const char gateway_rcs[] = "$Id: gateway.c,v 1.14 2002/03/24 13:25:43 swa Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/gateway.c,v $ * * Purpose : Contains functions to connect to a server, possibly * using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4 * proxy). * * Copyright : Written by and Copyright (C) 2001 the SourceForge * Privoxy team. http://www.privoxy.org/ * * Based on the Internet Junkbuster originally written * by and Copyright (C) 1997 Anonymous Coders and * Junkbusters Corporation. http://www.junkbusters.com * * This program is free software; you can redistribute it * and/or modify it under the terms of the GNU General * Public License as published by the Free Software * Foundation; either version 2 of the License, or (at * your option) any later version. * * This program is distributed in the hope that it will * be useful, but WITHOUT ANY WARRANTY; without even the * implied warranty of MERCHANTABILITY or FITNESS FOR A * PARTICULAR PURPOSE. See the GNU General Public * License for more details. * * The GNU General Public License should be included with * this file. If not, you can view it at * http://www.gnu.org/copyleft/gpl.html * or write to the Free Software Foundation, Inc., 59 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * * Revisions : * $Log: gateway.c,v $ * Revision 1.14 2002/03/24 13:25:43 swa * name change related issues * * Revision 1.13 2002/03/13 00:29:59 jongfoster * Killing warnings * * Revision 1.12 2002/03/09 20:03:52 jongfoster * - Making various functions return int rather than size_t. * (Undoing a recent change). Since size_t is unsigned on * Windows, functions like read_socket that return -1 on * error cannot return a size_t. * * THIS WAS A MAJOR BUG - it caused frequent, unpredictable * crashes, and also frequently caused JB to jump to 100% * CPU and stay there. (Because it thought it had just * read ((unsigned)-1) == 4Gb of data...) * * - The signature of write_socket has changed, it now simply * returns success=0/failure=nonzero. * * - Trying to get rid of a few warnings --with-debug on * Windows, I've introduced a new type "jb_socket". This is * used for the socket file descriptors. On Windows, this * is SOCKET (a typedef for unsigned). Everywhere else, it's * an int. The error value can't be -1 any more, so it's * now JB_INVALID_SOCKET (which is -1 on UNIX, and in * Windows it maps to the #define INVALID_SOCKET.) * * - The signature of bind_port has changed. * * Revision 1.11 2002/03/08 17:46:04 jongfoster * Fixing int/size_t warnings * * Revision 1.10 2002/03/07 03:50:19 oes * - Improved handling of failed DNS lookups * - Fixed compiler warnings * * Revision 1.9 2001/10/25 03:40:48 david__schmidt * Change in porting tactics: OS/2's EMX porting layer doesn't allow multiple * threads to call select() simultaneously. So, it's time to do a real, live, * native OS/2 port. See defines for __EMX__ (the porting layer) vs. __OS2__ * (native). Both versions will work, but using __OS2__ offers multi-threading. * * Revision 1.8 2001/09/13 20:10:12 jongfoster * Fixing missing #include under Windows * * Revision 1.7 2001/09/12 17:58:26 steudten * * add #include * * Revision 1.6 2001/09/10 10:41:16 oes * Added #include in.h * * Revision 1.5 2001/07/29 18:47:57 jongfoster * Adding missing #include project.h * * Revision 1.4 2001/07/24 12:47:06 oes * Applied BeOS support update by Eugenia * * Revision 1.3 2001/06/09 10:55:28 jongfoster * Changing BUFSIZ ==> BUFFER_SIZE * * Revision 1.2 2001/06/07 23:11:38 jongfoster * Removing gateways[] list - no longer used. * Replacing function pointer in struct gateway with a directly * called function forwarded_connect(), which can do the common * task of deciding whether to connect to the web server or HTTP * proxy. * Replacing struct gateway with struct forward_spec * Fixing bug with SOCKS4A and HTTP proxy server in combination. * It was a bug which led to the connection being made to the web * server rather than the HTTP proxy, and also a buffer overrun. * * Revision 1.1.1.1 2001/05/15 13:58:54 oes * Initial import of version 2.9.3 source tree * * *********************************************************************/ #include "config.h" #include #include #ifndef _WIN32 #include #endif #include #include #ifdef _WIN32 #include #endif /* def _WIN32 */ #ifdef __BEOS__ #include #endif /* def __BEOS__ */ #ifdef __OS2__ #include #endif /* def __OS2__ */ #include "project.h" #include "jcc.h" #include "errlog.h" #include "jbsockets.h" #include "gateway.h" const char gateway_h_rcs[] = GATEWAY_H_VERSION; static jb_socket socks4_connect(const struct forward_spec * fwd, const char * target_host, int target_port, struct client_state *csp); #define SOCKS_REQUEST_GRANTED 90 #define SOCKS_REQUEST_REJECT 91 #define SOCKS_REQUEST_IDENT_FAILED 92 #define SOCKS_REQUEST_IDENT_CONFLICT 93 /* structure of a socks client operation */ struct socks_op { unsigned char vn; /* socks version number */ unsigned char cd; /* command code */ unsigned char dstport[2]; /* destination port */ unsigned char dstip[4]; /* destination address */ unsigned char userid; /* first byte of userid */ /* more bytes of the userid follow, terminated by a NULL */ }; /* structure of a socks server reply */ struct socks_reply { unsigned char vn; /* socks version number */ unsigned char cd; /* command code */ unsigned char dstport[2]; /* destination port */ unsigned char dstip[4]; /* destination address */ }; static const char socks_userid[] = "anonymous"; /********************************************************************* * * Function : forwarded_connect * * Description : Connect to a specified web server, possibly via * a HTTP proxy and/or a SOCKS proxy. * * Parameters : * 1 : gw = pointer to a gateway structure (such as gw_default) * 2 : http = the http request and apropos headers * 3 : csp = Current client state (buffers, headers, etc...) * * Returns : -1 => failure, else it is the socket file descriptor. * *********************************************************************/ jb_socket forwarded_connect(const struct forward_spec * fwd, struct http_request *http, struct client_state *csp) { const char * dest_host; int dest_port; /* Figure out if we need to connect to the web server or a HTTP proxy. */ if (fwd->forward_host) { /* HTTP proxy */ dest_host = fwd->forward_host; dest_port = fwd->forward_port; } else { /* Web server */ dest_host = http->host; dest_port = http->port; } /* Connect, maybe using a SOCKS proxy */ switch (fwd->type) { case SOCKS_NONE: return (connect_to(dest_host, dest_port, csp)); case SOCKS_4: case SOCKS_4A: return (socks4_connect(fwd, dest_host, dest_port, csp)); default: /* Should never get here */ log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type."); errno = EINVAL; return(JB_INVALID_SOCKET); } } /********************************************************************* * * Function : socks4_connect * * Description : Connect to the SOCKS server, and connect through * it to the specified server. This handles * all the SOCKS negotiation, and returns a file * descriptor for a socket which can be treated as a * normal (non-SOCKS) socket. * * Parameters : * 1 : gw = pointer to a gateway structure (such as gw_default) * 2 : http = the http request and apropos headers * 3 : csp = Current client state (buffers, headers, etc...) * * Returns : -1 => failure, else a socket file descriptor. * *********************************************************************/ static jb_socket socks4_connect(const struct forward_spec * fwd, const char * target_host, int target_port, struct client_state *csp) { int web_server_addr; char cbuf[BUFFER_SIZE]; char sbuf[BUFFER_SIZE]; struct socks_op *c = (struct socks_op *)cbuf; struct socks_reply *s = (struct socks_reply *)sbuf; size_t n; size_t csiz; jb_socket sfd; int err = 0; char *errstr; if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0')) { log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified"); err = 1; } if (fwd->gateway_port <= 0) { log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified"); err = 1; } if (err) { errno = EINVAL; return(JB_INVALID_SOCKET); } /* build a socks request for connection to the web server */ strcpy((char *)&(c->userid), socks_userid); csiz = sizeof(*c) + sizeof(socks_userid) - 1; switch (fwd->type) { case SOCKS_4: web_server_addr = htonl(resolve_hostname_to_ip(target_host)); if (web_server_addr == INADDR_NONE) { log_error(LOG_LEVEL_CONNECT, "socks4_connect: could not resolve target host %s", target_host); return(JB_INVALID_SOCKET); } break; case SOCKS_4A: web_server_addr = 0x00000001; n = csiz + strlen(target_host) + 1; if (n > sizeof(cbuf)) { errno = EINVAL; return(JB_INVALID_SOCKET); } strcpy(cbuf + csiz, target_host); csiz = n; break; default: /* Should never get here */ log_error(LOG_LEVEL_FATAL, "SOCKS4 impossible internal error - bad SOCKS type."); errno = EINVAL; return(JB_INVALID_SOCKET); } c->vn = 4; c->cd = 1; c->dstport[0] = (target_port >> 8 ) & 0xff; c->dstport[1] = (target_port ) & 0xff; c->dstip[0] = (web_server_addr >> 24 ) & 0xff; c->dstip[1] = (web_server_addr >> 16 ) & 0xff; c->dstip[2] = (web_server_addr >> 8 ) & 0xff; c->dstip[3] = (web_server_addr ) & 0xff; /* pass the request to the socks server */ sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp); if (sfd == JB_INVALID_SOCKET) { return(JB_INVALID_SOCKET); } if (write_socket(sfd, (char *)c, csiz)) { log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed..."); close_socket(sfd); return(JB_INVALID_SOCKET); } if (read_socket(sfd, sbuf, sizeof(sbuf)) != sizeof(*s)) { log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed..."); close_socket(sfd); return(JB_INVALID_SOCKET); } switch (s->cd) { case SOCKS_REQUEST_GRANTED: return(sfd); break; case SOCKS_REQUEST_REJECT: errstr = "SOCKS request rejected or failed"; errno = EINVAL; break; case SOCKS_REQUEST_IDENT_FAILED: errstr = "SOCKS request rejected because " "SOCKS server cannot connect to identd on the client"; errno = EACCES; break; case SOCKS_REQUEST_IDENT_CONFLICT: errstr = "SOCKS request rejected because " "the client program and identd report " "different user-ids"; errno = EACCES; break; default: errstr = cbuf; errno = ENOENT; sprintf(errstr, "SOCKS request rejected for reason code %d\n", s->cd); } log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr); close_socket(sfd); return(JB_INVALID_SOCKET); } /* Local Variables: tab-width: 3 end: */