xref: /freebsd/sys/netinet/ip_input.c (revision 4b9d605768acabc460aa6dcfe8a1f8db35b16794)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include "opt_bootp.h"
34 #include "opt_inet.h"
35 #include "opt_ipstealth.h"
36 #include "opt_ipsec.h"
37 #include "opt_route.h"
38 #include "opt_rss.h"
39 #include "opt_sctp.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/hhook.h>
44 #include <sys/mbuf.h>
45 #include <sys/malloc.h>
46 #include <sys/domain.h>
47 #include <sys/protosw.h>
48 #include <sys/socket.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/rmlock.h>
53 #include <sys/rwlock.h>
54 #include <sys/sdt.h>
55 #include <sys/syslog.h>
56 #include <sys/sysctl.h>
57 
58 #include <net/if.h>
59 #include <net/if_types.h>
60 #include <net/if_var.h>
61 #include <net/if_dl.h>
62 #include <net/if_private.h>
63 #include <net/pfil.h>
64 #include <net/route.h>
65 #include <net/route/nhop.h>
66 #include <net/netisr.h>
67 #include <net/rss_config.h>
68 #include <net/vnet.h>
69 
70 #include <netinet/in.h>
71 #include <netinet/in_kdtrace.h>
72 #include <netinet/in_systm.h>
73 #include <netinet/in_var.h>
74 #include <netinet/ip.h>
75 #include <netinet/in_fib.h>
76 #include <netinet/in_pcb.h>
77 #include <netinet/ip_var.h>
78 #include <netinet/ip_encap.h>
79 #include <netinet/ip_fw.h>
80 #include <netinet/ip_icmp.h>
81 #include <netinet/igmp_var.h>
82 #include <netinet/ip_options.h>
83 #include <machine/in_cksum.h>
84 #include <netinet/ip_carp.h>
85 #include <netinet/in_rss.h>
86 #ifdef SCTP
87 #include <netinet/sctp_var.h>
88 #endif
89 
90 #include <netipsec/ipsec_support.h>
91 
92 #include <sys/socketvar.h>
93 
94 #include <security/mac/mac_framework.h>
95 
96 #ifdef CTASSERT
97 CTASSERT(sizeof(struct ip) == 20);
98 #endif
99 
100 /* IP reassembly functions are defined in ip_reass.c. */
101 extern void ipreass_init(void);
102 extern void ipreass_vnet_init(void);
103 #ifdef VIMAGE
104 extern void ipreass_destroy(void);
105 #endif
106 
107 VNET_DEFINE(int, rsvp_on);
108 
109 VNET_DEFINE(int, ipforwarding);
110 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
111     &VNET_NAME(ipforwarding), 0,
112     "Enable IP forwarding between interfaces");
113 
114 /*
115  * Respond with an ICMP host redirect when we forward a packet out of
116  * the same interface on which it was received.  See RFC 792.
117  */
118 VNET_DEFINE(int, ipsendredirects) = 1;
119 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
120     &VNET_NAME(ipsendredirects), 0,
121     "Enable sending IP redirects");
122 
123 VNET_DEFINE_STATIC(bool, ip_strong_es) = false;
124 #define	V_ip_strong_es	VNET(ip_strong_es)
125 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, rfc1122_strong_es,
126     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_strong_es), false,
127     "Packet's IP destination address must match address on arrival interface");
128 
129 VNET_DEFINE_STATIC(bool, ip_sav) = true;
130 #define	V_ip_sav	VNET(ip_sav)
131 SYSCTL_BOOL(_net_inet_ip, OID_AUTO, source_address_validation,
132     CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_sav), true,
133     "Drop incoming packets with source address that is a local address");
134 
135 /* Packet filter hooks */
136 VNET_DEFINE(pfil_head_t, inet_pfil_head);
137 VNET_DEFINE(pfil_head_t, inet_local_pfil_head);
138 
139 static struct netisr_handler ip_nh = {
140 	.nh_name = "ip",
141 	.nh_handler = ip_input,
142 	.nh_proto = NETISR_IP,
143 #ifdef	RSS
144 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
145 	.nh_policy = NETISR_POLICY_CPU,
146 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
147 #else
148 	.nh_policy = NETISR_POLICY_FLOW,
149 #endif
150 };
151 
152 #ifdef	RSS
153 /*
154  * Directly dispatched frames are currently assumed
155  * to have a flowid already calculated.
156  *
157  * It should likely have something that assert it
158  * actually has valid flow details.
159  */
160 static struct netisr_handler ip_direct_nh = {
161 	.nh_name = "ip_direct",
162 	.nh_handler = ip_direct_input,
163 	.nh_proto = NETISR_IP_DIRECT,
164 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
165 	.nh_policy = NETISR_POLICY_CPU,
166 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
167 };
168 #endif
169 
170 ipproto_input_t		*ip_protox[IPPROTO_MAX] = {
171 			    [0 ... IPPROTO_MAX - 1] = rip_input };
172 ipproto_ctlinput_t	*ip_ctlprotox[IPPROTO_MAX] = {
173 			    [0 ... IPPROTO_MAX - 1] = rip_ctlinput };
174 
175 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
176 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
177 VNET_DEFINE(u_long, in_ifaddrhmask);		/* mask for hash table */
178 
179 /* Make sure it is safe to use hashinit(9) on CK_LIST. */
180 CTASSERT(sizeof(struct in_ifaddrhashhead) == sizeof(LIST_HEAD(, in_addr)));
181 
182 #ifdef IPCTL_DEFMTU
183 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
184     &ip_mtu, 0, "Default MTU");
185 #endif
186 
187 #ifdef IPSTEALTH
188 VNET_DEFINE(int, ipstealth);
189 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
190     &VNET_NAME(ipstealth), 0,
191     "IP stealth mode, no TTL decrementation on forwarding");
192 #endif
193 
194 /*
195  * IP statistics are stored in the "array" of counter(9)s.
196  */
197 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
198 VNET_PCPUSTAT_SYSINIT(ipstat);
199 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
200     "IP statistics (struct ipstat, netinet/ip_var.h)");
201 
202 #ifdef VIMAGE
203 VNET_PCPUSTAT_SYSUNINIT(ipstat);
204 #endif /* VIMAGE */
205 
206 /*
207  * Kernel module interface for updating ipstat.  The argument is an index
208  * into ipstat treated as an array.
209  */
210 void
211 kmod_ipstat_inc(int statnum)
212 {
213 
214 	counter_u64_add(VNET(ipstat)[statnum], 1);
215 }
216 
217 void
218 kmod_ipstat_dec(int statnum)
219 {
220 
221 	counter_u64_add(VNET(ipstat)[statnum], -1);
222 }
223 
224 static int
225 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
226 {
227 	int error, qlimit;
228 
229 	netisr_getqlimit(&ip_nh, &qlimit);
230 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
231 	if (error || !req->newptr)
232 		return (error);
233 	if (qlimit < 1)
234 		return (EINVAL);
235 	return (netisr_setqlimit(&ip_nh, qlimit));
236 }
237 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
238     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
239     sysctl_netinet_intr_queue_maxlen, "I",
240     "Maximum size of the IP input queue");
241 
242 static int
243 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
244 {
245 	u_int64_t qdrops_long;
246 	int error, qdrops;
247 
248 	netisr_getqdrops(&ip_nh, &qdrops_long);
249 	qdrops = qdrops_long;
250 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
251 	if (error || !req->newptr)
252 		return (error);
253 	if (qdrops != 0)
254 		return (EINVAL);
255 	netisr_clearqdrops(&ip_nh);
256 	return (0);
257 }
258 
259 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
260     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
261     0, 0, sysctl_netinet_intr_queue_drops, "I",
262     "Number of packets dropped from the IP input queue");
263 
264 #ifdef	RSS
265 static int
266 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
267 {
268 	int error, qlimit;
269 
270 	netisr_getqlimit(&ip_direct_nh, &qlimit);
271 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
272 	if (error || !req->newptr)
273 		return (error);
274 	if (qlimit < 1)
275 		return (EINVAL);
276 	return (netisr_setqlimit(&ip_direct_nh, qlimit));
277 }
278 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
279     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
280     0, 0, sysctl_netinet_intr_direct_queue_maxlen,
281     "I", "Maximum size of the IP direct input queue");
282 
283 static int
284 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
285 {
286 	u_int64_t qdrops_long;
287 	int error, qdrops;
288 
289 	netisr_getqdrops(&ip_direct_nh, &qdrops_long);
290 	qdrops = qdrops_long;
291 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
292 	if (error || !req->newptr)
293 		return (error);
294 	if (qdrops != 0)
295 		return (EINVAL);
296 	netisr_clearqdrops(&ip_direct_nh);
297 	return (0);
298 }
299 
300 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops,
301     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
302     sysctl_netinet_intr_direct_queue_drops, "I",
303     "Number of packets dropped from the IP direct input queue");
304 #endif	/* RSS */
305 
306 /*
307  * IP initialization: fill in IP protocol switch table.
308  * All protocols not implemented in kernel go to raw IP protocol handler.
309  */
310 static void
311 ip_vnet_init(void *arg __unused)
312 {
313 	struct pfil_head_args args;
314 
315 	CK_STAILQ_INIT(&V_in_ifaddrhead);
316 	V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
317 
318 	/* Initialize IP reassembly queue. */
319 	ipreass_vnet_init();
320 
321 	/* Initialize packet filter hooks. */
322 	args.pa_version = PFIL_VERSION;
323 	args.pa_flags = PFIL_IN | PFIL_OUT;
324 	args.pa_type = PFIL_TYPE_IP4;
325 	args.pa_headname = PFIL_INET_NAME;
326 	V_inet_pfil_head = pfil_head_register(&args);
327 
328 	args.pa_flags = PFIL_OUT;
329 	args.pa_headname = PFIL_INET_LOCAL_NAME;
330 	V_inet_local_pfil_head = pfil_head_register(&args);
331 
332 	if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
333 	    &V_ipsec_hhh_in[HHOOK_IPSEC_INET],
334 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
335 		printf("%s: WARNING: unable to register input helper hook\n",
336 		    __func__);
337 	if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
338 	    &V_ipsec_hhh_out[HHOOK_IPSEC_INET],
339 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
340 		printf("%s: WARNING: unable to register output helper hook\n",
341 		    __func__);
342 
343 #ifdef VIMAGE
344 	netisr_register_vnet(&ip_nh);
345 #ifdef	RSS
346 	netisr_register_vnet(&ip_direct_nh);
347 #endif
348 #endif
349 }
350 VNET_SYSINIT(ip_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
351     ip_vnet_init, NULL);
352 
353 static void
354 ip_init(const void *unused __unused)
355 {
356 
357 	ipreass_init();
358 
359 	/*
360 	 * Register statically compiled protocols, that are unlikely to
361 	 * ever become dynamic.
362 	 */
363 	IPPROTO_REGISTER(IPPROTO_ICMP, icmp_input, NULL);
364 	IPPROTO_REGISTER(IPPROTO_IGMP, igmp_input, NULL);
365 	IPPROTO_REGISTER(IPPROTO_RSVP, rsvp_input, NULL);
366 	IPPROTO_REGISTER(IPPROTO_IPV4, encap4_input, NULL);
367 	IPPROTO_REGISTER(IPPROTO_MOBILE, encap4_input, NULL);
368 	IPPROTO_REGISTER(IPPROTO_ETHERIP, encap4_input, NULL);
369 	IPPROTO_REGISTER(IPPROTO_GRE, encap4_input, NULL);
370 	IPPROTO_REGISTER(IPPROTO_IPV6, encap4_input, NULL);
371 	IPPROTO_REGISTER(IPPROTO_PIM, encap4_input, NULL);
372 #ifdef SCTP	/* XXX: has a loadable & static version */
373 	IPPROTO_REGISTER(IPPROTO_SCTP, sctp_input, sctp_ctlinput);
374 #endif
375 
376 	netisr_register(&ip_nh);
377 #ifdef	RSS
378 	netisr_register(&ip_direct_nh);
379 #endif
380 }
381 SYSINIT(ip_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_init, NULL);
382 
383 #ifdef VIMAGE
384 static void
385 ip_destroy(void *unused __unused)
386 {
387 	int error;
388 
389 #ifdef	RSS
390 	netisr_unregister_vnet(&ip_direct_nh);
391 #endif
392 	netisr_unregister_vnet(&ip_nh);
393 
394 	pfil_head_unregister(V_inet_pfil_head);
395 	error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
396 	if (error != 0) {
397 		printf("%s: WARNING: unable to deregister input helper hook "
398 		    "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
399 		    "error %d returned\n", __func__, error);
400 	}
401 	error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
402 	if (error != 0) {
403 		printf("%s: WARNING: unable to deregister output helper hook "
404 		    "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
405 		    "error %d returned\n", __func__, error);
406 	}
407 
408 	/* Remove the IPv4 addresses from all interfaces. */
409 	in_ifscrub_all();
410 
411 	/* Make sure the IPv4 routes are gone as well. */
412 	rib_flush_routes_family(AF_INET);
413 
414 	/* Destroy IP reassembly queue. */
415 	ipreass_destroy();
416 
417 	/* Cleanup in_ifaddr hash table; should be empty. */
418 	hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
419 }
420 
421 VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
422 #endif
423 
424 #ifdef	RSS
425 /*
426  * IP direct input routine.
427  *
428  * This is called when reinjecting completed fragments where
429  * all of the previous checking and book-keeping has been done.
430  */
431 void
432 ip_direct_input(struct mbuf *m)
433 {
434 	struct ip *ip;
435 	int hlen;
436 
437 	ip = mtod(m, struct ip *);
438 	hlen = ip->ip_hl << 2;
439 
440 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
441 	if (IPSEC_ENABLED(ipv4)) {
442 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
443 			return;
444 	}
445 #endif /* IPSEC */
446 	IPSTAT_INC(ips_delivered);
447 	ip_protox[ip->ip_p](&m, &hlen, ip->ip_p);
448 }
449 #endif
450 
451 /*
452  * Ip input routine.  Checksum and byte swap header.  If fragmented
453  * try to reassemble.  Process options.  Pass to next level.
454  */
455 void
456 ip_input(struct mbuf *m)
457 {
458 	struct ip *ip = NULL;
459 	struct in_ifaddr *ia = NULL;
460 	struct ifaddr *ifa;
461 	struct ifnet *ifp;
462 	int hlen = 0;
463 	uint16_t sum, ip_len;
464 	int dchg = 0;				/* dest changed after fw */
465 	struct in_addr odst;			/* original dst address */
466 	bool strong_es;
467 
468 	M_ASSERTPKTHDR(m);
469 	NET_EPOCH_ASSERT();
470 
471 	if (m->m_flags & M_FASTFWD_OURS) {
472 		m->m_flags &= ~M_FASTFWD_OURS;
473 		/* Set up some basics that will be used later. */
474 		ip = mtod(m, struct ip *);
475 		hlen = ip->ip_hl << 2;
476 		ip_len = ntohs(ip->ip_len);
477 		goto ours;
478 	}
479 
480 	IPSTAT_INC(ips_total);
481 
482 	if (__predict_false(m->m_pkthdr.len < sizeof(struct ip)))
483 		goto tooshort;
484 
485 	if (m->m_len < sizeof(struct ip)) {
486 		m = m_pullup(m, sizeof(struct ip));
487 		if (__predict_false(m == NULL)) {
488 			IPSTAT_INC(ips_toosmall);
489 			return;
490 		}
491 	}
492 	ip = mtod(m, struct ip *);
493 
494 	if (__predict_false(ip->ip_v != IPVERSION)) {
495 		IPSTAT_INC(ips_badvers);
496 		goto bad;
497 	}
498 
499 	hlen = ip->ip_hl << 2;
500 	if (__predict_false(hlen < sizeof(struct ip))) {	/* minimum header length */
501 		IPSTAT_INC(ips_badhlen);
502 		goto bad;
503 	}
504 	if (hlen > m->m_len) {
505 		m = m_pullup(m, hlen);
506 		if (__predict_false(m == NULL)) {
507 			IPSTAT_INC(ips_badhlen);
508 			return;
509 		}
510 		ip = mtod(m, struct ip *);
511 	}
512 
513 	IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
514 
515 	/* IN_LOOPBACK must not appear on the wire - RFC1122 */
516 	ifp = m->m_pkthdr.rcvif;
517 	if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) ||
518 	    IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) {
519 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
520 			IPSTAT_INC(ips_badaddr);
521 			goto bad;
522 		}
523 	}
524 	/* The unspecified address can appear only as a src address - RFC1122 */
525 	if (__predict_false(ntohl(ip->ip_dst.s_addr) == INADDR_ANY)) {
526 		IPSTAT_INC(ips_badaddr);
527 		goto bad;
528 	}
529 
530 	if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
531 		sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
532 	} else {
533 		if (hlen == sizeof(struct ip)) {
534 			sum = in_cksum_hdr(ip);
535 		} else {
536 			sum = in_cksum(m, hlen);
537 		}
538 	}
539 	if (__predict_false(sum)) {
540 		IPSTAT_INC(ips_badsum);
541 		goto bad;
542 	}
543 
544 	ip_len = ntohs(ip->ip_len);
545 	if (__predict_false(ip_len < hlen)) {
546 		IPSTAT_INC(ips_badlen);
547 		goto bad;
548 	}
549 
550 	/*
551 	 * Check that the amount of data in the buffers
552 	 * is as at least much as the IP header would have us expect.
553 	 * Trim mbufs if longer than we expect.
554 	 * Drop packet if shorter than we expect.
555 	 */
556 	if (__predict_false(m->m_pkthdr.len < ip_len)) {
557 tooshort:
558 		IPSTAT_INC(ips_tooshort);
559 		goto bad;
560 	}
561 	if (m->m_pkthdr.len > ip_len) {
562 		if (m->m_len == m->m_pkthdr.len) {
563 			m->m_len = ip_len;
564 			m->m_pkthdr.len = ip_len;
565 		} else
566 			m_adj(m, ip_len - m->m_pkthdr.len);
567 	}
568 
569 	/*
570 	 * Try to forward the packet, but if we fail continue.
571 	 * ip_tryforward() may generate redirects these days.
572 	 * XXX the logic below falling through to normal processing
573 	 * if redirects are required should be revisited as well.
574 	 * ip_tryforward() does inbound and outbound packet firewall
575 	 * processing. If firewall has decided that destination becomes
576 	 * our local address, it sets M_FASTFWD_OURS flag. In this
577 	 * case skip another inbound firewall processing and update
578 	 * ip pointer.
579 	 */
580 	if (V_ipforwarding != 0
581 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
582 	    && (!IPSEC_ENABLED(ipv4) ||
583 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
584 #endif
585 	    ) {
586 		/*
587 		 * ip_dooptions() was run so we can ignore the source route (or
588 		 * any IP options case) case for redirects in ip_tryforward().
589 		 */
590 		if ((m = ip_tryforward(m)) == NULL)
591 			return;
592 		if (m->m_flags & M_FASTFWD_OURS) {
593 			m->m_flags &= ~M_FASTFWD_OURS;
594 			ip = mtod(m, struct ip *);
595 			goto ours;
596 		}
597 	}
598 
599 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
600 	/*
601 	 * Bypass packet filtering for packets previously handled by IPsec.
602 	 */
603 	if (IPSEC_ENABLED(ipv4) &&
604 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
605 			goto passin;
606 #endif
607 
608 	/*
609 	 * Run through list of hooks for input packets.
610 	 *
611 	 * NB: Beware of the destination address changing (e.g.
612 	 *     by NAT rewriting).  When this happens, tell
613 	 *     ip_forward to do the right thing.
614 	 */
615 
616 	/* Jump over all PFIL processing if hooks are not active. */
617 	if (!PFIL_HOOKED_IN(V_inet_pfil_head))
618 		goto passin;
619 
620 	odst = ip->ip_dst;
621 	if (pfil_mbuf_in(V_inet_pfil_head, &m, ifp, NULL) !=
622 	    PFIL_PASS)
623 		return;
624 	if (m == NULL)			/* consumed by filter */
625 		return;
626 
627 	ip = mtod(m, struct ip *);
628 	dchg = (odst.s_addr != ip->ip_dst.s_addr);
629 
630 	if (m->m_flags & M_FASTFWD_OURS) {
631 		m->m_flags &= ~M_FASTFWD_OURS;
632 		goto ours;
633 	}
634 	if (m->m_flags & M_IP_NEXTHOP) {
635 		if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
636 			/*
637 			 * Directly ship the packet on.  This allows
638 			 * forwarding packets originally destined to us
639 			 * to some other directly connected host.
640 			 */
641 			ip_forward(m, 1);
642 			return;
643 		}
644 	}
645 passin:
646 
647 	/*
648 	 * Process options and, if not destined for us,
649 	 * ship it on.  ip_dooptions returns 1 when an
650 	 * error was detected (causing an icmp message
651 	 * to be sent and the original packet to be freed).
652 	 */
653 	if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
654 		return;
655 
656         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
657          * matter if it is destined to another node, or whether it is
658          * a multicast one, RSVP wants it! and prevents it from being forwarded
659          * anywhere else. Also checks if the rsvp daemon is running before
660 	 * grabbing the packet.
661          */
662 	if (ip->ip_p == IPPROTO_RSVP && V_rsvp_on)
663 		goto ours;
664 
665 	/*
666 	 * Check our list of addresses, to see if the packet is for us.
667 	 * If we don't have any addresses, assume any unicast packet
668 	 * we receive might be for us (and let the upper layers deal
669 	 * with it).
670 	 */
671 	if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) &&
672 	    (m->m_flags & (M_MCAST|M_BCAST)) == 0)
673 		goto ours;
674 
675 	/*
676 	 * Enable a consistency check between the destination address
677 	 * and the arrival interface for a unicast packet (the RFC 1122
678 	 * strong ES model) with a list of additional predicates:
679 	 * - if IP forwarding is disabled
680 	 * - the packet is not locally generated
681 	 * - the packet is not subject to 'ipfw fwd'
682 	 * - Interface is not running CARP. If the packet got here, we already
683 	 *   checked it with carp_iamatch() and carp_forus().
684 	 */
685 	strong_es = V_ip_strong_es && (V_ipforwarding == 0) &&
686 	    ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
687 	    ifp->if_carp == NULL && (dchg == 0);
688 
689 	/*
690 	 * Check for exact addresses in the hash bucket.
691 	 */
692 	CK_LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
693 		if (IA_SIN(ia)->sin_addr.s_addr != ip->ip_dst.s_addr)
694 			continue;
695 
696 		/*
697 		 * net.inet.ip.rfc1122_strong_es: the address matches, verify
698 		 * that the packet arrived via the correct interface.
699 		 */
700 		if (__predict_false(strong_es && ia->ia_ifp != ifp)) {
701 			IPSTAT_INC(ips_badaddr);
702 			goto bad;
703 		}
704 
705 		/*
706 		 * net.inet.ip.source_address_validation: drop incoming
707 		 * packets that pretend to be ours.
708 		 */
709 		if (V_ip_sav && !(ifp->if_flags & IFF_LOOPBACK) &&
710 		    __predict_false(in_localip_fib(ip->ip_src, ifp->if_fib))) {
711 			IPSTAT_INC(ips_badaddr);
712 			goto bad;
713 		}
714 
715 		counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
716 		counter_u64_add(ia->ia_ifa.ifa_ibytes, m->m_pkthdr.len);
717 		goto ours;
718 	}
719 
720 	/*
721 	 * Check for broadcast addresses.
722 	 *
723 	 * Only accept broadcast packets that arrive via the matching
724 	 * interface.  Reception of forwarded directed broadcasts would
725 	 * be handled via ip_forward() and ether_output() with the loopback
726 	 * into the stack for SIMPLEX interfaces handled by ether_output().
727 	 */
728 	if (ifp->if_flags & IFF_BROADCAST) {
729 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
730 			if (ifa->ifa_addr->sa_family != AF_INET)
731 				continue;
732 			ia = ifatoia(ifa);
733 			if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
734 			    ip->ip_dst.s_addr) {
735 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
736 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
737 				    m->m_pkthdr.len);
738 				goto ours;
739 			}
740 #ifdef BOOTP_COMPAT
741 			if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
742 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
743 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
744 				    m->m_pkthdr.len);
745 				goto ours;
746 			}
747 #endif
748 		}
749 		ia = NULL;
750 	}
751 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
752 		/*
753 		 * RFC 3927 2.7: Do not forward multicast packets from
754 		 * IN_LINKLOCAL.
755 		 */
756 		if (V_ip_mrouter && !IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) {
757 			/*
758 			 * If we are acting as a multicast router, all
759 			 * incoming multicast packets are passed to the
760 			 * kernel-level multicast forwarding function.
761 			 * The packet is returned (relatively) intact; if
762 			 * ip_mforward() returns a non-zero value, the packet
763 			 * must be discarded, else it may be accepted below.
764 			 */
765 			if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
766 				IPSTAT_INC(ips_cantforward);
767 				m_freem(m);
768 				return;
769 			}
770 
771 			/*
772 			 * The process-level routing daemon needs to receive
773 			 * all multicast IGMP packets, whether or not this
774 			 * host belongs to their destination groups.
775 			 */
776 			if (ip->ip_p == IPPROTO_IGMP) {
777 				goto ours;
778 			}
779 			IPSTAT_INC(ips_forward);
780 		}
781 		/*
782 		 * Assume the packet is for us, to avoid prematurely taking
783 		 * a lock on the in_multi hash. Protocols must perform
784 		 * their own filtering and update statistics accordingly.
785 		 */
786 		goto ours;
787 	}
788 	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
789 		goto ours;
790 	if (ip->ip_dst.s_addr == INADDR_ANY)
791 		goto ours;
792 	/* RFC 3927 2.7: Do not forward packets to or from IN_LINKLOCAL. */
793 	if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) ||
794 	    IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) {
795 		IPSTAT_INC(ips_cantforward);
796 		m_freem(m);
797 		return;
798 	}
799 
800 	/*
801 	 * Not for us; forward if possible and desirable.
802 	 */
803 	if (V_ipforwarding == 0) {
804 		IPSTAT_INC(ips_cantforward);
805 		m_freem(m);
806 	} else {
807 		ip_forward(m, dchg);
808 	}
809 	return;
810 
811 ours:
812 #ifdef IPSTEALTH
813 	/*
814 	 * IPSTEALTH: Process non-routing options only
815 	 * if the packet is destined for us.
816 	 */
817 	if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
818 		return;
819 #endif /* IPSTEALTH */
820 
821 	/*
822 	 * We are going to ship the packet to the local protocol stack. Call the
823 	 * filter again for this 'output' action, allowing redirect-like rules
824 	 * to adjust the source address.
825 	 */
826 	if (PFIL_HOOKED_OUT(V_inet_local_pfil_head)) {
827 		if (pfil_mbuf_out(V_inet_local_pfil_head, &m, V_loif, NULL) !=
828 		    PFIL_PASS)
829 			return;
830 		if (m == NULL)			/* consumed by filter */
831 			return;
832 		ip = mtod(m, struct ip *);
833 	}
834 
835 	/*
836 	 * Attempt reassembly; if it succeeds, proceed.
837 	 * ip_reass() will return a different mbuf.
838 	 */
839 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
840 		/* XXXGL: shouldn't we save & set m_flags? */
841 		m = ip_reass(m);
842 		if (m == NULL)
843 			return;
844 		ip = mtod(m, struct ip *);
845 		/* Get the header length of the reassembled packet */
846 		hlen = ip->ip_hl << 2;
847 	}
848 
849 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
850 	if (IPSEC_ENABLED(ipv4)) {
851 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
852 			return;
853 	}
854 #endif /* IPSEC */
855 
856 	/*
857 	 * Switch out to protocol's input routine.
858 	 */
859 	IPSTAT_INC(ips_delivered);
860 
861 	ip_protox[ip->ip_p](&m, &hlen, ip->ip_p);
862 	return;
863 bad:
864 	m_freem(m);
865 }
866 
867 int
868 ipproto_register(uint8_t proto, ipproto_input_t input, ipproto_ctlinput_t ctl)
869 {
870 
871 	MPASS(proto > 0);
872 
873 	/*
874 	 * The protocol slot must not be occupied by another protocol
875 	 * already.  An index pointing to rip_input() is unused.
876 	 */
877 	if (ip_protox[proto] == rip_input) {
878 		ip_protox[proto] = input;
879 		ip_ctlprotox[proto] = ctl;
880 		return (0);
881 	} else
882 		return (EEXIST);
883 }
884 
885 int
886 ipproto_unregister(uint8_t proto)
887 {
888 
889 	MPASS(proto > 0);
890 
891 	if (ip_protox[proto] != rip_input) {
892 		ip_protox[proto] = rip_input;
893 		ip_ctlprotox[proto] = rip_ctlinput;
894 		return (0);
895 	} else
896 		return (ENOENT);
897 }
898 
899 /*
900  * Forward a packet.  If some error occurs return the sender
901  * an icmp packet.  Note we can't always generate a meaningful
902  * icmp message because icmp doesn't have a large enough repertoire
903  * of codes and types.
904  *
905  * If not forwarding, just drop the packet.  This could be confusing
906  * if ipforwarding was zero but some routing protocol was advancing
907  * us as a gateway to somewhere.  However, we must let the routing
908  * protocol deal with that.
909  *
910  * The srcrt parameter indicates whether the packet is being forwarded
911  * via a source route.
912  */
913 void
914 ip_forward(struct mbuf *m, int srcrt)
915 {
916 	struct ip *ip = mtod(m, struct ip *);
917 	struct in_ifaddr *ia;
918 	struct mbuf *mcopy;
919 	struct sockaddr_in *sin;
920 	struct in_addr dest;
921 	struct route ro;
922 	uint32_t flowid;
923 	int error, type = 0, code = 0, mtu = 0;
924 
925 	NET_EPOCH_ASSERT();
926 
927 	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
928 		IPSTAT_INC(ips_cantforward);
929 		m_freem(m);
930 		return;
931 	}
932 	if (
933 #ifdef IPSTEALTH
934 	    V_ipstealth == 0 &&
935 #endif
936 	    ip->ip_ttl <= IPTTLDEC) {
937 		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
938 		return;
939 	}
940 
941 	bzero(&ro, sizeof(ro));
942 	sin = (struct sockaddr_in *)&ro.ro_dst;
943 	sin->sin_family = AF_INET;
944 	sin->sin_len = sizeof(*sin);
945 	sin->sin_addr = ip->ip_dst;
946 	flowid = m->m_pkthdr.flowid;
947 	ro.ro_nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_REF, flowid);
948 	if (ro.ro_nh != NULL) {
949 		ia = ifatoia(ro.ro_nh->nh_ifa);
950 	} else
951 		ia = NULL;
952 	/*
953 	 * Save the IP header and at most 8 bytes of the payload,
954 	 * in case we need to generate an ICMP message to the src.
955 	 *
956 	 * XXX this can be optimized a lot by saving the data in a local
957 	 * buffer on the stack (72 bytes at most), and only allocating the
958 	 * mbuf if really necessary. The vast majority of the packets
959 	 * are forwarded without having to send an ICMP back (either
960 	 * because unnecessary, or because rate limited), so we are
961 	 * really we are wasting a lot of work here.
962 	 *
963 	 * We don't use m_copym() because it might return a reference
964 	 * to a shared cluster. Both this function and ip_output()
965 	 * assume exclusive access to the IP header in `m', so any
966 	 * data in a cluster may change before we reach icmp_error().
967 	 */
968 	mcopy = m_gethdr(M_NOWAIT, m->m_type);
969 	if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
970 		/*
971 		 * It's probably ok if the pkthdr dup fails (because
972 		 * the deep copy of the tag chain failed), but for now
973 		 * be conservative and just discard the copy since
974 		 * code below may some day want the tags.
975 		 */
976 		m_free(mcopy);
977 		mcopy = NULL;
978 	}
979 	if (mcopy != NULL) {
980 		mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
981 		mcopy->m_pkthdr.len = mcopy->m_len;
982 		m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
983 	}
984 #ifdef IPSTEALTH
985 	if (V_ipstealth == 0)
986 #endif
987 		ip->ip_ttl -= IPTTLDEC;
988 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
989 	if (IPSEC_ENABLED(ipv4)) {
990 		if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
991 			/* mbuf consumed by IPsec */
992 			RO_NHFREE(&ro);
993 			m_freem(mcopy);
994 			if (error != EINPROGRESS)
995 				IPSTAT_INC(ips_cantforward);
996 			return;
997 		}
998 		/* No IPsec processing required */
999 	}
1000 #endif /* IPSEC */
1001 	/*
1002 	 * If forwarding packet using same interface that it came in on,
1003 	 * perhaps should send a redirect to sender to shortcut a hop.
1004 	 * Only send redirect if source is sending directly to us,
1005 	 * and if packet was not source routed (or has any options).
1006 	 * Also, don't send redirect if forwarding using a default route
1007 	 * or a route modified by a redirect.
1008 	 */
1009 	dest.s_addr = 0;
1010 	if (!srcrt && V_ipsendredirects &&
1011 	    ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1012 		struct nhop_object *nh;
1013 
1014 		nh = ro.ro_nh;
1015 
1016 		if (nh != NULL && ((nh->nh_flags & (NHF_REDIRECT|NHF_DEFAULT)) == 0)) {
1017 			struct in_ifaddr *nh_ia = (struct in_ifaddr *)(nh->nh_ifa);
1018 			u_long src = ntohl(ip->ip_src.s_addr);
1019 
1020 			if (nh_ia != NULL &&
1021 			    (src & nh_ia->ia_subnetmask) == nh_ia->ia_subnet) {
1022 				/* Router requirements says to only send host redirects */
1023 				type = ICMP_REDIRECT;
1024 				code = ICMP_REDIRECT_HOST;
1025 				if (nh->nh_flags & NHF_GATEWAY) {
1026 				    if (nh->gw_sa.sa_family == AF_INET)
1027 					dest.s_addr = nh->gw4_sa.sin_addr.s_addr;
1028 				    else /* Do not redirect in case gw is AF_INET6 */
1029 					type = 0;
1030 				} else
1031 					dest.s_addr = ip->ip_dst.s_addr;
1032 			}
1033 		}
1034 	}
1035 
1036 	error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1037 
1038 	if (error == EMSGSIZE && ro.ro_nh)
1039 		mtu = ro.ro_nh->nh_mtu;
1040 	RO_NHFREE(&ro);
1041 
1042 	if (error)
1043 		IPSTAT_INC(ips_cantforward);
1044 	else {
1045 		IPSTAT_INC(ips_forward);
1046 		if (type)
1047 			IPSTAT_INC(ips_redirectsent);
1048 		else {
1049 			if (mcopy)
1050 				m_freem(mcopy);
1051 			return;
1052 		}
1053 	}
1054 	if (mcopy == NULL)
1055 		return;
1056 
1057 	switch (error) {
1058 	case 0:				/* forwarded, but need redirect */
1059 		/* type, code set above */
1060 		break;
1061 
1062 	case ENETUNREACH:
1063 	case EHOSTUNREACH:
1064 	case ENETDOWN:
1065 	case EHOSTDOWN:
1066 	default:
1067 		type = ICMP_UNREACH;
1068 		code = ICMP_UNREACH_HOST;
1069 		break;
1070 
1071 	case EMSGSIZE:
1072 		type = ICMP_UNREACH;
1073 		code = ICMP_UNREACH_NEEDFRAG;
1074 		/*
1075 		 * If the MTU was set before make sure we are below the
1076 		 * interface MTU.
1077 		 * If the MTU wasn't set before use the interface mtu or
1078 		 * fall back to the next smaller mtu step compared to the
1079 		 * current packet size.
1080 		 */
1081 		if (mtu != 0) {
1082 			if (ia != NULL)
1083 				mtu = min(mtu, ia->ia_ifp->if_mtu);
1084 		} else {
1085 			if (ia != NULL)
1086 				mtu = ia->ia_ifp->if_mtu;
1087 			else
1088 				mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1089 		}
1090 		IPSTAT_INC(ips_cantfrag);
1091 		break;
1092 
1093 	case ENOBUFS:
1094 	case EACCES:			/* ipfw denied packet */
1095 		m_freem(mcopy);
1096 		return;
1097 	}
1098 	icmp_error(mcopy, type, code, dest.s_addr, mtu);
1099 }
1100 
1101 #define	CHECK_SO_CT(sp, ct) \
1102     (((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0)
1103 
1104 void
1105 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1106     struct mbuf *m)
1107 {
1108 	bool stamped;
1109 
1110 	stamped = false;
1111 	if ((inp->inp_socket->so_options & SO_BINTIME) ||
1112 	    CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) {
1113 		struct bintime boottimebin, bt;
1114 		struct timespec ts1;
1115 
1116 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1117 		    M_TSTMP)) {
1118 			mbuf_tstmp2timespec(m, &ts1);
1119 			timespec2bintime(&ts1, &bt);
1120 			getboottimebin(&boottimebin);
1121 			bintime_add(&bt, &boottimebin);
1122 		} else {
1123 			bintime(&bt);
1124 		}
1125 		*mp = sbcreatecontrol(&bt, sizeof(bt), SCM_BINTIME,
1126 		    SOL_SOCKET, M_NOWAIT);
1127 		if (*mp != NULL) {
1128 			mp = &(*mp)->m_next;
1129 			stamped = true;
1130 		}
1131 	}
1132 	if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) {
1133 		struct bintime boottimebin, bt1;
1134 		struct timespec ts1;
1135 		struct timeval tv;
1136 
1137 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1138 		    M_TSTMP)) {
1139 			mbuf_tstmp2timespec(m, &ts1);
1140 			timespec2bintime(&ts1, &bt1);
1141 			getboottimebin(&boottimebin);
1142 			bintime_add(&bt1, &boottimebin);
1143 			bintime2timeval(&bt1, &tv);
1144 		} else {
1145 			microtime(&tv);
1146 		}
1147 		*mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv), SCM_TIMESTAMP,
1148 		    SOL_SOCKET, M_NOWAIT);
1149 		if (*mp != NULL) {
1150 			mp = &(*mp)->m_next;
1151 			stamped = true;
1152 		}
1153 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) {
1154 		struct bintime boottimebin;
1155 		struct timespec ts, ts1;
1156 
1157 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1158 		    M_TSTMP)) {
1159 			mbuf_tstmp2timespec(m, &ts);
1160 			getboottimebin(&boottimebin);
1161 			bintime2timespec(&boottimebin, &ts1);
1162 			timespecadd(&ts, &ts1, &ts);
1163 		} else {
1164 			nanotime(&ts);
1165 		}
1166 		*mp = sbcreatecontrol(&ts, sizeof(ts), SCM_REALTIME,
1167 		    SOL_SOCKET, M_NOWAIT);
1168 		if (*mp != NULL) {
1169 			mp = &(*mp)->m_next;
1170 			stamped = true;
1171 		}
1172 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) {
1173 		struct timespec ts;
1174 
1175 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1176 		    M_TSTMP))
1177 			mbuf_tstmp2timespec(m, &ts);
1178 		else
1179 			nanouptime(&ts);
1180 		*mp = sbcreatecontrol(&ts, sizeof(ts), SCM_MONOTONIC,
1181 		    SOL_SOCKET, M_NOWAIT);
1182 		if (*mp != NULL) {
1183 			mp = &(*mp)->m_next;
1184 			stamped = true;
1185 		}
1186 	}
1187 	if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1188 	    M_TSTMP)) {
1189 		struct sock_timestamp_info sti;
1190 
1191 		bzero(&sti, sizeof(sti));
1192 		sti.st_info_flags = ST_INFO_HW;
1193 		if ((m->m_flags & M_TSTMP_HPREC) != 0)
1194 			sti.st_info_flags |= ST_INFO_HW_HPREC;
1195 		*mp = sbcreatecontrol(&sti, sizeof(sti), SCM_TIME_INFO,
1196 		    SOL_SOCKET, M_NOWAIT);
1197 		if (*mp != NULL)
1198 			mp = &(*mp)->m_next;
1199 	}
1200 	if (inp->inp_flags & INP_RECVDSTADDR) {
1201 		*mp = sbcreatecontrol(&ip->ip_dst, sizeof(struct in_addr),
1202 		    IP_RECVDSTADDR, IPPROTO_IP, M_NOWAIT);
1203 		if (*mp)
1204 			mp = &(*mp)->m_next;
1205 	}
1206 	if (inp->inp_flags & INP_RECVTTL) {
1207 		*mp = sbcreatecontrol(&ip->ip_ttl, sizeof(u_char), IP_RECVTTL,
1208 		    IPPROTO_IP, M_NOWAIT);
1209 		if (*mp)
1210 			mp = &(*mp)->m_next;
1211 	}
1212 #ifdef notyet
1213 	/* XXX
1214 	 * Moving these out of udp_input() made them even more broken
1215 	 * than they already were.
1216 	 */
1217 	/* options were tossed already */
1218 	if (inp->inp_flags & INP_RECVOPTS) {
1219 		*mp = sbcreatecontrol(opts_deleted_above,
1220 		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP, M_NOWAIT);
1221 		if (*mp)
1222 			mp = &(*mp)->m_next;
1223 	}
1224 	/* ip_srcroute doesn't do what we want here, need to fix */
1225 	if (inp->inp_flags & INP_RECVRETOPTS) {
1226 		*mp = sbcreatecontrol(ip_srcroute(m), sizeof(struct in_addr),
1227 		    IP_RECVRETOPTS, IPPROTO_IP, M_NOWAIT);
1228 		if (*mp)
1229 			mp = &(*mp)->m_next;
1230 	}
1231 #endif
1232 	if (inp->inp_flags & INP_RECVIF) {
1233 		struct ifnet *ifp;
1234 		struct sdlbuf {
1235 			struct sockaddr_dl sdl;
1236 			u_char	pad[32];
1237 		} sdlbuf;
1238 		struct sockaddr_dl *sdp;
1239 		struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1240 
1241 		if ((ifp = m->m_pkthdr.rcvif)) {
1242 			sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1243 			/*
1244 			 * Change our mind and don't try copy.
1245 			 */
1246 			if (sdp->sdl_family != AF_LINK ||
1247 			    sdp->sdl_len > sizeof(sdlbuf)) {
1248 				goto makedummy;
1249 			}
1250 			bcopy(sdp, sdl2, sdp->sdl_len);
1251 		} else {
1252 makedummy:
1253 			sdl2->sdl_len =
1254 			    offsetof(struct sockaddr_dl, sdl_data[0]);
1255 			sdl2->sdl_family = AF_LINK;
1256 			sdl2->sdl_index = 0;
1257 			sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1258 		}
1259 		*mp = sbcreatecontrol(sdl2, sdl2->sdl_len, IP_RECVIF,
1260 		    IPPROTO_IP, M_NOWAIT);
1261 		if (*mp)
1262 			mp = &(*mp)->m_next;
1263 	}
1264 	if (inp->inp_flags & INP_RECVTOS) {
1265 		*mp = sbcreatecontrol(&ip->ip_tos, sizeof(u_char), IP_RECVTOS,
1266 		    IPPROTO_IP, M_NOWAIT);
1267 		if (*mp)
1268 			mp = &(*mp)->m_next;
1269 	}
1270 
1271 	if (inp->inp_flags2 & INP_RECVFLOWID) {
1272 		uint32_t flowid, flow_type;
1273 
1274 		flowid = m->m_pkthdr.flowid;
1275 		flow_type = M_HASHTYPE_GET(m);
1276 
1277 		/*
1278 		 * XXX should handle the failure of one or the
1279 		 * other - don't populate both?
1280 		 */
1281 		*mp = sbcreatecontrol(&flowid, sizeof(uint32_t), IP_FLOWID,
1282 		    IPPROTO_IP, M_NOWAIT);
1283 		if (*mp)
1284 			mp = &(*mp)->m_next;
1285 		*mp = sbcreatecontrol(&flow_type, sizeof(uint32_t),
1286 		    IP_FLOWTYPE, IPPROTO_IP, M_NOWAIT);
1287 		if (*mp)
1288 			mp = &(*mp)->m_next;
1289 	}
1290 
1291 #ifdef	RSS
1292 	if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1293 		uint32_t flowid, flow_type;
1294 		uint32_t rss_bucketid;
1295 
1296 		flowid = m->m_pkthdr.flowid;
1297 		flow_type = M_HASHTYPE_GET(m);
1298 
1299 		if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1300 			*mp = sbcreatecontrol(&rss_bucketid, sizeof(uint32_t),
1301 			    IP_RSSBUCKETID, IPPROTO_IP, M_NOWAIT);
1302 			if (*mp)
1303 				mp = &(*mp)->m_next;
1304 		}
1305 	}
1306 #endif
1307 }
1308 
1309 /*
1310  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1311  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1312  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
1313  * compiled.
1314  */
1315 VNET_DEFINE_STATIC(int, ip_rsvp_on);
1316 VNET_DEFINE(struct socket *, ip_rsvpd);
1317 
1318 #define	V_ip_rsvp_on		VNET(ip_rsvp_on)
1319 
1320 int
1321 ip_rsvp_init(struct socket *so)
1322 {
1323 
1324 	if (V_ip_rsvpd != NULL)
1325 		return EADDRINUSE;
1326 
1327 	V_ip_rsvpd = so;
1328 	/*
1329 	 * This may seem silly, but we need to be sure we don't over-increment
1330 	 * the RSVP counter, in case something slips up.
1331 	 */
1332 	if (!V_ip_rsvp_on) {
1333 		V_ip_rsvp_on = 1;
1334 		V_rsvp_on++;
1335 	}
1336 
1337 	return 0;
1338 }
1339 
1340 int
1341 ip_rsvp_done(void)
1342 {
1343 
1344 	V_ip_rsvpd = NULL;
1345 	/*
1346 	 * This may seem silly, but we need to be sure we don't over-decrement
1347 	 * the RSVP counter, in case something slips up.
1348 	 */
1349 	if (V_ip_rsvp_on) {
1350 		V_ip_rsvp_on = 0;
1351 		V_rsvp_on--;
1352 	}
1353 	return 0;
1354 }
1355 
1356 int
1357 rsvp_input(struct mbuf **mp, int *offp, int proto)
1358 {
1359 	struct mbuf *m;
1360 
1361 	m = *mp;
1362 	*mp = NULL;
1363 
1364 	if (rsvp_input_p) { /* call the real one if loaded */
1365 		*mp = m;
1366 		rsvp_input_p(mp, offp, proto);
1367 		return (IPPROTO_DONE);
1368 	}
1369 
1370 	/* Can still get packets with rsvp_on = 0 if there is a local member
1371 	 * of the group to which the RSVP packet is addressed.  But in this
1372 	 * case we want to throw the packet away.
1373 	 */
1374 
1375 	if (!V_rsvp_on) {
1376 		m_freem(m);
1377 		return (IPPROTO_DONE);
1378 	}
1379 
1380 	if (V_ip_rsvpd != NULL) {
1381 		*mp = m;
1382 		rip_input(mp, offp, proto);
1383 		return (IPPROTO_DONE);
1384 	}
1385 	/* Drop the packet */
1386 	m_freem(m);
1387 	return (IPPROTO_DONE);
1388 }
1389