From 9a07f75bdfb740f684410b523e55de661552f664 Mon Sep 17 00:00:00 2001
From: Lilleman auf Larv <lilleman@larvit.se>
Date: Mon, 28 Sep 2026 04:05:07 +0200
Subject: [PATCH] Refuse a bind the server cannot record as it refuses one
 authenticate turns down

---
 MIGRATION.md           |  5 ++---
 src/server.ts          | 23 ++++++++++-------------
 src/session-options.ts |  6 ++----
 3 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/MIGRATION.md b/MIGRATION.md
index a3a4579..256297a 100644
--- a/MIGRATION.md
+++ b/MIGRATION.md
@@ -36,9 +36,8 @@ shape is the same, connect, send, listen for delivery reports, with callbacks re
   Write `alert_on_message_delivery` and `broadcast_area_identifier`, the names they read back
   under, for `alert_on_msg_delivery` and `failed_broadcast_area_identifier`, which are gone from
   `tlvs` too.
-- **`session.loggedIn` is gone**: read `session.boundAs !== undefined`. `boundAs` and
-  `peerInterfaceVersion` are read-only; a session you construct yourself records a bind with
-  `session.bound()`.
+- **`session.loggedIn` is gone**: read `session.boundAs !== undefined`. A session you construct
+  yourself records a bind with `session.bound()`.
 - **The `error` event is `sessionError`**, and `serverError` on the server handle.
 - **`log`** takes any object with `debug`, `error`, `info`, `verbose` and `warn` methods instead of
   a `larvitutils` one, and is silent by default: [README](README.md#logging).
diff --git a/src/server.ts b/src/server.ts
index c069187..2b9aefe 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -170,18 +170,6 @@ function bindRespTlvs(session: Session, options: ServerOptions): TlvInputs | und
 	};
 }
 
-async function acceptBind(
-	session: Session,
-	pduObj: PduObject,
-	bindType: BindType,
-	options: ServerOptions,
-	identity: Record<string, string>,
-): Promise<void> {
-	const recorded = session.bound(bindType, pduObj.params.interface_version);
-
-	await session.sendReturn(pduObj, recorded.err ? 'ESME_RBINDFAIL' : 'ESME_ROK', identity, bindRespTlvs(session, options));
-}
-
 async function onBind(
 	session: Session,
 	pduObj: PduObject,
@@ -198,7 +186,16 @@ async function onBind(
 		return;
 	}
 
-	await acceptBind(session, pduObj, bindType, options, identity);
+	const recorded = session.bound(bindType, pduObj.params.interface_version);
+
+	if (recorded.err) {
+		session.log.info('server - bind refused', { message: recorded.err.message, systemId });
+		await session.sendReturn(pduObj, 'ESME_RBINDFAIL', identity);
+
+		return;
+	}
+
+	await session.sendReturn(pduObj, 'ESME_ROK', identity, bindRespTlvs(session, options));
 	session.log.verbose('server - bound', { systemId });
 }
 
diff --git a/src/session-options.ts b/src/session-options.ts
index dfb3325..15d8405 100644
--- a/src/session-options.ts
+++ b/src/session-options.ts
@@ -123,16 +123,14 @@ export const undeclaredInterfaceVersion = 0x00;
 
 export type SessionBind = { as: BindType; peerVersion: number };
 
-const bindTypes: readonly string[] = ['receiver', 'transceiver', 'transmitter'];
-
 function isBindType(value: unknown): value is BindType {
-	return typeof value === 'string' && bindTypes.includes(value);
+	return typeof value === 'string' && bindTypeFromCommand(`bind_${value}`) !== undefined;
 }
 
 /** A bind as `Session.bound()` records it: undefined declares no version, which is pre-3.4. */
 export function checkedBind(bindType: unknown, declaredVersion: unknown): Result<{ bind: SessionBind }> {
 	if (!isBindType(bindType)) {
-		return { err: new Error(`bindType must be ${bindTypes.join(', ')}, got ${namedValue(bindType)}`) };
+		return { err: new Error(`bindType must be receiver, transceiver or transmitter, got ${namedValue(bindType)}`) };
 	}
 
 	if (declaredVersion === undefined) return { bind: { as: bindType, peerVersion: undeclaredInterfaceVersion } };