.csum_flags |=
526 CSUM_IP_CHECKED | CSUM_IP_VALID;
528 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
529 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
531 error = netisr_queue(NETISR_IP, m);
535 ifa_free(&ia->ia_ifa);
536 goto again; /* Redo the routing table lookup. */
540 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
541 if (m->m_flags & M_FASTFWD_OURS) {
542 if (m->m_pkthdr.rcvif == NULL)
543 m->m_pkthdr.rcvif = V_loif;
544 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
545 m->m_pkthdr.csum_flags |=
546 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
547 m->m_pkthdr.csum_data = 0xffff;
550 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
551 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
553 m->m_pkthdr.csum_flags |=
554 CSUM_IP_CHECKED | CSUM_IP_VALID;
556 error = netisr_queue(NETISR_IP, m);
559 /* Or forward to some other address? */
560 if ((m->m_flags & M_IP_NEXTHOP) &&
561 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
562 dst = (struct sockaddr_in *)&ro->ro_dst;
563 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
564 m->m_flags |= M_SKIP_FIREWALL;
565 m->m_flags &= ~M_IP_NEXTHOP;
566 m_tag_delete(m, fwd_tag);
568 ifa_free(&ia->ia_ifa);
573 /* 127/8 must not appear on wire - RFC1122. */
574 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
575 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
576 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
577 IPSTAT_INC(ips_badaddr);
578 error = EADDRNOTAVAIL;
583 m->m_pkthdr.csum_flags |= CSUM_IP;
584 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
586 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
589 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
590 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
591 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
596 * If small enough for interface, or the interface will take
597 * care of the fragmentation for us, we can just send directly.
600 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
601 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
603 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
604 ip->ip_sum = in_cksum(m, hlen);
605 m->m_pkthdr.csum_flags &= ~CSUM_IP;
609 * Record statistics for this interface address.
610 * With CSUM_TSO the byte/packet count will be slightly
611 * incorrect because we count the IP+TCP headers only
612 * once instead of for every generated packet.
614 if (!(flags & IP_FORWARDING) && ia) {
615 if (m->m_pkthdr.csum_flags & CSUM_TSO)
616 ia->ia_ifa.if_opackets +=
617 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
619 ia->ia_ifa.if_opackets++;
620 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
622 #ifdef MBUF_STRESS_TEST
623 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
624 m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
627 * Reset layer specific mbuf flags
628 * to avoid confusing lower layers.
630 m->m_flags &= ~(M_PROTOFLAGS);
631 error = (*ifp->if_output)(ifp, m,
632 (struct sockaddr *)dst, ro);
636 /* Balk when DF bit is set or the interface didn't support TSO. */
637 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
639 IPSTAT_INC(ips_cantfrag);
644 * Too large for interface; fragment if possible. If successful,
645 * on return, m will point to a list of packets to be sent.
647 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
654 /* Record statistics for this interface address. */
656 ia->ia_ifa.if_opackets++;
657 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
660 * Reset layer specific mbuf flags
661 * to avoid confusing upper layers.
663 m->m_flags &= ~(M_PROTOFLAGS);
665 error = (*ifp->if_output)(ifp, m,
666 (struct sockaddr *)dst, ro);
672 IPSTAT_INC(ips_fragmented);
678 ifa_free(&ia->ia_ifa);
686 * Create a chain of fragments which fit the given mtu. m_frag points to the
687 * mbuf to be fragmented; on return it points to the chain with the fragments.
688 * Return 0 if no error. If error, m_frag may contain a partially built
689 * chain of fragments that should be freed by the caller.
691 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
694 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
695 u_long if_hwassist_flags)
698 int hlen = ip->ip_hl << 2;
699 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
701 struct mbuf *m0 = *m_frag; /* the original packet */
705 uint16_t ip_len, ip_off;
707 ip_len = ntohs(ip->ip_len);
708 ip_off = ntohs(ip->ip_off);
710 if (ip_off & IP_DF) { /* Fragmentation not allowed */
711 IPSTAT_INC(ips_cantfrag);
716 * Must be able to put at least 8 bytes per fragment.
722 * If the interface will not calculate checksums on
723 * fragmented packets, then do it here.
725 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
726 in_delayed_cksum(m0);
727 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
730 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
731 sctp_delayed_cksum(m0, hlen);
732 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
735 if (len > PAGE_SIZE) {
737 * Fragment large datagrams such that each segment
738 * contains a multiple of PAGE_SIZE amount of data,
739 * plus headers. This enables a receiver to perform
740 * page-flipping zero-copy optimizations.
742 * XXX When does this help given that sender and receiver
743 * could have different page sizes, and also mtu could
744 * be less than the receiver's page size ?
749 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
753 * firstlen (off - hlen) must be aligned on an
757 goto smart_frag_failure;
758 off = ((off - hlen) & ~7) + hlen;
759 newlen = (~PAGE_MASK) & mtu;
760 if ((newlen + sizeof (struct ip)) > mtu) {
761 /* we failed, go back the default */
772 firstlen = off - hlen;
773 mnext = &m0->m_nextpkt; /* pointer to next packet */
776 * Loop through length of segment after first fragment,
777 * make new header and copy data of each part and link onto chain.
778 * Here, m0 is the original packet, m is the fragment being created.
779 * The fragments are linked off the m_nextpkt of the original
780 * packet, which after processing serves as the first fragment.
782 for (nfrags = 1; off < ip_len; off += len, nfrags++) {
783 struct ip *mhip; /* ip header on the fragment */
785 int mhlen = sizeof (struct ip);
787 MGETHDR(m, M_NOWAIT, MT_DATA);
790 IPSTAT_INC(ips_odropped);
793 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
795 * In the first mbuf, leave room for the link header, then
796 * copy the original IP header including options. The payload
797 * goes into an additional mbuf chain returned by m_copym().
799 m->m_data += max_linkhdr;
800 mhip = mtod(m, struct ip *);
802 if (hlen > sizeof (struct ip)) {
803 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
804 mhip->ip_v = IPVERSION;
805 mhip->ip_hl = mhlen >> 2;
808 /* XXX do we need to add ip_off below ? */
809 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
810 if (off + len >= ip_len) { /* last fragment */
812 m->m_flags |= M_LASTFRAG;
814 mhip->ip_off |= IP_MF;
815 mhip->ip_len = htons((u_short)(len + mhlen));
816 m->m_next = m_copym(m0, off, len, M_NOWAIT);
817 if (m->m_next == NULL) { /* copy failed */
819 error = ENOBUFS; /* ??? */
820 IPSTAT_INC(ips_odropped);
823 m->m_pkthdr.len = mhlen + len;
824 m->m_pkthdr.rcvif = NULL;
826 mac_netinet_fragment(m0, m);
828 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
829 mhip->ip_off = htons(mhip->ip_off);
831 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
832 mhip->ip_sum = in_cksum(m, mhlen);
833 m->m_pkthdr.csum_flags &= ~CSUM_IP;
836 mnext = &m->m_nextpkt;
838 IPSTAT_ADD(ips_ofragments, nfrags);
840 /* set first marker for fragment chain */
841 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
842 m0->m_pkthdr.csum_data = 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 (IN_MULTICAST(ntohl(inp->inp_laddr.s_addr))) {
910 if ((so->so_options &
911 (SO_REUSEADDR | SO_REUSEPORT)) != 0)
912 inp->inp_flags2 |= INP_REUSEPORT;
914 inp->inp_flags2 &= ~INP_REUSEPORT;
921 if ((so->so_options & SO_REUSEPORT) != 0)
922 inp->inp_flags2 |= INP_REUSEPORT;
924 inp->inp_flags2 &= ~INP_REUSEPORT;
930 inp->inp_inc.inc_fibnum = so->so_fibnum;
941 switch (sopt->sopt_dir) {
943 switch (sopt->sopt_name) {
950 if (sopt->sopt_valsize > MLEN) {
954 MGET(m, sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
959 m->m_len = sopt->sopt_valsize;
960 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
967 error = ip_pcbopts(inp, sopt->sopt_name, m);
973 if (sopt->sopt_td != NULL) {
974 error = priv_check(sopt->sopt_td,
975 PRIV_NETINET_BINDANY);
992 error = sooptcopyin(sopt, &optval, sizeof optval,
997 switch (sopt->sopt_name) {
999 inp->inp_ip_tos = optval;
1003 inp->inp_ip_ttl = optval;
1007 if (optval >= 0 && optval <= MAXTTL)
1008 inp->inp_ip_minttl = optval;
1013 #define OPTSET(bit) do { \
1016 inp->inp_flags |= bit; \
1018 inp->inp_flags &= ~bit; \
1023 OPTSET(INP_RECVOPTS);
1026 case IP_RECVRETOPTS:
1027 OPTSET(INP_RECVRETOPTS);
1030 case IP_RECVDSTADDR:
1031 OPTSET(INP_RECVDSTADDR);
1035 OPTSET(INP_RECVTTL);
1047 OPTSET(INP_ONESBCAST);
1050 OPTSET(INP_DONTFRAG);
1053 OPTSET(INP_BINDANY);
1056 OPTSET(INP_RECVTOS);
1063 * Multicast socket options are processed by the in_mcast
1066 case IP_MULTICAST_IF:
1067 case IP_MULTICAST_VIF:
1068 case IP_MULTICAST_TTL:
1069 case IP_MULTICAST_LOOP:
1070 case IP_ADD_MEMBERSHIP:
1071 case IP_DROP_MEMBERSHIP:
1072 case IP_ADD_SOURCE_MEMBERSHIP:
1073 case IP_DROP_SOURCE_MEMBERSHIP:
1074 case IP_BLOCK_SOURCE:
1075 case IP_UNBLOCK_SOURCE:
1077 case MCAST_JOIN_GROUP:
1078 case MCAST_LEAVE_GROUP:
1079 case MCAST_JOIN_SOURCE_GROUP:
1080 case MCAST_LEAVE_SOURCE_GROUP:
1081 case MCAST_BLOCK_SOURCE:
1082 case MCAST_UNBLOCK_SOURCE:
1083 error = inp_setmoptions(inp, sopt);
1087 error = sooptcopyin(sopt, &optval, sizeof optval,
1094 case IP_PORTRANGE_DEFAULT:
1095 inp->inp_flags &= ~(INP_LOWPORT);
1096 inp->inp_flags &= ~(INP_HIGHPORT);
1099 case IP_PORTRANGE_HIGH:
1100 inp->inp_flags &= ~(INP_LOWPORT);
1101 inp->inp_flags |= INP_HIGHPORT;
1104 case IP_PORTRANGE_LOW:
1105 inp->inp_flags &= ~(INP_HIGHPORT);
1106 inp->inp_flags |= INP_LOWPORT;
1117 case IP_IPSEC_POLICY:
1122 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1124 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1126 req = mtod(m, caddr_t);
1127 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1128 m->m_len, (sopt->sopt_td != NULL) ?
1129 sopt->sopt_td->td_ucred : NULL);
1136 error = ENOPROTOOPT;
1142 switch (sopt->sopt_name) {
1145 if (inp->inp_options)
1146 error = sooptcopyout(sopt,
1147 mtod(inp->inp_options,
1149 inp->inp_options->m_len);
1151 sopt->sopt_valsize = 0;
1158 case IP_RECVRETOPTS:
1159 case IP_RECVDSTADDR:
1168 switch (sopt->sopt_name) {
1171 optval = inp->inp_ip_tos;
1175 optval = inp->inp_ip_ttl;
1179 optval = inp->inp_ip_minttl;
1182 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1185 optval = OPTBIT(INP_RECVOPTS);
1188 case IP_RECVRETOPTS:
1189 optval = OPTBIT(INP_RECVRETOPTS);
1192 case IP_RECVDSTADDR:
1193 optval = OPTBIT(INP_RECVDSTADDR);
1197 optval = OPTBIT(INP_RECVTTL);
1201 optval = OPTBIT(INP_RECVIF);
1205 if (inp->inp_flags & INP_HIGHPORT)
1206 optval = IP_PORTRANGE_HIGH;
1207 else if (inp->inp_flags & INP_LOWPORT)
1208 optval = IP_PORTRANGE_LOW;
1214 optval = OPTBIT(INP_FAITH);
1218 optval = OPTBIT(INP_ONESBCAST);
1221 optval = OPTBIT(INP_DONTFRAG);
1224 optval = OPTBIT(INP_BINDANY);
1227 optval = OPTBIT(INP_RECVTOS);
1230 error = sooptcopyout(sopt, &optval, sizeof optval);
1234 * Multicast socket options are processed by the in_mcast
1237 case IP_MULTICAST_IF:
1238 case IP_MULTICAST_VIF:
1239 case IP_MULTICAST_TTL:
1240 case IP_MULTICAST_LOOP:
1242 error = inp_getmoptions(inp, sopt);
1246 case IP_IPSEC_POLICY:
1248 struct mbuf *m = NULL;
1253 req = mtod(m, caddr_t);
1256 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1258 error = soopt_mcopyout(sopt, m); /* XXX */
1266 error = ENOPROTOOPT;
1275 * Routine called from ip_output() to loop back a copy of an IP multicast
1276 * packet to the input queue of a specified interface. Note that this
1277 * calls the output routine of the loopback "driver", but with an interface
1278 * pointer that might NOT be a loopback interface -- evil, but easier than
1279 * replicating that code here.
1282 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1285 register struct ip *ip;
1289 * Make a deep copy of the packet because we're going to
1290 * modify the pack in order to generate checksums.
1292 copym = m_dup(m, M_NOWAIT);
1293 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1294 copym = m_pullup(copym, hlen);
1295 if (copym != NULL) {
1296 /* If needed, compute the checksum and mark it as valid. */
1297 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1298 in_delayed_cksum(copym);
1299 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1300 copym->m_pkthdr.csum_flags |=
1301 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1302 copym->m_pkthdr.csum_data = 0xffff;
1305 * We don't bother to fragment if the IP length is greater
1306 * than the interface's MTU. Can this possibly matter?
1308 ip = mtod(copym, struct ip *);
1310 ip->ip_sum = in_cksum(copym, hlen);
1312 if (dst->sin_family != AF_INET) {
1313 printf("ip_mloopback: bad address family %d\n",
1315 dst->sin_family = AF_INET;
1318 if_simloop(ifp, copym, dst->sin_family, 0);