xref: /freebsd/sys/netinet/ip_input.c (revision 81b22a9892b1047e551fc3f1d6d58031bc59a4c3)
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  *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include "opt_bootp.h"
38 #include "opt_ipstealth.h"
39 #include "opt_ipsec.h"
40 #include "opt_route.h"
41 #include "opt_rss.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/hhook.h>
46 #include <sys/mbuf.h>
47 #include <sys/malloc.h>
48 #include <sys/domain.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/time.h>
52 #include <sys/kernel.h>
53 #include <sys/lock.h>
54 #include <sys/rmlock.h>
55 #include <sys/rwlock.h>
56 #include <sys/sdt.h>
57 #include <sys/syslog.h>
58 #include <sys/sysctl.h>
59 
60 #include <net/if.h>
61 #include <net/if_types.h>
62 #include <net/if_var.h>
63 #include <net/if_dl.h>
64 #include <net/pfil.h>
65 #include <net/route.h>
66 #include <net/route/nhop.h>
67 #include <net/netisr.h>
68 #include <net/rss_config.h>
69 #include <net/vnet.h>
70 
71 #include <netinet/in.h>
72 #include <netinet/in_kdtrace.h>
73 #include <netinet/in_systm.h>
74 #include <netinet/in_var.h>
75 #include <netinet/ip.h>
76 #include <netinet/in_fib.h>
77 #include <netinet/in_pcb.h>
78 #include <netinet/ip_var.h>
79 #include <netinet/ip_fw.h>
80 #include <netinet/ip_icmp.h>
81 #include <netinet/ip_options.h>
82 #include <machine/in_cksum.h>
83 #include <netinet/ip_carp.h>
84 #include <netinet/in_rss.h>
85 #include <netinet/ip_mroute.h>
86 
87 #include <netipsec/ipsec_support.h>
88 
89 #include <sys/socketvar.h>
90 
91 #include <security/mac/mac_framework.h>
92 
93 #ifdef CTASSERT
94 CTASSERT(sizeof(struct ip) == 20);
95 #endif
96 
97 /* IP reassembly functions are defined in ip_reass.c. */
98 extern void ipreass_init(void);
99 extern void ipreass_drain(void);
100 extern void ipreass_slowtimo(void);
101 #ifdef VIMAGE
102 extern void ipreass_destroy(void);
103 #endif
104 
105 VNET_DEFINE(int, rsvp_on);
106 
107 VNET_DEFINE(int, ipforwarding);
108 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
109     &VNET_NAME(ipforwarding), 0,
110     "Enable IP forwarding between interfaces");
111 
112 /*
113  * Respond with an ICMP host redirect when we forward a packet out of
114  * the same interface on which it was received.  See RFC 792.
115  */
116 VNET_DEFINE(int, ipsendredirects) = 1;
117 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
118     &VNET_NAME(ipsendredirects), 0,
119     "Enable sending IP redirects");
120 
121 /*
122  * XXX - Setting ip_checkinterface mostly implements the receive side of
123  * the Strong ES model described in RFC 1122, but since the routing table
124  * and transmit implementation do not implement the Strong ES model,
125  * setting this to 1 results in an odd hybrid.
126  *
127  * XXX - ip_checkinterface currently must be disabled if you use ipnat
128  * to translate the destination address to another local interface.
129  *
130  * XXX - ip_checkinterface must be disabled if you add IP aliases
131  * to the loopback interface instead of the interface where the
132  * packets for those addresses are received.
133  */
134 VNET_DEFINE_STATIC(int, ip_checkinterface);
135 #define	V_ip_checkinterface	VNET(ip_checkinterface)
136 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
137     &VNET_NAME(ip_checkinterface), 0,
138     "Verify packet arrives on correct interface");
139 
140 VNET_DEFINE(pfil_head_t, inet_pfil_head);	/* Packet filter hooks */
141 
142 static struct netisr_handler ip_nh = {
143 	.nh_name = "ip",
144 	.nh_handler = ip_input,
145 	.nh_proto = NETISR_IP,
146 #ifdef	RSS
147 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
148 	.nh_policy = NETISR_POLICY_CPU,
149 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
150 #else
151 	.nh_policy = NETISR_POLICY_FLOW,
152 #endif
153 };
154 
155 #ifdef	RSS
156 /*
157  * Directly dispatched frames are currently assumed
158  * to have a flowid already calculated.
159  *
160  * It should likely have something that assert it
161  * actually has valid flow details.
162  */
163 static struct netisr_handler ip_direct_nh = {
164 	.nh_name = "ip_direct",
165 	.nh_handler = ip_direct_input,
166 	.nh_proto = NETISR_IP_DIRECT,
167 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
168 	.nh_policy = NETISR_POLICY_CPU,
169 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
170 };
171 #endif
172 
173 extern	struct domain inetdomain;
174 extern	struct protosw inetsw[];
175 u_char	ip_protox[IPPROTO_MAX];
176 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
177 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
178 VNET_DEFINE(u_long, in_ifaddrhmask);		/* mask for hash table */
179 
180 /* Make sure it is safe to use hashinit(9) on CK_LIST. */
181 CTASSERT(sizeof(struct in_ifaddrhashhead) == sizeof(LIST_HEAD(, in_addr)));
182 
183 #ifdef IPCTL_DEFMTU
184 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
185     &ip_mtu, 0, "Default MTU");
186 #endif
187 
188 #ifdef IPSTEALTH
189 VNET_DEFINE(int, ipstealth);
190 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
191     &VNET_NAME(ipstealth), 0,
192     "IP stealth mode, no TTL decrementation on forwarding");
193 #endif
194 
195 /*
196  * IP statistics are stored in the "array" of counter(9)s.
197  */
198 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
199 VNET_PCPUSTAT_SYSINIT(ipstat);
200 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
201     "IP statistics (struct ipstat, netinet/ip_var.h)");
202 
203 #ifdef VIMAGE
204 VNET_PCPUSTAT_SYSUNINIT(ipstat);
205 #endif /* VIMAGE */
206 
207 /*
208  * Kernel module interface for updating ipstat.  The argument is an index
209  * into ipstat treated as an array.
210  */
211 void
212 kmod_ipstat_inc(int statnum)
213 {
214 
215 	counter_u64_add(VNET(ipstat)[statnum], 1);
216 }
217 
218 void
219 kmod_ipstat_dec(int statnum)
220 {
221 
222 	counter_u64_add(VNET(ipstat)[statnum], -1);
223 }
224 
225 static int
226 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
227 {
228 	int error, qlimit;
229 
230 	netisr_getqlimit(&ip_nh, &qlimit);
231 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
232 	if (error || !req->newptr)
233 		return (error);
234 	if (qlimit < 1)
235 		return (EINVAL);
236 	return (netisr_setqlimit(&ip_nh, qlimit));
237 }
238 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
239     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
240     sysctl_netinet_intr_queue_maxlen, "I",
241     "Maximum size of the IP input queue");
242 
243 static int
244 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
245 {
246 	u_int64_t qdrops_long;
247 	int error, qdrops;
248 
249 	netisr_getqdrops(&ip_nh, &qdrops_long);
250 	qdrops = qdrops_long;
251 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
252 	if (error || !req->newptr)
253 		return (error);
254 	if (qdrops != 0)
255 		return (EINVAL);
256 	netisr_clearqdrops(&ip_nh);
257 	return (0);
258 }
259 
260 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
261     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE,
262     0, 0, sysctl_netinet_intr_queue_drops, "I",
263     "Number of packets dropped from the IP input queue");
264 
265 #ifdef	RSS
266 static int
267 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
268 {
269 	int error, qlimit;
270 
271 	netisr_getqlimit(&ip_direct_nh, &qlimit);
272 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
273 	if (error || !req->newptr)
274 		return (error);
275 	if (qlimit < 1)
276 		return (EINVAL);
277 	return (netisr_setqlimit(&ip_direct_nh, qlimit));
278 }
279 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
280     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
281     0, 0, sysctl_netinet_intr_direct_queue_maxlen,
282     "I", "Maximum size of the IP direct input queue");
283 
284 static int
285 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
286 {
287 	u_int64_t qdrops_long;
288 	int error, qdrops;
289 
290 	netisr_getqdrops(&ip_direct_nh, &qdrops_long);
291 	qdrops = qdrops_long;
292 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
293 	if (error || !req->newptr)
294 		return (error);
295 	if (qdrops != 0)
296 		return (EINVAL);
297 	netisr_clearqdrops(&ip_direct_nh);
298 	return (0);
299 }
300 
301 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops,
302     CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 0,
303     sysctl_netinet_intr_direct_queue_drops, "I",
304     "Number of packets dropped from the IP direct input queue");
305 #endif	/* RSS */
306 
307 /*
308  * IP initialization: fill in IP protocol switch table.
309  * All protocols not implemented in kernel go to raw IP protocol handler.
310  */
311 void
312 ip_init(void)
313 {
314 	struct pfil_head_args args;
315 	struct protosw *pr;
316 	int i;
317 
318 	CK_STAILQ_INIT(&V_in_ifaddrhead);
319 	V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
320 
321 	/* Initialize IP reassembly queue. */
322 	ipreass_init();
323 
324 	/* Initialize packet filter hooks. */
325 	args.pa_version = PFIL_VERSION;
326 	args.pa_flags = PFIL_IN | PFIL_OUT;
327 	args.pa_type = PFIL_TYPE_IP4;
328 	args.pa_headname = PFIL_INET_NAME;
329 	V_inet_pfil_head = pfil_head_register(&args);
330 
331 	if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
332 	    &V_ipsec_hhh_in[HHOOK_IPSEC_INET],
333 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
334 		printf("%s: WARNING: unable to register input helper hook\n",
335 		    __func__);
336 	if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
337 	    &V_ipsec_hhh_out[HHOOK_IPSEC_INET],
338 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
339 		printf("%s: WARNING: unable to register output helper hook\n",
340 		    __func__);
341 
342 	/* Skip initialization of globals for non-default instances. */
343 #ifdef VIMAGE
344 	if (!IS_DEFAULT_VNET(curvnet)) {
345 		netisr_register_vnet(&ip_nh);
346 #ifdef	RSS
347 		netisr_register_vnet(&ip_direct_nh);
348 #endif
349 		return;
350 	}
351 #endif
352 
353 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
354 	if (pr == NULL)
355 		panic("ip_init: PF_INET not found");
356 
357 	/* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
358 	for (i = 0; i < IPPROTO_MAX; i++)
359 		ip_protox[i] = pr - inetsw;
360 	/*
361 	 * Cycle through IP protocols and put them into the appropriate place
362 	 * in ip_protox[].
363 	 */
364 	for (pr = inetdomain.dom_protosw;
365 	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
366 		if (pr->pr_domain->dom_family == PF_INET &&
367 		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
368 			/* Be careful to only index valid IP protocols. */
369 			if (pr->pr_protocol < IPPROTO_MAX)
370 				ip_protox[pr->pr_protocol] = pr - inetsw;
371 		}
372 
373 	netisr_register(&ip_nh);
374 #ifdef	RSS
375 	netisr_register(&ip_direct_nh);
376 #endif
377 }
378 
379 #ifdef VIMAGE
380 static void
381 ip_destroy(void *unused __unused)
382 {
383 	int error;
384 
385 #ifdef	RSS
386 	netisr_unregister_vnet(&ip_direct_nh);
387 #endif
388 	netisr_unregister_vnet(&ip_nh);
389 
390 	pfil_head_unregister(V_inet_pfil_head);
391 	error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
392 	if (error != 0) {
393 		printf("%s: WARNING: unable to deregister input helper hook "
394 		    "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
395 		    "error %d returned\n", __func__, error);
396 	}
397 	error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
398 	if (error != 0) {
399 		printf("%s: WARNING: unable to deregister output helper hook "
400 		    "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
401 		    "error %d returned\n", __func__, error);
402 	}
403 
404 	/* Remove the IPv4 addresses from all interfaces. */
405 	in_ifscrub_all();
406 
407 	/* Make sure the IPv4 routes are gone as well. */
408 	rib_flush_routes_family(AF_INET);
409 
410 	/* Destroy IP reassembly queue. */
411 	ipreass_destroy();
412 
413 	/* Cleanup in_ifaddr hash table; should be empty. */
414 	hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
415 }
416 
417 VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
418 #endif
419 
420 #ifdef	RSS
421 /*
422  * IP direct input routine.
423  *
424  * This is called when reinjecting completed fragments where
425  * all of the previous checking and book-keeping has been done.
426  */
427 void
428 ip_direct_input(struct mbuf *m)
429 {
430 	struct ip *ip;
431 	int hlen;
432 
433 	ip = mtod(m, struct ip *);
434 	hlen = ip->ip_hl << 2;
435 
436 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
437 	if (IPSEC_ENABLED(ipv4)) {
438 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
439 			return;
440 	}
441 #endif /* IPSEC */
442 	IPSTAT_INC(ips_delivered);
443 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
444 	return;
445 }
446 #endif
447 
448 /*
449  * Ip input routine.  Checksum and byte swap header.  If fragmented
450  * try to reassemble.  Process options.  Pass to next level.
451  */
452 void
453 ip_input(struct mbuf *m)
454 {
455 	MROUTER_RLOCK_TRACKER;
456 	struct ip *ip = NULL;
457 	struct in_ifaddr *ia = NULL;
458 	struct ifaddr *ifa;
459 	struct ifnet *ifp;
460 	int    checkif, hlen = 0;
461 	uint16_t sum, ip_len;
462 	int dchg = 0;				/* dest changed after fw */
463 	struct in_addr odst;			/* original dst address */
464 
465 	M_ASSERTPKTHDR(m);
466 	NET_EPOCH_ASSERT();
467 
468 	if (m->m_flags & M_FASTFWD_OURS) {
469 		m->m_flags &= ~M_FASTFWD_OURS;
470 		/* Set up some basics that will be used later. */
471 		ip = mtod(m, struct ip *);
472 		hlen = ip->ip_hl << 2;
473 		ip_len = ntohs(ip->ip_len);
474 		goto ours;
475 	}
476 
477 	IPSTAT_INC(ips_total);
478 
479 	if (m->m_pkthdr.len < sizeof(struct ip))
480 		goto tooshort;
481 
482 	if (m->m_len < sizeof (struct ip) &&
483 	    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
484 		IPSTAT_INC(ips_toosmall);
485 		return;
486 	}
487 	ip = mtod(m, struct ip *);
488 
489 	if (ip->ip_v != IPVERSION) {
490 		IPSTAT_INC(ips_badvers);
491 		goto bad;
492 	}
493 
494 	hlen = ip->ip_hl << 2;
495 	if (hlen < sizeof(struct ip)) {	/* minimum header length */
496 		IPSTAT_INC(ips_badhlen);
497 		goto bad;
498 	}
499 	if (hlen > m->m_len) {
500 		if ((m = m_pullup(m, hlen)) == NULL) {
501 			IPSTAT_INC(ips_badhlen);
502 			return;
503 		}
504 		ip = mtod(m, struct ip *);
505 	}
506 
507 	IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
508 
509 	/* IN_LOOPBACK must not appear on the wire - RFC1122 */
510 	ifp = m->m_pkthdr.rcvif;
511 	if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) ||
512 	    IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) {
513 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
514 			IPSTAT_INC(ips_badaddr);
515 			goto bad;
516 		}
517 	}
518 
519 	if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
520 		sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
521 	} else {
522 		if (hlen == sizeof(struct ip)) {
523 			sum = in_cksum_hdr(ip);
524 		} else {
525 			sum = in_cksum(m, hlen);
526 		}
527 	}
528 	if (sum) {
529 		IPSTAT_INC(ips_badsum);
530 		goto bad;
531 	}
532 
533 #ifdef ALTQ
534 	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
535 		/* packet is dropped by traffic conditioner */
536 		return;
537 #endif
538 
539 	ip_len = ntohs(ip->ip_len);
540 	if (ip_len < hlen) {
541 		IPSTAT_INC(ips_badlen);
542 		goto bad;
543 	}
544 
545 	/*
546 	 * Check that the amount of data in the buffers
547 	 * is as at least much as the IP header would have us expect.
548 	 * Trim mbufs if longer than we expect.
549 	 * Drop packet if shorter than we expect.
550 	 */
551 	if (m->m_pkthdr.len < ip_len) {
552 tooshort:
553 		IPSTAT_INC(ips_tooshort);
554 		goto bad;
555 	}
556 	if (m->m_pkthdr.len > ip_len) {
557 		if (m->m_len == m->m_pkthdr.len) {
558 			m->m_len = ip_len;
559 			m->m_pkthdr.len = ip_len;
560 		} else
561 			m_adj(m, ip_len - m->m_pkthdr.len);
562 	}
563 
564 	/*
565 	 * Try to forward the packet, but if we fail continue.
566 	 * ip_tryforward() does not generate redirects, so fall
567 	 * through to normal processing if redirects are required.
568 	 * ip_tryforward() does inbound and outbound packet firewall
569 	 * processing. If firewall has decided that destination becomes
570 	 * our local address, it sets M_FASTFWD_OURS flag. In this
571 	 * case skip another inbound firewall processing and update
572 	 * ip pointer.
573 	 */
574 	if (V_ipforwarding != 0
575 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
576 	    && (!IPSEC_ENABLED(ipv4) ||
577 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
578 #endif
579 	    ) {
580 		if ((m = ip_tryforward(m)) == NULL)
581 			return;
582 		if (m->m_flags & M_FASTFWD_OURS) {
583 			m->m_flags &= ~M_FASTFWD_OURS;
584 			ip = mtod(m, struct ip *);
585 			goto ours;
586 		}
587 	}
588 
589 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
590 	/*
591 	 * Bypass packet filtering for packets previously handled by IPsec.
592 	 */
593 	if (IPSEC_ENABLED(ipv4) &&
594 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
595 			goto passin;
596 #endif
597 
598 	/*
599 	 * Run through list of hooks for input packets.
600 	 *
601 	 * NB: Beware of the destination address changing (e.g.
602 	 *     by NAT rewriting).  When this happens, tell
603 	 *     ip_forward to do the right thing.
604 	 */
605 
606 	/* Jump over all PFIL processing if hooks are not active. */
607 	if (!PFIL_HOOKED_IN(V_inet_pfil_head))
608 		goto passin;
609 
610 	odst = ip->ip_dst;
611 	if (pfil_run_hooks(V_inet_pfil_head, &m, ifp, PFIL_IN, NULL) !=
612 	    PFIL_PASS)
613 		return;
614 	if (m == NULL)			/* consumed by filter */
615 		return;
616 
617 	ip = mtod(m, struct ip *);
618 	dchg = (odst.s_addr != ip->ip_dst.s_addr);
619 	ifp = m->m_pkthdr.rcvif;
620 
621 	if (m->m_flags & M_FASTFWD_OURS) {
622 		m->m_flags &= ~M_FASTFWD_OURS;
623 		goto ours;
624 	}
625 	if (m->m_flags & M_IP_NEXTHOP) {
626 		if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
627 			/*
628 			 * Directly ship the packet on.  This allows
629 			 * forwarding packets originally destined to us
630 			 * to some other directly connected host.
631 			 */
632 			ip_forward(m, 1);
633 			return;
634 		}
635 	}
636 passin:
637 
638 	/*
639 	 * Process options and, if not destined for us,
640 	 * ship it on.  ip_dooptions returns 1 when an
641 	 * error was detected (causing an icmp message
642 	 * to be sent and the original packet to be freed).
643 	 */
644 	if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
645 		return;
646 
647         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
648          * matter if it is destined to another node, or whether it is
649          * a multicast one, RSVP wants it! and prevents it from being forwarded
650          * anywhere else. Also checks if the rsvp daemon is running before
651 	 * grabbing the packet.
652          */
653 	if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
654 		goto ours;
655 
656 	/*
657 	 * Check our list of addresses, to see if the packet is for us.
658 	 * If we don't have any addresses, assume any unicast packet
659 	 * we receive might be for us (and let the upper layers deal
660 	 * with it).
661 	 */
662 	if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) &&
663 	    (m->m_flags & (M_MCAST|M_BCAST)) == 0)
664 		goto ours;
665 
666 	/*
667 	 * Enable a consistency check between the destination address
668 	 * and the arrival interface for a unicast packet (the RFC 1122
669 	 * strong ES model) if IP forwarding is disabled and the packet
670 	 * is not locally generated and the packet is not subject to
671 	 * 'ipfw fwd'.
672 	 *
673 	 * XXX - Checking also should be disabled if the destination
674 	 * address is ipnat'ed to a different interface.
675 	 *
676 	 * XXX - Checking is incompatible with IP aliases added
677 	 * to the loopback interface instead of the interface where
678 	 * the packets are received.
679 	 *
680 	 * XXX - This is the case for carp vhost IPs as well so we
681 	 * insert a workaround. If the packet got here, we already
682 	 * checked with carp_iamatch() and carp_forus().
683 	 */
684 	checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
685 	    ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
686 	    ifp->if_carp == NULL && (dchg == 0);
687 
688 	/*
689 	 * Check for exact addresses in the hash bucket.
690 	 */
691 	CK_LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
692 		/*
693 		 * If the address matches, verify that the packet
694 		 * arrived via the correct interface if checking is
695 		 * enabled.
696 		 */
697 		if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
698 		    (!checkif || ia->ia_ifp == ifp)) {
699 			counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
700 			counter_u64_add(ia->ia_ifa.ifa_ibytes,
701 			    m->m_pkthdr.len);
702 			goto ours;
703 		}
704 	}
705 
706 	/*
707 	 * Check for broadcast addresses.
708 	 *
709 	 * Only accept broadcast packets that arrive via the matching
710 	 * interface.  Reception of forwarded directed broadcasts would
711 	 * be handled via ip_forward() and ether_output() with the loopback
712 	 * into the stack for SIMPLEX interfaces handled by ether_output().
713 	 */
714 	if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
715 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
716 			if (ifa->ifa_addr->sa_family != AF_INET)
717 				continue;
718 			ia = ifatoia(ifa);
719 			if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
720 			    ip->ip_dst.s_addr) {
721 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
722 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
723 				    m->m_pkthdr.len);
724 				goto ours;
725 			}
726 #ifdef BOOTP_COMPAT
727 			if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
728 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
729 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
730 				    m->m_pkthdr.len);
731 				goto ours;
732 			}
733 #endif
734 		}
735 		ia = NULL;
736 	}
737 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
738 		MROUTER_RLOCK();
739 		/*
740 		 * RFC 3927 2.7: Do not forward multicast packets from
741 		 * IN_LINKLOCAL.
742 		 */
743 		if (V_ip_mrouter && !IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) {
744 			/*
745 			 * If we are acting as a multicast router, all
746 			 * incoming multicast packets are passed to the
747 			 * kernel-level multicast forwarding function.
748 			 * The packet is returned (relatively) intact; if
749 			 * ip_mforward() returns a non-zero value, the packet
750 			 * must be discarded, else it may be accepted below.
751 			 */
752 			if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
753 				MROUTER_RUNLOCK();
754 				IPSTAT_INC(ips_cantforward);
755 				m_freem(m);
756 				return;
757 			}
758 
759 			/*
760 			 * The process-level routing daemon needs to receive
761 			 * all multicast IGMP packets, whether or not this
762 			 * host belongs to their destination groups.
763 			 */
764 			if (ip->ip_p == IPPROTO_IGMP) {
765 				MROUTER_RUNLOCK();
766 				goto ours;
767 			}
768 			IPSTAT_INC(ips_forward);
769 		}
770 		MROUTER_RUNLOCK();
771 		/*
772 		 * Assume the packet is for us, to avoid prematurely taking
773 		 * a lock on the in_multi hash. Protocols must perform
774 		 * their own filtering and update statistics accordingly.
775 		 */
776 		goto ours;
777 	}
778 	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
779 		goto ours;
780 	if (ip->ip_dst.s_addr == INADDR_ANY)
781 		goto ours;
782 	/* RFC 3927 2.7: Do not forward packets to or from IN_LINKLOCAL. */
783 	if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) ||
784 	    IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) {
785 		IPSTAT_INC(ips_cantforward);
786 		m_freem(m);
787 		return;
788 	}
789 
790 	/*
791 	 * Not for us; forward if possible and desirable.
792 	 */
793 	if (V_ipforwarding == 0) {
794 		IPSTAT_INC(ips_cantforward);
795 		m_freem(m);
796 	} else {
797 		ip_forward(m, dchg);
798 	}
799 	return;
800 
801 ours:
802 #ifdef IPSTEALTH
803 	/*
804 	 * IPSTEALTH: Process non-routing options only
805 	 * if the packet is destined for us.
806 	 */
807 	if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
808 		return;
809 #endif /* IPSTEALTH */
810 
811 	/*
812 	 * Attempt reassembly; if it succeeds, proceed.
813 	 * ip_reass() will return a different mbuf.
814 	 */
815 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
816 		/* XXXGL: shouldn't we save & set m_flags? */
817 		m = ip_reass(m);
818 		if (m == NULL)
819 			return;
820 		ip = mtod(m, struct ip *);
821 		/* Get the header length of the reassembled packet */
822 		hlen = ip->ip_hl << 2;
823 	}
824 
825 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
826 	if (IPSEC_ENABLED(ipv4)) {
827 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
828 			return;
829 	}
830 #endif /* IPSEC */
831 
832 	/*
833 	 * Switch out to protocol's input routine.
834 	 */
835 	IPSTAT_INC(ips_delivered);
836 
837 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
838 	return;
839 bad:
840 	m_freem(m);
841 }
842 
843 /*
844  * IP timer processing;
845  * if a timer expires on a reassembly
846  * queue, discard it.
847  */
848 void
849 ip_slowtimo(void)
850 {
851 	VNET_ITERATOR_DECL(vnet_iter);
852 
853 	VNET_LIST_RLOCK_NOSLEEP();
854 	VNET_FOREACH(vnet_iter) {
855 		CURVNET_SET(vnet_iter);
856 		ipreass_slowtimo();
857 		CURVNET_RESTORE();
858 	}
859 	VNET_LIST_RUNLOCK_NOSLEEP();
860 }
861 
862 void
863 ip_drain(void)
864 {
865 	VNET_ITERATOR_DECL(vnet_iter);
866 
867 	VNET_LIST_RLOCK_NOSLEEP();
868 	VNET_FOREACH(vnet_iter) {
869 		CURVNET_SET(vnet_iter);
870 		ipreass_drain();
871 		CURVNET_RESTORE();
872 	}
873 	VNET_LIST_RUNLOCK_NOSLEEP();
874 }
875 
876 /*
877  * The protocol to be inserted into ip_protox[] must be already registered
878  * in inetsw[], either statically or through pf_proto_register().
879  */
880 int
881 ipproto_register(short ipproto)
882 {
883 	struct protosw *pr;
884 
885 	/* Sanity checks. */
886 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
887 		return (EPROTONOSUPPORT);
888 
889 	/*
890 	 * The protocol slot must not be occupied by another protocol
891 	 * already.  An index pointing to IPPROTO_RAW is unused.
892 	 */
893 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
894 	if (pr == NULL)
895 		return (EPFNOSUPPORT);
896 	if (ip_protox[ipproto] != pr - inetsw)	/* IPPROTO_RAW */
897 		return (EEXIST);
898 
899 	/* Find the protocol position in inetsw[] and set the index. */
900 	for (pr = inetdomain.dom_protosw;
901 	     pr < inetdomain.dom_protoswNPROTOSW; pr++) {
902 		if (pr->pr_domain->dom_family == PF_INET &&
903 		    pr->pr_protocol && pr->pr_protocol == ipproto) {
904 			ip_protox[pr->pr_protocol] = pr - inetsw;
905 			return (0);
906 		}
907 	}
908 	return (EPROTONOSUPPORT);
909 }
910 
911 int
912 ipproto_unregister(short ipproto)
913 {
914 	struct protosw *pr;
915 
916 	/* Sanity checks. */
917 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
918 		return (EPROTONOSUPPORT);
919 
920 	/* Check if the protocol was indeed registered. */
921 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
922 	if (pr == NULL)
923 		return (EPFNOSUPPORT);
924 	if (ip_protox[ipproto] == pr - inetsw)  /* IPPROTO_RAW */
925 		return (ENOENT);
926 
927 	/* Reset the protocol slot to IPPROTO_RAW. */
928 	ip_protox[ipproto] = pr - inetsw;
929 	return (0);
930 }
931 
932 u_char inetctlerrmap[PRC_NCMDS] = {
933 	0,		0,		0,		0,
934 	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
935 	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
936 	EMSGSIZE,	EHOSTUNREACH,	0,		0,
937 	0,		0,		EHOSTUNREACH,	0,
938 	ENOPROTOOPT,	ECONNREFUSED
939 };
940 
941 /*
942  * Forward a packet.  If some error occurs return the sender
943  * an icmp packet.  Note we can't always generate a meaningful
944  * icmp message because icmp doesn't have a large enough repertoire
945  * of codes and types.
946  *
947  * If not forwarding, just drop the packet.  This could be confusing
948  * if ipforwarding was zero but some routing protocol was advancing
949  * us as a gateway to somewhere.  However, we must let the routing
950  * protocol deal with that.
951  *
952  * The srcrt parameter indicates whether the packet is being forwarded
953  * via a source route.
954  */
955 void
956 ip_forward(struct mbuf *m, int srcrt)
957 {
958 	struct ip *ip = mtod(m, struct ip *);
959 	struct in_ifaddr *ia;
960 	struct mbuf *mcopy;
961 	struct sockaddr_in *sin;
962 	struct in_addr dest;
963 	struct route ro;
964 	uint32_t flowid;
965 	int error, type = 0, code = 0, mtu = 0;
966 
967 	NET_EPOCH_ASSERT();
968 
969 	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
970 		IPSTAT_INC(ips_cantforward);
971 		m_freem(m);
972 		return;
973 	}
974 	if (
975 #ifdef IPSTEALTH
976 	    V_ipstealth == 0 &&
977 #endif
978 	    ip->ip_ttl <= IPTTLDEC) {
979 		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
980 		return;
981 	}
982 
983 	bzero(&ro, sizeof(ro));
984 	sin = (struct sockaddr_in *)&ro.ro_dst;
985 	sin->sin_family = AF_INET;
986 	sin->sin_len = sizeof(*sin);
987 	sin->sin_addr = ip->ip_dst;
988 	flowid = m->m_pkthdr.flowid;
989 	ro.ro_nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_REF, flowid);
990 	if (ro.ro_nh != NULL) {
991 		ia = ifatoia(ro.ro_nh->nh_ifa);
992 	} else
993 		ia = NULL;
994 	/*
995 	 * Save the IP header and at most 8 bytes of the payload,
996 	 * in case we need to generate an ICMP message to the src.
997 	 *
998 	 * XXX this can be optimized a lot by saving the data in a local
999 	 * buffer on the stack (72 bytes at most), and only allocating the
1000 	 * mbuf if really necessary. The vast majority of the packets
1001 	 * are forwarded without having to send an ICMP back (either
1002 	 * because unnecessary, or because rate limited), so we are
1003 	 * really we are wasting a lot of work here.
1004 	 *
1005 	 * We don't use m_copym() because it might return a reference
1006 	 * to a shared cluster. Both this function and ip_output()
1007 	 * assume exclusive access to the IP header in `m', so any
1008 	 * data in a cluster may change before we reach icmp_error().
1009 	 */
1010 	mcopy = m_gethdr(M_NOWAIT, m->m_type);
1011 	if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
1012 		/*
1013 		 * It's probably ok if the pkthdr dup fails (because
1014 		 * the deep copy of the tag chain failed), but for now
1015 		 * be conservative and just discard the copy since
1016 		 * code below may some day want the tags.
1017 		 */
1018 		m_free(mcopy);
1019 		mcopy = NULL;
1020 	}
1021 	if (mcopy != NULL) {
1022 		mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1023 		mcopy->m_pkthdr.len = mcopy->m_len;
1024 		m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1025 	}
1026 #ifdef IPSTEALTH
1027 	if (V_ipstealth == 0)
1028 #endif
1029 		ip->ip_ttl -= IPTTLDEC;
1030 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1031 	if (IPSEC_ENABLED(ipv4)) {
1032 		if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
1033 			/* mbuf consumed by IPsec */
1034 			RO_NHFREE(&ro);
1035 			m_freem(mcopy);
1036 			if (error != EINPROGRESS)
1037 				IPSTAT_INC(ips_cantforward);
1038 			return;
1039 		}
1040 		/* No IPsec processing required */
1041 	}
1042 #endif /* IPSEC */
1043 	/*
1044 	 * If forwarding packet using same interface that it came in on,
1045 	 * perhaps should send a redirect to sender to shortcut a hop.
1046 	 * Only send redirect if source is sending directly to us,
1047 	 * and if packet was not source routed (or has any options).
1048 	 * Also, don't send redirect if forwarding using a default route
1049 	 * or a route modified by a redirect.
1050 	 */
1051 	dest.s_addr = 0;
1052 	if (!srcrt && V_ipsendredirects &&
1053 	    ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1054 		struct nhop_object *nh;
1055 
1056 		nh = ro.ro_nh;
1057 
1058 		if (nh != NULL && ((nh->nh_flags & (NHF_REDIRECT|NHF_DEFAULT)) == 0)) {
1059 			struct in_ifaddr *nh_ia = (struct in_ifaddr *)(nh->nh_ifa);
1060 			u_long src = ntohl(ip->ip_src.s_addr);
1061 
1062 			if (nh_ia != NULL &&
1063 			    (src & nh_ia->ia_subnetmask) == nh_ia->ia_subnet) {
1064 				/* Router requirements says to only send host redirects */
1065 				type = ICMP_REDIRECT;
1066 				code = ICMP_REDIRECT_HOST;
1067 				if (nh->nh_flags & NHF_GATEWAY) {
1068 				    if (nh->gw_sa.sa_family == AF_INET)
1069 					dest.s_addr = nh->gw4_sa.sin_addr.s_addr;
1070 				    else /* Do not redirect in case gw is AF_INET6 */
1071 					type = 0;
1072 				} else
1073 					dest.s_addr = ip->ip_dst.s_addr;
1074 			}
1075 		}
1076 	}
1077 
1078 	error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1079 
1080 	if (error == EMSGSIZE && ro.ro_nh)
1081 		mtu = ro.ro_nh->nh_mtu;
1082 	RO_NHFREE(&ro);
1083 
1084 	if (error)
1085 		IPSTAT_INC(ips_cantforward);
1086 	else {
1087 		IPSTAT_INC(ips_forward);
1088 		if (type)
1089 			IPSTAT_INC(ips_redirectsent);
1090 		else {
1091 			if (mcopy)
1092 				m_freem(mcopy);
1093 			return;
1094 		}
1095 	}
1096 	if (mcopy == NULL)
1097 		return;
1098 
1099 	switch (error) {
1100 	case 0:				/* forwarded, but need redirect */
1101 		/* type, code set above */
1102 		break;
1103 
1104 	case ENETUNREACH:
1105 	case EHOSTUNREACH:
1106 	case ENETDOWN:
1107 	case EHOSTDOWN:
1108 	default:
1109 		type = ICMP_UNREACH;
1110 		code = ICMP_UNREACH_HOST;
1111 		break;
1112 
1113 	case EMSGSIZE:
1114 		type = ICMP_UNREACH;
1115 		code = ICMP_UNREACH_NEEDFRAG;
1116 		/*
1117 		 * If the MTU was set before make sure we are below the
1118 		 * interface MTU.
1119 		 * If the MTU wasn't set before use the interface mtu or
1120 		 * fall back to the next smaller mtu step compared to the
1121 		 * current packet size.
1122 		 */
1123 		if (mtu != 0) {
1124 			if (ia != NULL)
1125 				mtu = min(mtu, ia->ia_ifp->if_mtu);
1126 		} else {
1127 			if (ia != NULL)
1128 				mtu = ia->ia_ifp->if_mtu;
1129 			else
1130 				mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1131 		}
1132 		IPSTAT_INC(ips_cantfrag);
1133 		break;
1134 
1135 	case ENOBUFS:
1136 	case EACCES:			/* ipfw denied packet */
1137 		m_freem(mcopy);
1138 		return;
1139 	}
1140 	icmp_error(mcopy, type, code, dest.s_addr, mtu);
1141 }
1142 
1143 #define	CHECK_SO_CT(sp, ct) \
1144     (((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0)
1145 
1146 void
1147 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1148     struct mbuf *m)
1149 {
1150 	bool stamped;
1151 
1152 	stamped = false;
1153 	if ((inp->inp_socket->so_options & SO_BINTIME) ||
1154 	    CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) {
1155 		struct bintime boottimebin, bt;
1156 		struct timespec ts1;
1157 
1158 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1159 		    M_TSTMP)) {
1160 			mbuf_tstmp2timespec(m, &ts1);
1161 			timespec2bintime(&ts1, &bt);
1162 			getboottimebin(&boottimebin);
1163 			bintime_add(&bt, &boottimebin);
1164 		} else {
1165 			bintime(&bt);
1166 		}
1167 		*mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1168 		    SCM_BINTIME, SOL_SOCKET);
1169 		if (*mp != NULL) {
1170 			mp = &(*mp)->m_next;
1171 			stamped = true;
1172 		}
1173 	}
1174 	if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) {
1175 		struct bintime boottimebin, bt1;
1176 		struct timespec ts1;
1177 		struct timeval tv;
1178 
1179 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1180 		    M_TSTMP)) {
1181 			mbuf_tstmp2timespec(m, &ts1);
1182 			timespec2bintime(&ts1, &bt1);
1183 			getboottimebin(&boottimebin);
1184 			bintime_add(&bt1, &boottimebin);
1185 			bintime2timeval(&bt1, &tv);
1186 		} else {
1187 			microtime(&tv);
1188 		}
1189 		*mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1190 		    SCM_TIMESTAMP, SOL_SOCKET);
1191 		if (*mp != NULL) {
1192 			mp = &(*mp)->m_next;
1193 			stamped = true;
1194 		}
1195 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) {
1196 		struct bintime boottimebin;
1197 		struct timespec ts, ts1;
1198 
1199 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1200 		    M_TSTMP)) {
1201 			mbuf_tstmp2timespec(m, &ts);
1202 			getboottimebin(&boottimebin);
1203 			bintime2timespec(&boottimebin, &ts1);
1204 			timespecadd(&ts, &ts1, &ts);
1205 		} else {
1206 			nanotime(&ts);
1207 		}
1208 		*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
1209 		    SCM_REALTIME, SOL_SOCKET);
1210 		if (*mp != NULL) {
1211 			mp = &(*mp)->m_next;
1212 			stamped = true;
1213 		}
1214 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) {
1215 		struct timespec ts;
1216 
1217 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1218 		    M_TSTMP))
1219 			mbuf_tstmp2timespec(m, &ts);
1220 		else
1221 			nanouptime(&ts);
1222 		*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
1223 		    SCM_MONOTONIC, SOL_SOCKET);
1224 		if (*mp != NULL) {
1225 			mp = &(*mp)->m_next;
1226 			stamped = true;
1227 		}
1228 	}
1229 	if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1230 	    M_TSTMP)) {
1231 		struct sock_timestamp_info sti;
1232 
1233 		bzero(&sti, sizeof(sti));
1234 		sti.st_info_flags = ST_INFO_HW;
1235 		if ((m->m_flags & M_TSTMP_HPREC) != 0)
1236 			sti.st_info_flags |= ST_INFO_HW_HPREC;
1237 		*mp = sbcreatecontrol((caddr_t)&sti, sizeof(sti), SCM_TIME_INFO,
1238 		    SOL_SOCKET);
1239 		if (*mp != NULL)
1240 			mp = &(*mp)->m_next;
1241 	}
1242 	if (inp->inp_flags & INP_RECVDSTADDR) {
1243 		*mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1244 		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1245 		if (*mp)
1246 			mp = &(*mp)->m_next;
1247 	}
1248 	if (inp->inp_flags & INP_RECVTTL) {
1249 		*mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1250 		    sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1251 		if (*mp)
1252 			mp = &(*mp)->m_next;
1253 	}
1254 #ifdef notyet
1255 	/* XXX
1256 	 * Moving these out of udp_input() made them even more broken
1257 	 * than they already were.
1258 	 */
1259 	/* options were tossed already */
1260 	if (inp->inp_flags & INP_RECVOPTS) {
1261 		*mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1262 		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1263 		if (*mp)
1264 			mp = &(*mp)->m_next;
1265 	}
1266 	/* ip_srcroute doesn't do what we want here, need to fix */
1267 	if (inp->inp_flags & INP_RECVRETOPTS) {
1268 		*mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1269 		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1270 		if (*mp)
1271 			mp = &(*mp)->m_next;
1272 	}
1273 #endif
1274 	if (inp->inp_flags & INP_RECVIF) {
1275 		struct ifnet *ifp;
1276 		struct sdlbuf {
1277 			struct sockaddr_dl sdl;
1278 			u_char	pad[32];
1279 		} sdlbuf;
1280 		struct sockaddr_dl *sdp;
1281 		struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1282 
1283 		if ((ifp = m->m_pkthdr.rcvif) &&
1284 		    ifp->if_index && ifp->if_index <= V_if_index) {
1285 			sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1286 			/*
1287 			 * Change our mind and don't try copy.
1288 			 */
1289 			if (sdp->sdl_family != AF_LINK ||
1290 			    sdp->sdl_len > sizeof(sdlbuf)) {
1291 				goto makedummy;
1292 			}
1293 			bcopy(sdp, sdl2, sdp->sdl_len);
1294 		} else {
1295 makedummy:
1296 			sdl2->sdl_len =
1297 			    offsetof(struct sockaddr_dl, sdl_data[0]);
1298 			sdl2->sdl_family = AF_LINK;
1299 			sdl2->sdl_index = 0;
1300 			sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1301 		}
1302 		*mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1303 		    IP_RECVIF, IPPROTO_IP);
1304 		if (*mp)
1305 			mp = &(*mp)->m_next;
1306 	}
1307 	if (inp->inp_flags & INP_RECVTOS) {
1308 		*mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1309 		    sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1310 		if (*mp)
1311 			mp = &(*mp)->m_next;
1312 	}
1313 
1314 	if (inp->inp_flags2 & INP_RECVFLOWID) {
1315 		uint32_t flowid, flow_type;
1316 
1317 		flowid = m->m_pkthdr.flowid;
1318 		flow_type = M_HASHTYPE_GET(m);
1319 
1320 		/*
1321 		 * XXX should handle the failure of one or the
1322 		 * other - don't populate both?
1323 		 */
1324 		*mp = sbcreatecontrol((caddr_t) &flowid,
1325 		    sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
1326 		if (*mp)
1327 			mp = &(*mp)->m_next;
1328 		*mp = sbcreatecontrol((caddr_t) &flow_type,
1329 		    sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
1330 		if (*mp)
1331 			mp = &(*mp)->m_next;
1332 	}
1333 
1334 #ifdef	RSS
1335 	if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1336 		uint32_t flowid, flow_type;
1337 		uint32_t rss_bucketid;
1338 
1339 		flowid = m->m_pkthdr.flowid;
1340 		flow_type = M_HASHTYPE_GET(m);
1341 
1342 		if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1343 			*mp = sbcreatecontrol((caddr_t) &rss_bucketid,
1344 			   sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
1345 			if (*mp)
1346 				mp = &(*mp)->m_next;
1347 		}
1348 	}
1349 #endif
1350 }
1351 
1352 /*
1353  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1354  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1355  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
1356  * compiled.
1357  */
1358 VNET_DEFINE_STATIC(int, ip_rsvp_on);
1359 VNET_DEFINE(struct socket *, ip_rsvpd);
1360 
1361 #define	V_ip_rsvp_on		VNET(ip_rsvp_on)
1362 
1363 int
1364 ip_rsvp_init(struct socket *so)
1365 {
1366 
1367 	if (so->so_type != SOCK_RAW ||
1368 	    so->so_proto->pr_protocol != IPPROTO_RSVP)
1369 		return EOPNOTSUPP;
1370 
1371 	if (V_ip_rsvpd != NULL)
1372 		return EADDRINUSE;
1373 
1374 	V_ip_rsvpd = so;
1375 	/*
1376 	 * This may seem silly, but we need to be sure we don't over-increment
1377 	 * the RSVP counter, in case something slips up.
1378 	 */
1379 	if (!V_ip_rsvp_on) {
1380 		V_ip_rsvp_on = 1;
1381 		V_rsvp_on++;
1382 	}
1383 
1384 	return 0;
1385 }
1386 
1387 int
1388 ip_rsvp_done(void)
1389 {
1390 
1391 	V_ip_rsvpd = NULL;
1392 	/*
1393 	 * This may seem silly, but we need to be sure we don't over-decrement
1394 	 * the RSVP counter, in case something slips up.
1395 	 */
1396 	if (V_ip_rsvp_on) {
1397 		V_ip_rsvp_on = 0;
1398 		V_rsvp_on--;
1399 	}
1400 	return 0;
1401 }
1402 
1403 int
1404 rsvp_input(struct mbuf **mp, int *offp, int proto)
1405 {
1406 	struct mbuf *m;
1407 
1408 	m = *mp;
1409 	*mp = NULL;
1410 
1411 	if (rsvp_input_p) { /* call the real one if loaded */
1412 		*mp = m;
1413 		rsvp_input_p(mp, offp, proto);
1414 		return (IPPROTO_DONE);
1415 	}
1416 
1417 	/* Can still get packets with rsvp_on = 0 if there is a local member
1418 	 * of the group to which the RSVP packet is addressed.  But in this
1419 	 * case we want to throw the packet away.
1420 	 */
1421 
1422 	if (!V_rsvp_on) {
1423 		m_freem(m);
1424 		return (IPPROTO_DONE);
1425 	}
1426 
1427 	if (V_ip_rsvpd != NULL) {
1428 		*mp = m;
1429 		rip_input(mp, offp, proto);
1430 		return (IPPROTO_DONE);
1431 	}
1432 	/* Drop the packet */
1433 	m_freem(m);
1434 	return (IPPROTO_DONE);
1435 }
1436