svn commit: r359125 - head/lib/geom/eli

[Mateusz Piotrowski]

Author: 0mp (doc,ports committer)
Date: Thu Mar 19 09:23:26 2020
New Revision: 359125
URL: https://svnweb.freebsd.org/changeset/base/359125

Log:
  Document geli(8) loader variables conventions
  
  The geli(8) manual page has an example for preloading keyfiles during boot.
  There is no detail though on how the lookup of these variables actually
  works.
  
  Let's document that the name of a device does not have to be a part
  of the variable.
  
  PR:		243261
  Submitted by:	johannes at jo-t.de
  Approved by:	bcr (mentor)
  MFC after:	3 weeks
  Differential Revision:	https://reviews.freebsd.org/D24114

Modified:
  head/lib/geom/eli/geli.8

Modified: head/lib/geom/eli/geli.8
==============================================================================
--- head/lib/geom/eli/geli.8	Thu Mar 19 09:21:27 2020	(r359124)
+++ head/lib/geom/eli/geli.8	Thu Mar 19 09:23:26 2020	(r359125)
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 23, 2019
+.Dd March 19, 2020
 .Dt GELI 8
 .Os
 .Sh NAME
@@ -1012,6 +1012,35 @@ geli_da1s3a_keyfile_load="YES"
 geli_da1s3a_keyfile_type="da1s3a:geli_keyfile"
 geli_da1s3a_keyfile_name="/boot/keys/da1s3a.key"
 .Ed
+.Pp
+By convention, these loader variables are called
+.Sm off
+.Va geli_ No < Ar device No > Va _load .
+.Sm on
+However, the actual name prefix before
+.Va _load , _type ,
+or
+.Va _name
+does not matter.
+At boot time, the
+.Nm
+module searches through all
+.Sm off
+.No < Va prefix No > Va _type No -like
+.Sm on
+variables that have a value of
+.Sm off
+.Dq < Ar device No > :geli_keyfile .
+.Sm on
+The paths to keyfiles are then extracted from
+.Sm off
+.No < Ar prefix No > Va _name
+.Sm on
+variables.
+In the example above,
+.Ar prefix
+is
+.Dq Li geli_da1s3a_keyfile .
 .Pp
 Not only configure encryption, but also data integrity verification using
 .Nm HMAC/SHA256 .