Only allocate some TCP connections for onion use when needed.

Added a function to enable and disable TCP onion connections.

toxcore/TCP_connection.c

@@ -997,7 +997,7 @@ static int tcp_relay_on_online(TCP_Connections *tcp_c, int tcp_connections_numbe
         tcp_con->connected_time = 0;
     }
 
-    if (tcp_c->onion_num_conns < NUM_ONION_TCP_CONNECTIONS) {
+    if (tcp_c->onion_status && tcp_c->onion_num_conns < NUM_ONION_TCP_CONNECTIONS) {
         tcp_con->onion = 1;
         ++tcp_c->onion_num_conns;
     }
@@ -1156,6 +1156,73 @@ unsigned int tcp_copy_connected_relays(TCP_Connections *tcp_c, Node_format *tcp_
     return copied;
 }
 
+/* Set if we want TCP_connection to allocate some connection for onion use.
+ *
+ * If status is 1, allocate some connections. if status is 0, don't.
+ *
+ * return 0 on success.
+ * return -1 on failure.
+ */
+int set_tcp_onion_status(TCP_Connections *tcp_c, _Bool status)
+{
+    if (tcp_c->onion_status == status)
+        return -1;
+
+    if (status) {
+        unsigned int i;
+
+        for (i = 0; i < tcp_c->tcp_connections_length; ++i) {
+            TCP_con *tcp_con = get_tcp_connection(tcp_c, i);
+
+            if (tcp_con) {
+                if (tcp_con->status == TCP_CONN_CONNECTED && !tcp_con->onion) {
+                    ++tcp_c->onion_num_conns;
+                    tcp_con->onion = 1;
+                }
+            }
+
+            if (tcp_c->onion_num_conns >= NUM_ONION_TCP_CONNECTIONS)
+                break;
+        }
+
+        if (tcp_c->onion_num_conns < NUM_ONION_TCP_CONNECTIONS) {
+            unsigned int wakeup = NUM_ONION_TCP_CONNECTIONS - tcp_c->onion_num_conns;
+
+            for (i = 0; i < tcp_c->tcp_connections_length; ++i) {
+                TCP_con *tcp_con = get_tcp_connection(tcp_c, i);
+
+                if (tcp_con) {
+                    if (tcp_con->status == TCP_CONN_SLEEPING) {
+                        tcp_con->unsleep = 1;
+                    }
+                }
+
+                if (!wakeup)
+                    break;
+            }
+        }
+
+        tcp_c->onion_status = 1;
+    } else {
+        unsigned int i;
+
+        for (i = 0; i < tcp_c->tcp_connections_length; ++i) {
+            TCP_con *tcp_con = get_tcp_connection(tcp_c, i);
+
+            if (tcp_con) {
+                if (tcp_con->onion) {
+                    --tcp_c->onion_num_conns;
+                    tcp_con->onion = 0;
+                }
+            }
+        }
+
+        tcp_c->onion_status = 0;
+    }
+
+    return 0;
+}
+
 TCP_Connections *new_tcp_connections(DHT *dht, TCP_Proxy_Info *proxy_info)
 {
     if (dht == NULL)

toxcore/TCP_connection.h

@@ -99,6 +99,7 @@ typedef struct {
 
     TCP_Proxy_Info proxy_info;
 
+    _Bool onion_status;
     uint16_t onion_num_conns;
 } TCP_Connections;
 
@@ -127,6 +128,15 @@ int get_random_tcp_onion_conn_number(TCP_Connections *tcp_c);
 int tcp_send_onion_request(TCP_Connections *tcp_c, unsigned int tcp_connections_number, const uint8_t *data,
                            uint16_t length);
 
+/* Set if we want TCP_connection to allocate some connection for onion use.
+ *
+ * If status is 1, allocate some connections. if status is 0, don't.
+ *
+ * return 0 on success.
+ * return -1 on failure.
+ */
+int set_tcp_onion_status(TCP_Connections *tcp_c, _Bool status);
+
 /* Send an oob packet via the TCP relay corresponding to tcp_connections_number.
  *
  * return 0 on success.

toxcore/onion_client.c

@@ -1425,7 +1425,6 @@ void do_onion_client(Onion_Client *onion_c)
             ++onion_c->onion_connected;
         }
 
-        onion_c->UDP_connected = DHT_non_lan_connected(onion_c->dht);
     } else {
         populate_path_nodes_tcp(onion_c);
 
@@ -1434,12 +1433,22 @@ void do_onion_client(Onion_Client *onion_c)
         }
     }
 
+    onion_c->UDP_connected = DHT_non_lan_connected(onion_c->dht);
+
+    if (is_timeout(onion_c->first_run, ONION_CONNECTION_SECONDS)) {
+        set_tcp_onion_status(onion_c->c->tcp_c, !onion_c->UDP_connected);
+    }
+
     if (onion_connection_status(onion_c)) {
         for (i = 0; i < onion_c->num_friends; ++i) {
             do_friend(onion_c, i);
         }
     }
 
+    if (onion_c->last_run == 0) {
+        onion_c->first_run = unix_time();
+    }
+
     onion_c->last_run = unix_time();
 }
 

toxcore/onion_client.h

@@ -136,7 +136,7 @@ typedef struct {
     Onion_Client_Paths onion_paths_friends;
 
     uint8_t secret_symmetric_key[crypto_box_KEYBYTES];
-    uint64_t last_run;
+    uint64_t last_run, first_run;
 
     uint8_t temp_public_key[crypto_box_PUBLICKEYBYTES];
     uint8_t temp_secret_key[crypto_box_SECRETKEYBYTES];