ip_input.c revision 1.289
1/*	$NetBSD: ip_input.c,v 1.289 2010/07/19 14:09:45 rmind Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * 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 project 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 PROJECT 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 PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32/*-
33 * Copyright (c) 1998 The NetBSD Foundation, Inc.
34 * All rights reserved.
35 *
36 * This code is derived from software contributed to The NetBSD Foundation
37 * by Public Access Networks Corporation ("Panix").  It was developed under
38 * contract to Panix by Eric Haszlakiewicz and Thor Lancelot Simon.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 *    notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 *    notice, this list of conditions and the following disclaimer in the
47 *    documentation and/or other materials provided with the distribution.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
50 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
53 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59 * POSSIBILITY OF SUCH DAMAGE.
60 */
61
62/*
63 * Copyright (c) 1982, 1986, 1988, 1993
64 *	The Regents of the University of California.  All rights reserved.
65 *
66 * Redistribution and use in source and binary forms, with or without
67 * modification, are permitted provided that the following conditions
68 * are met:
69 * 1. Redistributions of source code must retain the above copyright
70 *    notice, this list of conditions and the following disclaimer.
71 * 2. Redistributions in binary form must reproduce the above copyright
72 *    notice, this list of conditions and the following disclaimer in the
73 *    documentation and/or other materials provided with the distribution.
74 * 3. Neither the name of the University nor the names of its contributors
75 *    may be used to endorse or promote products derived from this software
76 *    without specific prior written permission.
77 *
78 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
79 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
80 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
81 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
82 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
83 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
84 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
85 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
86 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
87 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
88 * SUCH DAMAGE.
89 *
90 *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
91 */
92
93#include <sys/cdefs.h>
94__KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.289 2010/07/19 14:09:45 rmind Exp $");
95
96#include "opt_inet.h"
97#include "opt_compat_netbsd.h"
98#include "opt_gateway.h"
99#include "opt_pfil_hooks.h"
100#include "opt_ipsec.h"
101#include "opt_mrouting.h"
102#include "opt_mbuftrace.h"
103#include "opt_inet_csum.h"
104
105#include <sys/param.h>
106#include <sys/systm.h>
107#include <sys/mbuf.h>
108#include <sys/domain.h>
109#include <sys/protosw.h>
110#include <sys/socket.h>
111#include <sys/socketvar.h>
112#include <sys/errno.h>
113#include <sys/time.h>
114#include <sys/kernel.h>
115#include <sys/pool.h>
116#include <sys/sysctl.h>
117#include <sys/kauth.h>
118
119#include <net/if.h>
120#include <net/if_dl.h>
121#include <net/route.h>
122#include <net/pfil.h>
123
124#include <netinet/in.h>
125#include <netinet/in_systm.h>
126#include <netinet/ip.h>
127#include <netinet/in_pcb.h>
128#include <netinet/in_proto.h>
129#include <netinet/in_var.h>
130#include <netinet/ip_var.h>
131#include <netinet/ip_private.h>
132#include <netinet/ip_icmp.h>
133/* just for gif_ttl */
134#include <netinet/in_gif.h>
135#include "gif.h"
136#include <net/if_gre.h>
137#include "gre.h"
138
139#ifdef MROUTING
140#include <netinet/ip_mroute.h>
141#endif
142
143#ifdef IPSEC
144#include <netinet6/ipsec.h>
145#include <netinet6/ipsec_private.h>
146#include <netkey/key.h>
147#endif
148#ifdef FAST_IPSEC
149#include <netipsec/ipsec.h>
150#include <netipsec/key.h>
151#endif	/* FAST_IPSEC*/
152
153#ifndef	IPFORWARDING
154#ifdef GATEWAY
155#define	IPFORWARDING	1	/* forward IP packets not for us */
156#else /* GATEWAY */
157#define	IPFORWARDING	0	/* don't forward IP packets not for us */
158#endif /* GATEWAY */
159#endif /* IPFORWARDING */
160#ifndef	IPSENDREDIRECTS
161#define	IPSENDREDIRECTS	1
162#endif
163#ifndef IPFORWSRCRT
164#define	IPFORWSRCRT	1	/* forward source-routed packets */
165#endif
166#ifndef IPALLOWSRCRT
167#define	IPALLOWSRCRT	1	/* allow source-routed packets */
168#endif
169#ifndef IPMTUDISC
170#define IPMTUDISC	1
171#endif
172#ifndef IPMTUDISCTIMEOUT
173#define IPMTUDISCTIMEOUT (10 * 60)	/* as per RFC 1191 */
174#endif
175
176#ifdef COMPAT_50
177#include <compat/sys/time.h>
178#include <compat/sys/socket.h>
179#endif
180
181/*
182 * Note: DIRECTED_BROADCAST is handled this way so that previous
183 * configuration using this option will Just Work.
184 */
185#ifndef IPDIRECTEDBCAST
186#ifdef DIRECTED_BROADCAST
187#define IPDIRECTEDBCAST	1
188#else
189#define	IPDIRECTEDBCAST	0
190#endif /* DIRECTED_BROADCAST */
191#endif /* IPDIRECTEDBCAST */
192int	ipforwarding = IPFORWARDING;
193int	ipsendredirects = IPSENDREDIRECTS;
194int	ip_defttl = IPDEFTTL;
195int	ip_forwsrcrt = IPFORWSRCRT;
196int	ip_directedbcast = IPDIRECTEDBCAST;
197int	ip_allowsrcrt = IPALLOWSRCRT;
198int	ip_mtudisc = IPMTUDISC;
199int	ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
200#ifdef DIAGNOSTIC
201int	ipprintfs = 0;
202#endif
203
204int	ip_do_randomid = 0;
205
206/*
207 * XXX - Setting ip_checkinterface mostly implements the receive side of
208 * the Strong ES model described in RFC 1122, but since the routing table
209 * and transmit implementation do not implement the Strong ES model,
210 * setting this to 1 results in an odd hybrid.
211 *
212 * XXX - ip_checkinterface currently must be disabled if you use ipnat
213 * to translate the destination address to another local interface.
214 *
215 * XXX - ip_checkinterface must be disabled if you add IP aliases
216 * to the loopback interface instead of the interface where the
217 * packets for those addresses are received.
218 */
219int	ip_checkinterface = 0;
220
221
222struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
223
224int	ipqmaxlen = IFQ_MAXLEN;
225u_long	in_ifaddrhash;				/* size of hash table - 1 */
226int	in_ifaddrentries;			/* total number of addrs */
227struct in_ifaddrhead in_ifaddrhead;
228struct	in_ifaddrhashhead *in_ifaddrhashtbl;
229u_long	in_multihash;				/* size of hash table - 1 */
230int	in_multientries;			/* total number of addrs */
231struct	in_multihashhead *in_multihashtbl;
232struct	ifqueue ipintrq;
233
234uint16_t ip_id;
235
236percpu_t *ipstat_percpu;
237
238#ifdef PFIL_HOOKS
239struct pfil_head inet_pfil_hook;
240#endif
241
242struct pool inmulti_pool;
243
244#ifdef INET_CSUM_COUNTERS
245#include <sys/device.h>
246
247struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
248    NULL, "inet", "hwcsum bad");
249struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
250    NULL, "inet", "hwcsum ok");
251struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
252    NULL, "inet", "swcsum");
253
254#define	INET_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
255
256EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
257EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
258EVCNT_ATTACH_STATIC(ip_swcsum);
259
260#else
261
262#define	INET_CSUM_COUNTER_INCR(ev)	/* nothing */
263
264#endif /* INET_CSUM_COUNTERS */
265
266/*
267 * We need to save the IP options in case a protocol wants to respond
268 * to an incoming packet over the same route if the packet got here
269 * using IP source routing.  This allows connection establishment and
270 * maintenance when the remote end is on a network that is not known
271 * to us.
272 */
273int	ip_nhops = 0;
274static	struct ip_srcrt {
275	struct	in_addr dst;			/* final destination */
276	char	nop;				/* one NOP to align */
277	char	srcopt[IPOPT_OFFSET + 1];	/* OPTVAL, OLEN and OFFSET */
278	struct	in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
279} ip_srcrt;
280
281static void save_rte(u_char *, struct in_addr);
282
283#ifdef MBUFTRACE
284struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
285struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
286#endif
287
288static void sysctl_net_inet_ip_setup(struct sysctllog **);
289
290/*
291 * IP initialization: fill in IP protocol switch table.
292 * All protocols not implemented in kernel go to raw IP protocol handler.
293 */
294void
295ip_init(void)
296{
297	const struct protosw *pr;
298	int i;
299
300	sysctl_net_inet_ip_setup(NULL);
301
302	pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
303	    NULL, IPL_SOFTNET);
304
305	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
306	if (pr == 0)
307		panic("ip_init");
308	for (i = 0; i < IPPROTO_MAX; i++)
309		ip_protox[i] = pr - inetsw;
310	for (pr = inetdomain.dom_protosw;
311	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
312		if (pr->pr_domain->dom_family == PF_INET &&
313		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
314			ip_protox[pr->pr_protocol] = pr - inetsw;
315
316	ip_reass_init();
317
318	ip_initid();
319	ip_id = time_second & 0xfffff;
320
321	ipintrq.ifq_maxlen = ipqmaxlen;
322
323	TAILQ_INIT(&in_ifaddrhead);
324	in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, true,
325	    &in_ifaddrhash);
326	in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, true,
327	    &in_multihash);
328	ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
329#ifdef GATEWAY
330	ipflow_init(ip_hashsize);
331#endif
332
333#ifdef PFIL_HOOKS
334	/* Register our Packet Filter hook. */
335	inet_pfil_hook.ph_type = PFIL_TYPE_AF;
336	inet_pfil_hook.ph_af   = AF_INET;
337	i = pfil_head_register(&inet_pfil_hook);
338	if (i != 0)
339		printf("ip_init: WARNING: unable to register pfil hook, "
340		    "error %d\n", i);
341#endif /* PFIL_HOOKS */
342
343#ifdef MBUFTRACE
344	MOWNER_ATTACH(&ip_tx_mowner);
345	MOWNER_ATTACH(&ip_rx_mowner);
346#endif /* MBUFTRACE */
347
348	ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
349}
350
351struct	sockaddr_in ipaddr = {
352	.sin_len = sizeof(ipaddr),
353	.sin_family = AF_INET,
354};
355struct	route ipforward_rt;
356
357/*
358 * IP software interrupt routine
359 */
360void
361ipintr(void)
362{
363	int s;
364	struct mbuf *m;
365	struct ifqueue lcl_intrq;
366
367	memset(&lcl_intrq, 0, sizeof(lcl_intrq));
368	ipintrq.ifq_maxlen = ipqmaxlen;
369
370	mutex_enter(softnet_lock);
371	KERNEL_LOCK(1, NULL);
372	if (!IF_IS_EMPTY(&ipintrq)) {
373		s = splnet();
374
375		/* Take existing queue onto stack */
376		lcl_intrq = ipintrq;
377
378		/* Zero out global queue, preserving maxlen and drops */
379		ipintrq.ifq_head = NULL;
380		ipintrq.ifq_tail = NULL;
381		ipintrq.ifq_len = 0;
382		ipintrq.ifq_maxlen = lcl_intrq.ifq_maxlen;
383		ipintrq.ifq_drops = lcl_intrq.ifq_drops;
384
385		splx(s);
386	}
387	KERNEL_UNLOCK_ONE(NULL);
388	while (!IF_IS_EMPTY(&lcl_intrq)) {
389		IF_DEQUEUE(&lcl_intrq, m);
390		if (m == NULL)
391			break;
392		ip_input(m);
393	}
394	mutex_exit(softnet_lock);
395}
396
397/*
398 * Ip input routine.  Checksum and byte swap header.  If fragmented
399 * try to reassemble.  Process options.  Pass to next level.
400 */
401void
402ip_input(struct mbuf *m)
403{
404	struct ip *ip = NULL;
405	struct in_ifaddr *ia;
406	struct ifaddr *ifa;
407	int hlen = 0, len;
408	int downmatch;
409	int checkif;
410	int srcrt = 0;
411#ifdef FAST_IPSEC
412	struct m_tag *mtag;
413	struct tdb_ident *tdbi;
414	struct secpolicy *sp;
415	int error, s;
416#endif /* FAST_IPSEC */
417
418	MCLAIM(m, &ip_rx_mowner);
419	KASSERT((m->m_flags & M_PKTHDR) != 0);
420
421	/*
422	 * If no IP addresses have been set yet but the interfaces
423	 * are receiving, can't do anything with incoming packets yet.
424	 */
425	if (TAILQ_FIRST(&in_ifaddrhead) == 0)
426		goto bad;
427	IP_STATINC(IP_STAT_TOTAL);
428	/*
429	 * If the IP header is not aligned, slurp it up into a new
430	 * mbuf with space for link headers, in the event we forward
431	 * it.  Otherwise, if it is aligned, make sure the entire
432	 * base IP header is in the first mbuf of the chain.
433	 */
434	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
435		if ((m = m_copyup(m, sizeof(struct ip),
436				  (max_linkhdr + 3) & ~3)) == NULL) {
437			/* XXXJRT new stat, please */
438			IP_STATINC(IP_STAT_TOOSMALL);
439			return;
440		}
441	} else if (__predict_false(m->m_len < sizeof (struct ip))) {
442		if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
443			IP_STATINC(IP_STAT_TOOSMALL);
444			return;
445		}
446	}
447	ip = mtod(m, struct ip *);
448	if (ip->ip_v != IPVERSION) {
449		IP_STATINC(IP_STAT_BADVERS);
450		goto bad;
451	}
452	hlen = ip->ip_hl << 2;
453	if (hlen < sizeof(struct ip)) {	/* minimum header length */
454		IP_STATINC(IP_STAT_BADHLEN);
455		goto bad;
456	}
457	if (hlen > m->m_len) {
458		if ((m = m_pullup(m, hlen)) == 0) {
459			IP_STATINC(IP_STAT_BADHLEN);
460			return;
461		}
462		ip = mtod(m, struct ip *);
463	}
464
465	/*
466	 * RFC1122: packets with a multicast source address are
467	 * not allowed.
468	 */
469	if (IN_MULTICAST(ip->ip_src.s_addr)) {
470		IP_STATINC(IP_STAT_BADADDR);
471		goto bad;
472	}
473
474	/* 127/8 must not appear on wire - RFC1122 */
475	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
476	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
477		if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
478			IP_STATINC(IP_STAT_BADADDR);
479			goto bad;
480		}
481	}
482
483	switch (m->m_pkthdr.csum_flags &
484		((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
485		 M_CSUM_IPv4_BAD)) {
486	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
487		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
488		goto badcsum;
489
490	case M_CSUM_IPv4:
491		/* Checksum was okay. */
492		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
493		break;
494
495	default:
496		/*
497		 * Must compute it ourselves.  Maybe skip checksum on
498		 * loopback interfaces.
499		 */
500		if (__predict_true(!(m->m_pkthdr.rcvif->if_flags &
501				     IFF_LOOPBACK) || ip_do_loopback_cksum)) {
502			INET_CSUM_COUNTER_INCR(&ip_swcsum);
503			if (in_cksum(m, hlen) != 0)
504				goto badcsum;
505		}
506		break;
507	}
508
509	/* Retrieve the packet length. */
510	len = ntohs(ip->ip_len);
511
512	/*
513	 * Check for additional length bogosity
514	 */
515	if (len < hlen) {
516		IP_STATINC(IP_STAT_BADLEN);
517		goto bad;
518	}
519
520	/*
521	 * Check that the amount of data in the buffers
522	 * is as at least much as the IP header would have us expect.
523	 * Trim mbufs if longer than we expect.
524	 * Drop packet if shorter than we expect.
525	 */
526	if (m->m_pkthdr.len < len) {
527		IP_STATINC(IP_STAT_TOOSHORT);
528		goto bad;
529	}
530	if (m->m_pkthdr.len > len) {
531		if (m->m_len == m->m_pkthdr.len) {
532			m->m_len = len;
533			m->m_pkthdr.len = len;
534		} else
535			m_adj(m, len - m->m_pkthdr.len);
536	}
537
538#if defined(IPSEC)
539	/* ipflow (IP fast forwarding) is not compatible with IPsec. */
540	m->m_flags &= ~M_CANFASTFWD;
541#else
542	/*
543	 * Assume that we can create a fast-forward IP flow entry
544	 * based on this packet.
545	 */
546	m->m_flags |= M_CANFASTFWD;
547#endif
548
549#ifdef PFIL_HOOKS
550	/*
551	 * Run through list of hooks for input packets.  If there are any
552	 * filters which require that additional packets in the flow are
553	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
554	 * Note that filters must _never_ set this flag, as another filter
555	 * in the list may have previously cleared it.
556	 */
557	/*
558	 * let ipfilter look at packet on the wire,
559	 * not the decapsulated packet.
560	 */
561#ifdef IPSEC
562	if (!ipsec_getnhist(m))
563#elif defined(FAST_IPSEC)
564	if (!ipsec_indone(m))
565#else
566	if (1)
567#endif
568	{
569		struct in_addr odst;
570
571		odst = ip->ip_dst;
572		if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
573		    PFIL_IN) != 0)
574			return;
575		if (m == NULL)
576			return;
577		ip = mtod(m, struct ip *);
578		hlen = ip->ip_hl << 2;
579		/*
580		 * XXX The setting of "srcrt" here is to prevent ip_forward()
581		 * from generating ICMP redirects for packets that have
582		 * been redirected by a hook back out on to the same LAN that
583		 * they came from and is not an indication that the packet
584		 * is being inffluenced by source routing options.  This
585		 * allows things like
586		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
587		 * where tlp0 is both on the 1.1.1.0/24 network and is the
588		 * default route for hosts on 1.1.1.0/24.  Of course this
589		 * also requires a "map tlp0 ..." to complete the story.
590		 * One might argue whether or not this kind of network config.
591		 * should be supported in this manner...
592		 */
593		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
594	}
595#endif /* PFIL_HOOKS */
596
597#ifdef ALTQ
598	/* XXX Temporary until ALTQ is changed to use a pfil hook */
599	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
600		/* packet dropped by traffic conditioner */
601		return;
602	}
603#endif
604
605	/*
606	 * Process options and, if not destined for us,
607	 * ship it on.  ip_dooptions returns 1 when an
608	 * error was detected (causing an icmp message
609	 * to be sent and the original packet to be freed).
610	 */
611	ip_nhops = 0;		/* for source routed packets */
612	if (hlen > sizeof (struct ip) && ip_dooptions(m))
613		return;
614
615	/*
616	 * Enable a consistency check between the destination address
617	 * and the arrival interface for a unicast packet (the RFC 1122
618	 * strong ES model) if IP forwarding is disabled and the packet
619	 * is not locally generated.
620	 *
621	 * XXX - Checking also should be disabled if the destination
622	 * address is ipnat'ed to a different interface.
623	 *
624	 * XXX - Checking is incompatible with IP aliases added
625	 * to the loopback interface instead of the interface where
626	 * the packets are received.
627	 *
628	 * XXX - We need to add a per ifaddr flag for this so that
629	 * we get finer grain control.
630	 */
631	checkif = ip_checkinterface && (ipforwarding == 0) &&
632	    (m->m_pkthdr.rcvif != NULL) &&
633	    ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
634
635	/*
636	 * Check our list of addresses, to see if the packet is for us.
637	 *
638	 * Traditional 4.4BSD did not consult IFF_UP at all.
639	 * The behavior here is to treat addresses on !IFF_UP interface
640	 * as not mine.
641	 */
642	downmatch = 0;
643	LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
644		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
645			if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
646				continue;
647			if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
648				break;
649			else
650				downmatch++;
651		}
652	}
653	if (ia != NULL)
654		goto ours;
655	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
656		IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) {
657			if (ifa->ifa_addr->sa_family != AF_INET)
658				continue;
659			ia = ifatoia(ifa);
660			if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
661			    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
662			    /*
663			     * Look for all-0's host part (old broadcast addr),
664			     * either for subnet or net.
665			     */
666			    ip->ip_dst.s_addr == ia->ia_subnet ||
667			    ip->ip_dst.s_addr == ia->ia_net)
668				goto ours;
669			/*
670			 * An interface with IP address zero accepts
671			 * all packets that arrive on that interface.
672			 */
673			if (in_nullhost(ia->ia_addr.sin_addr))
674				goto ours;
675		}
676	}
677	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
678		struct in_multi *inm;
679#ifdef MROUTING
680		extern struct socket *ip_mrouter;
681
682		if (ip_mrouter) {
683			/*
684			 * If we are acting as a multicast router, all
685			 * incoming multicast packets are passed to the
686			 * kernel-level multicast forwarding function.
687			 * The packet is returned (relatively) intact; if
688			 * ip_mforward() returns a non-zero value, the packet
689			 * must be discarded, else it may be accepted below.
690			 *
691			 * (The IP ident field is put in the same byte order
692			 * as expected when ip_mforward() is called from
693			 * ip_output().)
694			 */
695			if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
696				IP_STATINC(IP_STAT_CANTFORWARD);
697				m_freem(m);
698				return;
699			}
700
701			/*
702			 * The process-level routing demon needs to receive
703			 * all multicast IGMP packets, whether or not this
704			 * host belongs to their destination groups.
705			 */
706			if (ip->ip_p == IPPROTO_IGMP)
707				goto ours;
708			IP_STATINC(IP_STAT_CANTFORWARD);
709		}
710#endif
711		/*
712		 * See if we belong to the destination multicast group on the
713		 * arrival interface.
714		 */
715		IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
716		if (inm == NULL) {
717			IP_STATINC(IP_STAT_CANTFORWARD);
718			m_freem(m);
719			return;
720		}
721		goto ours;
722	}
723	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
724	    in_nullhost(ip->ip_dst))
725		goto ours;
726
727	/*
728	 * Not for us; forward if possible and desirable.
729	 */
730	if (ipforwarding == 0) {
731		IP_STATINC(IP_STAT_CANTFORWARD);
732		m_freem(m);
733	} else {
734		/*
735		 * If ip_dst matched any of my address on !IFF_UP interface,
736		 * and there's no IFF_UP interface that matches ip_dst,
737		 * send icmp unreach.  Forwarding it will result in in-kernel
738		 * forwarding loop till TTL goes to 0.
739		 */
740		if (downmatch) {
741			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
742			IP_STATINC(IP_STAT_CANTFORWARD);
743			return;
744		}
745#ifdef IPSEC
746		if (ipsec4_in_reject(m, NULL)) {
747			IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
748			goto bad;
749		}
750#endif
751#ifdef FAST_IPSEC
752		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
753		s = splsoftnet();
754		if (mtag != NULL) {
755			tdbi = (struct tdb_ident *)(mtag + 1);
756			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
757		} else {
758			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
759						   IP_FORWARDING, &error);
760		}
761		if (sp == NULL) {	/* NB: can happen if error */
762			splx(s);
763			/*XXX error stat???*/
764			DPRINTF(("ip_input: no SP for forwarding\n"));	/*XXX*/
765			goto bad;
766		}
767
768		/*
769		 * Check security policy against packet attributes.
770		 */
771		error = ipsec_in_reject(sp, m);
772		KEY_FREESP(&sp);
773		splx(s);
774		if (error) {
775			IP_STATINC(IP_STAT_CANTFORWARD);
776			goto bad;
777		}
778
779		/*
780		 * Peek at the outbound SP for this packet to determine if
781		 * it's a Fast Forward candidate.
782		 */
783		mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
784		if (mtag != NULL)
785			m->m_flags &= ~M_CANFASTFWD;
786		else {
787			s = splsoftnet();
788			sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND,
789			    (IP_FORWARDING |
790			     (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
791			    &error, NULL);
792			if (sp != NULL) {
793				m->m_flags &= ~M_CANFASTFWD;
794				KEY_FREESP(&sp);
795			}
796			splx(s);
797		}
798#endif	/* FAST_IPSEC */
799
800		ip_forward(m, srcrt);
801	}
802	return;
803
804ours:
805	/*
806	 * If offset or IP_MF are set, must reassemble.
807	 */
808	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
809		struct mbuf *m_final;
810		u_int off, flen;
811		bool mff;
812
813		/*
814		 * Prevent TCP blind data attacks by not allowing non-initial
815		 * fragments to start at less than 68 bytes (minimal fragment
816		 * size) and making sure the first fragment is at least 68
817		 * bytes.
818		 */
819		off = (ntohs(ip->ip_off) & IP_OFFMASK) << 3;
820		if ((off > 0 ? off + hlen : len) < IP_MINFRAGSIZE - 1) {
821			IP_STATINC(IP_STAT_BADFRAGS);
822			goto bad;
823		}
824
825		/* Fragment length and MF flag. */
826		flen = ntohs(ip->ip_len) - hlen;
827		mff = (ip->ip_off & htons(IP_MF)) != 0;
828		if (mff) {
829			/*
830			 * Make sure that fragments have a data length
831			 * which is non-zero and multiple of 8 bytes.
832			 */
833			if (flen == 0 || (flen & 0x7) != 0) {
834				IP_STATINC(IP_STAT_BADFRAGS);
835				goto bad;
836			}
837		}
838
839		/*
840		 * Adjust total IP length to not reflect header and convert
841		 * offset of this to bytes.  XXX: clobbers struct ip.
842		 */
843		ip->ip_len = htons(flen);
844		ip->ip_off = htons(off);
845
846		/*
847		 * Pass to IP reassembly mechanism.
848		 */
849		if (ip_reass_packet(m, ip, mff, &m_final) != 0) {
850			/* Failed; invalid fragment(s) or packet. */
851			goto bad;
852		}
853		if (m_final == NULL) {
854			/* More fragments should come; silently return. */
855			return;
856		}
857		/* Reassembly is done, we have the final packet. */
858		m = m_final;
859
860		/* Updated local variable(s). */
861		ip = mtod(m, struct ip *);
862		hlen = ip->ip_hl << 2;
863	}
864
865#if defined(IPSEC)
866	/*
867	 * enforce IPsec policy checking if we are seeing last header.
868	 * note that we do not visit this with protocols with pcb layer
869	 * code - like udp/tcp/raw ip.
870	 */
871	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
872	    ipsec4_in_reject(m, NULL)) {
873		IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
874		goto bad;
875	}
876#endif
877#ifdef FAST_IPSEC
878	/*
879	 * enforce IPsec policy checking if we are seeing last header.
880	 * note that we do not visit this with protocols with pcb layer
881	 * code - like udp/tcp/raw ip.
882	 */
883	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
884		/*
885		 * Check if the packet has already had IPsec processing
886		 * done.  If so, then just pass it along.  This tag gets
887		 * set during AH, ESP, etc. input handling, before the
888		 * packet is returned to the ip input queue for delivery.
889		 */
890		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
891		s = splsoftnet();
892		if (mtag != NULL) {
893			tdbi = (struct tdb_ident *)(mtag + 1);
894			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
895		} else {
896			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
897						   IP_FORWARDING, &error);
898		}
899		if (sp != NULL) {
900			/*
901			 * Check security policy against packet attributes.
902			 */
903			error = ipsec_in_reject(sp, m);
904			KEY_FREESP(&sp);
905		} else {
906			/* XXX error stat??? */
907			error = EINVAL;
908DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
909		}
910		splx(s);
911		if (error)
912			goto bad;
913	}
914#endif /* FAST_IPSEC */
915
916	/*
917	 * Switch out to protocol's input routine.
918	 */
919#if IFA_STATS
920	if (ia && ip)
921		ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
922#endif
923	IP_STATINC(IP_STAT_DELIVERED);
924    {
925	int off = hlen, nh = ip->ip_p;
926
927	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
928	return;
929    }
930bad:
931	m_freem(m);
932	return;
933
934badcsum:
935	IP_STATINC(IP_STAT_BADSUM);
936	m_freem(m);
937}
938
939/*
940 * IP timer processing.
941 */
942void
943ip_slowtimo(void)
944{
945
946	mutex_enter(softnet_lock);
947	KERNEL_LOCK(1, NULL);
948
949	ip_reass_slowtimo();
950
951	KERNEL_UNLOCK_ONE(NULL);
952	mutex_exit(softnet_lock);
953}
954
955/*
956 * IP drain processing.
957 */
958void
959ip_drain(void)
960{
961
962	KERNEL_LOCK(1, NULL);
963	ip_reass_drain();
964	KERNEL_UNLOCK_ONE(NULL);
965}
966
967/*
968 * Do option processing on a datagram,
969 * possibly discarding it if bad options are encountered,
970 * or forwarding it if source-routed.
971 * Returns 1 if packet has been forwarded/freed,
972 * 0 if the packet should be processed further.
973 */
974int
975ip_dooptions(struct mbuf *m)
976{
977	struct ip *ip = mtod(m, struct ip *);
978	u_char *cp, *cp0;
979	struct ip_timestamp *ipt;
980	struct in_ifaddr *ia;
981	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
982	struct in_addr dst;
983	n_time ntime;
984
985	dst = ip->ip_dst;
986	cp = (u_char *)(ip + 1);
987	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
988	for (; cnt > 0; cnt -= optlen, cp += optlen) {
989		opt = cp[IPOPT_OPTVAL];
990		if (opt == IPOPT_EOL)
991			break;
992		if (opt == IPOPT_NOP)
993			optlen = 1;
994		else {
995			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
996				code = &cp[IPOPT_OLEN] - (u_char *)ip;
997				goto bad;
998			}
999			optlen = cp[IPOPT_OLEN];
1000			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
1001				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1002				goto bad;
1003			}
1004		}
1005		switch (opt) {
1006
1007		default:
1008			break;
1009
1010		/*
1011		 * Source routing with record.
1012		 * Find interface with current destination address.
1013		 * If none on this machine then drop if strictly routed,
1014		 * or do nothing if loosely routed.
1015		 * Record interface address and bring up next address
1016		 * component.  If strictly routed make sure next
1017		 * address is on directly accessible net.
1018		 */
1019		case IPOPT_LSRR:
1020		case IPOPT_SSRR:
1021			if (ip_allowsrcrt == 0) {
1022				type = ICMP_UNREACH;
1023				code = ICMP_UNREACH_NET_PROHIB;
1024				goto bad;
1025			}
1026			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1027				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1028				goto bad;
1029			}
1030			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1031				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1032				goto bad;
1033			}
1034			ipaddr.sin_addr = ip->ip_dst;
1035			ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1036			if (ia == 0) {
1037				if (opt == IPOPT_SSRR) {
1038					type = ICMP_UNREACH;
1039					code = ICMP_UNREACH_SRCFAIL;
1040					goto bad;
1041				}
1042				/*
1043				 * Loose routing, and not at next destination
1044				 * yet; nothing to do except forward.
1045				 */
1046				break;
1047			}
1048			off--;			/* 0 origin */
1049			if ((off + sizeof(struct in_addr)) > optlen) {
1050				/*
1051				 * End of source route.  Should be for us.
1052				 */
1053				save_rte(cp, ip->ip_src);
1054				break;
1055			}
1056			/*
1057			 * locate outgoing interface
1058			 */
1059			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
1060			    sizeof(ipaddr.sin_addr));
1061			if (opt == IPOPT_SSRR)
1062				ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr)));
1063			else
1064				ia = ip_rtaddr(ipaddr.sin_addr);
1065			if (ia == 0) {
1066				type = ICMP_UNREACH;
1067				code = ICMP_UNREACH_SRCFAIL;
1068				goto bad;
1069			}
1070			ip->ip_dst = ipaddr.sin_addr;
1071			bcopy((void *)&ia->ia_addr.sin_addr,
1072			    (void *)(cp + off), sizeof(struct in_addr));
1073			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1074			/*
1075			 * Let ip_intr's mcast routing check handle mcast pkts
1076			 */
1077			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1078			break;
1079
1080		case IPOPT_RR:
1081			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1082				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1083				goto bad;
1084			}
1085			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1086				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1087				goto bad;
1088			}
1089			/*
1090			 * If no space remains, ignore.
1091			 */
1092			off--;			/* 0 origin */
1093			if ((off + sizeof(struct in_addr)) > optlen)
1094				break;
1095			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1096			    sizeof(ipaddr.sin_addr));
1097			/*
1098			 * locate outgoing interface; if we're the destination,
1099			 * use the incoming interface (should be same).
1100			 */
1101			if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1102			    == NULL &&
1103			    (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1104				type = ICMP_UNREACH;
1105				code = ICMP_UNREACH_HOST;
1106				goto bad;
1107			}
1108			bcopy((void *)&ia->ia_addr.sin_addr,
1109			    (void *)(cp + off), sizeof(struct in_addr));
1110			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1111			break;
1112
1113		case IPOPT_TS:
1114			code = cp - (u_char *)ip;
1115			ipt = (struct ip_timestamp *)cp;
1116			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1117				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1118				goto bad;
1119			}
1120			if (ipt->ipt_ptr < 5) {
1121				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1122				goto bad;
1123			}
1124			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1125				if (++ipt->ipt_oflw == 0) {
1126					code = (u_char *)&ipt->ipt_ptr -
1127					    (u_char *)ip;
1128					goto bad;
1129				}
1130				break;
1131			}
1132			cp0 = (cp + ipt->ipt_ptr - 1);
1133			switch (ipt->ipt_flg) {
1134
1135			case IPOPT_TS_TSONLY:
1136				break;
1137
1138			case IPOPT_TS_TSANDADDR:
1139				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1140				    sizeof(struct in_addr) > ipt->ipt_len) {
1141					code = (u_char *)&ipt->ipt_ptr -
1142					    (u_char *)ip;
1143					goto bad;
1144				}
1145				ipaddr.sin_addr = dst;
1146				ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1147				    m->m_pkthdr.rcvif));
1148				if (ia == 0)
1149					continue;
1150				bcopy(&ia->ia_addr.sin_addr,
1151				    cp0, sizeof(struct in_addr));
1152				ipt->ipt_ptr += sizeof(struct in_addr);
1153				break;
1154
1155			case IPOPT_TS_PRESPEC:
1156				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1157				    sizeof(struct in_addr) > ipt->ipt_len) {
1158					code = (u_char *)&ipt->ipt_ptr -
1159					    (u_char *)ip;
1160					goto bad;
1161				}
1162				memcpy(&ipaddr.sin_addr, cp0,
1163				    sizeof(struct in_addr));
1164				if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1165				    == NULL)
1166					continue;
1167				ipt->ipt_ptr += sizeof(struct in_addr);
1168				break;
1169
1170			default:
1171				/* XXX can't take &ipt->ipt_flg */
1172				code = (u_char *)&ipt->ipt_ptr -
1173				    (u_char *)ip + 1;
1174				goto bad;
1175			}
1176			ntime = iptime();
1177			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1178			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1179			    sizeof(n_time));
1180			ipt->ipt_ptr += sizeof(n_time);
1181		}
1182	}
1183	if (forward) {
1184		if (ip_forwsrcrt == 0) {
1185			type = ICMP_UNREACH;
1186			code = ICMP_UNREACH_SRCFAIL;
1187			goto bad;
1188		}
1189		ip_forward(m, 1);
1190		return (1);
1191	}
1192	return (0);
1193bad:
1194	icmp_error(m, type, code, 0, 0);
1195	IP_STATINC(IP_STAT_BADOPTIONS);
1196	return (1);
1197}
1198
1199/*
1200 * Given address of next destination (final or next hop),
1201 * return internet address info of interface to be used to get there.
1202 */
1203struct in_ifaddr *
1204ip_rtaddr(struct in_addr dst)
1205{
1206	struct rtentry *rt;
1207	union {
1208		struct sockaddr		dst;
1209		struct sockaddr_in	dst4;
1210	} u;
1211
1212	sockaddr_in_init(&u.dst4, &dst, 0);
1213
1214	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL)
1215		return NULL;
1216
1217	return ifatoia(rt->rt_ifa);
1218}
1219
1220/*
1221 * Save incoming source route for use in replies,
1222 * to be picked up later by ip_srcroute if the receiver is interested.
1223 */
1224void
1225save_rte(u_char *option, struct in_addr dst)
1226{
1227	unsigned olen;
1228
1229	olen = option[IPOPT_OLEN];
1230#ifdef DIAGNOSTIC
1231	if (ipprintfs)
1232		printf("save_rte: olen %d\n", olen);
1233#endif /* 0 */
1234	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1235		return;
1236	memcpy((void *)ip_srcrt.srcopt, (void *)option, olen);
1237	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1238	ip_srcrt.dst = dst;
1239}
1240
1241/*
1242 * Retrieve incoming source route for use in replies,
1243 * in the same form used by setsockopt.
1244 * The first hop is placed before the options, will be removed later.
1245 */
1246struct mbuf *
1247ip_srcroute(void)
1248{
1249	struct in_addr *p, *q;
1250	struct mbuf *m;
1251
1252	if (ip_nhops == 0)
1253		return NULL;
1254	m = m_get(M_DONTWAIT, MT_SOOPTS);
1255	if (m == 0)
1256		return NULL;
1257
1258	MCLAIM(m, &inetdomain.dom_mowner);
1259#define OPTSIZ	(sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1260
1261	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1262	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1263	    OPTSIZ;
1264#ifdef DIAGNOSTIC
1265	if (ipprintfs)
1266		printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1267#endif
1268
1269	/*
1270	 * First save first hop for return route
1271	 */
1272	p = &ip_srcrt.route[ip_nhops - 1];
1273	*(mtod(m, struct in_addr *)) = *p--;
1274#ifdef DIAGNOSTIC
1275	if (ipprintfs)
1276		printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1277#endif
1278
1279	/*
1280	 * Copy option fields and padding (nop) to mbuf.
1281	 */
1282	ip_srcrt.nop = IPOPT_NOP;
1283	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1284	memmove(mtod(m, char *) + sizeof(struct in_addr), &ip_srcrt.nop,
1285	    OPTSIZ);
1286	q = (struct in_addr *)(mtod(m, char *) +
1287	    sizeof(struct in_addr) + OPTSIZ);
1288#undef OPTSIZ
1289	/*
1290	 * Record return path as an IP source route,
1291	 * reversing the path (pointers are now aligned).
1292	 */
1293	while (p >= ip_srcrt.route) {
1294#ifdef DIAGNOSTIC
1295		if (ipprintfs)
1296			printf(" %x", ntohl(q->s_addr));
1297#endif
1298		*q++ = *p--;
1299	}
1300	/*
1301	 * Last hop goes to final destination.
1302	 */
1303	*q = ip_srcrt.dst;
1304#ifdef DIAGNOSTIC
1305	if (ipprintfs)
1306		printf(" %x\n", ntohl(q->s_addr));
1307#endif
1308	return (m);
1309}
1310
1311const int inetctlerrmap[PRC_NCMDS] = {
1312	[PRC_MSGSIZE] = EMSGSIZE,
1313	[PRC_HOSTDEAD] = EHOSTDOWN,
1314	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1315	[PRC_UNREACH_NET] = EHOSTUNREACH,
1316	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1317	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1318	[PRC_UNREACH_PORT] = ECONNREFUSED,
1319	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1320	[PRC_PARAMPROB] = ENOPROTOOPT,
1321};
1322
1323/*
1324 * Forward a packet.  If some error occurs return the sender
1325 * an icmp packet.  Note we can't always generate a meaningful
1326 * icmp message because icmp doesn't have a large enough repertoire
1327 * of codes and types.
1328 *
1329 * If not forwarding, just drop the packet.  This could be confusing
1330 * if ipforwarding was zero but some routing protocol was advancing
1331 * us as a gateway to somewhere.  However, we must let the routing
1332 * protocol deal with that.
1333 *
1334 * The srcrt parameter indicates whether the packet is being forwarded
1335 * via a source route.
1336 */
1337void
1338ip_forward(struct mbuf *m, int srcrt)
1339{
1340	struct ip *ip = mtod(m, struct ip *);
1341	struct rtentry *rt;
1342	int error, type = 0, code = 0, destmtu = 0;
1343	struct mbuf *mcopy;
1344	n_long dest;
1345	union {
1346		struct sockaddr		dst;
1347		struct sockaddr_in	dst4;
1348	} u;
1349
1350	/*
1351	 * We are now in the output path.
1352	 */
1353	MCLAIM(m, &ip_tx_mowner);
1354
1355	/*
1356	 * Clear any in-bound checksum flags for this packet.
1357	 */
1358	m->m_pkthdr.csum_flags = 0;
1359
1360	dest = 0;
1361#ifdef DIAGNOSTIC
1362	if (ipprintfs) {
1363		printf("forward: src %s ", inet_ntoa(ip->ip_src));
1364		printf("dst %s ttl %x\n", inet_ntoa(ip->ip_dst), ip->ip_ttl);
1365	}
1366#endif
1367	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1368		IP_STATINC(IP_STAT_CANTFORWARD);
1369		m_freem(m);
1370		return;
1371	}
1372	if (ip->ip_ttl <= IPTTLDEC) {
1373		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1374		return;
1375	}
1376
1377	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1378	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) {
1379		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1380		return;
1381	}
1382
1383	/*
1384	 * Save at most 68 bytes of the packet in case
1385	 * we need to generate an ICMP message to the src.
1386	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1387	 */
1388	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1389	if (mcopy)
1390		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1391
1392	ip->ip_ttl -= IPTTLDEC;
1393
1394	/*
1395	 * If forwarding packet using same interface that it came in on,
1396	 * perhaps should send a redirect to sender to shortcut a hop.
1397	 * Only send redirect if source is sending directly to us,
1398	 * and if packet was not source routed (or has any options).
1399	 * Also, don't send redirect if forwarding using a default route
1400	 * or a route modified by a redirect.
1401	 */
1402	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1403	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1404	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1405	    ipsendredirects && !srcrt) {
1406		if (rt->rt_ifa &&
1407		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1408		    ifatoia(rt->rt_ifa)->ia_subnet) {
1409			if (rt->rt_flags & RTF_GATEWAY)
1410				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1411			else
1412				dest = ip->ip_dst.s_addr;
1413			/*
1414			 * Router requirements says to only send host
1415			 * redirects.
1416			 */
1417			type = ICMP_REDIRECT;
1418			code = ICMP_REDIRECT_HOST;
1419#ifdef DIAGNOSTIC
1420			if (ipprintfs)
1421				printf("redirect (%d) to %x\n", code,
1422				    (u_int32_t)dest);
1423#endif
1424		}
1425	}
1426
1427	error = ip_output(m, NULL, &ipforward_rt,
1428	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1429	    (struct ip_moptions *)NULL, (struct socket *)NULL);
1430
1431	if (error)
1432		IP_STATINC(IP_STAT_CANTFORWARD);
1433	else {
1434		uint64_t *ips = IP_STAT_GETREF();
1435		ips[IP_STAT_FORWARD]++;
1436		if (type) {
1437			ips[IP_STAT_REDIRECTSENT]++;
1438			IP_STAT_PUTREF();
1439		} else {
1440			IP_STAT_PUTREF();
1441			if (mcopy) {
1442#ifdef GATEWAY
1443				if (mcopy->m_flags & M_CANFASTFWD)
1444					ipflow_create(&ipforward_rt, mcopy);
1445#endif
1446				m_freem(mcopy);
1447			}
1448			return;
1449		}
1450	}
1451	if (mcopy == NULL)
1452		return;
1453
1454	switch (error) {
1455
1456	case 0:				/* forwarded, but need redirect */
1457		/* type, code set above */
1458		break;
1459
1460	case ENETUNREACH:		/* shouldn't happen, checked above */
1461	case EHOSTUNREACH:
1462	case ENETDOWN:
1463	case EHOSTDOWN:
1464	default:
1465		type = ICMP_UNREACH;
1466		code = ICMP_UNREACH_HOST;
1467		break;
1468
1469	case EMSGSIZE:
1470		type = ICMP_UNREACH;
1471		code = ICMP_UNREACH_NEEDFRAG;
1472
1473		if ((rt = rtcache_validate(&ipforward_rt)) != NULL)
1474			destmtu = rt->rt_ifp->if_mtu;
1475
1476#if defined(IPSEC) || defined(FAST_IPSEC)
1477		{
1478			/*
1479			 * If the packet is routed over IPsec tunnel, tell the
1480			 * originator the tunnel MTU.
1481			 *	tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1482			 * XXX quickhack!!!
1483			 */
1484
1485			struct secpolicy *sp;
1486			int ipsecerror;
1487			size_t ipsechdr;
1488			struct route *ro;
1489
1490			sp = ipsec4_getpolicybyaddr(mcopy,
1491			    IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1492			    &ipsecerror);
1493
1494			if (sp != NULL) {
1495				/* count IPsec header size */
1496				ipsechdr = ipsec4_hdrsiz(mcopy,
1497				    IPSEC_DIR_OUTBOUND, NULL);
1498
1499				/*
1500				 * find the correct route for outer IPv4
1501				 * header, compute tunnel MTU.
1502				 */
1503
1504				if (sp->req != NULL
1505				 && sp->req->sav != NULL
1506				 && sp->req->sav->sah != NULL) {
1507					ro = &sp->req->sav->sah->sa_route;
1508					rt = rtcache_validate(ro);
1509					if (rt && rt->rt_ifp) {
1510						destmtu =
1511						    rt->rt_rmx.rmx_mtu ?
1512						    rt->rt_rmx.rmx_mtu :
1513						    rt->rt_ifp->if_mtu;
1514						destmtu -= ipsechdr;
1515					}
1516				}
1517
1518#ifdef	IPSEC
1519				key_freesp(sp);
1520#else
1521				KEY_FREESP(&sp);
1522#endif
1523			}
1524		}
1525#endif /*defined(IPSEC) || defined(FAST_IPSEC)*/
1526		IP_STATINC(IP_STAT_CANTFRAG);
1527		break;
1528
1529	case ENOBUFS:
1530#if 1
1531		/*
1532		 * a router should not generate ICMP_SOURCEQUENCH as
1533		 * required in RFC1812 Requirements for IP Version 4 Routers.
1534		 * source quench could be a big problem under DoS attacks,
1535		 * or if the underlying interface is rate-limited.
1536		 */
1537		if (mcopy)
1538			m_freem(mcopy);
1539		return;
1540#else
1541		type = ICMP_SOURCEQUENCH;
1542		code = 0;
1543		break;
1544#endif
1545	}
1546	icmp_error(mcopy, type, code, dest, destmtu);
1547}
1548
1549void
1550ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1551    struct mbuf *m)
1552{
1553
1554	if (inp->inp_socket->so_options & SO_TIMESTAMP
1555#ifdef SO_OTIMESTAMP
1556	    || inp->inp_socket->so_options & SO_OTIMESTAMP
1557#endif
1558	    ) {
1559		struct timeval tv;
1560
1561		microtime(&tv);
1562#ifdef SO_OTIMESTAMP
1563		if (inp->inp_socket->so_options & SO_OTIMESTAMP) {
1564			struct timeval50 tv50;
1565			timeval_to_timeval50(&tv, &tv50);
1566			*mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
1567			    SCM_OTIMESTAMP, SOL_SOCKET);
1568		} else
1569#endif
1570		*mp = sbcreatecontrol((void *) &tv, sizeof(tv),
1571		    SCM_TIMESTAMP, SOL_SOCKET);
1572		if (*mp)
1573			mp = &(*mp)->m_next;
1574	}
1575	if (inp->inp_flags & INP_RECVDSTADDR) {
1576		*mp = sbcreatecontrol((void *) &ip->ip_dst,
1577		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1578		if (*mp)
1579			mp = &(*mp)->m_next;
1580	}
1581#ifdef notyet
1582	/*
1583	 * XXX
1584	 * Moving these out of udp_input() made them even more broken
1585	 * than they already were.
1586	 *	- fenner@parc.xerox.com
1587	 */
1588	/* options were tossed already */
1589	if (inp->inp_flags & INP_RECVOPTS) {
1590		*mp = sbcreatecontrol((void *) opts_deleted_above,
1591		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1592		if (*mp)
1593			mp = &(*mp)->m_next;
1594	}
1595	/* ip_srcroute doesn't do what we want here, need to fix */
1596	if (inp->inp_flags & INP_RECVRETOPTS) {
1597		*mp = sbcreatecontrol((void *) ip_srcroute(),
1598		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1599		if (*mp)
1600			mp = &(*mp)->m_next;
1601	}
1602#endif
1603	if (inp->inp_flags & INP_RECVIF) {
1604		struct sockaddr_dl sdl;
1605
1606		sockaddr_dl_init(&sdl, sizeof(sdl),
1607		    (m->m_pkthdr.rcvif != NULL)
1608		        ?  m->m_pkthdr.rcvif->if_index
1609			: 0,
1610			0, NULL, 0, NULL, 0);
1611		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1612		if (*mp)
1613			mp = &(*mp)->m_next;
1614	}
1615	if (inp->inp_flags & INP_RECVTTL) {
1616		*mp = sbcreatecontrol((void *) &ip->ip_ttl,
1617		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1618		if (*mp)
1619			mp = &(*mp)->m_next;
1620	}
1621}
1622
1623/*
1624 * sysctl helper routine for net.inet.ip.forwsrcrt.
1625 */
1626static int
1627sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1628{
1629	int error, tmp;
1630	struct sysctlnode node;
1631
1632	node = *rnode;
1633	tmp = ip_forwsrcrt;
1634	node.sysctl_data = &tmp;
1635	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1636	if (error || newp == NULL)
1637		return (error);
1638
1639	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1640	    0, NULL, NULL, NULL);
1641	if (error)
1642		return (error);
1643
1644	ip_forwsrcrt = tmp;
1645
1646	return (0);
1647}
1648
1649/*
1650 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1651 * range of the new value and tweaks timers if it changes.
1652 */
1653static int
1654sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1655{
1656	int error, tmp;
1657	struct sysctlnode node;
1658
1659	node = *rnode;
1660	tmp = ip_mtudisc_timeout;
1661	node.sysctl_data = &tmp;
1662	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1663	if (error || newp == NULL)
1664		return (error);
1665	if (tmp < 0)
1666		return (EINVAL);
1667
1668	mutex_enter(softnet_lock);
1669
1670	ip_mtudisc_timeout = tmp;
1671	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1672
1673	mutex_exit(softnet_lock);
1674
1675	return (0);
1676}
1677
1678#ifdef GATEWAY
1679/*
1680 * sysctl helper routine for net.inet.ip.maxflows.
1681 */
1682static int
1683sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
1684{
1685	int error;
1686
1687	error = sysctl_lookup(SYSCTLFN_CALL(rnode));
1688	if (error || newp == NULL)
1689		return (error);
1690
1691	mutex_enter(softnet_lock);
1692	KERNEL_LOCK(1, NULL);
1693
1694	ipflow_prune();
1695
1696	KERNEL_UNLOCK_ONE(NULL);
1697	mutex_exit(softnet_lock);
1698
1699	return (0);
1700}
1701
1702static int
1703sysctl_net_inet_ip_hashsize(SYSCTLFN_ARGS)
1704{
1705	int error, tmp;
1706	struct sysctlnode node;
1707
1708	node = *rnode;
1709	tmp = ip_hashsize;
1710	node.sysctl_data = &tmp;
1711	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1712	if (error || newp == NULL)
1713		return (error);
1714
1715	if ((tmp & (tmp - 1)) == 0 && tmp != 0) {
1716		/*
1717		 * Can only fail due to malloc()
1718		 */
1719		mutex_enter(softnet_lock);
1720		KERNEL_LOCK(1, NULL);
1721
1722		error = ipflow_invalidate_all(tmp);
1723
1724		KERNEL_UNLOCK_ONE(NULL);
1725		mutex_exit(softnet_lock);
1726
1727	} else {
1728		/*
1729		 * EINVAL if not a power of 2
1730	         */
1731		error = EINVAL;
1732	}
1733
1734	return error;
1735}
1736#endif /* GATEWAY */
1737
1738static int
1739sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1740{
1741
1742	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1743}
1744
1745static void
1746sysctl_net_inet_ip_setup(struct sysctllog **clog)
1747{
1748	extern int subnetsarelocal, hostzeroisbroadcast;
1749
1750	sysctl_createv(clog, 0, NULL, NULL,
1751		       CTLFLAG_PERMANENT,
1752		       CTLTYPE_NODE, "net", NULL,
1753		       NULL, 0, NULL, 0,
1754		       CTL_NET, CTL_EOL);
1755	sysctl_createv(clog, 0, NULL, NULL,
1756		       CTLFLAG_PERMANENT,
1757		       CTLTYPE_NODE, "inet",
1758		       SYSCTL_DESCR("PF_INET related settings"),
1759		       NULL, 0, NULL, 0,
1760		       CTL_NET, PF_INET, CTL_EOL);
1761	sysctl_createv(clog, 0, NULL, NULL,
1762		       CTLFLAG_PERMANENT,
1763		       CTLTYPE_NODE, "ip",
1764		       SYSCTL_DESCR("IPv4 related settings"),
1765		       NULL, 0, NULL, 0,
1766		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1767
1768	sysctl_createv(clog, 0, NULL, NULL,
1769		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1770		       CTLTYPE_INT, "forwarding",
1771		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1772		       NULL, 0, &ipforwarding, 0,
1773		       CTL_NET, PF_INET, IPPROTO_IP,
1774		       IPCTL_FORWARDING, CTL_EOL);
1775	sysctl_createv(clog, 0, NULL, NULL,
1776		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1777		       CTLTYPE_INT, "redirect",
1778		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1779		       NULL, 0, &ipsendredirects, 0,
1780		       CTL_NET, PF_INET, IPPROTO_IP,
1781		       IPCTL_SENDREDIRECTS, CTL_EOL);
1782	sysctl_createv(clog, 0, NULL, NULL,
1783		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1784		       CTLTYPE_INT, "ttl",
1785		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1786		       NULL, 0, &ip_defttl, 0,
1787		       CTL_NET, PF_INET, IPPROTO_IP,
1788		       IPCTL_DEFTTL, CTL_EOL);
1789#ifdef IPCTL_DEFMTU
1790	sysctl_createv(clog, 0, NULL, NULL,
1791		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1792		       CTLTYPE_INT, "mtu",
1793		       SYSCTL_DESCR("Default MTA for an INET route"),
1794		       NULL, 0, &ip_mtu, 0,
1795		       CTL_NET, PF_INET, IPPROTO_IP,
1796		       IPCTL_DEFMTU, CTL_EOL);
1797#endif /* IPCTL_DEFMTU */
1798	sysctl_createv(clog, 0, NULL, NULL,
1799		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1800		       CTLTYPE_INT, "forwsrcrt",
1801		       SYSCTL_DESCR("Enable forwarding of source-routed "
1802				    "datagrams"),
1803		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1804		       CTL_NET, PF_INET, IPPROTO_IP,
1805		       IPCTL_FORWSRCRT, CTL_EOL);
1806	sysctl_createv(clog, 0, NULL, NULL,
1807		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1808		       CTLTYPE_INT, "directed-broadcast",
1809		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1810		       NULL, 0, &ip_directedbcast, 0,
1811		       CTL_NET, PF_INET, IPPROTO_IP,
1812		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1813	sysctl_createv(clog, 0, NULL, NULL,
1814		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1815		       CTLTYPE_INT, "allowsrcrt",
1816		       SYSCTL_DESCR("Accept source-routed datagrams"),
1817		       NULL, 0, &ip_allowsrcrt, 0,
1818		       CTL_NET, PF_INET, IPPROTO_IP,
1819		       IPCTL_ALLOWSRCRT, CTL_EOL);
1820	sysctl_createv(clog, 0, NULL, NULL,
1821		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1822		       CTLTYPE_INT, "subnetsarelocal",
1823		       SYSCTL_DESCR("Whether logical subnets are considered "
1824				    "local"),
1825		       NULL, 0, &subnetsarelocal, 0,
1826		       CTL_NET, PF_INET, IPPROTO_IP,
1827		       IPCTL_SUBNETSARELOCAL, CTL_EOL);
1828	sysctl_createv(clog, 0, NULL, NULL,
1829		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1830		       CTLTYPE_INT, "mtudisc",
1831		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1832		       NULL, 0, &ip_mtudisc, 0,
1833		       CTL_NET, PF_INET, IPPROTO_IP,
1834		       IPCTL_MTUDISC, CTL_EOL);
1835	sysctl_createv(clog, 0, NULL, NULL,
1836		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1837		       CTLTYPE_INT, "anonportmin",
1838		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1839		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1840		       CTL_NET, PF_INET, IPPROTO_IP,
1841		       IPCTL_ANONPORTMIN, CTL_EOL);
1842	sysctl_createv(clog, 0, NULL, NULL,
1843		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1844		       CTLTYPE_INT, "anonportmax",
1845		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1846		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1847		       CTL_NET, PF_INET, IPPROTO_IP,
1848		       IPCTL_ANONPORTMAX, CTL_EOL);
1849	sysctl_createv(clog, 0, NULL, NULL,
1850		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1851		       CTLTYPE_INT, "mtudisctimeout",
1852		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1853		       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
1854		       CTL_NET, PF_INET, IPPROTO_IP,
1855		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1856#ifdef GATEWAY
1857	sysctl_createv(clog, 0, NULL, NULL,
1858		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1859		       CTLTYPE_INT, "maxflows",
1860		       SYSCTL_DESCR("Number of flows for fast forwarding"),
1861		       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
1862		       CTL_NET, PF_INET, IPPROTO_IP,
1863		       IPCTL_MAXFLOWS, CTL_EOL);
1864	sysctl_createv(clog, 0, NULL, NULL,
1865			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1866			CTLTYPE_INT, "hashsize",
1867			SYSCTL_DESCR("Size of hash table for fast forwarding (IPv4)"),
1868			sysctl_net_inet_ip_hashsize, 0, &ip_hashsize, 0,
1869			CTL_NET, PF_INET, IPPROTO_IP,
1870			CTL_CREATE, CTL_EOL);
1871#endif /* GATEWAY */
1872	sysctl_createv(clog, 0, NULL, NULL,
1873		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1874		       CTLTYPE_INT, "hostzerobroadcast",
1875		       SYSCTL_DESCR("All zeroes address is broadcast address"),
1876		       NULL, 0, &hostzeroisbroadcast, 0,
1877		       CTL_NET, PF_INET, IPPROTO_IP,
1878		       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
1879#if NGIF > 0
1880	sysctl_createv(clog, 0, NULL, NULL,
1881		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1882		       CTLTYPE_INT, "gifttl",
1883		       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
1884		       NULL, 0, &ip_gif_ttl, 0,
1885		       CTL_NET, PF_INET, IPPROTO_IP,
1886		       IPCTL_GIF_TTL, CTL_EOL);
1887#endif /* NGIF */
1888#ifndef IPNOPRIVPORTS
1889	sysctl_createv(clog, 0, NULL, NULL,
1890		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1891		       CTLTYPE_INT, "lowportmin",
1892		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1893				    "to assign"),
1894		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1895		       CTL_NET, PF_INET, IPPROTO_IP,
1896		       IPCTL_LOWPORTMIN, CTL_EOL);
1897	sysctl_createv(clog, 0, NULL, NULL,
1898		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1899		       CTLTYPE_INT, "lowportmax",
1900		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1901				    "to assign"),
1902		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1903		       CTL_NET, PF_INET, IPPROTO_IP,
1904		       IPCTL_LOWPORTMAX, CTL_EOL);
1905#endif /* IPNOPRIVPORTS */
1906#if NGRE > 0
1907	sysctl_createv(clog, 0, NULL, NULL,
1908		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1909		       CTLTYPE_INT, "grettl",
1910		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1911		       NULL, 0, &ip_gre_ttl, 0,
1912		       CTL_NET, PF_INET, IPPROTO_IP,
1913		       IPCTL_GRE_TTL, CTL_EOL);
1914#endif /* NGRE */
1915	sysctl_createv(clog, 0, NULL, NULL,
1916		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1917		       CTLTYPE_INT, "checkinterface",
1918		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1919				    "from RFC1122"),
1920		       NULL, 0, &ip_checkinterface, 0,
1921		       CTL_NET, PF_INET, IPPROTO_IP,
1922		       IPCTL_CHECKINTERFACE, CTL_EOL);
1923	sysctl_createv(clog, 0, NULL, NULL,
1924		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1925		       CTLTYPE_INT, "random_id",
1926		       SYSCTL_DESCR("Assign random ip_id values"),
1927		       NULL, 0, &ip_do_randomid, 0,
1928		       CTL_NET, PF_INET, IPPROTO_IP,
1929		       IPCTL_RANDOMID, CTL_EOL);
1930	sysctl_createv(clog, 0, NULL, NULL,
1931		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1932		       CTLTYPE_INT, "do_loopback_cksum",
1933		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1934		       NULL, 0, &ip_do_loopback_cksum, 0,
1935		       CTL_NET, PF_INET, IPPROTO_IP,
1936		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1937	sysctl_createv(clog, 0, NULL, NULL,
1938		       CTLFLAG_PERMANENT,
1939		       CTLTYPE_STRUCT, "stats",
1940		       SYSCTL_DESCR("IP statistics"),
1941		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1942		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1943		       CTL_EOL);
1944}
1945
1946void
1947ip_statinc(u_int stat)
1948{
1949
1950	KASSERT(stat < IP_NSTATS);
1951	IP_STATINC(stat);
1952}
1953