Networking: Fix a runaway recursion problem introduced the previous fixe for shutting down dup'ed sockets.

net/inet/inet_close.c

@@ -508,7 +508,7 @@ int inet_close(FAR struct socket *psock)
 
               /* Stop the network monitor */
 
-              tcp_stop_monitor(conn);
+              tcp_stop_monitor(conn, TCP_CLOSE);
             }
           else
             {

net/inet/inet_recvfrom.c

@@ -737,15 +737,9 @@ static uint16_t inet_tcp_interrupt(FAR struct net_driver_s *dev,
         {
           ninfo("Lost connection\n");
 
-          /* Stop further callbacks */
-
-          pstate->ir_cb->flags   = 0;
-          pstate->ir_cb->priv    = NULL;
-          pstate->ir_cb->event   = NULL;
-
           /* Handle loss-of-connection event */
 
-          tcp_lost_connection(pstate->ir_sock, flags);
+          tcp_lost_connection(pstate->ir_sock, pstate->ir_cb, flags);
 
           /* Check if the peer gracefully closed the connection. */
 

net/sixlowpan/sixlowpan_tcpsend.c

@@ -439,11 +439,11 @@ static uint16_t tcp_send_interrupt(FAR struct net_driver_s *dev,
 
   else if ((flags & TCP_DISCONN_EVENTS) != 0)
     {
-      /* Report not connected */
-
       ninfo("Lost connection\n");
 
-      tcp_lost_connection(sinfo->s_sock, flags);
+      /* Report the disconnection event to all socket clones */
+
+      tcp_lost_connection(sinfo->s_sock, sinfo->s_cb, flags);
       sinfo->s_result = -ENOTCONN;
       goto end_wait;
     }

net/socket/net_clone.c

@@ -62,6 +62,15 @@
  * Description:
  *   Performs the low level, common portion of net_dupsd() and net_dupsd2()
  *
+ * Input Parameters:
+ *   psock1 - The existing socket that is being cloned.
+ *   psock2 - A reference to an uninitialized socket structure alloated by
+ *            the caller.
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; a negated errno value is returned on
+ *   any failure.
+ *
  ****************************************************************************/
 
 int net_clone(FAR struct socket *psock1, FAR struct socket *psock2)

net/tcp/tcp.h

@@ -557,10 +557,12 @@ int tcp_start_monitor(FAR struct socket *psock);
  * Name: tcp_stop_monitor
  *
  * Description:
- *   Stop monitoring TCP connection changes for a given socket
+ *   Stop monitoring TCP connection changes for a sockets associated with
+ *   a given TCP connection stucture.
  *
  * Input Parameters:
  *   conn - The TCP connection of interest
+ *   flags    Set of disconnection events
  *
  * Returned Value:
  *   None
@@ -571,27 +573,33 @@ int tcp_start_monitor(FAR struct socket *psock);
  *
  ****************************************************************************/
 
-void tcp_stop_monitor(FAR struct tcp_conn_s *conn);
+void tcp_stop_monitor(FAR struct tcp_conn_s *conn, uint16_t flags);
 
 /****************************************************************************
  * Name: tcp_lost_connection
  *
  * Description:
- *   Called when a loss-of-connection event has occurred.
+ *   Called when a loss-of-connection event has been detected by network
+ *   "interrupt" handling logic.  Perform operations like tcp_stop_monitor
+ *   but (1) explicitly amek this socket and (2) disable further callbacks
+ *   the "interrupt handler".
  *
  * Parameters:
- *   psock    The TCP socket structure associated.
+ *   psock - The TCP socket structure associated.
- *   flags    Set of connection events events
+ *   cb    - devif callback structure
+ *   flags - Set of connection events events
  *
  * Returned Value:
  *   None
  *
  * Assumptions:
- *   The caller holds the network lock.
+ *   The caller holds the network lock (if not, it will be locked momentarily
+ *   by this function).
  *
  ****************************************************************************/
 
-void tcp_lost_connection(FAR struct socket *psock, uint16_t flags);
+void tcp_lost_connection(FAR struct socket *psock,
+                         FAR struct devif_callback_s *cb, uint16_t flags);
 
 /****************************************************************************
  * Name: tcp_ipv4_select

net/tcp/tcp_connect.c

@@ -152,7 +152,7 @@ static void psock_teardown_callbacks(FAR struct tcp_connect_s *pstate,
     {
       /* Failed to connect. Stop the connection event monitor */
 
-      tcp_stop_monitor(conn);
+      tcp_stop_monitor(conn, TCP_CLOSE);
     }
 }
 
@@ -411,7 +411,7 @@ int psock_tcp_connect(FAR struct socket *psock,
                * happen in this context, but just in case...
                */
 
-              tcp_lost_connection(psock, TCP_ABORT);
+              tcp_stop_monitor(psock->s_conn, TCP_ABORT);
             }
         }
     }

net/tcp/tcp_monitor.c

@@ -302,11 +302,12 @@ int tcp_start_monitor(FAR struct socket *psock)
  * Name: tcp_stop_monitor
  *
  * Description:
- *   Stop monitoring TCP connection changes for a given socket.  This is part
+ *   Stop monitoring TCP connection changes for a sockets associated with
- *   of a graceful shutdown.
+ *   a given TCP connection stucture.
  *
  * Input Parameters:
  *   conn - The TCP connection of interest
+ *   flags    Set of disconnection events
  *
  * Returned Value:
  *   None
@@ -317,24 +318,27 @@ int tcp_start_monitor(FAR struct socket *psock)
  *
  ****************************************************************************/
 
-void tcp_stop_monitor(FAR struct tcp_conn_s *conn)
+void tcp_stop_monitor(FAR struct tcp_conn_s *conn, uint16_t flags)
 {
   DEBUGASSERT(conn != NULL);
 
   /* Stop the network monitor */
 
-  tcp_shutdown_monitor(conn, TCP_CLOSE);
+  tcp_shutdown_monitor(conn, flags);
 }
 
 /****************************************************************************
  * Name: tcp_lost_connection
  *
  * Description:
- *   Called when a loss-of-connection event has occurred.  This is for an
+ *   Called when a loss-of-connection event has been detected by network
- *   unexpected disconnection of some sort from the host.
+ *   "interrupt" handling logic.  Perform operations like tcp_stop_monitor
+ *   but (1) explicitly amek this socket and (2) disable further callbacks
+ *   the "interrupt handler".
  *
  * Parameters:
  *   psock - The TCP socket structure associated.
+ *   cb    - devif callback structure
  *   flags - Set of connection events events
  *
  * Returned Value:
@@ -346,11 +350,26 @@ void tcp_stop_monitor(FAR struct tcp_conn_s *conn)
  *
  ****************************************************************************/
 
-void tcp_lost_connection(FAR struct socket *psock, uint16_t flags)
+void tcp_lost_connection(FAR struct socket *psock,
+                         FAR struct devif_callback_s *cb, uint16_t flags)
 {
   DEBUGASSERT(psock != NULL && psock->s_conn != NULL);
 
-  /* Stop the network monitor */
+  /* Nullify the callback structure so that recursive callbacks are not
+   * received by the "interrupt handler" due to disconnection processing.
+   */
+
+  cb->flags = 0;
+  cb->priv  = NULL;
+  cb->event = NULL;
+
+  /* Make sure that this socket is explicitly marked.  It may not bet a
+   * callback due to the above nullification.
+   */
+
+  tcp_close_connection(psock, flags);
+
+  /* Then stop the network monitor */
 
   tcp_shutdown_monitor((FAR struct tcp_conn_s *)psock->s_conn, flags);
 }

net/tcp/tcp_netpoll.c

@@ -73,8 +73,8 @@ struct tcp_poll_s
  * Name: tcp_poll_interrupt
  *
  * Description:
- *   This function is called from the interrupt level to perform the actual
+ *   This function is called to perform the actual TCP receive operation via
- *   TCP receive operation via by the device interface layer.
+ *   the device interface layer.
  *
  * Parameters:
  *   dev      The structure of the network driver that caused the interrupt
@@ -124,14 +124,20 @@ static uint16_t tcp_poll_interrupt(FAR struct net_driver_s *dev, FAR void *conn,
         {
           /* Mark that the connection has been lost */
 
-          tcp_lost_connection(info->psock, flags);
+          tcp_lost_connection(info->psock, pstate->cb, flags);
           eventset |= (POLLERR | POLLHUP);
         }
 
       /* Awaken the caller of poll() if requested event occurred. */
 
-      if (eventset)
+      if (eventset != 0)
         {
+          /* Stop further callbacks */
+
+          pstate->cb->flags   = 0;
+          pstate->cb->priv    = NULL;
+          pstate->cb->event   = NULL;
+
           info->fds->revents |= eventset;
           sem_post(info->fds->sem);
         }

net/tcp/tcp_send_buffered.c

@@ -515,7 +515,7 @@ static uint16_t psock_send_interrupt(FAR struct net_driver_s *dev,
         {
           /* Report not connected */
 
-          tcp_lost_connection(psock, flags);
+          tcp_lost_connection(psock, psock->s_sndcb, flags);
         }
 
       /* Free write buffers and terminate polling */
@@ -1030,14 +1030,14 @@ ssize_t psock_tcp_send(FAR struct socket *psock, FAR const void *buf,
 
       /* Allocate resources to receive a callback */
 
-      if (!psock->s_sndcb)
+      if (psock->s_sndcb == NULL)
         {
           psock->s_sndcb = tcp_callback_alloc(conn);
         }
 
       /* Test if the callback has been allocated */
 
-      if (!psock->s_sndcb)
+      if (psock->s_sndcb == NULL)
         {
           /* A buffer allocation error occurred */
 

net/tcp/tcp_send_unbuffered.c

@@ -396,11 +396,11 @@ static uint16_t tcpsend_interrupt(FAR struct net_driver_s *dev,
 
   else if ((flags & TCP_DISCONN_EVENTS) != 0)
     {
-      /* Report not connected */
-
       ninfo("Lost connection\n");
 
-      tcp_lost_connection(pstate->snd_sock, flags);
+      /* Report not connected */
+
+      tcp_lost_connection(pstate->snd_sock, pstate->snd_cb, flags);
       pstate->snd_sent = -ENOTCONN;
       goto end_wait;
     }

net/tcp/tcp_sendfile.c

@@ -222,14 +222,20 @@ static uint16_t ack_interrupt(FAR struct net_driver_s *dev, FAR void *pvconn,
 
   else if ((flags & TCP_DISCONN_EVENTS) != 0)
     {
-      /* Report not connected */
-
       nwarn("WARNING: Lost connection\n");
 
-      tcp_lost_connection(pstate->snd_sock, flags);
+      /* Report not connected */
+
+      tcp_lost_connection(pstate->snd_sock, pstate->snd_ackcb, flags);
       pstate->snd_sent = -ENOTCONN;
     }
 
+  /* Prohibit further callbacks */
+
+  pstate->snd_ackcb->flags = 0;
+  pstate->snd_ackcb->priv  = NULL;
+  pstate->snd_ackcb->event = NULL;
+
   /* Wake up the waiting thread */
 
   sem_post(&pstate->snd_sem);
@@ -344,11 +350,11 @@ static uint16_t sendfile_interrupt(FAR struct net_driver_s *dev, FAR void *pvcon
 
   if ((flags & TCP_DISCONN_EVENTS) != 0)
     {
-      /* Report not connected */
-
       nwarn("WARNING: Lost connection\n");
 
-      tcp_lost_connection(pstate->snd_sock, flags);
+      /* Report not connected */
+
+      tcp_lost_connection(pstate->snd_sock, pstate->snd_datacb, flags);
       pstate->snd_sent = -ENOTCONN;
       goto end_wait;
     }