[DCCP]: Make PARTOPEN an autonomous state

This decouples PARTOPEN from TCP-specific stream-states.

It thus addresses the FIXME.

The code has been checked with regard to dependency on PARTOPEN and FIN_WAIT1
states (to which PARTOPEN previously was mapped): there is no difference, as
PARTOPEN is always referred to directly (i.e. not via the mapping to TCP
state).
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NIan McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/dccp.h

@@ -229,21 +229,13 @@ struct dccp_so_feat {
 enum dccp_state {
 	DCCP_OPEN	= TCP_ESTABLISHED,
 	DCCP_REQUESTING	= TCP_SYN_SENT,
-	DCCP_PARTOPEN	= TCP_FIN_WAIT1, /* FIXME:
-					    This mapping is horrible, but TCP has
-					    no matching state for DCCP_PARTOPEN,
-					    as TCP_SYN_RECV is already used by
-					    DCCP_RESPOND, why don't stop using TCP
-					    mapping of states? OK, now we don't use
-					    sk_stream_sendmsg anymore, so doesn't
-					    seem to exist any reason for us to
-					    do the TCP mapping here */
 	DCCP_LISTEN	= TCP_LISTEN,
 	DCCP_RESPOND	= TCP_SYN_RECV,
 	DCCP_CLOSING	= TCP_CLOSING,
 	DCCP_TIME_WAIT	= TCP_TIME_WAIT,
 	DCCP_CLOSED	= TCP_CLOSE,
-	DCCP_MAX_STATES = TCP_MAX_STATES,
+	DCCP_PARTOPEN	= TCP_MAX_STATES,
+	DCCP_MAX_STATES
 };
 
 #define DCCP_STATE_MASK 0xf
@@ -252,12 +244,12 @@ enum dccp_state {
 enum {
 	DCCPF_OPEN	 = TCPF_ESTABLISHED,
 	DCCPF_REQUESTING = TCPF_SYN_SENT,
-	DCCPF_PARTOPEN	 = TCPF_FIN_WAIT1,
 	DCCPF_LISTEN	 = TCPF_LISTEN,
 	DCCPF_RESPOND	 = TCPF_SYN_RECV,
 	DCCPF_CLOSING	 = TCPF_CLOSING,
 	DCCPF_TIME_WAIT	 = TCPF_TIME_WAIT,
 	DCCPF_CLOSED	 = TCPF_CLOSE,
+	DCCPF_PARTOPEN	 = 1 << DCCP_PARTOPEN,
 };
 
 static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)