ip_input.c revision 1.362
1/*	$NetBSD: ip_input.c,v 1.362 2017/11/17 07:37:12 ozaki-r 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 1.362 2017/11/17 07:37:12 ozaki-r 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	1	/* forward source-routed packets */
165#endif
166#ifndef IPALLOWSRCRT
167#define	IPALLOWSRCRT	1	/* allow source-routed packets */
168#endif
169#ifndef IPMTUDISC
170#define IPMTUDISC	1
171#endif
172#ifndef IPMTUDISCTIMEOUT
173#define IPMTUDISCTIMEOUT (10 * 60)	/* as per RFC 1191 */
174#endif
175
176/*
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 */
214static int		ip_checkinterface	__read_mostly = 0;
215
216struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
217
218pktqueue_t *		ip_pktq			__read_mostly;
219pfil_head_t *		inet_pfil_hook		__read_mostly;
220ipid_state_t *		ip_ids			__read_mostly;
221percpu_t *		ipstat_percpu		__read_mostly;
222
223static percpu_t		*ipforward_rt_percpu	__cacheline_aligned;
224
225uint16_t ip_id;
226
227#ifdef INET_CSUM_COUNTERS
228#include <sys/device.h>
229
230struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
231    NULL, "inet", "hwcsum bad");
232struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
233    NULL, "inet", "hwcsum ok");
234struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
235    NULL, "inet", "swcsum");
236
237#define	INET_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
238
239EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
240EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
241EVCNT_ATTACH_STATIC(ip_swcsum);
242
243#else
244
245#define	INET_CSUM_COUNTER_INCR(ev)	/* nothing */
246
247#endif /* INET_CSUM_COUNTERS */
248
249/*
250 * Used to save the IP options in case a protocol wants to respond
251 * to an incoming packet over the same route if the packet got here
252 * using IP source routing.  This allows connection establishment and
253 * maintenance when the remote end is on a network that is not known
254 * to us.
255 */
256struct ip_srcrt {
257	int		isr_nhops;		   /* number of hops */
258	struct in_addr	isr_dst;		   /* final destination */
259	char		isr_nop;		   /* one NOP to align */
260	char		isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */
261	struct in_addr	isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)];
262};
263
264static int ip_drainwanted;
265
266static void save_rte(struct mbuf *, u_char *, struct in_addr);
267
268#ifdef MBUFTRACE
269struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
270struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
271#endif
272
273static void		ipintr(void *);
274static void		ip_input(struct mbuf *);
275static void		ip_forward(struct mbuf *, int, struct ifnet *);
276static bool		ip_dooptions(struct mbuf *);
277static struct in_ifaddr *ip_rtaddr(struct in_addr, struct psref *);
278static void		sysctl_net_inet_ip_setup(struct sysctllog **);
279
280static struct in_ifaddr	*ip_match_our_address(struct ifnet *, struct ip *,
281			    int *);
282static struct in_ifaddr	*ip_match_our_address_broadcast(struct ifnet *,
283			    struct ip *);
284
285#ifdef NET_MPSAFE
286#define	SOFTNET_LOCK()		mutex_enter(softnet_lock)
287#define	SOFTNET_UNLOCK()	mutex_exit(softnet_lock)
288#else
289#define	SOFTNET_LOCK()		KASSERT(mutex_owned(softnet_lock))
290#define	SOFTNET_UNLOCK()	KASSERT(mutex_owned(softnet_lock))
291#endif
292
293/*
294 * IP initialization: fill in IP protocol switch table.
295 * All protocols not implemented in kernel go to raw IP protocol handler.
296 */
297void
298ip_init(void)
299{
300	const struct protosw *pr;
301
302	in_init();
303	sysctl_net_inet_ip_setup(NULL);
304
305	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
306	KASSERT(pr != NULL);
307
308	ip_pktq = pktq_create(IFQ_MAXLEN, ipintr, NULL);
309	KASSERT(ip_pktq != NULL);
310
311	for (u_int i = 0; i < IPPROTO_MAX; i++) {
312		ip_protox[i] = pr - inetsw;
313	}
314	for (pr = inetdomain.dom_protosw;
315	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
316		if (pr->pr_domain->dom_family == PF_INET &&
317		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
318			ip_protox[pr->pr_protocol] = pr - inetsw;
319
320	ip_reass_init();
321
322	ip_ids = ip_id_init();
323	ip_id = time_uptime & 0xfffff;
324
325#ifdef GATEWAY
326	ipflow_init();
327#endif
328
329	/* Register our Packet Filter hook. */
330	inet_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET);
331	KASSERT(inet_pfil_hook != NULL);
332
333#ifdef MBUFTRACE
334	MOWNER_ATTACH(&ip_tx_mowner);
335	MOWNER_ATTACH(&ip_rx_mowner);
336#endif /* MBUFTRACE */
337
338	ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
339	ipforward_rt_percpu = percpu_alloc(sizeof(struct route));
340	ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
341}
342
343static struct in_ifaddr *
344ip_match_our_address(struct ifnet *ifp, struct ip *ip, int *downmatch)
345{
346	struct in_ifaddr *ia = NULL;
347	int checkif;
348
349	/*
350	 * Enable a consistency check between the destination address
351	 * and the arrival interface for a unicast packet (the RFC 1122
352	 * strong ES model) if IP forwarding is disabled and the packet
353	 * is not locally generated.
354	 *
355	 * XXX - Checking also should be disabled if the destination
356	 * address is ipnat'ed to a different interface.
357	 *
358	 * XXX - Checking is incompatible with IP aliases added
359	 * to the loopback interface instead of the interface where
360	 * the packets are received.
361	 *
362	 * XXX - We need to add a per ifaddr flag for this so that
363	 * we get finer grain control.
364	 */
365	checkif = ip_checkinterface && (ipforwarding == 0) &&
366	    (ifp->if_flags & IFF_LOOPBACK) == 0;
367
368	IN_ADDRHASH_READER_FOREACH(ia, ip->ip_dst.s_addr) {
369		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
370			if (ia->ia4_flags & IN_IFF_NOTREADY)
371				continue;
372			if (checkif && ia->ia_ifp != ifp)
373				continue;
374			if ((ia->ia_ifp->if_flags & IFF_UP) != 0 &&
375			    (ia->ia4_flags & IN_IFF_DETACHED) == 0)
376				break;
377			else
378				(*downmatch)++;
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 | IN_IFF_DETACHED))
396			continue;
397		if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
398		    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
399		    /*
400		     * Look for all-0's host part (old broadcast addr),
401		     * either for subnet or net.
402		     */
403		    ip->ip_dst.s_addr == ia->ia_subnet ||
404		    ip->ip_dst.s_addr == ia->ia_net)
405			goto matched;
406		/*
407		 * An interface with IP address zero accepts
408		 * all packets that arrive on that interface.
409		 */
410		if (in_nullhost(ia->ia_addr.sin_addr))
411			goto matched;
412	}
413	ia = NULL;
414
415matched:
416	return ia;
417}
418
419/*
420 * IP software interrupt routine.
421 */
422static void
423ipintr(void *arg __unused)
424{
425	struct mbuf *m;
426
427	KASSERT(cpu_softintr_p());
428
429	SOFTNET_LOCK_UNLESS_NET_MPSAFE();
430	while ((m = pktq_dequeue(ip_pktq)) != NULL) {
431		ip_input(m);
432	}
433	SOFTNET_UNLOCK_UNLESS_NET_MPSAFE();
434}
435
436/*
437 * IP input routine.  Checksum and byte swap header.  If fragmented
438 * try to reassemble.  Process options.  Pass to next level.
439 */
440static void
441ip_input(struct mbuf *m)
442{
443	struct ip *ip = NULL;
444	struct in_ifaddr *ia = NULL;
445	int hlen = 0, len;
446	int downmatch;
447	int srcrt = 0;
448	ifnet_t *ifp;
449	struct psref psref;
450	int s;
451
452	KASSERTMSG(cpu_softintr_p(), "ip_input: not in the software "
453	    "interrupt handler; synchronization assumptions violated");
454
455	MCLAIM(m, &ip_rx_mowner);
456	KASSERT((m->m_flags & M_PKTHDR) != 0);
457
458	ifp = m_get_rcvif_psref(m, &psref);
459	if (__predict_false(ifp == NULL))
460		goto out;
461
462	/*
463	 * If no IP addresses have been set yet but the interfaces
464	 * are receiving, can't do anything with incoming packets yet.
465	 * Note: we pre-check without locks held.
466	 */
467	if (IN_ADDRLIST_READER_EMPTY())
468		goto out;
469	IP_STATINC(IP_STAT_TOTAL);
470
471	/*
472	 * If the IP header is not aligned, slurp it up into a new
473	 * mbuf with space for link headers, in the event we forward
474	 * it.  Otherwise, if it is aligned, make sure the entire
475	 * base IP header is in the first mbuf of the chain.
476	 */
477	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
478		if ((m = m_copyup(m, sizeof(struct ip),
479				  (max_linkhdr + 3) & ~3)) == NULL) {
480			/* XXXJRT new stat, please */
481			IP_STATINC(IP_STAT_TOOSMALL);
482			goto out;
483		}
484	} else if (__predict_false(m->m_len < sizeof (struct ip))) {
485		if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
486			IP_STATINC(IP_STAT_TOOSMALL);
487			goto out;
488		}
489	}
490	ip = mtod(m, struct ip *);
491	if (ip->ip_v != IPVERSION) {
492		IP_STATINC(IP_STAT_BADVERS);
493		goto out;
494	}
495	hlen = ip->ip_hl << 2;
496	if (hlen < sizeof(struct ip)) {	/* minimum header length */
497		IP_STATINC(IP_STAT_BADHLEN);
498		goto out;
499	}
500	if (hlen > m->m_len) {
501		if ((m = m_pullup(m, hlen)) == NULL) {
502			IP_STATINC(IP_STAT_BADHLEN);
503			goto out;
504		}
505		ip = mtod(m, struct ip *);
506	}
507
508	/*
509	 * RFC1122: packets with a multicast source address are
510	 * not allowed.
511	 */
512	if (IN_MULTICAST(ip->ip_src.s_addr)) {
513		IP_STATINC(IP_STAT_BADADDR);
514		goto out;
515	}
516
517	/* 127/8 must not appear on wire - RFC1122 */
518	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
519	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
520		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
521			IP_STATINC(IP_STAT_BADADDR);
522			goto out;
523		}
524	}
525
526	switch (m->m_pkthdr.csum_flags &
527		((ifp->if_csum_flags_rx & M_CSUM_IPv4) |
528		 M_CSUM_IPv4_BAD)) {
529	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
530		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
531		IP_STATINC(IP_STAT_BADSUM);
532		goto out;
533
534	case M_CSUM_IPv4:
535		/* Checksum was okay. */
536		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
537		break;
538
539	default:
540		/*
541		 * Must compute it ourselves.  Maybe skip checksum on
542		 * loopback interfaces.
543		 */
544		if (__predict_true(!(ifp->if_flags & IFF_LOOPBACK) ||
545		    ip_do_loopback_cksum)) {
546			INET_CSUM_COUNTER_INCR(&ip_swcsum);
547			if (in_cksum(m, hlen) != 0) {
548				IP_STATINC(IP_STAT_BADSUM);
549				goto out;
550			}
551		}
552		break;
553	}
554
555	/* Retrieve the packet length. */
556	len = ntohs(ip->ip_len);
557
558	/*
559	 * Check for additional length bogosity
560	 */
561	if (len < hlen) {
562		IP_STATINC(IP_STAT_BADLEN);
563		goto out;
564	}
565
566	/*
567	 * Check that the amount of data in the buffers
568	 * is as at least much as the IP header would have us expect.
569	 * Trim mbufs if longer than we expect.
570	 * Drop packet if shorter than we expect.
571	 */
572	if (m->m_pkthdr.len < len) {
573		IP_STATINC(IP_STAT_TOOSHORT);
574		goto out;
575	}
576	if (m->m_pkthdr.len > len) {
577		if (m->m_len == m->m_pkthdr.len) {
578			m->m_len = len;
579			m->m_pkthdr.len = len;
580		} else
581			m_adj(m, len - m->m_pkthdr.len);
582	}
583
584	/*
585	 * Assume that we can create a fast-forward IP flow entry
586	 * based on this packet.
587	 */
588	m->m_flags |= M_CANFASTFWD;
589
590	/*
591	 * Run through list of hooks for input packets.  If there are any
592	 * filters which require that additional packets in the flow are
593	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
594	 * Note that filters must _never_ set this flag, as another filter
595	 * in the list may have previously cleared it.
596	 */
597#if defined(IPSEC)
598	if (!ipsec_used || !ipsec_indone(m))
599#else
600	if (1)
601#endif
602	{
603		struct in_addr odst = ip->ip_dst;
604		bool freed;
605
606		freed = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_IN) != 0;
607		if (freed || m == NULL) {
608			m = NULL;
609			goto out;
610		}
611		ip = mtod(m, struct ip *);
612		hlen = ip->ip_hl << 2;
613
614		/*
615		 * XXX The setting of "srcrt" here is to prevent ip_forward()
616		 * from generating ICMP redirects for packets that have
617		 * been redirected by a hook back out on to the same LAN that
618		 * they came from and is not an indication that the packet
619		 * is being inffluenced by source routing options.  This
620		 * allows things like
621		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
622		 * where tlp0 is both on the 1.1.1.0/24 network and is the
623		 * default route for hosts on 1.1.1.0/24.  Of course this
624		 * also requires a "map tlp0 ..." to complete the story.
625		 * One might argue whether or not this kind of network config.
626		 * should be supported in this manner...
627		 */
628		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
629	}
630
631#ifdef ALTQ
632	/* XXX Temporary until ALTQ is changed to use a pfil hook */
633	if (altq_input) {
634		SOFTNET_LOCK();
635		if ((*altq_input)(m, AF_INET) == 0) {
636			/* Packet dropped by traffic conditioner. */
637			SOFTNET_UNLOCK();
638			m = NULL;
639			goto out;
640		}
641		SOFTNET_UNLOCK();
642	}
643#endif
644
645	/*
646	 * Process options and, if not destined for us,
647	 * ship it on.  ip_dooptions returns 1 when an
648	 * error was detected (causing an icmp message
649	 * to be sent and the original packet to be freed).
650	 */
651	if (hlen > sizeof (struct ip) && ip_dooptions(m)) {
652		m = NULL;
653		goto out;
654	}
655
656	/*
657	 * Check our list of addresses, to see if the packet is for us.
658	 *
659	 * Traditional 4.4BSD did not consult IFF_UP at all.
660	 * The behavior here is to treat addresses on !IFF_UP interface
661	 * or IN_IFF_NOTREADY addresses as not mine.
662	 */
663	downmatch = 0;
664	s = pserialize_read_enter();
665	ia = ip_match_our_address(ifp, ip, &downmatch);
666	if (ia != NULL) {
667		pserialize_read_exit(s);
668		goto ours;
669	}
670
671	if (ifp->if_flags & IFF_BROADCAST) {
672		ia = ip_match_our_address_broadcast(ifp, ip);
673		if (ia != NULL) {
674			pserialize_read_exit(s);
675			goto ours;
676		}
677	}
678	pserialize_read_exit(s);
679
680	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
681#ifdef MROUTING
682		extern struct socket *ip_mrouter;
683
684		if (ip_mrouter) {
685			/*
686			 * If we are acting as a multicast router, all
687			 * incoming multicast packets are passed to the
688			 * kernel-level multicast forwarding function.
689			 * The packet is returned (relatively) intact; if
690			 * ip_mforward() returns a non-zero value, the packet
691			 * must be discarded, else it may be accepted below.
692			 *
693			 * (The IP ident field is put in the same byte order
694			 * as expected when ip_mforward() is called from
695			 * ip_output().)
696			 */
697			SOFTNET_LOCK();
698			if (ip_mforward(m, ifp) != 0) {
699				SOFTNET_UNLOCK();
700				IP_STATINC(IP_STAT_CANTFORWARD);
701				goto out;
702			}
703			SOFTNET_UNLOCK();
704
705			/*
706			 * The process-level routing demon needs to receive
707			 * all multicast IGMP packets, whether or not this
708			 * host belongs to their destination groups.
709			 */
710			if (ip->ip_p == IPPROTO_IGMP) {
711				goto ours;
712			}
713			IP_STATINC(IP_STAT_CANTFORWARD);
714		}
715#endif
716		/*
717		 * See if we belong to the destination multicast group on the
718		 * arrival interface.
719		 */
720		if (!in_multi_group(ip->ip_dst, ifp, 0)) {
721			IP_STATINC(IP_STAT_CANTFORWARD);
722			goto out;
723		}
724		goto ours;
725	}
726	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
727	    in_nullhost(ip->ip_dst))
728		goto ours;
729
730	/*
731	 * Not for us; forward if possible and desirable.
732	 */
733	if (ipforwarding == 0) {
734		m_put_rcvif_psref(ifp, &psref);
735		IP_STATINC(IP_STAT_CANTFORWARD);
736		m_freem(m);
737	} else {
738		/*
739		 * If ip_dst matched any of my address on !IFF_UP interface,
740		 * and there's no IFF_UP interface that matches ip_dst,
741		 * send icmp unreach.  Forwarding it will result in in-kernel
742		 * forwarding loop till TTL goes to 0.
743		 */
744		if (downmatch) {
745			m_put_rcvif_psref(ifp, &psref);
746			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
747			IP_STATINC(IP_STAT_CANTFORWARD);
748			return;
749		}
750#ifdef IPSEC
751		/* Check the security policy (SP) for the packet */
752		if (ipsec_used) {
753			if (ipsec4_input(m, IP_FORWARDING |
754			    (ip_directedbcast ? IP_ALLOWBROADCAST : 0)) != 0) {
755				goto out;
756			}
757		}
758#endif
759		ip_forward(m, srcrt, ifp);
760		m_put_rcvif_psref(ifp, &psref);
761	}
762	return;
763
764ours:
765	m_put_rcvif_psref(ifp, &psref);
766	ifp = NULL;
767
768	/*
769	 * If offset or IP_MF are set, must reassemble.
770	 */
771	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
772		/*
773		 * Pass to IP reassembly mechanism.
774		 */
775		if (ip_reass_packet(&m, ip) != 0) {
776			/* Failed; invalid fragment(s) or packet. */
777			goto out;
778		}
779		if (m == NULL) {
780			/* More fragments should come; silently return. */
781			goto out;
782		}
783		/*
784		 * Reassembly is done, we have the final packet.
785		 * Updated cached data in local variable(s).
786		 */
787		ip = mtod(m, struct ip *);
788		hlen = ip->ip_hl << 2;
789	}
790
791#ifdef IPSEC
792	/*
793	 * Enforce IPsec policy checking if we are seeing last header.
794	 * Note that we do not visit this with protocols with PCB layer
795	 * code - like UDP/TCP/raw IP.
796	 */
797	if (ipsec_used &&
798	    (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
799		if (ipsec4_input(m, 0) != 0) {
800			goto out;
801		}
802	}
803#endif
804
805	/*
806	 * Switch out to protocol's input routine.
807	 */
808#if IFA_STATS
809	if (ia && ip) {
810		struct in_ifaddr *_ia;
811		/*
812		 * Keep a reference from ip_match_our_address with psref
813		 * is expensive, so explore ia here again.
814		 */
815		s = pserialize_read_enter();
816		_ia = in_get_ia(ip->ip_dst);
817		_ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
818		pserialize_read_exit(s);
819	}
820#endif
821	IP_STATINC(IP_STAT_DELIVERED);
822
823	const int off = hlen, nh = ip->ip_p;
824
825	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
826	return;
827
828out:
829	m_put_rcvif_psref(ifp, &psref);
830	if (m != NULL)
831		m_freem(m);
832}
833
834/*
835 * IP timer processing.
836 */
837void
838ip_slowtimo(void)
839{
840
841	SOFTNET_KERNEL_LOCK_UNLESS_NET_MPSAFE();
842
843	ip_reass_slowtimo();
844
845	SOFTNET_KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
846}
847
848/*
849 * IP drain processing.
850 */
851void
852ip_drain(void)
853{
854
855	KERNEL_LOCK(1, NULL);
856	ip_reass_drain();
857	KERNEL_UNLOCK_ONE(NULL);
858}
859
860/*
861 * ip_dooptions: perform option processing on a datagram, possibly discarding
862 * it if bad options are encountered, or forwarding it if source-routed.
863 *
864 * => Returns true if packet has been forwarded/freed.
865 * => Returns false if the packet should be processed further.
866 */
867static bool
868ip_dooptions(struct mbuf *m)
869{
870	struct ip *ip = mtod(m, struct ip *);
871	u_char *cp, *cp0;
872	struct ip_timestamp *ipt;
873	struct in_ifaddr *ia;
874	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
875	struct in_addr dst;
876	n_time ntime;
877	struct ifaddr *ifa = NULL;
878	int s;
879
880	dst = ip->ip_dst;
881	cp = (u_char *)(ip + 1);
882	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
883	for (; cnt > 0; cnt -= optlen, cp += optlen) {
884		opt = cp[IPOPT_OPTVAL];
885		if (opt == IPOPT_EOL)
886			break;
887		if (opt == IPOPT_NOP)
888			optlen = 1;
889		else {
890			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
891				code = &cp[IPOPT_OLEN] - (u_char *)ip;
892				goto bad;
893			}
894			optlen = cp[IPOPT_OLEN];
895			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
896				code = &cp[IPOPT_OLEN] - (u_char *)ip;
897				goto bad;
898			}
899		}
900		switch (opt) {
901
902		default:
903			break;
904
905		/*
906		 * Source routing with record.
907		 * Find interface with current destination address.
908		 * If none on this machine then drop if strictly routed,
909		 * or do nothing if loosely routed.
910		 * Record interface address and bring up next address
911		 * component.  If strictly routed make sure next
912		 * address is on directly accessible net.
913		 */
914		case IPOPT_LSRR:
915		case IPOPT_SSRR: {
916			struct psref psref;
917			struct sockaddr_in ipaddr = {
918			    .sin_len = sizeof(ipaddr),
919			    .sin_family = AF_INET,
920			};
921
922			if (ip_allowsrcrt == 0) {
923				type = ICMP_UNREACH;
924				code = ICMP_UNREACH_NET_PROHIB;
925				goto bad;
926			}
927			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
928				code = &cp[IPOPT_OLEN] - (u_char *)ip;
929				goto bad;
930			}
931			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
932				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
933				goto bad;
934			}
935			ipaddr.sin_addr = ip->ip_dst;
936
937			s = pserialize_read_enter();
938			ifa = ifa_ifwithaddr(sintosa(&ipaddr));
939			if (ifa == NULL) {
940				pserialize_read_exit(s);
941				if (opt == IPOPT_SSRR) {
942					type = ICMP_UNREACH;
943					code = ICMP_UNREACH_SRCFAIL;
944					goto bad;
945				}
946				/*
947				 * Loose routing, and not at next destination
948				 * yet; nothing to do except forward.
949				 */
950				break;
951			}
952			pserialize_read_exit(s);
953
954			off--;			/* 0 origin */
955			if ((off + sizeof(struct in_addr)) > optlen) {
956				/*
957				 * End of source route.  Should be for us.
958				 */
959				save_rte(m, cp, ip->ip_src);
960				break;
961			}
962			/*
963			 * locate outgoing interface
964			 */
965			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
966			    sizeof(ipaddr.sin_addr));
967			if (opt == IPOPT_SSRR) {
968				ifa = ifa_ifwithladdr_psref(sintosa(&ipaddr),
969				    &psref);
970				if (ifa != NULL)
971					ia = ifatoia(ifa);
972				else
973					ia = NULL;
974			} else {
975				ia = ip_rtaddr(ipaddr.sin_addr, &psref);
976			}
977			if (ia == NULL) {
978				type = ICMP_UNREACH;
979				code = ICMP_UNREACH_SRCFAIL;
980				goto bad;
981			}
982			ip->ip_dst = ipaddr.sin_addr;
983			bcopy((void *)&ia->ia_addr.sin_addr,
984			    (void *)(cp + off), sizeof(struct in_addr));
985			ia4_release(ia, &psref);
986			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
987			/*
988			 * Let ip_intr's mcast routing check handle mcast pkts
989			 */
990			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
991			break;
992		    }
993
994		case IPOPT_RR: {
995			struct psref psref;
996			struct sockaddr_in ipaddr = {
997			    .sin_len = sizeof(ipaddr),
998			    .sin_family = AF_INET,
999			};
1000
1001			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1002				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1003				goto bad;
1004			}
1005			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1006				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1007				goto bad;
1008			}
1009			/*
1010			 * If no space remains, ignore.
1011			 */
1012			off--;			/* 0 origin */
1013			if ((off + sizeof(struct in_addr)) > optlen)
1014				break;
1015			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1016			    sizeof(ipaddr.sin_addr));
1017			/*
1018			 * locate outgoing interface; if we're the destination,
1019			 * use the incoming interface (should be same).
1020			 */
1021			ifa = ifa_ifwithaddr_psref(sintosa(&ipaddr), &psref);
1022			if (ifa == NULL) {
1023				ia = ip_rtaddr(ipaddr.sin_addr, &psref);
1024				if (ia == NULL) {
1025					type = ICMP_UNREACH;
1026					code = ICMP_UNREACH_HOST;
1027					goto bad;
1028				}
1029			} else {
1030				ia = ifatoia(ifa);
1031			}
1032			bcopy((void *)&ia->ia_addr.sin_addr,
1033			    (void *)(cp + off), sizeof(struct in_addr));
1034			ia4_release(ia, &psref);
1035			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1036			break;
1037		    }
1038
1039		case IPOPT_TS:
1040			code = cp - (u_char *)ip;
1041			ipt = (struct ip_timestamp *)cp;
1042			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1043				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1044				goto bad;
1045			}
1046			if (ipt->ipt_ptr < 5) {
1047				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1048				goto bad;
1049			}
1050			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1051				if (++ipt->ipt_oflw == 0) {
1052					code = (u_char *)&ipt->ipt_ptr -
1053					    (u_char *)ip;
1054					goto bad;
1055				}
1056				break;
1057			}
1058			cp0 = (cp + ipt->ipt_ptr - 1);
1059			switch (ipt->ipt_flg) {
1060
1061			case IPOPT_TS_TSONLY:
1062				break;
1063
1064			case IPOPT_TS_TSANDADDR: {
1065				struct ifnet *rcvif;
1066				int _s, _ss;
1067				struct sockaddr_in ipaddr = {
1068				    .sin_len = sizeof(ipaddr),
1069				    .sin_family = AF_INET,
1070				};
1071
1072				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1073				    sizeof(struct in_addr) > ipt->ipt_len) {
1074					code = (u_char *)&ipt->ipt_ptr -
1075					    (u_char *)ip;
1076					goto bad;
1077				}
1078				ipaddr.sin_addr = dst;
1079				_ss = pserialize_read_enter();
1080				rcvif = m_get_rcvif(m, &_s);
1081				if (__predict_true(rcvif != NULL)) {
1082					ifa = ifaof_ifpforaddr(sintosa(&ipaddr),
1083					    rcvif);
1084				}
1085				m_put_rcvif(rcvif, &_s);
1086				if (ifa == NULL) {
1087					pserialize_read_exit(_ss);
1088					break;
1089				}
1090				ia = ifatoia(ifa);
1091				bcopy(&ia->ia_addr.sin_addr,
1092				    cp0, sizeof(struct in_addr));
1093				pserialize_read_exit(_ss);
1094				ipt->ipt_ptr += sizeof(struct in_addr);
1095				break;
1096			}
1097
1098			case IPOPT_TS_PRESPEC: {
1099				struct sockaddr_in ipaddr = {
1100				    .sin_len = sizeof(ipaddr),
1101				    .sin_family = AF_INET,
1102				};
1103
1104				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1105				    sizeof(struct in_addr) > ipt->ipt_len) {
1106					code = (u_char *)&ipt->ipt_ptr -
1107					    (u_char *)ip;
1108					goto bad;
1109				}
1110				memcpy(&ipaddr.sin_addr, cp0,
1111				    sizeof(struct in_addr));
1112				s = pserialize_read_enter();
1113				ifa = ifa_ifwithaddr(sintosa(&ipaddr));
1114				if (ifa == NULL) {
1115					pserialize_read_exit(s);
1116					continue;
1117				}
1118				pserialize_read_exit(s);
1119				ipt->ipt_ptr += sizeof(struct in_addr);
1120				break;
1121			    }
1122
1123			default:
1124				/* XXX can't take &ipt->ipt_flg */
1125				code = (u_char *)&ipt->ipt_ptr -
1126				    (u_char *)ip + 1;
1127				goto bad;
1128			}
1129			ntime = iptime();
1130			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1131			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1132			    sizeof(n_time));
1133			ipt->ipt_ptr += sizeof(n_time);
1134		}
1135	}
1136	if (forward) {
1137		struct ifnet *rcvif;
1138		struct psref _psref;
1139
1140		if (ip_forwsrcrt == 0) {
1141			type = ICMP_UNREACH;
1142			code = ICMP_UNREACH_SRCFAIL;
1143			goto bad;
1144		}
1145
1146		rcvif = m_get_rcvif_psref(m, &_psref);
1147		if (__predict_false(rcvif == NULL)) {
1148			type = ICMP_UNREACH;
1149			code = ICMP_UNREACH_HOST;
1150			goto bad;
1151		}
1152		ip_forward(m, 1, rcvif);
1153		m_put_rcvif_psref(rcvif, &_psref);
1154		return true;
1155	}
1156	return false;
1157bad:
1158	icmp_error(m, type, code, 0, 0);
1159	IP_STATINC(IP_STAT_BADOPTIONS);
1160	return true;
1161}
1162
1163/*
1164 * ip_rtaddr: given address of next destination (final or next hop),
1165 * return internet address info of interface to be used to get there.
1166 */
1167static struct in_ifaddr *
1168ip_rtaddr(struct in_addr dst, struct psref *psref)
1169{
1170	struct rtentry *rt;
1171	union {
1172		struct sockaddr		dst;
1173		struct sockaddr_in	dst4;
1174	} u;
1175	struct route *ro;
1176
1177	sockaddr_in_init(&u.dst4, &dst, 0);
1178
1179	ro = percpu_getref(ipforward_rt_percpu);
1180	rt = rtcache_lookup(ro, &u.dst);
1181	if (rt == NULL) {
1182		percpu_putref(ipforward_rt_percpu);
1183		return NULL;
1184	}
1185
1186	ia4_acquire(ifatoia(rt->rt_ifa), psref);
1187	rtcache_unref(rt, ro);
1188	percpu_putref(ipforward_rt_percpu);
1189
1190	return ifatoia(rt->rt_ifa);
1191}
1192
1193/*
1194 * save_rte: save incoming source route for use in replies, to be picked
1195 * up later by ip_srcroute if the receiver is interested.
1196 */
1197static void
1198save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1199{
1200	struct ip_srcrt *isr;
1201	struct m_tag *mtag;
1202	unsigned olen;
1203
1204	olen = option[IPOPT_OLEN];
1205	if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes))
1206		return;
1207
1208	mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT);
1209	if (mtag == NULL)
1210		return;
1211	isr = (struct ip_srcrt *)(mtag + 1);
1212
1213	memcpy(isr->isr_hdr, option, olen);
1214	isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1215	isr->isr_dst = dst;
1216	m_tag_prepend(m, mtag);
1217}
1218
1219/*
1220 * Retrieve incoming source route for use in replies,
1221 * in the same form used by setsockopt.
1222 * The first hop is placed before the options, will be removed later.
1223 */
1224struct mbuf *
1225ip_srcroute(struct mbuf *m0)
1226{
1227	struct in_addr *p, *q;
1228	struct mbuf *m;
1229	struct ip_srcrt *isr;
1230	struct m_tag *mtag;
1231
1232	mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE, NULL);
1233	if (mtag == NULL)
1234		return NULL;
1235	isr = (struct ip_srcrt *)(mtag + 1);
1236
1237	if (isr->isr_nhops == 0)
1238		return NULL;
1239
1240	m = m_get(M_DONTWAIT, MT_SOOPTS);
1241	if (m == NULL)
1242		return NULL;
1243
1244	MCLAIM(m, &inetdomain.dom_mowner);
1245#define OPTSIZ	(sizeof(isr->isr_nop) + sizeof(isr->isr_hdr))
1246
1247	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */
1248	m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ;
1249
1250	/*
1251	 * First save first hop for return route
1252	 */
1253	p = &(isr->isr_routes[isr->isr_nhops - 1]);
1254	*(mtod(m, struct in_addr *)) = *p--;
1255
1256	/*
1257	 * Copy option fields and padding (nop) to mbuf.
1258	 */
1259	isr->isr_nop = IPOPT_NOP;
1260	isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF;
1261	memmove(mtod(m, char *) + sizeof(struct in_addr), &isr->isr_nop,
1262	    OPTSIZ);
1263	q = (struct in_addr *)(mtod(m, char *) +
1264	    sizeof(struct in_addr) + OPTSIZ);
1265#undef OPTSIZ
1266	/*
1267	 * Record return path as an IP source route,
1268	 * reversing the path (pointers are now aligned).
1269	 */
1270	while (p >= isr->isr_routes) {
1271		*q++ = *p--;
1272	}
1273	/*
1274	 * Last hop goes to final destination.
1275	 */
1276	*q = isr->isr_dst;
1277	m_tag_delete(m0, mtag);
1278	return m;
1279}
1280
1281const int inetctlerrmap[PRC_NCMDS] = {
1282	[PRC_MSGSIZE] = EMSGSIZE,
1283	[PRC_HOSTDEAD] = EHOSTDOWN,
1284	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1285	[PRC_UNREACH_NET] = EHOSTUNREACH,
1286	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1287	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1288	[PRC_UNREACH_PORT] = ECONNREFUSED,
1289	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1290	[PRC_PARAMPROB] = ENOPROTOOPT,
1291};
1292
1293void
1294ip_fasttimo(void)
1295{
1296	if (ip_drainwanted) {
1297		ip_drain();
1298		ip_drainwanted = 0;
1299	}
1300}
1301
1302void
1303ip_drainstub(void)
1304{
1305	ip_drainwanted = 1;
1306}
1307
1308/*
1309 * Forward a packet.  If some error occurs return the sender
1310 * an icmp packet.  Note we can't always generate a meaningful
1311 * icmp message because icmp doesn't have a large enough repertoire
1312 * of codes and types.
1313 *
1314 * If not forwarding, just drop the packet.  This could be confusing
1315 * if ipforwarding was zero but some routing protocol was advancing
1316 * us as a gateway to somewhere.  However, we must let the routing
1317 * protocol deal with that.
1318 *
1319 * The srcrt parameter indicates whether the packet is being forwarded
1320 * via a source route.
1321 */
1322static void
1323ip_forward(struct mbuf *m, int srcrt, struct ifnet *rcvif)
1324{
1325	struct ip *ip = mtod(m, struct ip *);
1326	struct rtentry *rt;
1327	int error, type = 0, code = 0, destmtu = 0;
1328	struct mbuf *mcopy;
1329	n_long dest;
1330	union {
1331		struct sockaddr		dst;
1332		struct sockaddr_in	dst4;
1333	} u;
1334	uint64_t *ips;
1335	struct route *ro;
1336
1337	KASSERTMSG(cpu_softintr_p(), "ip_forward: not in the software "
1338	    "interrupt handler; synchronization assumptions violated");
1339
1340	/*
1341	 * We are now in the output path.
1342	 */
1343	MCLAIM(m, &ip_tx_mowner);
1344
1345	/*
1346	 * Clear any in-bound checksum flags for this packet.
1347	 */
1348	m->m_pkthdr.csum_flags = 0;
1349
1350	dest = 0;
1351	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1352		IP_STATINC(IP_STAT_CANTFORWARD);
1353		m_freem(m);
1354		return;
1355	}
1356
1357	if (ip->ip_ttl <= IPTTLDEC) {
1358		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1359		return;
1360	}
1361
1362	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1363
1364	ro = percpu_getref(ipforward_rt_percpu);
1365	rt = rtcache_lookup(ro, &u.dst);
1366	if (rt == NULL) {
1367		percpu_putref(ipforward_rt_percpu);
1368		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1369		return;
1370	}
1371
1372	/*
1373	 * Save at most 68 bytes of the packet in case
1374	 * we need to generate an ICMP message to the src.
1375	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1376	 */
1377	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1378	if (mcopy)
1379		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1380
1381	ip->ip_ttl -= IPTTLDEC;
1382
1383	/*
1384	 * If forwarding packet using same interface that it came in on,
1385	 * perhaps should send a redirect to sender to shortcut a hop.
1386	 * Only send redirect if source is sending directly to us,
1387	 * and if packet was not source routed (or has any options).
1388	 * Also, don't send redirect if forwarding using a default route
1389	 * or a route modified by a redirect.
1390	 */
1391	if (rt->rt_ifp == rcvif &&
1392	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1393	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1394	    ipsendredirects && !srcrt) {
1395		if (rt->rt_ifa &&
1396		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1397		    ifatoia(rt->rt_ifa)->ia_subnet) {
1398			if (rt->rt_flags & RTF_GATEWAY)
1399				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1400			else
1401				dest = ip->ip_dst.s_addr;
1402			/*
1403			 * Router requirements says to only send host
1404			 * redirects.
1405			 */
1406			type = ICMP_REDIRECT;
1407			code = ICMP_REDIRECT_HOST;
1408		}
1409	}
1410	rtcache_unref(rt, ro);
1411
1412	error = ip_output(m, NULL, ro,
1413	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1414	    NULL, NULL);
1415
1416	if (error) {
1417		IP_STATINC(IP_STAT_CANTFORWARD);
1418		goto error;
1419	}
1420
1421	ips = IP_STAT_GETREF();
1422	ips[IP_STAT_FORWARD]++;
1423
1424	if (type) {
1425		ips[IP_STAT_REDIRECTSENT]++;
1426		IP_STAT_PUTREF();
1427		goto redirect;
1428	}
1429
1430	IP_STAT_PUTREF();
1431	if (mcopy) {
1432#ifdef GATEWAY
1433		if (mcopy->m_flags & M_CANFASTFWD)
1434			ipflow_create(ro, mcopy);
1435#endif
1436		m_freem(mcopy);
1437	}
1438
1439	percpu_putref(ipforward_rt_percpu);
1440	return;
1441
1442redirect:
1443error:
1444	if (mcopy == NULL) {
1445		percpu_putref(ipforward_rt_percpu);
1446		return;
1447	}
1448
1449	switch (error) {
1450
1451	case 0:				/* forwarded, but need redirect */
1452		/* type, code set above */
1453		break;
1454
1455	case ENETUNREACH:		/* shouldn't happen, checked above */
1456	case EHOSTUNREACH:
1457	case ENETDOWN:
1458	case EHOSTDOWN:
1459	default:
1460		type = ICMP_UNREACH;
1461		code = ICMP_UNREACH_HOST;
1462		break;
1463
1464	case EMSGSIZE:
1465		type = ICMP_UNREACH;
1466		code = ICMP_UNREACH_NEEDFRAG;
1467
1468		if ((rt = rtcache_validate(ro)) != NULL) {
1469			destmtu = rt->rt_ifp->if_mtu;
1470			rtcache_unref(rt, ro);
1471		}
1472#ifdef IPSEC
1473		if (ipsec_used)
1474			(void)ipsec4_forward(mcopy, &destmtu);
1475#endif
1476		IP_STATINC(IP_STAT_CANTFRAG);
1477		break;
1478
1479	case ENOBUFS:
1480		/*
1481		 * Do not generate ICMP_SOURCEQUENCH as required in RFC 1812,
1482		 * Requirements for IP Version 4 Routers.  Source quench can
1483		 * big problem under DoS attacks or if the underlying
1484		 * interface is rate-limited.
1485		 */
1486		if (mcopy)
1487			m_freem(mcopy);
1488		percpu_putref(ipforward_rt_percpu);
1489		return;
1490	}
1491	icmp_error(mcopy, type, code, dest, destmtu);
1492	percpu_putref(ipforward_rt_percpu);
1493}
1494
1495void
1496ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1497    struct mbuf *m)
1498{
1499	struct socket *so = inp->inp_socket;
1500	int inpflags = inp->inp_flags;
1501
1502	if (SOOPT_TIMESTAMP(so->so_options))
1503		mp = sbsavetimestamp(so->so_options, m, mp);
1504
1505	if (inpflags & INP_RECVDSTADDR) {
1506		*mp = sbcreatecontrol(&ip->ip_dst,
1507		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1508		if (*mp)
1509			mp = &(*mp)->m_next;
1510	}
1511
1512	if (inpflags & INP_RECVTTL) {
1513		*mp = sbcreatecontrol(&ip->ip_ttl,
1514		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1515		if (*mp)
1516			mp = &(*mp)->m_next;
1517	}
1518
1519	struct psref psref;
1520	ifnet_t *ifp = m_get_rcvif_psref(m, &psref);
1521	if (__predict_false(ifp == NULL)) {
1522#ifdef DIAGNOSTIC
1523		printf("%s: missing receive interface\n", __func__);
1524#endif
1525		return; /* XXX should report error? */
1526	}
1527
1528	if (inpflags & INP_RECVPKTINFO) {
1529		struct in_pktinfo ipi;
1530		ipi.ipi_addr = ip->ip_src;
1531		ipi.ipi_ifindex = ifp->if_index;
1532		*mp = sbcreatecontrol(&ipi,
1533		    sizeof(ipi), IP_RECVPKTINFO, IPPROTO_IP);
1534		if (*mp)
1535			mp = &(*mp)->m_next;
1536	}
1537	if (inpflags & INP_PKTINFO) {
1538		struct in_pktinfo ipi;
1539		ipi.ipi_addr = ip->ip_dst;
1540		ipi.ipi_ifindex = ifp->if_index;
1541		*mp = sbcreatecontrol(&ipi,
1542		    sizeof(ipi), IP_PKTINFO, IPPROTO_IP);
1543		if (*mp)
1544			mp = &(*mp)->m_next;
1545	}
1546	if (inpflags & INP_RECVIF) {
1547		struct sockaddr_dl sdl;
1548
1549		sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, 0, NULL, 0,
1550		    NULL, 0);
1551		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1552		if (*mp)
1553			mp = &(*mp)->m_next;
1554	}
1555	m_put_rcvif_psref(ifp, &psref);
1556}
1557
1558/*
1559 * sysctl helper routine for net.inet.ip.forwsrcrt.
1560 */
1561static int
1562sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1563{
1564	int error, tmp;
1565	struct sysctlnode node;
1566
1567	node = *rnode;
1568	tmp = ip_forwsrcrt;
1569	node.sysctl_data = &tmp;
1570	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1571	if (error || newp == NULL)
1572		return (error);
1573
1574	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1575	    0, NULL, NULL, NULL);
1576	if (error)
1577		return (error);
1578
1579	ip_forwsrcrt = tmp;
1580
1581	return (0);
1582}
1583
1584/*
1585 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1586 * range of the new value and tweaks timers if it changes.
1587 */
1588static int
1589sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1590{
1591	int error, tmp;
1592	struct sysctlnode node;
1593
1594	icmp_mtudisc_lock();
1595
1596	node = *rnode;
1597	tmp = ip_mtudisc_timeout;
1598	node.sysctl_data = &tmp;
1599	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1600	if (error || newp == NULL)
1601		goto out;
1602	if (tmp < 0) {
1603		error = EINVAL;
1604		goto out;
1605	}
1606
1607	ip_mtudisc_timeout = tmp;
1608	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1609	error = 0;
1610out:
1611	icmp_mtudisc_unlock();
1612	return error;
1613}
1614
1615static int
1616sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1617{
1618
1619	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1620}
1621
1622static void
1623sysctl_net_inet_ip_setup(struct sysctllog **clog)
1624{
1625	sysctl_createv(clog, 0, NULL, NULL,
1626		       CTLFLAG_PERMANENT,
1627		       CTLTYPE_NODE, "inet",
1628		       SYSCTL_DESCR("PF_INET related settings"),
1629		       NULL, 0, NULL, 0,
1630		       CTL_NET, PF_INET, CTL_EOL);
1631	sysctl_createv(clog, 0, NULL, NULL,
1632		       CTLFLAG_PERMANENT,
1633		       CTLTYPE_NODE, "ip",
1634		       SYSCTL_DESCR("IPv4 related settings"),
1635		       NULL, 0, NULL, 0,
1636		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1637
1638	sysctl_createv(clog, 0, NULL, NULL,
1639		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1640		       CTLTYPE_INT, "forwarding",
1641		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1642		       NULL, 0, &ipforwarding, 0,
1643		       CTL_NET, PF_INET, IPPROTO_IP,
1644		       IPCTL_FORWARDING, CTL_EOL);
1645	sysctl_createv(clog, 0, NULL, NULL,
1646		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1647		       CTLTYPE_INT, "redirect",
1648		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1649		       NULL, 0, &ipsendredirects, 0,
1650		       CTL_NET, PF_INET, IPPROTO_IP,
1651		       IPCTL_SENDREDIRECTS, CTL_EOL);
1652	sysctl_createv(clog, 0, NULL, NULL,
1653		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1654		       CTLTYPE_INT, "ttl",
1655		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1656		       NULL, 0, &ip_defttl, 0,
1657		       CTL_NET, PF_INET, IPPROTO_IP,
1658		       IPCTL_DEFTTL, CTL_EOL);
1659#ifdef IPCTL_DEFMTU
1660	sysctl_createv(clog, 0, NULL, NULL,
1661		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1662		       CTLTYPE_INT, "mtu",
1663		       SYSCTL_DESCR("Default MTA for an INET route"),
1664		       NULL, 0, &ip_mtu, 0,
1665		       CTL_NET, PF_INET, IPPROTO_IP,
1666		       IPCTL_DEFMTU, CTL_EOL);
1667#endif /* IPCTL_DEFMTU */
1668	sysctl_createv(clog, 0, NULL, NULL,
1669		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1670		       CTLTYPE_INT, "forwsrcrt",
1671		       SYSCTL_DESCR("Enable forwarding of source-routed "
1672				    "datagrams"),
1673		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1674		       CTL_NET, PF_INET, IPPROTO_IP,
1675		       IPCTL_FORWSRCRT, CTL_EOL);
1676	sysctl_createv(clog, 0, NULL, NULL,
1677		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1678		       CTLTYPE_INT, "directed-broadcast",
1679		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1680		       NULL, 0, &ip_directedbcast, 0,
1681		       CTL_NET, PF_INET, IPPROTO_IP,
1682		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1683	sysctl_createv(clog, 0, NULL, NULL,
1684		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1685		       CTLTYPE_INT, "allowsrcrt",
1686		       SYSCTL_DESCR("Accept source-routed datagrams"),
1687		       NULL, 0, &ip_allowsrcrt, 0,
1688		       CTL_NET, PF_INET, IPPROTO_IP,
1689		       IPCTL_ALLOWSRCRT, CTL_EOL);
1690
1691	sysctl_createv(clog, 0, NULL, NULL,
1692		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1693		       CTLTYPE_INT, "mtudisc",
1694		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1695		       NULL, 0, &ip_mtudisc, 0,
1696		       CTL_NET, PF_INET, IPPROTO_IP,
1697		       IPCTL_MTUDISC, CTL_EOL);
1698	sysctl_createv(clog, 0, NULL, NULL,
1699		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1700		       CTLTYPE_INT, "anonportmin",
1701		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1702		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1703		       CTL_NET, PF_INET, IPPROTO_IP,
1704		       IPCTL_ANONPORTMIN, CTL_EOL);
1705	sysctl_createv(clog, 0, NULL, NULL,
1706		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1707		       CTLTYPE_INT, "anonportmax",
1708		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1709		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1710		       CTL_NET, PF_INET, IPPROTO_IP,
1711		       IPCTL_ANONPORTMAX, CTL_EOL);
1712	sysctl_createv(clog, 0, NULL, NULL,
1713		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1714		       CTLTYPE_INT, "mtudisctimeout",
1715		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1716		       sysctl_net_inet_ip_pmtudto, 0, (void *)&ip_mtudisc_timeout, 0,
1717		       CTL_NET, PF_INET, IPPROTO_IP,
1718		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1719#ifndef IPNOPRIVPORTS
1720	sysctl_createv(clog, 0, NULL, NULL,
1721		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1722		       CTLTYPE_INT, "lowportmin",
1723		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1724				    "to assign"),
1725		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1726		       CTL_NET, PF_INET, IPPROTO_IP,
1727		       IPCTL_LOWPORTMIN, CTL_EOL);
1728	sysctl_createv(clog, 0, NULL, NULL,
1729		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1730		       CTLTYPE_INT, "lowportmax",
1731		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1732				    "to assign"),
1733		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1734		       CTL_NET, PF_INET, IPPROTO_IP,
1735		       IPCTL_LOWPORTMAX, CTL_EOL);
1736#endif /* IPNOPRIVPORTS */
1737#if NGRE > 0
1738	sysctl_createv(clog, 0, NULL, NULL,
1739		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1740		       CTLTYPE_INT, "grettl",
1741		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1742		       NULL, 0, &ip_gre_ttl, 0,
1743		       CTL_NET, PF_INET, IPPROTO_IP,
1744		       IPCTL_GRE_TTL, CTL_EOL);
1745#endif /* NGRE */
1746	sysctl_createv(clog, 0, NULL, NULL,
1747		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1748		       CTLTYPE_INT, "checkinterface",
1749		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1750				    "from RFC1122"),
1751		       NULL, 0, &ip_checkinterface, 0,
1752		       CTL_NET, PF_INET, IPPROTO_IP,
1753		       IPCTL_CHECKINTERFACE, CTL_EOL);
1754	sysctl_createv(clog, 0, NULL, NULL,
1755		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1756		       CTLTYPE_INT, "random_id",
1757		       SYSCTL_DESCR("Assign random ip_id values"),
1758		       NULL, 0, &ip_do_randomid, 0,
1759		       CTL_NET, PF_INET, IPPROTO_IP,
1760		       IPCTL_RANDOMID, CTL_EOL);
1761	sysctl_createv(clog, 0, NULL, NULL,
1762		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1763		       CTLTYPE_INT, "do_loopback_cksum",
1764		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1765		       NULL, 0, &ip_do_loopback_cksum, 0,
1766		       CTL_NET, PF_INET, IPPROTO_IP,
1767		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1768	sysctl_createv(clog, 0, NULL, NULL,
1769		       CTLFLAG_PERMANENT,
1770		       CTLTYPE_STRUCT, "stats",
1771		       SYSCTL_DESCR("IP statistics"),
1772		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1773		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1774		       CTL_EOL);
1775#if NARP
1776	sysctl_createv(clog, 0, NULL, NULL,
1777		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1778		       CTLTYPE_INT, "dad_count",
1779		       SYSCTL_DESCR("Number of Duplicate Address Detection "
1780				    "probes to send"),
1781		       NULL, 0, &ip_dad_count, 0,
1782		       CTL_NET, PF_INET, IPPROTO_IP,
1783		       IPCTL_DAD_COUNT, CTL_EOL);
1784#endif
1785
1786	/* anonportalgo RFC6056 subtree */
1787	const struct sysctlnode *portalgo_node;
1788	sysctl_createv(clog, 0, NULL, &portalgo_node,
1789		       CTLFLAG_PERMANENT,
1790		       CTLTYPE_NODE, "anonportalgo",
1791		       SYSCTL_DESCR("Anonymous Port Algorithm Selection (RFC 6056)"),
1792	    	       NULL, 0, NULL, 0,
1793		       CTL_NET, PF_INET, IPPROTO_IP, CTL_CREATE, CTL_EOL);
1794	sysctl_createv(clog, 0, &portalgo_node, NULL,
1795		       CTLFLAG_PERMANENT,
1796		       CTLTYPE_STRING, "available",
1797		       SYSCTL_DESCR("available algorithms"),
1798		       sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN,
1799		       CTL_CREATE, CTL_EOL);
1800	sysctl_createv(clog, 0, &portalgo_node, NULL,
1801		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1802		       CTLTYPE_STRING, "selected",
1803		       SYSCTL_DESCR("selected algorithm"),
1804		       sysctl_portalgo_selected4, 0, NULL, PORTALGO_MAXLEN,
1805		       CTL_CREATE, CTL_EOL);
1806	sysctl_createv(clog, 0, &portalgo_node, NULL,
1807		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1808		       CTLTYPE_STRUCT, "reserve",
1809		       SYSCTL_DESCR("bitmap of reserved ports"),
1810		       sysctl_portalgo_reserve4, 0, NULL, 0,
1811		       CTL_CREATE, CTL_EOL);
1812}
1813
1814void
1815ip_statinc(u_int stat)
1816{
1817
1818	KASSERT(stat < IP_NSTATS);
1819	IP_STATINC(stat);
1820}
1821