1 const char gateway_rcs[] = "$Id: gateway.c,v 1.9 2001/10/25 03:40:48 david__schmidt 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 1.9 2001/10/25 03:40:48 david__schmidt
38 * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple
39 * threads to call select() simultaneously. So, it's time to do a real, live,
40 * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__
41 * (native). Both versions will work, but using __OS2__ offers multi-threading.
43 * Revision 1.8 2001/09/13 20:10:12 jongfoster
44 * Fixing missing #include under Windows
46 * Revision 1.7 2001/09/12 17:58:26 steudten
48 * add #include <string.h>
50 * Revision 1.6 2001/09/10 10:41:16 oes
53 * Revision 1.5 2001/07/29 18:47:57 jongfoster
54 * Adding missing #include project.h
56 * Revision 1.4 2001/07/24 12:47:06 oes
57 * Applied BeOS support update by Eugenia
59 * Revision 1.3 2001/06/09 10:55:28 jongfoster
60 * Changing BUFSIZ ==> BUFFER_SIZE
62 * Revision 1.2 2001/06/07 23:11:38 jongfoster
63 * Removing gateways[] list - no longer used.
64 * Replacing function pointer in struct gateway with a directly
65 * called function forwarded_connect(), which can do the common
66 * task of deciding whether to connect to the web server or HTTP
68 * Replacing struct gateway with struct forward_spec
69 * Fixing bug with SOCKS4A and HTTP proxy server in combination.
70 * It was a bug which led to the connection being made to the web
71 * server rather than the HTTP proxy, and also a buffer overrun.
73 * Revision 1.1.1.1 2001/05/15 13:58:54 oes
74 * Initial import of version 2.9.3 source tree
77 *********************************************************************/
83 #include <sys/types.h>
86 #include <netinet/in.h>
94 #endif /* def _WIN32 */
98 #endif /* def __BEOS__ */
102 #endif /* def __OS2__ */
107 #include "jbsockets.h"
110 const char gateway_h_rcs[] = GATEWAY_H_VERSION;
112 static int socks4_connect(const struct forward_spec * fwd,
113 const char * target_host,
115 struct client_state *csp);
118 #define SOCKS_REQUEST_GRANTED 90
119 #define SOCKS_REQUEST_REJECT 91
120 #define SOCKS_REQUEST_IDENT_FAILED 92
121 #define SOCKS_REQUEST_IDENT_CONFLICT 93
123 /* structure of a socks client operation */
125 unsigned char vn; /* socks version number */
126 unsigned char cd; /* command code */
127 unsigned char dstport[2]; /* destination port */
128 unsigned char dstip[4]; /* destination address */
129 unsigned char userid; /* first byte of userid */
130 /* more bytes of the userid follow, terminated by a NULL */
133 /* structure of a socks server reply */
135 unsigned char vn; /* socks version number */
136 unsigned char cd; /* command code */
137 unsigned char dstport[2]; /* destination port */
138 unsigned char dstip[4]; /* destination address */
141 static const char socks_userid[] = "anonymous";
144 /*********************************************************************
146 * Function : forwarded_connect
148 * Description : Connect to a specified web server, possibly via
149 * a HTTP proxy and/or a SOCKS proxy.
152 * 1 : gw = pointer to a gateway structure (such as gw_default)
153 * 2 : http = the http request and apropos headers
154 * 3 : csp = Current client state (buffers, headers, etc...)
156 * Returns : -1 => failure, else it is the socket file descriptor.
158 *********************************************************************/
159 int forwarded_connect(const struct forward_spec * fwd,
160 struct http_request *http,
161 struct client_state *csp)
163 const char * dest_host;
166 /* Figure out if we need to connect to the web server or a HTTP proxy. */
167 if (fwd->forward_host)
170 dest_host = fwd->forward_host;
171 dest_port = fwd->forward_port;
176 dest_host = http->host;
177 dest_port = http->port;
180 /* Connect, maybe using a SOCKS proxy */
184 return (connect_to(dest_host, dest_port, csp));
188 return (socks4_connect(fwd, dest_host, dest_port, csp));
191 /* Should never get here */
192 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
199 /*********************************************************************
201 * Function : socks4_connect
203 * Description : Connect to the SOCKS server, and connect through
204 * it to the specified server. This handles
205 * all the SOCKS negotiation, and returns a file
206 * descriptor for a socket which can be treated as a
207 * normal (non-SOCKS) socket.
210 * 1 : gw = pointer to a gateway structure (such as gw_default)
211 * 2 : http = the http request and apropos headers
212 * 3 : csp = Current client state (buffers, headers, etc...)
214 * Returns : -1 => failure, else a socket file descriptor.
216 *********************************************************************/
217 static int socks4_connect(const struct forward_spec * fwd,
218 const char * target_host,
220 struct client_state *csp)
223 char cbuf[BUFFER_SIZE];
224 char sbuf[BUFFER_SIZE];
225 struct socks_op *c = (struct socks_op *)cbuf;
226 struct socks_reply *s = (struct socks_reply *)sbuf;
233 if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
235 log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified");
239 if (fwd->gateway_port <= 0)
241 log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified");
251 /* build a socks request for connection to the web server */
253 strcpy((char *)&(c->userid), socks_userid);
255 csiz = sizeof(*c) + sizeof(socks_userid) - 1;
260 web_server_addr = htonl(resolve_hostname_to_ip(target_host));
261 if (web_server_addr == INADDR_NONE)
263 log_error(LOG_LEVEL_CONNECT, "socks4_connect: could not resolve target host %s", target_host);
268 web_server_addr = 0x00000001;
269 n = csiz + strlen(target_host) + 1;
270 if (n > sizeof(cbuf))
275 strcpy(cbuf + csiz, target_host);
279 /* Should never get here */
280 log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type.");
287 c->dstport[0] = (target_port >> 8 ) & 0xff;
288 c->dstport[1] = (target_port ) & 0xff;
289 c->dstip[0] = (web_server_addr >> 24 ) & 0xff;
290 c->dstip[1] = (web_server_addr >> 16 ) & 0xff;
291 c->dstip[2] = (web_server_addr >> 8 ) & 0xff;
292 c->dstip[3] = (web_server_addr ) & 0xff;
294 /* pass the request to the socks server */
295 sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
302 if ((n = write_socket(sfd, (char *)c, csiz)) != csiz)
304 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed...");
309 if ((n = read_socket(sfd, sbuf, sizeof(sbuf))) != sizeof(*s))
311 log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed...");
318 case SOCKS_REQUEST_GRANTED:
321 case SOCKS_REQUEST_REJECT:
322 errstr = "SOCKS request rejected or failed";
325 case SOCKS_REQUEST_IDENT_FAILED:
326 errstr = "SOCKS request rejected because "
327 "SOCKS server cannot connect to identd on the client";
330 case SOCKS_REQUEST_IDENT_CONFLICT:
331 errstr = "SOCKS request rejected because "
332 "the client program and identd report "
333 "different user-ids";
340 "SOCKS request rejected for reason code %d\n", s->cd);
343 log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr);