84 lines
4.3 KiB
Markdown
84 lines
4.3 KiB
Markdown
# PF on Linux
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Port of the OpenBSD **PF** (packet filter) to **Linux 7.3.4** as an
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out-of-tree kernel module — the real PF engine (`pf.c`, `pf_norm.c`,
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`pf_table.c`, `pf_lb.c`, … ported from OpenBSD 8.0 sources) driven by the
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real OpenBSD `pfctl` over the `/dev/pf` ioctl ABI. (A second module for the
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`pfq` qdisc arrives with M5.)
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**Status:** early milestones. The engine port and control plane (M1) are
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working; the M2 filter core is being gated in the VM lab; everything later
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is pending. Honest per-feature status:
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[`docs/en/feature-matrix.md`](docs/en/feature-matrix.md).
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Design: [`docs/superpowers/specs/2026-11-11-pf-linux-port-design.md`](docs/superpowers/specs/2026-11-11-pf-linux-port-design.md)
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· plan: [`docs/superpowers/plans/2026-11-11-pf-linux-port.md`](docs/superpowers/plans/2026-11-11-pf-linux-port.md).
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## Milestones
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| Milestone | Scope | Status (2026-11-11) |
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|---|---|---|
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| M0 | repo, scripts, kernel build, VM boots the custom kernel | done |
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| M1 | compat layer, `pf.ko` loads, `/dev/pf`, `pfctl -f` / `-s info` | done |
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| M2 | filter core: rules/states/tables/anchors, VM gates 01–04 | **in progress** — data path implemented, gates not all green yet |
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| M3 | NAT (nat/rdr/binat), scrub e2e, pflog | pending |
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| M4 | route-to/dup-to/fail-to, divert e2e | pending |
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| M5 | queues: HFSC/FQ-CoDel back ends + `pfq` qdisc | pending |
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| M6 | docs complete, patchset tidy, full suite green, tagged release | in progress (docs) |
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## What you get (planned)
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| Area | Feature |
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|---|---|
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| Filtering | rules, anchors, quick, `match`/`block`(drop/return/return-rst)/`pass`, `keep state`, syncookies |
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| State/Tables | stateful firewall engine, `pfr` tables (radix + hash, `pfctl -t`) |
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| NAT | `nat-to` (port pools, sticky-port, static-port), `rdr-to`, `binat-to` |
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| Scrub | fragment reassembly, overlap drop, `min-ttl`/`max-mss`/`df`/`no-df`, `set reassemble` |
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| QoS (ALTQ successor) | `queue`/`queue on` with OpenBSD 8.0 `ifq` schedulers: **default (priq), HFSC, FQ-CoDel**, attached via the `pfq` qdisc; `pfctl -s queue -v` stats |
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| Divert | `divert-to` / `divert` tag + `pdivert` relay over an in-module `PF_DIVERT` socket family (pending — see `docs/en/feature-matrix.md`) |
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| Route | `route-to` (pools rr/hash-source/hash-state, `fail-to`), `reply-to`, `dup-to` |
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| Logging | `pflogd` via netlink pflog channel (DLT_PFLOG pcap) |
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| Control | `/dev/pf` (0600), OpenBSD 8.0 ioctl ABI, Linux build of `pfctl` (single binary) |
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Not in scope: `pfsync`/CARP failover, IPsec/pfkey, `ftp-proxy`, per-netns PF
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instances, classic-ALTQ-only schedulers (cbq/wfq/red — removed upstream before
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OpenBSD 8.0).
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## Quick start
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Full recipe: [`docs/en/install.md`](docs/en/install.md). Short version
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(commands are read from the scripts; a fresh-clone end-to-end run is still
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pending):
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```sh
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./scripts/fetch-sources.sh # OpenBSD 8.0 sources (C3SL mirror, sha256-pinned)
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./scripts/vendorize.sh # stage the pristine files we port
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./scripts/build-kernel.sh # kernel 7.3.4: bzImage + modules_prepare (export patch: none needed)
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./scripts/build-module.sh # -> module/pf.ko
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make -C tools # -> tools/out/pfctl (static), ABI harness
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sudo insmod module/pf.ko # /dev/pf (0600) + netfilter hooks
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sudo pfctl -f /etc/pf.conf && sudo pfctl -e
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```
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Read [`docs/en/pf-guide.md`](docs/en/pf-guide.md) **before** enabling PF on a
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path you need: only the M2 filter core is gated today; NAT/scrub/queues/
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divert/pflog are not usable yet ([`docs/en/feature-matrix.md`](docs/en/feature-matrix.md)).
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VM validation lab (Alpine on libvirt): [`docs/en/vm-lab.md`](docs/en/vm-lab.md).
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Documentação em português: [`README.pt-BR.md`](README.pt-BR.md) e
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[`docs/pt-BR/`](docs/pt-BR/README.md).
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## Layout
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- `module/` — kernel sources (ported PF + compat layer; the `pfq` qdisc lands with M5)
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- `tools/` — pfctl (static Linux build), pdivert relay source, ABI harness (`pflogd` not ported yet)
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- `patches/kernel/` — Linux core patch set (currently empty; evidence in `p1-needs.txt`, see `docs/en/patches.md`)
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- `scripts/` — fetch/build/patch/VM automation
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- `tests/` — VM suite (`tests/vm/NN-*.sh`, scapy helpers)
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- `docs/en/` + `docs/pt-BR/` — full bilingual documentation
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- `docs/superpowers/` — design spec + implementation plan
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## License
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Ported OpenBSD code retains its original [ISC license and copyright notices](LICENSE).
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New Linux-side code: ISC.
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