README.md

@@ -2552,7 +2552,7 @@ arrived uncut — never the numbers.
 
 Every limiter here — receiver, login, and password change — identifies
 the client the same way, through one shared key function: the
-connection's own address, unless the peer is listed in
+connection's own address, unless the peer is inside
 `TRUSTED_PROXIES`, in which case the forwarded client address is used
 instead. That address becomes a bucket by family: IPv4 keys on the full
 address, IPv6 on its `/64` prefix. A routed `/64` is the normal
@@ -2590,7 +2590,8 @@ opposite directions:
 
 The login `POST` is the one endpoint with no pre-emptive limiter in
 front of it, and that is deliberate. A limiter that spends budget on
-arrival is a lockout in this deployment shape: sharing one bucket, a
+arrival is a lockout wherever clients share one bucket, as they do
+behind a reverse proxy that `TRUSTED_PROXIES` does not cover: a
 stranger sending five POSTs a minute — about 0.08 requests per second,
 from anywhere — keeps it permanently full, and the operator has no
 second administrative path. So the handler inverts the order:

internal/middleware/ratelimit_test.go

@@ -384,8 +384,8 @@ const (
 	// trustedProxyCIDR is the proxy network the forwarded-path
 	// tests configure, and trustedPeer an address inside it. A
 	// production deployment is required to run behind a reverse
-	// proxy with TRUSTED_PROXIES set, so this is the shape the
+	// proxy that TRUSTED_PROXIES covers, either by the default or by
-	// bucketing has to hold in.
+	// a set value, so this is the shape the bucketing has to hold in.
 	trustedProxyCIDR = "10.0.0.0/8"
 	trustedPeer      = "10.0.0.1:44444"
 )
@@ -1097,8 +1097,9 @@ func TestPostRateLimit_IPv4IndependentPerAddress(t *testing.T) {
 // that arrives from trustedPeer — a configured trusted proxy — and
 // names forwarded as its client in X-Forwarded-For. That is the
 // production path: a deployment is required to run behind a reverse
-// proxy with TRUSTED_PROXIES set, so the forwarded address, not the
+// proxy that TRUSTED_PROXIES covers, either by the default or by a
-// peer, is what the limiters bucket on there.
+// set value, so the forwarded address, not the peer, is what the
+// limiters bucket on there.
 func forwardedKeyFor(
 	t *testing.T, m *middleware.Middleware, forwarded string,
 ) string {
@@ -1178,9 +1179,9 @@ func TestRateLimitKey_ForwardedIPv6BucketsByPrefix(t *testing.T) {
 //
 // Every existing test of this fallback uses an IPv4 proxy, where
 // bucketKey is the identity function, so replacing the call with
-// peer.String() leaves the whole suite green. Only operator-listed
+// peer.String() leaves the whole suite green. Only addresses inside
-// addresses reach this line and the fallback is fail-closed, so this
+// TRUSTED_PROXIES reach this line and the fallback is fail-closed, so
-// pins behaviour rather than fixing a defect.
+// this pins behaviour rather than fixing a defect.
 func TestRateLimitKey_TrustedPeerUnusableForwardedMasksPeer(
 	t *testing.T,
 ) {