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ip_input.c @ 0e16fa45

Last change on this file since 0e16fa45 was cb68253, checked in by Sebastian Huber <sebastian.huber@…>, on 09/07/18 at 04:19:02

network: Use kernel/user space header files

Add and use <machine/rtems-bsd-kernel-space.h> and
<machine/rtems-bsd-user-space.h> similar to the libbsd to avoid command
line defines and defines scattered throught the code base.

Simplify cpukit/libnetworking/Makefile.am.

Update #3375.

Property mode set to 100644

File size: 36.3 KB

Line
1	#include <machine/rtems-bsd-kernel-space.h>
2
3	/*
4	* Copyright (c) 1982, 1986, 1988, 1993
5	* The Regents of the University of California. All rights reserved.
6	*
7	* Redistribution and use in source and binary forms, with or without
8	* modification, are permitted provided that the following conditions
9	* are met:
10	* 1. Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.
12	* 2. Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.
15	* 4. Neither the name of the University nor the names of its contributors
16	* may be used to endorse or promote products derived from this software
17	* without specific prior written permission.
18	*
19	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29	* SUCH DAMAGE.
30	*
31	* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
32	* $ANA: ip_input.c,v 1.5 1996/09/18 14:34:59 wollman Exp $
33	*/
34
35	#ifdef HAVE_CONFIG_H
36	#include "config.h"
37	#endif
38
39	#define _IP_VHL
40
41	#include "opt_ipfw.h"
42
43	#include <stddef.h>
44	#include <inttypes.h>
45
46	#include <sys/param.h>
47	#include <sys/systm.h>
48	#include <sys/mbuf.h>
49	#include <sys/malloc.h>
50	#include <sys/domain.h>
51	#include <sys/protosw.h>
52	#include <sys/socket.h>
53	#include <errno.h>
54	#include <sys/time.h>
55	#include <sys/kernel.h>
56	#include <sys/syslog.h>
57	#include <sys/sysctl.h>
58
59	#include <net/if.h>
60	#include <net/if_dl.h>
61	#include <net/route.h>
62	#include <net/netisr.h>
63
64	#include <netinet/in.h>
65	#include <rtems/rtems_netinet_in.h>
66	#include <netinet/in_systm.h>
67	#include <netinet/in_var.h>
68	#include <netinet/ip.h>
69	#include <netinet/in_pcb.h>
70	#include <netinet/ip_var.h>
71	#include <netinet/ip_icmp.h>
72	#include <machine/in_cksum.h>
73
74	#include <sys/socketvar.h>
75
76	#ifdef IPFIREWALL
77	#include <netinet/ip_fw.h>
78	#endif
79
80	int rsvp_on = 0;
81	static int ip_rsvp_on;
82	struct socket *ip_rsvpd;
83
84	int ipforwarding = 0;
85	SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
86	&ipforwarding, 0, "Enable IP forwarding between interfaces");
87
88	static int ipsendredirects = 1; /* XXX */
89	SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
90	&ipsendredirects, 0, "Enable sending IP redirects");
91
92	int ip_defttl = IPDEFTTL;
93	SYSCTL_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
94	&ip_defttl, 0, "Maximum TTL on IP packets");
95
96	static int ip_dosourceroute = 0;
97	SYSCTL_INT(_net_inet_ip, IPCTL_SOURCEROUTE, sourceroute, CTLFLAG_RW,
98	&ip_dosourceroute, 0, "");
99
100	static int ip_acceptsourceroute = 0;
101	SYSCTL_INT(_net_inet_ip, IPCTL_ACCEPTSOURCEROUTE, accept_sourceroute,
102	CTLFLAG_RW, &ip_acceptsourceroute, 0, "");
103	#ifdef DIAGNOSTIC
104	static int ipprintfs = 0;
105	#endif
106
107	extern struct domain inetdomain;
108	extern struct protosw inetsw[];
109	u_char ip_protox[IPPROTO_MAX];
110	static int ipqmaxlen = IFQ_MAXLEN;
111	struct in_ifaddr in_ifaddr; / first inet address */
112	struct ifqueue ipintrq;
113	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RD,
114	&ipintrq.ifq_maxlen, 0, "");
115	SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
116	&ipintrq.ifq_drops, 0,
117	"Number of packets dropped from the IP input queue");
118
119	struct ipstat ipstat;
120
121	/* Packet reassembly stuff */
122	#define IPREASS_NHASH_LOG2 6
123	#define IPREASS_NHASH (1 << IPREASS_NHASH_LOG2)
124	#define IPREASS_HMASK (IPREASS_NHASH - 1)
125	#define IPREASS_HASH(x,y) \
126	(((((x) & 0xF) \| ((((x) >> 8) & 0xF) << 4)) ^ (y)) & IPREASS_HMASK)
127
128	static struct ipq ipq[IPREASS_NHASH];
129	static int nipq = 0; /* total # of reass queues */
130	static int maxnipq;
131
132	#ifdef IPCTL_DEFMTU
133	SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
134	&ip_mtu, 0, "Default MTU");
135	#endif
136
137	#if !defined(COMPAT_IPFW) \|\| COMPAT_IPFW == 1
138	#undef COMPAT_IPFW
139	#define COMPAT_IPFW 1
140	#else
141	#undef COMPAT_IPFW
142	#endif
143
144	#ifdef COMPAT_IPFW
145	/* Firewall hooks */
146	ip_fw_chk_t *ip_fw_chk_ptr;
147	ip_fw_ctl_t *ip_fw_ctl_ptr;
148
149	/* IP Network Address Translation (NAT) hooks */
150	ip_nat_t *ip_nat_ptr;
151	ip_nat_ctl_t *ip_nat_ctl_ptr;
152	#endif
153
154	/*
155	* We need to save the IP options in case a protocol wants to respond
156	* to an incoming packet over the same route if the packet got here
157	* using IP source routing. This allows connection establishment and
158	* maintenance when the remote end is on a network that is not known
159	* to us.
160	*/
161	static int ip_nhops = 0;
162	static struct ip_srcrt {
163	struct in_addr dst; /* final destination */
164	char nop; /* one NOP to align */
165	char srcopt[IPOPT_OFFSET + 1]; /* OPTVAL, OLEN and OFFSET */
166	struct in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
167	} ip_srcrt;
168
169	#ifdef IPDIVERT
170	/*
171	* Shared variable between ip_input() and ip_reass() to communicate
172	* about which packets, once assembled from fragments, get diverted,
173	* and to which port.
174	*/
175	static u_short frag_divert_port;
176	#endif
177
178	static void save_rte(u_char *, struct in_addr);
179	static void ip_deq(struct ipasfrag *);
180	static int ip_dooptions(struct mbuf *);
181	static void ip_enq(struct ipasfrag , struct ipasfrag );
182	static void ip_forward(struct mbuf *, int);
183	static void ip_freef(struct ipq *);
184	static struct ip *
185	ip_reass(struct ipasfrag , struct ipq , struct ipq *);
186	static struct in_ifaddr *
187	ip_rtaddr(struct in_addr);
188	void ipintr(void);
189	/*
190	* IP initialization: fill in IP protocol switch table.
191	* All protocols not implemented in kernel go to raw IP protocol handler.
192	*/
193	void
194	ip_init(void)
195	{
196	register struct protosw *pr;
197	register int i;
198
199	pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
200	if (pr == NULL)
201	panic("ip_init: PF_INET not found");
202
203	/* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
204	for (i = 0; i < IPPROTO_MAX; i++)
205	ip_protox[i] = pr - inetsw;
206	/*
207	* Cycle through IP protocols and put them into the appropriate place
208	* in ip_protox[].
209	*/
210	for (pr = inetdomain.dom_protosw;
211	pr < inetdomain.dom_protoswNPROTOSW; pr++)
212	if (pr->pr_domain->dom_family == PF_INET &&
213	pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
214	ip_protox[pr->pr_protocol] = pr - inetsw;
215	}
216
217	for (i = 0; i < IPREASS_NHASH; i++)
218	ipq[i].next = ipq[i].prev = &ipq[i];
219
220	maxnipq = nmbclusters/4;
221
222	/* Initialize various other remaining things. */
223	ip_id = rtems_bsdnet_seconds_since_boot() & 0xffff;
224	ipintrq.ifq_maxlen = ipqmaxlen;
225	#ifdef IPFIREWALL
226	ip_fw_init();
227	#endif
228	#ifdef IPNAT
229	ip_nat_init();
230	#endif
231
232	}
233
234	static struct sockaddr_in ipaddr = { sizeof(ipaddr), AF_INET, 0, {0}, {0} };
235	static struct route ipforward_rt;
236
237	/*
238	* Ip input routine. Checksum and byte swap header. If fragmented
239	* try to reassemble. Process options. Pass to next level.
240	*/
241	void
242	ip_input(struct mbuf *m)
243	{
244	struct ip *ip = NULL;
245	struct ipq *fp;
246	struct in_ifaddr *ia = NULL;
247	int i, hlen;
248	u_short sum;
249
250	#ifdef DIAGNOSTIC
251	if ((m->m_flags & M_PKTHDR) == 0)
252	panic("ip_input no HDR");
253	#endif
254	/*
255	* If no IP addresses have been set yet but the interfaces
256	* are receiving, can't do anything with incoming packets yet.
257	*/
258	if (in_ifaddr == NULL)
259	goto bad;
260	ipstat.ips_total++;
261
262	if (m->m_pkthdr.len < sizeof(struct ip))
263	goto tooshort;
264
265	#if defined(DIAGNOSTIC) && defined(ORIGINAL_FREEBSD_CODE)
266	if (m->m_len < sizeof(struct ip))
267	panic("ipintr mbuf too short");
268	#endif
269
270	if (m->m_len < sizeof (struct ip) &&
271	(m = m_pullup(m, sizeof (struct ip))) == NULL) {
272	ipstat.ips_toosmall++;
273	return;
274	}
275	ip = mtod(m, struct ip *);
276
277	#ifdef _IP_VHL
278	if (IP_VHL_V(ip->ip_vhl) != IPVERSION) {
279	#else
280	if (ip->ip_v != IPVERSION) {
281	#endif
282	ipstat.ips_badvers++;
283	goto bad;
284	}
285
286	#ifdef _IP_VHL
287	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
288	#else
289	hlen = ip->ip_hl << 2;
290	#endif
291	if (hlen < sizeof(struct ip)) { /* minimum header length */
292	ipstat.ips_badhlen++;
293	goto bad;
294	}
295	if (hlen > m->m_len) {
296	if ((m = m_pullup(m, hlen)) == NULL) {
297	ipstat.ips_badhlen++;
298	return;
299	}
300	ip = mtod(m, struct ip *);
301	}
302	if (hlen == sizeof(struct ip)) {
303	sum = in_cksum_hdr(ip);
304	} else {
305	sum = in_cksum(m, hlen);
306	}
307	if (sum) {
308	ipstat.ips_badsum++;
309	goto bad;
310	}
311
312	/*
313	* Convert fields to host representation.
314	*/
315	ip->ip_len = ntohs(ip->ip_len);
316	if (ip->ip_len < hlen) {
317	ipstat.ips_badlen++;
318	goto bad;
319	}
320	NTOHS(ip->ip_id);
321	ip->ip_off = ntohs(ip->ip_off);
322
323	/*
324	* Check that the amount of data in the buffers
325	* is as at least much as the IP header would have us expect.
326	* Trim mbufs if longer than we expect.
327	* Drop packet if shorter than we expect.
328	*/
329	if (m->m_pkthdr.len < ip->ip_len) {
330	tooshort:
331	ipstat.ips_tooshort++;
332	goto bad;
333	}
334	if (m->m_pkthdr.len > ip->ip_len) {
335	if (m->m_len == m->m_pkthdr.len) {
336	m->m_len = ip->ip_len;
337	m->m_pkthdr.len = ip->ip_len;
338	} else
339	m_adj(m, ip->ip_len - m->m_pkthdr.len);
340	}
341	/*
342	* IpHack's section.
343	* Right now when no processing on packet has done
344	* and it is still fresh out of network we do our black
345	* deals with it.
346	* - Firewall: deny/allow/divert
347	* - Xlate: translate packet's addr/port (NAT).
348	* - Wrap: fake packet's addr/port <unimpl.>
349	* - Encapsulate: put it in another IP and send out. <unimp.>
350	*/
351
352	#ifdef COMPAT_IPFW
353	if (ip_fw_chk_ptr) {
354	#ifdef IPDIVERT
355	u_short port;
356
357	port = (*ip_fw_chk_ptr)(&ip, hlen, NULL, ip_divert_ignore, &m);
358	ip_divert_ignore = 0;
359	if (port) { /* Divert packet */
360	frag_divert_port = port;
361	goto ours;
362	}
363	#else
364	/* If ipfw says divert, we have to just drop packet */
365	if ((*ip_fw_chk_ptr)(&ip, hlen, NULL, 0, &m)) {
366	m_freem(m);
367	m = NULL;
368	}
369	#endif
370	if (!m)
371	return;
372	}
373
374	if (ip_nat_ptr && !(*ip_nat_ptr)(&ip, &m, m->m_pkthdr.rcvif, IP_NAT_IN))
375	return;
376	#endif
377
378	/*
379	* Process options and, if not destined for us,
380	* ship it on. ip_dooptions returns 1 when an
381	* error was detected (causing an icmp message
382	* to be sent and the original packet to be freed).
383	*/
384	ip_nhops = 0; /* for source routed packets */
385	if (hlen > sizeof (struct ip) && ip_dooptions(m))
386	return;
387
388	/* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
389	* matter if it is destined to another node, or whether it is
390	* a multicast one, RSVP wants it! and prevents it from being forwarded
391	* anywhere else. Also checks if the rsvp daemon is running before
392	* grabbing the packet.
393	*/
394	if (rsvp_on && ip->ip_p==IPPROTO_RSVP)
395	goto ours;
396
397	/*
398	* Check our list of addresses, to see if the packet is for us.
399	*/
400	for (ia = in_ifaddr; ia; ia = ia->ia_next) {
401	#define satosin(sa) ((struct sockaddr_in *)(sa))
402
403	if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr)
404	goto ours;
405	#ifdef BOOTP_COMPAT
406	if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
407	goto ours;
408	#endif
409	if (ia->ia_ifp && ia->ia_ifp->if_flags & IFF_BROADCAST) {
410	if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
411	ip->ip_dst.s_addr)
412	goto ours;
413	if (ip->ip_dst.s_addr == ia->ia_netbroadcast.s_addr)
414	goto ours;
415	}
416	}
417	if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
418	struct in_multi *inm;
419	if (ip_mrouter) {
420	/*
421	* If we are acting as a multicast router, all
422	* incoming multicast packets are passed to the
423	* kernel-level multicast forwarding function.
424	* The packet is returned (relatively) intact; if
425	* ip_mforward() returns a non-zero value, the packet
426	* must be discarded, else it may be accepted below.
427	*
428	* (The IP ident field is put in the same byte order
429	* as expected when ip_mforward() is called from
430	* ip_output().)
431	*/
432	ip->ip_id = htons(ip->ip_id);
433	if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
434	ipstat.ips_cantforward++;
435	m_freem(m);
436	return;
437	}
438	ip->ip_id = ntohs(ip->ip_id);
439
440	/*
441	* The process-level routing daemon needs to receive
442	* all multicast IGMP packets, whether or not this
443	* host belongs to their destination groups.
444	*/
445	if (ip->ip_p == IPPROTO_IGMP)
446	goto ours;
447	ipstat.ips_forward++;
448	}
449	/*
450	* See if we belong to the destination multicast group on the
451	* arrival interface.
452	*/
453	IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
454	if (inm == NULL) {
455	ipstat.ips_cantforward++;
456	m_freem(m);
457	return;
458	}
459	goto ours;
460	}
461	if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
462	goto ours;
463	if (ip->ip_dst.s_addr == INADDR_ANY)
464	goto ours;
465
466	/*
467	* Not for us; forward if possible and desirable.
468	*/
469	if (ipforwarding == 0) {
470	ipstat.ips_cantforward++;
471	m_freem(m);
472	} else {
473	ip_forward(m, 0);
474	}
475	return;
476
477	ours:
478
479	/*
480	* If offset or IP_MF are set, must reassemble.
481	* Otherwise, nothing need be done.
482	* (We could look in the reassembly queue to see
483	* if the packet was previously fragmented,
484	* but it's not worth the time; just let them time out.)
485	*/
486	if (ip->ip_off &~ (IP_DF \| IP_RF)) {
487	if (m->m_flags & M_EXT) { /* XXX */
488	if ((m = m_pullup(m, sizeof (struct ip))) == 0) {
489	ipstat.ips_toosmall++;
490	#ifdef IPDIVERT
491	frag_divert_port = 0;
492	#endif
493	return;
494	}
495	ip = mtod(m, struct ip *);
496	}
497	sum = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
498	/*
499	* Look for queue of fragments
500	* of this datagram.
501	*/
502	for (fp = ipq[sum].next; fp != &ipq[sum]; fp = fp->next)
503	if (ip->ip_id == fp->ipq_id &&
504	ip->ip_src.s_addr == fp->ipq_src.s_addr &&
505	ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
506	ip->ip_p == fp->ipq_p)
507	goto found;
508
509	fp = 0;
510
511	/* check if there's a place for the new queue */
512	if (nipq > maxnipq) {
513	/*
514	* drop something from the tail of the current queue
515	* before proceeding further
516	*/
517	if (ipq[sum].prev == &ipq[sum]) { /* gak */
518	for (i = 0; i < IPREASS_NHASH; i++) {
519	if (ipq[i].prev != &ipq[i]) {
520	ip_freef(ipq[i].prev);
521	break;
522	}
523	}
524	} else
525	ip_freef(ipq[sum].prev);
526	}
527	found:
528	/*
529	* Adjust ip_len to not reflect header,
530	* set ip_mff if more fragments are expected,
531	* convert offset of this to bytes.
532	*/
533	ip->ip_len -= hlen;
534	((struct ipasfrag *)ip)->ipf_mff &= ~1;
535	if (ip->ip_off & IP_MF)
536	((struct ipasfrag *)ip)->ipf_mff \|= 1;
537	ip->ip_off <<= 3;
538
539	/*
540	* If datagram marked as having more fragments
541	* or if this is not the first fragment,
542	* attempt reassembly; if it succeeds, proceed.
543	*/
544	if (((struct ipasfrag *)ip)->ipf_mff & 1 \|\| ip->ip_off) {
545	ipstat.ips_fragments++;
546	ip = ip_reass((struct ipasfrag *)ip, fp, &ipq[sum]);
547	if (ip == 0)
548	return;
549	ipstat.ips_reassembled++;
550	m = dtom(ip);
551	#ifdef IPDIVERT
552	if (frag_divert_port) {
553	ip->ip_len += hlen;
554	HTONS(ip->ip_len);
555	HTONS(ip->ip_off);
556	HTONS(ip->ip_id);
557	ip->ip_sum = 0;
558	ip->ip_sum = in_cksum_hdr(ip);
559	NTOHS(ip->ip_id);
560	NTOHS(ip->ip_off);
561	NTOHS(ip->ip_len);
562	ip->ip_len -= hlen;
563	}
564	#endif
565	} else
566	if (fp)
567	ip_freef(fp);
568	} else
569	ip->ip_len -= hlen;
570
571	#ifdef IPDIVERT
572	/*
573	* Divert reassembled packets to the divert protocol if required
574	*/
575	if (frag_divert_port) {
576	ipstat.ips_delivered++;
577	ip_divert_port = frag_divert_port;
578	frag_divert_port = 0;
579	(*inetsw[ip_protox[IPPROTO_DIVERT]].pr_input)(m, hlen);
580	return;
581	}
582
583	/* Don't let packets divert themselves */
584	if (ip->ip_p == IPPROTO_DIVERT) {
585	ipstat.ips_noproto++;
586	goto bad;
587	}
588	#endif
589
590	/*
591	* Switch out to protocol's input routine.
592	*/
593	ipstat.ips_delivered++;
594
595	(*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
596	return;
597	bad:
598	m_freem(m);
599	}
600
601	/*
602	* IP software interrupt routine - to go away sometime soon
603	*/
604	void
605	ipintr(void)
606	{
607	int s;
608	struct mbuf *m;
609
610	while(1) {
611	s = splimp();
612	IF_DEQUEUE(&ipintrq, m);
613	splx(s);
614	if (m == 0)
615	return;
616	ip_input(m);
617	}
618	}
619
620	NETISR_SET(NETISR_IP, ipintr);
621
622	/*
623	* Take incoming datagram fragment and try to
624	* reassemble it into whole datagram. If a chain for
625	* reassembly of this datagram already exists, then it
626	* is given as fp; otherwise have to make a chain.
627	*/
628	static struct ip *
629	ip_reass(struct ipasfrag ip, struct ipq fp, struct ipq *where)
630	{
631	register struct mbuf *m = dtom(ip);
632	register struct ipasfrag *q;
633	struct mbuf *t;
634	int hlen = ip->ip_hl << 2;
635	int i;
636	int32_t next;
637
638	/*
639	* Presence of header sizes in mbufs
640	* would confuse code below.
641	*/
642	m->m_data += hlen;
643	m->m_len -= hlen;
644
645	/*
646	* If first fragment to arrive, create a reassembly queue.
647	*/
648	if (fp == NULL) {
649	if ((t = m_get(M_DONTWAIT, MT_FTABLE)) == NULL)
650	goto dropfrag;
651	fp = mtod(t, struct ipq *);
652	insque(fp, where);
653	nipq++;
654	fp->ipq_ttl = IPFRAGTTL;
655	fp->ipq_p = ip->ip_p;
656	fp->ipq_id = ip->ip_id;
657	fp->ipq_next = fp->ipq_prev = (struct ipasfrag *)fp;
658	fp->ipq_src = ((struct ip *)ip)->ip_src;
659	fp->ipq_dst = ((struct ip *)ip)->ip_dst;
660	#ifdef IPDIVERT
661	fp->ipq_divert = 0;
662	#endif
663	q = (struct ipasfrag *)fp;
664	goto insert;
665	}
666
667	/*
668	* Find a segment which begins after this one does.
669	*/
670	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next)
671	if (q->ip_off > ip->ip_off)
672	break;
673
674	/*
675	* If there is a preceding segment, it may provide some of
676	* our data already. If so, drop the data from the incoming
677	* segment. If it provides all of our data, drop us.
678	*/
679	if (q->ipf_prev != (struct ipasfrag *)fp) {
680	i = q->ipf_prev->ip_off + q->ipf_prev->ip_len - ip->ip_off;
681	if (i > 0) {
682	if (i >= ip->ip_len)
683	goto dropfrag;
684	m_adj(dtom(ip), i);
685	ip->ip_off += i;
686	ip->ip_len -= i;
687	}
688	}
689
690	/*
691	* While we overlap succeeding segments trim them or,
692	* if they are completely covered, dequeue them.
693	*/
694	while (q != (struct ipasfrag *)fp && ip->ip_off + ip->ip_len > q->ip_off) {
695	struct mbuf *m0;
696
697	i = (ip->ip_off + ip->ip_len) - q->ip_off;
698	if (i < q->ip_len) {
699	q->ip_len -= i;
700	q->ip_off += i;
701	m_adj(dtom(q), i);
702	break;
703	}
704	m0 = dtom(q);
705	q = q->ipf_next;
706	ip_deq(q->ipf_prev);
707	m_freem(m0);
708	}
709
710	insert:
711
712	#ifdef IPDIVERT
713	/*
714	* Any fragment diverting causes the whole packet to divert
715	*/
716	if (frag_divert_port != 0)
717	fp->ipq_divert = frag_divert_port;
718	frag_divert_port = 0;
719	#endif
720
721	/*
722	* Stick new segment in its place;
723	* check for complete reassembly.
724	*/
725	ip_enq(ip, q->ipf_prev);
726	next = 0;
727	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = q->ipf_next) {
728	if (q->ip_off != next)
729	return (0);
730	next += q->ip_len;
731	}
732	if (q->ipf_prev->ipf_mff & 1)
733	return (0);
734
735	/*
736	* Reassembly is complete. Make sure the packet is a sane size.
737	*/
738	#ifdef _IP_VHL
739	if (next + (IP_VHL_HL(((struct ip *)fp->ipq_next)->ip_vhl) << 2)
740	#else
741	if (next + ((((struct ip *)fp->ipq_next)->ip_hl) << 2)
742	#endif
743	> IP_MAXPACKET) {
744	ipstat.ips_toolong++;
745	ip_freef(fp);
746	return (0);
747	}
748
749	/*
750	* Concatenate fragments.
751	*/
752	q = fp->ipq_next;
753	m = dtom(q);
754	t = m->m_next;
755	m->m_next = NULL;
756	m_cat(m, t);
757	q = q->ipf_next;
758	while (q != (struct ipasfrag *)fp) {
759	t = dtom(q);
760	q = q->ipf_next;
761	m_cat(m, t);
762	}
763
764	#ifdef IPDIVERT
765	/*
766	* Record divert port for packet, if any
767	*/
768	frag_divert_port = fp->ipq_divert;
769	#endif
770
771	/*
772	* Create header for new ip packet by modifying header of first
773	* packet; dequeue and discard fragment reassembly header.
774	* Make header visible.
775	*/
776	ip = fp->ipq_next;
777	ip->ip_len = next;
778	ip->ipf_mff &= ~1;
779	((struct ip *)ip)->ip_src = fp->ipq_src;
780	((struct ip *)ip)->ip_dst = fp->ipq_dst;
781	remque(fp);
782	nipq--;
783	(void) m_free(dtom(fp));
784	m = dtom(ip);
785	m->m_len += (ip->ip_hl << 2);
786	m->m_data -= (ip->ip_hl << 2);
787	/* some debugging cruft by sklower, below, will go away soon */
788	if (m->m_flags & M_PKTHDR) { /* XXX this should be done elsewhere */
789	register int plen = 0;
790	for (t = m; m; m = m->m_next)
791	plen += m->m_len;
792	t->m_pkthdr.len = plen;
793	}
794	return ((struct ip *)ip);
795
796	dropfrag:
797	ipstat.ips_fragdropped++;
798	m_freem(m);
799	return (0);
800	}
801
802	/*
803	* Free a fragment reassembly header and all
804	* associated datagrams.
805	*/
806	static void
807	ip_freef(struct ipq *fp)
808	{
809	register struct ipasfrag q, p;
810
811	for (q = fp->ipq_next; q != (struct ipasfrag *)fp; q = p) {
812	p = q->ipf_next;
813	ip_deq(q);
814	m_freem(dtom(q));
815	}
816	remque(fp);
817	(void) m_free(dtom(fp));
818	nipq--;
819	}
820
821	/*
822	* Put an ip fragment on a reassembly chain.
823	* Like insque, but pointers in middle of structure.
824	*/
825	static void
826	ip_enq(struct ipasfrag p, struct ipasfrag prev)
827	{
828
829	p->ipf_prev = prev;
830	p->ipf_next = prev->ipf_next;
831	prev->ipf_next->ipf_prev = p;
832	prev->ipf_next = p;
833	}
834
835	/*
836	* To ip_enq as remque is to insque.
837	*/
838	static void
839	ip_deq(struct ipasfrag *p)
840	{
841
842	p->ipf_prev->ipf_next = p->ipf_next;
843	p->ipf_next->ipf_prev = p->ipf_prev;
844	}
845
846	/*
847	* IP timer processing;
848	* if a timer expires on a reassembly
849	* queue, discard it.
850	*/
851	void
852	ip_slowtimo(void)
853	{
854	register struct ipq *fp;
855	int s = splnet();
856	int i;
857
858	for (i = 0; i < IPREASS_NHASH; i++) {
859	fp = ipq[i].next;
860	if (fp == 0)
861	continue;
862	while (fp != &ipq[i]) {
863	--fp->ipq_ttl;
864	fp = fp->next;
865	if (fp->prev->ipq_ttl == 0) {
866	ipstat.ips_fragtimeout++;
867	ip_freef(fp->prev);
868	}
869	}
870	}
871	splx(s);
872	}
873
874	/*
875	* Drain off all datagram fragments.
876	*/
877	void
878	ip_drain(void)
879	{
880	int i;
881
882	for (i = 0; i < IPREASS_NHASH; i++) {
883	while (ipq[i].next != &ipq[i]) {
884	ipstat.ips_fragdropped++;
885	ip_freef(ipq[i].next);
886	}
887	}
888	in_rtqdrain();
889	}
890
891	/*
892	* Do option processing on a datagram,
893	* possibly discarding it if bad options are encountered,
894	* or forwarding it if source-routed.
895	* Returns 1 if packet has been forwarded/freed,
896	* 0 if the packet should be processed further.
897	*/
898	static int
899	ip_dooptions(struct mbuf *m)
900	{
901	register struct ip ip = mtod(m, struct ip );
902	register u_char *cp;
903	register struct ip_timestamp *ipt;
904	register struct in_ifaddr *ia;
905	int opt, optlen, cnt, off, code, type = ICMP_PARAMPROB, forward = 0;
906	struct in_addr *sin, dst;
907	n_time ntime;
908
909	dst = ip->ip_dst;
910	cp = (u_char *)(ip + 1);
911	#ifdef _IP_VHL
912	cnt = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
913	#else
914	cnt = (ip->ip_hl << 2) - sizeof (struct ip);
915	#endif
916	for (; cnt > 0; cnt -= optlen, cp += optlen) {
917	opt = cp[IPOPT_OPTVAL];
918	if (opt == IPOPT_EOL)
919	break;
920	if (opt == IPOPT_NOP)
921	optlen = 1;
922	else {
923	optlen = cp[IPOPT_OLEN];
924	if (optlen <= 0 \|\| optlen > cnt) {
925	code = &cp[IPOPT_OLEN] - (u_char *)ip;
926	goto bad;
927	}
928	}
929	switch (opt) {
930
931	default:
932	break;
933
934	/*
935	* Source routing with record.
936	* Find interface with current destination address.
937	* If none on this machine then drop if strictly routed,
938	* or do nothing if loosely routed.
939	* Record interface address and bring up next address
940	* component. If strictly routed make sure next
941	* address is on directly accessible net.
942	*/
943	case IPOPT_LSRR:
944	case IPOPT_SSRR:
945	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
946	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
947	goto bad;
948	}
949	ipaddr.sin_addr = ip->ip_dst;
950	ia = (struct in_ifaddr *)
951	ifa_ifwithaddr((struct sockaddr *)&ipaddr);
952	if (ia == 0) {
953	if (opt == IPOPT_SSRR) {
954	type = ICMP_UNREACH;
955	code = ICMP_UNREACH_SRCFAIL;
956	goto bad;
957	}
958	if (!ip_dosourceroute)
959	goto nosourcerouting;
960	/*
961	* Loose routing, and not at next destination
962	* yet; nothing to do except forward.
963	*/
964	break;
965	}
966	off--; /* 0 origin */
967	if (off > optlen - sizeof(struct in_addr)) {
968	/*
969	* End of source route. Should be for us.
970	*/
971	if (!ip_acceptsourceroute)
972	goto nosourcerouting;
973	save_rte(cp, ip->ip_src);
974	break;
975	}
976
977	if (!ip_dosourceroute) {
978	char buf0[INET_ADDRSTRLEN];
979	char buf1[INET_ADDRSTRLEN];
980
981	nosourcerouting:
982	log(LOG_WARNING,
983	"attempted source route from %s to %s\n",
984	inet_ntoa_r(ip->ip_dst, buf0),
985	inet_ntoa_r(ip->ip_src, buf1));
986	type = ICMP_UNREACH;
987	code = ICMP_UNREACH_SRCFAIL;
988	goto bad;
989	}
990
991	/*
992	* locate outgoing interface
993	*/
994	(void)memcpy(&ipaddr.sin_addr, cp + off,
995	sizeof(ipaddr.sin_addr));
996
997	if (opt == IPOPT_SSRR) {
998	#define INA struct in_ifaddr *
999	#define SA struct sockaddr *
1000	if ((ia = (INA)ifa_ifwithdstaddr((SA)&ipaddr)) == 0)
1001	ia = (INA)ifa_ifwithnet((SA)&ipaddr);
1002	} else
1003	ia = ip_rtaddr(ipaddr.sin_addr);
1004	if (ia == 0) {
1005	type = ICMP_UNREACH;
1006	code = ICMP_UNREACH_SRCFAIL;
1007	goto bad;
1008	}
1009	ip->ip_dst = ipaddr.sin_addr;
1010	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1011	sizeof(struct in_addr));
1012	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1013	/*
1014	* Let ip_intr's mcast routing check handle mcast pkts
1015	*/
1016	forward = !IN_MULTICAST(ntohl(ip->ip_dst.s_addr));
1017	break;
1018
1019	case IPOPT_RR:
1020	if ((off = cp[IPOPT_OFFSET]) < IPOPT_MINOFF) {
1021	code = &cp[IPOPT_OFFSET] - (u_char *)ip;
1022	goto bad;
1023	}
1024	/*
1025	* If no space remains, ignore.
1026	*/
1027	off--; /* 0 origin */
1028	if (off > optlen - sizeof(struct in_addr))
1029	break;
1030	(void)memcpy(&ipaddr.sin_addr, &ip->ip_dst,
1031	sizeof(ipaddr.sin_addr));
1032	/*
1033	* locate outgoing interface; if we're the destination,
1034	* use the incoming interface (should be same).
1035	*/
1036	if ((ia = (INA)ifa_ifwithaddr((SA)&ipaddr)) == 0 &&
1037	(ia = ip_rtaddr(ipaddr.sin_addr)) == 0) {
1038	type = ICMP_UNREACH;
1039	code = ICMP_UNREACH_HOST;
1040	goto bad;
1041	}
1042	(void)memcpy(cp + off, &(IA_SIN(ia)->sin_addr),
1043	sizeof(struct in_addr));
1044	cp[IPOPT_OFFSET] += sizeof(struct in_addr);
1045	break;
1046
1047	case IPOPT_TS:
1048	code = cp - (u_char *)ip;
1049	ipt = (struct ip_timestamp *)cp;
1050	if (ipt->ipt_len < 5)
1051	goto bad;
1052	if (ipt->ipt_ptr > ipt->ipt_len - sizeof (long)) {
1053	if (++ipt->ipt_oflw == 0)
1054	goto bad;
1055	break;
1056	}
1057	sin = (struct in_addr *)(cp + ipt->ipt_ptr - 1);
1058	switch (ipt->ipt_flg) {
1059
1060	case IPOPT_TS_TSONLY:
1061	break;
1062
1063	case IPOPT_TS_TSANDADDR:
1064	if (ipt->ipt_ptr + sizeof(n_time) +
1065	sizeof(struct in_addr) > ipt->ipt_len)
1066	goto bad;
1067	ipaddr.sin_addr = dst;
1068	ia = (INA)ifaof_ifpforaddr((SA)&ipaddr,
1069	m->m_pkthdr.rcvif);
1070	if (ia == 0)
1071	continue;
1072	(void)memcpy(sin, &IA_SIN(ia)->sin_addr,
1073	sizeof(struct in_addr));
1074	ipt->ipt_ptr += sizeof(struct in_addr);
1075	break;
1076
1077	case IPOPT_TS_PRESPEC:
1078	if (ipt->ipt_ptr + sizeof(n_time) +
1079	sizeof(struct in_addr) > ipt->ipt_len)
1080	goto bad;
1081	(void)memcpy(&ipaddr.sin_addr, sin,
1082	sizeof(struct in_addr));
1083	if (ifa_ifwithaddr((SA)&ipaddr) == 0)
1084	continue;
1085	ipt->ipt_ptr += sizeof(struct in_addr);
1086	break;
1087
1088	default:
1089	goto bad;
1090	}
1091	ntime = iptime();
1092	(void)memcpy(cp + ipt->ipt_ptr - 1, &ntime,
1093	sizeof(n_time));
1094	ipt->ipt_ptr += sizeof(n_time);
1095	}
1096	}
1097	if (forward && ipforwarding) {
1098	ip_forward(m, 1);
1099	return (1);
1100	}
1101	return (0);
1102	bad:
1103	#ifdef _IP_VHL
1104	ip->ip_len -= IP_VHL_HL(ip->ip_vhl) << 2; /* XXX icmp_error adds in hdr length */
1105	#else
1106	ip->ip_len -= ip->ip_hl << 2; /* XXX icmp_error adds in hdr length */
1107	#endif
1108	icmp_error(m, type, code, 0, 0);
1109	ipstat.ips_badoptions++;
1110	return (1);
1111	}
1112
1113	/*
1114	* Given address of next destination (final or next hop),
1115	* return internet address info of interface to be used to get there.
1116	*/
1117	static struct in_ifaddr *
1118	ip_rtaddr(struct in_addr dst)
1119	{
1120	struct sockaddr_in *sin;
1121
1122	sin = (struct sockaddr_in *) &ipforward_rt.ro_dst;
1123
1124	if (ipforward_rt.ro_rt == 0 \|\| dst.s_addr != sin->sin_addr.s_addr) {
1125	if (ipforward_rt.ro_rt) {
1126	RTFREE(ipforward_rt.ro_rt);
1127	ipforward_rt.ro_rt = 0;
1128	}
1129	sin->sin_family = AF_INET;
1130	sin->sin_len = sizeof(*sin);
1131	sin->sin_addr = dst;
1132
1133	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1134	}
1135	if (ipforward_rt.ro_rt == 0)
1136	return ((struct in_ifaddr *)0);
1137	return ((struct in_ifaddr *) ipforward_rt.ro_rt->rt_ifa);
1138	}
1139
1140	/*
1141	* Save incoming source route for use in replies,
1142	* to be picked up later by ip_srcroute if the receiver is interested.
1143	*/
1144	void
1145	save_rte(u_char *option, struct in_addr dst)
1146	{
1147	unsigned olen;
1148
1149	olen = option[IPOPT_OLEN];
1150	#ifdef DIAGNOSTIC
1151	if (ipprintfs)
1152	printf("save_rte: olen %d\n", olen);
1153	#endif
1154	if (olen > sizeof(ip_srcrt) - (1 + sizeof(dst)))
1155	return;
1156	bcopy(option, ip_srcrt.srcopt, olen);
1157	ip_nhops = (olen - IPOPT_OFFSET - 1) / sizeof(struct in_addr);
1158	ip_srcrt.dst = dst;
1159	}
1160
1161	/*
1162	* Retrieve incoming source route for use in replies,
1163	* in the same form used by setsockopt.
1164	* The first hop is placed before the options, will be removed later.
1165	*/
1166	struct mbuf *
1167	ip_srcroute(void)
1168	{
1169	register struct in_addr p, q;
1170	register struct mbuf *m;
1171
1172	if (ip_nhops == 0)
1173	return ((struct mbuf *)0);
1174	m = m_get(M_DONTWAIT, MT_SOOPTS);
1175	if (m == 0)
1176	return ((struct mbuf *)0);
1177
1178	#define OPTSIZ (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
1179
1180	/* length is (nhops+1)sizeof(addr) + sizeof(nop + srcrt header) /
1181	m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
1182	OPTSIZ;
1183	#ifdef DIAGNOSTIC
1184	if (ipprintfs)
1185	printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
1186	#endif
1187
1188	/*
1189	* First save first hop for return route
1190	*/
1191	p = &ip_srcrt.route[ip_nhops - 1];
1192	(mtod(m, struct in_addr )) = *p--;
1193	#ifdef DIAGNOSTIC
1194	if (ipprintfs)
1195	printf(" hops %"PRIx32, ntohl(mtod(m, struct in_addr *)->s_addr));
1196	#endif
1197
1198	/*
1199	* Copy option fields and padding (nop) to mbuf.
1200	*/
1201	ip_srcrt.nop = IPOPT_NOP;
1202	ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
1203	(void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
1204	&ip_srcrt.nop, OPTSIZ);
1205	q = (struct in_addr *)(mtod(m, caddr_t) +
1206	sizeof(struct in_addr) + OPTSIZ);
1207	#undef OPTSIZ
1208	/*
1209	* Record return path as an IP source route,
1210	* reversing the path (pointers are now aligned).
1211	*/
1212	while (p >= ip_srcrt.route) {
1213	#ifdef DIAGNOSTIC
1214	if (ipprintfs)
1215	printf(" %"PRIx32, ntohl(q->s_addr));
1216	#endif
1217	q++ = p--;
1218	}
1219	/*
1220	* Last hop goes to final destination.
1221	*/
1222	*q = ip_srcrt.dst;
1223	#ifdef DIAGNOSTIC
1224	if (ipprintfs)
1225	printf(" %"PRIx32"\n", ntohl(q->s_addr));
1226	#endif
1227	return (m);
1228	}
1229
1230	/*
1231	* Strip out IP options, at higher
1232	* level protocol in the kernel.
1233	* Second argument is buffer to which options
1234	* will be moved, and return value is their length.
1235	* XXX should be deleted; last arg currently ignored.
1236	*/
1237	void
1238	ip_stripoptions(struct mbuf m, struct mbuf mopt)
1239	{
1240	register int i;
1241	struct ip ip = mtod(m, struct ip );
1242	register caddr_t opts;
1243	int olen;
1244
1245	#ifdef _IP_VHL
1246	olen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof (struct ip);
1247	#else
1248	olen = (ip->ip_hl << 2) - sizeof (struct ip);
1249	#endif
1250	opts = (caddr_t)(ip + 1);
1251	i = m->m_len - (sizeof (struct ip) + olen);
1252	bcopy(opts + olen, opts, (unsigned)i);
1253	m->m_len -= olen;
1254	if (m->m_flags & M_PKTHDR)
1255	m->m_pkthdr.len -= olen;
1256	#ifdef _IP_VHL
1257	ip->ip_vhl = IP_MAKE_VHL(IPVERSION, sizeof(struct ip) >> 2);
1258	#else
1259	ip->ip_v = IPVERSION;
1260	ip->ip_hl = (sizeof(struct ip) >> 2);
1261	#endif
1262	}
1263
1264	u_char inetctlerrmap[PRC_NCMDS] = {
1265	0, 0, 0, 0,
1266	0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1267	EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1268	EMSGSIZE, EHOSTUNREACH, 0, 0,
1269	0, 0, 0, 0,
1270	ENOPROTOOPT
1271	};
1272
1273	/*
1274	* Forward a packet. If some error occurs return the sender
1275	* an icmp packet. Note we can't always generate a meaningful
1276	* icmp message because icmp doesn't have a large enough repertoire
1277	* of codes and types.
1278	*
1279	* If not forwarding, just drop the packet. This could be confusing
1280	* if ipforwarding was zero but some routing protocol was advancing
1281	* us as a gateway to somewhere. However, we must let the routing
1282	* protocol deal with that.
1283	*
1284	* The srcrt parameter indicates whether the packet is being forwarded
1285	* via a source route.
1286	*/
1287	static void
1288	ip_forward(struct mbuf *m, int srcrt)
1289	{
1290	struct ip ip = mtod(m, struct ip );
1291	register struct sockaddr_in *sin;
1292	register struct rtentry *rt;
1293	int error, type = 0, code = 0;
1294	struct mbuf *mcopy;
1295	n_long dest;
1296	struct ifnet *destifp;
1297
1298	dest = 0;
1299	#ifdef DIAGNOSTIC
1300	if (ipprintfs)
1301	printf("forward: src %"PRIx32" dst %"PRIx32" ttl %x\n",
1302	ip->ip_src.s_addr, ip->ip_dst.s_addr, ip->ip_ttl);
1303	#endif
1304
1305
1306	if (m->m_flags & M_BCAST \|\| in_canforward(ip->ip_dst) == 0) {
1307	ipstat.ips_cantforward++;
1308	m_freem(m);
1309	return;
1310	}
1311	HTONS(ip->ip_id);
1312	if (ip->ip_ttl <= IPTTLDEC) {
1313	icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, dest, 0);
1314	return;
1315	}
1316	ip->ip_ttl -= IPTTLDEC;
1317
1318	sin = (struct sockaddr_in *)&ipforward_rt.ro_dst;
1319	if ((rt = ipforward_rt.ro_rt) == 0 \|\|
1320	ip->ip_dst.s_addr != sin->sin_addr.s_addr) {
1321	if (ipforward_rt.ro_rt) {
1322	RTFREE(ipforward_rt.ro_rt);
1323	ipforward_rt.ro_rt = 0;
1324	}
1325	sin->sin_family = AF_INET;
1326	sin->sin_len = sizeof(*sin);
1327	sin->sin_addr = ip->ip_dst;
1328
1329	rtalloc_ign(&ipforward_rt, RTF_PRCLONING);
1330	if (ipforward_rt.ro_rt == 0) {
1331	icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, dest, 0);
1332	return;
1333	}
1334	rt = ipforward_rt.ro_rt;
1335	}
1336
1337	/*
1338	* Save at most 64 bytes of the packet in case
1339	* we need to generate an ICMP message to the src.
1340	*/
1341	mcopy = m_copy(m, 0, imin((int)ip->ip_len, 64));
1342
1343	/*
1344	* If forwarding packet using same interface that it came in on,
1345	* perhaps should send a redirect to sender to shortcut a hop.
1346	* Only send redirect if source is sending directly to us,
1347	* and if packet was not source routed (or has any options).
1348	* Also, don't send redirect if forwarding using a default route
1349	* or a route modified by a redirect.
1350	*/
1351	#define satosin(sa) ((struct sockaddr_in *)(sa))
1352	if (rt->rt_ifp == m->m_pkthdr.rcvif &&
1353	(rt->rt_flags & (RTF_DYNAMIC\|RTF_MODIFIED)) == 0 &&
1354	satosin(rt_key(rt))->sin_addr.s_addr != 0 &&
1355	ipsendredirects && !srcrt) {
1356	#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1357	u_long src = ntohl(ip->ip_src.s_addr);
1358
1359	if (RTA(rt) &&
1360	(src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1361	if (rt->rt_flags & RTF_GATEWAY)
1362	dest = satosin(rt->rt_gateway)->sin_addr.s_addr;
1363	else
1364	dest = ip->ip_dst.s_addr;
1365	/* Router requirements says to only send host redirects */
1366	type = ICMP_REDIRECT;
1367	code = ICMP_REDIRECT_HOST;
1368	}
1369	}
1370
1371	error = ip_output(m, (struct mbuf *)0, &ipforward_rt,
1372	IP_FORWARDING, 0);
1373	if (error)
1374	ipstat.ips_cantforward++;
1375	else {
1376	ipstat.ips_forward++;
1377	if (type)
1378	ipstat.ips_redirectsent++;
1379	else {
1380	if (mcopy)
1381	m_freem(mcopy);
1382	return;
1383	}
1384	}
1385	if (mcopy == NULL)
1386	return;
1387	destifp = NULL;
1388
1389	switch (error) {
1390
1391	case 0: /* forwarded, but need redirect */
1392	/* type, code set above */
1393	break;
1394
1395	case ENETUNREACH: /* shouldn't happen, checked above */
1396	case EHOSTUNREACH:
1397	case ENETDOWN:
1398	case EHOSTDOWN:
1399	default:
1400	type = ICMP_UNREACH;
1401	code = ICMP_UNREACH_HOST;
1402	break;
1403
1404	case EMSGSIZE:
1405	type = ICMP_UNREACH;
1406	code = ICMP_UNREACH_NEEDFRAG;
1407	if (ipforward_rt.ro_rt)
1408	destifp = ipforward_rt.ro_rt->rt_ifp;
1409	ipstat.ips_cantfrag++;
1410	break;
1411
1412	case ENOBUFS:
1413	type = ICMP_SOURCEQUENCH;
1414	code = 0;
1415	break;
1416	}
1417	icmp_error(mcopy, type, code, dest, destifp);
1418	}
1419
1420	void
1421	ip_savecontrol(struct inpcb inp, struct mbuf mp, struct ip ip,
1422	struct mbuf *m)
1423	{
1424	if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1425	struct timeval tv;
1426
1427	microtime(&tv);
1428	*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1429	SCM_TIMESTAMP, SOL_SOCKET);
1430	if (*mp)
1431	mp = &(*mp)->m_next;
1432	}
1433	if (inp->inp_flags & INP_RECVDSTADDR) {
1434	*mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1435	sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1436	if (*mp)
1437	mp = &(*mp)->m_next;
1438	}
1439	#ifdef notyet
1440	/* XXX
1441	* Moving these out of udp_input() made them even more broken
1442	* than they already were.
1443	*/
1444	/* options were tossed already */
1445	if (inp->inp_flags & INP_RECVOPTS) {
1446	*mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1447	sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1448	if (*mp)
1449	mp = &(*mp)->m_next;
1450	}
1451	/* ip_srcroute doesn't do what we want here, need to fix */
1452	if (inp->inp_flags & INP_RECVRETOPTS) {
1453	*mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
1454	sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1455	if (*mp)
1456	mp = &(*mp)->m_next;
1457	}
1458	#endif
1459	if (inp->inp_flags & INP_RECVIF) {
1460	struct sockaddr_dl sdl;
1461
1462	sdl.sdl_len = offsetof(struct sockaddr_dl, sdl_data[0]);
1463	sdl.sdl_family = AF_LINK;
1464	sdl.sdl_index = m->m_pkthdr.rcvif ?
1465	m->m_pkthdr.rcvif->if_index : 0;
1466	sdl.sdl_nlen = sdl.sdl_alen = sdl.sdl_slen = 0;
1467	*mp = sbcreatecontrol((caddr_t) &sdl, sdl.sdl_len,
1468	IP_RECVIF, IPPROTO_IP);
1469	if (*mp)
1470	mp = &(*mp)->m_next;
1471	}
1472	}
1473
1474	int
1475	ip_rsvp_init(struct socket *so)
1476	{
1477	if (so->so_type != SOCK_RAW \|\|
1478	so->so_proto->pr_protocol != IPPROTO_RSVP)
1479	return EOPNOTSUPP;
1480
1481	if (ip_rsvpd != NULL)
1482	return EADDRINUSE;
1483
1484	ip_rsvpd = so;
1485	/*
1486	* This may seem silly, but we need to be sure we don't over-increment
1487	* the RSVP counter, in case something slips up.
1488	*/
1489	if (!ip_rsvp_on) {
1490	ip_rsvp_on = 1;
1491	rsvp_on++;
1492	}
1493
1494	return 0;
1495	}
1496
1497	int
1498	ip_rsvp_done(void)
1499	{
1500	ip_rsvpd = NULL;
1501	/*
1502	* This may seem silly, but we need to be sure we don't over-decrement
1503	* the RSVP counter, in case something slips up.
1504	*/
1505	if (ip_rsvp_on) {
1506	ip_rsvp_on = 0;
1507	rsvp_on--;
1508	}
1509	return 0;
1510	}

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source: rtems/cpukit/libnetworking/netinet/ip_input.c @ 0e16fa45

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