Yet another repair for the previouis botched recvfrom() fix; Fix telnet driver: It needs to break out of the read loop if 0 (meaning not conneced) of a value < 0 (an error) is encountered.

git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5541 42af7a65-404d-4744-a932-0658087f49c3

apps/ChangeLog.txt

@@ -490,3 +490,5 @@
 	* apps/builtin/: Extensions from Mike Smith.
 	* apps/examples/ftpd/Makefile: Name ftpd_start is not the name of
 	  the entrypoint.  Should be ftpd_main (from Yan T.)
+	* apps/netutils/telnetd/telnetd_driver: Was stuck in a loop if
+	  recv[from]() ever returned a value <= 0.

apps/netutils/telnetd/telnetd_driver.c

@@ -558,6 +558,8 @@ static ssize_t telnetd_read(FAR struct file *filep, FAR char *buffer, size_t len
     {
       if (priv->td_pending > 0)
         {
+          /* Process the buffered telnet data */
+
           FAR const char *src = &priv->td_rxbuffer[priv->td_offset];
           ret = telnetd_receive(priv, src, priv->td_pending, buffer, len);
         }
@@ -568,13 +570,25 @@ static ssize_t telnetd_read(FAR struct file *filep, FAR char *buffer, size_t len
         {
           ret = psock_recv(&priv->td_psock, priv->td_rxbuffer,
                           CONFIG_TELNETD_RXBUFFER_SIZE, 0);
+
+          /* Did we receive anything? */
+
           if (ret > 0)
             {
-              /* Process the received telnet data */
+              /* Yes.. Process the newly received telnet data */
 
               telnetd_dumpbuffer("Received buffer", priv->td_rxbuffer, ret);
               ret = telnetd_receive(priv, priv->td_rxbuffer, ret, buffer, len);
            }
+
+          /* Otherwise the peer closed the connection (ret == 0) or an error
+           * occurred (ret < 0).
+           */
+
+          else
+            {
+              break;
+            }
         }
     }
   while (ret == 0);
@@ -746,7 +760,7 @@ FAR char *telnetd_driver(int sd, FAR struct telnetd_s *daemon)
    * instance resided in the daemon's socket array).
    */
 
-  psock =  sockfd_socket(sd);
+  psock = sockfd_socket(sd);
   if (!psock)
     {
       nlldbg("Failed to convert sd=%d to a socket structure\n", sd);

nuttx/ChangeLog

@@ -3993,3 +3993,6 @@
 	  (gracefully).  recv[from]() returned success and the closure
 	  was never detected.  Hmmm.. I don't know why the network monitor
 	  did not catch this event.  This is an important bug fix.
+	* net/recvfrom():  Fix a introduced with the last bugfix.  If
+	  the peer does an orderly closure of the socket, report 0 not
+	  -ENOTCONN

nuttx/net/recvfrom.c

@@ -571,40 +571,47 @@ static uint16_t recvfrom_tcpinterrupt(struct uip_driver_s *dev, void *conn,
            *     gracefully disconnected
            *   _SF_CONNECTED==0 && _SF_CLOSED==0 - the socket was
            *     rudely disconnected
-           *
-           * These flag settings are probably not necessary if
-           * CONFIG_NET_TCP_RECVDELAY == 0; in that case we know that
-           * pstate->rf_recvlen == 0 and we will always return -ENOTCONN.
            */
 
           psock = pstate->rf_sock;
           if ((flags & UIP_CLOSE) != 0)
             {
+              /* Report that the connection was gracefully closed */
+
               psock->s_flags &= ~_SF_CONNECTED;
               psock->s_flags |= _SF_CLOSED;
-            }
-          else
-            {
-              psock->s_flags &= ~(_SF_CONNECTED |_SF_CLOSED);
-            }
 
-          /* If no data has been received, then return ENOTCONN.
-           * Otherwise, let this return success.  The failure will
-           * be reported the next time that recv[from]() is called.
-           */
+              /* This case should always return success (zero)! The value of
+               * rf_recvlen, if zero, will indicate that the connection was
+               * gracefully closed.
+               */
 
-#if CONFIG_NET_TCP_RECVDELAY > 0
-          if (pstate->rf_recvlen > 0)
-            {
               pstate->rf_result = 0;
             }
           else
             {
-              pstate->rf_result = -ENOTCONN;
-            }
+              /* Report that the connection was rudely lost */
+
+              psock->s_flags &= ~(_SF_CONNECTED |_SF_CLOSED);
+
+              /* If no data has been received, then return ENOTCONN.
+               * Otherwise, let this return success.  The failure will
+               * be reported the next time that recv[from]() is called.
+               */
+
+#if CONFIG_NET_TCP_RECVDELAY > 0
+              if (pstate->rf_recvlen > 0)
+                {
+                  pstate->rf_result = 0;
+                }
+              else
+                {
+                  pstate->rf_result = -ENOTCONN;
+                }
 #else
-          pstate->rf_result = -ENOTCONN;
+              pstate->rf_result = -ENOTCONN;
 #endif
+            }
 
           /* Wake up the waiting thread */