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source: rtems/cpukit/libnetworking/netinet/ip_input.c @ dd967330

4.104.114.95

Last change on this file since dd967330 was dd967330, checked in by Ralf Corsepius <ralf.corsepius@…>, on 09/01/08 at 06:36:17
Stop using old-style function definitions.
Property mode set to `100644`
File size: 36.1 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/mbuf.h>
43	#include <sys/malloc.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/ip_var.h>
64	#include <netinet/ip_icmp.h>
65	#include <machine/in_cksum.h>
66
67	#include <sys/socketvar.h>
68
69	#ifdef IPFIREWALL
70	#include <netinet/ip_fw.h>
71	#endif
72
73	int rsvp_on = 0;
74	static int ip_rsvp_on;
75	struct socket *ip_rsvpd;
76
77	int ipforwarding = 0;
78	SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
79	&ipforwarding, 0, "Enable IP forwarding between interfaces");
80
81	static int ipsendredirects = 1; /* XXX */
82	SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
83	&ipsendredirects, 0, "Enable sending IP redirects");
84
85	int ip_defttl = IPDEFTTL;
86	SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
87	&ip_defttl, 0, "Maximum TTL on IP packets");
88
89	static int ip_dosourceroute = 0;
90	SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
91	&ip_dosourceroute, 0, "");
92
93	static int ip_acceptsourceroute = 0;
94	SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
95	CTLFLAG_RW, &ip_acceptsourceroute, 0, "");
96	#ifdef DIAGNOSTIC
97	static int ipprintfs = 0;
98	#endif
99
100	extern struct domain inetdomain;
101	extern struct protosw inetsw[];
102	u_char ip_protox[IPPROTO_MAX];
103	static int ipqmaxlen = IFQ_MAXLEN;
104	struct in_ifaddr in_ifaddr; / first inet address */
105	struct ifqueue ipintrq;
106	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD,
107	&ipintrq.ifq_maxlen, 0, "");
108	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
109	&ipintrq.ifq_drops, 0,
110	"Number of packets dropped from the IP input queue");
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, "Default MTU");
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(void)
188	{
189	register struct protosw *pr;
190	register int i;
191
192	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
193	if (pr == NULL)
194	panic("ip_init: PF_INET not found");
195
196	/* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
197	for (i = 0; i < IPPROTO_MAX; i++)
198	ip_protox[i] = pr - inetsw;
199	/*
200	* Cycle through IP protocols and put them into the appropriate place
201	* in ip_protox[].
202	*/
203	for (pr = inetdomain.dom_protosw;
204	pr < inetdomain.dom_protoswNPROTOSW; pr++)
205	if (pr->pr_domain->dom_family == PF_INET &&
206	pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
207	ip_protox[pr->pr_protocol] = pr - inetsw;
208	}
209
210	for (i = 0; i < IPREASS_NHASH; i++)
211	ipq[i].next = ipq[i].prev = &ipq[i];
212
213	maxnipq = nmbclusters/4;
214
215	/* Initialize various other remaining things. */
216	ip_id = rtems_bsdnet_seconds_since_boot() & 0xffff;
217	ipintrq.ifq_maxlen = ipqmaxlen;
218	#ifdef IPFIREWALL
219	ip_fw_init();
220	#endif
221	#ifdef IPNAT
222	ip_nat_init();
223	#endif
224
225	}
226
227	static struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
228	static struct route ipforward_rt;
229
230	/*
231	* Ip input routine. Checksum and byte swap header. If fragmented
232	* try to reassemble. Process options. Pass to next level.
233	*/
234	void
235	ip_input(struct mbuf *m)
236	{
237	struct ip *ip = NULL;
238	struct ipq *fp;
239	struct in_ifaddr *ia = NULL;
240	int i, hlen;
241	u_short sum;
242
243	#ifdef DIAGNOSTIC
244	if ((m->m_flags & M_PKTHDR) == 0)
245	panic("ip_input no HDR");
246	#endif
247	/*
248	* If no IP addresses have been set yet but the interfaces
249	* are receiving, can't do anything with incoming packets yet.
250	*/
251	if (in_ifaddr == NULL)
252	goto bad;
253	ipstat.ips_total++;
254
255	if (m->m_pkthdr.len < sizeof(struct ip))
256	goto tooshort;
257
258	#if defined(DIAGNOSTIC) && defined(ORIGINAL_FREEBSD_CODE)
259	if (m->m_len < sizeof(struct ip))
260	panic("ipintr mbuf too short");
261	#endif
262
263	if (m->m_len < sizeof (struct ip) &&
264	(m = m_pullup(m, sizeof (struct ip))) == NULL) {
265	ipstat.ips_toosmall++;
266	return;
267	}
268	ip = mtod(m, struct ip *);
269
270	#ifdef _IP_VHL
271	if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
272	#else
273	if (ip->ip_v != IPVERSION) {
274	#endif
275	ipstat.ips_badvers++;
276	goto bad;
277	}
278
279	#ifdef _IP_VHL
280	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
281	#else
282	hlen = ip->ip_hl << 2;
283	#endif
284	if (hlen < sizeof(struct ip)) { /* minimum header length */
285	ipstat.ips_badhlen++;
286	goto bad;
287	}
288	if (hlen > m->m_len) {
289	if ((m = m_pullup(m, hlen)) == NULL) {
290	ipstat.ips_badhlen++;
291	return;
292	}
293	ip = mtod(m, struct ip *);
294	}
295	if (hlen == sizeof(struct ip)) {
296	sum = in_cksum_hdr(ip);
297	} else {
298	sum = in_cksum(m, hlen);
299	}
300	if (sum) {
301	ipstat.ips_badsum++;
302	goto bad;
303	}
304
305	/*
306	* Convert fields to host representation.
307	*/
308	ip->ip_len = ntohs(ip->ip_len);
309	if (ip->ip_len < hlen) {
310	ipstat.ips_badlen++;
311	goto bad;
312	}
313	NTOHS(ip->ip_id);
314	ip->ip_off = ntohs(ip->ip_off);
315
316	/*
317	* Check that the amount of data in the buffers
318	* is as at least much as the IP header would have us expect.
319	* Trim mbufs if longer than we expect.
320	* Drop packet if shorter than we expect.
321	*/
322	if (m->m_pkthdr.len < ip->ip_len) {
323	tooshort:
324	ipstat.ips_tooshort++;
325	goto bad;
326	}
327	if (m->m_pkthdr.len > ip->ip_len) {
328	if (m->m_len == m->m_pkthdr.len) {
329	m->m_len = ip->ip_len;
330	m->m_pkthdr.len = ip->ip_len;
331	} else
332	m_adj(m, ip->ip_len - m->m_pkthdr.len);
333	}
334	/*
335	* IpHack's section.
336	* Right now when no processing on packet has done
337	* and it is still fresh out of network we do our black
338	* deals with it.
339	* - Firewall: deny/allow/divert
340	* - Xlate: translate packet's addr/port (NAT).
341	* - Wrap: fake packet's addr/port <unimpl.>
342	* - Encapsulate: put it in another IP and send out. <unimp.>
343	*/
344
345	#ifdef COMPAT_IPFW
346	if (ip_fw_chk_ptr) {
347	#ifdef IPDIVERT
348	u_short port;
349
350	port = (*ip_fw_chk_ptr)(&ip, hlen, NULL, ip_divert_ignore, &m);
351	ip_divert_ignore = 0;
352	if (port) { /* Divert packet */
353	frag_divert_port = port;
354	goto ours;
355	}
356	#else
357	/* If ipfw says divert, we have to just drop packet */
358	if ((*ip_fw_chk_ptr)(&ip, hlen, NULL, 0, &m)) {
359	m_freem(m);
360	m = NULL;
361	}
362	#endif
363	if (!m)
364	return;
365	}
366
367	if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN))
368	return;
369	#endif
370
371	/*
372	* Process options and, if not destined for us,
373	* ship it on. ip_dooptions returns 1 when an
374	* error was detected (causing an icmp message
375	* to be sent and the original packet to be freed).
376	*/
377	ip_nhops = 0; /* for source routed packets */
378	if (hlen > sizeof (struct ip) && ip_dooptions(m))
379	return;
380
381	/* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
382	* matter if it is destined to another node, or whether it is
383	* a multicast one, RSVP wants it! and prevents it from being forwarded
384	* anywhere else. Also checks if the rsvp daemon is running before
385	* grabbing the packet.
386	*/
387	if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
388	goto ours;
389
390	/*
391	* Check our list of addresses, to see if the packet is for us.
392	*/
393	for (ia = in_ifaddr; ia; ia = ia->ia_next) {
394	#define satosin(sa) ((struct sockaddr_in *)(sa))
395
396	if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
397	goto ours;
398	#ifdef BOOTP_COMPAT
399	if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
400	goto ours;
401	#endif
402	if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
403	if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
404	ip->ip_dst.s_addr)
405	goto ours;
406	if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
407	goto ours;
408	}
409	}
410	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
411	struct in_multi *inm;
412	if (ip_mrouter) {
413	/*
414	* If we are acting as a multicast router, all
415	* incoming multicast packets are passed to the
416	* kernel-level multicast forwarding function.
417	* The packet is returned (relatively) intact; if
418	* ip_mforward() returns a non-zero value, the packet
419	* must be discarded, else it may be accepted below.
420	*
421	* (The IP ident field is put in the same byte order
422	* as expected when ip_mforward() is called from
423	* ip_output().)
424	*/
425	ip->ip_id = htons(ip->ip_id);
426	if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
427	ipstat.ips_cantforward++;
428	m_freem(m);
429	return;
430	}
431	ip->ip_id = ntohs(ip->ip_id);
432
433	/*
434	* The process-level routing daemon needs to receive
435	* all multicast IGMP packets, whether or not this
436	* host belongs to their destination groups.
437	*/
438	if (ip->ip_p == IPPROTO_IGMP)
439	goto ours;
440	ipstat.ips_forward++;
441	}
442	/*
443	* See if we belong to the destination multicast group on the
444	* arrival interface.
445	*/
446	IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
447	if (inm == NULL) {
448	ipstat.ips_cantforward++;
449	m_freem(m);
450	return;
451	}
452	goto ours;
453	}
454	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
455	goto ours;
456	if (ip->ip_dst.s_addr == INADDR_ANY)
457	goto ours;
458
459	/*
460	* Not for us; forward if possible and desirable.
461	*/
462	if (ipforwarding == 0) {
463	ipstat.ips_cantforward++;
464	m_freem(m);
465	} else {
466	ip_forward(m, 0);
467	}
468	return;
469
470	ours:
471
472	/*
473	* If offset or IP_MF are set, must reassemble.
474	* Otherwise, nothing need be done.
475	* (We could look in the reassembly queue to see
476	* if the packet was previously fragmented,
477	* but it's not worth the time; just let them time out.)
478	*/
479	if (ip->ip_off &~ (IP_DF \| IP_RF)) {
480	if (m->m_flags & M_EXT) { /* XXX */
481	if ((m = m_pullup(m, sizeof (struct ip))) == 0) {
482	ipstat.ips_toosmall++;
483	#ifdef IPDIVERT
484	frag_divert_port = 0;
485	#endif
486	return;
487	}
488	ip = mtod(m, struct ip *);
489	}
490	sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
491	/*
492	* Look for queue of fragments
493	* of this datagram.
494	*/
495	for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
496	if (ip->ip_id == fp->ipq_id &&
497	ip->ip_src.s_addr == fp->ipq_src.s_addr &&
498	ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
499	ip->ip_p == fp->ipq_p)
500	goto found;
501
502	fp = 0;
503
504	/* check if there's a place for the new queue */
505	if (nipq > maxnipq) {
506	/*
507	* drop something from the tail of the current queue
508	* before proceeding further
509	*/
510	if (ipq[sum].prev == &ipq[sum]) { /* gak */
511	for (i = 0; i < IPREASS_NHASH; i++) {
512	if (ipq[i].prev != &ipq[i]) {
513	ip_freef(ipq[i].prev);
514	break;
515	}
516	}
517	} else
518	ip_freef(ipq[sum].prev);
519	}
520	found:
521	/*
522	* Adjust ip_len to not reflect header,
523	* set ip_mff if more fragments are expected,
524	* convert offset of this to bytes.
525	*/
526	ip->ip_len -= hlen;
527	((struct ipasfrag *)ip)->ipf_mff &= ~1;
528	if (ip->ip_off & IP_MF)
529	((struct ipasfrag *)ip)->ipf_mff \|= 1;
530	ip->ip_off <<= 3;
531
532	/*
533	* If datagram marked as having more fragments
534	* or if this is not the first fragment,
535	* attempt reassembly; if it succeeds, proceed.
536	*/
537	if (((struct ipasfrag *)ip)->ipf_mff & 1 \|\| ip->ip_off) {
538	ipstat.ips_fragments++;
539	ip = ip_reass((struct ipasfrag *)ip, fp, &ipq[sum]);
540	if (ip == 0)
541	return;
542	ipstat.ips_reassembled++;
543	m = dtom(ip);
544	#ifdef IPDIVERT
545	if (frag_divert_port) {
546	ip->ip_len += hlen;
547	HTONS(ip->ip_len);
548	HTONS(ip->ip_off);
549	HTONS(ip->ip_id);
550	ip->ip_sum = 0;
551	ip->ip_sum = in_cksum_hdr(ip);
552	NTOHS(ip->ip_id);
553	NTOHS(ip->ip_off);
554	NTOHS(ip->ip_len);
555	ip->ip_len -= hlen;
556	}
557	#endif
558	} else
559	if (fp)
560	ip_freef(fp);
561	} else
562	ip->ip_len -= hlen;
563
564	#ifdef IPDIVERT
565	/*
566	* Divert reassembled packets to the divert protocol if required
567	*/
568	if (frag_divert_port) {
569	ipstat.ips_delivered++;
570	ip_divert_port = frag_divert_port;
571	frag_divert_port = 0;
572	(*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, hlen);
573	return;
574	}
575
576	/* Don't let packets divert themselves */
577	if (ip->ip_p == IPPROTO_DIVERT) {
578	ipstat.ips_noproto++;
579	goto bad;
580	}
581	#endif
582
583	/*
584	* Switch out to protocol's input routine.
585	*/
586	ipstat.ips_delivered++;
587
588	(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
589	return;
590	bad:
591	m_freem(m);
592	}
593
594	/*
595	* IP software interrupt routine - to go away sometime soon
596	*/
597	void
598	ipintr(void)
599	{
600	int s;
601	struct mbuf *m;
602
603	while(1) {
604	s = splimp();
605	IF_DEQUEUE(&ipintrq, m);
606	splx(s);
607	if (m == 0)
608	return;
609	ip_input(m);
610	}
611	}
612
613	NETISR_SET(NETISR_IP, ipintr);
614
615	/*
616	* Take incoming datagram fragment and try to
617	* reassemble it into whole datagram. If a chain for
618	* reassembly of this datagram already exists, then it
619	* is given as fp; otherwise have to make a chain.
620	*/
621	static struct ip *
622	ip_reass(struct ipasfrag ip, struct ipq fp, struct ipq *where)
623	{
624	register struct mbuf *m = dtom(ip);
625	register struct ipasfrag *q;
626	struct mbuf *t;
627	int hlen = ip->ip_hl << 2;
628	int i;
629	int32_t next;
630
631	/*
632	* Presence of header sizes in mbufs
633	* would confuse code below.
634	*/
635	m->m_data += hlen;
636	m->m_len -= hlen;
637
638	/*
639	* If first fragment to arrive, create a reassembly queue.
640	*/
641	if (fp == NULL) {
642	if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
643	goto dropfrag;
644	fp = mtod(t, struct ipq *);
645	insque(fp, where);
646	nipq++;
647	fp->ipq_ttl = IPFRAGTTL;
648	fp->ipq_p = ip->ip_p;
649	fp->ipq_id = ip->ip_id;
650	fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp;
651	fp->ipq_src = ((struct ip *)ip)->ip_src;
652	fp->ipq_dst = ((struct ip *)ip)->ip_dst;
653	#ifdef IPDIVERT
654	fp->ipq_divert = 0;
655	#endif
656	q = (struct ipasfrag *)fp;
657	goto insert;
658	}
659
660	/*
661	* Find a segment which begins after this one does.
662	*/
663	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next)
664	if (q->ip_off > ip->ip_off)
665	break;
666
667	/*
668	* If there is a preceding segment, it may provide some of
669	* our data already. If so, drop the data from the incoming
670	* segment. If it provides all of our data, drop us.
671	*/
672	if (q->ipf_prev != (struct ipasfrag *)fp) {
673	i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off;
674	if (i > 0) {
675	if (i >= ip->ip_len)
676	goto dropfrag;
677	m_adj(dtom(ip), i);
678	ip->ip_off += i;
679	ip->ip_len -= i;
680	}
681	}
682
683	/*
684	* While we overlap succeeding segments trim them or,
685	* if they are completely covered, dequeue them.
686	*/
687	while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) {
688	struct mbuf *m0;
689
690	i = (ip->ip_off + ip->ip_len) - q->ip_off;
691	if (i < q->ip_len) {
692	q->ip_len -= i;
693	q->ip_off += i;
694	m_adj(dtom(q), i);
695	break;
696	}
697	m0 = dtom(q);
698	q = q->ipf_next;
699	ip_deq(q->ipf_prev);
700	m_freem(m0);
701	}
702
703	insert:
704
705	#ifdef IPDIVERT
706	/*
707	* Any fragment diverting causes the whole packet to divert
708	*/
709	if (frag_divert_port != 0)
710	fp->ipq_divert = frag_divert_port;
711	frag_divert_port = 0;
712	#endif
713
714	/*
715	* Stick new segment in its place;
716	* check for complete reassembly.
717	*/
718	ip_enq(ip, q->ipf_prev);
719	next = 0;
720	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) {
721	if (q->ip_off != next)
722	return (0);
723	next += q->ip_len;
724	}
725	if (q->ipf_prev->ipf_mff & 1)
726	return (0);
727
728	/*
729	* Reassembly is complete. Make sure the packet is a sane size.
730	*/
731	#ifdef _IP_VHL
732	if (next + (IP_VHL_HL(((struct ip *)fp->ipq_next)->ip_vhl) << 2)
733	#else
734	if (next + ((((struct ip *)fp->ipq_next)->ip_hl) << 2)
735	#endif
736	> IP_MAXPACKET) {
737	ipstat.ips_toolong++;
738	ip_freef(fp);
739	return (0);
740	}
741
742	/*
743	* Concatenate fragments.
744	*/
745	q = fp->ipq_next;
746	m = dtom(q);
747	t = m->m_next;
748	m->m_next = NULL;
749	m_cat(m, t);
750	q = q->ipf_next;
751	while (q != (struct ipasfrag *)fp) {
752	t = dtom(q);
753	q = q->ipf_next;
754	m_cat(m, t);
755	}
756
757	#ifdef IPDIVERT
758	/*
759	* Record divert port for packet, if any
760	*/
761	frag_divert_port = fp->ipq_divert;
762	#endif
763
764	/*
765	* Create header for new ip packet by modifying header of first
766	* packet; dequeue and discard fragment reassembly header.
767	* Make header visible.
768	*/
769	ip = fp->ipq_next;
770	ip->ip_len = next;
771	ip->ipf_mff &= ~1;
772	((struct ip *)ip)->ip_src = fp->ipq_src;
773	((struct ip *)ip)->ip_dst = fp->ipq_dst;
774	remque(fp);
775	nipq--;
776	(void) m_free(dtom(fp));
777	m = dtom(ip);
778	m->m_len += (ip->ip_hl << 2);
779	m->m_data -= (ip->ip_hl << 2);
780	/* some debugging cruft by sklower, below, will go away soon */
781	if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
782	register int plen = 0;
783	for (t = m; m; m = m->m_next)
784	plen += m->m_len;
785	t->m_pkthdr.len = plen;
786	}
787	return ((struct ip *)ip);
788
789	dropfrag:
790	ipstat.ips_fragdropped++;
791	m_freem(m);
792	return (0);
793	}
794
795	/*
796	* Free a fragment reassembly header and all
797	* associated datagrams.
798	*/
799	static void
800	ip_freef(struct ipq *fp)
801	{
802	register struct ipasfrag q, p;
803
804	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) {
805	p = q->ipf_next;
806	ip_deq(q);
807	m_freem(dtom(q));
808	}
809	remque(fp);
810	(void) m_free(dtom(fp));
811	nipq--;
812	}
813
814	/*
815	* Put an ip fragment on a reassembly chain.
816	* Like insque, but pointers in middle of structure.
817	*/
818	static void
819	ip_enq(struct ipasfrag p, struct ipasfrag prev)
820	{
821
822	p->ipf_prev = prev;
823	p->ipf_next = prev->ipf_next;
824	prev->ipf_next->ipf_prev = p;
825	prev->ipf_next = p;
826	}
827
828	/*
829	* To ip_enq as remque is to insque.
830	*/
831	static void
832	ip_deq(struct ipasfrag *p)
833	{
834
835	p->ipf_prev->ipf_next = p->ipf_next;
836	p->ipf_next->ipf_prev = p->ipf_prev;
837	}
838
839	/*
840	* IP timer processing;
841	* if a timer expires on a reassembly
842	* queue, discard it.
843	*/
844	void
845	ip_slowtimo(void)
846	{
847	register struct ipq *fp;
848	int s = splnet();
849	int i;
850
851	for (i = 0; i < IPREASS_NHASH; i++) {
852	fp = ipq[i].next;
853	if (fp == 0)
854	continue;
855	while (fp != &ipq[i]) {
856	--fp->ipq_ttl;
857	fp = fp->next;
858	if (fp->prev->ipq_ttl == 0) {
859	ipstat.ips_fragtimeout++;
860	ip_freef(fp->prev);
861	}
862	}
863	}
864	splx(s);
865	}
866
867	/*
868	* Drain off all datagram fragments.
869	*/
870	void
871	ip_drain(void)
872	{
873	int i;
874
875	for (i = 0; i < IPREASS_NHASH; i++) {
876	while (ipq[i].next != &ipq[i]) {
877	ipstat.ips_fragdropped++;
878	ip_freef(ipq[i].next);
879	}
880	}
881	in_rtqdrain();
882	}
883
884	/*
885	* Do option processing on a datagram,
886	* possibly discarding it if bad options are encountered,
887	* or forwarding it if source-routed.
888	* Returns 1 if packet has been forwarded/freed,
889	* 0 if the packet should be processed further.
890	*/
891	static int
892	ip_dooptions(struct mbuf *m)
893	{
894	register struct ip ip = mtod(m, struct ip );
895	register u_char *cp;
896	register struct ip_timestamp *ipt;
897	register struct in_ifaddr *ia;
898	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
899	struct in_addr *sin, dst;
900	n_time ntime;
901
902	dst = ip->ip_dst;
903	cp = (u_char *)(ip + 1);
904	#ifdef _IP_VHL
905	cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
906	#else
907	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
908	#endif
909	for (; cnt > 0; cnt -= optlen, cp += optlen) {
910	opt = cp[IPOPT_OPTVAL];
911	if (opt == IPOPT_EOL)
912	break;
913	if (opt == IPOPT_NOP)
914	optlen = 1;
915	else {
916	optlen = cp[IPOPT_OLEN];
917	if (optlen <= 0 \|\| optlen > cnt) {
918	code = &cp[IPOPT_OLEN] - (u_char *)ip;
919	goto bad;
920	}
921	}
922	switch (opt) {
923
924	default:
925	break;
926
927	/*
928	* Source routing with record.
929	* Find interface with current destination address.
930	* If none on this machine then drop if strictly routed,
931	* or do nothing if loosely routed.
932	* Record interface address and bring up next address
933	* component. If strictly routed make sure next
934	* address is on directly accessible net.
935	*/
936	case IPOPT_LSRR:
937	case IPOPT_SSRR:
938	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
939	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
940	goto bad;
941	}
942	ipaddr.sin_addr = ip->ip_dst;
943	ia = (struct in_ifaddr *)
944	ifa_ifwithaddr((struct sockaddr *)&ipaddr);
945	if (ia == 0) {
946	if (opt == IPOPT_SSRR) {
947	type = ICMP_UNREACH;
948	code = ICMP_UNREACH_SRCFAIL;
949	goto bad;
950	}
951	if (!ip_dosourceroute)
952	goto nosourcerouting;
953	/*
954	* Loose routing, and not at next destination
955	* yet; nothing to do except forward.
956	*/
957	break;
958	}
959	off--; /* 0 origin */
960	if (off > optlen - sizeof(struct in_addr)) {
961	/*
962	* End of source route. Should be for us.
963	*/
964	if (!ip_acceptsourceroute)
965	goto nosourcerouting;
966	save_rte(cp, ip->ip_src);
967	break;
968	}
969
970	if (!ip_dosourceroute) {
971	char buf[4*sizeof "123"];
972
973	nosourcerouting:
974	strcpy(buf, inet_ntoa(ip->ip_dst));
975	log(LOG_WARNING,
976	"attempted source route from %s to %s\n",
977	inet_ntoa(ip->ip_src), buf);
978	type = ICMP_UNREACH;
979	code = ICMP_UNREACH_SRCFAIL;
980	goto bad;
981	}
982
983	/*
984	* locate outgoing interface
985	*/
986	(void)memcpy(&ipaddr.sin_addr, cp + off,
987	sizeof(ipaddr.sin_addr));
988
989	if (opt == IPOPT_SSRR) {
990	#define INA struct in_ifaddr *
991	#define SA struct sockaddr *
992	if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
993	ia = (INA)ifa_ifwithnet((SA)&ipaddr);
994	} else
995	ia = ip_rtaddr(ipaddr.sin_addr);
996	if (ia == 0) {
997	type = ICMP_UNREACH;
998	code = ICMP_UNREACH_SRCFAIL;
999	goto bad;
1000	}
1001	ip->ip_dst = ipaddr.sin_addr;
1002	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1003	sizeof(struct in_addr));
1004	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1005	/*
1006	* Let ip_intr's mcast routing check handle mcast pkts
1007	*/
1008	forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1009	break;
1010
1011	case IPOPT_RR:
1012	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1013	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1014	goto bad;
1015	}
1016	/*
1017	* If no space remains, ignore.
1018	*/
1019	off--; /* 0 origin */
1020	if (off > optlen - sizeof(struct in_addr))
1021	break;
1022	(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1023	sizeof(ipaddr.sin_addr));
1024	/*
1025	* locate outgoing interface; if we're the destination,
1026	* use the incoming interface (should be same).
1027	*/
1028	if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1029	(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1030	type = ICMP_UNREACH;
1031	code = ICMP_UNREACH_HOST;
1032	goto bad;
1033	}
1034	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1035	sizeof(struct in_addr));
1036	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1037	break;
1038
1039	case IPOPT_TS:
1040	code = cp - (u_char *)ip;
1041	ipt = (struct ip_timestamp *)cp;
1042	if (ipt->ipt_len < 5)
1043	goto bad;
1044	if (ipt->ipt_ptr > ipt->ipt_len - sizeof (long)) {
1045	if (++ipt->ipt_oflw == 0)
1046	goto bad;
1047	break;
1048	}
1049	sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1050	switch (ipt->ipt_flg) {
1051
1052	case IPOPT_TS_TSONLY:
1053	break;
1054
1055	case IPOPT_TS_TSANDADDR:
1056	if (ipt->ipt_ptr + sizeof(n_time) +
1057	sizeof(struct in_addr) > ipt->ipt_len)
1058	goto bad;
1059	ipaddr.sin_addr = dst;
1060	ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1061	m->m_pkthdr.rcvif);
1062	if (ia == 0)
1063	continue;
1064	(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1065	sizeof(struct in_addr));
1066	ipt->ipt_ptr += sizeof(struct in_addr);
1067	break;
1068
1069	case IPOPT_TS_PRESPEC:
1070	if (ipt->ipt_ptr + sizeof(n_time) +
1071	sizeof(struct in_addr) > ipt->ipt_len)
1072	goto bad;
1073	(void)memcpy(&ipaddr.sin_addr, sin,
1074	sizeof(struct in_addr));
1075	if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1076	continue;
1077	ipt->ipt_ptr += sizeof(struct in_addr);
1078	break;
1079
1080	default:
1081	goto bad;
1082	}
1083	ntime = iptime();
1084	(void)memcpy(cp + ipt->ipt_ptr - 1, &ntime,
1085	sizeof(n_time));
1086	ipt->ipt_ptr += sizeof(n_time);
1087	}
1088	}
1089	if (forward && ipforwarding) {
1090	ip_forward(m, 1);
1091	return (1);
1092	}
1093	return (0);
1094	bad:
1095	#ifdef _IP_VHL
1096	ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hdr length */
1097	#else
1098	ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */
1099	#endif
1100	icmp_error(m, type, code, 0, 0);
1101	ipstat.ips_badoptions++;
1102	return (1);
1103	}
1104
1105	/*
1106	* Given address of next destination (final or next hop),
1107	* return internet address info of interface to be used to get there.
1108	*/
1109	static struct in_ifaddr *
1110	ip_rtaddr(struct in_addr dst)
1111	{
1112	struct sockaddr_in *sin;
1113
1114	sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
1115
1116	if (ipforward_rt.ro_rt == 0 \|\| dst.s_addr != sin->sin_addr.s_addr) {
1117	if (ipforward_rt.ro_rt) {
1118	RTFREE(ipforward_rt.ro_rt);
1119	ipforward_rt.ro_rt = 0;
1120	}
1121	sin->sin_family = AF_INET;
1122	sin->sin_len = sizeof(*sin);
1123	sin->sin_addr = dst;
1124
1125	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1126	}
1127	if (ipforward_rt.ro_rt == 0)
1128	return ((struct in_ifaddr *)0);
1129	return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa);
1130	}
1131
1132	/*
1133	* Save incoming source route for use in replies,
1134	* to be picked up later by ip_srcroute if the receiver is interested.
1135	*/
1136	void
1137	save_rte(u_char *option, struct in_addr dst)
1138	{
1139	unsigned olen;
1140
1141	olen = option[IPOPT_OLEN];
1142	#ifdef DIAGNOSTIC
1143	if (ipprintfs)
1144	printf("save_rte: olen %d\n", olen);
1145	#endif
1146	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1147	return;
1148	bcopy(option, ip_srcrt.srcopt, olen);
1149	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1150	ip_srcrt.dst = dst;
1151	}
1152
1153	/*
1154	* Retrieve incoming source route for use in replies,
1155	* in the same form used by setsockopt.
1156	* The first hop is placed before the options, will be removed later.
1157	*/
1158	struct mbuf *
1159	ip_srcroute(void)
1160	{
1161	register struct in_addr p, q;
1162	register struct mbuf *m;
1163
1164	if (ip_nhops == 0)
1165	return ((struct mbuf *)0);
1166	m = m_get(M_DONTWAIT, MT_SOOPTS);
1167	if (m == 0)
1168	return ((struct mbuf *)0);
1169
1170	#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1171
1172	/* length is (nhops+1)sizeof(addr) + sizeof(nop + srcrt header) /
1173	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1174	OPTSIZ;
1175	#ifdef DIAGNOSTIC
1176	if (ipprintfs)
1177	printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1178	#endif
1179
1180	/*
1181	* First save first hop for return route
1182	*/
1183	p = &ip_srcrt.route[ip_nhops - 1];
1184	(mtod(m, struct in_addr )) = *p--;
1185	#ifdef DIAGNOSTIC
1186	if (ipprintfs)
1187	printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr));
1188	#endif
1189
1190	/*
1191	* Copy option fields and padding (nop) to mbuf.
1192	*/
1193	ip_srcrt.nop = IPOPT_NOP;
1194	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1195	(void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1196	&ip_srcrt.nop, OPTSIZ);
1197	q = (struct in_addr *)(mtod(m, caddr_t) +
1198	sizeof(struct in_addr) + OPTSIZ);
1199	#undef OPTSIZ
1200	/*
1201	* Record return path as an IP source route,
1202	* reversing the path (pointers are now aligned).
1203	*/
1204	while (p >= ip_srcrt.route) {
1205	#ifdef DIAGNOSTIC
1206	if (ipprintfs)
1207	printf(" %lx", ntohl(q->s_addr));
1208	#endif
1209	q++ = p--;
1210	}
1211	/*
1212	* Last hop goes to final destination.
1213	*/
1214	*q = ip_srcrt.dst;
1215	#ifdef DIAGNOSTIC
1216	if (ipprintfs)
1217	printf(" %lx\n", ntohl(q->s_addr));
1218	#endif
1219	return (m);
1220	}
1221
1222	/*
1223	* Strip out IP options, at higher
1224	* level protocol in the kernel.
1225	* Second argument is buffer to which options
1226	* will be moved, and return value is their length.
1227	* XXX should be deleted; last arg currently ignored.
1228	*/
1229	void
1230	ip_stripoptions(struct mbuf m, struct mbuf mopt)
1231	{
1232	register int i;
1233	struct ip ip = mtod(m, struct ip );
1234	register caddr_t opts;
1235	int olen;
1236
1237	#ifdef _IP_VHL
1238	olen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
1239	#else
1240	olen = (ip->ip_hl << 2) - sizeof (struct ip);
1241	#endif
1242	opts = (caddr_t)(ip + 1);
1243	i = m->m_len - (sizeof (struct ip) + olen);
1244	bcopy(opts + olen, opts, (unsigned)i);
1245	m->m_len -= olen;
1246	if (m->m_flags & M_PKTHDR)
1247	m->m_pkthdr.len -= olen;
1248	#ifdef _IP_VHL
1249	ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1250	#else
1251	ip->ip_v = IPVERSION;
1252	ip->ip_hl = (sizeof(struct ip) >> 2);
1253	#endif
1254	}
1255
1256	u_char inetctlerrmap[PRC_NCMDS] = {
1257	0, 0, 0, 0,
1258	0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1259	EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1260	EMSGSIZE, EHOSTUNREACH, 0, 0,
1261	0, 0, 0, 0,
1262	ENOPROTOOPT
1263	};
1264
1265	/*
1266	* Forward a packet. If some error occurs return the sender
1267	* an icmp packet. Note we can't always generate a meaningful
1268	* icmp message because icmp doesn't have a large enough repertoire
1269	* of codes and types.
1270	*
1271	* If not forwarding, just drop the packet. This could be confusing
1272	* if ipforwarding was zero but some routing protocol was advancing
1273	* us as a gateway to somewhere. However, we must let the routing
1274	* protocol deal with that.
1275	*
1276	* The srcrt parameter indicates whether the packet is being forwarded
1277	* via a source route.
1278	*/
1279	static void
1280	ip_forward(struct mbuf *m, int srcrt)
1281	{
1282	struct ip ip = mtod(m, struct ip );
1283	register struct sockaddr_in *sin;
1284	register struct rtentry *rt;
1285	int error, type = 0, code = 0;
1286	struct mbuf *mcopy;
1287	n_long dest;
1288	struct ifnet *destifp;
1289
1290	dest = 0;
1291	#ifdef DIAGNOSTIC
1292	if (ipprintfs)
1293	printf("forward: src %lx dst %lx ttl %x\n",
1294	ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1295	#endif
1296
1297
1298	if (m->m_flags & M_BCAST \|\| in_canforward(ip->ip_dst) == 0) {
1299	ipstat.ips_cantforward++;
1300	m_freem(m);
1301	return;
1302	}
1303	HTONS(ip->ip_id);
1304	if (ip->ip_ttl <= IPTTLDEC) {
1305	icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1306	return;
1307	}
1308	ip->ip_ttl -= IPTTLDEC;
1309
1310	sin = (struct sockaddr_in *)&ipforward_rt.ro_dst;
1311	if ((rt = ipforward_rt.ro_rt) == 0 \|\|
1312	ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
1313	if (ipforward_rt.ro_rt) {
1314	RTFREE(ipforward_rt.ro_rt);
1315	ipforward_rt.ro_rt = 0;
1316	}
1317	sin->sin_family = AF_INET;
1318	sin->sin_len = sizeof(*sin);
1319	sin->sin_addr = ip->ip_dst;
1320
1321	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1322	if (ipforward_rt.ro_rt == 0) {
1323	icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1324	return;
1325	}
1326	rt = ipforward_rt.ro_rt;
1327	}
1328
1329	/*
1330	* Save at most 64 bytes of the packet in case
1331	* we need to generate an ICMP message to the src.
1332	*/
1333	mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
1334
1335	/*
1336	* If forwarding packet using same interface that it came in on,
1337	* perhaps should send a redirect to sender to shortcut a hop.
1338	* Only send redirect if source is sending directly to us,
1339	* and if packet was not source routed (or has any options).
1340	* Also, don't send redirect if forwarding using a default route
1341	* or a route modified by a redirect.
1342	*/
1343	#define satosin(sa) ((struct sockaddr_in *)(sa))
1344	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1345	(rt->rt_flags & (RTF_DYNAMIC\|RTF_MODIFIED)) == 0 &&
1346	satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
1347	ipsendredirects && !srcrt) {
1348	#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1349	u_long src = ntohl(ip->ip_src.s_addr);
1350
1351	if (RTA(rt) &&
1352	(src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1353	if (rt->rt_flags & RTF_GATEWAY)
1354	dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1355	else
1356	dest = ip->ip_dst.s_addr;
1357	/* Router requirements says to only send host redirects */
1358	type = ICMP_REDIRECT;
1359	code = ICMP_REDIRECT_HOST;
1360	}
1361	}
1362
1363	error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1364	IP_FORWARDING, 0);
1365	if (error)
1366	ipstat.ips_cantforward++;
1367	else {
1368	ipstat.ips_forward++;
1369	if (type)
1370	ipstat.ips_redirectsent++;
1371	else {
1372	if (mcopy)
1373	m_freem(mcopy);
1374	return;
1375	}
1376	}
1377	if (mcopy == NULL)
1378	return;
1379	destifp = NULL;
1380
1381	switch (error) {
1382
1383	case 0: /* forwarded, but need redirect */
1384	/* type, code set above */
1385	break;
1386
1387	case ENETUNREACH: /* shouldn't happen, checked above */
1388	case EHOSTUNREACH:
1389	case ENETDOWN:
1390	case EHOSTDOWN:
1391	default:
1392	type = ICMP_UNREACH;
1393	code = ICMP_UNREACH_HOST;
1394	break;
1395
1396	case EMSGSIZE:
1397	type = ICMP_UNREACH;
1398	code = ICMP_UNREACH_NEEDFRAG;
1399	if (ipforward_rt.ro_rt)
1400	destifp = ipforward_rt.ro_rt->rt_ifp;
1401	ipstat.ips_cantfrag++;
1402	break;
1403
1404	case ENOBUFS:
1405	type = ICMP_SOURCEQUENCH;
1406	code = 0;
1407	break;
1408	}
1409	icmp_error(mcopy, type, code, dest, destifp);
1410	}
1411
1412	void
1413	ip_savecontrol(struct inpcb inp, struct mbuf mp, struct ip ip,
1414	struct mbuf *m)
1415	{
1416	if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1417	struct timeval tv;
1418
1419	microtime(&tv);
1420	*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1421	SCM_TIMESTAMP, SOL_SOCKET);
1422	if (*mp)
1423	mp = &(*mp)->m_next;
1424	}
1425	if (inp->inp_flags & INP_RECVDSTADDR) {
1426	*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1427	sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1428	if (*mp)
1429	mp = &(*mp)->m_next;
1430	}
1431	#ifdef notyet
1432	/* XXX
1433	* Moving these out of udp_input() made them even more broken
1434	* than they already were.
1435	*/
1436	/* options were tossed already */
1437	if (inp->inp_flags & INP_RECVOPTS) {
1438	*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1439	sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1440	if (*mp)
1441	mp = &(*mp)->m_next;
1442	}
1443	/* ip_srcroute doesn't do what we want here, need to fix */
1444	if (inp->inp_flags & INP_RECVRETOPTS) {
1445	*mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
1446	sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1447	if (*mp)
1448	mp = &(*mp)->m_next;
1449	}
1450	#endif
1451	if (inp->inp_flags & INP_RECVIF) {
1452	struct sockaddr_dl sdl;
1453
1454	sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1455	sdl.sdl_family = AF_LINK;
1456	sdl.sdl_index = m->m_pkthdr.rcvif ?
1457	m->m_pkthdr.rcvif->if_index : 0;
1458	sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1459	*mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1460	IP_RECVIF, IPPROTO_IP);
1461	if (*mp)
1462	mp = &(*mp)->m_next;
1463	}
1464	}
1465
1466	int
1467	ip_rsvp_init(struct socket *so)
1468	{
1469	if (so->so_type != SOCK_RAW \|\|
1470	so->so_proto->pr_protocol != IPPROTO_RSVP)
1471	return EOPNOTSUPP;
1472
1473	if (ip_rsvpd != NULL)
1474	return EADDRINUSE;
1475
1476	ip_rsvpd = so;
1477	/*
1478	* This may seem silly, but we need to be sure we don't over-increment
1479	* the RSVP counter, in case something slips up.
1480	*/
1481	if (!ip_rsvp_on) {
1482	ip_rsvp_on = 1;
1483	rsvp_on++;
1484	}
1485
1486	return 0;
1487	}
1488
1489	int
1490	ip_rsvp_done(void)
1491	{
1492	ip_rsvpd = NULL;
1493	/*
1494	* This may seem silly, but we need to be sure we don't over-decrement
1495	* the RSVP counter, in case something slips up.
1496	*/
1497	if (ip_rsvp_on) {
1498	ip_rsvp_on = 0;
1499	rsvp_on--;
1500	}
1501	return 0;
1502	}

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