xref: /freebsd/sys/netinet/ip_input.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*-
2  * Copyright (c) 1982, 1986, 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_bootp.h"
36 #include "opt_ipfw.h"
37 #include "opt_ipstealth.h"
38 #include "opt_ipsec.h"
39 #include "opt_route.h"
40 #include "opt_rss.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.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/rwlock.h>
53 #include <sys/sdt.h>
54 #include <sys/syslog.h>
55 #include <sys/sysctl.h>
56 
57 #include <net/pfil.h>
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/route.h>
63 #include <net/netisr.h>
64 #include <net/rss_config.h>
65 #include <net/vnet.h>
66 
67 #include <netinet/in.h>
68 #include <netinet/in_kdtrace.h>
69 #include <netinet/in_systm.h>
70 #include <netinet/in_var.h>
71 #include <netinet/ip.h>
72 #include <netinet/in_pcb.h>
73 #include <netinet/ip_var.h>
74 #include <netinet/ip_fw.h>
75 #include <netinet/ip_icmp.h>
76 #include <netinet/ip_options.h>
77 #include <machine/in_cksum.h>
78 #include <netinet/ip_carp.h>
79 #ifdef IPSEC
80 #include <netinet/ip_ipsec.h>
81 #endif /* IPSEC */
82 #include <netinet/in_rss.h>
83 
84 #include <sys/socketvar.h>
85 
86 #include <security/mac/mac_framework.h>
87 
88 #ifdef CTASSERT
89 CTASSERT(sizeof(struct ip) == 20);
90 #endif
91 
92 /* IP reassembly functions are defined in ip_reass.c. */
93 extern void ipreass_init(void);
94 extern void ipreass_drain(void);
95 extern void ipreass_slowtimo(void);
96 #ifdef VIMAGE
97 extern void ipreass_destroy(void);
98 #endif
99 
100 struct	rwlock in_ifaddr_lock;
101 RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
102 
103 VNET_DEFINE(int, rsvp_on);
104 
105 VNET_DEFINE(int, ipforwarding);
106 SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
107     &VNET_NAME(ipforwarding), 0,
108     "Enable IP forwarding between interfaces");
109 
110 static VNET_DEFINE(int, ipsendredirects) = 1;	/* XXX */
111 #define	V_ipsendredirects	VNET(ipsendredirects)
112 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
113     &VNET_NAME(ipsendredirects), 0,
114     "Enable sending IP redirects");
115 
116 /*
117  * XXX - Setting ip_checkinterface mostly implements the receive side of
118  * the Strong ES model described in RFC 1122, but since the routing table
119  * and transmit implementation do not implement the Strong ES model,
120  * setting this to 1 results in an odd hybrid.
121  *
122  * XXX - ip_checkinterface currently must be disabled if you use ipnat
123  * to translate the destination address to another local interface.
124  *
125  * XXX - ip_checkinterface must be disabled if you add IP aliases
126  * to the loopback interface instead of the interface where the
127  * packets for those addresses are received.
128  */
129 static VNET_DEFINE(int, ip_checkinterface);
130 #define	V_ip_checkinterface	VNET(ip_checkinterface)
131 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
132     &VNET_NAME(ip_checkinterface), 0,
133     "Verify packet arrives on correct interface");
134 
135 VNET_DEFINE(struct pfil_head, inet_pfil_hook);	/* Packet filter hooks */
136 
137 static struct netisr_handler ip_nh = {
138 	.nh_name = "ip",
139 	.nh_handler = ip_input,
140 	.nh_proto = NETISR_IP,
141 #ifdef	RSS
142 	.nh_m2cpuid = rss_soft_m2cpuid,
143 	.nh_policy = NETISR_POLICY_CPU,
144 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
145 #else
146 	.nh_policy = NETISR_POLICY_FLOW,
147 #endif
148 };
149 
150 #ifdef	RSS
151 /*
152  * Directly dispatched frames are currently assumed
153  * to have a flowid already calculated.
154  *
155  * It should likely have something that assert it
156  * actually has valid flow details.
157  */
158 static struct netisr_handler ip_direct_nh = {
159 	.nh_name = "ip_direct",
160 	.nh_handler = ip_direct_input,
161 	.nh_proto = NETISR_IP_DIRECT,
162 	.nh_m2cpuid = rss_m2cpuid,
163 	.nh_policy = NETISR_POLICY_CPU,
164 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
165 };
166 #endif
167 
168 extern	struct domain inetdomain;
169 extern	struct protosw inetsw[];
170 u_char	ip_protox[IPPROTO_MAX];
171 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
172 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
173 VNET_DEFINE(u_long, in_ifaddrhmask);		/* mask for hash table */
174 
175 #ifdef IPCTL_DEFMTU
176 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
177     &ip_mtu, 0, "Default MTU");
178 #endif
179 
180 #ifdef IPSTEALTH
181 VNET_DEFINE(int, ipstealth);
182 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
183     &VNET_NAME(ipstealth), 0,
184     "IP stealth mode, no TTL decrementation on forwarding");
185 #endif
186 
187 /*
188  * IP statistics are stored in the "array" of counter(9)s.
189  */
190 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
191 VNET_PCPUSTAT_SYSINIT(ipstat);
192 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
193     "IP statistics (struct ipstat, netinet/ip_var.h)");
194 
195 #ifdef VIMAGE
196 VNET_PCPUSTAT_SYSUNINIT(ipstat);
197 #endif /* VIMAGE */
198 
199 /*
200  * Kernel module interface for updating ipstat.  The argument is an index
201  * into ipstat treated as an array.
202  */
203 void
204 kmod_ipstat_inc(int statnum)
205 {
206 
207 	counter_u64_add(VNET(ipstat)[statnum], 1);
208 }
209 
210 void
211 kmod_ipstat_dec(int statnum)
212 {
213 
214 	counter_u64_add(VNET(ipstat)[statnum], -1);
215 }
216 
217 static int
218 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
219 {
220 	int error, qlimit;
221 
222 	netisr_getqlimit(&ip_nh, &qlimit);
223 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
224 	if (error || !req->newptr)
225 		return (error);
226 	if (qlimit < 1)
227 		return (EINVAL);
228 	return (netisr_setqlimit(&ip_nh, qlimit));
229 }
230 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
231     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
232     "Maximum size of the IP input queue");
233 
234 static int
235 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
236 {
237 	u_int64_t qdrops_long;
238 	int error, qdrops;
239 
240 	netisr_getqdrops(&ip_nh, &qdrops_long);
241 	qdrops = qdrops_long;
242 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
243 	if (error || !req->newptr)
244 		return (error);
245 	if (qdrops != 0)
246 		return (EINVAL);
247 	netisr_clearqdrops(&ip_nh);
248 	return (0);
249 }
250 
251 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
252     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
253     "Number of packets dropped from the IP input queue");
254 
255 #ifdef	RSS
256 static int
257 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
258 {
259 	int error, qlimit;
260 
261 	netisr_getqlimit(&ip_direct_nh, &qlimit);
262 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
263 	if (error || !req->newptr)
264 		return (error);
265 	if (qlimit < 1)
266 		return (EINVAL);
267 	return (netisr_setqlimit(&ip_direct_nh, qlimit));
268 }
269 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_direct_queue_maxlen,
270     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen, "I",
271     "Maximum size of the IP direct input queue");
272 
273 static int
274 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
275 {
276 	u_int64_t qdrops_long;
277 	int error, qdrops;
278 
279 	netisr_getqdrops(&ip_direct_nh, &qdrops_long);
280 	qdrops = qdrops_long;
281 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
282 	if (error || !req->newptr)
283 		return (error);
284 	if (qdrops != 0)
285 		return (EINVAL);
286 	netisr_clearqdrops(&ip_direct_nh);
287 	return (0);
288 }
289 
290 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_direct_queue_drops,
291     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I",
292     "Number of packets dropped from the IP direct input queue");
293 #endif	/* RSS */
294 
295 /*
296  * IP initialization: fill in IP protocol switch table.
297  * All protocols not implemented in kernel go to raw IP protocol handler.
298  */
299 void
300 ip_init(void)
301 {
302 	struct protosw *pr;
303 	int i;
304 
305 	TAILQ_INIT(&V_in_ifaddrhead);
306 	V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
307 
308 	/* Initialize IP reassembly queue. */
309 	ipreass_init();
310 
311 	/* Initialize packet filter hooks. */
312 	V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
313 	V_inet_pfil_hook.ph_af = AF_INET;
314 	if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
315 		printf("%s: WARNING: unable to register pfil hook, "
316 			"error %d\n", __func__, i);
317 
318 	/* Skip initialization of globals for non-default instances. */
319 	if (!IS_DEFAULT_VNET(curvnet))
320 		return;
321 
322 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
323 	if (pr == NULL)
324 		panic("ip_init: PF_INET not found");
325 
326 	/* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
327 	for (i = 0; i < IPPROTO_MAX; i++)
328 		ip_protox[i] = pr - inetsw;
329 	/*
330 	 * Cycle through IP protocols and put them into the appropriate place
331 	 * in ip_protox[].
332 	 */
333 	for (pr = inetdomain.dom_protosw;
334 	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
335 		if (pr->pr_domain->dom_family == PF_INET &&
336 		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
337 			/* Be careful to only index valid IP protocols. */
338 			if (pr->pr_protocol < IPPROTO_MAX)
339 				ip_protox[pr->pr_protocol] = pr - inetsw;
340 		}
341 
342 	netisr_register(&ip_nh);
343 #ifdef	RSS
344 	netisr_register(&ip_direct_nh);
345 #endif
346 }
347 
348 #ifdef VIMAGE
349 void
350 ip_destroy(void)
351 {
352 	int i;
353 
354 	if ((i = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
355 		printf("%s: WARNING: unable to unregister pfil hook, "
356 		    "error %d\n", __func__, i);
357 
358 	/* Cleanup in_ifaddr hash table; should be empty. */
359 	hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
360 
361 	/* Destroy IP reassembly queue. */
362 	ipreass_destroy();
363 }
364 #endif
365 
366 #ifdef	RSS
367 /*
368  * IP direct input routine.
369  *
370  * This is called when reinjecting completed fragments where
371  * all of the previous checking and book-keeping has been done.
372  */
373 void
374 ip_direct_input(struct mbuf *m)
375 {
376 	struct ip *ip;
377 	int hlen;
378 
379 	ip = mtod(m, struct ip *);
380 	hlen = ip->ip_hl << 2;
381 
382 	IPSTAT_INC(ips_delivered);
383 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
384 	return;
385 }
386 #endif
387 
388 /*
389  * Ip input routine.  Checksum and byte swap header.  If fragmented
390  * try to reassemble.  Process options.  Pass to next level.
391  */
392 void
393 ip_input(struct mbuf *m)
394 {
395 	struct ip *ip = NULL;
396 	struct in_ifaddr *ia = NULL;
397 	struct ifaddr *ifa;
398 	struct ifnet *ifp;
399 	int    checkif, hlen = 0;
400 	uint16_t sum, ip_len;
401 	int dchg = 0;				/* dest changed after fw */
402 	struct in_addr odst;			/* original dst address */
403 
404 	M_ASSERTPKTHDR(m);
405 
406 	if (m->m_flags & M_FASTFWD_OURS) {
407 		m->m_flags &= ~M_FASTFWD_OURS;
408 		/* Set up some basics that will be used later. */
409 		ip = mtod(m, struct ip *);
410 		hlen = ip->ip_hl << 2;
411 		ip_len = ntohs(ip->ip_len);
412 		goto ours;
413 	}
414 
415 	IPSTAT_INC(ips_total);
416 
417 	if (m->m_pkthdr.len < sizeof(struct ip))
418 		goto tooshort;
419 
420 	if (m->m_len < sizeof (struct ip) &&
421 	    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
422 		IPSTAT_INC(ips_toosmall);
423 		return;
424 	}
425 	ip = mtod(m, struct ip *);
426 
427 	if (ip->ip_v != IPVERSION) {
428 		IPSTAT_INC(ips_badvers);
429 		goto bad;
430 	}
431 
432 	hlen = ip->ip_hl << 2;
433 	if (hlen < sizeof(struct ip)) {	/* minimum header length */
434 		IPSTAT_INC(ips_badhlen);
435 		goto bad;
436 	}
437 	if (hlen > m->m_len) {
438 		if ((m = m_pullup(m, hlen)) == NULL) {
439 			IPSTAT_INC(ips_badhlen);
440 			return;
441 		}
442 		ip = mtod(m, struct ip *);
443 	}
444 
445 	IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
446 
447 	/* 127/8 must not appear on wire - RFC1122 */
448 	ifp = m->m_pkthdr.rcvif;
449 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
450 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
451 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
452 			IPSTAT_INC(ips_badaddr);
453 			goto bad;
454 		}
455 	}
456 
457 	if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
458 		sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
459 	} else {
460 		if (hlen == sizeof(struct ip)) {
461 			sum = in_cksum_hdr(ip);
462 		} else {
463 			sum = in_cksum(m, hlen);
464 		}
465 	}
466 	if (sum) {
467 		IPSTAT_INC(ips_badsum);
468 		goto bad;
469 	}
470 
471 #ifdef ALTQ
472 	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
473 		/* packet is dropped by traffic conditioner */
474 		return;
475 #endif
476 
477 	ip_len = ntohs(ip->ip_len);
478 	if (ip_len < hlen) {
479 		IPSTAT_INC(ips_badlen);
480 		goto bad;
481 	}
482 
483 	/*
484 	 * Check that the amount of data in the buffers
485 	 * is as at least much as the IP header would have us expect.
486 	 * Trim mbufs if longer than we expect.
487 	 * Drop packet if shorter than we expect.
488 	 */
489 	if (m->m_pkthdr.len < ip_len) {
490 tooshort:
491 		IPSTAT_INC(ips_tooshort);
492 		goto bad;
493 	}
494 	if (m->m_pkthdr.len > ip_len) {
495 		if (m->m_len == m->m_pkthdr.len) {
496 			m->m_len = ip_len;
497 			m->m_pkthdr.len = ip_len;
498 		} else
499 			m_adj(m, ip_len - m->m_pkthdr.len);
500 	}
501 
502 #ifdef IPSEC
503 	/*
504 	 * Bypass packet filtering for packets previously handled by IPsec.
505 	 */
506 	if (ip_ipsec_filtertunnel(m))
507 		goto passin;
508 #endif /* IPSEC */
509 
510 	/*
511 	 * Run through list of hooks for input packets.
512 	 *
513 	 * NB: Beware of the destination address changing (e.g.
514 	 *     by NAT rewriting).  When this happens, tell
515 	 *     ip_forward to do the right thing.
516 	 */
517 
518 	/* Jump over all PFIL processing if hooks are not active. */
519 	if (!PFIL_HOOKED(&V_inet_pfil_hook))
520 		goto passin;
521 
522 	odst = ip->ip_dst;
523 	if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
524 		return;
525 	if (m == NULL)			/* consumed by filter */
526 		return;
527 
528 	ip = mtod(m, struct ip *);
529 	dchg = (odst.s_addr != ip->ip_dst.s_addr);
530 	ifp = m->m_pkthdr.rcvif;
531 
532 	if (m->m_flags & M_FASTFWD_OURS) {
533 		m->m_flags &= ~M_FASTFWD_OURS;
534 		goto ours;
535 	}
536 	if (m->m_flags & M_IP_NEXTHOP) {
537 		dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL);
538 		if (dchg != 0) {
539 			/*
540 			 * Directly ship the packet on.  This allows
541 			 * forwarding packets originally destined to us
542 			 * to some other directly connected host.
543 			 */
544 			ip_forward(m, 1);
545 			return;
546 		}
547 	}
548 passin:
549 
550 	/*
551 	 * Process options and, if not destined for us,
552 	 * ship it on.  ip_dooptions returns 1 when an
553 	 * error was detected (causing an icmp message
554 	 * to be sent and the original packet to be freed).
555 	 */
556 	if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
557 		return;
558 
559         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
560          * matter if it is destined to another node, or whether it is
561          * a multicast one, RSVP wants it! and prevents it from being forwarded
562          * anywhere else. Also checks if the rsvp daemon is running before
563 	 * grabbing the packet.
564          */
565 	if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
566 		goto ours;
567 
568 	/*
569 	 * Check our list of addresses, to see if the packet is for us.
570 	 * If we don't have any addresses, assume any unicast packet
571 	 * we receive might be for us (and let the upper layers deal
572 	 * with it).
573 	 */
574 	if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
575 	    (m->m_flags & (M_MCAST|M_BCAST)) == 0)
576 		goto ours;
577 
578 	/*
579 	 * Enable a consistency check between the destination address
580 	 * and the arrival interface for a unicast packet (the RFC 1122
581 	 * strong ES model) if IP forwarding is disabled and the packet
582 	 * is not locally generated and the packet is not subject to
583 	 * 'ipfw fwd'.
584 	 *
585 	 * XXX - Checking also should be disabled if the destination
586 	 * address is ipnat'ed to a different interface.
587 	 *
588 	 * XXX - Checking is incompatible with IP aliases added
589 	 * to the loopback interface instead of the interface where
590 	 * the packets are received.
591 	 *
592 	 * XXX - This is the case for carp vhost IPs as well so we
593 	 * insert a workaround. If the packet got here, we already
594 	 * checked with carp_iamatch() and carp_forus().
595 	 */
596 	checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
597 	    ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
598 	    ifp->if_carp == NULL && (dchg == 0);
599 
600 	/*
601 	 * Check for exact addresses in the hash bucket.
602 	 */
603 	/* IN_IFADDR_RLOCK(); */
604 	LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
605 		/*
606 		 * If the address matches, verify that the packet
607 		 * arrived via the correct interface if checking is
608 		 * enabled.
609 		 */
610 		if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
611 		    (!checkif || ia->ia_ifp == ifp)) {
612 			counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
613 			counter_u64_add(ia->ia_ifa.ifa_ibytes,
614 			    m->m_pkthdr.len);
615 			/* IN_IFADDR_RUNLOCK(); */
616 			goto ours;
617 		}
618 	}
619 	/* IN_IFADDR_RUNLOCK(); */
620 
621 	/*
622 	 * Check for broadcast addresses.
623 	 *
624 	 * Only accept broadcast packets that arrive via the matching
625 	 * interface.  Reception of forwarded directed broadcasts would
626 	 * be handled via ip_forward() and ether_output() with the loopback
627 	 * into the stack for SIMPLEX interfaces handled by ether_output().
628 	 */
629 	if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
630 		IF_ADDR_RLOCK(ifp);
631 	        TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
632 			if (ifa->ifa_addr->sa_family != AF_INET)
633 				continue;
634 			ia = ifatoia(ifa);
635 			if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
636 			    ip->ip_dst.s_addr) {
637 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
638 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
639 				    m->m_pkthdr.len);
640 				IF_ADDR_RUNLOCK(ifp);
641 				goto ours;
642 			}
643 #ifdef BOOTP_COMPAT
644 			if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
645 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
646 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
647 				    m->m_pkthdr.len);
648 				IF_ADDR_RUNLOCK(ifp);
649 				goto ours;
650 			}
651 #endif
652 		}
653 		IF_ADDR_RUNLOCK(ifp);
654 		ia = NULL;
655 	}
656 	/* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
657 	if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
658 		IPSTAT_INC(ips_cantforward);
659 		m_freem(m);
660 		return;
661 	}
662 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
663 		if (V_ip_mrouter) {
664 			/*
665 			 * If we are acting as a multicast router, all
666 			 * incoming multicast packets are passed to the
667 			 * kernel-level multicast forwarding function.
668 			 * The packet is returned (relatively) intact; if
669 			 * ip_mforward() returns a non-zero value, the packet
670 			 * must be discarded, else it may be accepted below.
671 			 */
672 			if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
673 				IPSTAT_INC(ips_cantforward);
674 				m_freem(m);
675 				return;
676 			}
677 
678 			/*
679 			 * The process-level routing daemon needs to receive
680 			 * all multicast IGMP packets, whether or not this
681 			 * host belongs to their destination groups.
682 			 */
683 			if (ip->ip_p == IPPROTO_IGMP)
684 				goto ours;
685 			IPSTAT_INC(ips_forward);
686 		}
687 		/*
688 		 * Assume the packet is for us, to avoid prematurely taking
689 		 * a lock on the in_multi hash. Protocols must perform
690 		 * their own filtering and update statistics accordingly.
691 		 */
692 		goto ours;
693 	}
694 	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
695 		goto ours;
696 	if (ip->ip_dst.s_addr == INADDR_ANY)
697 		goto ours;
698 
699 	/*
700 	 * Not for us; forward if possible and desirable.
701 	 */
702 	if (V_ipforwarding == 0) {
703 		IPSTAT_INC(ips_cantforward);
704 		m_freem(m);
705 	} else {
706 		ip_forward(m, dchg);
707 	}
708 	return;
709 
710 ours:
711 #ifdef IPSTEALTH
712 	/*
713 	 * IPSTEALTH: Process non-routing options only
714 	 * if the packet is destined for us.
715 	 */
716 	if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
717 		return;
718 #endif /* IPSTEALTH */
719 
720 	/*
721 	 * Attempt reassembly; if it succeeds, proceed.
722 	 * ip_reass() will return a different mbuf.
723 	 */
724 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
725 		/* XXXGL: shouldn't we save & set m_flags? */
726 		m = ip_reass(m);
727 		if (m == NULL)
728 			return;
729 		ip = mtod(m, struct ip *);
730 		/* Get the header length of the reassembled packet */
731 		hlen = ip->ip_hl << 2;
732 	}
733 
734 #ifdef IPSEC
735 	/*
736 	 * enforce IPsec policy checking if we are seeing last header.
737 	 * note that we do not visit this with protocols with pcb layer
738 	 * code - like udp/tcp/raw ip.
739 	 */
740 	if (ip_ipsec_input(m, ip->ip_p) != 0)
741 		goto bad;
742 #endif /* IPSEC */
743 
744 	/*
745 	 * Switch out to protocol's input routine.
746 	 */
747 	IPSTAT_INC(ips_delivered);
748 
749 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
750 	return;
751 bad:
752 	m_freem(m);
753 }
754 
755 /*
756  * IP timer processing;
757  * if a timer expires on a reassembly
758  * queue, discard it.
759  */
760 void
761 ip_slowtimo(void)
762 {
763 	VNET_ITERATOR_DECL(vnet_iter);
764 
765 	VNET_LIST_RLOCK_NOSLEEP();
766 	VNET_FOREACH(vnet_iter) {
767 		CURVNET_SET(vnet_iter);
768 		ipreass_slowtimo();
769 		CURVNET_RESTORE();
770 	}
771 	VNET_LIST_RUNLOCK_NOSLEEP();
772 }
773 
774 void
775 ip_drain(void)
776 {
777 	VNET_ITERATOR_DECL(vnet_iter);
778 
779 	VNET_LIST_RLOCK_NOSLEEP();
780 	VNET_FOREACH(vnet_iter) {
781 		CURVNET_SET(vnet_iter);
782 		ipreass_drain();
783 		CURVNET_RESTORE();
784 	}
785 	VNET_LIST_RUNLOCK_NOSLEEP();
786 }
787 
788 /*
789  * The protocol to be inserted into ip_protox[] must be already registered
790  * in inetsw[], either statically or through pf_proto_register().
791  */
792 int
793 ipproto_register(short ipproto)
794 {
795 	struct protosw *pr;
796 
797 	/* Sanity checks. */
798 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
799 		return (EPROTONOSUPPORT);
800 
801 	/*
802 	 * The protocol slot must not be occupied by another protocol
803 	 * already.  An index pointing to IPPROTO_RAW is unused.
804 	 */
805 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
806 	if (pr == NULL)
807 		return (EPFNOSUPPORT);
808 	if (ip_protox[ipproto] != pr - inetsw)	/* IPPROTO_RAW */
809 		return (EEXIST);
810 
811 	/* Find the protocol position in inetsw[] and set the index. */
812 	for (pr = inetdomain.dom_protosw;
813 	     pr < inetdomain.dom_protoswNPROTOSW; pr++) {
814 		if (pr->pr_domain->dom_family == PF_INET &&
815 		    pr->pr_protocol && pr->pr_protocol == ipproto) {
816 			ip_protox[pr->pr_protocol] = pr - inetsw;
817 			return (0);
818 		}
819 	}
820 	return (EPROTONOSUPPORT);
821 }
822 
823 int
824 ipproto_unregister(short ipproto)
825 {
826 	struct protosw *pr;
827 
828 	/* Sanity checks. */
829 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
830 		return (EPROTONOSUPPORT);
831 
832 	/* Check if the protocol was indeed registered. */
833 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
834 	if (pr == NULL)
835 		return (EPFNOSUPPORT);
836 	if (ip_protox[ipproto] == pr - inetsw)  /* IPPROTO_RAW */
837 		return (ENOENT);
838 
839 	/* Reset the protocol slot to IPPROTO_RAW. */
840 	ip_protox[ipproto] = pr - inetsw;
841 	return (0);
842 }
843 
844 /*
845  * Given address of next destination (final or next hop), return (referenced)
846  * internet address info of interface to be used to get there.
847  */
848 struct in_ifaddr *
849 ip_rtaddr(struct in_addr dst, u_int fibnum)
850 {
851 	struct route sro;
852 	struct sockaddr_in *sin;
853 	struct in_ifaddr *ia;
854 
855 	bzero(&sro, sizeof(sro));
856 	sin = (struct sockaddr_in *)&sro.ro_dst;
857 	sin->sin_family = AF_INET;
858 	sin->sin_len = sizeof(*sin);
859 	sin->sin_addr = dst;
860 	in_rtalloc_ign(&sro, 0, fibnum);
861 
862 	if (sro.ro_rt == NULL)
863 		return (NULL);
864 
865 	ia = ifatoia(sro.ro_rt->rt_ifa);
866 	ifa_ref(&ia->ia_ifa);
867 	RTFREE(sro.ro_rt);
868 	return (ia);
869 }
870 
871 u_char inetctlerrmap[PRC_NCMDS] = {
872 	0,		0,		0,		0,
873 	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
874 	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
875 	EMSGSIZE,	EHOSTUNREACH,	0,		0,
876 	0,		0,		EHOSTUNREACH,	0,
877 	ENOPROTOOPT,	ECONNREFUSED
878 };
879 
880 /*
881  * Forward a packet.  If some error occurs return the sender
882  * an icmp packet.  Note we can't always generate a meaningful
883  * icmp message because icmp doesn't have a large enough repertoire
884  * of codes and types.
885  *
886  * If not forwarding, just drop the packet.  This could be confusing
887  * if ipforwarding was zero but some routing protocol was advancing
888  * us as a gateway to somewhere.  However, we must let the routing
889  * protocol deal with that.
890  *
891  * The srcrt parameter indicates whether the packet is being forwarded
892  * via a source route.
893  */
894 void
895 ip_forward(struct mbuf *m, int srcrt)
896 {
897 	struct ip *ip = mtod(m, struct ip *);
898 	struct in_ifaddr *ia;
899 	struct mbuf *mcopy;
900 	struct sockaddr_in *sin;
901 	struct in_addr dest;
902 	struct route ro;
903 	int error, type = 0, code = 0, mtu = 0;
904 
905 	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
906 		IPSTAT_INC(ips_cantforward);
907 		m_freem(m);
908 		return;
909 	}
910 #ifdef IPSEC
911 	if (ip_ipsec_fwd(m) != 0) {
912 		IPSTAT_INC(ips_cantforward);
913 		m_freem(m);
914 		return;
915 	}
916 #endif /* IPSEC */
917 #ifdef IPSTEALTH
918 	if (!V_ipstealth) {
919 #endif
920 		if (ip->ip_ttl <= IPTTLDEC) {
921 			icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
922 			    0, 0);
923 			return;
924 		}
925 #ifdef IPSTEALTH
926 	}
927 #endif
928 
929 	bzero(&ro, sizeof(ro));
930 	sin = (struct sockaddr_in *)&ro.ro_dst;
931 	sin->sin_family = AF_INET;
932 	sin->sin_len = sizeof(*sin);
933 	sin->sin_addr = ip->ip_dst;
934 #ifdef RADIX_MPATH
935 	rtalloc_mpath_fib(&ro,
936 	    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
937 	    M_GETFIB(m));
938 #else
939 	in_rtalloc_ign(&ro, 0, M_GETFIB(m));
940 #endif
941 	if (ro.ro_rt != NULL) {
942 		ia = ifatoia(ro.ro_rt->rt_ifa);
943 		ifa_ref(&ia->ia_ifa);
944 	} else
945 		ia = NULL;
946 #ifndef IPSEC
947 	/*
948 	 * 'ia' may be NULL if there is no route for this destination.
949 	 * In case of IPsec, Don't discard it just yet, but pass it to
950 	 * ip_output in case of outgoing IPsec policy.
951 	 */
952 	if (!srcrt && ia == NULL) {
953 		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
954 		RO_RTFREE(&ro);
955 		return;
956 	}
957 #endif
958 
959 	/*
960 	 * Save the IP header and at most 8 bytes of the payload,
961 	 * in case we need to generate an ICMP message to the src.
962 	 *
963 	 * XXX this can be optimized a lot by saving the data in a local
964 	 * buffer on the stack (72 bytes at most), and only allocating the
965 	 * mbuf if really necessary. The vast majority of the packets
966 	 * are forwarded without having to send an ICMP back (either
967 	 * because unnecessary, or because rate limited), so we are
968 	 * really we are wasting a lot of work here.
969 	 *
970 	 * We don't use m_copy() because it might return a reference
971 	 * to a shared cluster. Both this function and ip_output()
972 	 * assume exclusive access to the IP header in `m', so any
973 	 * data in a cluster may change before we reach icmp_error().
974 	 */
975 	mcopy = m_gethdr(M_NOWAIT, m->m_type);
976 	if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
977 		/*
978 		 * It's probably ok if the pkthdr dup fails (because
979 		 * the deep copy of the tag chain failed), but for now
980 		 * be conservative and just discard the copy since
981 		 * code below may some day want the tags.
982 		 */
983 		m_free(mcopy);
984 		mcopy = NULL;
985 	}
986 	if (mcopy != NULL) {
987 		mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
988 		mcopy->m_pkthdr.len = mcopy->m_len;
989 		m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
990 	}
991 
992 #ifdef IPSTEALTH
993 	if (!V_ipstealth) {
994 #endif
995 		ip->ip_ttl -= IPTTLDEC;
996 #ifdef IPSTEALTH
997 	}
998 #endif
999 
1000 	/*
1001 	 * If forwarding packet using same interface that it came in on,
1002 	 * perhaps should send a redirect to sender to shortcut a hop.
1003 	 * Only send redirect if source is sending directly to us,
1004 	 * and if packet was not source routed (or has any options).
1005 	 * Also, don't send redirect if forwarding using a default route
1006 	 * or a route modified by a redirect.
1007 	 */
1008 	dest.s_addr = 0;
1009 	if (!srcrt && V_ipsendredirects &&
1010 	    ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1011 		struct rtentry *rt;
1012 
1013 		rt = ro.ro_rt;
1014 
1015 		if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1016 		    satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1017 #define	RTA(rt)	((struct in_ifaddr *)(rt->rt_ifa))
1018 			u_long src = ntohl(ip->ip_src.s_addr);
1019 
1020 			if (RTA(rt) &&
1021 			    (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1022 				if (rt->rt_flags & RTF_GATEWAY)
1023 					dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1024 				else
1025 					dest.s_addr = ip->ip_dst.s_addr;
1026 				/* Router requirements says to only send host redirects */
1027 				type = ICMP_REDIRECT;
1028 				code = ICMP_REDIRECT_HOST;
1029 			}
1030 		}
1031 	}
1032 
1033 	error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1034 
1035 	if (error == EMSGSIZE && ro.ro_rt)
1036 		mtu = ro.ro_rt->rt_mtu;
1037 	RO_RTFREE(&ro);
1038 
1039 	if (error)
1040 		IPSTAT_INC(ips_cantforward);
1041 	else {
1042 		IPSTAT_INC(ips_forward);
1043 		if (type)
1044 			IPSTAT_INC(ips_redirectsent);
1045 		else {
1046 			if (mcopy)
1047 				m_freem(mcopy);
1048 			if (ia != NULL)
1049 				ifa_free(&ia->ia_ifa);
1050 			return;
1051 		}
1052 	}
1053 	if (mcopy == NULL) {
1054 		if (ia != NULL)
1055 			ifa_free(&ia->ia_ifa);
1056 		return;
1057 	}
1058 
1059 	switch (error) {
1060 
1061 	case 0:				/* forwarded, but need redirect */
1062 		/* type, code set above */
1063 		break;
1064 
1065 	case ENETUNREACH:
1066 	case EHOSTUNREACH:
1067 	case ENETDOWN:
1068 	case EHOSTDOWN:
1069 	default:
1070 		type = ICMP_UNREACH;
1071 		code = ICMP_UNREACH_HOST;
1072 		break;
1073 
1074 	case EMSGSIZE:
1075 		type = ICMP_UNREACH;
1076 		code = ICMP_UNREACH_NEEDFRAG;
1077 
1078 #ifdef IPSEC
1079 		/*
1080 		 * If IPsec is configured for this path,
1081 		 * override any possibly mtu value set by ip_output.
1082 		 */
1083 		mtu = ip_ipsec_mtu(mcopy, mtu);
1084 #endif /* IPSEC */
1085 		/*
1086 		 * If the MTU was set before make sure we are below the
1087 		 * interface MTU.
1088 		 * If the MTU wasn't set before use the interface mtu or
1089 		 * fall back to the next smaller mtu step compared to the
1090 		 * current packet size.
1091 		 */
1092 		if (mtu != 0) {
1093 			if (ia != NULL)
1094 				mtu = min(mtu, ia->ia_ifp->if_mtu);
1095 		} else {
1096 			if (ia != NULL)
1097 				mtu = ia->ia_ifp->if_mtu;
1098 			else
1099 				mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1100 		}
1101 		IPSTAT_INC(ips_cantfrag);
1102 		break;
1103 
1104 	case ENOBUFS:
1105 	case EACCES:			/* ipfw denied packet */
1106 		m_freem(mcopy);
1107 		if (ia != NULL)
1108 			ifa_free(&ia->ia_ifa);
1109 		return;
1110 	}
1111 	if (ia != NULL)
1112 		ifa_free(&ia->ia_ifa);
1113 	icmp_error(mcopy, type, code, dest.s_addr, mtu);
1114 }
1115 
1116 void
1117 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1118     struct mbuf *m)
1119 {
1120 
1121 	if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1122 		struct bintime bt;
1123 
1124 		bintime(&bt);
1125 		if (inp->inp_socket->so_options & SO_BINTIME) {
1126 			*mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1127 			    SCM_BINTIME, SOL_SOCKET);
1128 			if (*mp)
1129 				mp = &(*mp)->m_next;
1130 		}
1131 		if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1132 			struct timeval tv;
1133 
1134 			bintime2timeval(&bt, &tv);
1135 			*mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1136 			    SCM_TIMESTAMP, SOL_SOCKET);
1137 			if (*mp)
1138 				mp = &(*mp)->m_next;
1139 		}
1140 	}
1141 	if (inp->inp_flags & INP_RECVDSTADDR) {
1142 		*mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1143 		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1144 		if (*mp)
1145 			mp = &(*mp)->m_next;
1146 	}
1147 	if (inp->inp_flags & INP_RECVTTL) {
1148 		*mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1149 		    sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1150 		if (*mp)
1151 			mp = &(*mp)->m_next;
1152 	}
1153 #ifdef notyet
1154 	/* XXX
1155 	 * Moving these out of udp_input() made them even more broken
1156 	 * than they already were.
1157 	 */
1158 	/* options were tossed already */
1159 	if (inp->inp_flags & INP_RECVOPTS) {
1160 		*mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1161 		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1162 		if (*mp)
1163 			mp = &(*mp)->m_next;
1164 	}
1165 	/* ip_srcroute doesn't do what we want here, need to fix */
1166 	if (inp->inp_flags & INP_RECVRETOPTS) {
1167 		*mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1168 		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1169 		if (*mp)
1170 			mp = &(*mp)->m_next;
1171 	}
1172 #endif
1173 	if (inp->inp_flags & INP_RECVIF) {
1174 		struct ifnet *ifp;
1175 		struct sdlbuf {
1176 			struct sockaddr_dl sdl;
1177 			u_char	pad[32];
1178 		} sdlbuf;
1179 		struct sockaddr_dl *sdp;
1180 		struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1181 
1182 		if ((ifp = m->m_pkthdr.rcvif) &&
1183 		    ifp->if_index && ifp->if_index <= V_if_index) {
1184 			sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1185 			/*
1186 			 * Change our mind and don't try copy.
1187 			 */
1188 			if (sdp->sdl_family != AF_LINK ||
1189 			    sdp->sdl_len > sizeof(sdlbuf)) {
1190 				goto makedummy;
1191 			}
1192 			bcopy(sdp, sdl2, sdp->sdl_len);
1193 		} else {
1194 makedummy:
1195 			sdl2->sdl_len =
1196 			    offsetof(struct sockaddr_dl, sdl_data[0]);
1197 			sdl2->sdl_family = AF_LINK;
1198 			sdl2->sdl_index = 0;
1199 			sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1200 		}
1201 		*mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1202 		    IP_RECVIF, IPPROTO_IP);
1203 		if (*mp)
1204 			mp = &(*mp)->m_next;
1205 	}
1206 	if (inp->inp_flags & INP_RECVTOS) {
1207 		*mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1208 		    sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1209 		if (*mp)
1210 			mp = &(*mp)->m_next;
1211 	}
1212 
1213 	if (inp->inp_flags2 & INP_RECVFLOWID) {
1214 		uint32_t flowid, flow_type;
1215 
1216 		flowid = m->m_pkthdr.flowid;
1217 		flow_type = M_HASHTYPE_GET(m);
1218 
1219 		/*
1220 		 * XXX should handle the failure of one or the
1221 		 * other - don't populate both?
1222 		 */
1223 		*mp = sbcreatecontrol((caddr_t) &flowid,
1224 		    sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
1225 		if (*mp)
1226 			mp = &(*mp)->m_next;
1227 		*mp = sbcreatecontrol((caddr_t) &flow_type,
1228 		    sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
1229 		if (*mp)
1230 			mp = &(*mp)->m_next;
1231 	}
1232 
1233 #ifdef	RSS
1234 	if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1235 		uint32_t flowid, flow_type;
1236 		uint32_t rss_bucketid;
1237 
1238 		flowid = m->m_pkthdr.flowid;
1239 		flow_type = M_HASHTYPE_GET(m);
1240 
1241 		if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1242 			*mp = sbcreatecontrol((caddr_t) &rss_bucketid,
1243 			   sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
1244 			if (*mp)
1245 				mp = &(*mp)->m_next;
1246 		}
1247 	}
1248 #endif
1249 }
1250 
1251 /*
1252  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1253  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1254  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
1255  * compiled.
1256  */
1257 static VNET_DEFINE(int, ip_rsvp_on);
1258 VNET_DEFINE(struct socket *, ip_rsvpd);
1259 
1260 #define	V_ip_rsvp_on		VNET(ip_rsvp_on)
1261 
1262 int
1263 ip_rsvp_init(struct socket *so)
1264 {
1265 
1266 	if (so->so_type != SOCK_RAW ||
1267 	    so->so_proto->pr_protocol != IPPROTO_RSVP)
1268 		return EOPNOTSUPP;
1269 
1270 	if (V_ip_rsvpd != NULL)
1271 		return EADDRINUSE;
1272 
1273 	V_ip_rsvpd = so;
1274 	/*
1275 	 * This may seem silly, but we need to be sure we don't over-increment
1276 	 * the RSVP counter, in case something slips up.
1277 	 */
1278 	if (!V_ip_rsvp_on) {
1279 		V_ip_rsvp_on = 1;
1280 		V_rsvp_on++;
1281 	}
1282 
1283 	return 0;
1284 }
1285 
1286 int
1287 ip_rsvp_done(void)
1288 {
1289 
1290 	V_ip_rsvpd = NULL;
1291 	/*
1292 	 * This may seem silly, but we need to be sure we don't over-decrement
1293 	 * the RSVP counter, in case something slips up.
1294 	 */
1295 	if (V_ip_rsvp_on) {
1296 		V_ip_rsvp_on = 0;
1297 		V_rsvp_on--;
1298 	}
1299 	return 0;
1300 }
1301 
1302 int
1303 rsvp_input(struct mbuf **mp, int *offp, int proto)
1304 {
1305 	struct mbuf *m;
1306 
1307 	m = *mp;
1308 	*mp = NULL;
1309 
1310 	if (rsvp_input_p) { /* call the real one if loaded */
1311 		*mp = m;
1312 		rsvp_input_p(mp, offp, proto);
1313 		return (IPPROTO_DONE);
1314 	}
1315 
1316 	/* Can still get packets with rsvp_on = 0 if there is a local member
1317 	 * of the group to which the RSVP packet is addressed.  But in this
1318 	 * case we want to throw the packet away.
1319 	 */
1320 
1321 	if (!V_rsvp_on) {
1322 		m_freem(m);
1323 		return (IPPROTO_DONE);
1324 	}
1325 
1326 	if (V_ip_rsvpd != NULL) {
1327 		*mp = m;
1328 		rip_input(mp, offp, proto);
1329 		return (IPPROTO_DONE);
1330 	}
1331 	/* Drop the packet */
1332 	m_freem(m);
1333 	return (IPPROTO_DONE);
1334 }
1335