MFC r333084:

pfctl: Don't break connections on skipped interfaces on reload

On reload we used to first flush everything, including the list of skipped
interfaces. This can lead to termination of these connections if they send
packets before the new configuration is applied.

Note that this doesn't currently happen on 12 or 11, because of special EACCES
handling introduced in r315514. This special behaviour in tcp_output() may
change, hence the fix in pfctl.

PR: 214613
Submitted by: Andreas Longwitz <longwitz at incore.de>

MFC 285730
Only report the lack of ALTQ support if pfctl is using verbose (-v) mode.

PR: 194935
Submitted by: Jim Thompson
Approved by: re (gjb)

MFC r290236

pfctl: Fix uninitialised veriable

In pfctl_set_debug() we used 'level' without ever initialising it.
We correctly parsed the option, but them failed to actually assign the parsed
value to 'level' before performing to ioctl() to configure the debug level.

PR: 202996
Submitted by: Andrej Kolontai

Merge r261882, r261898, r261937, r262760, r262799:
Once pf became not covered by a single mutex, many counters in it became
race prone. Some just gather statistics, but some are later used in
different calculations.

A real problem was the race provoked underflow of the states_cur counter
on a rule. Once it goes below zero, it wraps to UINT32_MAX. Later this
value is used in pf_state_expires() and any state created by this rule
is immediately expired.

Thus, make fields states_cur, states_tot and src_nodes of struct
pf_rule be counter(9)s.

Merge r261882, r261898, r261937, r262760, r262799:
Once pf became not covered by a single mutex, many counters in it became
race prone. Some just gather statistics, but some are later used in
different calculations.

A real problem was the race provoked underflow of the states_cur counter
on a rule. Once it goes below zero, it wraps to UINT32_MAX. Later this
value is used in pf_state_expires() and any state created by this rule
is immediately expired.

Thus, make fields states_cur, states_tot and src_nodes of struct
pf_rule be counter(9)s.