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source: rtems/cpukit/libnetworking/netinet/ip_input.c @ 0b07d87

4.104.114.84.95

Last change on this file since 0b07d87 was 0b07d87, checked in by Ralf Corsepius <ralf.corsepius@…>, on 03/28/07 at 04:40:36

2007-03-28 Ralf Corsépius <ralf.corsepius@…>

libnetworking/netinet/ip_input.c: Eliminate P(). Change "int next" to "int32_t next" for 16bit targets.

Property mode set to 100644

File size: 35.4 KB

Line
1	/*
2	* Copyright (c) 1982, 1986, 1988, 1993
3	* The Regents of the University of California. All rights reserved.
4	*
5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions
7	* are met:
8	* 1. Redistributions of source code must retain the above copyright
9	* notice, this list of conditions and the following disclaimer.
10	* 2. Redistributions in binary form must reproduce the above copyright
11	* notice, this list of conditions and the following disclaimer in the
12	* documentation and/or other materials provided with the distribution.
13	* 4. Neither the name of the University nor the names of its contributors
14	* may be used to endorse or promote products derived from this software
15	* without specific prior written permission.
16	*
17	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27	* SUCH DAMAGE.
28	*
29	* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
30	* $Id$
31	* $ANA: ip_input.c,v 1.5 1996/09/18 14:34:59 wollman Exp $
32	*/
33
34	#define _IP_VHL
35
36	#include "opt_ipfw.h"
37
38	#include <stddef.h>
39
40	#include <sys/param.h>
41	#include <sys/systm.h>
42	#include <sys/malloc.h>
43	#include <sys/mbuf.h>
44	#include <sys/domain.h>
45	#include <sys/protosw.h>
46	#include <sys/socket.h>
47	#include <sys/errno.h>
48	#include <sys/time.h>
49	#include <sys/kernel.h>
50	#include <sys/syslog.h>
51	#include <sys/sysctl.h>
52
53	#include <net/if.h>
54	#include <net/if_dl.h>
55	#include <net/route.h>
56	#include <net/netisr.h>
57
58	#include <netinet/in.h>
59	#include <netinet/in_systm.h>
60	#include <netinet/in_var.h>
61	#include <netinet/ip.h>
62	#include <netinet/in_pcb.h>
63	#include <netinet/in_var.h>
64	#include <netinet/ip_var.h>
65	#include <netinet/ip_icmp.h>
66	#include <machine/in_cksum.h>
67
68	#include <sys/socketvar.h>
69
70	#ifdef IPFIREWALL
71	#include <netinet/ip_fw.h>
72	#endif
73
74	int rsvp_on = 0;
75	static int ip_rsvp_on;
76	struct socket *ip_rsvpd;
77
78	int ipforwarding = 0;
79	SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
80	&ipforwarding, 0, "");
81
82	static int ipsendredirects = 1; /* XXX */
83	SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
84	&ipsendredirects, 0, "");
85
86	int ip_defttl = IPDEFTTL;
87	SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
88	&ip_defttl, 0, "");
89
90	static int ip_dosourceroute = 0;
91	SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
92	&ip_dosourceroute, 0, "");
93
94	static int ip_acceptsourceroute = 0;
95	SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
96	CTLFLAG_RW, &ip_acceptsourceroute, 0, "");
97	#ifdef DIAGNOSTIC
98	static int ipprintfs = 0;
99	#endif
100
101	extern struct domain inetdomain;
102	extern struct protosw inetsw[];
103	u_char ip_protox[IPPROTO_MAX];
104	static int ipqmaxlen = IFQ_MAXLEN;
105	struct in_ifaddr in_ifaddr; / first inet address */
106	struct ifqueue ipintrq;
107	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD,
108	&ipintrq.ifq_maxlen, 0, "");
109	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
110	&ipintrq.ifq_drops, 0, "");
111
112	struct ipstat ipstat;
113
114	/* Packet reassembly stuff */
115	#define IPREASS_NHASH_LOG2 6
116	#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
117	#define IPREASS_HMASK (IPREASS_NHASH - 1)
118	#define IPREASS_HASH(x,y) \
119	(((((x) & 0xF) \| ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
120
121	static struct ipq ipq[IPREASS_NHASH];
122	static int nipq = 0; /* total # of reass queues */
123	static int maxnipq;
124
125	#ifdef IPCTL_DEFMTU
126	SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
127	&ip_mtu, 0, "");
128	#endif
129
130	#if !defined(COMPAT_IPFW) \|\| COMPAT_IPFW == 1
131	#undef COMPAT_IPFW
132	#define COMPAT_IPFW 1
133	#else
134	#undef COMPAT_IPFW
135	#endif
136
137	#ifdef COMPAT_IPFW
138	/* Firewall hooks */
139	ip_fw_chk_t *ip_fw_chk_ptr;
140	ip_fw_ctl_t *ip_fw_ctl_ptr;
141
142	/* IP Network Address Translation (NAT) hooks */
143	ip_nat_t *ip_nat_ptr;
144	ip_nat_ctl_t *ip_nat_ctl_ptr;
145	#endif
146
147	/*
148	* We need to save the IP options in case a protocol wants to respond
149	* to an incoming packet over the same route if the packet got here
150	* using IP source routing. This allows connection establishment and
151	* maintenance when the remote end is on a network that is not known
152	* to us.
153	*/
154	static int ip_nhops = 0;
155	static struct ip_srcrt {
156	struct in_addr dst; /* final destination */
157	char nop; /* one NOP to align */
158	char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
159	struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
160	} ip_srcrt;
161
162	#ifdef IPDIVERT
163	/*
164	* Shared variable between ip_input() and ip_reass() to communicate
165	* about which packets, once assembled from fragments, get diverted,
166	* and to which port.
167	*/
168	static u_short frag_divert_port;
169	#endif
170
171	static void save_rte(u_char *, struct in_addr);
172	static void ip_deq(struct ipasfrag *);
173	static int ip_dooptions(struct mbuf *);
174	static void ip_enq(struct ipasfrag , struct ipasfrag );
175	static void ip_forward(struct mbuf *, int);
176	static void ip_freef(struct ipq *);
177	static struct ip *
178	ip_reass(struct ipasfrag , struct ipq , struct ipq *);
179	static struct in_ifaddr *
180	ip_rtaddr(struct in_addr);
181	void ipintr(void);
182	/*
183	* IP initialization: fill in IP protocol switch table.
184	* All protocols not implemented in kernel go to raw IP protocol handler.
185	*/
186	void
187	ip_init()
188	{
189	register struct protosw *pr;
190	register int i;
191
192	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
193	if (pr == 0)
194	panic("ip_init");
195	for (i = 0; i < IPPROTO_MAX; i++)
196	ip_protox[i] = pr - inetsw;
197	for (pr = inetdomain.dom_protosw;
198	pr < inetdomain.dom_protoswNPROTOSW; pr++)
199	if (pr->pr_domain->dom_family == PF_INET &&
200	pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
201	ip_protox[pr->pr_protocol] = pr - inetsw;
202
203	for (i = 0; i < IPREASS_NHASH; i++)
204	ipq[i].next = ipq[i].prev = &ipq[i];
205
206	maxnipq = nmbclusters/4;
207
208	ip_id = rtems_bsdnet_seconds_since_boot() & 0xffff;
209	ipintrq.ifq_maxlen = ipqmaxlen;
210	#ifdef IPFIREWALL
211	ip_fw_init();
212	#endif
213	#ifdef IPNAT
214	ip_nat_init();
215	#endif
216
217	}
218
219	static struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
220	static struct route ipforward_rt;
221
222	/*
223	* Ip input routine. Checksum and byte swap header. If fragmented
224	* try to reassemble. Process options. Pass to next level.
225	*/
226	void
227	ip_input(struct mbuf *m)
228	{
229	struct ip *ip = NULL;
230	struct ipq *fp;
231	struct in_ifaddr *ia = NULL;
232	int i, hlen;
233	u_short sum;
234
235	#ifdef DIAGNOSTIC
236	if ((m->m_flags & M_PKTHDR) == 0)
237	panic("ip_input no HDR");
238	#endif
239	/*
240	* If no IP addresses have been set yet but the interfaces
241	* are receiving, can't do anything with incoming packets yet.
242	*/
243	if (in_ifaddr == NULL)
244	goto bad;
245	ipstat.ips_total++;
246
247	if (m->m_pkthdr.len < sizeof(struct ip))
248	goto tooshort;
249
250	#if defined(DIAGNOSTIC) && defined(ORIGINAL_FREEBSD_CODE)
251	if (m->m_len < sizeof(struct ip))
252	panic("ipintr mbuf too short");
253	#endif
254
255	if (m->m_len < sizeof (struct ip) &&
256	(m = m_pullup(m, sizeof (struct ip))) == NULL) {
257	ipstat.ips_toosmall++;
258	return;
259	}
260	ip = mtod(m, struct ip *);
261
262	if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
263	ipstat.ips_badvers++;
264	goto bad;
265	}
266
267	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
268	if (hlen < sizeof(struct ip)) { /* minimum header length */
269	ipstat.ips_badhlen++;
270	goto bad;
271	}
272	if (hlen > m->m_len) {
273	if ((m = m_pullup(m, hlen)) == NULL) {
274	ipstat.ips_badhlen++;
275	return;
276	}
277	ip = mtod(m, struct ip *);
278	}
279	if (hlen == sizeof(struct ip)) {
280	sum = in_cksum_hdr(ip);
281	} else {
282	sum = in_cksum(m, hlen);
283	}
284	if (sum) {
285	ipstat.ips_badsum++;
286	goto bad;
287	}
288
289	/*
290	* Convert fields to host representation.
291	*/
292	NTOHS(ip->ip_len);
293	if (ip->ip_len < hlen) {
294	ipstat.ips_badlen++;
295	goto bad;
296	}
297	NTOHS(ip->ip_id);
298	NTOHS(ip->ip_off);
299
300	/*
301	* Check that the amount of data in the buffers
302	* is as at least much as the IP header would have us expect.
303	* Trim mbufs if longer than we expect.
304	* Drop packet if shorter than we expect.
305	*/
306	if (m->m_pkthdr.len < ip->ip_len) {
307	tooshort:
308	ipstat.ips_tooshort++;
309	goto bad;
310	}
311	if (m->m_pkthdr.len > ip->ip_len) {
312	if (m->m_len == m->m_pkthdr.len) {
313	m->m_len = ip->ip_len;
314	m->m_pkthdr.len = ip->ip_len;
315	} else
316	m_adj(m, ip->ip_len - m->m_pkthdr.len);
317	}
318	/*
319	* IpHack's section.
320	* Right now when no processing on packet has done
321	* and it is still fresh out of network we do our black
322	* deals with it.
323	* - Firewall: deny/allow/divert
324	* - Xlate: translate packet's addr/port (NAT).
325	* - Wrap: fake packet's addr/port <unimpl.>
326	* - Encapsulate: put it in another IP and send out. <unimp.>
327	*/
328
329	#ifdef COMPAT_IPFW
330	if (ip_fw_chk_ptr) {
331	#ifdef IPDIVERT
332	u_short port;
333
334	port = (*ip_fw_chk_ptr)(&ip, hlen, NULL, ip_divert_ignore, &m);
335	ip_divert_ignore = 0;
336	if (port) { /* Divert packet */
337	frag_divert_port = port;
338	goto ours;
339	}
340	#else
341	/* If ipfw says divert, we have to just drop packet */
342	if ((*ip_fw_chk_ptr)(&ip, hlen, NULL, 0, &m)) {
343	m_freem(m);
344	m = NULL;
345	}
346	#endif
347	if (!m)
348	return;
349	}
350
351	if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN))
352	return;
353	#endif
354
355	/*
356	* Process options and, if not destined for us,
357	* ship it on. ip_dooptions returns 1 when an
358	* error was detected (causing an icmp message
359	* to be sent and the original packet to be freed).
360	*/
361	ip_nhops = 0; /* for source routed packets */
362	if (hlen > sizeof (struct ip) && ip_dooptions(m))
363	return;
364
365	/* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
366	* matter if it is destined to another node, or whether it is
367	* a multicast one, RSVP wants it! and prevents it from being forwarded
368	* anywhere else. Also checks if the rsvp daemon is running before
369	* grabbing the packet.
370	*/
371	if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
372	goto ours;
373
374	/*
375	* Check our list of addresses, to see if the packet is for us.
376	*/
377	for (ia = in_ifaddr; ia; ia = ia->ia_next) {
378	#define satosin(sa) ((struct sockaddr_in *)(sa))
379
380	if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
381	goto ours;
382	#ifdef BOOTP_COMPAT
383	if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
384	goto ours;
385	#endif
386	if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
387	if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
388	ip->ip_dst.s_addr)
389	goto ours;
390	if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
391	goto ours;
392	}
393	}
394	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
395	struct in_multi *inm;
396	if (ip_mrouter) {
397	/*
398	* If we are acting as a multicast router, all
399	* incoming multicast packets are passed to the
400	* kernel-level multicast forwarding function.
401	* The packet is returned (relatively) intact; if
402	* ip_mforward() returns a non-zero value, the packet
403	* must be discarded, else it may be accepted below.
404	*
405	* (The IP ident field is put in the same byte order
406	* as expected when ip_mforward() is called from
407	* ip_output().)
408	*/
409	ip->ip_id = htons(ip->ip_id);
410	if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
411	ipstat.ips_cantforward++;
412	m_freem(m);
413	return;
414	}
415	ip->ip_id = ntohs(ip->ip_id);
416
417	/*
418	* The process-level routing daemon needs to receive
419	* all multicast IGMP packets, whether or not this
420	* host belongs to their destination groups.
421	*/
422	if (ip->ip_p == IPPROTO_IGMP)
423	goto ours;
424	ipstat.ips_forward++;
425	}
426	/*
427	* See if we belong to the destination multicast group on the
428	* arrival interface.
429	*/
430	IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
431	if (inm == NULL) {
432	ipstat.ips_cantforward++;
433	m_freem(m);
434	return;
435	}
436	goto ours;
437	}
438	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
439	goto ours;
440	if (ip->ip_dst.s_addr == INADDR_ANY)
441	goto ours;
442
443	/*
444	* Not for us; forward if possible and desirable.
445	*/
446	if (ipforwarding == 0) {
447	ipstat.ips_cantforward++;
448	m_freem(m);
449	} else {
450	ip_forward(m, 0);
451	}
452	return;
453
454	ours:
455
456	/*
457	* If offset or IP_MF are set, must reassemble.
458	* Otherwise, nothing need be done.
459	* (We could look in the reassembly queue to see
460	* if the packet was previously fragmented,
461	* but it's not worth the time; just let them time out.)
462	*/
463	if (ip->ip_off &~ (IP_DF \| IP_RF)) {
464	if (m->m_flags & M_EXT) { /* XXX */
465	if ((m = m_pullup(m, sizeof (struct ip))) == 0) {
466	ipstat.ips_toosmall++;
467	#ifdef IPDIVERT
468	frag_divert_port = 0;
469	#endif
470	return;
471	}
472	ip = mtod(m, struct ip *);
473	}
474	sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
475	/*
476	* Look for queue of fragments
477	* of this datagram.
478	*/
479	for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
480	if (ip->ip_id == fp->ipq_id &&
481	ip->ip_src.s_addr == fp->ipq_src.s_addr &&
482	ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
483	ip->ip_p == fp->ipq_p)
484	goto found;
485
486	fp = 0;
487
488	/* check if there's a place for the new queue */
489	if (nipq > maxnipq) {
490	/*
491	* drop something from the tail of the current queue
492	* before proceeding further
493	*/
494	if (ipq[sum].prev == &ipq[sum]) { /* gak */
495	for (i = 0; i < IPREASS_NHASH; i++) {
496	if (ipq[i].prev != &ipq[i]) {
497	ip_freef(ipq[i].prev);
498	break;
499	}
500	}
501	} else
502	ip_freef(ipq[sum].prev);
503	}
504	found:
505	/*
506	* Adjust ip_len to not reflect header,
507	* set ip_mff if more fragments are expected,
508	* convert offset of this to bytes.
509	*/
510	ip->ip_len -= hlen;
511	((struct ipasfrag *)ip)->ipf_mff &= ~1;
512	if (ip->ip_off & IP_MF)
513	((struct ipasfrag *)ip)->ipf_mff \|= 1;
514	ip->ip_off <<= 3;
515
516	/*
517	* If datagram marked as having more fragments
518	* or if this is not the first fragment,
519	* attempt reassembly; if it succeeds, proceed.
520	*/
521	if (((struct ipasfrag *)ip)->ipf_mff & 1 \|\| ip->ip_off) {
522	ipstat.ips_fragments++;
523	ip = ip_reass((struct ipasfrag *)ip, fp, &ipq[sum]);
524	if (ip == 0)
525	return;
526	ipstat.ips_reassembled++;
527	m = dtom(ip);
528	#ifdef IPDIVERT
529	if (frag_divert_port) {
530	ip->ip_len += hlen;
531	HTONS(ip->ip_len);
532	HTONS(ip->ip_off);
533	HTONS(ip->ip_id);
534	ip->ip_sum = 0;
535	ip->ip_sum = in_cksum_hdr(ip);
536	NTOHS(ip->ip_id);
537	NTOHS(ip->ip_off);
538	NTOHS(ip->ip_len);
539	ip->ip_len -= hlen;
540	}
541	#endif
542	} else
543	if (fp)
544	ip_freef(fp);
545	} else
546	ip->ip_len -= hlen;
547
548	#ifdef IPDIVERT
549	/*
550	* Divert reassembled packets to the divert protocol if required
551	*/
552	if (frag_divert_port) {
553	ipstat.ips_delivered++;
554	ip_divert_port = frag_divert_port;
555	frag_divert_port = 0;
556	(*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, hlen);
557	return;
558	}
559
560	/* Don't let packets divert themselves */
561	if (ip->ip_p == IPPROTO_DIVERT) {
562	ipstat.ips_noproto++;
563	goto bad;
564	}
565	#endif
566
567	/*
568	* Switch out to protocol's input routine.
569	*/
570	ipstat.ips_delivered++;
571	(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
572	return;
573	bad:
574	m_freem(m);
575	}
576
577	/*
578	* IP software interrupt routine - to go away sometime soon
579	*/
580	void
581	ipintr(void)
582	{
583	int s;
584	struct mbuf *m;
585
586	while(1) {
587	s = splimp();
588	IF_DEQUEUE(&ipintrq, m);
589	splx(s);
590	if (m == 0)
591	return;
592	ip_input(m);
593	}
594	}
595
596	NETISR_SET(NETISR_IP, ipintr);
597
598	/*
599	* Take incoming datagram fragment and try to
600	* reassemble it into whole datagram. If a chain for
601	* reassembly of this datagram already exists, then it
602	* is given as fp; otherwise have to make a chain.
603	*/
604	static struct ip *
605	ip_reass(ip, fp, where)
606	register struct ipasfrag *ip;
607	register struct ipq *fp;
608	struct ipq *where;
609	{
610	register struct mbuf *m = dtom(ip);
611	register struct ipasfrag *q;
612	struct mbuf *t;
613	int hlen = ip->ip_hl << 2;
614	int i;
615	int32_t next;
616
617	/*
618	* Presence of header sizes in mbufs
619	* would confuse code below.
620	*/
621	m->m_data += hlen;
622	m->m_len -= hlen;
623
624	/*
625	* If first fragment to arrive, create a reassembly queue.
626	*/
627	if (fp == 0) {
628	if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
629	goto dropfrag;
630	fp = mtod(t, struct ipq *);
631	insque(fp, where);
632	nipq++;
633	fp->ipq_ttl = IPFRAGTTL;
634	fp->ipq_p = ip->ip_p;
635	fp->ipq_id = ip->ip_id;
636	fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp;
637	fp->ipq_src = ((struct ip *)ip)->ip_src;
638	fp->ipq_dst = ((struct ip *)ip)->ip_dst;
639	#ifdef IPDIVERT
640	fp->ipq_divert = 0;
641	#endif
642	q = (struct ipasfrag *)fp;
643	goto insert;
644	}
645
646	/*
647	* Find a segment which begins after this one does.
648	*/
649	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next)
650	if (q->ip_off > ip->ip_off)
651	break;
652
653	/*
654	* If there is a preceding segment, it may provide some of
655	* our data already. If so, drop the data from the incoming
656	* segment. If it provides all of our data, drop us.
657	*/
658	if (q->ipf_prev != (struct ipasfrag *)fp) {
659	i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off;
660	if (i > 0) {
661	if (i >= ip->ip_len)
662	goto dropfrag;
663	m_adj(dtom(ip), i);
664	ip->ip_off += i;
665	ip->ip_len -= i;
666	}
667	}
668
669	/*
670	* While we overlap succeeding segments trim them or,
671	* if they are completely covered, dequeue them.
672	*/
673	while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) {
674	struct mbuf *m0;
675
676	i = (ip->ip_off + ip->ip_len) - q->ip_off;
677	if (i < q->ip_len) {
678	q->ip_len -= i;
679	q->ip_off += i;
680	m_adj(dtom(q), i);
681	break;
682	}
683	m0 = dtom(q);
684	q = q->ipf_next;
685	ip_deq(q->ipf_prev);
686	m_freem(m0);
687	}
688
689	insert:
690
691	#ifdef IPDIVERT
692	/*
693	* Any fragment diverting causes the whole packet to divert
694	*/
695	if (frag_divert_port != 0)
696	fp->ipq_divert = frag_divert_port;
697	frag_divert_port = 0;
698	#endif
699
700	/*
701	* Stick new segment in its place;
702	* check for complete reassembly.
703	*/
704	ip_enq(ip, q->ipf_prev);
705	next = 0;
706	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) {
707	if (q->ip_off != next)
708	return (0);
709	next += q->ip_len;
710	}
711	if (q->ipf_prev->ipf_mff & 1)
712	return (0);
713
714	/*
715	* Reassembly is complete. Make sure the packet is a sane size.
716	*/
717	if (next + (IP_VHL_HL(((struct ip *)fp->ipq_next)->ip_vhl) << 2)
718	> IP_MAXPACKET) {
719	ipstat.ips_toolong++;
720	ip_freef(fp);
721	return (0);
722	}
723
724	/*
725	* Concatenate fragments.
726	*/
727	q = fp->ipq_next;
728	m = dtom(q);
729	t = m->m_next;
730	m->m_next = 0;
731	m_cat(m, t);
732	q = q->ipf_next;
733	while (q != (struct ipasfrag *)fp) {
734	t = dtom(q);
735	q = q->ipf_next;
736	m_cat(m, t);
737	}
738
739	#ifdef IPDIVERT
740	/*
741	* Record divert port for packet, if any
742	*/
743	frag_divert_port = fp->ipq_divert;
744	#endif
745
746	/*
747	* Create header for new ip packet by modifying header of first
748	* packet; dequeue and discard fragment reassembly header.
749	* Make header visible.
750	*/
751	ip = fp->ipq_next;
752	ip->ip_len = next;
753	ip->ipf_mff &= ~1;
754	((struct ip *)ip)->ip_src = fp->ipq_src;
755	((struct ip *)ip)->ip_dst = fp->ipq_dst;
756	remque(fp);
757	nipq--;
758	(void) m_free(dtom(fp));
759	m = dtom(ip);
760	m->m_len += (ip->ip_hl << 2);
761	m->m_data -= (ip->ip_hl << 2);
762	/* some debugging cruft by sklower, below, will go away soon */
763	if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
764	register int plen = 0;
765	for (t = m; m; m = m->m_next)
766	plen += m->m_len;
767	t->m_pkthdr.len = plen;
768	}
769	return ((struct ip *)ip);
770
771	dropfrag:
772	ipstat.ips_fragdropped++;
773	m_freem(m);
774	return (0);
775	}
776
777	/*
778	* Free a fragment reassembly header and all
779	* associated datagrams.
780	*/
781	static void
782	ip_freef(fp)
783	struct ipq *fp;
784	{
785	register struct ipasfrag q, p;
786
787	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) {
788	p = q->ipf_next;
789	ip_deq(q);
790	m_freem(dtom(q));
791	}
792	remque(fp);
793	(void) m_free(dtom(fp));
794	nipq--;
795	}
796
797	/*
798	* Put an ip fragment on a reassembly chain.
799	* Like insque, but pointers in middle of structure.
800	*/
801	static void
802	ip_enq(p, prev)
803	register struct ipasfrag p, prev;
804	{
805
806	p->ipf_prev = prev;
807	p->ipf_next = prev->ipf_next;
808	prev->ipf_next->ipf_prev = p;
809	prev->ipf_next = p;
810	}
811
812	/*
813	* To ip_enq as remque is to insque.
814	*/
815	static void
816	ip_deq(p)
817	register struct ipasfrag *p;
818	{
819
820	p->ipf_prev->ipf_next = p->ipf_next;
821	p->ipf_next->ipf_prev = p->ipf_prev;
822	}
823
824	/*
825	* IP timer processing;
826	* if a timer expires on a reassembly
827	* queue, discard it.
828	*/
829	void
830	ip_slowtimo()
831	{
832	register struct ipq *fp;
833	int s = splnet();
834	int i;
835
836	for (i = 0; i < IPREASS_NHASH; i++) {
837	fp = ipq[i].next;
838	if (fp == 0)
839	continue;
840	while (fp != &ipq[i]) {
841	--fp->ipq_ttl;
842	fp = fp->next;
843	if (fp->prev->ipq_ttl == 0) {
844	ipstat.ips_fragtimeout++;
845	ip_freef(fp->prev);
846	}
847	}
848	}
849	splx(s);
850	}
851
852	/*
853	* Drain off all datagram fragments.
854	*/
855	void
856	ip_drain()
857	{
858	int i;
859
860	for (i = 0; i < IPREASS_NHASH; i++) {
861	while (ipq[i].next != &ipq[i]) {
862	ipstat.ips_fragdropped++;
863	ip_freef(ipq[i].next);
864	}
865	}
866	in_rtqdrain();
867	}
868
869	/*
870	* Do option processing on a datagram,
871	* possibly discarding it if bad options are encountered,
872	* or forwarding it if source-routed.
873	* Returns 1 if packet has been forwarded/freed,
874	* 0 if the packet should be processed further.
875	*/
876	static int
877	ip_dooptions(m)
878	struct mbuf *m;
879	{
880	register struct ip ip = mtod(m, struct ip );
881	register u_char *cp;
882	register struct ip_timestamp *ipt;
883	register struct in_ifaddr *ia;
884	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
885	struct in_addr *sin, dst;
886	n_time ntime;
887
888	dst = ip->ip_dst;
889	cp = (u_char *)(ip + 1);
890	cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
891	for (; cnt > 0; cnt -= optlen, cp += optlen) {
892	opt = cp[IPOPT_OPTVAL];
893	if (opt == IPOPT_EOL)
894	break;
895	if (opt == IPOPT_NOP)
896	optlen = 1;
897	else {
898	optlen = cp[IPOPT_OLEN];
899	if (optlen <= 0 \|\| optlen > cnt) {
900	code = &cp[IPOPT_OLEN] - (u_char *)ip;
901	goto bad;
902	}
903	}
904	switch (opt) {
905
906	default:
907	break;
908
909	/*
910	* Source routing with record.
911	* Find interface with current destination address.
912	* If none on this machine then drop if strictly routed,
913	* or do nothing if loosely routed.
914	* Record interface address and bring up next address
915	* component. If strictly routed make sure next
916	* address is on directly accessible net.
917	*/
918	case IPOPT_LSRR:
919	case IPOPT_SSRR:
920	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
921	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
922	goto bad;
923	}
924	ipaddr.sin_addr = ip->ip_dst;
925	ia = (struct in_ifaddr *)
926	ifa_ifwithaddr((struct sockaddr *)&ipaddr);
927	if (ia == 0) {
928	if (opt == IPOPT_SSRR) {
929	type = ICMP_UNREACH;
930	code = ICMP_UNREACH_SRCFAIL;
931	goto bad;
932	}
933	if (!ip_dosourceroute)
934	goto nosourcerouting;
935	/*
936	* Loose routing, and not at next destination
937	* yet; nothing to do except forward.
938	*/
939	break;
940	}
941	off--; /* 0 origin */
942	if (off > optlen - sizeof(struct in_addr)) {
943	/*
944	* End of source route. Should be for us.
945	*/
946	if (!ip_acceptsourceroute)
947	goto nosourcerouting;
948	save_rte(cp, ip->ip_src);
949	break;
950	}
951
952	if (!ip_dosourceroute) {
953	char buf[4*sizeof "123"];
954
955	nosourcerouting:
956	strcpy(buf, inet_ntoa(ip->ip_dst));
957	log(LOG_WARNING,
958	"attempted source route from %s to %s\n",
959	inet_ntoa(ip->ip_src), buf);
960	type = ICMP_UNREACH;
961	code = ICMP_UNREACH_SRCFAIL;
962	goto bad;
963	}
964
965	/*
966	* locate outgoing interface
967	*/
968	(void)memcpy(&ipaddr.sin_addr, cp + off,
969	sizeof(ipaddr.sin_addr));
970
971	if (opt == IPOPT_SSRR) {
972	#define INA struct in_ifaddr *
973	#define SA struct sockaddr *
974	if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
975	ia = (INA)ifa_ifwithnet((SA)&ipaddr);
976	} else
977	ia = ip_rtaddr(ipaddr.sin_addr);
978	if (ia == 0) {
979	type = ICMP_UNREACH;
980	code = ICMP_UNREACH_SRCFAIL;
981	goto bad;
982	}
983	ip->ip_dst = ipaddr.sin_addr;
984	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
985	sizeof(struct in_addr));
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(ntohl(ip->ip_dst.s_addr));
991	break;
992
993	case IPOPT_RR:
994	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
995	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
996	goto bad;
997	}
998	/*
999	* If no space remains, ignore.
1000	*/
1001	off--; /* 0 origin */
1002	if (off > optlen - sizeof(struct in_addr))
1003	break;
1004	(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1005	sizeof(ipaddr.sin_addr));
1006	/*
1007	* locate outgoing interface; if we're the destination,
1008	* use the incoming interface (should be same).
1009	*/
1010	if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1011	(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1012	type = ICMP_UNREACH;
1013	code = ICMP_UNREACH_HOST;
1014	goto bad;
1015	}
1016	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1017	sizeof(struct in_addr));
1018	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1019	break;
1020
1021	case IPOPT_TS:
1022	code = cp - (u_char *)ip;
1023	ipt = (struct ip_timestamp *)cp;
1024	if (ipt->ipt_len < 5)
1025	goto bad;
1026	if (ipt->ipt_ptr > ipt->ipt_len - sizeof (long)) {
1027	if (++ipt->ipt_oflw == 0)
1028	goto bad;
1029	break;
1030	}
1031	sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1032	switch (ipt->ipt_flg) {
1033
1034	case IPOPT_TS_TSONLY:
1035	break;
1036
1037	case IPOPT_TS_TSANDADDR:
1038	if (ipt->ipt_ptr + sizeof(n_time) +
1039	sizeof(struct in_addr) > ipt->ipt_len)
1040	goto bad;
1041	ipaddr.sin_addr = dst;
1042	ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1043	m->m_pkthdr.rcvif);
1044	if (ia == 0)
1045	continue;
1046	(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1047	sizeof(struct in_addr));
1048	ipt->ipt_ptr += sizeof(struct in_addr);
1049	break;
1050
1051	case IPOPT_TS_PRESPEC:
1052	if (ipt->ipt_ptr + sizeof(n_time) +
1053	sizeof(struct in_addr) > ipt->ipt_len)
1054	goto bad;
1055	(void)memcpy(&ipaddr.sin_addr, sin,
1056	sizeof(struct in_addr));
1057	if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1058	continue;
1059	ipt->ipt_ptr += sizeof(struct in_addr);
1060	break;
1061
1062	default:
1063	goto bad;
1064	}
1065	ntime = iptime();
1066	(void)memcpy(cp + ipt->ipt_ptr - 1, &ntime,
1067	sizeof(n_time));
1068	ipt->ipt_ptr += sizeof(n_time);
1069	}
1070	}
1071	if (forward && ipforwarding) {
1072	ip_forward(m, 1);
1073	return (1);
1074	}
1075	return (0);
1076	bad:
1077	ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hdr length */
1078	icmp_error(m, type, code, 0, 0);
1079	ipstat.ips_badoptions++;
1080	return (1);
1081	}
1082
1083	/*
1084	* Given address of next destination (final or next hop),
1085	* return internet address info of interface to be used to get there.
1086	*/
1087	static struct in_ifaddr *
1088	ip_rtaddr(dst)
1089	struct in_addr dst;
1090	{
1091	register struct sockaddr_in *sin;
1092
1093	sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
1094
1095	if (ipforward_rt.ro_rt == 0 \|\| dst.s_addr != sin->sin_addr.s_addr) {
1096	if (ipforward_rt.ro_rt) {
1097	RTFREE(ipforward_rt.ro_rt);
1098	ipforward_rt.ro_rt = 0;
1099	}
1100	sin->sin_family = AF_INET;
1101	sin->sin_len = sizeof(*sin);
1102	sin->sin_addr = dst;
1103
1104	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1105	}
1106	if (ipforward_rt.ro_rt == 0)
1107	return ((struct in_ifaddr *)0);
1108	return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa);
1109	}
1110
1111	/*
1112	* Save incoming source route for use in replies,
1113	* to be picked up later by ip_srcroute if the receiver is interested.
1114	*/
1115	void
1116	save_rte(option, dst)
1117	u_char *option;
1118	struct in_addr dst;
1119	{
1120	unsigned olen;
1121
1122	olen = option[IPOPT_OLEN];
1123	#ifdef DIAGNOSTIC
1124	if (ipprintfs)
1125	printf("save_rte: olen %d\n", olen);
1126	#endif
1127	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1128	return;
1129	bcopy(option, ip_srcrt.srcopt, olen);
1130	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1131	ip_srcrt.dst = dst;
1132	}
1133
1134	/*
1135	* Retrieve incoming source route for use in replies,
1136	* in the same form used by setsockopt.
1137	* The first hop is placed before the options, will be removed later.
1138	*/
1139	struct mbuf *
1140	ip_srcroute()
1141	{
1142	register struct in_addr p, q;
1143	register struct mbuf *m;
1144
1145	if (ip_nhops == 0)
1146	return ((struct mbuf *)0);
1147	m = m_get(M_DONTWAIT, MT_SOOPTS);
1148	if (m == 0)
1149	return ((struct mbuf *)0);
1150
1151	#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1152
1153	/* length is (nhops+1)sizeof(addr) + sizeof(nop + srcrt header) /
1154	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1155	OPTSIZ;
1156	#ifdef DIAGNOSTIC
1157	if (ipprintfs)
1158	printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1159	#endif
1160
1161	/*
1162	* First save first hop for return route
1163	*/
1164	p = &ip_srcrt.route[ip_nhops - 1];
1165	(mtod(m, struct in_addr )) = *p--;
1166	#ifdef DIAGNOSTIC
1167	if (ipprintfs)
1168	printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr));
1169	#endif
1170
1171	/*
1172	* Copy option fields and padding (nop) to mbuf.
1173	*/
1174	ip_srcrt.nop = IPOPT_NOP;
1175	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1176	(void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1177	&ip_srcrt.nop, OPTSIZ);
1178	q = (struct in_addr *)(mtod(m, caddr_t) +
1179	sizeof(struct in_addr) + OPTSIZ);
1180	#undef OPTSIZ
1181	/*
1182	* Record return path as an IP source route,
1183	* reversing the path (pointers are now aligned).
1184	*/
1185	while (p >= ip_srcrt.route) {
1186	#ifdef DIAGNOSTIC
1187	if (ipprintfs)
1188	printf(" %lx", ntohl(q->s_addr));
1189	#endif
1190	q++ = p--;
1191	}
1192	/*
1193	* Last hop goes to final destination.
1194	*/
1195	*q = ip_srcrt.dst;
1196	#ifdef DIAGNOSTIC
1197	if (ipprintfs)
1198	printf(" %lx\n", ntohl(q->s_addr));
1199	#endif
1200	return (m);
1201	}
1202
1203	/*
1204	* Strip out IP options, at higher
1205	* level protocol in the kernel.
1206	* Second argument is buffer to which options
1207	* will be moved, and return value is their length.
1208	* XXX should be deleted; last arg currently ignored.
1209	*/
1210	void
1211	ip_stripoptions(m, mopt)
1212	register struct mbuf *m;
1213	struct mbuf *mopt;
1214	{
1215	register int i;
1216	struct ip ip = mtod(m, struct ip );
1217	register caddr_t opts;
1218	int olen;
1219
1220	olen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
1221	opts = (caddr_t)(ip + 1);
1222	i = m->m_len - (sizeof (struct ip) + olen);
1223	bcopy(opts + olen, opts, (unsigned)i);
1224	m->m_len -= olen;
1225	if (m->m_flags & M_PKTHDR)
1226	m->m_pkthdr.len -= olen;
1227	ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1228	}
1229
1230	u_char inetctlerrmap[PRC_NCMDS] = {
1231	0, 0, 0, 0,
1232	0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1233	EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1234	EMSGSIZE, EHOSTUNREACH, 0, 0,
1235	0, 0, 0, 0,
1236	ENOPROTOOPT
1237	};
1238
1239	/*
1240	* Forward a packet. If some error occurs return the sender
1241	* an icmp packet. Note we can't always generate a meaningful
1242	* icmp message because icmp doesn't have a large enough repertoire
1243	* of codes and types.
1244	*
1245	* If not forwarding, just drop the packet. This could be confusing
1246	* if ipforwarding was zero but some routing protocol was advancing
1247	* us as a gateway to somewhere. However, we must let the routing
1248	* protocol deal with that.
1249	*
1250	* The srcrt parameter indicates whether the packet is being forwarded
1251	* via a source route.
1252	*/
1253	static void
1254	ip_forward(struct mbuf *m, int srcrt)
1255	{
1256	struct ip ip = mtod(m, struct ip );
1257	register struct sockaddr_in *sin;
1258	register struct rtentry *rt;
1259	int error, type = 0, code = 0;
1260	struct mbuf *mcopy;
1261	n_long dest;
1262	struct ifnet *destifp;
1263
1264	dest = 0;
1265	#ifdef DIAGNOSTIC
1266	if (ipprintfs)
1267	printf("forward: src %lx dst %lx ttl %x\n",
1268	ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1269	#endif
1270
1271
1272	if (m->m_flags & M_BCAST \|\| in_canforward(ip->ip_dst) == 0) {
1273	ipstat.ips_cantforward++;
1274	m_freem(m);
1275	return;
1276	}
1277	HTONS(ip->ip_id);
1278	if (ip->ip_ttl <= IPTTLDEC) {
1279	icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1280	return;
1281	}
1282	ip->ip_ttl -= IPTTLDEC;
1283
1284	sin = (struct sockaddr_in *)&ipforward_rt.ro_dst;
1285	if ((rt = ipforward_rt.ro_rt) == 0 \|\|
1286	ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
1287	if (ipforward_rt.ro_rt) {
1288	RTFREE(ipforward_rt.ro_rt);
1289	ipforward_rt.ro_rt = 0;
1290	}
1291	sin->sin_family = AF_INET;
1292	sin->sin_len = sizeof(*sin);
1293	sin->sin_addr = ip->ip_dst;
1294
1295	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1296	if (ipforward_rt.ro_rt == 0) {
1297	icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1298	return;
1299	}
1300	rt = ipforward_rt.ro_rt;
1301	}
1302
1303	/*
1304	* Save at most 64 bytes of the packet in case
1305	* we need to generate an ICMP message to the src.
1306	*/
1307	mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
1308
1309	/*
1310	* If forwarding packet using same interface that it came in on,
1311	* perhaps should send a redirect to sender to shortcut a hop.
1312	* Only send redirect if source is sending directly to us,
1313	* and if packet was not source routed (or has any options).
1314	* Also, don't send redirect if forwarding using a default route
1315	* or a route modified by a redirect.
1316	*/
1317	#define satosin(sa) ((struct sockaddr_in *)(sa))
1318	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1319	(rt->rt_flags & (RTF_DYNAMIC\|RTF_MODIFIED)) == 0 &&
1320	satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
1321	ipsendredirects && !srcrt) {
1322	#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1323	u_long src = ntohl(ip->ip_src.s_addr);
1324
1325	if (RTA(rt) &&
1326	(src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1327	if (rt->rt_flags & RTF_GATEWAY)
1328	dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1329	else
1330	dest = ip->ip_dst.s_addr;
1331	/* Router requirements says to only send host redirects */
1332	type = ICMP_REDIRECT;
1333	code = ICMP_REDIRECT_HOST;
1334	#ifdef DIAGNOSTIC
1335	if (ipprintfs)
1336	printf("redirect (%d) to %lx\n", code, (u_long)dest);
1337	#endif
1338	}
1339	}
1340
1341	error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1342	IP_FORWARDING, 0);
1343	if (error)
1344	ipstat.ips_cantforward++;
1345	else {
1346	ipstat.ips_forward++;
1347	if (type)
1348	ipstat.ips_redirectsent++;
1349	else {
1350	if (mcopy)
1351	m_freem(mcopy);
1352	return;
1353	}
1354	}
1355	if (mcopy == NULL)
1356	return;
1357	destifp = NULL;
1358
1359	switch (error) {
1360
1361	case 0: /* forwarded, but need redirect */
1362	/* type, code set above */
1363	break;
1364
1365	case ENETUNREACH: /* shouldn't happen, checked above */
1366	case EHOSTUNREACH:
1367	case ENETDOWN:
1368	case EHOSTDOWN:
1369	default:
1370	type = ICMP_UNREACH;
1371	code = ICMP_UNREACH_HOST;
1372	break;
1373
1374	case EMSGSIZE:
1375	type = ICMP_UNREACH;
1376	code = ICMP_UNREACH_NEEDFRAG;
1377	if (ipforward_rt.ro_rt)
1378	destifp = ipforward_rt.ro_rt->rt_ifp;
1379	ipstat.ips_cantfrag++;
1380	break;
1381
1382	case ENOBUFS:
1383	type = ICMP_SOURCEQUENCH;
1384	code = 0;
1385	break;
1386	}
1387	icmp_error(mcopy, type, code, dest, destifp);
1388	}
1389
1390	void
1391	ip_savecontrol(inp, mp, ip, m)
1392	register struct inpcb *inp;
1393	register struct mbuf **mp;
1394	register struct ip *ip;
1395	register struct mbuf *m;
1396	{
1397	if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1398	struct timeval tv;
1399
1400	microtime(&tv);
1401	*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1402	SCM_TIMESTAMP, SOL_SOCKET);
1403	if (*mp)
1404	mp = &(*mp)->m_next;
1405	}
1406	if (inp->inp_flags & INP_RECVDSTADDR) {
1407	*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1408	sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1409	if (*mp)
1410	mp = &(*mp)->m_next;
1411	}
1412	#ifdef notyet
1413	/* XXX
1414	* Moving these out of udp_input() made them even more broken
1415	* than they already were.
1416	*/
1417	/* options were tossed already */
1418	if (inp->inp_flags & INP_RECVOPTS) {
1419	*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1420	sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1421	if (*mp)
1422	mp = &(*mp)->m_next;
1423	}
1424	/* ip_srcroute doesn't do what we want here, need to fix */
1425	if (inp->inp_flags & INP_RECVRETOPTS) {
1426	*mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1427	sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1428	if (*mp)
1429	mp = &(*mp)->m_next;
1430	}
1431	#endif
1432	if (inp->inp_flags & INP_RECVIF) {
1433	struct sockaddr_dl sdl;
1434
1435	sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1436	sdl.sdl_family = AF_LINK;
1437	sdl.sdl_index = m->m_pkthdr.rcvif ?
1438	m->m_pkthdr.rcvif->if_index : 0;
1439	sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1440	*mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1441	IP_RECVIF, IPPROTO_IP);
1442	if (*mp)
1443	mp = &(*mp)->m_next;
1444	}
1445	}
1446
1447	int
1448	ip_rsvp_init(struct socket *so)
1449	{
1450	if (so->so_type != SOCK_RAW \|\|
1451	so->so_proto->pr_protocol != IPPROTO_RSVP)
1452	return EOPNOTSUPP;
1453
1454	if (ip_rsvpd != NULL)
1455	return EADDRINUSE;
1456
1457	ip_rsvpd = so;
1458	/*
1459	* This may seem silly, but we need to be sure we don't over-increment
1460	* the RSVP counter, in case something slips up.
1461	*/
1462	if (!ip_rsvp_on) {
1463	ip_rsvp_on = 1;
1464	rsvp_on++;
1465	}
1466
1467	return 0;
1468	}
1469
1470	int
1471	ip_rsvp_done(void)
1472	{
1473	ip_rsvpd = NULL;
1474	/*
1475	* This may seem silly, but we need to be sure we don't over-decrement
1476	* the RSVP counter, in case something slips up.
1477	*/
1478	if (ip_rsvp_on) {
1479	ip_rsvp_on = 0;
1480	rsvp_on--;
1481	}
1482	return 0;
1483	}

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