xref: /freebsd/sys/netinet/ip_input.c (revision 6829dae12bb055451fa467da4589c43bd03b1e64)
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/netisr.h>
67 #include <net/rss_config.h>
68 #include <net/vnet.h>
69 
70 #include <netinet/in.h>
71 #include <netinet/in_kdtrace.h>
72 #include <netinet/in_systm.h>
73 #include <netinet/in_var.h>
74 #include <netinet/ip.h>
75 #include <netinet/in_pcb.h>
76 #include <netinet/ip_var.h>
77 #include <netinet/ip_fw.h>
78 #include <netinet/ip_icmp.h>
79 #include <netinet/ip_options.h>
80 #include <machine/in_cksum.h>
81 #include <netinet/ip_carp.h>
82 #include <netinet/in_rss.h>
83 
84 #include <netipsec/ipsec_support.h>
85 
86 #include <sys/socketvar.h>
87 
88 #include <security/mac/mac_framework.h>
89 
90 #ifdef CTASSERT
91 CTASSERT(sizeof(struct ip) == 20);
92 #endif
93 
94 /* IP reassembly functions are defined in ip_reass.c. */
95 extern void ipreass_init(void);
96 extern void ipreass_drain(void);
97 extern void ipreass_slowtimo(void);
98 #ifdef VIMAGE
99 extern void ipreass_destroy(void);
100 #endif
101 
102 struct rmlock in_ifaddr_lock;
103 RM_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
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 VNET_DEFINE_STATIC(int, ipsendredirects) = 1;	/* XXX */
113 #define	V_ipsendredirects	VNET(ipsendredirects)
114 SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
115     &VNET_NAME(ipsendredirects), 0,
116     "Enable sending IP redirects");
117 
118 /*
119  * XXX - Setting ip_checkinterface mostly implements the receive side of
120  * the Strong ES model described in RFC 1122, but since the routing table
121  * and transmit implementation do not implement the Strong ES model,
122  * setting this to 1 results in an odd hybrid.
123  *
124  * XXX - ip_checkinterface currently must be disabled if you use ipnat
125  * to translate the destination address to another local interface.
126  *
127  * XXX - ip_checkinterface must be disabled if you add IP aliases
128  * to the loopback interface instead of the interface where the
129  * packets for those addresses are received.
130  */
131 VNET_DEFINE_STATIC(int, ip_checkinterface);
132 #define	V_ip_checkinterface	VNET(ip_checkinterface)
133 SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
134     &VNET_NAME(ip_checkinterface), 0,
135     "Verify packet arrives on correct interface");
136 
137 VNET_DEFINE(pfil_head_t, inet_pfil_head);	/* Packet filter hooks */
138 
139 static struct netisr_handler ip_nh = {
140 	.nh_name = "ip",
141 	.nh_handler = ip_input,
142 	.nh_proto = NETISR_IP,
143 #ifdef	RSS
144 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
145 	.nh_policy = NETISR_POLICY_CPU,
146 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
147 #else
148 	.nh_policy = NETISR_POLICY_FLOW,
149 #endif
150 };
151 
152 #ifdef	RSS
153 /*
154  * Directly dispatched frames are currently assumed
155  * to have a flowid already calculated.
156  *
157  * It should likely have something that assert it
158  * actually has valid flow details.
159  */
160 static struct netisr_handler ip_direct_nh = {
161 	.nh_name = "ip_direct",
162 	.nh_handler = ip_direct_input,
163 	.nh_proto = NETISR_IP_DIRECT,
164 	.nh_m2cpuid = rss_soft_m2cpuid_v4,
165 	.nh_policy = NETISR_POLICY_CPU,
166 	.nh_dispatch = NETISR_DISPATCH_HYBRID,
167 };
168 #endif
169 
170 extern	struct domain inetdomain;
171 extern	struct protosw inetsw[];
172 u_char	ip_protox[IPPROTO_MAX];
173 VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead);  /* first inet address */
174 VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table  */
175 VNET_DEFINE(u_long, in_ifaddrhmask);		/* mask for hash table */
176 
177 #ifdef IPCTL_DEFMTU
178 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
179     &ip_mtu, 0, "Default MTU");
180 #endif
181 
182 #ifdef IPSTEALTH
183 VNET_DEFINE(int, ipstealth);
184 SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
185     &VNET_NAME(ipstealth), 0,
186     "IP stealth mode, no TTL decrementation on forwarding");
187 #endif
188 
189 /*
190  * IP statistics are stored in the "array" of counter(9)s.
191  */
192 VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
193 VNET_PCPUSTAT_SYSINIT(ipstat);
194 SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
195     "IP statistics (struct ipstat, netinet/ip_var.h)");
196 
197 #ifdef VIMAGE
198 VNET_PCPUSTAT_SYSUNINIT(ipstat);
199 #endif /* VIMAGE */
200 
201 /*
202  * Kernel module interface for updating ipstat.  The argument is an index
203  * into ipstat treated as an array.
204  */
205 void
206 kmod_ipstat_inc(int statnum)
207 {
208 
209 	counter_u64_add(VNET(ipstat)[statnum], 1);
210 }
211 
212 void
213 kmod_ipstat_dec(int statnum)
214 {
215 
216 	counter_u64_add(VNET(ipstat)[statnum], -1);
217 }
218 
219 static int
220 sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
221 {
222 	int error, qlimit;
223 
224 	netisr_getqlimit(&ip_nh, &qlimit);
225 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
226 	if (error || !req->newptr)
227 		return (error);
228 	if (qlimit < 1)
229 		return (EINVAL);
230 	return (netisr_setqlimit(&ip_nh, qlimit));
231 }
232 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
233     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
234     "Maximum size of the IP input queue");
235 
236 static int
237 sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
238 {
239 	u_int64_t qdrops_long;
240 	int error, qdrops;
241 
242 	netisr_getqdrops(&ip_nh, &qdrops_long);
243 	qdrops = qdrops_long;
244 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
245 	if (error || !req->newptr)
246 		return (error);
247 	if (qdrops != 0)
248 		return (EINVAL);
249 	netisr_clearqdrops(&ip_nh);
250 	return (0);
251 }
252 
253 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
254     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
255     "Number of packets dropped from the IP input queue");
256 
257 #ifdef	RSS
258 static int
259 sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
260 {
261 	int error, qlimit;
262 
263 	netisr_getqlimit(&ip_direct_nh, &qlimit);
264 	error = sysctl_handle_int(oidp, &qlimit, 0, req);
265 	if (error || !req->newptr)
266 		return (error);
267 	if (qlimit < 1)
268 		return (EINVAL);
269 	return (netisr_setqlimit(&ip_direct_nh, qlimit));
270 }
271 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
272     CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen,
273     "I", "Maximum size of the IP direct input queue");
274 
275 static int
276 sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
277 {
278 	u_int64_t qdrops_long;
279 	int error, qdrops;
280 
281 	netisr_getqdrops(&ip_direct_nh, &qdrops_long);
282 	qdrops = qdrops_long;
283 	error = sysctl_handle_int(oidp, &qdrops, 0, req);
284 	if (error || !req->newptr)
285 		return (error);
286 	if (qdrops != 0)
287 		return (EINVAL);
288 	netisr_clearqdrops(&ip_direct_nh);
289 	return (0);
290 }
291 
292 SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops,
293     CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I",
294     "Number of packets dropped from the IP direct input queue");
295 #endif	/* RSS */
296 
297 /*
298  * IP initialization: fill in IP protocol switch table.
299  * All protocols not implemented in kernel go to raw IP protocol handler.
300  */
301 void
302 ip_init(void)
303 {
304 	struct pfil_head_args args;
305 	struct protosw *pr;
306 	int i;
307 
308 	CK_STAILQ_INIT(&V_in_ifaddrhead);
309 	V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
310 
311 	/* Initialize IP reassembly queue. */
312 	ipreass_init();
313 
314 	/* Initialize packet filter hooks. */
315 	args.pa_version = PFIL_VERSION;
316 	args.pa_flags = PFIL_IN | PFIL_OUT;
317 	args.pa_type = PFIL_TYPE_IP4;
318 	args.pa_headname = PFIL_INET_NAME;
319 	V_inet_pfil_head = pfil_head_register(&args);
320 
321 	if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
322 	    &V_ipsec_hhh_in[HHOOK_IPSEC_INET],
323 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
324 		printf("%s: WARNING: unable to register input helper hook\n",
325 		    __func__);
326 	if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
327 	    &V_ipsec_hhh_out[HHOOK_IPSEC_INET],
328 	    HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
329 		printf("%s: WARNING: unable to register output helper hook\n",
330 		    __func__);
331 
332 	/* Skip initialization of globals for non-default instances. */
333 #ifdef VIMAGE
334 	if (!IS_DEFAULT_VNET(curvnet)) {
335 		netisr_register_vnet(&ip_nh);
336 #ifdef	RSS
337 		netisr_register_vnet(&ip_direct_nh);
338 #endif
339 		return;
340 	}
341 #endif
342 
343 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
344 	if (pr == NULL)
345 		panic("ip_init: PF_INET not found");
346 
347 	/* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
348 	for (i = 0; i < IPPROTO_MAX; i++)
349 		ip_protox[i] = pr - inetsw;
350 	/*
351 	 * Cycle through IP protocols and put them into the appropriate place
352 	 * in ip_protox[].
353 	 */
354 	for (pr = inetdomain.dom_protosw;
355 	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
356 		if (pr->pr_domain->dom_family == PF_INET &&
357 		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
358 			/* Be careful to only index valid IP protocols. */
359 			if (pr->pr_protocol < IPPROTO_MAX)
360 				ip_protox[pr->pr_protocol] = pr - inetsw;
361 		}
362 
363 	netisr_register(&ip_nh);
364 #ifdef	RSS
365 	netisr_register(&ip_direct_nh);
366 #endif
367 }
368 
369 #ifdef VIMAGE
370 static void
371 ip_destroy(void *unused __unused)
372 {
373 	struct ifnet *ifp;
374 	int error;
375 
376 #ifdef	RSS
377 	netisr_unregister_vnet(&ip_direct_nh);
378 #endif
379 	netisr_unregister_vnet(&ip_nh);
380 
381 	pfil_head_unregister(V_inet_pfil_head);
382 	error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
383 	if (error != 0) {
384 		printf("%s: WARNING: unable to deregister input helper hook "
385 		    "type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
386 		    "error %d returned\n", __func__, error);
387 	}
388 	error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
389 	if (error != 0) {
390 		printf("%s: WARNING: unable to deregister output helper hook "
391 		    "type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
392 		    "error %d returned\n", __func__, error);
393 	}
394 
395 	/* Remove the IPv4 addresses from all interfaces. */
396 	in_ifscrub_all();
397 
398 	/* Make sure the IPv4 routes are gone as well. */
399 	IFNET_RLOCK();
400 	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link)
401 		rt_flushifroutes_af(ifp, AF_INET);
402 	IFNET_RUNLOCK();
403 
404 	/* Destroy IP reassembly queue. */
405 	ipreass_destroy();
406 
407 	/* Cleanup in_ifaddr hash table; should be empty. */
408 	hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
409 }
410 
411 VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
412 #endif
413 
414 #ifdef	RSS
415 /*
416  * IP direct input routine.
417  *
418  * This is called when reinjecting completed fragments where
419  * all of the previous checking and book-keeping has been done.
420  */
421 void
422 ip_direct_input(struct mbuf *m)
423 {
424 	struct ip *ip;
425 	int hlen;
426 
427 	ip = mtod(m, struct ip *);
428 	hlen = ip->ip_hl << 2;
429 
430 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
431 	if (IPSEC_ENABLED(ipv4)) {
432 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
433 			return;
434 	}
435 #endif /* IPSEC */
436 	IPSTAT_INC(ips_delivered);
437 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
438 	return;
439 }
440 #endif
441 
442 /*
443  * Ip input routine.  Checksum and byte swap header.  If fragmented
444  * try to reassemble.  Process options.  Pass to next level.
445  */
446 void
447 ip_input(struct mbuf *m)
448 {
449 	struct rm_priotracker in_ifa_tracker;
450 	struct ip *ip = NULL;
451 	struct in_ifaddr *ia = NULL;
452 	struct ifaddr *ifa;
453 	struct ifnet *ifp;
454 	int    checkif, hlen = 0;
455 	uint16_t sum, ip_len;
456 	int dchg = 0;				/* dest changed after fw */
457 	struct in_addr odst;			/* original dst address */
458 
459 	M_ASSERTPKTHDR(m);
460 
461 	if (m->m_flags & M_FASTFWD_OURS) {
462 		m->m_flags &= ~M_FASTFWD_OURS;
463 		/* Set up some basics that will be used later. */
464 		ip = mtod(m, struct ip *);
465 		hlen = ip->ip_hl << 2;
466 		ip_len = ntohs(ip->ip_len);
467 		goto ours;
468 	}
469 
470 	IPSTAT_INC(ips_total);
471 
472 	if (m->m_pkthdr.len < sizeof(struct ip))
473 		goto tooshort;
474 
475 	if (m->m_len < sizeof (struct ip) &&
476 	    (m = m_pullup(m, sizeof (struct ip))) == NULL) {
477 		IPSTAT_INC(ips_toosmall);
478 		return;
479 	}
480 	ip = mtod(m, struct ip *);
481 
482 	if (ip->ip_v != IPVERSION) {
483 		IPSTAT_INC(ips_badvers);
484 		goto bad;
485 	}
486 
487 	hlen = ip->ip_hl << 2;
488 	if (hlen < sizeof(struct ip)) {	/* minimum header length */
489 		IPSTAT_INC(ips_badhlen);
490 		goto bad;
491 	}
492 	if (hlen > m->m_len) {
493 		if ((m = m_pullup(m, hlen)) == NULL) {
494 			IPSTAT_INC(ips_badhlen);
495 			return;
496 		}
497 		ip = mtod(m, struct ip *);
498 	}
499 
500 	IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
501 
502 	/* 127/8 must not appear on wire - RFC1122 */
503 	ifp = m->m_pkthdr.rcvif;
504 	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
505 	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
506 		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
507 			IPSTAT_INC(ips_badaddr);
508 			goto bad;
509 		}
510 	}
511 
512 	if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
513 		sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
514 	} else {
515 		if (hlen == sizeof(struct ip)) {
516 			sum = in_cksum_hdr(ip);
517 		} else {
518 			sum = in_cksum(m, hlen);
519 		}
520 	}
521 	if (sum) {
522 		IPSTAT_INC(ips_badsum);
523 		goto bad;
524 	}
525 
526 #ifdef ALTQ
527 	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
528 		/* packet is dropped by traffic conditioner */
529 		return;
530 #endif
531 
532 	ip_len = ntohs(ip->ip_len);
533 	if (ip_len < hlen) {
534 		IPSTAT_INC(ips_badlen);
535 		goto bad;
536 	}
537 
538 	/*
539 	 * Check that the amount of data in the buffers
540 	 * is as at least much as the IP header would have us expect.
541 	 * Trim mbufs if longer than we expect.
542 	 * Drop packet if shorter than we expect.
543 	 */
544 	if (m->m_pkthdr.len < ip_len) {
545 tooshort:
546 		IPSTAT_INC(ips_tooshort);
547 		goto bad;
548 	}
549 	if (m->m_pkthdr.len > ip_len) {
550 		if (m->m_len == m->m_pkthdr.len) {
551 			m->m_len = ip_len;
552 			m->m_pkthdr.len = ip_len;
553 		} else
554 			m_adj(m, ip_len - m->m_pkthdr.len);
555 	}
556 
557 	/*
558 	 * Try to forward the packet, but if we fail continue.
559 	 * ip_tryforward() does not generate redirects, so fall
560 	 * through to normal processing if redirects are required.
561 	 * ip_tryforward() does inbound and outbound packet firewall
562 	 * processing. If firewall has decided that destination becomes
563 	 * our local address, it sets M_FASTFWD_OURS flag. In this
564 	 * case skip another inbound firewall processing and update
565 	 * ip pointer.
566 	 */
567 	if (V_ipforwarding != 0 && V_ipsendredirects == 0
568 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
569 	    && (!IPSEC_ENABLED(ipv4) ||
570 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
571 #endif
572 	    ) {
573 		if ((m = ip_tryforward(m)) == NULL)
574 			return;
575 		if (m->m_flags & M_FASTFWD_OURS) {
576 			m->m_flags &= ~M_FASTFWD_OURS;
577 			ip = mtod(m, struct ip *);
578 			goto ours;
579 		}
580 	}
581 
582 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
583 	/*
584 	 * Bypass packet filtering for packets previously handled by IPsec.
585 	 */
586 	if (IPSEC_ENABLED(ipv4) &&
587 	    IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
588 			goto passin;
589 #endif
590 
591 	/*
592 	 * Run through list of hooks for input packets.
593 	 *
594 	 * NB: Beware of the destination address changing (e.g.
595 	 *     by NAT rewriting).  When this happens, tell
596 	 *     ip_forward to do the right thing.
597 	 */
598 
599 	/* Jump over all PFIL processing if hooks are not active. */
600 	if (!PFIL_HOOKED_IN(V_inet_pfil_head))
601 		goto passin;
602 
603 	odst = ip->ip_dst;
604 	if (pfil_run_hooks(V_inet_pfil_head, &m, ifp, PFIL_IN, NULL) !=
605 	    PFIL_PASS)
606 		return;
607 	if (m == NULL)			/* consumed by filter */
608 		return;
609 
610 	ip = mtod(m, struct ip *);
611 	dchg = (odst.s_addr != ip->ip_dst.s_addr);
612 	ifp = m->m_pkthdr.rcvif;
613 
614 	if (m->m_flags & M_FASTFWD_OURS) {
615 		m->m_flags &= ~M_FASTFWD_OURS;
616 		goto ours;
617 	}
618 	if (m->m_flags & M_IP_NEXTHOP) {
619 		if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
620 			/*
621 			 * Directly ship the packet on.  This allows
622 			 * forwarding packets originally destined to us
623 			 * to some other directly connected host.
624 			 */
625 			ip_forward(m, 1);
626 			return;
627 		}
628 	}
629 passin:
630 
631 	/*
632 	 * Process options and, if not destined for us,
633 	 * ship it on.  ip_dooptions returns 1 when an
634 	 * error was detected (causing an icmp message
635 	 * to be sent and the original packet to be freed).
636 	 */
637 	if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
638 		return;
639 
640         /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
641          * matter if it is destined to another node, or whether it is
642          * a multicast one, RSVP wants it! and prevents it from being forwarded
643          * anywhere else. Also checks if the rsvp daemon is running before
644 	 * grabbing the packet.
645          */
646 	if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
647 		goto ours;
648 
649 	/*
650 	 * Check our list of addresses, to see if the packet is for us.
651 	 * If we don't have any addresses, assume any unicast packet
652 	 * we receive might be for us (and let the upper layers deal
653 	 * with it).
654 	 */
655 	if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) &&
656 	    (m->m_flags & (M_MCAST|M_BCAST)) == 0)
657 		goto ours;
658 
659 	/*
660 	 * Enable a consistency check between the destination address
661 	 * and the arrival interface for a unicast packet (the RFC 1122
662 	 * strong ES model) if IP forwarding is disabled and the packet
663 	 * is not locally generated and the packet is not subject to
664 	 * 'ipfw fwd'.
665 	 *
666 	 * XXX - Checking also should be disabled if the destination
667 	 * address is ipnat'ed to a different interface.
668 	 *
669 	 * XXX - Checking is incompatible with IP aliases added
670 	 * to the loopback interface instead of the interface where
671 	 * the packets are received.
672 	 *
673 	 * XXX - This is the case for carp vhost IPs as well so we
674 	 * insert a workaround. If the packet got here, we already
675 	 * checked with carp_iamatch() and carp_forus().
676 	 */
677 	checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
678 	    ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
679 	    ifp->if_carp == NULL && (dchg == 0);
680 
681 	/*
682 	 * Check for exact addresses in the hash bucket.
683 	 */
684 	IN_IFADDR_RLOCK(&in_ifa_tracker);
685 	LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
686 		/*
687 		 * If the address matches, verify that the packet
688 		 * arrived via the correct interface if checking is
689 		 * enabled.
690 		 */
691 		if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
692 		    (!checkif || ia->ia_ifp == ifp)) {
693 			counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
694 			counter_u64_add(ia->ia_ifa.ifa_ibytes,
695 			    m->m_pkthdr.len);
696 			IN_IFADDR_RUNLOCK(&in_ifa_tracker);
697 			goto ours;
698 		}
699 	}
700 	IN_IFADDR_RUNLOCK(&in_ifa_tracker);
701 
702 	/*
703 	 * Check for broadcast addresses.
704 	 *
705 	 * Only accept broadcast packets that arrive via the matching
706 	 * interface.  Reception of forwarded directed broadcasts would
707 	 * be handled via ip_forward() and ether_output() with the loopback
708 	 * into the stack for SIMPLEX interfaces handled by ether_output().
709 	 */
710 	if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
711 		struct epoch_tracker et;
712 
713 		NET_EPOCH_ENTER(et);
714 		CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
715 			if (ifa->ifa_addr->sa_family != AF_INET)
716 				continue;
717 			ia = ifatoia(ifa);
718 			if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
719 			    ip->ip_dst.s_addr) {
720 				counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
721 				counter_u64_add(ia->ia_ifa.ifa_ibytes,
722 				    m->m_pkthdr.len);
723 				NET_EPOCH_EXIT(et);
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 				NET_EPOCH_EXIT(et);
732 				goto ours;
733 			}
734 #endif
735 		}
736 		NET_EPOCH_EXIT(et);
737 		ia = NULL;
738 	}
739 	/* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
740 	if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
741 		IPSTAT_INC(ips_cantforward);
742 		m_freem(m);
743 		return;
744 	}
745 	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
746 		if (V_ip_mrouter) {
747 			/*
748 			 * If we are acting as a multicast router, all
749 			 * incoming multicast packets are passed to the
750 			 * kernel-level multicast forwarding function.
751 			 * The packet is returned (relatively) intact; if
752 			 * ip_mforward() returns a non-zero value, the packet
753 			 * must be discarded, else it may be accepted below.
754 			 */
755 			if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
756 				IPSTAT_INC(ips_cantforward);
757 				m_freem(m);
758 				return;
759 			}
760 
761 			/*
762 			 * The process-level routing daemon needs to receive
763 			 * all multicast IGMP packets, whether or not this
764 			 * host belongs to their destination groups.
765 			 */
766 			if (ip->ip_p == IPPROTO_IGMP)
767 				goto ours;
768 			IPSTAT_INC(ips_forward);
769 		}
770 		/*
771 		 * Assume the packet is for us, to avoid prematurely taking
772 		 * a lock on the in_multi hash. Protocols must perform
773 		 * their own filtering and update statistics accordingly.
774 		 */
775 		goto ours;
776 	}
777 	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
778 		goto ours;
779 	if (ip->ip_dst.s_addr == INADDR_ANY)
780 		goto ours;
781 
782 	/*
783 	 * Not for us; forward if possible and desirable.
784 	 */
785 	if (V_ipforwarding == 0) {
786 		IPSTAT_INC(ips_cantforward);
787 		m_freem(m);
788 	} else {
789 		ip_forward(m, dchg);
790 	}
791 	return;
792 
793 ours:
794 #ifdef IPSTEALTH
795 	/*
796 	 * IPSTEALTH: Process non-routing options only
797 	 * if the packet is destined for us.
798 	 */
799 	if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
800 		return;
801 #endif /* IPSTEALTH */
802 
803 	/*
804 	 * Attempt reassembly; if it succeeds, proceed.
805 	 * ip_reass() will return a different mbuf.
806 	 */
807 	if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
808 		/* XXXGL: shouldn't we save & set m_flags? */
809 		m = ip_reass(m);
810 		if (m == NULL)
811 			return;
812 		ip = mtod(m, struct ip *);
813 		/* Get the header length of the reassembled packet */
814 		hlen = ip->ip_hl << 2;
815 	}
816 
817 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
818 	if (IPSEC_ENABLED(ipv4)) {
819 		if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
820 			return;
821 	}
822 #endif /* IPSEC */
823 
824 	/*
825 	 * Switch out to protocol's input routine.
826 	 */
827 	IPSTAT_INC(ips_delivered);
828 
829 	(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
830 	return;
831 bad:
832 	m_freem(m);
833 }
834 
835 /*
836  * IP timer processing;
837  * if a timer expires on a reassembly
838  * queue, discard it.
839  */
840 void
841 ip_slowtimo(void)
842 {
843 	VNET_ITERATOR_DECL(vnet_iter);
844 
845 	VNET_LIST_RLOCK_NOSLEEP();
846 	VNET_FOREACH(vnet_iter) {
847 		CURVNET_SET(vnet_iter);
848 		ipreass_slowtimo();
849 		CURVNET_RESTORE();
850 	}
851 	VNET_LIST_RUNLOCK_NOSLEEP();
852 }
853 
854 void
855 ip_drain(void)
856 {
857 	VNET_ITERATOR_DECL(vnet_iter);
858 
859 	VNET_LIST_RLOCK_NOSLEEP();
860 	VNET_FOREACH(vnet_iter) {
861 		CURVNET_SET(vnet_iter);
862 		ipreass_drain();
863 		CURVNET_RESTORE();
864 	}
865 	VNET_LIST_RUNLOCK_NOSLEEP();
866 }
867 
868 /*
869  * The protocol to be inserted into ip_protox[] must be already registered
870  * in inetsw[], either statically or through pf_proto_register().
871  */
872 int
873 ipproto_register(short ipproto)
874 {
875 	struct protosw *pr;
876 
877 	/* Sanity checks. */
878 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
879 		return (EPROTONOSUPPORT);
880 
881 	/*
882 	 * The protocol slot must not be occupied by another protocol
883 	 * already.  An index pointing to IPPROTO_RAW is unused.
884 	 */
885 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
886 	if (pr == NULL)
887 		return (EPFNOSUPPORT);
888 	if (ip_protox[ipproto] != pr - inetsw)	/* IPPROTO_RAW */
889 		return (EEXIST);
890 
891 	/* Find the protocol position in inetsw[] and set the index. */
892 	for (pr = inetdomain.dom_protosw;
893 	     pr < inetdomain.dom_protoswNPROTOSW; pr++) {
894 		if (pr->pr_domain->dom_family == PF_INET &&
895 		    pr->pr_protocol && pr->pr_protocol == ipproto) {
896 			ip_protox[pr->pr_protocol] = pr - inetsw;
897 			return (0);
898 		}
899 	}
900 	return (EPROTONOSUPPORT);
901 }
902 
903 int
904 ipproto_unregister(short ipproto)
905 {
906 	struct protosw *pr;
907 
908 	/* Sanity checks. */
909 	if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
910 		return (EPROTONOSUPPORT);
911 
912 	/* Check if the protocol was indeed registered. */
913 	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
914 	if (pr == NULL)
915 		return (EPFNOSUPPORT);
916 	if (ip_protox[ipproto] == pr - inetsw)  /* IPPROTO_RAW */
917 		return (ENOENT);
918 
919 	/* Reset the protocol slot to IPPROTO_RAW. */
920 	ip_protox[ipproto] = pr - inetsw;
921 	return (0);
922 }
923 
924 u_char inetctlerrmap[PRC_NCMDS] = {
925 	0,		0,		0,		0,
926 	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
927 	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
928 	EMSGSIZE,	EHOSTUNREACH,	0,		0,
929 	0,		0,		EHOSTUNREACH,	0,
930 	ENOPROTOOPT,	ECONNREFUSED
931 };
932 
933 /*
934  * Forward a packet.  If some error occurs return the sender
935  * an icmp packet.  Note we can't always generate a meaningful
936  * icmp message because icmp doesn't have a large enough repertoire
937  * of codes and types.
938  *
939  * If not forwarding, just drop the packet.  This could be confusing
940  * if ipforwarding was zero but some routing protocol was advancing
941  * us as a gateway to somewhere.  However, we must let the routing
942  * protocol deal with that.
943  *
944  * The srcrt parameter indicates whether the packet is being forwarded
945  * via a source route.
946  */
947 void
948 ip_forward(struct mbuf *m, int srcrt)
949 {
950 	struct ip *ip = mtod(m, struct ip *);
951 	struct in_ifaddr *ia;
952 	struct mbuf *mcopy;
953 	struct sockaddr_in *sin;
954 	struct in_addr dest;
955 	struct route ro;
956 	struct epoch_tracker et;
957 	int error, type = 0, code = 0, mtu = 0;
958 
959 	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
960 		IPSTAT_INC(ips_cantforward);
961 		m_freem(m);
962 		return;
963 	}
964 	if (
965 #ifdef IPSTEALTH
966 	    V_ipstealth == 0 &&
967 #endif
968 	    ip->ip_ttl <= IPTTLDEC) {
969 		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
970 		return;
971 	}
972 
973 	bzero(&ro, sizeof(ro));
974 	sin = (struct sockaddr_in *)&ro.ro_dst;
975 	sin->sin_family = AF_INET;
976 	sin->sin_len = sizeof(*sin);
977 	sin->sin_addr = ip->ip_dst;
978 #ifdef RADIX_MPATH
979 	rtalloc_mpath_fib(&ro,
980 	    ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
981 	    M_GETFIB(m));
982 #else
983 	in_rtalloc_ign(&ro, 0, M_GETFIB(m));
984 #endif
985 	NET_EPOCH_ENTER(et);
986 	if (ro.ro_rt != NULL) {
987 		ia = ifatoia(ro.ro_rt->rt_ifa);
988 	} else
989 		ia = NULL;
990 	/*
991 	 * Save the IP header and at most 8 bytes of the payload,
992 	 * in case we need to generate an ICMP message to the src.
993 	 *
994 	 * XXX this can be optimized a lot by saving the data in a local
995 	 * buffer on the stack (72 bytes at most), and only allocating the
996 	 * mbuf if really necessary. The vast majority of the packets
997 	 * are forwarded without having to send an ICMP back (either
998 	 * because unnecessary, or because rate limited), so we are
999 	 * really we are wasting a lot of work here.
1000 	 *
1001 	 * We don't use m_copym() because it might return a reference
1002 	 * to a shared cluster. Both this function and ip_output()
1003 	 * assume exclusive access to the IP header in `m', so any
1004 	 * data in a cluster may change before we reach icmp_error().
1005 	 */
1006 	mcopy = m_gethdr(M_NOWAIT, m->m_type);
1007 	if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
1008 		/*
1009 		 * It's probably ok if the pkthdr dup fails (because
1010 		 * the deep copy of the tag chain failed), but for now
1011 		 * be conservative and just discard the copy since
1012 		 * code below may some day want the tags.
1013 		 */
1014 		m_free(mcopy);
1015 		mcopy = NULL;
1016 	}
1017 	if (mcopy != NULL) {
1018 		mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1019 		mcopy->m_pkthdr.len = mcopy->m_len;
1020 		m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1021 	}
1022 #ifdef IPSTEALTH
1023 	if (V_ipstealth == 0)
1024 #endif
1025 		ip->ip_ttl -= IPTTLDEC;
1026 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
1027 	if (IPSEC_ENABLED(ipv4)) {
1028 		if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
1029 			/* mbuf consumed by IPsec */
1030 			m_freem(mcopy);
1031 			if (error != EINPROGRESS)
1032 				IPSTAT_INC(ips_cantforward);
1033 			goto out;
1034 		}
1035 		/* No IPsec processing required */
1036 	}
1037 #endif /* IPSEC */
1038 	/*
1039 	 * If forwarding packet using same interface that it came in on,
1040 	 * perhaps should send a redirect to sender to shortcut a hop.
1041 	 * Only send redirect if source is sending directly to us,
1042 	 * and if packet was not source routed (or has any options).
1043 	 * Also, don't send redirect if forwarding using a default route
1044 	 * or a route modified by a redirect.
1045 	 */
1046 	dest.s_addr = 0;
1047 	if (!srcrt && V_ipsendredirects &&
1048 	    ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1049 		struct rtentry *rt;
1050 
1051 		rt = ro.ro_rt;
1052 
1053 		if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1054 		    satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1055 #define	RTA(rt)	((struct in_ifaddr *)(rt->rt_ifa))
1056 			u_long src = ntohl(ip->ip_src.s_addr);
1057 
1058 			if (RTA(rt) &&
1059 			    (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1060 				if (rt->rt_flags & RTF_GATEWAY)
1061 					dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1062 				else
1063 					dest.s_addr = ip->ip_dst.s_addr;
1064 				/* Router requirements says to only send host redirects */
1065 				type = ICMP_REDIRECT;
1066 				code = ICMP_REDIRECT_HOST;
1067 			}
1068 		}
1069 	}
1070 
1071 	error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1072 
1073 	if (error == EMSGSIZE && ro.ro_rt)
1074 		mtu = ro.ro_rt->rt_mtu;
1075 	RO_RTFREE(&ro);
1076 
1077 	if (error)
1078 		IPSTAT_INC(ips_cantforward);
1079 	else {
1080 		IPSTAT_INC(ips_forward);
1081 		if (type)
1082 			IPSTAT_INC(ips_redirectsent);
1083 		else {
1084 			if (mcopy)
1085 				m_freem(mcopy);
1086 			goto out;
1087 		}
1088 	}
1089 	if (mcopy == NULL)
1090 		goto out;
1091 
1092 
1093 	switch (error) {
1094 
1095 	case 0:				/* forwarded, but need redirect */
1096 		/* type, code set above */
1097 		break;
1098 
1099 	case ENETUNREACH:
1100 	case EHOSTUNREACH:
1101 	case ENETDOWN:
1102 	case EHOSTDOWN:
1103 	default:
1104 		type = ICMP_UNREACH;
1105 		code = ICMP_UNREACH_HOST;
1106 		break;
1107 
1108 	case EMSGSIZE:
1109 		type = ICMP_UNREACH;
1110 		code = ICMP_UNREACH_NEEDFRAG;
1111 		/*
1112 		 * If the MTU was set before make sure we are below the
1113 		 * interface MTU.
1114 		 * If the MTU wasn't set before use the interface mtu or
1115 		 * fall back to the next smaller mtu step compared to the
1116 		 * current packet size.
1117 		 */
1118 		if (mtu != 0) {
1119 			if (ia != NULL)
1120 				mtu = min(mtu, ia->ia_ifp->if_mtu);
1121 		} else {
1122 			if (ia != NULL)
1123 				mtu = ia->ia_ifp->if_mtu;
1124 			else
1125 				mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1126 		}
1127 		IPSTAT_INC(ips_cantfrag);
1128 		break;
1129 
1130 	case ENOBUFS:
1131 	case EACCES:			/* ipfw denied packet */
1132 		m_freem(mcopy);
1133 		goto out;
1134 	}
1135 	icmp_error(mcopy, type, code, dest.s_addr, mtu);
1136  out:
1137 	NET_EPOCH_EXIT(et);
1138 }
1139 
1140 #define	CHECK_SO_CT(sp, ct) \
1141     (((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0)
1142 
1143 void
1144 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1145     struct mbuf *m)
1146 {
1147 	bool stamped;
1148 
1149 	stamped = false;
1150 	if ((inp->inp_socket->so_options & SO_BINTIME) ||
1151 	    CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) {
1152 		struct bintime boottimebin, bt;
1153 		struct timespec ts1;
1154 
1155 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1156 		    M_TSTMP)) {
1157 			mbuf_tstmp2timespec(m, &ts1);
1158 			timespec2bintime(&ts1, &bt);
1159 			getboottimebin(&boottimebin);
1160 			bintime_add(&bt, &boottimebin);
1161 		} else {
1162 			bintime(&bt);
1163 		}
1164 		*mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1165 		    SCM_BINTIME, SOL_SOCKET);
1166 		if (*mp != NULL) {
1167 			mp = &(*mp)->m_next;
1168 			stamped = true;
1169 		}
1170 	}
1171 	if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) {
1172 		struct bintime boottimebin, bt1;
1173 		struct timespec ts1;;
1174 		struct timeval tv;
1175 
1176 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1177 		    M_TSTMP)) {
1178 			mbuf_tstmp2timespec(m, &ts1);
1179 			timespec2bintime(&ts1, &bt1);
1180 			getboottimebin(&boottimebin);
1181 			bintime_add(&bt1, &boottimebin);
1182 			bintime2timeval(&bt1, &tv);
1183 		} else {
1184 			microtime(&tv);
1185 		}
1186 		*mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1187 		    SCM_TIMESTAMP, SOL_SOCKET);
1188 		if (*mp != NULL) {
1189 			mp = &(*mp)->m_next;
1190 			stamped = true;
1191 		}
1192 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) {
1193 		struct bintime boottimebin;
1194 		struct timespec ts, ts1;
1195 
1196 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1197 		    M_TSTMP)) {
1198 			mbuf_tstmp2timespec(m, &ts);
1199 			getboottimebin(&boottimebin);
1200 			bintime2timespec(&boottimebin, &ts1);
1201 			timespecadd(&ts, &ts1, &ts);
1202 		} else {
1203 			nanotime(&ts);
1204 		}
1205 		*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
1206 		    SCM_REALTIME, SOL_SOCKET);
1207 		if (*mp != NULL) {
1208 			mp = &(*mp)->m_next;
1209 			stamped = true;
1210 		}
1211 	} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) {
1212 		struct timespec ts;
1213 
1214 		if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1215 		    M_TSTMP))
1216 			mbuf_tstmp2timespec(m, &ts);
1217 		else
1218 			nanouptime(&ts);
1219 		*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
1220 		    SCM_MONOTONIC, SOL_SOCKET);
1221 		if (*mp != NULL) {
1222 			mp = &(*mp)->m_next;
1223 			stamped = true;
1224 		}
1225 	}
1226 	if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
1227 	    M_TSTMP)) {
1228 		struct sock_timestamp_info sti;
1229 
1230 		bzero(&sti, sizeof(sti));
1231 		sti.st_info_flags = ST_INFO_HW;
1232 		if ((m->m_flags & M_TSTMP_HPREC) != 0)
1233 			sti.st_info_flags |= ST_INFO_HW_HPREC;
1234 		*mp = sbcreatecontrol((caddr_t)&sti, sizeof(sti), SCM_TIME_INFO,
1235 		    SOL_SOCKET);
1236 		if (*mp != NULL)
1237 			mp = &(*mp)->m_next;
1238 	}
1239 	if (inp->inp_flags & INP_RECVDSTADDR) {
1240 		*mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1241 		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1242 		if (*mp)
1243 			mp = &(*mp)->m_next;
1244 	}
1245 	if (inp->inp_flags & INP_RECVTTL) {
1246 		*mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1247 		    sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1248 		if (*mp)
1249 			mp = &(*mp)->m_next;
1250 	}
1251 #ifdef notyet
1252 	/* XXX
1253 	 * Moving these out of udp_input() made them even more broken
1254 	 * than they already were.
1255 	 */
1256 	/* options were tossed already */
1257 	if (inp->inp_flags & INP_RECVOPTS) {
1258 		*mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1259 		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1260 		if (*mp)
1261 			mp = &(*mp)->m_next;
1262 	}
1263 	/* ip_srcroute doesn't do what we want here, need to fix */
1264 	if (inp->inp_flags & INP_RECVRETOPTS) {
1265 		*mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1266 		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1267 		if (*mp)
1268 			mp = &(*mp)->m_next;
1269 	}
1270 #endif
1271 	if (inp->inp_flags & INP_RECVIF) {
1272 		struct ifnet *ifp;
1273 		struct sdlbuf {
1274 			struct sockaddr_dl sdl;
1275 			u_char	pad[32];
1276 		} sdlbuf;
1277 		struct sockaddr_dl *sdp;
1278 		struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1279 
1280 		if ((ifp = m->m_pkthdr.rcvif) &&
1281 		    ifp->if_index && ifp->if_index <= V_if_index) {
1282 			sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1283 			/*
1284 			 * Change our mind and don't try copy.
1285 			 */
1286 			if (sdp->sdl_family != AF_LINK ||
1287 			    sdp->sdl_len > sizeof(sdlbuf)) {
1288 				goto makedummy;
1289 			}
1290 			bcopy(sdp, sdl2, sdp->sdl_len);
1291 		} else {
1292 makedummy:
1293 			sdl2->sdl_len =
1294 			    offsetof(struct sockaddr_dl, sdl_data[0]);
1295 			sdl2->sdl_family = AF_LINK;
1296 			sdl2->sdl_index = 0;
1297 			sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1298 		}
1299 		*mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1300 		    IP_RECVIF, IPPROTO_IP);
1301 		if (*mp)
1302 			mp = &(*mp)->m_next;
1303 	}
1304 	if (inp->inp_flags & INP_RECVTOS) {
1305 		*mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1306 		    sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1307 		if (*mp)
1308 			mp = &(*mp)->m_next;
1309 	}
1310 
1311 	if (inp->inp_flags2 & INP_RECVFLOWID) {
1312 		uint32_t flowid, flow_type;
1313 
1314 		flowid = m->m_pkthdr.flowid;
1315 		flow_type = M_HASHTYPE_GET(m);
1316 
1317 		/*
1318 		 * XXX should handle the failure of one or the
1319 		 * other - don't populate both?
1320 		 */
1321 		*mp = sbcreatecontrol((caddr_t) &flowid,
1322 		    sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
1323 		if (*mp)
1324 			mp = &(*mp)->m_next;
1325 		*mp = sbcreatecontrol((caddr_t) &flow_type,
1326 		    sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
1327 		if (*mp)
1328 			mp = &(*mp)->m_next;
1329 	}
1330 
1331 #ifdef	RSS
1332 	if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
1333 		uint32_t flowid, flow_type;
1334 		uint32_t rss_bucketid;
1335 
1336 		flowid = m->m_pkthdr.flowid;
1337 		flow_type = M_HASHTYPE_GET(m);
1338 
1339 		if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
1340 			*mp = sbcreatecontrol((caddr_t) &rss_bucketid,
1341 			   sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
1342 			if (*mp)
1343 				mp = &(*mp)->m_next;
1344 		}
1345 	}
1346 #endif
1347 }
1348 
1349 /*
1350  * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1351  * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1352  * locking.  This code remains in ip_input.c as ip_mroute.c is optionally
1353  * compiled.
1354  */
1355 VNET_DEFINE_STATIC(int, ip_rsvp_on);
1356 VNET_DEFINE(struct socket *, ip_rsvpd);
1357 
1358 #define	V_ip_rsvp_on		VNET(ip_rsvp_on)
1359 
1360 int
1361 ip_rsvp_init(struct socket *so)
1362 {
1363 
1364 	if (so->so_type != SOCK_RAW ||
1365 	    so->so_proto->pr_protocol != IPPROTO_RSVP)
1366 		return EOPNOTSUPP;
1367 
1368 	if (V_ip_rsvpd != NULL)
1369 		return EADDRINUSE;
1370 
1371 	V_ip_rsvpd = so;
1372 	/*
1373 	 * This may seem silly, but we need to be sure we don't over-increment
1374 	 * the RSVP counter, in case something slips up.
1375 	 */
1376 	if (!V_ip_rsvp_on) {
1377 		V_ip_rsvp_on = 1;
1378 		V_rsvp_on++;
1379 	}
1380 
1381 	return 0;
1382 }
1383 
1384 int
1385 ip_rsvp_done(void)
1386 {
1387 
1388 	V_ip_rsvpd = NULL;
1389 	/*
1390 	 * This may seem silly, but we need to be sure we don't over-decrement
1391 	 * the RSVP counter, in case something slips up.
1392 	 */
1393 	if (V_ip_rsvp_on) {
1394 		V_ip_rsvp_on = 0;
1395 		V_rsvp_on--;
1396 	}
1397 	return 0;
1398 }
1399 
1400 int
1401 rsvp_input(struct mbuf **mp, int *offp, int proto)
1402 {
1403 	struct mbuf *m;
1404 
1405 	m = *mp;
1406 	*mp = NULL;
1407 
1408 	if (rsvp_input_p) { /* call the real one if loaded */
1409 		*mp = m;
1410 		rsvp_input_p(mp, offp, proto);
1411 		return (IPPROTO_DONE);
1412 	}
1413 
1414 	/* Can still get packets with rsvp_on = 0 if there is a local member
1415 	 * of the group to which the RSVP packet is addressed.  But in this
1416 	 * case we want to throw the packet away.
1417 	 */
1418 
1419 	if (!V_rsvp_on) {
1420 		m_freem(m);
1421 		return (IPPROTO_DONE);
1422 	}
1423 
1424 	if (V_ip_rsvpd != NULL) {
1425 		*mp = m;
1426 		rip_input(mp, offp, proto);
1427 		return (IPPROTO_DONE);
1428 	}
1429 	/* Drop the packet */
1430 	m_freem(m);
1431 	return (IPPROTO_DONE);
1432 }
1433