swanctl: Document the type/size of interface IDs

diff --git a/src/swanctl/swanctl.opt b/src/swanctl/swanctl.opt
index 9cdf78434d85a5cd98664413dc551766d004e02a..92da6103724c2c68cdef19b6f9660e94747a998e 100644 (file)
--- a/src/swanctl/swanctl.opt
+++ b/src/swanctl/swanctl.opt
@@ -1002,7 +1002,7 @@ connections.<conn>.children.<child>.set_mark_out = 0/0x00000000
        requires at least Linux 4.19.
 
 connections.<conn>.children.<child>.if_id_in = 0
-       Inbound XFRM interface ID.
+       Inbound XFRM interface ID (32-bit unsigned integer).
 
        XFRM interface ID set on inbound policies/SA. This allows installing
        duplicate policies/SAs and associates them with an interface with the same
@@ -1011,7 +1011,7 @@ connections.<conn>.children.<child>.if_id_in = 0
        interface ID for each CHILD_SA direction (in/out).
 
 connections.<conn>.children.<child>.if_id_out = 0
-       Outbound XFRM interface ID.
+       Outbound XFRM interface ID (32-bit unsigned integer).
 
        XFRM interface ID set on outbound policies/SA. This allows installing
        duplicate policies/SAs and associates them with an interface with the same