1 const char gateway_rcs[] = "$Id: gateway.c,v 1.2 2001/06/07 23:11:38 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 1.2 2001/06/07 23:11:38 jongfoster
38 * Removing gateways[] list - no longer used.
39 * Replacing function pointer in struct gateway with a directly
40 * called function forwarded_connect(), which can do the common
41 * task of deciding whether to connect to the web server or HTTP
43 * Replacing struct gateway with struct forward_spec
44 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
45 * It was a bug which led to the connection being made to the web
46 * server rather than the HTTP proxy, and also a buffer overrun.
48 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
49 * Initial import of version 2.9.3 source tree
52 *********************************************************************/
58 #include <sys/types.h>
63 #endif /* def _WIN32 */
67 #include "jbsockets.h"
70 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
72 static int socks4_connect(const struct forward_spec * fwd,
73 const char * target_host,
75 struct client_state *csp);
78 #define SOCKS_REQUEST_GRANTED 90
79 #define SOCKS_REQUEST_REJECT 91
80 #define SOCKS_REQUEST_IDENT_FAILED 92
81 #define SOCKS_REQUEST_IDENT_CONFLICT 93
83 /* structure of a socks client operation */
85 unsigned char vn; /* socks version number */
86 unsigned char cd; /* command code */
87 unsigned char dstport[2]; /* destination port */
88 unsigned char dstip[4]; /* destination address */
89 unsigned char userid; /* first byte of userid */
90 /* more bytes of the userid follow, terminated by a NULL */
93 /* structure of a socks server reply */
95 unsigned char vn; /* socks version number */
96 unsigned char cd; /* command code */
97 unsigned char dstport[2]; /* destination port */
98 unsigned char dstip[4]; /* destination address */
101 static const char socks_userid[] = "anonymous";
104 /*********************************************************************
106 * Function : forwarded_connect
108 * Description : Connect to a specified web server, possibly via
109 * a HTTP proxy and/or a SOCKS proxy.
112 * 1 : gw = pointer to a gateway structure (such as gw_default)
113 * 2 : http = the http request and apropos headers
114 * 3 : csp = Current client state (buffers, headers, etc...)
116 * Returns : -1 => failure, else it is the socket file descriptor.
118 *********************************************************************/
119 int forwarded_connect(const struct forward_spec * fwd,
120 struct http_request *http,
121 struct client_state *csp)
123 const char * dest_host;
126 /* Figure out if we need to connect to the web server or a HTTP proxy. */
127 if (fwd->forward_host)
130 dest_host = fwd->forward_host;
131 dest_port = fwd->forward_port;
136 dest_host = http->host;
137 dest_port = http->port;
140 /* Connect, maybe using a SOCKS proxy */
144 return (connect_to(dest_host, dest_port, csp));
148 return (socks4_connect(fwd, dest_host, dest_port, csp));
151 /* Should never get here */
152 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
159 /*********************************************************************
161 * Function : socks4_connect
163 * Description : Connect to the SOCKS server, and connect through
164 * it to the specified server. This handles
165 * all the SOCKS negotiation, and returns a file
166 * descriptor for a socket which can be treated as a
167 * normal (non-SOCKS) socket.
170 * 1 : gw = pointer to a gateway structure (such as gw_default)
171 * 2 : http = the http request and apropos headers
172 * 3 : csp = Current client state (buffers, headers, etc...)
174 * Returns : -1 => failure, else a socket file descriptor.
176 *********************************************************************/
177 static int socks4_connect(const struct forward_spec * fwd,
178 const char * target_host,
180 struct client_state *csp)
183 unsigned char cbuf[BUFFER_SIZE];
184 unsigned char sbuf[BUFFER_SIZE];
185 struct socks_op *c = (struct socks_op *)cbuf;
186 struct socks_reply *s = (struct socks_reply *)sbuf;
193 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
195 log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified");
199 if (fwd->gateway_port <= 0)
201 log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified");
211 /* build a socks request for connection to the web server */
213 strcpy((char *)&(c->userid), socks_userid);
215 csiz = sizeof(*c) + sizeof(socks_userid) - 1;
220 web_server_addr = htonl(resolve_hostname_to_ip(target_host));
223 web_server_addr = 0x00000001;
224 n = csiz + strlen(target_host) + 1;
225 if (n > sizeof(cbuf))
230 strcpy(((char *)cbuf) + csiz, target_host);
234 /* Should never get here */
235 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
242 c->dstport[0] = (target_port >> 8 ) & 0xff;
243 c->dstport[1] = (target_port ) & 0xff;
244 c->dstip[0] = (web_server_addr >> 24 ) & 0xff;
245 c->dstip[1] = (web_server_addr >> 16 ) & 0xff;
246 c->dstip[2] = (web_server_addr >> 8 ) & 0xff;
247 c->dstip[3] = (web_server_addr ) & 0xff;
249 /* pass the request to the socks server */
250 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
257 if ((n = write_socket(sfd, (char *)c, csiz)) != csiz)
259 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed...");
264 if ((n = read_socket(sfd, sbuf, sizeof(sbuf))) != sizeof(*s))
266 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed...");
273 case SOCKS_REQUEST_GRANTED:
276 case SOCKS_REQUEST_REJECT:
277 errstr = "SOCKS request rejected or failed";
280 case SOCKS_REQUEST_IDENT_FAILED:
281 errstr = "SOCKS request rejected because "
282 "SOCKS server cannot connect to identd on the client";
285 case SOCKS_REQUEST_IDENT_CONFLICT:
286 errstr = "SOCKS request rejected because "
287 "the client program and identd report "
288 "different user-ids";
292 errstr = (char *) cbuf;
295 "SOCKS request rejected for reason code %d\n", s->cd);
298 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr);