udp.c@ 30363

Last change on this file since 30363 was 30363, checked in by vboxsync, 14 years ago
NAT: more comments + cosmetics
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 15.8 KB

Line
1	/* $Id: udp.c 30363 2010-06-22 11:21:22Z vboxsync $ */
2	/** @file
3	* NAT - UDP protocol.
4	*/
5
6	/*
7	* Copyright (C) 2006-2010 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18	/*
19	* This code is based on:
20	*
21	* Copyright (c) 1982, 1986, 1988, 1990, 1993
22	* The Regents of the University of California. All rights reserved.
23	*
24	* Redistribution and use in source and binary forms, with or without
25	* modification, are permitted provided that the following conditions
26	* are met:
27	* 1. Redistributions of source code must retain the above copyright
28	* notice, this list of conditions and the following disclaimer.
29	* 2. Redistributions in binary form must reproduce the above copyright
30	* notice, this list of conditions and the following disclaimer in the
31	* documentation and/or other materials provided with the distribution.
32	* 3. All advertising materials mentioning features or use of this software
33	* must display the following acknowledgement:
34	* This product includes software developed by the University of
35	* California, Berkeley and its contributors.
36	* 4. Neither the name of the University nor the names of its contributors
37	* may be used to endorse or promote products derived from this software
38	* without specific prior written permission.
39	*
40	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
41	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
44	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50	* SUCH DAMAGE.
51	*
52	* @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94
53	* udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp
54	*/
55
56	/*
57	* Changes and additions relating to SLiRP
58	* Copyright (c) 1995 Danny Gasparovski.
59	*
60	* Please read the file COPYRIGHT for the
61	* terms and conditions of the copyright.
62	*/
63
64	#include <slirp.h>
65	#include "ip_icmp.h"
66	#include "ctl.h"
67
68
69	/*
70	* UDP protocol implementation.
71	* Per RFC 768, August, 1980.
72	*/
73	#define udpcksum 1
74
75	void
76	udp_init(PNATState pData)
77	{
78	udp_last_so = &udb;
79	udb.so_next = udb.so_prev = &udb;
80	}
81
82	/* m->m_data points at ip packet header
83	* m->m_len length ip packet
84	* ip->ip_len length data (IPDU)
85	*/
86	void
87	udp_input(PNATState pData, register struct mbuf *m, int iphlen)
88	{
89	register struct ip *ip;
90	register struct udphdr *uh;
91	int len;
92	struct ip save_ip;
93	struct socket *so;
94	int ret;
95	int ttl;
96
97	DEBUG_CALL("udp_input");
98	DEBUG_ARG("m = %lx", (long)m);
99	ip = mtod(m, struct ip *);
100	DEBUG_ARG("iphlen = %d", iphlen);
101	Log2(("%R[IP4] iphlen = %d\n", &ip->ip_dst, iphlen));
102
103	udpstat.udps_ipackets++;
104
105	/*
106	* Strip IP options, if any; should skip this,
107	* make available to user, and use on returned packets,
108	* but we don't yet have a way to check the checksum
109	* with options still present.
110	*/
111	if (iphlen > sizeof(struct ip))
112	{
113	ip_stripoptions(m, (struct mbuf *)0);
114	iphlen = sizeof(struct ip);
115	}
116
117	/*
118	* Get IP and UDP header together in first mbuf.
119	*/
120	ip = mtod(m, struct ip *);
121	uh = (struct udphdr *)((caddr_t)ip + iphlen);
122
123	/*
124	* Make mbuf data length reflect UDP length.
125	* If not enough data to reflect UDP length, drop.
126	*/
127	len = RT_N2H_U16((u_int16_t)uh->uh_ulen);
128	Assert((ip->ip_len == len));
129	Assert((ip->ip_len + iphlen == m_length(m, NULL)));
130
131	if (ip->ip_len != len)
132	{
133	if (len > ip->ip_len)
134	{
135	udpstat.udps_badlen++;
136	Log3(("NAT: IP(id: %hd) has bad size\n", ip->ip_id));
137	}
138	m_adj(m, len - ip->ip_len);
139	ip->ip_len = len;
140	}
141
142	/*
143	* Save a copy of the IP header in case we want restore it
144	* for sending an ICMP error message in response.
145	*/
146	save_ip = *ip;
147	save_ip.ip_len+= iphlen; /* tcp_input subtracts this */
148
149	/*
150	* Checksum extended UDP header and data.
151	*/
152	if (udpcksum && uh->uh_sum)
153	{
154	memset(((struct ipovly *)ip)->ih_x1, 0, 9);
155	((struct ipovly *)ip)->ih_len = uh->uh_ulen;
156	#if 0
157	/* keep uh_sum for ICMP reply */
158	uh->uh_sum = cksum(m, len + sizeof (struct ip));
159	if (uh->uh_sum)
160	{
161
162	#endif
163	if (cksum(m, len + iphlen))
164	{
165	udpstat.udps_badsum++;
166	Log3(("NAT: IP(id: %hd) has bad (udp) cksum\n", ip->ip_id));
167	goto bad_free_mbuf;
168	}
169	}
170	#if 0
171	}
172	#endif
173
174	/*
175	* handle DHCP/BOOTP
176	*/
177	if (uh->uh_dport == RT_H2N_U16_C(BOOTP_SERVER))
178	{
179	bootp_input(pData, m);
180	goto done_free_mbuf;
181	}
182
183	if ( pData->fUseHostResolver
184	&& uh->uh_dport == RT_H2N_U16_C(53)
185	&& CTL_CHECK(RT_N2H_U32(ip->ip_dst.s_addr), CTL_DNS))
186	{
187	struct sockaddr_in dst, src;
188	src.sin_addr.s_addr = ip->ip_dst.s_addr;
189	src.sin_port = uh->uh_dport;
190	dst.sin_addr.s_addr = ip->ip_src.s_addr;
191	dst.sin_port = uh->uh_sport;
192
193	/* udp_output2() expects a pointer to the body of UDP packet. */
194	m->m_data += sizeof(struct udpiphdr);
195	m->m_len -= sizeof(struct udpiphdr);
196	udp_output2(pData, NULL, m, &src, &dst, IPTOS_LOWDELAY);
197	return;
198	}
199	/*
200	* handle TFTP
201	*/
202	if ( uh->uh_dport == RT_H2N_U16_C(TFTP_SERVER)
203	&& CTL_CHECK(RT_N2H_U32(ip->ip_dst.s_addr), CTL_TFTP))
204	{
205	tftp_input(pData, m);
206	goto done_free_mbuf;
207	}
208
209	/*
210	* Locate pcb for datagram.
211	*/
212	so = udp_last_so;
213	if ( so->so_lport != uh->uh_sport
214	\|\| so->so_laddr.s_addr != ip->ip_src.s_addr)
215	{
216	struct socket *tmp;
217
218	for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next)
219	{
220	if ( tmp->so_lport == uh->uh_sport
221	&& tmp->so_laddr.s_addr == ip->ip_src.s_addr)
222	{
223	so = tmp;
224	break;
225	}
226	}
227	if (tmp == &udb)
228	so = NULL;
229	else
230	{
231	udpstat.udpps_pcbcachemiss++;
232	udp_last_so = so;
233	}
234	}
235
236	if (so == NULL)
237	{
238	/*
239	* If there's no socket for this packet,
240	* create one
241	*/
242	if ((so = socreate()) == NULL)
243	{
244	Log2(("NAT: IP(id: %hd) failed to create socket\n", ip->ip_id));
245	goto bad_free_mbuf;
246	}
247	if (udp_attach(pData, so, 0) == -1)
248	{
249	Log2(("NAT: IP(id: %hd) udp_attach errno = %d-%s\n",
250	ip->ip_id, errno, strerror(errno)));
251	sofree(pData, so);
252	goto bad_free_mbuf;
253	}
254
255	/*
256	* Setup fields
257	*/
258	/* udp_last_so = so; */
259	so->so_laddr = ip->ip_src;
260	so->so_lport = uh->uh_sport;
261
262	so->so_iptos = ip->ip_tos;
263
264	/*
265	* XXXXX Here, check if it's in udpexec_list,
266	* and if it is, do the fork_exec() etc.
267	*/
268	}
269
270	so->so_faddr = ip->ip_dst; /* XXX */
271	so->so_fport = uh->uh_dport; /* XXX */
272
273	/*
274	* DNS proxy
275	*/
276	if ( pData->fUseDnsProxy
277	&& (ip->ip_dst.s_addr == RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) \| CTL_DNS))
278	&& (uh->uh_dport == RT_H2N_U16_C(53)))
279	{
280	dnsproxy_query(pData, so, m, iphlen);
281	goto done_free_mbuf;
282	}
283
284	iphlen += sizeof(struct udphdr);
285	m->m_len -= iphlen;
286	m->m_data += iphlen;
287
288	ttl = ip->ip_ttl = save_ip.ip_ttl;
289	ret = setsockopt(so->s, IPPROTO_IP, IP_TTL, (const char*)&ttl, sizeof(ttl));
290	if (ret < 0)
291	LogRel(("NAT: Error (%s) occurred while setting TTL(%d) attribute "
292	"of IP packet to socket %R[natsock]\n", strerror(errno), ip->ip_ttl, so));
293
294	if (sosendto(pData, so, m) == -1)
295	{
296	m->m_len += iphlen;
297	m->m_data -= iphlen;
298	*ip = save_ip;
299	DEBUG_MISC((dfd,"NAT: UDP tx errno = %d-%s (on sent to %R[IP4])\n", errno,
300	strerror(errno), &ip->ip_dst));
301	icmp_error(pData, m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno));
302	/* in case we receive ICMP on this socket we'll aware that ICMP has been already sent to host*/
303	so->so_m = NULL;
304	}
305
306	if (so->so_m)
307	m_freem(pData, so->so_m); /* used for ICMP if error on sorecvfrom */
308
309	/* restore the orig mbuf packet */
310	m->m_len += iphlen;
311	m->m_data -= iphlen;
312	*ip = save_ip;
313	so->so_m = m; /* ICMP backup */
314	return;
315
316	bad_free_mbuf:
317	Log2(("NAT: UDP(id: %hd) datagram to %R[IP4] with size(%d) claimed as bad\n",
318	ip->ip_id, &ip->ip_dst, ip->ip_len));
319
320	done_free_mbuf:
321	/* some services like bootp(built-in), dns(buildt-in) and dhcp don't need sockets
322	* and create new m'buffers to send them to guest, so we'll free their incomming
323	* buffers here.
324	*/
325	m_freem(pData, m);
326	return;
327	}
328
329	/**
330	* Output a UDP packet.
331	*
332	* @note This function will finally free m!
333	*/
334	int udp_output2(PNATState pData, struct socket so, struct mbuf m,
335	struct sockaddr_in saddr, struct sockaddr_in daddr,
336	int iptos)
337	{
338	register struct udpiphdr *ui;
339	int error;
340
341	DEBUG_CALL("udp_output");
342	DEBUG_ARG("so = %lx", (long)so);
343	DEBUG_ARG("m = %lx", (long)m);
344	DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
345	DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);
346
347	/*
348	* Adjust for header
349	*/
350	m->m_data -= sizeof(struct udpiphdr);
351	m->m_len += sizeof(struct udpiphdr);
352
353	/*
354	* Fill in mbuf with extended UDP header
355	* and addresses and length put into network format.
356	*/
357	ui = mtod(m, struct udpiphdr *);
358	memset(ui->ui_x1, 0, 9);
359	ui->ui_pr = IPPROTO_UDP;
360	ui->ui_len = RT_H2N_U16(m->m_len - sizeof(struct ip));
361	/* XXXXX Check for from-one-location sockets, or from-any-location sockets */
362	ui->ui_src = saddr->sin_addr;
363	ui->ui_dst = daddr->sin_addr;
364	ui->ui_sport = saddr->sin_port;
365	ui->ui_dport = daddr->sin_port;
366	ui->ui_ulen = ui->ui_len;
367
368	/*
369	* Stuff checksum and output datagram.
370	*/
371	ui->ui_sum = 0;
372	if (udpcksum)
373	{
374	if ((ui->ui_sum = cksum(m, /* sizeof (struct udpiphdr) + */ m->m_len)) == 0)
375	ui->ui_sum = 0xffff;
376	}
377	((struct ip *)ui)->ip_len = m->m_len;
378	((struct ip *)ui)->ip_ttl = ip_defttl;
379	((struct ip *)ui)->ip_tos = iptos;
380
381	udpstat.udps_opackets++;
382
383	error = ip_output(pData, so, m);
384
385	return error;
386	}
387
388	/**
389	* @note This function will free m!
390	*/
391	int udp_output(PNATState pData, struct socket so, struct mbuf m,
392	struct sockaddr_in *addr)
393	{
394	struct sockaddr_in saddr, daddr;
395
396	saddr = *addr;
397	if ((so->so_faddr.s_addr & RT_H2N_U32(pData->netmask)) == pData->special_addr.s_addr)
398	{
399	saddr.sin_addr.s_addr = so->so_faddr.s_addr;
400	if ((so->so_faddr.s_addr & RT_H2N_U32(~pData->netmask)) == RT_H2N_U32(~pData->netmask))
401	saddr.sin_addr.s_addr = alias_addr.s_addr;
402	}
403
404	/* Any UDP packet to the loopback address must be translated to be from
405	* the forwarding address, i.e. 10.0.2.2. */
406	if ( (saddr.sin_addr.s_addr & RT_H2N_U32_C(IN_CLASSA_NET))
407	== RT_H2N_U32_C(INADDR_LOOPBACK & IN_CLASSA_NET))
408	saddr.sin_addr.s_addr = alias_addr.s_addr;
409
410	daddr.sin_addr = so->so_laddr;
411	daddr.sin_port = so->so_lport;
412
413	return udp_output2(pData, so, m, &saddr, &daddr, so->so_iptos);
414	}
415
416	int
417	udp_attach(PNATState pData, struct socket *so, int service_port)
418	{
419	struct sockaddr_in *addr;
420	struct sockaddr sa_addr;
421	socklen_t socklen = sizeof(struct sockaddr);
422	int status;
423	int opt = 1;
424
425	if ((so->s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
426	goto error;
427	/*
428	* Here, we bind() the socket. Although not really needed
429	* (sendto() on an unbound socket will bind it), it's done
430	* here so that emulation of ytalk etc. don't have to do it
431	*/
432	memset(&sa_addr, 0, sizeof(struct sockaddr));
433	addr = (struct sockaddr_in *)&sa_addr;
434	#ifdef RT_OS_DARWIN
435	addr->sin_len = sizeof(struct sockaddr_in);
436	#endif
437	addr->sin_family = AF_INET;
438	addr->sin_port = service_port;
439	addr->sin_addr.s_addr = pData->bindIP.s_addr;
440	fd_nonblock(so->s);
441	if (bind(so->s, &sa_addr, sizeof(struct sockaddr_in)) < 0)
442	{
443	int lasterrno = errno;
444	closesocket(so->s);
445	so->s = -1;
446	#ifdef RT_OS_WINDOWS
447	WSASetLastError(lasterrno);
448	#else
449	errno = lasterrno;
450	#endif
451	goto error;
452	}
453	/* success, insert in queue */
454	so->so_expire = curtime + SO_EXPIRE;
455	/* enable broadcast for later use */
456	setsockopt(so->s, SOL_SOCKET, SO_BROADCAST, (const char *)&opt, sizeof(opt));
457	status = getsockname(so->s, &sa_addr, &socklen);
458	Assert(status == 0 && sa_addr.sa_family == AF_INET);
459	so->so_hlport = ((struct sockaddr_in *)&sa_addr)->sin_port;
460	so->so_hladdr.s_addr = ((struct sockaddr_in *)&sa_addr)->sin_addr.s_addr;
461	SOCKET_LOCK_CREATE(so);
462	QSOCKET_LOCK(udb);
463	insque(pData, so, &udb);
464	NSOCK_INC();
465	QSOCKET_UNLOCK(udb);
466	return so->s;
467	error:
468	Log2(("NAT: can't create datagramm socket\n"));
469	return -1;
470	}
471
472	void
473	udp_detach(PNATState pData, struct socket *so)
474	{
475	if (so != &pData->icmp_socket)
476	{
477	QSOCKET_LOCK(udb);
478	SOCKET_LOCK(so);
479	QSOCKET_UNLOCK(udb);
480	closesocket(so->s);
481	sofree(pData, so);
482	SOCKET_UNLOCK(so);
483	}
484	}
485
486	struct socket *
487	udp_listen(PNATState pData, u_int32_t bind_addr, u_int port, u_int32_t laddr, u_int lport, int flags)
488	{
489	struct sockaddr_in addr;
490	struct socket *so;
491	socklen_t addrlen = sizeof(struct sockaddr_in);
492	int opt = 1;
493
494	if ((so = socreate()) == NULL)
495	return NULL;
496
497	so->s = socket(AF_INET, SOCK_DGRAM, 0);
498	if (so->s == -1)
499	{
500	LogRel(("NAT: can't create datagram socket\n"));
501	RTMemFree(so);
502	return NULL;
503	}
504	so->so_expire = curtime + SO_EXPIRE;
505	fd_nonblock(so->s);
506	SOCKET_LOCK_CREATE(so);
507	QSOCKET_LOCK(udb);
508	insque(pData, so, &udb);
509	NSOCK_INC();
510	QSOCKET_UNLOCK(udb);
511
512	memset(&addr, 0, sizeof(addr));
513	#ifdef RT_OS_DARWIN
514	addr.sin_len = sizeof(addr);
515	#endif
516	addr.sin_family = AF_INET;
517	addr.sin_addr.s_addr = bind_addr;
518	addr.sin_port = port;
519
520	if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0)
521	{
522	LogRel(("NAT: bind to %R[IP4] has been failed\n", &addr.sin_addr));
523	udp_detach(pData, so);
524	return NULL;
525	}
526	setsockopt(so->s, SOL_SOCKET, SO_REUSEADDR,(char *)&opt, sizeof(int));
527	/* setsockopt(so->s, SOL_SOCKET, SO_OOBINLINE,(char )&opt, sizeof(int)); /
528
529	getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
530	so->so_fport = addr.sin_port;
531	/* The original check was completely broken, as the commented out
532	* if statement was always true (INADDR_ANY=0). */
533	/* if (addr.sin_addr.s_addr == 0 \|\| addr.sin_addr.s_addr == loopback_addr.s_addr) */
534	if (1 == 0) /* always use the else part */
535	so->so_faddr = alias_addr;
536	else
537	so->so_faddr = addr.sin_addr;
538
539	so->so_lport = lport;
540	so->so_laddr.s_addr = laddr;
541	if (flags != SS_FACCEPTONCE)
542	so->so_expire = 0;
543
544	so->so_state = SS_ISFCONNECTED;
545
546	return so;
547	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/udp.c@ 30363

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