ip_input.c revision 1.299
1/*	$NetBSD: ip_input.c,v 1.299 2012/03/22 20:34:39 drochner 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 1.299 2012/03/22 20:34:39 drochner 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 FAST_IPSEC
144#include <netipsec/ipsec.h>
145#include <netipsec/key.h>
146#endif	/* FAST_IPSEC*/
147
148#ifndef	IPFORWARDING
149#ifdef GATEWAY
150#define	IPFORWARDING	1	/* forward IP packets not for us */
151#else /* GATEWAY */
152#define	IPFORWARDING	0	/* don't forward IP packets not for us */
153#endif /* GATEWAY */
154#endif /* IPFORWARDING */
155#ifndef	IPSENDREDIRECTS
156#define	IPSENDREDIRECTS	1
157#endif
158#ifndef IPFORWSRCRT
159#define	IPFORWSRCRT	1	/* forward source-routed packets */
160#endif
161#ifndef IPALLOWSRCRT
162#define	IPALLOWSRCRT	1	/* allow source-routed packets */
163#endif
164#ifndef IPMTUDISC
165#define IPMTUDISC	1
166#endif
167#ifndef IPMTUDISCTIMEOUT
168#define IPMTUDISCTIMEOUT (10 * 60)	/* as per RFC 1191 */
169#endif
170
171#ifdef COMPAT_50
172#include <compat/sys/time.h>
173#include <compat/sys/socket.h>
174#endif
175
176/*
177 * Note: DIRECTED_BROADCAST is handled this way so that previous
178 * configuration using this option will Just Work.
179 */
180#ifndef IPDIRECTEDBCAST
181#ifdef DIRECTED_BROADCAST
182#define IPDIRECTEDBCAST	1
183#else
184#define	IPDIRECTEDBCAST	0
185#endif /* DIRECTED_BROADCAST */
186#endif /* IPDIRECTEDBCAST */
187int	ipforwarding = IPFORWARDING;
188int	ipsendredirects = IPSENDREDIRECTS;
189int	ip_defttl = IPDEFTTL;
190int	ip_forwsrcrt = IPFORWSRCRT;
191int	ip_directedbcast = IPDIRECTEDBCAST;
192int	ip_allowsrcrt = IPALLOWSRCRT;
193int	ip_mtudisc = IPMTUDISC;
194int	ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
195#ifdef DIAGNOSTIC
196int	ipprintfs = 0;
197#endif
198
199int	ip_do_randomid = 0;
200
201/*
202 * XXX - Setting ip_checkinterface mostly implements the receive side of
203 * the Strong ES model described in RFC 1122, but since the routing table
204 * and transmit implementation do not implement the Strong ES model,
205 * setting this to 1 results in an odd hybrid.
206 *
207 * XXX - ip_checkinterface currently must be disabled if you use ipnat
208 * to translate the destination address to another local interface.
209 *
210 * XXX - ip_checkinterface must be disabled if you add IP aliases
211 * to the loopback interface instead of the interface where the
212 * packets for those addresses are received.
213 */
214int	ip_checkinterface = 0;
215
216
217struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
218
219u_long	in_ifaddrhash;				/* size of hash table - 1 */
220int	in_ifaddrentries;			/* total number of addrs */
221struct in_ifaddrhead in_ifaddrhead;
222struct	in_ifaddrhashhead *in_ifaddrhashtbl;
223u_long	in_multihash;				/* size of hash table - 1 */
224int	in_multientries;			/* total number of addrs */
225struct	in_multihashhead *in_multihashtbl;
226struct	ifqueue ipintrq;
227
228ipid_state_t *		ip_ids;
229uint16_t ip_id;
230
231percpu_t *ipstat_percpu;
232
233#ifdef PFIL_HOOKS
234struct pfil_head inet_pfil_hook;
235#endif
236
237struct pool inmulti_pool;
238
239#ifdef INET_CSUM_COUNTERS
240#include <sys/device.h>
241
242struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
243    NULL, "inet", "hwcsum bad");
244struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
245    NULL, "inet", "hwcsum ok");
246struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
247    NULL, "inet", "swcsum");
248
249#define	INET_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
250
251EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
252EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
253EVCNT_ATTACH_STATIC(ip_swcsum);
254
255#else
256
257#define	INET_CSUM_COUNTER_INCR(ev)	/* nothing */
258
259#endif /* INET_CSUM_COUNTERS */
260
261/*
262 * We need to save the IP options in case a protocol wants to respond
263 * to an incoming packet over the same route if the packet got here
264 * using IP source routing.  This allows connection establishment and
265 * maintenance when the remote end is on a network that is not known
266 * to us.
267 */
268int	ip_nhops = 0;
269static	struct ip_srcrt {
270	struct	in_addr dst;			/* final destination */
271	char	nop;				/* one NOP to align */
272	char	srcopt[IPOPT_OFFSET + 1];	/* OPTVAL, OLEN and OFFSET */
273	struct	in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
274} ip_srcrt;
275
276static int ip_drainwanted;
277
278static void save_rte(u_char *, struct in_addr);
279
280#ifdef MBUFTRACE
281struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
282struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
283#endif
284
285static void sysctl_net_inet_ip_setup(struct sysctllog **);
286
287/*
288 * IP initialization: fill in IP protocol switch table.
289 * All protocols not implemented in kernel go to raw IP protocol handler.
290 */
291void
292ip_init(void)
293{
294	const struct protosw *pr;
295	int i;
296
297	sysctl_net_inet_ip_setup(NULL);
298
299	pool_init(&inmulti_pool, sizeof(struct in_multi), 0, 0, 0, "inmltpl",
300	    NULL, IPL_SOFTNET);
301
302	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
303	if (pr == 0)
304		panic("ip_init");
305	for (i = 0; i < IPPROTO_MAX; i++)
306		ip_protox[i] = pr - inetsw;
307	for (pr = inetdomain.dom_protosw;
308	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
309		if (pr->pr_domain->dom_family == PF_INET &&
310		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
311			ip_protox[pr->pr_protocol] = pr - inetsw;
312
313	ip_reass_init();
314
315	ip_ids = ip_id_init();
316	ip_id = time_second & 0xfffff;
317
318	ipintrq.ifq_maxlen = IFQ_MAXLEN;
319
320	TAILQ_INIT(&in_ifaddrhead);
321	in_ifaddrhashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, true,
322	    &in_ifaddrhash);
323	in_multihashtbl = hashinit(IN_IFADDR_HASH_SIZE, HASH_LIST, true,
324	    &in_multihash);
325	ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
326#ifdef GATEWAY
327	ipflow_init(ip_hashsize);
328#endif
329
330#ifdef PFIL_HOOKS
331	/* Register our Packet Filter hook. */
332	inet_pfil_hook.ph_type = PFIL_TYPE_AF;
333	inet_pfil_hook.ph_af   = AF_INET;
334	i = pfil_head_register(&inet_pfil_hook);
335	if (i != 0)
336		printf("ip_init: WARNING: unable to register pfil hook, "
337		    "error %d\n", i);
338#endif /* PFIL_HOOKS */
339
340#ifdef MBUFTRACE
341	MOWNER_ATTACH(&ip_tx_mowner);
342	MOWNER_ATTACH(&ip_rx_mowner);
343#endif /* MBUFTRACE */
344
345	ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
346}
347
348struct	sockaddr_in ipaddr = {
349	.sin_len = sizeof(ipaddr),
350	.sin_family = AF_INET,
351};
352struct	route ipforward_rt;
353
354/*
355 * IP software interrupt routine
356 */
357void
358ipintr(void)
359{
360	int s;
361	struct mbuf *m;
362	struct ifqueue lcl_intrq;
363
364	memset(&lcl_intrq, 0, sizeof(lcl_intrq));
365
366	mutex_enter(softnet_lock);
367	KERNEL_LOCK(1, NULL);
368	if (!IF_IS_EMPTY(&ipintrq)) {
369		s = splnet();
370
371		/* Take existing queue onto stack */
372		lcl_intrq = ipintrq;
373
374		/* Zero out global queue, preserving maxlen and drops */
375		ipintrq.ifq_head = NULL;
376		ipintrq.ifq_tail = NULL;
377		ipintrq.ifq_len = 0;
378		ipintrq.ifq_maxlen = lcl_intrq.ifq_maxlen;
379		ipintrq.ifq_drops = lcl_intrq.ifq_drops;
380
381		splx(s);
382	}
383	KERNEL_UNLOCK_ONE(NULL);
384	while (!IF_IS_EMPTY(&lcl_intrq)) {
385		IF_DEQUEUE(&lcl_intrq, m);
386		if (m == NULL)
387			break;
388		ip_input(m);
389	}
390	mutex_exit(softnet_lock);
391}
392
393/*
394 * Ip input routine.  Checksum and byte swap header.  If fragmented
395 * try to reassemble.  Process options.  Pass to next level.
396 */
397void
398ip_input(struct mbuf *m)
399{
400	struct ip *ip = NULL;
401	struct in_ifaddr *ia;
402	struct ifaddr *ifa;
403	int hlen = 0, len;
404	int downmatch;
405	int checkif;
406	int srcrt = 0;
407#ifdef FAST_IPSEC
408	struct m_tag *mtag;
409	struct tdb_ident *tdbi;
410	struct secpolicy *sp;
411	int error, s;
412#endif /* FAST_IPSEC */
413
414	MCLAIM(m, &ip_rx_mowner);
415	KASSERT((m->m_flags & M_PKTHDR) != 0);
416
417	/*
418	 * If no IP addresses have been set yet but the interfaces
419	 * are receiving, can't do anything with incoming packets yet.
420	 */
421	if (TAILQ_FIRST(&in_ifaddrhead) == 0)
422		goto bad;
423	IP_STATINC(IP_STAT_TOTAL);
424	/*
425	 * If the IP header is not aligned, slurp it up into a new
426	 * mbuf with space for link headers, in the event we forward
427	 * it.  Otherwise, if it is aligned, make sure the entire
428	 * base IP header is in the first mbuf of the chain.
429	 */
430	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
431		if ((m = m_copyup(m, sizeof(struct ip),
432				  (max_linkhdr + 3) & ~3)) == NULL) {
433			/* XXXJRT new stat, please */
434			IP_STATINC(IP_STAT_TOOSMALL);
435			return;
436		}
437	} else if (__predict_false(m->m_len < sizeof (struct ip))) {
438		if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
439			IP_STATINC(IP_STAT_TOOSMALL);
440			return;
441		}
442	}
443	ip = mtod(m, struct ip *);
444	if (ip->ip_v != IPVERSION) {
445		IP_STATINC(IP_STAT_BADVERS);
446		goto bad;
447	}
448	hlen = ip->ip_hl << 2;
449	if (hlen < sizeof(struct ip)) {	/* minimum header length */
450		IP_STATINC(IP_STAT_BADHLEN);
451		goto bad;
452	}
453	if (hlen > m->m_len) {
454		if ((m = m_pullup(m, hlen)) == NULL) {
455			IP_STATINC(IP_STAT_BADHLEN);
456			return;
457		}
458		ip = mtod(m, struct ip *);
459	}
460
461	/*
462	 * RFC1122: packets with a multicast source address are
463	 * not allowed.
464	 */
465	if (IN_MULTICAST(ip->ip_src.s_addr)) {
466		IP_STATINC(IP_STAT_BADADDR);
467		goto bad;
468	}
469
470	/* 127/8 must not appear on wire - RFC1122 */
471	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
472	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
473		if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
474			IP_STATINC(IP_STAT_BADADDR);
475			goto bad;
476		}
477	}
478
479	switch (m->m_pkthdr.csum_flags &
480		((m->m_pkthdr.rcvif->if_csum_flags_rx & M_CSUM_IPv4) |
481		 M_CSUM_IPv4_BAD)) {
482	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
483		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
484		goto badcsum;
485
486	case M_CSUM_IPv4:
487		/* Checksum was okay. */
488		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
489		break;
490
491	default:
492		/*
493		 * Must compute it ourselves.  Maybe skip checksum on
494		 * loopback interfaces.
495		 */
496		if (__predict_true(!(m->m_pkthdr.rcvif->if_flags &
497				     IFF_LOOPBACK) || ip_do_loopback_cksum)) {
498			INET_CSUM_COUNTER_INCR(&ip_swcsum);
499			if (in_cksum(m, hlen) != 0)
500				goto badcsum;
501		}
502		break;
503	}
504
505	/* Retrieve the packet length. */
506	len = ntohs(ip->ip_len);
507
508	/*
509	 * Check for additional length bogosity
510	 */
511	if (len < hlen) {
512		IP_STATINC(IP_STAT_BADLEN);
513		goto bad;
514	}
515
516	/*
517	 * Check that the amount of data in the buffers
518	 * is as at least much as the IP header would have us expect.
519	 * Trim mbufs if longer than we expect.
520	 * Drop packet if shorter than we expect.
521	 */
522	if (m->m_pkthdr.len < len) {
523		IP_STATINC(IP_STAT_TOOSHORT);
524		goto bad;
525	}
526	if (m->m_pkthdr.len > len) {
527		if (m->m_len == m->m_pkthdr.len) {
528			m->m_len = len;
529			m->m_pkthdr.len = len;
530		} else
531			m_adj(m, len - m->m_pkthdr.len);
532	}
533
534	/*
535	 * Assume that we can create a fast-forward IP flow entry
536	 * based on this packet.
537	 */
538	m->m_flags |= M_CANFASTFWD;
539
540#ifdef PFIL_HOOKS
541	/*
542	 * Run through list of hooks for input packets.  If there are any
543	 * filters which require that additional packets in the flow are
544	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
545	 * Note that filters must _never_ set this flag, as another filter
546	 * in the list may have previously cleared it.
547	 */
548	/*
549	 * let ipfilter look at packet on the wire,
550	 * not the decapsulated packet.
551	 */
552#if defined(FAST_IPSEC)
553	if (!ipsec_indone(m))
554#else
555	if (1)
556#endif
557	{
558		struct in_addr odst;
559
560		odst = ip->ip_dst;
561		if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
562		    PFIL_IN) != 0)
563			return;
564		if (m == NULL)
565			return;
566		ip = mtod(m, struct ip *);
567		hlen = ip->ip_hl << 2;
568		/*
569		 * XXX The setting of "srcrt" here is to prevent ip_forward()
570		 * from generating ICMP redirects for packets that have
571		 * been redirected by a hook back out on to the same LAN that
572		 * they came from and is not an indication that the packet
573		 * is being inffluenced by source routing options.  This
574		 * allows things like
575		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
576		 * where tlp0 is both on the 1.1.1.0/24 network and is the
577		 * default route for hosts on 1.1.1.0/24.  Of course this
578		 * also requires a "map tlp0 ..." to complete the story.
579		 * One might argue whether or not this kind of network config.
580		 * should be supported in this manner...
581		 */
582		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
583	}
584#endif /* PFIL_HOOKS */
585
586#ifdef ALTQ
587	/* XXX Temporary until ALTQ is changed to use a pfil hook */
588	if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0) {
589		/* packet dropped by traffic conditioner */
590		return;
591	}
592#endif
593
594	/*
595	 * Process options and, if not destined for us,
596	 * ship it on.  ip_dooptions returns 1 when an
597	 * error was detected (causing an icmp message
598	 * to be sent and the original packet to be freed).
599	 */
600	ip_nhops = 0;		/* for source routed packets */
601	if (hlen > sizeof (struct ip) && ip_dooptions(m))
602		return;
603
604	/*
605	 * Enable a consistency check between the destination address
606	 * and the arrival interface for a unicast packet (the RFC 1122
607	 * strong ES model) if IP forwarding is disabled and the packet
608	 * is not locally generated.
609	 *
610	 * XXX - Checking also should be disabled if the destination
611	 * address is ipnat'ed to a different interface.
612	 *
613	 * XXX - Checking is incompatible with IP aliases added
614	 * to the loopback interface instead of the interface where
615	 * the packets are received.
616	 *
617	 * XXX - We need to add a per ifaddr flag for this so that
618	 * we get finer grain control.
619	 */
620	checkif = ip_checkinterface && (ipforwarding == 0) &&
621	    (m->m_pkthdr.rcvif != NULL) &&
622	    ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0);
623
624	/*
625	 * Check our list of addresses, to see if the packet is for us.
626	 *
627	 * Traditional 4.4BSD did not consult IFF_UP at all.
628	 * The behavior here is to treat addresses on !IFF_UP interface
629	 * as not mine.
630	 */
631	downmatch = 0;
632	LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
633		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
634			if (checkif && ia->ia_ifp != m->m_pkthdr.rcvif)
635				continue;
636			if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
637				break;
638			else
639				downmatch++;
640		}
641	}
642	if (ia != NULL)
643		goto ours;
644	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
645		IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) {
646			if (ifa->ifa_addr->sa_family != AF_INET)
647				continue;
648			ia = ifatoia(ifa);
649			if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
650			    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
651			    /*
652			     * Look for all-0's host part (old broadcast addr),
653			     * either for subnet or net.
654			     */
655			    ip->ip_dst.s_addr == ia->ia_subnet ||
656			    ip->ip_dst.s_addr == ia->ia_net)
657				goto ours;
658			/*
659			 * An interface with IP address zero accepts
660			 * all packets that arrive on that interface.
661			 */
662			if (in_nullhost(ia->ia_addr.sin_addr))
663				goto ours;
664		}
665	}
666	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
667		struct in_multi *inm;
668#ifdef MROUTING
669		extern struct socket *ip_mrouter;
670
671		if (ip_mrouter) {
672			/*
673			 * If we are acting as a multicast router, all
674			 * incoming multicast packets are passed to the
675			 * kernel-level multicast forwarding function.
676			 * The packet is returned (relatively) intact; if
677			 * ip_mforward() returns a non-zero value, the packet
678			 * must be discarded, else it may be accepted below.
679			 *
680			 * (The IP ident field is put in the same byte order
681			 * as expected when ip_mforward() is called from
682			 * ip_output().)
683			 */
684			if (ip_mforward(m, m->m_pkthdr.rcvif) != 0) {
685				IP_STATINC(IP_STAT_CANTFORWARD);
686				m_freem(m);
687				return;
688			}
689
690			/*
691			 * The process-level routing demon needs to receive
692			 * all multicast IGMP packets, whether or not this
693			 * host belongs to their destination groups.
694			 */
695			if (ip->ip_p == IPPROTO_IGMP)
696				goto ours;
697			IP_STATINC(IP_STAT_CANTFORWARD);
698		}
699#endif
700		/*
701		 * See if we belong to the destination multicast group on the
702		 * arrival interface.
703		 */
704		IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
705		if (inm == NULL) {
706			IP_STATINC(IP_STAT_CANTFORWARD);
707			m_freem(m);
708			return;
709		}
710		goto ours;
711	}
712	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
713	    in_nullhost(ip->ip_dst))
714		goto ours;
715
716	/*
717	 * Not for us; forward if possible and desirable.
718	 */
719	if (ipforwarding == 0) {
720		IP_STATINC(IP_STAT_CANTFORWARD);
721		m_freem(m);
722	} else {
723		/*
724		 * If ip_dst matched any of my address on !IFF_UP interface,
725		 * and there's no IFF_UP interface that matches ip_dst,
726		 * send icmp unreach.  Forwarding it will result in in-kernel
727		 * forwarding loop till TTL goes to 0.
728		 */
729		if (downmatch) {
730			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
731			IP_STATINC(IP_STAT_CANTFORWARD);
732			return;
733		}
734#ifdef FAST_IPSEC
735		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
736		s = splsoftnet();
737		if (mtag != NULL) {
738			tdbi = (struct tdb_ident *)(mtag + 1);
739			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
740		} else {
741			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
742						   IP_FORWARDING, &error);
743		}
744		if (sp == NULL) {	/* NB: can happen if error */
745			splx(s);
746			/*XXX error stat???*/
747			DPRINTF(("ip_input: no SP for forwarding\n"));	/*XXX*/
748			goto bad;
749		}
750
751		/*
752		 * Check security policy against packet attributes.
753		 */
754		error = ipsec_in_reject(sp, m);
755		KEY_FREESP(&sp);
756		splx(s);
757		if (error) {
758			IP_STATINC(IP_STAT_CANTFORWARD);
759			goto bad;
760		}
761
762		/*
763		 * Peek at the outbound SP for this packet to determine if
764		 * it's a Fast Forward candidate.
765		 */
766		mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
767		if (mtag != NULL)
768			m->m_flags &= ~M_CANFASTFWD;
769		else {
770			s = splsoftnet();
771			sp = ipsec4_checkpolicy(m, IPSEC_DIR_OUTBOUND,
772			    (IP_FORWARDING |
773			     (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
774			    &error, NULL);
775			if (sp != NULL) {
776				m->m_flags &= ~M_CANFASTFWD;
777				KEY_FREESP(&sp);
778			}
779			splx(s);
780		}
781#endif	/* FAST_IPSEC */
782
783		ip_forward(m, srcrt);
784	}
785	return;
786
787ours:
788	/*
789	 * If offset or IP_MF are set, must reassemble.
790	 */
791	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
792		/*
793		 * Pass to IP reassembly mechanism.
794		 */
795		if (ip_reass_packet(&m, ip) != 0) {
796			/* Failed; invalid fragment(s) or packet. */
797			goto bad;
798		}
799		if (m == NULL) {
800			/* More fragments should come; silently return. */
801			return;
802		}
803		/*
804		 * Reassembly is done, we have the final packet.
805		 * Updated cached data in local variable(s).
806		 */
807		ip = mtod(m, struct ip *);
808		hlen = ip->ip_hl << 2;
809	}
810
811#ifdef FAST_IPSEC
812	/*
813	 * enforce IPsec policy checking if we are seeing last header.
814	 * note that we do not visit this with protocols with pcb layer
815	 * code - like udp/tcp/raw ip.
816	 */
817	if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
818		/*
819		 * Check if the packet has already had IPsec processing
820		 * done.  If so, then just pass it along.  This tag gets
821		 * set during AH, ESP, etc. input handling, before the
822		 * packet is returned to the ip input queue for delivery.
823		 */
824		mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
825		s = splsoftnet();
826		if (mtag != NULL) {
827			tdbi = (struct tdb_ident *)(mtag + 1);
828			sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
829		} else {
830			sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
831						   IP_FORWARDING, &error);
832		}
833		if (sp != NULL) {
834			/*
835			 * Check security policy against packet attributes.
836			 */
837			error = ipsec_in_reject(sp, m);
838			KEY_FREESP(&sp);
839		} else {
840			/* XXX error stat??? */
841			error = EINVAL;
842DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
843		}
844		splx(s);
845		if (error)
846			goto bad;
847	}
848#endif /* FAST_IPSEC */
849
850	/*
851	 * Switch out to protocol's input routine.
852	 */
853#if IFA_STATS
854	if (ia && ip)
855		ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
856#endif
857	IP_STATINC(IP_STAT_DELIVERED);
858    {
859	int off = hlen, nh = ip->ip_p;
860
861	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
862	return;
863    }
864bad:
865	m_freem(m);
866	return;
867
868badcsum:
869	IP_STATINC(IP_STAT_BADSUM);
870	m_freem(m);
871}
872
873/*
874 * IP timer processing.
875 */
876void
877ip_slowtimo(void)
878{
879
880	mutex_enter(softnet_lock);
881	KERNEL_LOCK(1, NULL);
882
883	ip_reass_slowtimo();
884
885	KERNEL_UNLOCK_ONE(NULL);
886	mutex_exit(softnet_lock);
887}
888
889/*
890 * IP drain processing.
891 */
892void
893ip_drain(void)
894{
895
896	KERNEL_LOCK(1, NULL);
897	ip_reass_drain();
898	KERNEL_UNLOCK_ONE(NULL);
899}
900
901/*
902 * Do option processing on a datagram,
903 * possibly discarding it if bad options are encountered,
904 * or forwarding it if source-routed.
905 * Returns 1 if packet has been forwarded/freed,
906 * 0 if the packet should be processed further.
907 */
908int
909ip_dooptions(struct mbuf *m)
910{
911	struct ip *ip = mtod(m, struct ip *);
912	u_char *cp, *cp0;
913	struct ip_timestamp *ipt;
914	struct in_ifaddr *ia;
915	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
916	struct in_addr dst;
917	n_time ntime;
918
919	dst = ip->ip_dst;
920	cp = (u_char *)(ip + 1);
921	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
922	for (; cnt > 0; cnt -= optlen, cp += optlen) {
923		opt = cp[IPOPT_OPTVAL];
924		if (opt == IPOPT_EOL)
925			break;
926		if (opt == IPOPT_NOP)
927			optlen = 1;
928		else {
929			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
930				code = &cp[IPOPT_OLEN] - (u_char *)ip;
931				goto bad;
932			}
933			optlen = cp[IPOPT_OLEN];
934			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
935				code = &cp[IPOPT_OLEN] - (u_char *)ip;
936				goto bad;
937			}
938		}
939		switch (opt) {
940
941		default:
942			break;
943
944		/*
945		 * Source routing with record.
946		 * Find interface with current destination address.
947		 * If none on this machine then drop if strictly routed,
948		 * or do nothing if loosely routed.
949		 * Record interface address and bring up next address
950		 * component.  If strictly routed make sure next
951		 * address is on directly accessible net.
952		 */
953		case IPOPT_LSRR:
954		case IPOPT_SSRR:
955			if (ip_allowsrcrt == 0) {
956				type = ICMP_UNREACH;
957				code = ICMP_UNREACH_NET_PROHIB;
958				goto bad;
959			}
960			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
961				code = &cp[IPOPT_OLEN] - (u_char *)ip;
962				goto bad;
963			}
964			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
965				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
966				goto bad;
967			}
968			ipaddr.sin_addr = ip->ip_dst;
969			ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)));
970			if (ia == 0) {
971				if (opt == IPOPT_SSRR) {
972					type = ICMP_UNREACH;
973					code = ICMP_UNREACH_SRCFAIL;
974					goto bad;
975				}
976				/*
977				 * Loose routing, and not at next destination
978				 * yet; nothing to do except forward.
979				 */
980				break;
981			}
982			off--;			/* 0 origin */
983			if ((off + sizeof(struct in_addr)) > optlen) {
984				/*
985				 * End of source route.  Should be for us.
986				 */
987				save_rte(cp, ip->ip_src);
988				break;
989			}
990			/*
991			 * locate outgoing interface
992			 */
993			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
994			    sizeof(ipaddr.sin_addr));
995			if (opt == IPOPT_SSRR)
996				ia = ifatoia(ifa_ifwithladdr(sintosa(&ipaddr)));
997			else
998				ia = ip_rtaddr(ipaddr.sin_addr);
999			if (ia == 0) {
1000				type = ICMP_UNREACH;
1001				code = ICMP_UNREACH_SRCFAIL;
1002				goto bad;
1003			}
1004			ip->ip_dst = ipaddr.sin_addr;
1005			bcopy((void *)&ia->ia_addr.sin_addr,
1006			    (void *)(cp + off), sizeof(struct in_addr));
1007			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1008			/*
1009			 * Let ip_intr's mcast routing check handle mcast pkts
1010			 */
1011			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1012			break;
1013
1014		case IPOPT_RR:
1015			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1016				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1017				goto bad;
1018			}
1019			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1020				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1021				goto bad;
1022			}
1023			/*
1024			 * If no space remains, ignore.
1025			 */
1026			off--;			/* 0 origin */
1027			if ((off + sizeof(struct in_addr)) > optlen)
1028				break;
1029			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1030			    sizeof(ipaddr.sin_addr));
1031			/*
1032			 * locate outgoing interface; if we're the destination,
1033			 * use the incoming interface (should be same).
1034			 */
1035			if ((ia = ifatoia(ifa_ifwithaddr(sintosa(&ipaddr))))
1036			    == NULL &&
1037			    (ia = ip_rtaddr(ipaddr.sin_addr)) == NULL) {
1038				type = ICMP_UNREACH;
1039				code = ICMP_UNREACH_HOST;
1040				goto bad;
1041			}
1042			bcopy((void *)&ia->ia_addr.sin_addr,
1043			    (void *)(cp + off), sizeof(struct in_addr));
1044			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1045			break;
1046
1047		case IPOPT_TS:
1048			code = cp - (u_char *)ip;
1049			ipt = (struct ip_timestamp *)cp;
1050			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1051				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1052				goto bad;
1053			}
1054			if (ipt->ipt_ptr < 5) {
1055				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1056				goto bad;
1057			}
1058			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1059				if (++ipt->ipt_oflw == 0) {
1060					code = (u_char *)&ipt->ipt_ptr -
1061					    (u_char *)ip;
1062					goto bad;
1063				}
1064				break;
1065			}
1066			cp0 = (cp + ipt->ipt_ptr - 1);
1067			switch (ipt->ipt_flg) {
1068
1069			case IPOPT_TS_TSONLY:
1070				break;
1071
1072			case IPOPT_TS_TSANDADDR:
1073				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1074				    sizeof(struct in_addr) > ipt->ipt_len) {
1075					code = (u_char *)&ipt->ipt_ptr -
1076					    (u_char *)ip;
1077					goto bad;
1078				}
1079				ipaddr.sin_addr = dst;
1080				ia = ifatoia(ifaof_ifpforaddr(sintosa(&ipaddr),
1081				    m->m_pkthdr.rcvif));
1082				if (ia == 0)
1083					continue;
1084				bcopy(&ia->ia_addr.sin_addr,
1085				    cp0, sizeof(struct in_addr));
1086				ipt->ipt_ptr += sizeof(struct in_addr);
1087				break;
1088
1089			case IPOPT_TS_PRESPEC:
1090				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1091				    sizeof(struct in_addr) > ipt->ipt_len) {
1092					code = (u_char *)&ipt->ipt_ptr -
1093					    (u_char *)ip;
1094					goto bad;
1095				}
1096				memcpy(&ipaddr.sin_addr, cp0,
1097				    sizeof(struct in_addr));
1098				if (ifatoia(ifa_ifwithaddr(sintosa(&ipaddr)))
1099				    == NULL)
1100					continue;
1101				ipt->ipt_ptr += sizeof(struct in_addr);
1102				break;
1103
1104			default:
1105				/* XXX can't take &ipt->ipt_flg */
1106				code = (u_char *)&ipt->ipt_ptr -
1107				    (u_char *)ip + 1;
1108				goto bad;
1109			}
1110			ntime = iptime();
1111			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1112			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1113			    sizeof(n_time));
1114			ipt->ipt_ptr += sizeof(n_time);
1115		}
1116	}
1117	if (forward) {
1118		if (ip_forwsrcrt == 0) {
1119			type = ICMP_UNREACH;
1120			code = ICMP_UNREACH_SRCFAIL;
1121			goto bad;
1122		}
1123		ip_forward(m, 1);
1124		return (1);
1125	}
1126	return (0);
1127bad:
1128	icmp_error(m, type, code, 0, 0);
1129	IP_STATINC(IP_STAT_BADOPTIONS);
1130	return (1);
1131}
1132
1133/*
1134 * Given address of next destination (final or next hop),
1135 * return internet address info of interface to be used to get there.
1136 */
1137struct in_ifaddr *
1138ip_rtaddr(struct in_addr dst)
1139{
1140	struct rtentry *rt;
1141	union {
1142		struct sockaddr		dst;
1143		struct sockaddr_in	dst4;
1144	} u;
1145
1146	sockaddr_in_init(&u.dst4, &dst, 0);
1147
1148	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL)
1149		return NULL;
1150
1151	return ifatoia(rt->rt_ifa);
1152}
1153
1154/*
1155 * Save incoming source route for use in replies,
1156 * to be picked up later by ip_srcroute if the receiver is interested.
1157 */
1158void
1159save_rte(u_char *option, struct in_addr dst)
1160{
1161	unsigned olen;
1162
1163	olen = option[IPOPT_OLEN];
1164#ifdef DIAGNOSTIC
1165	if (ipprintfs)
1166		printf("save_rte: olen %d\n", olen);
1167#endif /* 0 */
1168	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1169		return;
1170	memcpy((void *)ip_srcrt.srcopt, (void *)option, olen);
1171	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1172	ip_srcrt.dst = dst;
1173}
1174
1175/*
1176 * Retrieve incoming source route for use in replies,
1177 * in the same form used by setsockopt.
1178 * The first hop is placed before the options, will be removed later.
1179 */
1180struct mbuf *
1181ip_srcroute(void)
1182{
1183	struct in_addr *p, *q;
1184	struct mbuf *m;
1185
1186	if (ip_nhops == 0)
1187		return NULL;
1188	m = m_get(M_DONTWAIT, MT_SOOPTS);
1189	if (m == 0)
1190		return NULL;
1191
1192	MCLAIM(m, &inetdomain.dom_mowner);
1193#define OPTSIZ	(sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1194
1195	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
1196	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1197	    OPTSIZ;
1198#ifdef DIAGNOSTIC
1199	if (ipprintfs)
1200		printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1201#endif
1202
1203	/*
1204	 * First save first hop for return route
1205	 */
1206	p = &ip_srcrt.route[ip_nhops - 1];
1207	*(mtod(m, struct in_addr *)) = *p--;
1208#ifdef DIAGNOSTIC
1209	if (ipprintfs)
1210		printf(" hops %x", ntohl(mtod(m, struct in_addr *)->s_addr));
1211#endif
1212
1213	/*
1214	 * Copy option fields and padding (nop) to mbuf.
1215	 */
1216	ip_srcrt.nop = IPOPT_NOP;
1217	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1218	memmove(mtod(m, char *) + sizeof(struct in_addr), &ip_srcrt.nop,
1219	    OPTSIZ);
1220	q = (struct in_addr *)(mtod(m, char *) +
1221	    sizeof(struct in_addr) + OPTSIZ);
1222#undef OPTSIZ
1223	/*
1224	 * Record return path as an IP source route,
1225	 * reversing the path (pointers are now aligned).
1226	 */
1227	while (p >= ip_srcrt.route) {
1228#ifdef DIAGNOSTIC
1229		if (ipprintfs)
1230			printf(" %x", ntohl(q->s_addr));
1231#endif
1232		*q++ = *p--;
1233	}
1234	/*
1235	 * Last hop goes to final destination.
1236	 */
1237	*q = ip_srcrt.dst;
1238#ifdef DIAGNOSTIC
1239	if (ipprintfs)
1240		printf(" %x\n", ntohl(q->s_addr));
1241#endif
1242	return (m);
1243}
1244
1245const int inetctlerrmap[PRC_NCMDS] = {
1246	[PRC_MSGSIZE] = EMSGSIZE,
1247	[PRC_HOSTDEAD] = EHOSTDOWN,
1248	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1249	[PRC_UNREACH_NET] = EHOSTUNREACH,
1250	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1251	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1252	[PRC_UNREACH_PORT] = ECONNREFUSED,
1253	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1254	[PRC_PARAMPROB] = ENOPROTOOPT,
1255};
1256
1257void
1258ip_fasttimo(void)
1259{
1260	if (ip_drainwanted) {
1261		ip_drain();
1262		ip_drainwanted = 0;
1263	}
1264}
1265
1266void
1267ip_drainstub(void)
1268{
1269	ip_drainwanted = 1;
1270}
1271
1272/*
1273 * Forward a packet.  If some error occurs return the sender
1274 * an icmp packet.  Note we can't always generate a meaningful
1275 * icmp message because icmp doesn't have a large enough repertoire
1276 * of codes and types.
1277 *
1278 * If not forwarding, just drop the packet.  This could be confusing
1279 * if ipforwarding was zero but some routing protocol was advancing
1280 * us as a gateway to somewhere.  However, we must let the routing
1281 * protocol deal with that.
1282 *
1283 * The srcrt parameter indicates whether the packet is being forwarded
1284 * via a source route.
1285 */
1286void
1287ip_forward(struct mbuf *m, int srcrt)
1288{
1289	struct ip *ip = mtod(m, struct ip *);
1290	struct rtentry *rt;
1291	int error, type = 0, code = 0, destmtu = 0;
1292	struct mbuf *mcopy;
1293	n_long dest;
1294	union {
1295		struct sockaddr		dst;
1296		struct sockaddr_in	dst4;
1297	} u;
1298
1299	/*
1300	 * We are now in the output path.
1301	 */
1302	MCLAIM(m, &ip_tx_mowner);
1303
1304	/*
1305	 * Clear any in-bound checksum flags for this packet.
1306	 */
1307	m->m_pkthdr.csum_flags = 0;
1308
1309	dest = 0;
1310#ifdef DIAGNOSTIC
1311	if (ipprintfs) {
1312		printf("forward: src %s ", inet_ntoa(ip->ip_src));
1313		printf("dst %s ttl %x\n", inet_ntoa(ip->ip_dst), ip->ip_ttl);
1314	}
1315#endif
1316	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1317		IP_STATINC(IP_STAT_CANTFORWARD);
1318		m_freem(m);
1319		return;
1320	}
1321	if (ip->ip_ttl <= IPTTLDEC) {
1322		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1323		return;
1324	}
1325
1326	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1327	if ((rt = rtcache_lookup(&ipforward_rt, &u.dst)) == NULL) {
1328		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1329		return;
1330	}
1331
1332	/*
1333	 * Save at most 68 bytes of the packet in case
1334	 * we need to generate an ICMP message to the src.
1335	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1336	 */
1337	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1338	if (mcopy)
1339		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1340
1341	ip->ip_ttl -= IPTTLDEC;
1342
1343	/*
1344	 * If forwarding packet using same interface that it came in on,
1345	 * perhaps should send a redirect to sender to shortcut a hop.
1346	 * Only send redirect if source is sending directly to us,
1347	 * and if packet was not source routed (or has any options).
1348	 * Also, don't send redirect if forwarding using a default route
1349	 * or a route modified by a redirect.
1350	 */
1351	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1352	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1353	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1354	    ipsendredirects && !srcrt) {
1355		if (rt->rt_ifa &&
1356		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1357		    ifatoia(rt->rt_ifa)->ia_subnet) {
1358			if (rt->rt_flags & RTF_GATEWAY)
1359				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1360			else
1361				dest = ip->ip_dst.s_addr;
1362			/*
1363			 * Router requirements says to only send host
1364			 * redirects.
1365			 */
1366			type = ICMP_REDIRECT;
1367			code = ICMP_REDIRECT_HOST;
1368#ifdef DIAGNOSTIC
1369			if (ipprintfs)
1370				printf("redirect (%d) to %x\n", code,
1371				    (u_int32_t)dest);
1372#endif
1373		}
1374	}
1375
1376	error = ip_output(m, NULL, &ipforward_rt,
1377	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1378	    NULL, NULL);
1379
1380	if (error)
1381		IP_STATINC(IP_STAT_CANTFORWARD);
1382	else {
1383		uint64_t *ips = IP_STAT_GETREF();
1384		ips[IP_STAT_FORWARD]++;
1385		if (type) {
1386			ips[IP_STAT_REDIRECTSENT]++;
1387			IP_STAT_PUTREF();
1388		} else {
1389			IP_STAT_PUTREF();
1390			if (mcopy) {
1391#ifdef GATEWAY
1392				if (mcopy->m_flags & M_CANFASTFWD)
1393					ipflow_create(&ipforward_rt, mcopy);
1394#endif
1395				m_freem(mcopy);
1396			}
1397			return;
1398		}
1399	}
1400	if (mcopy == NULL)
1401		return;
1402
1403	switch (error) {
1404
1405	case 0:				/* forwarded, but need redirect */
1406		/* type, code set above */
1407		break;
1408
1409	case ENETUNREACH:		/* shouldn't happen, checked above */
1410	case EHOSTUNREACH:
1411	case ENETDOWN:
1412	case EHOSTDOWN:
1413	default:
1414		type = ICMP_UNREACH;
1415		code = ICMP_UNREACH_HOST;
1416		break;
1417
1418	case EMSGSIZE:
1419		type = ICMP_UNREACH;
1420		code = ICMP_UNREACH_NEEDFRAG;
1421
1422		if ((rt = rtcache_validate(&ipforward_rt)) != NULL)
1423			destmtu = rt->rt_ifp->if_mtu;
1424
1425#if defined(FAST_IPSEC)
1426		{
1427			/*
1428			 * If the packet is routed over IPsec tunnel, tell the
1429			 * originator the tunnel MTU.
1430			 *	tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
1431			 * XXX quickhack!!!
1432			 */
1433
1434			struct secpolicy *sp;
1435			int ipsecerror;
1436			size_t ipsechdr;
1437			struct route *ro;
1438
1439			sp = ipsec4_getpolicybyaddr(mcopy,
1440			    IPSEC_DIR_OUTBOUND, IP_FORWARDING,
1441			    &ipsecerror);
1442
1443			if (sp != NULL) {
1444				/* count IPsec header size */
1445				ipsechdr = ipsec4_hdrsiz(mcopy,
1446				    IPSEC_DIR_OUTBOUND, NULL);
1447
1448				/*
1449				 * find the correct route for outer IPv4
1450				 * header, compute tunnel MTU.
1451				 */
1452
1453				if (sp->req != NULL
1454				 && sp->req->sav != NULL
1455				 && sp->req->sav->sah != NULL) {
1456					ro = &sp->req->sav->sah->sa_route;
1457					rt = rtcache_validate(ro);
1458					if (rt && rt->rt_ifp) {
1459						destmtu =
1460						    rt->rt_rmx.rmx_mtu ?
1461						    rt->rt_rmx.rmx_mtu :
1462						    rt->rt_ifp->if_mtu;
1463						destmtu -= ipsechdr;
1464					}
1465				}
1466
1467				KEY_FREESP(&sp);
1468			}
1469		}
1470#endif /*defined(FAST_IPSEC)*/
1471		IP_STATINC(IP_STAT_CANTFRAG);
1472		break;
1473
1474	case ENOBUFS:
1475#if 1
1476		/*
1477		 * a router should not generate ICMP_SOURCEQUENCH as
1478		 * required in RFC1812 Requirements for IP Version 4 Routers.
1479		 * source quench could be a big problem under DoS attacks,
1480		 * or if the underlying interface is rate-limited.
1481		 */
1482		if (mcopy)
1483			m_freem(mcopy);
1484		return;
1485#else
1486		type = ICMP_SOURCEQUENCH;
1487		code = 0;
1488		break;
1489#endif
1490	}
1491	icmp_error(mcopy, type, code, dest, destmtu);
1492}
1493
1494void
1495ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1496    struct mbuf *m)
1497{
1498
1499	if (inp->inp_socket->so_options & SO_TIMESTAMP
1500#ifdef SO_OTIMESTAMP
1501	    || inp->inp_socket->so_options & SO_OTIMESTAMP
1502#endif
1503	    ) {
1504		struct timeval tv;
1505
1506		microtime(&tv);
1507#ifdef SO_OTIMESTAMP
1508		if (inp->inp_socket->so_options & SO_OTIMESTAMP) {
1509			struct timeval50 tv50;
1510			timeval_to_timeval50(&tv, &tv50);
1511			*mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
1512			    SCM_OTIMESTAMP, SOL_SOCKET);
1513		} else
1514#endif
1515		*mp = sbcreatecontrol((void *) &tv, sizeof(tv),
1516		    SCM_TIMESTAMP, SOL_SOCKET);
1517		if (*mp)
1518			mp = &(*mp)->m_next;
1519	}
1520	if (inp->inp_flags & INP_RECVDSTADDR) {
1521		*mp = sbcreatecontrol((void *) &ip->ip_dst,
1522		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1523		if (*mp)
1524			mp = &(*mp)->m_next;
1525	}
1526#ifdef notyet
1527	/*
1528	 * XXX
1529	 * Moving these out of udp_input() made them even more broken
1530	 * than they already were.
1531	 *	- fenner@parc.xerox.com
1532	 */
1533	/* options were tossed already */
1534	if (inp->inp_flags & INP_RECVOPTS) {
1535		*mp = sbcreatecontrol((void *) opts_deleted_above,
1536		    sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1537		if (*mp)
1538			mp = &(*mp)->m_next;
1539	}
1540	/* ip_srcroute doesn't do what we want here, need to fix */
1541	if (inp->inp_flags & INP_RECVRETOPTS) {
1542		*mp = sbcreatecontrol((void *) ip_srcroute(),
1543		    sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1544		if (*mp)
1545			mp = &(*mp)->m_next;
1546	}
1547#endif
1548	if (inp->inp_flags & INP_RECVIF) {
1549		struct sockaddr_dl sdl;
1550
1551		sockaddr_dl_init(&sdl, sizeof(sdl),
1552		    (m->m_pkthdr.rcvif != NULL)
1553		        ?  m->m_pkthdr.rcvif->if_index
1554			: 0,
1555			0, NULL, 0, NULL, 0);
1556		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1557		if (*mp)
1558			mp = &(*mp)->m_next;
1559	}
1560	if (inp->inp_flags & INP_RECVTTL) {
1561		*mp = sbcreatecontrol((void *) &ip->ip_ttl,
1562		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1563		if (*mp)
1564			mp = &(*mp)->m_next;
1565	}
1566}
1567
1568/*
1569 * sysctl helper routine for net.inet.ip.forwsrcrt.
1570 */
1571static int
1572sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1573{
1574	int error, tmp;
1575	struct sysctlnode node;
1576
1577	node = *rnode;
1578	tmp = ip_forwsrcrt;
1579	node.sysctl_data = &tmp;
1580	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1581	if (error || newp == NULL)
1582		return (error);
1583
1584	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1585	    0, NULL, NULL, NULL);
1586	if (error)
1587		return (error);
1588
1589	ip_forwsrcrt = tmp;
1590
1591	return (0);
1592}
1593
1594/*
1595 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1596 * range of the new value and tweaks timers if it changes.
1597 */
1598static int
1599sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1600{
1601	int error, tmp;
1602	struct sysctlnode node;
1603
1604	node = *rnode;
1605	tmp = ip_mtudisc_timeout;
1606	node.sysctl_data = &tmp;
1607	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1608	if (error || newp == NULL)
1609		return (error);
1610	if (tmp < 0)
1611		return (EINVAL);
1612
1613	mutex_enter(softnet_lock);
1614
1615	ip_mtudisc_timeout = tmp;
1616	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1617
1618	mutex_exit(softnet_lock);
1619
1620	return (0);
1621}
1622
1623#ifdef GATEWAY
1624/*
1625 * sysctl helper routine for net.inet.ip.maxflows.
1626 */
1627static int
1628sysctl_net_inet_ip_maxflows(SYSCTLFN_ARGS)
1629{
1630	int error;
1631
1632	error = sysctl_lookup(SYSCTLFN_CALL(rnode));
1633	if (error || newp == NULL)
1634		return (error);
1635
1636	mutex_enter(softnet_lock);
1637	KERNEL_LOCK(1, NULL);
1638
1639	ipflow_prune();
1640
1641	KERNEL_UNLOCK_ONE(NULL);
1642	mutex_exit(softnet_lock);
1643
1644	return (0);
1645}
1646
1647static int
1648sysctl_net_inet_ip_hashsize(SYSCTLFN_ARGS)
1649{
1650	int error, tmp;
1651	struct sysctlnode node;
1652
1653	node = *rnode;
1654	tmp = ip_hashsize;
1655	node.sysctl_data = &tmp;
1656	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1657	if (error || newp == NULL)
1658		return (error);
1659
1660	if ((tmp & (tmp - 1)) == 0 && tmp != 0) {
1661		/*
1662		 * Can only fail due to malloc()
1663		 */
1664		mutex_enter(softnet_lock);
1665		KERNEL_LOCK(1, NULL);
1666
1667		error = ipflow_invalidate_all(tmp);
1668
1669		KERNEL_UNLOCK_ONE(NULL);
1670		mutex_exit(softnet_lock);
1671
1672	} else {
1673		/*
1674		 * EINVAL if not a power of 2
1675	         */
1676		error = EINVAL;
1677	}
1678
1679	return error;
1680}
1681#endif /* GATEWAY */
1682
1683static int
1684sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1685{
1686
1687	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1688}
1689
1690static void
1691sysctl_net_inet_ip_setup(struct sysctllog **clog)
1692{
1693	extern int subnetsarelocal, hostzeroisbroadcast;
1694
1695	sysctl_createv(clog, 0, NULL, NULL,
1696		       CTLFLAG_PERMANENT,
1697		       CTLTYPE_NODE, "net", NULL,
1698		       NULL, 0, NULL, 0,
1699		       CTL_NET, CTL_EOL);
1700	sysctl_createv(clog, 0, NULL, NULL,
1701		       CTLFLAG_PERMANENT,
1702		       CTLTYPE_NODE, "inet",
1703		       SYSCTL_DESCR("PF_INET related settings"),
1704		       NULL, 0, NULL, 0,
1705		       CTL_NET, PF_INET, CTL_EOL);
1706	sysctl_createv(clog, 0, NULL, NULL,
1707		       CTLFLAG_PERMANENT,
1708		       CTLTYPE_NODE, "ip",
1709		       SYSCTL_DESCR("IPv4 related settings"),
1710		       NULL, 0, NULL, 0,
1711		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1712
1713	sysctl_createv(clog, 0, NULL, NULL,
1714		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1715		       CTLTYPE_INT, "forwarding",
1716		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1717		       NULL, 0, &ipforwarding, 0,
1718		       CTL_NET, PF_INET, IPPROTO_IP,
1719		       IPCTL_FORWARDING, CTL_EOL);
1720	sysctl_createv(clog, 0, NULL, NULL,
1721		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1722		       CTLTYPE_INT, "redirect",
1723		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1724		       NULL, 0, &ipsendredirects, 0,
1725		       CTL_NET, PF_INET, IPPROTO_IP,
1726		       IPCTL_SENDREDIRECTS, CTL_EOL);
1727	sysctl_createv(clog, 0, NULL, NULL,
1728		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1729		       CTLTYPE_INT, "ttl",
1730		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1731		       NULL, 0, &ip_defttl, 0,
1732		       CTL_NET, PF_INET, IPPROTO_IP,
1733		       IPCTL_DEFTTL, CTL_EOL);
1734#ifdef IPCTL_DEFMTU
1735	sysctl_createv(clog, 0, NULL, NULL,
1736		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1737		       CTLTYPE_INT, "mtu",
1738		       SYSCTL_DESCR("Default MTA for an INET route"),
1739		       NULL, 0, &ip_mtu, 0,
1740		       CTL_NET, PF_INET, IPPROTO_IP,
1741		       IPCTL_DEFMTU, CTL_EOL);
1742#endif /* IPCTL_DEFMTU */
1743	sysctl_createv(clog, 0, NULL, NULL,
1744		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1745		       CTLTYPE_INT, "forwsrcrt",
1746		       SYSCTL_DESCR("Enable forwarding of source-routed "
1747				    "datagrams"),
1748		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1749		       CTL_NET, PF_INET, IPPROTO_IP,
1750		       IPCTL_FORWSRCRT, CTL_EOL);
1751	sysctl_createv(clog, 0, NULL, NULL,
1752		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1753		       CTLTYPE_INT, "directed-broadcast",
1754		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1755		       NULL, 0, &ip_directedbcast, 0,
1756		       CTL_NET, PF_INET, IPPROTO_IP,
1757		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1758	sysctl_createv(clog, 0, NULL, NULL,
1759		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1760		       CTLTYPE_INT, "allowsrcrt",
1761		       SYSCTL_DESCR("Accept source-routed datagrams"),
1762		       NULL, 0, &ip_allowsrcrt, 0,
1763		       CTL_NET, PF_INET, IPPROTO_IP,
1764		       IPCTL_ALLOWSRCRT, CTL_EOL);
1765	sysctl_createv(clog, 0, NULL, NULL,
1766		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1767		       CTLTYPE_INT, "subnetsarelocal",
1768		       SYSCTL_DESCR("Whether logical subnets are considered "
1769				    "local"),
1770		       NULL, 0, &subnetsarelocal, 0,
1771		       CTL_NET, PF_INET, IPPROTO_IP,
1772		       IPCTL_SUBNETSARELOCAL, CTL_EOL);
1773	sysctl_createv(clog, 0, NULL, NULL,
1774		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1775		       CTLTYPE_INT, "mtudisc",
1776		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1777		       NULL, 0, &ip_mtudisc, 0,
1778		       CTL_NET, PF_INET, IPPROTO_IP,
1779		       IPCTL_MTUDISC, CTL_EOL);
1780	sysctl_createv(clog, 0, NULL, NULL,
1781		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1782		       CTLTYPE_INT, "anonportmin",
1783		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1784		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1785		       CTL_NET, PF_INET, IPPROTO_IP,
1786		       IPCTL_ANONPORTMIN, CTL_EOL);
1787	sysctl_createv(clog, 0, NULL, NULL,
1788		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1789		       CTLTYPE_INT, "anonportmax",
1790		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1791		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1792		       CTL_NET, PF_INET, IPPROTO_IP,
1793		       IPCTL_ANONPORTMAX, CTL_EOL);
1794	sysctl_createv(clog, 0, NULL, NULL,
1795		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1796		       CTLTYPE_INT, "mtudisctimeout",
1797		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1798		       sysctl_net_inet_ip_pmtudto, 0, &ip_mtudisc_timeout, 0,
1799		       CTL_NET, PF_INET, IPPROTO_IP,
1800		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1801#ifdef GATEWAY
1802	sysctl_createv(clog, 0, NULL, NULL,
1803		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1804		       CTLTYPE_INT, "maxflows",
1805		       SYSCTL_DESCR("Number of flows for fast forwarding"),
1806		       sysctl_net_inet_ip_maxflows, 0, &ip_maxflows, 0,
1807		       CTL_NET, PF_INET, IPPROTO_IP,
1808		       IPCTL_MAXFLOWS, CTL_EOL);
1809	sysctl_createv(clog, 0, NULL, NULL,
1810			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1811			CTLTYPE_INT, "hashsize",
1812			SYSCTL_DESCR("Size of hash table for fast forwarding (IPv4)"),
1813			sysctl_net_inet_ip_hashsize, 0, &ip_hashsize, 0,
1814			CTL_NET, PF_INET, IPPROTO_IP,
1815			CTL_CREATE, CTL_EOL);
1816#endif /* GATEWAY */
1817	sysctl_createv(clog, 0, NULL, NULL,
1818		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1819		       CTLTYPE_INT, "hostzerobroadcast",
1820		       SYSCTL_DESCR("All zeroes address is broadcast address"),
1821		       NULL, 0, &hostzeroisbroadcast, 0,
1822		       CTL_NET, PF_INET, IPPROTO_IP,
1823		       IPCTL_HOSTZEROBROADCAST, CTL_EOL);
1824#if NGIF > 0
1825	sysctl_createv(clog, 0, NULL, NULL,
1826		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1827		       CTLTYPE_INT, "gifttl",
1828		       SYSCTL_DESCR("Default TTL for a gif tunnel datagram"),
1829		       NULL, 0, &ip_gif_ttl, 0,
1830		       CTL_NET, PF_INET, IPPROTO_IP,
1831		       IPCTL_GIF_TTL, CTL_EOL);
1832#endif /* NGIF */
1833#ifndef IPNOPRIVPORTS
1834	sysctl_createv(clog, 0, NULL, NULL,
1835		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1836		       CTLTYPE_INT, "lowportmin",
1837		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1838				    "to assign"),
1839		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1840		       CTL_NET, PF_INET, IPPROTO_IP,
1841		       IPCTL_LOWPORTMIN, CTL_EOL);
1842	sysctl_createv(clog, 0, NULL, NULL,
1843		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1844		       CTLTYPE_INT, "lowportmax",
1845		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1846				    "to assign"),
1847		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1848		       CTL_NET, PF_INET, IPPROTO_IP,
1849		       IPCTL_LOWPORTMAX, CTL_EOL);
1850#endif /* IPNOPRIVPORTS */
1851#if NGRE > 0
1852	sysctl_createv(clog, 0, NULL, NULL,
1853		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1854		       CTLTYPE_INT, "grettl",
1855		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1856		       NULL, 0, &ip_gre_ttl, 0,
1857		       CTL_NET, PF_INET, IPPROTO_IP,
1858		       IPCTL_GRE_TTL, CTL_EOL);
1859#endif /* NGRE */
1860	sysctl_createv(clog, 0, NULL, NULL,
1861		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1862		       CTLTYPE_INT, "checkinterface",
1863		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1864				    "from RFC1122"),
1865		       NULL, 0, &ip_checkinterface, 0,
1866		       CTL_NET, PF_INET, IPPROTO_IP,
1867		       IPCTL_CHECKINTERFACE, CTL_EOL);
1868	sysctl_createv(clog, 0, NULL, NULL,
1869		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1870		       CTLTYPE_INT, "random_id",
1871		       SYSCTL_DESCR("Assign random ip_id values"),
1872		       NULL, 0, &ip_do_randomid, 0,
1873		       CTL_NET, PF_INET, IPPROTO_IP,
1874		       IPCTL_RANDOMID, CTL_EOL);
1875	sysctl_createv(clog, 0, NULL, NULL,
1876		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1877		       CTLTYPE_INT, "do_loopback_cksum",
1878		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1879		       NULL, 0, &ip_do_loopback_cksum, 0,
1880		       CTL_NET, PF_INET, IPPROTO_IP,
1881		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1882	sysctl_createv(clog, 0, NULL, NULL,
1883		       CTLFLAG_PERMANENT,
1884		       CTLTYPE_STRUCT, "stats",
1885		       SYSCTL_DESCR("IP statistics"),
1886		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1887		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1888		       CTL_EOL);
1889}
1890
1891void
1892ip_statinc(u_int stat)
1893{
1894
1895	KASSERT(stat < IP_NSTATS);
1896	IP_STATINC(stat);
1897}
1898