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ip_icmp.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: 19.3 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_icmp.c 8.2 (Berkeley) 1/4/94
32	* $FreeBSD: src/sys/netinet/ip_icmp.c,v 1.101 2005/05/04 13:23:54 andre Exp $
33	*/
34
35
36	#ifdef HAVE_CONFIG_H
37	#include "config.h"
38	#endif
39
40	#include <sys/param.h>
41	#include <sys/systm.h>
42	#include <sys/mbuf.h>
43	#include <sys/protosw.h>
44	#include <sys/socket.h>
45	#include <sys/time.h>
46	#include <sys/kernel.h>
47	#include <sys/sysctl.h>
48
49	#include <net/if.h>
50	#include <net/if_types.h>
51	#include <net/route.h>
52
53	#define _IP_VHL
54	#include <netinet/in.h>
55	#include <rtems/rtems_netinet_in.h>
56	#include <netinet/in_pcb.h>
57	#include <netinet/in_systm.h>
58	#include <netinet/in_var.h>
59	#include <netinet/ip.h>
60	#include <netinet/ip_icmp.h>
61	#include <netinet/ip_var.h>
62	#include <netinet/tcp.h>
63	#include <netinet/tcp_var.h>
64	#include <netinet/tcpip.h>
65	#include <netinet/icmp_var.h>
66
67	#ifdef IPSEC
68	#include <netinet6/ipsec.h>
69	#include <netkey/key.h>
70	#endif
71
72	#ifdef FAST_IPSEC
73	#include <netipsec/ipsec.h>
74	#include <netipsec/key.h>
75	#define IPSEC
76	#endif
77
78	#include <machine/in_cksum.h>
79
80	/*
81	* ICMP routines: error generation, receive packet processing, and
82	* routines to turnaround packets back to the originator, and
83	* host table maintenance routines.
84	*/
85
86	struct icmpstat icmpstat;
87	SYSCTL_STRUCT(_net_inet_icmp, ICMPCTL_STATS, stats, CTLFLAG_RD,
88	&icmpstat, icmpstat, "");
89
90	static int icmpmaskrepl = 0;
91	SYSCTL_INT(_net_inet_icmp, ICMPCTL_MASKREPL, maskrepl, CTLFLAG_RW,
92	&icmpmaskrepl, 0, "");
93
94	static int icmpbmcastecho = 1;
95	SYSCTL_INT(_net_inet_icmp, OID_AUTO, bmcastecho, CTLFLAG_RW, &icmpbmcastecho,
96	0, "");
97
98	static int icmpallecho = 1;
99	SYSCTL_INT(_net_inet_icmp, OID_AUTO, allecho, CTLFLAG_RW, &icmpallecho,
100	0, "");
101
102	#ifdef ICMPPRINTFS
103	int icmpprintfs = 0;
104	#endif
105
106	static void icmp_reflect(struct mbuf *);
107	static void icmp_send(struct mbuf , struct mbuf );
108
109	extern struct protosw inetsw[];
110	unsigned int icmplenPanicAvoided;
111
112	/*
113	* Generate an error packet of type error
114	* in response to bad packet ip.
115	*/
116	void
117	icmp_error(struct mbuf *n, int type, int code, n_long dest,
118	struct ifnet *destifp)
119	{
120	register struct ip oip = mtod(n, struct ip ), *nip;
121	#ifdef _IP_VHL
122	register unsigned oiplen = IP_VHL_HL(oip->ip_vhl) << 2;
123	#else
124	register unsigned oiplen = oip->ip_hl << 2;
125	#endif
126	register struct icmp *icp;
127	register struct mbuf *m;
128	unsigned icmplen;
129
130	#ifdef ICMPPRINTFS
131	if (icmpprintfs)
132	printf("icmp_error(%p, %x, %d)\n", oip, type, code);
133	#endif
134	if (type != ICMP_REDIRECT)
135	icmpstat.icps_error++;
136	/*
137	* Don't send error if not the first fragment of message.
138	* Don't error if the old packet protocol was ICMP
139	* error message, only known informational types.
140	*/
141	if (oip->ip_off &~ (IP_MF\|IP_DF))
142	goto freeit;
143	if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
144	n->m_len >= oiplen + ICMP_MINLEN &&
145	!ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
146	icmpstat.icps_oldicmp++;
147	goto freeit;
148	}
149	/* Don't send error in response to a multicast or broadcast packet */
150	if (n->m_flags & (M_BCAST\|M_MCAST))
151	goto freeit;
152	/* Don't send error in response to malicious packet */
153	icmplen = min(oiplen + 8, oip->ip_len);
154	if (icmplen < sizeof(struct ip)) {
155	icmplenPanicAvoided++;
156	goto freeit;
157	}
158
159	/*
160	* First, formulate icmp message
161	*/
162	m = m_gethdr(M_DONTWAIT, MT_HEADER);
163	if (m == NULL)
164	goto freeit;
165	#ifdef MAC
166	mac_create_mbuf_netlayer(n, m);
167	#endif
168	m->m_len = icmplen + ICMP_MINLEN;
169	MH_ALIGN(m, m->m_len);
170	icp = mtod(m, struct icmp *);
171	if ((u_int)type > ICMP_MAXTYPE)
172	panic("icmp_error");
173	icmpstat.icps_outhist[type]++;
174	icp->icmp_type = type;
175	if (type == ICMP_REDIRECT)
176	icp->icmp_gwaddr.s_addr = dest;
177	else {
178	icp->icmp_void = 0;
179	/*
180	* The following assignments assume an overlay with the
181	* zeroed icmp_void field.
182	*/
183	if (type == ICMP_PARAMPROB) {
184	icp->icmp_pptr = code;
185	code = 0;
186	} else if (type == ICMP_UNREACH &&
187	code == ICMP_UNREACH_NEEDFRAG && destifp) {
188	icp->icmp_nextmtu = htons(destifp->if_mtu);
189	}
190	}
191
192	icp->icmp_code = code;
193	bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, icmplen);
194	nip = &icp->icmp_ip;
195	nip->ip_len = htons((u_short)(nip->ip_len + oiplen));
196
197	/*
198	* Now, copy old ip header (without options)
199	* in front of icmp message.
200	*/
201	if (m->m_data - sizeof(struct ip) < m->m_pktdat)
202	panic("icmp len");
203	m->m_data -= sizeof(struct ip);
204	m->m_len += sizeof(struct ip);
205	m->m_pkthdr.len = m->m_len;
206	m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
207	nip = mtod(m, struct ip *);
208	bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
209	nip->ip_len = m->m_len;
210	#ifdef _IP_VHL
211	nip->ip_vhl = IP_VHL_BORING;
212	#else
213	nip->ip_v = IPVERSION;
214	nip->ip_hl = 5;
215	#endif
216	nip->ip_p = IPPROTO_ICMP;
217	nip->ip_tos = 0;
218	icmp_reflect(m);
219
220	freeit:
221	m_freem(n);
222	}
223
224	static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET, 0, {0}, {0} };
225	static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET, 0, {0}, {0} };
226	static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET, 0, {0}, {0} };
227
228	/*
229	* Process a received ICMP message.
230	*/
231	void
232	icmp_input(struct mbuf *m, int off)
233	{
234	struct icmp *icp;
235	struct in_ifaddr *ia;
236	struct ip ip = mtod(m, struct ip );
237	int hlen = off;
238	int icmplen = ip->ip_len;
239	int i, code;
240	void (ctlfunc)(int, struct sockaddr , void *);
241
242	/*
243	* Locate icmp structure in mbuf, and check
244	* that not corrupted and of at least minimum length.
245	*/
246	#ifdef ICMPPRINTFS
247	if (icmpprintfs) {
248	char buf[4 * sizeof "123"];
249	strcpy(buf, inet_ntoa(ip->ip_src));
250	printf("icmp_input from %s to %s, len %d\n",
251	buf, inet_ntoa(ip->ip_dst), icmplen);
252	}
253	#endif
254	if (icmplen < ICMP_MINLEN) {
255	icmpstat.icps_tooshort++;
256	goto freeit;
257	}
258	i = hlen + min(icmplen, ICMP_ADVLENMIN);
259	if (m->m_len < i && (m = m_pullup(m, i)) == NULL) {
260	icmpstat.icps_tooshort++;
261	return;
262	}
263	ip = mtod(m, struct ip *);
264	m->m_len -= hlen;
265	m->m_data += hlen;
266	icp = mtod(m, struct icmp *);
267	if (in_cksum(m, icmplen)) {
268	icmpstat.icps_checksum++;
269	goto freeit;
270	}
271	m->m_len += hlen;
272	m->m_data -= hlen;
273
274	#ifdef ICMPPRINTFS
275	if (icmpprintfs)
276	printf("icmp_input, type %d code %d\n", icp->icmp_type,
277	icp->icmp_code);
278	#endif
279
280	/*
281	* Message type specific processing.
282	*/
283	if (icp->icmp_type > ICMP_MAXTYPE)
284	goto raw;
285	icmpstat.icps_inhist[icp->icmp_type]++;
286	code = icp->icmp_code;
287	switch (icp->icmp_type) {
288
289	case ICMP_UNREACH:
290	switch (code) {
291	case ICMP_UNREACH_NET:
292	case ICMP_UNREACH_HOST:
293	case ICMP_UNREACH_PROTOCOL:
294	case ICMP_UNREACH_PORT:
295	case ICMP_UNREACH_SRCFAIL:
296	code = PRC_UNREACH_NET;
297	break;
298
299	case ICMP_UNREACH_NEEDFRAG:
300	code = PRC_MSGSIZE;
301	break;
302
303	case ICMP_UNREACH_NET_UNKNOWN:
304	case ICMP_UNREACH_NET_PROHIB:
305	case ICMP_UNREACH_TOSNET:
306	code = PRC_UNREACH_NET;
307	break;
308
309	case ICMP_UNREACH_HOST_UNKNOWN:
310	case ICMP_UNREACH_ISOLATED:
311	case ICMP_UNREACH_HOST_PROHIB:
312	case ICMP_UNREACH_TOSHOST:
313	code = PRC_UNREACH_HOST;
314	break;
315
316	case ICMP_UNREACH_FILTER_PROHIB:
317	case ICMP_UNREACH_HOST_PRECEDENCE:
318	case ICMP_UNREACH_PRECEDENCE_CUTOFF:
319	code = PRC_UNREACH_PORT;
320	break;
321
322	default:
323	goto badcode;
324	}
325	goto deliver;
326
327	case ICMP_TIMXCEED:
328	if (code > 1)
329	goto badcode;
330	code += PRC_TIMXCEED_INTRANS;
331	goto deliver;
332
333	case ICMP_PARAMPROB:
334	if (code > 1)
335	goto badcode;
336	code = PRC_PARAMPROB;
337	goto deliver;
338
339	case ICMP_SOURCEQUENCH:
340	if (code)
341	goto badcode;
342	code = PRC_QUENCH;
343	deliver:
344	/*
345	* Problem with datagram; advise higher level routines.
346	*/
347	if (icmplen < ICMP_ADVLENMIN \|\| icmplen < ICMP_ADVLEN(icp) \|\|
348	#ifdef _IP_VHL
349	IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
350	#else
351	icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
352	#endif
353	icmpstat.icps_badlen++;
354	goto freeit;
355	}
356	NTOHS(icp->icmp_ip.ip_len);
357	/* Discard ICMP's in response to multicast packets */
358	if (IN_MULTICAST(ntohl(icp->icmp_ip.ip_dst.s_addr)))
359	goto badcode;
360	#ifdef ICMPPRINTFS
361	if (icmpprintfs)
362	printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
363	#endif
364	icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
365	#if 1
366	/*
367	* MTU discovery:
368	* If we got a needfrag and there is a host route to the
369	* original destination, and the MTU is not locked, then
370	* set the MTU in the route to the suggested new value
371	* (if given) and then notify as usual. The ULPs will
372	* notice that the MTU has changed and adapt accordingly.
373	* If no new MTU was suggested, then we guess a new one
374	* less than the current value. If the new MTU is
375	* unreasonably small (arbitrarily set at 296), then
376	* we reset the MTU to the interface value and enable the
377	* lock bit, indicating that we are no longer doing MTU
378	* discovery.
379	*/
380	if (code == PRC_MSGSIZE) {
381	struct rtentry *rt;
382	int mtu;
383
384	rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
385	RTF_CLONING \| RTF_PRCLONING);
386	if (rt && (rt->rt_flags & RTF_HOST)
387	&& !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
388	mtu = ntohs(icp->icmp_nextmtu);
389	if (!mtu)
390	mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
391	1);
392	#ifdef DEBUG_MTUDISC
393	printf("MTU for %s reduced to %d\n",
394	inet_ntoa(icmpsrc.sin_addr), mtu);
395	#endif
396	if (mtu < 296) {
397	/* rt->rt_rmx.rmx_mtu =
398	rt->rt_ifp->if_mtu; */
399	rt->rt_rmx.rmx_locks \|= RTV_MTU;
400	} else if (rt->rt_rmx.rmx_mtu > mtu) {
401	rt->rt_rmx.rmx_mtu = mtu;
402	}
403	}
404	if (rt)
405	RTFREE(rt);
406	}
407
408	#endif
409	ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
410	if (ctlfunc)
411	(ctlfunc)(code, (struct sockaddr )&icmpsrc,
412	(void *)&icp->icmp_ip);
413	break;
414
415	badcode:
416	icmpstat.icps_badcode++;
417	break;
418
419	case ICMP_ECHO:
420	if (!icmpallecho) {
421	icmpstat.icps_allecho++;
422	break;
423	}
424	if (!icmpbmcastecho
425	&& (m->m_flags & (M_MCAST \| M_BCAST)) != 0
426	&& IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
427	icmpstat.icps_bmcastecho++;
428	break;
429	}
430	icp->icmp_type = ICMP_ECHOREPLY;
431	goto reflect;
432
433	case ICMP_TSTAMP:
434	if (!icmpbmcastecho
435	&& (m->m_flags & (M_MCAST \| M_BCAST)) != 0
436	&& IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
437	icmpstat.icps_bmcasttstamp++;
438	break;
439	}
440	if (icmplen < ICMP_TSLEN) {
441	icmpstat.icps_badlen++;
442	break;
443	}
444	icp->icmp_type = ICMP_TSTAMPREPLY;
445	icp->icmp_rtime = iptime();
446	icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */
447	goto reflect;
448
449	case ICMP_MASKREQ:
450	#define satosin(sa) ((struct sockaddr_in *)(sa))
451	if (icmpmaskrepl == 0)
452	break;
453	/*
454	* We are not able to respond with all ones broadcast
455	* unless we receive it over a point-to-point interface.
456	*/
457	if (icmplen < ICMP_MASKLEN)
458	break;
459	switch (ip->ip_dst.s_addr) {
460
461	case INADDR_BROADCAST:
462	case INADDR_ANY:
463	icmpdst.sin_addr = ip->ip_src;
464	break;
465
466	default:
467	icmpdst.sin_addr = ip->ip_dst;
468	}
469	ia = (struct in_ifaddr *)ifaof_ifpforaddr(
470	(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
471	if (ia == NULL)
472	break;
473	if (ia->ia_ifp == NULL) {
474	break;
475	}
476	icp->icmp_type = ICMP_MASKREPLY;
477	icp->icmp_mask = ia->ia_sockmask.sin_addr.s_addr;
478	if (ip->ip_src.s_addr == 0) {
479	if (ia->ia_ifp->if_flags & IFF_BROADCAST)
480	ip->ip_src = satosin(&ia->ia_broadaddr)->sin_addr;
481	else if (ia->ia_ifp->if_flags & IFF_POINTOPOINT)
482	ip->ip_src = satosin(&ia->ia_dstaddr)->sin_addr;
483	}
484	reflect:
485	ip->ip_len += hlen; /* since ip_input deducts this */
486	icmpstat.icps_reflect++;
487	icmpstat.icps_outhist[icp->icmp_type]++;
488	icmp_reflect(m);
489	return;
490
491	case ICMP_REDIRECT:
492	if (code > 3)
493	goto badcode;
494	if (icmplen < ICMP_ADVLENMIN \|\| icmplen < ICMP_ADVLEN(icp) \|\|
495	#ifdef _IP_VHL
496	IP_VHL_HL(icp->icmp_ip.ip_vhl) < (sizeof(struct ip) >> 2)) {
497	#else
498	icp->icmp_ip.ip_hl < (sizeof(struct ip) >> 2)) {
499	#endif
500	icmpstat.icps_badlen++;
501	break;
502	}
503	/*
504	* Short circuit routing redirects to force
505	* immediate change in the kernel's routing
506	* tables. The message is also handed to anyone
507	* listening on a raw socket (e.g. the routing
508	* daemon for use in updating its tables).
509	*/
510	icmpgw.sin_addr = ip->ip_src;
511	icmpdst.sin_addr = icp->icmp_gwaddr;
512	#ifdef ICMPPRINTFS
513	if (icmpprintfs) {
514	char buf[4 * sizeof "123"];
515	strcpy(buf, inet_ntoa(icp->icmp_ip.ip_dst));
516
517	printf("redirect dst %s to %s\n",
518	buf, inet_ntoa(icp->icmp_gwaddr));
519	}
520	#endif
521	icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
522	rtredirect((struct sockaddr *)&icmpsrc,
523	(struct sockaddr *)&icmpdst,
524	(struct sockaddr *)0, RTF_GATEWAY \| RTF_HOST,
525	(struct sockaddr )&icmpgw, (struct rtentry *)0);
526	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&icmpsrc);
527	break;
528
529	/*
530	* No kernel processing for the following;
531	* just fall through to send to raw listener.
532	*/
533	case ICMP_ECHOREPLY:
534	case ICMP_ROUTERADVERT:
535	case ICMP_ROUTERSOLICIT:
536	case ICMP_TSTAMPREPLY:
537	case ICMP_IREQREPLY:
538	case ICMP_MASKREPLY:
539	default:
540	break;
541	}
542
543	raw:
544	rip_input(m, hlen);
545	return;
546
547	freeit:
548	m_freem(m);
549	}
550
551	/*
552	* Reflect the ip packet back to the source
553	*/
554	static void
555	icmp_reflect(struct mbuf *m)
556	{
557	struct ip ip = mtod(m, struct ip );
558	struct in_ifaddr *ia;
559	struct in_addr t;
560	struct mbuf *opts = 0;
561	#ifdef _IP_VHL
562	int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
563	#else
564	int optlen = (ip->ip_hl << 2) - sizeof(struct ip);
565	#endif
566	if (!in_canforward(ip->ip_src) &&
567	((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
568	(IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
569	m_freem(m); /* Bad return address */
570	goto done; /* Ip_output() will check for broadcast */
571	}
572	t = ip->ip_dst;
573	ip->ip_dst = ip->ip_src;
574	/*
575	* If the incoming packet was addressed directly to us,
576	* use dst as the src for the reply. Otherwise (broadcast
577	* or anonymous), use the address which corresponds
578	* to the incoming interface.
579	*/
580	for (ia = in_ifaddr; ia; ia = ia->ia_next) {
581	if (t.s_addr == IA_SIN(ia)->sin_addr.s_addr)
582	break;
583	if (ia->ia_ifp && (ia->ia_ifp->if_flags & IFF_BROADCAST) &&
584	t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr)
585	break;
586	}
587	icmpdst.sin_addr = t;
588	if ((ia == (struct in_ifaddr *)0) && m->m_pkthdr.rcvif)
589	ia = (struct in_ifaddr *)ifaof_ifpforaddr(
590	(struct sockaddr *)&icmpdst, m->m_pkthdr.rcvif);
591	/*
592	* The following happens if the packet was not addressed to us,
593	* and was received on an interface with no IP address.
594	*/
595	if (ia == (struct in_ifaddr *)0)
596	ia = in_ifaddr;
597	t = IA_SIN(ia)->sin_addr;
598	ip->ip_src = t;
599	ip->ip_ttl = MAXTTL;
600
601	if (optlen > 0) {
602	register u_char *cp;
603	int opt, cnt;
604	u_int len;
605
606	/*
607	* Retrieve any source routing from the incoming packet;
608	* add on any record-route or timestamp options.
609	*/
610	cp = (u_char *) (ip + 1);
611	if ((opts = ip_srcroute()) == 0 &&
612	(opts = m_gethdr(M_DONTWAIT, MT_HEADER))) {
613	opts->m_len = sizeof(struct in_addr);
614	mtod(opts, struct in_addr *)->s_addr = 0;
615	}
616	if (opts) {
617	#ifdef ICMPPRINTFS
618	if (icmpprintfs)
619	printf("icmp_reflect optlen %d rt %d => ",
620	optlen, opts->m_len);
621	#endif
622	for (cnt = optlen; cnt > 0; cnt -= len, cp += len) {
623	opt = cp[IPOPT_OPTVAL];
624	if (opt == IPOPT_EOL)
625	break;
626	if (opt == IPOPT_NOP)
627	len = 1;
628	else {
629	if (cnt < IPOPT_OLEN + sizeof(*cp))
630	break;
631	len = cp[IPOPT_OLEN];
632	if (len < IPOPT_OLEN + sizeof(*cp) \|\|
633	len > cnt)
634	break;
635	}
636	/*
637	* Should check for overflow, but it "can't happen"
638	*/
639	if (opt == IPOPT_RR \|\| opt == IPOPT_TS \|\|
640	opt == IPOPT_SECURITY) {
641	bcopy((caddr_t)cp,
642	mtod(opts, caddr_t) + opts->m_len, len);
643	opts->m_len += len;
644	}
645	}
646	/* Terminate & pad, if necessary */
647	cnt = opts->m_len % 4;
648	if (cnt) {
649	for (; cnt < 4; cnt++) {
650	*(mtod(opts, caddr_t) + opts->m_len) =
651	IPOPT_EOL;
652	opts->m_len++;
653	}
654	}
655	#ifdef ICMPPRINTFS
656	if (icmpprintfs)
657	printf("%d\n", opts->m_len);
658	#endif
659	}
660	/*
661	* Now strip out original options by copying rest of first
662	* mbuf's data back, and adjust the IP length.
663	*/
664	ip->ip_len -= optlen;
665	#ifdef _IP_VHL
666	ip->ip_vhl = IP_VHL_BORING;
667	#else
668	ip->ip_v = IPVERSION;
669	ip->ip_hl = 5;
670	#endif
671	m->m_len -= optlen;
672	if (m->m_flags & M_PKTHDR)
673	m->m_pkthdr.len -= optlen;
674	optlen += sizeof(struct ip);
675	bcopy((caddr_t)ip + optlen, (caddr_t)(ip + 1),
676	(unsigned)(m->m_len - sizeof(struct ip)));
677	}
678	m->m_flags &= ~(M_BCAST\|M_MCAST);
679	icmp_send(m, opts);
680	done:
681	if (opts)
682	(void)m_free(opts);
683	}
684
685	/*
686	* Send an icmp packet back to the ip level,
687	* after supplying a checksum.
688	*/
689	static void
690	icmp_send(struct mbuf m, struct mbuf opts)
691	{
692	register struct ip ip = mtod(m, struct ip );
693	register int hlen;
694	register struct icmp *icp;
695	struct route ro;
696
697	#ifdef _IP_VHL
698	hlen = IP_VHL_HL(ip->ip_vhl) << 2;
699	#else
700	hlen = ip->ip_hl << 2;
701	#endif
702	m->m_data += hlen;
703	m->m_len -= hlen;
704	icp = mtod(m, struct icmp *);
705	icp->icmp_cksum = 0;
706	icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen);
707	m->m_data -= hlen;
708	m->m_len += hlen;
709	#ifdef ICMPPRINTFS
710	if (icmpprintfs) {
711	char buf[4 * sizeof "123"];
712	strcpy(buf, inet_ntoa(ip->ip_dst));
713	printf("icmp_send dst %s src %s\n",
714	buf, inet_ntoa(ip->ip_src));
715	}
716	#endif
717	bzero(&ro, sizeof ro);
718	(void) ip_output(m, opts, &ro, 0, NULL);
719	if (ro.ro_rt)
720	RTFREE(ro.ro_rt);
721	}
722
723	/*
724	* Return milliseconds since 00:00 GMT in network format.
725	*/
726	uint32_t
727	iptime(void)
728	{
729	struct timeval atv;
730	u_long t;
731
732	microtime(&atv);
733	t = (atv.tv_sec % (24L60L60L)) * 1000L + atv.tv_usec / 1000L;
734	return (htonl(t));
735	}
736
737	/*
738	* Return the next larger or smaller MTU plateau (table from RFC 1191)
739	* given current value MTU. If DIR is less than zero, a larger plateau
740	* is returned; otherwise, a smaller value is returned.
741	*/
742	int
743	ip_next_mtu(int mtu, int dir)
744	{
745	static int mtutab[] = {
746	65535, 32000, 17914, 8166, 4352, 2002, 1492, 1280, 1006, 508,
747	296, 68, 0
748	};
749	int i;
750
751	for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
752	if (mtu >= mtutab[i])
753	break;
754	}
755
756	if (dir < 0) {
757	if (i == 0) {
758	return 0;
759	} else {
760	return mtutab[i - 1];
761	}
762	} else {
763	if (mtutab[i] == 0) {
764	return 0;
765	} else if(mtu > mtutab[i]) {
766	return mtutab[i];
767	} else {
768	return mtutab[i + 1];
769	}
770	}
771	}

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

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