Introduce a MAC label reference in 'struct inpcb', which caches

the   MAC label referenced from 'struct socket' in the IPv4 and
IPv6-based protocols.  This permits MAC labels to be checked during
network delivery operations without dereferencing inp->inp_socket
to get to so->so_label, which will eventually avoid our having to
grab the socket lock during delivery at the network layer.

This change introduces 'struct inpcb' as a labeled object to the
MAC Framework, along with the normal circus of entry points:
initialization, creation from socket, destruction, as well as a
delivery access control check.

For most policies, the inpcb label will simply be a cache of the
socket label, so a new protocol switch method is introduced,
pr_sosetlabel() to notify protocols that the socket layer label
has been updated so that the cache can be updated while holding
appropriate locks.  Most protocols implement this using
pru_sosetlabel_null(), but IPv4/IPv6 protocols using inpcbs use
the the worker function in_pcbsosetlabel(), which calls into the
MAC Framework to perform a cache update.

Biba, LOMAC, and MLS implement these entry points, as do the stub
policy, and test policy.

Reviewed by:	sam, bms
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories

1 files changed, 2 insertions, 1 deletions

diff --git a/sys/netatm/atm_aal5.c b/sys/netatm/atm_aal5.c
index 9c11b93..81fcce8 100644
--- a/sys/netatm/atm_aal5.c
+++ b/sys/netatm/atm_aal5.c
@@ -112,7 +112,8 @@ struct pr_usrreqs	atm_aal5_usrreqs = {
 	atm_aal5_sockaddr,		/* pru_sockaddr */
 	sosend,				/* pru_sosend */
 	soreceive,			/* pru_soreceive */
-	sopoll				/* pru_sopoll */
+	sopoll,				/* pru_sopoll */
+	pru_sosetlabel_null		/* pru_sosetlabel */
 };
 
 /*