Bug 1956 – It is not possible to reuse a PacketSocket after a Close()

Bug 1956 - It is not possible to reuse a PacketSocket after a Close()


Summary:	It is not possible to reuse a PacketSocket after a Close()

Status:	CONFIRMED

Product:	ns-3
Classification:	Unclassified
Component:	network
Version:	ns-3-dev
Hardware:	All All

Importance:	P5 minor
Assigned To:	ns-bugs

URL:
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2014-07-28 16:48 EDT by Tommaso Pecorella
Modified:	2014-07-29 17:41 EDT (History)
CC List:	0 users

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Description Tommaso Pecorella 2014-07-28 16:48:16 EDT

Reported here:
https://groups.google.com/forum/?hl=en#!topic/ns-3-users/2sJBuHQkWz8

If you use Close on a PacketSocket, both m_shutdownSend and m_shutdownRecv are set.
However, they are not set back to false when the socket is re-opened with a new Connect.

Comment 1 Tommaso Pecorella 2014-07-29 17:41:02 EDT

The bug is more complex. The PacketSocket has an internal state machine. The states are:
  /**
   * \brief States of the socket
   */
  enum State {
    STATE_OPEN,
    STATE_BOUND,     // open and bound
    STATE_CONNECTED, // open, bound and connected
    STATE_CLOSED
  };

The real issue is that a socket starts in STATE_OPEN and it is left in STATE_CLOSED after a Close().
There is no way to return from STATE_CLOSED to STATE_OPEN, effectively making it impossible to "restart" the socket.

Funny enough, it is possible to "use" a PacketSocket also in STATE_OPEN: SendTo () can be used on non-bound and non-connected sockets.
The only trick is that non-bound sockets can not receive packets (missing m_node->RegisterProtocolHandler).