ip_input.c revision 1.354
1/*	$NetBSD: ip_input.c,v 1.354 2017/03/31 06:49:44 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 1.354 2017/03/31 06:49:44 ozaki-r Exp $");
95
96#ifdef _KERNEL_OPT
97#include "opt_inet.h"
98#include "opt_compat_netbsd.h"
99#include "opt_gateway.h"
100#include "opt_ipsec.h"
101#include "opt_mrouting.h"
102#include "opt_mbuftrace.h"
103#include "opt_inet_csum.h"
104#include "opt_net_mpsafe.h"
105#endif
106
107#include "arp.h"
108
109#include <sys/param.h>
110#include <sys/systm.h>
111#include <sys/cpu.h>
112#include <sys/mbuf.h>
113#include <sys/domain.h>
114#include <sys/protosw.h>
115#include <sys/socket.h>
116#include <sys/socketvar.h>
117#include <sys/errno.h>
118#include <sys/time.h>
119#include <sys/kernel.h>
120#include <sys/pool.h>
121#include <sys/sysctl.h>
122#include <sys/kauth.h>
123
124#include <net/if.h>
125#include <net/if_dl.h>
126#include <net/route.h>
127#include <net/pktqueue.h>
128#include <net/pfil.h>
129
130#include <netinet/in.h>
131#include <netinet/in_systm.h>
132#include <netinet/ip.h>
133#include <netinet/in_pcb.h>
134#include <netinet/in_proto.h>
135#include <netinet/in_var.h>
136#include <netinet/ip_var.h>
137#include <netinet/ip_private.h>
138#include <netinet/ip_icmp.h>
139/* just for gif_ttl */
140#include <netinet/in_gif.h>
141#include "gif.h"
142#include <net/if_gre.h>
143#include "gre.h"
144
145#ifdef MROUTING
146#include <netinet/ip_mroute.h>
147#endif
148#include <netinet/portalgo.h>
149
150#ifdef IPSEC
151#include <netipsec/ipsec.h>
152#endif
153
154#ifndef	IPFORWARDING
155#ifdef GATEWAY
156#define	IPFORWARDING	1	/* forward IP packets not for us */
157#else /* GATEWAY */
158#define	IPFORWARDING	0	/* don't forward IP packets not for us */
159#endif /* GATEWAY */
160#endif /* IPFORWARDING */
161#ifndef	IPSENDREDIRECTS
162#define	IPSENDREDIRECTS	1
163#endif
164#ifndef IPFORWSRCRT
165#define	IPFORWSRCRT	1	/* forward source-routed packets */
166#endif
167#ifndef IPALLOWSRCRT
168#define	IPALLOWSRCRT	1	/* allow source-routed packets */
169#endif
170#ifndef IPMTUDISC
171#define IPMTUDISC	1
172#endif
173#ifndef IPMTUDISCTIMEOUT
174#define IPMTUDISCTIMEOUT (10 * 60)	/* as per RFC 1191 */
175#endif
176
177#ifdef COMPAT_50
178#include <compat/sys/time.h>
179#include <compat/sys/socket.h>
180#endif
181
182/*
183 * Note: DIRECTED_BROADCAST is handled this way so that previous
184 * configuration using this option will Just Work.
185 */
186#ifndef IPDIRECTEDBCAST
187#ifdef DIRECTED_BROADCAST
188#define IPDIRECTEDBCAST	1
189#else
190#define	IPDIRECTEDBCAST	0
191#endif /* DIRECTED_BROADCAST */
192#endif /* IPDIRECTEDBCAST */
193int	ipforwarding = IPFORWARDING;
194int	ipsendredirects = IPSENDREDIRECTS;
195int	ip_defttl = IPDEFTTL;
196int	ip_forwsrcrt = IPFORWSRCRT;
197int	ip_directedbcast = IPDIRECTEDBCAST;
198int	ip_allowsrcrt = IPALLOWSRCRT;
199int	ip_mtudisc = IPMTUDISC;
200int	ip_mtudisc_timeout = IPMTUDISCTIMEOUT;
201#ifdef DIAGNOSTIC
202int	ipprintfs = 0;
203#endif
204
205int	ip_do_randomid = 0;
206
207/*
208 * XXX - Setting ip_checkinterface mostly implements the receive side of
209 * the Strong ES model described in RFC 1122, but since the routing table
210 * and transmit implementation do not implement the Strong ES model,
211 * setting this to 1 results in an odd hybrid.
212 *
213 * XXX - ip_checkinterface currently must be disabled if you use ipnat
214 * to translate the destination address to another local interface.
215 *
216 * XXX - ip_checkinterface must be disabled if you add IP aliases
217 * to the loopback interface instead of the interface where the
218 * packets for those addresses are received.
219 */
220static int		ip_checkinterface	__read_mostly = 0;
221
222struct rttimer_queue *ip_mtudisc_timeout_q = NULL;
223
224pktqueue_t *		ip_pktq			__read_mostly;
225pfil_head_t *		inet_pfil_hook		__read_mostly;
226ipid_state_t *		ip_ids			__read_mostly;
227percpu_t *		ipstat_percpu		__read_mostly;
228
229static percpu_t		*ipforward_rt_percpu	__cacheline_aligned;
230
231uint16_t ip_id;
232
233#ifdef INET_CSUM_COUNTERS
234#include <sys/device.h>
235
236struct evcnt ip_hwcsum_bad = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
237    NULL, "inet", "hwcsum bad");
238struct evcnt ip_hwcsum_ok = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
239    NULL, "inet", "hwcsum ok");
240struct evcnt ip_swcsum = EVCNT_INITIALIZER(EVCNT_TYPE_MISC,
241    NULL, "inet", "swcsum");
242
243#define	INET_CSUM_COUNTER_INCR(ev)	(ev)->ev_count++
244
245EVCNT_ATTACH_STATIC(ip_hwcsum_bad);
246EVCNT_ATTACH_STATIC(ip_hwcsum_ok);
247EVCNT_ATTACH_STATIC(ip_swcsum);
248
249#else
250
251#define	INET_CSUM_COUNTER_INCR(ev)	/* nothing */
252
253#endif /* INET_CSUM_COUNTERS */
254
255/*
256 * Used to save the IP options in case a protocol wants to respond
257 * to an incoming packet over the same route if the packet got here
258 * using IP source routing.  This allows connection establishment and
259 * maintenance when the remote end is on a network that is not known
260 * to us.
261 */
262struct ip_srcrt {
263	int		isr_nhops;		   /* number of hops */
264	struct in_addr	isr_dst;		   /* final destination */
265	char		isr_nop;		   /* one NOP to align */
266	char		isr_hdr[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN & OFFSET */
267	struct in_addr	isr_routes[MAX_IPOPTLEN/sizeof(struct in_addr)];
268};
269
270static int ip_drainwanted;
271
272static void save_rte(struct mbuf *, u_char *, struct in_addr);
273
274#ifdef MBUFTRACE
275struct mowner ip_rx_mowner = MOWNER_INIT("internet", "rx");
276struct mowner ip_tx_mowner = MOWNER_INIT("internet", "tx");
277#endif
278
279static void		ipintr(void *);
280static void		ip_input(struct mbuf *);
281static void		ip_forward(struct mbuf *, int, struct ifnet *);
282static bool		ip_dooptions(struct mbuf *);
283static struct in_ifaddr *ip_rtaddr(struct in_addr, struct psref *);
284static void		sysctl_net_inet_ip_setup(struct sysctllog **);
285
286static struct in_ifaddr	*ip_match_our_address(struct ifnet *, struct ip *,
287			    int *);
288static struct in_ifaddr	*ip_match_our_address_broadcast(struct ifnet *,
289			    struct ip *);
290
291#ifdef NET_MPSAFE
292#define	SOFTNET_LOCK()		mutex_enter(softnet_lock)
293#define	SOFTNET_UNLOCK()	mutex_exit(softnet_lock)
294#else
295#define	SOFTNET_LOCK()		KASSERT(mutex_owned(softnet_lock))
296#define	SOFTNET_UNLOCK()	KASSERT(mutex_owned(softnet_lock))
297#endif
298
299/*
300 * IP initialization: fill in IP protocol switch table.
301 * All protocols not implemented in kernel go to raw IP protocol handler.
302 */
303void
304ip_init(void)
305{
306	const struct protosw *pr;
307
308	in_init();
309	sysctl_net_inet_ip_setup(NULL);
310
311	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
312	KASSERT(pr != NULL);
313
314	ip_pktq = pktq_create(IFQ_MAXLEN, ipintr, NULL);
315	KASSERT(ip_pktq != NULL);
316
317	for (u_int i = 0; i < IPPROTO_MAX; i++) {
318		ip_protox[i] = pr - inetsw;
319	}
320	for (pr = inetdomain.dom_protosw;
321	    pr < inetdomain.dom_protoswNPROTOSW; pr++)
322		if (pr->pr_domain->dom_family == PF_INET &&
323		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
324			ip_protox[pr->pr_protocol] = pr - inetsw;
325
326	ip_reass_init();
327
328	ip_ids = ip_id_init();
329	ip_id = time_uptime & 0xfffff;
330
331#ifdef GATEWAY
332	ipflow_init();
333#endif
334
335	/* Register our Packet Filter hook. */
336	inet_pfil_hook = pfil_head_create(PFIL_TYPE_AF, (void *)AF_INET);
337	KASSERT(inet_pfil_hook != NULL);
338
339#ifdef MBUFTRACE
340	MOWNER_ATTACH(&ip_tx_mowner);
341	MOWNER_ATTACH(&ip_rx_mowner);
342#endif /* MBUFTRACE */
343
344	ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
345
346	ipforward_rt_percpu = percpu_alloc(sizeof(struct route));
347	if (ipforward_rt_percpu == NULL)
348		panic("failed to allocate ipforward_rt_percpu");
349
350	ip_mtudisc_timeout_q = rt_timer_queue_create(ip_mtudisc_timeout);
351}
352
353static struct in_ifaddr *
354ip_match_our_address(struct ifnet *ifp, struct ip *ip, int *downmatch)
355{
356	struct in_ifaddr *ia = NULL;
357	int checkif;
358
359	/*
360	 * Enable a consistency check between the destination address
361	 * and the arrival interface for a unicast packet (the RFC 1122
362	 * strong ES model) if IP forwarding is disabled and the packet
363	 * is not locally generated.
364	 *
365	 * XXX - Checking also should be disabled if the destination
366	 * address is ipnat'ed to a different interface.
367	 *
368	 * XXX - Checking is incompatible with IP aliases added
369	 * to the loopback interface instead of the interface where
370	 * the packets are received.
371	 *
372	 * XXX - We need to add a per ifaddr flag for this so that
373	 * we get finer grain control.
374	 */
375	checkif = ip_checkinterface && (ipforwarding == 0) &&
376	    (ifp->if_flags & IFF_LOOPBACK) == 0;
377
378	IN_ADDRHASH_READER_FOREACH(ia, ip->ip_dst.s_addr) {
379		if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
380			if (ia->ia4_flags & IN_IFF_NOTREADY)
381				continue;
382			if (checkif && ia->ia_ifp != ifp)
383				continue;
384			if ((ia->ia_ifp->if_flags & IFF_UP) != 0 &&
385			    (ia->ia4_flags & IN_IFF_DETACHED) == 0)
386				break;
387			else
388				(*downmatch)++;
389		}
390	}
391
392	return ia;
393}
394
395static struct in_ifaddr *
396ip_match_our_address_broadcast(struct ifnet *ifp, struct ip *ip)
397{
398	struct in_ifaddr *ia = NULL;
399	struct ifaddr *ifa;
400
401	IFADDR_READER_FOREACH(ifa, ifp) {
402		if (ifa->ifa_addr->sa_family != AF_INET)
403			continue;
404		ia = ifatoia(ifa);
405		if (ia->ia4_flags & (IN_IFF_NOTREADY | IN_IFF_DETACHED))
406			continue;
407		if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
408		    in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
409		    /*
410		     * Look for all-0's host part (old broadcast addr),
411		     * either for subnet or net.
412		     */
413		    ip->ip_dst.s_addr == ia->ia_subnet ||
414		    ip->ip_dst.s_addr == ia->ia_net)
415			goto matched;
416		/*
417		 * An interface with IP address zero accepts
418		 * all packets that arrive on that interface.
419		 */
420		if (in_nullhost(ia->ia_addr.sin_addr))
421			goto matched;
422	}
423	ia = NULL;
424
425matched:
426	return ia;
427}
428
429/*
430 * IP software interrupt routine.
431 */
432static void
433ipintr(void *arg __unused)
434{
435	struct mbuf *m;
436
437	KASSERT(cpu_softintr_p());
438
439#ifndef NET_MPSAFE
440	mutex_enter(softnet_lock);
441#endif
442	while ((m = pktq_dequeue(ip_pktq)) != NULL) {
443		ip_input(m);
444	}
445#ifndef NET_MPSAFE
446	mutex_exit(softnet_lock);
447#endif
448}
449
450/*
451 * IP input routine.  Checksum and byte swap header.  If fragmented
452 * try to reassemble.  Process options.  Pass to next level.
453 */
454static void
455ip_input(struct mbuf *m)
456{
457	struct ip *ip = NULL;
458	struct in_ifaddr *ia = NULL;
459	int hlen = 0, len;
460	int downmatch;
461	int srcrt = 0;
462	ifnet_t *ifp;
463	struct psref psref;
464	int s;
465
466	KASSERTMSG(cpu_softintr_p(), "ip_input: not in the software "
467	    "interrupt handler; synchronization assumptions violated");
468
469	MCLAIM(m, &ip_rx_mowner);
470	KASSERT((m->m_flags & M_PKTHDR) != 0);
471
472	ifp = m_get_rcvif_psref(m, &psref);
473	if (__predict_false(ifp == NULL))
474		goto out;
475
476	/*
477	 * If no IP addresses have been set yet but the interfaces
478	 * are receiving, can't do anything with incoming packets yet.
479	 * Note: we pre-check without locks held.
480	 */
481	if (IN_ADDRLIST_READER_EMPTY())
482		goto out;
483	IP_STATINC(IP_STAT_TOTAL);
484
485	/*
486	 * If the IP header is not aligned, slurp it up into a new
487	 * mbuf with space for link headers, in the event we forward
488	 * it.  Otherwise, if it is aligned, make sure the entire
489	 * base IP header is in the first mbuf of the chain.
490	 */
491	if (IP_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
492		if ((m = m_copyup(m, sizeof(struct ip),
493				  (max_linkhdr + 3) & ~3)) == NULL) {
494			/* XXXJRT new stat, please */
495			IP_STATINC(IP_STAT_TOOSMALL);
496			goto out;
497		}
498	} else if (__predict_false(m->m_len < sizeof (struct ip))) {
499		if ((m = m_pullup(m, sizeof (struct ip))) == NULL) {
500			IP_STATINC(IP_STAT_TOOSMALL);
501			goto out;
502		}
503	}
504	ip = mtod(m, struct ip *);
505	if (ip->ip_v != IPVERSION) {
506		IP_STATINC(IP_STAT_BADVERS);
507		goto out;
508	}
509	hlen = ip->ip_hl << 2;
510	if (hlen < sizeof(struct ip)) {	/* minimum header length */
511		IP_STATINC(IP_STAT_BADHLEN);
512		goto out;
513	}
514	if (hlen > m->m_len) {
515		if ((m = m_pullup(m, hlen)) == NULL) {
516			IP_STATINC(IP_STAT_BADHLEN);
517			goto out;
518		}
519		ip = mtod(m, struct ip *);
520	}
521
522	/*
523	 * RFC1122: packets with a multicast source address are
524	 * not allowed.
525	 */
526	if (IN_MULTICAST(ip->ip_src.s_addr)) {
527		IP_STATINC(IP_STAT_BADADDR);
528		goto out;
529	}
530
531	/* 127/8 must not appear on wire - RFC1122 */
532	if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
533	    (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
534		if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
535			IP_STATINC(IP_STAT_BADADDR);
536			goto out;
537		}
538	}
539
540	switch (m->m_pkthdr.csum_flags &
541		((ifp->if_csum_flags_rx & M_CSUM_IPv4) |
542		 M_CSUM_IPv4_BAD)) {
543	case M_CSUM_IPv4|M_CSUM_IPv4_BAD:
544		INET_CSUM_COUNTER_INCR(&ip_hwcsum_bad);
545		IP_STATINC(IP_STAT_BADSUM);
546		goto out;
547
548	case M_CSUM_IPv4:
549		/* Checksum was okay. */
550		INET_CSUM_COUNTER_INCR(&ip_hwcsum_ok);
551		break;
552
553	default:
554		/*
555		 * Must compute it ourselves.  Maybe skip checksum on
556		 * loopback interfaces.
557		 */
558		if (__predict_true(!(ifp->if_flags & IFF_LOOPBACK) ||
559		    ip_do_loopback_cksum)) {
560			INET_CSUM_COUNTER_INCR(&ip_swcsum);
561			if (in_cksum(m, hlen) != 0) {
562				IP_STATINC(IP_STAT_BADSUM);
563				goto out;
564			}
565		}
566		break;
567	}
568
569	/* Retrieve the packet length. */
570	len = ntohs(ip->ip_len);
571
572	/*
573	 * Check for additional length bogosity
574	 */
575	if (len < hlen) {
576		IP_STATINC(IP_STAT_BADLEN);
577		goto out;
578	}
579
580	/*
581	 * Check that the amount of data in the buffers
582	 * is as at least much as the IP header would have us expect.
583	 * Trim mbufs if longer than we expect.
584	 * Drop packet if shorter than we expect.
585	 */
586	if (m->m_pkthdr.len < len) {
587		IP_STATINC(IP_STAT_TOOSHORT);
588		goto out;
589	}
590	if (m->m_pkthdr.len > len) {
591		if (m->m_len == m->m_pkthdr.len) {
592			m->m_len = len;
593			m->m_pkthdr.len = len;
594		} else
595			m_adj(m, len - m->m_pkthdr.len);
596	}
597
598	/*
599	 * Assume that we can create a fast-forward IP flow entry
600	 * based on this packet.
601	 */
602	m->m_flags |= M_CANFASTFWD;
603
604	/*
605	 * Run through list of hooks for input packets.  If there are any
606	 * filters which require that additional packets in the flow are
607	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
608	 * Note that filters must _never_ set this flag, as another filter
609	 * in the list may have previously cleared it.
610	 */
611#if defined(IPSEC)
612	if (!ipsec_used || !ipsec_indone(m))
613#else
614	if (1)
615#endif
616	{
617		struct in_addr odst = ip->ip_dst;
618		bool freed;
619
620		freed = pfil_run_hooks(inet_pfil_hook, &m, ifp, PFIL_IN) != 0;
621		if (freed || m == NULL) {
622			m = NULL;
623			goto out;
624		}
625		ip = mtod(m, struct ip *);
626		hlen = ip->ip_hl << 2;
627
628		/*
629		 * XXX The setting of "srcrt" here is to prevent ip_forward()
630		 * from generating ICMP redirects for packets that have
631		 * been redirected by a hook back out on to the same LAN that
632		 * they came from and is not an indication that the packet
633		 * is being inffluenced by source routing options.  This
634		 * allows things like
635		 * "rdr tlp0 0/0 port 80 -> 1.1.1.200 3128 tcp"
636		 * where tlp0 is both on the 1.1.1.0/24 network and is the
637		 * default route for hosts on 1.1.1.0/24.  Of course this
638		 * also requires a "map tlp0 ..." to complete the story.
639		 * One might argue whether or not this kind of network config.
640		 * should be supported in this manner...
641		 */
642		srcrt = (odst.s_addr != ip->ip_dst.s_addr);
643	}
644
645#ifdef ALTQ
646	/* XXX Temporary until ALTQ is changed to use a pfil hook */
647	if (altq_input) {
648		SOFTNET_LOCK();
649		if ((*altq_input)(m, AF_INET) == 0) {
650			/* Packet dropped by traffic conditioner. */
651			SOFTNET_UNLOCK();
652			m = NULL;
653			goto out;
654		}
655		SOFTNET_UNLOCK();
656	}
657#endif
658
659	/*
660	 * Process options and, if not destined for us,
661	 * ship it on.  ip_dooptions returns 1 when an
662	 * error was detected (causing an icmp message
663	 * to be sent and the original packet to be freed).
664	 */
665	if (hlen > sizeof (struct ip) && ip_dooptions(m)) {
666		m = NULL;
667		goto out;
668	}
669
670	/*
671	 * Check our list of addresses, to see if the packet is for us.
672	 *
673	 * Traditional 4.4BSD did not consult IFF_UP at all.
674	 * The behavior here is to treat addresses on !IFF_UP interface
675	 * or IN_IFF_NOTREADY addresses as not mine.
676	 */
677	downmatch = 0;
678	s = pserialize_read_enter();
679	ia = ip_match_our_address(ifp, ip, &downmatch);
680	if (ia != NULL) {
681		pserialize_read_exit(s);
682		goto ours;
683	}
684
685	if (ifp->if_flags & IFF_BROADCAST) {
686		ia = ip_match_our_address_broadcast(ifp, ip);
687		if (ia != NULL) {
688			pserialize_read_exit(s);
689			goto ours;
690		}
691	}
692	pserialize_read_exit(s);
693
694	if (IN_MULTICAST(ip->ip_dst.s_addr)) {
695#ifdef MROUTING
696		extern struct socket *ip_mrouter;
697
698		if (ip_mrouter) {
699			/*
700			 * If we are acting as a multicast router, all
701			 * incoming multicast packets are passed to the
702			 * kernel-level multicast forwarding function.
703			 * The packet is returned (relatively) intact; if
704			 * ip_mforward() returns a non-zero value, the packet
705			 * must be discarded, else it may be accepted below.
706			 *
707			 * (The IP ident field is put in the same byte order
708			 * as expected when ip_mforward() is called from
709			 * ip_output().)
710			 */
711			SOFTNET_LOCK();
712			if (ip_mforward(m, ifp) != 0) {
713				SOFTNET_UNLOCK();
714				IP_STATINC(IP_STAT_CANTFORWARD);
715				goto out;
716			}
717			SOFTNET_UNLOCK();
718
719			/*
720			 * The process-level routing demon needs to receive
721			 * all multicast IGMP packets, whether or not this
722			 * host belongs to their destination groups.
723			 */
724			if (ip->ip_p == IPPROTO_IGMP) {
725				goto ours;
726			}
727			IP_STATINC(IP_STAT_CANTFORWARD);
728		}
729#endif
730		/*
731		 * See if we belong to the destination multicast group on the
732		 * arrival interface.
733		 */
734		if (!in_multi_group(ip->ip_dst, ifp, 0)) {
735			IP_STATINC(IP_STAT_CANTFORWARD);
736			goto out;
737		}
738		goto ours;
739	}
740	if (ip->ip_dst.s_addr == INADDR_BROADCAST ||
741	    in_nullhost(ip->ip_dst))
742		goto ours;
743
744	/*
745	 * Not for us; forward if possible and desirable.
746	 */
747	if (ipforwarding == 0) {
748		m_put_rcvif_psref(ifp, &psref);
749		IP_STATINC(IP_STAT_CANTFORWARD);
750		m_freem(m);
751	} else {
752		/*
753		 * If ip_dst matched any of my address on !IFF_UP interface,
754		 * and there's no IFF_UP interface that matches ip_dst,
755		 * send icmp unreach.  Forwarding it will result in in-kernel
756		 * forwarding loop till TTL goes to 0.
757		 */
758		if (downmatch) {
759			m_put_rcvif_psref(ifp, &psref);
760			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
761			IP_STATINC(IP_STAT_CANTFORWARD);
762			return;
763		}
764#ifdef IPSEC
765		/* Perform IPsec, if any. */
766		if (ipsec_used) {
767			SOFTNET_LOCK();
768			if (ipsec4_input(m, IP_FORWARDING |
769			    (ip_directedbcast ? IP_ALLOWBROADCAST : 0)) != 0) {
770				SOFTNET_UNLOCK();
771				goto out;
772			}
773			SOFTNET_UNLOCK();
774		}
775#endif
776		ip_forward(m, srcrt, ifp);
777		m_put_rcvif_psref(ifp, &psref);
778	}
779	return;
780
781ours:
782	m_put_rcvif_psref(ifp, &psref);
783	ifp = NULL;
784
785	/*
786	 * If offset or IP_MF are set, must reassemble.
787	 */
788	if (ip->ip_off & ~htons(IP_DF|IP_RF)) {
789		/*
790		 * Pass to IP reassembly mechanism.
791		 */
792		if (ip_reass_packet(&m, ip) != 0) {
793			/* Failed; invalid fragment(s) or packet. */
794			goto out;
795		}
796		if (m == NULL) {
797			/* More fragments should come; silently return. */
798			goto out;
799		}
800		/*
801		 * Reassembly is done, we have the final packet.
802		 * Updated cached data in local variable(s).
803		 */
804		ip = mtod(m, struct ip *);
805		hlen = ip->ip_hl << 2;
806	}
807
808#ifdef IPSEC
809	/*
810	 * Enforce IPsec policy checking if we are seeing last header.
811	 * Note that we do not visit this with protocols with PCB layer
812	 * code - like UDP/TCP/raw IP.
813	 */
814	if (ipsec_used &&
815	    (inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
816		SOFTNET_LOCK();
817		if (ipsec4_input(m, 0) != 0) {
818			SOFTNET_UNLOCK();
819			goto out;
820		}
821		SOFTNET_UNLOCK();
822	}
823#endif
824
825	/*
826	 * Switch out to protocol's input routine.
827	 */
828#if IFA_STATS
829	if (ia && ip) {
830		struct in_ifaddr *_ia;
831		/*
832		 * Keep a reference from ip_match_our_address with psref
833		 * is expensive, so explore ia here again.
834		 */
835		s = pserialize_read_enter();
836		_ia = in_get_ia(ip->ip_dst);
837		_ia->ia_ifa.ifa_data.ifad_inbytes += ntohs(ip->ip_len);
838		pserialize_read_exit(s);
839	}
840#endif
841	IP_STATINC(IP_STAT_DELIVERED);
842
843	const int off = hlen, nh = ip->ip_p;
844
845	SOFTNET_LOCK();
846	(*inetsw[ip_protox[nh]].pr_input)(m, off, nh);
847	SOFTNET_UNLOCK();
848	return;
849
850out:
851	m_put_rcvif_psref(ifp, &psref);
852	if (m != NULL)
853		m_freem(m);
854}
855
856/*
857 * IP timer processing.
858 */
859void
860ip_slowtimo(void)
861{
862
863#ifndef NET_MPSAFE
864	mutex_enter(softnet_lock);
865	KERNEL_LOCK(1, NULL);
866#endif
867
868	ip_reass_slowtimo();
869
870#ifndef NET_MPSAFE
871	KERNEL_UNLOCK_ONE(NULL);
872	mutex_exit(softnet_lock);
873#endif
874}
875
876/*
877 * IP drain processing.
878 */
879void
880ip_drain(void)
881{
882
883	KERNEL_LOCK(1, NULL);
884	ip_reass_drain();
885	KERNEL_UNLOCK_ONE(NULL);
886}
887
888/*
889 * ip_dooptions: perform option processing on a datagram, possibly discarding
890 * it if bad options are encountered, or forwarding it if source-routed.
891 *
892 * => Returns true if packet has been forwarded/freed.
893 * => Returns false if the packet should be processed further.
894 */
895static bool
896ip_dooptions(struct mbuf *m)
897{
898	struct ip *ip = mtod(m, struct ip *);
899	u_char *cp, *cp0;
900	struct ip_timestamp *ipt;
901	struct in_ifaddr *ia;
902	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
903	struct in_addr dst;
904	n_time ntime;
905	struct ifaddr *ifa = NULL;
906	int s;
907
908	dst = ip->ip_dst;
909	cp = (u_char *)(ip + 1);
910	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
911	for (; cnt > 0; cnt -= optlen, cp += optlen) {
912		opt = cp[IPOPT_OPTVAL];
913		if (opt == IPOPT_EOL)
914			break;
915		if (opt == IPOPT_NOP)
916			optlen = 1;
917		else {
918			if (cnt < IPOPT_OLEN + sizeof(*cp)) {
919				code = &cp[IPOPT_OLEN] - (u_char *)ip;
920				goto bad;
921			}
922			optlen = cp[IPOPT_OLEN];
923			if (optlen < IPOPT_OLEN + sizeof(*cp) || optlen > cnt) {
924				code = &cp[IPOPT_OLEN] - (u_char *)ip;
925				goto bad;
926			}
927		}
928		switch (opt) {
929
930		default:
931			break;
932
933		/*
934		 * Source routing with record.
935		 * Find interface with current destination address.
936		 * If none on this machine then drop if strictly routed,
937		 * or do nothing if loosely routed.
938		 * Record interface address and bring up next address
939		 * component.  If strictly routed make sure next
940		 * address is on directly accessible net.
941		 */
942		case IPOPT_LSRR:
943		case IPOPT_SSRR: {
944			struct psref psref;
945			struct sockaddr_in ipaddr = {
946			    .sin_len = sizeof(ipaddr),
947			    .sin_family = AF_INET,
948			};
949
950			if (ip_allowsrcrt == 0) {
951				type = ICMP_UNREACH;
952				code = ICMP_UNREACH_NET_PROHIB;
953				goto bad;
954			}
955			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
956				code = &cp[IPOPT_OLEN] - (u_char *)ip;
957				goto bad;
958			}
959			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
960				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
961				goto bad;
962			}
963			ipaddr.sin_addr = ip->ip_dst;
964
965			s = pserialize_read_enter();
966			ifa = ifa_ifwithaddr(sintosa(&ipaddr));
967			if (ifa == NULL) {
968				pserialize_read_exit(s);
969				if (opt == IPOPT_SSRR) {
970					type = ICMP_UNREACH;
971					code = ICMP_UNREACH_SRCFAIL;
972					goto bad;
973				}
974				/*
975				 * Loose routing, and not at next destination
976				 * yet; nothing to do except forward.
977				 */
978				break;
979			}
980			pserialize_read_exit(s);
981
982			off--;			/* 0 origin */
983			if ((off + sizeof(struct in_addr)) > optlen) {
984				/*
985				 * End of source route.  Should be for us.
986				 */
987				save_rte(m, cp, ip->ip_src);
988				break;
989			}
990			/*
991			 * locate outgoing interface
992			 */
993			memcpy((void *)&ipaddr.sin_addr, (void *)(cp + off),
994			    sizeof(ipaddr.sin_addr));
995			if (opt == IPOPT_SSRR) {
996				ifa = ifa_ifwithladdr_psref(sintosa(&ipaddr),
997				    &psref);
998				if (ifa != NULL)
999					ia = ifatoia(ifa);
1000				else
1001					ia = NULL;
1002			} else {
1003				ia = ip_rtaddr(ipaddr.sin_addr, &psref);
1004			}
1005			if (ia == NULL) {
1006				type = ICMP_UNREACH;
1007				code = ICMP_UNREACH_SRCFAIL;
1008				goto bad;
1009			}
1010			ip->ip_dst = ipaddr.sin_addr;
1011			bcopy((void *)&ia->ia_addr.sin_addr,
1012			    (void *)(cp + off), sizeof(struct in_addr));
1013			ia4_release(ia, &psref);
1014			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1015			/*
1016			 * Let ip_intr's mcast routing check handle mcast pkts
1017			 */
1018			forward = !IN_MULTICAST(ip->ip_dst.s_addr);
1019			break;
1020		    }
1021
1022		case IPOPT_RR: {
1023			struct psref psref;
1024			struct sockaddr_in ipaddr = {
1025			    .sin_len = sizeof(ipaddr),
1026			    .sin_family = AF_INET,
1027			};
1028
1029			if (optlen < IPOPT_OFFSET + sizeof(*cp)) {
1030				code = &cp[IPOPT_OLEN] - (u_char *)ip;
1031				goto bad;
1032			}
1033			if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1034				code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1035				goto bad;
1036			}
1037			/*
1038			 * If no space remains, ignore.
1039			 */
1040			off--;			/* 0 origin */
1041			if ((off + sizeof(struct in_addr)) > optlen)
1042				break;
1043			memcpy((void *)&ipaddr.sin_addr, (void *)(&ip->ip_dst),
1044			    sizeof(ipaddr.sin_addr));
1045			/*
1046			 * locate outgoing interface; if we're the destination,
1047			 * use the incoming interface (should be same).
1048			 */
1049			ifa = ifa_ifwithaddr_psref(sintosa(&ipaddr), &psref);
1050			if (ifa == NULL) {
1051				ia = ip_rtaddr(ipaddr.sin_addr, &psref);
1052				if (ia == NULL) {
1053					type = ICMP_UNREACH;
1054					code = ICMP_UNREACH_HOST;
1055					goto bad;
1056				}
1057			} else {
1058				ia = ifatoia(ifa);
1059			}
1060			bcopy((void *)&ia->ia_addr.sin_addr,
1061			    (void *)(cp + off), sizeof(struct in_addr));
1062			ia4_release(ia, &psref);
1063			cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1064			break;
1065		    }
1066
1067		case IPOPT_TS:
1068			code = cp - (u_char *)ip;
1069			ipt = (struct ip_timestamp *)cp;
1070			if (ipt->ipt_len < 4 || ipt->ipt_len > 40) {
1071				code = (u_char *)&ipt->ipt_len - (u_char *)ip;
1072				goto bad;
1073			}
1074			if (ipt->ipt_ptr < 5) {
1075				code = (u_char *)&ipt->ipt_ptr - (u_char *)ip;
1076				goto bad;
1077			}
1078			if (ipt->ipt_ptr > ipt->ipt_len - sizeof (int32_t)) {
1079				if (++ipt->ipt_oflw == 0) {
1080					code = (u_char *)&ipt->ipt_ptr -
1081					    (u_char *)ip;
1082					goto bad;
1083				}
1084				break;
1085			}
1086			cp0 = (cp + ipt->ipt_ptr - 1);
1087			switch (ipt->ipt_flg) {
1088
1089			case IPOPT_TS_TSONLY:
1090				break;
1091
1092			case IPOPT_TS_TSANDADDR: {
1093				struct ifnet *rcvif;
1094				int _s, _ss;
1095				struct sockaddr_in ipaddr = {
1096				    .sin_len = sizeof(ipaddr),
1097				    .sin_family = AF_INET,
1098				};
1099
1100				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1101				    sizeof(struct in_addr) > ipt->ipt_len) {
1102					code = (u_char *)&ipt->ipt_ptr -
1103					    (u_char *)ip;
1104					goto bad;
1105				}
1106				ipaddr.sin_addr = dst;
1107				_ss = pserialize_read_enter();
1108				rcvif = m_get_rcvif(m, &_s);
1109				if (__predict_true(rcvif != NULL)) {
1110					ifa = ifaof_ifpforaddr(sintosa(&ipaddr),
1111					    rcvif);
1112				}
1113				m_put_rcvif(rcvif, &_s);
1114				if (ifa == NULL) {
1115					pserialize_read_exit(_ss);
1116					break;
1117				}
1118				ia = ifatoia(ifa);
1119				bcopy(&ia->ia_addr.sin_addr,
1120				    cp0, sizeof(struct in_addr));
1121				pserialize_read_exit(_ss);
1122				ipt->ipt_ptr += sizeof(struct in_addr);
1123				break;
1124			}
1125
1126			case IPOPT_TS_PRESPEC: {
1127				struct sockaddr_in ipaddr = {
1128				    .sin_len = sizeof(ipaddr),
1129				    .sin_family = AF_INET,
1130				};
1131
1132				if (ipt->ipt_ptr - 1 + sizeof(n_time) +
1133				    sizeof(struct in_addr) > ipt->ipt_len) {
1134					code = (u_char *)&ipt->ipt_ptr -
1135					    (u_char *)ip;
1136					goto bad;
1137				}
1138				memcpy(&ipaddr.sin_addr, cp0,
1139				    sizeof(struct in_addr));
1140				s = pserialize_read_enter();
1141				ifa = ifa_ifwithaddr(sintosa(&ipaddr));
1142				if (ifa == NULL) {
1143					pserialize_read_exit(s);
1144					continue;
1145				}
1146				pserialize_read_exit(s);
1147				ipt->ipt_ptr += sizeof(struct in_addr);
1148				break;
1149			    }
1150
1151			default:
1152				/* XXX can't take &ipt->ipt_flg */
1153				code = (u_char *)&ipt->ipt_ptr -
1154				    (u_char *)ip + 1;
1155				goto bad;
1156			}
1157			ntime = iptime();
1158			cp0 = (u_char *) &ntime; /* XXX grumble, GCC... */
1159			memmove((char *)cp + ipt->ipt_ptr - 1, cp0,
1160			    sizeof(n_time));
1161			ipt->ipt_ptr += sizeof(n_time);
1162		}
1163	}
1164	if (forward) {
1165		struct ifnet *rcvif;
1166		struct psref _psref;
1167
1168		if (ip_forwsrcrt == 0) {
1169			type = ICMP_UNREACH;
1170			code = ICMP_UNREACH_SRCFAIL;
1171			goto bad;
1172		}
1173
1174		rcvif = m_get_rcvif_psref(m, &_psref);
1175		if (__predict_false(rcvif == NULL)) {
1176			type = ICMP_UNREACH;
1177			code = ICMP_UNREACH_HOST;
1178			goto bad;
1179		}
1180		ip_forward(m, 1, rcvif);
1181		m_put_rcvif_psref(rcvif, &_psref);
1182		return true;
1183	}
1184	return false;
1185bad:
1186	icmp_error(m, type, code, 0, 0);
1187	IP_STATINC(IP_STAT_BADOPTIONS);
1188	return true;
1189}
1190
1191/*
1192 * ip_rtaddr: given address of next destination (final or next hop),
1193 * return internet address info of interface to be used to get there.
1194 */
1195static struct in_ifaddr *
1196ip_rtaddr(struct in_addr dst, struct psref *psref)
1197{
1198	struct rtentry *rt;
1199	union {
1200		struct sockaddr		dst;
1201		struct sockaddr_in	dst4;
1202	} u;
1203	struct route *ro;
1204
1205	sockaddr_in_init(&u.dst4, &dst, 0);
1206
1207	ro = percpu_getref(ipforward_rt_percpu);
1208	rt = rtcache_lookup(ro, &u.dst);
1209	if (rt == NULL) {
1210		percpu_putref(ipforward_rt_percpu);
1211		return NULL;
1212	}
1213
1214	ia4_acquire(ifatoia(rt->rt_ifa), psref);
1215	rtcache_unref(rt, ro);
1216	percpu_putref(ipforward_rt_percpu);
1217
1218	return ifatoia(rt->rt_ifa);
1219}
1220
1221/*
1222 * save_rte: save incoming source route for use in replies, to be picked
1223 * up later by ip_srcroute if the receiver is interested.
1224 */
1225static void
1226save_rte(struct mbuf *m, u_char *option, struct in_addr dst)
1227{
1228	struct ip_srcrt *isr;
1229	struct m_tag *mtag;
1230	unsigned olen;
1231
1232	olen = option[IPOPT_OLEN];
1233	if (olen > sizeof(isr->isr_hdr) + sizeof(isr->isr_routes))
1234		return;
1235
1236	mtag = m_tag_get(PACKET_TAG_SRCROUTE, sizeof(*isr), M_NOWAIT);
1237	if (mtag == NULL)
1238		return;
1239	isr = (struct ip_srcrt *)(mtag + 1);
1240
1241	memcpy(isr->isr_hdr, option, olen);
1242	isr->isr_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1243	isr->isr_dst = dst;
1244	m_tag_prepend(m, mtag);
1245}
1246
1247/*
1248 * Retrieve incoming source route for use in replies,
1249 * in the same form used by setsockopt.
1250 * The first hop is placed before the options, will be removed later.
1251 */
1252struct mbuf *
1253ip_srcroute(struct mbuf *m0)
1254{
1255	struct in_addr *p, *q;
1256	struct mbuf *m;
1257	struct ip_srcrt *isr;
1258	struct m_tag *mtag;
1259
1260	mtag = m_tag_find(m0, PACKET_TAG_SRCROUTE, NULL);
1261	if (mtag == NULL)
1262		return NULL;
1263	isr = (struct ip_srcrt *)(mtag + 1);
1264
1265	if (isr->isr_nhops == 0)
1266		return NULL;
1267
1268	m = m_get(M_DONTWAIT, MT_SOOPTS);
1269	if (m == NULL)
1270		return NULL;
1271
1272	MCLAIM(m, &inetdomain.dom_mowner);
1273#define OPTSIZ	(sizeof(isr->isr_nop) + sizeof(isr->isr_hdr))
1274
1275	/* length is (nhops+1)*sizeof(addr) + sizeof(nop + header) */
1276	m->m_len = (isr->isr_nhops + 1) * sizeof(struct in_addr) + OPTSIZ;
1277
1278	/*
1279	 * First save first hop for return route
1280	 */
1281	p = &(isr->isr_routes[isr->isr_nhops - 1]);
1282	*(mtod(m, struct in_addr *)) = *p--;
1283
1284	/*
1285	 * Copy option fields and padding (nop) to mbuf.
1286	 */
1287	isr->isr_nop = IPOPT_NOP;
1288	isr->isr_hdr[IPOPT_OFFSET] = IPOPT_MINOFF;
1289	memmove(mtod(m, char *) + sizeof(struct in_addr), &isr->isr_nop,
1290	    OPTSIZ);
1291	q = (struct in_addr *)(mtod(m, char *) +
1292	    sizeof(struct in_addr) + OPTSIZ);
1293#undef OPTSIZ
1294	/*
1295	 * Record return path as an IP source route,
1296	 * reversing the path (pointers are now aligned).
1297	 */
1298	while (p >= isr->isr_routes) {
1299		*q++ = *p--;
1300	}
1301	/*
1302	 * Last hop goes to final destination.
1303	 */
1304	*q = isr->isr_dst;
1305	m_tag_delete(m0, mtag);
1306	return m;
1307}
1308
1309const int inetctlerrmap[PRC_NCMDS] = {
1310	[PRC_MSGSIZE] = EMSGSIZE,
1311	[PRC_HOSTDEAD] = EHOSTDOWN,
1312	[PRC_HOSTUNREACH] = EHOSTUNREACH,
1313	[PRC_UNREACH_NET] = EHOSTUNREACH,
1314	[PRC_UNREACH_HOST] = EHOSTUNREACH,
1315	[PRC_UNREACH_PROTOCOL] = ECONNREFUSED,
1316	[PRC_UNREACH_PORT] = ECONNREFUSED,
1317	[PRC_UNREACH_SRCFAIL] = EHOSTUNREACH,
1318	[PRC_PARAMPROB] = ENOPROTOOPT,
1319};
1320
1321void
1322ip_fasttimo(void)
1323{
1324	if (ip_drainwanted) {
1325		ip_drain();
1326		ip_drainwanted = 0;
1327	}
1328}
1329
1330void
1331ip_drainstub(void)
1332{
1333	ip_drainwanted = 1;
1334}
1335
1336/*
1337 * Forward a packet.  If some error occurs return the sender
1338 * an icmp packet.  Note we can't always generate a meaningful
1339 * icmp message because icmp doesn't have a large enough repertoire
1340 * of codes and types.
1341 *
1342 * If not forwarding, just drop the packet.  This could be confusing
1343 * if ipforwarding was zero but some routing protocol was advancing
1344 * us as a gateway to somewhere.  However, we must let the routing
1345 * protocol deal with that.
1346 *
1347 * The srcrt parameter indicates whether the packet is being forwarded
1348 * via a source route.
1349 */
1350static void
1351ip_forward(struct mbuf *m, int srcrt, struct ifnet *rcvif)
1352{
1353	struct ip *ip = mtod(m, struct ip *);
1354	struct rtentry *rt;
1355	int error, type = 0, code = 0, destmtu = 0;
1356	struct mbuf *mcopy;
1357	n_long dest;
1358	union {
1359		struct sockaddr		dst;
1360		struct sockaddr_in	dst4;
1361	} u;
1362	uint64_t *ips;
1363	struct route *ro;
1364
1365	KASSERTMSG(cpu_softintr_p(), "ip_forward: not in the software "
1366	    "interrupt handler; synchronization assumptions violated");
1367
1368	/*
1369	 * We are now in the output path.
1370	 */
1371	MCLAIM(m, &ip_tx_mowner);
1372
1373	/*
1374	 * Clear any in-bound checksum flags for this packet.
1375	 */
1376	m->m_pkthdr.csum_flags = 0;
1377
1378	dest = 0;
1379	if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1380		IP_STATINC(IP_STAT_CANTFORWARD);
1381		m_freem(m);
1382		return;
1383	}
1384
1385	if (ip->ip_ttl <= IPTTLDEC) {
1386		icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1387		return;
1388	}
1389
1390	sockaddr_in_init(&u.dst4, &ip->ip_dst, 0);
1391
1392	ro = percpu_getref(ipforward_rt_percpu);
1393	rt = rtcache_lookup(ro, &u.dst);
1394	if (rt == NULL) {
1395		percpu_putref(ipforward_rt_percpu);
1396		icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, dest, 0);
1397		return;
1398	}
1399
1400	/*
1401	 * Save at most 68 bytes of the packet in case
1402	 * we need to generate an ICMP message to the src.
1403	 * Pullup to avoid sharing mbuf cluster between m and mcopy.
1404	 */
1405	mcopy = m_copym(m, 0, imin(ntohs(ip->ip_len), 68), M_DONTWAIT);
1406	if (mcopy)
1407		mcopy = m_pullup(mcopy, ip->ip_hl << 2);
1408
1409	ip->ip_ttl -= IPTTLDEC;
1410
1411	/*
1412	 * If forwarding packet using same interface that it came in on,
1413	 * perhaps should send a redirect to sender to shortcut a hop.
1414	 * Only send redirect if source is sending directly to us,
1415	 * and if packet was not source routed (or has any options).
1416	 * Also, don't send redirect if forwarding using a default route
1417	 * or a route modified by a redirect.
1418	 */
1419	if (rt->rt_ifp == rcvif &&
1420	    (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1421	    !in_nullhost(satocsin(rt_getkey(rt))->sin_addr) &&
1422	    ipsendredirects && !srcrt) {
1423		if (rt->rt_ifa &&
1424		    (ip->ip_src.s_addr & ifatoia(rt->rt_ifa)->ia_subnetmask) ==
1425		    ifatoia(rt->rt_ifa)->ia_subnet) {
1426			if (rt->rt_flags & RTF_GATEWAY)
1427				dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1428			else
1429				dest = ip->ip_dst.s_addr;
1430			/*
1431			 * Router requirements says to only send host
1432			 * redirects.
1433			 */
1434			type = ICMP_REDIRECT;
1435			code = ICMP_REDIRECT_HOST;
1436		}
1437	}
1438	rtcache_unref(rt, ro);
1439
1440	error = ip_output(m, NULL, ro,
1441	    (IP_FORWARDING | (ip_directedbcast ? IP_ALLOWBROADCAST : 0)),
1442	    NULL, NULL);
1443
1444	if (error) {
1445		IP_STATINC(IP_STAT_CANTFORWARD);
1446		goto error;
1447	}
1448
1449	ips = IP_STAT_GETREF();
1450	ips[IP_STAT_FORWARD]++;
1451
1452	if (type) {
1453		ips[IP_STAT_REDIRECTSENT]++;
1454		IP_STAT_PUTREF();
1455		goto redirect;
1456	}
1457
1458	IP_STAT_PUTREF();
1459	if (mcopy) {
1460#ifdef GATEWAY
1461		if (mcopy->m_flags & M_CANFASTFWD)
1462			ipflow_create(ro, mcopy);
1463#endif
1464		m_freem(mcopy);
1465	}
1466
1467	percpu_putref(ipforward_rt_percpu);
1468	return;
1469
1470redirect:
1471error:
1472	if (mcopy == NULL) {
1473		percpu_putref(ipforward_rt_percpu);
1474		return;
1475	}
1476
1477	switch (error) {
1478
1479	case 0:				/* forwarded, but need redirect */
1480		/* type, code set above */
1481		break;
1482
1483	case ENETUNREACH:		/* shouldn't happen, checked above */
1484	case EHOSTUNREACH:
1485	case ENETDOWN:
1486	case EHOSTDOWN:
1487	default:
1488		type = ICMP_UNREACH;
1489		code = ICMP_UNREACH_HOST;
1490		break;
1491
1492	case EMSGSIZE:
1493		type = ICMP_UNREACH;
1494		code = ICMP_UNREACH_NEEDFRAG;
1495
1496		if ((rt = rtcache_validate(ro)) != NULL) {
1497			destmtu = rt->rt_ifp->if_mtu;
1498			rtcache_unref(rt, ro);
1499		}
1500#ifdef IPSEC
1501		if (ipsec_used)
1502			(void)ipsec4_forward(mcopy, &destmtu);
1503#endif
1504		IP_STATINC(IP_STAT_CANTFRAG);
1505		break;
1506
1507	case ENOBUFS:
1508		/*
1509		 * Do not generate ICMP_SOURCEQUENCH as required in RFC 1812,
1510		 * Requirements for IP Version 4 Routers.  Source quench can
1511		 * big problem under DoS attacks or if the underlying
1512		 * interface is rate-limited.
1513		 */
1514		if (mcopy)
1515			m_freem(mcopy);
1516		percpu_putref(ipforward_rt_percpu);
1517		return;
1518	}
1519	icmp_error(mcopy, type, code, dest, destmtu);
1520	percpu_putref(ipforward_rt_percpu);
1521}
1522
1523void
1524ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1525    struct mbuf *m)
1526{
1527	struct socket *so = inp->inp_socket;
1528	ifnet_t *ifp;
1529	int inpflags = inp->inp_flags;
1530	struct psref psref;
1531
1532	ifp = m_get_rcvif_psref(m, &psref);
1533	if (__predict_false(ifp == NULL))
1534		return; /* XXX should report error? */
1535
1536	if (so->so_options & SO_TIMESTAMP
1537#ifdef SO_OTIMESTAMP
1538	    || so->so_options & SO_OTIMESTAMP
1539#endif
1540	    ) {
1541		struct timeval tv;
1542
1543		microtime(&tv);
1544#ifdef SO_OTIMESTAMP
1545		if (so->so_options & SO_OTIMESTAMP) {
1546			struct timeval50 tv50;
1547			timeval_to_timeval50(&tv, &tv50);
1548			*mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
1549			    SCM_OTIMESTAMP, SOL_SOCKET);
1550		} else
1551#endif
1552		*mp = sbcreatecontrol((void *) &tv, sizeof(tv),
1553		    SCM_TIMESTAMP, SOL_SOCKET);
1554		if (*mp)
1555			mp = &(*mp)->m_next;
1556	}
1557	if (inpflags & INP_RECVDSTADDR) {
1558		*mp = sbcreatecontrol((void *) &ip->ip_dst,
1559		    sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1560		if (*mp)
1561			mp = &(*mp)->m_next;
1562	}
1563	if (inpflags & INP_RECVPKTINFO) {
1564		struct in_pktinfo ipi;
1565		ipi.ipi_addr = ip->ip_src;
1566		ipi.ipi_ifindex = ifp->if_index;
1567		*mp = sbcreatecontrol((void *) &ipi,
1568		    sizeof(ipi), IP_RECVPKTINFO, IPPROTO_IP);
1569		if (*mp)
1570			mp = &(*mp)->m_next;
1571	}
1572	if (inpflags & INP_PKTINFO) {
1573		struct in_pktinfo ipi;
1574		ipi.ipi_addr = ip->ip_dst;
1575		ipi.ipi_ifindex = ifp->if_index;
1576		*mp = sbcreatecontrol((void *) &ipi,
1577		    sizeof(ipi), IP_PKTINFO, IPPROTO_IP);
1578		if (*mp)
1579			mp = &(*mp)->m_next;
1580	}
1581	if (inpflags & INP_RECVIF) {
1582		struct sockaddr_dl sdl;
1583
1584		sockaddr_dl_init(&sdl, sizeof(sdl), ifp->if_index, 0, NULL, 0,
1585		    NULL, 0);
1586		*mp = sbcreatecontrol(&sdl, sdl.sdl_len, IP_RECVIF, IPPROTO_IP);
1587		if (*mp)
1588			mp = &(*mp)->m_next;
1589	}
1590	if (inpflags & INP_RECVTTL) {
1591		*mp = sbcreatecontrol((void *) &ip->ip_ttl,
1592		    sizeof(uint8_t), IP_RECVTTL, IPPROTO_IP);
1593		if (*mp)
1594			mp = &(*mp)->m_next;
1595	}
1596	m_put_rcvif_psref(ifp, &psref);
1597}
1598
1599/*
1600 * sysctl helper routine for net.inet.ip.forwsrcrt.
1601 */
1602static int
1603sysctl_net_inet_ip_forwsrcrt(SYSCTLFN_ARGS)
1604{
1605	int error, tmp;
1606	struct sysctlnode node;
1607
1608	node = *rnode;
1609	tmp = ip_forwsrcrt;
1610	node.sysctl_data = &tmp;
1611	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1612	if (error || newp == NULL)
1613		return (error);
1614
1615	error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_FORWSRCRT,
1616	    0, NULL, NULL, NULL);
1617	if (error)
1618		return (error);
1619
1620	ip_forwsrcrt = tmp;
1621
1622	return (0);
1623}
1624
1625/*
1626 * sysctl helper routine for net.inet.ip.mtudisctimeout.  checks the
1627 * range of the new value and tweaks timers if it changes.
1628 */
1629static int
1630sysctl_net_inet_ip_pmtudto(SYSCTLFN_ARGS)
1631{
1632	int error, tmp;
1633	struct sysctlnode node;
1634
1635	icmp_mtudisc_lock();
1636
1637	node = *rnode;
1638	tmp = ip_mtudisc_timeout;
1639	node.sysctl_data = &tmp;
1640	error = sysctl_lookup(SYSCTLFN_CALL(&node));
1641	if (error || newp == NULL)
1642		goto out;
1643	if (tmp < 0) {
1644		error = EINVAL;
1645		goto out;
1646	}
1647
1648	ip_mtudisc_timeout = tmp;
1649	rt_timer_queue_change(ip_mtudisc_timeout_q, ip_mtudisc_timeout);
1650	error = 0;
1651out:
1652	icmp_mtudisc_unlock();
1653	return error;
1654}
1655
1656static int
1657sysctl_net_inet_ip_stats(SYSCTLFN_ARGS)
1658{
1659
1660	return (NETSTAT_SYSCTL(ipstat_percpu, IP_NSTATS));
1661}
1662
1663static void
1664sysctl_net_inet_ip_setup(struct sysctllog **clog)
1665{
1666	sysctl_createv(clog, 0, NULL, NULL,
1667		       CTLFLAG_PERMANENT,
1668		       CTLTYPE_NODE, "inet",
1669		       SYSCTL_DESCR("PF_INET related settings"),
1670		       NULL, 0, NULL, 0,
1671		       CTL_NET, PF_INET, CTL_EOL);
1672	sysctl_createv(clog, 0, NULL, NULL,
1673		       CTLFLAG_PERMANENT,
1674		       CTLTYPE_NODE, "ip",
1675		       SYSCTL_DESCR("IPv4 related settings"),
1676		       NULL, 0, NULL, 0,
1677		       CTL_NET, PF_INET, IPPROTO_IP, CTL_EOL);
1678
1679	sysctl_createv(clog, 0, NULL, NULL,
1680		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1681		       CTLTYPE_INT, "forwarding",
1682		       SYSCTL_DESCR("Enable forwarding of INET datagrams"),
1683		       NULL, 0, &ipforwarding, 0,
1684		       CTL_NET, PF_INET, IPPROTO_IP,
1685		       IPCTL_FORWARDING, CTL_EOL);
1686	sysctl_createv(clog, 0, NULL, NULL,
1687		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1688		       CTLTYPE_INT, "redirect",
1689		       SYSCTL_DESCR("Enable sending of ICMP redirect messages"),
1690		       NULL, 0, &ipsendredirects, 0,
1691		       CTL_NET, PF_INET, IPPROTO_IP,
1692		       IPCTL_SENDREDIRECTS, CTL_EOL);
1693	sysctl_createv(clog, 0, NULL, NULL,
1694		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1695		       CTLTYPE_INT, "ttl",
1696		       SYSCTL_DESCR("Default TTL for an INET datagram"),
1697		       NULL, 0, &ip_defttl, 0,
1698		       CTL_NET, PF_INET, IPPROTO_IP,
1699		       IPCTL_DEFTTL, CTL_EOL);
1700#ifdef IPCTL_DEFMTU
1701	sysctl_createv(clog, 0, NULL, NULL,
1702		       CTLFLAG_PERMANENT /* |CTLFLAG_READWRITE? */,
1703		       CTLTYPE_INT, "mtu",
1704		       SYSCTL_DESCR("Default MTA for an INET route"),
1705		       NULL, 0, &ip_mtu, 0,
1706		       CTL_NET, PF_INET, IPPROTO_IP,
1707		       IPCTL_DEFMTU, CTL_EOL);
1708#endif /* IPCTL_DEFMTU */
1709	sysctl_createv(clog, 0, NULL, NULL,
1710		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1711		       CTLTYPE_INT, "forwsrcrt",
1712		       SYSCTL_DESCR("Enable forwarding of source-routed "
1713				    "datagrams"),
1714		       sysctl_net_inet_ip_forwsrcrt, 0, &ip_forwsrcrt, 0,
1715		       CTL_NET, PF_INET, IPPROTO_IP,
1716		       IPCTL_FORWSRCRT, CTL_EOL);
1717	sysctl_createv(clog, 0, NULL, NULL,
1718		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1719		       CTLTYPE_INT, "directed-broadcast",
1720		       SYSCTL_DESCR("Enable forwarding of broadcast datagrams"),
1721		       NULL, 0, &ip_directedbcast, 0,
1722		       CTL_NET, PF_INET, IPPROTO_IP,
1723		       IPCTL_DIRECTEDBCAST, CTL_EOL);
1724	sysctl_createv(clog, 0, NULL, NULL,
1725		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1726		       CTLTYPE_INT, "allowsrcrt",
1727		       SYSCTL_DESCR("Accept source-routed datagrams"),
1728		       NULL, 0, &ip_allowsrcrt, 0,
1729		       CTL_NET, PF_INET, IPPROTO_IP,
1730		       IPCTL_ALLOWSRCRT, CTL_EOL);
1731
1732	sysctl_createv(clog, 0, NULL, NULL,
1733		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1734		       CTLTYPE_INT, "mtudisc",
1735		       SYSCTL_DESCR("Use RFC1191 Path MTU Discovery"),
1736		       NULL, 0, &ip_mtudisc, 0,
1737		       CTL_NET, PF_INET, IPPROTO_IP,
1738		       IPCTL_MTUDISC, CTL_EOL);
1739	sysctl_createv(clog, 0, NULL, NULL,
1740		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1741		       CTLTYPE_INT, "anonportmin",
1742		       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
1743		       sysctl_net_inet_ip_ports, 0, &anonportmin, 0,
1744		       CTL_NET, PF_INET, IPPROTO_IP,
1745		       IPCTL_ANONPORTMIN, CTL_EOL);
1746	sysctl_createv(clog, 0, NULL, NULL,
1747		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1748		       CTLTYPE_INT, "anonportmax",
1749		       SYSCTL_DESCR("Highest ephemeral port number to assign"),
1750		       sysctl_net_inet_ip_ports, 0, &anonportmax, 0,
1751		       CTL_NET, PF_INET, IPPROTO_IP,
1752		       IPCTL_ANONPORTMAX, CTL_EOL);
1753	sysctl_createv(clog, 0, NULL, NULL,
1754		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1755		       CTLTYPE_INT, "mtudisctimeout",
1756		       SYSCTL_DESCR("Lifetime of a Path MTU Discovered route"),
1757		       sysctl_net_inet_ip_pmtudto, 0, (void *)&ip_mtudisc_timeout, 0,
1758		       CTL_NET, PF_INET, IPPROTO_IP,
1759		       IPCTL_MTUDISCTIMEOUT, CTL_EOL);
1760#ifndef IPNOPRIVPORTS
1761	sysctl_createv(clog, 0, NULL, NULL,
1762		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1763		       CTLTYPE_INT, "lowportmin",
1764		       SYSCTL_DESCR("Lowest privileged ephemeral port number "
1765				    "to assign"),
1766		       sysctl_net_inet_ip_ports, 0, &lowportmin, 0,
1767		       CTL_NET, PF_INET, IPPROTO_IP,
1768		       IPCTL_LOWPORTMIN, CTL_EOL);
1769	sysctl_createv(clog, 0, NULL, NULL,
1770		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1771		       CTLTYPE_INT, "lowportmax",
1772		       SYSCTL_DESCR("Highest privileged ephemeral port number "
1773				    "to assign"),
1774		       sysctl_net_inet_ip_ports, 0, &lowportmax, 0,
1775		       CTL_NET, PF_INET, IPPROTO_IP,
1776		       IPCTL_LOWPORTMAX, CTL_EOL);
1777#endif /* IPNOPRIVPORTS */
1778#if NGRE > 0
1779	sysctl_createv(clog, 0, NULL, NULL,
1780		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1781		       CTLTYPE_INT, "grettl",
1782		       SYSCTL_DESCR("Default TTL for a gre tunnel datagram"),
1783		       NULL, 0, &ip_gre_ttl, 0,
1784		       CTL_NET, PF_INET, IPPROTO_IP,
1785		       IPCTL_GRE_TTL, CTL_EOL);
1786#endif /* NGRE */
1787	sysctl_createv(clog, 0, NULL, NULL,
1788		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1789		       CTLTYPE_INT, "checkinterface",
1790		       SYSCTL_DESCR("Enable receive side of Strong ES model "
1791				    "from RFC1122"),
1792		       NULL, 0, &ip_checkinterface, 0,
1793		       CTL_NET, PF_INET, IPPROTO_IP,
1794		       IPCTL_CHECKINTERFACE, CTL_EOL);
1795	sysctl_createv(clog, 0, NULL, NULL,
1796		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1797		       CTLTYPE_INT, "random_id",
1798		       SYSCTL_DESCR("Assign random ip_id values"),
1799		       NULL, 0, &ip_do_randomid, 0,
1800		       CTL_NET, PF_INET, IPPROTO_IP,
1801		       IPCTL_RANDOMID, CTL_EOL);
1802	sysctl_createv(clog, 0, NULL, NULL,
1803		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1804		       CTLTYPE_INT, "do_loopback_cksum",
1805		       SYSCTL_DESCR("Perform IP checksum on loopback"),
1806		       NULL, 0, &ip_do_loopback_cksum, 0,
1807		       CTL_NET, PF_INET, IPPROTO_IP,
1808		       IPCTL_LOOPBACKCKSUM, CTL_EOL);
1809	sysctl_createv(clog, 0, NULL, NULL,
1810		       CTLFLAG_PERMANENT,
1811		       CTLTYPE_STRUCT, "stats",
1812		       SYSCTL_DESCR("IP statistics"),
1813		       sysctl_net_inet_ip_stats, 0, NULL, 0,
1814		       CTL_NET, PF_INET, IPPROTO_IP, IPCTL_STATS,
1815		       CTL_EOL);
1816#if NARP
1817	sysctl_createv(clog, 0, NULL, NULL,
1818		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1819		       CTLTYPE_INT, "dad_count",
1820		       SYSCTL_DESCR("Number of Duplicate Address Detection "
1821				    "probes to send"),
1822		       NULL, 0, &ip_dad_count, 0,
1823		       CTL_NET, PF_INET, IPPROTO_IP,
1824		       IPCTL_DAD_COUNT, CTL_EOL);
1825#endif
1826
1827	/* anonportalgo RFC6056 subtree */
1828	const struct sysctlnode *portalgo_node;
1829	sysctl_createv(clog, 0, NULL, &portalgo_node,
1830		       CTLFLAG_PERMANENT,
1831		       CTLTYPE_NODE, "anonportalgo",
1832		       SYSCTL_DESCR("Anonymous Port Algorithm Selection (RFC 6056)"),
1833	    	       NULL, 0, NULL, 0,
1834		       CTL_NET, PF_INET, IPPROTO_IP, CTL_CREATE, CTL_EOL);
1835	sysctl_createv(clog, 0, &portalgo_node, NULL,
1836		       CTLFLAG_PERMANENT,
1837		       CTLTYPE_STRING, "available",
1838		       SYSCTL_DESCR("available algorithms"),
1839		       sysctl_portalgo_available, 0, NULL, PORTALGO_MAXLEN,
1840		       CTL_CREATE, CTL_EOL);
1841	sysctl_createv(clog, 0, &portalgo_node, NULL,
1842		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1843		       CTLTYPE_STRING, "selected",
1844		       SYSCTL_DESCR("selected algorithm"),
1845		       sysctl_portalgo_selected4, 0, NULL, PORTALGO_MAXLEN,
1846		       CTL_CREATE, CTL_EOL);
1847	sysctl_createv(clog, 0, &portalgo_node, NULL,
1848		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
1849		       CTLTYPE_STRUCT, "reserve",
1850		       SYSCTL_DESCR("bitmap of reserved ports"),
1851		       sysctl_portalgo_reserve4, 0, NULL, 0,
1852		       CTL_CREATE, CTL_EOL);
1853}
1854
1855void
1856ip_statinc(u_int stat)
1857{
1858
1859	KASSERT(stat < IP_NSTATS);
1860	IP_STATINC(stat);
1861}
1862