Context Navigation

ip_icmp.c @ 005c3fe7

Last change on this file since 005c3fe7 was 9b4422a2, checked in by Joel Sherrill <joel.sherrill@…>, on 05/03/12 at 15:09:24

Remove All CVS Id Strings Possible Using a Script

Script does what is expected and tries to do it as
smartly as possible.

+ remove occurrences of two blank comment lines

next to each other after Id string line removed.

+ remove entire comment blocks which only exited to

contain CVS Ids

+ If the processing left a blank line at the top of

a file, it was removed.

Property mode set to 100644

File size: 19.2 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_icmp.c 8.2 (Berkeley) 1/4/94
30	* $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.101 2005/05/04 13:23:54 andre Exp $
31	*/
32
33
34	#ifdef HAVE_CONFIG_H
35	#include "config.h"
36	#endif
37
38	#include <sys/param.h>
39	#include <sys/systm.h>
40	#include <sys/mbuf.h>
41	#include <sys/protosw.h>
42	#include <sys/socket.h>
43	#include <sys/time.h>
44	#include <sys/kernel.h>
45	#include <sys/sysctl.h>
46
47	#include <net/if.h>
48	#include <net/if_types.h>
49	#include <net/route.h>
50
51	#define _IP_VHL
52	#include <netinet/in.h>
53	#include <netinet/in_pcb.h>
54	#include <netinet/in_systm.h>
55	#include <netinet/in_var.h>
56	#include <netinet/ip.h>
57	#include <netinet/ip_icmp.h>
58	#include <netinet/ip_var.h>
59	#include <netinet/tcp.h>
60	#include <netinet/tcp_var.h>
61	#include <netinet/tcpip.h>
62	#include <netinet/icmp_var.h>
63
64	#ifdef IPSEC
65	#include <netinet6/ipsec.h>
66	#include <netkey/key.h>
67	#endif
68
69	#ifdef FAST_IPSEC
70	#include <netipsec/ipsec.h>
71	#include <netipsec/key.h>
72	#define IPSEC
73	#endif
74
75	#include <machine/in_cksum.h>
76
77	/*
78	* ICMP routines: error generation, receive packet processing, and
79	* routines to turnaround packets back to the originator, and
80	* host table maintenance routines.
81	*/
82
83	struct icmpstat icmpstat;
84	SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RD,
85	&icmpstat, icmpstat, "");
86
87	static int icmpmaskrepl = 0;
88	SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
89	&icmpmaskrepl, 0, "");
90
91	static int icmpbmcastecho = 1;
92	SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW, &icmpbmcastecho,
93	0, "");
94
95	static int icmpallecho = 1;
96	SYSCTL_INT(_net_inet_icmp, OID_AUTO, allecho, CTLFLAG_RW, &icmpallecho,
97	0, "");
98
99	#ifdef ICMPPRINTFS
100	int icmpprintfs = 0;
101	#endif
102
103	static void icmp_reflect(struct mbuf *);
104	static void icmp_send(struct mbuf , struct mbuf );
105
106	extern struct protosw inetsw[];
107	unsigned int icmplenPanicAvoided;
108
109	/*
110	* Generate an error packet of type error
111	* in response to bad packet ip.
112	*/
113	void
114	icmp_error(struct mbuf *n, int type, int code, n_long dest,
115	struct ifnet *destifp)
116	{
117	register struct ip oip = mtod(n, struct ip ), *nip;
118	#ifdef _IP_VHL
119	register unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
120	#else
121	register unsigned oiplen = oip->ip_hl << 2;
122	#endif
123	register struct icmp *icp;
124	register struct mbuf *m;
125	unsigned icmplen;
126
127	#ifdef ICMPPRINTFS
128	if (icmpprintfs)
129	printf("icmp_error(%p, %x, %d)\n", oip, type, code);
130	#endif
131	if (type != ICMP_REDIRECT)
132	icmpstat.icps_error++;
133	/*
134	* Don't send error if not the first fragment of message.
135	* Don't error if the old packet protocol was ICMP
136	* error message, only known informational types.
137	*/
138	if (oip->ip_off &~ (IP_MF\|IP_DF))
139	goto freeit;
140	if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
141	n->m_len >= oiplen + ICMP_MINLEN &&
142	!ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
143	icmpstat.icps_oldicmp++;
144	goto freeit;
145	}
146	/* Don't send error in response to a multicast or broadcast packet */
147	if (n->m_flags & (M_BCAST\|M_MCAST))
148	goto freeit;
149	/* Don't send error in response to malicious packet */
150	icmplen = min(oiplen + 8, oip->ip_len);
151	if (icmplen < sizeof(struct ip)) {
152	icmplenPanicAvoided++;
153	goto freeit;
154	}
155
156	/*
157	* First, formulate icmp message
158	*/
159	m = m_gethdr(M_DONTWAIT, MT_HEADER);
160	if (m == NULL)
161	goto freeit;
162	#ifdef MAC
163	mac_create_mbuf_netlayer(n, m);
164	#endif
165	m->m_len = icmplen + ICMP_MINLEN;
166	MH_ALIGN(m, m->m_len);
167	icp = mtod(m, struct icmp *);
168	if ((u_int)type > ICMP_MAXTYPE)
169	panic("icmp_error");
170	icmpstat.icps_outhist[type]++;
171	icp->icmp_type = type;
172	if (type == ICMP_REDIRECT)
173	icp->icmp_gwaddr.s_addr = dest;
174	else {
175	icp->icmp_void = 0;
176	/*
177	* The following assignments assume an overlay with the
178	* zeroed icmp_void field.
179	*/
180	if (type == ICMP_PARAMPROB) {
181	icp->icmp_pptr = code;
182	code = 0;
183	} else if (type == ICMP_UNREACH &&
184	code == ICMP_UNREACH_NEEDFRAG && destifp) {
185	icp->icmp_nextmtu = htons(destifp->if_mtu);
186	}
187	}
188
189	icp->icmp_code = code;
190	bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, icmplen);
191	nip = &icp->icmp_ip;
192	nip->ip_len = htons((u_short)(nip->ip_len + oiplen));
193
194	/*
195	* Now, copy old ip header (without options)
196	* in front of icmp message.
197	*/
198	if (m->m_data - sizeof(struct ip) < m->m_pktdat)
199	panic("icmp len");
200	m->m_data -= sizeof(struct ip);
201	m->m_len += sizeof(struct ip);
202	m->m_pkthdr.len = m->m_len;
203	m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
204	nip = mtod(m, struct ip *);
205	bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
206	nip->ip_len = m->m_len;
207	#ifdef _IP_VHL
208	nip->ip_vhl = IP_VHL_BORING;
209	#else
210	nip->ip_v = IPVERSION;
211	nip->ip_hl = 5;
212	#endif
213	nip->ip_p = IPPROTO_ICMP;
214	nip->ip_tos = 0;
215	icmp_reflect(m);
216
217	freeit:
218	m_freem(n);
219	}
220
221	static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET, 0, {0}, {0} };
222	static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET, 0, {0}, {0} };
223	static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET, 0, {0}, {0} };
224
225	/*
226	* Process a received ICMP message.
227	*/
228	void
229	icmp_input(struct mbuf *m, int off)
230	{
231	struct icmp *icp;
232	struct in_ifaddr *ia;
233	struct ip ip = mtod(m, struct ip );
234	int hlen = off;
235	int icmplen = ip->ip_len;
236	int i, code;
237	void (ctlfunc)(int, struct sockaddr , void *);
238
239	/*
240	* Locate icmp structure in mbuf, and check
241	* that not corrupted and of at least minimum length.
242	*/
243	#ifdef ICMPPRINTFS
244	if (icmpprintfs) {
245	char buf[4 * sizeof "123"];
246	strcpy(buf, inet_ntoa(ip->ip_src));
247	printf("icmp_input from %s to %s, len %d\n",
248	buf, inet_ntoa(ip->ip_dst), icmplen);
249	}
250	#endif
251	if (icmplen < ICMP_MINLEN) {
252	icmpstat.icps_tooshort++;
253	goto freeit;
254	}
255	i = hlen + min(icmplen, ICMP_ADVLENMIN);
256	if (m->m_len < i && (m = m_pullup(m, i)) == NULL) {
257	icmpstat.icps_tooshort++;
258	return;
259	}
260	ip = mtod(m, struct ip *);
261	m->m_len -= hlen;
262	m->m_data += hlen;
263	icp = mtod(m, struct icmp *);
264	if (in_cksum(m, icmplen)) {
265	icmpstat.icps_checksum++;
266	goto freeit;
267	}
268	m->m_len += hlen;
269	m->m_data -= hlen;
270
271	#ifdef ICMPPRINTFS
272	if (icmpprintfs)
273	printf("icmp_input, type %d code %d\n", icp->icmp_type,
274	icp->icmp_code);
275	#endif
276
277	/*
278	* Message type specific processing.
279	*/
280	if (icp->icmp_type > ICMP_MAXTYPE)
281	goto raw;
282	icmpstat.icps_inhist[icp->icmp_type]++;
283	code = icp->icmp_code;
284	switch (icp->icmp_type) {
285
286	case ICMP_UNREACH:
287	switch (code) {
288	case ICMP_UNREACH_NET:
289	case ICMP_UNREACH_HOST:
290	case ICMP_UNREACH_PROTOCOL:
291	case ICMP_UNREACH_PORT:
292	case ICMP_UNREACH_SRCFAIL:
293	code = PRC_UNREACH_NET;
294	break;
295
296	case ICMP_UNREACH_NEEDFRAG:
297	code = PRC_MSGSIZE;
298	break;
299
300	case ICMP_UNREACH_NET_UNKNOWN:
301	case ICMP_UNREACH_NET_PROHIB:
302	case ICMP_UNREACH_TOSNET:
303	code = PRC_UNREACH_NET;
304	break;
305
306	case ICMP_UNREACH_HOST_UNKNOWN:
307	case ICMP_UNREACH_ISOLATED:
308	case ICMP_UNREACH_HOST_PROHIB:
309	case ICMP_UNREACH_TOSHOST:
310	code = PRC_UNREACH_HOST;
311	break;
312
313	case ICMP_UNREACH_FILTER_PROHIB:
314	case ICMP_UNREACH_HOST_PRECEDENCE:
315	case ICMP_UNREACH_PRECEDENCE_CUTOFF:
316	code = PRC_UNREACH_PORT;
317	break;
318
319	default:
320	goto badcode;
321	}
322	goto deliver;
323
324	case ICMP_TIMXCEED:
325	if (code > 1)
326	goto badcode;
327	code += PRC_TIMXCEED_INTRANS;
328	goto deliver;
329
330	case ICMP_PARAMPROB:
331	if (code > 1)
332	goto badcode;
333	code = PRC_PARAMPROB;
334	goto deliver;
335
336	case ICMP_SOURCEQUENCH:
337	if (code)
338	goto badcode;
339	code = PRC_QUENCH;
340	deliver:
341	/*
342	* Problem with datagram; advise higher level routines.
343	*/
344	if (icmplen < ICMP_ADVLENMIN \|\| icmplen < ICMP_ADVLEN(icp) \|\|
345	#ifdef _IP_VHL
346	IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
347	#else
348	icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
349	#endif
350	icmpstat.icps_badlen++;
351	goto freeit;
352	}
353	NTOHS(icp->icmp_ip.ip_len);
354	/* Discard ICMP's in response to multicast packets */
355	if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
356	goto badcode;
357	#ifdef ICMPPRINTFS
358	if (icmpprintfs)
359	printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
360	#endif
361	icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
362	#if 1
363	/*
364	* MTU discovery:
365	* If we got a needfrag and there is a host route to the
366	* original destination, and the MTU is not locked, then
367	* set the MTU in the route to the suggested new value
368	* (if given) and then notify as usual. The ULPs will
369	* notice that the MTU has changed and adapt accordingly.
370	* If no new MTU was suggested, then we guess a new one
371	* less than the current value. If the new MTU is
372	* unreasonably small (arbitrarily set at 296), then
373	* we reset the MTU to the interface value and enable the
374	* lock bit, indicating that we are no longer doing MTU
375	* discovery.
376	*/
377	if (code == PRC_MSGSIZE) {
378	struct rtentry *rt;
379	int mtu;
380
381	rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
382	RTF_CLONING \| RTF_PRCLONING);
383	if (rt && (rt->rt_flags & RTF_HOST)
384	&& !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
385	mtu = ntohs(icp->icmp_nextmtu);
386	if (!mtu)
387	mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
388	1);
389	#ifdef DEBUG_MTUDISC
390	printf("MTU for %s reduced to %d\n",
391	inet_ntoa(icmpsrc.sin_addr), mtu);
392	#endif
393	if (mtu < 296) {
394	/* rt->rt_rmx.rmx_mtu =
395	rt->rt_ifp->if_mtu; */
396	rt->rt_rmx.rmx_locks \|= RTV_MTU;
397	} else if (rt->rt_rmx.rmx_mtu > mtu) {
398	rt->rt_rmx.rmx_mtu = mtu;
399	}
400	}
401	if (rt)
402	RTFREE(rt);
403	}
404
405	#endif
406	ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
407	if (ctlfunc)
408	(ctlfunc)(code, (struct sockaddr )&icmpsrc,
409	(void *)&icp->icmp_ip);
410	break;
411
412	badcode:
413	icmpstat.icps_badcode++;
414	break;
415
416	case ICMP_ECHO:
417	if (!icmpallecho) {
418	icmpstat.icps_allecho++;
419	break;
420	}
421	if (!icmpbmcastecho
422	&& (m->m_flags & (M_MCAST \| M_BCAST)) != 0
423	&& IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
424	icmpstat.icps_bmcastecho++;
425	break;
426	}
427	icp->icmp_type = ICMP_ECHOREPLY;
428	goto reflect;
429
430	case ICMP_TSTAMP:
431	if (!icmpbmcastecho
432	&& (m->m_flags & (M_MCAST \| M_BCAST)) != 0
433	&& IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
434	icmpstat.icps_bmcasttstamp++;
435	break;
436	}
437	if (icmplen < ICMP_TSLEN) {
438	icmpstat.icps_badlen++;
439	break;
440	}
441	icp->icmp_type = ICMP_TSTAMPREPLY;
442	icp->icmp_rtime = iptime();
443	icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
444	goto reflect;
445
446	case ICMP_MASKREQ:
447	#define satosin(sa) ((struct sockaddr_in *)(sa))
448	if (icmpmaskrepl == 0)
449	break;
450	/*
451	* We are not able to respond with all ones broadcast
452	* unless we receive it over a point-to-point interface.
453	*/
454	if (icmplen < ICMP_MASKLEN)
455	break;
456	switch (ip->ip_dst.s_addr) {
457
458	case INADDR_BROADCAST:
459	case INADDR_ANY:
460	icmpdst.sin_addr = ip->ip_src;
461	break;
462
463	default:
464	icmpdst.sin_addr = ip->ip_dst;
465	}
466	ia = (struct in_ifaddr *)ifaof_ifpforaddr(
467	(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
468	if (ia == NULL)
469	break;
470	if (ia->ia_ifp == NULL) {
471	break;
472	}
473	icp->icmp_type = ICMP_MASKREPLY;
474	icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
475	if (ip->ip_src.s_addr == 0) {
476	if (ia->ia_ifp->if_flags & IFF_BROADCAST)
477	ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
478	else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
479	ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
480	}
481	reflect:
482	ip->ip_len += hlen; /* since ip_input deducts this */
483	icmpstat.icps_reflect++;
484	icmpstat.icps_outhist[icp->icmp_type]++;
485	icmp_reflect(m);
486	return;
487
488	case ICMP_REDIRECT:
489	if (code > 3)
490	goto badcode;
491	if (icmplen < ICMP_ADVLENMIN \|\| icmplen < ICMP_ADVLEN(icp) \|\|
492	#ifdef _IP_VHL
493	IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
494	#else
495	icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
496	#endif
497	icmpstat.icps_badlen++;
498	break;
499	}
500	/*
501	* Short circuit routing redirects to force
502	* immediate change in the kernel's routing
503	* tables. The message is also handed to anyone
504	* listening on a raw socket (e.g. the routing
505	* daemon for use in updating its tables).
506	*/
507	icmpgw.sin_addr = ip->ip_src;
508	icmpdst.sin_addr = icp->icmp_gwaddr;
509	#ifdef ICMPPRINTFS
510	if (icmpprintfs) {
511	char buf[4 * sizeof "123"];
512	strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
513
514	printf("redirect dst %s to %s\n",
515	buf, inet_ntoa(icp->icmp_gwaddr));
516	}
517	#endif
518	icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
519	rtredirect((struct sockaddr *)&icmpsrc,
520	(struct sockaddr *)&icmpdst,
521	(struct sockaddr *)0, RTF_GATEWAY \| RTF_HOST,
522	(struct sockaddr )&icmpgw, (struct rtentry *)0);
523	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
524	break;
525
526	/*
527	* No kernel processing for the following;
528	* just fall through to send to raw listener.
529	*/
530	case ICMP_ECHOREPLY:
531	case ICMP_ROUTERADVERT:
532	case ICMP_ROUTERSOLICIT:
533	case ICMP_TSTAMPREPLY:
534	case ICMP_IREQREPLY:
535	case ICMP_MASKREPLY:
536	default:
537	break;
538	}
539
540	raw:
541	rip_input(m, hlen);
542	return;
543
544	freeit:
545	m_freem(m);
546	}
547
548	/*
549	* Reflect the ip packet back to the source
550	*/
551	static void
552	icmp_reflect(struct mbuf *m)
553	{
554	struct ip ip = mtod(m, struct ip );
555	struct in_ifaddr *ia;
556	struct in_addr t;
557	struct mbuf *opts = 0;
558	#ifdef _IP_VHL
559	int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
560	#else
561	int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
562	#endif
563	if (!in_canforward(ip->ip_src) &&
564	((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
565	(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
566	m_freem(m); /* Bad return address */
567	goto done; /* Ip_output() will check for broadcast */
568	}
569	t = ip->ip_dst;
570	ip->ip_dst = ip->ip_src;
571	/*
572	* If the incoming packet was addressed directly to us,
573	* use dst as the src for the reply. Otherwise (broadcast
574	* or anonymous), use the address which corresponds
575	* to the incoming interface.
576	*/
577	for (ia = in_ifaddr; ia; ia = ia->ia_next) {
578	if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
579	break;
580	if (ia->ia_ifp && (ia->ia_ifp->if_flags & IFF_BROADCAST) &&
581	t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr)
582	break;
583	}
584	icmpdst.sin_addr = t;
585	if ((ia == (struct in_ifaddr *)0) && m->m_pkthdr.rcvif)
586	ia = (struct in_ifaddr *)ifaof_ifpforaddr(
587	(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
588	/*
589	* The following happens if the packet was not addressed to us,
590	* and was received on an interface with no IP address.
591	*/
592	if (ia == (struct in_ifaddr *)0)
593	ia = in_ifaddr;
594	t = IA_SIN(ia)->sin_addr;
595	ip->ip_src = t;
596	ip->ip_ttl = MAXTTL;
597
598	if (optlen > 0) {
599	register u_char *cp;
600	int opt, cnt;
601	u_int len;
602
603	/*
604	* Retrieve any source routing from the incoming packet;
605	* add on any record-route or timestamp options.
606	*/
607	cp = (u_char *) (ip + 1);
608	if ((opts = ip_srcroute()) == 0 &&
609	(opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
610	opts->m_len = sizeof(struct in_addr);
611	mtod(opts, struct in_addr *)->s_addr = 0;
612	}
613	if (opts) {
614	#ifdef ICMPPRINTFS
615	if (icmpprintfs)
616	printf("icmp_reflect optlen %d rt %d => ",
617	optlen, opts->m_len);
618	#endif
619	for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
620	opt = cp[IPOPT_OPTVAL];
621	if (opt == IPOPT_EOL)
622	break;
623	if (opt == IPOPT_NOP)
624	len = 1;
625	else {
626	if (cnt < IPOPT_OLEN + sizeof(*cp))
627	break;
628	len = cp[IPOPT_OLEN];
629	if (len < IPOPT_OLEN + sizeof(*cp) \|\|
630	len > cnt)
631	break;
632	}
633	/*
634	* Should check for overflow, but it "can't happen"
635	*/
636	if (opt == IPOPT_RR \|\| opt == IPOPT_TS \|\|
637	opt == IPOPT_SECURITY) {
638	bcopy((caddr_t)cp,
639	mtod(opts, caddr_t) + opts->m_len, len);
640	opts->m_len += len;
641	}
642	}
643	/* Terminate & pad, if necessary */
644	cnt = opts->m_len % 4;
645	if (cnt) {
646	for (; cnt < 4; cnt++) {
647	*(mtod(opts, caddr_t) + opts->m_len) =
648	IPOPT_EOL;
649	opts->m_len++;
650	}
651	}
652	#ifdef ICMPPRINTFS
653	if (icmpprintfs)
654	printf("%d\n", opts->m_len);
655	#endif
656	}
657	/*
658	* Now strip out original options by copying rest of first
659	* mbuf's data back, and adjust the IP length.
660	*/
661	ip->ip_len -= optlen;
662	#ifdef _IP_VHL
663	ip->ip_vhl = IP_VHL_BORING;
664	#else
665	ip->ip_v = IPVERSION;
666	ip->ip_hl = 5;
667	#endif
668	m->m_len -= optlen;
669	if (m->m_flags & M_PKTHDR)
670	m->m_pkthdr.len -= optlen;
671	optlen += sizeof(struct ip);
672	bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
673	(unsigned)(m->m_len - sizeof(struct ip)));
674	}
675	m->m_flags &= ~(M_BCAST\|M_MCAST);
676	icmp_send(m, opts);
677	done:
678	if (opts)
679	(void)m_free(opts);
680	}
681
682	/*
683	* Send an icmp packet back to the ip level,
684	* after supplying a checksum.
685	*/
686	static void
687	icmp_send(struct mbuf m, struct mbuf opts)
688	{
689	register struct ip ip = mtod(m, struct ip );
690	register int hlen;
691	register struct icmp *icp;
692	struct route ro;
693
694	#ifdef _IP_VHL
695	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
696	#else
697	hlen = ip->ip_hl << 2;
698	#endif
699	m->m_data += hlen;
700	m->m_len -= hlen;
701	icp = mtod(m, struct icmp *);
702	icp->icmp_cksum = 0;
703	icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
704	m->m_data -= hlen;
705	m->m_len += hlen;
706	#ifdef ICMPPRINTFS
707	if (icmpprintfs) {
708	char buf[4 * sizeof "123"];
709	strcpy(buf, inet_ntoa(ip->ip_dst));
710	printf("icmp_send dst %s src %s\n",
711	buf, inet_ntoa(ip->ip_src));
712	}
713	#endif
714	bzero(&ro, sizeof ro);
715	(void) ip_output(m, opts, &ro, 0, NULL);
716	if (ro.ro_rt)
717	RTFREE(ro.ro_rt);
718	}
719
720	/*
721	* Return milliseconds since 00:00 GMT in network format.
722	*/
723	uint32_t
724	iptime(void)
725	{
726	struct timeval atv;
727	u_long t;
728
729	microtime(&atv);
730	t = (atv.tv_sec % (24L60L60L)) * 1000L + atv.tv_usec / 1000L;
731	return (htonl(t));
732	}
733
734	/*
735	* Return the next larger or smaller MTU plateau (table from RFC 1191)
736	* given current value MTU. If DIR is less than zero, a larger plateau
737	* is returned; otherwise, a smaller value is returned.
738	*/
739	int
740	ip_next_mtu(int mtu, int dir)
741	{
742	static int mtutab[] = {
743	65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508,
744	296, 68, 0
745	};
746	int i;
747
748	for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
749	if (mtu >= mtutab[i])
750	break;
751	}
752
753	if (dir < 0) {
754	if (i == 0) {
755	return 0;
756	} else {
757	return mtutab[i - 1];
758	}
759	} else {
760	if (mtutab[i] == 0) {
761	return 0;
762	} else if(mtu > mtutab[i]) {
763	return mtutab[i];
764	} else {
765	return mtutab[i + 1];
766	}
767	}
768	}

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

Context Navigation

source: rtems/cpukit/libnetworking/netinet/ip_icmp.c @ 005c3fe7

Download in other formats: