: DCCP's passive close needs to match TCP's half-close

[DCCP]: DCCP's passive close needs to match TCP's half-close

This fixes a problem of integrating the new auxiliary states PASSIVE_1/2 with the inet_xxx infrastructure.

The problem appears on the listening side and is that
* a Close may have been received on the socket while it is still in the accept queue of the master/listening socket;
* hence when it is taken out of the queue by inet_accept(), the state of the socket is PASSIVE_1 (whose value is greater than all registered TCP states);
* this triggers the following warning in inet_accept():

   Sep 10 16:52:27 kernel: KERNEL: \
	assertion ((1 << sk2->sk_state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE))\
	failed at /usr/src/main_davem-2.6/net/ipv4/af_inet.c (646)

The fix consists mapping PASSIVE_1 into TCPF_CLOSE_WAIT, which is possible since there is no other mapping from a DCCP state into it. Incidentally, the `semantics' of that state are also similar: in TCP's CLOSE_WAIT, a user confirmation to close up the socket is needed - and the same (calling close/exit) situation arises here.

For a server deciding to hold TIMEWAIT state there is no such problem, since DCCP_SOCKOPT_SERVER_TIMEWAIT can not be set on a listening socket, it is by default off and not inherited to child sockets.

Lastly, for PASSIVE_2 the situation is simpler, since this is a client-only state.

---
 include/linux/dccp.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -249,14 +249,14 @@ enum dccp_state {
 	 * CLOSING, corresponds to (b) above) are used.
 	 */
 	DCCP_CLOSEREQ	= TCP_FIN_WAIT1,
+	DCCP_PASSIVE_1	= TCP_CLOSE_WAIT,	/* any node receiving a Close */
 	DCCP_CLOSING	= TCP_CLOSING,
 	DCCP_TIME_WAIT	= TCP_TIME_WAIT,
 	DCCP_CLOSED	= TCP_CLOSE,
 	/* Everything below here is specific to DCCP only */
 	DCCP_INTRINSICS = TCP_MAX_STATES,
 	DCCP_PARTOPEN,
-	DCCP_PASSIVE_1,		/* any node receiving a Close  */
-	DCCP_PASSIVE_2,		/* client receiving a CloseReq */
+	DCCP_PASSIVE_2,				/* client receiving CloseReq  */
 	DCCP_MAX_STATES
 };