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
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)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 #include "opt_ipsec.h"
37 #include "opt_kdtrace.h"
38 #include "opt_mbuf_stress_test.h"
39 #include "opt_mpath.h"
40 #include "opt_route.h"
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/malloc.h>
50 #include <sys/protosw.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/ucred.h>
58 #include <net/if_llatbl.h>
59 #include <net/netisr.h>
61 #include <net/route.h>
62 #include <net/flowtable.h>
64 #include <net/radix_mpath.h>
68 #include <netinet/in.h>
69 #include <netinet/in_kdtrace.h>
70 #include <netinet/in_systm.h>
71 #include <netinet/ip.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/in_var.h>
74 #include <netinet/ip_var.h>
75 #include <netinet/ip_options.h>
77 #include <netinet/sctp.h>
78 #include <netinet/sctp_crc32.h>
82 #include <netinet/ip_ipsec.h>
83 #include <netipsec/ipsec.h>
86 #include <machine/in_cksum.h>
88 #include <security/mac/mac_framework.h>
90 VNET_DEFINE(u_short, ip_id);
92 #ifdef MBUF_STRESS_TEST
93 static int mbuf_frag_size = 0;
94 SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
95 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
98 static void ip_mloopback
99 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
102 extern int in_mcast_loop;
103 extern struct protosw inetsw[];
106 * IP output. The packet in mbuf chain m contains a skeletal IP
107 * header (with len, off, ttl, proto, tos, src, dst).
108 * The mbuf chain containing the packet will be freed.
109 * The mbuf opt, if present, will not be freed.
110 * If route ro is present and has ro_rt initialized, route lookup would be
111 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
112 * then result of route lookup is stored in ro->ro_rt.
114 * In the IP forwarding case, the packet will arrive with options already
115 * inserted, so must have a NULL opt pointer.
118 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
119 struct ip_moptions *imo, struct inpcb *inp)
122 struct ifnet *ifp = NULL; /* keep compiler happy */
124 int hlen = sizeof (struct ip);
126 int n; /* scratchpad */
128 struct sockaddr_in *dst;
129 const struct sockaddr_in *gw;
130 struct in_ifaddr *ia;
132 uint16_t ip_len, ip_off;
133 struct route iproute;
134 struct rtentry *rte; /* cache for ro->ro_rt */
136 struct m_tag *fwd_tag = NULL;
138 int no_route_but_check_spd = 0;
143 INP_LOCK_ASSERT(inp);
144 M_SETFIB(m, inp->inp_inc.inc_fibnum);
145 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
146 m->m_pkthdr.flowid = inp->inp_flowid;
147 m->m_flags |= M_FLOWID;
153 bzero(ro, sizeof (*ro));
157 if (ro->ro_rt == NULL) {
161 * The flow table returns route entries valid for up to 30
162 * seconds; we rely on the remainder of ip_output() taking no
163 * longer than that long for the stability of ro_rt. The
164 * flow ID assignment must have happened before this point.
166 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
168 flow_to_route(fle, ro);
174 m = ip_insertoptions(m, opt, &len);
176 hlen = len; /* ip->ip_hl is updated above */
178 ip = mtod(m, struct ip *);
179 ip_len = ntohs(ip->ip_len);
180 ip_off = ntohs(ip->ip_off);
183 * Fill in IP header. If we are not allowing fragmentation,
184 * then the ip_id field is meaningless, but we don't set it
185 * to zero. Doing so causes various problems when devices along
186 * the path (routers, load balancers, firewalls, etc.) illegally
187 * disable DF on our packet. Note that a 16-bit counter
188 * will wrap around in less than 10 seconds at 100 Mbit/s on a
189 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
190 * for Counting NATted Hosts", Proc. IMW'02, available at
191 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
193 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
194 ip->ip_v = IPVERSION;
195 ip->ip_hl = hlen >> 2;
196 ip->ip_id = ip_newid();
197 IPSTAT_INC(ips_localout);
199 /* Header already set, fetch hlen from there */
200 hlen = ip->ip_hl << 2;
203 gw = dst = (struct sockaddr_in *)&ro->ro_dst;
207 * If there is a cached route,
208 * check that it is to the same destination
209 * and is still up. If not, free it and try again.
210 * The address family should also be checked in case of sharing the
214 if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
215 rte->rt_ifp == NULL ||
216 !RT_LINK_IS_UP(rte->rt_ifp) ||
217 dst->sin_family != AF_INET ||
218 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
223 if (rte == NULL && fwd_tag == NULL) {
224 bzero(dst, sizeof(*dst));
225 dst->sin_family = AF_INET;
226 dst->sin_len = sizeof(*dst);
227 dst->sin_addr = ip->ip_dst;
230 * If routing to interface only, short circuit routing lookup.
231 * The use of an all-ones broadcast address implies this; an
232 * interface is specified by the broadcast address of an interface,
233 * or the destination address of a ptp interface.
235 if (flags & IP_SENDONES) {
236 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
237 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
238 IPSTAT_INC(ips_noroute);
242 ip->ip_dst.s_addr = INADDR_BROADCAST;
243 dst->sin_addr = ip->ip_dst;
247 } else if (flags & IP_ROUTETOIF) {
248 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
249 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
250 IPSTAT_INC(ips_noroute);
256 isbroadcast = in_broadcast(dst->sin_addr, ifp);
257 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
258 imo != NULL && imo->imo_multicast_ifp != NULL) {
260 * Bypass the normal routing lookup for multicast
261 * packets if the interface is specified.
263 ifp = imo->imo_multicast_ifp;
265 isbroadcast = 0; /* fool gcc */
268 * We want to do any cloning requested by the link layer,
269 * as this is probably required in all cases for correct
270 * operation (as it is for ARP).
274 rtalloc_mpath_fib(ro,
275 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
276 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
278 in_rtalloc_ign(ro, 0,
279 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
284 rte->rt_ifp == NULL ||
285 !RT_LINK_IS_UP(rte->rt_ifp)) {
288 * There is no route for this packet, but it is
289 * possible that a matching SPD entry exists.
291 no_route_but_check_spd = 1;
292 mtu = 0; /* Silence GCC warning. */
295 IPSTAT_INC(ips_noroute);
296 error = EHOSTUNREACH;
299 ia = ifatoia(rte->rt_ifa);
300 ifa_ref(&ia->ia_ifa);
302 rte->rt_rmx.rmx_pksent++;
303 if (rte->rt_flags & RTF_GATEWAY)
304 gw = (struct sockaddr_in *)rte->rt_gateway;
305 if (rte->rt_flags & RTF_HOST)
306 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
308 isbroadcast = in_broadcast(gw->sin_addr, ifp);
311 * Calculate MTU. If we have a route that is up, use that,
312 * otherwise use the interface's MTU.
314 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
316 * This case can happen if the user changed the MTU
317 * of an interface after enabling IP on it. Because
318 * most netifs don't keep track of routes pointing to
319 * them, there is no way for one to update all its
320 * routes when the MTU is changed.
322 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
323 rte->rt_rmx.rmx_mtu = ifp->if_mtu;
324 mtu = rte->rt_rmx.rmx_mtu;
328 /* Catch a possible divide by zero later. */
329 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
330 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
331 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
332 m->m_flags |= M_MCAST;
334 * See if the caller provided any multicast options
337 ip->ip_ttl = imo->imo_multicast_ttl;
338 if (imo->imo_multicast_vif != -1)
341 ip_mcast_src(imo->imo_multicast_vif) :
344 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
346 * Confirm that the outgoing interface supports multicast.
348 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
349 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
350 IPSTAT_INC(ips_noroute);
356 * If source address not specified yet, use address
357 * of outgoing interface.
359 if (ip->ip_src.s_addr == INADDR_ANY) {
360 /* Interface may have no addresses. */
362 ip->ip_src = IA_SIN(ia)->sin_addr;
365 if ((imo == NULL && in_mcast_loop) ||
366 (imo && imo->imo_multicast_loop)) {
368 * Loop back multicast datagram if not expressly
369 * forbidden to do so, even if we are not a member
370 * of the group; ip_input() will filter it later,
371 * thus deferring a hash lookup and mutex acquisition
372 * at the expense of a cheap copy using m_copym().
374 ip_mloopback(ifp, m, dst, hlen);
377 * If we are acting as a multicast router, perform
378 * multicast forwarding as if the packet had just
379 * arrived on the interface to which we are about
380 * to send. The multicast forwarding function
381 * recursively calls this function, using the
382 * IP_FORWARDING flag to prevent infinite recursion.
384 * Multicasts that are looped back by ip_mloopback(),
385 * above, will be forwarded by the ip_input() routine,
388 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
390 * If rsvp daemon is not running, do not
391 * set ip_moptions. This ensures that the packet
392 * is multicast and not just sent down one link
393 * as prescribed by rsvpd.
398 ip_mforward(ip, ifp, m, imo) != 0) {
406 * Multicasts with a time-to-live of zero may be looped-
407 * back, above, but must not be transmitted on a network.
408 * Also, multicasts addressed to the loopback interface
409 * are not sent -- the above call to ip_mloopback() will
410 * loop back a copy. ip_input() will drop the copy if
411 * this host does not belong to the destination group on
412 * the loopback interface.
414 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
423 * If the source address is not specified yet, use the address
424 * of the outoing interface.
426 if (ip->ip_src.s_addr == INADDR_ANY) {
427 /* Interface may have no addresses. */
429 ip->ip_src = IA_SIN(ia)->sin_addr;
434 * Verify that we have any chance at all of being able to queue the
435 * packet or packet fragments, unless ALTQ is enabled on the given
436 * interface in which case packetdrop should be done by queueing.
438 n = ip_len / mtu + 1; /* how many fragments ? */
441 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
443 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
445 IPSTAT_INC(ips_odropped);
446 ifp->if_snd.ifq_drops += n;
451 * Look for broadcast address and
452 * verify user is allowed to send
456 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
457 error = EADDRNOTAVAIL;
460 if ((flags & IP_ALLOWBROADCAST) == 0) {
464 /* don't allow broadcast messages to be fragmented */
469 m->m_flags |= M_BCAST;
471 m->m_flags &= ~M_BCAST;
476 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
483 break; /* Continue with packet processing. */
486 * Check if there was a route for this packet; return error if not.
488 if (no_route_but_check_spd) {
489 IPSTAT_INC(ips_noroute);
490 error = EHOSTUNREACH;
493 /* Update variables that are affected by ipsec4_output(). */
494 ip = mtod(m, struct ip *);
495 hlen = ip->ip_hl << 2;
498 /* Jump over all PFIL processing if hooks are not active. */
499 if (!PFIL_HOOKED(&V_inet_pfil_hook))
502 /* Run through list of hooks for output packets. */
503 odst.s_addr = ip->ip_dst.s_addr;
504 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
505 if (error != 0 || m == NULL)
508 ip = mtod(m, struct ip *);
510 /* See if destination IP address was changed by packet filter. */
511 if (odst.s_addr != ip->ip_dst.s_addr) {
512 m->m_flags |= M_SKIP_FIREWALL;
513 /* If destination is now ourself drop to ip_input(). */
514 if (in_localip(ip->ip_dst)) {
515 m->m_flags |= M_FASTFWD_OURS;
516 if (m->m_pkthdr.rcvif == NULL)
517 m->m_pkthdr.rcvif = V_loif;
518 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
519 m->m_pkthdr.csum_flags |=
520 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
521 m->m_pkthdr.csum_data = 0xffff;
523 m->m_pkthdr.csum_flags |=
524 CSUM_IP_CHECKED | CSUM_IP_VALID;
526 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
527 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
529 error = netisr_queue(NETISR_IP, m);
533 ifa_free(&ia->ia_ifa);
534 goto again; /* Redo the routing table lookup. */
538 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
539 if (m->m_flags & M_FASTFWD_OURS) {
540 if (m->m_pkthdr.rcvif == NULL)
541 m->m_pkthdr.rcvif = V_loif;
542 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
543 m->m_pkthdr.csum_flags |=
544 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
545 m->m_pkthdr.csum_data = 0xffff;
548 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
549 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
551 m->m_pkthdr.csum_flags |=
552 CSUM_IP_CHECKED | CSUM_IP_VALID;
554 error = netisr_queue(NETISR_IP, m);
557 /* Or forward to some other address? */
558 if ((m->m_flags & M_IP_NEXTHOP) &&
559 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
560 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
561 m->m_flags |= M_SKIP_FIREWALL;
562 m->m_flags &= ~M_IP_NEXTHOP;
563 m_tag_delete(m, fwd_tag);
565 ifa_free(&ia->ia_ifa);
570 /* 127/8 must not appear on wire - RFC1122. */
571 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
572 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
573 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
574 IPSTAT_INC(ips_badaddr);
575 error = EADDRNOTAVAIL;
580 m->m_pkthdr.csum_flags |= CSUM_IP;
581 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
583 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
586 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
587 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
588 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
593 * If small enough for interface, or the interface will take
594 * care of the fragmentation for us, we can just send directly.
597 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
598 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
600 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
601 ip->ip_sum = in_cksum(m, hlen);
602 m->m_pkthdr.csum_flags &= ~CSUM_IP;
606 * Record statistics for this interface address.
607 * With CSUM_TSO the byte/packet count will be slightly
608 * incorrect because we count the IP+TCP headers only
609 * once instead of for every generated packet.
611 if (!(flags & IP_FORWARDING) && ia) {
612 if (m->m_pkthdr.csum_flags & CSUM_TSO)
613 ia->ia_ifa.if_opackets +=
614 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
616 ia->ia_ifa.if_opackets++;
617 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
619 #ifdef MBUF_STRESS_TEST
620 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
621 m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
624 * Reset layer specific mbuf flags
625 * to avoid confusing lower layers.
628 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
629 error = (*ifp->if_output)(ifp, m,
630 (const struct sockaddr *)gw, ro);
634 /* Balk when DF bit is set or the interface didn't support TSO. */
635 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
637 IPSTAT_INC(ips_cantfrag);
642 * Too large for interface; fragment if possible. If successful,
643 * on return, m will point to a list of packets to be sent.
645 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
652 /* Record statistics for this interface address. */
654 ia->ia_ifa.if_opackets++;
655 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
658 * Reset layer specific mbuf flags
659 * to avoid confusing upper layers.
663 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
664 error = (*ifp->if_output)(ifp, m,
665 (const struct sockaddr *)gw, ro);
671 IPSTAT_INC(ips_fragmented);
677 ifa_free(&ia->ia_ifa);
685 * Create a chain of fragments which fit the given mtu. m_frag points to the
686 * mbuf to be fragmented; on return it points to the chain with the fragments.
687 * Return 0 if no error. If error, m_frag may contain a partially built
688 * chain of fragments that should be freed by the caller.
690 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
693 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
694 u_long if_hwassist_flags)
697 int hlen = ip->ip_hl << 2;
698 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
700 struct mbuf *m0 = *m_frag; /* the original packet */
704 uint16_t ip_len, ip_off;
706 ip_len = ntohs(ip->ip_len);
707 ip_off = ntohs(ip->ip_off);
709 if (ip_off & IP_DF) { /* Fragmentation not allowed */
710 IPSTAT_INC(ips_cantfrag);
715 * Must be able to put at least 8 bytes per fragment.
721 * If the interface will not calculate checksums on
722 * fragmented packets, then do it here.
724 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
725 in_delayed_cksum(m0);
726 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
729 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
730 sctp_delayed_cksum(m0, hlen);
731 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
734 if (len > PAGE_SIZE) {
736 * Fragment large datagrams such that each segment
737 * contains a multiple of PAGE_SIZE amount of data,
738 * plus headers. This enables a receiver to perform
739 * page-flipping zero-copy optimizations.
741 * XXX When does this help given that sender and receiver
742 * could have different page sizes, and also mtu could
743 * be less than the receiver's page size ?
748 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
752 * firstlen (off - hlen) must be aligned on an
756 goto smart_frag_failure;
757 off = ((off - hlen) & ~7) + hlen;
758 newlen = (~PAGE_MASK) & mtu;
759 if ((newlen + sizeof (struct ip)) > mtu) {
760 /* we failed, go back the default */
771 firstlen = off - hlen;
772 mnext = &m0->m_nextpkt; /* pointer to next packet */
775 * Loop through length of segment after first fragment,
776 * make new header and copy data of each part and link onto chain.
777 * Here, m0 is the original packet, m is the fragment being created.
778 * The fragments are linked off the m_nextpkt of the original
779 * packet, which after processing serves as the first fragment.
781 for (nfrags = 1; off < ip_len; off += len, nfrags++) {
782 struct ip *mhip; /* ip header on the fragment */
784 int mhlen = sizeof (struct ip);
786 m = m_gethdr(M_NOWAIT, MT_DATA);
789 IPSTAT_INC(ips_odropped);
792 m->m_flags |= (m0->m_flags & M_MCAST);
794 * In the first mbuf, leave room for the link header, then
795 * copy the original IP header including options. The payload
796 * goes into an additional mbuf chain returned by m_copym().
798 m->m_data += max_linkhdr;
799 mhip = mtod(m, struct ip *);
801 if (hlen > sizeof (struct ip)) {
802 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
803 mhip->ip_v = IPVERSION;
804 mhip->ip_hl = mhlen >> 2;
807 /* XXX do we need to add ip_off below ? */
808 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
809 if (off + len >= ip_len)
812 mhip->ip_off |= IP_MF;
813 mhip->ip_len = htons((u_short)(len + mhlen));
814 m->m_next = m_copym(m0, off, len, M_NOWAIT);
815 if (m->m_next == NULL) { /* copy failed */
817 error = ENOBUFS; /* ??? */
818 IPSTAT_INC(ips_odropped);
821 m->m_pkthdr.len = mhlen + len;
822 m->m_pkthdr.rcvif = NULL;
824 mac_netinet_fragment(m0, m);
826 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
827 mhip->ip_off = htons(mhip->ip_off);
829 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
830 mhip->ip_sum = in_cksum(m, mhlen);
831 m->m_pkthdr.csum_flags &= ~CSUM_IP;
834 mnext = &m->m_nextpkt;
836 IPSTAT_ADD(ips_ofragments, nfrags);
839 * Update first fragment by trimming what's been copied out
840 * and updating header.
842 m_adj(m0, hlen + firstlen - ip_len);
843 m0->m_pkthdr.len = hlen + firstlen;
844 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
845 ip->ip_off = htons(ip_off | IP_MF);
847 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
848 ip->ip_sum = in_cksum(m0, hlen);
849 m0->m_pkthdr.csum_flags &= ~CSUM_IP;
858 in_delayed_cksum(struct mbuf *m)
861 uint16_t csum, offset, ip_len;
863 ip = mtod(m, struct ip *);
864 offset = ip->ip_hl << 2 ;
865 ip_len = ntohs(ip->ip_len);
866 csum = in_cksum_skip(m, ip_len, offset);
867 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
869 offset += m->m_pkthdr.csum_data; /* checksum offset */
871 if (offset + sizeof(u_short) > m->m_len) {
872 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
873 m->m_len, offset, ip->ip_p);
876 * this shouldn't happen, but if it does, the
877 * correct behavior may be to insert the checksum
878 * in the appropriate next mbuf in the chain.
882 *(u_short *)(m->m_data + offset) = csum;
886 * IP socket option processing.
889 ip_ctloutput(struct socket *so, struct sockopt *sopt)
891 struct inpcb *inp = sotoinpcb(so);
895 if (sopt->sopt_level != IPPROTO_IP) {
898 if (sopt->sopt_level == SOL_SOCKET &&
899 sopt->sopt_dir == SOPT_SET) {
900 switch (sopt->sopt_name) {
903 if ((so->so_options & SO_REUSEADDR) != 0)
904 inp->inp_flags2 |= INP_REUSEADDR;
906 inp->inp_flags2 &= ~INP_REUSEADDR;
912 if ((so->so_options & SO_REUSEPORT) != 0)
913 inp->inp_flags2 |= INP_REUSEPORT;
915 inp->inp_flags2 &= ~INP_REUSEPORT;
921 inp->inp_inc.inc_fibnum = so->so_fibnum;
932 switch (sopt->sopt_dir) {
934 switch (sopt->sopt_name) {
941 if (sopt->sopt_valsize > MLEN) {
945 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
950 m->m_len = sopt->sopt_valsize;
951 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
958 error = ip_pcbopts(inp, sopt->sopt_name, m);
964 if (sopt->sopt_td != NULL) {
965 error = priv_check(sopt->sopt_td,
966 PRIV_NETINET_BINDANY);
983 error = sooptcopyin(sopt, &optval, sizeof optval,
988 switch (sopt->sopt_name) {
990 inp->inp_ip_tos = optval;
994 inp->inp_ip_ttl = optval;
998 if (optval >= 0 && optval <= MAXTTL)
999 inp->inp_ip_minttl = optval;
1004 #define OPTSET(bit) do { \
1007 inp->inp_flags |= bit; \
1009 inp->inp_flags &= ~bit; \
1014 OPTSET(INP_RECVOPTS);
1017 case IP_RECVRETOPTS:
1018 OPTSET(INP_RECVRETOPTS);
1021 case IP_RECVDSTADDR:
1022 OPTSET(INP_RECVDSTADDR);
1026 OPTSET(INP_RECVTTL);
1038 OPTSET(INP_ONESBCAST);
1041 OPTSET(INP_DONTFRAG);
1044 OPTSET(INP_BINDANY);
1047 OPTSET(INP_RECVTOS);
1054 * Multicast socket options are processed by the in_mcast
1057 case IP_MULTICAST_IF:
1058 case IP_MULTICAST_VIF:
1059 case IP_MULTICAST_TTL:
1060 case IP_MULTICAST_LOOP:
1061 case IP_ADD_MEMBERSHIP:
1062 case IP_DROP_MEMBERSHIP:
1063 case IP_ADD_SOURCE_MEMBERSHIP:
1064 case IP_DROP_SOURCE_MEMBERSHIP:
1065 case IP_BLOCK_SOURCE:
1066 case IP_UNBLOCK_SOURCE:
1068 case MCAST_JOIN_GROUP:
1069 case MCAST_LEAVE_GROUP:
1070 case MCAST_JOIN_SOURCE_GROUP:
1071 case MCAST_LEAVE_SOURCE_GROUP:
1072 case MCAST_BLOCK_SOURCE:
1073 case MCAST_UNBLOCK_SOURCE:
1074 error = inp_setmoptions(inp, sopt);
1078 error = sooptcopyin(sopt, &optval, sizeof optval,
1085 case IP_PORTRANGE_DEFAULT:
1086 inp->inp_flags &= ~(INP_LOWPORT);
1087 inp->inp_flags &= ~(INP_HIGHPORT);
1090 case IP_PORTRANGE_HIGH:
1091 inp->inp_flags &= ~(INP_LOWPORT);
1092 inp->inp_flags |= INP_HIGHPORT;
1095 case IP_PORTRANGE_LOW:
1096 inp->inp_flags &= ~(INP_HIGHPORT);
1097 inp->inp_flags |= INP_LOWPORT;
1108 case IP_IPSEC_POLICY:
1113 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1115 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1117 req = mtod(m, caddr_t);
1118 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1119 m->m_len, (sopt->sopt_td != NULL) ?
1120 sopt->sopt_td->td_ucred : NULL);
1127 error = ENOPROTOOPT;
1133 switch (sopt->sopt_name) {
1136 if (inp->inp_options)
1137 error = sooptcopyout(sopt,
1138 mtod(inp->inp_options,
1140 inp->inp_options->m_len);
1142 sopt->sopt_valsize = 0;
1149 case IP_RECVRETOPTS:
1150 case IP_RECVDSTADDR:
1159 switch (sopt->sopt_name) {
1162 optval = inp->inp_ip_tos;
1166 optval = inp->inp_ip_ttl;
1170 optval = inp->inp_ip_minttl;
1173 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1176 optval = OPTBIT(INP_RECVOPTS);
1179 case IP_RECVRETOPTS:
1180 optval = OPTBIT(INP_RECVRETOPTS);
1183 case IP_RECVDSTADDR:
1184 optval = OPTBIT(INP_RECVDSTADDR);
1188 optval = OPTBIT(INP_RECVTTL);
1192 optval = OPTBIT(INP_RECVIF);
1196 if (inp->inp_flags & INP_HIGHPORT)
1197 optval = IP_PORTRANGE_HIGH;
1198 else if (inp->inp_flags & INP_LOWPORT)
1199 optval = IP_PORTRANGE_LOW;
1205 optval = OPTBIT(INP_FAITH);
1209 optval = OPTBIT(INP_ONESBCAST);
1212 optval = OPTBIT(INP_DONTFRAG);
1215 optval = OPTBIT(INP_BINDANY);
1218 optval = OPTBIT(INP_RECVTOS);
1221 error = sooptcopyout(sopt, &optval, sizeof optval);
1225 * Multicast socket options are processed by the in_mcast
1228 case IP_MULTICAST_IF:
1229 case IP_MULTICAST_VIF:
1230 case IP_MULTICAST_TTL:
1231 case IP_MULTICAST_LOOP:
1233 error = inp_getmoptions(inp, sopt);
1237 case IP_IPSEC_POLICY:
1239 struct mbuf *m = NULL;
1244 req = mtod(m, caddr_t);
1247 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1249 error = soopt_mcopyout(sopt, m); /* XXX */
1257 error = ENOPROTOOPT;
1266 * Routine called from ip_output() to loop back a copy of an IP multicast
1267 * packet to the input queue of a specified interface. Note that this
1268 * calls the output routine of the loopback "driver", but with an interface
1269 * pointer that might NOT be a loopback interface -- evil, but easier than
1270 * replicating that code here.
1273 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1276 register struct ip *ip;
1280 * Make a deep copy of the packet because we're going to
1281 * modify the pack in order to generate checksums.
1283 copym = m_dup(m, M_NOWAIT);
1284 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1285 copym = m_pullup(copym, hlen);
1286 if (copym != NULL) {
1287 /* If needed, compute the checksum and mark it as valid. */
1288 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1289 in_delayed_cksum(copym);
1290 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1291 copym->m_pkthdr.csum_flags |=
1292 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1293 copym->m_pkthdr.csum_data = 0xffff;
1296 * We don't bother to fragment if the IP length is greater
1297 * than the interface's MTU. Can this possibly matter?
1299 ip = mtod(copym, struct ip *);
1301 ip->ip_sum = in_cksum(copym, hlen);
1303 if (dst->sin_family != AF_INET) {
1304 printf("ip_mloopback: bad address family %d\n",
1306 dst->sin_family = AF_INET;
1309 if_simloop(ifp, copym, dst->sin_family, 0);