Commit Graph

6 Commits

Author SHA1 Message Date
Robert Watson
3de4046939 Continue work to optimize performance of "options MAC" when no MAC policy
modules are loaded by avoiding mbuf label lookups when policies aren't
loaded, pushing further socket locking into MAC policy modules, and
avoiding locking MAC ifnet locks when no policies are loaded:

- Check mac_policies_count before looking for mbuf MAC label m_tags in MAC
  Framework entry points.  We will still pay label lookup costs if MAC
  policies are present but don't require labels (typically a single mbuf
  header field read, but perhaps further indirection if IPSEC or other
  m_tag consumers are in use).

- Further push socket locking for socket-related access control checks and
  events into MAC policies from the MAC Framework, so that sockets are
  only locked if a policy specifically requires a lock to protect a label.
  This resolves lock order issues during sonewconn() and also in local
  domain socket cross-connect where multiple socket locks could not be
  held at once for the purposes of propagatig MAC labels across multiple
  sockets.  Eliminate mac_policy_count check in some entry points where it
  no longer avoids locking.

- Add mac_policy_count checking in some entry points relating to network
  interfaces that otherwise lock a global MAC ifnet lock used to protect
  ifnet labels.

Obtained from:	TrustedBSD Project
2009-06-03 18:46:28 +00:00
Robert Watson
fa76567150 Rename MAC Framework-internal macros used to invoke policy entry points:
MAC_BOOLEAN           -> MAC_POLICY_BOOLEAN
  MAC_BOOLEAN_NOSLEEP   -> MAC_POLICY_BOOLEANN_NOSLEEP
  MAC_CHECK             -> MAC_POLICY_CHECK
  MAC_CHECK_NOSLEEP     -> MAC_POLICY_CHECK_NOSLEEP
  MAC_EXTERNALIZE       -> MAC_POLICY_EXTERNALIZE
  MAC_GRANT             -> MAC_POLICY_GRANT
  MAC_GRANT_NOSLEEP     -> MAC_POLICY_GRANT_NOSLEEP
  MAC_INTERNALIZE       -> MAC_POLICY_INTERNALIZE
  MAC_PERFORM           -> MAC_POLICY_PERFORM_CHECK
  MAC_PERFORM_NOSLEEP   -> MAC_POLICY_PERFORM_NOSLEEP

This frees up those macro names for use in wrapping calls into the MAC
Framework from the remainder of the kernel.

Obtained from:	TrustedBSD Project
2009-05-01 21:05:40 +00:00
Robert Watson
4020272933 Rework MAC Framework synchronization in a number of ways in order to
improve performance:

- Eliminate custom reference count and condition variable to monitor
  threads entering the framework, as this had both significant overhead
  and behaved badly in the face of contention.

- Replace reference count with two locks: an rwlock and an sx lock,
  which will be read-acquired by threads entering the framework
  depending on whether a give policy entry point is permitted to sleep
  or not.

- Replace previous mutex locking of the reference count for exclusive
  access with write acquiring of both the policy list sx and rw locks,
  which occurs only when policies are attached or detached.

- Do a lockless read of the dynamic policy list head before acquiring
  any locks in order to reduce overhead when no dynamic policies are
  loaded; this a race we can afford to lose.

- For every policy entry point invocation, decide whether sleeping is
  permitted, and if not, use a _NOSLEEP() variant of the composition
  macros, which will use the rwlock instead of the sxlock.  In some
  cases, we decide which to use based on allocation flags passed to the
  MAC Framework entry point.

As with the move to rwlocks/rmlocks in pfil, this may trigger witness
warnings, but these should (generally) be false positives as all
acquisition of the locks is for read with two very narrow exceptions
for policy load/unload, and those code blocks should never acquire
other locks.

Sponsored by:	Google, Inc.
Obtained from:	TrustedBSD Project
Discussed with:	csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
Robert Watson
dbdcb99498 Use MPC_OBJECT_IP6Q to indicate labeling of struct ip6q rather than
MPC_OBJECT_IPQ; it was already defined, just not used.

Obtained from:	TrustedBSD Project
Sponsored by:	Apple, Inc.
2009-01-10 09:17:16 +00:00
Robert Watson
4b908c8bb4 Add a MAC label, MAC Framework, and MAC policy entry points for IPv6
fragment reassembly queues.

This allows policies to label reassembly queues, perform access
control checks when matching fragments to a queue, update a queue
label when fragments are matched, and label the resulting
reassembled datagram.

Obtained from:	TrustedBSD Project
2008-10-26 22:45:18 +00:00
Robert Watson
b9b0dac33b Move towards more explicit support for various network protocol stacks
in the TrustedBSD MAC Framework:

- Add mac_atalk.c and add explicit entry point mac_netatalk_aarp_send()
  for AARP packet labeling, rather than using a generic link layer
  entry point.

- Add mac_inet6.c and add explicit entry point mac_netinet6_nd6_send()
  for ND6 packet labeling, rather than using a generic link layer entry
  point.

- Add expliict entry point mac_netinet_arp_send() for ARP packet
  labeling, and mac_netinet_igmp_send() for IGMP packet labeling,
  rather than using a generic link layer entry point.

- Remove previous genering link layer entry point,
  mac_mbuf_create_linklayer() as it is no longer used.

- Add implementations of new entry points to various policies, largely
  by replicating the existing link layer entry point for them; remove
  old link layer entry point implementation.

- Make MAC_IFNET_LOCK(), MAC_IFNET_UNLOCK(), and mac_ifnet_mtx global
  to the MAC Framework rather than static to mac_net.c as it is now
  needed outside of mac_net.c.

Obtained from:	TrustedBSD Project
2007-10-28 15:55:23 +00:00