ip_input.c revision 1.293
1/*	$NetBSD: ip_input.c,v 1.293 2010/12/13 14:18:50 matt 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 1.293 2010/12/13 14:18:50 matt 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
234ipid_state_t *		ip_ids;
235uint16_t ip_id;
236
237percpu_t *ipstat_percpu;
238
239#ifdef PFIL_HOOKS
240struct pfil_head inet_pfil_hook;
241#endif
242
243struct pool inmulti_pool;
244
245#ifdef INET_CSUM_COUNTERS
246#include <sys/device.h>
247
248struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
249    NULL, "inet", "hwcsum bad");
250struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
251    NULL, "inet", "hwcsum ok");
252struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
253    NULL, "inet", "swcsum");
254
255#define	INET_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
256
257EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
258EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
259EVCNT_ATTACH_STATIC(ip_swcsum);
260
261#else
262
263#define	INET_CSUM_COUNTER_INCR(ev)	/* nothing */
264
265#endif /* INET_CSUM_COUNTERS */
266
267/*
268 * We need to save the IP options in case a protocol wants to respond
269 * to an incoming packet over the same route if the packet got here
270 * using IP source routing.  This allows connection establishment and
271 * maintenance when the remote end is on a network that is not known
272 * to us.
273 */
274int	ip_nhops = 0;
275static	struct ip_srcrt {
276	struct	in_addr dst;			/* final destination */
277	char	nop;				/* one NOP to align */
278	char	srcopt[IPOPT_OFFSET + 1];	/* OPTVAL, OLEN and OFFSET */
279	struct	in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
280} ip_srcrt;
281
282static void save_rte(u_char *, struct in_addr);
283
284#ifdef MBUFTRACE
285struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
286struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
287#endif
288
289static void sysctl_net_inet_ip_setup(struct sysctllog **);
290
291/*
292 * IP initialization: fill in IP protocol switch table.
293 * All protocols not implemented in kernel go to raw IP protocol handler.
294 */
295void
296ip_init(void)
297{
298	const struct protosw *pr;
299	int i;
300
301	sysctl_net_inet_ip_setup(NULL);
302
303	pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
304	    NULL, IPL_SOFTNET);
305
306	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
307	if (pr == 0)
308		panic("ip_init");
309	for (i = 0; i < IPPROTO_MAX; i++)
310		ip_protox[i] = pr - inetsw;
311	for (pr = inetdomain.dom_protosw;
312	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
313		if (pr->pr_domain->dom_family == PF_INET &&
314		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
315			ip_protox[pr->pr_protocol] = pr - inetsw;
316
317	ip_reass_init();
318
319	ip_ids = ip_id_init();
320	ip_id = time_second & 0xfffff;
321
322	ipintrq.ifq_maxlen = ipqmaxlen;
323
324	TAILQ_INIT(&in_ifaddrhead);
325	in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, true,
326	    &in_ifaddrhash);
327	in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, true,
328	    &in_multihash);
329	ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
330#ifdef GATEWAY
331	ipflow_init(ip_hashsize);
332#endif
333
334#ifdef PFIL_HOOKS
335	/* Register our Packet Filter hook. */
336	inet_pfil_hook.ph_type = PFIL_TYPE_AF;
337	inet_pfil_hook.ph_af   = AF_INET;
338	i = pfil_head_register(&inet_pfil_hook);
339	if (i != 0)
340		printf("ip_init: WARNING: unable to register pfil hook, "
341		    "error %d\n", i);
342#endif /* PFIL_HOOKS */
343
344#ifdef MBUFTRACE
345	MOWNER_ATTACH(&ip_tx_mowner);
346	MOWNER_ATTACH(&ip_rx_mowner);
347#endif /* MBUFTRACE */
348
349	ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
350}
351
352struct	sockaddr_in ipaddr = {
353	.sin_len = sizeof(ipaddr),
354	.sin_family = AF_INET,
355};
356struct	route ipforward_rt;
357
358/*
359 * IP software interrupt routine
360 */
361void
362ipintr(void)
363{
364	int s;
365	struct mbuf *m;
366	struct ifqueue lcl_intrq;
367
368	memset(&lcl_intrq, 0, sizeof(lcl_intrq));
369	ipintrq.ifq_maxlen = ipqmaxlen;
370
371	mutex_enter(softnet_lock);
372	KERNEL_LOCK(1, NULL);
373	if (!IF_IS_EMPTY(&ipintrq)) {
374		s = splnet();
375
376		/* Take existing queue onto stack */
377		lcl_intrq = ipintrq;
378
379		/* Zero out global queue, preserving maxlen and drops */
380		ipintrq.ifq_head = NULL;
381		ipintrq.ifq_tail = NULL;
382		ipintrq.ifq_len = 0;
383		ipintrq.ifq_maxlen = lcl_intrq.ifq_maxlen;
384		ipintrq.ifq_drops = lcl_intrq.ifq_drops;
385
386		splx(s);
387	}
388	KERNEL_UNLOCK_ONE(NULL);
389	while (!IF_IS_EMPTY(&lcl_intrq)) {
390		IF_DEQUEUE(&lcl_intrq, m);
391		if (m == NULL)
392			break;
393		ip_input(m);
394	}
395	mutex_exit(softnet_lock);
396}
397
398/*
399 * Ip input routine.  Checksum and byte swap header.  If fragmented
400 * try to reassemble.  Process options.  Pass to next level.
401 */
402void
403ip_input(struct mbuf *m)
404{
405	struct ip *ip = NULL;
406	struct in_ifaddr *ia;
407	struct ifaddr *ifa;
408	int hlen = 0, len;
409	int downmatch;
410	int checkif;
411	int srcrt = 0;
412#ifdef FAST_IPSEC
413	struct m_tag *mtag;
414	struct tdb_ident *tdbi;
415	struct secpolicy *sp;
416	int error, s;
417#endif /* FAST_IPSEC */
418
419	MCLAIM(m, &ip_rx_mowner);
420	KASSERT((m->m_flags & M_PKTHDR) != 0);
421
422	/*
423	 * If no IP addresses have been set yet but the interfaces
424	 * are receiving, can't do anything with incoming packets yet.
425	 */
426	if (TAILQ_FIRST(&in_ifaddrhead) == 0)
427		goto bad;
428	IP_STATINC(IP_STAT_TOTAL);
429	/*
430	 * If the IP header is not aligned, slurp it up into a new
431	 * mbuf with space for link headers, in the event we forward
432	 * it.  Otherwise, if it is aligned, make sure the entire
433	 * base IP header is in the first mbuf of the chain.
434	 */
435	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
436		if ((m = m_copyup(m, sizeof(struct ip),
437				  (max_linkhdr + 3) & ~3)) == NULL) {
438			/* XXXJRT new stat, please */
439			IP_STATINC(IP_STAT_TOOSMALL);
440			return;
441		}
442	} else if (__predict_false(m->m_len < sizeof (struct ip))) {
443		if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
444			IP_STATINC(IP_STAT_TOOSMALL);
445			return;
446		}
447	}
448	ip = mtod(m, struct ip *);
449	if (ip->ip_v != IPVERSION) {
450		IP_STATINC(IP_STAT_BADVERS);
451		goto bad;
452	}
453	hlen = ip->ip_hl << 2;
454	if (hlen < sizeof(struct ip)) {	/* minimum header length */
455		IP_STATINC(IP_STAT_BADHLEN);
456		goto bad;
457	}
458	if (hlen > m->m_len) {
459		if ((m = m_pullup(m, hlen)) == 0) {
460			IP_STATINC(IP_STAT_BADHLEN);
461			return;
462		}
463		ip = mtod(m, struct ip *);
464	}
465
466	/*
467	 * RFC1122: packets with a multicast source address are
468	 * not allowed.
469	 */
470	if (IN_MULTICAST(ip->ip_src.s_addr)) {
471		IP_STATINC(IP_STAT_BADADDR);
472		goto bad;
473	}
474
475	/* 127/8 must not appear on wire - RFC1122 */
476	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
477	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
478		if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
479			IP_STATINC(IP_STAT_BADADDR);
480			goto bad;
481		}
482	}
483
484	switch (m->m_pkthdr.csum_flags &
485		((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
486		 M_CSUM_IPv4_BAD)) {
487	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
488		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
489		goto badcsum;
490
491	case M_CSUM_IPv4:
492		/* Checksum was okay. */
493		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
494		break;
495
496	default:
497		/*
498		 * Must compute it ourselves.  Maybe skip checksum on
499		 * loopback interfaces.
500		 */
501		if (__predict_true(!(m->m_pkthdr.rcvif->if_flags &
502				     IFF_LOOPBACK) || ip_do_loopback_cksum)) {
503			INET_CSUM_COUNTER_INCR(&ip_swcsum);
504			if (in_cksum(m, hlen) != 0)
505				goto badcsum;
506		}
507		break;
508	}
509
510	/* Retrieve the packet length. */
511	len = ntohs(ip->ip_len);
512
513	/*
514	 * Check for additional length bogosity
515	 */
516	if (len < hlen) {
517		IP_STATINC(IP_STAT_BADLEN);
518		goto bad;
519	}
520
521	/*
522	 * Check that the amount of data in the buffers
523	 * is as at least much as the IP header would have us expect.
524	 * Trim mbufs if longer than we expect.
525	 * Drop packet if shorter than we expect.
526	 */
527	if (m->m_pkthdr.len < len) {
528		IP_STATINC(IP_STAT_TOOSHORT);
529		goto bad;
530	}
531	if (m->m_pkthdr.len > len) {
532		if (m->m_len == m->m_pkthdr.len) {
533			m->m_len = len;
534			m->m_pkthdr.len = len;
535		} else
536			m_adj(m, len - m->m_pkthdr.len);
537	}
538
539#if defined(IPSEC)
540	/* ipflow (IP fast forwarding) is not compatible with IPsec. */
541	m->m_flags &= ~M_CANFASTFWD;
542#else
543	/*
544	 * Assume that we can create a fast-forward IP flow entry
545	 * based on this packet.
546	 */
547	m->m_flags |= M_CANFASTFWD;
548#endif
549
550#ifdef PFIL_HOOKS
551	/*
552	 * Run through list of hooks for input packets.  If there are any
553	 * filters which require that additional packets in the flow are
554	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
555	 * Note that filters must _never_ set this flag, as another filter
556	 * in the list may have previously cleared it.
557	 */
558	/*
559	 * let ipfilter look at packet on the wire,
560	 * not the decapsulated packet.
561	 */
562#ifdef IPSEC
563	if (!ipsec_getnhist(m))
564#elif defined(FAST_IPSEC)
565	if (!ipsec_indone(m))
566#else
567	if (1)
568#endif
569	{
570		struct in_addr odst;
571
572		odst = ip->ip_dst;
573		if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
574		    PFIL_IN) != 0)
575			return;
576		if (m == NULL)
577			return;
578		ip = mtod(m, struct ip *);
579		hlen = ip->ip_hl << 2;
580		/*
581		 * XXX The setting of "srcrt" here is to prevent ip_forward()
582		 * from generating ICMP redirects for packets that have
583		 * been redirected by a hook back out on to the same LAN that
584		 * they came from and is not an indication that the packet
585		 * is being inffluenced by source routing options.  This
586		 * allows things like
587		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
588		 * where tlp0 is both on the 1.1.1.0/24 network and is the
589		 * default route for hosts on 1.1.1.0/24.  Of course this
590		 * also requires a "map tlp0 ..." to complete the story.
591		 * One might argue whether or not this kind of network config.
592		 * should be supported in this manner...
593		 */
594		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
595	}
596#endif /* PFIL_HOOKS */
597
598#ifdef ALTQ
599	/* XXX Temporary until ALTQ is changed to use a pfil hook */
600	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
601		/* packet dropped by traffic conditioner */
602		return;
603	}
604#endif
605
606	/*
607	 * Process options and, if not destined for us,
608	 * ship it on.  ip_dooptions returns 1 when an
609	 * error was detected (causing an icmp message
610	 * to be sent and the original packet to be freed).
611	 */
612	ip_nhops = 0;		/* for source routed packets */
613	if (hlen > sizeof (struct ip) && ip_dooptions(m))
614		return;
615
616	/*
617	 * Enable a consistency check between the destination address
618	 * and the arrival interface for a unicast packet (the RFC 1122
619	 * strong ES model) if IP forwarding is disabled and the packet
620	 * is not locally generated.
621	 *
622	 * XXX - Checking also should be disabled if the destination
623	 * address is ipnat'ed to a different interface.
624	 *
625	 * XXX - Checking is incompatible with IP aliases added
626	 * to the loopback interface instead of the interface where
627	 * the packets are received.
628	 *
629	 * XXX - We need to add a per ifaddr flag for this so that
630	 * we get finer grain control.
631	 */
632	checkif = ip_checkinterface && (ipforwarding == 0) &&
633	    (m->m_pkthdr.rcvif != NULL) &&
634	    ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
635
636	/*
637	 * Check our list of addresses, to see if the packet is for us.
638	 *
639	 * Traditional 4.4BSD did not consult IFF_UP at all.
640	 * The behavior here is to treat addresses on !IFF_UP interface
641	 * as not mine.
642	 */
643	downmatch = 0;
644	LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
645		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
646			if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
647				continue;
648			if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
649				break;
650			else
651				downmatch++;
652		}
653	}
654	if (ia != NULL)
655		goto ours;
656	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
657		IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) {
658			if (ifa->ifa_addr->sa_family != AF_INET)
659				continue;
660			ia = ifatoia(ifa);
661			if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
662			    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
663			    /*
664			     * Look for all-0's host part (old broadcast addr),
665			     * either for subnet or net.
666			     */
667			    ip->ip_dst.s_addr == ia->ia_subnet ||
668			    ip->ip_dst.s_addr == ia->ia_net)
669				goto ours;
670			/*
671			 * An interface with IP address zero accepts
672			 * all packets that arrive on that interface.
673			 */
674			if (in_nullhost(ia->ia_addr.sin_addr))
675				goto ours;
676		}
677	}
678	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
679		struct in_multi *inm;
680#ifdef MROUTING
681		extern struct socket *ip_mrouter;
682
683		if (ip_mrouter) {
684			/*
685			 * If we are acting as a multicast router, all
686			 * incoming multicast packets are passed to the
687			 * kernel-level multicast forwarding function.
688			 * The packet is returned (relatively) intact; if
689			 * ip_mforward() returns a non-zero value, the packet
690			 * must be discarded, else it may be accepted below.
691			 *
692			 * (The IP ident field is put in the same byte order
693			 * as expected when ip_mforward() is called from
694			 * ip_output().)
695			 */
696			if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
697				IP_STATINC(IP_STAT_CANTFORWARD);
698				m_freem(m);
699				return;
700			}
701
702			/*
703			 * The process-level routing demon needs to receive
704			 * all multicast IGMP packets, whether or not this
705			 * host belongs to their destination groups.
706			 */
707			if (ip->ip_p == IPPROTO_IGMP)
708				goto ours;
709			IP_STATINC(IP_STAT_CANTFORWARD);
710		}
711#endif
712		/*
713		 * See if we belong to the destination multicast group on the
714		 * arrival interface.
715		 */
716		IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
717		if (inm == NULL) {
718			IP_STATINC(IP_STAT_CANTFORWARD);
719			m_freem(m);
720			return;
721		}
722		goto ours;
723	}
724	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
725	    in_nullhost(ip->ip_dst))
726		goto ours;
727
728	/*
729	 * Not for us; forward if possible and desirable.
730	 */
731	if (ipforwarding == 0) {
732		IP_STATINC(IP_STAT_CANTFORWARD);
733		m_freem(m);
734	} else {
735		/*
736		 * If ip_dst matched any of my address on !IFF_UP interface,
737		 * and there's no IFF_UP interface that matches ip_dst,
738		 * send icmp unreach.  Forwarding it will result in in-kernel
739		 * forwarding loop till TTL goes to 0.
740		 */
741		if (downmatch) {
742			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
743			IP_STATINC(IP_STAT_CANTFORWARD);
744			return;
745		}
746#ifdef IPSEC
747		if (ipsec4_in_reject(m, NULL)) {
748			IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
749			goto bad;
750		}
751#endif
752#ifdef FAST_IPSEC
753		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
754		s = splsoftnet();
755		if (mtag != NULL) {
756			tdbi = (struct tdb_ident *)(mtag + 1);
757			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
758		} else {
759			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
760						   IP_FORWARDING, &error);
761		}
762		if (sp == NULL) {	/* NB: can happen if error */
763			splx(s);
764			/*XXX error stat???*/
765			DPRINTF(("ip_input: no SP for forwarding\n"));	/*XXX*/
766			goto bad;
767		}
768
769		/*
770		 * Check security policy against packet attributes.
771		 */
772		error = ipsec_in_reject(sp, m);
773		KEY_FREESP(&sp);
774		splx(s);
775		if (error) {
776			IP_STATINC(IP_STAT_CANTFORWARD);
777			goto bad;
778		}
779
780		/*
781		 * Peek at the outbound SP for this packet to determine if
782		 * it's a Fast Forward candidate.
783		 */
784		mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
785		if (mtag != NULL)
786			m->m_flags &= ~M_CANFASTFWD;
787		else {
788			s = splsoftnet();
789			sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND,
790			    (IP_FORWARDING |
791			     (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
792			    &error, NULL);
793			if (sp != NULL) {
794				m->m_flags &= ~M_CANFASTFWD;
795				KEY_FREESP(&sp);
796			}
797			splx(s);
798		}
799#endif	/* FAST_IPSEC */
800
801		ip_forward(m, srcrt);
802	}
803	return;
804
805ours:
806	/*
807	 * If offset or IP_MF are set, must reassemble.
808	 */
809	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
810		/*
811		 * Pass to IP reassembly mechanism.
812		 */
813		if (ip_reass_packet(&m, ip) != 0) {
814			/* Failed; invalid fragment(s) or packet. */
815			goto bad;
816		}
817		if (m == NULL) {
818			/* More fragments should come; silently return. */
819			return;
820		}
821		/*
822		 * Reassembly is done, we have the final packet.
823		 * Updated cached data in local variable(s).
824		 */
825		ip = mtod(m, struct ip *);
826		hlen = ip->ip_hl << 2;
827	}
828
829#if defined(IPSEC)
830	/*
831	 * enforce IPsec policy checking if we are seeing last header.
832	 * note that we do not visit this with protocols with pcb layer
833	 * code - like udp/tcp/raw ip.
834	 */
835	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0 &&
836	    ipsec4_in_reject(m, NULL)) {
837		IPSEC_STATINC(IPSEC_STAT_IN_POLVIO);
838		goto bad;
839	}
840#endif
841#ifdef FAST_IPSEC
842	/*
843	 * enforce IPsec policy checking if we are seeing last header.
844	 * note that we do not visit this with protocols with pcb layer
845	 * code - like udp/tcp/raw ip.
846	 */
847	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
848		/*
849		 * Check if the packet has already had IPsec processing
850		 * done.  If so, then just pass it along.  This tag gets
851		 * set during AH, ESP, etc. input handling, before the
852		 * packet is returned to the ip input queue for delivery.
853		 */
854		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
855		s = splsoftnet();
856		if (mtag != NULL) {
857			tdbi = (struct tdb_ident *)(mtag + 1);
858			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
859		} else {
860			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
861						   IP_FORWARDING, &error);
862		}
863		if (sp != NULL) {
864			/*
865			 * Check security policy against packet attributes.
866			 */
867			error = ipsec_in_reject(sp, m);
868			KEY_FREESP(&sp);
869		} else {
870			/* XXX error stat??? */
871			error = EINVAL;
872DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
873		}
874		splx(s);
875		if (error)
876			goto bad;
877	}
878#endif /* FAST_IPSEC */
879
880	/*
881	 * Switch out to protocol's input routine.
882	 */
883#if IFA_STATS
884	if (ia && ip)
885		ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
886#endif
887	IP_STATINC(IP_STAT_DELIVERED);
888    {
889	int off = hlen, nh = ip->ip_p;
890
891	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
892	return;
893    }
894bad:
895	m_freem(m);
896	return;
897
898badcsum:
899	IP_STATINC(IP_STAT_BADSUM);
900	m_freem(m);
901}
902
903/*
904 * IP timer processing.
905 */
906void
907ip_slowtimo(void)
908{
909
910	mutex_enter(softnet_lock);
911	KERNEL_LOCK(1, NULL);
912
913	ip_reass_slowtimo();
914
915	KERNEL_UNLOCK_ONE(NULL);
916	mutex_exit(softnet_lock);
917}
918
919/*
920 * IP drain processing.
921 */
922void
923ip_drain(void)
924{
925
926	KERNEL_LOCK(1, NULL);
927	ip_reass_drain();
928	KERNEL_UNLOCK_ONE(NULL);
929}
930
931/*
932 * Do option processing on a datagram,
933 * possibly discarding it if bad options are encountered,
934 * or forwarding it if source-routed.
935 * Returns 1 if packet has been forwarded/freed,
936 * 0 if the packet should be processed further.
937 */
938int
939ip_dooptions(struct mbuf *m)
940{
941	struct ip *ip = mtod(m, struct ip *);
942	u_char *cp, *cp0;
943	struct ip_timestamp *ipt;
944	struct in_ifaddr *ia;
945	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
946	struct in_addr dst;
947	n_time ntime;
948
949	dst = ip->ip_dst;
950	cp = (u_char *)(ip + 1);
951	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
952	for (; cnt > 0; cnt -= optlen, cp += optlen) {
953		opt = cp[IPOPT_OPTVAL];
954		if (opt == IPOPT_EOL)
955			break;
956		if (opt == IPOPT_NOP)
957			optlen = 1;
958		else {
959			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
960				code = &cp[IPOPT_OLEN] - (u_char *)ip;
961				goto bad;
962			}
963			optlen = cp[IPOPT_OLEN];
964			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
965				code = &cp[IPOPT_OLEN] - (u_char *)ip;
966				goto bad;
967			}
968		}
969		switch (opt) {
970
971		default:
972			break;
973
974		/*
975		 * Source routing with record.
976		 * Find interface with current destination address.
977		 * If none on this machine then drop if strictly routed,
978		 * or do nothing if loosely routed.
979		 * Record interface address and bring up next address
980		 * component.  If strictly routed make sure next
981		 * address is on directly accessible net.
982		 */
983		case IPOPT_LSRR:
984		case IPOPT_SSRR:
985			if (ip_allowsrcrt == 0) {
986				type = ICMP_UNREACH;
987				code = ICMP_UNREACH_NET_PROHIB;
988				goto bad;
989			}
990			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
991				code = &cp[IPOPT_OLEN] - (u_char *)ip;
992				goto bad;
993			}
994			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
995				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
996				goto bad;
997			}
998			ipaddr.sin_addr = ip->ip_dst;
999			ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
1000			if (ia == 0) {
1001				if (opt == IPOPT_SSRR) {
1002					type = ICMP_UNREACH;
1003					code = ICMP_UNREACH_SRCFAIL;
1004					goto bad;
1005				}
1006				/*
1007				 * Loose routing, and not at next destination
1008				 * yet; nothing to do except forward.
1009				 */
1010				break;
1011			}
1012			off--;			/* 0 origin */
1013			if ((off + sizeof(struct in_addr)) > optlen) {
1014				/*
1015				 * End of source route.  Should be for us.
1016				 */
1017				save_rte(cp, ip->ip_src);
1018				break;
1019			}
1020			/*
1021			 * locate outgoing interface
1022			 */
1023			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
1024			    sizeof(ipaddr.sin_addr));
1025			if (opt == IPOPT_SSRR)
1026				ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr)));
1027			else
1028				ia = ip_rtaddr(ipaddr.sin_addr);
1029			if (ia == 0) {
1030				type = ICMP_UNREACH;
1031				code = ICMP_UNREACH_SRCFAIL;
1032				goto bad;
1033			}
1034			ip->ip_dst = ipaddr.sin_addr;
1035			bcopy((void *)&ia->ia_addr.sin_addr,
1036			    (void *)(cp + off), sizeof(struct in_addr));
1037			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1038			/*
1039			 * Let ip_intr's mcast routing check handle mcast pkts
1040			 */
1041			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1042			break;
1043
1044		case IPOPT_RR:
1045			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1046				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1047				goto bad;
1048			}
1049			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1050				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1051				goto bad;
1052			}
1053			/*
1054			 * If no space remains, ignore.
1055			 */
1056			off--;			/* 0 origin */
1057			if ((off + sizeof(struct in_addr)) > optlen)
1058				break;
1059			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1060			    sizeof(ipaddr.sin_addr));
1061			/*
1062			 * locate outgoing interface; if we're the destination,
1063			 * use the incoming interface (should be same).
1064			 */
1065			if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1066			    == NULL &&
1067			    (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1068				type = ICMP_UNREACH;
1069				code = ICMP_UNREACH_HOST;
1070				goto bad;
1071			}
1072			bcopy((void *)&ia->ia_addr.sin_addr,
1073			    (void *)(cp + off), sizeof(struct in_addr));
1074			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1075			break;
1076
1077		case IPOPT_TS:
1078			code = cp - (u_char *)ip;
1079			ipt = (struct ip_timestamp *)cp;
1080			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1081				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1082				goto bad;
1083			}
1084			if (ipt->ipt_ptr < 5) {
1085				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1086				goto bad;
1087			}
1088			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1089				if (++ipt->ipt_oflw == 0) {
1090					code = (u_char *)&ipt->ipt_ptr -
1091					    (u_char *)ip;
1092					goto bad;
1093				}
1094				break;
1095			}
1096			cp0 = (cp + ipt->ipt_ptr - 1);
1097			switch (ipt->ipt_flg) {
1098
1099			case IPOPT_TS_TSONLY:
1100				break;
1101
1102			case IPOPT_TS_TSANDADDR:
1103				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1104				    sizeof(struct in_addr) > ipt->ipt_len) {
1105					code = (u_char *)&ipt->ipt_ptr -
1106					    (u_char *)ip;
1107					goto bad;
1108				}
1109				ipaddr.sin_addr = dst;
1110				ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1111				    m->m_pkthdr.rcvif));
1112				if (ia == 0)
1113					continue;
1114				bcopy(&ia->ia_addr.sin_addr,
1115				    cp0, sizeof(struct in_addr));
1116				ipt->ipt_ptr += sizeof(struct in_addr);
1117				break;
1118
1119			case IPOPT_TS_PRESPEC:
1120				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1121				    sizeof(struct in_addr) > ipt->ipt_len) {
1122					code = (u_char *)&ipt->ipt_ptr -
1123					    (u_char *)ip;
1124					goto bad;
1125				}
1126				memcpy(&ipaddr.sin_addr, cp0,
1127				    sizeof(struct in_addr));
1128				if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1129				    == NULL)
1130					continue;
1131				ipt->ipt_ptr += sizeof(struct in_addr);
1132				break;
1133
1134			default:
1135				/* XXX can't take &ipt->ipt_flg */
1136				code = (u_char *)&ipt->ipt_ptr -
1137				    (u_char *)ip + 1;
1138				goto bad;
1139			}
1140			ntime = iptime();
1141			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1142			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1143			    sizeof(n_time));
1144			ipt->ipt_ptr += sizeof(n_time);
1145		}
1146	}
1147	if (forward) {
1148		if (ip_forwsrcrt == 0) {
1149			type = ICMP_UNREACH;
1150			code = ICMP_UNREACH_SRCFAIL;
1151			goto bad;
1152		}
1153		ip_forward(m, 1);
1154		return (1);
1155	}
1156	return (0);
1157bad:
1158	icmp_error(m, type, code, 0, 0);
1159	IP_STATINC(IP_STAT_BADOPTIONS);
1160	return (1);
1161}
1162
1163/*
1164 * Given address of next destination (final or next hop),
1165 * return internet address info of interface to be used to get there.
1166 */
1167struct in_ifaddr *
1168ip_rtaddr(struct in_addr dst)
1169{
1170	struct rtentry *rt;
1171	union {
1172		struct sockaddr		dst;
1173		struct sockaddr_in	dst4;
1174	} u;
1175
1176	sockaddr_in_init(&u.dst4, &dst, 0);
1177
1178	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL)
1179		return NULL;
1180
1181	return ifatoia(rt->rt_ifa);
1182}
1183
1184/*
1185 * Save incoming source route for use in replies,
1186 * to be picked up later by ip_srcroute if the receiver is interested.
1187 */
1188void
1189save_rte(u_char *option, struct in_addr dst)
1190{
1191	unsigned olen;
1192
1193	olen = option[IPOPT_OLEN];
1194#ifdef DIAGNOSTIC
1195	if (ipprintfs)
1196		printf("save_rte: olen %d\n", olen);
1197#endif /* 0 */
1198	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1199		return;
1200	memcpy((void *)ip_srcrt.srcopt, (void *)option, olen);
1201	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1202	ip_srcrt.dst = dst;
1203}
1204
1205/*
1206 * Retrieve incoming source route for use in replies,
1207 * in the same form used by setsockopt.
1208 * The first hop is placed before the options, will be removed later.
1209 */
1210struct mbuf *
1211ip_srcroute(void)
1212{
1213	struct in_addr *p, *q;
1214	struct mbuf *m;
1215
1216	if (ip_nhops == 0)
1217		return NULL;
1218	m = m_get(M_DONTWAIT, MT_SOOPTS);
1219	if (m == 0)
1220		return NULL;
1221
1222	MCLAIM(m, &inetdomain.dom_mowner);
1223#define OPTSIZ	(sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1224
1225	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1226	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1227	    OPTSIZ;
1228#ifdef DIAGNOSTIC
1229	if (ipprintfs)
1230		printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1231#endif
1232
1233	/*
1234	 * First save first hop for return route
1235	 */
1236	p = &ip_srcrt.route[ip_nhops - 1];
1237	*(mtod(m, struct in_addr *)) = *p--;
1238#ifdef DIAGNOSTIC
1239	if (ipprintfs)
1240		printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1241#endif
1242
1243	/*
1244	 * Copy option fields and padding (nop) to mbuf.
1245	 */
1246	ip_srcrt.nop = IPOPT_NOP;
1247	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1248	memmove(mtod(m, char *) + sizeof(struct in_addr), &ip_srcrt.nop,
1249	    OPTSIZ);
1250	q = (struct in_addr *)(mtod(m, char *) +
1251	    sizeof(struct in_addr) + OPTSIZ);
1252#undef OPTSIZ
1253	/*
1254	 * Record return path as an IP source route,
1255	 * reversing the path (pointers are now aligned).
1256	 */
1257	while (p >= ip_srcrt.route) {
1258#ifdef DIAGNOSTIC
1259		if (ipprintfs)
1260			printf(" %x", ntohl(q->s_addr));
1261#endif
1262		*q++ = *p--;
1263	}
1264	/*
1265	 * Last hop goes to final destination.
1266	 */
1267	*q = ip_srcrt.dst;
1268#ifdef DIAGNOSTIC
1269	if (ipprintfs)
1270		printf(" %x\n", ntohl(q->s_addr));
1271#endif
1272	return (m);
1273}
1274
1275const int inetctlerrmap[PRC_NCMDS] = {
1276	[PRC_MSGSIZE] = EMSGSIZE,
1277	[PRC_HOSTDEAD] = EHOSTDOWN,
1278	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1279	[PRC_UNREACH_NET] = EHOSTUNREACH,
1280	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1281	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1282	[PRC_UNREACH_PORT] = ECONNREFUSED,
1283	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1284	[PRC_PARAMPROB] = ENOPROTOOPT,
1285};
1286
1287/*
1288 * Forward a packet.  If some error occurs return the sender
1289 * an icmp packet.  Note we can't always generate a meaningful
1290 * icmp message because icmp doesn't have a large enough repertoire
1291 * of codes and types.
1292 *
1293 * If not forwarding, just drop the packet.  This could be confusing
1294 * if ipforwarding was zero but some routing protocol was advancing
1295 * us as a gateway to somewhere.  However, we must let the routing
1296 * protocol deal with that.
1297 *
1298 * The srcrt parameter indicates whether the packet is being forwarded
1299 * via a source route.
1300 */
1301void
1302ip_forward(struct mbuf *m, int srcrt)
1303{
1304	struct ip *ip = mtod(m, struct ip *);
1305	struct rtentry *rt;
1306	int error, type = 0, code = 0, destmtu = 0;
1307	struct mbuf *mcopy;
1308	n_long dest;
1309	union {
1310		struct sockaddr		dst;
1311		struct sockaddr_in	dst4;
1312	} u;
1313
1314	/*
1315	 * We are now in the output path.
1316	 */
1317	MCLAIM(m, &ip_tx_mowner);
1318
1319	/*
1320	 * Clear any in-bound checksum flags for this packet.
1321	 */
1322	m->m_pkthdr.csum_flags = 0;
1323
1324	dest = 0;
1325#ifdef DIAGNOSTIC
1326	if (ipprintfs) {
1327		printf("forward: src %s ", inet_ntoa(ip->ip_src));
1328		printf("dst %s ttl %x\n", inet_ntoa(ip->ip_dst), ip->ip_ttl);
1329	}
1330#endif
1331	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1332		IP_STATINC(IP_STAT_CANTFORWARD);
1333		m_freem(m);
1334		return;
1335	}
1336	if (ip->ip_ttl <= IPTTLDEC) {
1337		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1338		return;
1339	}
1340
1341	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1342	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) {
1343		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1344		return;
1345	}
1346
1347	/*
1348	 * Save at most 68 bytes of the packet in case
1349	 * we need to generate an ICMP message to the src.
1350	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1351	 */
1352	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1353	if (mcopy)
1354		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1355
1356	ip->ip_ttl -= IPTTLDEC;
1357
1358	/*
1359	 * If forwarding packet using same interface that it came in on,
1360	 * perhaps should send a redirect to sender to shortcut a hop.
1361	 * Only send redirect if source is sending directly to us,
1362	 * and if packet was not source routed (or has any options).
1363	 * Also, don't send redirect if forwarding using a default route
1364	 * or a route modified by a redirect.
1365	 */
1366	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1367	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1368	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1369	    ipsendredirects && !srcrt) {
1370		if (rt->rt_ifa &&
1371		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1372		    ifatoia(rt->rt_ifa)->ia_subnet) {
1373			if (rt->rt_flags & RTF_GATEWAY)
1374				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1375			else
1376				dest = ip->ip_dst.s_addr;
1377			/*
1378			 * Router requirements says to only send host
1379			 * redirects.
1380			 */
1381			type = ICMP_REDIRECT;
1382			code = ICMP_REDIRECT_HOST;
1383#ifdef DIAGNOSTIC
1384			if (ipprintfs)
1385				printf("redirect (%d) to %x\n", code,
1386				    (u_int32_t)dest);
1387#endif
1388		}
1389	}
1390
1391	error = ip_output(m, NULL, &ipforward_rt,
1392	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1393	    (struct ip_moptions *)NULL, (struct socket *)NULL);
1394
1395	if (error)
1396		IP_STATINC(IP_STAT_CANTFORWARD);
1397	else {
1398		uint64_t *ips = IP_STAT_GETREF();
1399		ips[IP_STAT_FORWARD]++;
1400		if (type) {
1401			ips[IP_STAT_REDIRECTSENT]++;
1402			IP_STAT_PUTREF();
1403		} else {
1404			IP_STAT_PUTREF();
1405			if (mcopy) {
1406#ifdef GATEWAY
1407				if (mcopy->m_flags & M_CANFASTFWD)
1408					ipflow_create(&ipforward_rt, mcopy);
1409#endif
1410				m_freem(mcopy);
1411			}
1412			return;
1413		}
1414	}
1415	if (mcopy == NULL)
1416		return;
1417
1418	switch (error) {
1419
1420	case 0:				/* forwarded, but need redirect */
1421		/* type, code set above */
1422		break;
1423
1424	case ENETUNREACH:		/* shouldn't happen, checked above */
1425	case EHOSTUNREACH:
1426	case ENETDOWN:
1427	case EHOSTDOWN:
1428	default:
1429		type = ICMP_UNREACH;
1430		code = ICMP_UNREACH_HOST;
1431		break;
1432
1433	case EMSGSIZE:
1434		type = ICMP_UNREACH;
1435		code = ICMP_UNREACH_NEEDFRAG;
1436
1437		if ((rt = rtcache_validate(&ipforward_rt)) != NULL)
1438			destmtu = rt->rt_ifp->if_mtu;
1439
1440#if defined(IPSEC) || defined(FAST_IPSEC)
1441		{
1442			/*
1443			 * If the packet is routed over IPsec tunnel, tell the
1444			 * originator the tunnel MTU.
1445			 *	tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1446			 * XXX quickhack!!!
1447			 */
1448
1449			struct secpolicy *sp;
1450			int ipsecerror;
1451			size_t ipsechdr;
1452			struct route *ro;
1453
1454			sp = ipsec4_getpolicybyaddr(mcopy,
1455			    IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1456			    &ipsecerror);
1457
1458			if (sp != NULL) {
1459				/* count IPsec header size */
1460				ipsechdr = ipsec4_hdrsiz(mcopy,
1461				    IPSEC_DIR_OUTBOUND, NULL);
1462
1463				/*
1464				 * find the correct route for outer IPv4
1465				 * header, compute tunnel MTU.
1466				 */
1467
1468				if (sp->req != NULL
1469				 && sp->req->sav != NULL
1470				 && sp->req->sav->sah != NULL) {
1471					ro = &sp->req->sav->sah->sa_route;
1472					rt = rtcache_validate(ro);
1473					if (rt && rt->rt_ifp) {
1474						destmtu =
1475						    rt->rt_rmx.rmx_mtu ?
1476						    rt->rt_rmx.rmx_mtu :
1477						    rt->rt_ifp->if_mtu;
1478						destmtu -= ipsechdr;
1479					}
1480				}
1481
1482#ifdef	IPSEC
1483				key_freesp(sp);
1484#else
1485				KEY_FREESP(&sp);
1486#endif
1487			}
1488		}
1489#endif /*defined(IPSEC) || defined(FAST_IPSEC)*/
1490		IP_STATINC(IP_STAT_CANTFRAG);
1491		break;
1492
1493	case ENOBUFS:
1494#if 1
1495		/*
1496		 * a router should not generate ICMP_SOURCEQUENCH as
1497		 * required in RFC1812 Requirements for IP Version 4 Routers.
1498		 * source quench could be a big problem under DoS attacks,
1499		 * or if the underlying interface is rate-limited.
1500		 */
1501		if (mcopy)
1502			m_freem(mcopy);
1503		return;
1504#else
1505		type = ICMP_SOURCEQUENCH;
1506		code = 0;
1507		break;
1508#endif
1509	}
1510	icmp_error(mcopy, type, code, dest, destmtu);
1511}
1512
1513void
1514ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1515    struct mbuf *m)
1516{
1517
1518	if (inp->inp_socket->so_options & SO_TIMESTAMP
1519#ifdef SO_OTIMESTAMP
1520	    || inp->inp_socket->so_options & SO_OTIMESTAMP
1521#endif
1522	    ) {
1523		struct timeval tv;
1524
1525		microtime(&tv);
1526#ifdef SO_OTIMESTAMP
1527		if (inp->inp_socket->so_options & SO_OTIMESTAMP) {
1528			struct timeval50 tv50;
1529			timeval_to_timeval50(&tv, &tv50);
1530			*mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
1531			    SCM_OTIMESTAMP, SOL_SOCKET);
1532		} else
1533#endif
1534		*mp = sbcreatecontrol((void *) &tv, sizeof(tv),
1535		    SCM_TIMESTAMP, SOL_SOCKET);
1536		if (*mp)
1537			mp = &(*mp)->m_next;
1538	}
1539	if (inp->inp_flags & INP_RECVDSTADDR) {
1540		*mp = sbcreatecontrol((void *) &ip->ip_dst,
1541		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1542		if (*mp)
1543			mp = &(*mp)->m_next;
1544	}
1545#ifdef notyet
1546	/*
1547	 * XXX
1548	 * Moving these out of udp_input() made them even more broken
1549	 * than they already were.
1550	 *	- fenner@parc.xerox.com
1551	 */
1552	/* options were tossed already */
1553	if (inp->inp_flags & INP_RECVOPTS) {
1554		*mp = sbcreatecontrol((void *) opts_deleted_above,
1555		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1556		if (*mp)
1557			mp = &(*mp)->m_next;
1558	}
1559	/* ip_srcroute doesn't do what we want here, need to fix */
1560	if (inp->inp_flags & INP_RECVRETOPTS) {
1561		*mp = sbcreatecontrol((void *) ip_srcroute(),
1562		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1563		if (*mp)
1564			mp = &(*mp)->m_next;
1565	}
1566#endif
1567	if (inp->inp_flags & INP_RECVIF) {
1568		struct sockaddr_dl sdl;
1569
1570		sockaddr_dl_init(&sdl, sizeof(sdl),
1571		    (m->m_pkthdr.rcvif != NULL)
1572		        ?  m->m_pkthdr.rcvif->if_index
1573			: 0,
1574			0, NULL, 0, NULL, 0);
1575		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1576		if (*mp)
1577			mp = &(*mp)->m_next;
1578	}
1579	if (inp->inp_flags & INP_RECVTTL) {
1580		*mp = sbcreatecontrol((void *) &ip->ip_ttl,
1581		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1582		if (*mp)
1583			mp = &(*mp)->m_next;
1584	}
1585}
1586
1587/*
1588 * sysctl helper routine for net.inet.ip.forwsrcrt.
1589 */
1590static int
1591sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1592{
1593	int error, tmp;
1594	struct sysctlnode node;
1595
1596	node = *rnode;
1597	tmp = ip_forwsrcrt;
1598	node.sysctl_data = &tmp;
1599	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1600	if (error || newp == NULL)
1601		return (error);
1602
1603	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1604	    0, NULL, NULL, NULL);
1605	if (error)
1606		return (error);
1607
1608	ip_forwsrcrt = tmp;
1609
1610	return (0);
1611}
1612
1613/*
1614 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1615 * range of the new value and tweaks timers if it changes.
1616 */
1617static int
1618sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1619{
1620	int error, tmp;
1621	struct sysctlnode node;
1622
1623	node = *rnode;
1624	tmp = ip_mtudisc_timeout;
1625	node.sysctl_data = &tmp;
1626	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1627	if (error || newp == NULL)
1628		return (error);
1629	if (tmp < 0)
1630		return (EINVAL);
1631
1632	mutex_enter(softnet_lock);
1633
1634	ip_mtudisc_timeout = tmp;
1635	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1636
1637	mutex_exit(softnet_lock);
1638
1639	return (0);
1640}
1641
1642#ifdef GATEWAY
1643/*
1644 * sysctl helper routine for net.inet.ip.maxflows.
1645 */
1646static int
1647sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
1648{
1649	int error;
1650
1651	error = sysctl_lookup(SYSCTLFN_CALL(rnode));
1652	if (error || newp == NULL)
1653		return (error);
1654
1655	mutex_enter(softnet_lock);
1656	KERNEL_LOCK(1, NULL);
1657
1658	ipflow_prune();
1659
1660	KERNEL_UNLOCK_ONE(NULL);
1661	mutex_exit(softnet_lock);
1662
1663	return (0);
1664}
1665
1666static int
1667sysctl_net_inet_ip_hashsize(SYSCTLFN_ARGS)
1668{
1669	int error, tmp;
1670	struct sysctlnode node;
1671
1672	node = *rnode;
1673	tmp = ip_hashsize;
1674	node.sysctl_data = &tmp;
1675	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1676	if (error || newp == NULL)
1677		return (error);
1678
1679	if ((tmp & (tmp - 1)) == 0 && tmp != 0) {
1680		/*
1681		 * Can only fail due to malloc()
1682		 */
1683		mutex_enter(softnet_lock);
1684		KERNEL_LOCK(1, NULL);
1685
1686		error = ipflow_invalidate_all(tmp);
1687
1688		KERNEL_UNLOCK_ONE(NULL);
1689		mutex_exit(softnet_lock);
1690
1691	} else {
1692		/*
1693		 * EINVAL if not a power of 2
1694	         */
1695		error = EINVAL;
1696	}
1697
1698	return error;
1699}
1700#endif /* GATEWAY */
1701
1702static int
1703sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1704{
1705
1706	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1707}
1708
1709static void
1710sysctl_net_inet_ip_setup(struct sysctllog **clog)
1711{
1712	extern int subnetsarelocal, hostzeroisbroadcast;
1713
1714	sysctl_createv(clog, 0, NULL, NULL,
1715		       CTLFLAG_PERMANENT,
1716		       CTLTYPE_NODE, "net", NULL,
1717		       NULL, 0, NULL, 0,
1718		       CTL_NET, CTL_EOL);
1719	sysctl_createv(clog, 0, NULL, NULL,
1720		       CTLFLAG_PERMANENT,
1721		       CTLTYPE_NODE, "inet",
1722		       SYSCTL_DESCR("PF_INET related settings"),
1723		       NULL, 0, NULL, 0,
1724		       CTL_NET, PF_INET, CTL_EOL);
1725	sysctl_createv(clog, 0, NULL, NULL,
1726		       CTLFLAG_PERMANENT,
1727		       CTLTYPE_NODE, "ip",
1728		       SYSCTL_DESCR("IPv4 related settings"),
1729		       NULL, 0, NULL, 0,
1730		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1731
1732	sysctl_createv(clog, 0, NULL, NULL,
1733		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1734		       CTLTYPE_INT, "forwarding",
1735		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1736		       NULL, 0, &ipforwarding, 0,
1737		       CTL_NET, PF_INET, IPPROTO_IP,
1738		       IPCTL_FORWARDING, CTL_EOL);
1739	sysctl_createv(clog, 0, NULL, NULL,
1740		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1741		       CTLTYPE_INT, "redirect",
1742		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1743		       NULL, 0, &ipsendredirects, 0,
1744		       CTL_NET, PF_INET, IPPROTO_IP,
1745		       IPCTL_SENDREDIRECTS, CTL_EOL);
1746	sysctl_createv(clog, 0, NULL, NULL,
1747		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1748		       CTLTYPE_INT, "ttl",
1749		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1750		       NULL, 0, &ip_defttl, 0,
1751		       CTL_NET, PF_INET, IPPROTO_IP,
1752		       IPCTL_DEFTTL, CTL_EOL);
1753#ifdef IPCTL_DEFMTU
1754	sysctl_createv(clog, 0, NULL, NULL,
1755		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1756		       CTLTYPE_INT, "mtu",
1757		       SYSCTL_DESCR("Default MTA for an INET route"),
1758		       NULL, 0, &ip_mtu, 0,
1759		       CTL_NET, PF_INET, IPPROTO_IP,
1760		       IPCTL_DEFMTU, CTL_EOL);
1761#endif /* IPCTL_DEFMTU */
1762	sysctl_createv(clog, 0, NULL, NULL,
1763		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1764		       CTLTYPE_INT, "forwsrcrt",
1765		       SYSCTL_DESCR("Enable forwarding of source-routed "
1766				    "datagrams"),
1767		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1768		       CTL_NET, PF_INET, IPPROTO_IP,
1769		       IPCTL_FORWSRCRT, CTL_EOL);
1770	sysctl_createv(clog, 0, NULL, NULL,
1771		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1772		       CTLTYPE_INT, "directed-broadcast",
1773		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1774		       NULL, 0, &ip_directedbcast, 0,
1775		       CTL_NET, PF_INET, IPPROTO_IP,
1776		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1777	sysctl_createv(clog, 0, NULL, NULL,
1778		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1779		       CTLTYPE_INT, "allowsrcrt",
1780		       SYSCTL_DESCR("Accept source-routed datagrams"),
1781		       NULL, 0, &ip_allowsrcrt, 0,
1782		       CTL_NET, PF_INET, IPPROTO_IP,
1783		       IPCTL_ALLOWSRCRT, CTL_EOL);
1784	sysctl_createv(clog, 0, NULL, NULL,
1785		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1786		       CTLTYPE_INT, "subnetsarelocal",
1787		       SYSCTL_DESCR("Whether logical subnets are considered "
1788				    "local"),
1789		       NULL, 0, &subnetsarelocal, 0,
1790		       CTL_NET, PF_INET, IPPROTO_IP,
1791		       IPCTL_SUBNETSARELOCAL, CTL_EOL);
1792	sysctl_createv(clog, 0, NULL, NULL,
1793		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1794		       CTLTYPE_INT, "mtudisc",
1795		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1796		       NULL, 0, &ip_mtudisc, 0,
1797		       CTL_NET, PF_INET, IPPROTO_IP,
1798		       IPCTL_MTUDISC, CTL_EOL);
1799	sysctl_createv(clog, 0, NULL, NULL,
1800		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1801		       CTLTYPE_INT, "anonportmin",
1802		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1803		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1804		       CTL_NET, PF_INET, IPPROTO_IP,
1805		       IPCTL_ANONPORTMIN, CTL_EOL);
1806	sysctl_createv(clog, 0, NULL, NULL,
1807		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1808		       CTLTYPE_INT, "anonportmax",
1809		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1810		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1811		       CTL_NET, PF_INET, IPPROTO_IP,
1812		       IPCTL_ANONPORTMAX, CTL_EOL);
1813	sysctl_createv(clog, 0, NULL, NULL,
1814		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1815		       CTLTYPE_INT, "mtudisctimeout",
1816		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1817		       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
1818		       CTL_NET, PF_INET, IPPROTO_IP,
1819		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1820#ifdef GATEWAY
1821	sysctl_createv(clog, 0, NULL, NULL,
1822		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1823		       CTLTYPE_INT, "maxflows",
1824		       SYSCTL_DESCR("Number of flows for fast forwarding"),
1825		       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
1826		       CTL_NET, PF_INET, IPPROTO_IP,
1827		       IPCTL_MAXFLOWS, CTL_EOL);
1828	sysctl_createv(clog, 0, NULL, NULL,
1829			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1830			CTLTYPE_INT, "hashsize",
1831			SYSCTL_DESCR("Size of hash table for fast forwarding (IPv4)"),
1832			sysctl_net_inet_ip_hashsize, 0, &ip_hashsize, 0,
1833			CTL_NET, PF_INET, IPPROTO_IP,
1834			CTL_CREATE, CTL_EOL);
1835#endif /* GATEWAY */
1836	sysctl_createv(clog, 0, NULL, NULL,
1837		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1838		       CTLTYPE_INT, "hostzerobroadcast",
1839		       SYSCTL_DESCR("All zeroes address is broadcast address"),
1840		       NULL, 0, &hostzeroisbroadcast, 0,
1841		       CTL_NET, PF_INET, IPPROTO_IP,
1842		       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
1843#if NGIF > 0
1844	sysctl_createv(clog, 0, NULL, NULL,
1845		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1846		       CTLTYPE_INT, "gifttl",
1847		       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
1848		       NULL, 0, &ip_gif_ttl, 0,
1849		       CTL_NET, PF_INET, IPPROTO_IP,
1850		       IPCTL_GIF_TTL, CTL_EOL);
1851#endif /* NGIF */
1852#ifndef IPNOPRIVPORTS
1853	sysctl_createv(clog, 0, NULL, NULL,
1854		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1855		       CTLTYPE_INT, "lowportmin",
1856		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1857				    "to assign"),
1858		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1859		       CTL_NET, PF_INET, IPPROTO_IP,
1860		       IPCTL_LOWPORTMIN, CTL_EOL);
1861	sysctl_createv(clog, 0, NULL, NULL,
1862		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1863		       CTLTYPE_INT, "lowportmax",
1864		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1865				    "to assign"),
1866		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1867		       CTL_NET, PF_INET, IPPROTO_IP,
1868		       IPCTL_LOWPORTMAX, CTL_EOL);
1869#endif /* IPNOPRIVPORTS */
1870#if NGRE > 0
1871	sysctl_createv(clog, 0, NULL, NULL,
1872		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1873		       CTLTYPE_INT, "grettl",
1874		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1875		       NULL, 0, &ip_gre_ttl, 0,
1876		       CTL_NET, PF_INET, IPPROTO_IP,
1877		       IPCTL_GRE_TTL, CTL_EOL);
1878#endif /* NGRE */
1879	sysctl_createv(clog, 0, NULL, NULL,
1880		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1881		       CTLTYPE_INT, "checkinterface",
1882		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1883				    "from RFC1122"),
1884		       NULL, 0, &ip_checkinterface, 0,
1885		       CTL_NET, PF_INET, IPPROTO_IP,
1886		       IPCTL_CHECKINTERFACE, CTL_EOL);
1887	sysctl_createv(clog, 0, NULL, NULL,
1888		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1889		       CTLTYPE_INT, "random_id",
1890		       SYSCTL_DESCR("Assign random ip_id values"),
1891		       NULL, 0, &ip_do_randomid, 0,
1892		       CTL_NET, PF_INET, IPPROTO_IP,
1893		       IPCTL_RANDOMID, CTL_EOL);
1894	sysctl_createv(clog, 0, NULL, NULL,
1895		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1896		       CTLTYPE_INT, "do_loopback_cksum",
1897		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1898		       NULL, 0, &ip_do_loopback_cksum, 0,
1899		       CTL_NET, PF_INET, IPPROTO_IP,
1900		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1901	sysctl_createv(clog, 0, NULL, NULL,
1902		       CTLFLAG_PERMANENT,
1903		       CTLTYPE_STRUCT, "stats",
1904		       SYSCTL_DESCR("IP statistics"),
1905		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1906		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1907		       CTL_EOL);
1908}
1909
1910void
1911ip_statinc(u_int stat)
1912{
1913
1914	KASSERT(stat < IP_NSTATS);
1915	IP_STATINC(stat);
1916}
1917