ip_icmp.c@ 25265

Last change on this file since 25265 was 25265, checked in by vboxsync, 15 years ago
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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	# 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 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	AssertRelease(ip0->ip_p == IPPROTO_ICMP);
185	icp0 = (struct icmp )((char )ip0 + (ip0->ip_hl << 2));
186	if ( ( (icp->icmp_type != ICMP_ECHO && ip->ip_src.s_addr == ip0->ip_dst.s_addr)
187	\|\| (icp->icmp_type == ICMP_ECHO && ip->ip_dst.s_addr == ip0->ip_dst.s_addr))
188	&& icp->icmp_id == icp0->icmp_id
189	&& icp->icmp_seq == icp0->icmp_seq)
190	{
191	found = 1;
192	Log(("Have found %R[natsock]\n", icm->im_so));
193	break;
194	}
195	Log(("Have found nothing\n"));
196	}
197	break;
198
199	/*
200	* for TCP and UDP logic little bit reverted, we try to find the HOST socket
201	* from which the IP package has been sent.
202	*/
203	case IPPROTO_UDP:
204	head_socket = &udb;
205	udp = (struct udphdr )((char )ip + (ip->ip_hl << 2));
206	faddr.s_addr = ip->ip_dst.s_addr;
207	fport = udp->uh_dport;
208	laddr.s_addr = ip->ip_src.s_addr;
209	lport = udp->uh_sport;
210	last_socket = udp_last_so;
211	/* fall through */
212
213	case IPPROTO_TCP:
214	if (head_socket == NULL)
215	{
216	tcp = (struct tcphdr )((char )ip + (ip->ip_hl << 2));
217	head_socket = &tcb; /* head_socket could be initialized with udb*/
218	faddr.s_addr = ip->ip_dst.s_addr;
219	fport = tcp->th_dport;
220	laddr.s_addr = ip->ip_src.s_addr;
221	lport = tcp->th_sport;
222	last_socket = tcp_last_so;
223	}
224	/* check last socket first */
225	if ( last_socket->so_faddr.s_addr == faddr.s_addr
226	&& last_socket->so_fport == fport
227	&& last_socket->so_hlport == lport)
228	{
229	found = 1;
230	so = last_socket;
231	goto sofound;
232	}
233	for (so = head_socket->so_prev; so != head_socket; so = so->so_prev)
234	{
235	/* Should be reaplaced by hash here */
236	Log(("trying:%R[natsock] against %R[IP4]:%d lport=%d hlport=%d\n", so, &faddr, fport, lport, so->so_hlport));
237	if ( so->so_faddr.s_addr == faddr.s_addr
238	&& so->so_fport == fport
239	&& so->so_hlport == lport)
240	{
241	found = 1;
242	break;
243	}
244	}
245	break;
246
247	default:
248	LogRel(("%s:ICMP: unsupported protocol(%d)\n", __FUNCTION__, ip->ip_p));
249	}
250	sofound:
251	if (found == 1 && icm == NULL)
252	{
253	if (so->so_state == SS_NOFDREF)
254	{
255	/* socket is shutdowning we've already sent ICMP on it.*/
256	LogRel(("NAT: Received icmp on shutdowning socket (probably corresponding ICMP socket has been already sent)\n"));
257	return NULL;
258	}
259	icm = RTMemAlloc(sizeof(struct icmp_msg));
260	icm->im_m = so->so_m;
261	icm->im_so = so;
262	found = 1;
263	Log(("hit:%R[natsock]\n", so));
264	/*XXX: this storage not very long,
265	* better add flag if it should removed from lis
266	*/
267	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
268	return (icm);
269	}
270	if (found == 1)
271	return icm;
272
273	return NULL;
274	}
275
276	static int
277	icmp_attach(PNATState pData, struct mbuf *m)
278	{
279	struct icmp_msg *icm;
280	struct ip *ip;
281	ip = mtod(m, struct ip *);
282	Assert(ip->ip_p == IPPROTO_ICMP);
283	icm = RTMemAlloc(sizeof(struct icmp_msg));
284	icm->im_m = m;
285	icm->im_so = m->m_so;
286	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
287	return 0;
288	}
289
290	/*
291	* Process a received ICMP message.
292	*/
293	void
294	icmp_input(PNATState pData, struct mbuf *m, int hlen)
295	{
296	register struct icmp *icp;
297	register struct ip ip = mtod(m, struct ip );
298	int icmplen = ip->ip_len;
299	int status;
300	uint32_t dst;
301	#if !defined(RT_OS_WINDOWS)
302	int ttl;
303	#endif
304
305	/* int code; */
306
307	DEBUG_CALL("icmp_input");
308	DEBUG_ARG("m = %lx", (long )m);
309	DEBUG_ARG("m_len = %d", m ? m->m_len : 0);
310
311	icmpstat.icps_received++;
312
313	/*
314	* Locate icmp structure in mbuf, and check
315	* that its not corrupted and of at least minimum length.
316	*/
317	if (icmplen < ICMP_MINLEN)
318	{
319	/* min 8 bytes payload */
320	icmpstat.icps_tooshort++;
321	freeit:
322	m_freem(pData, m);
323	goto end_error;
324	}
325
326	m->m_len -= hlen;
327	m->m_data += hlen;
328	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
329	icp = mtod(m, struct icmp *);
330	#else
331	if (m->m_next != NULL)
332	{
333	char *buf = RTMemAlloc(icmplen);
334	m_copydata(m, 0, icmplen, buf);
335	icp = (struct icmp *)buf;
336	}
337	else
338	{
339	icp = mtod(m, struct icmp *);
340	}
341	#endif
342	if (cksum(m, icmplen))
343	{
344	icmpstat.icps_checksum++;
345	goto freeit;
346	}
347	m->m_len += hlen;
348	m->m_data -= hlen;
349
350	/* icmpstat.icps_inhist[icp->icmp_type]++; */
351	/* code = icp->icmp_code; */
352
353	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
354	switch (icp->icmp_type)
355	{
356	case ICMP_ECHO:
357	ip->ip_len += hlen; /* since ip_input subtracts this */
358	dst = ip->ip_dst.s_addr;
359	if (dst == alias_addr.s_addr)
360	{
361	icp->icmp_type = ICMP_ECHOREPLY;
362	ip->ip_dst.s_addr = ip->ip_src.s_addr;
363	ip->ip_src.s_addr = dst;
364	icmp_reflect(pData, m);
365	}
366	else
367	{
368	struct sockaddr_in addr;
369	#ifdef RT_OS_WINDOWS
370	IP_OPTION_INFORMATION ipopt;
371	int error;
372	#endif
373	addr.sin_family = AF_INET;
374	if ((ip->ip_dst.s_addr & htonl(pData->netmask)) == pData->special_addr.s_addr)
375	{
376	/* It's an alias */
377	switch (ntohl(ip->ip_dst.s_addr) & ~pData->netmask)
378	{
379	case CTL_DNS:
380	case CTL_ALIAS:
381	default:
382	addr.sin_addr = loopback_addr;
383	break;
384	}
385	}
386	else
387	addr.sin_addr.s_addr = ip->ip_dst.s_addr;
388	#ifndef RT_OS_WINDOWS
389	if (pData->icmp_socket.s != -1)
390	{
391	m->m_so = &pData->icmp_socket;
392	icmp_attach(pData, m);
393	ttl = ip->ip_ttl;
394	Log(("NAT/ICMP: try to set TTL(%d)\n", ttl));
395	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL,
396	(void *)&ttl, sizeof(ttl));
397	if (status < 0)
398	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n",
399	strerror(errno)));
400	if (sendto(pData->icmp_socket.s, icp, icmplen, 0,
401	(struct sockaddr *)&addr, sizeof(addr)) == -1)
402	{
403	LogRel((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
404	errno, strerror(errno)));
405	icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
406	}
407	}
408	else
409	{
410	/*
411	* We're freeing the ICMP message, which unable sent or process.
412	* That behavior described in rfc 793, we shouldn't notify sender about
413	* fail of processing it's ICMP packets
414	*/
415	m_free(pData, m);
416	return;
417	}
418	#else /* RT_OS_WINDOWS */
419	icmp_attach(pData, m);
420	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
421	pData->icmp_socket.so_icmp_id = icp->icmp_id;
422	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
423	m->m_so = &pData->icmp_socket;
424	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
425	ipopt.Ttl = ip->ip_ttl;
426	status = ICMP_SEND_ECHO(pData->phEvents[VBOX_ICMP_EVENT_INDEX], notify_slirp, addr.sin_addr.s_addr,
427	icp->icmp_data, icmplen - ICMP_MINLEN, &ipopt);
428	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
429	{
430	error = GetLastError();
431	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
432	switch (error)
433	{
434	case ERROR_INVALID_PARAMETER:
435	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
436	break;
437	case ERROR_NOT_SUPPORTED:
438	LogRel(("operation is unsupported)\n"));
439	break;
440	case ERROR_NOT_ENOUGH_MEMORY:
441	LogRel(("OOM!!!)\n"));
442	break;
443	case IP_BUF_TOO_SMALL:
444	LogRel(("Buffer too small)\n"));
445	break;
446	default:
447	LogRel(("Other error!!!)\n"));
448	break;
449	}
450	}
451	#endif /* RT_OS_WINDOWS */
452	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
453	break;
454	case ICMP_UNREACH:
455	/* XXX? report error? close socket? */
456	case ICMP_TIMXCEED:
457	case ICMP_PARAMPROB:
458	case ICMP_SOURCEQUENCH:
459	case ICMP_TSTAMP:
460	case ICMP_MASKREQ:
461	case ICMP_REDIRECT:
462	icmpstat.icps_notsupp++;
463	m_freem(pData, m);
464	break;
465
466	default:
467	icmpstat.icps_badtype++;
468	m_freem(pData, m);
469	} /* switch */
470	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
471	if (m->m_next != NULL && icp != NULL)
472	RTMemFree(icp);
473	#endif
474
475	end_error:
476	/* m is m_free()'d xor put in a socket xor or given to ip_send */
477	;
478	}
479
480
481	/*
482	* Send an ICMP message in response to a situation
483	*
484	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
485	* MUST NOT change this header information.
486	* MUST NOT reply to a multicast/broadcast IP address.
487	* MUST NOT reply to a multicast/broadcast MAC address.
488	* MUST reply to only the first fragment.
489	*/
490	/*
491	* Send ICMP_UNREACH back to the source regarding msrc.
492	* mbuf *msrc is used as a template, but is NOT m_free()'d.
493	* It is reported as the bad ip packet. The header should
494	* be fully correct and in host byte order.
495	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
496	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
497	*/
498
499	#define ICMP_MAXDATALEN (IP_MSS-28)
500	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, const char message)
501	{
502	unsigned hlen, shlen, s_ip_len;
503	register struct ip *ip;
504	register struct icmp *icp;
505	register struct mbuf *m;
506	int new_m_size = 0;
507	int size = 0;
508
509	DEBUG_CALL("icmp_error");
510	DEBUG_ARG("msrc = %lx", (long )msrc);
511	DEBUG_ARG("msrc_len = %d", msrc ? msrc->m_len : 0);
512	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
513	if (msrc != NULL)
514	M_ASSERTPKTHDR(msrc);
515	#endif
516
517	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED && type != ICMP_SOURCEQUENCH)
518	goto end_error;
519
520	/* check msrc */
521	if (!msrc)
522	goto end_error;
523
524	ip = mtod(msrc, struct ip *);
525	#if DEBUG
526	{
527	char bufa[20], bufb[20];
528	strcpy(bufa, inet_ntoa(ip->ip_src));
529	strcpy(bufb, inet_ntoa(ip->ip_dst));
530	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
531	}
532	#endif
533	if (ip->ip_off & IP_OFFMASK && type != ICMP_SOURCEQUENCH)
534	goto end_error; /* Only reply to fragment 0 */
535
536	shlen = ip->ip_hl << 2;
537	s_ip_len = ip->ip_len;
538	if (ip->ip_p == IPPROTO_ICMP)
539	{
540	icp = (struct icmp )((char )ip + shlen);
541	/*
542	* Assume any unknown ICMP type is an error. This isn't
543	* specified by the RFC, but think about it..
544	*/
545	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
546	goto end_error;
547	}
548
549	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
550	/* make a copy */
551	m = m_get(pData);
552	#else
553	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
554	if (new_m_size < MSIZE)
555	{
556	size = MCLBYTES;
557	}
558	else if (new_m_size < MCLBYTES)
559	{
560	size = MCLBYTES;
561	}
562	else if(new_m_size < MJUM9BYTES)
563	{
564	size = MJUM9BYTES;
565	}
566	else if (new_m_size < MJUM16BYTES)
567	{
568	size = MJUM16BYTES;
569	}
570	else
571	{
572	AssertMsgFailed(("Unsupported size"));
573	}
574	m = m_getjcl(pData, M_NOWAIT, MT_HEADER, M_PKTHDR, size);
575	#endif
576	if (m == NULL)
577	goto end_error; /* get mbuf */
578
579	m->m_data += if_maxlinkhdr;
580	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
581	m->m_pkthdr.header = mtod(m, void *);
582	#else
583	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
584	if (new_m_size > m->m_size)
585	m_inc(m, new_m_size);
586	#endif
587
588	memcpy(m->m_data, msrc->m_data, msrc->m_len);
589	m->m_len = msrc->m_len; /* copy msrc to m */
590
591	/* make the header of the reply packet */
592	ip = mtod(m, struct ip *);
593	hlen = sizeof(struct ip ); /* no options in reply */
594
595	/* fill in icmp */
596	m->m_data += hlen;
597	m->m_len -= hlen;
598
599	icp = mtod(m, struct icmp *);
600
601	if (minsize)
602	s_ip_len = shlen+ICMP_MINLEN; /* return header+8b only */
603	else if (s_ip_len > ICMP_MAXDATALEN) /* maximum size */
604	s_ip_len = ICMP_MAXDATALEN;
605
606	m->m_len = ICMP_MINLEN + s_ip_len; /* 8 bytes ICMP header */
607
608	/* min. size = 8+sizeof(struct ip)+8 */
609
610	icp->icmp_type = type;
611	icp->icmp_code = code;
612	icp->icmp_id = 0;
613	icp->icmp_seq = 0;
614
615	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
616
617	HTONS(icp->icmp_ip.ip_len);
618	HTONS(icp->icmp_ip.ip_id);
619	HTONS(icp->icmp_ip.ip_off);
620
621	#if DEBUG
622	if (message)
623	{
624	/* DEBUG : append message to ICMP packet */
625	int message_len;
626	char *cpnt;
627	message_len = strlen(message);
628	if (message_len > ICMP_MAXDATALEN)
629	message_len = ICMP_MAXDATALEN;
630	cpnt = (char *)m->m_data+m->m_len;
631	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
632	memcpy(cpnt, message, message_len);
633	m->m_len += message_len;
634	#else
635	m_append(pData, m, message_len, message);
636	#endif
637	}
638	#endif
639
640	icp->icmp_cksum = 0;
641	icp->icmp_cksum = cksum(m, m->m_len);
642
643	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
644	m->m_data -= hlen;
645	m->m_len += hlen;
646	#endif
647
648	/* fill in ip */
649	ip->ip_hl = hlen >> 2;
650	ip->ip_len = m->m_len;
651
652	ip->ip_tos = ((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
653
654	ip->ip_ttl = MAXTTL;
655	ip->ip_p = IPPROTO_ICMP;
656	ip->ip_dst = ip->ip_src; /* ip adresses */
657	ip->ip_src = alias_addr;
658
659	(void ) ip_output0(pData, (struct socket *)NULL, m, 1);
660
661	icmpstat.icps_reflect++;
662
663	return;
664
665	end_error:
666	LogRel(("NAT: error occurred while sending ICMP error message \n"));
667	}
668	#undef ICMP_MAXDATALEN
669
670	/*
671	* Reflect the ip packet back to the source
672	*/
673	void
674	icmp_reflect(PNATState pData, struct mbuf *m)
675	{
676	register struct ip ip = mtod(m, struct ip );
677	int hlen = ip->ip_hl << 2;
678	int optlen = hlen - sizeof(struct ip );
679	register struct icmp *icp;
680
681	/*
682	* Send an icmp packet back to the ip level,
683	* after supplying a checksum.
684	*/
685	m->m_data += hlen;
686	m->m_len -= hlen;
687	icp = mtod(m, struct icmp *);
688
689	icp->icmp_cksum = 0;
690	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
691
692	m->m_data -= hlen;
693	m->m_len += hlen;
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@ 25265

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