Minor fix for re-bind and remove debug print.

port/platform/linux/src/u_port_ppp.c

@@ -468,10 +468,6 @@ static void socketTask(void *pParameters)
                         if ((dataSize > 0) &&
                             (pPppInterface->pTransmitCallback != NULL) &&
                             !pPppInterface->dataTransferSuspended) {
-                            for (size_t rob = 0; rob < dataSize; rob++) {
-                                uPortLog(" 0x%02x", buffer[rob]);
-                            }
-                            uPortLog("\n");
                             // Write the data to the cellular module
                             retryCount = 0;
                             pData = buffer;
@@ -525,6 +521,7 @@ static int32_t startSocketTask(uPortPppInterface_t *pPppInterface,
     int32_t errorCode;
     struct sockaddr_in socketAddress = {0};
     uSockAddress_t sockUbxlib;
+    int reuse = 1;
 
     errorCode = uSockStringToAddress(pAddressString, &sockUbxlib);
     if (errorCode == 0) {
@@ -533,6 +530,24 @@ static int32_t startSocketTask(uPortPppInterface_t *pPppInterface,
         pPppInterface->connectedSocket = -1;
         pPppInterface->listeningSocket = socket(AF_INET, SOCK_STREAM, 0);
         if (pPppInterface->listeningSocket >= 0) {
+            if (setsockopt(pPppInterface->listeningSocket, SOL_SOCKET, SO_REUSEADDR,
+                           (const char*) &reuse, sizeof(reuse)) < 0) {
+                // This is not fatal, it just means that the OS might prevent
+                // us binding to the same address again if we come back into
+                // here too quickly
+                uPortLog("U_PORT_PPP: *** WARNING *** setting socket option SO_REUSEADDR"
+                         " returned errno %d.\n", errno);
+            }
+#ifdef SO_REUSEPORT
+            if (setsockopt(pPppInterface->listeningSocket, SOL_SOCKET, SO_REUSEPORT,
+                           (const char*) &reuse, sizeof(reuse)) < 0) {
+                // This is not fatal, it just means that the OS might prevent
+                // us binding to the same address again if we come back into
+                // here too quickly
+                uPortLog("U_PORT_PPP: *** WARNING *** setting socket option SO_REUSEPORT"
+                         " returned errno %d.\n", errno);
+            }
+#endif
             errorCode = (int32_t) U_ERROR_COMMON_INVALID_ADDRESS;
             socketAddress.sin_family = AF_INET;
             if (sockUbxlib.ipAddress.type == U_SOCK_ADDRESS_TYPE_V4) {
@@ -541,6 +556,8 @@ static int32_t startSocketTask(uPortPppInterface_t *pPppInterface,
                 // TODO: find out how this copy should work for an IPV6 address
                 errorCode = (int32_t) U_ERROR_COMMON_NOT_SUPPORTED;
             }
+            // Set SO_REUSEADDR (and, in some cases SO_REUSEPORT) so that we
+            // can re-bind to the socket when we come back into here
             socketAddress.sin_port = htons(sockUbxlib.port);
             if (bind(pPppInterface->listeningSocket,
                      (struct sockaddr *) &socketAddress,