ip_icmp.c@ 15266

Last change on this file since 15266 was 15241, checked in by vboxsync, 16 years ago
slirp:icmp: Vista fix (according the forums) IcmpSendEchoes require any non-0 timeout to work on Vista.
Property svn:eol-style set to `native`
File size: 21.5 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(PF_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, so;
149	struct in_addr laddr, faddr;
150	u_int lport, fport;
151
152	laddr.s_addr = ~0;
153	faddr.s_addr = ~0;
154
155	lport = ~0;
156	fport = ~0;
157
158
159	switch (ip->ip_p)
160	{
161	case IPPROTO_ICMP:
162	icp = (struct icmp )((char )ip + (ip->ip_hl << 2));
163	LIST_FOREACH(icm, &pData->icmp_msg_head, im_list)
164	{
165	m0 = icm->im_m;
166	ip0 = mtod(m0, struct ip *);
167	AssertRelease(ip0->ip_p == IPPROTO_ICMP);
168	icp0 = (struct icmp )((char )ip0 + (ip0->ip_hl << 2));
169	if ( ( (icp->icmp_type != ICMP_ECHO && ip->ip_src.s_addr == ip0->ip_dst.s_addr)
170	\|\| (icp->icmp_type == ICMP_ECHO && ip->ip_dst.s_addr == ip0->ip_dst.s_addr))
171	&& icp->icmp_id == icp0->icmp_id
172	&& icp->icmp_seq == icp->icmp_seq)
173	{
174	found = 1;
175	break;
176	}
177	}
178	/*
179	* for TCP and UDP logic little bit reverted, we try to find the HOST socket
180	* from which the IP package has been sent.
181	*/
182	case IPPROTO_UDP:
183	head_socket = &udb;
184	udp = (struct udphdr )((char )ip + (ip->ip_hl >> 2));
185	faddr.s_addr = ip->ip_dst.s_addr;
186	fport = udp->uh_dport;
187	laddr.s_addr = ip->ip_src.s_addr;
188	lport = udp->uh_sport;
189	case IPPROTO_TCP:
190	if (head_socket == NULL)
191	{
192	tcp = (struct tcphdr )((char )ip + (ip->ip_hl >> 2));
193	head_socket = &tcb; /* head_socket could be initialized with udb*/
194	faddr.s_addr = ip->ip_dst.s_addr;
195	fport = tcp->th_dport;
196	laddr.s_addr = ip->ip_src.s_addr;
197	lport = tcp->th_sport;
198	}
199	for (so = head_socket; so != head_socket; so = so->so_next)
200	{
201	/* Should be reaplaced by hash here */
202	if (so->so_faddr.s_addr == faddr.s_addr
203	&& so->so_fport == fport
204	&& so->so_hladdr.s_addr == laddr.s_addr
205	&& so->so_hlport == lport) {
206	icm = malloc(sizeof(struct icmp_msg));
207	icm->im_m = so->so_m;
208	found = 1;
209	}
210	}
211	break;
212	default:
213	LogRel(("%s:ICMP: unsupported protocol(%d)\n", __FUNCTION__, ip->ip_p));
214	}
215	if (found == 1)
216	return icm;
217
218	return NULL;
219	}
220
221	static int
222	icmp_attach(PNATState pData, struct mbuf *m)
223	{
224	struct icmp_msg *icm;
225	struct ip *ip;
226	ip = mtod(m, struct ip *);
227	Assert(ip->ip_p == IPPROTO_ICMP);
228	icm = malloc(sizeof(struct icmp_msg));
229	icm->im_m = m;
230	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
231	return (0);
232	}
233	#endif /* VBOX_WITH_SLIRP_ICMP */
234
235	/*
236	* Process a received ICMP message.
237	*/
238	void
239	icmp_input(PNATState pData, struct mbuf *m, int hlen)
240	{
241	register struct icmp *icp;
242	register struct ip ip=mtod(m, struct ip );
243	int icmplen=ip->ip_len;
244	int status;
245	uint32_t dst;
246
247	/* int code; */
248
249	DEBUG_CALL("icmp_input");
250	DEBUG_ARG("m = %lx", (long )m);
251	DEBUG_ARG("m_len = %d", m->m_len);
252
253	icmpstat.icps_received++;
254
255	/*
256	* Locate icmp structure in mbuf, and check
257	* that its not corrupted and of at least minimum length.
258	*/
259	if (icmplen < ICMP_MINLEN)
260	{
261	/* min 8 bytes payload */
262	icmpstat.icps_tooshort++;
263	freeit:
264	m_freem(pData, m);
265	goto end_error;
266	}
267
268	m->m_len -= hlen;
269	m->m_data += hlen;
270	icp = mtod(m, struct icmp *);
271	if (cksum(m, icmplen))
272	{
273	icmpstat.icps_checksum++;
274	goto freeit;
275	}
276	m->m_len += hlen;
277	m->m_data -= hlen;
278
279	/* icmpstat.icps_inhist[icp->icmp_type]++; */
280	/* code = icp->icmp_code; */
281
282	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
283	switch (icp->icmp_type)
284	{
285	case ICMP_ECHO:
286	#ifndef VBOX_WITH_SLIRP_ICMP
287	icp->icmp_type = ICMP_ECHOREPLY;
288	#endif /* !VBOX_WITH_SLIRP_ICMP */
289
290	ip->ip_len += hlen; /* since ip_input subtracts this */
291	dst = ip->ip_dst.s_addr;
292	if (dst == alias_addr.s_addr)
293	{
294	#ifdef VBOX_WITH_SLIRP_ICMP
295	icp->icmp_type = ICMP_ECHOREPLY;
296	ip->ip_dst.s_addr = ip->ip_src.s_addr;
297	ip->ip_src.s_addr = dst;
298	#endif /* VBOX_WITH_SLIRP_ICMP */
299	icmp_reflect(pData, m);
300	}
301	else
302	{
303	struct socket *so;
304	struct sockaddr_in addr;
305	#ifndef VBOX_WITH_SLIRP_ICMP
306	if ((so = socreate()) == NULL)
307	goto freeit;
308	if (udp_attach(pData, so) == -1)
309	{
310	DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n",
311	errno,strerror(errno)));
312	sofree(pData, so);
313	m_free(pData, m);
314	goto end_error;
315	}
316	so->so_m = m;
317	so->so_faddr = ip->ip_dst;
318	so->so_fport = htons(7);
319	so->so_laddr = ip->ip_src;
320	so->so_lport = htons(9);
321	so->so_iptos = ip->ip_tos;
322	so->so_type = IPPROTO_ICMP;
323	so->so_state = SS_ISFCONNECTED;
324
325	addr.sin_family = AF_INET;
326	if ((so->so_faddr.s_addr & htonl(pData->netmask)) == special_addr.s_addr)
327	{
328	/* It's an alias */
329	switch (ntohl(so->so_faddr.s_addr) & ~pData->netmask)
330	{
331	case CTL_DNS:
332	addr.sin_addr = dns_addr;
333	break;
334	case CTL_ALIAS:
335	default:
336	addr.sin_addr = loopback_addr;
337	break;
338	}
339	}
340	else
341	addr.sin_addr = so->so_faddr;
342	addr.sin_port = so->so_fport;
343	if (sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0,
344	(struct sockaddr *)&addr, sizeof(addr)) == -1)
345	{
346	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
347	errno,strerror(errno)));
348	icmp_error(pData, m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
349	udp_detach(pData, so);
350	}
351	#else /* VBOX_WITH_SLIRP_ICMP */
352	# ifdef RT_OS_WINDOWS
353	IP_OPTION_INFORMATION ipopt;
354	int error;
355	# endif
356	addr.sin_family = AF_INET;
357	if ((ip->ip_dst.s_addr & htonl(pData->netmask)) == special_addr.s_addr)
358	{
359	/* It's an alias */
360	switch(ntohl(ip->ip_dst.s_addr) & ~pData->netmask)
361	{
362	case CTL_DNS:
363	addr.sin_addr = dns_addr;
364	break;
365	case CTL_ALIAS:
366	default:
367	addr.sin_addr = loopback_addr;
368	break;
369	}
370	}
371	else
372	addr.sin_addr.s_addr = ip->ip_dst.s_addr;
373	icmp_attach(pData, m);
374	/* Send the packet */
375	# ifndef RT_OS_WINDOWS
376	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL, (void *)&ip->ip_ttl, sizeof(ip->ip_ttl));
377	if (status < 0)
378	{
379	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n", strerror(errno)));
380	}
381	if (sendto(pData->icmp_socket.s, icp, icmplen, 0,
382	(struct sockaddr *)&addr, sizeof(addr)) == -1)
383	{
384	DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
385	errno,strerror(errno)));
386	icmp_error(pData, m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
387	m_free(pData, m);
388	}
389	# else /* RT_OS_WINDOWS */
390	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
391	pData->icmp_socket.so_icmp_id = icp->icmp_id;
392	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
393	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
394	ipopt.Ttl = ip->ip_ttl;
395	status = IcmpSendEcho2(pData->icmp_socket.sh, pData->phEvents[VBOX_ICMP_EVENT_INDEX],
396	NULL, NULL, addr.sin_addr.s_addr, icp->icmp_data,
397	icmplen - offsetof(struct icmp, icmp_data) , &ipopt,
398	pData->pvIcmpBuffer, pData->szIcmpBuffer, 1);
399	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
400	{
401	error = GetLastError();
402	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
403	switch (error)
404	{
405	case ERROR_INVALID_PARAMETER:
406	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
407	break;
408	case ERROR_NOT_SUPPORTED:
409	LogRel(("operation is unsupported)\n"));
410	break;
411	case ERROR_NOT_ENOUGH_MEMORY:
412	LogRel(("OOM!!!)\n"));
413	break;
414	case IP_BUF_TOO_SMALL:
415	LogRel(("Buffer too small)\n"));
416	break;
417	default:
418	LogRel(("Other error!!!)\n"));
419	break;
420	}
421	}
422	# endif /* RT_OS_WINDOWS */
423	#endif /* VBOX_WITH_SLIRP_ICMP */
424	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
425	break;
426	case ICMP_UNREACH:
427	/* XXX? report error? close socket? */
428	case ICMP_TIMXCEED:
429	case ICMP_PARAMPROB:
430	case ICMP_SOURCEQUENCH:
431	case ICMP_TSTAMP:
432	case ICMP_MASKREQ:
433	case ICMP_REDIRECT:
434	icmpstat.icps_notsupp++;
435	m_freem(pData, m);
436	break;
437
438	default:
439	icmpstat.icps_badtype++;
440	m_freem(pData, m);
441	} /* switch */
442
443	end_error:
444	/* m is m_free()'d xor put in a socket xor or given to ip_send */
445	;
446	}
447
448
449	/*
450	* Send an ICMP message in response to a situation
451	*
452	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
453	* MUST NOT change this header information.
454	* MUST NOT reply to a multicast/broadcast IP address.
455	* MUST NOT reply to a multicast/broadcast MAC address.
456	* MUST reply to only the first fragment.
457	*/
458	/*
459	* Send ICMP_UNREACH back to the source regarding msrc.
460	* mbuf *msrc is used as a template, but is NOT m_free()'d.
461	* It is reported as the bad ip packet. The header should
462	* be fully correct and in host byte order.
463	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
464	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
465	*/
466
467	#define ICMP_MAXDATALEN (IP_MSS-28)
468	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, char message)
469	{
470	unsigned hlen, shlen, s_ip_len;
471	register struct ip *ip;
472	register struct icmp *icp;
473	register struct mbuf *m;
474
475	DEBUG_CALL("icmp_error");
476	DEBUG_ARG("msrc = %lx", (long )msrc);
477	DEBUG_ARG("msrc_len = %d", msrc->m_len);
478
479	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED)
480	goto end_error;
481
482	/* check msrc */
483	if (!msrc)
484	goto end_error;
485
486	ip = mtod(msrc, struct ip *);
487	#if DEBUG
488	{
489	char bufa[20], bufb[20];
490	strcpy(bufa, inet_ntoa(ip->ip_src));
491	strcpy(bufb, inet_ntoa(ip->ip_dst));
492	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
493	}
494	#endif
495	if (ip->ip_off & IP_OFFMASK)
496	goto end_error; /* Only reply to fragment 0 */
497
498	shlen=ip->ip_hl << 2;
499	s_ip_len=ip->ip_len;
500	if (ip->ip_p == IPPROTO_ICMP)
501	{
502	icp = (struct icmp )((char )ip + shlen);
503	/*
504	* Assume any unknown ICMP type is an error. This isn't
505	* specified by the RFC, but think about it..
506	*/
507	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
508	goto end_error;
509	}
510
511	/* make a copy */
512	if (!(m=m_get(pData)))
513	goto end_error; /* get mbuf */
514	{
515	int new_m_size;
516	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
517	if (new_m_size>m->m_size)
518	m_inc(m, new_m_size);
519	}
520	memcpy(m->m_data, msrc->m_data, msrc->m_len);
521	m->m_len = msrc->m_len; /* copy msrc to m */
522
523	/* make the header of the reply packet */
524	ip = mtod(m, struct ip *);
525	hlen = sizeof(struct ip ); /* no options in reply */
526
527	/* fill in icmp */
528	m->m_data += hlen;
529	m->m_len -= hlen;
530
531	icp = mtod(m, struct icmp *);
532
533	if (minsize)
534	s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */
535	else if (s_ip_len>ICMP_MAXDATALEN) /* maximum size */
536	s_ip_len=ICMP_MAXDATALEN;
537
538	m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */
539
540	/* min. size = 8+sizeof(struct ip)+8 */
541
542	icp->icmp_type = type;
543	icp->icmp_code = code;
544	icp->icmp_id = 0;
545	icp->icmp_seq = 0;
546
547	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
548	HTONS(icp->icmp_ip.ip_len);
549	HTONS(icp->icmp_ip.ip_id);
550	HTONS(icp->icmp_ip.ip_off);
551
552	#if DEBUG
553	if (message)
554	{
555	/* DEBUG : append message to ICMP packet */
556	int message_len;
557	char *cpnt;
558	message_len=strlen(message);
559	if (message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN;
560	cpnt=(char *)m->m_data+m->m_len;
561	memcpy(cpnt, message, message_len);
562	m->m_len+=message_len;
563	}
564	#endif
565
566	icp->icmp_cksum = 0;
567	icp->icmp_cksum = cksum(m, m->m_len);
568
569	m->m_data -= hlen;
570	m->m_len += hlen;
571
572	/* fill in ip */
573	ip->ip_hl = hlen >> 2;
574	ip->ip_len = m->m_len;
575
576	ip->ip_tos=((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
577
578	ip->ip_ttl = MAXTTL;
579	ip->ip_p = IPPROTO_ICMP;
580	ip->ip_dst = ip->ip_src; /* ip adresses */
581	ip->ip_src = alias_addr;
582
583	(void ) ip_output(pData, (struct socket *)NULL, m);
584
585	icmpstat.icps_reflect++;
586
587	end_error:
588	;
589	}
590	#undef ICMP_MAXDATALEN
591
592	/*
593	* Reflect the ip packet back to the source
594	*/
595	void
596	icmp_reflect(PNATState pData, struct mbuf *m)
597	{
598	register struct ip ip = mtod(m, struct ip );
599	int hlen = ip->ip_hl << 2;
600	int optlen = hlen - sizeof(struct ip );
601	register struct icmp *icp;
602
603	/*
604	* Send an icmp packet back to the ip level,
605	* after supplying a checksum.
606	*/
607	m->m_data += hlen;
608	m->m_len -= hlen;
609	icp = mtod(m, struct icmp *);
610
611	icp->icmp_cksum = 0;
612	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
613
614	m->m_data -= hlen;
615	m->m_len += hlen;
616
617	#ifndef VBOX_WITH_SLIRP_ICMP
618	/* fill in ip */
619	if (optlen > 0)
620	{
621	/*
622	* Strip out original options by copying rest of first
623	* mbuf's data back, and adjust the IP length.
624	*/
625	memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen,
626	(unsigned )(m->m_len - hlen));
627	hlen -= optlen;
628	ip->ip_hl = hlen >> 2;
629	ip->ip_len -= optlen;
630	m->m_len -= optlen;
631	}
632	ip->ip_ttl = MAXTTL;
633	{
634	/* swap */
635	struct in_addr icmp_dst;
636	icmp_dst = ip->ip_dst;
637	ip->ip_dst = ip->ip_src;
638	ip->ip_src = icmp_dst;
639	}
640	#endif /* !VBOX_WITH_SLIRP_ICMP */
641
642	(void ) ip_output(pData, (struct socket *)NULL, m);
643
644	icmpstat.icps_reflect++;
645	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 15266

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