Change semantics of socket close and detach. Add a new protocol switch

function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket.  pru_abort is now a
notification of close also, and no longer detaches.  pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket.  This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.

This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree().  With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.

Reviewed by:	gnn

2 files changed, 15 insertions, 1 deletions

diff --git a/sys/netatm/atm_aal5.c b/sys/netatm/atm_aal5.c
index f21ad798..a0534b7 100644
--- a/sys/netatm/atm_aal5.c
+++ b/sys/netatm/atm_aal5.c
@@ -88,6 +88,7 @@ static int	atm_aal5_incoming(void *, Atm_connection *,
 			Atm_attributes *, void **);
 static void	atm_aal5_cpcs_data(void *, KBuffer *);
 static caddr_t	atm_aal5_getname(void *);
+static void	atm_aal5_close(struct socket *);
 
 
 /*
@@ -108,6 +109,7 @@ struct pr_usrreqs	atm_aal5_usrreqs = {
 	.pru_sense =		atm_aal5_sense,
 	.pru_shutdown =		atm_aal5_shutdown,
 	.pru_sockaddr =		atm_aal5_sockaddr,
+	.pru_close =		atm_aal5_close,
 };
 
 /*
@@ -565,8 +567,19 @@ atm_aal5_abort(so)
 {
 	ATM_INTRO_NOERR("abort");
 
+	(void)atm_sock_disconnect(so);
 	so->so_error = ECONNABORTED;
-	atm_sock_detach(so);
+
+	ATM_OUTRO_NOERR();
+}
+
+static void
+atm_aal5_close(so)
+	struct socket	*so;
+{
+	ATM_INTRO_NOERR("close");
+
+	(void)atm_sock_disconnect(so);
 
 	ATM_OUTRO_NOERR();
 }
diff --git a/sys/netatm/atm_usrreq.c b/sys/netatm/atm_usrreq.c
index 8facb95..ad14e84 100644
--- a/sys/netatm/atm_usrreq.c
+++ b/sys/netatm/atm_usrreq.c
@@ -79,6 +79,7 @@ struct pr_usrreqs	atm_dgram_usrreqs = {
 	.pru_sosend =		NULL,
 	.pru_soreceive =	NULL,
 	.pru_sopoll =		NULL,
+	.pru_close =		atm_proto_notsupp5,
 };