Chance protocol switch method pru_detach() so that it returns void

rather than an error.  Detaches do not "fail", they other occur or
the protocol flags SS_PROTOREF to take ownership of the socket.

soclose() no longer looks at so_pcb to see if it's NULL, relying
entirely on the protocol to decide whether it's time to free the
socket or not using SS_PROTOREF.  so_pcb is now entirely owned and
managed by the protocol code.  Likewise, no longer test so_pcb in
other socket functions, such as soreceive(), which have no business
digging into protocol internals.

Protocol detach routines no longer try to free the socket on detach,
this is performed in the socket code if the protocol permits it.

In rts_detach(), no longer test for rp != NULL in detach, and
likewise in other protocols that don't permit a NULL so_pcb, reduce
the incidence of testing for it during detach.

netinet and netinet6 are not fully updated to this change, which
will be in an upcoming commit.  In their current state they may leak
memory or panic.

MFC after:	3 months

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/sys/protosw.h b/sys/sys/protosw.h
index 5f39c69..760aa7e 100644
--- a/sys/sys/protosw.h
+++ b/sys/sys/protosw.h
@@ -206,7 +206,7 @@ struct pr_usrreqs {
 	int	(*pru_connect2)(struct socket *so1, struct socket *so2);
 	int	(*pru_control)(struct socket *so, u_long cmd, caddr_t data,
 		    struct ifnet *ifp, struct thread *td);
-	int	(*pru_detach)(struct socket *so);
+	void	(*pru_detach)(struct socket *so);
 	int	(*pru_disconnect)(struct socket *so);
 	int	(*pru_listen)(struct socket *so, int backlog,
 		    struct thread *td);
@@ -256,7 +256,7 @@ int	pru_connect_notsupp(struct socket *so, struct sockaddr *nam,
 int	pru_connect2_notsupp(struct socket *so1, struct socket *so2);
 int	pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data,
 	    struct ifnet *ifp, struct thread *td);
-int	pru_detach_notsupp(struct socket *so);
+void	pru_detach_notsupp(struct socket *so);
 int	pru_disconnect_notsupp(struct socket *so);
 int	pru_listen_notsupp(struct socket *so, int backlog, struct thread *td);
 int	pru_peeraddr_notsupp(struct socket *so, struct sockaddr **nam);