Commit Graph

124 Commits

Author SHA1 Message Date
Kristof Provost
4eabfe468b pfctl: Fix clearing rules counters
After the migration to libpfctl for rule retrieval we accidentally lost
support for clearing the rules counters.

Introduce a get_clear variant of pfctl_get_rule() which allows rules
counters to be cleared.

MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29727
2021-04-14 13:33:02 +02:00
Kurosawa Takahiro
2aa21096c7 pf: Implement the NAT source port selection of MAP-E Customer Edge
MAP-E (RFC 7597) requires special care for selecting source ports
in NAT operation on the Customer Edge because a part of bits of the port
numbers are used by the Border Relay to distinguish another side of the
IPv4-over-IPv6 tunnel.

PR:		254577
Reviewed by:	kp
Differential Revision:	https://reviews.freebsd.org/D29468
2021-04-13 10:53:18 +02:00
Kurosawa Takahiro
600bd6ce06 pfctl, libpfctl: introduce pfctl_pool
Introduce pfctl_pool to be able to extend the pool part of the pf rule
without breaking the ABI.

Reviewed by:	kp
MFC after:	4 weeks
Differential Revision:	https://reviews.freebsd.org/D29721
2021-04-12 18:30:29 +02:00
Kristof Provost
ab5707a5cf libpfctl: Fix u_* counters
struct pf_rule had a few counter_u64_t counters. Those couldn't be
usefully comminicated with userspace, so the fields were doubled up in
uint64_t u_* versions.

Now that we use struct pfctl_rule (i.e. a fully userspace version) we
can safely change the structure and remove this wart.

Reviewed by:	glebius
MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29645
2021-04-10 11:16:03 +02:00
Kristof Provost
e9eb09414a libpfctl: Switch to pfctl_rule
Stop using the kernel's struct pf_rule, switch to libpfctl's pfctl_rule.
Now that we use nvlists to communicate with the kernel these structures
can be fully decoupled.

Reviewed by:	glebius
MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29644
2021-04-10 11:16:02 +02:00
Kristof Provost
a9b338b260 pf: Move prototypes for userspace functions to userspace header
These functions no longer exist in the kernel, so there's no reason to
keep the prototypes in a kernel header. Move them to pfctl where they're
actually implemented.

Reviewed by:	glebius
MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29643
2021-04-10 11:16:02 +02:00
Kristof Provost
0d71f9f36e pfctl: Move ioctl abstraction functions into libpfctl
Introduce a library to wrap the pf ioctl interface.

MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29562
2021-04-10 11:16:02 +02:00
Kristof Provost
0d6c8174ef pfctl: Use the new DIOCGETRULENV ioctl
Create wrapper functions to handle the parsing of the nvlist and move
that code into pfctl_ioctl.c.
At some point this should be moved into a libpfctl.

MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29560
2021-04-10 11:16:01 +02:00
Kristof Provost
5c11c5a365 pfctl: Move to DIOCADDRULENV
Start using the new nvlist based ioctl to add rules.

MFC after:	4 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29558
2021-04-10 11:16:01 +02:00
Kristof Provost
b4e3f3c2de pfctl: Add missing 'va' code point name
Add the 'va' (voice-admit, RFC5865) symbolic name.

Reviewed by:	rgrimes, gbe (man page)
MFC after:	2 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D29069
2021-03-06 10:07:55 +01:00
Alex Richardson
58de61b996 sbin/pfctl: fix tests after recent output changes
The output now contains http-alt instead of 8080 and personal-agent
instead of 5555.
This was probably caused by 228e2087a3.

Reviewed By:	kp
Differential Revision: https://reviews.freebsd.org/D28481
2021-02-04 17:56:26 +00:00
Kristof Provost
dcd1e41f0c pfctl: FreeBSD now supports DIOCGIFSPEED
There's no need for a special case here to work around the lack of
DIOCGIFSPEED. That was introduced in FreeBSD in
c1aedfcbd9.

Reported by:	jmg@
Reviewed by:	donner@
Differential Revision:	https://reviews.freebsd.org/D28305
2021-01-25 19:58:22 +01:00
Kristof Provost
0c156a3c32 pfctl: Another set skip <group> fix
When retrieving the list of group members we cannot simply use
ifa_lookup(), because it expects the interface to have an IP (v4 or v6)
address. This means that interfaces with no address are not found.
This presents as interfacing being alternately marked as skip and not
whenever the rules are re-loaded.

Happily we only need to fix ifa_grouplookup(). Teach it to also accept
AF_LINK (i.e. interface) node_hosts.

PR:     	250994
MFC after:	3 days
2021-01-11 22:30:44 +01:00
Kristof Provost
fda7daf063 pfctl: Stop sharing pf_ruleset.c with the kernel
Now that we've split up the datastructures used by the kernel and
userspace there's essentually no more overlap between the pf_ruleset.c
code used by userspace and kernelspace.

Copy the userspace bits to the pfctl directory and stop using the kernel
file.

Reviewed by:	philip
MFC after:	2 weeks
Sponsored by:	Orange Business Services
Differential Revision:	https://reviews.freebsd.org/D27764
2021-01-05 23:35:37 +01:00
Adrian Chadd
d80b9f8d51 [pfctl_tests] Add missing void to empty function declaration
Our gcc-6.4 flags require non-empty function declarations.
Fix this to match the rest of the codebase.

Tested:

* compiled on gcc-6.4 for amd64

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D26795
2020-10-15 14:56:51 +00:00
Alex Richardson
44ec023c17 Rewrite pfctl_test in C to reduce testsuite run time
The new C test takes 25 seconds on QEMU-RISC-V, wheras the shell version
takes 332 seconds.

Even with the latest optimizations to atf-sh this test still takes a few
seconds to startup in QEMU. Re-writing it in C reduces the runtime for a
single test from about 2-3 seconds to less than .5 seconds. Since there
are ~80 tests, this adds up to about 3-4 minutes.
This may not seem like a big speedup, but before the recent optimizations
to avoid atf_get_srcdir, each test took almost 100 seconds on QEMU RISC-V
instead of 3. This also significantly reduces the time it takes to list
the available test cases, which speeds up running the tests via kyua:

```
root@qemu-riscv64-alex:~ # /usr/bin/time kyua test -k /usr/tests/sbin/pfctl/Kyuafile pfctl_test_old
...
158/158 passed (0 failed)
      332.08 real        42.58 user       286.17 sys
root@qemu-riscv64-alex:~ # /usr/bin/time kyua test -k /usr/tests/sbin/pfctl/Kyuafile pfctl_test
158/158 passed (0 failed)
       24.96 real         9.75 user        14.26 sys

root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test pf1001
pfctl_test: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Running pfctl -o none -nvf /usr/tests/sbin/pfctl/./files/pf1001.in
---
binat on em0 inet6 from fc00::/64 to any -> fc00:0:0:1::/64
binat on em0 inet6 from any to fc00:0:0:1::/64 -> fc00::/64
---
passed
        0.17 real         0.06 user         0.08 sys
root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_old pf1001
pfctl_test_old: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test_old: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Id  Refs Name
141    1 pf
Executing command [ pfctl -o none -nvf - ]
passed
        1.73 real         0.25 user         1.41 sys
root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_old -l > /dev/null
       24.36 real         2.26 user        21.86 sys
root@qemu-riscv64-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test -l > /dev/null
        0.04 real         0.02 user         0.01 sys
```

The speedups are even more noticeable on CHERI-RISC-V (since QEMU runs
slower when emulating CHERI instructions):
```
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_new -l > /dev/null
        0.51 real         0.49 user         0.00 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test -l > /dev/null
       34.20 real        32.69 user         0.16 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test pf1001
pfctl_test: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Id  Refs Name
147    1 pf
Executing command [ pfctl -o none -nvf - ]
passed
        5.74 real         5.41 user         0.03 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl # /usr/bin/time ./pfctl_test_new pf1001
pfctl_test_new: WARNING: Running test cases outside of kyua(1) is unsupported
pfctl_test_new: WARNING: No isolation nor timeout control is being applied; you may get unexpected failures; see atf-test-case(4)
Running pfctl -o none -nvf /usr/tests/sbin/pfctl/./files/pf1001.in
---
binat on em0 inet6 from fc00::/64 to any -> fc00:0:0:1::/64
binat on em0 inet6 from any to fc00:0:0:1::/64 -> fc00::/64
---
passed
        0.68 real         0.66 user         0.00 sys
root@qemu-cheri-alex:/usr/tests/sbin/pfctl #
```

Reviewed By:	kp
Differential Revision: https://reviews.freebsd.org/D26779
2020-10-14 17:39:50 +00:00
Alex Richardson
d815e42419 pfctl_test: avoid 200 calls to atf_get_srcdir
I have been trying to reduce the time that testsuite runs take for CheriBSD
on QEMU (currently about 22 hours). One of the slowest tests is pfctl_test:
Just listing the available test cases currently takes 98 seconds on a
CheriBSD RISC-V system due to all the processes being spawned. This trivial
patch reduces the time to 92 seconds. The better solution would be to
rewrite the test in C/C++ which I may do as a follow-up change.

Reviewed By:	kp
Differential Revision: https://reviews.freebsd.org/D26417
2020-09-14 08:51:18 +00:00
Kristof Provost
8fd675d8a0 pfctl: Call ifa_load() before ifa_grouplookup()
ifa_grouplookup() uses the data loaded in ifa_load() (through is_a_group()), so
we must call ifa_load() before we can rely on any of the data it populates.

Submitted by:	Nick Rogers
MFC after:	1 week
Sponsored by:	RG Nets
2020-04-19 15:37:13 +00:00
Kristof Provost
681652667a pfctl: Remove unused variable
Submitted by:	Nick Rogers
MFC after:	1 week
Sponsored by:	RG Nets
2020-04-19 15:32:14 +00:00
Kristof Provost
d2568b024d pfctl: improve rule load times with thousands of interfaces
r343287 / D18759 introduced ifa_add_groups_to_map() which is now run by
ifa_load/ifa_lookup/host_if. When loading an anchor or ruleset via pfctl that
does NOT contain ifnames as hosts, host() still ends up iterating all
interfaces twice, grabbing SIOCGIFGROUP ioctl twice for each. This adds an
unnecessary amount of time on systems with thousands or tens of thousands of
interfaces.

Prioritize the IPv4/6 check over the interface name lookup, which skips loading
the iftab and iterating all interfaces when the configuration does not contain
interface names.

Submitted by:	Nick Rogers
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D24100
2020-03-19 12:54:43 +00:00
Li-Wen Hsu
fe44c67716 Fix test cases after r358448
sbin.pfctl.pfctl_test.pf0087
sbin.pfctl.pfctl_test.selfpf0087

MFC with:	r358448
Sponsored by:	The FreeBSD Foundation
2020-02-29 13:24:41 +00:00
Kristof Provost
3c7fbb06a0 pfctl: Warn users when they run into kernel limits
Warn users when they try to add/delete/modify more items than the kernel will
allow.

Reviewed by:	allanjude (previous version), Lutz Donnerhacke
Differential Revision:	https://reviews.freebsd.org/D22733
2019-12-14 02:03:47 +00:00
Emmanuel Vadot
92fd0827c1 pkgbase: pfctl: tests: Put tests files in the FreeBSD-tests package
Reviewed by:	kp, gjb
Differential Revision:	https://reviews.freebsd.org/D21521
2019-09-05 14:19:06 +00:00
Kristof Provost
7296d6c9bf pfctl: Fix ifgroup check
We cannot just assume that any name which ends with a letter is a group
That's not been true since we allowed renaming of network interfaces. It's also
not true for things like epair0a.

Try to retrieve the group members for the name to check, since we'll get ENOENT
if the group doesn't exist.

MFC after:	1 week
Event:		Aberdeen hackathon 2019
2019-04-19 10:52:54 +00:00
Patrick Kelsey
997667302f Fix the fix added in r343287 for spurious HFSC bandwidth check errors
The logic added in r343287 to avoid false-positive
sum-of-child-bandwidth check errors for HFSC queues has a bug in it
that causes the upperlimit service curve of an HFSC queue to be pulled
down to its parent's linkshare service curve if it happens to be above
it.

Upon further inspection/reflection, this generic
sum-of-child-bandwidths check does not need to be fixed for HFSC - it
needs to be skipped.  For HFSC, the equivalent check is to ensure the
sum of child linkshare service curves are at or below the parent's
linkshare service curve, and this check is already being performed by
eval_pfqueue_hfsc().

This commit reverts the affected parts of r343287 and adds new logic
to skip the generic sum-of-child-bandwidths check for HFSC.

MFC after:	1 day
Sponsored by:	RG Nets
Differential Revision:	https://reviews.freebsd.org/D19124
2019-02-11 22:58:43 +00:00
Kristof Provost
4c8fb952b5 pfctl: Fix ifa_grouplookup()
Setting the length of the request got lost in r343287, which means SIOCGIFGMEMB
gives us the required length, but does not copy the names of the group members.
As a result we don't get a correct list of group members, and 'set skip on
<ifgroup>' broke.

This produced all sorts of very unexpected results, because we would end up
applying 'set skip' to unexpected interfaces.

X-MFC-with:	r343287
2019-02-10 21:22:55 +00:00
Kristof Provost
542feeff96 pfctl: Point users to net.pf.request_maxcount if large requests are rejected
The kernel will reject very large tables to avoid resource exhaustion
attacks. Some users run into this limit with legitimate table
configurations.

The error message in this case was not very clear:

    pf.conf:1: cannot define table nets: Invalid argument
    pfctl: Syntax error in config file: pf rules not loaded

If a table definition fails we now check the request_maxcount sysctl,
and if we've tried to create more than that point the user at
net.pf.request_maxcount:

    pf.conf:1: cannot define table nets: too many elements.
    Consider increasing net.pf.request_maxcount.
    pfctl: Syntax error in config file: pf rules not loaded

PR:		235076
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D18909
2019-01-28 08:36:10 +00:00
Patrick Kelsey
0e4ef871dc Remove unused function gsc_destroy()
gsc_destroy() is no longer needed as of r343287.

MFC after:	1 week
2019-01-22 02:53:59 +00:00
Patrick Kelsey
1d34c9dac8 Reduce pf.conf parsing cost for configs that define N queues from O(N^2) to O(N)
The number of syscalls made during parsing of any config that
defines tables is also reduced, and incorrect warnings that HFSC
parent queue bandwidths were smaller than the sum of their child
bandwidths have been fixed.

Reviewed by:	kp
MFC after:	1 week
Sponsored by:	RG Nets
Differential Revision:	https://reviews.freebsd.org/D18759
2019-01-22 00:50:24 +00:00
Kristof Provost
b1f3ab0051 pfctl: Fix 'set skip' handling for groups
When we skip on a group the kernel will automatically skip on the member
interfaces. We still need to update our own cache though, or we risk
overruling the kernel afterwards.

This manifested as 'set skip' working initially, then not working when
the rules were reloaded.

PR:		229241
MFC after:	1 week
2019-01-13 05:30:26 +00:00
Kristof Provost
0f9e47a9c4 pfctl: Populate ifname in ifa_lookup()
pfctl_adjust_skip_ifaces() relies on this name.

MFC after:	2 weeks
2018-11-08 21:53:09 +00:00
Kristof Provost
c964e17bfe pfctl test: Add a test for macro names with a space in it 2018-10-28 05:50:04 +00:00
Kristof Provost
d3f6532494 pfctl: Do not allow whitespace in macro names
i.e. "this is" = "a variable" is not valid. It was accepted by the
parser, but the variable could not be used afterwards.

Obtained from:	OpenBSD
2018-10-28 05:41:13 +00:00
Kristof Provost
99eb00558a pf: Make ':0' ignore link-local v6 addresses too
When users mark an interface to not use aliases they likely also don't
want to use the link-local v6 address there.

PR:		201695
Submitted by:	Russell Yount <Russell.Yount AT gmail.com>
Differential Revision:	https://reviews.freebsd.org/D17633
2018-10-28 05:32:50 +00:00
Kristof Provost
db2380870c pf tests: Fix incorrect test for PR 231323
Fix r339466.  The test result file did not list the rdr rule.
Additionally, the route-to rule needs a redirection address.

X-MFC-with:	339466
2018-10-22 23:33:48 +00:00
Kristof Provost
4a8e4793ed pfctl: Fix line numbers when \ is used inside ""
PR:		201520
Obtained from:	OpenBSD
MFC after:	2 weeks
2018-10-22 04:12:51 +00:00
Kristof Provost
63488b6e4e pfctl tests: Basic test case for PR 231323
PR:		231323
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D17508
2018-10-20 18:18:28 +00:00
Kristof Provost
a2a90d6ee5 pfctl: Dup strings
When we set the ifname we have to copy the string, rather than just keep
the pointer.

PR:		231323
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D17507
2018-10-20 18:11:46 +00:00
Patrick Kelsey
ef9afde438 Fix warning about crossing INT32_MAX boundary in computation of constant value. 2018-08-23 17:41:39 +00:00
Patrick Kelsey
ff7b3f731a Extend tbrsize heuristic in pfctl(8) to provide a sensible value for
higher bandwidth interfaces.  The new value is used above 2.5 Gbps,
which is the highest standard rate that could be used prior to
r338209, so the default behavior for all existing systems should
remain the same.

The value of 128 chosen is a balance between being big enough to
reduce potential precision/quantization effects stemming from frequent
bucket refills over small time intervals and being small enough to
prevent a greedy driver from burst dequeuing more packets than it has
available hardware ring slots for whenever altq transitions from idle
to backlogged.

Reviewed by:	jmallett, kp
MFC after:	2 weeks
Sponsored by:	RG Nets
Differential Revision: https://reviews.freebsd.org/D16852
2018-08-23 16:10:28 +00:00
Patrick Kelsey
249cc75fd1 Extended pf(4) ioctl interface and pfctl(8) to allow bandwidths of
2^32 bps or greater to be used.  Prior to this, bandwidth parameters
would simply wrap at the 2^32 boundary.  The computations in the HFSC
scheduler and token bucket regulator have been modified to operate
correctly up to at least 100 Gbps.  No other algorithms have been
examined or modified for correct operation above 2^32 bps (some may
have existing computation resolution or overflow issues at rates below
that threshold).  pfctl(8) will now limit non-HFSC bandwidth
parameters to 2^32 - 1 before passing them to the kernel.

The extensions to the pf(4) ioctl interface have been made in a
backwards-compatible way by versioning affected data structures,
supporting all versions in the kernel, and implementing macros that
will cause existing code that consumes that interface to use version 0
without source modifications.  If version 0 consumers of the interface
are used against a new kernel that has had bandwidth parameters of
2^32 or greater configured by updated tools, such bandwidth parameters
will be reported as 2^32 - 1 bps by those old consumers.

All in-tree consumers of the pf(4) interface have been updated.  To
update out-of-tree consumers to the latest version of the interface,
define PFIOC_USE_LATEST ahead of any includes and use the code of
pfctl(8) as a guide for the ioctls of interest.

PR:	211730
Reviewed by:	jmallett, kp, loos
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	RG Nets
Differential Revision:	https://reviews.freebsd.org/D16782
2018-08-22 19:38:48 +00:00
Kristof Provost
cd615bf560 pfctl: Remove unused function
Fix compile issues.

MFC after:	1 week
2018-08-22 08:27:49 +00:00
Kristof Provost
7a831fecc8 pfctl: Improve set skip handling for groups
Rely on the kernel to appropriately mark group members as skipped.
Once a group is skipped we can clear the update flag on all the members.

PR:		229241
Submitted by:	Andreas Longwitz <longwitz AT incore.de>
MFC after:	1 week
2018-08-22 08:14:29 +00:00
Brad Davis
6d76ed56a0 Move pf.os to sbin/pfctl/
Approved by:	will (mentor)
Glanced at by:	kp
Sponsored by:	Essen Hackathon
Differential Revision:	https://reviews.freebsd.org/D16557
2018-08-11 13:58:26 +00:00
Brad Davis
7b821f55bd Convert bsd.files.mk to support DIRS and simplify by only having one install
target.

Also update the pfctl tests Makefile to work with this change.

Approved by:	bapt (mentor)
Differential Revision:	https://reviews.freebsd.org/D16430
2018-07-26 17:05:33 +00:00
Alan Somers
8707733f71 Skip the pftcl(8) tests if pf isn't loaded.
Previously, they would simply fail.

MFC after:	2 weeks
2018-07-22 03:58:01 +00:00
Kristof Provost
7a2bf4c52e pfctl: Don't retrieve interface list if '-n' is set
If '-n' is set we don't use the list of skip interfaces, so don't retrieve it.
This fixes issues if 'pfctl -n' is used before the pf module is loaded. This
was broken by r333181.

Reported by:	Jakub Chromy <hicks AT cgi.cz>
MFC after:	1 week
2018-07-03 08:50:49 +00:00
Sean Bruno
2d0730b243 Assuming that the intent (from the white space) is that the fprintf()
be executed in the if() conditional.  If its not supposed to be printed
inside the conditional, then the braces should be removed and the extra
tabs on the fprintf() should be removed.

Noted by cross compilation with gcc-mips.
2018-06-24 21:19:08 +00:00
Kristof Provost
150182e309 pf: Support "return" statements in passing rules when they fail.
Normally pf rules are expected to do one of two things: pass the traffic or
block it. Blocking can be silent - "drop", or loud - "return", "return-rst",
"return-icmp". Yet there is a 3rd category of traffic passing through pf:
Packets matching a "pass" rule but when applying the rule fails. This happens
when redirection table is empty or when src node or state creation fails. Such
rules always fail silently without notifying the sender.

Allow users to configure this behaviour too, so that pf returns an error packet
in these cases.

PR:		226850
Submitted by:	Kajetan Staszkiewicz <vegeta tuxpowered.net>
MFC after:	1 week
Sponsored by:	InnoGames GmbH
2018-06-22 21:59:30 +00:00
Kristof Provost
fa1d4439f9 pf: Return non-zero from 'status' if pf is not enabled
In the pf rc.d script the output of `/etc/rc.d/pf status` or `/etc/rc.d/pf
onestatus` always provided an exit status of zero. This made it fiddly to
programmatically determine if pf was running or not.

Return a non-zero status if the pf module is not loaded, extend pfctl to have
an option to return an error status if pf is not enabled.

PR:		228632
Submitted by:	James Park-Watt <jimmypw AT gmail.com>
MFC after:	1 week
2018-06-06 19:36:37 +00:00