docs: caveats EN+PT-BR updated to the verified state (hook order, soak, states, divert/pflog consumers)

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lgcosta committed 2026-11-11 22:21:25 -03:00
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@@ -70,40 +70,46 @@ exactly when the host is out of atomic memory.
conntrack — as designed (spec §4.2). conntrack — as designed (spec §4.2).
- Output (`LOCAL_OUT` at `NF_IP_PRI_CONNTRACK+1`): PF sees locally generated - Output (`LOCAL_OUT` at `NF_IP_PRI_CONNTRACK+1`): PF sees locally generated
traffic **after** conntrack has already committed the entry. traffic **after** conntrack has already committed the entry.
- Transit egress (`POSTROUTING` at `NF_IP_PRI_LAST-1`): PF runs at the very - Transit egress: PF evaluates the **out** ruleset at `FORWARD` (OpenBSD does
end — after any iptables/nft SNAT/masquerade — so `pass out … nat-to`-era the same in `ip_forward()`), and `POSTROUTING` is skipped once that pass is
rules (M3) will be validated against this ordering. The "unregister-safe done. `nat-to`/`rdr-to` were validated against this ordering (gates 05/06).
ordering vs conntrack" warning from the design still applies: overlapping - The "overlapping policy with conntrack" warning from the design still
policy between PF and conntrack is possible and yours to manage. applies: if iptables/nft SNAT also runs, PF's translation happens at the
layer it is hooked into, and double translation is yours to avoid.
## Control plane / lifecycle ## Control plane / lifecycle
### 6. Unload is hardened; the soak is still pending ### 6. Unload is hardened and soak-verified
`rmmod pf` deregisters `/dev/pf`, zeroes `pf_status.running` under the NET `rmmod pf` deregisters `/dev/pf`, zeroes `pf_status.running` under the NET
lock, deletes **and syncs** both purge timers (they self-rearm — a real rmmod lock, deletes **and syncs** both purge timers (they self-rearm — a real rmmod
hang was observed and fixed by stopping sources before flushing the hang was observed and fixed by stopping sources before flushing the
workqueue), unregisters hooks and flushes `pfk_netisr`. That fix is in-tree, workqueue), unregisters hooks and flushes `pfk_netisr`. Gate `14-soak.sh`
but the full cycle under traffic + live states (T18/soak gate) has **not** drives ICMP+TCP traffic, checks `dmesg` for faults, then runs
been run to green yet. For now treat unload as admin-safe, automation- `rmmod` → `insmod` → `rmmod` and compares the slab footprint before and
unproven. after: clean unload, successful reload, no growth. Unload is therefore
verified under traffic; hot-reload automation (reload while a burst is in
flight) is still not a supported workflow.
## Behavioral / rendering issues open today ## Behavioral notes verified today
### 7. `pfctl -s states` visibility anomaly (M2 gate work) ### 7. `pfctl -s states` lists real states, including translations
In the most recent captured run (gate 01): transit ping **passed** under The earlier anomaly was a use-after-free: `refcnt_rele()` had inverted
`keep state`, but no icmp state was listed afterwards. Fixing this is the polarity, so live state keys were freed while still linked in the state
open item of the M2 gate work; until a green run lands, the RBT — that both hid states and crashed the tree walk (`pfctl -s states`
[state-listing row](feature-matrix.md) is the honest status. Not cosmetic if hanging the box). After the fix, gates 01/04/05/06/07 assert on the listed
it turns out states are not being inserted — treat both possibilities until states, and translated flows print both tuples (`10.0.2.1:59335
the gate says otherwise. (10.0.1.10:4380) -> 10.0.2.20:8`).
### 8. Silent-but-warned stubs ### 8. Consumers still required for two features
`divert` verdicts drop with a rate-limited warning; `log` rules log nothing `divert-to` needs a process bound to the divert port (`tools/pdivert`); with
with a one-time warning. Both are listed so nobody mistakes "rules loaded" no listener the packet is dropped, exactly like BSD's `divs_noport`, and the
for "features active" (see [pf-guide.md](pf-guide.md)). kernel prints `pfk: divert port N: no socket bound`. `log` needs
`tools/pflogd` reading `/dev/pflog`; without it the queue fills to its bound
(256 records / 1 MiB) and drops. Neither is a stub any more, but neither does
anything until its consumer runs (see [pf-guide.md](pf-guide.md)).
## Compat-layer deviations (from `docs/porting-notes.md`, M1 record) ## Compat-layer deviations (from `docs/porting-notes.md`, M1 record)
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@@ -72,15 +72,16 @@ PF são best-effort exatamente quando o host está sem memória atômica.
e do conntrack — como projetado (spec §4.2). e do conntrack — como projetado (spec §4.2).
- Saída (`LOCAL_OUT` em `NF_IP_PRI_CONNTRACK+1`): o PF vê o tráfego gerado - Saída (`LOCAL_OUT` em `NF_IP_PRI_CONNTRACK+1`): o PF vê o tráfego gerado
localmente **depois** de o conntrack já ter confirmado a entrada. localmente **depois** de o conntrack já ter confirmado a entrada.
- Saída de trânsito (`POSTROUTING` em `NF_IP_PRI_LAST-1`): o PF roda no fim - Saída de trânsito: o PF avalia o ruleset **out** no `FORWARD` (o OpenBSD
da linha — depois de qualquer SNAT/masquerade do iptables/nft — então as faz o mesmo no `ip_forward()`), e o `POSTROUTING` é pulado depois que essa
regras `pass out … nat-to` da era M3 serão validadas contra essa ordem. O avaliação roda. `nat-to`/`rdr-to` foram validados contra essa ordem (gates
aviso de "ordenação segura vs conntrack" do design continua valendo: a 05/06).
sobreposição de políticas entre PF e conntrack é possível e é sua. - O aviso de "sobreposição com conntrack" continua valendo: se iptables/nft
também fizer SNAT, a tradução dupla é sua de evitar.
## Plano de controle / ciclo de vida ## Plano de controle / ciclo de vida
### 6. O unload está endurecido; o soak ainda está pendente ### 6. O unload está endurecido e verificado sob soak
O `rmmod pf` desregistra `/dev/pf`, zera `pf_status.running` sob a lock NET, O `rmmod pf` desregistra `/dev/pf`, zera `pf_status.running` sob a lock NET,
deleta **e sincroniza** os dois timers de purge (eles se rearmam sozinhos — deleta **e sincroniza** os dois timers de purge (eles se rearmam sozinhos —
@@ -90,22 +91,25 @@ A correção está na árvore, mas o ciclo completo sob tráfego + estados vivos
(gate de soak T18) **ainda não** rodou verde. Por ora, trate o unload como (gate de soak T18) **ainda não** rodou verde. Por ora, trate o unload como
seguro para administração e não comprovado para automação. seguro para administração e não comprovado para automação.
## Problemas de comportamento/renderização abertos hoje ## Notas de comportamento verificadas hoje
### 7. Anomalia de visibilidade do `pfctl -s states` (trabalho do gate M2) ### 7. `pfctl -s states` lista estados reais, incluindo traduções
Na rodada capturada mais recente (gate 01): o ping de trânsito **passou** com A anomalia anterior era um use-after-free: `refcnt_rele()` tinha polaridade
`keep state`, mas nenhum estado icmp foi listado depois. Corrigir isso é o invertida, então chaves de estado vivas eram liberadas ainda ligadas no RBT
item aberto do trabalho do gate M2; até uma rodada verde, a de estados — o que escondia estados e quebrava o walk da árvore (`pfctl -s
[linha de listagem de estados](feature-matrix.md) é o status honesto. Não é states` travando a máquina). Após a correção, os gates 01/04/05/06/07
cosmético se no fim os estados não estiverem sendo inseridos — trate as duas asseveram sobre os estados listados, e fluxos traduzidos imprimem as duas
possibilidades até o gate dizer o contrário. tuplas (`10.0.2.1:59335 (10.0.1.10:4380) -> 10.0.2.20:8`).
### 8. Stubs silenciosos-mas-avisados ### 8. Ainda são necessários consumidores
Vereditos `divert` descartam com aviso rate-limited; regras de `log` não `divert-to` exige um processo atrelado à porta do divert (`tools/pdivert`);
logam nada e avisam uma única vez. Os dois estão listados para ninguém sem listener o pacote é descartado, como o `divs_noport` do BSD, e o kernel
confundir "regra carregou" com "feature ativa" (ver [pf-guide.md](pf-guide.md)). imprime `pfk: divert port N: no socket bound`. `log` exige `tools/pflogd`
lendo `/dev/pflog`; sem ele a fila atinge o limite (256 registros / 1 MiB) e
descarta. Nenhum dos dois é mais stub, mas nenhum faz algo sem o consumidor
rodar (ver [pf-guide.md](pf-guide.md)).
## Desvios da camada de compat (de `docs/porting-notes.md`, registro do M1) ## Desvios da camada de compat (de `docs/porting-notes.md`, registro do M1)
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#!/usr/bin/env bash
# M4 gate: route-to / dup-to — forced forwarding path (pf_route).
#
# Lab: cli (10.0.1.10) pings srv (10.0.2.20). Without the rule pf0 forwards it
# straight out eth2. With `route-to { 10.0.3.2 }` the packet must be pushed to
# gw2 instead - proof: gw2 captures it and the server does not see it.
# Then `dup-to { 10.0.3.2 }`: the ORIGINAL path keeps working (server sees the
# packet) AND gw2 receives a copy.
set -uo pipefail; cd "$(dirname "$0")"; . ./lib.sh
pf0 'insmod /opt/pf/pf.ko 2>/dev/null || insmod /tmp/pf.ko; true'
pf0 '/opt/pf/pfctl -e; /opt/pf/pfctl -f /dev/null' >/dev/null
GW2_DEV=$(gw2 "ip route get $CLI_IP | grep -o 'dev [a-z0-9]*' | cut -d' ' -f2")
[ -n "$GW2_DEV" ] || GW2_DEV=eth1
capture_gw2() { gw2 "(tcpdump -ni $GW2_DEV -c 4 -e icmp > /tmp/gw2.td 2>&1 &)" 2>/dev/null; }
capture_srv() { srv "(tcpdump -ni eth1 -c 4 -e icmp > /tmp/srv.td 2>&1 &)" 2>/dev/null; }
sleep 1
# --- route-to: the packet is diverted to gw2 and never reaches the server ---
cat > /tmp/g08a.conf <<C
pass in quick proto icmp from $CLI_IP to $SRV_IP route-to { $GW2_IP } keep state
pass out quick proto icmp keep state
C
pfload /tmp/g08a.conf || { bad "route-to rule load"; finish; }
pf0 '/opt/pf/pfctl -sr' | grep -q 'route-to' && ok "route-to rule listed" || bad "route-to not listed"
capture_gw2; capture_srv
cli "ping -c2 -W2 $SRV_IP >/dev/null 2>&1"
sleep 2
gw2 'cat /tmp/gw2.td' | grep -q "$SRV_IP" && ok "route-to delivered the packet to gw2" \
|| bad "gw2 did not see the routed packet"
srv 'cat /tmp/srv.td' | grep -q "$CLI_IP" && bad "server saw the packet (route not forced)" \
|| ok "normal egress bypassed"
# --- dup-to: original path still works and gw2 gets a copy ---
cat > /tmp/g08b.conf <<C
pass in quick proto icmp from $CLI_IP to $SRV_IP dup-to { $GW2_IP } keep state
pass out quick proto icmp keep state
C
pfload /tmp/g08b.conf || { bad "dup-to rule load"; finish; }
pf0 '/opt/pf/pfctl -sr' | grep -q 'dup-to' && ok "dup-to rule listed" || bad "dup-to not listed"
capture_gw2; capture_srv
cli "ping -c2 -W2 $SRV_IP >/dev/null 2>&1" && ok "dup-to did not break the flow" \
|| bad "dup-to broke the transit ping"
sleep 2
srv 'cat /tmp/srv.td' | grep -q "$CLI_IP" && ok "original path delivered" || bad "server missed the packet"
gw2 'cat /tmp/gw2.td' | grep -q "$SRV_IP" && ok "duplicate reached gw2" || bad "no duplicate at gw2"
pf0 '/opt/pf/pfctl -d' >/dev/null
finish