ip_icmp.c@ 17151

Last change on this file since 17151 was 17151, checked in by vboxsync, 16 years ago
NAT: ICMP logging
Property svn:eol-style set to `native`
File size: 21.9 KB

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

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 17151

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