npfctl: remove no-op NOLINT definition

Setting NOLINT must be done before including <bsd.own.mk> to have an
effect.

Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

libnpf fix: link the library itself to libnv; libnpf users should not be
expected to assume this dependency.

branches: 1.13.2;
NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.12.14; 1.12.16;
remove libcrypto dependency, fix other dependencies.

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

put in /sbin

Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

branches: 1.7.2;
npfctl(8): add show-config command. Also, update syntax.

Add a small disassembler.

branches: 1.5.2;
Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

branches: 1.4.4;
Fix sun2 builds. Noted by joerg@.

NPF checkpoint:
- Add libnpf(3) - a library to control NPF (configuration, ruleset, etc).
- Add NPF support for ftp-proxy(8).
- Add rc.d script for NPF.
- Convert npfctl(8) to use libnpf(3) and thus make it less depressive.
Note: next clean-up step should be a parser, once dholland@ will finish it.
- Add more documentation.
- Various fixes.

branches: 1.2.2;
Move npf.conf(5-8) into the correct section, hence npf.conf(5).

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

npf.conf.5: various grammar, spelling, formatting tweaks

Layer 2 filtering man

One line, one sentence.

npf.conf.5: bump date to reflect recent material changes

npf.conf.5: minor style consistency tweaks

user/group filtering manuel

PR/58116: Attaulah: Allow comments inside lists in npf.conf

branches: 1.91.8;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

Use -width Pa for FILES.

libnpf/npfctl: support dynamic NAT rulesets using a name prefix.

branches: 1.88.2;
New sentence, new line. Avoid formatting punctuation. Remove superfluous Pp.

NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

Improve wording.

npf.conf(5): Add more info about ifaddrs().

Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

Actually, according to the grammar the square brackets in the "tcp
flags" are not literal, so use .Op to show that /mask is optional.

Restore macro with effect. Fix the real problem that prevented it to
have the effect.

New sentence, new line. Punctuation fixes. Remove macros without effect.

npf.conf(5): add a minor clarification about table types that can't
accept masks on IP addresses. Prompted by Rob Hunter in PR bin/51900.

According to the grammar and examples the static table is defined with
"file" keyword, not "static".

Improve markup.

Wrap long lines, so that nothing overflows.

Switch back to tabs, it was nicer this way.

Fix the "Interfaces" section, I understood wrong. Talk about inference,
because it was not mentioned before, and it plays an important role.
Discussed with rmind. Probably not the last pass.

New sentence, new line. Use Fn for functions.

Be clearer about the difference between static vs dynamic interface list,
and slightly improve wording.

My understanding is that when none of inet4/inet6/ifaddrs is passed, NPF
assumes ifaddrs.

Remove superfluous Pp.

npf.conf(5): fix some of the previous incorrect or inaccurate changes.
The TCP flags option is not only for the stateful tracking. Dynamic NAT
implies NAPT; algorithms, at least for now, are for static NAT mappings.
Mention that ALG ICMP is also for traceroute behind NAT; also mention
"MSS clamping" (some users might search for this term, so keeping the
terminology is helpful).

rename net-seg -> map-seg, and document it

"interface" already contains "var-name", so don't mention it in "filt-addr",
that's redundant

should be port-opts

Clarify the "Groups" section.

Add missing -width; remove unnecessary .Pp.

Improve the "Map" section.

Document ALGs.

Add the values of "algo" in the grammar, and use # as comment marker for
man-k.org (and others) not to highlight things in an incorrect way.

Add missing quote in static-rule, it causes man-k.org (and other tools)
to wrongly highlight the grammar.

Replace "rproc"->"proc" in the grammar (spotted by he@), and slightly
reword.

Replace () by [] in tcp-flags.

Fix proc-opts, the value is optional, noted by he@.

Improve wording.

Improve the "Map" section a little.

Document the "flags" keyword.

Improve the "Rules" section: better explain the "final" keyword (it is
the same as PF's "quick", so use the same wording), and document the
"return" options.

While here simplify the man code, suggested by wiz.

Add quotes around the option names, to match the actual npf conf.

Enlighten the "Procedures" section. In particular document the "no-df"
option. Also replace "normalisation" -> "normalization", to match the
name of the rule.

Add missing El. Remove trailing whitespace.

First pass at editing this manual.
Add a link to the NPF documentation website and refer to it.
Switch the multiple structural elements to a list to make it easier to read and
extend.
Clarify tables, re-order so all terms are before the example.
Clarify obtaining addresses per family
Move the minimum requirement for a default group to the group section.

branches: 1.51.2; 1.51.4;
Remove superfluous Pp.

npfctl: add support for the 'no-ports' flag in the 'map' statements.
This allows us to create a NAT policy without the port translation.

Remove workaround for ancient HTML generation code.

branches: 1.48.4;
Bump date for previous.

npfctl:
- Add protocol filter option for "map".
- Print user-friendly error if table contains an entry with invalid netmask.
- Add support for inline ports.

branches: 1.46.2;
npfctl: dynamic interface address handling; update npf.conf(8).

npf.conf: add support for logical NOT, e.g.: pass from ! 10.0.0.1 to any

branches: 1.44.2;
npf.conf(5): mention alg, include in the example, minor fix.

allow turning off the bpf jit loading.

branches: 1.42.2;
Cross-link npf(7).

Wording, typo fixes.

NPF: imply SYN-only check for the stateful rules by default (when inspecting
TCP packets). Many users trip here. This behaviour can be overriden with the
explicit "flags" keyword, but other configuration does not really make sense.

branches: 1.39.2;
Document NAT algorithm option in the grammar of "map".

NPF:
- Adjust the syntax - remove "inet" keyword in favour of more explicit
"inet4" for the address family. Consistent with "inet6" for IPv6.
- Adjust and improve the man page a little bit.

Update count. Add serial comma.

Add support for CDB based NPF tables.

Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

Remove trailing whitespace.

NPF: add support for table naming and remove NPF_TABLE_SLOTS (there is
just an arbitrary sanity limit of NPF_MAX_TABLES currently set to 128).

Few misc fixes. Bump NPF_VERSION.

sync an example with the latest group syntax change

- NPF: change the group/ruleset syntax - simplify. Update npf.conf(5) manual.
- Add support for the inline pcap-filter(7) syntax in the rule, e.g.:
block out final pcap-filter "tcp and dst 10.1.1.252"

npfctl: remove some n-code leftovers, fix the build, update the man pages.

normalise -> normalize

Fix the example (deja vu?).

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

- Add NPF version check in proplist as well, not only ioctl. Bump the version.
- Fix a bug in table entry lookup.
- Updates/fixes to the man pages. Misc.

- npf.conf(5): fix of the example config.
- Mention npf_ext_log in a comment.

npfctl: extend syntax for extracting interface IP address(es) by the family.

Wording, more macros.

Add some content to the Procedures section.

Use more markup. New sentence, new line.

Add some content to the "Rules" section.

Whitespace fixes, remove unnecessary Pp
XXX: Subsections Rules and Procedures seem empty?

npf.conf(5): add syntax section and a first cut describing the structural
elements. Some improvements and fixes from spz@.

re-work the description part of the man page, as discussed with rmind@

npf.conf(5): improve and explain grammar definition.

branches: 1.15.2;
- npfctl show: add most of the missing cases.
- Few minor improvements to NPF man pages.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

Fix and update npf.conf(5), npfctl(8) and its usage message.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

Remove superfluous Pp

npfctl(8): add show-config command. Also, update syntax.

branches: 1.9.2;
Fix the family option in the grammar and example.

- Handle NPF rule procedures in the parser and thus re-enable them.
- Few small updates to the man page.

update.

Remove quotes from "hash" and "tree" in the table examples so
the example stands a chance of actually working as written. There appear
to be other problems, too.

branches: 1.5.4;
Use .Ss for non-standard subtitles in the DESCRIPTION.

NPF checkpoint:
- Add libnpf(3) - a library to control NPF (configuration, ruleset, etc).
- Add NPF support for ftp-proxy(8).
- Add rc.d script for NPF.
- Convert npfctl(8) to use libnpf(3) and thus make it less depressive.
Note: next clean-up step should be a parser, once dholland@ will finish it.
- Add more documentation.
- Various fixes.

branches: 1.3.2;
NPF checkpoint:
- Add the concept of rule procedure: separate normalization, logging and
potentially other functions from the rule structure. Rule procedure can be
shared amongst the rules. Separation is both at kernel level (npf_rproc_t)
and configuration ("procedure" + "apply").
- Fix portmap sharing for NAT policy.
- Update TCP state tracking logic. Use TCP FSM definitions.
- Add if_byindex(), OK by matt@. Use in logging for the lookup.
- Fix traceroute ALG and many other bugs; misc clean-up.

NPF checkpoint:
- Add support for bi-directional NAT and redirection / port forwarding.
- Finish filtering on ICMP type/code and add filtering on TCP flags.
- Add support for TCP reset (RST) or ICMP destination unreachable on block.
- Fix a bunch of bugs; misc cleanup.

Move npf.conf(5-8) into the correct section, hence npf.conf(5).

Move npf.conf(5-8) into the correct section, hence npf.conf(5).

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

Add more test to layer2 filtering for variables as a set

simplify the BPF code for multiword
we have tests to cover all possible cases in layer2 filtering

userland code for layer 2 filtering in NPF

reviewed by christos@

npfctl(8): Fix compiling multiword comparisons, i.e., IPv6 addrs.

PR bin/55403: npfctl miscompiles IPv6 rules

branches: 1.16.6; 1.16.8;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

- npfctl_load_nvlist: simplify the config loading logic.
- Fix a small race condition in npf_nat_getaddr().
- Rework pserialize/EBR wrappers, make it easier to maintain.

NPF: fix BPF byte-code generation for a port-range used in a group.
Resolved PR/52609 and PR/54169.

branches: 1.13.2;
NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

Summary: Ensure default TCP flags are applied to rules like 'pass stateful all'

The documented default "flags S/SAFR" for stateful rules that affect
TCP packets but don't specify any flags, doesn't actually get applied
to a rule like "pass stateful out all". The big problem with this is
that when you then do a "block return-rst" for an incoming packet, the
generated RST packet will create state for the connection attempt it's
blocking, so that a second attempt from the same source will pass.

This change makes the default flags actually apply to such simple
rules. It also fixes a related bug in the code generation for the
flag matching, where part of the action could erroneously be omitted.

Reviewed by <rmind>
Closes PR bin/54124
Pullup to NetBSD 8

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.10.6; 1.10.12; 1.10.14;
npf.conf: add support for logical NOT, e.g.: pass from ! 10.0.0.1 to any

Sync NPF with the version on github: backport standalone NPF changes,
which allow us to create and run separate NPF instances. Minor fixes.
(from rmind@)

branches: 1.8.2;
- npfctl: fix the confusion in the parser (0/0 case with no other filter).
- Always populate the error dictionary, not only for DEBUG/DIAGNOSTIC.

branches: 1.7.2; 1.7.4;
NPF:
- Populate the BPF external memory store with L3 information.
- Eliminate NPF_COP_L3 call and just use the data in the memstore.
- Bump NPF_VERSION.

npfctl_build_code: generate TCP/UDP check for ports case when other blocks
do not imply L4 check; add an assert in npfctl_bpf_proto() and elsewhere.

branches: 1.5.2;
NPF: imply SYN-only check for the stateful rules by default (when inspecting
TCP packets). Many users trip here. This behaviour can be overriden with the
explicit "flags" keyword, but other configuration does not really make sense.

branches: 1.4.2;
npfctl_bpf_cidr: another buf fix in handling IPv6 masks (bug found on ARM).

npfctl_bpf_cidr: fix a bug in handling of smaller IPv6 masks.

npfctl: optimise fetch_l3() to avoid unnecessary call to NPF_COP_L3.

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

enclose NPF_VAR_ID case in braces to fix linter build

PR bin/59511

when extracting variables for filtering in NPF, allow the handler to
recursively extract all variables that might be present in the parent variable
to fully get all the filter elements present in them. this issue poses a security risk
as intruders can find their way into your machine if you intend to block them
but have their IPs in a nested variable with other IPs as well.

so this needs to be pulled up to 9, 10, 11


this fix has been reviewed by christos@ and martin@ and tests have been included.

pcap rules don't pass filter options. Provide default filter opts
(layer 3 for compat with previous behaviour) to prevent npfctl from
crashing.

PR bin/59581

set layer bit in dynamic rule attributes
effectively use it when listing either layer 2 or 3 rules

This fixes it
pullup-11

branches: 1.59.2;
userland code for layer 2 filtering in NPF

reviewed by christos@

NPF copyright 2025

Userland: npf rule parser for user and group id

branches: 1.56.2;
npfctl: adapt to new libpcap API

Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

Backport selected NPF fixes from the upstream (to be pulled up):

- npf_conndb_lookup: protect the connection lookup with pserialize(9),
instead of incorrectly assuming that the handler always runs at IPL_SOFNET.
Should fix crashes reported on high load (PR/55182).

- npf_config_destroy: handle partially initialized config; fixes crashes
with some invalid configurations.

- NAT policy creation / destruction: set the initial reference and do not
wait for reference draining on destruction; destroy the policy on the
last reference drop instead. Fixes a lockup with the dynamic NAT rules.

- npf_nat_{export,import}: fix a regression since dynamic NAT rules.

- npfctl: fix a regression and restore the default group behaviour.

- Add npf_cache_tcp() and validate the TCP data offset (from maxv@).

libnpf/npfctl: support dynamic NAT rulesets using a name prefix.

npfctl: implement table replace subcommand.
Contributed by Timshel Knoll-Miller.

(missed a file in previous commit; cvs is so helpful..)

NPF: fix BPF byte-code generation for a port-range used in a group.
Resolved PR/52609 and PR/54169.

branches: 1.50.2;
npfctl: fix the bpf.jit parameter handling.

NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

Summary: Ensure default TCP flags are applied to rules like 'pass stateful all'

The documented default "flags S/SAFR" for stateful rules that affect
TCP packets but don't specify any flags, doesn't actually get applied
to a rule like "pass stateful out all". The big problem with this is
that when you then do a "block return-rst" for an incoming packet, the
generated RST packet will create state for the connection attempt it's
blocking, so that a second attempt from the same source will pass.

This change makes the default flags actually apply to such simple
rules. It also fixes a related bug in the code generation for the
flag matching, where part of the action could erroneously be omitted.

Reviewed by <rmind>
Closes PR bin/54124
Pullup to NetBSD 8

Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.45.2; 1.45.4;
npfctl: add support for the 'no-ports' flag in the 'map' statements.
This allows us to create a NAT policy without the port translation.

branches: 1.44.4;
npfctl:
- Add protocol filter option for "map".
- Print user-friendly error if table contains an entry with invalid netmask.
- Add support for inline ports.

branches: 1.43.2;
npfctl: dynamic interface address handling; update npf.conf(8).

npf.conf: add support for logical NOT, e.g.: pass from ! 10.0.0.1 to any

Sync NPF with the version on github: backport standalone NPF changes,
which allow us to create and run separate NPF instances. Minor fixes.
(from rmind@)

branches: 1.40.2;
- npfctl: fix the confusion in the parser (0/0 case with no other filter).
- Always populate the error dictionary, not only for DEBUG/DIAGNOSTIC.

npfctl:
- Fix the filter criteria when to/from is omitted but port used.
- Print more user-friendly error if an NPF table has a duplicate entry.

branches: 1.38.2;
npfctl_build_code: generate TCP/UDP check for ports case when other blocks
do not imply L4 check; add an assert in npfctl_bpf_proto() and elsewhere.

NPF: imply SYN-only check for the stateful rules by default (when inspecting
TCP packets). Many users trip here. This behaviour can be overriden with the
explicit "flags" keyword, but other configuration does not really make sense.

branches: 1.36.2;
NPF: add support for IPv6-to-IPv6 Network Prefix Translation (NPTv6),
as per RFC 6296. Add a unit test. Also, bump NPF_VERSION.

Thanks to S.P.Zeidler for the help with NPTv6 work!

NPF: add support for static (stateless) NAT.

fix vax build.

Add support for CDB based NPF tables.

- npfctl: fix table IDs (breakage since the table naming was added).
- libnpf: remove npf_table_exists_p() from public API.

Add npf_tableset_syncdict() to sync the table IDs in the proplib dictionary,
as they can change on reload now. Also, fix table name checking in npfctl.

Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

NPF: add support for table naming and remove NPF_TABLE_SLOTS (there is
just an arbitrary sanity limit of NPF_MAX_TABLES currently set to 128).

Few misc fixes. Bump NPF_VERSION.

NPF: add support for specifying the interfaces before they are attached.
If an interface is or gets detached, all associated rules and connections
will be deactivated (it might be useful to have an option to invalidate
the associated connections). Once the interface is reattached they will
become active.

Bump NPF_VERSION.

- NPF: change the group/ruleset syntax - simplify. Update npf.conf(5) manual.
- Add support for the inline pcap-filter(7) syntax in the rule, e.g.:
block out final pcap-filter "tcp and dst 10.1.1.252"

npfctl: remove some n-code leftovers, fix the build, update the man pages.

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

- Add NPF table flushing functionality.
- Fix line numbering for npfctl debug command.

Make ALG's autoloadable by providing in the config file:
alg "algname"

- Extend npf.conf syntax to support dynamic NAT policies.
- Imply dynamic group when using "ruleset" keyword.

- Convert NPF dynamic rule ID to just incremented 64-bit counter.
- Fix multiple bugs. Also, update the man page.

Allow filtering on IP addresses even if the L4 protocol is unknown.
Patch from spz@.

- Fix NPF config reload with dynamic rules present.
- Implement list and flush commands on a dynamic ruleset.

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

- Add NPF version check in proplist as well, not only ioctl. Bump the version.
- Fix a bug in table entry lookup.
- Updates/fixes to the man pages. Misc.

npfctl: add 'validate' command to check the config, but not load it. Update
the man page. Also add a small note about 'debug' command, PR/47298.

npfctl: extend syntax for extracting interface IP address(es) by the family.

Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

branches: 1.13.2;
- Extend npftest: add ruleset inspection testing from the config generated
by npfctl debug functionality. Auto-create npftest interfaces for this.
- NPF sessions: combine protocol and interface into a separate substructure,
share between the entries and thus fix the handling of them. Constify.
- npftest: add regression tests for NAT policies.
- npf_build_nat: simplify and fix bi-NAT regression.
- Bump yacc stack size for npfctl.

teach npf ipv6-icmp
reviewed by rmind@

- Rework NPF tables and fix support for IPv6. Implement tree table type
using radix / Patricia tree. Universal IPv4/IPv6 comparator for ptree(3)
was contributed by Matt Thomas.
- NPF tables: update regression tests, improve npfctl(8) error messages.
- Fix few bugs when using kernel modules and handle module autounloader.
- Few other fixes and misc cleanups.
- Bump the version.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

remove error(1) output

make this compile again.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

branches: 1.6.2;
- make each element of a variable hold a type
- change get_type to take an index, so we can get the individual types of
each element (since primitive elements can be in lists)
- make port_range primitive
- add a routine to convert a variable of primitives to a variable containing
- only port ranges.

- Add NPF_DECISION_BLOCK and NPF_DECISION_PASS. Be more defensive in the
packet handler. Change the default policy to block when the config is
loaded and set it to pass when flush operation is performed.
- Use kmem_zalloc(9) instead of kmem_alloc(9) in few places.
- npf_rproc_{create,release}: use kmem_intr_{alloc,free} as the destruction
of rule procedure might happen in the interrupt handler (under a very rare
condition, if config reload races with the handler).
- npf_session_establish: check whether layer 3 and 4 are cached.
- npfctl_build_group: do not make groups as passing rules.
- Remove some unecessary header inclusion.

branches: 1.4.2;
- Handle NPF rule procedures in the parser and thus re-enable them.
- Few small updates to the man page.

Multiple NPF fixes, add better error reporting from kernel side, add some
asserts, bump the version.

- Expire all sessions on flush.
- Enable checking for zero mask in IP{4,6}MATCH after npfctl changes.
- Make locking symmetric for npf_ruleset_inspect().
- Sync function prototypes in npf(3) man page with reality.
- Rename NPF_TABLE_RBTREE to NPF_TABLE_TREE.

Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

branches: 1.1.2;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

userland code for layer 2 filtering in NPF

reviewed by christos@

Fix open-coded npfvar_expand_number() copy to assume the same size for
NPFVAR_NUM variables.

NPF copyright 2025

Userland: npf rule parser for user and group id

branches: 1.30.12;
Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.28.10; 1.28.12;
npfctl:
- Add protocol filter option for "map".
- Print user-friendly error if table contains an entry with invalid netmask.
- Add support for inline ports.

branches: 1.27.2;
npf.conf: add support for logical NOT, e.g.: pass from ! 10.0.0.1 to any

Sync NPF with the version on github: backport standalone NPF changes,
which allow us to create and run separate NPF instances. Minor fixes.
(from rmind@)

branches: 1.25.8;
NPF: add support for IPv6-to-IPv6 Network Prefix Translation (NPTv6),
as per RFC 6296. Add a unit test. Also, bump NPF_VERSION.

Thanks to S.P.Zeidler for the help with NPTv6 work!

- npfctl: fix table IDs (breakage since the table naming was added).
- libnpf: remove npf_table_exists_p() from public API.

Add npf_tableset_syncdict() to sync the table IDs in the proplib dictionary,
as they can change on reload now. Also, fix table name checking in npfctl.

Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

NPF: add support for specifying the interfaces before they are attached.
If an interface is or gets detached, all associated rules and connections
will be deactivated (it might be useful to have an option to invalidate
the associated connections). Once the interface is reattached they will
become active.

Bump NPF_VERSION.

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

npfctl: extend syntax for extracting interface IP address(es) by the family.

branches: 1.18.2;
- Extend npftest: add ruleset inspection testing from the config generated
by npfctl debug functionality. Auto-create npftest interfaces for this.
- NPF sessions: combine protocol and interface into a separate substructure,
share between the entries and thus fix the handling of them. Constify.
- npftest: add regression tests for NAT policies.
- npf_build_nat: simplify and fix bi-NAT regression.
- Bump yacc stack size for npfctl.

- npfctl_print_stats: beautification a la French style.
- npfctl_icmpcode: fix the build break.

teach npf ipv6-icmp
reviewed by rmind@

- Rework NPF tables and fix support for IPv6. Implement tree table type
using radix / Patricia tree. Universal IPv4/IPv6 comparator for ptree(3)
was contributed by Matt Thomas.
- NPF tables: update regression tests, improve npfctl(8) error messages.
- Fix few bugs when using kernel modules and handle module autounloader.
- Few other fixes and misc cleanups.
- Bump the version.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

npfctl(8): add show-config command. Also, update syntax.

- make each element of a variable hold a type
- change get_type to take an index, so we can get the individual types of
each element (since primitive elements can be in lists)
- make port_range primitive
- add a routine to convert a variable of primitives to a variable containing
- only port ranges.

branches: 1.10.2;
Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

freeaddrinfo() only on getaddrinfo() success.

Add IPv6 support for NPF.

branches: 1.7.4;
NPF checkpoint:
- Add libnpf(3) - a library to control NPF (configuration, ruleset, etc).
- Add NPF support for ftp-proxy(8).
- Add rc.d script for NPF.
- Convert npfctl(8) to use libnpf(3) and thus make it less depressive.
Note: next clean-up step should be a parser, once dholland@ will finish it.
- Add more documentation.
- Various fixes.

branches: 1.6.2;
NPF checkpoint:
- Add the concept of rule procedure: separate normalization, logging and
potentially other functions from the rule structure. Rule procedure can be
shared amongst the rules. Separation is both at kernel level (npf_rproc_t)
and configuration ("procedure" + "apply").
- Fix portmap sharing for NAT policy.
- Update TCP state tracking logic. Use TCP FSM definitions.
- Add if_byindex(), OK by matt@. Use in logging for the lookup.
- Fix traceroute ALG and many other bugs; misc clean-up.

NPF checkpoint:
- Add support for session saving/restoring.
- Add packet logging support (can tcpdump a pseudo-interface).
- Support reload without flushing of sessions; rework some locking.
- Revisit session mangement, replace linking with npf_sentry_t entries.
- Add some counters for statistics, using percpu(9).
- Add IP_DF flag cleansing.
- Fix various bugs; misc clean-up.

NPF checkpoint:
- Add proper TCP state tracking as described in Guido van Rooij paper,
plus handle TCP Window Scaling option.
- Completely rework npf_cache_t, reduce granularity, simplify code.
- Add npf_addr_t as an abstraction, amend session handling code, as well
as NAT code et al, to use it. Now design is prepared for IPv6 support.
- Handle IPv4 fragments i.e. perform packet reassembly.
- Add support for IPv4 ID randomization and minimum TTL enforcement.
- Add support for TCP MSS "clamping".
- Random bits for IPv6. Various fixes and clean-up.

NPF checkpoint:
- Add support for bi-directional NAT and redirection / port forwarding.
- Finish filtering on ICMP type/code and add filtering on TCP flags.
- Add support for TCP reset (RST) or ICMP destination unreachable on block.
- Fix a bunch of bugs; misc cleanup.

fix build failure -- correct printf sizes

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

NPF: G/C n-code in favour of BPF byte-code. Delete lots of code, mmm!

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

- Convert NPF dynamic rule ID to just incremented 64-bit counter.
- Fix multiple bugs. Also, update the man page.

- Fix NPF config reload with dynamic rules present.
- Implement list and flush commands on a dynamic ruleset.

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

IPv6 linklocal address printing cosmetics

npfctl: add 'validate' command to check the config, but not load it. Update
the man page. Also add a small note about 'debug' command, PR/47298.

npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

Implement NPF table listing and preservation of entries on reload.
Bump the version.

branches: 1.9.2;
- npfctl show: add most of the missing cases.
- Few minor improvements to NPF man pages.

teach npf ipv6-icmp
reviewed by rmind@

- Rework NPF tables and fix support for IPv6. Implement tree table type
using radix / Patricia tree. Universal IPv4/IPv6 comparator for ptree(3)
was contributed by Matt Thomas.
- NPF tables: update regression tests, improve npfctl(8) error messages.
- Fix few bugs when using kernel modules and handle module autounloader.
- Few other fixes and misc cleanups.
- Bump the version.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

npfctl(8): add show-config command. Also, update syntax.

branches: 1.3.2; 1.3.4;
don't leak the branch target array.

- better printing of type/code flags/mask
- pass the instruction start pointer, instead of subtracting 1 to account for it

Add a small disassembler.

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.4.28; 1.4.30;
modules moved to /lib

branches: 1.3.2; 1.3.4;
npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

branches: 1.1.2;
Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

NPF: G/C n-code in favour of BPF byte-code. Delete lots of code, mmm!

npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

branches: 1.13.2;
teach npf ipv6-icmp
reviewed by rmind@

- Rework NPF tables and fix support for IPv6. Implement tree table type
using radix / Patricia tree. Universal IPv4/IPv6 comparator for ptree(3)
was contributed by Matt Thomas.
- NPF tables: update regression tests, improve npfctl(8) error messages.
- Fix few bugs when using kernel modules and handle module autounloader.
- Few other fixes and misc cleanups.
- Bump the version.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

npfctl(8): add show-config command. Also, update syntax.

Add a small disassembler.

branches: 1.7.2;
npfctl_ncgen_putptr: use correct format for size_t.

Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

Add IPv6 support for NPF.

branches: 1.4.6;
NPF checkpoint:
- Add support for session saving/restoring.
- Add packet logging support (can tcpdump a pseudo-interface).
- Support reload without flushing of sessions; rework some locking.
- Revisit session mangement, replace linking with npf_sentry_t entries.
- Add some counters for statistics, using percpu(9).
- Add IP_DF flag cleansing.
- Fix various bugs; misc clean-up.

NPF checkpoint:
- Add proper TCP state tracking as described in Guido van Rooij paper,
plus handle TCP Window Scaling option.
- Completely rework npf_cache_t, reduce granularity, simplify code.
- Add npf_addr_t as an abstraction, amend session handling code, as well
as NAT code et al, to use it. Now design is prepared for IPv6 support.
- Handle IPv4 fragments i.e. perform packet reassembly.
- Add support for IPv4 ID randomization and minimum TTL enforcement.
- Add support for TCP MSS "clamping".
- Random bits for IPv6. Various fixes and clean-up.

NPF checkpoint:
- Add support for bi-directional NAT and redirection / port forwarding.
- Finish filtering on ICMP type/code and add filtering on TCP flags.
- Add support for TCP reset (RST) or ICMP destination unreachable on block.
- Fix a bunch of bugs; misc cleanup.

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

Fix various typos, mainly in comments.

define op tokens to kill warnings

userland code for layer 2 filtering in NPF

reviewed by christos@

NPF variables of type NPFVAR_NUM are only ever retrieved as
uint32_t values in npfvar_expand_number(). It makes no sense
to store them as unsigned long values (sizeof(yylval.num))
internally.

Besides the code in npfvar_expand_number() did not properly retrieve
values if sizeof(unsigned long) > sizeof(uint32_t), e.g. on sparc64
it picked the wrong 4 bytes and always returned 0.

So use uint32_t to create the value, saving memory and fixing a bug.

NPF copyright 2025

Userland: npf rule parser for user and group id

notify us when we use undefined port variable

PR/58116: Attaulah: Allow comments inside lists in npf.conf

branches: 1.51.8;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

libnpf/npfctl: support dynamic NAT rulesets using a name prefix.

branches: 1.49.2;
NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.46.2; 1.46.4;
npfctl: add support for the 'no-ports' flag in the 'map' statements.
This allows us to create a NAT policy without the port translation.

allow PASS opt_proto ALL syntax in map statement.

npfctl: fix shift/reduce conflicts, thanks to riastradh@.

Add missing ; - hopefully unbreak build.

npfctl:
- Add protocol filter option for "map".
- Print user-friendly error if table contains an entry with invalid netmask.
- Add support for inline ports.

branches: 1.41.2;
Don't silently take the first element of multiple element variables.

npfctl: dynamic interface address handling; update npf.conf(8).

npf.conf: add support for logical NOT, e.g.: pass from ! 10.0.0.1 to any

branches: 1.38.2;
allow lists as filter addresses.

Don't depend on yacc to include stdlib.h or string.h.

allow turning off the bpf jit loading.

branches: 1.35.4;
Convert right-recursive rules to left-recursive ones.

This should obviate the need for the workaround of a large stack in
order to handle many rules.

No change in the resulting plists.

ok rmind

NPF: add support for "stateful-ends".

npfctl: take into account all addresses when multiple interfaces are
specified in a set of elements.

NPF: add support for IPv6-to-IPv6 Network Prefix Translation (NPTv6),
as per RFC 6296. Add a unit test. Also, bump NPF_VERSION.

Thanks to S.P.Zeidler for the help with NPTv6 work!

NPF:
- Adjust the syntax - remove "inet" keyword in favour of more explicit
"inet4" for the address family. Consistent with "inet6" for IPv6.
- Adjust and improve the man page a little bit.

Add support for CDB based NPF tables.

Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

Rename some tokens, use more accurate names (the current ones are incorrect
or missleading) and add few comments in the parser code.

NPF: add support for specifying the interfaces before they are attached.
If an interface is or gets detached, all associated rules and connections
will be deactivated (it might be useful to have an option to invalidate
the associated connections). Once the interface is reattached they will
become active.

Bump NPF_VERSION.

- NPF: change the group/ruleset syntax - simplify. Update npf.conf(5) manual.
- Add support for the inline pcap-filter(7) syntax in the rule, e.g.:
block out final pcap-filter "tcp and dst 10.1.1.252"

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

- Add NPF table flushing functionality.
- Fix line numbering for npfctl debug command.

always allow hex where decimal is allowed.

Make ALG's autoloadable by providing in the config file:
alg "algname"

- Extend npf.conf syntax to support dynamic NAT policies.
- Imply dynamic group when using "ruleset" keyword.

handle port "ftp-data"

deal with strings as interfaces

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

npfctl: extend syntax for extracting interface IP address(es) by the family.

npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

npfctl/yyerror(): print the right line number if we already parsed the line.

Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

branches: 1.12.2;
- Extend npftest: add ruleset inspection testing from the config generated
by npfctl debug functionality. Auto-create npftest interfaces for this.
- NPF sessions: combine protocol and interface into a separate substructure,
share between the entries and thus fix the handling of them. Constify.
- npftest: add regression tests for NAT policies.
- npf_build_nat: simplify and fix bi-NAT regression.
- Bump yacc stack size for npfctl.

teach npf ipv6-icmp
reviewed by rmind@

- Rework NPF tables and fix support for IPv6. Implement tree table type
using radix / Patricia tree. Universal IPv4/IPv6 comparator for ptree(3)
was contributed by Matt Thomas.
- NPF tables: update regression tests, improve npfctl(8) error messages.
- Fix few bugs when using kernel modules and handle module autounloader.
- Few other fixes and misc cleanups.
- Bump the version.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

npfctl(8): add show-config command. Also, update syntax.

branches: 1.6.2;
remove extra rule that got merged...

- make each element of a variable hold a type
- change get_type to take an index, so we can get the individual types of
each element (since primitive elements can be in lists)
- make port_range primitive
- add a routine to convert a variable of primitives to a variable containing
- only port ranges.

Simplify slightly: merge iface into addr_or_iface, use it in filt_addr.

branches: 1.3.2;
- Expire all sessions on flush.
- Enable checking for zero mask in IP{4,6}MATCH after npfctl changes.
- Make locking symmetric for npf_ruleset_inspect().
- Sync function prototypes in npf(3) man page with reality.
- Rename NPF_TABLE_RBTREE to NPF_TABLE_TREE.

handle variables that contain variables

Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

Add IPv6 support for NPF.

branches: 1.6.4;
NPF checkpoint:
- Add libnpf(3) - a library to control NPF (configuration, ruleset, etc).
- Add NPF support for ftp-proxy(8).
- Add rc.d script for NPF.
- Convert npfctl(8) to use libnpf(3) and thus make it less depressive.
Note: next clean-up step should be a parser, once dholland@ will finish it.
- Add more documentation.
- Various fixes.

branches: 1.5.2;
NPF checkpoint:
- Add the concept of rule procedure: separate normalization, logging and
potentially other functions from the rule structure. Rule procedure can be
shared amongst the rules. Separation is both at kernel level (npf_rproc_t)
and configuration ("procedure" + "apply").
- Fix portmap sharing for NAT policy.
- Update TCP state tracking logic. Use TCP FSM definitions.
- Add if_byindex(), OK by matt@. Use in logging for the lookup.
- Fix traceroute ALG and many other bugs; misc clean-up.

NPF checkpoint:
- Add support for session saving/restoring.
- Add packet logging support (can tcpdump a pseudo-interface).
- Support reload without flushing of sessions; rework some locking.
- Revisit session mangement, replace linking with npf_sentry_t entries.
- Add some counters for statistics, using percpu(9).
- Add IP_DF flag cleansing.
- Fix various bugs; misc clean-up.

NPF checkpoint:
- Add proper TCP state tracking as described in Guido van Rooij paper,
plus handle TCP Window Scaling option.
- Completely rework npf_cache_t, reduce granularity, simplify code.
- Add npf_addr_t as an abstraction, amend session handling code, as well
as NAT code et al, to use it. Now design is prepared for IPv6 support.
- Handle IPv4 fragments i.e. perform packet reassembly.
- Add support for IPv4 ID randomization and minimum TTL enforcement.
- Add support for TCP MSS "clamping".
- Random bits for IPv6. Various fixes and clean-up.

NPF checkpoint:
- Add support for bi-directional NAT and redirection / port forwarding.
- Finish filtering on ICMP type/code and add filtering on TCP flags.
- Add support for TCP reset (RST) or ICMP destination unreachable on block.
- Fix a bunch of bugs; misc cleanup.

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

Temporarily remove dash and dot separated MAC address rule in scanner.

this avoids breaking existing configurations where spaceless port ranges are used
as the parser tries to resolve the MAC address rules instead.

Also, add a simple test for port ranges in the NPF rump test suite

@Greg Troxel

userland code for layer 2 filtering in NPF

reviewed by christos@

NPF copyright 2025

Userland: npf rule parser for user and group id

PR/58116: Attaulah: Allow comments inside lists in npf.conf

branches: 1.32.8;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

PR/55288: npfctl: change parameter syntax to be more permissive.

libnpf/npfctl: support dynamic NAT rulesets using a name prefix.

branches: 1.29.2;
NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.26.2; 1.26.4;
npfctl: add support for the 'no-ports' flag in the 'map' statements.
This allows us to create a NAT policy without the port translation.

npfctl: dynamic interface address handling; update npf.conf(8).

npf.conf: add support for logical NOT, e.g.: pass from ! 10.0.0.1 to any

branches: 1.23.2;
handle v4 mapped addresses

allow turning off the bpf jit loading.

branches: 1.21.2;
npfctl: allow group of zeroes in IPv6 address; noted by spz@.

branches: 1.20.2;
NPF: add support for "stateful-ends".

NPF: add support for IPv6-to-IPv6 Network Prefix Translation (NPTv6),
as per RFC 6296. Add a unit test. Also, bump NPF_VERSION.

Thanks to S.P.Zeidler for the help with NPTv6 work!

NPF:
- Adjust the syntax - remove "inet" keyword in favour of more explicit
"inet4" for the address family. Consistent with "inet6" for IPv6.
- Adjust and improve the man page a little bit.

Add support for CDB based NPF tables.

Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

Rename some tokens, use more accurate names (the current ones are incorrect
or missleading) and add few comments in the parser code.

NPF: add support for table naming and remove NPF_TABLE_SLOTS (there is
just an arbitrary sanity limit of NPF_MAX_TABLES currently set to 128).

Few misc fixes. Bump NPF_VERSION.

- NPF: change the group/ruleset syntax - simplify. Update npf.conf(5) manual.
- Add support for the inline pcap-filter(7) syntax in the rule, e.g.:
block out final pcap-filter "tcp and dst 10.1.1.252"

Make ALG's autoloadable by providing in the config file:
alg "algname"

- Extend npf.conf syntax to support dynamic NAT policies.
- Imply dynamic group when using "ruleset" keyword.

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

npfctl: extend syntax for extracting interface IP address(es) by the family.

npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

branches: 1.5.2;
teach npf ipv6-icmp
reviewed by rmind@

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

npfctl(8): add show-config command. Also, update syntax.

branches: 1.1.2; 1.1.4;
Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

fix missing attribute for NAT in npfctl show/validate

it can now rightfully fetch the layer3 bit and use it to print rightly

userland code for layer 2 filtering in NPF

reviewed by christos@

NPF copyright 2025

npfctl: show user/group in retrieved rule

Collect compiler marks for decompilation.
Fixes PR 58884

branches: 1.33.2;
fix RCSIDs.

Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

Backport selected NPF fixes from the upstream (to be pulled up):

- npf_conndb_lookup: protect the connection lookup with pserialize(9),
instead of incorrectly assuming that the handler always runs at IPL_SOFNET.
Should fix crashes reported on high load (PR/55182).

- npf_config_destroy: handle partially initialized config; fixes crashes
with some invalid configurations.

- NAT policy creation / destruction: set the initial reference and do not
wait for reference draining on destruction; destroy the policy on the
last reference drop instead. Fixes a lockup with the dynamic NAT rules.

- npf_nat_{export,import}: fix a regression since dynamic NAT rules.

- npfctl: fix a regression and restore the default group behaviour.

- Add npf_cache_tcp() and validate the TCP data offset (from maxv@).

PR/54670: Azuma OKAMOTO: Consistently use 'W' for TH_CWN, and bump buffer
size.

npfctl show/validate: fix couple bugs in multiple table/port representation.
Fixes PR/54122.

branches: 1.28.2;
NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.25.2; 1.25.4;
npfctl: add support for the 'no-ports' flag in the 'map' statements.
This allows us to create a NAT policy without the port translation.

don't print decimal and parse hex!

branches: 1.23.2;
Always print the rule id associated with a rule.

branches: 1.22.2;
Improve 'npfctl debug' a little bit.

Add a list command to iterate over connection and nat endpoints.

Sync NPF with the version on github: backport standalone NPF changes,
which allow us to create and run separate NPF instances. Minor fixes.
(from rmind@)

branches: 1.19.2;
npfctl: fix the from/to port mess up when showing the rules.

npfctl:
- Fix the filter criteria when to/from is omitted but port used.
- Print more user-friendly error if an NPF table has a duplicate entry.

npfctl_print_rule: print the ID in hex, not decimal.

npfctl(8): report dynamic rule ID in a comment, print the case when libpcap
is used correctly. Also, add npf_ruleset_dump() helper in the kernel.

branches: 1.15.2; 1.15.4;
formatting

npfctl_build_code: generate TCP/UDP check for ports case when other blocks
do not imply L4 check; add an assert in npfctl_bpf_proto() and elsewhere.

branches: 1.13.2; 1.13.4;
NPF: add support for "stateful-ends".

npfctl_print_nat: fix the byte-order of the port.

npfctl_print_table: add a "cdb" type.

NPF:
- Adjust the syntax - remove "inet" keyword in favour of more explicit
"inet4" for the address family. Consistent with "inet6" for IPv6.
- Adjust and improve the man page a little bit.

NPF: add support for static (stateless) NAT.

npfctl: need to rewind the list after calling print_table(). XXX libnpf.

Add npf_tableset_syncdict() to sync the table IDs in the proplib dictionary,
as they can change on reload now. Also, fix table name checking in npfctl.

CID 1129614: dereference after null

Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

NPF: add support for table naming and remove NPF_TABLE_SLOTS (there is
just an arbitrary sanity limit of NPF_MAX_TABLES currently set to 128).

Few misc fixes. Bump NPF_VERSION.

NPF: add support for specifying the interfaces before they are attached.
If an interface is or gets detached, all associated rules and connections
will be deactivated (it might be useful to have an option to invalidate
the associated connections). Once the interface is reattached they will
become active.

Bump NPF_VERSION.

- NPF: change the group/ruleset syntax - simplify. Update npf.conf(5) manual.
- Add support for the inline pcap-filter(7) syntax in the rule, e.g.:
block out final pcap-filter "tcp and dst 10.1.1.252"

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

PR bin/59511

when extracting variables for filtering in NPF, allow the handler to
recursively extract all variables that might be present in the parent variable
to fully get all the filter elements present in them. this issue poses a security risk
as intruders can find their way into your machine if you intend to block them
but have their IPs in a nested variable with other IPs as well.

so this needs to be pulled up to 9, 10, 11


this fix has been reviewed by christos@ and martin@ and tests have been included.

NPF copyright 2025

Userland: npf rule parser for user and group id

branches: 1.13.8;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

branches: 1.12.2;
Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.10.12; 1.10.14;
Don't silently take the first element of multiple element variables.

branches: 1.9.2;
- npfvar_get_type1: check for NULL first.
- Minor fix for the npf(7) man page.

branches: 1.8.4;
Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

branches: 1.5.2;
npfctl(8): add show-config command. Also, update syntax.

branches: 1.4.2;
- make each element of a variable hold a type
- change get_type to take an index, so we can get the individual types of
each element (since primitive elements can be in lists)
- make port_range primitive
- add a routine to convert a variable of primitives to a variable containing
- only port ranges.

branches: 1.3.2;
- Expire all sessions on flush.
- Enable checking for zero mask in IP{4,6}MATCH after npfctl changes.
- Make locking symmetric for npf_ruleset_inspect().
- Sync function prototypes in npf(3) man page with reality.
- Rename NPF_TABLE_RBTREE to NPF_TABLE_TREE.

handle variables that contain variables

Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

PR bin/59511

when extracting variables for filtering in NPF, allow the handler to
recursively extract all variables that might be present in the parent variable
to fully get all the filter elements present in them. this issue poses a security risk
as intruders can find their way into your machine if you intend to block them
but have their IPs in a nested variable with other IPs as well.

so this needs to be pulled up to 9, 10, 11


this fix has been reviewed by christos@ and martin@ and tests have been included.

userland code for layer 2 filtering in NPF

reviewed by christos@

NPF copyright 2025

Userland: npf rule parser for user and group id

branches: 1.10.8;
Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

branches: 1.9.2;
NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.8.24; 1.8.26;
Simplify parsing of npf.conf elements, create the npfvar_t when a value is
parsed (to be used as a general structured for variables and inlined values),
few misc improvements.

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

npfctl: extend syntax for extracting interface IP address(es) by the family.

Fix for npfctl show case. Improve some description while here.

Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

branches: 1.3.2;
teach npf ipv6-icmp
reviewed by rmind@

branches: 1.2.2;
- make each element of a variable hold a type
- change get_type to take an index, so we can get the individual types of
each element (since primitive elements can be in lists)
- make port_range primitive
- add a routine to convert a variable of primitives to a variable containing
- only port ranges.

branches: 1.1.2;
Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

Use -width Pa for FILES.

Fix pasto in table replace -t type

npfctl: implement table replace subcommand.
Contributed by Timshel Knoll-Miller.

branches: 1.21.2;
Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

branches: 1.20.2; 1.20.4;
npfctl: add support for the 'no-ports' flag in the 'map' statements.
This allows us to create a NAT policy without the port translation.

Document list

branches: 1.18.2;
Fix typo. From Michael Scherer in PR 51162.

Cross-link npf(7).

NPF: rework of the connection saving and restoring:
- Add support for saving a snapshot of the current connections together
with a full configuration. Support a reverse load operation. Eliminate
the old 'sess-save' and 'sess-load' in favour of the new mechanism.
- Share code between load and reload operations: the latter performs
load from npf.conf without affecting the connections.
- Simplify and fix races with connection loading.
- Bump NPF_VERSION.

branches: 1.15.2;
Remove trailing whitespace.

npfctl: remove some n-code leftovers, fix the build, update the man pages.

- Convert NPF dynamic rule ID to just incremented 64-bit counter.
- Fix multiple bugs. Also, update the man page.

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

npfctl: add 'validate' command to check the config, but not load it. Update
the man page. Also add a small note about 'debug' command, PR/47298.

npfctl(8): mention table listing.

branches: 1.9.2;
- npfctl show: add most of the missing cases.
- Few minor improvements to NPF man pages.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

Fix and update npf.conf(5), npfctl(8) and its usage message.

branches: 1.6.4; 1.6.6;
As per request from the author, put non-standard PERFORMANCE back.

Use 'offset indent' for the list of commands. Emphasize valid commands.
Remove PERFORMANCE (too small paragraph to warrant a section).

NPF checkpoint:
- Add the concept of rule procedure: separate normalization, logging and
potentially other functions from the rule structure. Rule procedure can be
shared amongst the rules. Separation is both at kernel level (npf_rproc_t)
and configuration ("procedure" + "apply").
- Fix portmap sharing for NAT policy.
- Update TCP state tracking logic. Use TCP FSM definitions.
- Add if_byindex(), OK by matt@. Use in logging for the lookup.
- Fix traceroute ALG and many other bugs; misc clean-up.

Fix remaining references for npf.conf(8) to npf.conf(5)

Move npf.conf(5-8) into the correct section, hence npf.conf(5).

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

userland code for layer 2 filtering in NPF

reviewed by christos@

NPF copyright 2025

branches: 1.65.4;
PR/56307: Konrad Schroder: npfctl's error messages don't report the failing
filename.
Add the filename (but in quotes for consistency with other places in the file).
Also fix an err -> errx

Major NPF improvements (merge from upstream):

- Switch to the C11-style atomic primitives using atomic_loadstore(9).

- npfkern: introduce the 'state.key.interface' and 'state.key.direction'
settings. Users can now choose whether the connection state should be
strictly per-interface or global at the configuration level. Keep NAT
logic to be always per-interface, though.

- npfkern: rewrite the G/C worker logic and make it self-tuning.

- npfkern and libnpf: multiple bug fixes; add param exporting; introduce
more parameters. Remove npf_nvlist_{copyin,copyout}() functions and
refactor npfctl_load_nvlist() with others; add npfctl_run_op() to have
a single entry point for operations. Introduce npf_flow_t and clean up
some code.

- npfctl: lots of fixes for the 'npfctl show' logic; make 'npfctl list'
more informative; misc usability improvements and more user-friendly
error messages.

- Amend and improve the manual pages.

libnpf/npfctl: support dynamic NAT rulesets using a name prefix.

npfctl: implement table replace subcommand.
Contributed by Timshel Knoll-Miller.

- npftest: fix a memleak in a unit test (standalone path only).
- Minor style fixes. No functional change.

branches: 1.60.2;
npfctl: fix the bpf.jit parameter handling.

NPF improvements:
- Add support for dynamic NETMAP algorithm (stateful net-to-net).
- Add most of the support for the dynamic NAT rules; a little bit more
userland work is needed to finish this up and enable.
- Replace 'stateful-ends' with more permissive 'stateful-all'.
- Add various tunable parameters and document them, see npf-params(7).
- Reduce the memory usage of the connection state table (conndb).
- Portmap rewrite: use memory more efficiently, handle addresses dynamically.
- Bug fix: add splsoftnet()/splx() around the thmap writers and comment.
- npftest: clean up and simplify; fix some memleaks to make ASAN happy.

- add or adjust /* FALLTHROUGH */ where appropriate
- add __unreachable() after functions that can return but won't in
this case, and thus can't be marked __dead easily

Major NPF improvements:
- Convert NPF connection table to thmap. State lookup is now lock-free.
- Improve connection state G/C: it is now incremental and tunable.
- Add support for dynamic NAT address. Translation addresses can now be
selected from a pool of addresses. There are two selection algorithms,
"ip-hash" and "round-robin" (see the man page).
- Translation address can be specified as e.g. ifaddrs(wm0) in npf.conf
to dynamically choose an IP from the interface address(es).
- Add support for the NETMAP algorithm with static NAT for net-to-net
translation (it is equivalent to iptables NETMAP logic).
- Convert 'ipset' tables to use thmap; the table lookup is now lock-free.
- Misc improvements, bug fixes and more unit tests.
- Bump NPF_VERSION (will also bump libnpf).

NPF: Major rework -- migrate NPF to the libnv library.
- This conversion significantly simplifies the code and moves NPF to
a binary serialisation format (replacing the XML-like format).
- Fix some memory/reference leaks and possibly use-after-free bugs.
- Bump NPF_VERSION as this change makes libnpf incompatible with the
previous versions. Also, different serialisation format means NPF
connection/config saving and loading is not compatible with the
previous versions either.

Thanks to christos@ for extra testing.

branches: 1.55.2;
Document "debug" in usage().

branches: 1.54.2;
Fix showing translated port (ntohs-ed twice wrongly)

branches: 1.53.6;
fix hint.

Improve 'npfctl debug' a little bit.

Sort options in usage.

Add a list command to iterate over connection and nat endpoints.

We don't use openssl for NPF in NetBSD, so don't include the header, and
provide a compatibility define.

Sync NPF with the version on github: backport standalone NPF changes,
which allow us to create and run separate NPF instances. Minor fixes.
(from rmind@)

branches: 1.47.2;
use sha1 from libc

load the config file before bpfjit so that we can disable the warning.

allow turning off the bpf jit loading.

npfctl(8): attempt to preload bpfjit kernel module and print the
warning on failure.

- Add and use npf_alg_export().
- npf_conn_import: handle NAT metadata correctly.
- npf_nat_newpolicy: restore the policy ID.
- npfctl_load: fix error code handling for the limit cases.
- npf_config_import: fix the inverted logic.
- npfctl_load: improve error handling.

branches: 1.42.2;
Build fix (use error when defined).

NPF: rework of the connection saving and restoring:
- Add support for saving a snapshot of the current connections together
with a full configuration. Support a reverse load operation. Eliminate
the old 'sess-save' and 'sess-load' in favour of the new mechanism.
- Share code between load and reload operations: the latter performs
load from npf.conf without affecting the connections.
- Simplify and fix races with connection loading.
- Bump NPF_VERSION.

branches: 1.40.2;
NPF: add support for table naming and remove NPF_TABLE_SLOTS (there is
just an arbitrary sanity limit of NPF_MAX_TABLES currently set to 128).

Few misc fixes. Bump NPF_VERSION.

npfctl: remove some n-code leftovers, fix the build, update the man pages.

- Convert NPF to use BPF byte-code by default. Compile BPF byte-code in
npfctl(8) and generate separate marks to describe the filter criteria.
- Rewrite 'npfctl show' functionality and fix some of the bugs.
- npftest: add a test for BPF COP.
- Bump NPF_VERSION.

- Add NPF table flushing functionality.
- Fix line numbering for npfctl debug command.

- Extend npf.conf syntax to support dynamic NAT policies.
- Imply dynamic group when using "ruleset" keyword.

separate sess commands.

remove dup usage.

fix usage

centralize error handling and print what went wrong instead of "ioctl"

- Convert NPF dynamic rule ID to just incremented 64-bit counter.
- Fix multiple bugs. Also, update the man page.

- Fix NPF config reload with dynamic rules present.
- Implement list and flush commands on a dynamic ruleset.

NPF:
- Implement dynamic NPF rules. Controlled through npf(3) library of via
npfctl rule command. A rule can be removed using a unique identifier,
returned on addition, or using a key which is SHA1 hash of the rule.
Adjust npftest and add a regression test.
- Improvements to rule inspection mechanism.
- Initial BPF support as an alternative to n-code.
- Minor fixes; bump the version.

IPv6 linklocal address printing cosmetics

- Rework NPF's nbuf interface: use advancing and ensuring as a main method.
Eliminate unnecessary copy and simplify. Adapt regression tests.
- Simplify ICMP ALG a little. While here, handle ICMP ECHO for traceroute.
- Minor fixes, misc cleanup.

- Add NPF version check in proplist as well, not only ioctl. Bump the version.
- Fix a bug in table entry lookup.
- Updates/fixes to the man pages. Misc.

npfctl: add 'validate' command to check the config, but not load it. Update
the man page. Also add a small note about 'debug' command, PR/47298.

npfctl: switch to ecalloc(3).

npfctl: switch to efun(3) routines.

gcc 4.1 is not smart enough to notice "arg" is only used when initialized
correctly and produces a "might be used unintialized" warning.

Implement NPF table listing and preservation of entries on reload.
Bump the version.

Implement dynamic NPF extensions interface. An extension consists of
dynamically loaded module (.so) supplementing npfctl(8) and a kernel
module. Move normalisation and logging functionality into their own
extensions. More improvements to come.

branches: 1.19.2;
npfctl usage: minor formatting fix.

- Extend npftest: add ruleset inspection testing from the config generated
by npfctl debug functionality. Auto-create npftest interfaces for this.
- NPF sessions: combine protocol and interface into a separate substructure,
share between the entries and thus fix the handling of them. Constify.
- npftest: add regression tests for NAT policies.
- npf_build_nat: simplify and fix bi-NAT regression.
- Bump yacc stack size for npfctl.

- npfctl_print_stats: beautification a la French style.
- npfctl_icmpcode: fix the build break.

Add missing __dead.

- Rework NPF tables and fix support for IPv6. Implement tree table type
using radix / Patricia tree. Universal IPv4/IPv6 comparator for ptree(3)
was contributed by Matt Thomas.
- NPF tables: update regression tests, improve npfctl(8) error messages.
- Fix few bugs when using kernel modules and handle module autounloader.
- Few other fixes and misc cleanups.
- Bump the version.

NPF improvements:
- Add NPF_OPCODE_PROTO to match the address and/or protocol only.
- Update parser to support arbitrary "pass proto <name/number>".
- Fix IPv6 address and protocol handling (add a regression test).
- Fix few theorethical races in session handling module.
- Misc fixes, simplifications and some clean up.

Fix and update npf.conf(5), npfctl(8) and its usage message.

- Rework NPF NAT syntax to be more structured and support future additions
of different types and configurations of NAT.
- npfctl: improve disassemble and show-config command functionality.
- Fix custom ICMP code and type filtering.

npfctl(8): add show-config command. Also, update syntax.

branches: 1.10.2;
Multiple NPF fixes, add better error reporting from kernel side, add some
asserts, bump the version.

- Expire all sessions on flush.
- Enable checking for zero mask in IP{4,6}MATCH after npfctl changes.
- Make locking symmetric for npf_ruleset_inspect().
- Sync function prototypes in npf(3) man page with reality.
- Rename NPF_TABLE_RBTREE to NPF_TABLE_TREE.

Full rewrite of npfctl(8) parser and rework of n-code generation part.
Fixes most of the known bugs and issues with the utility. Note: rule
procedures are not yet (as we want to make them fully modular).

Huge thanks to Martin Husemann who wrote the parser and Christos Zoulas
who wrote intermediate structures and helped to complete the work.

Add IPv6 support for NPF.

branches: 1.6.2;
Use __dead

NPF checkpoint:
- Add libnpf(3) - a library to control NPF (configuration, ruleset, etc).
- Add NPF support for ftp-proxy(8).
- Add rc.d script for NPF.
- Convert npfctl(8) to use libnpf(3) and thus make it less depressive.
Note: next clean-up step should be a parser, once dholland@ will finish it.
- Add more documentation.
- Various fixes.

branches: 1.4.2;
NPF checkpoint:
- Add the concept of rule procedure: separate normalization, logging and
potentially other functions from the rule structure. Rule procedure can be
shared amongst the rules. Separation is both at kernel level (npf_rproc_t)
and configuration ("procedure" + "apply").
- Fix portmap sharing for NAT policy.
- Update TCP state tracking logic. Use TCP FSM definitions.
- Add if_byindex(), OK by matt@. Use in logging for the lookup.
- Fix traceroute ALG and many other bugs; misc clean-up.

NPF checkpoint:
- Add support for session saving/restoring.
- Add packet logging support (can tcpdump a pseudo-interface).
- Support reload without flushing of sessions; rework some locking.
- Revisit session mangement, replace linking with npf_sentry_t entries.
- Add some counters for statistics, using percpu(9).
- Add IP_DF flag cleansing.
- Fix various bugs; misc clean-up.

NPF checkpoint:
- Add proper TCP state tracking as described in Guido van Rooij paper,
plus handle TCP Window Scaling option.
- Completely rework npf_cache_t, reduce granularity, simplify code.
- Add npf_addr_t as an abstraction, amend session handling code, as well
as NAT code et al, to use it. Now design is prepared for IPv6 support.
- Handle IPv4 fragments i.e. perform packet reassembly.
- Add support for IPv4 ID randomization and minimum TTL enforcement.
- Add support for TCP MSS "clamping".
- Random bits for IPv6. Various fixes and clean-up.

Import NPF - a packet filter. Some features:

- Designed to be fully MP-safe and highly efficient.

- Tables/IP sets (hash or red-black tree) for high performance lookups.

- Stateful filtering and Network Address Port Translation (NAPT).
Framework for application level gateways (ALGs).

- Packet inspection engine called n-code processor - inspired by BPF -
supporting generic RISC-like and specific CISC-like instructions for
common patterns (e.g. IPv4 address matching). See npf_ncode(9) manual.

- Convenient userland utility npfctl(8) with npf.conf(8).

NOTE: This is not yet a fully capable alternative to PF or IPFilter.
Further work (support for binat/rdr, return-rst/return-icmp, common ALGs,
state saving/restoring, logging, etc) is in progress.

Thanks a lot to Matt Thomas for various useful comments and code review.
Aye by: board@

userland code for layer 2 filtering in NPF

reviewed by christos@

NPF copyright 2025

Userland: npf rule parser for user and group id