+/*********************************************************************
+ *
+ * Function : get_reusable_connection
+ *
+ * Description : Returns an open socket to a previously remembered
+ * open connection (if there is one).
+ *
+ * Parameters :
+ * 1 : http = The destination for the connection.
+ * 2 : fwd = The forwarder settings.
+ *
+ * Returns : JB_INVALID_SOCKET => No reusable connection found,
+ * otherwise a usable socket.
+ *
+ *********************************************************************/
+static jb_socket get_reusable_connection(const struct http_request *http,
+ const struct forward_spec *fwd)
+{
+ jb_socket sfd = JB_INVALID_SOCKET;
+ unsigned int slot = 0;
+
+ close_unusable_connections();
+
+ privoxy_mutex_lock(&connection_reuse_mutex);
+
+ for (slot = 0; slot < SZ(reusable_connection); slot++)
+ {
+ if (!reusable_connection[slot].in_use
+ && (JB_INVALID_SOCKET != reusable_connection[slot].sfd))
+ {
+ if (connection_destination_matches(&reusable_connection[slot], http, fwd))
+ {
+ reusable_connection[slot].in_use = TRUE;
+ sfd = reusable_connection[slot].sfd;
+ log_error(LOG_LEVEL_CONNECT,
+ "Found reusable socket %d for %s:%d in slot %d. Timestamp made %ld "
+ "seconds ago. Timeout: %d. Latency: %d. Requests served: %d",
+ sfd, reusable_connection[slot].host, reusable_connection[slot].port,
+ slot, time(NULL) - reusable_connection[slot].timestamp,
+ reusable_connection[slot].keep_alive_timeout,
+ (int)(reusable_connection[slot].response_received -
+ reusable_connection[slot].request_sent),
+ reusable_connection[slot].requests_sent_total);
+ break;
+ }
+ }
+ }
+
+ privoxy_mutex_unlock(&connection_reuse_mutex);
+
+ return sfd;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : mark_connection_unused
+ *
+ * Description : Gives a remembered connection free for reuse.
+ *
+ * Parameters :
+ * 1 : connection = The connection in question.
+ *
+ * Returns : TRUE => Socket found and marked as unused.
+ * FALSE => Socket not found.
+ *
+ *********************************************************************/
+static int mark_connection_unused(const struct reusable_connection *connection)
+{
+ unsigned int slot = 0;
+ int socket_found = FALSE;
+
+ assert(connection->sfd != JB_INVALID_SOCKET);
+
+ privoxy_mutex_lock(&connection_reuse_mutex);
+
+ for (slot = 0; slot < SZ(reusable_connection); slot++)
+ {
+ if (reusable_connection[slot].sfd == connection->sfd)
+ {
+ assert(reusable_connection[slot].in_use);
+ socket_found = TRUE;
+ log_error(LOG_LEVEL_CONNECT,
+ "Marking open socket %d for %s:%d in slot %d as unused.",
+ connection->sfd, reusable_connection[slot].host,
+ reusable_connection[slot].port, slot);
+ reusable_connection[slot].in_use = 0;
+ reusable_connection[slot].timestamp = connection->timestamp;
+ break;
+ }
+ }
+
+ privoxy_mutex_unlock(&connection_reuse_mutex);
+
+ return socket_found;
+
+}
+#endif /* def FEATURE_CONNECTION_SHARING */
+
+
+/*********************************************************************
+ *
+ * Function : forwarded_connect
+ *
+ * Description : Connect to a specified web server, possibly via
+ * a HTTP proxy and/or a SOCKS proxy.
+ *
+ * Parameters :
+ * 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 : JB_INVALID_SOCKET => 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;
+ jb_socket sfd = JB_INVALID_SOCKET;
+
+#ifdef FEATURE_CONNECTION_SHARING
+ if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
+ && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
+ {
+ sfd = get_reusable_connection(http, fwd);
+ if (JB_INVALID_SOCKET != sfd)
+ {
+ return sfd;
+ }
+ }
+#endif /* def FEATURE_CONNECTION_SHARING */
+
+ /* 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:
+ case FORWARD_WEBSERVER:
+ sfd = connect_to(dest_host, dest_port, csp);
+ break;
+ case SOCKS_4:
+ case SOCKS_4A:
+ sfd = socks4_connect(fwd, dest_host, dest_port, csp);
+ break;
+ case SOCKS_5:
+ case SOCKS_5T:
+ sfd = socks5_connect(fwd, dest_host, dest_port, csp);
+ break;
+ default:
+ /* Should never get here */
+ log_error(LOG_LEVEL_FATAL,
+ "Internal error in forwarded_connect(). Bad proxy type: %d", fwd->type);
+ }
+
+ if (JB_INVALID_SOCKET != sfd)
+ {
+ log_error(LOG_LEVEL_CONNECT,
+ "Created new connection to %s:%d on socket %d.",
+ http->host, http->port, sfd);
+ }
+
+ return sfd;
+
+}
+
+
+#ifdef FUZZ
+/*********************************************************************
+ *
+ * Function : socks_fuzz
+ *
+ * Description : Wrapper around socks[45]_connect() used for fuzzing.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns : JB_ERR_OK or JB_ERR_PARSE
+ *
+ *********************************************************************/
+extern jb_err socks_fuzz(struct client_state *csp)
+{
+ jb_socket socket;
+ static struct forward_spec fwd;
+ char target_host[] = "fuzz.example.org";
+ int target_port = 12345;
+
+ fwd.gateway_host = strdup_or_die("fuzz.example.org");
+ fwd.gateway_port = 12345;
+
+ fwd.type = SOCKS_4A;
+ socket = socks4_connect(&fwd, target_host, target_port, csp);
+
+ if (JB_INVALID_SOCKET != socket)
+ {
+ fwd.type = SOCKS_5;
+ socket = socks5_connect(&fwd, target_host, target_port, csp);
+ }
+
+ if (JB_INVALID_SOCKET == socket)
+ {
+ log_error(LOG_LEVEL_ERROR, "%s", csp->error_message);
+ return JB_ERR_PARSE;
+ }
+
+ log_error(LOG_LEVEL_INFO, "Input looks like an acceptable socks response");
+
+ return JB_ERR_OK;
+
+}
+#endif
+
+/*********************************************************************
+ *
+ * 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.
+ *
+ * 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 : 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 socks4_connect(const struct forward_spec *fwd,
+ const char *target_host,
+ int target_port,
+ struct client_state *csp)
+{
+ unsigned long 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 = NULL;
+
+ if ((fwd->gateway_host == NULL) || (*fwd->gateway_host == '\0'))
+ {
+ /* XXX: Shouldn't the config file parser prevent this? */
+ errstr = "NULL gateway host specified.";
+ err = 1;
+ }
+
+ if (fwd->gateway_port <= 0)
+ {
+ 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 */
+
+ strlcpy(&(c->userid), socks_userid, sizeof(buf) - sizeof(struct socks_op));
+
+ csiz = sizeof(*c) + sizeof(socks_userid) - sizeof(c->userid) - sizeof(c->padding);
+
+ switch (fwd->type)
+ {
+ case SOCKS_4:
+ 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(buf))
+ {
+ errno = EINVAL;
+ 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;
+ }
+ break;
+ default:
+ /* Should never get here */
+ 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] = (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);
+
+#ifdef FUZZ
+ sfd = 0;
+#else
+ /* pass the request to the socks server */
+ sfd = connect_to(fwd->gateway_host, fwd->gateway_port, csp);
+
+ if (sfd == JB_INVALID_SOCKET)
+ {
+ /* The error an its reason have already been logged by connect_to() */
+ return(JB_INVALID_SOCKET);
+ }
+ else if (write_socket(sfd, (char *)c, csiz))
+ {
+ errstr = "SOCKS4 negotiation write failed.";
+ log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
+ err = 1;
+ close_socket(sfd);
+ }
+ else if (!data_is_available(sfd, csp->config->socket_timeout))
+ {
+ if (socket_is_still_alive(sfd))
+ {
+ errstr = "SOCKS4 negotiation timed out";
+ }
+ else
+ {
+ errstr = "SOCKS4 negotiation got aborted by the server";
+ }
+ log_error(LOG_LEVEL_CONNECT, "socks4_connect: %s", errstr);
+ err = 1;
+ close_socket(sfd);
+ }
+ else
+#endif
+ if (read_socket(sfd, buf, sizeof(buf)) != sizeof(*s))
+ {
+ 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);
+ }
+
+ switch (s->cd)
+ {
+ case SOCKS4_REQUEST_GRANTED:
+ return(sfd);
+ case SOCKS4_REQUEST_REJECT:
+ errstr = "SOCKS request rejected or failed.";
+ errno = EINVAL;
+ break;
+ case SOCKS4_REQUEST_IDENT_FAILED:
+ errstr = "SOCKS request rejected because "
+ "SOCKS server cannot connect to identd on the client.";
+ errno = EACCES;
+ break;
+ case SOCKS4_REQUEST_IDENT_CONFLICT:
+ errstr = "SOCKS request rejected because "
+ "the client program and identd report "
+ "different user-ids.";
+ errno = EACCES;
+ break;
+ default:
+ errno = ENOENT;
+ snprintf(buf, sizeof(buf),
+ "SOCKS request rejected for reason code %d.", s->cd);
+ errstr = buf;
+ }
+
+ 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 destination host unreachable";
+ case SOCKS5_REQUEST_CONNECTION_REFUSED:
+ 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 : convert_ipv4_address_to_bytes
+ *
+ * Description : Converts an IPv4 address from string to bytes.
+ *
+ * Parameters :
+ * 1 : address = The IPv4 address string to convert.
+ * 2 : buf = The buffer to write the bytes to.
+ * Must be at least four bytes long.
+ *
+ * Returns : JB_ERR_OK on success, JB_ERR_PARSE otherwise.
+ *
+ *********************************************************************/
+static jb_err convert_ipv4_address_to_bytes(const char *address, char *buf)
+{
+ int i;
+ const char *p = address;
+
+ for (i = 0; i < 4; i++)
+ {
+ unsigned byte;
+ if (1 != sscanf(p, "%u", &byte))
+ {
+ return JB_ERR_PARSE;
+ }
+ if (byte > 255)
+ {
+ return JB_ERR_PARSE;
+ }
+ buf[i] = (char)byte;
+ if (i < 3)
+ {
+ p = strstr(p, ".");
+ if (p == NULL)
+ {
+ return JB_ERR_PARSE;
+ }
+ p++;
+ }
+ }
+
+ return JB_ERR_OK;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : read_socks_reply
+ *
+ * Description : Read from a socket connected to a socks server.
+ *
+ * Parameters :
+ * 1 : sfd = file descriptor of the socket to read
+ * 2 : buf = pointer to buffer where data will be written
+ * Must be >= len bytes long.
+ * 3 : len = maximum number of bytes to read
+ * 4 : timeout = Number of seconds to wait.
+ *
+ * Returns : On success, the number of bytes read is returned (zero
+ * indicates end of file), and the file position is advanced
+ * by this number. It is not an error if this number is
+ * smaller than the number of bytes requested; this may hap-
+ * pen for example because fewer bytes are actually available
+ * right now (maybe because we were close to end-of-file, or
+ * because we are reading from a pipe, or from a terminal,
+ * or because read() was interrupted by a signal). On error,
+ * -1 is returned, and errno is set appropriately. In this
+ * case it is left unspecified whether the file position (if
+ * any) changes.
+ *
+ *********************************************************************/
+static int read_socks_reply(jb_socket sfd, char *buf, int len, int timeout)
+{
+ if (!data_is_available(sfd, timeout))
+ {
+ if (socket_is_still_alive(sfd))
+ {
+ log_error(LOG_LEVEL_ERROR,
+ "The socks connection timed out after %d seconds.", timeout);
+ }
+ else
+ {
+ log_error(LOG_LEVEL_ERROR, "The socks server hung "
+ "up the connection without sending a response.");
+ }
+ return -1;
+ }
+
+ return read_socket(sfd, buf, len);
+
+}
+
+
+/*********************************************************************
+ *
+ * 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)
+{
+#define SIZE_SOCKS5_REPLY_IPV4 10
+#define SIZE_SOCKS5_REPLY_IPV6 22
+#define SIZE_SOCKS5_REPLY_DOMAIN 300
+#define SOCKS5_REPLY_DIFFERENCE (SIZE_SOCKS5_REPLY_IPV6 - SIZE_SOCKS5_REPLY_IPV4)
+ int err = 0;
+ char cbuf[300];
+ char sbuf[SIZE_SOCKS5_REPLY_DOMAIN];
+ 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 > (size_t)255)
+ {
+ errstr = "target host name is longer than 255 characters";
+ err = 1;
+ }
+
+ if ((fwd->type != SOCKS_5) && (fwd->type != SOCKS_5T))
+ {
+ /* 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);
+ }
+
+#ifdef FUZZ
+ sfd = 0;
+ if (!err && read_socket(sfd, sbuf, 2) != 2)
+#else
+ /* 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);
+ /* Free the generic error message provided by connect_to() */
+ freez(csp->error_message);
+ csp->error_message = strdup(errstr);
+ return(JB_INVALID_SOCKET);
+ }
+
+ client_pos = 0;
+ cbuf[client_pos++] = '\x05'; /* Version */
+
+ if (fwd->auth_username && fwd->auth_password)
+ {
+ cbuf[client_pos++] = '\x02'; /* Two authentication methods supported */
+ cbuf[client_pos++] = '\x02'; /* Username/password */
+ }
+ else
+ {
+ 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_socks_reply(sfd, sbuf, sizeof(sbuf),
+ csp->config->socket_timeout) != 2)
+#endif
+ {
+ 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] == '\x02'))
+ {
+ if (fwd->auth_username && fwd->auth_password)
+ {
+ /* check cbuf overflow */
+ size_t auth_len = strlen(fwd->auth_username) + strlen(fwd->auth_password) + 3;
+ if (auth_len > sizeof(cbuf))
+ {
+ errstr = "SOCKS5 username and/or password too long";
+ err = 1;
+ }
+ }
+ else
+ {
+ errstr = "SOCKS5 server requested authentication while "
+ "no credentials are configured";
+ err = 1;
+ }
+
+ if (!err)
+ {
+ client_pos = 0;
+ cbuf[client_pos++] = '\x01'; /* Version */
+ cbuf[client_pos++] = (char)strlen(fwd->auth_username);
+
+ memcpy(cbuf + client_pos, fwd->auth_username, strlen(fwd->auth_username));
+ client_pos += strlen(fwd->auth_username);
+ cbuf[client_pos++] = (char)strlen(fwd->auth_password);
+ memcpy(cbuf + client_pos, fwd->auth_password, strlen(fwd->auth_password));
+ client_pos += strlen(fwd->auth_password);
+
+ if (write_socket(sfd, cbuf, client_pos))
+ {
+ errstr = "SOCKS5 negotiation auth write failed";
+ csp->error_message = strdup(errstr);
+ log_error(LOG_LEVEL_CONNECT, "%s", errstr);
+ close_socket(sfd);
+ return(JB_INVALID_SOCKET);
+ }
+
+ if (read_socks_reply(sfd, sbuf, sizeof(sbuf),
+ csp->config->socket_timeout) != 2)
+ {
+ errstr = "SOCKS5 negotiation auth read failed";
+ err = 1;
+ }
+ }
+
+ if (!err && (sbuf[1] != '\x00'))
+ {
+ errstr = "SOCKS5 authentication failed";
+ err = 1;
+ }
+ }
+ else 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 */
+ if (host_is_ip_address(target_host) && NULL == strstr(target_host, ":"))
+ {
+ cbuf[client_pos++] = '\x01'; /* Address is IPv4 address. */
+ if (JB_ERR_OK != convert_ipv4_address_to_bytes(target_host, &cbuf[client_pos]))
+ {
+ errstr = "SOCKS5 error. Failed to convert target address to IP address";
+ csp->error_message = strdup(errstr);
+ log_error(LOG_LEVEL_CONNECT, "%s", errstr);
+ close_socket(sfd);
+ errno = EINVAL;
+ return(JB_INVALID_SOCKET);
+ }
+ client_pos += 4;
+ }
+ else
+ {
+ /*
+ * XXX: This branch is currently also used for IPv6 addresses
+ */
+ cbuf[client_pos++] = '\x03'; /* Address is domain name. */
+ cbuf[client_pos++] = (char)(hostlen & 0xffu);
+ assert(sizeof(cbuf) - client_pos > (size_t)255);
+ /* Using strncpy because we really want the nul byte padding. */
+ strncpy(cbuf + client_pos, target_host, sizeof(cbuf) - client_pos - 1);
+ client_pos += (hostlen & 0xffu);
+ }
+ cbuf[client_pos++] = (char)((target_port >> 8) & 0xff);
+ cbuf[client_pos++] = (char)((target_port ) & 0xff);
+
+#ifndef FUZZ
+ 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);
+ errno = EINVAL;
+ return(JB_INVALID_SOCKET);
+ }
+
+ /*
+ * Optimistically send the HTTP request with the initial
+ * SOCKS request if the user enabled the use of Tor extensions,
+ * the CONNECT method isn't being used (in which case the client
+ * doesn't send data until it gets our 200 response) and the
+ * client request has actually been completely read already.
+ */
+ if ((fwd->type == SOCKS_5T) && (csp->http->ssl == 0)
+ && (csp->flags & CSP_FLAG_CLIENT_REQUEST_COMPLETELY_READ))
+ {
+ char *client_headers = list_to_text(csp->headers);
+ size_t header_length;
+
+ if (client_headers == NULL)
+ {
+ log_error(LOG_LEVEL_FATAL, "Out of memory rebuilding client headers");
+ }
+ list_remove_all(csp->headers);
+ header_length= strlen(client_headers);
+
+ log_error(LOG_LEVEL_CONNECT,
+ "Optimistically sending %lu bytes of client headers intended for %s",
+ header_length, csp->http->hostport);
+
+ if (write_socket(sfd, client_headers, header_length))
+ {
+ log_error(LOG_LEVEL_CONNECT,
+ "optimistically writing header to: %s failed: %E", csp->http->hostport);
+ freez(client_headers);
+ return(JB_INVALID_SOCKET);
+ }
+ freez(client_headers);
+ if (csp->expected_client_content_length != 0)
+ {
+ unsigned long long buffered_request_bytes =
+ (unsigned long long)(csp->client_iob->eod - csp->client_iob->cur);
+ log_error(LOG_LEVEL_CONNECT,
+ "Optimistically sending %llu bytes of client body. Expected %llu",
+ csp->expected_client_content_length, buffered_request_bytes);
+ assert(csp->expected_client_content_length == buffered_request_bytes);
+ if (write_socket(sfd, csp->client_iob->cur, buffered_request_bytes))
+ {
+ log_error(LOG_LEVEL_CONNECT,
+ "optimistically writing %llu bytes of client body to: %s failed: %E",
+ buffered_request_bytes, csp->http->hostport);
+ return(JB_INVALID_SOCKET);
+ }
+ clear_iob(csp->client_iob);
+ }
+ }
+#endif
+
+ server_size = read_socks_reply(sfd, sbuf, SIZE_SOCKS5_REPLY_IPV4,
+ csp->config->socket_timeout);
+ if (server_size != SIZE_SOCKS5_REPLY_IPV4)
+ {
+ errstr = "SOCKS5 negotiation read failed";
+ }
+ else
+ {
+ if (sbuf[0] != '\x05')
+ {
+ errstr = "SOCKS5 negotiation protocol version error";
+ }
+ else if (sbuf[2] != '\x00')
+ {
+ errstr = "SOCKS5 negotiation protocol error";
+ }
+ else if (sbuf[1] != SOCKS5_REQUEST_GRANTED)
+ {
+ errstr = translate_socks5_error(sbuf[1]);
+ }
+ else
+ {
+ if (sbuf[3] == '\x04')
+ {
+ /*
+ * The address field contains an IPv6 address
+ * which means we didn't get the whole reply
+ * yet. Read and discard the rest of it to make
+ * sure it isn't treated as HTTP data later on.
+ */
+ server_size = read_socks_reply(sfd, sbuf, SOCKS5_REPLY_DIFFERENCE,
+ csp->config->socket_timeout);
+ if (server_size != SOCKS5_REPLY_DIFFERENCE)
+ {
+ errstr = "SOCKS5 negotiation read failed (IPv6 address)";
+ }
+ }
+ else if (sbuf[3] == '\x03')
+ {
+ /*
+ * The address field contains a domain name
+ * which means we didn't get the whole reply
+ * yet. Read and discard the rest of it to make
+ * sure it isn't treated as HTTP data later on.
+ */
+ unsigned domain_length = (unsigned)sbuf[4];
+ int bytes_left_to_read = 5 + (int)domain_length + 2 - SIZE_SOCKS5_REPLY_IPV4;
+ if (bytes_left_to_read <= 0 || sizeof(sbuf) < bytes_left_to_read)
+ {
+ errstr = "SOCKS5 negotiation read failed (Invalid domain length)";
+ }
+ else
+ {
+ server_size = read_socks_reply(sfd, sbuf, bytes_left_to_read,
+ csp->config->socket_timeout);
+ if (server_size != bytes_left_to_read)
+ {
+ errstr = "SOCKS5 negotiation read failed (Domain name)";
+ }
+ }
+ }
+ else if (sbuf[3] != '\x01')
+ {
+ errstr = "SOCKS5 reply contains unsupported address type";
+ }
+ if (errstr == NULL)
+ {
+ return(sfd);
+ }
+ }
+ }
+
+ 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);
+
+}
+