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>
| 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: head/sys/netinet/ip_output.c 254523 2013-08-19 13:27:32Z andre $");
| 33__FBSDID("$FreeBSD: head/sys/netinet/ip_output.c 254889 2013-08-25 21:54:41Z markj $");
|
34
35#include "opt_ipfw.h"
36#include "opt_ipsec.h"
| 34
35#include "opt_ipfw.h"
36#include "opt_ipsec.h"
|
37#include "opt_route.h"
| 37#include "opt_kdtrace.h"
|
38#include "opt_mbuf_stress_test.h"
39#include "opt_mpath.h"
| 38#include "opt_mbuf_stress_test.h"
39#include "opt_mpath.h"
|
| 40#include "opt_route.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>
| 41#include "opt_sctp.h"
42
43#include <sys/param.h>
44#include <sys/systm.h>
45#include <sys/kernel.h>
46#include <sys/malloc.h>
47#include <sys/mbuf.h>
48#include <sys/priv.h>
49#include <sys/proc.h>
50#include <sys/protosw.h>
|
| 51#include <sys/sdt.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>
| 52#include <sys/socket.h>
53#include <sys/socketvar.h>
54#include <sys/sysctl.h>
55#include <sys/ucred.h>
56
57#include <net/if.h>
58#include <net/if_llatbl.h>
59#include <net/netisr.h>
60#include <net/pfil.h>
61#include <net/route.h>
62#include <net/flowtable.h>
63#ifdef RADIX_MPATH
64#include <net/radix_mpath.h>
65#endif
66#include <net/vnet.h>
67
68#include <netinet/in.h>
|
| 69#include <netinet/in_kdtrace.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
87VNET_DEFINE(u_short, ip_id);
88
89#ifdef MBUF_STRESS_TEST
90static int mbuf_frag_size = 0;
91SYSCTL_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
95static void ip_mloopback
96 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
97
98
99extern int in_mcast_loop;
100extern 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 * The mbuf chain containing the packet will be freed.
106 * The mbuf opt, if present, will not be freed.
107 * If route ro is present and has ro_rt initialized, route lookup would be
108 * skipped and ro->ro_rt would be used. If ro is present but ro->ro_rt is NULL,
109 * then result of route lookup is stored in ro->ro_rt.
110 *
111 * In the IP forwarding case, the packet will arrive with options already
112 * inserted, so must have a NULL opt pointer.
113 */
114int
115ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
116 struct ip_moptions *imo, struct inpcb *inp)
117{
118 struct ip *ip;
119 struct ifnet *ifp = NULL; /* keep compiler happy */
120 struct mbuf *m0;
121 int hlen = sizeof (struct ip);
122 int mtu;
123 int n; /* scratchpad */
124 int error = 0;
125 struct sockaddr_in *dst;
126 const struct sockaddr_in *gw;
127 struct in_ifaddr *ia;
128 int isbroadcast;
129 uint16_t ip_len, ip_off;
130 struct route iproute;
131 struct rtentry *rte; /* cache for ro->ro_rt */
132 struct in_addr odst;
133 struct m_tag *fwd_tag = NULL;
134#ifdef IPSEC
135 int no_route_but_check_spd = 0;
136#endif
137 M_ASSERTPKTHDR(m);
138
139 if (inp != NULL) {
140 INP_LOCK_ASSERT(inp);
141 M_SETFIB(m, inp->inp_inc.inc_fibnum);
142 if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
143 m->m_pkthdr.flowid = inp->inp_flowid;
144 m->m_flags |= M_FLOWID;
145 }
146 }
147
148 if (ro == NULL) {
149 ro = &iproute;
150 bzero(ro, sizeof (*ro));
151 }
152
153#ifdef FLOWTABLE
154 if (ro->ro_rt == NULL) {
155 struct flentry *fle;
156
157 /*
158 * The flow table returns route entries valid for up to 30
159 * seconds; we rely on the remainder of ip_output() taking no
160 * longer than that long for the stability of ro_rt. The
161 * flow ID assignment must have happened before this point.
162 */
163 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
164 if (fle != NULL)
165 flow_to_route(fle, ro);
166 }
167#endif
168
169 if (opt) {
170 int len = 0;
171 m = ip_insertoptions(m, opt, &len);
172 if (len != 0)
173 hlen = len; /* ip->ip_hl is updated above */
174 }
175 ip = mtod(m, struct ip *);
176 ip_len = ntohs(ip->ip_len);
177 ip_off = ntohs(ip->ip_off);
178
179 /*
180 * Fill in IP header. If we are not allowing fragmentation,
181 * then the ip_id field is meaningless, but we don't set it
182 * to zero. Doing so causes various problems when devices along
183 * the path (routers, load balancers, firewalls, etc.) illegally
184 * disable DF on our packet. Note that a 16-bit counter
185 * will wrap around in less than 10 seconds at 100 Mbit/s on a
186 * medium with MTU 1500. See Steven M. Bellovin, "A Technique
187 * for Counting NATted Hosts", Proc. IMW'02, available at
188 * <http://www.cs.columbia.edu/~smb/papers/fnat.pdf>.
189 */
190 if ((flags & (IP_FORWARDING|IP_RAWOUTPUT)) == 0) {
191 ip->ip_v = IPVERSION;
192 ip->ip_hl = hlen >> 2;
193 ip->ip_id = ip_newid();
194 IPSTAT_INC(ips_localout);
195 } else {
196 /* Header already set, fetch hlen from there */
197 hlen = ip->ip_hl << 2;
198 }
199
200 gw = dst = (struct sockaddr_in *)&ro->ro_dst;
201again:
202 ia = NULL;
203 /*
204 * If there is a cached route,
205 * check that it is to the same destination
206 * and is still up. If not, free it and try again.
207 * The address family should also be checked in case of sharing the
208 * cache with IPv6.
209 */
210 rte = ro->ro_rt;
211 if (rte && ((rte->rt_flags & RTF_UP) == 0 ||
212 rte->rt_ifp == NULL ||
213 !RT_LINK_IS_UP(rte->rt_ifp) ||
214 dst->sin_family != AF_INET ||
215 dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
216 RO_RTFREE(ro);
217 ro->ro_lle = NULL;
218 rte = NULL;
219 }
220 if (rte == NULL && fwd_tag == NULL) {
221 bzero(dst, sizeof(*dst));
222 dst->sin_family = AF_INET;
223 dst->sin_len = sizeof(*dst);
224 dst->sin_addr = ip->ip_dst;
225 }
226 /*
227 * If routing to interface only, short circuit routing lookup.
228 * The use of an all-ones broadcast address implies this; an
229 * interface is specified by the broadcast address of an interface,
230 * or the destination address of a ptp interface.
231 */
232 if (flags & IP_SENDONES) {
233 if ((ia = ifatoia(ifa_ifwithbroadaddr(sintosa(dst)))) == NULL &&
234 (ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL) {
235 IPSTAT_INC(ips_noroute);
236 error = ENETUNREACH;
237 goto bad;
238 }
239 ip->ip_dst.s_addr = INADDR_BROADCAST;
240 dst->sin_addr = ip->ip_dst;
241 ifp = ia->ia_ifp;
242 ip->ip_ttl = 1;
243 isbroadcast = 1;
244 } else if (flags & IP_ROUTETOIF) {
245 if ((ia = ifatoia(ifa_ifwithdstaddr(sintosa(dst)))) == NULL &&
246 (ia = ifatoia(ifa_ifwithnet(sintosa(dst), 0))) == NULL) {
247 IPSTAT_INC(ips_noroute);
248 error = ENETUNREACH;
249 goto bad;
250 }
251 ifp = ia->ia_ifp;
252 ip->ip_ttl = 1;
253 isbroadcast = in_broadcast(dst->sin_addr, ifp);
254 } else if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) &&
255 imo != NULL && imo->imo_multicast_ifp != NULL) {
256 /*
257 * Bypass the normal routing lookup for multicast
258 * packets if the interface is specified.
259 */
260 ifp = imo->imo_multicast_ifp;
261 IFP_TO_IA(ifp, ia);
262 isbroadcast = 0; /* fool gcc */
263 } else {
264 /*
265 * We want to do any cloning requested by the link layer,
266 * as this is probably required in all cases for correct
267 * operation (as it is for ARP).
268 */
269 if (rte == NULL) {
270#ifdef RADIX_MPATH
271 rtalloc_mpath_fib(ro,
272 ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
273 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
274#else
275 in_rtalloc_ign(ro, 0,
276 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
277#endif
278 rte = ro->ro_rt;
279 }
280 if (rte == NULL ||
281 rte->rt_ifp == NULL ||
282 !RT_LINK_IS_UP(rte->rt_ifp)) {
283#ifdef IPSEC
284 /*
285 * There is no route for this packet, but it is
286 * possible that a matching SPD entry exists.
287 */
288 no_route_but_check_spd = 1;
289 mtu = 0; /* Silence GCC warning. */
290 goto sendit;
291#endif
292 IPSTAT_INC(ips_noroute);
293 error = EHOSTUNREACH;
294 goto bad;
295 }
296 ia = ifatoia(rte->rt_ifa);
297 ifa_ref(&ia->ia_ifa);
298 ifp = rte->rt_ifp;
299 rte->rt_rmx.rmx_pksent++;
300 if (rte->rt_flags & RTF_GATEWAY)
301 gw = (struct sockaddr_in *)rte->rt_gateway;
302 if (rte->rt_flags & RTF_HOST)
303 isbroadcast = (rte->rt_flags & RTF_BROADCAST);
304 else
305 isbroadcast = in_broadcast(gw->sin_addr, ifp);
306 }
307 /*
308 * Calculate MTU. If we have a route that is up, use that,
309 * otherwise use the interface's MTU.
310 */
311 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
312 /*
313 * This case can happen if the user changed the MTU
314 * of an interface after enabling IP on it. Because
315 * most netifs don't keep track of routes pointing to
316 * them, there is no way for one to update all its
317 * routes when the MTU is changed.
318 */
319 if (rte->rt_rmx.rmx_mtu > ifp->if_mtu)
320 rte->rt_rmx.rmx_mtu = ifp->if_mtu;
321 mtu = rte->rt_rmx.rmx_mtu;
322 } else {
323 mtu = ifp->if_mtu;
324 }
325 /* Catch a possible divide by zero later. */
326 KASSERT(mtu > 0, ("%s: mtu %d <= 0, rte=%p (rt_flags=0x%08x) ifp=%p",
327 __func__, mtu, rte, (rte != NULL) ? rte->rt_flags : 0, ifp));
328 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
329 m->m_flags |= M_MCAST;
330 /*
331 * See if the caller provided any multicast options
332 */
333 if (imo != NULL) {
334 ip->ip_ttl = imo->imo_multicast_ttl;
335 if (imo->imo_multicast_vif != -1)
336 ip->ip_src.s_addr =
337 ip_mcast_src ?
338 ip_mcast_src(imo->imo_multicast_vif) :
339 INADDR_ANY;
340 } else
341 ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
342 /*
343 * Confirm that the outgoing interface supports multicast.
344 */
345 if ((imo == NULL) || (imo->imo_multicast_vif == -1)) {
346 if ((ifp->if_flags & IFF_MULTICAST) == 0) {
347 IPSTAT_INC(ips_noroute);
348 error = ENETUNREACH;
349 goto bad;
350 }
351 }
352 /*
353 * If source address not specified yet, use address
354 * of outgoing interface.
355 */
356 if (ip->ip_src.s_addr == INADDR_ANY) {
357 /* Interface may have no addresses. */
358 if (ia != NULL)
359 ip->ip_src = IA_SIN(ia)->sin_addr;
360 }
361
362 if ((imo == NULL && in_mcast_loop) ||
363 (imo && imo->imo_multicast_loop)) {
364 /*
365 * Loop back multicast datagram if not expressly
366 * forbidden to do so, even if we are not a member
367 * of the group; ip_input() will filter it later,
368 * thus deferring a hash lookup and mutex acquisition
369 * at the expense of a cheap copy using m_copym().
370 */
371 ip_mloopback(ifp, m, dst, hlen);
372 } else {
373 /*
374 * If we are acting as a multicast router, perform
375 * multicast forwarding as if the packet had just
376 * arrived on the interface to which we are about
377 * to send. The multicast forwarding function
378 * recursively calls this function, using the
379 * IP_FORWARDING flag to prevent infinite recursion.
380 *
381 * Multicasts that are looped back by ip_mloopback(),
382 * above, will be forwarded by the ip_input() routine,
383 * if necessary.
384 */
385 if (V_ip_mrouter && (flags & IP_FORWARDING) == 0) {
386 /*
387 * If rsvp daemon is not running, do not
388 * set ip_moptions. This ensures that the packet
389 * is multicast and not just sent down one link
390 * as prescribed by rsvpd.
391 */
392 if (!V_rsvp_on)
393 imo = NULL;
394 if (ip_mforward &&
395 ip_mforward(ip, ifp, m, imo) != 0) {
396 m_freem(m);
397 goto done;
398 }
399 }
400 }
401
402 /*
403 * Multicasts with a time-to-live of zero may be looped-
404 * back, above, but must not be transmitted on a network.
405 * Also, multicasts addressed to the loopback interface
406 * are not sent -- the above call to ip_mloopback() will
407 * loop back a copy. ip_input() will drop the copy if
408 * this host does not belong to the destination group on
409 * the loopback interface.
410 */
411 if (ip->ip_ttl == 0 || ifp->if_flags & IFF_LOOPBACK) {
412 m_freem(m);
413 goto done;
414 }
415
416 goto sendit;
417 }
418
419 /*
420 * If the source address is not specified yet, use the address
421 * of the outoing interface.
422 */
423 if (ip->ip_src.s_addr == INADDR_ANY) {
424 /* Interface may have no addresses. */
425 if (ia != NULL) {
426 ip->ip_src = IA_SIN(ia)->sin_addr;
427 }
428 }
429
430 /*
431 * Verify that we have any chance at all of being able to queue the
432 * packet or packet fragments, unless ALTQ is enabled on the given
433 * interface in which case packetdrop should be done by queueing.
434 */
435 n = ip_len / mtu + 1; /* how many fragments ? */
436 if (
437#ifdef ALTQ
438 (!ALTQ_IS_ENABLED(&ifp->if_snd)) &&
439#endif /* ALTQ */
440 (ifp->if_snd.ifq_len + n) >= ifp->if_snd.ifq_maxlen ) {
441 error = ENOBUFS;
442 IPSTAT_INC(ips_odropped);
443 ifp->if_snd.ifq_drops += n;
444 goto bad;
445 }
446
447 /*
448 * Look for broadcast address and
449 * verify user is allowed to send
450 * such a packet.
451 */
452 if (isbroadcast) {
453 if ((ifp->if_flags & IFF_BROADCAST) == 0) {
454 error = EADDRNOTAVAIL;
455 goto bad;
456 }
457 if ((flags & IP_ALLOWBROADCAST) == 0) {
458 error = EACCES;
459 goto bad;
460 }
461 /* don't allow broadcast messages to be fragmented */
462 if (ip_len > mtu) {
463 error = EMSGSIZE;
464 goto bad;
465 }
466 m->m_flags |= M_BCAST;
467 } else {
468 m->m_flags &= ~M_BCAST;
469 }
470
471sendit:
472#ifdef IPSEC
473 switch(ip_ipsec_output(&m, inp, &flags, &error)) {
474 case 1:
475 goto bad;
476 case -1:
477 goto done;
478 case 0:
479 default:
480 break; /* Continue with packet processing. */
481 }
482 /*
483 * Check if there was a route for this packet; return error if not.
484 */
485 if (no_route_but_check_spd) {
486 IPSTAT_INC(ips_noroute);
487 error = EHOSTUNREACH;
488 goto bad;
489 }
490 /* Update variables that are affected by ipsec4_output(). */
491 ip = mtod(m, struct ip *);
492 hlen = ip->ip_hl << 2;
493#endif /* IPSEC */
494
495 /* Jump over all PFIL processing if hooks are not active. */
496 if (!PFIL_HOOKED(&V_inet_pfil_hook))
497 goto passout;
498
499 /* Run through list of hooks for output packets. */
500 odst.s_addr = ip->ip_dst.s_addr;
501 error = pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_OUT, inp);
502 if (error != 0 || m == NULL)
503 goto done;
504
505 ip = mtod(m, struct ip *);
506
507 /* See if destination IP address was changed by packet filter. */
508 if (odst.s_addr != ip->ip_dst.s_addr) {
509 m->m_flags |= M_SKIP_FIREWALL;
510 /* If destination is now ourself drop to ip_input(). */
511 if (in_localip(ip->ip_dst)) {
512 m->m_flags |= M_FASTFWD_OURS;
513 if (m->m_pkthdr.rcvif == NULL)
514 m->m_pkthdr.rcvif = V_loif;
515 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
516 m->m_pkthdr.csum_flags |=
517 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
518 m->m_pkthdr.csum_data = 0xffff;
519 }
520 m->m_pkthdr.csum_flags |=
521 CSUM_IP_CHECKED | CSUM_IP_VALID;
522#ifdef SCTP
523 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
524 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
525#endif
526 error = netisr_queue(NETISR_IP, m);
527 goto done;
528 } else {
529 if (ia != NULL)
530 ifa_free(&ia->ia_ifa);
531 goto again; /* Redo the routing table lookup. */
532 }
533 }
534
535 /* See if local, if yes, send it to netisr with IP_FASTFWD_OURS. */
536 if (m->m_flags & M_FASTFWD_OURS) {
537 if (m->m_pkthdr.rcvif == NULL)
538 m->m_pkthdr.rcvif = V_loif;
539 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
540 m->m_pkthdr.csum_flags |=
541 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
542 m->m_pkthdr.csum_data = 0xffff;
543 }
544#ifdef SCTP
545 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
546 m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
547#endif
548 m->m_pkthdr.csum_flags |=
549 CSUM_IP_CHECKED | CSUM_IP_VALID;
550
551 error = netisr_queue(NETISR_IP, m);
552 goto done;
553 }
554 /* Or forward to some other address? */
555 if ((m->m_flags & M_IP_NEXTHOP) &&
556 (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
557 bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
558 m->m_flags |= M_SKIP_FIREWALL;
559 m->m_flags &= ~M_IP_NEXTHOP;
560 m_tag_delete(m, fwd_tag);
561 if (ia != NULL)
562 ifa_free(&ia->ia_ifa);
563 goto again;
564 }
565
566passout:
567 /* 127/8 must not appear on wire - RFC1122. */
568 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
569 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
570 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
571 IPSTAT_INC(ips_badaddr);
572 error = EADDRNOTAVAIL;
573 goto bad;
574 }
575 }
576
577 m->m_pkthdr.csum_flags |= CSUM_IP;
578 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
579 in_delayed_cksum(m);
580 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
581 }
582#ifdef SCTP
583 if (m->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
584 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
585 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
586 }
587#endif
588
589 /*
590 * If small enough for interface, or the interface will take
591 * care of the fragmentation for us, we can just send directly.
592 */
593 if (ip_len <= mtu ||
594 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
595 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
596 ip->ip_sum = 0;
597 if (m->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
598 ip->ip_sum = in_cksum(m, hlen);
599 m->m_pkthdr.csum_flags &= ~CSUM_IP;
600 }
601
602 /*
603 * Record statistics for this interface address.
604 * With CSUM_TSO the byte/packet count will be slightly
605 * incorrect because we count the IP+TCP headers only
606 * once instead of for every generated packet.
607 */
608 if (!(flags & IP_FORWARDING) && ia) {
609 if (m->m_pkthdr.csum_flags & CSUM_TSO)
610 ia->ia_ifa.if_opackets +=
611 m->m_pkthdr.len / m->m_pkthdr.tso_segsz;
612 else
613 ia->ia_ifa.if_opackets++;
614 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
615 }
616#ifdef MBUF_STRESS_TEST
617 if (mbuf_frag_size && m->m_pkthdr.len > mbuf_frag_size)
618 m = m_fragment(m, M_NOWAIT, mbuf_frag_size);
619#endif
620 /*
621 * Reset layer specific mbuf flags
622 * to avoid confusing lower layers.
623 */
624 m_clrprotoflags(m);
| 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>
76#ifdef SCTP
77#include <netinet/sctp.h>
78#include <netinet/sctp_crc32.h>
79#endif
80
81#ifdef IPSEC
82#include <netinet/ip_ipsec.h>
83#include <netipsec/ipsec.h>
84#endif /* IPSEC*/
85
86#include <machine/in_cksum.h>
87
88#include <security/mac/mac_framework.h>
89
90VNET_DEFINE(u_short, ip_id);
91
92#ifdef MBUF_STRESS_TEST
93static int mbuf_frag_size = 0;
94SYSCTL_INT(_net_inet_ip, OID_AUTO, mbuf_frag_size, CTLFLAG_RW,
95 &mbuf_frag_size, 0, "Fragment outgoing mbufs to this size");
96#endif
97
98static void ip_mloopback
99 (struct ifnet *, struct mbuf *, struct sockaddr_in *, int);
100
101
102extern int in_mcast_loop;
103extern struct protosw inetsw[];
104
105/*
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.
113 *
114 * In the IP forwarding case, the packet will arrive with options already
115 * inserted, so must have a NULL opt pointer.
116 */
117int
118ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
119 struct ip_moptions *imo, struct inpcb *inp)
120{
121 struct ip *ip;
122 struct ifnet *ifp = NULL; /* keep compiler happy */
123 struct mbuf *m0;
124 int hlen = sizeof (struct ip);
125 int mtu;
126 int n; /* scratchpad */
127 int error = 0;
128 struct sockaddr_in *dst;
129 const struct sockaddr_in *gw;
130 struct in_ifaddr *ia;
131 int isbroadcast;
132 uint16_t ip_len, ip_off;
133 struct route iproute;
134 struct rtentry *rte; /* cache for ro->ro_rt */
135 struct in_addr odst;
136 struct m_tag *fwd_tag = NULL;
137#ifdef IPSEC
138 int no_route_but_check_spd = 0;
139#endif
140 M_ASSERTPKTHDR(m);
141
142 if (inp != NULL) {
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;
148 }
149 }
150
151 if (ro == NULL) {
152 ro = &iproute;
153 bzero(ro, sizeof (*ro));
154 }
155
156#ifdef FLOWTABLE
157 if (ro->ro_rt == NULL) {
158 struct flentry *fle;
159
160 /*
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.
165 */
166 fle = flowtable_lookup_mbuf(V_ip_ft, m, AF_INET);
167 if (fle != NULL)
168 flow_to_route(fle, ro);
169 }
170#endif
171
172 if (opt) {
173 int len = 0;
174 m = ip_insertoptions(m, opt, &len);
175 if (len != 0)
176 hlen = len; /* ip->ip_hl is updated above */
177 }
178 ip = mtod(m, struct ip *);
179 ip_len = ntohs(ip->ip_len);
180 ip_off = ntohs(ip->ip_off);
181
182 /*
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>.
192 */
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);
198 } else {
199 /* Header already set, fetch hlen from there */
200 hlen = ip->ip_hl << 2;
201 }
202
203 gw = dst = (struct sockaddr_in *)&ro->ro_dst;
204again:
205 ia = NULL;
206 /*
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
211 * cache with IPv6.
212 */
213 rte = ro->ro_rt;
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)) {
219 RO_RTFREE(ro);
220 ro->ro_lle = NULL;
221 rte = NULL;
222 }
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;
228 }
229 /*
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.
234 */
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);
239 error = ENETUNREACH;
240 goto bad;
241 }
242 ip->ip_dst.s_addr = INADDR_BROADCAST;
243 dst->sin_addr = ip->ip_dst;
244 ifp = ia->ia_ifp;
245 ip->ip_ttl = 1;
246 isbroadcast = 1;
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);
251 error = ENETUNREACH;
252 goto bad;
253 }
254 ifp = ia->ia_ifp;
255 ip->ip_ttl = 1;
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) {
259 /*
260 * Bypass the normal routing lookup for multicast
261 * packets if the interface is specified.
262 */
263 ifp = imo->imo_multicast_ifp;
264 IFP_TO_IA(ifp, ia);
265 isbroadcast = 0; /* fool gcc */
266 } else {
267 /*
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).
271 */
272 if (rte == NULL) {
273#ifdef RADIX_MPATH
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));
277#else
278 in_rtalloc_ign(ro, 0,
279 inp ? inp->inp_inc.inc_fibnum : M_GETFIB(m));
280#endif
281 rte = ro->ro_rt;
282 }
283 if (rte == NULL ||
284 rte->rt_ifp == NULL ||
285 !RT_LINK_IS_UP(rte->rt_ifp)) {
286#ifdef IPSEC
287 /*
288 * There is no route for this packet, but it is
289 * possible that a matching SPD entry exists.
290 */
291 no_route_but_check_spd = 1;
292 mtu = 0; /* Silence GCC warning. */
293 goto sendit;
294#endif
295 IPSTAT_INC(ips_noroute);
296 error = EHOSTUNREACH;
297 goto bad;
298 }
299 ia = ifatoia(rte->rt_ifa);
300 ifa_ref(&ia->ia_ifa);
301 ifp = rte->rt_ifp;
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);
307 else
308 isbroadcast = in_broadcast(gw->sin_addr, ifp);
309 }
310 /*
311 * Calculate MTU. If we have a route that is up, use that,
312 * otherwise use the interface's MTU.
313 */
314 if (rte != NULL && (rte->rt_flags & (RTF_UP|RTF_HOST))) {
315 /*
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.
321 */
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;
325 } else {
326 mtu = ifp->if_mtu;
327 }
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;
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_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_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
474sendit:
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 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);
564 if (ia != NULL)
565 ifa_free(&ia->ia_ifa);
566 goto again;
567 }
568
569passout:
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;
576 goto bad;
577 }
578 }
579
580 m->m_pkthdr.csum_flags |= CSUM_IP;
581 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
582 in_delayed_cksum(m);
583 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
584 }
585#ifdef SCTP
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;
589 }
590#endif
591
592 /*
593 * If small enough for interface, or the interface will take
594 * care of the fragmentation for us, we can just send directly.
595 */
596 if (ip_len <= mtu ||
597 (m->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0 ||
598 ((ip_off & IP_DF) == 0 && (ifp->if_hwassist & CSUM_FRAGMENT))) {
599 ip->ip_sum = 0;
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;
603 }
604
605 /*
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.
610 */
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;
615 else
616 ia->ia_ifa.if_opackets++;
617 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
618 }
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);
622#endif
623 /*
624 * Reset layer specific mbuf flags
625 * to avoid confusing lower layers.
626 */
627 m_clrprotoflags(m);
|
| 628 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
|
625 error = (*ifp->if_output)(ifp, m,
626 (const struct sockaddr *)gw, ro);
627 goto done;
628 }
629
630 /* Balk when DF bit is set or the interface didn't support TSO. */
631 if ((ip_off & IP_DF) || (m->m_pkthdr.csum_flags & CSUM_TSO)) {
632 error = EMSGSIZE;
633 IPSTAT_INC(ips_cantfrag);
634 goto bad;
635 }
636
637 /*
638 * Too large for interface; fragment if possible. If successful,
639 * on return, m will point to a list of packets to be sent.
640 */
641 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
642 if (error)
643 goto bad;
644 for (; m; m = m0) {
645 m0 = m->m_nextpkt;
646 m->m_nextpkt = 0;
647 if (error == 0) {
648 /* Record statistics for this interface address. */
649 if (ia != NULL) {
650 ia->ia_ifa.if_opackets++;
651 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
652 }
653 /*
654 * Reset layer specific mbuf flags
655 * to avoid confusing upper layers.
656 */
657 m_clrprotoflags(m);
658
| 629 error = (*ifp->if_output)(ifp, m,
630 (const struct sockaddr *)gw, ro);
631 goto done;
632 }
633
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)) {
636 error = EMSGSIZE;
637 IPSTAT_INC(ips_cantfrag);
638 goto bad;
639 }
640
641 /*
642 * Too large for interface; fragment if possible. If successful,
643 * on return, m will point to a list of packets to be sent.
644 */
645 error = ip_fragment(ip, &m, mtu, ifp->if_hwassist);
646 if (error)
647 goto bad;
648 for (; m; m = m0) {
649 m0 = m->m_nextpkt;
650 m->m_nextpkt = 0;
651 if (error == 0) {
652 /* Record statistics for this interface address. */
653 if (ia != NULL) {
654 ia->ia_ifa.if_opackets++;
655 ia->ia_ifa.if_obytes += m->m_pkthdr.len;
656 }
657 /*
658 * Reset layer specific mbuf flags
659 * to avoid confusing upper layers.
660 */
661 m_clrprotoflags(m);
662
|
| 663 IP_PROBE(send, NULL, NULL, ip, ifp, ip, NULL);
|
659 error = (*ifp->if_output)(ifp, m,
660 (const struct sockaddr *)gw, ro);
661 } else
662 m_freem(m);
663 }
664
665 if (error == 0)
666 IPSTAT_INC(ips_fragmented);
667
668done:
669 if (ro == &iproute)
670 RO_RTFREE(ro);
671 if (ia != NULL)
672 ifa_free(&ia->ia_ifa);
673 return (error);
674bad:
675 m_freem(m);
676 goto done;
677}
678
679/*
680 * Create a chain of fragments which fit the given mtu. m_frag points to the
681 * mbuf to be fragmented; on return it points to the chain with the fragments.
682 * Return 0 if no error. If error, m_frag may contain a partially built
683 * chain of fragments that should be freed by the caller.
684 *
685 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
686 */
687int
688ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
689 u_long if_hwassist_flags)
690{
691 int error = 0;
692 int hlen = ip->ip_hl << 2;
693 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
694 int off;
695 struct mbuf *m0 = *m_frag; /* the original packet */
696 int firstlen;
697 struct mbuf **mnext;
698 int nfrags;
699 uint16_t ip_len, ip_off;
700
701 ip_len = ntohs(ip->ip_len);
702 ip_off = ntohs(ip->ip_off);
703
704 if (ip_off & IP_DF) { /* Fragmentation not allowed */
705 IPSTAT_INC(ips_cantfrag);
706 return EMSGSIZE;
707 }
708
709 /*
710 * Must be able to put at least 8 bytes per fragment.
711 */
712 if (len < 8)
713 return EMSGSIZE;
714
715 /*
716 * If the interface will not calculate checksums on
717 * fragmented packets, then do it here.
718 */
719 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
720 in_delayed_cksum(m0);
721 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
722 }
723#ifdef SCTP
724 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
725 sctp_delayed_cksum(m0, hlen);
726 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
727 }
728#endif
729 if (len > PAGE_SIZE) {
730 /*
731 * Fragment large datagrams such that each segment
732 * contains a multiple of PAGE_SIZE amount of data,
733 * plus headers. This enables a receiver to perform
734 * page-flipping zero-copy optimizations.
735 *
736 * XXX When does this help given that sender and receiver
737 * could have different page sizes, and also mtu could
738 * be less than the receiver's page size ?
739 */
740 int newlen;
741 struct mbuf *m;
742
743 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
744 off += m->m_len;
745
746 /*
747 * firstlen (off - hlen) must be aligned on an
748 * 8-byte boundary
749 */
750 if (off < hlen)
751 goto smart_frag_failure;
752 off = ((off - hlen) & ~7) + hlen;
753 newlen = (~PAGE_MASK) & mtu;
754 if ((newlen + sizeof (struct ip)) > mtu) {
755 /* we failed, go back the default */
756smart_frag_failure:
757 newlen = len;
758 off = hlen + len;
759 }
760 len = newlen;
761
762 } else {
763 off = hlen + len;
764 }
765
766 firstlen = off - hlen;
767 mnext = &m0->m_nextpkt; /* pointer to next packet */
768
769 /*
770 * Loop through length of segment after first fragment,
771 * make new header and copy data of each part and link onto chain.
772 * Here, m0 is the original packet, m is the fragment being created.
773 * The fragments are linked off the m_nextpkt of the original
774 * packet, which after processing serves as the first fragment.
775 */
776 for (nfrags = 1; off < ip_len; off += len, nfrags++) {
777 struct ip *mhip; /* ip header on the fragment */
778 struct mbuf *m;
779 int mhlen = sizeof (struct ip);
780
781 m = m_gethdr(M_NOWAIT, MT_DATA);
782 if (m == NULL) {
783 error = ENOBUFS;
784 IPSTAT_INC(ips_odropped);
785 goto done;
786 }
787 m->m_flags |= (m0->m_flags & M_MCAST);
788 /*
789 * In the first mbuf, leave room for the link header, then
790 * copy the original IP header including options. The payload
791 * goes into an additional mbuf chain returned by m_copym().
792 */
793 m->m_data += max_linkhdr;
794 mhip = mtod(m, struct ip *);
795 *mhip = *ip;
796 if (hlen > sizeof (struct ip)) {
797 mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
798 mhip->ip_v = IPVERSION;
799 mhip->ip_hl = mhlen >> 2;
800 }
801 m->m_len = mhlen;
802 /* XXX do we need to add ip_off below ? */
803 mhip->ip_off = ((off - hlen) >> 3) + ip_off;
804 if (off + len >= ip_len)
805 len = ip_len - off;
806 else
807 mhip->ip_off |= IP_MF;
808 mhip->ip_len = htons((u_short)(len + mhlen));
809 m->m_next = m_copym(m0, off, len, M_NOWAIT);
810 if (m->m_next == NULL) { /* copy failed */
811 m_free(m);
812 error = ENOBUFS; /* ??? */
813 IPSTAT_INC(ips_odropped);
814 goto done;
815 }
816 m->m_pkthdr.len = mhlen + len;
817 m->m_pkthdr.rcvif = NULL;
818#ifdef MAC
819 mac_netinet_fragment(m0, m);
820#endif
821 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
822 mhip->ip_off = htons(mhip->ip_off);
823 mhip->ip_sum = 0;
824 if (m->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
825 mhip->ip_sum = in_cksum(m, mhlen);
826 m->m_pkthdr.csum_flags &= ~CSUM_IP;
827 }
828 *mnext = m;
829 mnext = &m->m_nextpkt;
830 }
831 IPSTAT_ADD(ips_ofragments, nfrags);
832
833 /*
834 * Update first fragment by trimming what's been copied out
835 * and updating header.
836 */
837 m_adj(m0, hlen + firstlen - ip_len);
838 m0->m_pkthdr.len = hlen + firstlen;
839 ip->ip_len = htons((u_short)m0->m_pkthdr.len);
840 ip->ip_off = htons(ip_off | IP_MF);
841 ip->ip_sum = 0;
842 if (m0->m_pkthdr.csum_flags & CSUM_IP & ~if_hwassist_flags) {
843 ip->ip_sum = in_cksum(m0, hlen);
844 m0->m_pkthdr.csum_flags &= ~CSUM_IP;
845 }
846
847done:
848 *m_frag = m0;
849 return error;
850}
851
852void
853in_delayed_cksum(struct mbuf *m)
854{
855 struct ip *ip;
856 uint16_t csum, offset, ip_len;
857
858 ip = mtod(m, struct ip *);
859 offset = ip->ip_hl << 2 ;
860 ip_len = ntohs(ip->ip_len);
861 csum = in_cksum_skip(m, ip_len, offset);
862 if (m->m_pkthdr.csum_flags & CSUM_UDP && csum == 0)
863 csum = 0xffff;
864 offset += m->m_pkthdr.csum_data; /* checksum offset */
865
866 if (offset + sizeof(u_short) > m->m_len) {
867 printf("delayed m_pullup, m->len: %d off: %d p: %d\n",
868 m->m_len, offset, ip->ip_p);
869 /*
870 * XXX
871 * this shouldn't happen, but if it does, the
872 * correct behavior may be to insert the checksum
873 * in the appropriate next mbuf in the chain.
874 */
875 return;
876 }
877 *(u_short *)(m->m_data + offset) = csum;
878}
879
880/*
881 * IP socket option processing.
882 */
883int
884ip_ctloutput(struct socket *so, struct sockopt *sopt)
885{
886 struct inpcb *inp = sotoinpcb(so);
887 int error, optval;
888
889 error = optval = 0;
890 if (sopt->sopt_level != IPPROTO_IP) {
891 error = EINVAL;
892
893 if (sopt->sopt_level == SOL_SOCKET &&
894 sopt->sopt_dir == SOPT_SET) {
895 switch (sopt->sopt_name) {
896 case SO_REUSEADDR:
897 INP_WLOCK(inp);
898 if ((so->so_options & SO_REUSEADDR) != 0)
899 inp->inp_flags2 |= INP_REUSEADDR;
900 else
901 inp->inp_flags2 &= ~INP_REUSEADDR;
902 INP_WUNLOCK(inp);
903 error = 0;
904 break;
905 case SO_REUSEPORT:
906 INP_WLOCK(inp);
907 if ((so->so_options & SO_REUSEPORT) != 0)
908 inp->inp_flags2 |= INP_REUSEPORT;
909 else
910 inp->inp_flags2 &= ~INP_REUSEPORT;
911 INP_WUNLOCK(inp);
912 error = 0;
913 break;
914 case SO_SETFIB:
915 INP_WLOCK(inp);
916 inp->inp_inc.inc_fibnum = so->so_fibnum;
917 INP_WUNLOCK(inp);
918 error = 0;
919 break;
920 default:
921 break;
922 }
923 }
924 return (error);
925 }
926
927 switch (sopt->sopt_dir) {
928 case SOPT_SET:
929 switch (sopt->sopt_name) {
930 case IP_OPTIONS:
931#ifdef notyet
932 case IP_RETOPTS:
933#endif
934 {
935 struct mbuf *m;
936 if (sopt->sopt_valsize > MLEN) {
937 error = EMSGSIZE;
938 break;
939 }
940 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
941 if (m == NULL) {
942 error = ENOBUFS;
943 break;
944 }
945 m->m_len = sopt->sopt_valsize;
946 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
947 m->m_len);
948 if (error) {
949 m_free(m);
950 break;
951 }
952 INP_WLOCK(inp);
953 error = ip_pcbopts(inp, sopt->sopt_name, m);
954 INP_WUNLOCK(inp);
955 return (error);
956 }
957
958 case IP_BINDANY:
959 if (sopt->sopt_td != NULL) {
960 error = priv_check(sopt->sopt_td,
961 PRIV_NETINET_BINDANY);
962 if (error)
963 break;
964 }
965 /* FALLTHROUGH */
966 case IP_TOS:
967 case IP_TTL:
968 case IP_MINTTL:
969 case IP_RECVOPTS:
970 case IP_RECVRETOPTS:
971 case IP_RECVDSTADDR:
972 case IP_RECVTTL:
973 case IP_RECVIF:
974 case IP_FAITH:
975 case IP_ONESBCAST:
976 case IP_DONTFRAG:
977 case IP_RECVTOS:
978 error = sooptcopyin(sopt, &optval, sizeof optval,
979 sizeof optval);
980 if (error)
981 break;
982
983 switch (sopt->sopt_name) {
984 case IP_TOS:
985 inp->inp_ip_tos = optval;
986 break;
987
988 case IP_TTL:
989 inp->inp_ip_ttl = optval;
990 break;
991
992 case IP_MINTTL:
993 if (optval >= 0 && optval <= MAXTTL)
994 inp->inp_ip_minttl = optval;
995 else
996 error = EINVAL;
997 break;
998
999#define OPTSET(bit) do { \
1000 INP_WLOCK(inp); \
1001 if (optval) \
1002 inp->inp_flags |= bit; \
1003 else \
1004 inp->inp_flags &= ~bit; \
1005 INP_WUNLOCK(inp); \
1006} while (0)
1007
1008 case IP_RECVOPTS:
1009 OPTSET(INP_RECVOPTS);
1010 break;
1011
1012 case IP_RECVRETOPTS:
1013 OPTSET(INP_RECVRETOPTS);
1014 break;
1015
1016 case IP_RECVDSTADDR:
1017 OPTSET(INP_RECVDSTADDR);
1018 break;
1019
1020 case IP_RECVTTL:
1021 OPTSET(INP_RECVTTL);
1022 break;
1023
1024 case IP_RECVIF:
1025 OPTSET(INP_RECVIF);
1026 break;
1027
1028 case IP_FAITH:
1029 OPTSET(INP_FAITH);
1030 break;
1031
1032 case IP_ONESBCAST:
1033 OPTSET(INP_ONESBCAST);
1034 break;
1035 case IP_DONTFRAG:
1036 OPTSET(INP_DONTFRAG);
1037 break;
1038 case IP_BINDANY:
1039 OPTSET(INP_BINDANY);
1040 break;
1041 case IP_RECVTOS:
1042 OPTSET(INP_RECVTOS);
1043 break;
1044 }
1045 break;
1046#undef OPTSET
1047
1048 /*
1049 * Multicast socket options are processed by the in_mcast
1050 * module.
1051 */
1052 case IP_MULTICAST_IF:
1053 case IP_MULTICAST_VIF:
1054 case IP_MULTICAST_TTL:
1055 case IP_MULTICAST_LOOP:
1056 case IP_ADD_MEMBERSHIP:
1057 case IP_DROP_MEMBERSHIP:
1058 case IP_ADD_SOURCE_MEMBERSHIP:
1059 case IP_DROP_SOURCE_MEMBERSHIP:
1060 case IP_BLOCK_SOURCE:
1061 case IP_UNBLOCK_SOURCE:
1062 case IP_MSFILTER:
1063 case MCAST_JOIN_GROUP:
1064 case MCAST_LEAVE_GROUP:
1065 case MCAST_JOIN_SOURCE_GROUP:
1066 case MCAST_LEAVE_SOURCE_GROUP:
1067 case MCAST_BLOCK_SOURCE:
1068 case MCAST_UNBLOCK_SOURCE:
1069 error = inp_setmoptions(inp, sopt);
1070 break;
1071
1072 case IP_PORTRANGE:
1073 error = sooptcopyin(sopt, &optval, sizeof optval,
1074 sizeof optval);
1075 if (error)
1076 break;
1077
1078 INP_WLOCK(inp);
1079 switch (optval) {
1080 case IP_PORTRANGE_DEFAULT:
1081 inp->inp_flags &= ~(INP_LOWPORT);
1082 inp->inp_flags &= ~(INP_HIGHPORT);
1083 break;
1084
1085 case IP_PORTRANGE_HIGH:
1086 inp->inp_flags &= ~(INP_LOWPORT);
1087 inp->inp_flags |= INP_HIGHPORT;
1088 break;
1089
1090 case IP_PORTRANGE_LOW:
1091 inp->inp_flags &= ~(INP_HIGHPORT);
1092 inp->inp_flags |= INP_LOWPORT;
1093 break;
1094
1095 default:
1096 error = EINVAL;
1097 break;
1098 }
1099 INP_WUNLOCK(inp);
1100 break;
1101
1102#ifdef IPSEC
1103 case IP_IPSEC_POLICY:
1104 {
1105 caddr_t req;
1106 struct mbuf *m;
1107
1108 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1109 break;
1110 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1111 break;
1112 req = mtod(m, caddr_t);
1113 error = ipsec_set_policy(inp, sopt->sopt_name, req,
1114 m->m_len, (sopt->sopt_td != NULL) ?
1115 sopt->sopt_td->td_ucred : NULL);
1116 m_freem(m);
1117 break;
1118 }
1119#endif /* IPSEC */
1120
1121 default:
1122 error = ENOPROTOOPT;
1123 break;
1124 }
1125 break;
1126
1127 case SOPT_GET:
1128 switch (sopt->sopt_name) {
1129 case IP_OPTIONS:
1130 case IP_RETOPTS:
1131 if (inp->inp_options)
1132 error = sooptcopyout(sopt,
1133 mtod(inp->inp_options,
1134 char *),
1135 inp->inp_options->m_len);
1136 else
1137 sopt->sopt_valsize = 0;
1138 break;
1139
1140 case IP_TOS:
1141 case IP_TTL:
1142 case IP_MINTTL:
1143 case IP_RECVOPTS:
1144 case IP_RECVRETOPTS:
1145 case IP_RECVDSTADDR:
1146 case IP_RECVTTL:
1147 case IP_RECVIF:
1148 case IP_PORTRANGE:
1149 case IP_FAITH:
1150 case IP_ONESBCAST:
1151 case IP_DONTFRAG:
1152 case IP_BINDANY:
1153 case IP_RECVTOS:
1154 switch (sopt->sopt_name) {
1155
1156 case IP_TOS:
1157 optval = inp->inp_ip_tos;
1158 break;
1159
1160 case IP_TTL:
1161 optval = inp->inp_ip_ttl;
1162 break;
1163
1164 case IP_MINTTL:
1165 optval = inp->inp_ip_minttl;
1166 break;
1167
1168#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1169
1170 case IP_RECVOPTS:
1171 optval = OPTBIT(INP_RECVOPTS);
1172 break;
1173
1174 case IP_RECVRETOPTS:
1175 optval = OPTBIT(INP_RECVRETOPTS);
1176 break;
1177
1178 case IP_RECVDSTADDR:
1179 optval = OPTBIT(INP_RECVDSTADDR);
1180 break;
1181
1182 case IP_RECVTTL:
1183 optval = OPTBIT(INP_RECVTTL);
1184 break;
1185
1186 case IP_RECVIF:
1187 optval = OPTBIT(INP_RECVIF);
1188 break;
1189
1190 case IP_PORTRANGE:
1191 if (inp->inp_flags & INP_HIGHPORT)
1192 optval = IP_PORTRANGE_HIGH;
1193 else if (inp->inp_flags & INP_LOWPORT)
1194 optval = IP_PORTRANGE_LOW;
1195 else
1196 optval = 0;
1197 break;
1198
1199 case IP_FAITH:
1200 optval = OPTBIT(INP_FAITH);
1201 break;
1202
1203 case IP_ONESBCAST:
1204 optval = OPTBIT(INP_ONESBCAST);
1205 break;
1206 case IP_DONTFRAG:
1207 optval = OPTBIT(INP_DONTFRAG);
1208 break;
1209 case IP_BINDANY:
1210 optval = OPTBIT(INP_BINDANY);
1211 break;
1212 case IP_RECVTOS:
1213 optval = OPTBIT(INP_RECVTOS);
1214 break;
1215 }
1216 error = sooptcopyout(sopt, &optval, sizeof optval);
1217 break;
1218
1219 /*
1220 * Multicast socket options are processed by the in_mcast
1221 * module.
1222 */
1223 case IP_MULTICAST_IF:
1224 case IP_MULTICAST_VIF:
1225 case IP_MULTICAST_TTL:
1226 case IP_MULTICAST_LOOP:
1227 case IP_MSFILTER:
1228 error = inp_getmoptions(inp, sopt);
1229 break;
1230
1231#ifdef IPSEC
1232 case IP_IPSEC_POLICY:
1233 {
1234 struct mbuf *m = NULL;
1235 caddr_t req = NULL;
1236 size_t len = 0;
1237
1238 if (m != 0) {
1239 req = mtod(m, caddr_t);
1240 len = m->m_len;
1241 }
1242 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1243 if (error == 0)
1244 error = soopt_mcopyout(sopt, m); /* XXX */
1245 if (error == 0)
1246 m_freem(m);
1247 break;
1248 }
1249#endif /* IPSEC */
1250
1251 default:
1252 error = ENOPROTOOPT;
1253 break;
1254 }
1255 break;
1256 }
1257 return (error);
1258}
1259
1260/*
1261 * Routine called from ip_output() to loop back a copy of an IP multicast
1262 * packet to the input queue of a specified interface. Note that this
1263 * calls the output routine of the loopback "driver", but with an interface
1264 * pointer that might NOT be a loopback interface -- evil, but easier than
1265 * replicating that code here.
1266 */
1267static void
1268ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1269 int hlen)
1270{
1271 register struct ip *ip;
1272 struct mbuf *copym;
1273
1274 /*
1275 * Make a deep copy of the packet because we're going to
1276 * modify the pack in order to generate checksums.
1277 */
1278 copym = m_dup(m, M_NOWAIT);
1279 if (copym != NULL && (copym->m_flags & M_EXT || copym->m_len < hlen))
1280 copym = m_pullup(copym, hlen);
1281 if (copym != NULL) {
1282 /* If needed, compute the checksum and mark it as valid. */
1283 if (copym->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
1284 in_delayed_cksum(copym);
1285 copym->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
1286 copym->m_pkthdr.csum_flags |=
1287 CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
1288 copym->m_pkthdr.csum_data = 0xffff;
1289 }
1290 /*
1291 * We don't bother to fragment if the IP length is greater
1292 * than the interface's MTU. Can this possibly matter?
1293 */
1294 ip = mtod(copym, struct ip *);
1295 ip->ip_sum = 0;
1296 ip->ip_sum = in_cksum(copym, hlen);
1297#if 1 /* XXX */
1298 if (dst->sin_family != AF_INET) {
1299 printf("ip_mloopback: bad address family %d\n",
1300 dst->sin_family);
1301 dst->sin_family = AF_INET;
1302 }
1303#endif
1304 if_simloop(ifp, copym, dst->sin_family, 0);
1305 }
1306}
| 664 error = (*ifp->if_output)(ifp, m,
665 (const struct sockaddr *)gw, ro);
666 } else
667 m_freem(m);
668 }
669
670 if (error == 0)
671 IPSTAT_INC(ips_fragmented);
672
673done:
674 if (ro == &iproute)
675 RO_RTFREE(ro);
676 if (ia != NULL)
677 ifa_free(&ia->ia_ifa);
678 return (error);
679bad:
680 m_freem(m);
681 goto done;
682}
683
684/*
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.
689 *
690 * if_hwassist_flags is the hw offload capabilities (see if_data.ifi_hwassist)
691 */
692int
693ip_fragment(struct ip *ip, struct mbuf **m_frag, int mtu,
694 u_long if_hwassist_flags)
695{
696 int error = 0;
697 int hlen = ip->ip_hl << 2;
698 int len = (mtu - hlen) & ~7; /* size of payload in each fragment */
699 int off;
700 struct mbuf *m0 = *m_frag; /* the original packet */
701 int firstlen;
702 struct mbuf **mnext;
703 int nfrags;
704 uint16_t ip_len, ip_off;
705
706 ip_len = ntohs(ip->ip_len);
707 ip_off = ntohs(ip->ip_off);
708
709 if (ip_off & IP_DF) { /* Fragmentation not allowed */
710 IPSTAT_INC(ips_cantfrag);
711 return EMSGSIZE;
712 }
713
714 /*
715 * Must be able to put at least 8 bytes per fragment.
716 */
717 if (len < 8)
718 return EMSGSIZE;
719
720 /*
721 * If the interface will not calculate checksums on
722 * fragmented packets, then do it here.
723 */
724 if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
725 in_delayed_cksum(m0);
726 m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
727 }
728#ifdef SCTP
729 if (m0->m_pkthdr.csum_flags & CSUM_SCTP) {
730 sctp_delayed_cksum(m0, hlen);
731 m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
732 }
733#endif
734 if (len > PAGE_SIZE) {
735 /*
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.
740 *
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 ?
744 */
745 int newlen;
746 struct mbuf *m;
747
748 for (m = m0, off = 0; m && (off+m->m_len) <= mtu; m = m->m_next)
749 off += m->m_len;
750
751 /*
752 * firstlen (off - hlen) must be aligned on an
753 * 8-byte boundary
754 */
755 if (off < hlen)
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 */
761smart_frag_failure:
762 newlen = len;
763 off = hlen + len;
764 }
765 len = newlen;
766
767 } else {
768 off = hlen + len;
769 }
770
771 firstlen = off - hlen;
772 mnext = &m0->m_nextpkt; /* pointer to next packet */
773
774 /*
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.
780 */
781 for (nfrags = 1; off < ip_len; off += len, nfrags++) {
782 struct ip *mhip; /* ip header on the fragment */
783 struct mbuf *m;
784 int mhlen = sizeof (struct ip);
785
786 m = m_gethdr(M_NOWAIT, MT_DATA);
787 if (m == NULL) {
788 error = ENOBUFS;
789 IPSTAT_INC(ips_odropped);
790 goto done;
791 }
792 m->m_flags |= (m0->m_flags & M_MCAST);
793 /*
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().
797 */
798 m->m_data += max_linkhdr;
799 mhip = mtod(m, struct ip *);
800 *mhip = *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;
805 }
806 m->m_len = mhlen;
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)
810 len = ip_len - off;
811 else
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 */
816 m_free(m);
817 error = ENOBUFS; /* ??? */
818 IPSTAT_INC(ips_odropped);
819 goto done;
820 }
821 m->m_pkthdr.len = mhlen + len;
822 m->m_pkthdr.rcvif = NULL;
823#ifdef MAC
824 mac_netinet_fragment(m0, m);
825#endif
826 m->m_pkthdr.csum_flags = m0->m_pkthdr.csum_flags;
827 mhip->ip_off = htons(mhip->ip_off);
828 mhip->ip_sum = 0;
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;
832 }
833 *mnext = m;
834 mnext = &m->m_nextpkt;
835 }
836 IPSTAT_ADD(ips_ofragments, nfrags);
837
838 /*
839 * Update first fragment by trimming what's been copied out
840 * and updating header.
841 */
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);
846 ip->ip_sum = 0;
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;
850 }
851
852done:
853 *m_frag = m0;
854 return error;
855}
856
857void
858in_delayed_cksum(struct mbuf *m)
859{
860 struct ip *ip;
861 uint16_t csum, offset, ip_len;
862
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)
868 csum = 0xffff;
869 offset += m->m_pkthdr.csum_data; /* checksum offset */
870
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);
874 /*
875 * XXX
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.
879 */
880 return;
881 }
882 *(u_short *)(m->m_data + offset) = csum;
883}
884
885/*
886 * IP socket option processing.
887 */
888int
889ip_ctloutput(struct socket *so, struct sockopt *sopt)
890{
891 struct inpcb *inp = sotoinpcb(so);
892 int error, optval;
893
894 error = optval = 0;
895 if (sopt->sopt_level != IPPROTO_IP) {
896 error = EINVAL;
897
898 if (sopt->sopt_level == SOL_SOCKET &&
899 sopt->sopt_dir == SOPT_SET) {
900 switch (sopt->sopt_name) {
901 case SO_REUSEADDR:
902 INP_WLOCK(inp);
903 if ((so->so_options & SO_REUSEADDR) != 0)
904 inp->inp_flags2 |= INP_REUSEADDR;
905 else
906 inp->inp_flags2 &= ~INP_REUSEADDR;
907 INP_WUNLOCK(inp);
908 error = 0;
909 break;
910 case SO_REUSEPORT:
911 INP_WLOCK(inp);
912 if ((so->so_options & SO_REUSEPORT) != 0)
913 inp->inp_flags2 |= INP_REUSEPORT;
914 else
915 inp->inp_flags2 &= ~INP_REUSEPORT;
916 INP_WUNLOCK(inp);
917 error = 0;
918 break;
919 case SO_SETFIB:
920 INP_WLOCK(inp);
921 inp->inp_inc.inc_fibnum = so->so_fibnum;
922 INP_WUNLOCK(inp);
923 error = 0;
924 break;
925 default:
926 break;
927 }
928 }
929 return (error);
930 }
931
932 switch (sopt->sopt_dir) {
933 case SOPT_SET:
934 switch (sopt->sopt_name) {
935 case IP_OPTIONS:
936#ifdef notyet
937 case IP_RETOPTS:
938#endif
939 {
940 struct mbuf *m;
941 if (sopt->sopt_valsize > MLEN) {
942 error = EMSGSIZE;
943 break;
944 }
945 m = m_get(sopt->sopt_td ? M_WAITOK : M_NOWAIT, MT_DATA);
946 if (m == NULL) {
947 error = ENOBUFS;
948 break;
949 }
950 m->m_len = sopt->sopt_valsize;
951 error = sooptcopyin(sopt, mtod(m, char *), m->m_len,
952 m->m_len);
953 if (error) {
954 m_free(m);
955 break;
956 }
957 INP_WLOCK(inp);
958 error = ip_pcbopts(inp, sopt->sopt_name, m);
959 INP_WUNLOCK(inp);
960 return (error);
961 }
962
963 case IP_BINDANY:
964 if (sopt->sopt_td != NULL) {
965 error = priv_check(sopt->sopt_td,
966 PRIV_NETINET_BINDANY);
967 if (error)
968 break;
969 }
970 /* FALLTHROUGH */
971 case IP_TOS:
972 case IP_TTL:
973 case IP_MINTTL:
974 case IP_RECVOPTS:
975 case IP_RECVRETOPTS:
976 case IP_RECVDSTADDR:
977 case IP_RECVTTL:
978 case IP_RECVIF:
979 case IP_FAITH:
980 case IP_ONESBCAST:
981 case IP_DONTFRAG:
982 case IP_RECVTOS:
983 error = sooptcopyin(sopt, &optval, sizeof optval,
984 sizeof optval);
985 if (error)
986 break;
987
988 switch (sopt->sopt_name) {
989 case IP_TOS:
990 inp->inp_ip_tos = optval;
991 break;
992
993 case IP_TTL:
994 inp->inp_ip_ttl = optval;
995 break;
996
997 case IP_MINTTL:
998 if (optval >= 0 && optval <= MAXTTL)
999 inp->inp_ip_minttl = optval;
1000 else
1001 error = EINVAL;
1002 break;
1003
1004#define OPTSET(bit) do { \
1005 INP_WLOCK(inp); \
1006 if (optval) \
1007 inp->inp_flags |= bit; \
1008 else \
1009 inp->inp_flags &= ~bit; \
1010 INP_WUNLOCK(inp); \
1011} while (0)
1012
1013 case IP_RECVOPTS:
1014 OPTSET(INP_RECVOPTS);
1015 break;
1016
1017 case IP_RECVRETOPTS:
1018 OPTSET(INP_RECVRETOPTS);
1019 break;
1020
1021 case IP_RECVDSTADDR:
1022 OPTSET(INP_RECVDSTADDR);
1023 break;
1024
1025 case IP_RECVTTL:
1026 OPTSET(INP_RECVTTL);
1027 break;
1028
1029 case IP_RECVIF:
1030 OPTSET(INP_RECVIF);
1031 break;
1032
1033 case IP_FAITH:
1034 OPTSET(INP_FAITH);
1035 break;
1036
1037 case IP_ONESBCAST:
1038 OPTSET(INP_ONESBCAST);
1039 break;
1040 case IP_DONTFRAG:
1041 OPTSET(INP_DONTFRAG);
1042 break;
1043 case IP_BINDANY:
1044 OPTSET(INP_BINDANY);
1045 break;
1046 case IP_RECVTOS:
1047 OPTSET(INP_RECVTOS);
1048 break;
1049 }
1050 break;
1051#undef OPTSET
1052
1053 /*
1054 * Multicast socket options are processed by the in_mcast
1055 * module.
1056 */
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:
1067 case IP_MSFILTER:
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);
1075 break;
1076
1077 case IP_PORTRANGE:
1078 error = sooptcopyin(sopt, &optval, sizeof optval,
1079 sizeof optval);
1080 if (error)
1081 break;
1082
1083 INP_WLOCK(inp);
1084 switch (optval) {
1085 case IP_PORTRANGE_DEFAULT:
1086 inp->inp_flags &= ~(INP_LOWPORT);
1087 inp->inp_flags &= ~(INP_HIGHPORT);
1088 break;
1089
1090 case IP_PORTRANGE_HIGH:
1091 inp->inp_flags &= ~(INP_LOWPORT);
1092 inp->inp_flags |= INP_HIGHPORT;
1093 break;
1094
1095 case IP_PORTRANGE_LOW:
1096 inp->inp_flags &= ~(INP_HIGHPORT);
1097 inp->inp_flags |= INP_LOWPORT;
1098 break;
1099
1100 default:
1101 error = EINVAL;
1102 break;
1103 }
1104 INP_WUNLOCK(inp);
1105 break;
1106
1107#ifdef IPSEC
1108 case IP_IPSEC_POLICY:
1109 {
1110 caddr_t req;
1111 struct mbuf *m;
1112
1113 if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
1114 break;
1115 if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
1116 break;
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);
1121 m_freem(m);
1122 break;
1123 }
1124#endif /* IPSEC */
1125
1126 default:
1127 error = ENOPROTOOPT;
1128 break;
1129 }
1130 break;
1131
1132 case SOPT_GET:
1133 switch (sopt->sopt_name) {
1134 case IP_OPTIONS:
1135 case IP_RETOPTS:
1136 if (inp->inp_options)
1137 error = sooptcopyout(sopt,
1138 mtod(inp->inp_options,
1139 char *),
1140 inp->inp_options->m_len);
1141 else
1142 sopt->sopt_valsize = 0;
1143 break;
1144
1145 case IP_TOS:
1146 case IP_TTL:
1147 case IP_MINTTL:
1148 case IP_RECVOPTS:
1149 case IP_RECVRETOPTS:
1150 case IP_RECVDSTADDR:
1151 case IP_RECVTTL:
1152 case IP_RECVIF:
1153 case IP_PORTRANGE:
1154 case IP_FAITH:
1155 case IP_ONESBCAST:
1156 case IP_DONTFRAG:
1157 case IP_BINDANY:
1158 case IP_RECVTOS:
1159 switch (sopt->sopt_name) {
1160
1161 case IP_TOS:
1162 optval = inp->inp_ip_tos;
1163 break;
1164
1165 case IP_TTL:
1166 optval = inp->inp_ip_ttl;
1167 break;
1168
1169 case IP_MINTTL:
1170 optval = inp->inp_ip_minttl;
1171 break;
1172
1173#define OPTBIT(bit) (inp->inp_flags & bit ? 1 : 0)
1174
1175 case IP_RECVOPTS:
1176 optval = OPTBIT(INP_RECVOPTS);
1177 break;
1178
1179 case IP_RECVRETOPTS:
1180 optval = OPTBIT(INP_RECVRETOPTS);
1181 break;
1182
1183 case IP_RECVDSTADDR:
1184 optval = OPTBIT(INP_RECVDSTADDR);
1185 break;
1186
1187 case IP_RECVTTL:
1188 optval = OPTBIT(INP_RECVTTL);
1189 break;
1190
1191 case IP_RECVIF:
1192 optval = OPTBIT(INP_RECVIF);
1193 break;
1194
1195 case IP_PORTRANGE:
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;
1200 else
1201 optval = 0;
1202 break;
1203
1204 case IP_FAITH:
1205 optval = OPTBIT(INP_FAITH);
1206 break;
1207
1208 case IP_ONESBCAST:
1209 optval = OPTBIT(INP_ONESBCAST);
1210 break;
1211 case IP_DONTFRAG:
1212 optval = OPTBIT(INP_DONTFRAG);
1213 break;
1214 case IP_BINDANY:
1215 optval = OPTBIT(INP_BINDANY);
1216 break;
1217 case IP_RECVTOS:
1218 optval = OPTBIT(INP_RECVTOS);
1219 break;
1220 }
1221 error = sooptcopyout(sopt, &optval, sizeof optval);
1222 break;
1223
1224 /*
1225 * Multicast socket options are processed by the in_mcast
1226 * module.
1227 */
1228 case IP_MULTICAST_IF:
1229 case IP_MULTICAST_VIF:
1230 case IP_MULTICAST_TTL:
1231 case IP_MULTICAST_LOOP:
1232 case IP_MSFILTER:
1233 error = inp_getmoptions(inp, sopt);
1234 break;
1235
1236#ifdef IPSEC
1237 case IP_IPSEC_POLICY:
1238 {
1239 struct mbuf *m = NULL;
1240 caddr_t req = NULL;
1241 size_t len = 0;
1242
1243 if (m != 0) {
1244 req = mtod(m, caddr_t);
1245 len = m->m_len;
1246 }
1247 error = ipsec_get_policy(sotoinpcb(so), req, len, &m);
1248 if (error == 0)
1249 error = soopt_mcopyout(sopt, m); /* XXX */
1250 if (error == 0)
1251 m_freem(m);
1252 break;
1253 }
1254#endif /* IPSEC */
1255
1256 default:
1257 error = ENOPROTOOPT;
1258 break;
1259 }
1260 break;
1261 }
1262 return (error);
1263}
1264
1265/*
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.
1271 */
1272static void
1273ip_mloopback(struct ifnet *ifp, struct mbuf *m, struct sockaddr_in *dst,
1274 int hlen)
1275{
1276 register struct ip *ip;
1277 struct mbuf *copym;
1278
1279 /*
1280 * Make a deep copy of the packet because we're going to
1281 * modify the pack in order to generate checksums.
1282 */
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;
1294 }
1295 /*
1296 * We don't bother to fragment if the IP length is greater
1297 * than the interface's MTU. Can this possibly matter?
1298 */
1299 ip = mtod(copym, struct ip *);
1300 ip->ip_sum = 0;
1301 ip->ip_sum = in_cksum(copym, hlen);
1302#if 1 /* XXX */
1303 if (dst->sin_family != AF_INET) {
1304 printf("ip_mloopback: bad address family %d\n",
1305 dst->sin_family);
1306 dst->sin_family = AF_INET;
1307 }
1308#endif
1309 if_simloop(ifp, copym, dst->sin_family, 0);
1310 }
1311}
|