1 /*
2 * Copyright (c) 1997, 1998, 1999, 2000, 2001, 2008, 2009, 2011, 2012
3 * Inferno Nettverk A/S, Norway. 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. The above copyright notice, this list of conditions and the following
9 * disclaimer must appear in all copies of the software, derivative works
10 * or modified versions, and any portions thereof, aswell as in all
11 * supporting documentation.
12 * 2. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by
15 * Inferno Nettverk A/S, Norway.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Inferno Nettverk A/S requests users of this software to return to
31 *
32 * Software Distribution Coordinator or sdc@inet.no
33 * Inferno Nettverk A/S
34 * Oslo Research Park
35 * Gaustadall�en 21
36 * NO-0349 Oslo
37 * Norway
38 *
39 * any improvements or extensions that they make and grant Inferno Nettverk A/S
40 * the rights to redistribute these changes.
41 *
42 */
43
44 #include "common.h"
45
46 static const char rcsid[] =
47 "$Id: udp_util.c,v 1.68 2013/01/02 13:22:39 karls Exp $";
48
49 void *
udpheader_add(host,msg,len,msgsize)50 udpheader_add(host, msg, len, msgsize)
51 const sockshost_t *host;
52 void *msg;
53 size_t *len;
54 const size_t msgsize;
55 {
56 const char *function = "udpheader_add()";
57 udpheader_t header;
58 unsigned char *offset;
59
60 bzero(&header, sizeof(header));
61 header.host = *host;
62
63 if (msgsize < (size_t)(*len + HEADERSIZE_UDP(&header))) {
64 swarnx("%s: could not prefix socks udp header of size %lu to udp "
65 "payload of length %lu: msgsize (%lu) is too short",
66 function,
67 (unsigned long)HEADERSIZE_UDP(&header),
68 (unsigned long)*len,
69 (unsigned long)msgsize);
70
71 errno = EMSGSIZE;
72 return NULL;
73 }
74
75 slog(LOG_DEBUG,
76 "%s: prefixing udp header with addr %s to buffer of len %lu, size %lu",
77 function,
78 sockshost2string(&header.host, NULL, 0),
79 (unsigned long)*len,
80 (unsigned long)msgsize);
81
82 /* offset old contents by size of header we are about to prefix. */
83 memmove((char *)msg + HEADERSIZE_UDP(&header), msg, *len);
84 offset = msg;
85
86 memcpy(offset, &header.flag, sizeof(header.flag));
87 offset += sizeof(header.flag);
88
89 memcpy(offset, &header.frag, sizeof(header.frag));
90 offset += sizeof(header.frag);
91
92 offset = sockshost2mem(&header.host, offset, PROXY_SOCKS_V5);
93 offset += *len; /* len bytes copied above. */
94
95 *len = (char *)offset - (char *)msg;
96
97 return msg;
98 }
99