1 const char gateway_rcs[] = "$Id: gateway.c,v 1.8 2001/09/13 20:10:12 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 1.8 2001/09/13 20:10:12 jongfoster
38 * Fixing missing #include under Windows
40 * Revision 1.7 2001/09/12 17:58:26 steudten
42 * add #include <string.h>
44 * Revision 1.6 2001/09/10 10:41:16 oes
47 * Revision 1.5 2001/07/29 18:47:57 jongfoster
48 * Adding missing #include project.h
50 * Revision 1.4 2001/07/24 12:47:06 oes
51 * Applied BeOS support update by Eugenia
53 * Revision 1.3 2001/06/09 10:55:28 jongfoster
54 * Changing BUFSIZ ==> BUFFER_SIZE
56 * Revision 1.2 2001/06/07 23:11:38 jongfoster
57 * Removing gateways[] list - no longer used.
58 * Replacing function pointer in struct gateway with a directly
59 * called function forwarded_connect(), which can do the common
60 * task of deciding whether to connect to the web server or HTTP
62 * Replacing struct gateway with struct forward_spec
63 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
64 * It was a bug which led to the connection being made to the web
65 * server rather than the HTTP proxy, and also a buffer overrun.
67 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
68 * Initial import of version 2.9.3 source tree
71 *********************************************************************/
77 #include <sys/types.h>
80 #include <netinet/in.h>
88 #endif /* def _WIN32 */
92 #endif /* def __BEOS__ */
96 #endif /* def __OS2__ */
101 #include "jbsockets.h"
104 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
106 static int socks4_connect(const struct forward_spec * fwd,
107 const char * target_host,
109 struct client_state *csp);
112 #define SOCKS_REQUEST_GRANTED 90
113 #define SOCKS_REQUEST_REJECT 91
114 #define SOCKS_REQUEST_IDENT_FAILED 92
115 #define SOCKS_REQUEST_IDENT_CONFLICT 93
117 /* structure of a socks client operation */
119 unsigned char vn; /* socks version number */
120 unsigned char cd; /* command code */
121 unsigned char dstport[2]; /* destination port */
122 unsigned char dstip[4]; /* destination address */
123 unsigned char userid; /* first byte of userid */
124 /* more bytes of the userid follow, terminated by a NULL */
127 /* structure of a socks server reply */
129 unsigned char vn; /* socks version number */
130 unsigned char cd; /* command code */
131 unsigned char dstport[2]; /* destination port */
132 unsigned char dstip[4]; /* destination address */
135 static const char socks_userid[] = "anonymous";
138 /*********************************************************************
140 * Function : forwarded_connect
142 * Description : Connect to a specified web server, possibly via
143 * a HTTP proxy and/or a SOCKS proxy.
146 * 1 : gw = pointer to a gateway structure (such as gw_default)
147 * 2 : http = the http request and apropos headers
148 * 3 : csp = Current client state (buffers, headers, etc...)
150 * Returns : -1 => failure, else it is the socket file descriptor.
152 *********************************************************************/
153 int forwarded_connect(const struct forward_spec * fwd,
154 struct http_request *http,
155 struct client_state *csp)
157 const char * dest_host;
160 /* Figure out if we need to connect to the web server or a HTTP proxy. */
161 if (fwd->forward_host)
164 dest_host = fwd->forward_host;
165 dest_port = fwd->forward_port;
170 dest_host = http->host;
171 dest_port = http->port;
174 /* Connect, maybe using a SOCKS proxy */
178 return (connect_to(dest_host, dest_port, csp));
182 return (socks4_connect(fwd, dest_host, dest_port, csp));
185 /* Should never get here */
186 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
193 /*********************************************************************
195 * Function : socks4_connect
197 * Description : Connect to the SOCKS server, and connect through
198 * it to the specified server. This handles
199 * all the SOCKS negotiation, and returns a file
200 * descriptor for a socket which can be treated as a
201 * normal (non-SOCKS) socket.
204 * 1 : gw = pointer to a gateway structure (such as gw_default)
205 * 2 : http = the http request and apropos headers
206 * 3 : csp = Current client state (buffers, headers, etc...)
208 * Returns : -1 => failure, else a socket file descriptor.
210 *********************************************************************/
211 static int socks4_connect(const struct forward_spec * fwd,
212 const char * target_host,
214 struct client_state *csp)
217 unsigned char cbuf[BUFFER_SIZE];
218 unsigned char sbuf[BUFFER_SIZE];
219 struct socks_op *c = (struct socks_op *)cbuf;
220 struct socks_reply *s = (struct socks_reply *)sbuf;
227 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
229 log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified");
233 if (fwd->gateway_port <= 0)
235 log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified");
245 /* build a socks request for connection to the web server */
247 strcpy((char *)&(c->userid), socks_userid);
249 csiz = sizeof(*c) + sizeof(socks_userid) - 1;
254 web_server_addr = htonl(resolve_hostname_to_ip(target_host));
257 web_server_addr = 0x00000001;
258 n = csiz + strlen(target_host) + 1;
259 if (n > sizeof(cbuf))
264 strcpy(((char *)cbuf) + csiz, target_host);
268 /* Should never get here */
269 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
276 c->dstport[0] = (target_port >> 8 ) & 0xff;
277 c->dstport[1] = (target_port ) & 0xff;
278 c->dstip[0] = (web_server_addr >> 24 ) & 0xff;
279 c->dstip[1] = (web_server_addr >> 16 ) & 0xff;
280 c->dstip[2] = (web_server_addr >> 8 ) & 0xff;
281 c->dstip[3] = (web_server_addr ) & 0xff;
283 /* pass the request to the socks server */
284 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
291 if ((n = write_socket(sfd, (char *)c, csiz)) != csiz)
293 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed...");
298 if ((n = read_socket(sfd, sbuf, sizeof(sbuf))) != sizeof(*s))
300 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed...");
307 case SOCKS_REQUEST_GRANTED:
310 case SOCKS_REQUEST_REJECT:
311 errstr = "SOCKS request rejected or failed";
314 case SOCKS_REQUEST_IDENT_FAILED:
315 errstr = "SOCKS request rejected because "
316 "SOCKS server cannot connect to identd on the client";
319 case SOCKS_REQUEST_IDENT_CONFLICT:
320 errstr = "SOCKS request rejected because "
321 "the client program and identd report "
322 "different user-ids";
326 errstr = (char *) cbuf;
329 "SOCKS request rejected for reason code %d\n", s->cd);
332 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr);