ip_icmp.c@ 27467

Last change on this file since 27467 was 27467, checked in by vboxsync, 15 years ago
NAT: comment to ICMP find routine.
Property svn:eol-style set to `native`
File size: 23.6 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	#ifdef RT_OS_WINDOWS
45	# define ICMP_SEND_ECHO(event, routine, addr, data, datasize, ipopt) \
46	IcmpSendEcho2(pData->icmp_socket.sh, (event), NULL, NULL, (addr), (data), (datasize), \
47	(ipopt), pData->pvIcmpBuffer, pData->szIcmpBuffer, 1)
48	#endif /* RT_OS_WINDOWS */
49
50	/* The message sent when emulating PING */
51	/* Be nice and tell them it's just a psuedo-ping packet */
52	static const char icmp_ping_msg[] = "This is a psuedo-PING packet used by Slirp to emulate ICMP ECHO-REQUEST packets.\n";
53
54	/* list of actions for icmp_error() on RX of an icmp message */
55	static const int icmp_flush[19] =
56	{
57	/* ECHO REPLY (0) */ 0,
58	1,
59	1,
60	/* DEST UNREACH (3) */ 1,
61	/* SOURCE QUENCH (4)*/ 1,
62	/* REDIRECT (5) */ 1,
63	1,
64	1,
65	/* ECHO (8) */ 0,
66	/* ROUTERADVERT (9) */ 1,
67	/* ROUTERSOLICIT (10) */ 1,
68	/* TIME EXCEEDED (11) */ 1,
69	/* PARAMETER PROBLEM (12) */ 1,
70	/* TIMESTAMP (13) */ 0,
71	/* TIMESTAMP REPLY (14) */ 0,
72	/* INFO (15) */ 0,
73	/* INFO REPLY (16) */ 0,
74	/* ADDR MASK (17) */ 0,
75	/* ADDR MASK REPLY (18) */ 0
76	};
77
78	int
79	icmp_init(PNATState pData)
80	{
81	pData->icmp_socket.so_type = IPPROTO_ICMP;
82	pData->icmp_socket.so_state = SS_ISFCONNECTED;
83	#ifndef RT_OS_WINDOWS
84	# ifndef RT_OS_DARWIN
85	pData->icmp_socket.s = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP);
86	# else /* !RT_OS_DARWIN */
87	pData->icmp_socket.s = socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP);
88	# endif /* RT_OS_DARWIN */
89	if (pData->icmp_socket.s == -1)
90	{
91	int rc = RTErrConvertFromErrno(errno);
92	LogRel(("NAT: ICMP/ping not available (could not open ICMP socket, error %Rrc)\n", rc));
93	return 1;
94	}
95	fd_nonblock(pData->icmp_socket.s);
96	NSOCK_INC();
97	#else /* RT_OS_WINDOWS */
98	pData->hmIcmpLibrary = LoadLibrary("Iphlpapi.dll");
99	if (pData->hmIcmpLibrary != NULL)
100	{
101	pData->pfIcmpParseReplies = (long (WINAPI )(void , long))
102	GetProcAddress(pData->hmIcmpLibrary, "IcmpParseReplies");
103	pData->pfIcmpCloseHandle = (BOOL (WINAPI *)(HANDLE))
104	GetProcAddress(pData->hmIcmpLibrary, "IcmpCloseHandle");
105	pData->pfGetAdaptersAddresses = (ULONG (WINAPI *)(ULONG, ULONG, PVOID, PIP_ADAPTER_ADDRESSES, PULONG))
106	GetProcAddress(pData->hmIcmpLibrary, "GetAdaptersAddresses");
107	if (pData->pfGetAdaptersAddresses == NULL)
108	{
109	LogRel(("NAT: Can't find GetAdapterAddresses in Iphlpapi.dll"));
110	}
111	}
112
113	if (pData->pfIcmpParseReplies == NULL)
114	{
115	if(pData->pfGetAdaptersAddresses == NULL)
116	FreeLibrary(pData->hmIcmpLibrary);
117	pData->hmIcmpLibrary = LoadLibrary("Icmp.dll");
118	if (pData->hmIcmpLibrary == NULL)
119	{
120	LogRel(("NAT: Icmp.dll could not be loaded\n"));
121	return 1;
122	}
123	pData->pfIcmpParseReplies = (long (WINAPI )(void , long))
124	GetProcAddress(pData->hmIcmpLibrary, "IcmpParseReplies");
125	pData->pfIcmpCloseHandle = (BOOL (WINAPI *)(HANDLE))
126	GetProcAddress(pData->hmIcmpLibrary, "IcmpCloseHandle");
127	}
128	if (pData->pfIcmpParseReplies == NULL)
129	{
130	LogRel(("NAT: Can't find IcmpParseReplies symbol\n"));
131	FreeLibrary(pData->hmIcmpLibrary);
132	return 1;
133	}
134	if (pData->pfIcmpCloseHandle == NULL)
135	{
136	LogRel(("NAT: Can't find IcmpCloseHandle symbol\n"));
137	FreeLibrary(pData->hmIcmpLibrary);
138	return 1;
139	}
140	pData->icmp_socket.sh = IcmpCreateFile();
141	pData->phEvents[VBOX_ICMP_EVENT_INDEX] = CreateEvent(NULL, FALSE, FALSE, NULL);
142	pData->szIcmpBuffer = sizeof(ICMP_ECHO_REPLY) * 10;
143	pData->pvIcmpBuffer = RTMemAlloc(pData->szIcmpBuffer);
144	#endif /* RT_OS_WINDOWS */
145	LIST_INIT(&pData->icmp_msg_head);
146	return 0;
147	}
148
149	/*
150	* ip here is ip header + 64bytes readed from ICMP packet
151	*/
152	struct icmp_msg *
153	icmp_find_original_mbuf(PNATState pData, struct ip *ip)
154	{
155	struct mbuf *m0;
156	struct ip *ip0;
157	struct icmp icp, icp0;
158	struct icmp_msg *icm = NULL;
159	int found = 0;
160	struct udphdr *udp;
161	struct tcphdr *tcp;
162	struct socket *head_socket = NULL;
163	struct socket *last_socket = NULL;
164	struct socket *so = NULL;
165	struct in_addr laddr, faddr;
166	u_short lport, fport;
167
168	laddr.s_addr = ~0;
169	faddr.s_addr = ~0;
170
171	lport = ~0;
172	fport = ~0;
173
174
175	Log(("%s: processing (proto:%d)\n", __FUNCTION__, ip->ip_p));
176	switch (ip->ip_p)
177	{
178	case IPPROTO_ICMP:
179	icp = (struct icmp )((char )ip + (ip->ip_hl << 2));
180	LIST_FOREACH(icm, &pData->icmp_msg_head, im_list)
181	{
182	m0 = icm->im_m;
183	ip0 = mtod(m0, struct ip *);
184	if (ip0->ip_p != IPPROTO_ICMP)
185	{
186	/* try next item */
187	continue;
188	}
189	icp0 = (struct icmp )((char )ip0 + (ip0->ip_hl << 2));
190	/*
191	* IP could pointer to ICMP_REPLY datagram (1)
192	* or pointer IP header in ICMP payload in case of
193	* ICMP_TIMXCEED or ICMP_UNREACH (2)
194	*
195	* if (1) and then ICMP (type should be ICMP_ECHOREPLY) and we need check that
196	* IP.IP_SRC == IP0.IP_DST received datagramm comes from destination.
197	*
198	* if (2) then check that payload ICMP has got type ICMP_ECHO and
199	* IP.IP_DST == IP0.IP_DST destination of returned datagram is the same as
200	* one was sent.
201	*/
202	if ( ( (icp->icmp_type != ICMP_ECHO && ip->ip_src.s_addr == ip0->ip_dst.s_addr)
203	\|\| (icp->icmp_type == ICMP_ECHO && ip->ip_dst.s_addr == ip0->ip_dst.s_addr))
204	&& icp->icmp_id == icp0->icmp_id
205	&& icp->icmp_seq == icp0->icmp_seq)
206	{
207	found = 1;
208	Log(("Have found %R[natsock]\n", icm->im_so));
209	break;
210	}
211	Log(("Have found nothing\n"));
212	}
213	break;
214
215	/*
216	* for TCP and UDP logic little bit reverted, we try to find the HOST socket
217	* from which the IP package has been sent.
218	*/
219	case IPPROTO_UDP:
220	head_socket = &udb;
221	udp = (struct udphdr )((char )ip + (ip->ip_hl << 2));
222	faddr.s_addr = ip->ip_dst.s_addr;
223	fport = udp->uh_dport;
224	laddr.s_addr = ip->ip_src.s_addr;
225	lport = udp->uh_sport;
226	last_socket = udp_last_so;
227	/* fall through */
228
229	case IPPROTO_TCP:
230	if (head_socket == NULL)
231	{
232	tcp = (struct tcphdr )((char )ip + (ip->ip_hl << 2));
233	head_socket = &tcb; /* head_socket could be initialized with udb*/
234	faddr.s_addr = ip->ip_dst.s_addr;
235	fport = tcp->th_dport;
236	laddr.s_addr = ip->ip_src.s_addr;
237	lport = tcp->th_sport;
238	last_socket = tcp_last_so;
239	}
240	/* check last socket first */
241	if ( last_socket->so_faddr.s_addr == faddr.s_addr
242	&& last_socket->so_fport == fport
243	&& last_socket->so_hlport == lport)
244	{
245	found = 1;
246	so = last_socket;
247	goto sofound;
248	}
249	for (so = head_socket->so_prev; so != head_socket; so = so->so_prev)
250	{
251	/* Should be reaplaced by hash here */
252	Log(("trying:%R[natsock] against %R[IP4]:%d lport=%d hlport=%d\n", so, &faddr, fport, lport, so->so_hlport));
253	if ( so->so_faddr.s_addr == faddr.s_addr
254	&& so->so_fport == fport
255	&& so->so_hlport == lport)
256	{
257	found = 1;
258	break;
259	}
260	}
261	break;
262
263	default:
264	LogRel(("%s:ICMP: unsupported protocol(%d)\n", __FUNCTION__, ip->ip_p));
265	}
266	sofound:
267	if (found == 1 && icm == NULL)
268	{
269	if (so->so_state == SS_NOFDREF)
270	{
271	/* socket is shutdowning we've already sent ICMP on it.*/
272	LogRel(("NAT: Received icmp on shutdowning socket (probably corresponding ICMP socket has been already sent)\n"));
273	return NULL;
274	}
275	icm = RTMemAlloc(sizeof(struct icmp_msg));
276	icm->im_m = so->so_m;
277	icm->im_so = so;
278	found = 1;
279	Log(("hit:%R[natsock]\n", so));
280	/*XXX: this storage not very long,
281	* better add flag if it should removed from lis
282	*/
283	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
284	return (icm);
285	}
286	if (found == 1)
287	return icm;
288
289	return NULL;
290	}
291
292	static int
293	icmp_attach(PNATState pData, struct mbuf *m)
294	{
295	struct icmp_msg *icm;
296	struct ip *ip;
297	ip = mtod(m, struct ip *);
298	Assert(ip->ip_p == IPPROTO_ICMP);
299	icm = RTMemAlloc(sizeof(struct icmp_msg));
300	icm->im_m = m;
301	icm->im_so = m->m_so;
302	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
303	return 0;
304	}
305
306	/*
307	* Process a received ICMP message.
308	*/
309	void
310	icmp_input(PNATState pData, struct mbuf *m, int hlen)
311	{
312	register struct icmp *icp;
313	register struct ip ip = mtod(m, struct ip );
314	int icmplen = ip->ip_len;
315	int status;
316	uint32_t dst;
317	#if !defined(RT_OS_WINDOWS)
318	int ttl;
319	#endif
320
321	/* int code; */
322
323	DEBUG_CALL("icmp_input");
324	DEBUG_ARG("m = %lx", (long )m);
325	DEBUG_ARG("m_len = %d", m ? m->m_len : 0);
326
327	icmpstat.icps_received++;
328
329	/*
330	* Locate icmp structure in mbuf, and check
331	* that its not corrupted and of at least minimum length.
332	*/
333	if (icmplen < ICMP_MINLEN)
334	{
335	/* min 8 bytes payload */
336	icmpstat.icps_tooshort++;
337	freeit:
338	m_freem(pData, m);
339	goto end_error;
340	}
341
342	m->m_len -= hlen;
343	m->m_data += hlen;
344	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
345	icp = mtod(m, struct icmp *);
346	#else
347	if (m->m_next != NULL)
348	{
349	char *buf = RTMemAlloc(icmplen);
350	m_copydata(m, 0, icmplen, buf);
351	icp = (struct icmp *)buf;
352	}
353	else
354	{
355	icp = mtod(m, struct icmp *);
356	}
357	#endif
358	if (cksum(m, icmplen))
359	{
360	icmpstat.icps_checksum++;
361	goto freeit;
362	}
363	m->m_len += hlen;
364	m->m_data -= hlen;
365
366	/* icmpstat.icps_inhist[icp->icmp_type]++; */
367	/* code = icp->icmp_code; */
368
369	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
370	switch (icp->icmp_type)
371	{
372	case ICMP_ECHO:
373	ip->ip_len += hlen; /* since ip_input subtracts this */
374	dst = ip->ip_dst.s_addr;
375	if (dst == alias_addr.s_addr)
376	{
377	icp->icmp_type = ICMP_ECHOREPLY;
378	ip->ip_dst.s_addr = ip->ip_src.s_addr;
379	ip->ip_src.s_addr = dst;
380	icmp_reflect(pData, m);
381	}
382	else
383	{
384	struct sockaddr_in addr;
385	#ifdef RT_OS_WINDOWS
386	IP_OPTION_INFORMATION ipopt;
387	int error;
388	#endif
389	addr.sin_family = AF_INET;
390	if ((ip->ip_dst.s_addr & RT_H2N_U32(pData->netmask)) == pData->special_addr.s_addr)
391	{
392	/* It's an alias */
393	switch (RT_N2H_U32(ip->ip_dst.s_addr) & ~pData->netmask)
394	{
395	case CTL_DNS:
396	case CTL_ALIAS:
397	default:
398	addr.sin_addr = loopback_addr;
399	break;
400	}
401	}
402	else
403	addr.sin_addr.s_addr = ip->ip_dst.s_addr;
404	#ifndef RT_OS_WINDOWS
405	if (pData->icmp_socket.s != -1)
406	{
407	m->m_so = &pData->icmp_socket;
408	icmp_attach(pData, m);
409	ttl = ip->ip_ttl;
410	Log(("NAT/ICMP: try to set TTL(%d)\n", ttl));
411	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL,
412	(void *)&ttl, sizeof(ttl));
413	if (status < 0)
414	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n",
415	strerror(errno)));
416	if (sendto(pData->icmp_socket.s, icp, icmplen, 0,
417	(struct sockaddr *)&addr, sizeof(addr)) == -1)
418	{
419	LogRel((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
420	errno, strerror(errno)));
421	icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
422	}
423	}
424	else
425	{
426	/*
427	* We're freeing the ICMP message, which unable sent or process.
428	* That behavior described in rfc 793, we shouldn't notify sender about
429	* fail of processing it's ICMP packets
430	*/
431	m_free(pData, m);
432	return;
433	}
434	#else /* RT_OS_WINDOWS */
435	icmp_attach(pData, m);
436	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
437	pData->icmp_socket.so_icmp_id = icp->icmp_id;
438	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
439	m->m_so = &pData->icmp_socket;
440	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
441	ipopt.Ttl = ip->ip_ttl;
442	status = ICMP_SEND_ECHO(pData->phEvents[VBOX_ICMP_EVENT_INDEX], notify_slirp, addr.sin_addr.s_addr,
443	icp->icmp_data, icmplen - ICMP_MINLEN, &ipopt);
444	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
445	{
446	error = GetLastError();
447	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
448	switch (error)
449	{
450	case ERROR_INVALID_PARAMETER:
451	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
452	break;
453	case ERROR_NOT_SUPPORTED:
454	LogRel(("operation is unsupported)\n"));
455	break;
456	case ERROR_NOT_ENOUGH_MEMORY:
457	LogRel(("OOM!!!)\n"));
458	break;
459	case IP_BUF_TOO_SMALL:
460	LogRel(("Buffer too small)\n"));
461	break;
462	default:
463	LogRel(("Other error!!!)\n"));
464	break;
465	}
466	}
467	#endif /* RT_OS_WINDOWS */
468	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
469	break;
470	case ICMP_UNREACH:
471	/* XXX? report error? close socket? */
472	case ICMP_TIMXCEED:
473	case ICMP_PARAMPROB:
474	case ICMP_SOURCEQUENCH:
475	case ICMP_TSTAMP:
476	case ICMP_MASKREQ:
477	case ICMP_REDIRECT:
478	icmpstat.icps_notsupp++;
479	m_freem(pData, m);
480	break;
481
482	default:
483	icmpstat.icps_badtype++;
484	m_freem(pData, m);
485	} /* switch */
486	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
487	if (m->m_next != NULL && icp != NULL)
488	RTMemFree(icp);
489	#endif
490
491	end_error:
492	/* m is m_free()'d xor put in a socket xor or given to ip_send */
493	;
494	}
495
496
497	/*
498	* Send an ICMP message in response to a situation
499	*
500	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
501	* MUST NOT change this header information.
502	* MUST NOT reply to a multicast/broadcast IP address.
503	* MUST NOT reply to a multicast/broadcast MAC address.
504	* MUST reply to only the first fragment.
505	*/
506	/*
507	* Send ICMP_UNREACH back to the source regarding msrc.
508	* mbuf *msrc is used as a template, but is NOT m_free()'d.
509	* It is reported as the bad ip packet. The header should
510	* be fully correct and in host byte order.
511	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
512	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
513	*/
514
515	#define ICMP_MAXDATALEN (IP_MSS-28)
516	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, const char message)
517	{
518	unsigned hlen, shlen, s_ip_len;
519	register struct ip *ip;
520	register struct icmp *icp;
521	register struct mbuf *m;
522	int new_m_size = 0;
523	int size = 0;
524
525	DEBUG_CALL("icmp_error");
526	DEBUG_ARG("msrc = %lx", (long )msrc);
527	DEBUG_ARG("msrc_len = %d", msrc ? msrc->m_len : 0);
528	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
529	if (msrc != NULL)
530	M_ASSERTPKTHDR(msrc);
531	#endif
532
533	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED && type != ICMP_SOURCEQUENCH)
534	goto end_error;
535
536	/* check msrc */
537	if (!msrc)
538	goto end_error;
539
540	ip = mtod(msrc, struct ip *);
541	#if DEBUG
542	{
543	char bufa[20], bufb[20];
544	strcpy(bufa, inet_ntoa(ip->ip_src));
545	strcpy(bufb, inet_ntoa(ip->ip_dst));
546	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
547	}
548	#endif
549	if (ip->ip_off & IP_OFFMASK && type != ICMP_SOURCEQUENCH)
550	goto end_error; /* Only reply to fragment 0 */
551
552	shlen = ip->ip_hl << 2;
553	s_ip_len = ip->ip_len;
554	if (ip->ip_p == IPPROTO_ICMP)
555	{
556	icp = (struct icmp )((char )ip + shlen);
557	/*
558	* Assume any unknown ICMP type is an error. This isn't
559	* specified by the RFC, but think about it..
560	*/
561	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
562	goto end_error;
563	}
564
565	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
566	/* make a copy */
567	m = m_get(pData);
568	#else
569	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
570	if (new_m_size < MSIZE)
571	{
572	size = MCLBYTES;
573	}
574	else if (new_m_size < MCLBYTES)
575	{
576	size = MCLBYTES;
577	}
578	else if(new_m_size < MJUM9BYTES)
579	{
580	size = MJUM9BYTES;
581	}
582	else if (new_m_size < MJUM16BYTES)
583	{
584	size = MJUM16BYTES;
585	}
586	else
587	{
588	AssertMsgFailed(("Unsupported size"));
589	}
590	m = m_getjcl(pData, M_NOWAIT, MT_HEADER, M_PKTHDR, size);
591	#endif
592	if (m == NULL)
593	goto end_error; /* get mbuf */
594
595	m->m_data += if_maxlinkhdr;
596	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
597	m->m_pkthdr.header = mtod(m, void *);
598	#else
599	new_m_size = if_maxlinkhdr + sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
600	if (new_m_size > m->m_size)
601	{
602	m_inc(m, new_m_size);
603	if (new_m_size > m->m_size)
604	goto end_error_free_m;
605	}
606	#endif
607
608	memcpy(m->m_data, msrc->m_data, msrc->m_len);
609	m->m_len = msrc->m_len; /* copy msrc to m */
610
611	/* make the header of the reply packet */
612	ip = mtod(m, struct ip *);
613	hlen = sizeof(struct ip ); /* no options in reply */
614
615	/* fill in icmp */
616	m->m_data += hlen;
617	m->m_len -= hlen;
618
619	icp = mtod(m, struct icmp *);
620
621	if (minsize)
622	s_ip_len = shlen+ICMP_MINLEN; /* return header+8b only */
623	else if (s_ip_len > ICMP_MAXDATALEN) /* maximum size */
624	s_ip_len = ICMP_MAXDATALEN;
625
626	m->m_len = ICMP_MINLEN + s_ip_len; /* 8 bytes ICMP header */
627
628	/* min. size = 8+sizeof(struct ip)+8 */
629
630	icp->icmp_type = type;
631	icp->icmp_code = code;
632	icp->icmp_id = 0;
633	icp->icmp_seq = 0;
634
635	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
636
637	HTONS(icp->icmp_ip.ip_len);
638	HTONS(icp->icmp_ip.ip_id);
639	HTONS(icp->icmp_ip.ip_off);
640
641	#if DEBUG
642	if (message)
643	{
644	/* DEBUG : append message to ICMP packet */
645	int message_len;
646	char *cpnt;
647	message_len = strlen(message);
648	if (message_len > ICMP_MAXDATALEN)
649	message_len = ICMP_MAXDATALEN;
650	cpnt = (char *)m->m_data+m->m_len;
651	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
652	memcpy(cpnt, message, message_len);
653	m->m_len += message_len;
654	#else
655	m_append(pData, m, message_len, message);
656	#endif
657	}
658	#endif
659
660	icp->icmp_cksum = 0;
661	icp->icmp_cksum = cksum(m, m->m_len);
662
663	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
664	m->m_data -= hlen;
665	m->m_len += hlen;
666	#endif
667
668	/* fill in ip */
669	ip->ip_hl = hlen >> 2;
670	ip->ip_len = m->m_len;
671
672	ip->ip_tos = ((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
673
674	ip->ip_ttl = MAXTTL;
675	ip->ip_p = IPPROTO_ICMP;
676	ip->ip_dst = ip->ip_src; /* ip adresses */
677	ip->ip_src = alias_addr;
678
679	(void ) ip_output0(pData, (struct socket *)NULL, m, 1);
680
681	icmpstat.icps_reflect++;
682
683	return;
684
685	end_error_free_m:
686	m_free(pData, m);
687	end_error:
688	LogRel(("NAT: error occurred while sending ICMP error message \n"));
689	}
690	#undef ICMP_MAXDATALEN
691
692	/*
693	* Reflect the ip packet back to the source
694	*/
695	void
696	icmp_reflect(PNATState pData, struct mbuf *m)
697	{
698	register struct ip ip = mtod(m, struct ip );
699	int hlen = ip->ip_hl << 2;
700	int optlen = hlen - sizeof(struct ip );
701	register struct icmp *icp;
702
703	/*
704	* Send an icmp packet back to the ip level,
705	* after supplying a checksum.
706	*/
707	m->m_data += hlen;
708	m->m_len -= hlen;
709	icp = mtod(m, struct icmp *);
710
711	icp->icmp_cksum = 0;
712	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
713
714	m->m_data -= hlen;
715	m->m_len += hlen;
716
717	(void ) ip_output(pData, (struct socket *)NULL, m);
718
719	icmpstat.icps_reflect++;
720	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 27467

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