INTERNET-DRAFT Leif Johansson Intented Category: Experimental Stockholm University A directory (X.500 and LDAPv3) schema for Berkely automounter 1. Status of this Memo This memo describes a directory (LDAP or X.500) schema for storing amd (Berkely- style automounter) mount info maps. The schema is currently beeing supported by the (beta version of the) am-utils version 6 package [AMUTILS]. 2. Overview and Rationale Directory services such as X.500 [X500] or LDAP [RFC2251] are a natural choice of repository for amd mount map databases. All Object Identifiers in this document are prefixed by amdSchema-id to be assigned later. The relation between this schema and the automount schema elements in [HOWARD] are mostly superficial. The model for the elements in [HOWARD] was the SUN automounter which has quite a different syntax for mount maps. Furthermore the intended usage of this schema differs from that of [HOWARD] in many respects. 3. DSA requirements Directory servers implementing this schema SHOULD maintain the modifyTimestamp operational attribute. If not the amdMapCacheTtl attribute SHOULD be set to 0 indicating to clients that caching of map entries SHOULD be turned off. Clients wishing to use the amdMap schema MAY use the modifyTimestamp information to set the ttl for internal caching schemes. A value of 0 for the amdMapCacheTtl must result in clients turning off any local caching. 4. Syntax definitions The following attribute syntax is defined in this document: amdlocationlist This syntax represents a amd map value. This is the syntax expressed in BNF using definitions from [RFC2252]: amdlocationlist = amdlocationselection | amdlocationlist whsp "||" whsp amdlocationselection amdlocationselection = amdlocation | amdlocationselection whsp amdlocation Johansson [Page 1] Internet draft Berkeley AMD LDAP Schema 30 March 1998 amdlocation = amdlocationinfo | "-" amdlocationinfo | "-" amdlocationinfo = seloropt | amdlocationinfo ";" seloropt | ";" seloropt = seletion | optass selection = keystring "==" printablestring keystring "!=" printablestring optass = keystring X.500 servers or LDAPv3 servers (supporting the binary attribute option) may use the following syntax definition: AmdLocationList ::= SEQUENCE OF { SEQUENCE OF { location AmdLocation } } AmdLocation ::= SET OF { CHOICE { location [0] AmdLocationInfo notlocation [1] AmdLocationInfo not [2] NULL } } AmdLocationInfo ::= SET OF { CHOICE { selection [0] AmdSelection option [1] AmdOption } } AmdSelection ::= CHOICE { eq [0] AttributeAndValue ne [1] AttributeAndValue } AmdOption ::= AttributeAndValue AttributeAndValue ::= SEQUENCE { attribute IA5String Johansson [Page 2] Internet draft Berkeley AMD LDAP Schema 30 March 1998 value IA5String } 5. Attribute types The following attribute types are defined in this document: amdMapName amdMapCacheTtl amdMapEntry amdMapEntryKey amdMapEntryValue amdSchema-a OBJECT IDENTIFIER ::= { amdSchema-id 1 } amdMapName ATTRIBUTE ::= { WITH SYNTAX IA5String EQUALITY MATCHING RULE caseIgoreExactMatch --ID { amdSchema-a 1 } DESCRIPTION "This attribute is the symbolic and in the naming context unique name of an amd map. This corresponds in the case of a flat file database to the name of the file or the mount-point of the map." } amdMapCacheTtl ATTRIBUTE ::= { WITH SYNTAX Integer EQUALITY MATCHING RULE integerExactMatch --ID { amdSchema-a 2 } SINGLE VALUED DESCRIPTION "The maximum time-to-live for the entries in this map. After this many milliseconds the map has to be cleared from local caches and reloaded. A value of 0 disables caching." } amdMapEntry ATTRIBUTE ::= { WITH SYNTAX DistinguishedName EQUALITY MATHCING RULE dNCaseIgnoreExactMatch --ID { amdSchema-a 3 } DESCRIPTION "A multivalued attribute listing the distinguished names of the amdMapEntries making up this amdMap Johansson [Page 3] Internet draft Berkeley AMD LDAP Schema 30 March 1998 object." } amdMapEntryKey ::= { ATTRIBUTE ::= { WITH SYNTAX IA5String EQUALITY MATCHING RULE stringExactMatch --ID { amdSchema-a 4 } SINGLE VALUED DESCRIPTION "The value of this attribute is usually the name of a mountpoint for this amdMapEntry." } amdMapEntryValue ::= { ATTRIBUTE ::= { WITH SYNTAX AmdLocationList --ID { amdSchema-a 5 } DESCRIPTION "This is the actual mount information for the amdMapEntry using the syntax described above." } amdMapEntryKey ::= { ATTRIBUTE ::= { WITH SYNTAX IA5String EQUALITY MATCHING RULE stringExactMatch --ID { amdSchema-a 4 } SINGLE VALUED DESCRIPTION "The value of this attribute is usually the name of a mountpoint for this amdMapEntry." } amdMapEntryValue ::= { ATTRIBUTE ::= { WITH SYNTAX AmdLocationList --ID { amdSchema-a 5 } DESCRIPTION "This is the actual mount information for the amdMapEntry using the syntax described above." } 6. Object classes The following object classes are defined in this document: amdMap Johansson [Page 4] Internet draft Berkeley AMD LDAP Schema 30 March 1998 amdMapEntry defined as follows: amdSchema-oc ::= { amdSchema-id 2 } amdMap OBJECT-CLASS ::= { SUBCLASS OF { top } KIND auxiliary --ID { amdSchema-oc 1 } MAY CONTAIN { amdMapCacheTtl , cn } MUST CONTAIN { amdMapName , amdMapEntry } } amdMapEntry OBJECT-CLASS ::= { SUBCLASS OF { top } KIND structural --ID { amdSchema-oc 2 } MUST CONTAIN { amdMapName , amdEntryKey , amdEntryValue , } MAY CONTAIN { cn } DESCRIPTION "An entry of this object class describes mount information relative to a certain amdMap entry" } 7. Examples 8. Security Considerations Due to the security problems posed by NFS care should be taken not to advertise exported filesystems. Therefore it is often desirable to limit access to entries carrying amd mount map information to those systems to which the corresponding filesystems have been exported. 9. References [AMUTILS] am-utils homepage: http://shekel.cs.columbia.edu/~erez/am-utils.html [RFC2251] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access Protocol (v3)", RFC 2251, December 1997. Johansson [Page 5] Internet draft Berkeley AMD LDAP Schema 30 March 1998 [RFC2252] M. Wahl, A. Coulbeck, T. Howes, S. Kille, "Lightweight Directory Access Protocol (v3): Attribute Syntax Definitions", RFC 2252, December 1997. [RFC2253] M. Wahl, S. Kille, T. Howes, "Lightweight Directory Access Protocol (v3): UTF-8 String Representation of Distinguished Names", RFC 2253, December 1997. [HOWARD] Luke Howard, "An Approach for Using LDAP as a Network Information Service", draft-howard-nis-schema-??.txt, Internet draft. [X500] ITU something or other. Author's Address Leif Johansson Department of Mathematics Stockholm University S-106 91 Stockholm SWEDEN Email: leifj@matematik.su.se Johansson [Page 6]