First try at disconnect/reconnect detection. No idea if it's going to work on WIN32.

client/cmdhw.c

@@ -405,11 +405,19 @@ int CmdTune(const char *Cmd)
 
 int CmdVersion(const char *Cmd)
 {
+	return CmdVersionC(Cmd, false);
+}
 
-	clearCommandBuffer();
+int CmdVersionC(const char *Cmd, const bool no_cache)
+{
 	UsbCommand c = {CMD_VERSION};
 	static UsbCommand resp = {0, {0, 0, 0}};
 
+	if( no_cache )
+		memset( &resp, 0, sizeof(resp) );
+	else
+		clearCommandBuffer();
+
 	if (resp.arg[0] == 0 && resp.arg[1] == 0) { // no cached information available
 		SendCommand(&c);
 		if (WaitForResponseTimeout(CMD_ACK,&resp,1000)) {

client/cmdhw.h

@@ -23,5 +23,6 @@ int CmdSetDivisor(const char *Cmd);
 int CmdSetMux(const char *Cmd);
 int CmdTune(const char *Cmd);
 int CmdVersion(const char *Cmd);
+int CmdVersionC(const char *Cmd, const bool no_cache);
 
 #endif

client/proxmark3.c

@@ -38,6 +38,7 @@
 pthread_mutex_t print_lock;
 
 static serial_port sp;
+static char* sp_name;
 static UsbCommand txcmd;
 volatile static bool txcmd_pending = false;
 
@@ -70,16 +71,63 @@ byte_t* prx = rx;
 static void *uart_receiver(void *targ) {
 	struct receiver_arg *arg = (struct receiver_arg*)targ;
 	size_t rxlen;
+	bool need_reconnect = false;
+	UsbCommand version_cmd = {CMD_VERSION};
+	static bool request_version = false;
 
 	while (arg->run) {
-		rxlen = 0;
-		if (uart_receive(sp, prx, sizeof(UsbCommand) - (prx-rx), &rxlen) && rxlen) {
-			prx += rxlen;
-			if (prx-rx < sizeof(UsbCommand)) {
+		if( need_reconnect ) {
+			sp = uart_open(sp_name);
+
+			if( sp == INVALID_SERIAL_PORT || sp == CLAIMED_SERIAL_PORT )
+			{
+				PrintAndLog("Reconnect failed, retrying...");
+
+				if( txcmd_pending ) {
+					PrintAndLog("Cannot send bytes to offline proxmark");
+					txcmd_pending = false;
+				}
+
+				sleep(2);
 				continue;
 			}
-			UsbCommandReceived((UsbCommand*)rx);
+
+			PrintAndLog("Proxmark reconnected!");
+			need_reconnect = false;
+			offline = 0;
+			//CmdVersionW(NULL, true);
+			clearCommandBuffer();
+			uart_send(sp, (byte_t*) &version_cmd, sizeof(UsbCommand)); // request it from the HW
+			request_version = true;
 		}
+
+		rxlen = 0;
+		if (uart_receive(sp, prx, sizeof(UsbCommand) - (prx-rx), &rxlen) ) {
+			if( rxlen ) {
+				prx += rxlen;
+				if (prx-rx < sizeof(UsbCommand)) {
+					continue;
+				}
+
+				UsbCommandReceived((UsbCommand*)rx);
+
+				if( request_version && ((UsbCommand*)rx)->cmd == CMD_ACK)
+				{
+					request_version = false;
+					CmdVersionW(NULL, true);
+				}
+			}
+		}
+		else {
+			PrintAndLog("Receiving data from proxmark failed, attempting a reconnect");
+			uart_close(sp);
+			sp = INVALID_SERIAL_PORT;
+			offline = 1;
+			txcmd_pending = false;
+			need_reconnect = true;
+			continue;
+		}
+
 		prx = rx;
 
 		if(txcmd_pending) {
@@ -351,6 +399,7 @@ int main(int argc, char* argv[]) {
 	set_my_executable_path();
 	
 	// open uart
+	sp_name = argv[1];
 	if (!waitCOMPort) {
 		sp = uart_open(argv[1]);
 	} else {
@@ -405,7 +454,7 @@ int main(int argc, char* argv[]) {
 #endif	
 
 	// Clean up the port
-	if (usb_present) {
+	if (sp != INVALID_SERIAL_PORT && sp != CLAIMED_SERIAL_PORT) {
 		uart_close(sp);
 	}
 

uart/uart_posix.c

@@ -158,7 +158,7 @@ bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t pszMaxRxLen, size_
     if (res == 0) {
       if (*pszRxLen == 0) {
         // Error, we received no data
-        return false;
+        return true;
       } else {
         // We received some data, but nothing more is available
         return true;
@@ -178,7 +178,7 @@ bool uart_receive(const serial_port sp, byte_t* pbtRx, size_t pszMaxRxLen, size_
     res = read(((serial_port_unix*)sp)->fd, pbtRx+(*pszRxLen), byteCount);
 
     // Stop if the OS has some troubles reading the data
-    if (res <= 0) return false;
+    if (res < 0) return false;
 
     *pszRxLen += res;