1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
16 *
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
27 * SUCH DAMAGE.
28 *
29 * @(#)ip_output.c 8.3 (Berkeley) 1/21/94
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: stable/9/sys/netinet/ip_output.c 284497 2015-06-17 07:28:51Z hselasky $");
34
35 #include "opt_ipfw.h"
36 #include "opt_ipsec.h"
37 #include "opt_route.h"
38 #include "opt_mbuf_stress_test.h"
39 #include "opt_mpath.h"
40 #include "opt_sctp.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/priv.h>
48 #include <sys/proc.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>
54
55 #include <net/if.h>
56 #include <net/if_llatbl.h>
57 #include <net/netisr.h>
58 #include <net/pfil.h>
59 #include <net/route.h>
60 #include <net/flowtable.h>
61 #ifdef RADIX_MPATH
62 #include <net/radix_mpath.h>
63 #endif
64 #include <net/vnet.h>
65
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>
73 #ifdef SCTP
74 #include <netinet/sctp.h>
75 #include <netinet/sctp_crc32.h>
76 #endif
77
78 #ifdef IPSEC
79 #include <netinet/ip_ipsec.h>
80 #include <netipsec/ipsec.h>
81 #endif /* IPSEC*/
82
83 #include <machine/in_cksum.h>
84
85 #include <security/mac/mac_framework.h>
86
87 VNET_DEFINE(u_short, ip_id);
88
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");
93 #endif
94
95 static void ip_mloopback
96 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
97
98
99 extern int in_mcast_loop;
100 extern struct protosw inetsw[];
101
102 /*
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 * If route ro is present and has ro_rt initialized, route lookup would be
109 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
110 * then result of route lookup is stored in ro->ro_rt.
111 *
112 * In the IP forwarding case, the packet will arrive with options already
113 * inserted, so must have a NULL opt pointer.
114 */
115 int
ip_output(struct mbuf * m,struct mbuf * opt,struct route * ro,int flags,struct ip_moptions * imo,struct inpcb * inp)116 ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
117 struct ip_moptions *imo, struct inpcb *inp)
118 {
119 struct ip *ip;
120 struct ifnet *ifp = NULL; /* keep compiler happy */
121 struct mbuf *m0;
122 int hlen = sizeof (struct ip);
123 int mtu;
124 int n; /* scratchpad */
125 int error = 0;
126 struct sockaddr_in *dst;
127 struct in_ifaddr *ia;
128 int isbroadcast, sw_csum;
129 struct route iproute;
130 struct rtentry *rte; /* cache for ro->ro_rt */
131 struct in_addr odst;
132 struct m_tag *fwd_tag = NULL;
133 #ifdef IPSEC
134 int no_route_but_check_spd = 0;
135 #endif
136 M_ASSERTPKTHDR(m);
137
138 if (inp != NULL) {
139 INP_LOCK_ASSERT(inp);
140 M_SETFIB(m, inp->inp_inc.inc_fibnum);
141 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
142 m->m_pkthdr.flowid = inp->inp_flowid;
143 m->m_flags |= M_FLOWID;
144 }
145 }
146
147 if (ro == NULL) {
148 ro = &iproute;
149 bzero(ro, sizeof (*ro));
150 }
151
152 #ifdef FLOWTABLE
153 if (ro->ro_rt == NULL) {
154 struct flentry *fle;
155
156 /*
157 * The flow table returns route entries valid for up to 30
158 * seconds; we rely on the remainder of ip_output() taking no
159 * longer than that long for the stability of ro_rt. The
160 * flow ID assignment must have happened before this point.
161 */
162 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
163 if (fle != NULL)
164 flow_to_route(fle, ro);
165 }
166 #endif
167
168 if (opt) {
169 int len = 0;
170 m = ip_insertoptions(m, opt, &len);
171 if (len != 0)
172 hlen = len; /* ip->ip_hl is updated above */
173 }
174 ip = mtod(m, struct ip *);
175
176 /*
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>.
186 */
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);
192 } else {
193 /* Header already set, fetch hlen from there */
194 hlen = ip->ip_hl << 2;
195 }
196
197 again:
198 dst = (struct sockaddr_in *)&ro->ro_dst;
199 ia = NULL;
200 /*
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
205 * cache with IPv6.
206 */
207 rte = ro->ro_rt;
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)) {
213 RO_RTFREE(ro);
214 ro->ro_lle = NULL;
215 rte = NULL;
216 }
217 if (rte == NULL && fwd_tag == NULL) {
218 bzero(dst, sizeof(*dst));
219 dst->sin_family = AF_INET;
220 dst->sin_len = sizeof(*dst);
221 dst->sin_addr = ip->ip_dst;
222 }
223 /*
224 * If routing to interface only, short circuit routing lookup.
225 * The use of an all-ones broadcast address implies this; an
226 * interface is specified by the broadcast address of an interface,
227 * or the destination address of a ptp interface.
228 */
229 if (flags & IP_SENDONES) {
230 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
231 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
232 IPSTAT_INC(ips_noroute);
233 error = ENETUNREACH;
234 goto bad;
235 }
236 ip->ip_dst.s_addr = INADDR_BROADCAST;
237 dst->sin_addr = ip->ip_dst;
238 ifp = ia->ia_ifp;
239 ip->ip_ttl = 1;
240 isbroadcast = 1;
241 } else if (flags & IP_ROUTETOIF) {
242 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
243 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
244 IPSTAT_INC(ips_noroute);
245 error = ENETUNREACH;
246 goto bad;
247 }
248 ifp = ia->ia_ifp;
249 ip->ip_ttl = 1;
250 isbroadcast = in_broadcast(dst->sin_addr, ifp);
251 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
252 imo != NULL && imo->imo_multicast_ifp != NULL) {
253 /*
254 * Bypass the normal routing lookup for multicast
255 * packets if the interface is specified.
256 */
257 ifp = imo->imo_multicast_ifp;
258 IFP_TO_IA(ifp, ia);
259 isbroadcast = 0; /* fool gcc */
260 } else {
261 /*
262 * We want to do any cloning requested by the link layer,
263 * as this is probably required in all cases for correct
264 * operation (as it is for ARP).
265 */
266 if (rte == NULL) {
267 #ifdef RADIX_MPATH
268 rtalloc_mpath_fib(ro,
269 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
270 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
271 #else
272 in_rtalloc_ign(ro, 0,
273 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
274 #endif
275 rte = ro->ro_rt;
276 }
277 if (rte == NULL ||
278 rte->rt_ifp == NULL ||
279 !RT_LINK_IS_UP(rte->rt_ifp)) {
280 #ifdef IPSEC
281 /*
282 * There is no route for this packet, but it is
283 * possible that a matching SPD entry exists.
284 */
285 no_route_but_check_spd = 1;
286 mtu = 0; /* Silence GCC warning. */
287 goto sendit;
288 #endif
289 IPSTAT_INC(ips_noroute);
290 error = EHOSTUNREACH;
291 goto bad;
292 }
293 ia = ifatoia(rte->rt_ifa);
294 ifa_ref(&ia->ia_ifa);
295 ifp = rte->rt_ifp;
296 rte->rt_rmx.rmx_pksent++;
297 if (rte->rt_flags & RTF_GATEWAY)
298 dst = (struct sockaddr_in *)rte->rt_gateway;
299 if (rte->rt_flags & RTF_HOST)
300 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
301 else
302 isbroadcast = in_broadcast(dst->sin_addr, ifp);
303 }
304 /*
305 * Calculate MTU. If we have a route that is up, use that,
306 * otherwise use the interface's MTU.
307 */
308 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
309 /*
310 * This case can happen if the user changed the MTU
311 * of an interface after enabling IP on it. Because
312 * most netifs don't keep track of routes pointing to
313 * them, there is no way for one to update all its
314 * routes when the MTU is changed.
315 */
316 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
317 rte->rt_rmx.rmx_mtu = ifp->if_mtu;
318 mtu = rte->rt_rmx.rmx_mtu;
319 } else {
320 mtu = ifp->if_mtu;
321 }
322 /* Catch a possible divide by zero later. */
323 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
324 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
325 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
326 m->m_flags |= M_MCAST;
327 /*
328 * IP destination address is multicast. Make sure "dst"
329 * still points to the address in "ro". (It may have been
330 * changed to point to a gateway address, above.)
331 */
332 dst = (struct sockaddr_in *)&ro->ro_dst;
333 /*
334 * See if the caller provided any multicast options
335 */
336 if (imo != NULL) {
337 ip->ip_ttl = imo->imo_multicast_ttl;
338 if (imo->imo_multicast_vif != -1)
339 ip->ip_src.s_addr =
340 ip_mcast_src ?
341 ip_mcast_src(imo->imo_multicast_vif) :
342 INADDR_ANY;
343 } else
344 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
345 /*
346 * Confirm that the outgoing interface supports multicast.
347 */
348 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
349 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
350 IPSTAT_INC(ips_noroute);
351 error = ENETUNREACH;
352 goto bad;
353 }
354 }
355 /*
356 * If source address not specified yet, use address
357 * of outgoing interface.
358 */
359 if (ip->ip_src.s_addr == INADDR_ANY) {
360 /* Interface may have no addresses. */
361 if (ia != NULL)
362 ip->ip_src = IA_SIN(ia)->sin_addr;
363 }
364
365 if ((imo == NULL && in_mcast_loop) ||
366 (imo && imo->imo_multicast_loop)) {
367 /*
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().
373 */
374 ip_mloopback(ifp, m, dst, hlen);
375 } else {
376 /*
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.
383 *
384 * Multicasts that are looped back by ip_mloopback(),
385 * above, will be forwarded by the ip_input() routine,
386 * if necessary.
387 */
388 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
389 /*
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.
394 */
395 if (!V_rsvp_on)
396 imo = NULL;
397 if (ip_mforward &&
398 ip_mforward(ip, ifp, m, imo) != 0) {
399 m_freem(m);
400 goto done;
401 }
402 }
403 }
404
405 /*
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.
413 */
414 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
415 m_freem(m);
416 goto done;
417 }
418
419 goto sendit;
420 }
421
422 /*
423 * If the source address is not specified yet, use the address
424 * of the outoing interface.
425 */
426 if (ip->ip_src.s_addr == INADDR_ANY) {
427 /* Interface may have no addresses. */
428 if (ia != NULL) {
429 ip->ip_src = IA_SIN(ia)->sin_addr;
430 }
431 }
432
433 /*
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.
437 */
438 n = ip->ip_len / mtu + 1; /* how many fragments ? */
439 if (
440 #ifdef ALTQ
441 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
442 #endif /* ALTQ */
443 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
444 error = ENOBUFS;
445 IPSTAT_INC(ips_odropped);
446 ifp->if_snd.ifq_drops += n;
447 goto bad;
448 }
449
450 /*
451 * Look for broadcast address and
452 * verify user is allowed to send
453 * such a packet.
454 */
455 if (isbroadcast) {
456 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
457 error = EADDRNOTAVAIL;
458 goto bad;
459 }
460 if ((flags & IP_ALLOWBROADCAST) == 0) {
461 error = EACCES;
462 goto bad;
463 }
464 /* don't allow broadcast messages to be fragmented */
465 if (ip->ip_len > mtu) {
466 error = EMSGSIZE;
467 goto bad;
468 }
469 m->m_flags |= M_BCAST;
470 } else {
471 m->m_flags &= ~M_BCAST;
472 }
473
474 sendit:
475 #ifdef IPSEC
476 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
477 case 1:
478 goto bad;
479 case -1:
480 goto done;
481 case 0:
482 default:
483 break; /* Continue with packet processing. */
484 }
485 /*
486 * Check if there was a route for this packet; return error if not.
487 */
488 if (no_route_but_check_spd) {
489 IPSTAT_INC(ips_noroute);
490 error = EHOSTUNREACH;
491 goto bad;
492 }
493 /* Update variables that are affected by ipsec4_output(). */
494 ip = mtod(m, struct ip *);
495 hlen = ip->ip_hl << 2;
496 #endif /* IPSEC */
497
498 /* Jump over all PFIL processing if hooks are not active. */
499 if (!PFIL_HOOKED(&V_inet_pfil_hook))
500 goto passout;
501
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)
506 goto done;
507
508 ip = mtod(m, struct ip *);
509
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;
522 }
523 m->m_pkthdr.csum_flags |=
524 CSUM_IP_CHECKED | CSUM_IP_VALID;
525 #ifdef SCTP
526 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
527 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
528 #endif
529 error = netisr_queue(NETISR_IP, m);
530 goto done;
531 } else {
532 if (ia != NULL)
533 ifa_free(&ia->ia_ifa);
534 goto again; /* Redo the routing table lookup. */
535 }
536 }
537
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;
546 }
547 #ifdef SCTP
548 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
549 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
550 #endif
551 m->m_pkthdr.csum_flags |=
552 CSUM_IP_CHECKED | CSUM_IP_VALID;
553
554 error = netisr_queue(NETISR_IP, m);
555 goto done;
556 }
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 dst = (struct sockaddr_in *)&ro->ro_dst;
561 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
562 m->m_flags |= M_SKIP_FIREWALL;
563 m->m_flags &= ~M_IP_NEXTHOP;
564 m_tag_delete(m, fwd_tag);
565 if (ia != NULL)
566 ifa_free(&ia->ia_ifa);
567 goto again;
568 }
569
570 passout:
571 /* 127/8 must not appear on wire - RFC1122. */
572 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
573 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
574 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
575 IPSTAT_INC(ips_badaddr);
576 error = EADDRNOTAVAIL;
577 goto bad;
578 }
579 }
580
581 m->m_pkthdr.csum_flags |= CSUM_IP;
582 sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
583 if (sw_csum & CSUM_DELAY_DATA) {
584 in_delayed_cksum(m);
585 sw_csum &= ~CSUM_DELAY_DATA;
586 }
587 #ifdef SCTP
588 if (sw_csum & CSUM_SCTP) {
589 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
590 sw_csum &= ~CSUM_SCTP;
591 }
592 #endif
593 m->m_pkthdr.csum_flags &= ifp->if_hwassist;
594
595 /*
596 * If small enough for interface, or the interface will take
597 * care of the fragmentation for us, we can just send directly.
598 */
599 if (ip->ip_len <= mtu ||
600 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
601 ((ip->ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
602 ip->ip_len = htons(ip->ip_len);
603 ip->ip_off = htons(ip->ip_off);
604 ip->ip_sum = 0;
605 if (sw_csum & CSUM_DELAY_IP)
606 ip->ip_sum = in_cksum(m, hlen);
607
608 /*
609 * Record statistics for this interface address.
610 * With CSUM_TSO the byte/packet count will be slightly
611 * incorrect because we count the IP+TCP headers only
612 * once instead of for every generated packet.
613 */
614 if (!(flags & IP_FORWARDING) && ia) {
615 if (m->m_pkthdr.csum_flags & CSUM_TSO)
616 ia->ia_ifa.if_opackets +=
617 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
618 else
619 ia->ia_ifa.if_opackets++;
620 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
621 }
622 #ifdef MBUF_STRESS_TEST
623 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
624 m = m_fragment(m, M_DONTWAIT, mbuf_frag_size);
625 #endif
626 /*
627 * Reset layer specific mbuf flags
628 * to avoid confusing lower layers.
629 */
630 m->m_flags &= ~(M_PROTOFLAGS);
631 error = (*ifp->if_output)(ifp, m,
632 (struct sockaddr *)dst, ro);
633 goto done;
634 }
635
636 /* Balk when DF bit is set or the interface didn't support TSO. */
637 if ((ip->ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
638 error = EMSGSIZE;
639 IPSTAT_INC(ips_cantfrag);
640 goto bad;
641 }
642
643 /*
644 * Too large for interface; fragment if possible. If successful,
645 * on return, m will point to a list of packets to be sent.
646 */
647 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist, sw_csum);
648 if (error)
649 goto bad;
650 for (; m; m = m0) {
651 m0 = m->m_nextpkt;
652 m->m_nextpkt = 0;
653 if (error == 0) {
654 /* Record statistics for this interface address. */
655 if (ia != NULL) {
656 ia->ia_ifa.if_opackets++;
657 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
658 }
659 /*
660 * Reset layer specific mbuf flags
661 * to avoid confusing upper layers.
662 */
663 m->m_flags &= ~(M_PROTOFLAGS);
664
665 error = (*ifp->if_output)(ifp, m,
666 (struct sockaddr *)dst, ro);
667 } else
668 m_freem(m);
669 }
670
671 if (error == 0)
672 IPSTAT_INC(ips_fragmented);
673
674 done:
675 if (ro == &iproute)
676 RO_RTFREE(ro);
677 if (ia != NULL)
678 ifa_free(&ia->ia_ifa);
679 return (error);
680 bad:
681 m_freem(m);
682 goto done;
683 }
684
685 /*
686 * Create a chain of fragments which fit the given mtu. m_frag points to the
687 * mbuf to be fragmented; on return it points to the chain with the fragments.
688 * Return 0 if no error. If error, m_frag may contain a partially built
689 * chain of fragments that should be freed by the caller.
690 *
691 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
692 * sw_csum contains the delayed checksums flags (e.g., CSUM_DELAY_IP).
693 */
694 int
ip_fragment(struct ip * ip,struct mbuf ** m_frag,int mtu,u_long if_hwassist_flags,int sw_csum)695 ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
696 u_long if_hwassist_flags, int sw_csum)
697 {
698 int error = 0;
699 int hlen = ip->ip_hl << 2;
700 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
701 int off;
702 struct mbuf *m0 = *m_frag; /* the original packet */
703 int firstlen;
704 struct mbuf **mnext;
705 int nfrags;
706
707 if (ip->ip_off & IP_DF) { /* Fragmentation not allowed */
708 IPSTAT_INC(ips_cantfrag);
709 return EMSGSIZE;
710 }
711
712 /*
713 * Must be able to put at least 8 bytes per fragment.
714 */
715 if (len < 8)
716 return EMSGSIZE;
717
718 /*
719 * If the interface will not calculate checksums on
720 * fragmented packets, then do it here.
721 */
722 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
723 in_delayed_cksum(m0);
724 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
725 }
726 #ifdef SCTP
727 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
728 sctp_delayed_cksum(m0, hlen);
729 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
730 }
731 #endif
732 if (len > PAGE_SIZE) {
733 /*
734 * Fragment large datagrams such that each segment
735 * contains a multiple of PAGE_SIZE amount of data,
736 * plus headers. This enables a receiver to perform
737 * page-flipping zero-copy optimizations.
738 *
739 * XXX When does this help given that sender and receiver
740 * could have different page sizes, and also mtu could
741 * be less than the receiver's page size ?
742 */
743 int newlen;
744
745 off = MIN(mtu, m0->m_pkthdr.len);
746
747 /*
748 * firstlen (off - hlen) must be aligned on an
749 * 8-byte boundary
750 */
751 if (off < hlen)
752 goto smart_frag_failure;
753 off = ((off - hlen) & ~7) + hlen;
754 newlen = (~PAGE_MASK) & mtu;
755 if ((newlen + sizeof (struct ip)) > mtu) {
756 /* we failed, go back the default */
757 smart_frag_failure:
758 newlen = len;
759 off = hlen + len;
760 }
761 len = newlen;
762
763 } else {
764 off = hlen + len;
765 }
766
767 firstlen = off - hlen;
768 mnext = &m0->m_nextpkt; /* pointer to next packet */
769
770 /*
771 * Loop through length of segment after first fragment,
772 * make new header and copy data of each part and link onto chain.
773 * Here, m0 is the original packet, m is the fragment being created.
774 * The fragments are linked off the m_nextpkt of the original
775 * packet, which after processing serves as the first fragment.
776 */
777 for (nfrags = 1; off < ip->ip_len; off += len, nfrags++) {
778 struct ip *mhip; /* ip header on the fragment */
779 struct mbuf *m;
780 int mhlen = sizeof (struct ip);
781
782 MGETHDR(m, M_DONTWAIT, MT_DATA);
783 if (m == NULL) {
784 error = ENOBUFS;
785 IPSTAT_INC(ips_odropped);
786 goto done;
787 }
788 /*
789 * Make sure the complete packet header gets copied
790 * from the originating mbuf to the newly created
791 * mbuf. This also ensures that existing firewall
792 * classification(s), VLAN tags and so on get copied
793 * to the resulting fragmented packet(s):
794 */
795 if (m_dup_pkthdr(m, m0, M_NOWAIT) == 0) {
796 m_free(m);
797 error = ENOBUFS;
798 IPSTAT_INC(ips_odropped);
799 goto done;
800 }
801 m->m_flags |= M_FRAG;
802 /*
803 * In the first mbuf, leave room for the link header, then
804 * copy the original IP header including options. The payload
805 * goes into an additional mbuf chain returned by m_copym().
806 */
807 m->m_data += max_linkhdr;
808 mhip = mtod(m, struct ip *);
809 *mhip = *ip;
810 if (hlen > sizeof (struct ip)) {
811 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
812 mhip->ip_v = IPVERSION;
813 mhip->ip_hl = mhlen >> 2;
814 }
815 m->m_len = mhlen;
816 /* XXX do we need to add ip->ip_off below ? */
817 mhip->ip_off = ((off - hlen) >> 3) + ip->ip_off;
818 if (off + len >= ip->ip_len) { /* last fragment */
819 len = ip->ip_len - off;
820 m->m_flags |= M_LASTFRAG;
821 } else
822 mhip->ip_off |= IP_MF;
823 mhip->ip_len = htons((u_short)(len + mhlen));
824 m->m_next = m_copym(m0, off, len, M_DONTWAIT);
825 if (m->m_next == NULL) { /* copy failed */
826 m_free(m);
827 error = ENOBUFS; /* ??? */
828 IPSTAT_INC(ips_odropped);
829 goto done;
830 }
831 m->m_pkthdr.len = mhlen + len;
832 #ifdef MAC
833 mac_netinet_fragment(m0, m);
834 #endif
835 mhip->ip_off = htons(mhip->ip_off);
836 mhip->ip_sum = 0;
837 if (sw_csum & CSUM_DELAY_IP)
838 mhip->ip_sum = in_cksum(m, mhlen);
839 *mnext = m;
840 mnext = &m->m_nextpkt;
841 }
842 IPSTAT_ADD(ips_ofragments, nfrags);
843
844 /* set first marker for fragment chain */
845 m0->m_flags |= M_FIRSTFRAG | M_FRAG;
846 m0->m_pkthdr.csum_data = nfrags;
847
848 /*
849 * Update first fragment by trimming what's been copied out
850 * and updating header.
851 */
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);
855 ip->ip_off |= IP_MF;
856 ip->ip_off = htons(ip->ip_off);
857 ip->ip_sum = 0;
858 if (sw_csum & CSUM_DELAY_IP)
859 ip->ip_sum = in_cksum(m0, hlen);
860
861 done:
862 *m_frag = m0;
863 return error;
864 }
865
866 void
in_delayed_cksum(struct mbuf * m)867 in_delayed_cksum(struct mbuf *m)
868 {
869 struct ip *ip;
870 u_short csum, offset;
871
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)
876 csum = 0xffff;
877 offset += m->m_pkthdr.csum_data; /* checksum offset */
878
879 /* find the mbuf in the chain where the checksum starts*/
880 while ((m != NULL) && (offset >= m->m_len)) {
881 offset -= m->m_len;
882 m = m->m_next;
883 }
884 KASSERT(m != NULL, ("in_delayed_cksum: checksum outside mbuf chain."));
885 KASSERT(offset + sizeof(u_short) <= m->m_len, ("in_delayed_cksum: checksum split between mbufs."));
886 *(u_short *)(m->m_data + offset) = csum;
887 }
888
889 /*
890 * IP socket option processing.
891 */
892 int
ip_ctloutput(struct socket * so,struct sockopt * sopt)893 ip_ctloutput(struct socket *so, struct sockopt *sopt)
894 {
895 struct inpcb *inp = sotoinpcb(so);
896 int error, optval;
897
898 error = optval = 0;
899 if (sopt->sopt_level != IPPROTO_IP) {
900 error = EINVAL;
901
902 if (sopt->sopt_level == SOL_SOCKET &&
903 sopt->sopt_dir == SOPT_SET) {
904 switch (sopt->sopt_name) {
905 case SO_REUSEADDR:
906 INP_WLOCK(inp);
907 if ((so->so_options & SO_REUSEADDR) != 0)
908 inp->inp_flags2 |= INP_REUSEADDR;
909 else
910 inp->inp_flags2 &= ~INP_REUSEADDR;
911 INP_WUNLOCK(inp);
912 error = 0;
913 break;
914 case SO_REUSEPORT:
915 INP_WLOCK(inp);
916 if ((so->so_options & SO_REUSEPORT) != 0)
917 inp->inp_flags2 |= INP_REUSEPORT;
918 else
919 inp->inp_flags2 &= ~INP_REUSEPORT;
920 INP_WUNLOCK(inp);
921 error = 0;
922 break;
923 case SO_SETFIB:
924 INP_WLOCK(inp);
925 inp->inp_inc.inc_fibnum = so->so_fibnum;
926 INP_WUNLOCK(inp);
927 error = 0;
928 break;
929 default:
930 break;
931 }
932 }
933 return (error);
934 }
935
936 switch (sopt->sopt_dir) {
937 case SOPT_SET:
938 switch (sopt->sopt_name) {
939 case IP_OPTIONS:
940 #ifdef notyet
941 case IP_RETOPTS:
942 #endif
943 {
944 struct mbuf *m;
945 if (sopt->sopt_valsize > MLEN) {
946 error = EMSGSIZE;
947 break;
948 }
949 MGET(m, sopt->sopt_td ? M_WAIT : M_DONTWAIT, MT_DATA);
950 if (m == NULL) {
951 error = ENOBUFS;
952 break;
953 }
954 m->m_len = sopt->sopt_valsize;
955 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
956 m->m_len);
957 if (error) {
958 m_free(m);
959 break;
960 }
961 INP_WLOCK(inp);
962 error = ip_pcbopts(inp, sopt->sopt_name, m);
963 INP_WUNLOCK(inp);
964 return (error);
965 }
966
967 case IP_BINDANY:
968 if (sopt->sopt_td != NULL) {
969 error = priv_check(sopt->sopt_td,
970 PRIV_NETINET_BINDANY);
971 if (error)
972 break;
973 }
974 /* FALLTHROUGH */
975 case IP_TOS:
976 case IP_TTL:
977 case IP_MINTTL:
978 case IP_RECVOPTS:
979 case IP_RECVRETOPTS:
980 case IP_RECVDSTADDR:
981 case IP_RECVTTL:
982 case IP_RECVIF:
983 case IP_FAITH:
984 case IP_ONESBCAST:
985 case IP_DONTFRAG:
986 case IP_RECVTOS:
987 error = sooptcopyin(sopt, &optval, sizeof optval,
988 sizeof optval);
989 if (error)
990 break;
991
992 switch (sopt->sopt_name) {
993 case IP_TOS:
994 inp->inp_ip_tos = optval;
995 break;
996
997 case IP_TTL:
998 inp->inp_ip_ttl = optval;
999 break;
1000
1001 case IP_MINTTL:
1002 if (optval >= 0 && optval <= MAXTTL)
1003 inp->inp_ip_minttl = optval;
1004 else
1005 error = EINVAL;
1006 break;
1007
1008 #define OPTSET(bit) do { \
1009 INP_WLOCK(inp); \
1010 if (optval) \
1011 inp->inp_flags |= bit; \
1012 else \
1013 inp->inp_flags &= ~bit; \
1014 INP_WUNLOCK(inp); \
1015 } while (0)
1016
1017 case IP_RECVOPTS:
1018 OPTSET(INP_RECVOPTS);
1019 break;
1020
1021 case IP_RECVRETOPTS:
1022 OPTSET(INP_RECVRETOPTS);
1023 break;
1024
1025 case IP_RECVDSTADDR:
1026 OPTSET(INP_RECVDSTADDR);
1027 break;
1028
1029 case IP_RECVTTL:
1030 OPTSET(INP_RECVTTL);
1031 break;
1032
1033 case IP_RECVIF:
1034 OPTSET(INP_RECVIF);
1035 break;
1036
1037 case IP_FAITH:
1038 OPTSET(INP_FAITH);
1039 break;
1040
1041 case IP_ONESBCAST:
1042 OPTSET(INP_ONESBCAST);
1043 break;
1044 case IP_DONTFRAG:
1045 OPTSET(INP_DONTFRAG);
1046 break;
1047 case IP_BINDANY:
1048 OPTSET(INP_BINDANY);
1049 break;
1050 case IP_RECVTOS:
1051 OPTSET(INP_RECVTOS);
1052 break;
1053 }
1054 break;
1055 #undef OPTSET
1056
1057 /*
1058 * Multicast socket options are processed by the in_mcast
1059 * module.
1060 */
1061 case IP_MULTICAST_IF:
1062 case IP_MULTICAST_VIF:
1063 case IP_MULTICAST_TTL:
1064 case IP_MULTICAST_LOOP:
1065 case IP_ADD_MEMBERSHIP:
1066 case IP_DROP_MEMBERSHIP:
1067 case IP_ADD_SOURCE_MEMBERSHIP:
1068 case IP_DROP_SOURCE_MEMBERSHIP:
1069 case IP_BLOCK_SOURCE:
1070 case IP_UNBLOCK_SOURCE:
1071 case IP_MSFILTER:
1072 case MCAST_JOIN_GROUP:
1073 case MCAST_LEAVE_GROUP:
1074 case MCAST_JOIN_SOURCE_GROUP:
1075 case MCAST_LEAVE_SOURCE_GROUP:
1076 case MCAST_BLOCK_SOURCE:
1077 case MCAST_UNBLOCK_SOURCE:
1078 error = inp_setmoptions(inp, sopt);
1079 break;
1080
1081 case IP_PORTRANGE:
1082 error = sooptcopyin(sopt, &optval, sizeof optval,
1083 sizeof optval);
1084 if (error)
1085 break;
1086
1087 INP_WLOCK(inp);
1088 switch (optval) {
1089 case IP_PORTRANGE_DEFAULT:
1090 inp->inp_flags &= ~(INP_LOWPORT);
1091 inp->inp_flags &= ~(INP_HIGHPORT);
1092 break;
1093
1094 case IP_PORTRANGE_HIGH:
1095 inp->inp_flags &= ~(INP_LOWPORT);
1096 inp->inp_flags |= INP_HIGHPORT;
1097 break;
1098
1099 case IP_PORTRANGE_LOW:
1100 inp->inp_flags &= ~(INP_HIGHPORT);
1101 inp->inp_flags |= INP_LOWPORT;
1102 break;
1103
1104 default:
1105 error = EINVAL;
1106 break;
1107 }
1108 INP_WUNLOCK(inp);
1109 break;
1110
1111 #ifdef IPSEC
1112 case IP_IPSEC_POLICY:
1113 {
1114 caddr_t req;
1115 struct mbuf *m;
1116
1117 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1118 break;
1119 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1120 break;
1121 req = mtod(m, caddr_t);
1122 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1123 m->m_len, (sopt->sopt_td != NULL) ?
1124 sopt->sopt_td->td_ucred : NULL);
1125 m_freem(m);
1126 break;
1127 }
1128 #endif /* IPSEC */
1129
1130 default:
1131 error = ENOPROTOOPT;
1132 break;
1133 }
1134 break;
1135
1136 case SOPT_GET:
1137 switch (sopt->sopt_name) {
1138 case IP_OPTIONS:
1139 case IP_RETOPTS:
1140 if (inp->inp_options)
1141 error = sooptcopyout(sopt,
1142 mtod(inp->inp_options,
1143 char *),
1144 inp->inp_options->m_len);
1145 else
1146 sopt->sopt_valsize = 0;
1147 break;
1148
1149 case IP_TOS:
1150 case IP_TTL:
1151 case IP_MINTTL:
1152 case IP_RECVOPTS:
1153 case IP_RECVRETOPTS:
1154 case IP_RECVDSTADDR:
1155 case IP_RECVTTL:
1156 case IP_RECVIF:
1157 case IP_PORTRANGE:
1158 case IP_FAITH:
1159 case IP_ONESBCAST:
1160 case IP_DONTFRAG:
1161 case IP_BINDANY:
1162 case IP_RECVTOS:
1163 switch (sopt->sopt_name) {
1164
1165 case IP_TOS:
1166 optval = inp->inp_ip_tos;
1167 break;
1168
1169 case IP_TTL:
1170 optval = inp->inp_ip_ttl;
1171 break;
1172
1173 case IP_MINTTL:
1174 optval = inp->inp_ip_minttl;
1175 break;
1176
1177 #define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1178
1179 case IP_RECVOPTS:
1180 optval = OPTBIT(INP_RECVOPTS);
1181 break;
1182
1183 case IP_RECVRETOPTS:
1184 optval = OPTBIT(INP_RECVRETOPTS);
1185 break;
1186
1187 case IP_RECVDSTADDR:
1188 optval = OPTBIT(INP_RECVDSTADDR);
1189 break;
1190
1191 case IP_RECVTTL:
1192 optval = OPTBIT(INP_RECVTTL);
1193 break;
1194
1195 case IP_RECVIF:
1196 optval = OPTBIT(INP_RECVIF);
1197 break;
1198
1199 case IP_PORTRANGE:
1200 if (inp->inp_flags & INP_HIGHPORT)
1201 optval = IP_PORTRANGE_HIGH;
1202 else if (inp->inp_flags & INP_LOWPORT)
1203 optval = IP_PORTRANGE_LOW;
1204 else
1205 optval = 0;
1206 break;
1207
1208 case IP_FAITH:
1209 optval = OPTBIT(INP_FAITH);
1210 break;
1211
1212 case IP_ONESBCAST:
1213 optval = OPTBIT(INP_ONESBCAST);
1214 break;
1215 case IP_DONTFRAG:
1216 optval = OPTBIT(INP_DONTFRAG);
1217 break;
1218 case IP_BINDANY:
1219 optval = OPTBIT(INP_BINDANY);
1220 break;
1221 case IP_RECVTOS:
1222 optval = OPTBIT(INP_RECVTOS);
1223 break;
1224 }
1225 error = sooptcopyout(sopt, &optval, sizeof optval);
1226 break;
1227
1228 /*
1229 * Multicast socket options are processed by the in_mcast
1230 * module.
1231 */
1232 case IP_MULTICAST_IF:
1233 case IP_MULTICAST_VIF:
1234 case IP_MULTICAST_TTL:
1235 case IP_MULTICAST_LOOP:
1236 case IP_MSFILTER:
1237 error = inp_getmoptions(inp, sopt);
1238 break;
1239
1240 #ifdef IPSEC
1241 case IP_IPSEC_POLICY:
1242 {
1243 struct mbuf *m = NULL;
1244 caddr_t req = NULL;
1245 size_t len = 0;
1246
1247 if (m != 0) {
1248 req = mtod(m, caddr_t);
1249 len = m->m_len;
1250 }
1251 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1252 if (error == 0)
1253 error = soopt_mcopyout(sopt, m); /* XXX */
1254 if (error == 0)
1255 m_freem(m);
1256 break;
1257 }
1258 #endif /* IPSEC */
1259
1260 default:
1261 error = ENOPROTOOPT;
1262 break;
1263 }
1264 break;
1265 }
1266 return (error);
1267 }
1268
1269 /*
1270 * Routine called from ip_output() to loop back a copy of an IP multicast
1271 * packet to the input queue of a specified interface. Note that this
1272 * calls the output routine of the loopback "driver", but with an interface
1273 * pointer that might NOT be a loopback interface -- evil, but easier than
1274 * replicating that code here.
1275 */
1276 static void
ip_mloopback(struct ifnet * ifp,struct mbuf * m,struct sockaddr_in * dst,int hlen)1277 ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1278 int hlen)
1279 {
1280 register struct ip *ip;
1281 struct mbuf *copym;
1282
1283 /*
1284 * Make a deep copy of the packet because we're going to
1285 * modify the pack in order to generate checksums.
1286 */
1287 copym = m_dup(m, M_DONTWAIT);
1288 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1289 copym = m_pullup(copym, hlen);
1290 if (copym != NULL) {
1291 /* If needed, compute the checksum and mark it as valid. */
1292 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1293 in_delayed_cksum(copym);
1294 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1295 copym->m_pkthdr.csum_flags |=
1296 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1297 copym->m_pkthdr.csum_data = 0xffff;
1298 }
1299 /*
1300 * We don't bother to fragment if the IP length is greater
1301 * than the interface's MTU. Can this possibly matter?
1302 */
1303 ip = mtod(copym, struct ip *);
1304 ip->ip_len = htons(ip->ip_len);
1305 ip->ip_off = htons(ip->ip_off);
1306 ip->ip_sum = 0;
1307 ip->ip_sum = in_cksum(copym, hlen);
1308 #if 1 /* XXX */
1309 if (dst->sin_family != AF_INET) {
1310 printf("ip_mloopback: bad address family %d\n",
1311 dst->sin_family);
1312 dst->sin_family = AF_INET;
1313 }
1314 #endif
1315 if_simloop(ifp, copym, dst->sin_family, 0);
1316 }
1317 }
1318