X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=gateway.c;h=b83d10d9ea8579e4be1f649560dde29006039f87;hp=2ccf16761a4e4de2da7f2f4f8c23f4512e46cb66;hb=4f16012b9d35ddda56729420c2e9b3069d9a2f04;hpb=c75584ebcc79f939fb4ec9c8f842cef6692640c7 diff --git a/gateway.c b/gateway.c index 2ccf1676..b83d10d9 100644 --- a/gateway.c +++ b/gateway.c @@ -1,20 +1,20 @@ -const char gateway_rcs[] = "$Id: gateway.c,v 1.1 2001/05/13 21:57:06 administrator Exp $"; +const char gateway_rcs[] = "$Id: gateway.c,v 1.24 2008/02/04 14:56:29 fabiankeil Exp $"; /********************************************************************* * - * File : $Source: /home/administrator/cvs/ijb/gateway.c,v $ + * File : $Source: /cvsroot/ijbswa/current/gateway.c,v $ * * Purpose : Contains functions to connect to a server, possibly - * using a "gateway" (i.e. HTTP proxy and/or SOCKS4 - * proxy). Also contains the list of gateway types. + * using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4 + * proxy). * - * Copyright : Written by and Copyright (C) 2001 the SourceForge - * IJBSWA team. http://ijbswa.sourceforge.net + * Copyright : Written by and Copyright (C) 2001-2007 the SourceForge + * Privoxy team. http://www.privoxy.org/ * * Based on the Internet Junkbuster originally written - * by and Copyright (C) 1997 Anonymous Coders and + * by and Copyright (C) 1997 Anonymous Coders and * Junkbusters Corporation. http://www.junkbusters.com * - * This program is free software; you can redistribute it + * 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 @@ -34,6 +34,115 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.1 2001/05/13 21:57:06 administrat * * Revisions : * $Log: gateway.c,v $ + * Revision 1.24 2008/02/04 14:56:29 fabiankeil + * - Fix a compiler warning. + * - Stop assuming that htonl(INADDR_NONE) equals INADDR_NONE. + * + * Revision 1.23 2008/02/04 13:11:35 fabiankeil + * Remember the cause of the SOCKS5 error for the CGI message. + * + * Revision 1.22 2008/02/03 13:46:15 fabiankeil + * Add SOCKS5 support. Patch #1862863 by Eric M. Hopper with minor changes. + * + * Revision 1.21 2007/07/28 12:30:03 fabiankeil + * Modified patch from Song Weijia (#1762559) to + * fix socks requests on big-endian platforms. + * + * Revision 1.20 2007/05/14 10:23:48 fabiankeil + * - Use strlcpy() instead of strcpy(). + * - Use the same buffer for socks requests and socks responses. + * - Fix bogus warning about web_server_addr being used uninitialized. + * + * Revision 1.19 2007/01/25 14:09:45 fabiankeil + * - Save errors in socks4_connect() to csp->error_message. + * - Silence some gcc43 warnings, hopefully the right way. + * + * Revision 1.18 2006/07/18 14:48:46 david__schmidt + * Reorganizing the repository: swapping out what was HEAD (the old 3.1 branch) + * with what was really the latest development (the v_3_0_branch branch) + * + * Revision 1.16 2002/05/12 21:36:29 jongfoster + * Correcting function comments + * + * Revision 1.15 2002/03/26 22:29:54 swa + * we have a new homepage! + * + * 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 + * * *********************************************************************/ @@ -42,33 +151,45 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.1 2001/05/13 21:57:06 administrat #include #include + +#ifndef _WIN32 +#include +#endif + #include +#include +#include "assert.h" #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" +#include "miscutil.h" const char gateway_h_rcs[] = GATEWAY_H_VERSION; -#define SOCKS_4 40 /* original SOCKS 4 protocol */ -#define SOCKS_4A 41 /* as modified for hosts w/o external DNS */ - -const struct gateway gateways[] = { - /* type function gw type/host/port, fw host/port */ - { "direct", direct_connect, 0, NULL, 0, NULL, 0 }, - { ".", direct_connect, 0, NULL, 0, NULL, 0 }, - { "socks", socks4_connect, SOCKS_4, NULL, 1080, NULL, 0 }, - { "socks4", socks4_connect, SOCKS_4, NULL, 1080, NULL, 0 }, - { "socks4a", socks4_connect, SOCKS_4A, NULL, 1080, NULL, 0 }, - { NULL, NULL, 0, NULL, 0, NULL, 0 } -}; +static jb_socket socks4_connect(const struct forward_spec * fwd, + const char * target_host, + int target_port, + struct client_state *csp); -const struct gateway *gw_default = gateways; /* direct */ +static jb_socket socks5_connect(const struct forward_spec *fwd, + const char *target_host, + int target_port, + struct client_state *csp); #define SOCKS_REQUEST_GRANTED 90 @@ -76,13 +197,24 @@ const struct gateway *gw_default = gateways; /* direct */ #define SOCKS_REQUEST_IDENT_FAILED 92 #define SOCKS_REQUEST_IDENT_CONFLICT 93 +#define SOCKS5_REQUEST_GRANTED 0 +#define SOCKS5_REQUEST_FAILED 1 +#define SOCKS5_REQUEST_DENIED 2 +#define SOCKS5_REQUEST_NETWORK_UNREACHABLE 3 +#define SOCKS5_REQUEST_HOST_UNREACHABLE 4 +#define SOCKS5_REQUEST_CONNECTION_REFUSEDD 5 +#define SOCKS5_REQUEST_TTL_EXPIRED 6 +#define SOCKS5_REQUEST_PROTOCOL_ERROR 7 +#define SOCKS5_REQUEST_BAD_ADDRESS_TYPE 8 + /* 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 */ + char userid; /* first byte of userid */ + char padding[3]; /* make sure sizeof(struct socks_op) is endian-independent. */ /* more bytes of the userid follow, terminated by a NULL */ }; @@ -99,31 +231,59 @@ static const char socks_userid[] = "anonymous"; /********************************************************************* * - * Function : direct_connect + * Function : forwarded_connect * - * Description : Direct how we connect to the web. This can be: - * directly : no forwarding, or - * indirectly : through another proxy such as squid. + * 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) + * 1 : fwd = the proxies to use when connecting. * 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. + * Returns : JB_INVALID_SOCKET => failure, else it is the socket file descriptor. * *********************************************************************/ -int direct_connect(const struct gateway *gw, struct http_request *http, struct client_state *csp) +jb_socket forwarded_connect(const struct forward_spec * fwd, + struct http_request *http, + struct client_state *csp) { - if (gw->forward_host) + 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) { - return(connect_to(gw->forward_host, gw->forward_port, csp)); + /* HTTP proxy */ + dest_host = fwd->forward_host; + dest_port = fwd->forward_port; } else { - return(connect_to(http->host, http->port, csp)); + /* 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)); + + case SOCKS_5: + return (socks5_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); + } } @@ -132,117 +292,162 @@ int direct_connect(const struct gateway *gw, struct http_request *http, struct c * Function : socks4_connect * * Description : Connect to the SOCKS server, and connect through - * it to the web server or web proxy. This handles + * 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. * + * Logged error messages are saved to csp->error_message + * and later reused by error_response() for the CGI + * message. strdup allocation failures are handled there. + * * 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...) + * 1 : fwd = Specifies the SOCKS proxy to use. + * 2 : target_host = The final server to connect to. + * 3 : target_port = The final port to connect to. + * 4 : csp = Current client state (buffers, headers, etc...) * - * Returns : -1 => failure, else a socket file descriptor. + * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor. * *********************************************************************/ -int socks4_connect(const struct gateway *gw, struct http_request *http, struct client_state *csp) +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; - unsigned char cbuf[BUFSIZ]; - unsigned char sbuf[BUFSIZ]; - struct socks_op *c = (struct socks_op *)cbuf; - struct socks_reply *s = (struct socks_reply *)sbuf; - int n, csiz, sfd, target_port; + unsigned int web_server_addr; + char buf[BUFFER_SIZE]; + struct socks_op *c = (struct socks_op *)buf; + struct socks_reply *s = (struct socks_reply *)buf; + size_t n; + size_t csiz; + jb_socket sfd; int err = 0; - char *errstr, *target_host; + char *errstr = NULL; - if ((gw->gateway_host == NULL) || (*gw->gateway_host == '\0')) + if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0')) { - log_error(LOG_LEVEL_CONNECT, "socks4_connect: NULL gateway host specified"); + /* XXX: Shouldn't the config file parser prevent this? */ + errstr = "NULL gateway host specified."; err = 1; } - if (gw->gateway_port <= 0) + if (fwd->gateway_port <= 0) { - log_error(LOG_LEVEL_CONNECT, "socks4_connect: invalid gateway port specified"); + errstr = "invalid gateway port specified."; err = 1; } if (err) { + log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr); + csp->error_message = strdup(errstr); errno = EINVAL; - return(-1); - } - - if (gw->forward_host) - { - target_host = gw->forward_host; - target_port = gw->forward_port; - } - else - { - target_host = http->host; - target_port = http->port; + return(JB_INVALID_SOCKET); } /* build a socks request for connection to the web server */ - strcpy((char *)&(c->userid), socks_userid); + strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op)); - csiz = sizeof(*c) + sizeof(socks_userid) - 1; + csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding); - switch (gw->type) + switch (fwd->type) { case SOCKS_4: - web_server_addr = htonl(resolve_hostname_to_ip(target_host)); + web_server_addr = resolve_hostname_to_ip(target_host); + if (web_server_addr == INADDR_NONE) + { + errstr = "could not resolve target host"; + log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s %s", errstr, target_host); + err = 1; + } + else + { + web_server_addr = htonl(web_server_addr); + } break; case SOCKS_4A: web_server_addr = 0x00000001; n = csiz + strlen(target_host) + 1; - if (n > sizeof(cbuf)) + if (n > sizeof(buf)) { errno = EINVAL; - return(-1); + errstr = "buffer cbuf too small."; + log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr); + err = 1; + } + else + { + strlcpy(buf + csiz, target_host, sizeof(buf) - sizeof(struct socks_op) - csiz); + /* + * What we forward to the socks4a server should have the + * size of socks_op, plus the length of the userid plus + * its \0 byte (which we don't have to add because the + * first byte of the userid is counted twice as it's also + * part of sock_op) minus the padding bytes (which are part + * of the userid as well), plus the length of the target_host + * (which is stored csiz bytes after the beginning of the buffer), + * plus another \0 byte. + */ + assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1); + csiz = n; } - strcpy(((char *)cbuf) + csiz, http->host); - csiz = n; break; default: /* Should never get here */ - log_error(LOG_LEVEL_ERROR, "SOCKS4 impossible internal error - bad SOCKS type."); - errno = EINVAL; - return(-1); + log_error(LOG_LEVEL_FATAL, + "socks4_connect: SOCKS4 impossible internal error - bad SOCKS type."); + /* Not reached */ + return(JB_INVALID_SOCKET); + } + + if (err) + { + csp->error_message = strdup(errstr); + 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; + c->dstport[0] = (unsigned char)((target_port >> 8 ) & 0xff); + c->dstport[1] = (unsigned char)((target_port ) & 0xff); + c->dstip[0] = (unsigned char)((web_server_addr >> 24 ) & 0xff); + c->dstip[1] = (unsigned char)((web_server_addr >> 16 ) & 0xff); + c->dstip[2] = (unsigned char)((web_server_addr >> 8 ) & 0xff); + c->dstip[3] = (unsigned char)((web_server_addr ) & 0xff); /* pass the request to the socks server */ - sfd = connect_to(gw->gateway_host, gw->gateway_port, csp); + sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp); - if (sfd < 0) + if (sfd == JB_INVALID_SOCKET) { - return(-1); + /* + * XXX: connect_to should fill in the exact reason. + * Most likely resolving the IP of the forwarder failed. + */ + errstr = "connect_to failed: see logfile for details"; + err = 1; } - - if ((n = write_socket(sfd, (char *)c, csiz)) != csiz) + else if (write_socket(sfd, (char *)c, csiz)) { - log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation write failed..."); + errstr = "SOCKS4 negotiation write failed."; + log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr); + err = 1; close_socket(sfd); - return(-1); } - - if ((n = read_socket(sfd, sbuf, sizeof(sbuf))) != sizeof(*s)) + else if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s)) { - log_error(LOG_LEVEL_CONNECT, "SOCKS4 negotiation read failed..."); + errstr = "SOCKS4 negotiation read failed."; + log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr); + err = 1; close_socket(sfd); - return(-1); + } + + if (err) + { + csp->error_message = strdup(errstr); + return(JB_INVALID_SOCKET); } switch (s->cd) @@ -251,34 +456,277 @@ int socks4_connect(const struct gateway *gw, struct http_request *http, struct c return(sfd); break; case SOCKS_REQUEST_REJECT: - errstr = "SOCKS request rejected or failed"; + 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"; + "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"; + "different user-ids."; errno = EACCES; break; default: - errstr = (char *) cbuf; errno = ENOENT; - sprintf(errstr, - "SOCKS request rejected for reason code %d\n", s->cd); + snprintf(buf, sizeof(buf), + "SOCKS request rejected for reason code %d.", s->cd); + errstr = buf; } - log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s ...", errstr); - + log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr); + csp->error_message = strdup(errstr); close_socket(sfd); - return(-1); + + return(JB_INVALID_SOCKET); } +/********************************************************************* + * + * Function : translate_socks5_error + * + * Description : Translates a SOCKS errors to a string. + * + * Parameters : + * 1 : socks_error = The error code to translate. + * + * Returns : The string translation. + * + *********************************************************************/ +static const char *translate_socks5_error(int socks_error) +{ + switch (socks_error) + { + /* XXX: these should be more descriptive */ + case SOCKS5_REQUEST_FAILED: + return "SOCKS5 request failed"; + case SOCKS5_REQUEST_DENIED: + return "SOCKS5 request denied"; + case SOCKS5_REQUEST_NETWORK_UNREACHABLE: + return "SOCKS5 network unreachable"; + case SOCKS5_REQUEST_HOST_UNREACHABLE: + return "SOCKS5 host unreachable"; + case SOCKS5_REQUEST_CONNECTION_REFUSEDD: + return "SOCKS5 connection refused"; + case SOCKS5_REQUEST_TTL_EXPIRED: + return "SOCKS5 TTL expired"; + case SOCKS5_REQUEST_PROTOCOL_ERROR: + return "SOCKS5 client protocol error"; + case SOCKS5_REQUEST_BAD_ADDRESS_TYPE: + return "SOCKS5 domain names unsupported"; + case SOCKS5_REQUEST_GRANTED: + return "everything's peachy"; + default: + return "SOCKS5 negotiation protocol error"; + } +} + +/********************************************************************* + * + * Function : socks5_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 : fwd = Specifies the SOCKS proxy to use. + * 2 : target_host = The final server to connect to. + * 3 : target_port = The final port to connect to. + * 4 : csp = Current client state (buffers, headers, etc...) + * + * Returns : JB_INVALID_SOCKET => failure, else a socket file descriptor. + * + *********************************************************************/ +static jb_socket socks5_connect(const struct forward_spec *fwd, + const char *target_host, + int target_port, + struct client_state *csp) +{ + int err = 0; + char cbuf[300]; + char sbuf[30]; + size_t client_pos = 0; + int server_size = 0; + size_t hostlen = 0; + jb_socket sfd; + const char *errstr = NULL; + + assert(fwd->gateway_host); + if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0')) + { + errstr = "NULL gateway host specified"; + err = 1; + } + + if (fwd->gateway_port <= 0) + { + /* + * XXX: currently this can't happen because in + * case of invalid gateway ports we use the defaults. + * Of course we really shouldn't do that. + */ + errstr = "invalid gateway port specified"; + err = 1; + } + + hostlen = strlen(target_host); + if (hostlen > 255) + { + errstr = "target host name is longer than 255 characters"; + err = 1; + } + + if (fwd->type != SOCKS_5) + { + /* Should never get here */ + log_error(LOG_LEVEL_FATAL, + "SOCKS5 impossible internal error - bad SOCKS type"); + err = 1; + } + + if (err) + { + errno = EINVAL; + assert(errstr != NULL); + log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr); + csp->error_message = strdup(errstr); + return(JB_INVALID_SOCKET); + } + + /* pass the request to the socks server */ + sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp); + + if (sfd == JB_INVALID_SOCKET) + { + errstr = "socks5 server unreachable"; + log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr); + csp->error_message = strdup(errstr); + return(JB_INVALID_SOCKET); + } + + client_pos = 0; + cbuf[client_pos++] = '\x05'; /* Version */ + cbuf[client_pos++] = '\x01'; /* One authentication method supported */ + cbuf[client_pos++] = '\x00'; /* The no authentication authentication method */ + + if (write_socket(sfd, cbuf, client_pos)) + { + errstr = "SOCKS5 negotiation write failed"; + csp->error_message = strdup(errstr); + log_error(LOG_LEVEL_CONNECT, "%s", errstr); + close_socket(sfd); + return(JB_INVALID_SOCKET); + } + + if (read_socket(sfd, sbuf, sizeof(sbuf)) != 2) + { + errstr = "SOCKS5 negotiation read failed"; + err = 1; + } + + if (!err && (sbuf[0] != '\x05')) + { + errstr = "SOCKS5 negotiation protocol version error"; + err = 1; + } + + if (!err && (sbuf[1] == '\xff')) + { + errstr = "SOCKS5 authentication required"; + err = 1; + } + + if (!err && (sbuf[1] != '\x00')) + { + errstr = "SOCKS5 negotiation protocol error"; + err = 1; + } + + if (err) + { + assert(errstr != NULL); + log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr); + csp->error_message = strdup(errstr); + close_socket(sfd); + errno = EINVAL; + return(JB_INVALID_SOCKET); + } + + client_pos = 0; + cbuf[client_pos++] = '\x05'; /* Version */ + cbuf[client_pos++] = '\x01'; /* TCP connect */ + cbuf[client_pos++] = '\x00'; /* Reserved, must be 0x00 */ + cbuf[client_pos++] = '\x03'; /* Address is domain name */ + cbuf[client_pos++] = (char)(hostlen & 0xffu); + assert(sizeof(cbuf) - client_pos > 255); + /* Using strncpy because we really want the nul byte padding. */ + strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos); + client_pos += (hostlen & 0xffu); + cbuf[client_pos++] = (char)((target_port >> 8) & 0xffu); + cbuf[client_pos++] = (char)((target_port ) & 0xffu); + + if (write_socket(sfd, cbuf, client_pos)) + { + errstr = "SOCKS5 negotiation read failed"; + csp->error_message = strdup(errstr); + log_error(LOG_LEVEL_CONNECT, "%s", errstr); + close_socket(sfd); + errno = EINVAL; + return(JB_INVALID_SOCKET); + } + + server_size = read_socket(sfd, sbuf, sizeof(sbuf)); + if (server_size < 3) + { + errstr = "SOCKS5 negotiation read failed"; + err = 1; + } + else if (server_size > 20) + { + /* This is somewhat unexpected but doesn't realy matter. */ + log_error(LOG_LEVEL_CONNECT, "socks5_connect: read %d bytes " + "from socks server. Would have accepted up to %d.", + server_size, sizeof(sbuf)); + } + + if (!err && (sbuf[0] != '\x05')) + { + errstr = "SOCKS5 negotiation protocol version error"; + err = 1; + } + + if (!err && (sbuf[2] != '\x00')) + { + errstr = "SOCKS5 negotiation protocol error"; + err = 1; + } + + if (!err) + { + if (sbuf[1] == SOCKS5_REQUEST_GRANTED) + { + return(sfd); + } + errstr = translate_socks5_error(sbuf[1]); + err = 1; + } + + assert(errstr != NULL); + csp->error_message = strdup(errstr); + log_error(LOG_LEVEL_CONNECT, "socks5_connect: %s", errstr); + close_socket(sfd); + errno = EINVAL; + + return(JB_INVALID_SOCKET); + +} /* Local Variables: