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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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_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/netisr.h>
58 #include <net/route.h>
59 #include <net/flowtable.h>
61 #include <net/radix_mpath.h>
65 #include <netinet/in.h>
66 #include <netinet/in_systm.h>
67 #include <netinet/ip.h>
68 #include <netinet/in_pcb.h>
69 #include <netinet/in_var.h>
70 #include <netinet/ip_var.h>
71 #include <netinet/ip_options.h>
73 #include <netinet/sctp.h>
74 #include <netinet/sctp_crc32.h>
78 #include <netinet/ip_ipsec.h>
79 #include <netipsec/ipsec.h>
82 #include <machine/in_cksum.h>
84 #include <security/mac/mac_framework.h>
86 #define print_ip(x, a, y) printf("%s %d.%d.%d.%d%s",\
87 x, (ntohl(a.s_addr)>>24)&0xFF,\
88 (ntohl(a.s_addr)>>16)&0xFF,\
89 (ntohl(a.s_addr)>>8)&0xFF,\
90 (ntohl(a.s_addr))&0xFF, y);
92 VNET_DEFINE(u_short, ip_id);
94 #ifdef MBUF_STRESS_TEST
95 int mbuf_frag_size = 0;
96 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
97 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
100 static void ip_mloopback
101 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
104 extern int in_mcast_loop;
105 extern struct protosw inetsw[];
108 * IP output. The packet in mbuf chain m contains a skeletal IP
109 * header (with len, off, ttl, proto, tos, src, dst).
110 * The mbuf chain containing the packet will be freed.
111 * The mbuf opt, if present, will not be freed.
112 * In the IP forwarding case, the packet will arrive with options already
113 * inserted, so must have a NULL opt pointer.
116 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
117 struct ip_moptions *imo, struct inpcb *inp)
120 struct ifnet *ifp = NULL; /* keep compiler happy */
122 int hlen = sizeof (struct ip);
126 struct sockaddr_in *dst = NULL; /* keep compiler happy */
127 struct in_ifaddr *ia = NULL;
128 int isbroadcast, sw_csum;
129 struct route iproute;
131 #ifdef IPFIREWALL_FORWARD
132 struct m_tag *fwd_tag = NULL;
135 int no_route_but_check_spd = 0;
140 INP_LOCK_ASSERT(inp);
141 M_SETFIB(m, inp->inp_inc.inc_fibnum);
142 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
143 m->m_pkthdr.flowid = inp->inp_flowid;
144 m->m_flags |= M_FLOWID;
150 bzero(ro, sizeof (*ro));
154 * The flow table returns route entries valid for up to 30
155 * seconds; we rely on the remainder of ip_output() taking no
156 * longer than that long for the stability of ro_rt. The
157 * flow ID assignment must have happened before this point.
159 if (flowtable_lookup(V_ip_ft, m, ro) == 0)
166 m = ip_insertoptions(m, opt, &len);
170 ip = mtod(m, struct ip *);
173 * Fill in IP header. If we are not allowing fragmentation,
174 * then the ip_id field is meaningless, but we don't set it
175 * to zero. Doing so causes various problems when devices along
176 * the path (routers, load balancers, firewalls, etc.) illegally
177 * disable DF on our packet. Note that a 16-bit counter
178 * will wrap around in less than 10 seconds at 100 Mbit/s on a
179 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
180 * for Counting NATted Hosts", Proc. IMW'02, available at
181 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
183 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
184 ip->ip_v = IPVERSION;
185 ip->ip_hl = hlen >> 2;
186 ip->ip_id = ip_newid();
187 IPSTAT_INC(ips_localout);
189 hlen = ip->ip_hl << 2;
192 dst = (struct sockaddr_in *)&ro->ro_dst;
195 * If there is a cached route,
196 * check that it is to the same destination
197 * and is still up. If not, free it and try again.
198 * The address family should also be checked in case of sharing the
201 if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
202 dst->sin_family != AF_INET ||
203 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
206 ro->ro_rt = (struct rtentry *)NULL;
208 #ifdef IPFIREWALL_FORWARD
209 if (ro->ro_rt == NULL && fwd_tag == NULL) {
211 if (ro->ro_rt == NULL) {
213 bzero(dst, sizeof(*dst));
214 dst->sin_family = AF_INET;
215 dst->sin_len = sizeof(*dst);
216 dst->sin_addr = ip->ip_dst;
219 * If routing to interface only, short circuit routing lookup.
220 * The use of an all-ones broadcast address implies this; an
221 * interface is specified by the broadcast address of an interface,
222 * or the destination address of a ptp interface.
224 if (flags & IP_SENDONES) {
225 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
226 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
227 IPSTAT_INC(ips_noroute);
231 ip->ip_dst.s_addr = INADDR_BROADCAST;
232 dst->sin_addr = ip->ip_dst;
236 } else if (flags & IP_ROUTETOIF) {
237 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
238 (ia = ifatoia(ifa_ifwithnet(sintosa(dst)))) == NULL) {
239 IPSTAT_INC(ips_noroute);
245 isbroadcast = in_broadcast(dst->sin_addr, ifp);
246 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
247 imo != NULL && imo->imo_multicast_ifp != NULL) {
249 * Bypass the normal routing lookup for multicast
250 * packets if the interface is specified.
252 ifp = imo->imo_multicast_ifp;
254 isbroadcast = 0; /* fool gcc */
257 * We want to do any cloning requested by the link layer,
258 * as this is probably required in all cases for correct
259 * operation (as it is for ARP).
261 if (ro->ro_rt == NULL)
263 rtalloc_mpath_fib(ro,
264 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
265 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
267 in_rtalloc_ign(ro, 0,
268 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
270 if (ro->ro_rt == NULL) {
273 * There is no route for this packet, but it is
274 * possible that a matching SPD entry exists.
276 no_route_but_check_spd = 1;
277 mtu = 0; /* Silence GCC warning. */
280 IPSTAT_INC(ips_noroute);
281 error = EHOSTUNREACH;
284 ia = ifatoia(ro->ro_rt->rt_ifa);
285 ifa_ref(&ia->ia_ifa);
286 ifp = ro->ro_rt->rt_ifp;
287 ro->ro_rt->rt_rmx.rmx_pksent++;
288 if (ro->ro_rt->rt_flags & RTF_GATEWAY)
289 dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway;
290 if (ro->ro_rt->rt_flags & RTF_HOST)
291 isbroadcast = (ro->ro_rt->rt_flags & RTF_BROADCAST);
293 isbroadcast = in_broadcast(dst->sin_addr, ifp);
296 * Calculate MTU. If we have a route that is up, use that,
297 * otherwise use the interface's MTU.
299 if (ro->ro_rt != NULL && (ro->ro_rt->rt_flags & (RTF_UP|RTF_HOST))) {
301 * This case can happen if the user changed the MTU
302 * of an interface after enabling IP on it. Because
303 * most netifs don't keep track of routes pointing to
304 * them, there is no way for one to update all its
305 * routes when the MTU is changed.
307 if (ro->ro_rt->rt_rmx.rmx_mtu > ifp->if_mtu)
308 ro->ro_rt->rt_rmx.rmx_mtu = ifp->if_mtu;
309 mtu = ro->ro_rt->rt_rmx.rmx_mtu;
313 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
314 m->m_flags |= M_MCAST;
316 * IP destination address is multicast. Make sure "dst"
317 * still points to the address in "ro". (It may have been
318 * changed to point to a gateway address, above.)
320 dst = (struct sockaddr_in *)&ro->ro_dst;
322 * See if the caller provided any multicast options
325 ip->ip_ttl = imo->imo_multicast_ttl;
326 if (imo->imo_multicast_vif != -1)
329 ip_mcast_src(imo->imo_multicast_vif) :
332 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
334 * Confirm that the outgoing interface supports multicast.
336 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
337 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
338 IPSTAT_INC(ips_noroute);
344 * If source address not specified yet, use address
345 * of outgoing interface.
347 if (ip->ip_src.s_addr == INADDR_ANY) {
348 /* Interface may have no addresses. */
350 ip->ip_src = IA_SIN(ia)->sin_addr;
353 if ((imo == NULL && in_mcast_loop) ||
354 (imo && imo->imo_multicast_loop)) {
356 * Loop back multicast datagram if not expressly
357 * forbidden to do so, even if we are not a member
358 * of the group; ip_input() will filter it later,
359 * thus deferring a hash lookup and mutex acquisition
360 * at the expense of a cheap copy using m_copym().
362 ip_mloopback(ifp, m, dst, hlen);
365 * If we are acting as a multicast router, perform
366 * multicast forwarding as if the packet had just
367 * arrived on the interface to which we are about
368 * to send. The multicast forwarding function
369 * recursively calls this function, using the
370 * IP_FORWARDING flag to prevent infinite recursion.
372 * Multicasts that are looped back by ip_mloopback(),
373 * above, will be forwarded by the ip_input() routine,
376 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
378 * If rsvp daemon is not running, do not
379 * set ip_moptions. This ensures that the packet
380 * is multicast and not just sent down one link
381 * as prescribed by rsvpd.
386 ip_mforward(ip, ifp, m, imo) != 0) {
394 * Multicasts with a time-to-live of zero may be looped-
395 * back, above, but must not be transmitted on a network.
396 * Also, multicasts addressed to the loopback interface
397 * are not sent -- the above call to ip_mloopback() will
398 * loop back a copy. ip_input() will drop the copy if
399 * this host does not belong to the destination group on
400 * the loopback interface.
402 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
411 * If the source address is not specified yet, use the address
412 * of the outoing interface.
414 if (ip->ip_src.s_addr == INADDR_ANY) {
415 /* Interface may have no addresses. */
417 ip->ip_src = IA_SIN(ia)->sin_addr;
422 * Verify that we have any chance at all of being able to queue the
423 * packet or packet fragments, unless ALTQ is enabled on the given
424 * interface in which case packetdrop should be done by queueing.
427 if ((!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
428 ((ifp->if_snd.ifq_len + ip->ip_len / mtu + 1) >=
429 ifp->if_snd.ifq_maxlen))
431 if ((ifp->if_snd.ifq_len + ip->ip_len / mtu + 1) >=
432 ifp->if_snd.ifq_maxlen)
436 IPSTAT_INC(ips_odropped);
437 ifp->if_snd.ifq_drops += (ip->ip_len / ifp->if_mtu + 1);
442 * Look for broadcast address and
443 * verify user is allowed to send
447 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
448 error = EADDRNOTAVAIL;
451 if ((flags & IP_ALLOWBROADCAST) == 0) {
455 /* don't allow broadcast messages to be fragmented */
456 if (ip->ip_len > mtu) {
460 m->m_flags |= M_BCAST;
462 m->m_flags &= ~M_BCAST;
467 switch(ip_ipsec_output(&m, inp, &flags, &error, &ifp)) {
474 break; /* Continue with packet processing. */
477 * Check if there was a route for this packet; return error if not.
479 if (no_route_but_check_spd) {
480 IPSTAT_INC(ips_noroute);
481 error = EHOSTUNREACH;
484 /* Update variables that are affected by ipsec4_output(). */
485 ip = mtod(m, struct ip *);
486 hlen = ip->ip_hl << 2;
489 /* Jump over all PFIL processing if hooks are not active. */
490 if (!PFIL_HOOKED(&inet_pfil_hook))
493 /* Run through list of hooks for output packets. */
494 odst.s_addr = ip->ip_dst.s_addr;
495 error = pfil_run_hooks(&inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
496 if (error != 0 || m == NULL)
499 ip = mtod(m, struct ip *);
501 /* See if destination IP address was changed by packet filter. */
502 if (odst.s_addr != ip->ip_dst.s_addr) {
503 m->m_flags |= M_SKIP_FIREWALL;
504 /* If destination is now ourself drop to ip_input(). */
505 if (in_localip(ip->ip_dst)) {
506 m->m_flags |= M_FASTFWD_OURS;
507 if (m->m_pkthdr.rcvif == NULL)
508 m->m_pkthdr.rcvif = V_loif;
509 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
510 m->m_pkthdr.csum_flags |=
511 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
512 m->m_pkthdr.csum_data = 0xffff;
514 m->m_pkthdr.csum_flags |=
515 CSUM_IP_CHECKED | CSUM_IP_VALID;
517 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
518 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
520 error = netisr_queue(NETISR_IP, m);
523 goto again; /* Redo the routing table lookup. */
526 #ifdef IPFIREWALL_FORWARD
527 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
528 if (m->m_flags & M_FASTFWD_OURS) {
529 if (m->m_pkthdr.rcvif == NULL)
530 m->m_pkthdr.rcvif = V_loif;
531 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
532 m->m_pkthdr.csum_flags |=
533 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
534 m->m_pkthdr.csum_data = 0xffff;
537 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
538 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
540 m->m_pkthdr.csum_flags |=
541 CSUM_IP_CHECKED | CSUM_IP_VALID;
543 error = netisr_queue(NETISR_IP, m);
546 /* Or forward to some other address? */
547 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
549 dst = (struct sockaddr_in *)&ro->ro_dst;
550 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
551 m->m_flags |= M_SKIP_FIREWALL;
552 m_tag_delete(m, fwd_tag);
555 #endif /* IPFIREWALL_FORWARD */
558 /* 127/8 must not appear on wire - RFC1122. */
559 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
560 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
561 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
562 IPSTAT_INC(ips_badaddr);
563 error = EADDRNOTAVAIL;
568 m->m_pkthdr.csum_flags |= CSUM_IP;
569 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
570 if (sw_csum & CSUM_DELAY_DATA) {
572 sw_csum &= ~CSUM_DELAY_DATA;
575 if (sw_csum & CSUM_SCTP) {
576 sctp_delayed_cksum(m);
577 sw_csum &= ~CSUM_SCTP;
580 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
583 * If small enough for interface, or the interface will take
584 * care of the fragmentation for us, we can just send directly.
586 if (ip->ip_len <= mtu ||
587 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
588 ((ip->ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
589 ip->ip_len = htons(ip->ip_len);
590 ip->ip_off = htons(ip->ip_off);
592 if (sw_csum & CSUM_DELAY_IP)
593 ip->ip_sum = in_cksum(m, hlen);
596 * Record statistics for this interface address.
597 * With CSUM_TSO the byte/packet count will be slightly
598 * incorrect because we count the IP+TCP headers only
599 * once instead of for every generated packet.
601 if (!(flags & IP_FORWARDING) && ia) {
602 if (m->m_pkthdr.csum_flags & CSUM_TSO)
603 ia->ia_ifa.if_opackets +=
604 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
606 ia->ia_ifa.if_opackets++;
607 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
609 #ifdef MBUF_STRESS_TEST
610 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
611 m = m_fragment(m, M_DONTWAIT, mbuf_frag_size);
614 * Reset layer specific mbuf flags
615 * to avoid confusing lower layers.
617 m->m_flags &= ~(M_PROTOFLAGS);
618 error = (*ifp->if_output)(ifp, m,
619 (struct sockaddr *)dst, ro);
623 /* Balk when DF bit is set or the interface didn't support TSO. */
624 if ((ip->ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
626 IPSTAT_INC(ips_cantfrag);
631 * Too large for interface; fragment if possible. If successful,
632 * on return, m will point to a list of packets to be sent.
634 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist, sw_csum);
641 /* Record statistics for this interface address. */
643 ia->ia_ifa.if_opackets++;
644 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
647 * Reset layer specific mbuf flags
648 * to avoid confusing upper layers.
650 m->m_flags &= ~(M_PROTOFLAGS);
652 error = (*ifp->if_output)(ifp, m,
653 (struct sockaddr *)dst, ro);
659 IPSTAT_INC(ips_fragmented);
662 if (ro == &iproute && ro->ro_rt && !nortfree) {
666 ifa_free(&ia->ia_ifa);
674 * Create a chain of fragments which fit the given mtu. m_frag points to the
675 * mbuf to be fragmented; on return it points to the chain with the fragments.
676 * Return 0 if no error. If error, m_frag may contain a partially built
677 * chain of fragments that should be freed by the caller.
679 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
680 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
683 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
684 u_long if_hwassist_flags, int sw_csum)
687 int hlen = ip->ip_hl << 2;
688 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
690 struct mbuf *m0 = *m_frag; /* the original packet */
695 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
696 IPSTAT_INC(ips_cantfrag);
701 * Must be able to put at least 8 bytes per fragment.
707 * If the interface will not calculate checksums on
708 * fragmented packets, then do it here.
710 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA &&
711 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
712 in_delayed_cksum(m0);
713 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
716 if (m0->m_pkthdr.csum_flags & CSUM_SCTP &&
717 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
718 sctp_delayed_cksum(m0);
719 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
722 if (len > PAGE_SIZE) {
724 * Fragment large datagrams such that each segment
725 * contains a multiple of PAGE_SIZE amount of data,
726 * plus headers. This enables a receiver to perform
727 * page-flipping zero-copy optimizations.
729 * XXX When does this help given that sender and receiver
730 * could have different page sizes, and also mtu could
731 * be less than the receiver's page size ?
736 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
740 * firstlen (off - hlen) must be aligned on an
744 goto smart_frag_failure;
745 off = ((off - hlen) & ~7) + hlen;
746 newlen = (~PAGE_MASK) & mtu;
747 if ((newlen + sizeof (struct ip)) > mtu) {
748 /* we failed, go back the default */
759 firstlen = off - hlen;
760 mnext = &m0->m_nextpkt; /* pointer to next packet */
763 * Loop through length of segment after first fragment,
764 * make new header and copy data of each part and link onto chain.
765 * Here, m0 is the original packet, m is the fragment being created.
766 * The fragments are linked off the m_nextpkt of the original
767 * packet, which after processing serves as the first fragment.
769 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
770 struct ip *mhip; /* ip header on the fragment */
772 int mhlen = sizeof (struct ip);
774 MGETHDR(m, M_DONTWAIT, MT_DATA);
777 IPSTAT_INC(ips_odropped);
780 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
782 * In the first mbuf, leave room for the link header, then
783 * copy the original IP header including options. The payload
784 * goes into an additional mbuf chain returned by m_copym().
786 m->m_data += max_linkhdr;
787 mhip = mtod(m, struct ip *);
789 if (hlen > sizeof (struct ip)) {
790 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
791 mhip->ip_v = IPVERSION;
792 mhip->ip_hl = mhlen >> 2;
795 /* XXX do we need to add ip->ip_off below ? */
796 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
797 if (off + len >= ip->ip_len) { /* last fragment */
798 len = ip->ip_len - off;
799 m->m_flags |= M_LASTFRAG;
801 mhip->ip_off |= IP_MF;
802 mhip->ip_len = htons((u_short)(len + mhlen));
803 m->m_next = m_copym(m0, off, len, M_DONTWAIT);
804 if (m->m_next == NULL) { /* copy failed */
806 error = ENOBUFS; /* ??? */
807 IPSTAT_INC(ips_odropped);
810 m->m_pkthdr.len = mhlen + len;
811 m->m_pkthdr.rcvif = NULL;
813 mac_netinet_fragment(m0, m);
815 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
816 mhip->ip_off = htons(mhip->ip_off);
818 if (sw_csum & CSUM_DELAY_IP)
819 mhip->ip_sum = in_cksum(m, mhlen);
821 mnext = &m->m_nextpkt;
823 IPSTAT_ADD(ips_ofragments, nfrags);
825 /* set first marker for fragment chain */
826 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
827 m0->m_pkthdr.csum_data = nfrags;
830 * Update first fragment by trimming what's been copied out
831 * and updating header.
833 m_adj(m0, hlen + firstlen - ip->ip_len);
834 m0->m_pkthdr.len = hlen + firstlen;
835 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
837 ip->ip_off = htons(ip->ip_off);
839 if (sw_csum & CSUM_DELAY_IP)
840 ip->ip_sum = in_cksum(m0, hlen);
848 in_delayed_cksum(struct mbuf *m)
851 u_short csum, offset;
853 ip = mtod(m, struct ip *);
854 offset = ip->ip_hl << 2 ;
855 csum = in_cksum_skip(m, ip->ip_len, offset);
856 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
858 offset += m->m_pkthdr.csum_data; /* checksum offset */
860 if (offset + sizeof(u_short) > m->m_len) {
861 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
862 m->m_len, offset, ip->ip_p);
865 * this shouldn't happen, but if it does, the
866 * correct behavior may be to insert the checksum
867 * in the appropriate next mbuf in the chain.
871 *(u_short *)(m->m_data + offset) = csum;
875 * IP socket option processing.
878 ip_ctloutput(struct socket *so, struct sockopt *sopt)
880 struct inpcb *inp = sotoinpcb(so);
884 if (sopt->sopt_level != IPPROTO_IP) {
885 if ((sopt->sopt_level == SOL_SOCKET) &&
886 (sopt->sopt_name == SO_SETFIB)) {
887 inp->inp_inc.inc_fibnum = so->so_fibnum;
893 switch (sopt->sopt_dir) {
895 switch (sopt->sopt_name) {
902 if (sopt->sopt_valsize > MLEN) {
906 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
911 m->m_len = sopt->sopt_valsize;
912 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
919 error = ip_pcbopts(inp, sopt->sopt_name, m);
925 if (sopt->sopt_td != NULL) {
926 error = priv_check(sopt->sopt_td,
927 PRIV_NETINET_BINDANY);
943 error = sooptcopyin(sopt, &optval, sizeof optval,
948 switch (sopt->sopt_name) {
950 inp->inp_ip_tos = optval;
954 inp->inp_ip_ttl = optval;
958 if (optval >= 0 && optval <= MAXTTL)
959 inp->inp_ip_minttl = optval;
964 #define OPTSET(bit) do { \
967 inp->inp_flags |= bit; \
969 inp->inp_flags &= ~bit; \
974 OPTSET(INP_RECVOPTS);
978 OPTSET(INP_RECVRETOPTS);
982 OPTSET(INP_RECVDSTADDR);
998 OPTSET(INP_ONESBCAST);
1001 OPTSET(INP_DONTFRAG);
1004 OPTSET(INP_BINDANY);
1011 * Multicast socket options are processed by the in_mcast
1014 case IP_MULTICAST_IF:
1015 case IP_MULTICAST_VIF:
1016 case IP_MULTICAST_TTL:
1017 case IP_MULTICAST_LOOP:
1018 case IP_ADD_MEMBERSHIP:
1019 case IP_DROP_MEMBERSHIP:
1020 case IP_ADD_SOURCE_MEMBERSHIP:
1021 case IP_DROP_SOURCE_MEMBERSHIP:
1022 case IP_BLOCK_SOURCE:
1023 case IP_UNBLOCK_SOURCE:
1025 case MCAST_JOIN_GROUP:
1026 case MCAST_LEAVE_GROUP:
1027 case MCAST_JOIN_SOURCE_GROUP:
1028 case MCAST_LEAVE_SOURCE_GROUP:
1029 case MCAST_BLOCK_SOURCE:
1030 case MCAST_UNBLOCK_SOURCE:
1031 error = inp_setmoptions(inp, sopt);
1035 error = sooptcopyin(sopt, &optval, sizeof optval,
1042 case IP_PORTRANGE_DEFAULT:
1043 inp->inp_flags &= ~(INP_LOWPORT);
1044 inp->inp_flags &= ~(INP_HIGHPORT);
1047 case IP_PORTRANGE_HIGH:
1048 inp->inp_flags &= ~(INP_LOWPORT);
1049 inp->inp_flags |= INP_HIGHPORT;
1052 case IP_PORTRANGE_LOW:
1053 inp->inp_flags &= ~(INP_HIGHPORT);
1054 inp->inp_flags |= INP_LOWPORT;
1065 case IP_IPSEC_POLICY:
1070 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1072 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1074 req = mtod(m, caddr_t);
1075 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1076 m->m_len, (sopt->sopt_td != NULL) ?
1077 sopt->sopt_td->td_ucred : NULL);
1084 error = ENOPROTOOPT;
1090 switch (sopt->sopt_name) {
1093 if (inp->inp_options)
1094 error = sooptcopyout(sopt,
1095 mtod(inp->inp_options,
1097 inp->inp_options->m_len);
1099 sopt->sopt_valsize = 0;
1106 case IP_RECVRETOPTS:
1107 case IP_RECVDSTADDR:
1114 switch (sopt->sopt_name) {
1117 optval = inp->inp_ip_tos;
1121 optval = inp->inp_ip_ttl;
1125 optval = inp->inp_ip_minttl;
1128 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1131 optval = OPTBIT(INP_RECVOPTS);
1134 case IP_RECVRETOPTS:
1135 optval = OPTBIT(INP_RECVRETOPTS);
1138 case IP_RECVDSTADDR:
1139 optval = OPTBIT(INP_RECVDSTADDR);
1143 optval = OPTBIT(INP_RECVTTL);
1147 optval = OPTBIT(INP_RECVIF);
1151 if (inp->inp_flags & INP_HIGHPORT)
1152 optval = IP_PORTRANGE_HIGH;
1153 else if (inp->inp_flags & INP_LOWPORT)
1154 optval = IP_PORTRANGE_LOW;
1160 optval = OPTBIT(INP_FAITH);
1164 optval = OPTBIT(INP_ONESBCAST);
1167 optval = OPTBIT(INP_DONTFRAG);
1170 error = sooptcopyout(sopt, &optval, sizeof optval);
1174 * Multicast socket options are processed by the in_mcast
1177 case IP_MULTICAST_IF:
1178 case IP_MULTICAST_VIF:
1179 case IP_MULTICAST_TTL:
1180 case IP_MULTICAST_LOOP:
1182 error = inp_getmoptions(inp, sopt);
1186 case IP_IPSEC_POLICY:
1188 struct mbuf *m = NULL;
1193 req = mtod(m, caddr_t);
1196 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1198 error = soopt_mcopyout(sopt, m); /* XXX */
1206 error = ENOPROTOOPT;
1215 * Routine called from ip_output() to loop back a copy of an IP multicast
1216 * packet to the input queue of a specified interface. Note that this
1217 * calls the output routine of the loopback "driver", but with an interface
1218 * pointer that might NOT be a loopback interface -- evil, but easier than
1219 * replicating that code here.
1222 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1225 register struct ip *ip;
1229 * Make a deep copy of the packet because we're going to
1230 * modify the pack in order to generate checksums.
1232 copym = m_dup(m, M_DONTWAIT);
1233 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1234 copym = m_pullup(copym, hlen);
1235 if (copym != NULL) {
1236 /* If needed, compute the checksum and mark it as valid. */
1237 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1238 in_delayed_cksum(copym);
1239 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1240 copym->m_pkthdr.csum_flags |=
1241 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1242 copym->m_pkthdr.csum_data = 0xffff;
1245 * We don't bother to fragment if the IP length is greater
1246 * than the interface's MTU. Can this possibly matter?
1248 ip = mtod(copym, struct ip *);
1249 ip->ip_len = htons(ip->ip_len);
1250 ip->ip_off = htons(ip->ip_off);
1252 ip->ip_sum = in_cksum(copym, hlen);
1254 if (dst->sin_family != AF_INET) {
1255 printf("ip_mloopback: bad address family %d\n",
1257 dst->sin_family = AF_INET;
1260 if_simloop(ifp, copym, dst->sin_family, 0);