ip_icmp.c@ 15521

Last change on this file since 15521 was 15521, checked in by vboxsync, 16 years ago
slirp:icmp: handling the situation when we're unable open raw socket.
Property svn:eol-style set to `native`
File size: 23.1 KB

Line
1	/*
2	* Copyright (c) 1982, 1986, 1988, 1993
3	* The Regents of the University of California. All rights reserved.
4	*
5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions
7	* are met:
8	* 1. Redistributions of source code must retain the above copyright
9	* notice, this list of conditions and the following disclaimer.
10	* 2. Redistributions in binary form must reproduce the above copyright
11	* notice, this list of conditions and the following disclaimer in the
12	* documentation and/or other materials provided with the distribution.
13	* 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_icmp.c 8.2 (Berkeley) 1/4/94
34	* ip_icmp.c,v 1.7 1995/05/30 08:09:42 rgrimes Exp
35	*/
36
37	#include "slirp.h"
38	#include "ip_icmp.h"
39	#ifdef RT_OS_WINDOWS
40	#include <Icmpapi.h>
41	#include <Iphlpapi.h>
42	#endif
43
44
45	/* The message sent when emulating PING */
46	/* Be nice and tell them it's just a psuedo-ping packet */
47	static const char icmp_ping_msg[] = "This is a psuedo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
48
49	/* list of actions for icmp_error() on RX of an icmp message */
50	static const int icmp_flush[19] =
51	{
52	/* ECHO REPLY (0) */ 0,
53	1,
54	1,
55	/* DEST UNREACH (3) */ 1,
56	/* SOURCE QUENCH (4)*/ 1,
57	/* REDIRECT (5) */ 1,
58	1,
59	1,
60	/* ECHO (8) */ 0,
61	/* ROUTERADVERT (9) */ 1,
62	/* ROUTERSOLICIT (10) */ 1,
63	/* TIME EXCEEDED (11) */ 1,
64	/* PARAMETER PROBLEM (12) */ 1,
65	/* TIMESTAMP (13) */ 0,
66	/* TIMESTAMP REPLY (14) */ 0,
67	/* INFO (15) */ 0,
68	/* INFO REPLY (16) */ 0,
69	/* ADDR MASK (17) */ 0,
70	/* ADDR MASK REPLY (18) */ 0
71	};
72
73	#ifdef VBOX_WITH_SLIRP_ICMP
74	int
75	icmp_init(PNATState pData)
76	{
77	pData->icmp_socket.so_type = IPPROTO_ICMP;
78	pData->icmp_socket.so_state = SS_ISFCONNECTED;
79	#ifndef RT_OS_WINDOWS
80	# ifndef RT_OS_DARWIN
81	pData->icmp_socket.s = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP);
82	# else /* !RT_OS_DARWIN */
83	pData->icmp_socket.s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
84	# endif /* RT_OS_DARWIN */
85	if (pData->icmp_socket.s == -1)
86	{
87	int rc = RTErrConvertFromErrno(errno);
88	LogRel(("NAT: ICMP/ping not available (could open ICMP socket, error %Rrc)\n", rc));
89	return 1;
90	}
91	#else /* RT_OS_WINDOWS */
92	pData->hmIcmpLibrary = LoadLibrary("Iphlpapi.dll");
93	if (pData->hmIcmpLibrary != NULL)
94	{
95	pData->pfIcmpParseReplies = (long (WINAPI )(void , long))
96	GetProcAddress(pData->hmIcmpLibrary, "IcmpParseReplies");
97	pData->pfIcmpCloseHandle = (BOOL (WINAPI *)(HANDLE))
98	GetProcAddress(pData->hmIcmpLibrary, "IcmpCloseHandle");
99	}
100	if (pData->pfIcmpParseReplies == NULL)
101	{
102	FreeLibrary(pData->hmIcmpLibrary);
103	pData->hmIcmpLibrary = LoadLibrary("Icmp.dll");
104	if (pData->hmIcmpLibrary == NULL)
105	{
106	LogRel(("NAT: Icmp.dll could not be loaded\n"));
107	return 1;
108	}
109	pData->pfIcmpParseReplies = (long (WINAPI )(void , long))
110	GetProcAddress(pData->hmIcmpLibrary, "IcmpParseReplies");
111	pData->pfIcmpCloseHandle = (BOOL (WINAPI *)(HANDLE))
112	GetProcAddress(pData->hmIcmpLibrary, "IcmpCloseHandle");
113	}
114	if (pData->pfIcmpParseReplies == NULL)
115	{
116	LogRel(("NAT: Can't find IcmpParseReplies symbol\n"));
117	FreeLibrary(pData->hmIcmpLibrary);
118	return 1;
119	}
120	if (pData->pfIcmpCloseHandle == NULL)
121	{
122	LogRel(("NAT: Can't find IcmpCloseHandle symbol\n"));
123	FreeLibrary(pData->hmIcmpLibrary);
124	return 1;
125	}
126	pData->icmp_socket.sh = IcmpCreateFile();
127	pData->phEvents[VBOX_ICMP_EVENT_INDEX] = CreateEvent(NULL, FALSE, FALSE, NULL);
128	pData->szIcmpBuffer = sizeof(ICMP_ECHO_REPLY) * 10;
129	pData->pvIcmpBuffer = malloc(pData->szIcmpBuffer);
130	#endif /* RT_OS_WINDOWS */
131	LIST_INIT(&pData->icmp_msg_head);
132	return 0;
133	}
134
135	/*
136	* ip here is ip header + 64bytes readed from ICMP packet
137	*/
138	struct icmp_msg *
139	icmp_find_original_mbuf(PNATState pData, struct ip *ip)
140	{
141	struct mbuf *m0;
142	struct ip *ip0;
143	struct icmp icp, icp0;
144	struct icmp_msg *icm = NULL;
145	int found = 0;
146	struct udphdr *udp;
147	struct tcphdr *tcp;
148	struct socket *head_socket = NULL;
149	struct socket *last_socket = NULL;
150	struct socket *so = NULL;
151	struct in_addr laddr, faddr;
152	u_short lport, fport;
153
154	laddr.s_addr = ~0;
155	faddr.s_addr = ~0;
156
157	lport = ~0;
158	fport = ~0;
159
160
161	Log(("%s: processing (proto:%d)\n", __FUNCTION__, ip->ip_p));
162	switch (ip->ip_p)
163	{
164	case IPPROTO_ICMP:
165	icp = (struct icmp )((char )ip + (ip->ip_hl << 2));
166	LIST_FOREACH(icm, &pData->icmp_msg_head, im_list)
167	{
168	m0 = icm->im_m;
169	ip0 = mtod(m0, struct ip *);
170	AssertRelease(ip0->ip_p == IPPROTO_ICMP);
171	icp0 = (struct icmp )((char )ip0 + (ip0->ip_hl << 2));
172	if ( ( (icp->icmp_type != ICMP_ECHO && ip->ip_src.s_addr == ip0->ip_dst.s_addr)
173	\|\| (icp->icmp_type == ICMP_ECHO && ip->ip_dst.s_addr == ip0->ip_dst.s_addr))
174	&& icp->icmp_id == icp0->icmp_id
175	&& icp->icmp_seq == icp0->icmp_seq)
176	{
177	found = 1;
178	break;
179	}
180	Log(("Have found nothing\n"));
181	}
182	break;
183
184	/*
185	* for TCP and UDP logic little bit reverted, we try to find the HOST socket
186	* from which the IP package has been sent.
187	*/
188	case IPPROTO_UDP:
189	head_socket = &udb;
190	udp = (struct udphdr )((char )ip + (ip->ip_hl << 2));
191	faddr.s_addr = ip->ip_dst.s_addr;
192	fport = udp->uh_dport;
193	laddr.s_addr = ip->ip_src.s_addr;
194	lport = udp->uh_sport;
195	last_socket = udp_last_so;
196	/* fall through */
197
198	case IPPROTO_TCP:
199	if (head_socket == NULL)
200	{
201	tcp = (struct tcphdr )((char )ip + (ip->ip_hl << 2));
202	head_socket = &tcb; /* head_socket could be initialized with udb*/
203	faddr.s_addr = ip->ip_dst.s_addr;
204	fport = tcp->th_dport;
205	laddr.s_addr = ip->ip_src.s_addr;
206	lport = tcp->th_sport;
207	last_socket = tcp_last_so;
208	}
209	/* check last socket first */
210	if ( last_socket->so_faddr.s_addr == faddr.s_addr
211	&& last_socket->so_fport == fport
212	&& last_socket->so_hlport == lport)
213	{
214	found = 1;
215	so = last_socket;
216	goto sofound;
217	}
218	for (so = head_socket->so_prev; so != head_socket; so = so->so_prev)
219	{
220	/* Should be reaplaced by hash here */
221	Log(("trying:%R[natsock] against %R[IP4]:%d lport=%d hlport=%d\n", so, &faddr, fport, lport, so->so_hlport));
222	if ( so->so_faddr.s_addr == faddr.s_addr
223	&& so->so_fport == fport
224	&& so->so_hlport == lport)
225	{
226	found = 1;
227	break;
228	}
229	}
230	break;
231
232	default:
233	LogRel(("%s:ICMP: unsupported protocol(%d)\n", __FUNCTION__, ip->ip_p));
234	}
235	sofound:
236	if (found == 1 && icm == NULL)
237	{
238	icm = malloc(sizeof(struct icmp_msg));
239	icm->im_m = so->so_m;
240	icm->im_so = so;
241	found = 1;
242	Log(("hit:%R[natsock]\n", so));
243	/*XXX: this storage not very long,
244	* better add flag if it should removed from lis
245	*/
246	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
247	return (icm);
248	}
249	if (found == 1)
250	return icm;
251
252	return NULL;
253	}
254
255	static int
256	icmp_attach(PNATState pData, struct mbuf *m)
257	{
258	struct icmp_msg *icm;
259	struct ip *ip;
260	ip = mtod(m, struct ip *);
261	Assert(ip->ip_p == IPPROTO_ICMP);
262	icm = malloc(sizeof(struct icmp_msg));
263	icm->im_m = m;
264	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
265	return 0;
266	}
267	#endif /* VBOX_WITH_SLIRP_ICMP */
268
269	/*
270	* Process a received ICMP message.
271	*/
272	void
273	icmp_input(PNATState pData, struct mbuf *m, int hlen)
274	{
275	register struct icmp *icp;
276	register struct ip ip = mtod(m, struct ip );
277	int icmplen = ip->ip_len;
278	int status;
279	uint32_t dst;
280	#if defined(VBOX_WITH_SLIRP_ICMP) && !defined(RT_OS_WINDOWS)
281	int ttl;
282	#endif
283
284	/* int code; */
285
286	DEBUG_CALL("icmp_input");
287	DEBUG_ARG("m = %lx", (long )m);
288	DEBUG_ARG("m_len = %d", m->m_len);
289
290	icmpstat.icps_received++;
291
292	/*
293	* Locate icmp structure in mbuf, and check
294	* that its not corrupted and of at least minimum length.
295	*/
296	if (icmplen < ICMP_MINLEN)
297	{
298	/* min 8 bytes payload */
299	icmpstat.icps_tooshort++;
300	freeit:
301	m_freem(pData, m);
302	goto end_error;
303	}
304
305	m->m_len -= hlen;
306	m->m_data += hlen;
307	icp = mtod(m, struct icmp *);
308	if (cksum(m, icmplen))
309	{
310	icmpstat.icps_checksum++;
311	goto freeit;
312	}
313	m->m_len += hlen;
314	m->m_data -= hlen;
315
316	/* icmpstat.icps_inhist[icp->icmp_type]++; */
317	/* code = icp->icmp_code; */
318
319	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
320	switch (icp->icmp_type)
321	{
322	case ICMP_ECHO:
323	#ifndef VBOX_WITH_SLIRP_ICMP
324	icp->icmp_type = ICMP_ECHOREPLY;
325	#endif /* !VBOX_WITH_SLIRP_ICMP */
326
327	ip->ip_len += hlen; /* since ip_input subtracts this */
328	dst = ip->ip_dst.s_addr;
329	if (dst == alias_addr.s_addr)
330	{
331	#ifdef VBOX_WITH_SLIRP_ICMP
332	icp->icmp_type = ICMP_ECHOREPLY;
333	ip->ip_dst.s_addr = ip->ip_src.s_addr;
334	ip->ip_src.s_addr = dst;
335	#endif /* VBOX_WITH_SLIRP_ICMP */
336	icmp_reflect(pData, m);
337	}
338	else
339	{
340	struct sockaddr_in addr;
341	#ifndef VBOX_WITH_SLIRP_ICMP
342	struct socket *so;
343	if ((so = socreate()) == NULL)
344	goto freeit;
345	if (udp_attach(pData, so) == -1)
346	{
347	DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n",
348	errno,strerror(errno)));
349	sofree(pData, so);
350	m_free(pData, m);
351	goto end_error;
352	}
353	so->so_m = m;
354	so->so_faddr = ip->ip_dst;
355	so->so_fport = htons(7);
356	so->so_laddr = ip->ip_src;
357	so->so_lport = htons(9);
358	so->so_iptos = ip->ip_tos;
359	so->so_type = IPPROTO_ICMP;
360	so->so_state = SS_ISFCONNECTED;
361
362	addr.sin_family = AF_INET;
363	if ((so->so_faddr.s_addr & htonl(pData->netmask)) == special_addr.s_addr)
364	{
365	/* It's an alias */
366	switch (ntohl(so->so_faddr.s_addr) & ~pData->netmask)
367	{
368	case CTL_DNS:
369	addr.sin_addr = dns_addr;
370	break;
371	case CTL_ALIAS:
372	default:
373	addr.sin_addr = loopback_addr;
374	break;
375	}
376	}
377	else
378	addr.sin_addr = so->so_faddr;
379	addr.sin_port = so->so_fport;
380	if (sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0,
381	(struct sockaddr *)&addr, sizeof(addr)) == -1)
382	{
383	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
384	errno,strerror(errno)));
385	icmp_error(pData, m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
386	udp_detach(pData, so);
387	}
388	#else /* VBOX_WITH_SLIRP_ICMP */
389	# ifdef RT_OS_WINDOWS
390	IP_OPTION_INFORMATION ipopt;
391	int error;
392	# endif
393	addr.sin_family = AF_INET;
394	if ((ip->ip_dst.s_addr & htonl(pData->netmask)) == special_addr.s_addr)
395	{
396	/* It's an alias */
397	switch (ntohl(ip->ip_dst.s_addr) & ~pData->netmask)
398	{
399	case CTL_DNS:
400	addr.sin_addr = dns_addr;
401	break;
402	case CTL_ALIAS:
403	default:
404	addr.sin_addr = loopback_addr;
405	break;
406	}
407	}
408	else
409	addr.sin_addr.s_addr = ip->ip_dst.s_addr;
410	# ifndef RT_OS_WINDOWS
411	if (pData->icmp_socket.s != -1)
412	{
413	icmp_attach(pData, m);
414	ttl = ip->ip_ttl;
415	Log(("NAT/ICMP: try to set TTL(%d)\n", ttl));
416	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL,
417	(void *)&ttl, sizeof(ttl));
418	if (status < 0)
419	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n",
420	strerror(errno)));
421	if (sendto(pData->icmp_socket.s, icp, icmplen, 0,
422	(struct sockaddr *)&addr, sizeof(addr)) == -1)
423	{
424	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
425	errno, strerror(errno)));
426	icmp_error(pData, m, ICMP_UNREACH,ICMP_UNREACH_NET, 0, strerror(errno));
427	m_free(pData, m);
428	}
429	}
430	else
431	{
432	/*
433	* We're freeing the ICMP message, which unable sent or process.
434	* That behavior described in rfc 793, we shouldn't notify sender about
435	* fail of processing it's ICMP packets
436	*/
437	m_free(pData, m);
438	return;
439	}
440	# else /* RT_OS_WINDOWS */
441	icmp_attach(pData, m);
442	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
443	pData->icmp_socket.so_icmp_id = icp->icmp_id;
444	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
445	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
446	ipopt.Ttl = ip->ip_ttl;
447	status = IcmpSendEcho2(pData->icmp_socket.sh, pData->phEvents[VBOX_ICMP_EVENT_INDEX],
448	NULL, NULL, addr.sin_addr.s_addr, icp->icmp_data,
449	icmplen - offsetof(struct icmp, icmp_data) , &ipopt,
450	pData->pvIcmpBuffer, pData->szIcmpBuffer, 1);
451	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
452	{
453	error = GetLastError();
454	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
455	switch (error)
456	{
457	case ERROR_INVALID_PARAMETER:
458	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
459	break;
460	case ERROR_NOT_SUPPORTED:
461	LogRel(("operation is unsupported)\n"));
462	break;
463	case ERROR_NOT_ENOUGH_MEMORY:
464	LogRel(("OOM!!!)\n"));
465	break;
466	case IP_BUF_TOO_SMALL:
467	LogRel(("Buffer too small)\n"));
468	break;
469	default:
470	LogRel(("Other error!!!)\n"));
471	break;
472	}
473	}
474	# endif /* RT_OS_WINDOWS */
475	#endif /* VBOX_WITH_SLIRP_ICMP */
476	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
477	break;
478	case ICMP_UNREACH:
479	/* XXX? report error? close socket? */
480	case ICMP_TIMXCEED:
481	case ICMP_PARAMPROB:
482	case ICMP_SOURCEQUENCH:
483	case ICMP_TSTAMP:
484	case ICMP_MASKREQ:
485	case ICMP_REDIRECT:
486	icmpstat.icps_notsupp++;
487	m_freem(pData, m);
488	break;
489
490	default:
491	icmpstat.icps_badtype++;
492	m_freem(pData, m);
493	} /* switch */
494
495	end_error:
496	/* m is m_free()'d xor put in a socket xor or given to ip_send */
497	;
498	}
499
500
501	/*
502	* Send an ICMP message in response to a situation
503	*
504	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
505	* MUST NOT change this header information.
506	* MUST NOT reply to a multicast/broadcast IP address.
507	* MUST NOT reply to a multicast/broadcast MAC address.
508	* MUST reply to only the first fragment.
509	*/
510	/*
511	* Send ICMP_UNREACH back to the source regarding msrc.
512	* mbuf *msrc is used as a template, but is NOT m_free()'d.
513	* It is reported as the bad ip packet. The header should
514	* be fully correct and in host byte order.
515	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
516	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
517	*/
518
519	#define ICMP_MAXDATALEN (IP_MSS-28)
520	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, const char message)
521	{
522	unsigned hlen, shlen, s_ip_len;
523	register struct ip *ip;
524	register struct icmp *icp;
525	register struct mbuf *m;
526
527	DEBUG_CALL("icmp_error");
528	DEBUG_ARG("msrc = %lx", (long )msrc);
529	DEBUG_ARG("msrc_len = %d", msrc->m_len);
530
531	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED)
532	goto end_error;
533
534	/* check msrc */
535	if (!msrc)
536	goto end_error;
537
538	ip = mtod(msrc, struct ip *);
539	#if DEBUG
540	{
541	char bufa[20], bufb[20];
542	strcpy(bufa, inet_ntoa(ip->ip_src));
543	strcpy(bufb, inet_ntoa(ip->ip_dst));
544	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
545	}
546	#endif
547	if (ip->ip_off & IP_OFFMASK)
548	goto end_error; /* Only reply to fragment 0 */
549
550	shlen = ip->ip_hl << 2;
551	s_ip_len = ip->ip_len;
552	if (ip->ip_p == IPPROTO_ICMP)
553	{
554	icp = (struct icmp )((char )ip + shlen);
555	/*
556	* Assume any unknown ICMP type is an error. This isn't
557	* specified by the RFC, but think about it..
558	*/
559	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
560	goto end_error;
561	}
562
563	/* make a copy */
564	if (!(m = m_get(pData)))
565	goto end_error; /* get mbuf */
566	{
567	int new_m_size;
568	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
569	if (new_m_size>m->m_size)
570	m_inc(m, new_m_size);
571	}
572	memcpy(m->m_data, msrc->m_data, msrc->m_len);
573	m->m_len = msrc->m_len; /* copy msrc to m */
574
575	/* make the header of the reply packet */
576	ip = mtod(m, struct ip *);
577	hlen = sizeof(struct ip ); /* no options in reply */
578
579	/* fill in icmp */
580	m->m_data += hlen;
581	m->m_len -= hlen;
582
583	icp = mtod(m, struct icmp *);
584
585	if (minsize)
586	s_ip_len = shlen+ICMP_MINLEN; /* return header+8b only */
587	else if (s_ip_len > ICMP_MAXDATALEN) /* maximum size */
588	s_ip_len = ICMP_MAXDATALEN;
589
590	m->m_len = ICMP_MINLEN + s_ip_len; /* 8 bytes ICMP header */
591
592	/* min. size = 8+sizeof(struct ip)+8 */
593
594	icp->icmp_type = type;
595	icp->icmp_code = code;
596	icp->icmp_id = 0;
597	icp->icmp_seq = 0;
598
599	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
600	HTONS(icp->icmp_ip.ip_len);
601	HTONS(icp->icmp_ip.ip_id);
602	HTONS(icp->icmp_ip.ip_off);
603
604	#if DEBUG
605	if (message)
606	{
607	/* DEBUG : append message to ICMP packet */
608	int message_len;
609	char *cpnt;
610	message_len = strlen(message);
611	if (message_len > ICMP_MAXDATALEN)
612	message_len = ICMP_MAXDATALEN;
613	cpnt = (char *)m->m_data+m->m_len;
614	memcpy(cpnt, message, message_len);
615	m->m_len += message_len;
616	}
617	#endif
618
619	icp->icmp_cksum = 0;
620	icp->icmp_cksum = cksum(m, m->m_len);
621
622	m->m_data -= hlen;
623	m->m_len += hlen;
624
625	/* fill in ip */
626	ip->ip_hl = hlen >> 2;
627	ip->ip_len = m->m_len;
628
629	ip->ip_tos = ((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
630
631	ip->ip_ttl = MAXTTL;
632	ip->ip_p = IPPROTO_ICMP;
633	ip->ip_dst = ip->ip_src; /* ip adresses */
634	ip->ip_src = alias_addr;
635
636	(void ) ip_output(pData, (struct socket *)NULL, m);
637
638	icmpstat.icps_reflect++;
639
640	end_error:
641	;
642	}
643	#undef ICMP_MAXDATALEN
644
645	/*
646	* Reflect the ip packet back to the source
647	*/
648	void
649	icmp_reflect(PNATState pData, struct mbuf *m)
650	{
651	register struct ip ip = mtod(m, struct ip );
652	int hlen = ip->ip_hl << 2;
653	int optlen = hlen - sizeof(struct ip );
654	register struct icmp *icp;
655
656	/*
657	* Send an icmp packet back to the ip level,
658	* after supplying a checksum.
659	*/
660	m->m_data += hlen;
661	m->m_len -= hlen;
662	icp = mtod(m, struct icmp *);
663
664	icp->icmp_cksum = 0;
665	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
666
667	m->m_data -= hlen;
668	m->m_len += hlen;
669
670	#ifndef VBOX_WITH_SLIRP_ICMP
671	/* fill in ip */
672	if (optlen > 0)
673	{
674	/*
675	* Strip out original options by copying rest of first
676	* mbuf's data back, and adjust the IP length.
677	*/
678	memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen,
679	(unsigned )(m->m_len - hlen));
680	hlen -= optlen;
681	ip->ip_hl = hlen >> 2;
682	ip->ip_len -= optlen;
683	m->m_len -= optlen;
684	}
685	ip->ip_ttl = MAXTTL;
686	{
687	/* swap */
688	struct in_addr icmp_dst;
689	icmp_dst = ip->ip_dst;
690	ip->ip_dst = ip->ip_src;
691	ip->ip_src = icmp_dst;
692	}
693	#endif /* !VBOX_WITH_SLIRP_ICMP */
694
695	(void ) ip_output(pData, (struct socket *)NULL, m);
696
697	icmpstat.icps_reflect++;
698	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 15521

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