ip_icmp.c@ 26837

Last change on this file since 26837 was 26676, checked in by vboxsync, 15 years ago
Network/slirp: release log typo.
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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 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	if ( ( (icp->icmp_type != ICMP_ECHO && ip->ip_src.s_addr == ip0->ip_dst.s_addr)
191	\|\| (icp->icmp_type == ICMP_ECHO && ip->ip_dst.s_addr == ip0->ip_dst.s_addr))
192	&& icp->icmp_id == icp0->icmp_id
193	&& icp->icmp_seq == icp0->icmp_seq)
194	{
195	found = 1;
196	Log(("Have found %R[natsock]\n", icm->im_so));
197	break;
198	}
199	Log(("Have found nothing\n"));
200	}
201	break;
202
203	/*
204	* for TCP and UDP logic little bit reverted, we try to find the HOST socket
205	* from which the IP package has been sent.
206	*/
207	case IPPROTO_UDP:
208	head_socket = &udb;
209	udp = (struct udphdr )((char )ip + (ip->ip_hl << 2));
210	faddr.s_addr = ip->ip_dst.s_addr;
211	fport = udp->uh_dport;
212	laddr.s_addr = ip->ip_src.s_addr;
213	lport = udp->uh_sport;
214	last_socket = udp_last_so;
215	/* fall through */
216
217	case IPPROTO_TCP:
218	if (head_socket == NULL)
219	{
220	tcp = (struct tcphdr )((char )ip + (ip->ip_hl << 2));
221	head_socket = &tcb; /* head_socket could be initialized with udb*/
222	faddr.s_addr = ip->ip_dst.s_addr;
223	fport = tcp->th_dport;
224	laddr.s_addr = ip->ip_src.s_addr;
225	lport = tcp->th_sport;
226	last_socket = tcp_last_so;
227	}
228	/* check last socket first */
229	if ( last_socket->so_faddr.s_addr == faddr.s_addr
230	&& last_socket->so_fport == fport
231	&& last_socket->so_hlport == lport)
232	{
233	found = 1;
234	so = last_socket;
235	goto sofound;
236	}
237	for (so = head_socket->so_prev; so != head_socket; so = so->so_prev)
238	{
239	/* Should be reaplaced by hash here */
240	Log(("trying:%R[natsock] against %R[IP4]:%d lport=%d hlport=%d\n", so, &faddr, fport, lport, so->so_hlport));
241	if ( so->so_faddr.s_addr == faddr.s_addr
242	&& so->so_fport == fport
243	&& so->so_hlport == lport)
244	{
245	found = 1;
246	break;
247	}
248	}
249	break;
250
251	default:
252	LogRel(("%s:ICMP: unsupported protocol(%d)\n", __FUNCTION__, ip->ip_p));
253	}
254	sofound:
255	if (found == 1 && icm == NULL)
256	{
257	if (so->so_state == SS_NOFDREF)
258	{
259	/* socket is shutdowning we've already sent ICMP on it.*/
260	LogRel(("NAT: Received icmp on shutdowning socket (probably corresponding ICMP socket has been already sent)\n"));
261	return NULL;
262	}
263	icm = RTMemAlloc(sizeof(struct icmp_msg));
264	icm->im_m = so->so_m;
265	icm->im_so = so;
266	found = 1;
267	Log(("hit:%R[natsock]\n", so));
268	/*XXX: this storage not very long,
269	* better add flag if it should removed from lis
270	*/
271	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
272	return (icm);
273	}
274	if (found == 1)
275	return icm;
276
277	return NULL;
278	}
279
280	static int
281	icmp_attach(PNATState pData, struct mbuf *m)
282	{
283	struct icmp_msg *icm;
284	struct ip *ip;
285	ip = mtod(m, struct ip *);
286	Assert(ip->ip_p == IPPROTO_ICMP);
287	icm = RTMemAlloc(sizeof(struct icmp_msg));
288	icm->im_m = m;
289	icm->im_so = m->m_so;
290	LIST_INSERT_HEAD(&pData->icmp_msg_head, icm, im_list);
291	return 0;
292	}
293
294	/*
295	* Process a received ICMP message.
296	*/
297	void
298	icmp_input(PNATState pData, struct mbuf *m, int hlen)
299	{
300	register struct icmp *icp;
301	register struct ip ip = mtod(m, struct ip );
302	int icmplen = ip->ip_len;
303	int status;
304	uint32_t dst;
305	#if !defined(RT_OS_WINDOWS)
306	int ttl;
307	#endif
308
309	/* int code; */
310
311	DEBUG_CALL("icmp_input");
312	DEBUG_ARG("m = %lx", (long )m);
313	DEBUG_ARG("m_len = %d", m ? m->m_len : 0);
314
315	icmpstat.icps_received++;
316
317	/*
318	* Locate icmp structure in mbuf, and check
319	* that its not corrupted and of at least minimum length.
320	*/
321	if (icmplen < ICMP_MINLEN)
322	{
323	/* min 8 bytes payload */
324	icmpstat.icps_tooshort++;
325	freeit:
326	m_freem(pData, m);
327	goto end_error;
328	}
329
330	m->m_len -= hlen;
331	m->m_data += hlen;
332	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
333	icp = mtod(m, struct icmp *);
334	#else
335	if (m->m_next != NULL)
336	{
337	char *buf = RTMemAlloc(icmplen);
338	m_copydata(m, 0, icmplen, buf);
339	icp = (struct icmp *)buf;
340	}
341	else
342	{
343	icp = mtod(m, struct icmp *);
344	}
345	#endif
346	if (cksum(m, icmplen))
347	{
348	icmpstat.icps_checksum++;
349	goto freeit;
350	}
351	m->m_len += hlen;
352	m->m_data -= hlen;
353
354	/* icmpstat.icps_inhist[icp->icmp_type]++; */
355	/* code = icp->icmp_code; */
356
357	DEBUG_ARG("icmp_type = %d", icp->icmp_type);
358	switch (icp->icmp_type)
359	{
360	case ICMP_ECHO:
361	ip->ip_len += hlen; /* since ip_input subtracts this */
362	dst = ip->ip_dst.s_addr;
363	if (dst == alias_addr.s_addr)
364	{
365	icp->icmp_type = ICMP_ECHOREPLY;
366	ip->ip_dst.s_addr = ip->ip_src.s_addr;
367	ip->ip_src.s_addr = dst;
368	icmp_reflect(pData, m);
369	}
370	else
371	{
372	struct sockaddr_in addr;
373	#ifdef RT_OS_WINDOWS
374	IP_OPTION_INFORMATION ipopt;
375	int error;
376	#endif
377	addr.sin_family = AF_INET;
378	if ((ip->ip_dst.s_addr & RT_H2N_U32(pData->netmask)) == pData->special_addr.s_addr)
379	{
380	/* It's an alias */
381	switch (RT_N2H_U32(ip->ip_dst.s_addr) & ~pData->netmask)
382	{
383	case CTL_DNS:
384	case CTL_ALIAS:
385	default:
386	addr.sin_addr = loopback_addr;
387	break;
388	}
389	}
390	else
391	addr.sin_addr.s_addr = ip->ip_dst.s_addr;
392	#ifndef RT_OS_WINDOWS
393	if (pData->icmp_socket.s != -1)
394	{
395	m->m_so = &pData->icmp_socket;
396	icmp_attach(pData, m);
397	ttl = ip->ip_ttl;
398	Log(("NAT/ICMP: try to set TTL(%d)\n", ttl));
399	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL,
400	(void *)&ttl, sizeof(ttl));
401	if (status < 0)
402	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n",
403	strerror(errno)));
404	if (sendto(pData->icmp_socket.s, icp, icmplen, 0,
405	(struct sockaddr *)&addr, sizeof(addr)) == -1)
406	{
407	LogRel((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
408	errno, strerror(errno)));
409	icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
410	}
411	}
412	else
413	{
414	/*
415	* We're freeing the ICMP message, which unable sent or process.
416	* That behavior described in rfc 793, we shouldn't notify sender about
417	* fail of processing it's ICMP packets
418	*/
419	m_free(pData, m);
420	return;
421	}
422	#else /* RT_OS_WINDOWS */
423	icmp_attach(pData, m);
424	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
425	pData->icmp_socket.so_icmp_id = icp->icmp_id;
426	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
427	m->m_so = &pData->icmp_socket;
428	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
429	ipopt.Ttl = ip->ip_ttl;
430	status = ICMP_SEND_ECHO(pData->phEvents[VBOX_ICMP_EVENT_INDEX], notify_slirp, addr.sin_addr.s_addr,
431	icp->icmp_data, icmplen - ICMP_MINLEN, &ipopt);
432	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
433	{
434	error = GetLastError();
435	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
436	switch (error)
437	{
438	case ERROR_INVALID_PARAMETER:
439	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
440	break;
441	case ERROR_NOT_SUPPORTED:
442	LogRel(("operation is unsupported)\n"));
443	break;
444	case ERROR_NOT_ENOUGH_MEMORY:
445	LogRel(("OOM!!!)\n"));
446	break;
447	case IP_BUF_TOO_SMALL:
448	LogRel(("Buffer too small)\n"));
449	break;
450	default:
451	LogRel(("Other error!!!)\n"));
452	break;
453	}
454	}
455	#endif /* RT_OS_WINDOWS */
456	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
457	break;
458	case ICMP_UNREACH:
459	/* XXX? report error? close socket? */
460	case ICMP_TIMXCEED:
461	case ICMP_PARAMPROB:
462	case ICMP_SOURCEQUENCH:
463	case ICMP_TSTAMP:
464	case ICMP_MASKREQ:
465	case ICMP_REDIRECT:
466	icmpstat.icps_notsupp++;
467	m_freem(pData, m);
468	break;
469
470	default:
471	icmpstat.icps_badtype++;
472	m_freem(pData, m);
473	} /* switch */
474	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
475	if (m->m_next != NULL && icp != NULL)
476	RTMemFree(icp);
477	#endif
478
479	end_error:
480	/* m is m_free()'d xor put in a socket xor or given to ip_send */
481	;
482	}
483
484
485	/*
486	* Send an ICMP message in response to a situation
487	*
488	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
489	* MUST NOT change this header information.
490	* MUST NOT reply to a multicast/broadcast IP address.
491	* MUST NOT reply to a multicast/broadcast MAC address.
492	* MUST reply to only the first fragment.
493	*/
494	/*
495	* Send ICMP_UNREACH back to the source regarding msrc.
496	* mbuf *msrc is used as a template, but is NOT m_free()'d.
497	* It is reported as the bad ip packet. The header should
498	* be fully correct and in host byte order.
499	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
500	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
501	*/
502
503	#define ICMP_MAXDATALEN (IP_MSS-28)
504	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, const char message)
505	{
506	unsigned hlen, shlen, s_ip_len;
507	register struct ip *ip;
508	register struct icmp *icp;
509	register struct mbuf *m;
510	int new_m_size = 0;
511	int size = 0;
512
513	DEBUG_CALL("icmp_error");
514	DEBUG_ARG("msrc = %lx", (long )msrc);
515	DEBUG_ARG("msrc_len = %d", msrc ? msrc->m_len : 0);
516	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
517	if (msrc != NULL)
518	M_ASSERTPKTHDR(msrc);
519	#endif
520
521	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED && type != ICMP_SOURCEQUENCH)
522	goto end_error;
523
524	/* check msrc */
525	if (!msrc)
526	goto end_error;
527
528	ip = mtod(msrc, struct ip *);
529	#if DEBUG
530	{
531	char bufa[20], bufb[20];
532	strcpy(bufa, inet_ntoa(ip->ip_src));
533	strcpy(bufb, inet_ntoa(ip->ip_dst));
534	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
535	}
536	#endif
537	if (ip->ip_off & IP_OFFMASK && type != ICMP_SOURCEQUENCH)
538	goto end_error; /* Only reply to fragment 0 */
539
540	shlen = ip->ip_hl << 2;
541	s_ip_len = ip->ip_len;
542	if (ip->ip_p == IPPROTO_ICMP)
543	{
544	icp = (struct icmp )((char )ip + shlen);
545	/*
546	* Assume any unknown ICMP type is an error. This isn't
547	* specified by the RFC, but think about it..
548	*/
549	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
550	goto end_error;
551	}
552
553	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
554	/* make a copy */
555	m = m_get(pData);
556	#else
557	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
558	if (new_m_size < MSIZE)
559	{
560	size = MCLBYTES;
561	}
562	else if (new_m_size < MCLBYTES)
563	{
564	size = MCLBYTES;
565	}
566	else if(new_m_size < MJUM9BYTES)
567	{
568	size = MJUM9BYTES;
569	}
570	else if (new_m_size < MJUM16BYTES)
571	{
572	size = MJUM16BYTES;
573	}
574	else
575	{
576	AssertMsgFailed(("Unsupported size"));
577	}
578	m = m_getjcl(pData, M_NOWAIT, MT_HEADER, M_PKTHDR, size);
579	#endif
580	if (m == NULL)
581	goto end_error; /* get mbuf */
582
583	m->m_data += if_maxlinkhdr;
584	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
585	m->m_pkthdr.header = mtod(m, void *);
586	#else
587	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
588	if (new_m_size > m->m_size)
589	{
590	m_inc(m, new_m_size);
591	if (new_m_size > m->m_size)
592	goto end_error_free_m;
593	}
594	#endif
595
596	memcpy(m->m_data, msrc->m_data, msrc->m_len);
597	m->m_len = msrc->m_len; /* copy msrc to m */
598
599	/* make the header of the reply packet */
600	ip = mtod(m, struct ip *);
601	hlen = sizeof(struct ip ); /* no options in reply */
602
603	/* fill in icmp */
604	m->m_data += hlen;
605	m->m_len -= hlen;
606
607	icp = mtod(m, struct icmp *);
608
609	if (minsize)
610	s_ip_len = shlen+ICMP_MINLEN; /* return header+8b only */
611	else if (s_ip_len > ICMP_MAXDATALEN) /* maximum size */
612	s_ip_len = ICMP_MAXDATALEN;
613
614	m->m_len = ICMP_MINLEN + s_ip_len; /* 8 bytes ICMP header */
615
616	/* min. size = 8+sizeof(struct ip)+8 */
617
618	icp->icmp_type = type;
619	icp->icmp_code = code;
620	icp->icmp_id = 0;
621	icp->icmp_seq = 0;
622
623	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
624
625	HTONS(icp->icmp_ip.ip_len);
626	HTONS(icp->icmp_ip.ip_id);
627	HTONS(icp->icmp_ip.ip_off);
628
629	#if DEBUG
630	if (message)
631	{
632	/* DEBUG : append message to ICMP packet */
633	int message_len;
634	char *cpnt;
635	message_len = strlen(message);
636	if (message_len > ICMP_MAXDATALEN)
637	message_len = ICMP_MAXDATALEN;
638	cpnt = (char *)m->m_data+m->m_len;
639	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
640	memcpy(cpnt, message, message_len);
641	m->m_len += message_len;
642	#else
643	m_append(pData, m, message_len, message);
644	#endif
645	}
646	#endif
647
648	icp->icmp_cksum = 0;
649	icp->icmp_cksum = cksum(m, m->m_len);
650
651	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
652	m->m_data -= hlen;
653	m->m_len += hlen;
654	#endif
655
656	/* fill in ip */
657	ip->ip_hl = hlen >> 2;
658	ip->ip_len = m->m_len;
659
660	ip->ip_tos = ((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
661
662	ip->ip_ttl = MAXTTL;
663	ip->ip_p = IPPROTO_ICMP;
664	ip->ip_dst = ip->ip_src; /* ip adresses */
665	ip->ip_src = alias_addr;
666
667	(void ) ip_output0(pData, (struct socket *)NULL, m, 1);
668
669	icmpstat.icps_reflect++;
670
671	return;
672
673	end_error_free_m:
674	m_free(pData, m);
675	end_error:
676	LogRel(("NAT: error occurred while sending ICMP error message \n"));
677	}
678	#undef ICMP_MAXDATALEN
679
680	/*
681	* Reflect the ip packet back to the source
682	*/
683	void
684	icmp_reflect(PNATState pData, struct mbuf *m)
685	{
686	register struct ip ip = mtod(m, struct ip );
687	int hlen = ip->ip_hl << 2;
688	int optlen = hlen - sizeof(struct ip );
689	register struct icmp *icp;
690
691	/*
692	* Send an icmp packet back to the ip level,
693	* after supplying a checksum.
694	*/
695	m->m_data += hlen;
696	m->m_len -= hlen;
697	icp = mtod(m, struct icmp *);
698
699	icp->icmp_cksum = 0;
700	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
701
702	m->m_data -= hlen;
703	m->m_len += hlen;
704
705	(void ) ip_output(pData, (struct socket *)NULL, m);
706
707	icmpstat.icps_reflect++;
708	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 26837

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