3 files changed, 48 insertions, 12 deletions

diff --git a/toxcore/net_crypto.c b/toxcore/net_crypto.c
index 8af3cbbc..112931ad 100644
--- a/toxcore/net_crypto.c
+++ b/toxcore/net_crypto.c
@@ -2039,29 +2039,50 @@ int add_tcp_relay(Net_Crypto *c, IP_Port ip_port, const uint8_t *public_key)
     return -1;
 }
 
-/* Send an onion packet via a random connected TCP relay.
+/* Return a random TCP connection number for use in send_tcp_onion_request.
  *
- * return 0 on success.
+ * TODO: This number is just the index of an array that the elements can
+ * change without warning.
+ *
+ * return TCP connection number on success.
  * return -1 on failure.
  */
-int send_tcp_onion_request(Net_Crypto *c, const uint8_t *data, uint16_t length)
+int get_random_tcp_con_number(Net_Crypto *c)
 {
     unsigned int i, r = rand();
 
     for (i = 0; i < MAX_TCP_CONNECTIONS; ++i) {
         if (c->tcp_connections[(i + r) % MAX_TCP_CONNECTIONS]) {
-            pthread_mutex_lock(&c->tcp_mutex);
-            int ret = send_onion_request(c->tcp_connections[(i + r) % MAX_TCP_CONNECTIONS], data, length);
-            pthread_mutex_unlock(&c->tcp_mutex);
-
-            if (ret == 1)
-                return 0;
+            return (i + r) % MAX_TCP_CONNECTIONS;
         }
     }
 
     return -1;
 }
 
+/* Send an onion packet via the TCP relay corresponding to TCP_conn_number.
+ *
+ * return 0 on success.
+ * return -1 on failure.
+ */
+int send_tcp_onion_request(Net_Crypto *c, unsigned int TCP_conn_number, const uint8_t *data, uint16_t length)
+{
+    if (TCP_conn_number > MAX_TCP_CONNECTIONS) {
+        return -1;
+    }
+
+    if (c->tcp_connections[TCP_conn_number]) {
+        pthread_mutex_lock(&c->tcp_mutex);
+        int ret = send_onion_request(c->tcp_connections[TCP_conn_number], data, length);
+        pthread_mutex_unlock(&c->tcp_mutex);
+
+        if (ret == 1)
+            return 0;
+    }
+
+    return -1;
+}
+
 /* Set the function to be called when an onion response packet is received by one of the TCP connections.
  */
 void tcp_onion_response_handler(Net_Crypto *c, int (*tcp_onion_callback)(void *object, const uint8_t *data,
diff --git a/toxcore/net_crypto.h b/toxcore/net_crypto.h
index b9fb1747..9d699340 100644
--- a/toxcore/net_crypto.h
+++ b/toxcore/net_crypto.h
@@ -364,12 +364,19 @@ int add_tcp_relay(Net_Crypto *c, IP_Port ip_port, const uint8_t *public_key);
 void tcp_onion_response_handler(Net_Crypto *c, int (*tcp_onion_callback)(void *object, const uint8_t *data,
                                 uint16_t length), void *object);
 
-/* Send an onion packet via a random connected TCP relay.
+/* Return a random TCP connection number for use in send_tcp_onion_request.
+ *
+ * return TCP connection number on success.
+ * return -1 on failure.
+ */
+int get_random_tcp_con_number(Net_Crypto *c);
+
+/* Send an onion packet via the TCP relay corresponding to TCP_conn_number.
  *
  * return 0 on success.
  * return -1 on failure.
  */
-int send_tcp_onion_request(Net_Crypto *c, const uint8_t *data, uint16_t length);
+int send_tcp_onion_request(Net_Crypto *c, unsigned int TCP_conn_number, const uint8_t *data, uint16_t length);
 
 /* Copy a maximum of num TCP relays we are connected to to tcp_relays.
  * NOTE that the family of the copied ip ports will be set to TCP_INET or TCP_INET6.
diff --git a/toxcore/onion_client.c b/toxcore/onion_client.c
index f8d7630b..a9eb16a0 100644
--- a/toxcore/onion_client.c
+++ b/toxcore/onion_client.c
@@ -140,8 +140,15 @@ static uint16_t random_nodes_path_onion(const Onion_Client *onion_c, Node_format
             nodes[i] = onion_c->path_nodes[rand() % num_nodes];
         }
     } else {
+        int random_tcp = get_random_tcp_con_number(onion_c->c);
+
+        if (random_tcp == -1) {
+            return 0;
+        }
+
         if (num_nodes >= 2) {
             nodes[0].ip_port.ip.family = TCP_FAMILY;
+            nodes[0].ip_port.ip.ip4.uint32 = random_tcp;
 
             for (i = 1; i < max_num; ++i) {
                 nodes[i] = onion_c->path_nodes[rand() % num_nodes];
@@ -154,6 +161,7 @@ static uint16_t random_nodes_path_onion(const Onion_Client *onion_c, Node_format
                 return 0;
 
             nodes[0].ip_port.ip.family = TCP_FAMILY;
+            nodes[0].ip_port.ip.ip4.uint32 = random_tcp;
 
             for (i = 1; i < max_num; ++i) {
                 nodes[i] = onion_c->path_nodes_bs[rand() % num_nodes_bs];
@@ -301,7 +309,7 @@ static int send_onion_packet_tcp_udp(const Onion_Client *onion_c, const Onion_Pa
         if (len == -1)
             return -1;
 
-        return send_tcp_onion_request(onion_c->c, packet, len);
+        return send_tcp_onion_request(onion_c->c, path->ip_port1.ip.ip4.uint32, packet, len);
     } else {
         return -1;
     }