1 const char gateway_rcs[] = "$Id: gateway.c,v 1.5 2001/07/29 18:47:57 jongfoster Exp $";
2 /*********************************************************************
4 * File : $Source: /cvsroot/ijbswa/current/gateway.c,v $
6 * Purpose : Contains functions to connect to a server, possibly
7 * using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4
10 * Copyright : Written by and Copyright (C) 2001 the SourceForge
11 * IJBSWA team. http://ijbswa.sourceforge.net
13 * Based on the Internet Junkbuster originally written
14 * by and Copyright (C) 1997 Anonymous Coders and
15 * Junkbusters Corporation. http://www.junkbusters.com
17 * This program is free software; you can redistribute it
18 * and/or modify it under the terms of the GNU General
19 * Public License as published by the Free Software
20 * Foundation; either version 2 of the License, or (at
21 * your option) any later version.
23 * This program is distributed in the hope that it will
24 * be useful, but WITHOUT ANY WARRANTY; without even the
25 * implied warranty of MERCHANTABILITY or FITNESS FOR A
26 * PARTICULAR PURPOSE. See the GNU General Public
27 * License for more details.
29 * The GNU General Public License should be included with
30 * this file. If not, you can view it at
31 * http://www.gnu.org/copyleft/gpl.html
32 * or write to the Free Software Foundation, Inc., 59
33 * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
37 * Revision 1.5 2001/07/29 18:47:57 jongfoster
38 * Adding missing #include project.h
40 * Revision 1.4 2001/07/24 12:47:06 oes
41 * Applied BeOS support update by Eugenia
43 * Revision 1.3 2001/06/09 10:55:28 jongfoster
44 * Changing BUFSIZ ==> BUFFER_SIZE
46 * Revision 1.2 2001/06/07 23:11:38 jongfoster
47 * Removing gateways[] list - no longer used.
48 * Replacing function pointer in struct gateway with a directly
49 * called function forwarded_connect(), which can do the common
50 * task of deciding whether to connect to the web server or HTTP
52 * Replacing struct gateway with struct forward_spec
53 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
54 * It was a bug which led to the connection being made to the web
55 * server rather than the HTTP proxy, and also a buffer overrun.
57 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
58 * Initial import of version 2.9.3 source tree
61 *********************************************************************/
67 #include <sys/types.h>
68 #include <netinet/in.h>
73 #endif /* def _WIN32 */
77 #endif /* def __BEOS__ */
82 #include "jbsockets.h"
85 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
87 static int socks4_connect(const struct forward_spec * fwd,
88 const char * target_host,
90 struct client_state *csp);
93 #define SOCKS_REQUEST_GRANTED 90
94 #define SOCKS_REQUEST_REJECT 91
95 #define SOCKS_REQUEST_IDENT_FAILED 92
96 #define SOCKS_REQUEST_IDENT_CONFLICT 93
98 /* structure of a socks client operation */
100 unsigned char vn; /* socks version number */
101 unsigned char cd; /* command code */
102 unsigned char dstport[2]; /* destination port */
103 unsigned char dstip[4]; /* destination address */
104 unsigned char userid; /* first byte of userid */
105 /* more bytes of the userid follow, terminated by a NULL */
108 /* structure of a socks server reply */
110 unsigned char vn; /* socks version number */
111 unsigned char cd; /* command code */
112 unsigned char dstport[2]; /* destination port */
113 unsigned char dstip[4]; /* destination address */
116 static const char socks_userid[] = "anonymous";
119 /*********************************************************************
121 * Function : forwarded_connect
123 * Description : Connect to a specified web server, possibly via
124 * a HTTP proxy and/or a SOCKS proxy.
127 * 1 : gw = pointer to a gateway structure (such as gw_default)
128 * 2 : http = the http request and apropos headers
129 * 3 : csp = Current client state (buffers, headers, etc...)
131 * Returns : -1 => failure, else it is the socket file descriptor.
133 *********************************************************************/
134 int forwarded_connect(const struct forward_spec * fwd,
135 struct http_request *http,
136 struct client_state *csp)
138 const char * dest_host;
141 /* Figure out if we need to connect to the web server or a HTTP proxy. */
142 if (fwd->forward_host)
145 dest_host = fwd->forward_host;
146 dest_port = fwd->forward_port;
151 dest_host = http->host;
152 dest_port = http->port;
155 /* Connect, maybe using a SOCKS proxy */
159 return (connect_to(dest_host, dest_port, csp));
163 return (socks4_connect(fwd, dest_host, dest_port, csp));
166 /* Should never get here */
167 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
174 /*********************************************************************
176 * Function : socks4_connect
178 * Description : Connect to the SOCKS server, and connect through
179 * it to the specified server. This handles
180 * all the SOCKS negotiation, and returns a file
181 * descriptor for a socket which can be treated as a
182 * normal (non-SOCKS) socket.
185 * 1 : gw = pointer to a gateway structure (such as gw_default)
186 * 2 : http = the http request and apropos headers
187 * 3 : csp = Current client state (buffers, headers, etc...)
189 * Returns : -1 => failure, else a socket file descriptor.
191 *********************************************************************/
192 static int socks4_connect(const struct forward_spec * fwd,
193 const char * target_host,
195 struct client_state *csp)
198 unsigned char cbuf[BUFFER_SIZE];
199 unsigned char sbuf[BUFFER_SIZE];
200 struct socks_op *c = (struct socks_op *)cbuf;
201 struct socks_reply *s = (struct socks_reply *)sbuf;
208 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
210 log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified");
214 if (fwd->gateway_port <= 0)
216 log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified");
226 /* build a socks request for connection to the web server */
228 strcpy((char *)&(c->userid), socks_userid);
230 csiz = sizeof(*c) + sizeof(socks_userid) - 1;
235 web_server_addr = htonl(resolve_hostname_to_ip(target_host));
238 web_server_addr = 0x00000001;
239 n = csiz + strlen(target_host) + 1;
240 if (n > sizeof(cbuf))
245 strcpy(((char *)cbuf) + csiz, target_host);
249 /* Should never get here */
250 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
257 c->dstport[0] = (target_port >> 8 ) & 0xff;
258 c->dstport[1] = (target_port ) & 0xff;
259 c->dstip[0] = (web_server_addr >> 24 ) & 0xff;
260 c->dstip[1] = (web_server_addr >> 16 ) & 0xff;
261 c->dstip[2] = (web_server_addr >> 8 ) & 0xff;
262 c->dstip[3] = (web_server_addr ) & 0xff;
264 /* pass the request to the socks server */
265 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
272 if ((n = write_socket(sfd, (char *)c, csiz)) != csiz)
274 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed...");
279 if ((n = read_socket(sfd, sbuf, sizeof(sbuf))) != sizeof(*s))
281 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed...");
288 case SOCKS_REQUEST_GRANTED:
291 case SOCKS_REQUEST_REJECT:
292 errstr = "SOCKS request rejected or failed";
295 case SOCKS_REQUEST_IDENT_FAILED:
296 errstr = "SOCKS request rejected because "
297 "SOCKS server cannot connect to identd on the client";
300 case SOCKS_REQUEST_IDENT_CONFLICT:
301 errstr = "SOCKS request rejected because "
302 "the client program and identd report "
303 "different user-ids";
307 errstr = (char *) cbuf;
310 "SOCKS request rejected for reason code %d\n", s->cd);
313 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr);