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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14 * may be used to endorse or promote products derived from this software
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19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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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("$FreeBSD$");
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 * ip_len and ip_off are in host format.
106 * The mbuf chain containing the packet will be freed.
107 * The mbuf opt, if present, will not be freed.
108 * In the IP forwarding case, the packet will arrive with options already
109 * inserted, so must have a NULL opt pointer.
112 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
113 struct ip_moptions *imo, struct inpcb *inp)
116 struct ifnet *ifp = NULL; /* keep compiler happy */
118 int hlen = sizeof (struct ip);
120 int n; /* scratchpad */
123 struct sockaddr_in *dst;
124 struct in_ifaddr *ia;
125 int isbroadcast, sw_csum;
126 struct route iproute;
127 struct rtentry *rte; /* cache for ro->ro_rt */
129 #ifdef IPFIREWALL_FORWARD
130 struct m_tag *fwd_tag = NULL;
133 int no_route_but_check_spd = 0;
138 INP_LOCK_ASSERT(inp);
139 M_SETFIB(m, inp->inp_inc.inc_fibnum);
140 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
141 m->m_pkthdr.flowid = inp->inp_flowid;
142 m->m_flags |= M_FLOWID;
148 bzero(ro, sizeof (*ro));
155 * The flow table returns route entries valid for up to 30
156 * seconds; we rely on the remainder of ip_output() taking no
157 * longer than that long for the stability of ro_rt. The
158 * flow ID assignment must have happened before this point.
160 if ((fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET)) != NULL) {
161 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 *);
177 * Fill in IP header. If we are not allowing fragmentation,
178 * then the ip_id field is meaningless, but we don't set it
179 * to zero. Doing so causes various problems when devices along
180 * the path (routers, load balancers, firewalls, etc.) illegally
181 * disable DF on our packet. Note that a 16-bit counter
182 * will wrap around in less than 10 seconds at 100 Mbit/s on a
183 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
184 * for Counting NATted Hosts", Proc. IMW'02, available at
185 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
187 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
188 ip->ip_v = IPVERSION;
189 ip->ip_hl = hlen >> 2;
190 ip->ip_id = ip_newid();
191 IPSTAT_INC(ips_localout);
193 /* Header already set, fetch hlen from there */
194 hlen = ip->ip_hl << 2;
197 dst = (struct sockaddr_in *)&ro->ro_dst;
201 * If there is a cached route,
202 * check that it is to the same destination
203 * and is still up. If not, free it and try again.
204 * The address family should also be checked in case of sharing the
208 if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
209 rte->rt_ifp == NULL ||
210 !RT_LINK_IS_UP(rte->rt_ifp) ||
211 dst->sin_family != AF_INET ||
212 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
215 rte = ro->ro_rt = (struct rtentry *)NULL;
216 ro->ro_lle = (struct llentry *)NULL;
218 #ifdef IPFIREWALL_FORWARD
219 if (rte == NULL && fwd_tag == NULL) {
223 bzero(dst, sizeof(*dst));
224 dst->sin_family = AF_INET;
225 dst->sin_len = sizeof(*dst);
226 dst->sin_addr = ip->ip_dst;
229 * If routing to interface only, short circuit routing lookup.
230 * The use of an all-ones broadcast address implies this; an
231 * interface is specified by the broadcast address of an interface,
232 * or the destination address of a ptp interface.
234 if (flags & IP_SENDONES) {
235 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
236 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
237 IPSTAT_INC(ips_noroute);
241 ip->ip_dst.s_addr = INADDR_BROADCAST;
242 dst->sin_addr = ip->ip_dst;
246 } else if (flags & IP_ROUTETOIF) {
247 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
248 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
249 IPSTAT_INC(ips_noroute);
255 isbroadcast = in_broadcast(dst->sin_addr, ifp);
256 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
257 imo != NULL && imo->imo_multicast_ifp != NULL) {
259 * Bypass the normal routing lookup for multicast
260 * packets if the interface is specified.
262 ifp = imo->imo_multicast_ifp;
264 isbroadcast = 0; /* fool gcc */
267 * We want to do any cloning requested by the link layer,
268 * as this is probably required in all cases for correct
269 * operation (as it is for ARP).
273 rtalloc_mpath_fib(ro,
274 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
275 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
277 in_rtalloc_ign(ro, 0,
278 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
283 rte->rt_ifp == NULL ||
284 !RT_LINK_IS_UP(rte->rt_ifp)) {
287 * There is no route for this packet, but it is
288 * possible that a matching SPD entry exists.
290 no_route_but_check_spd = 1;
291 mtu = 0; /* Silence GCC warning. */
294 IPSTAT_INC(ips_noroute);
295 error = EHOSTUNREACH;
298 ia = ifatoia(rte->rt_ifa);
299 ifa_ref(&ia->ia_ifa);
301 rte->rt_rmx.rmx_pksent++;
302 if (rte->rt_flags & RTF_GATEWAY)
303 dst = (struct sockaddr_in *)rte->rt_gateway;
304 if (rte->rt_flags & RTF_HOST)
305 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
307 isbroadcast = in_broadcast(dst->sin_addr, ifp);
310 * Calculate MTU. If we have a route that is up, use that,
311 * otherwise use the interface's MTU.
313 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
315 * This case can happen if the user changed the MTU
316 * of an interface after enabling IP on it. Because
317 * most netifs don't keep track of routes pointing to
318 * them, there is no way for one to update all its
319 * routes when the MTU is changed.
321 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
322 rte->rt_rmx.rmx_mtu = ifp->if_mtu;
323 mtu = rte->rt_rmx.rmx_mtu;
327 /* Catch a possible divide by zero later. */
328 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
329 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
330 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
331 m->m_flags |= M_MCAST;
333 * IP destination address is multicast. Make sure "dst"
334 * still points to the address in "ro". (It may have been
335 * changed to point to a gateway address, above.)
337 dst = (struct sockaddr_in *)&ro->ro_dst;
339 * See if the caller provided any multicast options
342 ip->ip_ttl = imo->imo_multicast_ttl;
343 if (imo->imo_multicast_vif != -1)
346 ip_mcast_src(imo->imo_multicast_vif) :
349 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
351 * Confirm that the outgoing interface supports multicast.
353 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
354 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
355 IPSTAT_INC(ips_noroute);
361 * If source address not specified yet, use address
362 * of outgoing interface.
364 if (ip->ip_src.s_addr == INADDR_ANY) {
365 /* Interface may have no addresses. */
367 ip->ip_src = IA_SIN(ia)->sin_addr;
370 if ((imo == NULL && in_mcast_loop) ||
371 (imo && imo->imo_multicast_loop)) {
373 * Loop back multicast datagram if not expressly
374 * forbidden to do so, even if we are not a member
375 * of the group; ip_input() will filter it later,
376 * thus deferring a hash lookup and mutex acquisition
377 * at the expense of a cheap copy using m_copym().
379 ip_mloopback(ifp, m, dst, hlen);
382 * If we are acting as a multicast router, perform
383 * multicast forwarding as if the packet had just
384 * arrived on the interface to which we are about
385 * to send. The multicast forwarding function
386 * recursively calls this function, using the
387 * IP_FORWARDING flag to prevent infinite recursion.
389 * Multicasts that are looped back by ip_mloopback(),
390 * above, will be forwarded by the ip_input() routine,
393 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
395 * If rsvp daemon is not running, do not
396 * set ip_moptions. This ensures that the packet
397 * is multicast and not just sent down one link
398 * as prescribed by rsvpd.
403 ip_mforward(ip, ifp, m, imo) != 0) {
411 * Multicasts with a time-to-live of zero may be looped-
412 * back, above, but must not be transmitted on a network.
413 * Also, multicasts addressed to the loopback interface
414 * are not sent -- the above call to ip_mloopback() will
415 * loop back a copy. ip_input() will drop the copy if
416 * this host does not belong to the destination group on
417 * the loopback interface.
419 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
428 * If the source address is not specified yet, use the address
429 * of the outoing interface.
431 if (ip->ip_src.s_addr == INADDR_ANY) {
432 /* Interface may have no addresses. */
434 ip->ip_src = IA_SIN(ia)->sin_addr;
439 * Verify that we have any chance at all of being able to queue the
440 * packet or packet fragments, unless ALTQ is enabled on the given
441 * interface in which case packetdrop should be done by queueing.
443 n = ip->ip_len / mtu + 1; /* how many fragments ? */
446 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
448 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
450 IPSTAT_INC(ips_odropped);
451 ifp->if_snd.ifq_drops += n;
456 * Look for broadcast address and
457 * verify user is allowed to send
461 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
462 error = EADDRNOTAVAIL;
465 if ((flags & IP_ALLOWBROADCAST) == 0) {
469 /* don't allow broadcast messages to be fragmented */
470 if (ip->ip_len > mtu) {
474 m->m_flags |= M_BCAST;
476 m->m_flags &= ~M_BCAST;
481 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
488 break; /* Continue with packet processing. */
491 * Check if there was a route for this packet; return error if not.
493 if (no_route_but_check_spd) {
494 IPSTAT_INC(ips_noroute);
495 error = EHOSTUNREACH;
498 /* Update variables that are affected by ipsec4_output(). */
499 ip = mtod(m, struct ip *);
500 hlen = ip->ip_hl << 2;
503 /* Jump over all PFIL processing if hooks are not active. */
504 if (!PFIL_HOOKED(&V_inet_pfil_hook))
507 /* Run through list of hooks for output packets. */
508 odst.s_addr = ip->ip_dst.s_addr;
509 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
510 if (error != 0 || m == NULL)
513 ip = mtod(m, struct ip *);
515 /* See if destination IP address was changed by packet filter. */
516 if (odst.s_addr != ip->ip_dst.s_addr) {
517 m->m_flags |= M_SKIP_FIREWALL;
518 /* If destination is now ourself drop to ip_input(). */
519 if (in_localip(ip->ip_dst)) {
520 m->m_flags |= M_FASTFWD_OURS;
521 if (m->m_pkthdr.rcvif == NULL)
522 m->m_pkthdr.rcvif = V_loif;
523 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
524 m->m_pkthdr.csum_flags |=
525 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
526 m->m_pkthdr.csum_data = 0xffff;
528 m->m_pkthdr.csum_flags |=
529 CSUM_IP_CHECKED | CSUM_IP_VALID;
531 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
532 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
534 error = netisr_queue(NETISR_IP, m);
538 ifa_free(&ia->ia_ifa);
539 goto again; /* Redo the routing table lookup. */
543 #ifdef IPFIREWALL_FORWARD
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 fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
566 dst = (struct sockaddr_in *)&ro->ro_dst;
567 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
568 m->m_flags |= M_SKIP_FIREWALL;
569 m_tag_delete(m, fwd_tag);
571 ifa_free(&ia->ia_ifa);
574 #endif /* IPFIREWALL_FORWARD */
577 /* 127/8 must not appear on wire - RFC1122. */
578 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
579 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
580 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
581 IPSTAT_INC(ips_badaddr);
582 error = EADDRNOTAVAIL;
587 m->m_pkthdr.csum_flags |= CSUM_IP;
588 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
589 if (sw_csum & CSUM_DELAY_DATA) {
591 sw_csum &= ~CSUM_DELAY_DATA;
594 if (sw_csum & CSUM_SCTP) {
595 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
596 sw_csum &= ~CSUM_SCTP;
599 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
602 * If small enough for interface, or the interface will take
603 * care of the fragmentation for us, we can just send directly.
605 if (ip->ip_len <= mtu ||
606 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
607 ((ip->ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
608 ip->ip_len = htons(ip->ip_len);
609 ip->ip_off = htons(ip->ip_off);
611 if (sw_csum & CSUM_DELAY_IP)
612 ip->ip_sum = in_cksum(m, hlen);
615 * Record statistics for this interface address.
616 * With CSUM_TSO the byte/packet count will be slightly
617 * incorrect because we count the IP+TCP headers only
618 * once instead of for every generated packet.
620 if (!(flags & IP_FORWARDING) && ia) {
621 if (m->m_pkthdr.csum_flags & CSUM_TSO)
622 ia->ia_ifa.if_opackets +=
623 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
625 ia->ia_ifa.if_opackets++;
626 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
628 #ifdef MBUF_STRESS_TEST
629 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
630 m = m_fragment(m, M_DONTWAIT, mbuf_frag_size);
633 * Reset layer specific mbuf flags
634 * to avoid confusing lower layers.
636 m->m_flags &= ~(M_PROTOFLAGS);
637 error = (*ifp->if_output)(ifp, m,
638 (struct sockaddr *)dst, ro);
642 /* Balk when DF bit is set or the interface didn't support TSO. */
643 if ((ip->ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
645 IPSTAT_INC(ips_cantfrag);
650 * Too large for interface; fragment if possible. If successful,
651 * on return, m will point to a list of packets to be sent.
653 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist, sw_csum);
660 /* Record statistics for this interface address. */
662 ia->ia_ifa.if_opackets++;
663 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
666 * Reset layer specific mbuf flags
667 * to avoid confusing upper layers.
669 m->m_flags &= ~(M_PROTOFLAGS);
671 error = (*ifp->if_output)(ifp, m,
672 (struct sockaddr *)dst, ro);
678 IPSTAT_INC(ips_fragmented);
681 if (ro == &iproute && ro->ro_rt && !nortfree) {
685 ifa_free(&ia->ia_ifa);
693 * Create a chain of fragments which fit the given mtu. m_frag points to the
694 * mbuf to be fragmented; on return it points to the chain with the fragments.
695 * Return 0 if no error. If error, m_frag may contain a partially built
696 * chain of fragments that should be freed by the caller.
698 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
699 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
702 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
703 u_long if_hwassist_flags, int sw_csum)
706 int hlen = ip->ip_hl << 2;
707 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
709 struct mbuf *m0 = *m_frag; /* the original packet */
714 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
715 IPSTAT_INC(ips_cantfrag);
720 * Must be able to put at least 8 bytes per fragment.
726 * If the interface will not calculate checksums on
727 * fragmented packets, then do it here.
729 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA &&
730 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
731 in_delayed_cksum(m0);
732 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
735 if (m0->m_pkthdr.csum_flags & CSUM_SCTP &&
736 (if_hwassist_flags & CSUM_IP_FRAGS) == 0) {
737 sctp_delayed_cksum(m0, hlen);
738 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
741 if (len > PAGE_SIZE) {
743 * Fragment large datagrams such that each segment
744 * contains a multiple of PAGE_SIZE amount of data,
745 * plus headers. This enables a receiver to perform
746 * page-flipping zero-copy optimizations.
748 * XXX When does this help given that sender and receiver
749 * could have different page sizes, and also mtu could
750 * be less than the receiver's page size ?
755 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
759 * firstlen (off - hlen) must be aligned on an
763 goto smart_frag_failure;
764 off = ((off - hlen) & ~7) + hlen;
765 newlen = (~PAGE_MASK) & mtu;
766 if ((newlen + sizeof (struct ip)) > mtu) {
767 /* we failed, go back the default */
778 firstlen = off - hlen;
779 mnext = &m0->m_nextpkt; /* pointer to next packet */
782 * Loop through length of segment after first fragment,
783 * make new header and copy data of each part and link onto chain.
784 * Here, m0 is the original packet, m is the fragment being created.
785 * The fragments are linked off the m_nextpkt of the original
786 * packet, which after processing serves as the first fragment.
788 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
789 struct ip *mhip; /* ip header on the fragment */
791 int mhlen = sizeof (struct ip);
793 MGETHDR(m, M_DONTWAIT, MT_DATA);
796 IPSTAT_INC(ips_odropped);
799 m->m_flags |= (m0->m_flags & M_MCAST) | M_FRAG;
801 * In the first mbuf, leave room for the link header, then
802 * copy the original IP header including options. The payload
803 * goes into an additional mbuf chain returned by m_copym().
805 m->m_data += max_linkhdr;
806 mhip = mtod(m, struct ip *);
808 if (hlen > sizeof (struct ip)) {
809 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
810 mhip->ip_v = IPVERSION;
811 mhip->ip_hl = mhlen >> 2;
814 /* XXX do we need to add ip->ip_off below ? */
815 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
816 if (off + len >= ip->ip_len) { /* last fragment */
817 len = ip->ip_len - off;
818 m->m_flags |= M_LASTFRAG;
820 mhip->ip_off |= IP_MF;
821 mhip->ip_len = htons((u_short)(len + mhlen));
822 m->m_next = m_copym(m0, off, len, M_DONTWAIT);
823 if (m->m_next == NULL) { /* copy failed */
825 error = ENOBUFS; /* ??? */
826 IPSTAT_INC(ips_odropped);
829 m->m_pkthdr.len = mhlen + len;
830 m->m_pkthdr.rcvif = NULL;
832 mac_netinet_fragment(m0, m);
834 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
835 mhip->ip_off = htons(mhip->ip_off);
837 if (sw_csum & CSUM_DELAY_IP)
838 mhip->ip_sum = in_cksum(m, mhlen);
840 mnext = &m->m_nextpkt;
842 IPSTAT_ADD(ips_ofragments, nfrags);
844 /* set first marker for fragment chain */
845 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
846 m0->m_pkthdr.csum_data = nfrags;
849 * Update first fragment by trimming what's been copied out
850 * and updating header.
852 m_adj(m0, hlen + firstlen - ip->ip_len);
853 m0->m_pkthdr.len = hlen + firstlen;
854 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
856 ip->ip_off = htons(ip->ip_off);
858 if (sw_csum & CSUM_DELAY_IP)
859 ip->ip_sum = in_cksum(m0, hlen);
867 in_delayed_cksum(struct mbuf *m)
870 u_short csum, offset;
872 ip = mtod(m, struct ip *);
873 offset = ip->ip_hl << 2 ;
874 csum = in_cksum_skip(m, ip->ip_len, offset);
875 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
877 offset += m->m_pkthdr.csum_data; /* checksum offset */
879 if (offset + sizeof(u_short) > m->m_len) {
880 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
881 m->m_len, offset, ip->ip_p);
884 * this shouldn't happen, but if it does, the
885 * correct behavior may be to insert the checksum
886 * in the appropriate next mbuf in the chain.
890 *(u_short *)(m->m_data + offset) = csum;
894 * IP socket option processing.
897 ip_ctloutput(struct socket *so, struct sockopt *sopt)
899 struct inpcb *inp = sotoinpcb(so);
903 if (sopt->sopt_level != IPPROTO_IP) {
906 if (sopt->sopt_level == SOL_SOCKET &&
907 sopt->sopt_dir == SOPT_SET) {
908 switch (sopt->sopt_name) {
911 if (IN_MULTICAST(ntohl(inp->inp_laddr.s_addr))) {
912 if ((so->so_options &
913 (SO_REUSEADDR | SO_REUSEPORT)) != 0)
914 inp->inp_flags2 |= INP_REUSEPORT;
916 inp->inp_flags2 &= ~INP_REUSEPORT;
923 if ((so->so_options & SO_REUSEPORT) != 0)
924 inp->inp_flags2 |= INP_REUSEPORT;
926 inp->inp_flags2 &= ~INP_REUSEPORT;
932 inp->inp_inc.inc_fibnum = so->so_fibnum;
943 switch (sopt->sopt_dir) {
945 switch (sopt->sopt_name) {
952 if (sopt->sopt_valsize > MLEN) {
956 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
961 m->m_len = sopt->sopt_valsize;
962 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
969 error = ip_pcbopts(inp, sopt->sopt_name, m);
975 if (sopt->sopt_td != NULL) {
976 error = priv_check(sopt->sopt_td,
977 PRIV_NETINET_BINDANY);
994 error = sooptcopyin(sopt, &optval, sizeof optval,
999 switch (sopt->sopt_name) {
1001 inp->inp_ip_tos = optval;
1005 inp->inp_ip_ttl = optval;
1009 if (optval >= 0 && optval <= MAXTTL)
1010 inp->inp_ip_minttl = optval;
1015 #define OPTSET(bit) do { \
1018 inp->inp_flags |= bit; \
1020 inp->inp_flags &= ~bit; \
1025 OPTSET(INP_RECVOPTS);
1028 case IP_RECVRETOPTS:
1029 OPTSET(INP_RECVRETOPTS);
1032 case IP_RECVDSTADDR:
1033 OPTSET(INP_RECVDSTADDR);
1037 OPTSET(INP_RECVTTL);
1049 OPTSET(INP_ONESBCAST);
1052 OPTSET(INP_DONTFRAG);
1055 OPTSET(INP_BINDANY);
1058 OPTSET(INP_RECVTOS);
1065 * Multicast socket options are processed by the in_mcast
1068 case IP_MULTICAST_IF:
1069 case IP_MULTICAST_VIF:
1070 case IP_MULTICAST_TTL:
1071 case IP_MULTICAST_LOOP:
1072 case IP_ADD_MEMBERSHIP:
1073 case IP_DROP_MEMBERSHIP:
1074 case IP_ADD_SOURCE_MEMBERSHIP:
1075 case IP_DROP_SOURCE_MEMBERSHIP:
1076 case IP_BLOCK_SOURCE:
1077 case IP_UNBLOCK_SOURCE:
1079 case MCAST_JOIN_GROUP:
1080 case MCAST_LEAVE_GROUP:
1081 case MCAST_JOIN_SOURCE_GROUP:
1082 case MCAST_LEAVE_SOURCE_GROUP:
1083 case MCAST_BLOCK_SOURCE:
1084 case MCAST_UNBLOCK_SOURCE:
1085 error = inp_setmoptions(inp, sopt);
1089 error = sooptcopyin(sopt, &optval, sizeof optval,
1096 case IP_PORTRANGE_DEFAULT:
1097 inp->inp_flags &= ~(INP_LOWPORT);
1098 inp->inp_flags &= ~(INP_HIGHPORT);
1101 case IP_PORTRANGE_HIGH:
1102 inp->inp_flags &= ~(INP_LOWPORT);
1103 inp->inp_flags |= INP_HIGHPORT;
1106 case IP_PORTRANGE_LOW:
1107 inp->inp_flags &= ~(INP_HIGHPORT);
1108 inp->inp_flags |= INP_LOWPORT;
1119 case IP_IPSEC_POLICY:
1124 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1126 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1128 req = mtod(m, caddr_t);
1129 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1130 m->m_len, (sopt->sopt_td != NULL) ?
1131 sopt->sopt_td->td_ucred : NULL);
1138 error = ENOPROTOOPT;
1144 switch (sopt->sopt_name) {
1147 if (inp->inp_options)
1148 error = sooptcopyout(sopt,
1149 mtod(inp->inp_options,
1151 inp->inp_options->m_len);
1153 sopt->sopt_valsize = 0;
1160 case IP_RECVRETOPTS:
1161 case IP_RECVDSTADDR:
1170 switch (sopt->sopt_name) {
1173 optval = inp->inp_ip_tos;
1177 optval = inp->inp_ip_ttl;
1181 optval = inp->inp_ip_minttl;
1184 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1187 optval = OPTBIT(INP_RECVOPTS);
1190 case IP_RECVRETOPTS:
1191 optval = OPTBIT(INP_RECVRETOPTS);
1194 case IP_RECVDSTADDR:
1195 optval = OPTBIT(INP_RECVDSTADDR);
1199 optval = OPTBIT(INP_RECVTTL);
1203 optval = OPTBIT(INP_RECVIF);
1207 if (inp->inp_flags & INP_HIGHPORT)
1208 optval = IP_PORTRANGE_HIGH;
1209 else if (inp->inp_flags & INP_LOWPORT)
1210 optval = IP_PORTRANGE_LOW;
1216 optval = OPTBIT(INP_FAITH);
1220 optval = OPTBIT(INP_ONESBCAST);
1223 optval = OPTBIT(INP_DONTFRAG);
1226 optval = OPTBIT(INP_BINDANY);
1229 optval = OPTBIT(INP_RECVTOS);
1232 error = sooptcopyout(sopt, &optval, sizeof optval);
1236 * Multicast socket options are processed by the in_mcast
1239 case IP_MULTICAST_IF:
1240 case IP_MULTICAST_VIF:
1241 case IP_MULTICAST_TTL:
1242 case IP_MULTICAST_LOOP:
1244 error = inp_getmoptions(inp, sopt);
1248 case IP_IPSEC_POLICY:
1250 struct mbuf *m = NULL;
1255 req = mtod(m, caddr_t);
1258 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1260 error = soopt_mcopyout(sopt, m); /* XXX */
1268 error = ENOPROTOOPT;
1277 * Routine called from ip_output() to loop back a copy of an IP multicast
1278 * packet to the input queue of a specified interface. Note that this
1279 * calls the output routine of the loopback "driver", but with an interface
1280 * pointer that might NOT be a loopback interface -- evil, but easier than
1281 * replicating that code here.
1284 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1287 register struct ip *ip;
1291 * Make a deep copy of the packet because we're going to
1292 * modify the pack in order to generate checksums.
1294 copym = m_dup(m, M_DONTWAIT);
1295 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1296 copym = m_pullup(copym, hlen);
1297 if (copym != NULL) {
1298 /* If needed, compute the checksum and mark it as valid. */
1299 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1300 in_delayed_cksum(copym);
1301 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1302 copym->m_pkthdr.csum_flags |=
1303 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1304 copym->m_pkthdr.csum_data = 0xffff;
1307 * We don't bother to fragment if the IP length is greater
1308 * than the interface's MTU. Can this possibly matter?
1310 ip = mtod(copym, struct ip *);
1311 ip->ip_len = htons(ip->ip_len);
1312 ip->ip_off = htons(ip->ip_off);
1314 ip->ip_sum = in_cksum(copym, hlen);
1316 if (dst->sin_family != AF_INET) {
1317 printf("ip_mloopback: bad address family %d\n",
1319 dst->sin_family = AF_INET;
1322 if_simloop(ifp, copym, dst->sin_family, 0);