ip_input.c revision 1.368
1/*	$NetBSD: ip_input.c,v 1.368 2018/02/05 13:52:39 maxv 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 1.368 2018/02/05 13:52:39 maxv Exp $");
95
96#ifdef _KERNEL_OPT
97#include "opt_inet.h"
98#include "opt_gateway.h"
99#include "opt_ipsec.h"
100#include "opt_mrouting.h"
101#include "opt_mbuftrace.h"
102#include "opt_inet_csum.h"
103#include "opt_net_mpsafe.h"
104#endif
105
106#include "arp.h"
107
108#include <sys/param.h>
109#include <sys/systm.h>
110#include <sys/cpu.h>
111#include <sys/mbuf.h>
112#include <sys/domain.h>
113#include <sys/protosw.h>
114#include <sys/socket.h>
115#include <sys/socketvar.h>
116#include <sys/errno.h>
117#include <sys/time.h>
118#include <sys/kernel.h>
119#include <sys/pool.h>
120#include <sys/sysctl.h>
121#include <sys/kauth.h>
122
123#include <net/if.h>
124#include <net/if_dl.h>
125#include <net/route.h>
126#include <net/pktqueue.h>
127#include <net/pfil.h>
128
129#include <netinet/in.h>
130#include <netinet/in_systm.h>
131#include <netinet/ip.h>
132#include <netinet/in_pcb.h>
133#include <netinet/in_proto.h>
134#include <netinet/in_var.h>
135#include <netinet/ip_var.h>
136#include <netinet/ip_private.h>
137#include <netinet/ip_icmp.h>
138/* just for gif_ttl */
139#include <netinet/in_gif.h>
140#include "gif.h"
141#include <net/if_gre.h>
142#include "gre.h"
143
144#ifdef MROUTING
145#include <netinet/ip_mroute.h>
146#endif
147#include <netinet/portalgo.h>
148
149#ifdef IPSEC
150#include <netipsec/ipsec.h>
151#endif
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	0	/* forward source-routed packets */
165#endif
166#ifndef IPALLOWSRCRT
167#define	IPALLOWSRCRT	0	/* 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/*
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
196int	ip_do_randomid = 0;
197
198/*
199 * XXX - Setting ip_checkinterface mostly implements the receive side of
200 * the Strong ES model described in RFC 1122, but since the routing table
201 * and transmit implementation do not implement the Strong ES model,
202 * setting this to 1 results in an odd hybrid.
203 *
204 * XXX - ip_checkinterface currently must be disabled if you use ipnat
205 * to translate the destination address to another local interface.
206 *
207 * XXX - ip_checkinterface must be disabled if you add IP aliases
208 * to the loopback interface instead of the interface where the
209 * packets for those addresses are received.
210 */
211static int		ip_checkinterface	__read_mostly = 0;
212
213struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
214
215pktqueue_t *		ip_pktq			__read_mostly;
216pfil_head_t *		inet_pfil_hook		__read_mostly;
217ipid_state_t *		ip_ids			__read_mostly;
218percpu_t *		ipstat_percpu		__read_mostly;
219
220static percpu_t		*ipforward_rt_percpu	__cacheline_aligned;
221
222uint16_t ip_id;
223
224#ifdef INET_CSUM_COUNTERS
225#include <sys/device.h>
226
227struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
228    NULL, "inet", "hwcsum bad");
229struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
230    NULL, "inet", "hwcsum ok");
231struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
232    NULL, "inet", "swcsum");
233
234#define	INET_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
235
236EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
237EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
238EVCNT_ATTACH_STATIC(ip_swcsum);
239
240#else
241
242#define	INET_CSUM_COUNTER_INCR(ev)	/* nothing */
243
244#endif /* INET_CSUM_COUNTERS */
245
246/*
247 * Used to save the IP options in case a protocol wants to respond
248 * to an incoming packet over the same route if the packet got here
249 * using IP source routing.  This allows connection establishment and
250 * maintenance when the remote end is on a network that is not known
251 * to us.
252 */
253struct ip_srcrt {
254	int		isr_nhops;		   /* number of hops */
255	struct in_addr	isr_dst;		   /* final destination */
256	char		isr_nop;		   /* one NOP to align */
257	char		isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */
258	struct in_addr	isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)];
259};
260
261static int ip_drainwanted;
262
263static void save_rte(struct mbuf *, u_char *, struct in_addr);
264
265#ifdef MBUFTRACE
266struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
267struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
268#endif
269
270static void		ipintr(void *);
271static void		ip_input(struct mbuf *);
272static void		ip_forward(struct mbuf *, int, struct ifnet *);
273static bool		ip_dooptions(struct mbuf *);
274static struct in_ifaddr *ip_rtaddr(struct in_addr, struct psref *);
275static void		sysctl_net_inet_ip_setup(struct sysctllog **);
276
277static struct in_ifaddr	*ip_match_our_address(struct ifnet *, struct ip *,
278			    int *);
279static struct in_ifaddr	*ip_match_our_address_broadcast(struct ifnet *,
280			    struct ip *);
281
282#ifdef NET_MPSAFE
283#define	SOFTNET_LOCK()		mutex_enter(softnet_lock)
284#define	SOFTNET_UNLOCK()	mutex_exit(softnet_lock)
285#else
286#define	SOFTNET_LOCK()		KASSERT(mutex_owned(softnet_lock))
287#define	SOFTNET_UNLOCK()	KASSERT(mutex_owned(softnet_lock))
288#endif
289
290/*
291 * IP initialization: fill in IP protocol switch table.
292 * All protocols not implemented in kernel go to raw IP protocol handler.
293 */
294void
295ip_init(void)
296{
297	const struct protosw *pr;
298
299	in_init();
300	sysctl_net_inet_ip_setup(NULL);
301
302	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
303	KASSERT(pr != NULL);
304
305	ip_pktq = pktq_create(IFQ_MAXLEN, ipintr, NULL);
306	KASSERT(ip_pktq != NULL);
307
308	for (u_int i = 0; i < IPPROTO_MAX; i++) {
309		ip_protox[i] = pr - inetsw;
310	}
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_uptime & 0xfffff;
321
322#ifdef GATEWAY
323	ipflow_init();
324#endif
325
326	/* Register our Packet Filter hook. */
327	inet_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET);
328	KASSERT(inet_pfil_hook != NULL);
329
330#ifdef MBUFTRACE
331	MOWNER_ATTACH(&ip_tx_mowner);
332	MOWNER_ATTACH(&ip_rx_mowner);
333#endif /* MBUFTRACE */
334
335	ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
336	ipforward_rt_percpu = percpu_alloc(sizeof(struct route));
337	ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
338}
339
340static struct in_ifaddr *
341ip_match_our_address(struct ifnet *ifp, struct ip *ip, int *downmatch)
342{
343	struct in_ifaddr *ia = NULL;
344	int checkif;
345
346	/*
347	 * Enable a consistency check between the destination address
348	 * and the arrival interface for a unicast packet (the RFC 1122
349	 * strong ES model) if IP forwarding is disabled and the packet
350	 * is not locally generated.
351	 *
352	 * XXX - Checking also should be disabled if the destination
353	 * address is ipnat'ed to a different interface.
354	 *
355	 * XXX - Checking is incompatible with IP aliases added
356	 * to the loopback interface instead of the interface where
357	 * the packets are received.
358	 *
359	 * XXX - We need to add a per ifaddr flag for this so that
360	 * we get finer grain control.
361	 */
362	checkif = ip_checkinterface && (ipforwarding == 0) &&
363	    (ifp->if_flags & IFF_LOOPBACK) == 0;
364
365	IN_ADDRHASH_READER_FOREACH(ia, ip->ip_dst.s_addr) {
366		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
367			if (ia->ia4_flags & IN_IFF_NOTREADY)
368				continue;
369			if (checkif && ia->ia_ifp != ifp)
370				continue;
371			if ((ia->ia_ifp->if_flags & IFF_UP) == 0) {
372				(*downmatch)++;
373				continue;
374			}
375			if (ia->ia4_flags & IN_IFF_DETACHED &&
376			    (ifp->if_flags & IFF_LOOPBACK) == 0)
377				continue;
378			break;
379		}
380	}
381
382	return ia;
383}
384
385static struct in_ifaddr *
386ip_match_our_address_broadcast(struct ifnet *ifp, struct ip *ip)
387{
388	struct in_ifaddr *ia = NULL;
389	struct ifaddr *ifa;
390
391	IFADDR_READER_FOREACH(ifa, ifp) {
392		if (ifa->ifa_addr->sa_family != AF_INET)
393			continue;
394		ia = ifatoia(ifa);
395		if (ia->ia4_flags & IN_IFF_NOTREADY)
396			continue;
397		if (ia->ia4_flags & IN_IFF_DETACHED &&
398		    (ifp->if_flags & IFF_LOOPBACK) == 0)
399			continue;
400		if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
401		    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
402		    /*
403		     * Look for all-0's host part (old broadcast addr),
404		     * either for subnet or net.
405		     */
406		    ip->ip_dst.s_addr == ia->ia_subnet ||
407		    ip->ip_dst.s_addr == ia->ia_net)
408			goto matched;
409		/*
410		 * An interface with IP address zero accepts
411		 * all packets that arrive on that interface.
412		 */
413		if (in_nullhost(ia->ia_addr.sin_addr))
414			goto matched;
415	}
416	ia = NULL;
417
418matched:
419	return ia;
420}
421
422/*
423 * IP software interrupt routine.
424 */
425static void
426ipintr(void *arg __unused)
427{
428	struct mbuf *m;
429
430	KASSERT(cpu_softintr_p());
431
432	SOFTNET_LOCK_UNLESS_NET_MPSAFE();
433	while ((m = pktq_dequeue(ip_pktq)) != NULL) {
434		ip_input(m);
435	}
436	SOFTNET_UNLOCK_UNLESS_NET_MPSAFE();
437}
438
439/*
440 * IP input routine.  Checksum and byte swap header.  If fragmented
441 * try to reassemble.  Process options.  Pass to next level.
442 */
443static void
444ip_input(struct mbuf *m)
445{
446	struct ip *ip = NULL;
447	struct in_ifaddr *ia = NULL;
448	int hlen = 0, len;
449	int downmatch;
450	int srcrt = 0;
451	ifnet_t *ifp;
452	struct psref psref;
453	int s;
454
455	KASSERTMSG(cpu_softintr_p(), "ip_input: not in the software "
456	    "interrupt handler; synchronization assumptions violated");
457
458	MCLAIM(m, &ip_rx_mowner);
459	KASSERT((m->m_flags & M_PKTHDR) != 0);
460
461	ifp = m_get_rcvif_psref(m, &psref);
462	if (__predict_false(ifp == NULL))
463		goto out;
464
465	/*
466	 * If no IP addresses have been set yet but the interfaces
467	 * are receiving, can't do anything with incoming packets yet.
468	 * Note: we pre-check without locks held.
469	 */
470	if (IN_ADDRLIST_READER_EMPTY())
471		goto out;
472	IP_STATINC(IP_STAT_TOTAL);
473
474	/*
475	 * If the IP header is not aligned, slurp it up into a new
476	 * mbuf with space for link headers, in the event we forward
477	 * it.  Otherwise, if it is aligned, make sure the entire
478	 * base IP header is in the first mbuf of the chain.
479	 */
480	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
481		if ((m = m_copyup(m, sizeof(struct ip),
482		    (max_linkhdr + 3) & ~3)) == NULL) {
483			/* XXXJRT new stat, please */
484			IP_STATINC(IP_STAT_TOOSMALL);
485			goto out;
486		}
487	} else if (__predict_false(m->m_len < sizeof(struct ip))) {
488		if ((m = m_pullup(m, sizeof(struct ip))) == NULL) {
489			IP_STATINC(IP_STAT_TOOSMALL);
490			goto out;
491		}
492	}
493	ip = mtod(m, struct ip *);
494	if (ip->ip_v != IPVERSION) {
495		IP_STATINC(IP_STAT_BADVERS);
496		goto out;
497	}
498	hlen = ip->ip_hl << 2;
499	if (hlen < sizeof(struct ip)) {	/* minimum header length */
500		IP_STATINC(IP_STAT_BADHLEN);
501		goto out;
502	}
503	if (hlen > m->m_len) {
504		if ((m = m_pullup(m, hlen)) == NULL) {
505			IP_STATINC(IP_STAT_BADHLEN);
506			goto out;
507		}
508		ip = mtod(m, struct ip *);
509	}
510
511	/*
512	 * RFC1122: packets with a multicast source address are
513	 * not allowed.
514	 */
515	if (IN_MULTICAST(ip->ip_src.s_addr)) {
516		IP_STATINC(IP_STAT_BADADDR);
517		goto out;
518	}
519
520	/* 127/8 must not appear on wire - RFC1122 */
521	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
522	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
523		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
524			IP_STATINC(IP_STAT_BADADDR);
525			goto out;
526		}
527	}
528
529	switch (m->m_pkthdr.csum_flags &
530		((ifp->if_csum_flags_rx & M_CSUM_IPv4) | M_CSUM_IPv4_BAD)) {
531	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
532		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
533		IP_STATINC(IP_STAT_BADSUM);
534		goto out;
535
536	case M_CSUM_IPv4:
537		/* Checksum was okay. */
538		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
539		break;
540
541	default:
542		/*
543		 * Must compute it ourselves.  Maybe skip checksum on
544		 * loopback interfaces.
545		 */
546		if (__predict_true(!(ifp->if_flags & IFF_LOOPBACK) ||
547		    ip_do_loopback_cksum)) {
548			INET_CSUM_COUNTER_INCR(&ip_swcsum);
549			if (in_cksum(m, hlen) != 0) {
550				IP_STATINC(IP_STAT_BADSUM);
551				goto out;
552			}
553		}
554		break;
555	}
556
557	/* Retrieve the packet length. */
558	len = ntohs(ip->ip_len);
559
560	/*
561	 * Check for additional length bogosity
562	 */
563	if (len < hlen) {
564		IP_STATINC(IP_STAT_BADLEN);
565		goto out;
566	}
567
568	/*
569	 * Check that the amount of data in the buffers is at least as much
570	 * as the IP header would have us expect. Trim mbufs if longer than
571	 * we expect. Drop packet if shorter than we expect.
572	 */
573	if (m->m_pkthdr.len < len) {
574		IP_STATINC(IP_STAT_TOOSHORT);
575		goto out;
576	}
577	if (m->m_pkthdr.len > len) {
578		if (m->m_len == m->m_pkthdr.len) {
579			m->m_len = len;
580			m->m_pkthdr.len = len;
581		} else
582			m_adj(m, len - m->m_pkthdr.len);
583	}
584
585	/*
586	 * Assume that we can create a fast-forward IP flow entry
587	 * based on this packet.
588	 */
589	m->m_flags |= M_CANFASTFWD;
590
591	/*
592	 * Run through list of hooks for input packets.  If there are any
593	 * filters which require that additional packets in the flow are
594	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
595	 * Note that filters must _never_ set this flag, as another filter
596	 * in the list may have previously cleared it.
597	 */
598#if defined(IPSEC)
599	if (!ipsec_used || !ipsec_indone(m))
600#else
601	if (1)
602#endif
603	{
604		struct in_addr odst = ip->ip_dst;
605		bool freed;
606
607		freed = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_IN) != 0;
608		if (freed || m == NULL) {
609			m = NULL;
610			goto out;
611		}
612		ip = mtod(m, struct ip *);
613		hlen = ip->ip_hl << 2;
614
615		/*
616		 * XXX The setting of "srcrt" here is to prevent ip_forward()
617		 * from generating ICMP redirects for packets that have
618		 * been redirected by a hook back out on to the same LAN that
619		 * they came from and is not an indication that the packet
620		 * is being inffluenced by source routing options.  This
621		 * allows things like
622		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
623		 * where tlp0 is both on the 1.1.1.0/24 network and is the
624		 * default route for hosts on 1.1.1.0/24.  Of course this
625		 * also requires a "map tlp0 ..." to complete the story.
626		 * One might argue whether or not this kind of network config.
627		 * should be supported in this manner...
628		 */
629		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
630	}
631
632#ifdef ALTQ
633	/* XXX Temporary until ALTQ is changed to use a pfil hook */
634	if (altq_input) {
635		SOFTNET_LOCK();
636		if ((*altq_input)(m, AF_INET) == 0) {
637			/* Packet dropped by traffic conditioner. */
638			SOFTNET_UNLOCK();
639			m = NULL;
640			goto out;
641		}
642		SOFTNET_UNLOCK();
643	}
644#endif
645
646	/*
647	 * Process options and, if not destined for us,
648	 * ship it on.  ip_dooptions returns 1 when an
649	 * error was detected (causing an icmp message
650	 * to be sent and the original packet to be freed).
651	 */
652	if (hlen > sizeof(struct ip) && ip_dooptions(m)) {
653		m = NULL;
654		goto out;
655	}
656
657	/*
658	 * Check our list of addresses, to see if the packet is for us.
659	 *
660	 * Traditional 4.4BSD did not consult IFF_UP at all.
661	 * The behavior here is to treat addresses on !IFF_UP interface
662	 * or IN_IFF_NOTREADY addresses as not mine.
663	 */
664	downmatch = 0;
665	s = pserialize_read_enter();
666	ia = ip_match_our_address(ifp, ip, &downmatch);
667	if (ia != NULL) {
668		pserialize_read_exit(s);
669		goto ours;
670	}
671
672	if (ifp->if_flags & IFF_BROADCAST) {
673		ia = ip_match_our_address_broadcast(ifp, ip);
674		if (ia != NULL) {
675			pserialize_read_exit(s);
676			goto ours;
677		}
678	}
679	pserialize_read_exit(s);
680
681	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
682#ifdef MROUTING
683		extern struct socket *ip_mrouter;
684
685		if (ip_mrouter) {
686			/*
687			 * If we are acting as a multicast router, all
688			 * incoming multicast packets are passed to the
689			 * kernel-level multicast forwarding function.
690			 * The packet is returned (relatively) intact; if
691			 * ip_mforward() returns a non-zero value, the packet
692			 * must be discarded, else it may be accepted below.
693			 *
694			 * (The IP ident field is put in the same byte order
695			 * as expected when ip_mforward() is called from
696			 * ip_output().)
697			 */
698			SOFTNET_LOCK();
699			if (ip_mforward(m, ifp) != 0) {
700				SOFTNET_UNLOCK();
701				IP_STATINC(IP_STAT_CANTFORWARD);
702				goto out;
703			}
704			SOFTNET_UNLOCK();
705
706			/*
707			 * The process-level routing demon needs to receive
708			 * all multicast IGMP packets, whether or not this
709			 * host belongs to their destination groups.
710			 */
711			if (ip->ip_p == IPPROTO_IGMP) {
712				goto ours;
713			}
714			IP_STATINC(IP_STAT_CANTFORWARD);
715		}
716#endif
717		/*
718		 * See if we belong to the destination multicast group on the
719		 * arrival interface.
720		 */
721		if (!in_multi_group(ip->ip_dst, ifp, 0)) {
722			IP_STATINC(IP_STAT_CANTFORWARD);
723			goto out;
724		}
725		goto ours;
726	}
727	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
728	    in_nullhost(ip->ip_dst))
729		goto ours;
730
731	/*
732	 * Not for us; forward if possible and desirable.
733	 */
734	if (ipforwarding == 0) {
735		m_put_rcvif_psref(ifp, &psref);
736		IP_STATINC(IP_STAT_CANTFORWARD);
737		m_freem(m);
738	} else {
739		/*
740		 * If ip_dst matched any of my address on !IFF_UP interface,
741		 * and there's no IFF_UP interface that matches ip_dst,
742		 * send icmp unreach.  Forwarding it will result in in-kernel
743		 * forwarding loop till TTL goes to 0.
744		 */
745		if (downmatch) {
746			m_put_rcvif_psref(ifp, &psref);
747			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
748			IP_STATINC(IP_STAT_CANTFORWARD);
749			return;
750		}
751#ifdef IPSEC
752		/* Check the security policy (SP) for the packet */
753		if (ipsec_used) {
754			if (ipsec4_input(m, IP_FORWARDING |
755			    (ip_directedbcast ? IP_ALLOWBROADCAST : 0)) != 0) {
756				goto out;
757			}
758		}
759#endif
760		ip_forward(m, srcrt, ifp);
761		m_put_rcvif_psref(ifp, &psref);
762	}
763	return;
764
765ours:
766	m_put_rcvif_psref(ifp, &psref);
767	ifp = NULL;
768
769	/*
770	 * If offset or IP_MF are set, must reassemble.
771	 */
772	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
773		/*
774		 * Pass to IP reassembly mechanism.
775		 */
776		if (ip_reass_packet(&m, ip) != 0) {
777			/* Failed; invalid fragment(s) or packet. */
778			goto out;
779		}
780		if (m == NULL) {
781			/* More fragments should come; silently return. */
782			goto out;
783		}
784		/*
785		 * Reassembly is done, we have the final packet.
786		 * Update cached data in local variable(s).
787		 */
788		ip = mtod(m, struct ip *);
789		hlen = ip->ip_hl << 2;
790	}
791
792#ifdef IPSEC
793	/*
794	 * Enforce IPsec policy checking if we are seeing last header.
795	 * Note that we do not visit this with protocols with PCB layer
796	 * code - like UDP/TCP/raw IP.
797	 */
798	if (ipsec_used &&
799	    (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
800		if (ipsec4_input(m, 0) != 0) {
801			goto out;
802		}
803	}
804#endif
805
806	/*
807	 * Switch out to protocol's input routine.
808	 */
809#if IFA_STATS
810	if (ia && ip) {
811		struct in_ifaddr *_ia;
812		/*
813		 * Keep a reference from ip_match_our_address with psref
814		 * is expensive, so explore ia here again.
815		 */
816		s = pserialize_read_enter();
817		_ia = in_get_ia(ip->ip_dst);
818		_ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
819		pserialize_read_exit(s);
820	}
821#endif
822	IP_STATINC(IP_STAT_DELIVERED);
823
824	const int off = hlen, nh = ip->ip_p;
825
826	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
827	return;
828
829out:
830	m_put_rcvif_psref(ifp, &psref);
831	if (m != NULL)
832		m_freem(m);
833}
834
835/*
836 * IP timer processing.
837 */
838void
839ip_slowtimo(void)
840{
841
842	SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
843
844	ip_reass_slowtimo();
845
846	SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
847}
848
849/*
850 * IP drain processing.
851 */
852void
853ip_drain(void)
854{
855
856	KERNEL_LOCK(1, NULL);
857	ip_reass_drain();
858	KERNEL_UNLOCK_ONE(NULL);
859}
860
861/*
862 * ip_dooptions: perform option processing on a datagram, possibly discarding
863 * it if bad options are encountered, or forwarding it if source-routed.
864 *
865 * => Returns true if packet has been forwarded/freed.
866 * => Returns false if the packet should be processed further.
867 */
868static bool
869ip_dooptions(struct mbuf *m)
870{
871	struct ip *ip = mtod(m, struct ip *);
872	u_char *cp, *cp0;
873	struct ip_timestamp *ipt;
874	struct in_ifaddr *ia;
875	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
876	int lsrr_present, ssrr_present, rr_present, ts_present;
877	struct in_addr dst;
878	n_time ntime;
879	struct ifaddr *ifa = NULL;
880	int s;
881
882	lsrr_present = 0;
883	ssrr_present = 0;
884	rr_present = 0;
885	ts_present = 0;
886
887	dst = ip->ip_dst;
888	cp = (u_char *)(ip + 1);
889	cnt = (ip->ip_hl << 2) - sizeof(struct ip);
890	for (; cnt > 0; cnt -= optlen, cp += optlen) {
891		opt = cp[IPOPT_OPTVAL];
892		if (opt == IPOPT_EOL)
893			break;
894		if (opt == IPOPT_NOP)
895			optlen = 1;
896		else {
897			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
898				code = &cp[IPOPT_OLEN] - (u_char *)ip;
899				goto bad;
900			}
901			optlen = cp[IPOPT_OLEN];
902			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
903				code = &cp[IPOPT_OLEN] - (u_char *)ip;
904				goto bad;
905			}
906		}
907		switch (opt) {
908
909		default:
910			break;
911
912		/*
913		 * Source routing with record.
914		 * Find interface with current destination address.
915		 * If none on this machine then drop if strictly routed,
916		 * or do nothing if loosely routed.
917		 * Record interface address and bring up next address
918		 * component.  If strictly routed make sure next
919		 * address is on directly accessible net.
920		 */
921		case IPOPT_LSRR:
922		case IPOPT_SSRR: {
923			struct psref psref;
924			struct sockaddr_in ipaddr = {
925			    .sin_len = sizeof(ipaddr),
926			    .sin_family = AF_INET,
927			};
928
929			if (ip_allowsrcrt == 0) {
930				type = ICMP_UNREACH;
931				code = ICMP_UNREACH_NET_PROHIB;
932				goto bad;
933			}
934			if (opt == IPOPT_LSRR) {
935				if (lsrr_present++) {
936					code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
937					goto bad;
938				}
939			} else {
940				if (ssrr_present++) {
941					code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
942					goto bad;
943				}
944			}
945			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
946				code = &cp[IPOPT_OLEN] - (u_char *)ip;
947				goto bad;
948			}
949			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
950				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
951				goto bad;
952			}
953			ipaddr.sin_addr = ip->ip_dst;
954
955			s = pserialize_read_enter();
956			ifa = ifa_ifwithaddr(sintosa(&ipaddr));
957			if (ifa == NULL) {
958				pserialize_read_exit(s);
959				if (opt == IPOPT_SSRR) {
960					type = ICMP_UNREACH;
961					code = ICMP_UNREACH_SRCFAIL;
962					goto bad;
963				}
964				/*
965				 * Loose routing, and not at next destination
966				 * yet; nothing to do except forward.
967				 */
968				break;
969			}
970			pserialize_read_exit(s);
971
972			off--;			/* 0 origin */
973			if ((off + sizeof(struct in_addr)) > optlen) {
974				/*
975				 * End of source route.  Should be for us.
976				 */
977				save_rte(m, cp, ip->ip_src);
978				break;
979			}
980			/*
981			 * locate outgoing interface
982			 */
983			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
984			    sizeof(ipaddr.sin_addr));
985			if (opt == IPOPT_SSRR) {
986				ifa = ifa_ifwithladdr_psref(sintosa(&ipaddr),
987				    &psref);
988				if (ifa != NULL)
989					ia = ifatoia(ifa);
990				else
991					ia = NULL;
992			} else {
993				ia = ip_rtaddr(ipaddr.sin_addr, &psref);
994			}
995			if (ia == NULL) {
996				type = ICMP_UNREACH;
997				code = ICMP_UNREACH_SRCFAIL;
998				goto bad;
999			}
1000			ip->ip_dst = ipaddr.sin_addr;
1001			bcopy((void *)&ia->ia_addr.sin_addr,
1002			    (void *)(cp + off), sizeof(struct in_addr));
1003			ia4_release(ia, &psref);
1004			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1005			/*
1006			 * Let ip_intr's mcast routing check handle mcast pkts
1007			 */
1008			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1009			break;
1010		    }
1011
1012		case IPOPT_RR: {
1013			struct psref psref;
1014			struct sockaddr_in ipaddr = {
1015			    .sin_len = sizeof(ipaddr),
1016			    .sin_family = AF_INET,
1017			};
1018
1019			if (rr_present++) {
1020				code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
1021				goto bad;
1022			}
1023			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1024				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1025				goto bad;
1026			}
1027			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1028				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1029				goto bad;
1030			}
1031			/*
1032			 * If no space remains, ignore.
1033			 */
1034			off--;			/* 0 origin */
1035			if ((off + sizeof(struct in_addr)) > optlen)
1036				break;
1037			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1038			    sizeof(ipaddr.sin_addr));
1039			/*
1040			 * locate outgoing interface; if we're the destination,
1041			 * use the incoming interface (should be same).
1042			 */
1043			ifa = ifa_ifwithaddr_psref(sintosa(&ipaddr), &psref);
1044			if (ifa == NULL) {
1045				ia = ip_rtaddr(ipaddr.sin_addr, &psref);
1046				if (ia == NULL) {
1047					type = ICMP_UNREACH;
1048					code = ICMP_UNREACH_HOST;
1049					goto bad;
1050				}
1051			} else {
1052				ia = ifatoia(ifa);
1053			}
1054			bcopy((void *)&ia->ia_addr.sin_addr,
1055			    (void *)(cp + off), sizeof(struct in_addr));
1056			ia4_release(ia, &psref);
1057			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1058			break;
1059		    }
1060
1061		case IPOPT_TS:
1062			code = cp - (u_char *)ip;
1063			ipt = (struct ip_timestamp *)cp;
1064			if (ts_present++) {
1065				code = &cp[IPOPT_OPTVAL] - (u_char *)ip;
1066				goto bad;
1067			}
1068			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1069				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1070				goto bad;
1071			}
1072			if (ipt->ipt_ptr < 5) {
1073				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1074				goto bad;
1075			}
1076			if (ipt->ipt_ptr > ipt->ipt_len - sizeof(int32_t)) {
1077				if (++ipt->ipt_oflw == 0) {
1078					code = (u_char *)&ipt->ipt_ptr -
1079					    (u_char *)ip;
1080					goto bad;
1081				}
1082				break;
1083			}
1084			cp0 = (cp + ipt->ipt_ptr - 1);
1085			switch (ipt->ipt_flg) {
1086
1087			case IPOPT_TS_TSONLY:
1088				break;
1089
1090			case IPOPT_TS_TSANDADDR: {
1091				struct ifnet *rcvif;
1092				int _s, _ss;
1093				struct sockaddr_in ipaddr = {
1094				    .sin_len = sizeof(ipaddr),
1095				    .sin_family = AF_INET,
1096				};
1097
1098				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1099				    sizeof(struct in_addr) > ipt->ipt_len) {
1100					code = (u_char *)&ipt->ipt_ptr -
1101					    (u_char *)ip;
1102					goto bad;
1103				}
1104				ipaddr.sin_addr = dst;
1105				_ss = pserialize_read_enter();
1106				rcvif = m_get_rcvif(m, &_s);
1107				if (__predict_true(rcvif != NULL)) {
1108					ifa = ifaof_ifpforaddr(sintosa(&ipaddr),
1109					    rcvif);
1110				}
1111				m_put_rcvif(rcvif, &_s);
1112				if (ifa == NULL) {
1113					pserialize_read_exit(_ss);
1114					break;
1115				}
1116				ia = ifatoia(ifa);
1117				bcopy(&ia->ia_addr.sin_addr,
1118				    cp0, sizeof(struct in_addr));
1119				pserialize_read_exit(_ss);
1120				ipt->ipt_ptr += sizeof(struct in_addr);
1121				break;
1122			}
1123
1124			case IPOPT_TS_PRESPEC: {
1125				struct sockaddr_in ipaddr = {
1126				    .sin_len = sizeof(ipaddr),
1127				    .sin_family = AF_INET,
1128				};
1129
1130				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1131				    sizeof(struct in_addr) > ipt->ipt_len) {
1132					code = (u_char *)&ipt->ipt_ptr -
1133					    (u_char *)ip;
1134					goto bad;
1135				}
1136				memcpy(&ipaddr.sin_addr, cp0,
1137				    sizeof(struct in_addr));
1138				s = pserialize_read_enter();
1139				ifa = ifa_ifwithaddr(sintosa(&ipaddr));
1140				if (ifa == NULL) {
1141					pserialize_read_exit(s);
1142					continue;
1143				}
1144				pserialize_read_exit(s);
1145				ipt->ipt_ptr += sizeof(struct in_addr);
1146				break;
1147			    }
1148
1149			default:
1150				/* XXX can't take &ipt->ipt_flg */
1151				code = (u_char *)&ipt->ipt_ptr -
1152				    (u_char *)ip + 1;
1153				goto bad;
1154			}
1155			ntime = iptime();
1156			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1157			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1158			    sizeof(n_time));
1159			ipt->ipt_ptr += sizeof(n_time);
1160		}
1161	}
1162	if (forward) {
1163		struct ifnet *rcvif;
1164		struct psref _psref;
1165
1166		if (ip_forwsrcrt == 0) {
1167			type = ICMP_UNREACH;
1168			code = ICMP_UNREACH_SRCFAIL;
1169			goto bad;
1170		}
1171
1172		rcvif = m_get_rcvif_psref(m, &_psref);
1173		if (__predict_false(rcvif == NULL)) {
1174			type = ICMP_UNREACH;
1175			code = ICMP_UNREACH_HOST;
1176			goto bad;
1177		}
1178		ip_forward(m, 1, rcvif);
1179		m_put_rcvif_psref(rcvif, &_psref);
1180		return true;
1181	}
1182	return false;
1183bad:
1184	icmp_error(m, type, code, 0, 0);
1185	IP_STATINC(IP_STAT_BADOPTIONS);
1186	return true;
1187}
1188
1189/*
1190 * ip_rtaddr: given address of next destination (final or next hop),
1191 * return internet address info of interface to be used to get there.
1192 */
1193static struct in_ifaddr *
1194ip_rtaddr(struct in_addr dst, struct psref *psref)
1195{
1196	struct rtentry *rt;
1197	union {
1198		struct sockaddr		dst;
1199		struct sockaddr_in	dst4;
1200	} u;
1201	struct route *ro;
1202
1203	sockaddr_in_init(&u.dst4, &dst, 0);
1204
1205	ro = percpu_getref(ipforward_rt_percpu);
1206	rt = rtcache_lookup(ro, &u.dst);
1207	if (rt == NULL) {
1208		percpu_putref(ipforward_rt_percpu);
1209		return NULL;
1210	}
1211
1212	ia4_acquire(ifatoia(rt->rt_ifa), psref);
1213	rtcache_unref(rt, ro);
1214	percpu_putref(ipforward_rt_percpu);
1215
1216	return ifatoia(rt->rt_ifa);
1217}
1218
1219/*
1220 * save_rte: save incoming source route for use in replies, to be picked
1221 * up later by ip_srcroute if the receiver is interested.
1222 */
1223static void
1224save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1225{
1226	struct ip_srcrt *isr;
1227	struct m_tag *mtag;
1228	unsigned olen;
1229
1230	olen = option[IPOPT_OLEN];
1231	if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes))
1232		return;
1233
1234	mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT);
1235	if (mtag == NULL)
1236		return;
1237	isr = (struct ip_srcrt *)(mtag + 1);
1238
1239	memcpy(isr->isr_hdr, option, olen);
1240	isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1241	isr->isr_dst = dst;
1242	m_tag_prepend(m, mtag);
1243}
1244
1245/*
1246 * Retrieve incoming source route for use in replies,
1247 * in the same form used by setsockopt.
1248 * The first hop is placed before the options, will be removed later.
1249 */
1250struct mbuf *
1251ip_srcroute(struct mbuf *m0)
1252{
1253	struct in_addr *p, *q;
1254	struct mbuf *m;
1255	struct ip_srcrt *isr;
1256	struct m_tag *mtag;
1257
1258	mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE, NULL);
1259	if (mtag == NULL)
1260		return NULL;
1261	isr = (struct ip_srcrt *)(mtag + 1);
1262
1263	if (isr->isr_nhops == 0)
1264		return NULL;
1265
1266	m = m_get(M_DONTWAIT, MT_SOOPTS);
1267	if (m == NULL)
1268		return NULL;
1269
1270	MCLAIM(m, &inetdomain.dom_mowner);
1271#define OPTSIZ	(sizeof(isr->isr_nop) + sizeof(isr->isr_hdr))
1272
1273	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */
1274	m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ;
1275
1276	/*
1277	 * First save first hop for return route
1278	 */
1279	p = &(isr->isr_routes[isr->isr_nhops - 1]);
1280	*(mtod(m, struct in_addr *)) = *p--;
1281
1282	/*
1283	 * Copy option fields and padding (nop) to mbuf.
1284	 */
1285	isr->isr_nop = IPOPT_NOP;
1286	isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF;
1287	memmove(mtod(m, char *) + sizeof(struct in_addr), &isr->isr_nop,
1288	    OPTSIZ);
1289	q = (struct in_addr *)(mtod(m, char *) +
1290	    sizeof(struct in_addr) + OPTSIZ);
1291#undef OPTSIZ
1292	/*
1293	 * Record return path as an IP source route,
1294	 * reversing the path (pointers are now aligned).
1295	 */
1296	while (p >= isr->isr_routes) {
1297		*q++ = *p--;
1298	}
1299	/*
1300	 * Last hop goes to final destination.
1301	 */
1302	*q = isr->isr_dst;
1303	m_tag_delete(m0, mtag);
1304	return m;
1305}
1306
1307const int inetctlerrmap[PRC_NCMDS] = {
1308	[PRC_MSGSIZE] = EMSGSIZE,
1309	[PRC_HOSTDEAD] = EHOSTDOWN,
1310	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1311	[PRC_UNREACH_NET] = EHOSTUNREACH,
1312	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1313	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1314	[PRC_UNREACH_PORT] = ECONNREFUSED,
1315	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1316	[PRC_PARAMPROB] = ENOPROTOOPT,
1317};
1318
1319void
1320ip_fasttimo(void)
1321{
1322	if (ip_drainwanted) {
1323		ip_drain();
1324		ip_drainwanted = 0;
1325	}
1326}
1327
1328void
1329ip_drainstub(void)
1330{
1331	ip_drainwanted = 1;
1332}
1333
1334/*
1335 * Forward a packet.  If some error occurs return the sender
1336 * an icmp packet.  Note we can't always generate a meaningful
1337 * icmp message because icmp doesn't have a large enough repertoire
1338 * of codes and types.
1339 *
1340 * If not forwarding, just drop the packet.  This could be confusing
1341 * if ipforwarding was zero but some routing protocol was advancing
1342 * us as a gateway to somewhere.  However, we must let the routing
1343 * protocol deal with that.
1344 *
1345 * The srcrt parameter indicates whether the packet is being forwarded
1346 * via a source route.
1347 */
1348static void
1349ip_forward(struct mbuf *m, int srcrt, struct ifnet *rcvif)
1350{
1351	struct ip *ip = mtod(m, struct ip *);
1352	struct rtentry *rt;
1353	int error, type = 0, code = 0, destmtu = 0;
1354	struct mbuf *mcopy;
1355	n_long dest;
1356	union {
1357		struct sockaddr		dst;
1358		struct sockaddr_in	dst4;
1359	} u;
1360	uint64_t *ips;
1361	struct route *ro;
1362
1363	KASSERTMSG(cpu_softintr_p(), "ip_forward: not in the software "
1364	    "interrupt handler; synchronization assumptions violated");
1365
1366	/*
1367	 * We are now in the output path.
1368	 */
1369	MCLAIM(m, &ip_tx_mowner);
1370
1371	/*
1372	 * Clear any in-bound checksum flags for this packet.
1373	 */
1374	m->m_pkthdr.csum_flags = 0;
1375
1376	dest = 0;
1377	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1378		IP_STATINC(IP_STAT_CANTFORWARD);
1379		m_freem(m);
1380		return;
1381	}
1382
1383	if (ip->ip_ttl <= IPTTLDEC) {
1384		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1385		return;
1386	}
1387
1388	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1389
1390	ro = percpu_getref(ipforward_rt_percpu);
1391	rt = rtcache_lookup(ro, &u.dst);
1392	if (rt == NULL) {
1393		percpu_putref(ipforward_rt_percpu);
1394		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1395		return;
1396	}
1397
1398	/*
1399	 * Save at most 68 bytes of the packet in case
1400	 * we need to generate an ICMP message to the src.
1401	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1402	 */
1403	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1404	if (mcopy)
1405		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1406
1407	ip->ip_ttl -= IPTTLDEC;
1408
1409	/*
1410	 * If forwarding packet using same interface that it came in on,
1411	 * perhaps should send a redirect to sender to shortcut a hop.
1412	 * Only send redirect if source is sending directly to us,
1413	 * and if packet was not source routed (or has any options).
1414	 * Also, don't send redirect if forwarding using a default route
1415	 * or a route modified by a redirect.
1416	 */
1417	if (rt->rt_ifp == rcvif &&
1418	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1419	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1420	    ipsendredirects && !srcrt) {
1421		if (rt->rt_ifa &&
1422		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1423		    ifatoia(rt->rt_ifa)->ia_subnet) {
1424			if (rt->rt_flags & RTF_GATEWAY)
1425				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1426			else
1427				dest = ip->ip_dst.s_addr;
1428			/*
1429			 * Router requirements says to only send host
1430			 * redirects.
1431			 */
1432			type = ICMP_REDIRECT;
1433			code = ICMP_REDIRECT_HOST;
1434		}
1435	}
1436	rtcache_unref(rt, ro);
1437
1438	error = ip_output(m, NULL, ro,
1439	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1440	    NULL, NULL);
1441
1442	if (error) {
1443		IP_STATINC(IP_STAT_CANTFORWARD);
1444		goto error;
1445	}
1446
1447	ips = IP_STAT_GETREF();
1448	ips[IP_STAT_FORWARD]++;
1449
1450	if (type) {
1451		ips[IP_STAT_REDIRECTSENT]++;
1452		IP_STAT_PUTREF();
1453		goto redirect;
1454	}
1455
1456	IP_STAT_PUTREF();
1457	if (mcopy) {
1458#ifdef GATEWAY
1459		if (mcopy->m_flags & M_CANFASTFWD)
1460			ipflow_create(ro, mcopy);
1461#endif
1462		m_freem(mcopy);
1463	}
1464
1465	percpu_putref(ipforward_rt_percpu);
1466	return;
1467
1468redirect:
1469error:
1470	if (mcopy == NULL) {
1471		percpu_putref(ipforward_rt_percpu);
1472		return;
1473	}
1474
1475	switch (error) {
1476
1477	case 0:				/* forwarded, but need redirect */
1478		/* type, code set above */
1479		break;
1480
1481	case ENETUNREACH:		/* shouldn't happen, checked above */
1482	case EHOSTUNREACH:
1483	case ENETDOWN:
1484	case EHOSTDOWN:
1485	default:
1486		type = ICMP_UNREACH;
1487		code = ICMP_UNREACH_HOST;
1488		break;
1489
1490	case EMSGSIZE:
1491		type = ICMP_UNREACH;
1492		code = ICMP_UNREACH_NEEDFRAG;
1493
1494		if ((rt = rtcache_validate(ro)) != NULL) {
1495			destmtu = rt->rt_ifp->if_mtu;
1496			rtcache_unref(rt, ro);
1497		}
1498#ifdef IPSEC
1499		if (ipsec_used)
1500			(void)ipsec4_forward(mcopy, &destmtu);
1501#endif
1502		IP_STATINC(IP_STAT_CANTFRAG);
1503		break;
1504
1505	case ENOBUFS:
1506		/*
1507		 * Do not generate ICMP_SOURCEQUENCH as required in RFC 1812,
1508		 * Requirements for IP Version 4 Routers.  Source quench can
1509		 * big problem under DoS attacks or if the underlying
1510		 * interface is rate-limited.
1511		 */
1512		if (mcopy)
1513			m_freem(mcopy);
1514		percpu_putref(ipforward_rt_percpu);
1515		return;
1516	}
1517	icmp_error(mcopy, type, code, dest, destmtu);
1518	percpu_putref(ipforward_rt_percpu);
1519}
1520
1521void
1522ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1523    struct mbuf *m)
1524{
1525	struct socket *so = inp->inp_socket;
1526	int inpflags = inp->inp_flags;
1527
1528	if (SOOPT_TIMESTAMP(so->so_options))
1529		mp = sbsavetimestamp(so->so_options, m, mp);
1530
1531	if (inpflags & INP_RECVDSTADDR) {
1532		*mp = sbcreatecontrol(&ip->ip_dst,
1533		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1534		if (*mp)
1535			mp = &(*mp)->m_next;
1536	}
1537
1538	if (inpflags & INP_RECVTTL) {
1539		*mp = sbcreatecontrol(&ip->ip_ttl,
1540		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1541		if (*mp)
1542			mp = &(*mp)->m_next;
1543	}
1544
1545	struct psref psref;
1546	ifnet_t *ifp = m_get_rcvif_psref(m, &psref);
1547	if (__predict_false(ifp == NULL)) {
1548#ifdef DIAGNOSTIC
1549		printf("%s: missing receive interface\n", __func__);
1550#endif
1551		return; /* XXX should report error? */
1552	}
1553
1554	if (inpflags & INP_RECVPKTINFO) {
1555		struct in_pktinfo ipi;
1556		ipi.ipi_addr = ip->ip_dst;
1557		ipi.ipi_ifindex = ifp->if_index;
1558		*mp = sbcreatecontrol(&ipi,
1559		    sizeof(ipi), IP_PKTINFO, IPPROTO_IP);
1560		if (*mp)
1561			mp = &(*mp)->m_next;
1562	}
1563	if (inpflags & INP_RECVIF) {
1564		struct sockaddr_dl sdl;
1565
1566		sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, 0, NULL, 0,
1567		    NULL, 0);
1568		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1569		if (*mp)
1570			mp = &(*mp)->m_next;
1571	}
1572	m_put_rcvif_psref(ifp, &psref);
1573}
1574
1575/*
1576 * sysctl helper routine for net.inet.ip.forwsrcrt.
1577 */
1578static int
1579sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1580{
1581	int error, tmp;
1582	struct sysctlnode node;
1583
1584	node = *rnode;
1585	tmp = ip_forwsrcrt;
1586	node.sysctl_data = &tmp;
1587	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1588	if (error || newp == NULL)
1589		return (error);
1590
1591	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1592	    0, NULL, NULL, NULL);
1593	if (error)
1594		return (error);
1595
1596	ip_forwsrcrt = tmp;
1597
1598	return (0);
1599}
1600
1601/*
1602 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1603 * range of the new value and tweaks timers if it changes.
1604 */
1605static int
1606sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1607{
1608	int error, tmp;
1609	struct sysctlnode node;
1610
1611	icmp_mtudisc_lock();
1612
1613	node = *rnode;
1614	tmp = ip_mtudisc_timeout;
1615	node.sysctl_data = &tmp;
1616	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1617	if (error || newp == NULL)
1618		goto out;
1619	if (tmp < 0) {
1620		error = EINVAL;
1621		goto out;
1622	}
1623
1624	ip_mtudisc_timeout = tmp;
1625	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1626	error = 0;
1627out:
1628	icmp_mtudisc_unlock();
1629	return error;
1630}
1631
1632static int
1633sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1634{
1635
1636	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1637}
1638
1639static void
1640sysctl_net_inet_ip_setup(struct sysctllog **clog)
1641{
1642	sysctl_createv(clog, 0, NULL, NULL,
1643		       CTLFLAG_PERMANENT,
1644		       CTLTYPE_NODE, "inet",
1645		       SYSCTL_DESCR("PF_INET related settings"),
1646		       NULL, 0, NULL, 0,
1647		       CTL_NET, PF_INET, CTL_EOL);
1648	sysctl_createv(clog, 0, NULL, NULL,
1649		       CTLFLAG_PERMANENT,
1650		       CTLTYPE_NODE, "ip",
1651		       SYSCTL_DESCR("IPv4 related settings"),
1652		       NULL, 0, NULL, 0,
1653		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1654
1655	sysctl_createv(clog, 0, NULL, NULL,
1656		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1657		       CTLTYPE_INT, "forwarding",
1658		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1659		       NULL, 0, &ipforwarding, 0,
1660		       CTL_NET, PF_INET, IPPROTO_IP,
1661		       IPCTL_FORWARDING, CTL_EOL);
1662	sysctl_createv(clog, 0, NULL, NULL,
1663		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1664		       CTLTYPE_INT, "redirect",
1665		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1666		       NULL, 0, &ipsendredirects, 0,
1667		       CTL_NET, PF_INET, IPPROTO_IP,
1668		       IPCTL_SENDREDIRECTS, CTL_EOL);
1669	sysctl_createv(clog, 0, NULL, NULL,
1670		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1671		       CTLTYPE_INT, "ttl",
1672		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1673		       NULL, 0, &ip_defttl, 0,
1674		       CTL_NET, PF_INET, IPPROTO_IP,
1675		       IPCTL_DEFTTL, CTL_EOL);
1676#ifdef IPCTL_DEFMTU
1677	sysctl_createv(clog, 0, NULL, NULL,
1678		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1679		       CTLTYPE_INT, "mtu",
1680		       SYSCTL_DESCR("Default MTA for an INET route"),
1681		       NULL, 0, &ip_mtu, 0,
1682		       CTL_NET, PF_INET, IPPROTO_IP,
1683		       IPCTL_DEFMTU, CTL_EOL);
1684#endif /* IPCTL_DEFMTU */
1685	sysctl_createv(clog, 0, NULL, NULL,
1686		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1687		       CTLTYPE_INT, "forwsrcrt",
1688		       SYSCTL_DESCR("Enable forwarding of source-routed "
1689				    "datagrams"),
1690		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1691		       CTL_NET, PF_INET, IPPROTO_IP,
1692		       IPCTL_FORWSRCRT, CTL_EOL);
1693	sysctl_createv(clog, 0, NULL, NULL,
1694		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1695		       CTLTYPE_INT, "directed-broadcast",
1696		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1697		       NULL, 0, &ip_directedbcast, 0,
1698		       CTL_NET, PF_INET, IPPROTO_IP,
1699		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1700	sysctl_createv(clog, 0, NULL, NULL,
1701		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1702		       CTLTYPE_INT, "allowsrcrt",
1703		       SYSCTL_DESCR("Accept source-routed datagrams"),
1704		       NULL, 0, &ip_allowsrcrt, 0,
1705		       CTL_NET, PF_INET, IPPROTO_IP,
1706		       IPCTL_ALLOWSRCRT, CTL_EOL);
1707
1708	sysctl_createv(clog, 0, NULL, NULL,
1709		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1710		       CTLTYPE_INT, "mtudisc",
1711		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1712		       NULL, 0, &ip_mtudisc, 0,
1713		       CTL_NET, PF_INET, IPPROTO_IP,
1714		       IPCTL_MTUDISC, CTL_EOL);
1715	sysctl_createv(clog, 0, NULL, NULL,
1716		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1717		       CTLTYPE_INT, "anonportmin",
1718		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1719		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1720		       CTL_NET, PF_INET, IPPROTO_IP,
1721		       IPCTL_ANONPORTMIN, CTL_EOL);
1722	sysctl_createv(clog, 0, NULL, NULL,
1723		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1724		       CTLTYPE_INT, "anonportmax",
1725		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1726		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1727		       CTL_NET, PF_INET, IPPROTO_IP,
1728		       IPCTL_ANONPORTMAX, CTL_EOL);
1729	sysctl_createv(clog, 0, NULL, NULL,
1730		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1731		       CTLTYPE_INT, "mtudisctimeout",
1732		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1733		       sysctl_net_inet_ip_pmtudto, 0, (void *)&ip_mtudisc_timeout, 0,
1734		       CTL_NET, PF_INET, IPPROTO_IP,
1735		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1736#ifndef IPNOPRIVPORTS
1737	sysctl_createv(clog, 0, NULL, NULL,
1738		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1739		       CTLTYPE_INT, "lowportmin",
1740		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1741				    "to assign"),
1742		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1743		       CTL_NET, PF_INET, IPPROTO_IP,
1744		       IPCTL_LOWPORTMIN, CTL_EOL);
1745	sysctl_createv(clog, 0, NULL, NULL,
1746		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1747		       CTLTYPE_INT, "lowportmax",
1748		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1749				    "to assign"),
1750		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1751		       CTL_NET, PF_INET, IPPROTO_IP,
1752		       IPCTL_LOWPORTMAX, CTL_EOL);
1753#endif /* IPNOPRIVPORTS */
1754#if NGRE > 0
1755	sysctl_createv(clog, 0, NULL, NULL,
1756		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1757		       CTLTYPE_INT, "grettl",
1758		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1759		       NULL, 0, &ip_gre_ttl, 0,
1760		       CTL_NET, PF_INET, IPPROTO_IP,
1761		       IPCTL_GRE_TTL, CTL_EOL);
1762#endif /* NGRE */
1763	sysctl_createv(clog, 0, NULL, NULL,
1764		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1765		       CTLTYPE_INT, "checkinterface",
1766		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1767				    "from RFC1122"),
1768		       NULL, 0, &ip_checkinterface, 0,
1769		       CTL_NET, PF_INET, IPPROTO_IP,
1770		       IPCTL_CHECKINTERFACE, CTL_EOL);
1771	sysctl_createv(clog, 0, NULL, NULL,
1772		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1773		       CTLTYPE_INT, "random_id",
1774		       SYSCTL_DESCR("Assign random ip_id values"),
1775		       NULL, 0, &ip_do_randomid, 0,
1776		       CTL_NET, PF_INET, IPPROTO_IP,
1777		       IPCTL_RANDOMID, CTL_EOL);
1778	sysctl_createv(clog, 0, NULL, NULL,
1779		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1780		       CTLTYPE_INT, "do_loopback_cksum",
1781		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1782		       NULL, 0, &ip_do_loopback_cksum, 0,
1783		       CTL_NET, PF_INET, IPPROTO_IP,
1784		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1785	sysctl_createv(clog, 0, NULL, NULL,
1786		       CTLFLAG_PERMANENT,
1787		       CTLTYPE_STRUCT, "stats",
1788		       SYSCTL_DESCR("IP statistics"),
1789		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1790		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1791		       CTL_EOL);
1792#if NARP
1793	sysctl_createv(clog, 0, NULL, NULL,
1794		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1795		       CTLTYPE_INT, "dad_count",
1796		       SYSCTL_DESCR("Number of Duplicate Address Detection "
1797				    "probes to send"),
1798		       NULL, 0, &ip_dad_count, 0,
1799		       CTL_NET, PF_INET, IPPROTO_IP,
1800		       IPCTL_DAD_COUNT, CTL_EOL);
1801#endif
1802
1803	/* anonportalgo RFC6056 subtree */
1804	const struct sysctlnode *portalgo_node;
1805	sysctl_createv(clog, 0, NULL, &portalgo_node,
1806		       CTLFLAG_PERMANENT,
1807		       CTLTYPE_NODE, "anonportalgo",
1808		       SYSCTL_DESCR("Anonymous Port Algorithm Selection (RFC 6056)"),
1809	    	       NULL, 0, NULL, 0,
1810		       CTL_NET, PF_INET, IPPROTO_IP, CTL_CREATE, CTL_EOL);
1811	sysctl_createv(clog, 0, &portalgo_node, NULL,
1812		       CTLFLAG_PERMANENT,
1813		       CTLTYPE_STRING, "available",
1814		       SYSCTL_DESCR("available algorithms"),
1815		       sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN,
1816		       CTL_CREATE, CTL_EOL);
1817	sysctl_createv(clog, 0, &portalgo_node, NULL,
1818		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1819		       CTLTYPE_STRING, "selected",
1820		       SYSCTL_DESCR("selected algorithm"),
1821		       sysctl_portalgo_selected4, 0, NULL, PORTALGO_MAXLEN,
1822		       CTL_CREATE, CTL_EOL);
1823	sysctl_createv(clog, 0, &portalgo_node, NULL,
1824		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1825		       CTLTYPE_STRUCT, "reserve",
1826		       SYSCTL_DESCR("bitmap of reserved ports"),
1827		       sysctl_portalgo_reserve4, 0, NULL, 0,
1828		       CTL_CREATE, CTL_EOL);
1829}
1830
1831void
1832ip_statinc(u_int stat)
1833{
1834
1835	KASSERT(stat < IP_NSTATS);
1836	IP_STATINC(stat);
1837}
1838