Context Navigation

source: rtems/cpukit/libnetworking/netinet/ip_input.c @ 39e6e65a

4.104.114.84.95

Last change on this file since 39e6e65a was 39e6e65a, checked in by Joel Sherrill <joel.sherrill@…>, on 08/19/98 at 21:32:28
Base files
Property mode set to `100644`
File size: 35.7 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	* 3. All advertising materials mentioning features or use of this software
14	* must display the following acknowledgement:
15	* This product includes software developed by the University of
16	* California, Berkeley and its contributors.
17	* 4. Neither the name of the University nor the names of its contributors
18	* may be used to endorse or promote products derived from this software
19	* without specific prior written permission.
20	*
21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31	* SUCH DAMAGE.
32	*
33	* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
34	* $Id$
35	* $ANA: ip_input.c,v 1.5 1996/09/18 14:34:59 wollman Exp $
36	*/
37
38	#define _IP_VHL
39
40	#include "opt_ipfw.h"
41
42	#include <stddef.h>
43
44	#include <sys/param.h>
45	#include <sys/systm.h>
46	#include <sys/malloc.h>
47	#include <sys/mbuf.h>
48	#include <sys/domain.h>
49	#include <sys/protosw.h>
50	#include <sys/socket.h>
51	#include <sys/errno.h>
52	#include <sys/time.h>
53	#include <sys/kernel.h>
54	#include <sys/syslog.h>
55	#include <sys/sysctl.h>
56
57	#include <net/if.h>
58	#include <net/if_dl.h>
59	#include <net/route.h>
60	#include <net/netisr.h>
61
62	#include <netinet/in.h>
63	#include <netinet/in_systm.h>
64	#include <netinet/in_var.h>
65	#include <netinet/ip.h>
66	#include <netinet/in_pcb.h>
67	#include <netinet/in_var.h>
68	#include <netinet/ip_var.h>
69	#include <netinet/ip_icmp.h>
70	#include <machine/in_cksum.h>
71
72	#include <sys/socketvar.h>
73
74	#ifdef IPFIREWALL
75	#include <netinet/ip_fw.h>
76	#endif
77
78	int rsvp_on = 0;
79	static int ip_rsvp_on;
80	struct socket *ip_rsvpd;
81
82	static int ipforwarding = 0;
83	SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
84	&ipforwarding, 0, "");
85
86	static int ipsendredirects = 1; /* XXX */
87	SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
88	&ipsendredirects, 0, "");
89
90	int ip_defttl = IPDEFTTL;
91	SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
92	&ip_defttl, 0, "");
93
94	static int ip_dosourceroute = 0;
95	SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
96	&ip_dosourceroute, 0, "");
97
98	static int ip_acceptsourceroute = 0;
99	SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
100	CTLFLAG_RW, &ip_acceptsourceroute, 0, "");
101	#ifdef DIAGNOSTIC
102	static int ipprintfs = 0;
103	#endif
104
105	extern struct domain inetdomain;
106	extern struct protosw inetsw[];
107	u_char ip_protox[IPPROTO_MAX];
108	static int ipqmaxlen = IFQ_MAXLEN;
109	struct in_ifaddr in_ifaddr; / first inet address */
110	struct ifqueue ipintrq;
111	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD,
112	&ipintrq.ifq_maxlen, 0, "");
113	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
114	&ipintrq.ifq_drops, 0, "");
115
116	struct ipstat ipstat;
117
118	/* Packet reassembly stuff */
119	#define IPREASS_NHASH_LOG2 6
120	#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
121	#define IPREASS_HMASK (IPREASS_NHASH - 1)
122	#define IPREASS_HASH(x,y) \
123	((((x) & 0xF \| ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
124
125	static struct ipq ipq[IPREASS_NHASH];
126	static int nipq = 0; /* total # of reass queues */
127	static int maxnipq;
128
129	#ifdef IPCTL_DEFMTU
130	SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
131	&ip_mtu, 0, "");
132	#endif
133
134	#if !defined(COMPAT_IPFW) \|\| COMPAT_IPFW == 1
135	#undef COMPAT_IPFW
136	#define COMPAT_IPFW 1
137	#else
138	#undef COMPAT_IPFW
139	#endif
140
141	#ifdef COMPAT_IPFW
142	/* Firewall hooks */
143	ip_fw_chk_t *ip_fw_chk_ptr;
144	ip_fw_ctl_t *ip_fw_ctl_ptr;
145
146	/* IP Network Address Translation (NAT) hooks */
147	ip_nat_t *ip_nat_ptr;
148	ip_nat_ctl_t *ip_nat_ctl_ptr;
149	#endif
150
151	/*
152	* We need to save the IP options in case a protocol wants to respond
153	* to an incoming packet over the same route if the packet got here
154	* using IP source routing. This allows connection establishment and
155	* maintenance when the remote end is on a network that is not known
156	* to us.
157	*/
158	static int ip_nhops = 0;
159	static struct ip_srcrt {
160	struct in_addr dst; /* final destination */
161	char nop; /* one NOP to align */
162	char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
163	struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
164	} ip_srcrt;
165
166	#ifdef IPDIVERT
167	/*
168	* Shared variable between ip_input() and ip_reass() to communicate
169	* about which packets, once assembled from fragments, get diverted,
170	* and to which port.
171	*/
172	static u_short frag_divert_port;
173	#endif
174
175	static void save_rte __P((u_char *, struct in_addr));
176	static void ip_deq __P((struct ipasfrag *));
177	static int ip_dooptions __P((struct mbuf *));
178	static void ip_enq __P((struct ipasfrag , struct ipasfrag ));
179	static void ip_forward __P((struct mbuf *, int));
180	static void ip_freef __P((struct ipq *));
181	static struct ip *
182	ip_reass __P((struct ipasfrag , struct ipq , struct ipq *));
183	static struct in_ifaddr *
184	ip_rtaddr __P((struct in_addr));
185	void ipintr __P((void));
186	/*
187	* IP initialization: fill in IP protocol switch table.
188	* All protocols not implemented in kernel go to raw IP protocol handler.
189	*/
190	void
191	ip_init()
192	{
193	register struct protosw *pr;
194	register int i;
195
196	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
197	if (pr == 0)
198	panic("ip_init");
199	for (i = 0; i < IPPROTO_MAX; i++)
200	ip_protox[i] = pr - inetsw;
201	for (pr = inetdomain.dom_protosw;
202	pr < inetdomain.dom_protoswNPROTOSW; pr++)
203	if (pr->pr_domain->dom_family == PF_INET &&
204	pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
205	ip_protox[pr->pr_protocol] = pr - inetsw;
206
207	for (i = 0; i < IPREASS_NHASH; i++)
208	ipq[i].next = ipq[i].prev = &ipq[i];
209
210	maxnipq = nmbclusters/4;
211
212	ip_id = rtems_bsdnet_seconds_since_boot() & 0xffff;
213	ipintrq.ifq_maxlen = ipqmaxlen;
214	#ifdef IPFIREWALL
215	ip_fw_init();
216	#endif
217	#ifdef IPNAT
218	ip_nat_init();
219	#endif
220
221	}
222
223	static struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET };
224	static struct route ipforward_rt;
225
226	/*
227	* Ip input routine. Checksum and byte swap header. If fragmented
228	* try to reassemble. Process options. Pass to next level.
229	*/
230	void
231	ip_input(struct mbuf *m)
232	{
233	struct ip *ip;
234	struct ipq *fp;
235	struct in_ifaddr *ia;
236	int i, hlen;
237	u_short sum;
238
239	#ifdef DIAGNOSTIC
240	if ((m->m_flags & M_PKTHDR) == 0)
241	panic("ip_input no HDR");
242	#endif
243	/*
244	* If no IP addresses have been set yet but the interfaces
245	* are receiving, can't do anything with incoming packets yet.
246	*/
247	if (in_ifaddr == NULL)
248	goto bad;
249	ipstat.ips_total++;
250
251	if (m->m_pkthdr.len < sizeof(struct ip))
252	goto tooshort;
253
254	#ifdef DIAGNOSTIC
255	if (m->m_len < sizeof(struct ip))
256	panic("ipintr mbuf too short");
257	#endif
258
259	if (m->m_len < sizeof (struct ip) &&
260	(m = m_pullup(m, sizeof (struct ip))) == 0) {
261	ipstat.ips_toosmall++;
262	return;
263	}
264	ip = mtod(m, struct ip *);
265
266	if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
267	ipstat.ips_badvers++;
268	goto bad;
269	}
270
271	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
272	if (hlen < sizeof(struct ip)) { /* minimum header length */
273	ipstat.ips_badhlen++;
274	goto bad;
275	}
276	if (hlen > m->m_len) {
277	if ((m = m_pullup(m, hlen)) == 0) {
278	ipstat.ips_badhlen++;
279	return;
280	}
281	ip = mtod(m, struct ip *);
282	}
283	if (hlen == sizeof(struct ip)) {
284	sum = in_cksum_hdr(ip);
285	} else {
286	sum = in_cksum(m, hlen);
287	}
288	if (sum) {
289	ipstat.ips_badsum++;
290	goto bad;
291	}
292
293	/*
294	* Convert fields to host representation.
295	*/
296	NTOHS(ip->ip_len);
297	if (ip->ip_len < hlen) {
298	ipstat.ips_badlen++;
299	goto bad;
300	}
301	NTOHS(ip->ip_id);
302	NTOHS(ip->ip_off);
303
304	/*
305	* Check that the amount of data in the buffers
306	* is as at least much as the IP header would have us expect.
307	* Trim mbufs if longer than we expect.
308	* Drop packet if shorter than we expect.
309	*/
310	if (m->m_pkthdr.len < ip->ip_len) {
311	tooshort:
312	ipstat.ips_tooshort++;
313	goto bad;
314	}
315	if (m->m_pkthdr.len > ip->ip_len) {
316	if (m->m_len == m->m_pkthdr.len) {
317	m->m_len = ip->ip_len;
318	m->m_pkthdr.len = ip->ip_len;
319	} else
320	m_adj(m, ip->ip_len - m->m_pkthdr.len);
321	}
322	/*
323	* IpHack's section.
324	* Right now when no processing on packet has done
325	* and it is still fresh out of network we do our black
326	* deals with it.
327	* - Firewall: deny/allow/divert
328	* - Xlate: translate packet's addr/port (NAT).
329	* - Wrap: fake packet's addr/port <unimpl.>
330	* - Encapsulate: put it in another IP and send out. <unimp.>
331	*/
332
333	#ifdef COMPAT_IPFW
334	if (ip_fw_chk_ptr) {
335	#ifdef IPDIVERT
336	u_short port;
337
338	port = (*ip_fw_chk_ptr)(&ip, hlen, NULL, ip_divert_ignore, &m);
339	ip_divert_ignore = 0;
340	if (port) { /* Divert packet */
341	frag_divert_port = port;
342	goto ours;
343	}
344	#else
345	/* If ipfw says divert, we have to just drop packet */
346	if ((*ip_fw_chk_ptr)(&ip, hlen, NULL, 0, &m)) {
347	m_freem(m);
348	m = NULL;
349	}
350	#endif
351	if (!m)
352	return;
353	}
354
355	if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN))
356	return;
357	#endif
358
359	/*
360	* Process options and, if not destined for us,
361	* ship it on. ip_dooptions returns 1 when an
362	* error was detected (causing an icmp message
363	* to be sent and the original packet to be freed).
364	*/
365	ip_nhops = 0; /* for source routed packets */
366	if (hlen > sizeof (struct ip) && ip_dooptions(m))
367	return;
368
369	/* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
370	* matter if it is destined to another node, or whether it is
371	* a multicast one, RSVP wants it! and prevents it from being forwarded
372	* anywhere else. Also checks if the rsvp daemon is running before
373	* grabbing the packet.
374	*/
375	if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
376	goto ours;
377
378	/*
379	* Check our list of addresses, to see if the packet is for us.
380	*/
381	for (ia = in_ifaddr; ia; ia = ia->ia_next) {
382	#define satosin(sa) ((struct sockaddr_in *)(sa))
383
384	if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
385	goto ours;
386	#ifdef BOOTP_COMPAT
387	if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
388	goto ours;
389	#endif
390	if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
391	if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
392	ip->ip_dst.s_addr)
393	goto ours;
394	if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
395	goto ours;
396	}
397	}
398	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
399	struct in_multi *inm;
400	if (ip_mrouter) {
401	/*
402	* If we are acting as a multicast router, all
403	* incoming multicast packets are passed to the
404	* kernel-level multicast forwarding function.
405	* The packet is returned (relatively) intact; if
406	* ip_mforward() returns a non-zero value, the packet
407	* must be discarded, else it may be accepted below.
408	*
409	* (The IP ident field is put in the same byte order
410	* as expected when ip_mforward() is called from
411	* ip_output().)
412	*/
413	ip->ip_id = htons(ip->ip_id);
414	if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
415	ipstat.ips_cantforward++;
416	m_freem(m);
417	return;
418	}
419	ip->ip_id = ntohs(ip->ip_id);
420
421	/*
422	* The process-level routing demon needs to receive
423	* all multicast IGMP packets, whether or not this
424	* host belongs to their destination groups.
425	*/
426	if (ip->ip_p == IPPROTO_IGMP)
427	goto ours;
428	ipstat.ips_forward++;
429	}
430	/*
431	* See if we belong to the destination multicast group on the
432	* arrival interface.
433	*/
434	IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
435	if (inm == NULL) {
436	ipstat.ips_cantforward++;
437	m_freem(m);
438	return;
439	}
440	goto ours;
441	}
442	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
443	goto ours;
444	if (ip->ip_dst.s_addr == INADDR_ANY)
445	goto ours;
446
447	/*
448	* Not for us; forward if possible and desirable.
449	*/
450	if (ipforwarding == 0) {
451	ipstat.ips_cantforward++;
452	m_freem(m);
453	} else
454	ip_forward(m, 0);
455	return;
456
457	ours:
458
459	/*
460	* If offset or IP_MF are set, must reassemble.
461	* Otherwise, nothing need be done.
462	* (We could look in the reassembly queue to see
463	* if the packet was previously fragmented,
464	* but it's not worth the time; just let them time out.)
465	*/
466	if (ip->ip_off &~ (IP_DF \| IP_RF)) {
467	if (m->m_flags & M_EXT) { /* XXX */
468	if ((m = m_pullup(m, sizeof (struct ip))) == 0) {
469	ipstat.ips_toosmall++;
470	#ifdef IPDIVERT
471	frag_divert_port = 0;
472	#endif
473	return;
474	}
475	ip = mtod(m, struct ip *);
476	}
477	sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
478	/*
479	* Look for queue of fragments
480	* of this datagram.
481	*/
482	for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
483	if (ip->ip_id == fp->ipq_id &&
484	ip->ip_src.s_addr == fp->ipq_src.s_addr &&
485	ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
486	ip->ip_p == fp->ipq_p)
487	goto found;
488
489	fp = 0;
490
491	/* check if there's a place for the new queue */
492	if (nipq > maxnipq) {
493	/*
494	* drop something from the tail of the current queue
495	* before proceeding further
496	*/
497	if (ipq[sum].prev == &ipq[sum]) { /* gak */
498	for (i = 0; i < IPREASS_NHASH; i++) {
499	if (ipq[i].prev != &ipq[i]) {
500	ip_freef(ipq[i].prev);
501	break;
502	}
503	}
504	} else
505	ip_freef(ipq[sum].prev);
506	}
507	found:
508	/*
509	* Adjust ip_len to not reflect header,
510	* set ip_mff if more fragments are expected,
511	* convert offset of this to bytes.
512	*/
513	ip->ip_len -= hlen;
514	((struct ipasfrag *)ip)->ipf_mff &= ~1;
515	if (ip->ip_off & IP_MF)
516	((struct ipasfrag *)ip)->ipf_mff \|= 1;
517	ip->ip_off <<= 3;
518
519	/*
520	* If datagram marked as having more fragments
521	* or if this is not the first fragment,
522	* attempt reassembly; if it succeeds, proceed.
523	*/
524	if (((struct ipasfrag *)ip)->ipf_mff & 1 \|\| ip->ip_off) {
525	ipstat.ips_fragments++;
526	ip = ip_reass((struct ipasfrag *)ip, fp, &ipq[sum]);
527	if (ip == 0)
528	return;
529	ipstat.ips_reassembled++;
530	m = dtom(ip);
531	#ifdef IPDIVERT
532	if (frag_divert_port) {
533	ip->ip_len += hlen;
534	HTONS(ip->ip_len);
535	HTONS(ip->ip_off);
536	HTONS(ip->ip_id);
537	ip->ip_sum = 0;
538	ip->ip_sum = in_cksum_hdr(ip);
539	NTOHS(ip->ip_id);
540	NTOHS(ip->ip_off);
541	NTOHS(ip->ip_len);
542	ip->ip_len -= hlen;
543	}
544	#endif
545	} else
546	if (fp)
547	ip_freef(fp);
548	} else
549	ip->ip_len -= hlen;
550
551	#ifdef IPDIVERT
552	/*
553	* Divert reassembled packets to the divert protocol if required
554	*/
555	if (frag_divert_port) {
556	ipstat.ips_delivered++;
557	ip_divert_port = frag_divert_port;
558	frag_divert_port = 0;
559	(*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, hlen);
560	return;
561	}
562
563	/* Don't let packets divert themselves */
564	if (ip->ip_p == IPPROTO_DIVERT) {
565	ipstat.ips_noproto++;
566	goto bad;
567	}
568	#endif
569
570	/*
571	* Switch out to protocol's input routine.
572	*/
573	ipstat.ips_delivered++;
574	(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
575	return;
576	bad:
577	m_freem(m);
578	}
579
580	/*
581	* IP software interrupt routine - to go away sometime soon
582	*/
583	void
584	ipintr(void)
585	{
586	int s;
587	struct mbuf *m;
588
589	while(1) {
590	s = splimp();
591	IF_DEQUEUE(&ipintrq, m);
592	splx(s);
593	if (m == 0)
594	return;
595	ip_input(m);
596	}
597	}
598
599	NETISR_SET(NETISR_IP, ipintr);
600
601	/*
602	* Take incoming datagram fragment and try to
603	* reassemble it into whole datagram. If a chain for
604	* reassembly of this datagram already exists, then it
605	* is given as fp; otherwise have to make a chain.
606	*/
607	static struct ip *
608	ip_reass(ip, fp, where)
609	register struct ipasfrag *ip;
610	register struct ipq *fp;
611	struct ipq *where;
612	{
613	register struct mbuf *m = dtom(ip);
614	register struct ipasfrag *q;
615	struct mbuf *t;
616	int hlen = ip->ip_hl << 2;
617	int i, next;
618
619	/*
620	* Presence of header sizes in mbufs
621	* would confuse code below.
622	*/
623	m->m_data += hlen;
624	m->m_len -= hlen;
625
626	/*
627	* If first fragment to arrive, create a reassembly queue.
628	*/
629	if (fp == 0) {
630	if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
631	goto dropfrag;
632	fp = mtod(t, struct ipq *);
633	insque(fp, where);
634	nipq++;
635	fp->ipq_ttl = IPFRAGTTL;
636	fp->ipq_p = ip->ip_p;
637	fp->ipq_id = ip->ip_id;
638	fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp;
639	fp->ipq_src = ((struct ip *)ip)->ip_src;
640	fp->ipq_dst = ((struct ip *)ip)->ip_dst;
641	#ifdef IPDIVERT
642	fp->ipq_divert = 0;
643	#endif
644	q = (struct ipasfrag *)fp;
645	goto insert;
646	}
647
648	/*
649	* Find a segment which begins after this one does.
650	*/
651	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next)
652	if (q->ip_off > ip->ip_off)
653	break;
654
655	/*
656	* If there is a preceding segment, it may provide some of
657	* our data already. If so, drop the data from the incoming
658	* segment. If it provides all of our data, drop us.
659	*/
660	if (q->ipf_prev != (struct ipasfrag *)fp) {
661	i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off;
662	if (i > 0) {
663	if (i >= ip->ip_len)
664	goto dropfrag;
665	m_adj(dtom(ip), i);
666	ip->ip_off += i;
667	ip->ip_len -= i;
668	}
669	}
670
671	/*
672	* While we overlap succeeding segments trim them or,
673	* if they are completely covered, dequeue them.
674	*/
675	while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) {
676	struct mbuf *m0;
677
678	i = (ip->ip_off + ip->ip_len) - q->ip_off;
679	if (i < q->ip_len) {
680	q->ip_len -= i;
681	q->ip_off += i;
682	m_adj(dtom(q), i);
683	break;
684	}
685	m0 = dtom(q);
686	q = q->ipf_next;
687	ip_deq(q->ipf_prev);
688	m_freem(m0);
689	}
690
691	insert:
692
693	#ifdef IPDIVERT
694	/*
695	* Any fragment diverting causes the whole packet to divert
696	*/
697	if (frag_divert_port != 0)
698	fp->ipq_divert = frag_divert_port;
699	frag_divert_port = 0;
700	#endif
701
702	/*
703	* Stick new segment in its place;
704	* check for complete reassembly.
705	*/
706	ip_enq(ip, q->ipf_prev);
707	next = 0;
708	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) {
709	if (q->ip_off != next)
710	return (0);
711	next += q->ip_len;
712	}
713	if (q->ipf_prev->ipf_mff & 1)
714	return (0);
715
716	/*
717	* Reassembly is complete. Make sure the packet is a sane size.
718	*/
719	if (next + (IP_VHL_HL(((struct ip *)fp->ipq_next)->ip_vhl) << 2)
720	> IP_MAXPACKET) {
721	ipstat.ips_toolong++;
722	ip_freef(fp);
723	return (0);
724	}
725
726	/*
727	* Concatenate fragments.
728	*/
729	q = fp->ipq_next;
730	m = dtom(q);
731	t = m->m_next;
732	m->m_next = 0;
733	m_cat(m, t);
734	q = q->ipf_next;
735	while (q != (struct ipasfrag *)fp) {
736	t = dtom(q);
737	q = q->ipf_next;
738	m_cat(m, t);
739	}
740
741	#ifdef IPDIVERT
742	/*
743	* Record divert port for packet, if any
744	*/
745	frag_divert_port = fp->ipq_divert;
746	#endif
747
748	/*
749	* Create header for new ip packet by
750	* modifying header of first packet;
751	* dequeue and discard fragment reassembly header.
752	* Make header visible.
753	*/
754	ip = fp->ipq_next;
755	ip->ip_len = next;
756	ip->ipf_mff &= ~1;
757	((struct ip *)ip)->ip_src = fp->ipq_src;
758	((struct ip *)ip)->ip_dst = fp->ipq_dst;
759	remque(fp);
760	nipq--;
761	(void) m_free(dtom(fp));
762	m = dtom(ip);
763	m->m_len += (ip->ip_hl << 2);
764	m->m_data -= (ip->ip_hl << 2);
765	/* some debugging cruft by sklower, below, will go away soon */
766	if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
767	register int plen = 0;
768	for (t = m; m; m = m->m_next)
769	plen += m->m_len;
770	t->m_pkthdr.len = plen;
771	}
772	return ((struct ip *)ip);
773
774	dropfrag:
775	ipstat.ips_fragdropped++;
776	m_freem(m);
777	return (0);
778	}
779
780	/*
781	* Free a fragment reassembly header and all
782	* associated datagrams.
783	*/
784	static void
785	ip_freef(fp)
786	struct ipq *fp;
787	{
788	register struct ipasfrag q, p;
789
790	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) {
791	p = q->ipf_next;
792	ip_deq(q);
793	m_freem(dtom(q));
794	}
795	remque(fp);
796	(void) m_free(dtom(fp));
797	nipq--;
798	}
799
800	/*
801	* Put an ip fragment on a reassembly chain.
802	* Like insque, but pointers in middle of structure.
803	*/
804	static void
805	ip_enq(p, prev)
806	register struct ipasfrag p, prev;
807	{
808
809	p->ipf_prev = prev;
810	p->ipf_next = prev->ipf_next;
811	prev->ipf_next->ipf_prev = p;
812	prev->ipf_next = p;
813	}
814
815	/*
816	* To ip_enq as remque is to insque.
817	*/
818	static void
819	ip_deq(p)
820	register struct ipasfrag *p;
821	{
822
823	p->ipf_prev->ipf_next = p->ipf_next;
824	p->ipf_next->ipf_prev = p->ipf_prev;
825	}
826
827	/*
828	* IP timer processing;
829	* if a timer expires on a reassembly
830	* queue, discard it.
831	*/
832	void
833	ip_slowtimo()
834	{
835	register struct ipq *fp;
836	int s = splnet();
837	int i;
838
839	for (i = 0; i < IPREASS_NHASH; i++) {
840	fp = ipq[i].next;
841	if (fp == 0)
842	continue;
843	while (fp != &ipq[i]) {
844	--fp->ipq_ttl;
845	fp = fp->next;
846	if (fp->prev->ipq_ttl == 0) {
847	ipstat.ips_fragtimeout++;
848	ip_freef(fp->prev);
849	}
850	}
851	}
852	splx(s);
853	}
854
855	/*
856	* Drain off all datagram fragments.
857	*/
858	void
859	ip_drain()
860	{
861	int i;
862
863	for (i = 0; i < IPREASS_NHASH; i++) {
864	while (ipq[i].next != &ipq[i]) {
865	ipstat.ips_fragdropped++;
866	ip_freef(ipq[i].next);
867	}
868	}
869	in_rtqdrain();
870	}
871
872	/*
873	* Do option processing on a datagram,
874	* possibly discarding it if bad options are encountered,
875	* or forwarding it if source-routed.
876	* Returns 1 if packet has been forwarded/freed,
877	* 0 if the packet should be processed further.
878	*/
879	static int
880	ip_dooptions(m)
881	struct mbuf *m;
882	{
883	register struct ip ip = mtod(m, struct ip );
884	register u_char *cp;
885	register struct ip_timestamp *ipt;
886	register struct in_ifaddr *ia;
887	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
888	struct in_addr *sin, dst;
889	n_time ntime;
890
891	dst = ip->ip_dst;
892	cp = (u_char *)(ip + 1);
893	cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
894	for (; cnt > 0; cnt -= optlen, cp += optlen) {
895	opt = cp[IPOPT_OPTVAL];
896	if (opt == IPOPT_EOL)
897	break;
898	if (opt == IPOPT_NOP)
899	optlen = 1;
900	else {
901	optlen = cp[IPOPT_OLEN];
902	if (optlen <= 0 \|\| optlen > cnt) {
903	code = &cp[IPOPT_OLEN] - (u_char *)ip;
904	goto bad;
905	}
906	}
907	switch (opt) {
908
909	default:
910	break;
911
912	/*
913	* Source routing with record.
914	* Find interface with current destination address.
915	* If none on this machine then drop if strictly routed,
916	* or do nothing if loosely routed.
917	* Record interface address and bring up next address
918	* component. If strictly routed make sure next
919	* address is on directly accessible net.
920	*/
921	case IPOPT_LSRR:
922	case IPOPT_SSRR:
923	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
924	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
925	goto bad;
926	}
927	ipaddr.sin_addr = ip->ip_dst;
928	ia = (struct in_ifaddr *)
929	ifa_ifwithaddr((struct sockaddr *)&ipaddr);
930	if (ia == 0) {
931	if (opt == IPOPT_SSRR) {
932	type = ICMP_UNREACH;
933	code = ICMP_UNREACH_SRCFAIL;
934	goto bad;
935	}
936	if (!ip_dosourceroute)
937	goto nosourcerouting;
938	/*
939	* Loose routing, and not at next destination
940	* yet; nothing to do except forward.
941	*/
942	break;
943	}
944	off--; /* 0 origin */
945	if (off > optlen - sizeof(struct in_addr)) {
946	/*
947	* End of source route. Should be for us.
948	*/
949	if (!ip_acceptsourceroute)
950	goto nosourcerouting;
951	save_rte(cp, ip->ip_src);
952	break;
953	}
954
955	if (!ip_dosourceroute) {
956	char buf[4*sizeof "123"];
957
958	nosourcerouting:
959	strcpy(buf, inet_ntoa(ip->ip_dst));
960	log(LOG_WARNING,
961	"attempted source route from %s to %s\n",
962	inet_ntoa(ip->ip_src), buf);
963	type = ICMP_UNREACH;
964	code = ICMP_UNREACH_SRCFAIL;
965	goto bad;
966	}
967
968	/*
969	* locate outgoing interface
970	*/
971	(void)memcpy(&ipaddr.sin_addr, cp + off,
972	sizeof(ipaddr.sin_addr));
973
974	if (opt == IPOPT_SSRR) {
975	#define INA struct in_ifaddr *
976	#define SA struct sockaddr *
977	if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
978	ia = (INA)ifa_ifwithnet((SA)&ipaddr);
979	} else
980	ia = ip_rtaddr(ipaddr.sin_addr);
981	if (ia == 0) {
982	type = ICMP_UNREACH;
983	code = ICMP_UNREACH_SRCFAIL;
984	goto bad;
985	}
986	ip->ip_dst = ipaddr.sin_addr;
987	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
988	sizeof(struct in_addr));
989	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
990	/*
991	* Let ip_intr's mcast routing check handle mcast pkts
992	*/
993	forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
994	break;
995
996	case IPOPT_RR:
997	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
998	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
999	goto bad;
1000	}
1001	/*
1002	* If no space remains, ignore.
1003	*/
1004	off--; /* 0 origin */
1005	if (off > optlen - sizeof(struct in_addr))
1006	break;
1007	(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1008	sizeof(ipaddr.sin_addr));
1009	/*
1010	* locate outgoing interface; if we're the destination,
1011	* use the incoming interface (should be same).
1012	*/
1013	if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1014	(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1015	type = ICMP_UNREACH;
1016	code = ICMP_UNREACH_HOST;
1017	goto bad;
1018	}
1019	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1020	sizeof(struct in_addr));
1021	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1022	break;
1023
1024	case IPOPT_TS:
1025	code = cp - (u_char *)ip;
1026	ipt = (struct ip_timestamp *)cp;
1027	if (ipt->ipt_len < 5)
1028	goto bad;
1029	if (ipt->ipt_ptr > ipt->ipt_len - sizeof (long)) {
1030	if (++ipt->ipt_oflw == 0)
1031	goto bad;
1032	break;
1033	}
1034	sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1035	switch (ipt->ipt_flg) {
1036
1037	case IPOPT_TS_TSONLY:
1038	break;
1039
1040	case IPOPT_TS_TSANDADDR:
1041	if (ipt->ipt_ptr + sizeof(n_time) +
1042	sizeof(struct in_addr) > ipt->ipt_len)
1043	goto bad;
1044	ipaddr.sin_addr = dst;
1045	ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1046	m->m_pkthdr.rcvif);
1047	if (ia == 0)
1048	continue;
1049	(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1050	sizeof(struct in_addr));
1051	ipt->ipt_ptr += sizeof(struct in_addr);
1052	break;
1053
1054	case IPOPT_TS_PRESPEC:
1055	if (ipt->ipt_ptr + sizeof(n_time) +
1056	sizeof(struct in_addr) > ipt->ipt_len)
1057	goto bad;
1058	(void)memcpy(&ipaddr.sin_addr, sin,
1059	sizeof(struct in_addr));
1060	if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1061	continue;
1062	ipt->ipt_ptr += sizeof(struct in_addr);
1063	break;
1064
1065	default:
1066	goto bad;
1067	}
1068	ntime = iptime();
1069	(void)memcpy(cp + ipt->ipt_ptr - 1, &ntime,
1070	sizeof(n_time));
1071	ipt->ipt_ptr += sizeof(n_time);
1072	}
1073	}
1074	if (forward && ipforwarding) {
1075	ip_forward(m, 1);
1076	return (1);
1077	}
1078	return (0);
1079	bad:
1080	ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hdr length */
1081	icmp_error(m, type, code, 0, 0);
1082	ipstat.ips_badoptions++;
1083	return (1);
1084	}
1085
1086	/*
1087	* Given address of next destination (final or next hop),
1088	* return internet address info of interface to be used to get there.
1089	*/
1090	static struct in_ifaddr *
1091	ip_rtaddr(dst)
1092	struct in_addr dst;
1093	{
1094	register struct sockaddr_in *sin;
1095
1096	sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
1097
1098	if (ipforward_rt.ro_rt == 0 \|\| dst.s_addr != sin->sin_addr.s_addr) {
1099	if (ipforward_rt.ro_rt) {
1100	RTFREE(ipforward_rt.ro_rt);
1101	ipforward_rt.ro_rt = 0;
1102	}
1103	sin->sin_family = AF_INET;
1104	sin->sin_len = sizeof(*sin);
1105	sin->sin_addr = dst;
1106
1107	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1108	}
1109	if (ipforward_rt.ro_rt == 0)
1110	return ((struct in_ifaddr *)0);
1111	return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa);
1112	}
1113
1114	/*
1115	* Save incoming source route for use in replies,
1116	* to be picked up later by ip_srcroute if the receiver is interested.
1117	*/
1118	void
1119	save_rte(option, dst)
1120	u_char *option;
1121	struct in_addr dst;
1122	{
1123	unsigned olen;
1124
1125	olen = option[IPOPT_OLEN];
1126	#ifdef DIAGNOSTIC
1127	if (ipprintfs)
1128	printf("save_rte: olen %d\n", olen);
1129	#endif
1130	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1131	return;
1132	bcopy(option, ip_srcrt.srcopt, olen);
1133	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1134	ip_srcrt.dst = dst;
1135	}
1136
1137	/*
1138	* Retrieve incoming source route for use in replies,
1139	* in the same form used by setsockopt.
1140	* The first hop is placed before the options, will be removed later.
1141	*/
1142	struct mbuf *
1143	ip_srcroute()
1144	{
1145	register struct in_addr p, q;
1146	register struct mbuf *m;
1147
1148	if (ip_nhops == 0)
1149	return ((struct mbuf *)0);
1150	m = m_get(M_DONTWAIT, MT_SOOPTS);
1151	if (m == 0)
1152	return ((struct mbuf *)0);
1153
1154	#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1155
1156	/* length is (nhops+1)sizeof(addr) + sizeof(nop + srcrt header) /
1157	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1158	OPTSIZ;
1159	#ifdef DIAGNOSTIC
1160	if (ipprintfs)
1161	printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1162	#endif
1163
1164	/*
1165	* First save first hop for return route
1166	*/
1167	p = &ip_srcrt.route[ip_nhops - 1];
1168	(mtod(m, struct in_addr )) = *p--;
1169	#ifdef DIAGNOSTIC
1170	if (ipprintfs)
1171	printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr));
1172	#endif
1173
1174	/*
1175	* Copy option fields and padding (nop) to mbuf.
1176	*/
1177	ip_srcrt.nop = IPOPT_NOP;
1178	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1179	(void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1180	&ip_srcrt.nop, OPTSIZ);
1181	q = (struct in_addr *)(mtod(m, caddr_t) +
1182	sizeof(struct in_addr) + OPTSIZ);
1183	#undef OPTSIZ
1184	/*
1185	* Record return path as an IP source route,
1186	* reversing the path (pointers are now aligned).
1187	*/
1188	while (p >= ip_srcrt.route) {
1189	#ifdef DIAGNOSTIC
1190	if (ipprintfs)
1191	printf(" %lx", ntohl(q->s_addr));
1192	#endif
1193	q++ = p--;
1194	}
1195	/*
1196	* Last hop goes to final destination.
1197	*/
1198	*q = ip_srcrt.dst;
1199	#ifdef DIAGNOSTIC
1200	if (ipprintfs)
1201	printf(" %lx\n", ntohl(q->s_addr));
1202	#endif
1203	return (m);
1204	}
1205
1206	/*
1207	* Strip out IP options, at higher
1208	* level protocol in the kernel.
1209	* Second argument is buffer to which options
1210	* will be moved, and return value is their length.
1211	* XXX should be deleted; last arg currently ignored.
1212	*/
1213	void
1214	ip_stripoptions(m, mopt)
1215	register struct mbuf *m;
1216	struct mbuf *mopt;
1217	{
1218	register int i;
1219	struct ip ip = mtod(m, struct ip );
1220	register caddr_t opts;
1221	int olen;
1222
1223	olen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
1224	opts = (caddr_t)(ip + 1);
1225	i = m->m_len - (sizeof (struct ip) + olen);
1226	bcopy(opts + olen, opts, (unsigned)i);
1227	m->m_len -= olen;
1228	if (m->m_flags & M_PKTHDR)
1229	m->m_pkthdr.len -= olen;
1230	ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1231	}
1232
1233	u_char inetctlerrmap[PRC_NCMDS] = {
1234	0, 0, 0, 0,
1235	0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1236	EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1237	EMSGSIZE, EHOSTUNREACH, 0, 0,
1238	0, 0, 0, 0,
1239	ENOPROTOOPT
1240	};
1241
1242	/*
1243	* Forward a packet. If some error occurs return the sender
1244	* an icmp packet. Note we can't always generate a meaningful
1245	* icmp message because icmp doesn't have a large enough repertoire
1246	* of codes and types.
1247	*
1248	* If not forwarding, just drop the packet. This could be confusing
1249	* if ipforwarding was zero but some routing protocol was advancing
1250	* us as a gateway to somewhere. However, we must let the routing
1251	* protocol deal with that.
1252	*
1253	* The srcrt parameter indicates whether the packet is being forwarded
1254	* via a source route.
1255	*/
1256	static void
1257	ip_forward(m, srcrt)
1258	struct mbuf *m;
1259	int srcrt;
1260	{
1261	register struct ip ip = mtod(m, struct ip );
1262	register struct sockaddr_in *sin;
1263	register struct rtentry *rt;
1264	int error, type = 0, code = 0;
1265	struct mbuf *mcopy;
1266	n_long dest;
1267	struct ifnet *destifp;
1268
1269	dest = 0;
1270	#ifdef DIAGNOSTIC
1271	if (ipprintfs)
1272	printf("forward: src %lx dst %lx ttl %x\n",
1273	ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1274	#endif
1275
1276
1277	if (m->m_flags & M_BCAST \|\| in_canforward(ip->ip_dst) == 0) {
1278	ipstat.ips_cantforward++;
1279	m_freem(m);
1280	return;
1281	}
1282	HTONS(ip->ip_id);
1283	if (ip->ip_ttl <= IPTTLDEC) {
1284	icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1285	return;
1286	}
1287	ip->ip_ttl -= IPTTLDEC;
1288
1289	sin = (struct sockaddr_in *)&ipforward_rt.ro_dst;
1290	if ((rt = ipforward_rt.ro_rt) == 0 \|\|
1291	ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
1292	if (ipforward_rt.ro_rt) {
1293	RTFREE(ipforward_rt.ro_rt);
1294	ipforward_rt.ro_rt = 0;
1295	}
1296	sin->sin_family = AF_INET;
1297	sin->sin_len = sizeof(*sin);
1298	sin->sin_addr = ip->ip_dst;
1299
1300	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1301	if (ipforward_rt.ro_rt == 0) {
1302	icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1303	return;
1304	}
1305	rt = ipforward_rt.ro_rt;
1306	}
1307
1308	/*
1309	* Save at most 64 bytes of the packet in case
1310	* we need to generate an ICMP message to the src.
1311	*/
1312	mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
1313
1314	/*
1315	* If forwarding packet using same interface that it came in on,
1316	* perhaps should send a redirect to sender to shortcut a hop.
1317	* Only send redirect if source is sending directly to us,
1318	* and if packet was not source routed (or has any options).
1319	* Also, don't send redirect if forwarding using a default route
1320	* or a route modified by a redirect.
1321	*/
1322	#define satosin(sa) ((struct sockaddr_in *)(sa))
1323	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1324	(rt->rt_flags & (RTF_DYNAMIC\|RTF_MODIFIED)) == 0 &&
1325	satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
1326	ipsendredirects && !srcrt) {
1327	#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1328	u_long src = ntohl(ip->ip_src.s_addr);
1329
1330	if (RTA(rt) &&
1331	(src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1332	if (rt->rt_flags & RTF_GATEWAY)
1333	dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1334	else
1335	dest = ip->ip_dst.s_addr;
1336	/* Router requirements says to only send host redirects */
1337	type = ICMP_REDIRECT;
1338	code = ICMP_REDIRECT_HOST;
1339	#ifdef DIAGNOSTIC
1340	if (ipprintfs)
1341	printf("redirect (%d) to %lx\n", code, (u_long)dest);
1342	#endif
1343	}
1344	}
1345
1346	error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1347	IP_FORWARDING, 0);
1348	if (error)
1349	ipstat.ips_cantforward++;
1350	else {
1351	ipstat.ips_forward++;
1352	if (type)
1353	ipstat.ips_redirectsent++;
1354	else {
1355	if (mcopy)
1356	m_freem(mcopy);
1357	return;
1358	}
1359	}
1360	if (mcopy == NULL)
1361	return;
1362	destifp = NULL;
1363
1364	switch (error) {
1365
1366	case 0: /* forwarded, but need redirect */
1367	/* type, code set above */
1368	break;
1369
1370	case ENETUNREACH: /* shouldn't happen, checked above */
1371	case EHOSTUNREACH:
1372	case ENETDOWN:
1373	case EHOSTDOWN:
1374	default:
1375	type = ICMP_UNREACH;
1376	code = ICMP_UNREACH_HOST;
1377	break;
1378
1379	case EMSGSIZE:
1380	type = ICMP_UNREACH;
1381	code = ICMP_UNREACH_NEEDFRAG;
1382	if (ipforward_rt.ro_rt)
1383	destifp = ipforward_rt.ro_rt->rt_ifp;
1384	ipstat.ips_cantfrag++;
1385	break;
1386
1387	case ENOBUFS:
1388	type = ICMP_SOURCEQUENCH;
1389	code = 0;
1390	break;
1391	}
1392	icmp_error(mcopy, type, code, dest, destifp);
1393	}
1394
1395	void
1396	ip_savecontrol(inp, mp, ip, m)
1397	register struct inpcb *inp;
1398	register struct mbuf **mp;
1399	register struct ip *ip;
1400	register struct mbuf *m;
1401	{
1402	if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1403	struct timeval tv;
1404
1405	microtime(&tv);
1406	*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1407	SCM_TIMESTAMP, SOL_SOCKET);
1408	if (*mp)
1409	mp = &(*mp)->m_next;
1410	}
1411	if (inp->inp_flags & INP_RECVDSTADDR) {
1412	*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1413	sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1414	if (*mp)
1415	mp = &(*mp)->m_next;
1416	}
1417	#ifdef notyet
1418	/* XXX
1419	* Moving these out of udp_input() made them even more broken
1420	* than they already were.
1421	*/
1422	/* options were tossed already */
1423	if (inp->inp_flags & INP_RECVOPTS) {
1424	*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1425	sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1426	if (*mp)
1427	mp = &(*mp)->m_next;
1428	}
1429	/* ip_srcroute doesn't do what we want here, need to fix */
1430	if (inp->inp_flags & INP_RECVRETOPTS) {
1431	*mp = sbcreatecontrol((caddr_t) ip_srcroute(),
1432	sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1433	if (*mp)
1434	mp = &(*mp)->m_next;
1435	}
1436	#endif
1437	if (inp->inp_flags & INP_RECVIF) {
1438	struct sockaddr_dl sdl;
1439
1440	sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1441	sdl.sdl_family = AF_LINK;
1442	sdl.sdl_index = m->m_pkthdr.rcvif ?
1443	m->m_pkthdr.rcvif->if_index : 0;
1444	sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1445	*mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1446	IP_RECVIF, IPPROTO_IP);
1447	if (*mp)
1448	mp = &(*mp)->m_next;
1449	}
1450	}
1451
1452	int
1453	ip_rsvp_init(struct socket *so)
1454	{
1455	if (so->so_type != SOCK_RAW \|\|
1456	so->so_proto->pr_protocol != IPPROTO_RSVP)
1457	return EOPNOTSUPP;
1458
1459	if (ip_rsvpd != NULL)
1460	return EADDRINUSE;
1461
1462	ip_rsvpd = so;
1463	/*
1464	* This may seem silly, but we need to be sure we don't over-increment
1465	* the RSVP counter, in case something slips up.
1466	*/
1467	if (!ip_rsvp_on) {
1468	ip_rsvp_on = 1;
1469	rsvp_on++;
1470	}
1471
1472	return 0;
1473	}
1474
1475	int
1476	ip_rsvp_done(void)
1477	{
1478	ip_rsvpd = NULL;
1479	/*
1480	* This may seem silly, but we need to be sure we don't over-decrement
1481	* the RSVP counter, in case something slips up.
1482	*/
1483	if (ip_rsvp_on) {
1484	ip_rsvp_on = 0;
1485	rsvp_on--;
1486	}
1487	return 0;
1488	}

Note: See TracBrowser for help on using the repository browser.

Download in other formats: