pf_purge_expired_states().
Now pf purging daemon stores the current hash table index on stack
in pf_purge_thread(), and supplies it to next iteration of
pf_purge_expired_states(). The latter returns new index back.
The important change is that whenever pf_purge_expired_states() wraps
around the array it returns immediately. This makes our knowledge about
status of states expiry run more consistent. Prior to this change it
could happen that n-th run stopped on i-th entry, and returned (1) as
full run complete, then next (n+1) full run stopped on j-th entry, where
j < i, and that broke the mark-and-sweep algorythm that saves references
rules. A referenced rule was freed, and this later lead to a crash.
we are actually editing table, which means editing rules,
thus we need writer access to 'em.
Fix this by offloading the update of table to the same taskqueue,
we already use for flushing. Since taskqueues major task is now
overloading, and flushing is optional, do mechanical rename
s/flush/overload/ in the code related to the taskqueue.
Since overloading tasks do unsafe referencing of rules, provide
a bandaid in pf_purge_unlinked_rules(). If the latter sees any
queued tasks, then it skips purging for this run.
In table code:
- Assert any lock in pfr_lookup_addr().
- Assert writer lock in pfr_route_kentry().
This is important to secure a small timeframe at boot time, when
network is already configured, but pf(4) is not yet.
PR: kern/171622
Submitted by: Olivier Cochard-LabbИ <olivier cochard.me>
1) Ruleset parser uses a global variable for anchor stack.
2) When processing a wildcard anchor, matching anchors are marked.
To fix the first one:
o Allocate anchor processing stack on stack. To make this allocation
as small as possible, following measures taken:
- Maximum stack size reduced from 64 to 32.
- The struct pf_anchor_stackframe trimmed by one pointer - parent.
We can always obtain the parent via the rule pointer.
- When pf_test_rule() calls pf_get_translation(), the former lends
its stack to the latter, to avoid recursive allocation 32 entries.
The second one appeared more tricky. The code, that marks anchors was
added in OpenBSD rev. 1.516 of pf.c. According to commit log, the idea
is to enable the "quick" keyword on an anchor rule. The feature isn't
documented anywhere. The most obscure part of the 1.516 was that code
examines the "match" mark on a just processed child, which couldn't be
put here by current frame. Since this wasn't documented even in the
commit message and functionality of this is not clear to me, I decided
to drop this examination for now. The rest of 1.516 is redone in a
thread safe manner - the mark isn't put on the anchor itself, but on
current stack frame. To avoid growing stack frame, we utilize LSB
from the rule pointer, relying on kernel malloc(9) returning pointer
aligned addresses.
Discussed with: dhartmei
reside, and move there ipfw(4) and pf(4).
o Move most modified parts of pf out of contrib.
Actual movements:
sys/contrib/pf/net/*.c -> sys/netpfil/pf/
sys/contrib/pf/net/*.h -> sys/net/
contrib/pf/pfctl/*.c -> sbin/pfctl
contrib/pf/pfctl/*.h -> sbin/pfctl
contrib/pf/pfctl/pfctl.8 -> sbin/pfctl
contrib/pf/pfctl/*.4 -> share/man/man4
contrib/pf/pfctl/*.5 -> share/man/man5
sys/netinet/ipfw -> sys/netpfil/ipfw
The arguable movement is pf/net/*.h -> sys/net. There are
future plans to refactor pf includes, so I decided not to
break things twice.
Not modified bits of pf left in contrib: authpf, ftp-proxy,
tftp-proxy, pflogd.
The ipfw(4) movement is planned to be merged to stable/9,
to make head and stable match.
Discussed with: bz, luigi
