ip_icmp.c@ 28443

Last change on this file since 28443 was 28443, checked in by vboxsync, 15 years ago
NAT: m_free -> m_freem: BSD mbufs m_free releases only first element of the mbufs chain while m_freem releases whole chain. in Slirp m_free and m_freem are aliases that why this change do not broke build with original mbufs.
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	ssize_t rc;
408	m->m_so = &pData->icmp_socket;
409	icmp_attach(pData, m);
410	ttl = ip->ip_ttl;
411	Log(("NAT/ICMP: try to set TTL(%d)\n", ttl));
412	status = setsockopt(pData->icmp_socket.s, IPPROTO_IP, IP_TTL,
413	(void *)&ttl, sizeof(ttl));
414	if (status < 0)
415	LogRel(("NAT: Error (%s) occurred while setting TTL attribute of IP packet\n",
416	strerror(errno)));
417	rc = sendto(pData->icmp_socket.s, icp, icmplen, 0,
418	(struct sockaddr *)&addr, sizeof(addr));
419	if (rc < 0)
420	{
421	LogRel((dfd,"icmp_input udp sendto tx errno = %d-%s\n",
422	errno, strerror(errno)));
423	icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
424	}
425	}
426	else
427	{
428	/*
429	* We're freeing the ICMP message, which unable sent or process.
430	* That behavior described in rfc 793, we shouldn't notify sender about
431	* fail of processing it's ICMP packets
432	*/
433	m_free(pData, m);
434	return;
435	}
436	#else /* RT_OS_WINDOWS */
437	icmp_attach(pData, m);
438	pData->icmp_socket.so_laddr.s_addr = ip->ip_src.s_addr; /* XXX: hack*/
439	pData->icmp_socket.so_icmp_id = icp->icmp_id;
440	pData->icmp_socket.so_icmp_seq = icp->icmp_seq;
441	m->m_so = &pData->icmp_socket;
442	memset(&ipopt, 0, sizeof(IP_OPTION_INFORMATION));
443	ipopt.Ttl = ip->ip_ttl;
444	status = ICMP_SEND_ECHO(pData->phEvents[VBOX_ICMP_EVENT_INDEX], notify_slirp, addr.sin_addr.s_addr,
445	icp->icmp_data, icmplen - ICMP_MINLEN, &ipopt);
446	if (status == 0 && (error = GetLastError()) != ERROR_IO_PENDING)
447	{
448	error = GetLastError();
449	LogRel(("NAT: Error (%d) occurred while sending ICMP (", error));
450	switch (error)
451	{
452	case ERROR_INVALID_PARAMETER:
453	LogRel(("icmp_socket:%lx is invalid)\n", pData->icmp_socket.s));
454	break;
455	case ERROR_NOT_SUPPORTED:
456	LogRel(("operation is unsupported)\n"));
457	break;
458	case ERROR_NOT_ENOUGH_MEMORY:
459	LogRel(("OOM!!!)\n"));
460	break;
461	case IP_BUF_TOO_SMALL:
462	LogRel(("Buffer too small)\n"));
463	break;
464	default:
465	LogRel(("Other error!!!)\n"));
466	break;
467	}
468	}
469	#endif /* RT_OS_WINDOWS */
470	} /* if ip->ip_dst.s_addr == alias_addr.s_addr */
471	break;
472	case ICMP_UNREACH:
473	/* XXX? report error? close socket? */
474	case ICMP_TIMXCEED:
475	case ICMP_PARAMPROB:
476	case ICMP_SOURCEQUENCH:
477	case ICMP_TSTAMP:
478	case ICMP_MASKREQ:
479	case ICMP_REDIRECT:
480	icmpstat.icps_notsupp++;
481	m_freem(pData, m);
482	break;
483
484	default:
485	icmpstat.icps_badtype++;
486	m_freem(pData, m);
487	} /* switch */
488	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
489	if (m->m_next != NULL && icp != NULL)
490	RTMemFree(icp);
491	#endif
492
493	end_error:
494	/* m is m_free()'d xor put in a socket xor or given to ip_send */
495	;
496	}
497
498
499	/*
500	* Send an ICMP message in response to a situation
501	*
502	* RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header. MAY send more (we do).
503	* MUST NOT change this header information.
504	* MUST NOT reply to a multicast/broadcast IP address.
505	* MUST NOT reply to a multicast/broadcast MAC address.
506	* MUST reply to only the first fragment.
507	*/
508	/*
509	* Send ICMP_UNREACH back to the source regarding msrc.
510	* mbuf *msrc is used as a template, but is NOT m_free()'d.
511	* It is reported as the bad ip packet. The header should
512	* be fully correct and in host byte order.
513	* ICMP fragmentation is illegal. All machines must accept 576 bytes in one
514	* packet. The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
515	*/
516
517	#define ICMP_MAXDATALEN (IP_MSS-28)
518	void icmp_error(PNATState pData, struct mbuf msrc, u_char type, u_char code, int minsize, const char message)
519	{
520	unsigned hlen, shlen, s_ip_len;
521	register struct ip *ip;
522	register struct icmp *icp;
523	register struct mbuf *m;
524	int new_m_size = 0;
525	int size = 0;
526
527	DEBUG_CALL("icmp_error");
528	DEBUG_ARG("msrc = %lx", (long )msrc);
529	DEBUG_ARG("msrc_len = %d", msrc ? msrc->m_len : 0);
530	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
531	if (msrc != NULL)
532	M_ASSERTPKTHDR(msrc);
533	#endif
534
535	if (type!=ICMP_UNREACH && type!=ICMP_TIMXCEED && type != ICMP_SOURCEQUENCH)
536	goto end_error;
537
538	/* check msrc */
539	if (!msrc)
540	goto end_error;
541
542	ip = mtod(msrc, struct ip *);
543	#if DEBUG
544	{
545	char bufa[20], bufb[20];
546	strcpy(bufa, inet_ntoa(ip->ip_src));
547	strcpy(bufb, inet_ntoa(ip->ip_dst));
548	DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb));
549	}
550	#endif
551	if (ip->ip_off & IP_OFFMASK && type != ICMP_SOURCEQUENCH)
552	goto end_error; /* Only reply to fragment 0 */
553
554	shlen = ip->ip_hl << 2;
555	s_ip_len = ip->ip_len;
556	if (ip->ip_p == IPPROTO_ICMP)
557	{
558	icp = (struct icmp )((char )ip + shlen);
559	/*
560	* Assume any unknown ICMP type is an error. This isn't
561	* specified by the RFC, but think about it..
562	*/
563	if (icp->icmp_type>18 \|\| icmp_flush[icp->icmp_type])
564	goto end_error;
565	}
566
567	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
568	/* make a copy */
569	m = m_get(pData);
570	#else
571	new_m_size = sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
572	if (new_m_size < MSIZE)
573	{
574	size = MCLBYTES;
575	}
576	else if (new_m_size < MCLBYTES)
577	{
578	size = MCLBYTES;
579	}
580	else if(new_m_size < MJUM9BYTES)
581	{
582	size = MJUM9BYTES;
583	}
584	else if (new_m_size < MJUM16BYTES)
585	{
586	size = MJUM16BYTES;
587	}
588	else
589	{
590	AssertMsgFailed(("Unsupported size"));
591	}
592	m = m_getjcl(pData, M_NOWAIT, MT_HEADER, M_PKTHDR, size);
593	#endif
594	if (m == NULL)
595	goto end_error; /* get mbuf */
596
597	m->m_data += if_maxlinkhdr;
598	#ifdef VBOX_WITH_SLIRP_BSD_MBUF
599	m->m_pkthdr.header = mtod(m, void *);
600	#else
601	new_m_size = if_maxlinkhdr + sizeof(struct ip) + ICMP_MINLEN + msrc->m_len + ICMP_MAXDATALEN;
602	if (new_m_size > m->m_size)
603	{
604	m_inc(m, new_m_size);
605	if (new_m_size > m->m_size)
606	goto end_error_free_m;
607	}
608	#endif
609
610	memcpy(m->m_data, msrc->m_data, msrc->m_len);
611	m->m_len = msrc->m_len; /* copy msrc to m */
612
613	/* make the header of the reply packet */
614	ip = mtod(m, struct ip *);
615	hlen = sizeof(struct ip ); /* no options in reply */
616
617	/* fill in icmp */
618	m->m_data += hlen;
619	m->m_len -= hlen;
620
621	icp = mtod(m, struct icmp *);
622
623	if (minsize)
624	s_ip_len = shlen+ICMP_MINLEN; /* return header+8b only */
625	else if (s_ip_len > ICMP_MAXDATALEN) /* maximum size */
626	s_ip_len = ICMP_MAXDATALEN;
627
628	m->m_len = ICMP_MINLEN + s_ip_len; /* 8 bytes ICMP header */
629
630	/* min. size = 8+sizeof(struct ip)+8 */
631
632	icp->icmp_type = type;
633	icp->icmp_code = code;
634	icp->icmp_id = 0;
635	icp->icmp_seq = 0;
636
637	memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */
638
639	HTONS(icp->icmp_ip.ip_len);
640	HTONS(icp->icmp_ip.ip_id);
641	HTONS(icp->icmp_ip.ip_off);
642
643	#if DEBUG
644	if (message)
645	{
646	/* DEBUG : append message to ICMP packet */
647	int message_len;
648	char *cpnt;
649	message_len = strlen(message);
650	if (message_len > ICMP_MAXDATALEN)
651	message_len = ICMP_MAXDATALEN;
652	cpnt = (char *)m->m_data+m->m_len;
653	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
654	memcpy(cpnt, message, message_len);
655	m->m_len += message_len;
656	#else
657	m_append(pData, m, message_len, message);
658	#endif
659	}
660	#endif
661
662	icp->icmp_cksum = 0;
663	icp->icmp_cksum = cksum(m, m->m_len);
664
665	#ifndef VBOX_WITH_SLIRP_BSD_MBUF
666	m->m_data -= hlen;
667	m->m_len += hlen;
668	#endif
669
670	/* fill in ip */
671	ip->ip_hl = hlen >> 2;
672	ip->ip_len = m->m_len;
673
674	ip->ip_tos = ((ip->ip_tos & 0x1E) \| 0xC0); /* high priority for errors */
675
676	ip->ip_ttl = MAXTTL;
677	ip->ip_p = IPPROTO_ICMP;
678	ip->ip_dst = ip->ip_src; /* ip adresses */
679	ip->ip_src = alias_addr;
680
681	(void ) ip_output0(pData, (struct socket *)NULL, m, 1);
682
683	icmpstat.icps_reflect++;
684
685	return;
686
687	end_error_free_m:
688	m_freem(pData, m);
689	end_error:
690	LogRel(("NAT: error occurred while sending ICMP error message \n"));
691	}
692	#undef ICMP_MAXDATALEN
693
694	/*
695	* Reflect the ip packet back to the source
696	*/
697	void
698	icmp_reflect(PNATState pData, struct mbuf *m)
699	{
700	register struct ip ip = mtod(m, struct ip );
701	int hlen = ip->ip_hl << 2;
702	int optlen = hlen - sizeof(struct ip );
703	register struct icmp *icp;
704
705	/*
706	* Send an icmp packet back to the ip level,
707	* after supplying a checksum.
708	*/
709	m->m_data += hlen;
710	m->m_len -= hlen;
711	icp = mtod(m, struct icmp *);
712
713	icp->icmp_cksum = 0;
714	icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
715
716	m->m_data -= hlen;
717	m->m_len += hlen;
718
719	(void ) ip_output(pData, (struct socket *)NULL, m);
720
721	icmpstat.icps_reflect++;
722	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/ip_icmp.c@ 28443

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