X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=gateway.c;h=b83d10d9ea8579e4be1f649560dde29006039f87;hp=dbe4f32aa6755d363a7a6159a4f7a8fe943726d4;hb=4f16012b9d35ddda56729420c2e9b3069d9a2f04;hpb=b3ee70e4ee07171ad5cc5050748d53db7228f232 diff --git a/gateway.c b/gateway.c index dbe4f32a..b83d10d9 100644 --- a/gateway.c +++ b/gateway.c @@ -1,4 +1,4 @@ -const char gateway_rcs[] = "$Id: gateway.c,v 1.13 2002/03/13 00:29:59 jongfoster Exp $"; +const char gateway_rcs[] = "$Id: gateway.c,v 1.24 2008/02/04 14:56:29 fabiankeil Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/gateway.c,v $ @@ -7,8 +7,8 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.13 2002/03/13 00:29:59 jongfoster * using a "forwarder" (i.e. HTTP proxy and/or a SOCKS4 * proxy). * - * Copyright : Written by and Copyright (C) 2001 the SourceForge - * Privoxy team. http://ijbswa.sourceforge.net + * Copyright : Written by and Copyright (C) 2001-2007 the SourceForge + * Privoxy team. http://www.privoxy.org/ * * Based on the Internet Junkbuster originally written * by and Copyright (C) 1997 Anonymous Coders and @@ -34,6 +34,42 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.13 2002/03/13 00:29:59 jongfoster * * 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 * @@ -122,6 +158,7 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.13 2002/03/13 00:29:59 jongfoster #include #include +#include "assert.h" #ifdef _WIN32 #include @@ -140,6 +177,7 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.13 2002/03/13 00:29:59 jongfoster #include "errlog.h" #include "jbsockets.h" #include "gateway.h" +#include "miscutil.h" const char gateway_h_rcs[] = GATEWAY_H_VERSION; @@ -148,19 +186,35 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, int target_port, struct client_state *csp); +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 #define SOCKS_REQUEST_REJECT 91 #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 */ }; @@ -183,11 +237,11 @@ static const char socks_userid[] = "anonymous"; * 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. * *********************************************************************/ jb_socket forwarded_connect(const struct forward_spec * fwd, @@ -221,6 +275,9 @@ jb_socket forwarded_connect(const struct forward_spec * fwd, 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."); @@ -240,12 +297,17 @@ jb_socket forwarded_connect(const struct forward_spec * fwd, * 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. * *********************************************************************/ static jb_socket socks4_connect(const struct forward_spec * fwd, @@ -253,97 +315,138 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, 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; + 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; + char *errstr = NULL; 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 (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(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 (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) { - log_error(LOG_LEVEL_CONNECT, "socks4_connect: could not resolve target host %s", target_host); - return(JB_INVALID_SOCKET); + 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(JB_INVALID_SOCKET); + 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(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; + 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(fwd->gateway_host, fwd->gateway_port, csp); if (sfd == JB_INVALID_SOCKET) { - return(JB_INVALID_SOCKET); + /* + * 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 (write_socket(sfd, (char *)c, 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(JB_INVALID_SOCKET); } - - if (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); + } + + if (err) + { + csp->error_message = strdup(errstr); return(JB_INVALID_SOCKET); } @@ -353,34 +456,277 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, 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 = 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(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: