X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=gateway.c;h=b83d10d9ea8579e4be1f649560dde29006039f87;hp=cbaf74356ccf3184882e932462f6a0bc5b294981;hb=8bc46b23dcf95a9bb6f9c214613d2fad44a4c82a;hpb=26eb1e49894d7b970e3c234fe823fedb933ecc58 diff --git a/gateway.c b/gateway.c index cbaf7435..b83d10d9 100644 --- a/gateway.c +++ b/gateway.c @@ -1,4 +1,4 @@ -const char gateway_rcs[] = "$Id: gateway.c,v 1.19 2007/01/25 14:09:45 fabiankeil 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 $ @@ -34,6 +34,25 @@ const char gateway_rcs[] = "$Id: gateway.c,v 1.19 2007/01/25 14:09:45 fabiankeil * * 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. @@ -167,12 +186,27 @@ 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 */ @@ -180,6 +214,7 @@ struct socks_op { unsigned char dstport[2]; /* destination port */ unsigned char dstip[4]; /* destination address */ 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 */ }; @@ -240,6 +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."); @@ -277,7 +315,7 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, int target_port, struct client_state *csp) { - int web_server_addr; + 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; @@ -312,18 +350,22 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, 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) { 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; @@ -343,11 +385,12 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, * 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), plus the length of the target_host + * 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)) + strlen(buf + csiz) + 1); + assert(n == sizeof(struct socks_op) + strlen(&(c->userid)) - sizeof(c->padding) + strlen(buf + csiz) + 1); csiz = n; } break; @@ -442,6 +485,248 @@ static jb_socket socks4_connect(const struct forward_spec * fwd, } +/********************************************************************* + * + * 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: