We now warn the user if a proxy server is not up when we try to connect with it.

src/or/config.c

@@ -3565,8 +3565,17 @@ options_validate(or_options_t *old_options, or_options_t *options,
     }
   }
 
-  if (options->Socks4Proxy && options->Socks5Proxy)
-    REJECT("You cannot specify both Socks4Proxy and SOCKS5Proxy");
+  /* Check if more than one proxy type has been enabled. This looks REALLY ugly! */
+  if ((options->Socks4Proxy && (options->Socks5Proxy || options->HTTPSProxy
+                                || options->ClientTransportPlugin)) ||
+      (options->Socks5Proxy && (options->Socks4Proxy || options->HTTPSProxy
+                                || options->ClientTransportPlugin)) ||
+      (options->HTTPSProxy && (options->Socks4Proxy || options->Socks5Proxy
+                               || options->ClientTransportPlugin)) ||
+      (options->ClientTransportPlugin && (options->Socks4Proxy
+                                          || options->Socks5Proxy || options->HTTPSProxy)))
+    REJECT("You have configured more than one proxy types. "
+           "(Socks4Proxy|Socks5Proxy|HTTPSProxy|ClientTransportPlugin)");
 
   if (options->Socks5ProxyUsername) {
     size_t len;

src/or/connection.c

@@ -1461,6 +1461,7 @@ connection_proxy_state_to_string(int state)
   static const char *unknown = "???";
   static const char *states[] = {
     "PROXY_NONE",
+    "PROXY_INFANT",
     "PROXY_HTTPS_WANT_CONNECT_OK",
     "PROXY_SOCKS4_WANT_CONNECT_OK",
     "PROXY_SOCKS5_WANT_AUTH_METHOD_NONE",

src/or/connection_or.c

@@ -837,7 +837,6 @@ connection_or_connect(const tor_addr_t *_addr, uint16_t port,
   or_connection_t *conn;
   or_options_t *options = get_options();
   int socket_error = 0;
-  int using_proxy = 0;
   tor_addr_t addr;
 
   tor_assert(_addr);
@@ -858,15 +857,15 @@ connection_or_connect(const tor_addr_t *_addr, uint16_t port,
 
   /* use a proxy server if available */
   if (options->HTTPSProxy) {
-    using_proxy = 1;
+    conn->_base.proxy_state = PROXY_INFANT;
     tor_addr_copy(&addr, &options->HTTPSProxyAddr);
     port = options->HTTPSProxyPort;
   } else if (options->Socks4Proxy) {
-    using_proxy = 1;
+    conn->_base.proxy_state = PROXY_INFANT;
     tor_addr_copy(&addr, &options->Socks4ProxyAddr);
     port = options->Socks4ProxyPort;
   } else if (options->Socks5Proxy) {
-    using_proxy = 1;
+    conn->_base.proxy_state = PROXY_INFANT;
     tor_addr_copy(&addr, &options->Socks5ProxyAddr);
     port = options->Socks5ProxyPort;
   } else if (options->ClientTransportPlugin) {
@@ -874,7 +873,7 @@ connection_or_connect(const tor_addr_t *_addr, uint16_t port,
     transport = find_transport_by_bridge_addrport(&addr, port);
     if (transport) {
       log_debug(LD_GENERAL, "Found transport. Setting up proxying!");
-      using_proxy = 1;
+      conn->_base.proxy_state = PROXY_INFANT;
       tor_addr_copy(&addr, &transport->addr);
       port = transport->port;
     }
@@ -885,7 +884,7 @@ connection_or_connect(const tor_addr_t *_addr, uint16_t port,
     case -1:
       /* If the connection failed immediately, and we're using
        * a proxy, our proxy is down. Don't blame the Tor server. */
-      if (!using_proxy)
+      if (conn->_base.proxy_state == PROXY_INFANT)
         entry_guard_register_connect_status(conn->identity_digest,
                                             0, 1, time(NULL));
       connection_or_connect_failed(conn,

src/or/main.c

@@ -757,6 +757,16 @@ conn_close_if_marked(int i)
 #endif
 
   log_debug(LD_NET,"Cleaning up connection (fd %d).",conn->s);
+
+  /* If the connection we are about to close was trying to connect to
+  a proxy server and failed, the client won't be able to use that
+  proxy. We should warn him about this. */
+  if (conn->proxy_state == PROXY_INFANT) {
+    log_warn(LD_NET,
+             "The connection to a configured proxy server just failed. "
+             "Make sure that the proxy server is up and running.");  
+  }
+
   IF_HAS_BUFFEREVENT(conn, goto unlink);
   if ((SOCKET_OK(conn->s) || conn->linked_conn) &&
       connection_wants_to_flush(conn)) {

src/or/or.h

@@ -232,13 +232,24 @@ typedef enum {
 #define PROXY_SOCKS5 3
 
 /* Proxy client handshake states */
-#define PROXY_HTTPS_WANT_CONNECT_OK 1
-#define PROXY_SOCKS4_WANT_CONNECT_OK 2
-#define PROXY_SOCKS5_WANT_AUTH_METHOD_NONE 3
-#define PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929 4
-#define PROXY_SOCKS5_WANT_AUTH_RFC1929_OK 5
-#define PROXY_SOCKS5_WANT_CONNECT_OK 6
-#define PROXY_CONNECTED 7
+/* We use a proxy but we haven't even connected to it yet. */ 
+#define PROXY_INFANT 1
+/* We use an HTTP proxy and we've sent the CONNECT command. */
+#define PROXY_HTTPS_WANT_CONNECT_OK 2
+/* We use a SOCKS4 proxy and we've sent the CONNECT command. */
+#define PROXY_SOCKS4_WANT_CONNECT_OK 3
+/* We use a SOCKS5 proxy and we try to negotiate without
+   any authentication . */
+#define PROXY_SOCKS5_WANT_AUTH_METHOD_NONE 4
+/* We use a SOCKS5 proxy and we try to negotiate with
+   Username/Password authentication . */
+#define PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929 5
+/* We use a SOCKS5 proxy and we just sent our credentials. */
+#define PROXY_SOCKS5_WANT_AUTH_RFC1929_OK 6
+/* We use a SOCKS5 proxy and we just sent our CONNECT command. */
+#define PROXY_SOCKS5_WANT_CONNECT_OK 7
+/* We use a proxy and we CONNECTed successfully!. */
+#define PROXY_CONNECTED 8
 
 /** True iff <b>x</b> is an edge connection. */
 #define CONN_IS_EDGE(x) \