unregistration, and execution:
- Add some brackets for clarity and trim a bit of vertical whitespace.
- Remove comments that may not contribute to clarity, such as "Lock"
before acquiring a lock and "Get memory" before allocating memory.
- During hook registration, don't drop pfil_list_lock between checking
for a duplicate and registering the hook, as this leaves a race
condition by failing to enforce the "no duplicate hooks" invariant.
- Don't lock the hook during registration, since it's not yet in use.
- Document assumption that hooks will be quiesced before being
unregistered.
- Don't write-lock hooks during removal because they are assumed
quiesced.
- Rename "done" label to "locked_error" to be clear that it's an error
path on the way out of hook execution.
MFC after: pretty soon
This has the benefit that rmlocks have proper support for reader recursion
(in contrast to rwlock(9) which could potential lead to writer stravation).
It also means a significant performance gain, eventhough only visible in
microbenchmarks at the moment.
Discussed on: -arch, -net
filtering mechanisms to use the new rwlock(9) locking API:
- Drop the variables stored in the phil_head structure which were specific to
conditions and the home rolled read/write locking mechanism.
- Drop some includes which were used for condition variables
- Drop the inline functions, and convert them to macros. Also, move these
macros into pfil.h
- Move pfil list locking macros intp phil.h as well
- Rename ph_busy_count to ph_nhooks. This variable will represent the number
of IN/OUT hooks registered with the pfil head structure
- Define PFIL_HOOKED macro which evaluates to true if there are any
hooks to be ran by pfil_run_hooks
- In the IP/IP6 stacks, change the ph_busy_count comparison to use the new
PFIL_HOOKED macro.
- Drop optimization in pfil_run_hooks which checks to see if there are any
hooks to be ran, and returns if not. This check is already performed by the
IP stacks when they call:
if (!PFIL_HOOKED(ph))
goto skip_hooks;
- Drop in assertion which makes sure that the number of hooks never drops
below 0 for good measure. This in theory should never happen, and if it
does than there are problems somewhere
- Drop special logic around PFIL_WAITOK because rw_wlock(9) does not sleep
- Drop variables which support home rolled read/write locking mechanism from
the IPFW firewall chain structure.
- Swap out the read/write firewall chain lock internal to use the rwlock(9)
API instead of our home rolled version
- Convert the inlined functions to macros
Reviewed by: mlaier, andre, glebius
Thanks to: jhb for the new locking API
We return ENOBUF to indicate the problem, which is an errno that should be
handled well everywhere.
Requested & Submitted by: green
Silently okay'ed by: The rest of the firewall gang
MFC after: 3 days
passing along socket information. This is required to work around a LOR with
the socket code which results in an easy reproducible hard lockup with
debug.mpsafenet=1. This commit does *not* fix the LOR, but enables us to do
so later. The missing piece is to turn the filter locking into a leaf lock
and will follow in a seperate (later) commit.
This will hopefully be MT5'ed in order to fix the problem for RELENG_5 in
forseeable future.
Suggested by: rwatson
A lot of work by: csjp (he'd be even more helpful w/o mentor-reviews ;)
Reviewed by: rwatson, csjp
Tested by: -pf, -ipfw, LINT, csjp and myself
MFC after: 3 days
LOR IDs: 14 - 17 (not fixed yet)
A thread must hold mp while calling cv_signal(), cv_broadcast(), or
cv_broadcastpri() even though it isn't passed as an argument.
and is right with this claim.
While here remove a "\" from the macro -> __inline conversion.
Found by: csjp
MFC after: 4 days
o revamp IPv4+IPv6+bridge usage to match API changes
o remove pfil_head instances from protosw entries (no longer used)
o add locking
o bump FreeBSD version for 3rd party modules
Heavy lifting by: "Max Laier" <max@love2party.net>
Supported by: FreeBSD Foundation
Obtained from: NetBSD (bits of pfil.h and pfil.c)
