Files
selfpost/internal/milter/inflight.go
T
mix 5e5d157496 release: 0.5.0: Pre-1.0 security review, domain-admin role, doc consolidation
A bounce could be recorded as a successful delivery. The log-tailer's
Fixed:
  - A bounce could be recorded as a successful delivery. The log-tailer's
  - Log-tailer resumes where it stopped instead of jumping to end-of-file on
  - Level-2 rate limit no longer overshoots under concurrency: messages that
Changed:
  - The project has a single public home: `github.com/mixeme/selfpost`. Codeberg
  - Code comments no longer cite the archived specification. References like
  - `docs/code-review.md` is gone. Its plan is finished — phases 0 (bar the
  - `docs/architecture.md` gained a *Code layers* section: a diagram of
  - Phase 1 doc/code hygiene (`docs/code-review.md`): removed ~30 stale
  … (1 more in CHANGELOG)
Security:
  - Pre-release security review (plan § D, model Fable, 2026-08-06): full pass
  - `saslpasswd2` argv: the application login is now passed after a `--`
Added:
  - Optional password encryption for the two secret-bearing downloads (plan
  - Domain import accepts an encrypted export: the envelope is detected by its
  - `selfpost-backup` writes encrypted archives and reads them back:
  - `TestParseDelivery` covers the exotic mail.log shapes the review asked for
  - docs: README *Encrypting a backup or export*; `docs/security.md` §
  … (14 more in CHANGELOG)
Removed:
  - docs: `security.md` — accepted risk «restore old backup revives session rows»
Changed:
  - docs: `implementation-plan.md` trimmed to the sole open v1.x gate — pre-release
  - docs: `architecture.md` — sessions (SQLite, idle renew, password change),
  - docs: `development.md` — expanded e2e stack and `release.yml` matrix workflow.
  - docs: `security.md` — accepted risk for send-log rows stuck at `queued` after
  - docs: `roadmap.md` — optional send-log / `mail.log` follow-ups under v1.x tail.
  … (10 more in CHANGELOG)

Full detail: CHANGELOG.md (0.5.0).
2026-09-22 15:24:51 +03:00

100 lines
2.7 KiB
Go

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)
}
}