TCP should be a bit more solid.

When a TCP ping request is recieved, try to send the response until
success instead of just dropping it if sending the response fails on
the first try.

2 files changed, 21 insertions, 4 deletions

diff --git a/toxcore/TCP_client.c b/toxcore/TCP_client.c
index 087188f7..82720ae8 100644
--- a/toxcore/TCP_client.c
+++ b/toxcore/TCP_client.c
@@ -197,6 +197,8 @@ void routing_status_handler(TCP_Client_Connection *con, int (*status_callback)(v
     con->status_callback_object = object;
 }
 
+static int send_ping_response(TCP_Client_Connection *con);
+
 /* return 1 on success.
  * return 0 if could not send packet.
  * return -1 on failure.
@@ -209,6 +211,9 @@ int send_data(TCP_Client_Connection *con, uint8_t con_id, const uint8_t *data, u
     if (con->connections[con_id].status != 2)
         return -1;
 
+    if (send_ping_response(con) == 0)
+        return 0;
+
     uint8_t packet[1 + length];
     packet[0] = con_id + NUM_RESERVED_PORTS;
     memcpy(packet + 1, data, length);
@@ -293,12 +298,21 @@ static int send_ping_request(TCP_Client_Connection *con, uint64_t ping_id)
  * return 0 if could not send packet.
  * return -1 on failure (connection must be killed).
  */
-static int send_ping_response(TCP_Client_Connection *con, uint64_t ping_id)
+static int send_ping_response(TCP_Client_Connection *con)
 {
+    if (!con->ping_response_id)
+        return 1;
+
     uint8_t packet[1 + sizeof(uint64_t)];
     packet[0] = TCP_PACKET_PONG;
-    memcpy(packet + 1, &ping_id, sizeof(uint64_t));
-    return write_packet_TCP_secure_connection(con, packet, sizeof(packet));
+    memcpy(packet + 1, &con->ping_response_id, sizeof(uint64_t));
+    int ret;
+
+    if ((ret = write_packet_TCP_secure_connection(con, packet, sizeof(packet))) == 1) {
+        con->ping_response_id = 0;
+    }
+
+    return ret;
 }
 
 /* return 1 on success.
@@ -468,7 +482,8 @@ static int handle_TCP_packet(TCP_Client_Connection *conn, const uint8_t *data, u
 
             uint64_t ping_id;
             memcpy(&ping_id, data + 1, sizeof(uint64_t));
-            send_ping_response(conn, ping_id);
+            conn->ping_response_id = ping_id;
+            send_ping_response(conn);
             return 0;
         }
 
@@ -523,6 +538,7 @@ static int handle_TCP_packet(TCP_Client_Connection *conn, const uint8_t *data, u
 static int do_confirmed_TCP(TCP_Client_Connection *conn)
 {
     send_pending_data(conn);
+    send_ping_response(conn);
     uint8_t packet[MAX_PACKET_SIZE];
     int len;
 
diff --git a/toxcore/TCP_client.h b/toxcore/TCP_client.h
index 2622b4f7..e6d232ed 100644
--- a/toxcore/TCP_client.h
+++ b/toxcore/TCP_client.h
@@ -57,6 +57,7 @@ typedef struct  {
     uint64_t last_pinged;
     uint64_t ping_id;
 
+    uint64_t ping_response_id;
     void *net_crypto_pointer;
     uint32_t net_crypto_location;
     struct {