ip_icmp.c@ 17389

Last change on this file since 17389 was 17222, checked in by vboxsync, 16 years ago
NAT: Multi DNS takes DNS servers IP addresses only from UP interfaces
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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	# ifdef VBOX_WITH_MULTI_DNS
113	pData->pfGetAdaptersAddresses = (ULONG (WINAPI *)(HANDLE))
114	GetProcAddress(pData->hmIcmpLibrary, "GetAdaptersAddresses");
115	if (pData->pfGetAdaptersAddresses == NULL)
116	{
117	LogRel(("NAT: Can't find GetAdapterAddresses in Iphlpapi.dll"));
118	}
119	# endif
120	}
121
122	if (pData->pfIcmpParseReplies == NULL)
123	{
124	# ifdef VBOX_WITH_MULTI_DNS
125	if(pData->pfGetAdaptersAddresses == NULL)
126	FreeLibrary(pData->hmIcmpLibrary);
127	# else
128	FreeLibrary(pData->hmIcmpLibrary);
129	# endif
130	pData->hmIcmpLibrary = LoadLibrary("Icmp.dll");
131	if (pData->hmIcmpLibrary == NULL)
132	{
133	LogRel(("NAT: Icmp.dll could not be loaded\n"));
134	return 1;
135	}
136	pData->pfIcmpParseReplies = (long (WINAPI )(void , long))
137	GetProcAddress(pData->hmIcmpLibrary, "IcmpParseReplies");
138	pData->pfIcmpCloseHandle = (BOOL (WINAPI *)(HANDLE))
139	GetProcAddress(pData->hmIcmpLibrary, "IcmpCloseHandle");
140	}
141	if (pData->pfIcmpParseReplies == NULL)
142	{
143	LogRel(("NAT: Can't find IcmpParseReplies symbol\n"));
144	FreeLibrary(pData->hmIcmpLibrary);
145	return 1;
146	}
147	if (pData->pfIcmpCloseHandle == NULL)
148	{
149	LogRel(("NAT: Can't find IcmpCloseHandle symbol\n"));
150	FreeLibrary(pData->hmIcmpLibrary);
151	return 1;
152	}
153	pData->icmp_socket.sh = IcmpCreateFile();
154	# ifdef VBOX_WITH_SIMPLIFIED_SLIRP_SYNC
155	pData->phEvents[VBOX_ICMP_EVENT_INDEX] = CreateEvent(NULL, FALSE, FALSE, NULL);
156	# endif /* VBOX_WITH_SIMPLIFIED_SLIRP_SYNC */
157	pData->szIcmpBuffer = sizeof(ICMP_ECHO_REPLY) * 10;
158	pData->pvIcmpBuffer = RTMemAlloc(pData->szIcmpBuffer);
159	#endif /* RT_OS_WINDOWS */
160	LIST_INIT(&pData->icmp_msg_head);
161	return 0;
162	}
163
164	/*
165	* ip here is ip header + 64bytes readed from ICMP packet
166	*/
167	struct icmp_msg *
168	icmp_find_original_mbuf(PNATState pData, struct ip *ip)
169	{
170	struct mbuf *m0;
171	struct ip *ip0;
172	struct icmp icp, icp0;
173	struct icmp_msg *icm = NULL;
174	int found = 0;
175	struct udphdr *udp;
176	struct tcphdr *tcp;
177	struct socket *head_socket = NULL;
178	struct socket *last_socket = NULL;
179	struct socket *so = NULL;
180	struct in_addr laddr, faddr;
181	u_short lport, fport;
182
183	laddr.s_addr = ~0;
184	faddr.s_addr = ~0;
185
186	lport = ~0;
187	fport = ~0;
188
189
190	Log(("%s: processing (proto:%d)\n", __FUNCTION__, ip->ip_p));
191	switch (ip->ip_p)
192	{
193	case IPPROTO_ICMP:
194	icp = (struct icmp )((char )ip + (ip->ip_hl << 2));
195	LIST_FOREACH(icm, &pData->icmp_msg_head, im_list)
196	{
197	m0 = icm->im_m;
198	ip0 = mtod(m0, struct ip *);
199	AssertRelease(ip0->ip_p == IPPROTO_ICMP);
200	icp0 = (struct icmp )((char )ip0 + (ip0->ip_hl << 2));
201	if ( ( (icp->icmp_type != ICMP_ECHO && ip->ip_src.s_addr == ip0->ip_dst.s_addr)
202	\|\| (icp->icmp_type == ICMP_ECHO && ip->ip_dst.s_addr == ip0->ip_dst.s_addr))
203	&& icp->icmp_id == icp0->icmp_id
204	&& icp->icmp_seq == icp0->icmp_seq)
205	{
206	found = 1;
207	Log(("Have found %R[natsock]\n", icm->im_so));
208	break;
209	}
210	Log(("Have found nothing\n"));
211	}
212	break;
213
214	/*
215	* for TCP and UDP logic little bit reverted, we try to find the HOST socket
216	* from which the IP package has been sent.
217	*/
218	case IPPROTO_UDP:
219	head_socket = &udb;
220	udp = (struct udphdr )((char )ip + (ip->ip_hl << 2));
221	faddr.s_addr = ip->ip_dst.s_addr;
222	fport = udp->uh_dport;
223	laddr.s_addr = ip->ip_src.s_addr;
224	lport = udp->uh_sport;
225	last_socket = udp_last_so;
226	/* fall through */
227
228	case IPPROTO_TCP:
229	if (head_socket == NULL)
230	{
231	tcp = (struct tcphdr )((char )ip + (ip->ip_hl << 2));
232	head_socket = &tcb; /* head_socket could be initialized with udb*/
233	faddr.s_addr = ip->ip_dst.s_addr;
234	fport = tcp->th_dport;
235	laddr.s_addr = ip->ip_src.s_addr;
236	lport = tcp->th_sport;
237	last_socket = tcp_last_so;
238	}
239	/* check last socket first */
240	if ( last_socket->so_faddr.s_addr == faddr.s_addr
241	&& last_socket->so_fport == fport
242	&& last_socket->so_hlport == lport)
243	{
244	found = 1;
245	so = last_socket;
246	goto sofound;
247	}
248	for (so = head_socket->so_prev; so != head_socket; so = so->so_prev)
249	{
250	/* Should be reaplaced by hash here */
251	Log(("trying:%R[natsock] against %R[IP4]:%d lport=%d hlport=%d\n", so, &faddr, fport, lport, so->so_hlport));
252	if ( so->so_faddr.s_addr == faddr.s_addr
253	&& so->so_fport == fport
254	&& so->so_hlport == lport)
255	{
256	found = 1;
257	break;
258	}
259	}
260	break;
261
262	default:
263	LogRel(("%s:ICMP: unsupported protocol(%d)\n", __FUNCTION__, ip->ip_p));
264	}
265	sofound:
266	if (found == 1 && icm == NULL)
267	{
268	if (so->so_state == SS_NOFDREF)
269	{
270	/* socket is shutdowning we've already sent ICMP on it.*/
271	LogRel(("NAT: Received icmp on shutdowning socket (probably corresponding ICMP socket has been already sent)\n"));
272	return NULL;
273	}
274	icm = RTMemAlloc(sizeof(struct icmp_msg));
275	icm->im_m = so->so_m;
276	icm->im_so = so;
277	found = 1;
278	Log(("hit:%R[natsock]\n", so));
279	/*XXX: this storage not very long,
280	* better add flag if it should removed from lis
281	*/
282	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
283	return (icm);
284	}
285	if (found == 1)
286	return icm;
287
288	return NULL;
289	}
290
291	static int
292	icmp_attach(PNATState pData, struct mbuf *m)
293	{
294	struct icmp_msg *icm;
295	struct ip *ip;
296	ip = mtod(m, struct ip *);
297	Assert(ip->ip_p == IPPROTO_ICMP);
298	icm = RTMemAlloc(sizeof(struct icmp_msg));
299	icm->im_m = m;
300	icm->im_so = m->m_so;
301	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
302	return 0;
303	}
304
305	/*
306	* Process a received ICMP message.
307	*/
308	void
309	icmp_input(PNATState pData, struct mbuf *m, int hlen)
310	{
311	register struct icmp *icp;
312	register struct ip ip = mtod(m, struct ip );
313	int icmplen = ip->ip_len;
314	int status;
315	uint32_t dst;
316	#if !defined(RT_OS_WINDOWS)
317	int ttl;
318	#endif
319
320	/* int code; */
321
322	DEBUG_CALL("icmp_input");
323	DEBUG_ARG("m = %lx", (long )m);
324	DEBUG_ARG("m_len = %d", m->m_len);
325
326	icmpstat.icps_received++;
327
328	/*
329	* Locate icmp structure in mbuf, and check
330	* that its not corrupted and of at least minimum length.
331	*/
332	if (icmplen < ICMP_MINLEN)
333	{
334	/* min 8 bytes payload */
335	icmpstat.icps_tooshort++;
336	freeit:
337	m_freem(pData, m);
338	goto end_error;
339	}
340
341	m->m_len -= hlen;
342	m->m_data += hlen;
343	icp = mtod(m, struct icmp *);
344	if (cksum(m, icmplen))
345	{
346	icmpstat.icps_checksum++;
347	goto freeit;
348	}
349	m->m_len += hlen;
350	m->m_data -= hlen;
351
352	/* icmpstat.icps_inhist[icp->icmp_type]++; */
353	/* code = icp->icmp_code; */
354
355	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
356	switch (icp->icmp_type)
357	{
358	case ICMP_ECHO:
359	ip->ip_len += hlen; /* since ip_input subtracts this */
360	dst = ip->ip_dst.s_addr;
361	if (dst == alias_addr.s_addr)
362	{
363	icp->icmp_type = ICMP_ECHOREPLY;
364	ip->ip_dst.s_addr = ip->ip_src.s_addr;
365	ip->ip_src.s_addr = dst;
366	icmp_reflect(pData, m);
367	}
368	else
369	{
370	struct sockaddr_in addr;
371	#ifdef RT_OS_WINDOWS
372	IP_OPTION_INFORMATION ipopt;
373	int error;
374	#endif
375	addr.sin_family = AF_INET;
376	if ((ip->ip_dst.s_addr & htonl(pData->netmask)) == special_addr.s_addr)
377	{
378	/* It's an alias */
379	switch (ntohl(ip->ip_dst.s_addr) & ~pData->netmask)
380	{
381	case CTL_DNS:
382	#ifndef VBOX_WITH_MULTI_DNS
383	addr.sin_addr = dns_addr;
384	break;
385	#endif
386	case CTL_ALIAS:
387	default:
388	addr.sin_addr = loopback_addr;
389	break;
390	}
391	}
392	else
393	addr.sin_addr.s_addr = ip->ip_dst.s_addr;
394	#ifndef RT_OS_WINDOWS
395	if (pData->icmp_socket.s != -1)
396	{
397	m->m_so = &pData->icmp_socket;
398	icmp_attach(pData, m);
399	ttl = ip->ip_ttl;
400	Log(("NAT/ICMP: try to set TTL(%d)\n", ttl));
401	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL,
402	(void *)&ttl, sizeof(ttl));
403	if (status < 0)
404	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n",
405	strerror(errno)));
406	if (sendto(pData->icmp_socket.s, icp, icmplen, 0,
407	(struct sockaddr *)&addr, sizeof(addr)) == -1)
408	{
409	Log((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
410	errno, strerror(errno)));
411	icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
412	}
413	}
414	else
415	{
416	/*
417	* We're freeing the ICMP message, which unable sent or process.
418	* That behavior described in rfc 793, we shouldn't notify sender about
419	* fail of processing it's ICMP packets
420	*/
421	m_free(pData, m);
422	return;
423	}
424	#else /* RT_OS_WINDOWS */
425	icmp_attach(pData, m);
426	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
427	pData->icmp_socket.so_icmp_id = icp->icmp_id;
428	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
429	m->m_so = &pData->icmp_socket;
430	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
431	ipopt.Ttl = ip->ip_ttl;
432	status = ICMP_SEND_ECHO(pData->phEvents[VBOX_ICMP_EVENT_INDEX], notify_slirp, addr.sin_addr.s_addr,
433	icp->icmp_data, icmplen - ICMP_MINLEN, &ipopt);
434	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
435	{
436	error = GetLastError();
437	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
438	switch (error)
439	{
440	case ERROR_INVALID_PARAMETER:
441	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
442	break;
443	case ERROR_NOT_SUPPORTED:
444	LogRel(("operation is unsupported)\n"));
445	break;
446	case ERROR_NOT_ENOUGH_MEMORY:
447	LogRel(("OOM!!!)\n"));
448	break;
449	case IP_BUF_TOO_SMALL:
450	LogRel(("Buffer too small)\n"));
451	break;
452	default:
453	LogRel(("Other error!!!)\n"));
454	break;
455	}
456	}
457	#endif /* RT_OS_WINDOWS */
458	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
459	break;
460	case ICMP_UNREACH:
461	/* XXX? report error? close socket? */
462	case ICMP_TIMXCEED:
463	case ICMP_PARAMPROB:
464	case ICMP_SOURCEQUENCH:
465	case ICMP_TSTAMP:
466	case ICMP_MASKREQ:
467	case ICMP_REDIRECT:
468	icmpstat.icps_notsupp++;
469	m_freem(pData, m);
470	break;
471
472	default:
473	icmpstat.icps_badtype++;
474	m_freem(pData, m);
475	} /* switch */
476
477	end_error:
478	/* m is m_free()'d xor put in a socket xor or given to ip_send */
479	;
480	}
481
482
483	/*
484	* Send an ICMP message in response to a situation
485	*
486	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
487	* MUST NOT change this header information.
488	* MUST NOT reply to a multicast/broadcast IP address.
489	* MUST NOT reply to a multicast/broadcast MAC address.
490	* MUST reply to only the first fragment.
491	*/
492	/*
493	* Send ICMP_UNREACH back to the source regarding msrc.
494	* mbuf *msrc is used as a template, but is NOT m_free()'d.
495	* It is reported as the bad ip packet. The header should
496	* be fully correct and in host byte order.
497	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
498	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
499	*/
500
501	#define ICMP_MAXDATALEN (IP_MSS-28)
502	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, const char message)
503	{
504	unsigned hlen, shlen, s_ip_len;
505	register struct ip *ip;
506	register struct icmp *icp;
507	register struct mbuf *m;
508
509	DEBUG_CALL("icmp_error");
510	DEBUG_ARG("msrc = %lx", (long )msrc);
511	DEBUG_ARG("msrc_len = %d", msrc->m_len);
512
513	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED)
514	goto end_error;
515
516	/* check msrc */
517	if (!msrc)
518	goto end_error;
519
520	ip = mtod(msrc, struct ip *);
521	#if DEBUG
522	{
523	char bufa[20], bufb[20];
524	strcpy(bufa, inet_ntoa(ip->ip_src));
525	strcpy(bufb, inet_ntoa(ip->ip_dst));
526	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
527	}
528	#endif
529	if (ip->ip_off & IP_OFFMASK)
530	goto end_error; /* Only reply to fragment 0 */
531
532	shlen = ip->ip_hl << 2;
533	s_ip_len = ip->ip_len;
534	if (ip->ip_p == IPPROTO_ICMP)
535	{
536	icp = (struct icmp )((char )ip + shlen);
537	/*
538	* Assume any unknown ICMP type is an error. This isn't
539	* specified by the RFC, but think about it..
540	*/
541	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
542	goto end_error;
543	}
544
545	/* make a copy */
546	if (!(m = m_get(pData)))
547	goto end_error; /* get mbuf */
548	{
549	int new_m_size;
550	m->m_data += if_maxlinkhdr;
551	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
552	if (new_m_size>m->m_size)
553	m_inc(m, new_m_size);
554	}
555	memcpy(m->m_data, msrc->m_data, msrc->m_len);
556	m->m_len = msrc->m_len; /* copy msrc to m */
557
558	/* make the header of the reply packet */
559	ip = mtod(m, struct ip *);
560	hlen = sizeof(struct ip ); /* no options in reply */
561
562	/* fill in icmp */
563	m->m_data += hlen;
564	m->m_len -= hlen;
565
566	icp = mtod(m, struct icmp *);
567
568	if (minsize)
569	s_ip_len = shlen+ICMP_MINLEN; /* return header+8b only */
570	else if (s_ip_len > ICMP_MAXDATALEN) /* maximum size */
571	s_ip_len = ICMP_MAXDATALEN;
572
573	m->m_len = ICMP_MINLEN + s_ip_len; /* 8 bytes ICMP header */
574
575	/* min. size = 8+sizeof(struct ip)+8 */
576
577	icp->icmp_type = type;
578	icp->icmp_code = code;
579	icp->icmp_id = 0;
580	icp->icmp_seq = 0;
581
582	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
583	HTONS(icp->icmp_ip.ip_len);
584	HTONS(icp->icmp_ip.ip_id);
585	HTONS(icp->icmp_ip.ip_off);
586
587	#if DEBUG
588	if (message)
589	{
590	/* DEBUG : append message to ICMP packet */
591	int message_len;
592	char *cpnt;
593	message_len = strlen(message);
594	if (message_len > ICMP_MAXDATALEN)
595	message_len = ICMP_MAXDATALEN;
596	cpnt = (char *)m->m_data+m->m_len;
597	memcpy(cpnt, message, message_len);
598	m->m_len += message_len;
599	}
600	#endif
601
602	icp->icmp_cksum = 0;
603	icp->icmp_cksum = cksum(m, m->m_len);
604
605	m->m_data -= hlen;
606	m->m_len += hlen;
607
608	/* fill in ip */
609	ip->ip_hl = hlen >> 2;
610	ip->ip_len = m->m_len;
611
612	ip->ip_tos = ((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
613
614	ip->ip_ttl = MAXTTL;
615	ip->ip_p = IPPROTO_ICMP;
616	ip->ip_dst = ip->ip_src; /* ip adresses */
617	ip->ip_src = alias_addr;
618
619	(void ) ip_output(pData, (struct socket *)NULL, m);
620
621	icmpstat.icps_reflect++;
622
623	return;
624
625	end_error:
626	LogRel(("NAT: error occured while sending ICMP error message \n"));
627	}
628	#undef ICMP_MAXDATALEN
629
630	/*
631	* Reflect the ip packet back to the source
632	*/
633	void
634	icmp_reflect(PNATState pData, struct mbuf *m)
635	{
636	register struct ip ip = mtod(m, struct ip );
637	int hlen = ip->ip_hl << 2;
638	int optlen = hlen - sizeof(struct ip );
639	register struct icmp *icp;
640
641	/*
642	* Send an icmp packet back to the ip level,
643	* after supplying a checksum.
644	*/
645	m->m_data += hlen;
646	m->m_len -= hlen;
647	icp = mtod(m, struct icmp *);
648
649	icp->icmp_cksum = 0;
650	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
651
652	m->m_data -= hlen;
653	m->m_len += hlen;
654
655	(void ) ip_output(pData, (struct socket *)NULL, m);
656
657	icmpstat.icps_reflect++;
658	}
659	#if defined(RT_OS_WINDOWS) && !defined(VBOX_WITH_SIMPLIFIED_SLIRP_SYNC)
660	static void WINAPI
661	notify_slirp(void *ctx)
662	{
663	/* pData name is important see slirp_state.h */
664	PNATState pData = (PNATState)ctx;
665	fIcmp = 1;
666	}
667	#endif

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 17389

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