network: add timeout for client connections

Somtimes client connetions will not close therfore add a timeout. Add a
new timer that checks every 5s if we did not receive anything from a
client for (default) 60s. Can be configured via client_timeout.

Code is based on the work of ptpt52.

Signed-off-by: Nick Hainke <vincent@systemli.org>

src/include/datastorage.h

@@ -109,6 +109,7 @@ struct time_config_s {
     time_t update_tcp_con; // Refresh network connections
     time_t update_chan_util; // Refresh per radio / SSID channel util info
     time_t update_beacon_reports; // Request BEACON from capable clients
+    time_t client_timeout; // Check for client timeouts.
 };
 
 struct local_config_s {

src/include/tcpsocket.h

@@ -5,6 +5,7 @@
 #include <netinet/in.h>
 
 #define ARRAY_NETWORK_LEN 50
+#define CHECK_CLIENT_TIMEOUT 5
 
 struct network_con_s {
     struct list_head list;
@@ -36,6 +37,11 @@ int run_server(int port);
  */
 void send_tcp(char *msg);
 
+/**
+ * Check sockets for client timeouts.
+ */
+void check_client_timeout(int timeout);
+
 /**
  * Debug message.
  */