ip_input.c revision 1.290
1/*	$NetBSD: ip_input.c,v 1.290 2010/11/05 00:21:51 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 1.290 2010/11/05 00:21:51 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		/*
810		 * Pass to IP reassembly mechanism.
811		 */
812		if (ip_reass_packet(&m, ip) != 0) {
813			/* Failed; invalid fragment(s) or packet. */
814			goto bad;
815		}
816		if (m == NULL) {
817			/* More fragments should come; silently return. */
818			return;
819		}
820		/*
821		 * Reassembly is done, we have the final packet.
822		 * Updated cached data in local variable(s).
823		 */
824		ip = mtod(m, struct ip *);
825		hlen = ip->ip_hl << 2;
826	}
827
828#if defined(IPSEC)
829	/*
830	 * enforce IPsec policy checking if we are seeing last header.
831	 * note that we do not visit this with protocols with pcb layer
832	 * code - like udp/tcp/raw ip.
833	 */
834	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
835	    ipsec4_in_reject(m, NULL)) {
836		IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
837		goto bad;
838	}
839#endif
840#ifdef FAST_IPSEC
841	/*
842	 * enforce IPsec policy checking if we are seeing last header.
843	 * note that we do not visit this with protocols with pcb layer
844	 * code - like udp/tcp/raw ip.
845	 */
846	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
847		/*
848		 * Check if the packet has already had IPsec processing
849		 * done.  If so, then just pass it along.  This tag gets
850		 * set during AH, ESP, etc. input handling, before the
851		 * packet is returned to the ip input queue for delivery.
852		 */
853		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
854		s = splsoftnet();
855		if (mtag != NULL) {
856			tdbi = (struct tdb_ident *)(mtag + 1);
857			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
858		} else {
859			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
860						   IP_FORWARDING, &error);
861		}
862		if (sp != NULL) {
863			/*
864			 * Check security policy against packet attributes.
865			 */
866			error = ipsec_in_reject(sp, m);
867			KEY_FREESP(&sp);
868		} else {
869			/* XXX error stat??? */
870			error = EINVAL;
871DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
872		}
873		splx(s);
874		if (error)
875			goto bad;
876	}
877#endif /* FAST_IPSEC */
878
879	/*
880	 * Switch out to protocol's input routine.
881	 */
882#if IFA_STATS
883	if (ia && ip)
884		ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
885#endif
886	IP_STATINC(IP_STAT_DELIVERED);
887    {
888	int off = hlen, nh = ip->ip_p;
889
890	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
891	return;
892    }
893bad:
894	m_freem(m);
895	return;
896
897badcsum:
898	IP_STATINC(IP_STAT_BADSUM);
899	m_freem(m);
900}
901
902/*
903 * IP timer processing.
904 */
905void
906ip_slowtimo(void)
907{
908
909	mutex_enter(softnet_lock);
910	KERNEL_LOCK(1, NULL);
911
912	ip_reass_slowtimo();
913
914	KERNEL_UNLOCK_ONE(NULL);
915	mutex_exit(softnet_lock);
916}
917
918/*
919 * IP drain processing.
920 */
921void
922ip_drain(void)
923{
924
925	KERNEL_LOCK(1, NULL);
926	ip_reass_drain();
927	KERNEL_UNLOCK_ONE(NULL);
928}
929
930/*
931 * Do option processing on a datagram,
932 * possibly discarding it if bad options are encountered,
933 * or forwarding it if source-routed.
934 * Returns 1 if packet has been forwarded/freed,
935 * 0 if the packet should be processed further.
936 */
937int
938ip_dooptions(struct mbuf *m)
939{
940	struct ip *ip = mtod(m, struct ip *);
941	u_char *cp, *cp0;
942	struct ip_timestamp *ipt;
943	struct in_ifaddr *ia;
944	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
945	struct in_addr dst;
946	n_time ntime;
947
948	dst = ip->ip_dst;
949	cp = (u_char *)(ip + 1);
950	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
951	for (; cnt > 0; cnt -= optlen, cp += optlen) {
952		opt = cp[IPOPT_OPTVAL];
953		if (opt == IPOPT_EOL)
954			break;
955		if (opt == IPOPT_NOP)
956			optlen = 1;
957		else {
958			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
959				code = &cp[IPOPT_OLEN] - (u_char *)ip;
960				goto bad;
961			}
962			optlen = cp[IPOPT_OLEN];
963			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
964				code = &cp[IPOPT_OLEN] - (u_char *)ip;
965				goto bad;
966			}
967		}
968		switch (opt) {
969
970		default:
971			break;
972
973		/*
974		 * Source routing with record.
975		 * Find interface with current destination address.
976		 * If none on this machine then drop if strictly routed,
977		 * or do nothing if loosely routed.
978		 * Record interface address and bring up next address
979		 * component.  If strictly routed make sure next
980		 * address is on directly accessible net.
981		 */
982		case IPOPT_LSRR:
983		case IPOPT_SSRR:
984			if (ip_allowsrcrt == 0) {
985				type = ICMP_UNREACH;
986				code = ICMP_UNREACH_NET_PROHIB;
987				goto bad;
988			}
989			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
990				code = &cp[IPOPT_OLEN] - (u_char *)ip;
991				goto bad;
992			}
993			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
994				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
995				goto bad;
996			}
997			ipaddr.sin_addr = ip->ip_dst;
998			ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
999			if (ia == 0) {
1000				if (opt == IPOPT_SSRR) {
1001					type = ICMP_UNREACH;
1002					code = ICMP_UNREACH_SRCFAIL;
1003					goto bad;
1004				}
1005				/*
1006				 * Loose routing, and not at next destination
1007				 * yet; nothing to do except forward.
1008				 */
1009				break;
1010			}
1011			off--;			/* 0 origin */
1012			if ((off + sizeof(struct in_addr)) > optlen) {
1013				/*
1014				 * End of source route.  Should be for us.
1015				 */
1016				save_rte(cp, ip->ip_src);
1017				break;
1018			}
1019			/*
1020			 * locate outgoing interface
1021			 */
1022			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
1023			    sizeof(ipaddr.sin_addr));
1024			if (opt == IPOPT_SSRR)
1025				ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr)));
1026			else
1027				ia = ip_rtaddr(ipaddr.sin_addr);
1028			if (ia == 0) {
1029				type = ICMP_UNREACH;
1030				code = ICMP_UNREACH_SRCFAIL;
1031				goto bad;
1032			}
1033			ip->ip_dst = ipaddr.sin_addr;
1034			bcopy((void *)&ia->ia_addr.sin_addr,
1035			    (void *)(cp + off), sizeof(struct in_addr));
1036			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1037			/*
1038			 * Let ip_intr's mcast routing check handle mcast pkts
1039			 */
1040			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1041			break;
1042
1043		case IPOPT_RR:
1044			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1045				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1046				goto bad;
1047			}
1048			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1049				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1050				goto bad;
1051			}
1052			/*
1053			 * If no space remains, ignore.
1054			 */
1055			off--;			/* 0 origin */
1056			if ((off + sizeof(struct in_addr)) > optlen)
1057				break;
1058			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1059			    sizeof(ipaddr.sin_addr));
1060			/*
1061			 * locate outgoing interface; if we're the destination,
1062			 * use the incoming interface (should be same).
1063			 */
1064			if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1065			    == NULL &&
1066			    (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1067				type = ICMP_UNREACH;
1068				code = ICMP_UNREACH_HOST;
1069				goto bad;
1070			}
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			break;
1075
1076		case IPOPT_TS:
1077			code = cp - (u_char *)ip;
1078			ipt = (struct ip_timestamp *)cp;
1079			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1080				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1081				goto bad;
1082			}
1083			if (ipt->ipt_ptr < 5) {
1084				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1085				goto bad;
1086			}
1087			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1088				if (++ipt->ipt_oflw == 0) {
1089					code = (u_char *)&ipt->ipt_ptr -
1090					    (u_char *)ip;
1091					goto bad;
1092				}
1093				break;
1094			}
1095			cp0 = (cp + ipt->ipt_ptr - 1);
1096			switch (ipt->ipt_flg) {
1097
1098			case IPOPT_TS_TSONLY:
1099				break;
1100
1101			case IPOPT_TS_TSANDADDR:
1102				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1103				    sizeof(struct in_addr) > ipt->ipt_len) {
1104					code = (u_char *)&ipt->ipt_ptr -
1105					    (u_char *)ip;
1106					goto bad;
1107				}
1108				ipaddr.sin_addr = dst;
1109				ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1110				    m->m_pkthdr.rcvif));
1111				if (ia == 0)
1112					continue;
1113				bcopy(&ia->ia_addr.sin_addr,
1114				    cp0, sizeof(struct in_addr));
1115				ipt->ipt_ptr += sizeof(struct in_addr);
1116				break;
1117
1118			case IPOPT_TS_PRESPEC:
1119				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1120				    sizeof(struct in_addr) > ipt->ipt_len) {
1121					code = (u_char *)&ipt->ipt_ptr -
1122					    (u_char *)ip;
1123					goto bad;
1124				}
1125				memcpy(&ipaddr.sin_addr, cp0,
1126				    sizeof(struct in_addr));
1127				if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1128				    == NULL)
1129					continue;
1130				ipt->ipt_ptr += sizeof(struct in_addr);
1131				break;
1132
1133			default:
1134				/* XXX can't take &ipt->ipt_flg */
1135				code = (u_char *)&ipt->ipt_ptr -
1136				    (u_char *)ip + 1;
1137				goto bad;
1138			}
1139			ntime = iptime();
1140			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1141			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1142			    sizeof(n_time));
1143			ipt->ipt_ptr += sizeof(n_time);
1144		}
1145	}
1146	if (forward) {
1147		if (ip_forwsrcrt == 0) {
1148			type = ICMP_UNREACH;
1149			code = ICMP_UNREACH_SRCFAIL;
1150			goto bad;
1151		}
1152		ip_forward(m, 1);
1153		return (1);
1154	}
1155	return (0);
1156bad:
1157	icmp_error(m, type, code, 0, 0);
1158	IP_STATINC(IP_STAT_BADOPTIONS);
1159	return (1);
1160}
1161
1162/*
1163 * Given address of next destination (final or next hop),
1164 * return internet address info of interface to be used to get there.
1165 */
1166struct in_ifaddr *
1167ip_rtaddr(struct in_addr dst)
1168{
1169	struct rtentry *rt;
1170	union {
1171		struct sockaddr		dst;
1172		struct sockaddr_in	dst4;
1173	} u;
1174
1175	sockaddr_in_init(&u.dst4, &dst, 0);
1176
1177	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL)
1178		return NULL;
1179
1180	return ifatoia(rt->rt_ifa);
1181}
1182
1183/*
1184 * Save incoming source route for use in replies,
1185 * to be picked up later by ip_srcroute if the receiver is interested.
1186 */
1187void
1188save_rte(u_char *option, struct in_addr dst)
1189{
1190	unsigned olen;
1191
1192	olen = option[IPOPT_OLEN];
1193#ifdef DIAGNOSTIC
1194	if (ipprintfs)
1195		printf("save_rte: olen %d\n", olen);
1196#endif /* 0 */
1197	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1198		return;
1199	memcpy((void *)ip_srcrt.srcopt, (void *)option, olen);
1200	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1201	ip_srcrt.dst = dst;
1202}
1203
1204/*
1205 * Retrieve incoming source route for use in replies,
1206 * in the same form used by setsockopt.
1207 * The first hop is placed before the options, will be removed later.
1208 */
1209struct mbuf *
1210ip_srcroute(void)
1211{
1212	struct in_addr *p, *q;
1213	struct mbuf *m;
1214
1215	if (ip_nhops == 0)
1216		return NULL;
1217	m = m_get(M_DONTWAIT, MT_SOOPTS);
1218	if (m == 0)
1219		return NULL;
1220
1221	MCLAIM(m, &inetdomain.dom_mowner);
1222#define OPTSIZ	(sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1223
1224	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1225	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1226	    OPTSIZ;
1227#ifdef DIAGNOSTIC
1228	if (ipprintfs)
1229		printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1230#endif
1231
1232	/*
1233	 * First save first hop for return route
1234	 */
1235	p = &ip_srcrt.route[ip_nhops - 1];
1236	*(mtod(m, struct in_addr *)) = *p--;
1237#ifdef DIAGNOSTIC
1238	if (ipprintfs)
1239		printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1240#endif
1241
1242	/*
1243	 * Copy option fields and padding (nop) to mbuf.
1244	 */
1245	ip_srcrt.nop = IPOPT_NOP;
1246	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1247	memmove(mtod(m, char *) + sizeof(struct in_addr), &ip_srcrt.nop,
1248	    OPTSIZ);
1249	q = (struct in_addr *)(mtod(m, char *) +
1250	    sizeof(struct in_addr) + OPTSIZ);
1251#undef OPTSIZ
1252	/*
1253	 * Record return path as an IP source route,
1254	 * reversing the path (pointers are now aligned).
1255	 */
1256	while (p >= ip_srcrt.route) {
1257#ifdef DIAGNOSTIC
1258		if (ipprintfs)
1259			printf(" %x", ntohl(q->s_addr));
1260#endif
1261		*q++ = *p--;
1262	}
1263	/*
1264	 * Last hop goes to final destination.
1265	 */
1266	*q = ip_srcrt.dst;
1267#ifdef DIAGNOSTIC
1268	if (ipprintfs)
1269		printf(" %x\n", ntohl(q->s_addr));
1270#endif
1271	return (m);
1272}
1273
1274const int inetctlerrmap[PRC_NCMDS] = {
1275	[PRC_MSGSIZE] = EMSGSIZE,
1276	[PRC_HOSTDEAD] = EHOSTDOWN,
1277	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1278	[PRC_UNREACH_NET] = EHOSTUNREACH,
1279	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1280	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1281	[PRC_UNREACH_PORT] = ECONNREFUSED,
1282	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1283	[PRC_PARAMPROB] = ENOPROTOOPT,
1284};
1285
1286/*
1287 * Forward a packet.  If some error occurs return the sender
1288 * an icmp packet.  Note we can't always generate a meaningful
1289 * icmp message because icmp doesn't have a large enough repertoire
1290 * of codes and types.
1291 *
1292 * If not forwarding, just drop the packet.  This could be confusing
1293 * if ipforwarding was zero but some routing protocol was advancing
1294 * us as a gateway to somewhere.  However, we must let the routing
1295 * protocol deal with that.
1296 *
1297 * The srcrt parameter indicates whether the packet is being forwarded
1298 * via a source route.
1299 */
1300void
1301ip_forward(struct mbuf *m, int srcrt)
1302{
1303	struct ip *ip = mtod(m, struct ip *);
1304	struct rtentry *rt;
1305	int error, type = 0, code = 0, destmtu = 0;
1306	struct mbuf *mcopy;
1307	n_long dest;
1308	union {
1309		struct sockaddr		dst;
1310		struct sockaddr_in	dst4;
1311	} u;
1312
1313	/*
1314	 * We are now in the output path.
1315	 */
1316	MCLAIM(m, &ip_tx_mowner);
1317
1318	/*
1319	 * Clear any in-bound checksum flags for this packet.
1320	 */
1321	m->m_pkthdr.csum_flags = 0;
1322
1323	dest = 0;
1324#ifdef DIAGNOSTIC
1325	if (ipprintfs) {
1326		printf("forward: src %s ", inet_ntoa(ip->ip_src));
1327		printf("dst %s ttl %x\n", inet_ntoa(ip->ip_dst), ip->ip_ttl);
1328	}
1329#endif
1330	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1331		IP_STATINC(IP_STAT_CANTFORWARD);
1332		m_freem(m);
1333		return;
1334	}
1335	if (ip->ip_ttl <= IPTTLDEC) {
1336		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1337		return;
1338	}
1339
1340	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1341	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) {
1342		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1343		return;
1344	}
1345
1346	/*
1347	 * Save at most 68 bytes of the packet in case
1348	 * we need to generate an ICMP message to the src.
1349	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1350	 */
1351	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1352	if (mcopy)
1353		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1354
1355	ip->ip_ttl -= IPTTLDEC;
1356
1357	/*
1358	 * If forwarding packet using same interface that it came in on,
1359	 * perhaps should send a redirect to sender to shortcut a hop.
1360	 * Only send redirect if source is sending directly to us,
1361	 * and if packet was not source routed (or has any options).
1362	 * Also, don't send redirect if forwarding using a default route
1363	 * or a route modified by a redirect.
1364	 */
1365	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1366	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1367	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1368	    ipsendredirects && !srcrt) {
1369		if (rt->rt_ifa &&
1370		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1371		    ifatoia(rt->rt_ifa)->ia_subnet) {
1372			if (rt->rt_flags & RTF_GATEWAY)
1373				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1374			else
1375				dest = ip->ip_dst.s_addr;
1376			/*
1377			 * Router requirements says to only send host
1378			 * redirects.
1379			 */
1380			type = ICMP_REDIRECT;
1381			code = ICMP_REDIRECT_HOST;
1382#ifdef DIAGNOSTIC
1383			if (ipprintfs)
1384				printf("redirect (%d) to %x\n", code,
1385				    (u_int32_t)dest);
1386#endif
1387		}
1388	}
1389
1390	error = ip_output(m, NULL, &ipforward_rt,
1391	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1392	    (struct ip_moptions *)NULL, (struct socket *)NULL);
1393
1394	if (error)
1395		IP_STATINC(IP_STAT_CANTFORWARD);
1396	else {
1397		uint64_t *ips = IP_STAT_GETREF();
1398		ips[IP_STAT_FORWARD]++;
1399		if (type) {
1400			ips[IP_STAT_REDIRECTSENT]++;
1401			IP_STAT_PUTREF();
1402		} else {
1403			IP_STAT_PUTREF();
1404			if (mcopy) {
1405#ifdef GATEWAY
1406				if (mcopy->m_flags & M_CANFASTFWD)
1407					ipflow_create(&ipforward_rt, mcopy);
1408#endif
1409				m_freem(mcopy);
1410			}
1411			return;
1412		}
1413	}
1414	if (mcopy == NULL)
1415		return;
1416
1417	switch (error) {
1418
1419	case 0:				/* forwarded, but need redirect */
1420		/* type, code set above */
1421		break;
1422
1423	case ENETUNREACH:		/* shouldn't happen, checked above */
1424	case EHOSTUNREACH:
1425	case ENETDOWN:
1426	case EHOSTDOWN:
1427	default:
1428		type = ICMP_UNREACH;
1429		code = ICMP_UNREACH_HOST;
1430		break;
1431
1432	case EMSGSIZE:
1433		type = ICMP_UNREACH;
1434		code = ICMP_UNREACH_NEEDFRAG;
1435
1436		if ((rt = rtcache_validate(&ipforward_rt)) != NULL)
1437			destmtu = rt->rt_ifp->if_mtu;
1438
1439#if defined(IPSEC) || defined(FAST_IPSEC)
1440		{
1441			/*
1442			 * If the packet is routed over IPsec tunnel, tell the
1443			 * originator the tunnel MTU.
1444			 *	tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1445			 * XXX quickhack!!!
1446			 */
1447
1448			struct secpolicy *sp;
1449			int ipsecerror;
1450			size_t ipsechdr;
1451			struct route *ro;
1452
1453			sp = ipsec4_getpolicybyaddr(mcopy,
1454			    IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1455			    &ipsecerror);
1456
1457			if (sp != NULL) {
1458				/* count IPsec header size */
1459				ipsechdr = ipsec4_hdrsiz(mcopy,
1460				    IPSEC_DIR_OUTBOUND, NULL);
1461
1462				/*
1463				 * find the correct route for outer IPv4
1464				 * header, compute tunnel MTU.
1465				 */
1466
1467				if (sp->req != NULL
1468				 && sp->req->sav != NULL
1469				 && sp->req->sav->sah != NULL) {
1470					ro = &sp->req->sav->sah->sa_route;
1471					rt = rtcache_validate(ro);
1472					if (rt && rt->rt_ifp) {
1473						destmtu =
1474						    rt->rt_rmx.rmx_mtu ?
1475						    rt->rt_rmx.rmx_mtu :
1476						    rt->rt_ifp->if_mtu;
1477						destmtu -= ipsechdr;
1478					}
1479				}
1480
1481#ifdef	IPSEC
1482				key_freesp(sp);
1483#else
1484				KEY_FREESP(&sp);
1485#endif
1486			}
1487		}
1488#endif /*defined(IPSEC) || defined(FAST_IPSEC)*/
1489		IP_STATINC(IP_STAT_CANTFRAG);
1490		break;
1491
1492	case ENOBUFS:
1493#if 1
1494		/*
1495		 * a router should not generate ICMP_SOURCEQUENCH as
1496		 * required in RFC1812 Requirements for IP Version 4 Routers.
1497		 * source quench could be a big problem under DoS attacks,
1498		 * or if the underlying interface is rate-limited.
1499		 */
1500		if (mcopy)
1501			m_freem(mcopy);
1502		return;
1503#else
1504		type = ICMP_SOURCEQUENCH;
1505		code = 0;
1506		break;
1507#endif
1508	}
1509	icmp_error(mcopy, type, code, dest, destmtu);
1510}
1511
1512void
1513ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1514    struct mbuf *m)
1515{
1516
1517	if (inp->inp_socket->so_options & SO_TIMESTAMP
1518#ifdef SO_OTIMESTAMP
1519	    || inp->inp_socket->so_options & SO_OTIMESTAMP
1520#endif
1521	    ) {
1522		struct timeval tv;
1523
1524		microtime(&tv);
1525#ifdef SO_OTIMESTAMP
1526		if (inp->inp_socket->so_options & SO_OTIMESTAMP) {
1527			struct timeval50 tv50;
1528			timeval_to_timeval50(&tv, &tv50);
1529			*mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
1530			    SCM_OTIMESTAMP, SOL_SOCKET);
1531		} else
1532#endif
1533		*mp = sbcreatecontrol((void *) &tv, sizeof(tv),
1534		    SCM_TIMESTAMP, SOL_SOCKET);
1535		if (*mp)
1536			mp = &(*mp)->m_next;
1537	}
1538	if (inp->inp_flags & INP_RECVDSTADDR) {
1539		*mp = sbcreatecontrol((void *) &ip->ip_dst,
1540		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1541		if (*mp)
1542			mp = &(*mp)->m_next;
1543	}
1544#ifdef notyet
1545	/*
1546	 * XXX
1547	 * Moving these out of udp_input() made them even more broken
1548	 * than they already were.
1549	 *	- fenner@parc.xerox.com
1550	 */
1551	/* options were tossed already */
1552	if (inp->inp_flags & INP_RECVOPTS) {
1553		*mp = sbcreatecontrol((void *) opts_deleted_above,
1554		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1555		if (*mp)
1556			mp = &(*mp)->m_next;
1557	}
1558	/* ip_srcroute doesn't do what we want here, need to fix */
1559	if (inp->inp_flags & INP_RECVRETOPTS) {
1560		*mp = sbcreatecontrol((void *) ip_srcroute(),
1561		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1562		if (*mp)
1563			mp = &(*mp)->m_next;
1564	}
1565#endif
1566	if (inp->inp_flags & INP_RECVIF) {
1567		struct sockaddr_dl sdl;
1568
1569		sockaddr_dl_init(&sdl, sizeof(sdl),
1570		    (m->m_pkthdr.rcvif != NULL)
1571		        ?  m->m_pkthdr.rcvif->if_index
1572			: 0,
1573			0, NULL, 0, NULL, 0);
1574		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1575		if (*mp)
1576			mp = &(*mp)->m_next;
1577	}
1578	if (inp->inp_flags & INP_RECVTTL) {
1579		*mp = sbcreatecontrol((void *) &ip->ip_ttl,
1580		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1581		if (*mp)
1582			mp = &(*mp)->m_next;
1583	}
1584}
1585
1586/*
1587 * sysctl helper routine for net.inet.ip.forwsrcrt.
1588 */
1589static int
1590sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1591{
1592	int error, tmp;
1593	struct sysctlnode node;
1594
1595	node = *rnode;
1596	tmp = ip_forwsrcrt;
1597	node.sysctl_data = &tmp;
1598	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1599	if (error || newp == NULL)
1600		return (error);
1601
1602	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1603	    0, NULL, NULL, NULL);
1604	if (error)
1605		return (error);
1606
1607	ip_forwsrcrt = tmp;
1608
1609	return (0);
1610}
1611
1612/*
1613 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1614 * range of the new value and tweaks timers if it changes.
1615 */
1616static int
1617sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1618{
1619	int error, tmp;
1620	struct sysctlnode node;
1621
1622	node = *rnode;
1623	tmp = ip_mtudisc_timeout;
1624	node.sysctl_data = &tmp;
1625	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1626	if (error || newp == NULL)
1627		return (error);
1628	if (tmp < 0)
1629		return (EINVAL);
1630
1631	mutex_enter(softnet_lock);
1632
1633	ip_mtudisc_timeout = tmp;
1634	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1635
1636	mutex_exit(softnet_lock);
1637
1638	return (0);
1639}
1640
1641#ifdef GATEWAY
1642/*
1643 * sysctl helper routine for net.inet.ip.maxflows.
1644 */
1645static int
1646sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
1647{
1648	int error;
1649
1650	error = sysctl_lookup(SYSCTLFN_CALL(rnode));
1651	if (error || newp == NULL)
1652		return (error);
1653
1654	mutex_enter(softnet_lock);
1655	KERNEL_LOCK(1, NULL);
1656
1657	ipflow_prune();
1658
1659	KERNEL_UNLOCK_ONE(NULL);
1660	mutex_exit(softnet_lock);
1661
1662	return (0);
1663}
1664
1665static int
1666sysctl_net_inet_ip_hashsize(SYSCTLFN_ARGS)
1667{
1668	int error, tmp;
1669	struct sysctlnode node;
1670
1671	node = *rnode;
1672	tmp = ip_hashsize;
1673	node.sysctl_data = &tmp;
1674	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1675	if (error || newp == NULL)
1676		return (error);
1677
1678	if ((tmp & (tmp - 1)) == 0 && tmp != 0) {
1679		/*
1680		 * Can only fail due to malloc()
1681		 */
1682		mutex_enter(softnet_lock);
1683		KERNEL_LOCK(1, NULL);
1684
1685		error = ipflow_invalidate_all(tmp);
1686
1687		KERNEL_UNLOCK_ONE(NULL);
1688		mutex_exit(softnet_lock);
1689
1690	} else {
1691		/*
1692		 * EINVAL if not a power of 2
1693	         */
1694		error = EINVAL;
1695	}
1696
1697	return error;
1698}
1699#endif /* GATEWAY */
1700
1701static int
1702sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1703{
1704
1705	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1706}
1707
1708static void
1709sysctl_net_inet_ip_setup(struct sysctllog **clog)
1710{
1711	extern int subnetsarelocal, hostzeroisbroadcast;
1712
1713	sysctl_createv(clog, 0, NULL, NULL,
1714		       CTLFLAG_PERMANENT,
1715		       CTLTYPE_NODE, "net", NULL,
1716		       NULL, 0, NULL, 0,
1717		       CTL_NET, CTL_EOL);
1718	sysctl_createv(clog, 0, NULL, NULL,
1719		       CTLFLAG_PERMANENT,
1720		       CTLTYPE_NODE, "inet",
1721		       SYSCTL_DESCR("PF_INET related settings"),
1722		       NULL, 0, NULL, 0,
1723		       CTL_NET, PF_INET, CTL_EOL);
1724	sysctl_createv(clog, 0, NULL, NULL,
1725		       CTLFLAG_PERMANENT,
1726		       CTLTYPE_NODE, "ip",
1727		       SYSCTL_DESCR("IPv4 related settings"),
1728		       NULL, 0, NULL, 0,
1729		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1730
1731	sysctl_createv(clog, 0, NULL, NULL,
1732		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1733		       CTLTYPE_INT, "forwarding",
1734		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1735		       NULL, 0, &ipforwarding, 0,
1736		       CTL_NET, PF_INET, IPPROTO_IP,
1737		       IPCTL_FORWARDING, CTL_EOL);
1738	sysctl_createv(clog, 0, NULL, NULL,
1739		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1740		       CTLTYPE_INT, "redirect",
1741		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1742		       NULL, 0, &ipsendredirects, 0,
1743		       CTL_NET, PF_INET, IPPROTO_IP,
1744		       IPCTL_SENDREDIRECTS, CTL_EOL);
1745	sysctl_createv(clog, 0, NULL, NULL,
1746		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1747		       CTLTYPE_INT, "ttl",
1748		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1749		       NULL, 0, &ip_defttl, 0,
1750		       CTL_NET, PF_INET, IPPROTO_IP,
1751		       IPCTL_DEFTTL, CTL_EOL);
1752#ifdef IPCTL_DEFMTU
1753	sysctl_createv(clog, 0, NULL, NULL,
1754		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1755		       CTLTYPE_INT, "mtu",
1756		       SYSCTL_DESCR("Default MTA for an INET route"),
1757		       NULL, 0, &ip_mtu, 0,
1758		       CTL_NET, PF_INET, IPPROTO_IP,
1759		       IPCTL_DEFMTU, CTL_EOL);
1760#endif /* IPCTL_DEFMTU */
1761	sysctl_createv(clog, 0, NULL, NULL,
1762		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1763		       CTLTYPE_INT, "forwsrcrt",
1764		       SYSCTL_DESCR("Enable forwarding of source-routed "
1765				    "datagrams"),
1766		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1767		       CTL_NET, PF_INET, IPPROTO_IP,
1768		       IPCTL_FORWSRCRT, CTL_EOL);
1769	sysctl_createv(clog, 0, NULL, NULL,
1770		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1771		       CTLTYPE_INT, "directed-broadcast",
1772		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1773		       NULL, 0, &ip_directedbcast, 0,
1774		       CTL_NET, PF_INET, IPPROTO_IP,
1775		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1776	sysctl_createv(clog, 0, NULL, NULL,
1777		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1778		       CTLTYPE_INT, "allowsrcrt",
1779		       SYSCTL_DESCR("Accept source-routed datagrams"),
1780		       NULL, 0, &ip_allowsrcrt, 0,
1781		       CTL_NET, PF_INET, IPPROTO_IP,
1782		       IPCTL_ALLOWSRCRT, CTL_EOL);
1783	sysctl_createv(clog, 0, NULL, NULL,
1784		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1785		       CTLTYPE_INT, "subnetsarelocal",
1786		       SYSCTL_DESCR("Whether logical subnets are considered "
1787				    "local"),
1788		       NULL, 0, &subnetsarelocal, 0,
1789		       CTL_NET, PF_INET, IPPROTO_IP,
1790		       IPCTL_SUBNETSARELOCAL, CTL_EOL);
1791	sysctl_createv(clog, 0, NULL, NULL,
1792		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1793		       CTLTYPE_INT, "mtudisc",
1794		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1795		       NULL, 0, &ip_mtudisc, 0,
1796		       CTL_NET, PF_INET, IPPROTO_IP,
1797		       IPCTL_MTUDISC, CTL_EOL);
1798	sysctl_createv(clog, 0, NULL, NULL,
1799		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1800		       CTLTYPE_INT, "anonportmin",
1801		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1802		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1803		       CTL_NET, PF_INET, IPPROTO_IP,
1804		       IPCTL_ANONPORTMIN, CTL_EOL);
1805	sysctl_createv(clog, 0, NULL, NULL,
1806		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1807		       CTLTYPE_INT, "anonportmax",
1808		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1809		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1810		       CTL_NET, PF_INET, IPPROTO_IP,
1811		       IPCTL_ANONPORTMAX, CTL_EOL);
1812	sysctl_createv(clog, 0, NULL, NULL,
1813		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1814		       CTLTYPE_INT, "mtudisctimeout",
1815		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1816		       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
1817		       CTL_NET, PF_INET, IPPROTO_IP,
1818		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1819#ifdef GATEWAY
1820	sysctl_createv(clog, 0, NULL, NULL,
1821		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1822		       CTLTYPE_INT, "maxflows",
1823		       SYSCTL_DESCR("Number of flows for fast forwarding"),
1824		       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
1825		       CTL_NET, PF_INET, IPPROTO_IP,
1826		       IPCTL_MAXFLOWS, CTL_EOL);
1827	sysctl_createv(clog, 0, NULL, NULL,
1828			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1829			CTLTYPE_INT, "hashsize",
1830			SYSCTL_DESCR("Size of hash table for fast forwarding (IPv4)"),
1831			sysctl_net_inet_ip_hashsize, 0, &ip_hashsize, 0,
1832			CTL_NET, PF_INET, IPPROTO_IP,
1833			CTL_CREATE, CTL_EOL);
1834#endif /* GATEWAY */
1835	sysctl_createv(clog, 0, NULL, NULL,
1836		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1837		       CTLTYPE_INT, "hostzerobroadcast",
1838		       SYSCTL_DESCR("All zeroes address is broadcast address"),
1839		       NULL, 0, &hostzeroisbroadcast, 0,
1840		       CTL_NET, PF_INET, IPPROTO_IP,
1841		       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
1842#if NGIF > 0
1843	sysctl_createv(clog, 0, NULL, NULL,
1844		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1845		       CTLTYPE_INT, "gifttl",
1846		       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
1847		       NULL, 0, &ip_gif_ttl, 0,
1848		       CTL_NET, PF_INET, IPPROTO_IP,
1849		       IPCTL_GIF_TTL, CTL_EOL);
1850#endif /* NGIF */
1851#ifndef IPNOPRIVPORTS
1852	sysctl_createv(clog, 0, NULL, NULL,
1853		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1854		       CTLTYPE_INT, "lowportmin",
1855		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1856				    "to assign"),
1857		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1858		       CTL_NET, PF_INET, IPPROTO_IP,
1859		       IPCTL_LOWPORTMIN, CTL_EOL);
1860	sysctl_createv(clog, 0, NULL, NULL,
1861		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1862		       CTLTYPE_INT, "lowportmax",
1863		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1864				    "to assign"),
1865		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1866		       CTL_NET, PF_INET, IPPROTO_IP,
1867		       IPCTL_LOWPORTMAX, CTL_EOL);
1868#endif /* IPNOPRIVPORTS */
1869#if NGRE > 0
1870	sysctl_createv(clog, 0, NULL, NULL,
1871		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1872		       CTLTYPE_INT, "grettl",
1873		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1874		       NULL, 0, &ip_gre_ttl, 0,
1875		       CTL_NET, PF_INET, IPPROTO_IP,
1876		       IPCTL_GRE_TTL, CTL_EOL);
1877#endif /* NGRE */
1878	sysctl_createv(clog, 0, NULL, NULL,
1879		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1880		       CTLTYPE_INT, "checkinterface",
1881		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1882				    "from RFC1122"),
1883		       NULL, 0, &ip_checkinterface, 0,
1884		       CTL_NET, PF_INET, IPPROTO_IP,
1885		       IPCTL_CHECKINTERFACE, CTL_EOL);
1886	sysctl_createv(clog, 0, NULL, NULL,
1887		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1888		       CTLTYPE_INT, "random_id",
1889		       SYSCTL_DESCR("Assign random ip_id values"),
1890		       NULL, 0, &ip_do_randomid, 0,
1891		       CTL_NET, PF_INET, IPPROTO_IP,
1892		       IPCTL_RANDOMID, CTL_EOL);
1893	sysctl_createv(clog, 0, NULL, NULL,
1894		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1895		       CTLTYPE_INT, "do_loopback_cksum",
1896		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1897		       NULL, 0, &ip_do_loopback_cksum, 0,
1898		       CTL_NET, PF_INET, IPPROTO_IP,
1899		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1900	sysctl_createv(clog, 0, NULL, NULL,
1901		       CTLFLAG_PERMANENT,
1902		       CTLTYPE_STRUCT, "stats",
1903		       SYSCTL_DESCR("IP statistics"),
1904		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1905		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1906		       CTL_EOL);
1907}
1908
1909void
1910ip_statinc(u_int stat)
1911{
1912
1913	KASSERT(stat < IP_NSTATS);
1914	IP_STATINC(stat);
1915}
1916