ip_input.c revision 1.294
1/*	$NetBSD: ip_input.c,v 1.294 2011/04/14 20:32:04 dyoung 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 1.294 2011/04/14 20:32:04 dyoung 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
224u_long	in_ifaddrhash;				/* size of hash table - 1 */
225int	in_ifaddrentries;			/* total number of addrs */
226struct in_ifaddrhead in_ifaddrhead;
227struct	in_ifaddrhashhead *in_ifaddrhashtbl;
228u_long	in_multihash;				/* size of hash table - 1 */
229int	in_multientries;			/* total number of addrs */
230struct	in_multihashhead *in_multihashtbl;
231struct	ifqueue ipintrq;
232
233ipid_state_t *		ip_ids;
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_ids = ip_id_init();
319	ip_id = time_second & 0xfffff;
320
321	ipintrq.ifq_maxlen = IFQ_MAXLEN;
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
369	mutex_enter(softnet_lock);
370	KERNEL_LOCK(1, NULL);
371	if (!IF_IS_EMPTY(&ipintrq)) {
372		s = splnet();
373
374		/* Take existing queue onto stack */
375		lcl_intrq = ipintrq;
376
377		/* Zero out global queue, preserving maxlen and drops */
378		ipintrq.ifq_head = NULL;
379		ipintrq.ifq_tail = NULL;
380		ipintrq.ifq_len = 0;
381		ipintrq.ifq_maxlen = lcl_intrq.ifq_maxlen;
382		ipintrq.ifq_drops = lcl_intrq.ifq_drops;
383
384		splx(s);
385	}
386	KERNEL_UNLOCK_ONE(NULL);
387	while (!IF_IS_EMPTY(&lcl_intrq)) {
388		IF_DEQUEUE(&lcl_intrq, m);
389		if (m == NULL)
390			break;
391		ip_input(m);
392	}
393	mutex_exit(softnet_lock);
394}
395
396/*
397 * Ip input routine.  Checksum and byte swap header.  If fragmented
398 * try to reassemble.  Process options.  Pass to next level.
399 */
400void
401ip_input(struct mbuf *m)
402{
403	struct ip *ip = NULL;
404	struct in_ifaddr *ia;
405	struct ifaddr *ifa;
406	int hlen = 0, len;
407	int downmatch;
408	int checkif;
409	int srcrt = 0;
410#ifdef FAST_IPSEC
411	struct m_tag *mtag;
412	struct tdb_ident *tdbi;
413	struct secpolicy *sp;
414	int error, s;
415#endif /* FAST_IPSEC */
416
417	MCLAIM(m, &ip_rx_mowner);
418	KASSERT((m->m_flags & M_PKTHDR) != 0);
419
420	/*
421	 * If no IP addresses have been set yet but the interfaces
422	 * are receiving, can't do anything with incoming packets yet.
423	 */
424	if (TAILQ_FIRST(&in_ifaddrhead) == 0)
425		goto bad;
426	IP_STATINC(IP_STAT_TOTAL);
427	/*
428	 * If the IP header is not aligned, slurp it up into a new
429	 * mbuf with space for link headers, in the event we forward
430	 * it.  Otherwise, if it is aligned, make sure the entire
431	 * base IP header is in the first mbuf of the chain.
432	 */
433	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
434		if ((m = m_copyup(m, sizeof(struct ip),
435				  (max_linkhdr + 3) & ~3)) == NULL) {
436			/* XXXJRT new stat, please */
437			IP_STATINC(IP_STAT_TOOSMALL);
438			return;
439		}
440	} else if (__predict_false(m->m_len < sizeof (struct ip))) {
441		if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
442			IP_STATINC(IP_STAT_TOOSMALL);
443			return;
444		}
445	}
446	ip = mtod(m, struct ip *);
447	if (ip->ip_v != IPVERSION) {
448		IP_STATINC(IP_STAT_BADVERS);
449		goto bad;
450	}
451	hlen = ip->ip_hl << 2;
452	if (hlen < sizeof(struct ip)) {	/* minimum header length */
453		IP_STATINC(IP_STAT_BADHLEN);
454		goto bad;
455	}
456	if (hlen > m->m_len) {
457		if ((m = m_pullup(m, hlen)) == 0) {
458			IP_STATINC(IP_STAT_BADHLEN);
459			return;
460		}
461		ip = mtod(m, struct ip *);
462	}
463
464	/*
465	 * RFC1122: packets with a multicast source address are
466	 * not allowed.
467	 */
468	if (IN_MULTICAST(ip->ip_src.s_addr)) {
469		IP_STATINC(IP_STAT_BADADDR);
470		goto bad;
471	}
472
473	/* 127/8 must not appear on wire - RFC1122 */
474	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
475	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
476		if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
477			IP_STATINC(IP_STAT_BADADDR);
478			goto bad;
479		}
480	}
481
482	switch (m->m_pkthdr.csum_flags &
483		((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
484		 M_CSUM_IPv4_BAD)) {
485	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
486		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
487		goto badcsum;
488
489	case M_CSUM_IPv4:
490		/* Checksum was okay. */
491		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
492		break;
493
494	default:
495		/*
496		 * Must compute it ourselves.  Maybe skip checksum on
497		 * loopback interfaces.
498		 */
499		if (__predict_true(!(m->m_pkthdr.rcvif->if_flags &
500				     IFF_LOOPBACK) || ip_do_loopback_cksum)) {
501			INET_CSUM_COUNTER_INCR(&ip_swcsum);
502			if (in_cksum(m, hlen) != 0)
503				goto badcsum;
504		}
505		break;
506	}
507
508	/* Retrieve the packet length. */
509	len = ntohs(ip->ip_len);
510
511	/*
512	 * Check for additional length bogosity
513	 */
514	if (len < hlen) {
515		IP_STATINC(IP_STAT_BADLEN);
516		goto bad;
517	}
518
519	/*
520	 * Check that the amount of data in the buffers
521	 * is as at least much as the IP header would have us expect.
522	 * Trim mbufs if longer than we expect.
523	 * Drop packet if shorter than we expect.
524	 */
525	if (m->m_pkthdr.len < len) {
526		IP_STATINC(IP_STAT_TOOSHORT);
527		goto bad;
528	}
529	if (m->m_pkthdr.len > len) {
530		if (m->m_len == m->m_pkthdr.len) {
531			m->m_len = len;
532			m->m_pkthdr.len = len;
533		} else
534			m_adj(m, len - m->m_pkthdr.len);
535	}
536
537#if defined(IPSEC)
538	/* ipflow (IP fast forwarding) is not compatible with IPsec. */
539	m->m_flags &= ~M_CANFASTFWD;
540#else
541	/*
542	 * Assume that we can create a fast-forward IP flow entry
543	 * based on this packet.
544	 */
545	m->m_flags |= M_CANFASTFWD;
546#endif
547
548#ifdef PFIL_HOOKS
549	/*
550	 * Run through list of hooks for input packets.  If there are any
551	 * filters which require that additional packets in the flow are
552	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
553	 * Note that filters must _never_ set this flag, as another filter
554	 * in the list may have previously cleared it.
555	 */
556	/*
557	 * let ipfilter look at packet on the wire,
558	 * not the decapsulated packet.
559	 */
560#ifdef IPSEC
561	if (!ipsec_getnhist(m))
562#elif defined(FAST_IPSEC)
563	if (!ipsec_indone(m))
564#else
565	if (1)
566#endif
567	{
568		struct in_addr odst;
569
570		odst = ip->ip_dst;
571		if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
572		    PFIL_IN) != 0)
573			return;
574		if (m == NULL)
575			return;
576		ip = mtod(m, struct ip *);
577		hlen = ip->ip_hl << 2;
578		/*
579		 * XXX The setting of "srcrt" here is to prevent ip_forward()
580		 * from generating ICMP redirects for packets that have
581		 * been redirected by a hook back out on to the same LAN that
582		 * they came from and is not an indication that the packet
583		 * is being inffluenced by source routing options.  This
584		 * allows things like
585		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
586		 * where tlp0 is both on the 1.1.1.0/24 network and is the
587		 * default route for hosts on 1.1.1.0/24.  Of course this
588		 * also requires a "map tlp0 ..." to complete the story.
589		 * One might argue whether or not this kind of network config.
590		 * should be supported in this manner...
591		 */
592		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
593	}
594#endif /* PFIL_HOOKS */
595
596#ifdef ALTQ
597	/* XXX Temporary until ALTQ is changed to use a pfil hook */
598	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
599		/* packet dropped by traffic conditioner */
600		return;
601	}
602#endif
603
604	/*
605	 * Process options and, if not destined for us,
606	 * ship it on.  ip_dooptions returns 1 when an
607	 * error was detected (causing an icmp message
608	 * to be sent and the original packet to be freed).
609	 */
610	ip_nhops = 0;		/* for source routed packets */
611	if (hlen > sizeof (struct ip) && ip_dooptions(m))
612		return;
613
614	/*
615	 * Enable a consistency check between the destination address
616	 * and the arrival interface for a unicast packet (the RFC 1122
617	 * strong ES model) if IP forwarding is disabled and the packet
618	 * is not locally generated.
619	 *
620	 * XXX - Checking also should be disabled if the destination
621	 * address is ipnat'ed to a different interface.
622	 *
623	 * XXX - Checking is incompatible with IP aliases added
624	 * to the loopback interface instead of the interface where
625	 * the packets are received.
626	 *
627	 * XXX - We need to add a per ifaddr flag for this so that
628	 * we get finer grain control.
629	 */
630	checkif = ip_checkinterface && (ipforwarding == 0) &&
631	    (m->m_pkthdr.rcvif != NULL) &&
632	    ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
633
634	/*
635	 * Check our list of addresses, to see if the packet is for us.
636	 *
637	 * Traditional 4.4BSD did not consult IFF_UP at all.
638	 * The behavior here is to treat addresses on !IFF_UP interface
639	 * as not mine.
640	 */
641	downmatch = 0;
642	LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
643		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
644			if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
645				continue;
646			if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
647				break;
648			else
649				downmatch++;
650		}
651	}
652	if (ia != NULL)
653		goto ours;
654	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
655		IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) {
656			if (ifa->ifa_addr->sa_family != AF_INET)
657				continue;
658			ia = ifatoia(ifa);
659			if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
660			    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
661			    /*
662			     * Look for all-0's host part (old broadcast addr),
663			     * either for subnet or net.
664			     */
665			    ip->ip_dst.s_addr == ia->ia_subnet ||
666			    ip->ip_dst.s_addr == ia->ia_net)
667				goto ours;
668			/*
669			 * An interface with IP address zero accepts
670			 * all packets that arrive on that interface.
671			 */
672			if (in_nullhost(ia->ia_addr.sin_addr))
673				goto ours;
674		}
675	}
676	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
677		struct in_multi *inm;
678#ifdef MROUTING
679		extern struct socket *ip_mrouter;
680
681		if (ip_mrouter) {
682			/*
683			 * If we are acting as a multicast router, all
684			 * incoming multicast packets are passed to the
685			 * kernel-level multicast forwarding function.
686			 * The packet is returned (relatively) intact; if
687			 * ip_mforward() returns a non-zero value, the packet
688			 * must be discarded, else it may be accepted below.
689			 *
690			 * (The IP ident field is put in the same byte order
691			 * as expected when ip_mforward() is called from
692			 * ip_output().)
693			 */
694			if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
695				IP_STATINC(IP_STAT_CANTFORWARD);
696				m_freem(m);
697				return;
698			}
699
700			/*
701			 * The process-level routing demon needs to receive
702			 * all multicast IGMP packets, whether or not this
703			 * host belongs to their destination groups.
704			 */
705			if (ip->ip_p == IPPROTO_IGMP)
706				goto ours;
707			IP_STATINC(IP_STAT_CANTFORWARD);
708		}
709#endif
710		/*
711		 * See if we belong to the destination multicast group on the
712		 * arrival interface.
713		 */
714		IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
715		if (inm == NULL) {
716			IP_STATINC(IP_STAT_CANTFORWARD);
717			m_freem(m);
718			return;
719		}
720		goto ours;
721	}
722	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
723	    in_nullhost(ip->ip_dst))
724		goto ours;
725
726	/*
727	 * Not for us; forward if possible and desirable.
728	 */
729	if (ipforwarding == 0) {
730		IP_STATINC(IP_STAT_CANTFORWARD);
731		m_freem(m);
732	} else {
733		/*
734		 * If ip_dst matched any of my address on !IFF_UP interface,
735		 * and there's no IFF_UP interface that matches ip_dst,
736		 * send icmp unreach.  Forwarding it will result in in-kernel
737		 * forwarding loop till TTL goes to 0.
738		 */
739		if (downmatch) {
740			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
741			IP_STATINC(IP_STAT_CANTFORWARD);
742			return;
743		}
744#ifdef IPSEC
745		if (ipsec4_in_reject(m, NULL)) {
746			IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
747			goto bad;
748		}
749#endif
750#ifdef FAST_IPSEC
751		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
752		s = splsoftnet();
753		if (mtag != NULL) {
754			tdbi = (struct tdb_ident *)(mtag + 1);
755			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
756		} else {
757			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
758						   IP_FORWARDING, &error);
759		}
760		if (sp == NULL) {	/* NB: can happen if error */
761			splx(s);
762			/*XXX error stat???*/
763			DPRINTF(("ip_input: no SP for forwarding\n"));	/*XXX*/
764			goto bad;
765		}
766
767		/*
768		 * Check security policy against packet attributes.
769		 */
770		error = ipsec_in_reject(sp, m);
771		KEY_FREESP(&sp);
772		splx(s);
773		if (error) {
774			IP_STATINC(IP_STAT_CANTFORWARD);
775			goto bad;
776		}
777
778		/*
779		 * Peek at the outbound SP for this packet to determine if
780		 * it's a Fast Forward candidate.
781		 */
782		mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
783		if (mtag != NULL)
784			m->m_flags &= ~M_CANFASTFWD;
785		else {
786			s = splsoftnet();
787			sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND,
788			    (IP_FORWARDING |
789			     (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
790			    &error, NULL);
791			if (sp != NULL) {
792				m->m_flags &= ~M_CANFASTFWD;
793				KEY_FREESP(&sp);
794			}
795			splx(s);
796		}
797#endif	/* FAST_IPSEC */
798
799		ip_forward(m, srcrt);
800	}
801	return;
802
803ours:
804	/*
805	 * If offset or IP_MF are set, must reassemble.
806	 */
807	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
808		/*
809		 * Pass to IP reassembly mechanism.
810		 */
811		if (ip_reass_packet(&m, ip) != 0) {
812			/* Failed; invalid fragment(s) or packet. */
813			goto bad;
814		}
815		if (m == NULL) {
816			/* More fragments should come; silently return. */
817			return;
818		}
819		/*
820		 * Reassembly is done, we have the final packet.
821		 * Updated cached data in local variable(s).
822		 */
823		ip = mtod(m, struct ip *);
824		hlen = ip->ip_hl << 2;
825	}
826
827#if defined(IPSEC)
828	/*
829	 * enforce IPsec policy checking if we are seeing last header.
830	 * note that we do not visit this with protocols with pcb layer
831	 * code - like udp/tcp/raw ip.
832	 */
833	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
834	    ipsec4_in_reject(m, NULL)) {
835		IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
836		goto bad;
837	}
838#endif
839#ifdef FAST_IPSEC
840	/*
841	 * enforce IPsec policy checking if we are seeing last header.
842	 * note that we do not visit this with protocols with pcb layer
843	 * code - like udp/tcp/raw ip.
844	 */
845	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
846		/*
847		 * Check if the packet has already had IPsec processing
848		 * done.  If so, then just pass it along.  This tag gets
849		 * set during AH, ESP, etc. input handling, before the
850		 * packet is returned to the ip input queue for delivery.
851		 */
852		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
853		s = splsoftnet();
854		if (mtag != NULL) {
855			tdbi = (struct tdb_ident *)(mtag + 1);
856			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
857		} else {
858			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
859						   IP_FORWARDING, &error);
860		}
861		if (sp != NULL) {
862			/*
863			 * Check security policy against packet attributes.
864			 */
865			error = ipsec_in_reject(sp, m);
866			KEY_FREESP(&sp);
867		} else {
868			/* XXX error stat??? */
869			error = EINVAL;
870DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
871		}
872		splx(s);
873		if (error)
874			goto bad;
875	}
876#endif /* FAST_IPSEC */
877
878	/*
879	 * Switch out to protocol's input routine.
880	 */
881#if IFA_STATS
882	if (ia && ip)
883		ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
884#endif
885	IP_STATINC(IP_STAT_DELIVERED);
886    {
887	int off = hlen, nh = ip->ip_p;
888
889	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
890	return;
891    }
892bad:
893	m_freem(m);
894	return;
895
896badcsum:
897	IP_STATINC(IP_STAT_BADSUM);
898	m_freem(m);
899}
900
901/*
902 * IP timer processing.
903 */
904void
905ip_slowtimo(void)
906{
907
908	mutex_enter(softnet_lock);
909	KERNEL_LOCK(1, NULL);
910
911	ip_reass_slowtimo();
912
913	KERNEL_UNLOCK_ONE(NULL);
914	mutex_exit(softnet_lock);
915}
916
917/*
918 * IP drain processing.
919 */
920void
921ip_drain(void)
922{
923
924	KERNEL_LOCK(1, NULL);
925	ip_reass_drain();
926	KERNEL_UNLOCK_ONE(NULL);
927}
928
929/*
930 * Do option processing on a datagram,
931 * possibly discarding it if bad options are encountered,
932 * or forwarding it if source-routed.
933 * Returns 1 if packet has been forwarded/freed,
934 * 0 if the packet should be processed further.
935 */
936int
937ip_dooptions(struct mbuf *m)
938{
939	struct ip *ip = mtod(m, struct ip *);
940	u_char *cp, *cp0;
941	struct ip_timestamp *ipt;
942	struct in_ifaddr *ia;
943	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
944	struct in_addr dst;
945	n_time ntime;
946
947	dst = ip->ip_dst;
948	cp = (u_char *)(ip + 1);
949	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
950	for (; cnt > 0; cnt -= optlen, cp += optlen) {
951		opt = cp[IPOPT_OPTVAL];
952		if (opt == IPOPT_EOL)
953			break;
954		if (opt == IPOPT_NOP)
955			optlen = 1;
956		else {
957			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
958				code = &cp[IPOPT_OLEN] - (u_char *)ip;
959				goto bad;
960			}
961			optlen = cp[IPOPT_OLEN];
962			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
963				code = &cp[IPOPT_OLEN] - (u_char *)ip;
964				goto bad;
965			}
966		}
967		switch (opt) {
968
969		default:
970			break;
971
972		/*
973		 * Source routing with record.
974		 * Find interface with current destination address.
975		 * If none on this machine then drop if strictly routed,
976		 * or do nothing if loosely routed.
977		 * Record interface address and bring up next address
978		 * component.  If strictly routed make sure next
979		 * address is on directly accessible net.
980		 */
981		case IPOPT_LSRR:
982		case IPOPT_SSRR:
983			if (ip_allowsrcrt == 0) {
984				type = ICMP_UNREACH;
985				code = ICMP_UNREACH_NET_PROHIB;
986				goto bad;
987			}
988			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
989				code = &cp[IPOPT_OLEN] - (u_char *)ip;
990				goto bad;
991			}
992			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
993				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
994				goto bad;
995			}
996			ipaddr.sin_addr = ip->ip_dst;
997			ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
998			if (ia == 0) {
999				if (opt == IPOPT_SSRR) {
1000					type = ICMP_UNREACH;
1001					code = ICMP_UNREACH_SRCFAIL;
1002					goto bad;
1003				}
1004				/*
1005				 * Loose routing, and not at next destination
1006				 * yet; nothing to do except forward.
1007				 */
1008				break;
1009			}
1010			off--;			/* 0 origin */
1011			if ((off + sizeof(struct in_addr)) > optlen) {
1012				/*
1013				 * End of source route.  Should be for us.
1014				 */
1015				save_rte(cp, ip->ip_src);
1016				break;
1017			}
1018			/*
1019			 * locate outgoing interface
1020			 */
1021			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
1022			    sizeof(ipaddr.sin_addr));
1023			if (opt == IPOPT_SSRR)
1024				ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr)));
1025			else
1026				ia = ip_rtaddr(ipaddr.sin_addr);
1027			if (ia == 0) {
1028				type = ICMP_UNREACH;
1029				code = ICMP_UNREACH_SRCFAIL;
1030				goto bad;
1031			}
1032			ip->ip_dst = ipaddr.sin_addr;
1033			bcopy((void *)&ia->ia_addr.sin_addr,
1034			    (void *)(cp + off), sizeof(struct in_addr));
1035			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1036			/*
1037			 * Let ip_intr's mcast routing check handle mcast pkts
1038			 */
1039			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1040			break;
1041
1042		case IPOPT_RR:
1043			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1044				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1045				goto bad;
1046			}
1047			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1048				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1049				goto bad;
1050			}
1051			/*
1052			 * If no space remains, ignore.
1053			 */
1054			off--;			/* 0 origin */
1055			if ((off + sizeof(struct in_addr)) > optlen)
1056				break;
1057			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1058			    sizeof(ipaddr.sin_addr));
1059			/*
1060			 * locate outgoing interface; if we're the destination,
1061			 * use the incoming interface (should be same).
1062			 */
1063			if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1064			    == NULL &&
1065			    (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1066				type = ICMP_UNREACH;
1067				code = ICMP_UNREACH_HOST;
1068				goto bad;
1069			}
1070			bcopy((void *)&ia->ia_addr.sin_addr,
1071			    (void *)(cp + off), sizeof(struct in_addr));
1072			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1073			break;
1074
1075		case IPOPT_TS:
1076			code = cp - (u_char *)ip;
1077			ipt = (struct ip_timestamp *)cp;
1078			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1079				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1080				goto bad;
1081			}
1082			if (ipt->ipt_ptr < 5) {
1083				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1084				goto bad;
1085			}
1086			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1087				if (++ipt->ipt_oflw == 0) {
1088					code = (u_char *)&ipt->ipt_ptr -
1089					    (u_char *)ip;
1090					goto bad;
1091				}
1092				break;
1093			}
1094			cp0 = (cp + ipt->ipt_ptr - 1);
1095			switch (ipt->ipt_flg) {
1096
1097			case IPOPT_TS_TSONLY:
1098				break;
1099
1100			case IPOPT_TS_TSANDADDR:
1101				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1102				    sizeof(struct in_addr) > ipt->ipt_len) {
1103					code = (u_char *)&ipt->ipt_ptr -
1104					    (u_char *)ip;
1105					goto bad;
1106				}
1107				ipaddr.sin_addr = dst;
1108				ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1109				    m->m_pkthdr.rcvif));
1110				if (ia == 0)
1111					continue;
1112				bcopy(&ia->ia_addr.sin_addr,
1113				    cp0, sizeof(struct in_addr));
1114				ipt->ipt_ptr += sizeof(struct in_addr);
1115				break;
1116
1117			case IPOPT_TS_PRESPEC:
1118				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1119				    sizeof(struct in_addr) > ipt->ipt_len) {
1120					code = (u_char *)&ipt->ipt_ptr -
1121					    (u_char *)ip;
1122					goto bad;
1123				}
1124				memcpy(&ipaddr.sin_addr, cp0,
1125				    sizeof(struct in_addr));
1126				if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1127				    == NULL)
1128					continue;
1129				ipt->ipt_ptr += sizeof(struct in_addr);
1130				break;
1131
1132			default:
1133				/* XXX can't take &ipt->ipt_flg */
1134				code = (u_char *)&ipt->ipt_ptr -
1135				    (u_char *)ip + 1;
1136				goto bad;
1137			}
1138			ntime = iptime();
1139			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1140			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1141			    sizeof(n_time));
1142			ipt->ipt_ptr += sizeof(n_time);
1143		}
1144	}
1145	if (forward) {
1146		if (ip_forwsrcrt == 0) {
1147			type = ICMP_UNREACH;
1148			code = ICMP_UNREACH_SRCFAIL;
1149			goto bad;
1150		}
1151		ip_forward(m, 1);
1152		return (1);
1153	}
1154	return (0);
1155bad:
1156	icmp_error(m, type, code, 0, 0);
1157	IP_STATINC(IP_STAT_BADOPTIONS);
1158	return (1);
1159}
1160
1161/*
1162 * Given address of next destination (final or next hop),
1163 * return internet address info of interface to be used to get there.
1164 */
1165struct in_ifaddr *
1166ip_rtaddr(struct in_addr dst)
1167{
1168	struct rtentry *rt;
1169	union {
1170		struct sockaddr		dst;
1171		struct sockaddr_in	dst4;
1172	} u;
1173
1174	sockaddr_in_init(&u.dst4, &dst, 0);
1175
1176	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL)
1177		return NULL;
1178
1179	return ifatoia(rt->rt_ifa);
1180}
1181
1182/*
1183 * Save incoming source route for use in replies,
1184 * to be picked up later by ip_srcroute if the receiver is interested.
1185 */
1186void
1187save_rte(u_char *option, struct in_addr dst)
1188{
1189	unsigned olen;
1190
1191	olen = option[IPOPT_OLEN];
1192#ifdef DIAGNOSTIC
1193	if (ipprintfs)
1194		printf("save_rte: olen %d\n", olen);
1195#endif /* 0 */
1196	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1197		return;
1198	memcpy((void *)ip_srcrt.srcopt, (void *)option, olen);
1199	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1200	ip_srcrt.dst = dst;
1201}
1202
1203/*
1204 * Retrieve incoming source route for use in replies,
1205 * in the same form used by setsockopt.
1206 * The first hop is placed before the options, will be removed later.
1207 */
1208struct mbuf *
1209ip_srcroute(void)
1210{
1211	struct in_addr *p, *q;
1212	struct mbuf *m;
1213
1214	if (ip_nhops == 0)
1215		return NULL;
1216	m = m_get(M_DONTWAIT, MT_SOOPTS);
1217	if (m == 0)
1218		return NULL;
1219
1220	MCLAIM(m, &inetdomain.dom_mowner);
1221#define OPTSIZ	(sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1222
1223	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1224	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1225	    OPTSIZ;
1226#ifdef DIAGNOSTIC
1227	if (ipprintfs)
1228		printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1229#endif
1230
1231	/*
1232	 * First save first hop for return route
1233	 */
1234	p = &ip_srcrt.route[ip_nhops - 1];
1235	*(mtod(m, struct in_addr *)) = *p--;
1236#ifdef DIAGNOSTIC
1237	if (ipprintfs)
1238		printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1239#endif
1240
1241	/*
1242	 * Copy option fields and padding (nop) to mbuf.
1243	 */
1244	ip_srcrt.nop = IPOPT_NOP;
1245	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1246	memmove(mtod(m, char *) + sizeof(struct in_addr), &ip_srcrt.nop,
1247	    OPTSIZ);
1248	q = (struct in_addr *)(mtod(m, char *) +
1249	    sizeof(struct in_addr) + OPTSIZ);
1250#undef OPTSIZ
1251	/*
1252	 * Record return path as an IP source route,
1253	 * reversing the path (pointers are now aligned).
1254	 */
1255	while (p >= ip_srcrt.route) {
1256#ifdef DIAGNOSTIC
1257		if (ipprintfs)
1258			printf(" %x", ntohl(q->s_addr));
1259#endif
1260		*q++ = *p--;
1261	}
1262	/*
1263	 * Last hop goes to final destination.
1264	 */
1265	*q = ip_srcrt.dst;
1266#ifdef DIAGNOSTIC
1267	if (ipprintfs)
1268		printf(" %x\n", ntohl(q->s_addr));
1269#endif
1270	return (m);
1271}
1272
1273const int inetctlerrmap[PRC_NCMDS] = {
1274	[PRC_MSGSIZE] = EMSGSIZE,
1275	[PRC_HOSTDEAD] = EHOSTDOWN,
1276	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1277	[PRC_UNREACH_NET] = EHOSTUNREACH,
1278	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1279	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1280	[PRC_UNREACH_PORT] = ECONNREFUSED,
1281	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1282	[PRC_PARAMPROB] = ENOPROTOOPT,
1283};
1284
1285/*
1286 * Forward a packet.  If some error occurs return the sender
1287 * an icmp packet.  Note we can't always generate a meaningful
1288 * icmp message because icmp doesn't have a large enough repertoire
1289 * of codes and types.
1290 *
1291 * If not forwarding, just drop the packet.  This could be confusing
1292 * if ipforwarding was zero but some routing protocol was advancing
1293 * us as a gateway to somewhere.  However, we must let the routing
1294 * protocol deal with that.
1295 *
1296 * The srcrt parameter indicates whether the packet is being forwarded
1297 * via a source route.
1298 */
1299void
1300ip_forward(struct mbuf *m, int srcrt)
1301{
1302	struct ip *ip = mtod(m, struct ip *);
1303	struct rtentry *rt;
1304	int error, type = 0, code = 0, destmtu = 0;
1305	struct mbuf *mcopy;
1306	n_long dest;
1307	union {
1308		struct sockaddr		dst;
1309		struct sockaddr_in	dst4;
1310	} u;
1311
1312	/*
1313	 * We are now in the output path.
1314	 */
1315	MCLAIM(m, &ip_tx_mowner);
1316
1317	/*
1318	 * Clear any in-bound checksum flags for this packet.
1319	 */
1320	m->m_pkthdr.csum_flags = 0;
1321
1322	dest = 0;
1323#ifdef DIAGNOSTIC
1324	if (ipprintfs) {
1325		printf("forward: src %s ", inet_ntoa(ip->ip_src));
1326		printf("dst %s ttl %x\n", inet_ntoa(ip->ip_dst), ip->ip_ttl);
1327	}
1328#endif
1329	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1330		IP_STATINC(IP_STAT_CANTFORWARD);
1331		m_freem(m);
1332		return;
1333	}
1334	if (ip->ip_ttl <= IPTTLDEC) {
1335		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1336		return;
1337	}
1338
1339	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1340	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) {
1341		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1342		return;
1343	}
1344
1345	/*
1346	 * Save at most 68 bytes of the packet in case
1347	 * we need to generate an ICMP message to the src.
1348	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1349	 */
1350	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1351	if (mcopy)
1352		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1353
1354	ip->ip_ttl -= IPTTLDEC;
1355
1356	/*
1357	 * If forwarding packet using same interface that it came in on,
1358	 * perhaps should send a redirect to sender to shortcut a hop.
1359	 * Only send redirect if source is sending directly to us,
1360	 * and if packet was not source routed (or has any options).
1361	 * Also, don't send redirect if forwarding using a default route
1362	 * or a route modified by a redirect.
1363	 */
1364	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1365	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1366	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1367	    ipsendredirects && !srcrt) {
1368		if (rt->rt_ifa &&
1369		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1370		    ifatoia(rt->rt_ifa)->ia_subnet) {
1371			if (rt->rt_flags & RTF_GATEWAY)
1372				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1373			else
1374				dest = ip->ip_dst.s_addr;
1375			/*
1376			 * Router requirements says to only send host
1377			 * redirects.
1378			 */
1379			type = ICMP_REDIRECT;
1380			code = ICMP_REDIRECT_HOST;
1381#ifdef DIAGNOSTIC
1382			if (ipprintfs)
1383				printf("redirect (%d) to %x\n", code,
1384				    (u_int32_t)dest);
1385#endif
1386		}
1387	}
1388
1389	error = ip_output(m, NULL, &ipforward_rt,
1390	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1391	    (struct ip_moptions *)NULL, (struct socket *)NULL);
1392
1393	if (error)
1394		IP_STATINC(IP_STAT_CANTFORWARD);
1395	else {
1396		uint64_t *ips = IP_STAT_GETREF();
1397		ips[IP_STAT_FORWARD]++;
1398		if (type) {
1399			ips[IP_STAT_REDIRECTSENT]++;
1400			IP_STAT_PUTREF();
1401		} else {
1402			IP_STAT_PUTREF();
1403			if (mcopy) {
1404#ifdef GATEWAY
1405				if (mcopy->m_flags & M_CANFASTFWD)
1406					ipflow_create(&ipforward_rt, mcopy);
1407#endif
1408				m_freem(mcopy);
1409			}
1410			return;
1411		}
1412	}
1413	if (mcopy == NULL)
1414		return;
1415
1416	switch (error) {
1417
1418	case 0:				/* forwarded, but need redirect */
1419		/* type, code set above */
1420		break;
1421
1422	case ENETUNREACH:		/* shouldn't happen, checked above */
1423	case EHOSTUNREACH:
1424	case ENETDOWN:
1425	case EHOSTDOWN:
1426	default:
1427		type = ICMP_UNREACH;
1428		code = ICMP_UNREACH_HOST;
1429		break;
1430
1431	case EMSGSIZE:
1432		type = ICMP_UNREACH;
1433		code = ICMP_UNREACH_NEEDFRAG;
1434
1435		if ((rt = rtcache_validate(&ipforward_rt)) != NULL)
1436			destmtu = rt->rt_ifp->if_mtu;
1437
1438#if defined(IPSEC) || defined(FAST_IPSEC)
1439		{
1440			/*
1441			 * If the packet is routed over IPsec tunnel, tell the
1442			 * originator the tunnel MTU.
1443			 *	tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1444			 * XXX quickhack!!!
1445			 */
1446
1447			struct secpolicy *sp;
1448			int ipsecerror;
1449			size_t ipsechdr;
1450			struct route *ro;
1451
1452			sp = ipsec4_getpolicybyaddr(mcopy,
1453			    IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1454			    &ipsecerror);
1455
1456			if (sp != NULL) {
1457				/* count IPsec header size */
1458				ipsechdr = ipsec4_hdrsiz(mcopy,
1459				    IPSEC_DIR_OUTBOUND, NULL);
1460
1461				/*
1462				 * find the correct route for outer IPv4
1463				 * header, compute tunnel MTU.
1464				 */
1465
1466				if (sp->req != NULL
1467				 && sp->req->sav != NULL
1468				 && sp->req->sav->sah != NULL) {
1469					ro = &sp->req->sav->sah->sa_route;
1470					rt = rtcache_validate(ro);
1471					if (rt && rt->rt_ifp) {
1472						destmtu =
1473						    rt->rt_rmx.rmx_mtu ?
1474						    rt->rt_rmx.rmx_mtu :
1475						    rt->rt_ifp->if_mtu;
1476						destmtu -= ipsechdr;
1477					}
1478				}
1479
1480#ifdef	IPSEC
1481				key_freesp(sp);
1482#else
1483				KEY_FREESP(&sp);
1484#endif
1485			}
1486		}
1487#endif /*defined(IPSEC) || defined(FAST_IPSEC)*/
1488		IP_STATINC(IP_STAT_CANTFRAG);
1489		break;
1490
1491	case ENOBUFS:
1492#if 1
1493		/*
1494		 * a router should not generate ICMP_SOURCEQUENCH as
1495		 * required in RFC1812 Requirements for IP Version 4 Routers.
1496		 * source quench could be a big problem under DoS attacks,
1497		 * or if the underlying interface is rate-limited.
1498		 */
1499		if (mcopy)
1500			m_freem(mcopy);
1501		return;
1502#else
1503		type = ICMP_SOURCEQUENCH;
1504		code = 0;
1505		break;
1506#endif
1507	}
1508	icmp_error(mcopy, type, code, dest, destmtu);
1509}
1510
1511void
1512ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1513    struct mbuf *m)
1514{
1515
1516	if (inp->inp_socket->so_options & SO_TIMESTAMP
1517#ifdef SO_OTIMESTAMP
1518	    || inp->inp_socket->so_options & SO_OTIMESTAMP
1519#endif
1520	    ) {
1521		struct timeval tv;
1522
1523		microtime(&tv);
1524#ifdef SO_OTIMESTAMP
1525		if (inp->inp_socket->so_options & SO_OTIMESTAMP) {
1526			struct timeval50 tv50;
1527			timeval_to_timeval50(&tv, &tv50);
1528			*mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
1529			    SCM_OTIMESTAMP, SOL_SOCKET);
1530		} else
1531#endif
1532		*mp = sbcreatecontrol((void *) &tv, sizeof(tv),
1533		    SCM_TIMESTAMP, SOL_SOCKET);
1534		if (*mp)
1535			mp = &(*mp)->m_next;
1536	}
1537	if (inp->inp_flags & INP_RECVDSTADDR) {
1538		*mp = sbcreatecontrol((void *) &ip->ip_dst,
1539		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1540		if (*mp)
1541			mp = &(*mp)->m_next;
1542	}
1543#ifdef notyet
1544	/*
1545	 * XXX
1546	 * Moving these out of udp_input() made them even more broken
1547	 * than they already were.
1548	 *	- fenner@parc.xerox.com
1549	 */
1550	/* options were tossed already */
1551	if (inp->inp_flags & INP_RECVOPTS) {
1552		*mp = sbcreatecontrol((void *) opts_deleted_above,
1553		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1554		if (*mp)
1555			mp = &(*mp)->m_next;
1556	}
1557	/* ip_srcroute doesn't do what we want here, need to fix */
1558	if (inp->inp_flags & INP_RECVRETOPTS) {
1559		*mp = sbcreatecontrol((void *) ip_srcroute(),
1560		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1561		if (*mp)
1562			mp = &(*mp)->m_next;
1563	}
1564#endif
1565	if (inp->inp_flags & INP_RECVIF) {
1566		struct sockaddr_dl sdl;
1567
1568		sockaddr_dl_init(&sdl, sizeof(sdl),
1569		    (m->m_pkthdr.rcvif != NULL)
1570		        ?  m->m_pkthdr.rcvif->if_index
1571			: 0,
1572			0, NULL, 0, NULL, 0);
1573		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1574		if (*mp)
1575			mp = &(*mp)->m_next;
1576	}
1577	if (inp->inp_flags & INP_RECVTTL) {
1578		*mp = sbcreatecontrol((void *) &ip->ip_ttl,
1579		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1580		if (*mp)
1581			mp = &(*mp)->m_next;
1582	}
1583}
1584
1585/*
1586 * sysctl helper routine for net.inet.ip.forwsrcrt.
1587 */
1588static int
1589sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1590{
1591	int error, tmp;
1592	struct sysctlnode node;
1593
1594	node = *rnode;
1595	tmp = ip_forwsrcrt;
1596	node.sysctl_data = &tmp;
1597	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1598	if (error || newp == NULL)
1599		return (error);
1600
1601	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1602	    0, NULL, NULL, NULL);
1603	if (error)
1604		return (error);
1605
1606	ip_forwsrcrt = tmp;
1607
1608	return (0);
1609}
1610
1611/*
1612 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1613 * range of the new value and tweaks timers if it changes.
1614 */
1615static int
1616sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1617{
1618	int error, tmp;
1619	struct sysctlnode node;
1620
1621	node = *rnode;
1622	tmp = ip_mtudisc_timeout;
1623	node.sysctl_data = &tmp;
1624	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1625	if (error || newp == NULL)
1626		return (error);
1627	if (tmp < 0)
1628		return (EINVAL);
1629
1630	mutex_enter(softnet_lock);
1631
1632	ip_mtudisc_timeout = tmp;
1633	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1634
1635	mutex_exit(softnet_lock);
1636
1637	return (0);
1638}
1639
1640#ifdef GATEWAY
1641/*
1642 * sysctl helper routine for net.inet.ip.maxflows.
1643 */
1644static int
1645sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
1646{
1647	int error;
1648
1649	error = sysctl_lookup(SYSCTLFN_CALL(rnode));
1650	if (error || newp == NULL)
1651		return (error);
1652
1653	mutex_enter(softnet_lock);
1654	KERNEL_LOCK(1, NULL);
1655
1656	ipflow_prune();
1657
1658	KERNEL_UNLOCK_ONE(NULL);
1659	mutex_exit(softnet_lock);
1660
1661	return (0);
1662}
1663
1664static int
1665sysctl_net_inet_ip_hashsize(SYSCTLFN_ARGS)
1666{
1667	int error, tmp;
1668	struct sysctlnode node;
1669
1670	node = *rnode;
1671	tmp = ip_hashsize;
1672	node.sysctl_data = &tmp;
1673	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1674	if (error || newp == NULL)
1675		return (error);
1676
1677	if ((tmp & (tmp - 1)) == 0 && tmp != 0) {
1678		/*
1679		 * Can only fail due to malloc()
1680		 */
1681		mutex_enter(softnet_lock);
1682		KERNEL_LOCK(1, NULL);
1683
1684		error = ipflow_invalidate_all(tmp);
1685
1686		KERNEL_UNLOCK_ONE(NULL);
1687		mutex_exit(softnet_lock);
1688
1689	} else {
1690		/*
1691		 * EINVAL if not a power of 2
1692	         */
1693		error = EINVAL;
1694	}
1695
1696	return error;
1697}
1698#endif /* GATEWAY */
1699
1700static int
1701sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1702{
1703
1704	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1705}
1706
1707static void
1708sysctl_net_inet_ip_setup(struct sysctllog **clog)
1709{
1710	extern int subnetsarelocal, hostzeroisbroadcast;
1711
1712	sysctl_createv(clog, 0, NULL, NULL,
1713		       CTLFLAG_PERMANENT,
1714		       CTLTYPE_NODE, "net", NULL,
1715		       NULL, 0, NULL, 0,
1716		       CTL_NET, CTL_EOL);
1717	sysctl_createv(clog, 0, NULL, NULL,
1718		       CTLFLAG_PERMANENT,
1719		       CTLTYPE_NODE, "inet",
1720		       SYSCTL_DESCR("PF_INET related settings"),
1721		       NULL, 0, NULL, 0,
1722		       CTL_NET, PF_INET, CTL_EOL);
1723	sysctl_createv(clog, 0, NULL, NULL,
1724		       CTLFLAG_PERMANENT,
1725		       CTLTYPE_NODE, "ip",
1726		       SYSCTL_DESCR("IPv4 related settings"),
1727		       NULL, 0, NULL, 0,
1728		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1729
1730	sysctl_createv(clog, 0, NULL, NULL,
1731		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1732		       CTLTYPE_INT, "forwarding",
1733		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1734		       NULL, 0, &ipforwarding, 0,
1735		       CTL_NET, PF_INET, IPPROTO_IP,
1736		       IPCTL_FORWARDING, CTL_EOL);
1737	sysctl_createv(clog, 0, NULL, NULL,
1738		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1739		       CTLTYPE_INT, "redirect",
1740		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1741		       NULL, 0, &ipsendredirects, 0,
1742		       CTL_NET, PF_INET, IPPROTO_IP,
1743		       IPCTL_SENDREDIRECTS, CTL_EOL);
1744	sysctl_createv(clog, 0, NULL, NULL,
1745		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1746		       CTLTYPE_INT, "ttl",
1747		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1748		       NULL, 0, &ip_defttl, 0,
1749		       CTL_NET, PF_INET, IPPROTO_IP,
1750		       IPCTL_DEFTTL, CTL_EOL);
1751#ifdef IPCTL_DEFMTU
1752	sysctl_createv(clog, 0, NULL, NULL,
1753		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1754		       CTLTYPE_INT, "mtu",
1755		       SYSCTL_DESCR("Default MTA for an INET route"),
1756		       NULL, 0, &ip_mtu, 0,
1757		       CTL_NET, PF_INET, IPPROTO_IP,
1758		       IPCTL_DEFMTU, CTL_EOL);
1759#endif /* IPCTL_DEFMTU */
1760	sysctl_createv(clog, 0, NULL, NULL,
1761		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1762		       CTLTYPE_INT, "forwsrcrt",
1763		       SYSCTL_DESCR("Enable forwarding of source-routed "
1764				    "datagrams"),
1765		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1766		       CTL_NET, PF_INET, IPPROTO_IP,
1767		       IPCTL_FORWSRCRT, CTL_EOL);
1768	sysctl_createv(clog, 0, NULL, NULL,
1769		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1770		       CTLTYPE_INT, "directed-broadcast",
1771		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1772		       NULL, 0, &ip_directedbcast, 0,
1773		       CTL_NET, PF_INET, IPPROTO_IP,
1774		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1775	sysctl_createv(clog, 0, NULL, NULL,
1776		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1777		       CTLTYPE_INT, "allowsrcrt",
1778		       SYSCTL_DESCR("Accept source-routed datagrams"),
1779		       NULL, 0, &ip_allowsrcrt, 0,
1780		       CTL_NET, PF_INET, IPPROTO_IP,
1781		       IPCTL_ALLOWSRCRT, CTL_EOL);
1782	sysctl_createv(clog, 0, NULL, NULL,
1783		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1784		       CTLTYPE_INT, "subnetsarelocal",
1785		       SYSCTL_DESCR("Whether logical subnets are considered "
1786				    "local"),
1787		       NULL, 0, &subnetsarelocal, 0,
1788		       CTL_NET, PF_INET, IPPROTO_IP,
1789		       IPCTL_SUBNETSARELOCAL, CTL_EOL);
1790	sysctl_createv(clog, 0, NULL, NULL,
1791		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1792		       CTLTYPE_INT, "mtudisc",
1793		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1794		       NULL, 0, &ip_mtudisc, 0,
1795		       CTL_NET, PF_INET, IPPROTO_IP,
1796		       IPCTL_MTUDISC, CTL_EOL);
1797	sysctl_createv(clog, 0, NULL, NULL,
1798		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1799		       CTLTYPE_INT, "anonportmin",
1800		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1801		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1802		       CTL_NET, PF_INET, IPPROTO_IP,
1803		       IPCTL_ANONPORTMIN, CTL_EOL);
1804	sysctl_createv(clog, 0, NULL, NULL,
1805		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1806		       CTLTYPE_INT, "anonportmax",
1807		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1808		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1809		       CTL_NET, PF_INET, IPPROTO_IP,
1810		       IPCTL_ANONPORTMAX, CTL_EOL);
1811	sysctl_createv(clog, 0, NULL, NULL,
1812		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1813		       CTLTYPE_INT, "mtudisctimeout",
1814		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1815		       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
1816		       CTL_NET, PF_INET, IPPROTO_IP,
1817		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1818#ifdef GATEWAY
1819	sysctl_createv(clog, 0, NULL, NULL,
1820		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1821		       CTLTYPE_INT, "maxflows",
1822		       SYSCTL_DESCR("Number of flows for fast forwarding"),
1823		       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
1824		       CTL_NET, PF_INET, IPPROTO_IP,
1825		       IPCTL_MAXFLOWS, CTL_EOL);
1826	sysctl_createv(clog, 0, NULL, NULL,
1827			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1828			CTLTYPE_INT, "hashsize",
1829			SYSCTL_DESCR("Size of hash table for fast forwarding (IPv4)"),
1830			sysctl_net_inet_ip_hashsize, 0, &ip_hashsize, 0,
1831			CTL_NET, PF_INET, IPPROTO_IP,
1832			CTL_CREATE, CTL_EOL);
1833#endif /* GATEWAY */
1834	sysctl_createv(clog, 0, NULL, NULL,
1835		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1836		       CTLTYPE_INT, "hostzerobroadcast",
1837		       SYSCTL_DESCR("All zeroes address is broadcast address"),
1838		       NULL, 0, &hostzeroisbroadcast, 0,
1839		       CTL_NET, PF_INET, IPPROTO_IP,
1840		       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
1841#if NGIF > 0
1842	sysctl_createv(clog, 0, NULL, NULL,
1843		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1844		       CTLTYPE_INT, "gifttl",
1845		       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
1846		       NULL, 0, &ip_gif_ttl, 0,
1847		       CTL_NET, PF_INET, IPPROTO_IP,
1848		       IPCTL_GIF_TTL, CTL_EOL);
1849#endif /* NGIF */
1850#ifndef IPNOPRIVPORTS
1851	sysctl_createv(clog, 0, NULL, NULL,
1852		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1853		       CTLTYPE_INT, "lowportmin",
1854		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1855				    "to assign"),
1856		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1857		       CTL_NET, PF_INET, IPPROTO_IP,
1858		       IPCTL_LOWPORTMIN, CTL_EOL);
1859	sysctl_createv(clog, 0, NULL, NULL,
1860		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1861		       CTLTYPE_INT, "lowportmax",
1862		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1863				    "to assign"),
1864		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1865		       CTL_NET, PF_INET, IPPROTO_IP,
1866		       IPCTL_LOWPORTMAX, CTL_EOL);
1867#endif /* IPNOPRIVPORTS */
1868#if NGRE > 0
1869	sysctl_createv(clog, 0, NULL, NULL,
1870		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1871		       CTLTYPE_INT, "grettl",
1872		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1873		       NULL, 0, &ip_gre_ttl, 0,
1874		       CTL_NET, PF_INET, IPPROTO_IP,
1875		       IPCTL_GRE_TTL, CTL_EOL);
1876#endif /* NGRE */
1877	sysctl_createv(clog, 0, NULL, NULL,
1878		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1879		       CTLTYPE_INT, "checkinterface",
1880		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1881				    "from RFC1122"),
1882		       NULL, 0, &ip_checkinterface, 0,
1883		       CTL_NET, PF_INET, IPPROTO_IP,
1884		       IPCTL_CHECKINTERFACE, CTL_EOL);
1885	sysctl_createv(clog, 0, NULL, NULL,
1886		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1887		       CTLTYPE_INT, "random_id",
1888		       SYSCTL_DESCR("Assign random ip_id values"),
1889		       NULL, 0, &ip_do_randomid, 0,
1890		       CTL_NET, PF_INET, IPPROTO_IP,
1891		       IPCTL_RANDOMID, CTL_EOL);
1892	sysctl_createv(clog, 0, NULL, NULL,
1893		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1894		       CTLTYPE_INT, "do_loopback_cksum",
1895		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1896		       NULL, 0, &ip_do_loopback_cksum, 0,
1897		       CTL_NET, PF_INET, IPPROTO_IP,
1898		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1899	sysctl_createv(clog, 0, NULL, NULL,
1900		       CTLFLAG_PERMANENT,
1901		       CTLTYPE_STRUCT, "stats",
1902		       SYSCTL_DESCR("IP statistics"),
1903		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1904		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1905		       CTL_EOL);
1906}
1907
1908void
1909ip_statinc(u_int stat)
1910{
1911
1912	KASSERT(stat < IP_NSTATS);
1913	IP_STATINC(stat);
1914}
1915