xref: /freebsd/sys/netinet/ip_input.c (revision 79ac3c12a714bcd3f2354c52d948aed9575c46d6)
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 struct rmlock in_ifaddr_lock;
106 RM_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
107 
108 VNET_DEFINE(int, rsvp_on);
109 
110 VNET_DEFINE(int, ipforwarding);
111 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
112     &VNET_NAME(ipforwarding), 0,
113     "Enable IP forwarding between interfaces");
114 
115 /*
116  * Respond with an ICMP host redirect when we forward a packet out of
117  * the same interface on which it was received.  See RFC 792.
118  */
119 VNET_DEFINE(int, ipsendredirects) = 1;
120 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
121     &VNET_NAME(ipsendredirects), 0,
122     "Enable sending IP redirects");
123 
124 /*
125  * XXX - Setting ip_checkinterface mostly implements the receive side of
126  * the Strong ES model described in RFC 1122, but since the routing table
127  * and transmit implementation do not implement the Strong ES model,
128  * setting this to 1 results in an odd hybrid.
129  *
130  * XXX - ip_checkinterface currently must be disabled if you use ipnat
131  * to translate the destination address to another local interface.
132  *
133  * XXX - ip_checkinterface must be disabled if you add IP aliases
134  * to the loopback interface instead of the interface where the
135  * packets for those addresses are received.
136  */
137 VNET_DEFINE_STATIC(int, ip_checkinterface);
138 #define	V_ip_checkinterface	VNET(ip_checkinterface)
139 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
140     &VNET_NAME(ip_checkinterface), 0,
141     "Verify packet arrives on correct interface");
142 
143 VNET_DEFINE(pfil_head_t, inet_pfil_head);	/* Packet filter hooks */
144 
145 static struct netisr_handler ip_nh = {
146 	.nh_name = "ip",
147 	.nh_handler = ip_input,
148 	.nh_proto = NETISR_IP,
149 #ifdef	RSS
150 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
151 	.nh_policy = NETISR_POLICY_CPU,
152 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
153 #else
154 	.nh_policy = NETISR_POLICY_FLOW,
155 #endif
156 };
157 
158 #ifdef	RSS
159 /*
160  * Directly dispatched frames are currently assumed
161  * to have a flowid already calculated.
162  *
163  * It should likely have something that assert it
164  * actually has valid flow details.
165  */
166 static struct netisr_handler ip_direct_nh = {
167 	.nh_name = "ip_direct",
168 	.nh_handler = ip_direct_input,
169 	.nh_proto = NETISR_IP_DIRECT,
170 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
171 	.nh_policy = NETISR_POLICY_CPU,
172 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
173 };
174 #endif
175 
176 extern	struct domain inetdomain;
177 extern	struct protosw inetsw[];
178 u_char	ip_protox[IPPROTO_MAX];
179 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
180 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
181 VNET_DEFINE(u_long, in_ifaddrhmask);		/* mask for hash table */
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 rm_priotracker in_ifa_tracker;
457 	struct ip *ip = NULL;
458 	struct in_ifaddr *ia = NULL;
459 	struct ifaddr *ifa;
460 	struct ifnet *ifp;
461 	int    checkif, hlen = 0;
462 	uint16_t sum, ip_len;
463 	int dchg = 0;				/* dest changed after fw */
464 	struct in_addr odst;			/* original dst address */
465 
466 	M_ASSERTPKTHDR(m);
467 	NET_EPOCH_ASSERT();
468 
469 	if (m->m_flags & M_FASTFWD_OURS) {
470 		m->m_flags &= ~M_FASTFWD_OURS;
471 		/* Set up some basics that will be used later. */
472 		ip = mtod(m, struct ip *);
473 		hlen = ip->ip_hl << 2;
474 		ip_len = ntohs(ip->ip_len);
475 		goto ours;
476 	}
477 
478 	IPSTAT_INC(ips_total);
479 
480 	if (m->m_pkthdr.len < sizeof(struct ip))
481 		goto tooshort;
482 
483 	if (m->m_len < sizeof (struct ip) &&
484 	    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
485 		IPSTAT_INC(ips_toosmall);
486 		return;
487 	}
488 	ip = mtod(m, struct ip *);
489 
490 	if (ip->ip_v != IPVERSION) {
491 		IPSTAT_INC(ips_badvers);
492 		goto bad;
493 	}
494 
495 	hlen = ip->ip_hl << 2;
496 	if (hlen < sizeof(struct ip)) {	/* minimum header length */
497 		IPSTAT_INC(ips_badhlen);
498 		goto bad;
499 	}
500 	if (hlen > m->m_len) {
501 		if ((m = m_pullup(m, hlen)) == NULL) {
502 			IPSTAT_INC(ips_badhlen);
503 			return;
504 		}
505 		ip = mtod(m, struct ip *);
506 	}
507 
508 	IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
509 
510 	/* IN_LOOPBACK must not appear on the wire - RFC1122 */
511 	ifp = m->m_pkthdr.rcvif;
512 	if (IN_LOOPBACK(ntohl(ip->ip_dst.s_addr)) ||
513 	    IN_LOOPBACK(ntohl(ip->ip_src.s_addr))) {
514 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
515 			IPSTAT_INC(ips_badaddr);
516 			goto bad;
517 		}
518 	}
519 
520 	if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
521 		sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
522 	} else {
523 		if (hlen == sizeof(struct ip)) {
524 			sum = in_cksum_hdr(ip);
525 		} else {
526 			sum = in_cksum(m, hlen);
527 		}
528 	}
529 	if (sum) {
530 		IPSTAT_INC(ips_badsum);
531 		goto bad;
532 	}
533 
534 #ifdef ALTQ
535 	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
536 		/* packet is dropped by traffic conditioner */
537 		return;
538 #endif
539 
540 	ip_len = ntohs(ip->ip_len);
541 	if (ip_len < hlen) {
542 		IPSTAT_INC(ips_badlen);
543 		goto bad;
544 	}
545 
546 	/*
547 	 * Check that the amount of data in the buffers
548 	 * is as at least much as the IP header would have us expect.
549 	 * Trim mbufs if longer than we expect.
550 	 * Drop packet if shorter than we expect.
551 	 */
552 	if (m->m_pkthdr.len < ip_len) {
553 tooshort:
554 		IPSTAT_INC(ips_tooshort);
555 		goto bad;
556 	}
557 	if (m->m_pkthdr.len > ip_len) {
558 		if (m->m_len == m->m_pkthdr.len) {
559 			m->m_len = ip_len;
560 			m->m_pkthdr.len = ip_len;
561 		} else
562 			m_adj(m, ip_len - m->m_pkthdr.len);
563 	}
564 
565 	/*
566 	 * Try to forward the packet, but if we fail continue.
567 	 * ip_tryforward() does not generate redirects, so fall
568 	 * through to normal processing if redirects are required.
569 	 * ip_tryforward() does inbound and outbound packet firewall
570 	 * processing. If firewall has decided that destination becomes
571 	 * our local address, it sets M_FASTFWD_OURS flag. In this
572 	 * case skip another inbound firewall processing and update
573 	 * ip pointer.
574 	 */
575 	if (V_ipforwarding != 0
576 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
577 	    && (!IPSEC_ENABLED(ipv4) ||
578 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
579 #endif
580 	    ) {
581 		if ((m = ip_tryforward(m)) == NULL)
582 			return;
583 		if (m->m_flags & M_FASTFWD_OURS) {
584 			m->m_flags &= ~M_FASTFWD_OURS;
585 			ip = mtod(m, struct ip *);
586 			goto ours;
587 		}
588 	}
589 
590 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
591 	/*
592 	 * Bypass packet filtering for packets previously handled by IPsec.
593 	 */
594 	if (IPSEC_ENABLED(ipv4) &&
595 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
596 			goto passin;
597 #endif
598 
599 	/*
600 	 * Run through list of hooks for input packets.
601 	 *
602 	 * NB: Beware of the destination address changing (e.g.
603 	 *     by NAT rewriting).  When this happens, tell
604 	 *     ip_forward to do the right thing.
605 	 */
606 
607 	/* Jump over all PFIL processing if hooks are not active. */
608 	if (!PFIL_HOOKED_IN(V_inet_pfil_head))
609 		goto passin;
610 
611 	odst = ip->ip_dst;
612 	if (pfil_run_hooks(V_inet_pfil_head, &m, ifp, PFIL_IN, NULL) !=
613 	    PFIL_PASS)
614 		return;
615 	if (m == NULL)			/* consumed by filter */
616 		return;
617 
618 	ip = mtod(m, struct ip *);
619 	dchg = (odst.s_addr != ip->ip_dst.s_addr);
620 	ifp = m->m_pkthdr.rcvif;
621 
622 	if (m->m_flags & M_FASTFWD_OURS) {
623 		m->m_flags &= ~M_FASTFWD_OURS;
624 		goto ours;
625 	}
626 	if (m->m_flags & M_IP_NEXTHOP) {
627 		if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
628 			/*
629 			 * Directly ship the packet on.  This allows
630 			 * forwarding packets originally destined to us
631 			 * to some other directly connected host.
632 			 */
633 			ip_forward(m, 1);
634 			return;
635 		}
636 	}
637 passin:
638 
639 	/*
640 	 * Process options and, if not destined for us,
641 	 * ship it on.  ip_dooptions returns 1 when an
642 	 * error was detected (causing an icmp message
643 	 * to be sent and the original packet to be freed).
644 	 */
645 	if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
646 		return;
647 
648         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
649          * matter if it is destined to another node, or whether it is
650          * a multicast one, RSVP wants it! and prevents it from being forwarded
651          * anywhere else. Also checks if the rsvp daemon is running before
652 	 * grabbing the packet.
653          */
654 	if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
655 		goto ours;
656 
657 	/*
658 	 * Check our list of addresses, to see if the packet is for us.
659 	 * If we don't have any addresses, assume any unicast packet
660 	 * we receive might be for us (and let the upper layers deal
661 	 * with it).
662 	 */
663 	if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) &&
664 	    (m->m_flags & (M_MCAST|M_BCAST)) == 0)
665 		goto ours;
666 
667 	/*
668 	 * Enable a consistency check between the destination address
669 	 * and the arrival interface for a unicast packet (the RFC 1122
670 	 * strong ES model) if IP forwarding is disabled and the packet
671 	 * is not locally generated and the packet is not subject to
672 	 * 'ipfw fwd'.
673 	 *
674 	 * XXX - Checking also should be disabled if the destination
675 	 * address is ipnat'ed to a different interface.
676 	 *
677 	 * XXX - Checking is incompatible with IP aliases added
678 	 * to the loopback interface instead of the interface where
679 	 * the packets are received.
680 	 *
681 	 * XXX - This is the case for carp vhost IPs as well so we
682 	 * insert a workaround. If the packet got here, we already
683 	 * checked with carp_iamatch() and carp_forus().
684 	 */
685 	checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
686 	    ifp != NULL && ((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 	IN_IFADDR_RLOCK(&in_ifa_tracker);
693 	LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
694 		/*
695 		 * If the address matches, verify that the packet
696 		 * arrived via the correct interface if checking is
697 		 * enabled.
698 		 */
699 		if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
700 		    (!checkif || ia->ia_ifp == ifp)) {
701 			counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
702 			counter_u64_add(ia->ia_ifa.ifa_ibytes,
703 			    m->m_pkthdr.len);
704 			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
705 			goto ours;
706 		}
707 	}
708 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
709 
710 	/*
711 	 * Check for broadcast addresses.
712 	 *
713 	 * Only accept broadcast packets that arrive via the matching
714 	 * interface.  Reception of forwarded directed broadcasts would
715 	 * be handled via ip_forward() and ether_output() with the loopback
716 	 * into the stack for SIMPLEX interfaces handled by ether_output().
717 	 */
718 	if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
719 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
720 			if (ifa->ifa_addr->sa_family != AF_INET)
721 				continue;
722 			ia = ifatoia(ifa);
723 			if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
724 			    ip->ip_dst.s_addr) {
725 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
726 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
727 				    m->m_pkthdr.len);
728 				goto ours;
729 			}
730 #ifdef BOOTP_COMPAT
731 			if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
732 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
733 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
734 				    m->m_pkthdr.len);
735 				goto ours;
736 			}
737 #endif
738 		}
739 		ia = NULL;
740 	}
741 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
742 		MROUTER_RLOCK();
743 		/*
744 		 * RFC 3927 2.7: Do not forward multicast packets from
745 		 * IN_LINKLOCAL.
746 		 */
747 		if (V_ip_mrouter && !IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) {
748 			/*
749 			 * If we are acting as a multicast router, all
750 			 * incoming multicast packets are passed to the
751 			 * kernel-level multicast forwarding function.
752 			 * The packet is returned (relatively) intact; if
753 			 * ip_mforward() returns a non-zero value, the packet
754 			 * must be discarded, else it may be accepted below.
755 			 */
756 			if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
757 				MROUTER_RUNLOCK();
758 				IPSTAT_INC(ips_cantforward);
759 				m_freem(m);
760 				return;
761 			}
762 
763 			/*
764 			 * The process-level routing daemon needs to receive
765 			 * all multicast IGMP packets, whether or not this
766 			 * host belongs to their destination groups.
767 			 */
768 			if (ip->ip_p == IPPROTO_IGMP) {
769 				MROUTER_RUNLOCK();
770 				goto ours;
771 			}
772 			IPSTAT_INC(ips_forward);
773 		}
774 		MROUTER_RUNLOCK();
775 		/*
776 		 * Assume the packet is for us, to avoid prematurely taking
777 		 * a lock on the in_multi hash. Protocols must perform
778 		 * their own filtering and update statistics accordingly.
779 		 */
780 		goto ours;
781 	}
782 	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
783 		goto ours;
784 	if (ip->ip_dst.s_addr == INADDR_ANY)
785 		goto ours;
786 	/* RFC 3927 2.7: Do not forward packets to or from IN_LINKLOCAL. */
787 	if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr)) ||
788 	    IN_LINKLOCAL(ntohl(ip->ip_src.s_addr))) {
789 		IPSTAT_INC(ips_cantforward);
790 		m_freem(m);
791 		return;
792 	}
793 
794 	/*
795 	 * Not for us; forward if possible and desirable.
796 	 */
797 	if (V_ipforwarding == 0) {
798 		IPSTAT_INC(ips_cantforward);
799 		m_freem(m);
800 	} else {
801 		ip_forward(m, dchg);
802 	}
803 	return;
804 
805 ours:
806 #ifdef IPSTEALTH
807 	/*
808 	 * IPSTEALTH: Process non-routing options only
809 	 * if the packet is destined for us.
810 	 */
811 	if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
812 		return;
813 #endif /* IPSTEALTH */
814 
815 	/*
816 	 * Attempt reassembly; if it succeeds, proceed.
817 	 * ip_reass() will return a different mbuf.
818 	 */
819 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
820 		/* XXXGL: shouldn't we save & set m_flags? */
821 		m = ip_reass(m);
822 		if (m == NULL)
823 			return;
824 		ip = mtod(m, struct ip *);
825 		/* Get the header length of the reassembled packet */
826 		hlen = ip->ip_hl << 2;
827 	}
828 
829 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
830 	if (IPSEC_ENABLED(ipv4)) {
831 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
832 			return;
833 	}
834 #endif /* IPSEC */
835 
836 	/*
837 	 * Switch out to protocol's input routine.
838 	 */
839 	IPSTAT_INC(ips_delivered);
840 
841 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
842 	return;
843 bad:
844 	m_freem(m);
845 }
846 
847 /*
848  * IP timer processing;
849  * if a timer expires on a reassembly
850  * queue, discard it.
851  */
852 void
853 ip_slowtimo(void)
854 {
855 	VNET_ITERATOR_DECL(vnet_iter);
856 
857 	VNET_LIST_RLOCK_NOSLEEP();
858 	VNET_FOREACH(vnet_iter) {
859 		CURVNET_SET(vnet_iter);
860 		ipreass_slowtimo();
861 		CURVNET_RESTORE();
862 	}
863 	VNET_LIST_RUNLOCK_NOSLEEP();
864 }
865 
866 void
867 ip_drain(void)
868 {
869 	VNET_ITERATOR_DECL(vnet_iter);
870 
871 	VNET_LIST_RLOCK_NOSLEEP();
872 	VNET_FOREACH(vnet_iter) {
873 		CURVNET_SET(vnet_iter);
874 		ipreass_drain();
875 		CURVNET_RESTORE();
876 	}
877 	VNET_LIST_RUNLOCK_NOSLEEP();
878 }
879 
880 /*
881  * The protocol to be inserted into ip_protox[] must be already registered
882  * in inetsw[], either statically or through pf_proto_register().
883  */
884 int
885 ipproto_register(short ipproto)
886 {
887 	struct protosw *pr;
888 
889 	/* Sanity checks. */
890 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
891 		return (EPROTONOSUPPORT);
892 
893 	/*
894 	 * The protocol slot must not be occupied by another protocol
895 	 * already.  An index pointing to IPPROTO_RAW is unused.
896 	 */
897 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
898 	if (pr == NULL)
899 		return (EPFNOSUPPORT);
900 	if (ip_protox[ipproto] != pr - inetsw)	/* IPPROTO_RAW */
901 		return (EEXIST);
902 
903 	/* Find the protocol position in inetsw[] and set the index. */
904 	for (pr = inetdomain.dom_protosw;
905 	     pr < inetdomain.dom_protoswNPROTOSW; pr++) {
906 		if (pr->pr_domain->dom_family == PF_INET &&
907 		    pr->pr_protocol && pr->pr_protocol == ipproto) {
908 			ip_protox[pr->pr_protocol] = pr - inetsw;
909 			return (0);
910 		}
911 	}
912 	return (EPROTONOSUPPORT);
913 }
914 
915 int
916 ipproto_unregister(short ipproto)
917 {
918 	struct protosw *pr;
919 
920 	/* Sanity checks. */
921 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
922 		return (EPROTONOSUPPORT);
923 
924 	/* Check if the protocol was indeed registered. */
925 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
926 	if (pr == NULL)
927 		return (EPFNOSUPPORT);
928 	if (ip_protox[ipproto] == pr - inetsw)  /* IPPROTO_RAW */
929 		return (ENOENT);
930 
931 	/* Reset the protocol slot to IPPROTO_RAW. */
932 	ip_protox[ipproto] = pr - inetsw;
933 	return (0);
934 }
935 
936 u_char inetctlerrmap[PRC_NCMDS] = {
937 	0,		0,		0,		0,
938 	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
939 	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
940 	EMSGSIZE,	EHOSTUNREACH,	0,		0,
941 	0,		0,		EHOSTUNREACH,	0,
942 	ENOPROTOOPT,	ECONNREFUSED
943 };
944 
945 /*
946  * Forward a packet.  If some error occurs return the sender
947  * an icmp packet.  Note we can't always generate a meaningful
948  * icmp message because icmp doesn't have a large enough repertoire
949  * of codes and types.
950  *
951  * If not forwarding, just drop the packet.  This could be confusing
952  * if ipforwarding was zero but some routing protocol was advancing
953  * us as a gateway to somewhere.  However, we must let the routing
954  * protocol deal with that.
955  *
956  * The srcrt parameter indicates whether the packet is being forwarded
957  * via a source route.
958  */
959 void
960 ip_forward(struct mbuf *m, int srcrt)
961 {
962 	struct ip *ip = mtod(m, struct ip *);
963 	struct in_ifaddr *ia;
964 	struct mbuf *mcopy;
965 	struct sockaddr_in *sin;
966 	struct in_addr dest;
967 	struct route ro;
968 	uint32_t flowid;
969 	int error, type = 0, code = 0, mtu = 0;
970 
971 	NET_EPOCH_ASSERT();
972 
973 	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
974 		IPSTAT_INC(ips_cantforward);
975 		m_freem(m);
976 		return;
977 	}
978 	if (
979 #ifdef IPSTEALTH
980 	    V_ipstealth == 0 &&
981 #endif
982 	    ip->ip_ttl <= IPTTLDEC) {
983 		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
984 		return;
985 	}
986 
987 	bzero(&ro, sizeof(ro));
988 	sin = (struct sockaddr_in *)&ro.ro_dst;
989 	sin->sin_family = AF_INET;
990 	sin->sin_len = sizeof(*sin);
991 	sin->sin_addr = ip->ip_dst;
992 	flowid = m->m_pkthdr.flowid;
993 	ro.ro_nh = fib4_lookup(M_GETFIB(m), ip->ip_dst, 0, NHR_REF, flowid);
994 	if (ro.ro_nh != NULL) {
995 		ia = ifatoia(ro.ro_nh->nh_ifa);
996 	} else
997 		ia = NULL;
998 	/*
999 	 * Save the IP header and at most 8 bytes of the payload,
1000 	 * in case we need to generate an ICMP message to the src.
1001 	 *
1002 	 * XXX this can be optimized a lot by saving the data in a local
1003 	 * buffer on the stack (72 bytes at most), and only allocating the
1004 	 * mbuf if really necessary. The vast majority of the packets
1005 	 * are forwarded without having to send an ICMP back (either
1006 	 * because unnecessary, or because rate limited), so we are
1007 	 * really we are wasting a lot of work here.
1008 	 *
1009 	 * We don't use m_copym() because it might return a reference
1010 	 * to a shared cluster. Both this function and ip_output()
1011 	 * assume exclusive access to the IP header in `m', so any
1012 	 * data in a cluster may change before we reach icmp_error().
1013 	 */
1014 	mcopy = m_gethdr(M_NOWAIT, m->m_type);
1015 	if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
1016 		/*
1017 		 * It's probably ok if the pkthdr dup fails (because
1018 		 * the deep copy of the tag chain failed), but for now
1019 		 * be conservative and just discard the copy since
1020 		 * code below may some day want the tags.
1021 		 */
1022 		m_free(mcopy);
1023 		mcopy = NULL;
1024 	}
1025 	if (mcopy != NULL) {
1026 		mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1027 		mcopy->m_pkthdr.len = mcopy->m_len;
1028 		m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1029 	}
1030 #ifdef IPSTEALTH
1031 	if (V_ipstealth == 0)
1032 #endif
1033 		ip->ip_ttl -= IPTTLDEC;
1034 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1035 	if (IPSEC_ENABLED(ipv4)) {
1036 		if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
1037 			/* mbuf consumed by IPsec */
1038 			RO_NHFREE(&ro);
1039 			m_freem(mcopy);
1040 			if (error != EINPROGRESS)
1041 				IPSTAT_INC(ips_cantforward);
1042 			return;
1043 		}
1044 		/* No IPsec processing required */
1045 	}
1046 #endif /* IPSEC */
1047 	/*
1048 	 * If forwarding packet using same interface that it came in on,
1049 	 * perhaps should send a redirect to sender to shortcut a hop.
1050 	 * Only send redirect if source is sending directly to us,
1051 	 * and if packet was not source routed (or has any options).
1052 	 * Also, don't send redirect if forwarding using a default route
1053 	 * or a route modified by a redirect.
1054 	 */
1055 	dest.s_addr = 0;
1056 	if (!srcrt && V_ipsendredirects &&
1057 	    ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1058 		struct nhop_object *nh;
1059 
1060 		nh = ro.ro_nh;
1061 
1062 		if (nh != NULL && ((nh->nh_flags & (NHF_REDIRECT|NHF_DEFAULT)) == 0)) {
1063 			struct in_ifaddr *nh_ia = (struct in_ifaddr *)(nh->nh_ifa);
1064 			u_long src = ntohl(ip->ip_src.s_addr);
1065 
1066 			if (nh_ia != NULL &&
1067 			    (src & nh_ia->ia_subnetmask) == nh_ia->ia_subnet) {
1068 				if (nh->nh_flags & NHF_GATEWAY)
1069 					dest.s_addr = nh->gw4_sa.sin_addr.s_addr;
1070 				else
1071 					dest.s_addr = ip->ip_dst.s_addr;
1072 				/* Router requirements says to only send host redirects */
1073 				type = ICMP_REDIRECT;
1074 				code = ICMP_REDIRECT_HOST;
1075 			}
1076 		}
1077 	}
1078 
1079 	error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1080 
1081 	if (error == EMSGSIZE && ro.ro_nh)
1082 		mtu = ro.ro_nh->nh_mtu;
1083 	RO_NHFREE(&ro);
1084 
1085 	if (error)
1086 		IPSTAT_INC(ips_cantforward);
1087 	else {
1088 		IPSTAT_INC(ips_forward);
1089 		if (type)
1090 			IPSTAT_INC(ips_redirectsent);
1091 		else {
1092 			if (mcopy)
1093 				m_freem(mcopy);
1094 			return;
1095 		}
1096 	}
1097 	if (mcopy == NULL)
1098 		return;
1099 
1100 	switch (error) {
1101 	case 0:				/* forwarded, but need redirect */
1102 		/* type, code set above */
1103 		break;
1104 
1105 	case ENETUNREACH:
1106 	case EHOSTUNREACH:
1107 	case ENETDOWN:
1108 	case EHOSTDOWN:
1109 	default:
1110 		type = ICMP_UNREACH;
1111 		code = ICMP_UNREACH_HOST;
1112 		break;
1113 
1114 	case EMSGSIZE:
1115 		type = ICMP_UNREACH;
1116 		code = ICMP_UNREACH_NEEDFRAG;
1117 		/*
1118 		 * If the MTU was set before make sure we are below the
1119 		 * interface MTU.
1120 		 * If the MTU wasn't set before use the interface mtu or
1121 		 * fall back to the next smaller mtu step compared to the
1122 		 * current packet size.
1123 		 */
1124 		if (mtu != 0) {
1125 			if (ia != NULL)
1126 				mtu = min(mtu, ia->ia_ifp->if_mtu);
1127 		} else {
1128 			if (ia != NULL)
1129 				mtu = ia->ia_ifp->if_mtu;
1130 			else
1131 				mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1132 		}
1133 		IPSTAT_INC(ips_cantfrag);
1134 		break;
1135 
1136 	case ENOBUFS:
1137 	case EACCES:			/* ipfw denied packet */
1138 		m_freem(mcopy);
1139 		return;
1140 	}
1141 	icmp_error(mcopy, type, code, dest.s_addr, mtu);
1142 }
1143 
1144 #define	CHECK_SO_CT(sp, ct) \
1145     (((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0)
1146 
1147 void
1148 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1149     struct mbuf *m)
1150 {
1151 	bool stamped;
1152 
1153 	stamped = false;
1154 	if ((inp->inp_socket->so_options & SO_BINTIME) ||
1155 	    CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) {
1156 		struct bintime boottimebin, bt;
1157 		struct timespec ts1;
1158 
1159 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1160 		    M_TSTMP)) {
1161 			mbuf_tstmp2timespec(m, &ts1);
1162 			timespec2bintime(&ts1, &bt);
1163 			getboottimebin(&boottimebin);
1164 			bintime_add(&bt, &boottimebin);
1165 		} else {
1166 			bintime(&bt);
1167 		}
1168 		*mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1169 		    SCM_BINTIME, SOL_SOCKET);
1170 		if (*mp != NULL) {
1171 			mp = &(*mp)->m_next;
1172 			stamped = true;
1173 		}
1174 	}
1175 	if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) {
1176 		struct bintime boottimebin, bt1;
1177 		struct timespec ts1;
1178 		struct timeval tv;
1179 
1180 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1181 		    M_TSTMP)) {
1182 			mbuf_tstmp2timespec(m, &ts1);
1183 			timespec2bintime(&ts1, &bt1);
1184 			getboottimebin(&boottimebin);
1185 			bintime_add(&bt1, &boottimebin);
1186 			bintime2timeval(&bt1, &tv);
1187 		} else {
1188 			microtime(&tv);
1189 		}
1190 		*mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1191 		    SCM_TIMESTAMP, SOL_SOCKET);
1192 		if (*mp != NULL) {
1193 			mp = &(*mp)->m_next;
1194 			stamped = true;
1195 		}
1196 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) {
1197 		struct bintime boottimebin;
1198 		struct timespec ts, ts1;
1199 
1200 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1201 		    M_TSTMP)) {
1202 			mbuf_tstmp2timespec(m, &ts);
1203 			getboottimebin(&boottimebin);
1204 			bintime2timespec(&boottimebin, &ts1);
1205 			timespecadd(&ts, &ts1, &ts);
1206 		} else {
1207 			nanotime(&ts);
1208 		}
1209 		*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
1210 		    SCM_REALTIME, SOL_SOCKET);
1211 		if (*mp != NULL) {
1212 			mp = &(*mp)->m_next;
1213 			stamped = true;
1214 		}
1215 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) {
1216 		struct timespec ts;
1217 
1218 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1219 		    M_TSTMP))
1220 			mbuf_tstmp2timespec(m, &ts);
1221 		else
1222 			nanouptime(&ts);
1223 		*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
1224 		    SCM_MONOTONIC, SOL_SOCKET);
1225 		if (*mp != NULL) {
1226 			mp = &(*mp)->m_next;
1227 			stamped = true;
1228 		}
1229 	}
1230 	if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1231 	    M_TSTMP)) {
1232 		struct sock_timestamp_info sti;
1233 
1234 		bzero(&sti, sizeof(sti));
1235 		sti.st_info_flags = ST_INFO_HW;
1236 		if ((m->m_flags & M_TSTMP_HPREC) != 0)
1237 			sti.st_info_flags |= ST_INFO_HW_HPREC;
1238 		*mp = sbcreatecontrol((caddr_t)&sti, sizeof(sti), SCM_TIME_INFO,
1239 		    SOL_SOCKET);
1240 		if (*mp != NULL)
1241 			mp = &(*mp)->m_next;
1242 	}
1243 	if (inp->inp_flags & INP_RECVDSTADDR) {
1244 		*mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1245 		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1246 		if (*mp)
1247 			mp = &(*mp)->m_next;
1248 	}
1249 	if (inp->inp_flags & INP_RECVTTL) {
1250 		*mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1251 		    sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1252 		if (*mp)
1253 			mp = &(*mp)->m_next;
1254 	}
1255 #ifdef notyet
1256 	/* XXX
1257 	 * Moving these out of udp_input() made them even more broken
1258 	 * than they already were.
1259 	 */
1260 	/* options were tossed already */
1261 	if (inp->inp_flags & INP_RECVOPTS) {
1262 		*mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1263 		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1264 		if (*mp)
1265 			mp = &(*mp)->m_next;
1266 	}
1267 	/* ip_srcroute doesn't do what we want here, need to fix */
1268 	if (inp->inp_flags & INP_RECVRETOPTS) {
1269 		*mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1270 		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1271 		if (*mp)
1272 			mp = &(*mp)->m_next;
1273 	}
1274 #endif
1275 	if (inp->inp_flags & INP_RECVIF) {
1276 		struct ifnet *ifp;
1277 		struct sdlbuf {
1278 			struct sockaddr_dl sdl;
1279 			u_char	pad[32];
1280 		} sdlbuf;
1281 		struct sockaddr_dl *sdp;
1282 		struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1283 
1284 		if ((ifp = m->m_pkthdr.rcvif) &&
1285 		    ifp->if_index && ifp->if_index <= V_if_index) {
1286 			sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1287 			/*
1288 			 * Change our mind and don't try copy.
1289 			 */
1290 			if (sdp->sdl_family != AF_LINK ||
1291 			    sdp->sdl_len > sizeof(sdlbuf)) {
1292 				goto makedummy;
1293 			}
1294 			bcopy(sdp, sdl2, sdp->sdl_len);
1295 		} else {
1296 makedummy:
1297 			sdl2->sdl_len =
1298 			    offsetof(struct sockaddr_dl, sdl_data[0]);
1299 			sdl2->sdl_family = AF_LINK;
1300 			sdl2->sdl_index = 0;
1301 			sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1302 		}
1303 		*mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1304 		    IP_RECVIF, IPPROTO_IP);
1305 		if (*mp)
1306 			mp = &(*mp)->m_next;
1307 	}
1308 	if (inp->inp_flags & INP_RECVTOS) {
1309 		*mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1310 		    sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1311 		if (*mp)
1312 			mp = &(*mp)->m_next;
1313 	}
1314 
1315 	if (inp->inp_flags2 & INP_RECVFLOWID) {
1316 		uint32_t flowid, flow_type;
1317 
1318 		flowid = m->m_pkthdr.flowid;
1319 		flow_type = M_HASHTYPE_GET(m);
1320 
1321 		/*
1322 		 * XXX should handle the failure of one or the
1323 		 * other - don't populate both?
1324 		 */
1325 		*mp = sbcreatecontrol((caddr_t) &flowid,
1326 		    sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
1327 		if (*mp)
1328 			mp = &(*mp)->m_next;
1329 		*mp = sbcreatecontrol((caddr_t) &flow_type,
1330 		    sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
1331 		if (*mp)
1332 			mp = &(*mp)->m_next;
1333 	}
1334 
1335 #ifdef	RSS
1336 	if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1337 		uint32_t flowid, flow_type;
1338 		uint32_t rss_bucketid;
1339 
1340 		flowid = m->m_pkthdr.flowid;
1341 		flow_type = M_HASHTYPE_GET(m);
1342 
1343 		if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1344 			*mp = sbcreatecontrol((caddr_t) &rss_bucketid,
1345 			   sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
1346 			if (*mp)
1347 				mp = &(*mp)->m_next;
1348 		}
1349 	}
1350 #endif
1351 }
1352 
1353 /*
1354  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1355  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1356  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
1357  * compiled.
1358  */
1359 VNET_DEFINE_STATIC(int, ip_rsvp_on);
1360 VNET_DEFINE(struct socket *, ip_rsvpd);
1361 
1362 #define	V_ip_rsvp_on		VNET(ip_rsvp_on)
1363 
1364 int
1365 ip_rsvp_init(struct socket *so)
1366 {
1367 
1368 	if (so->so_type != SOCK_RAW ||
1369 	    so->so_proto->pr_protocol != IPPROTO_RSVP)
1370 		return EOPNOTSUPP;
1371 
1372 	if (V_ip_rsvpd != NULL)
1373 		return EADDRINUSE;
1374 
1375 	V_ip_rsvpd = so;
1376 	/*
1377 	 * This may seem silly, but we need to be sure we don't over-increment
1378 	 * the RSVP counter, in case something slips up.
1379 	 */
1380 	if (!V_ip_rsvp_on) {
1381 		V_ip_rsvp_on = 1;
1382 		V_rsvp_on++;
1383 	}
1384 
1385 	return 0;
1386 }
1387 
1388 int
1389 ip_rsvp_done(void)
1390 {
1391 
1392 	V_ip_rsvpd = NULL;
1393 	/*
1394 	 * This may seem silly, but we need to be sure we don't over-decrement
1395 	 * the RSVP counter, in case something slips up.
1396 	 */
1397 	if (V_ip_rsvp_on) {
1398 		V_ip_rsvp_on = 0;
1399 		V_rsvp_on--;
1400 	}
1401 	return 0;
1402 }
1403 
1404 int
1405 rsvp_input(struct mbuf **mp, int *offp, int proto)
1406 {
1407 	struct mbuf *m;
1408 
1409 	m = *mp;
1410 	*mp = NULL;
1411 
1412 	if (rsvp_input_p) { /* call the real one if loaded */
1413 		*mp = m;
1414 		rsvp_input_p(mp, offp, proto);
1415 		return (IPPROTO_DONE);
1416 	}
1417 
1418 	/* Can still get packets with rsvp_on = 0 if there is a local member
1419 	 * of the group to which the RSVP packet is addressed.  But in this
1420 	 * case we want to throw the packet away.
1421 	 */
1422 
1423 	if (!V_rsvp_on) {
1424 		m_freem(m);
1425 		return (IPPROTO_DONE);
1426 	}
1427 
1428 	if (V_ip_rsvpd != NULL) {
1429 		*mp = m;
1430 		rip_input(mp, offp, proto);
1431 		return (IPPROTO_DONE);
1432 	}
1433 	/* Drop the packet */
1434 	m_freem(m);
1435 	return (IPPROTO_DONE);
1436 }
1437