feat: log-tailer offset persistence + in-flight L2 rate-limit accounting (code-review.md § Phase 3)

- logtail: persist the read position (offset + fingerprint of the log's
  first 512 bytes) in a new logtail_state table (migration 0003) and
  resume from it on start, so delivery lines written while the panel was
  down are parsed instead of skipped and their send-log rows no longer
  stay "queued" forever. Fingerprint mismatch (rotated/recreated while
  down) reads the file from the start — re-parsing is idempotent; a
  first-ever start with nothing stored still begins at end-of-file.
  Writes are throttled to one per 5s, forced on rotation and shutdown.

- milter: count messages that passed the level-2 check but have not
  reached the send log yet (internal/milter/inflight.go), so concurrent
  SMTP sessions cannot each spend the same last slot. A literal
  count+insert transaction, as the review suggested, is not possible:
  the count happens at MAIL FROM and the insert at end-of-message.
  Reservations are released after the insert, on ABORT, and after a
  10-minute TTL — a client that drops mid-transaction must not be able
  to hold a slot, since the limiter is fail-open by design.

Docs: architecture.md (log tailer, persistence, L2 counting),
security.md and roadmap.md (restart gap closed, container recreate
remains), CHANGELOG, progress.md, code-review.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
2026-08-06 17:12:37 +03:00
parent 0093878eea
commit a92d583053
15 changed files with 683 additions and 40 deletions
+17
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@@ -5,6 +5,23 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); version
## [Unreleased]
### Fixed
- Log-tailer resumes where it stopped instead of jumping to end-of-file on
every start (phase 3, `docs/code-review.md`): the read position and a
fingerprint of the log's head are persisted (`logtail_state`, migration
`0003`), so delivery lines written while the panel was down are parsed and
their send-log rows no longer stay `queued` forever. A log that changed
identity while the panel was down is read from the start; a first-ever start,
with nothing stored, still begins at the end. Container recreate remains a
gap — `mail.log` is not in `/data` (`docs/security.md`).
- Level-2 rate limit no longer overshoots under concurrency: messages that
passed the check at MAIL FROM but have not reached the send log yet are
counted alongside the stored rows (`internal/milter/inflight.go`), so
parallel SMTP sessions cannot each spend the same last slot. Slots are
released at end-of-message, on ABORT, and after a 10-minute TTL, so a client
that drops mid-transaction cannot hold one — the limiter stays fail-open.
### Changed
- Phase 1 doc/code hygiene (`docs/code-review.md`): removed ~30 stale
+20 -8
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@@ -81,7 +81,11 @@ One process, three roles:
proxy only.
2. **journal-milter** — unix socket `JOURNAL_MILTER_SOCKET`; records From/To/
Subject/SASL user at DATA; enforces level-2 rate limits; **fail-open**
(`default_action=accept`) so milter failure does not stop mail.
(`default_action=accept`) so milter failure does not stop mail. The level-2
count is the stored send-log rows plus the messages this process has admitted
but not yet written (`internal/milter/inflight.go`), so concurrent sessions
cannot each spend the same last slot; a reservation is released at
end-of-message, on ABORT, or after a 10-minute TTL.
3. **log-tailer** — follows `MAIL_LOG`, updates send-log delivery status by
queue-id. Send-log `queued → sent` transitions depend on this goroutine alone
(`UpdateStatus` is only called from [internal/logtail](../internal/logtail/logtail.go)).
@@ -99,15 +103,23 @@ panel user cannot read). `follow()` drains the old inode once more before
switching descriptors; the panel treats a missing log file as an empty tail, not
an error.
**Known gaps (same class of loss, not fixed by rename rotation):**
**Read offset is persisted** (`logtail_state` table, migration `0003`): the
tailer stores its position plus a fingerprint of the log's first 512 bytes, and
on start resumes from it, parsing the tail written while the panel was down. If
the fingerprint no longer matches (rotated or recreated in the meantime) it reads
the current file from the start; re-parsing lines is harmless because
`UpdateStatus` writes the same status onto the same row. Only a first-ever start,
with nothing stored, begins at end-of-file, so installing the panel does not
replay a pre-existing log.
**Remaining gap:**
- **Panel restart**`follow()` starts at end-of-file; lines written while the
panel was down are never parsed; in-flight send-log rows may stay `queued`.
- **Container recreate**`/var/log` is ephemeral; the log is lost with the
container.
container, so the delivery lines for rows still `queued` are gone with it and
those rows stay `queued` forever.
Possible follow-ups if these become painful: persist read offset across restarts,
mount mail log under `/data`, or reconcile stuck rows via `postqueue`.
Possible follow-ups if this becomes painful: mount the mail log under `/data`, or
reconcile stuck rows via `postqueue`.
---
@@ -158,7 +170,7 @@ cookie and idle timeout has not expired.
| Path | Contents |
|---|---|
| `selfpost.db` | SQLite: domains, apps, admin, sessions, send log, L2 limits |
| `selfpost.db` | SQLite: domains, apps, admin, sessions, send log, L2 limits, log-tailer offset |
| `setup-token` | First-run setup token file |
| `opendkim/` | DKIM keys + tables |
| `sasl/sasldb2` | Application SASL credentials |
+21 -8
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@@ -72,7 +72,7 @@ flowchart TB
- **Layered / ports-and-adapters:** handlers → services (`domain`, `app`) → `store`; инфраструктура изолирована в адаптерах ([`internal/web/web.go`](../internal/web/web.go), [`internal/app/service.go`](../internal/app/service.go)).
- **Composition root** в [`cmd/panel/main.go`](../cmd/panel/main.go): три роли (HTTP, journal-milter, log-tailer) в одном процессе — оправдано для single-container deployment.
- **Interface seams** для тестов: `milter.Store`, `app.SenderMaps`, `logtail.StatusStore`.
- **Embedded migrations** ([`internal/store/store.go`](../internal/store/store.go)) — простой, надёжный подход для 2 миграций.
- **Embedded migrations** ([`internal/store/store.go`](../internal/store/store.go)) — простой, надёжный подход для 3 миграций.
- **E2E как отдельный модуль** (`test/e2e/go.mod`) — не загрязняет основной модуль.
### Замечания (не блокеры)
@@ -215,7 +215,7 @@ E2E покрывает: bootstrap, SMTP AUTH, DKIM, send-log lifecycle, negative
| Gap | Описание | Документировано |
|-----|----------|-----------------|
| Send-log `queued` forever | Log-tailer стартует с EOF; после restart пропущенный хвост не дочитывается | [security.md](security.md), [roadmap.md](roadmap.md) |
| Send-log `queued` forever | **Закрыто для рестарта:** Фаза 3 — offset персистится (`logtail_state`), хвост дочитывается. Остаётся пересоздание контейнера: `mail.log` не в `/data` | [security.md](security.md), [roadmap.md](roadmap.md) |
| CSRF without tokens | POST без Origin/Sec-Fetch-Site пропускается | [security.md](security.md) |
| Fail-open L2 rate limit | DB error → mail проходит | [`internal/milter/ratelimit.go`](../internal/milter/ratelimit.go) |
| Shallow SPF check | Не следует `include:`/`redirect=` | README, `internal/dnscheck/spf.go` |
@@ -235,8 +235,8 @@ E2E покрывает: bootstrap, SMTP AUTH, DKIM, send-log lifecycle, negative
|---|----------|-----------|--------|
| L1 | **Предрелизный security review** (§ D) — обязательный гейт | **P0** | **Fable** |
| L2 | **Шифрование бэкапа и экспорта домена** (R13) — optional, checkbox + password — **выполнено** | P1 | **Opus** + Sonnet |
| L3 | Send-log gap mitigation — опционально | P2 | Opus |
| L4 | Transaction wrap для rate limit count+insert — опционально | P3 | Opus |
| L3 | Send-log gap mitigation — **выполнено** (persist offset, Фаза 3) | P2 | Opus |
| L4 | Rate limit count+insert — **выполнено** (учёт «в полёте», Фаза 3; транзакция как таковая неприменима) | P3 | Opus |
---
@@ -246,6 +246,7 @@ E2E покрывает: bootstrap, SMTP AUTH, DKIM, send-log lifecycle, negative
- [`0001_init.sql`](../internal/store/migrations/0001_init.sql) — initial schema
- [`0002_sessions.sql`](../internal/store/migrations/0002_sessions.sql) — sessions (plan B.1)
- [`0003_logtail_state.sql`](../internal/store/migrations/0003_logtail_state.sql) — log-tailer read offset (Фаза 3)
- Механизм: `PRAGMA user_version`, embedded FS, transactional apply — **чистый**, без legacy branches в коде.
### Архивная документация
@@ -360,7 +361,7 @@ Go `html/template` + HTMX polling + [`panel.css`](../internal/web/static/panel.c
|---|--------|--------|
| R9 | Inbound relay (Phase O1) | **Opus** |
| R10 | Domain-admin role | Opus |
| R11 | Send-log gap fix (persist offset) | Opus |
| R11 | Send-log gap fix (persist offset)**выполнено в Фазе 3**, из 2.x снято | Opus |
| R12 | Split internal/web subpackages | Sonnet/Opus |
### CI/infra
@@ -423,10 +424,22 @@ Go `html/template` + HTMX polling + [`panel.css`](../internal/web/static/panel.c
2. Sonnet: CSS custom properties для dark mode
3. Haiku: consolidate main max-width rules
### Фаза 3 — Operational improvements (P2P3, optional)
### Фаза 3 — Operational improvements (P2P3, optional) — **выполнено 2026-08-06**
1. Opus: send-log read offset persistence
2. Opus: rate limit count transaction wrap
1. Opus: send-log read offset persistence**сделано**: `logtail_state`
(миграция `0003`) хранит offset + отпечаток головы лога; при совпадении
отпечатка чтение продолжается, при несовпадении файл читается с начала,
первый запуск (записи нет) — с конца, как раньше.
2. Opus: rate limit count transaction wrap — **сделано иначе**: буквальная
транзакция невозможна, count живёт на MAIL FROM, insert — на end-of-message,
это разные стадии SMTP-транзакции. Overshoot закрыт учётом сообщений «в
полёте» (`internal/milter/inflight.go`): к счёту из БД добавляются
резервации, взятые прошедшими проверку сессиями и снимаемые после записи в
send-log, на ABORT или по TTL 10 минут.
Остаток по send-log (не закрывается персистом offset): при пересоздании
контейнера `mail.log` теряется вместе с ним — принятый риск в
[security.md](security.md).
---
+1
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@@ -52,6 +52,7 @@
- **§ D выполнен (2026-08-06):** предрелизная ревизия безопасности моделью Fable — диф от аудита v1.0 (Фаза 11, `bd64e80`) до HEAD + полный проход по чек-листу [security.md](security.md) (бывшее ТЗ 7.6). Эксплуатируемых находок нет; одна правка defence-in-depth (`--` перед логином в argv `saslpasswd2`, `internal/app/sasl.go` + тест). Принятые риски не пополнились. Детали — [implementation-plan.md](implementation-plan.md) § D и CHANGELOG `[Unreleased]/Security`. Локально `go vet`/`go test ./internal/app/...` чистые; падения `internal/domain` (`TestWriteLoadPrivateKeyRoundtrip`, `TestRenderTables`) и `internal/logtail` (`TestFollowTailsAndRotates`) — Windows-специфика (права файлов/`\` в путях/rename открытого файла), на Linux CI зелено.
- **Фаза 1 выполнена (2026-08-06)** ([code-review.md](code-review.md) § Фаза 1 — doc/code hygiene, P1): cleanup ~30 stale «Phase N» комментариев в коде и shell-скриптах; исправлен stale-комментарий в `handlers_domains.go`; ADR CSRF (Origin vs токены) добавлен в [security.md](security.md); known-limitations по log-tailer уже был в [architecture.md](architecture.md) § Log tailer — отдельного действия не потребовалось; `docs/logo` в [roadmap.md](roadmap.md) закрыт (каталога нет, критерию соответствует); `gofmt -l` добавлен в CI (`.github/workflows/test.yml`). `gofmt`/`go vet`/`go test ./...` чистые в обоих модулях (dev-server).
- **Фаза 1.5 выполнена (2026-08-06)** ([code-review.md](code-review.md) § Фаза 1.5 — шифрование резервных копий, P1): новый пакет `internal/secretfile` — конверт `magic SELFPOST1 | type | scrypt-параметры | salt | nonce-prefix` + поток 64 KiB чанков AES-256-GCM, каждый с AAD `header+counter+last`, поэтому обрезка, перестановка и подмена не открываются (стриминг в обе стороны — полный бэкап не держится в памяти). Панель: чекбокс «Encrypt with a password» в форме полного бэкапа и экспорта домена (общий партиал `templates/encrypt_fields.html`, показ/очистка полей — `panel.js`, без inline-скриптов), импорт домена принимает `.spde` (шифрование определяется по magic, не по расширению) с полем пароля. CLI `selfpost-backup`: пишет `.spbk` при заданном пароле и умеет `-decrypt` (иначе зашифрованный бэкап нечем распаковать при restore); пароль — только `SELFPOST_BACKUP_PASSWORD` / `-password-file`, никогда argv. Умолчание не изменилось: галочка снята — прежние `.tar.gz` / `.json` байт в байт. Тесты: round-trip по размерам (0, границы чанка, несколько чанков), неверный пароль, обрезка, перестановка чанков, порча байта, чужие KDF-параметры; валидация формы пароля; round-trip CLI create→decrypt→tar. Docs: README § *Encrypting a backup or export*, [security.md](security.md) § «Резервная копия и экспорт домена» + принятый риск (шифрование опционально), [architecture.md](architecture.md) § Persistence. `gofmt`/`go vet`/`go test ./...` чистые (кроме известных Windows-падений `internal/domain`, `internal/logtail`). E2E-сценарий не добавлялся: в `test/e2e/` бэкапа не было и раньше, а прогнать новый тест локально нечем (нет Docker) — кандидат при следующем прогоне на dev-сервере.
- **Фаза 3 выполнена (2026-08-06)** ([code-review.md](code-review.md) § Фаза 3 — operational improvements, P2P3): (1) log-tailer сохраняет позицию чтения — таблица `logtail_state` (миграция `0003`, `internal/store/logtail.go`) хранит offset + отпечаток первых 512 байт лога, `internal/logtail/offset.go` решает откуда стартовать: отпечаток совпал → продолжаем с offset (дочитывается хвост, написанный пока панель лежала); не совпал (лог сменился/пересоздан) → читаем файл с начала (повторный разбор безвреден, `UpdateStatus` идемпотентен); записи нет вовсе (первый запуск) → с конца, как раньше. Запись offset — не чаще раза в 5 с, плюс форс при ротации и на выключении; сохраняется позиция *потреблённых* байт (минус недочитанная частичная строка). (2) L2-лимит перестал промахиваться при параллельных сессиях: между проверкой на MAIL FROM и вставкой строки на end-of-message сообщение не видно в БД, поэтому N одновременных сессий пропускали друг друга — теперь к счёту из БД добавляются «в полёте» (`internal/milter/inflight.go`, общий на процесс реестр резерваций); резервация освобождается после записи в send-log, на ABORT и по TTL 10 минут (у go-milter нет колбэка на закрытие соединения, а вечная резервация — это fail-closed-дрейф, которого у лимитера быть не должно). Транзакция «count+insert», как предлагал review, невозможна буквально: эти два шага разнесены по разным стадиям SMTP-транзакции. Тесты: restart/rotation-resume для tailer'а, четыре сценария резерваций для лимита. `gofmt`/`go vet` чистые; `go test ./...` — падения только известные Windows-специфичные (`internal/domain`, `TestFollowTailsAndRotates`). Не проверено на стенде (нет Docker локально) — кандидат на следующий прогон на dev-сервере.
- **Дальше:** релизный гейт (Фаза 0) закрыт по существу — e2e C.4 и ревизия § D пройдены; остаются только шаги, которые делаются в момент резки версии (бамп тега образа + Codeberg URL, git tag) по явной команде пользователя. Остальные пункты из [code-review.md](code-review.md) — polish (фазы 23).
- **Принятые риски** — [security.md](security.md). **Опционально v1.x / 2.x** — [roadmap.md](roadmap.md) (хвост документации, send-log gaps, Фаза O1+, роль администратора домена).
- **Прод:** `selfpost.example.com`, реальный Let's Encrypt сертификат, живой e2e (DKIM/SPF pass). Контейнер там всё ещё на образе v1.0 — Фаза 14 в него не выкатывалась. При апгрейде: админа один раз разлогинит (сменилось имя cookie), а от reverse-proxy требуется передача исходного `Host` (Apache-фрагмент из `deploy/` это делает).
+6 -5
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@@ -60,11 +60,12 @@ CHANGELOG `[Unreleased]/Security`, а разделы B.1–B.3 и C.4 вырез
(`docs/logo` уже отсутствует как каталог — критерию «либо содержит файлы, либо
отсутствует» удовлетворяет; отдельного действия не требуется.)
**Send-log vs `mail.log` (опционально).** После рестарта панели или пересоздания
контейнера строки send-log могут навсегда остаться `queued`log-tailer не
дочитывает пропущенный хвост, `mail.log` не в `/data`. Rename-ротация (B.2)
это не лечит. Кандидаты, если станет больно: persist позиции чтения, volume для
лога, сверка зависших строк через `postqueue`. As-built и принятый риск:
**Send-log vs `mail.log` (частично закрыто).** Persist позиции чтения сделан
(Фаза 3 [code-review.md](code-review.md), таблица `logtail_state`): после
рестарта панели log-tailer дочитывает пропущенный хвост. Остаётся пересоздание
контейнера — `mail.log` не в `/data` и теряется вместе с ним, такие строки
навсегда останутся `queued`. Кандидаты, если станет больно: volume для лога,
сверка зависших строк через `postqueue`. As-built и принятый риск:
[architecture.md](architecture.md) § Log tailer, [security.md](security.md).
---
+6 -4
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@@ -118,10 +118,12 @@ Hardening сверх обязательного (security-заголовки, п
безвозвратно нерасшифровываемый архив хуже незашифрованного: пароль SelfPost
не хранит. Триггером сделать шифрование обязательным считать появление
второго администратора (тогда «кто скачал» перестаёт быть одним человеком).
- **Send-log может навсегда остаться `queued` после рестарта панели или
пересоздания контейнера.** Log-tailer стартует с конца `mail.log`; файл не в
`/data` и теряется при recreate. Rename-ротация это не лечит. См. [architecture.md](architecture.md)
§ Log tailer — known gaps.
- **Send-log может навсегда остаться `queued` после пересоздания контейнера.**
Рестарт панели это больше не вызывает: log-tailer сохраняет позицию чтения
(`logtail_state`, миграция `0003`) и после старта дочитывает хвост, написанный
пока панель лежала. Но `mail.log` живёт не в `/data` и теряется вместе с
контейнером — строки, чьи delivery-строки были только в нём, останутся
`queued`. См. [architecture.md](architecture.md) § Log tailer.
## ADR: CSRF через проверку Origin, без токенов
+33 -11
View File
@@ -20,11 +20,14 @@ import (
"codeberg.org/mix/selfpost/internal/store"
)
// StatusStore is the slice of the store the log-tailer needs. *store.Store
// satisfies it.
// StatusStore is the slice of the store the log-tailer needs: advancing
// delivery statuses, pruning the retention window, and remembering how far into
// mail.log it has read. *store.Store satisfies it.
type StatusStore interface {
UpdateStatus(queueID, recipient, status string) (int64, error)
DeleteSendLogBefore(cutoff time.Time) (int64, error)
LogtailState(path string) (store.LogtailState, bool, error)
SaveLogtailState(path string, st store.LogtailState) error
}
// pollInterval is how often the tail loop checks for new bytes / rotation. It
@@ -73,12 +76,13 @@ func parseDelivery(line string) (queueID, recipient, status string, ok bool) {
}
// Run follows path and updates send-log statuses until ctx is cancelled, while
// a background sweep prunes rows older than retentionDays. It returns nil on a
// clean shutdown.
// a background sweep prunes rows older than retentionDays. Reading resumes at
// the offset the previous run persisted, so a restart parses the delivery lines
// written while the panel was down. It returns nil on a clean shutdown.
func Run(ctx context.Context, path string, st StatusStore, retentionDays int) error {
go retentionLoop(ctx, st, retentionDays)
return follow(ctx, path, func(line string) {
return follow(ctx, path, &tracker{st: st, path: path}, func(line string) {
queueID, recipient, status, ok := parseDelivery(line)
if !ok {
return
@@ -166,10 +170,11 @@ func TailLines(path string, n int) ([]string, error) {
}
// follow tails path line by line, calling handle for each complete line, until
// ctx is cancelled. It starts at end-of-file (so a restart does not reprocess
// history) and reopens the file when it is rotated (inode change from
// ctx is cancelled. Where it starts is tr's decision (a persisted offset, the
// start of a file that changed while the panel was down, or end-of-file on a
// first ever run); it reopens the file when it is rotated (inode change from
// logrotate's create, or truncation from copytruncate) so nothing is missed.
func follow(ctx context.Context, path string, handle func(string)) error {
func follow(ctx context.Context, path string, tr *tracker, handle func(string)) error {
var (
f *os.File
r *bufio.Reader
@@ -199,7 +204,7 @@ func follow(ctx context.Context, path string, handle func(string)) error {
// The container may start before Postfix has created mail.log; wait for it.
for {
if err := openAt(0, io.SeekEnd); err == nil {
if err := openAt(0, io.SeekStart); err == nil {
break
}
select {
@@ -208,6 +213,10 @@ func follow(ctx context.Context, path string, handle func(string)) error {
case <-time.After(pollInterval):
}
}
if _, err := f.Seek(tr.resume(f), io.SeekStart); err != nil {
log.Printf("log-tailer: seek %s: %v", path, err)
}
r.Reset(f) // the reader buffered from the pre-seek position
defer func() {
if f != nil {
f.Close()
@@ -231,11 +240,20 @@ func follow(ctx context.Context, path string, handle func(string)) error {
}
}
// read returns how many bytes of the open file have actually been consumed:
// the descriptor position less the partial line bufio handed back at EOF,
// which is re-read (and completed) on the next drain or the next start.
read := func() int64 {
pos, _ := f.Seek(0, io.SeekCurrent)
return pos - int64(len(pending))
}
ticker := time.NewTicker(pollInterval)
defer ticker.Stop()
for {
select {
case <-ctx.Done():
tr.record(f, read(), true) // shutdown: the next start resumes here
return nil
case <-ticker.C:
drain()
@@ -252,8 +270,12 @@ func follow(ctx context.Context, path string, handle func(string)) error {
drain()
if err := openAt(0, io.SeekStart); err != nil {
log.Printf("log-tailer: reopen %s: %v", path, err)
}
}
continue
}
tr.adopt(f)
continue
}
tr.record(f, read(), false)
}
}
}
+107 -1
View File
@@ -4,6 +4,7 @@ import (
"context"
"os"
"path/filepath"
"strings"
"sync"
"testing"
"time"
@@ -77,10 +78,16 @@ func TestParseDelivery(t *testing.T) {
}
}
// captureStore records UpdateStatus calls for the follow integration test.
// captureStore records UpdateStatus calls for the follow integration test and
// keeps the persisted read offset in memory, so a "restart" in a test is a
// second Run against the same captureStore.
type captureStore struct {
mu sync.Mutex
calls []string
state store.LogtailState
haveState bool
stateErr error
}
func (c *captureStore) UpdateStatus(queueID, recipient, status string) (int64, error) {
@@ -92,12 +99,37 @@ func (c *captureStore) UpdateStatus(queueID, recipient, status string) (int64, e
func (c *captureStore) DeleteSendLogBefore(time.Time) (int64, error) { return 0, nil }
func (c *captureStore) LogtailState(string) (store.LogtailState, bool, error) {
c.mu.Lock()
defer c.mu.Unlock()
if c.stateErr != nil {
return store.LogtailState{}, false, c.stateErr
}
return c.state, c.haveState, nil
}
func (c *captureStore) SaveLogtailState(_ string, st store.LogtailState) error {
c.mu.Lock()
defer c.mu.Unlock()
if c.stateErr != nil {
return c.stateErr
}
c.state, c.haveState = st, true
return nil
}
func (c *captureStore) snapshot() []string {
c.mu.Lock()
defer c.mu.Unlock()
return append([]string(nil), c.calls...)
}
func (c *captureStore) reset() {
c.mu.Lock()
defer c.mu.Unlock()
c.calls = nil
}
// TestFollowTailsAndRotates writes delivery lines to a log file, then rotates
// it (rename + fresh create, as logrotate does) and writes more, asserting the
// tailer picks up lines from both the original and rotated file.
@@ -142,6 +174,80 @@ func TestFollowTailsAndRotates(t *testing.T) {
}
}
// TestFollowResumesAfterRestart covers the persisted read offset: a restart
// must parse the delivery lines written while the tailer was down (rows that
// would otherwise stay "queued" forever), without re-parsing what it already
// read, and must fall back to reading the whole file when the log was rotated
// or recreated in the meantime.
func TestFollowResumesAfterRestart(t *testing.T) {
old := pollInterval
pollInterval = 10 * time.Millisecond
t.Cleanup(func() { pollInterval = old })
dir := t.TempDir()
path := filepath.Join(dir, "mail.log")
// A head longer than fingerprintSize, so the file stays identifiable across
// the restart; the lines themselves predate the first start and are ignored.
seed := strings.Repeat("host postfix/qmgr[1]: seed line, not a delivery\n", 20)
if err := os.WriteFile(path, []byte(seed), 0o644); err != nil {
t.Fatalf("seed log: %v", err)
}
cs := &captureStore{}
stop := startRun(t, path, cs)
appendLine(t, path, "host postfix/smtp[1]: Q1: to=<a@example.net>, dsn=2.0.0, status=sent (ok)")
waitFor(t, func() bool { return contains(cs.snapshot(), "Q1|a@example.net|sent") })
stop() // persists the offset past Q1
// Down: Postfix keeps delivering.
appendLine(t, path, "host postfix/smtp[1]: Q2: to=<b@example.net>, dsn=2.0.0, status=sent (ok)")
cs.reset()
stop = startRun(t, path, cs)
waitFor(t, func() bool { return contains(cs.snapshot(), "Q2|b@example.net|sent") })
if contains(cs.snapshot(), "Q1|a@example.net|sent") {
t.Fatal("resumed run re-parsed Q1: offset was not honoured")
}
stop()
// Down again, and this time the log is replaced (logrotate + fresh create).
// The stored offset belongs to a file that no longer exists, so the new one
// must be read from the start.
if err := os.WriteFile(path, []byte(strings.Repeat("host postfix/qmgr[1]: fresh log after rotation\n", 20)+
"host postfix/smtp[1]: Q3: to=<c@example.net>, dsn=5.1.1, status=bounced (nope)\n"), 0o644); err != nil {
t.Fatalf("recreate log: %v", err)
}
cs.reset()
stop = startRun(t, path, cs)
waitFor(t, func() bool { return contains(cs.snapshot(), "Q3|c@example.net|bounced") })
stop()
}
// startRun launches the tailer and returns a function that cancels it and waits
// for a clean return, the way a panel restart bookends a run.
func startRun(t *testing.T, path string, cs *captureStore) func() {
t.Helper()
ctx, cancel := context.WithCancel(context.Background())
done := make(chan error, 1)
go func() { done <- Run(ctx, path, cs, 90) }()
// follow() opens and seeks on start; give it a moment before the caller
// appends, so the append is not raced by the initial open.
time.Sleep(50 * time.Millisecond)
return func() {
t.Helper()
cancel()
select {
case err := <-done:
if err != nil {
t.Fatalf("Run: %v", err)
}
case <-time.After(2 * time.Second):
t.Fatal("Run did not return after cancel")
}
}
}
func appendLine(t *testing.T, path, line string) {
t.Helper()
f, err := os.OpenFile(path, os.O_APPEND|os.O_WRONLY, 0o644)
+136
View File
@@ -0,0 +1,136 @@
package logtail
import (
"crypto/sha256"
"encoding/hex"
"errors"
"io"
"log"
"os"
"time"
"codeberg.org/mix/selfpost/internal/store"
)
const (
// fingerprintSize is how many bytes from the head of the log identify it.
// Postfix writes a timestamped line per event, so the first 512 bytes are
// effectively unique per log generation — enough to tell "the file we were
// reading" from "a fresh one created by logrotate while we were down",
// which os.SameFile cannot answer across a restart.
fingerprintSize = 512
// persistInterval throttles the offset write. Losing up to this much
// progress on a crash only means re-parsing a few lines (UpdateStatus is
// idempotent), which is much cheaper than a database write per poll tick.
persistInterval = 5 * time.Second
)
// tracker persists the tailer's read position so a restart resumes where the
// previous run stopped instead of jumping to end-of-file — the "send-log rows
// stay queued forever" gap (architecture.md § Log tailer). It is used from the
// follow loop only, so it needs no locking.
type tracker struct {
st StatusStore
path string
fp string // fingerprint of the file currently open ("" if too short)
saved int64 // last offset written to the store
lastSave time.Time
}
// resume returns the byte offset the tailer should start reading f at, having
// recorded f's fingerprint for later saves.
//
// The rules, in order: no stored state at all (first ever start) means start at
// the end, so installing the panel does not replay a pre-existing log; a stored
// state whose fingerprint still matches means continue from it, parsing the
// tail written while the panel was down; anything else means the file is not
// the one the offset referred to (rotated, recreated or truncated in the
// meantime), so read it from the start. Re-parsing lines already seen is
// harmless: UpdateStatus writes the same status onto the same row.
func (t *tracker) resume(f *os.File) int64 {
size, err := fileSize(f)
if err != nil {
log.Printf("log-tailer: stat %s: %v (reading from the start)", t.path, err)
return 0
}
t.fp = fingerprintOf(f)
prev, ok, err := t.st.LogtailState(t.path)
if err != nil {
log.Printf("log-tailer: read stored offset: %v (starting at end)", err)
return size
}
switch {
case !ok:
t.saved = size
return size
case prev.Fingerprint != "" && prev.Fingerprint == t.fp && prev.Offset <= size:
t.saved = prev.Offset
if prev.Offset < size {
log.Printf("log-tailer: resuming %s at offset %d (%d bytes to catch up)",
t.path, prev.Offset, size-prev.Offset)
}
return prev.Offset
default:
log.Printf("log-tailer: %s changed while the panel was down; reading from the start", t.path)
t.saved = 0
return 0
}
}
// adopt re-fingerprints after the follow loop switched to a rotated-in file and
// persists the fresh start immediately, so a restart right after a rotation
// does not resume at the old file's offset.
func (t *tracker) adopt(f *os.File) {
t.fp = fingerprintOf(f)
t.saved = -1 // force the write below even if the old offset happened to be 0
t.record(f, 0, true)
}
// record persists offset, at most once per persistInterval unless force is set
// (rotation and shutdown, where the write must not be skipped).
func (t *tracker) record(f *os.File, offset int64, force bool) {
if offset == t.saved {
return
}
if !force && time.Since(t.lastSave) < persistInterval {
return
}
if t.fp == "" {
// The log was shorter than a fingerprint when we opened it; now that it
// has grown, an identifiable one may be available.
t.fp = fingerprintOf(f)
}
if err := t.st.SaveLogtailState(t.path, store.LogtailState{Fingerprint: t.fp, Offset: offset}); err != nil {
log.Printf("log-tailer: save offset: %v", err)
return
}
t.saved = offset
t.lastSave = time.Now()
}
// fingerprintOf hashes the head of the file. It returns "" for a file too short
// to identify — the head would still change as Postfix appends, so such a
// fingerprint could not be compared meaningfully on the next start.
func fingerprintOf(f *os.File) string {
buf := make([]byte, fingerprintSize)
n, err := f.ReadAt(buf, 0)
if err != nil && !errors.Is(err, io.EOF) {
log.Printf("log-tailer: fingerprint read: %v", err)
return ""
}
if n < fingerprintSize {
return ""
}
sum := sha256.Sum256(buf)
return hex.EncodeToString(sum[:])
}
func fileSize(f *os.File) (int64, error) {
info, err := f.Stat()
if err != nil {
return 0, err
}
return info.Size(), nil
}
+99
View File
@@ -0,0 +1,99 @@
package milter
import (
"sync"
"time"
)
// reservationTTL bounds how long a message may stay reserved. A reservation is
// released at end-of-message or on ABORT, but a client that simply drops the
// connection after MAIL FROM produces neither callback (go-milter has no
// connection-close hook), and a reservation that never expired would count
// against the limit forever — a fail-closed drift this milter must not have.
// The TTL is generously longer than any realistic DATA transfer, so a message
// still being received is never dropped from the count.
const reservationTTL = 10 * time.Minute
// reservation is one message that passed the level-2 check and has not been
// written to the send log yet.
type reservation struct {
key string
at time.Time
}
// inflight counts messages that are between the limit check (MAIL FROM) and the
// send-log insert (end-of-message). The stored count alone cannot see them, so
// without this several concurrent SMTP sessions each read the same pre-insert
// count, each conclude they are under the ceiling, and the limit is overshot by
// however many were in flight. Counting reservations closes that window without
// writing placeholder rows the operator would see in the UI.
//
// One instance is shared by every session of the process, hence the mutex.
// Methods tolerate a nil receiver so a session built without one (tests) simply
// behaves as it did before.
type inflight struct {
mu sync.Mutex
m map[string]map[*reservation]struct{}
}
// count returns how many reservations for key were taken within the limit's
// window (at or after since), pruning any that outlived reservationTTL.
func (f *inflight) count(key string, since time.Time) int64 {
if f == nil {
return 0
}
f.mu.Lock()
defer f.mu.Unlock()
set := f.m[key]
cutoff := time.Now().Add(-reservationTTL)
var n int64
for r := range set {
if r.at.Before(cutoff) {
delete(set, r)
continue
}
if !r.at.Before(since) {
n++
}
}
if len(set) == 0 {
delete(f.m, key)
}
return n
}
// reserve claims a slot for key until the message is recorded or released.
func (f *inflight) reserve(key string) *reservation {
if f == nil {
return nil
}
f.mu.Lock()
defer f.mu.Unlock()
if f.m == nil {
f.m = make(map[string]map[*reservation]struct{})
}
if f.m[key] == nil {
f.m[key] = make(map[*reservation]struct{})
}
r := &reservation{key: key, at: time.Now()}
f.m[key][r] = struct{}{}
return r
}
// release drops a reservation, either because the message reached the send log
// (where the stored count takes over) or because it never will.
func (f *inflight) release(r *reservation) {
if f == nil || r == nil {
return
}
f.mu.Lock()
defer f.mu.Unlock()
set := f.m[r.key]
delete(set, r)
if len(set) == 0 {
delete(f.m, r.key)
}
}
+21 -1
View File
@@ -45,6 +45,10 @@ type Store interface {
type session struct {
milter.NoOpMilter
rec Store
// flight is shared by every session of the process; it holds the messages
// that passed the level-2 check but are not in the send log yet. Nil is a
// valid zero value (no in-flight accounting).
flight *inflight
clientIP string // captured once per connection
@@ -52,6 +56,7 @@ type session struct {
from string
rcpts []string
subject string
reserved []*reservation // level-2 slots held by the current message
}
// Connect captures the client IP, which comes from the addr parameter rather
@@ -72,6 +77,7 @@ func (s *session) Connect(host, family string, port uint16, addr net.IP, m *milt
// tempfail before recipients are even offered (spec 7.4). Enforcement is
// fail-open — see overLimit.
func (s *session) MailFrom(from string, m *milter.Modifier) (milter.Response, error) {
s.releaseReservations() // a previous transaction that ended without EOM/ABORT
s.from = cleanAddress(from)
s.login = macro(m, "auth_authen")
s.rcpts = nil
@@ -127,9 +133,22 @@ func decodeSubject(v string) string {
// rows are written. We accept (this milter is done) without ever rejecting.
func (s *session) Body(m *milter.Modifier) (milter.Response, error) {
s.record(macro(m, "i"))
// The rows are in the send log now, so the stored count sees this message
// and its level-2 slots are no longer needed.
s.releaseReservations()
return milter.RespAccept, nil
}
// Abort ends the current transaction without an end-of-message (client RSET, or
// Postfix rejecting the message for its own reasons). No send-log row will be
// written, so the level-2 slots this message held must go back.
func (s *session) Abort(m *milter.Modifier) error {
s.releaseReservations()
s.rcpts = nil
s.subject = ""
return nil
}
// macro reads a milter macro, tolerating Postfix's convention of wrapping
// multi-character macro names in curly braces (e.g. {auth_authen}) while
// single-character names (e.g. i) arrive bare. go-milter stores whatever name
@@ -191,8 +210,9 @@ func domainOf(addr string) string {
// Serve runs the journal-milter on ln until ctx is cancelled. Each connection
// gets a fresh session bound to rec. It returns nil on a clean shutdown.
func Serve(ctx context.Context, ln net.Listener, rec Store) error {
flight := &inflight{} // shared: the level-2 window spans all connections
srv := &milter.Server{
NewMilter: func() milter.Milter { return &session{rec: rec} },
NewMilter: func() milter.Milter { return &session{rec: rec, flight: flight} },
Actions: 0, // read-only: we make no message modifications
Protocol: milter.OptNoBody, // the journal needs headers/EOM, not the body
}
+124
View File
@@ -331,6 +331,130 @@ func TestRateLimitNoIPKeyDoesNotApply(t *testing.T) {
}
}
// mailFromIn is mailFrom with an explicit shared in-flight registry, so a test
// can play several concurrent SMTP sessions of one process against each other.
func mailFromIn(t *testing.T, rec Store, fl *inflight, ip, from, login string) (*session, milter.Response) {
t.Helper()
s := &session{rec: rec, flight: fl}
if _, err := s.Connect("h", "tcp4", 0, net.ParseIP(ip), mods(nil)); err != nil {
t.Fatalf("Connect: %v", err)
}
resp, err := s.MailFrom(from, mods(map[string]string{"auth_authen": login}))
if err != nil {
t.Fatalf("MailFrom: %v", err)
}
return s, resp
}
func limitedRecorder(count int64) *fakeRecorder {
return &fakeRecorder{
limits: map[string]store.RateLimit{
store.RateLimitScopeDomain + "|example.com": activeLimit(limitIP),
},
counts: map[string]int64{store.RateLimitScopeDomain + "|example.com": count},
}
}
// Messages between MAIL FROM and end-of-message are not in the send log yet, so
// counting the stored rows alone lets concurrent sessions each pass the same
// check and overshoot the ceiling. The last free slot may only be taken once.
func TestRateLimitCountsInFlightMessages(t *testing.T) {
rec := limitedRecorder(4) // one below the ceiling of 5
fl := &inflight{}
if _, resp := mailFromIn(t, rec, fl, limitIP, "a@example.com", "app1"); resp != milter.RespContinue {
t.Fatalf("first message = %v, want Continue (4/5 stored)", resp)
}
// Same window, nothing written yet: the first message holds the fifth slot.
if _, resp := mailFromIn(t, rec, fl, limitIP, "b@example.com", "app1"); resp != milter.RespTempFail {
t.Fatalf("concurrent message = %v, want TempFail (would overshoot)", resp)
}
if len(rec.rejected) != 1 {
t.Fatalf("want one rejected send-log row, got %+v", rec.rejected)
}
}
// Once the message is recorded the stored count sees it, so its reservation
// must be given back — otherwise it would be counted twice and the ceiling
// would drift closed.
func TestReservationReleasedAtEndOfMessage(t *testing.T) {
rec := limitedRecorder(4)
fl := &inflight{}
s, resp := mailFromIn(t, rec, fl, limitIP, "a@example.com", "app1")
if resp != milter.RespContinue {
t.Fatalf("first message = %v, want Continue", resp)
}
if _, err := s.Body(mods(map[string]string{"i": "Q1"})); err != nil {
t.Fatalf("Body: %v", err)
}
if n := fl.count(store.RateLimitScopeDomain+"|example.com", time.Now().Add(-time.Hour)); n != 0 {
t.Fatalf("in-flight count after EOM = %d, want 0", n)
}
}
// A transaction the client abandons (RSET, or a Postfix-side rejection) never
// reaches the send log, so its slot must not stay claimed.
func TestReservationReleasedOnAbort(t *testing.T) {
rec := limitedRecorder(4)
fl := &inflight{}
s, resp := mailFromIn(t, rec, fl, limitIP, "a@example.com", "app1")
if resp != milter.RespContinue {
t.Fatalf("first message = %v, want Continue", resp)
}
if err := s.Abort(mods(nil)); err != nil {
t.Fatalf("Abort: %v", err)
}
if _, resp := mailFromIn(t, rec, fl, limitIP, "b@example.com", "app1"); resp != milter.RespContinue {
t.Fatalf("after abort = %v, want Continue (slot released)", resp)
}
}
// A refused message must not leave the slots it claimed for the limits checked
// before the one that tripped, or every refusal would tighten the ceiling.
func TestRefusalReleasesEarlierReservation(t *testing.T) {
rec := &fakeRecorder{
limits: map[string]store.RateLimit{
store.RateLimitScopeDomain + "|example.com": activeLimit(limitIP),
store.RateLimitScopeApp + "|app1": activeLimit(limitIP),
},
counts: map[string]int64{
store.RateLimitScopeDomain + "|example.com": 0, // domain: plenty of room
store.RateLimitScopeApp + "|app1": 5, // app: at the ceiling
},
}
fl := &inflight{}
if _, resp := mailFromIn(t, rec, fl, limitIP, "a@example.com", "app1"); resp != milter.RespTempFail {
t.Fatalf("app over limit = %v, want TempFail", resp)
}
if n := fl.count(store.RateLimitScopeDomain+"|example.com", time.Now().Add(-time.Hour)); n != 0 {
t.Fatalf("domain reservation left behind after refusal: %d", n)
}
}
// The in-flight count only covers the limit's own window: a reservation older
// than it (a session stuck mid-DATA for longer than the window) must not be
// counted against a window it no longer belongs to.
func TestInflightIgnoresReservationsOutsideWindow(t *testing.T) {
fl := &inflight{}
r := fl.reserve("domain|example.com")
r.at = time.Now().Add(-time.Minute)
if n := fl.count("domain|example.com", time.Now().Add(-time.Hour)); n != 1 {
t.Fatalf("count inside window = %d, want 1", n)
}
if n := fl.count("domain|example.com", time.Now().Add(-time.Second)); n != 0 {
t.Fatalf("count outside window = %d, want 0", n)
}
// Past the TTL the reservation is dropped even for a wide window, so a
// client that vanished after MAIL FROM cannot hold a slot forever.
r.at = time.Now().Add(-2 * reservationTTL)
if n := fl.count("domain|example.com", time.Now().Add(-3*reservationTTL)); n != 0 {
t.Fatalf("expired reservation still counted: %d", n)
}
}
func TestDomainOf(t *testing.T) {
cases := map[string]string{
"user@Example.COM": "example.com",
+24
View File
@@ -17,6 +17,10 @@ import (
// can never block mail — Postfix's level-1 anvil limit (spec 5) remains the
// backstop, and it does not depend on this milter at all. Only a clean count at
// or above a configured ceiling returns true.
//
// A message that passes reserves a slot per applicable limit, released once it
// reaches the send log (or is abandoned) — see inflight for why the stored
// count alone is not enough.
func (s *session) overLimit() bool {
if s.clientIP == "" {
return false // no client IP to key on; level-2 does not apply
@@ -25,6 +29,7 @@ func (s *session) overLimit() bool {
{store.RateLimitScopeDomain, domainOf(s.from)},
{store.RateLimitScopeApp, s.login},
}
var taken []*reservation
for _, c := range checks {
if c.ref == "" {
continue
@@ -45,15 +50,34 @@ func (s *session) overLimit() bool {
log.Printf("journal-milter: rate-limit count %s %q: %v (fail-open)", c.scope, c.ref, err)
continue
}
key := c.scope + "|" + c.ref
n += s.flight.count(key, since)
if n >= int64(rl.MaxMessages) {
log.Printf("journal-milter: %s %q over limit: %d/%d in %ds from %s — refusing 4xx",
c.scope, c.ref, n, rl.MaxMessages, rl.WindowSeconds, s.clientIP)
// The message is refused, so the slots claimed for the limits
// checked before this one must not stay claimed.
for _, r := range taken {
s.flight.release(r)
}
return true
}
taken = append(taken, s.flight.reserve(key))
}
s.reserved = append(s.reserved, taken...)
return false
}
// releaseReservations gives back every slot this message holds. It runs once
// the message is in the send log (where the stored count sees it), and whenever
// the transaction ends without getting there.
func (s *session) releaseReservations() {
for _, r := range s.reserved {
s.flight.release(r)
}
s.reserved = nil
}
// recordRejected writes a send-log row for a message refused by a level-2 limit
// (spec 7.4, "опционально фиксирует ... для видимости в UI"), so the rejection
// shows up in the monitoring screen. Only MAIL-stage fields are known; the write
+54
View File
@@ -0,0 +1,54 @@
package store
import (
"database/sql"
"errors"
"fmt"
"time"
)
// LogtailState is the persisted read position of the mail.log tailer: how far
// into the log it had got, and a fingerprint of the file that offset refers to.
// It lets the tailer resume after a panel restart instead of jumping to
// end-of-file and losing the delivery lines written while it was down.
type LogtailState struct {
Fingerprint string
Offset int64
}
// LogtailState returns the stored read position for path. ok is false the first
// time a path is followed (nothing persisted yet), which the tailer treats as
// "start at the end".
func (s *Store) LogtailState(path string) (LogtailState, bool, error) {
var st LogtailState
err := s.db.QueryRow(
`SELECT fingerprint, read_offset FROM logtail_state WHERE path = ?`,
path,
).Scan(&st.Fingerprint, &st.Offset)
if errors.Is(err, sql.ErrNoRows) {
return LogtailState{}, false, nil
}
if err != nil {
return LogtailState{}, false, fmt.Errorf("read logtail state for %q: %w", path, err)
}
return st, true, nil
}
// SaveLogtailState records the tailer's read position for path, replacing any
// previous one. It is called on a timer while tailing, so it is a single small
// upsert rather than a transaction.
func (s *Store) SaveLogtailState(path string, st LogtailState) error {
_, err := s.db.Exec(
`INSERT INTO logtail_state (path, fingerprint, read_offset, updated_at)
VALUES (?, ?, ?, ?)
ON CONFLICT(path) DO UPDATE SET
fingerprint = excluded.fingerprint,
read_offset = excluded.read_offset,
updated_at = excluded.updated_at`,
path, st.Fingerprint, st.Offset, time.Now().UTC().Format(time.RFC3339),
)
if err != nil {
return fmt.Errorf("save logtail state for %q: %w", path, err)
}
return nil
}
@@ -0,0 +1,12 @@
-- Log-tailer read position. Without it the tailer starts at end-of-file on
-- every start, so delivery lines written while the panel was down are never
-- parsed and their send-log rows stay "queued" forever. One row per followed
-- path; fingerprint identifies the file the offset belongs to (the head bytes
-- of the log), so a rotated or recreated mail.log is detected across a restart,
-- where os.SameFile cannot help.
CREATE TABLE logtail_state (
path TEXT PRIMARY KEY,
fingerprint TEXT NOT NULL,
read_offset INTEGER NOT NULL,
updated_at TEXT NOT NULL
);