Issues/issue 513 how to reinitialize a bacnet stack on windows (#514)

* Check init flag before cleaning up WSA for BACnet/IP

* Check for valid socket before cleaning up WSA for BACnet/IPv6

---------

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

ports/win32/bip-init.c

@@ -48,6 +48,7 @@
 /* Windows sockets */
 static SOCKET BIP_Socket = INVALID_SOCKET;
 static SOCKET BIP_Broadcast_Socket = INVALID_SOCKET;
+static bool BIP_Initialized;
 
 /* NOTE: we store address and port in network byte order
    since BACnet/IP uses network byte order for all address byte arrays
@@ -258,18 +259,17 @@ static void print_last_error(const char *info)
  */
 static void bip_init_windows(void)
 {
-    static bool initialized = false;
     int Result;
     WSADATA wd;
 
-    if (!initialized) {
+    if (!BIP_Initialized) {
         Result = WSAStartup((1 << 8) | 1, &wd);
         /*Result = WSAStartup(MAKEWORD(2,2), &wd); */
         if (Result != 0) {
             print_last_error("TCP/IP stack initialization failed");
             exit(1);
         }
-        initialized = true;
+        BIP_Initialized = true;
         atexit(bip_cleanup);
     }
 }
@@ -933,7 +933,10 @@ void bip_cleanup(void)
     }
     BIP_Broadcast_Socket = INVALID_SOCKET;
 
-    WSACleanup();
+    if (BIP_Initialized) {
+        BIP_Initialized = false;
+        WSACleanup();
+    }
 
     return;
 }

ports/win32/bip6.c

@@ -375,7 +375,7 @@ int bip6_send_mpdu(BACNET_IP6_ADDRESS *dest, uint8_t *mtu, uint16_t mtu_len)
     uint16_t addr16[8];
 
     /* assumes that the driver has already been initialized */
-    if (BIP6_Socket < 0) {
+    if (BIP6_Socket == INVALID_SOCKET) {
         return 0;
     }
     /* load destination IP address */
@@ -443,7 +443,7 @@ uint16_t bip6_receive(
     uint16_t i = 0;
 
     /* Make sure the socket is open */
-    if (BIP6_Socket < 0) {
+    if (BIP6_Socket == INVALID_SOCKET) {
         return 0;
     }
     /* we could just use a non-blocking socket, but that consumes all
@@ -503,10 +503,11 @@ uint16_t bip6_receive(
  */
 void bip6_cleanup(void)
 {
-    if (BIP6_Socket != -1) {
-        closesocket(BIP6_Socket);
+    if (BIP6_Socket == INVALID_SOCKET) {
+        return;
     }
-    BIP6_Socket = -1;
+    closesocket(BIP6_Socket);
+    BIP6_Socket = INVALID_SOCKET;
     WSACleanup();
 
     return;