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
11 * notice, this list of conditions and the following disclaimer in the
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
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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("$FreeBSD$");
37 #include "opt_ipsec.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_var.h>
59 #include <net/if_llatbl.h>
60 #include <net/netisr.h>
62 #include <net/route.h>
63 #include <net/flowtable.h>
65 #include <net/radix_mpath.h>
69 #include <netinet/in.h>
70 #include <netinet/in_kdtrace.h>
71 #include <netinet/in_systm.h>
72 #include <netinet/ip.h>
73 #include <netinet/in_pcb.h>
74 #include <netinet/in_var.h>
75 #include <netinet/ip_var.h>
76 #include <netinet/ip_options.h>
78 #include <netinet/sctp.h>
79 #include <netinet/sctp_crc32.h>
83 #include <netinet/ip_ipsec.h>
84 #include <netipsec/ipsec.h>
87 #include <machine/in_cksum.h>
89 #include <security/mac/mac_framework.h>
91 VNET_DEFINE(u_short, ip_id);
93 #ifdef MBUF_STRESS_TEST
94 static int mbuf_frag_size = 0;
95 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
96 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
99 static void ip_mloopback
100 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
103 extern int in_mcast_loop;
104 extern struct protosw inetsw[];
107 * IP output. The packet in mbuf chain m contains a skeletal IP
108 * header (with len, off, ttl, proto, tos, src, dst).
109 * The mbuf chain containing the packet will be freed.
110 * The mbuf opt, if present, will not be freed.
111 * If route ro is present and has ro_rt initialized, route lookup would be
112 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
113 * then result of route lookup is stored in ro->ro_rt.
115 * In the IP forwarding case, the packet will arrive with options already
116 * inserted, so must have a NULL opt pointer.
119 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
120 struct ip_moptions *imo, struct inpcb *inp)
123 struct ifnet *ifp = NULL; /* keep compiler happy */
125 int hlen = sizeof (struct ip);
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)
158 (void )flowtable_lookup(AF_INET, m, ro);
163 m = ip_insertoptions(m, opt, &len);
165 hlen = len; /* ip->ip_hl is updated above */
167 ip = mtod(m, struct ip *);
168 ip_len = ntohs(ip->ip_len);
169 ip_off = ntohs(ip->ip_off);
172 * Fill in IP header. If we are not allowing fragmentation,
173 * then the ip_id field is meaningless, but we don't set it
174 * to zero. Doing so causes various problems when devices along
175 * the path (routers, load balancers, firewalls, etc.) illegally
176 * disable DF on our packet. Note that a 16-bit counter
177 * will wrap around in less than 10 seconds at 100 Mbit/s on a
178 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
179 * for Counting NATted Hosts", Proc. IMW'02, available at
180 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
182 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
183 ip->ip_v = IPVERSION;
184 ip->ip_hl = hlen >> 2;
185 ip->ip_id = ip_newid();
186 IPSTAT_INC(ips_localout);
188 /* Header already set, fetch hlen from there */
189 hlen = ip->ip_hl << 2;
195 * dst can be rewritten but always points to &ro->ro_dst.
196 * gw is readonly but can point either to dst OR rt_gateway,
197 * therefore we need restore gw if we're redoing lookup.
199 gw = dst = (struct sockaddr_in *)&ro->ro_dst;
203 * If there is a cached route, check that it is to the same
204 * destination and is still up. If not, free it and try again.
205 * The address family should also be checked in case of sharing
206 * the cache with IPv6.
209 if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
210 rte->rt_ifp == NULL ||
211 !RT_LINK_IS_UP(rte->rt_ifp) ||
212 dst->sin_family != AF_INET ||
213 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 gw = (struct sockaddr_in *)rte->rt_gateway;
301 if (rte->rt_flags & RTF_HOST)
302 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
304 isbroadcast = in_broadcast(gw->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 "gw"
331 * still points to the address in "ro". (It may have been
332 * changed to point to a gateway address, above.)
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 * Both in the SMP world, pre-emption world if_transmit() world,
437 * the following code doesn't really function as intended any further.
439 * + There can and will be multiple CPUs running this code path
440 * in parallel, and we do no lock holding when checking the
442 * + And since other threads can be running concurrently, even if
443 * we do pass this check, another thread may queue some frames
444 * before this thread does and it will end up partially or fully
445 * failing to send anyway;
446 * + if_transmit() based drivers don't necessarily set ifq_len
449 * This should be replaced with a method of pushing an entire list
450 * of fragment frames to the driver and have the driver decide
451 * whether it can queue or not queue the entire set.
455 * Verify that we have any chance at all of being able to queue the
456 * packet or packet fragments, unless ALTQ is enabled on the given
457 * interface in which case packetdrop should be done by queueing.
459 n = ip_len / mtu + 1; /* how many fragments ? */
462 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
464 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
466 IPSTAT_INC(ips_odropped);
467 ifp->if_snd.ifq_drops += n;
473 * Look for broadcast address and
474 * verify user is allowed to send
478 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
479 error = EADDRNOTAVAIL;
482 if ((flags & IP_ALLOWBROADCAST) == 0) {
486 /* don't allow broadcast messages to be fragmented */
491 m->m_flags |= M_BCAST;
493 m->m_flags &= ~M_BCAST;
498 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
505 break; /* Continue with packet processing. */
508 * Check if there was a route for this packet; return error if not.
510 if (no_route_but_check_spd) {
511 IPSTAT_INC(ips_noroute);
512 error = EHOSTUNREACH;
515 /* Update variables that are affected by ipsec4_output(). */
516 ip = mtod(m, struct ip *);
517 hlen = ip->ip_hl << 2;
520 /* Jump over all PFIL processing if hooks are not active. */
521 if (!PFIL_HOOKED(&V_inet_pfil_hook))
524 /* Run through list of hooks for output packets. */
525 odst.s_addr = ip->ip_dst.s_addr;
526 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
527 if (error != 0 || m == NULL)
530 ip = mtod(m, struct ip *);
532 /* See if destination IP address was changed by packet filter. */
533 if (odst.s_addr != ip->ip_dst.s_addr) {
534 m->m_flags |= M_SKIP_FIREWALL;
535 /* If destination is now ourself drop to ip_input(). */
536 if (in_localip(ip->ip_dst)) {
537 m->m_flags |= M_FASTFWD_OURS;
538 if (m->m_pkthdr.rcvif == NULL)
539 m->m_pkthdr.rcvif = V_loif;
540 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
541 m->m_pkthdr.csum_flags |=
542 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
543 m->m_pkthdr.csum_data = 0xffff;
545 m->m_pkthdr.csum_flags |=
546 CSUM_IP_CHECKED | CSUM_IP_VALID;
548 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
549 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
551 error = netisr_queue(NETISR_IP, m);
555 ifa_free(&ia->ia_ifa);
556 goto again; /* Redo the routing table lookup. */
560 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
561 if (m->m_flags & M_FASTFWD_OURS) {
562 if (m->m_pkthdr.rcvif == NULL)
563 m->m_pkthdr.rcvif = V_loif;
564 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
565 m->m_pkthdr.csum_flags |=
566 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
567 m->m_pkthdr.csum_data = 0xffff;
570 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
571 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
573 m->m_pkthdr.csum_flags |=
574 CSUM_IP_CHECKED | CSUM_IP_VALID;
576 error = netisr_queue(NETISR_IP, m);
579 /* Or forward to some other address? */
580 if ((m->m_flags & M_IP_NEXTHOP) &&
581 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
582 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
583 m->m_flags |= M_SKIP_FIREWALL;
584 m->m_flags &= ~M_IP_NEXTHOP;
585 m_tag_delete(m, fwd_tag);
587 ifa_free(&ia->ia_ifa);
592 /* 127/8 must not appear on wire - RFC1122. */
593 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
594 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
595 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
596 IPSTAT_INC(ips_badaddr);
597 error = EADDRNOTAVAIL;
602 m->m_pkthdr.csum_flags |= CSUM_IP;
603 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
605 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
608 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
609 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
610 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
615 * If small enough for interface, or the interface will take
616 * care of the fragmentation for us, we can just send directly.
619 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
620 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
622 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
623 ip->ip_sum = in_cksum(m, hlen);
624 m->m_pkthdr.csum_flags &= ~CSUM_IP;
628 * Record statistics for this interface address.
629 * With CSUM_TSO the byte/packet count will be slightly
630 * incorrect because we count the IP+TCP headers only
631 * once instead of for every generated packet.
633 if (!(flags & IP_FORWARDING) && ia) {
634 if (m->m_pkthdr.csum_flags & CSUM_TSO)
635 counter_u64_add(ia->ia_ifa.ifa_opackets,
636 m->m_pkthdr.len / m->m_pkthdr.tso_segsz);
638 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
640 counter_u64_add(ia->ia_ifa.ifa_obytes, m->m_pkthdr.len);
642 #ifdef MBUF_STRESS_TEST
643 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
644 m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
647 * Reset layer specific mbuf flags
648 * to avoid confusing lower layers.
651 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
652 error = (*ifp->if_output)(ifp, m,
653 (const struct sockaddr *)gw, ro);
657 /* Balk when DF bit is set or the interface didn't support TSO. */
658 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
660 IPSTAT_INC(ips_cantfrag);
665 * Too large for interface; fragment if possible. If successful,
666 * on return, m will point to a list of packets to be sent.
668 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
675 /* Record statistics for this interface address. */
677 counter_u64_add(ia->ia_ifa.ifa_opackets, 1);
678 counter_u64_add(ia->ia_ifa.ifa_obytes,
682 * Reset layer specific mbuf flags
683 * to avoid confusing upper layers.
687 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
688 error = (*ifp->if_output)(ifp, m,
689 (const struct sockaddr *)gw, ro);
695 IPSTAT_INC(ips_fragmented);
701 ifa_free(&ia->ia_ifa);
709 * Create a chain of fragments which fit the given mtu. m_frag points to the
710 * mbuf to be fragmented; on return it points to the chain with the fragments.
711 * Return 0 if no error. If error, m_frag may contain a partially built
712 * chain of fragments that should be freed by the caller.
714 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
717 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
718 u_long if_hwassist_flags)
721 int hlen = ip->ip_hl << 2;
722 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
724 struct mbuf *m0 = *m_frag; /* the original packet */
728 uint16_t ip_len, ip_off;
730 ip_len = ntohs(ip->ip_len);
731 ip_off = ntohs(ip->ip_off);
733 if (ip_off & IP_DF) { /* Fragmentation not allowed */
734 IPSTAT_INC(ips_cantfrag);
739 * Must be able to put at least 8 bytes per fragment.
745 * If the interface will not calculate checksums on
746 * fragmented packets, then do it here.
748 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
749 in_delayed_cksum(m0);
750 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
753 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
754 sctp_delayed_cksum(m0, hlen);
755 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
758 if (len > PAGE_SIZE) {
760 * Fragment large datagrams such that each segment
761 * contains a multiple of PAGE_SIZE amount of data,
762 * plus headers. This enables a receiver to perform
763 * page-flipping zero-copy optimizations.
765 * XXX When does this help given that sender and receiver
766 * could have different page sizes, and also mtu could
767 * be less than the receiver's page size ?
772 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
776 * firstlen (off - hlen) must be aligned on an
780 goto smart_frag_failure;
781 off = ((off - hlen) & ~7) + hlen;
782 newlen = (~PAGE_MASK) & mtu;
783 if ((newlen + sizeof (struct ip)) > mtu) {
784 /* we failed, go back the default */
795 firstlen = off - hlen;
796 mnext = &m0->m_nextpkt; /* pointer to next packet */
799 * Loop through length of segment after first fragment,
800 * make new header and copy data of each part and link onto chain.
801 * Here, m0 is the original packet, m is the fragment being created.
802 * The fragments are linked off the m_nextpkt of the original
803 * packet, which after processing serves as the first fragment.
805 for (nfrags = 1; off < ip_len; off += len, nfrags++) {
806 struct ip *mhip; /* ip header on the fragment */
808 int mhlen = sizeof (struct ip);
810 m = m_gethdr(M_NOWAIT, MT_DATA);
813 IPSTAT_INC(ips_odropped);
816 m->m_flags |= (m0->m_flags & M_MCAST);
818 * In the first mbuf, leave room for the link header, then
819 * copy the original IP header including options. The payload
820 * goes into an additional mbuf chain returned by m_copym().
822 m->m_data += max_linkhdr;
823 mhip = mtod(m, struct ip *);
825 if (hlen > sizeof (struct ip)) {
826 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
827 mhip->ip_v = IPVERSION;
828 mhip->ip_hl = mhlen >> 2;
831 /* XXX do we need to add ip_off below ? */
832 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
833 if (off + len >= ip_len)
836 mhip->ip_off |= IP_MF;
837 mhip->ip_len = htons((u_short)(len + mhlen));
838 m->m_next = m_copym(m0, off, len, M_NOWAIT);
839 if (m->m_next == NULL) { /* copy failed */
841 error = ENOBUFS; /* ??? */
842 IPSTAT_INC(ips_odropped);
845 m->m_pkthdr.len = mhlen + len;
846 m->m_pkthdr.rcvif = NULL;
848 mac_netinet_fragment(m0, m);
850 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
851 mhip->ip_off = htons(mhip->ip_off);
853 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
854 mhip->ip_sum = in_cksum(m, mhlen);
855 m->m_pkthdr.csum_flags &= ~CSUM_IP;
858 mnext = &m->m_nextpkt;
860 IPSTAT_ADD(ips_ofragments, nfrags);
863 * Update first fragment by trimming what's been copied out
864 * and updating header.
866 m_adj(m0, hlen + firstlen - ip_len);
867 m0->m_pkthdr.len = hlen + firstlen;
868 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
869 ip->ip_off = htons(ip_off | IP_MF);
871 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
872 ip->ip_sum = in_cksum(m0, hlen);
873 m0->m_pkthdr.csum_flags &= ~CSUM_IP;
882 in_delayed_cksum(struct mbuf *m)
885 uint16_t csum, offset, ip_len;
887 ip = mtod(m, struct ip *);
888 offset = ip->ip_hl << 2 ;
889 ip_len = ntohs(ip->ip_len);
890 csum = in_cksum_skip(m, ip_len, offset);
891 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
893 offset += m->m_pkthdr.csum_data; /* checksum offset */
895 if (offset + sizeof(u_short) > m->m_len) {
896 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
897 m->m_len, offset, ip->ip_p);
900 * this shouldn't happen, but if it does, the
901 * correct behavior may be to insert the checksum
902 * in the appropriate next mbuf in the chain.
906 *(u_short *)(m->m_data + offset) = csum;
910 * IP socket option processing.
913 ip_ctloutput(struct socket *so, struct sockopt *sopt)
915 struct inpcb *inp = sotoinpcb(so);
919 if (sopt->sopt_level != IPPROTO_IP) {
922 if (sopt->sopt_level == SOL_SOCKET &&
923 sopt->sopt_dir == SOPT_SET) {
924 switch (sopt->sopt_name) {
927 if ((so->so_options & SO_REUSEADDR) != 0)
928 inp->inp_flags2 |= INP_REUSEADDR;
930 inp->inp_flags2 &= ~INP_REUSEADDR;
936 if ((so->so_options & SO_REUSEPORT) != 0)
937 inp->inp_flags2 |= INP_REUSEPORT;
939 inp->inp_flags2 &= ~INP_REUSEPORT;
945 inp->inp_inc.inc_fibnum = so->so_fibnum;
956 switch (sopt->sopt_dir) {
958 switch (sopt->sopt_name) {
965 if (sopt->sopt_valsize > MLEN) {
969 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
974 m->m_len = sopt->sopt_valsize;
975 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
982 error = ip_pcbopts(inp, sopt->sopt_name, m);
988 if (sopt->sopt_td != NULL) {
989 error = priv_check(sopt->sopt_td,
990 PRIV_NETINET_BINDANY);
1000 case IP_RECVDSTADDR:
1007 error = sooptcopyin(sopt, &optval, sizeof optval,
1012 switch (sopt->sopt_name) {
1014 inp->inp_ip_tos = optval;
1018 inp->inp_ip_ttl = optval;
1022 if (optval >= 0 && optval <= MAXTTL)
1023 inp->inp_ip_minttl = optval;
1028 #define OPTSET(bit) do { \
1031 inp->inp_flags |= bit; \
1033 inp->inp_flags &= ~bit; \
1038 OPTSET(INP_RECVOPTS);
1041 case IP_RECVRETOPTS:
1042 OPTSET(INP_RECVRETOPTS);
1045 case IP_RECVDSTADDR:
1046 OPTSET(INP_RECVDSTADDR);
1050 OPTSET(INP_RECVTTL);
1062 OPTSET(INP_ONESBCAST);
1065 OPTSET(INP_DONTFRAG);
1068 OPTSET(INP_BINDANY);
1071 OPTSET(INP_RECVTOS);
1078 * Multicast socket options are processed by the in_mcast
1081 case IP_MULTICAST_IF:
1082 case IP_MULTICAST_VIF:
1083 case IP_MULTICAST_TTL:
1084 case IP_MULTICAST_LOOP:
1085 case IP_ADD_MEMBERSHIP:
1086 case IP_DROP_MEMBERSHIP:
1087 case IP_ADD_SOURCE_MEMBERSHIP:
1088 case IP_DROP_SOURCE_MEMBERSHIP:
1089 case IP_BLOCK_SOURCE:
1090 case IP_UNBLOCK_SOURCE:
1092 case MCAST_JOIN_GROUP:
1093 case MCAST_LEAVE_GROUP:
1094 case MCAST_JOIN_SOURCE_GROUP:
1095 case MCAST_LEAVE_SOURCE_GROUP:
1096 case MCAST_BLOCK_SOURCE:
1097 case MCAST_UNBLOCK_SOURCE:
1098 error = inp_setmoptions(inp, sopt);
1102 error = sooptcopyin(sopt, &optval, sizeof optval,
1109 case IP_PORTRANGE_DEFAULT:
1110 inp->inp_flags &= ~(INP_LOWPORT);
1111 inp->inp_flags &= ~(INP_HIGHPORT);
1114 case IP_PORTRANGE_HIGH:
1115 inp->inp_flags &= ~(INP_LOWPORT);
1116 inp->inp_flags |= INP_HIGHPORT;
1119 case IP_PORTRANGE_LOW:
1120 inp->inp_flags &= ~(INP_HIGHPORT);
1121 inp->inp_flags |= INP_LOWPORT;
1132 case IP_IPSEC_POLICY:
1137 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1139 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1141 req = mtod(m, caddr_t);
1142 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1143 m->m_len, (sopt->sopt_td != NULL) ?
1144 sopt->sopt_td->td_ucred : NULL);
1151 error = ENOPROTOOPT;
1157 switch (sopt->sopt_name) {
1160 if (inp->inp_options)
1161 error = sooptcopyout(sopt,
1162 mtod(inp->inp_options,
1164 inp->inp_options->m_len);
1166 sopt->sopt_valsize = 0;
1173 case IP_RECVRETOPTS:
1174 case IP_RECVDSTADDR:
1183 switch (sopt->sopt_name) {
1186 optval = inp->inp_ip_tos;
1190 optval = inp->inp_ip_ttl;
1194 optval = inp->inp_ip_minttl;
1197 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1200 optval = OPTBIT(INP_RECVOPTS);
1203 case IP_RECVRETOPTS:
1204 optval = OPTBIT(INP_RECVRETOPTS);
1207 case IP_RECVDSTADDR:
1208 optval = OPTBIT(INP_RECVDSTADDR);
1212 optval = OPTBIT(INP_RECVTTL);
1216 optval = OPTBIT(INP_RECVIF);
1220 if (inp->inp_flags & INP_HIGHPORT)
1221 optval = IP_PORTRANGE_HIGH;
1222 else if (inp->inp_flags & INP_LOWPORT)
1223 optval = IP_PORTRANGE_LOW;
1229 optval = OPTBIT(INP_FAITH);
1233 optval = OPTBIT(INP_ONESBCAST);
1236 optval = OPTBIT(INP_DONTFRAG);
1239 optval = OPTBIT(INP_BINDANY);
1242 optval = OPTBIT(INP_RECVTOS);
1245 error = sooptcopyout(sopt, &optval, sizeof optval);
1249 * Multicast socket options are processed by the in_mcast
1252 case IP_MULTICAST_IF:
1253 case IP_MULTICAST_VIF:
1254 case IP_MULTICAST_TTL:
1255 case IP_MULTICAST_LOOP:
1257 error = inp_getmoptions(inp, sopt);
1261 case IP_IPSEC_POLICY:
1263 struct mbuf *m = NULL;
1268 req = mtod(m, caddr_t);
1271 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1273 error = soopt_mcopyout(sopt, m); /* XXX */
1281 error = ENOPROTOOPT;
1290 * Routine called from ip_output() to loop back a copy of an IP multicast
1291 * packet to the input queue of a specified interface. Note that this
1292 * calls the output routine of the loopback "driver", but with an interface
1293 * pointer that might NOT be a loopback interface -- evil, but easier than
1294 * replicating that code here.
1297 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1300 register struct ip *ip;
1304 * Make a deep copy of the packet because we're going to
1305 * modify the pack in order to generate checksums.
1307 copym = m_dup(m, M_NOWAIT);
1308 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1309 copym = m_pullup(copym, hlen);
1310 if (copym != NULL) {
1311 /* If needed, compute the checksum and mark it as valid. */
1312 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1313 in_delayed_cksum(copym);
1314 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1315 copym->m_pkthdr.csum_flags |=
1316 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1317 copym->m_pkthdr.csum_data = 0xffff;
1320 * We don't bother to fragment if the IP length is greater
1321 * than the interface's MTU. Can this possibly matter?
1323 ip = mtod(copym, struct ip *);
1325 ip->ip_sum = in_cksum(copym, hlen);
1327 if (dst->sin_family != AF_INET) {
1328 printf("ip_mloopback: bad address family %d\n",
1330 dst->sin_family = AF_INET;
1333 if_simloop(ifp, copym, dst->sin_family, 0);