for the last script that started execution by manipulating
this object. The value will be zero if no script started
execution yet.
A script is started by setting this object to an unused
smRunIndex value. A new row in the smRunTable will be
created which is indexed by the value supplied by the
set-request in addition to the value of smLaunchOwner and
smLaunchName. An unused value can be obtained by reading
the smLaunchRunIndexNext object.
Setting this object to the special value 0 will start
the script with a self-generated smRunIndex value. The
consequence is that the script invoker has no reliable
way to determine the smRunIndex value for this script
invocation and that the invoker has therefore no way
to obtain the results from this script invocation. The
special value 0 is however useful for scheduled script
invocations.
If this object is set, the following checks must be
performed:
1) The value of the smLaunchOperStatus object in this
entry of the smLaunchTable must be `enabled'.
2) The values of smLaunchScriptOwner and
smLaunchScriptName of this row must identify an
existing entry in the smScriptTable.
3) The value of smScriptOperStatus of this entry must
be `enabled'.
4) The principal performing the set operation must have
read access to the script. This must be checked by
calling the isAccessAllowed abstract service interface
defined in RFC2271 on the row in the smScriptTable
identified by smLaunchScriptOwner and smLaunchScriptName.
The isAccessAllowed abstract service interface must be
called on all columnar objects in the smScriptTable with
a MAX-ACCESS value different than `not-accessible'. The
test fails as soon as a call indicates that access is
not allowed.
5) If the value provided by the set operation is not 0,
a check must be made that the value is currently not
in use. Otherwise, if the value provided by the set
operation is 0, a suitable unused value must be
generated.
6) The number of currently executing scripts invoked
from this smLaunchTable entry must be less than
smLaunchMaxRunning.
Attempts to start a script will fail with an
inconsistentValue error if one of the checks described
above fails.
Otherwise, if all checks have been passed, a new entry
in the smRunTable will be created indexed by smLaunchOwner,
smLaunchName and the new value for smRunIndex. The value
of smLaunchArgument will be copied into smRunArgument,
the value of smLaunchLifeTime will be copied to
smRunLifeTime, and the value of smLaunchExpireTime
will be copied to smRunExpireTime.
The smRunStartTime will be set to the current time and
the smRunState will be set to `initializing' before the
script execution is initiated in the appropriate runtime
system.
Note, the data type and the range of this object must
be consistent with the smRunIndex object. Since this
object might be written from the scheduling MIB, the
data type Integer32 rather than Unsigned32 is used."
DEFVAL { 0 }
::= { smLaunchEntry 10 }
smLaunchControl OBJECT-TYPE
SYNTAX INTEGER {
abort(1),
suspend(2),
resume(3),
nop(4)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object is used to request a state change for all
running scripts in the smRunTable that were started from
this row in the smLaunchTable.
Setting this object to abort(1), suspend(2) or resume(3)
will set the smRunControl object of all applicable rows
in the smRunTable to abort(1), suspend(2) or resume(3)
respectively. The phrase `applicable rows' means the set of
rows which were created from this entry in the smLaunchTable
and whose value of smRunState allows the corresponding
state change as described in the definition of the
smRunControl object. Setting this object to nop(4) has no
effect."
DEFVAL { nop }
::= { smLaunchEntry 11 }
smLaunchAdminStatus OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The value of this object indicates the desired status of
this launch table entry."
DEFVAL { disabled }
::= { smLaunchEntry 12 }
smLaunchOperStatus OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object indicates the actual status of
this launch table entry. An `enabled' launch table
entry can be used to start scripts while a `disabled'
launch table entry will refuse any attempts to start
scripts. The value `enabled' requires that the
smLaunchRowStatus object is active. The value
`disabled' requires that there are no entries in the
smRunTable associated with this smLaunchTable entry."
DEFVAL { disabled }
::= { smLaunchEntry 13 }
smLaunchRunIndexNext OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This variable is used for creating rows in the smRunTable.
The value of this variable is a currently unused value
for smRunIndex, which can be written into the smLaunchStart
object associated with this row to launch a script.
The value returned when reading this variable must be unique
for the smLaunchOwner and smLauchName associated with this
row. Subsequent attempts to read this variable must return
different values.
This variable will return the special value 0 if no new rows
can be created.
Note, the data type and the range of this object must be
consistent with the definition of smRunIndex."
::= { smLaunchEntry 14 }
smLaunchStorageType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object defines if this row is kept in volatile storage
and lost upon reboot or if this row is backed up by stable
storage.
The value of smLaunchStorageType is only meaningful if the
value of the corresponding RowStatus object is active.
If smLaunchStorageType has the value permanent(4), then all
objects whose MAX-ACCESS value is read-create must be
writable, with the exception of the smLaunchStorageType and
smLaunchRowStatus objects, which shall be read-only."
DEFVAL { volatile }
::= { smLaunchEntry 15 }
smLaunchRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A control that allows entries to be added and removed from
this table.
Attempts to `destroy' a row or to set a row `notInService'
while scripts started from this launch table entry are
running will result in an inconsistentValue error.
Attempts to `destroy' a row or to set a row `notInService'
where the value of the smLaunchStorageType object is
`permanent' or `readOnly' will result in an
inconsistentValue error."
::= { smLaunchEntry 16 }
smRunTable OBJECT-TYPE
SYNTAX SEQUENCE OF SmRunEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table lists and describes scripts that are currently
running or have been running in the past."
::= { smRunObjects 2 }
smRunEntry OBJECT-TYPE
SYNTAX SmRunEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry describing a particular running or finished
script."
INDEX { smLaunchOwner, smLaunchName, smRunIndex }
::= { smRunTable 1 }
SmRunEntry ::= SEQUENCE {
smRunIndex Integer32,
smRunArgument OCTET STRING,
smRunStartTime DateAndTime,
smRunEndTime DateAndTime,
smRunLifeTime TimeInterval,
smRunExpireTime TimeInterval,
smRunExitCode INTEGER,
smRunResult OCTET STRING,
smRunControl INTEGER,
smRunState INTEGER,
smRunError SnmpAdminString
}
smRunIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The locally arbitrary, but unique identifier associated
with this running or finished script. This value must be
unique for all rows in the smRunTable with the same
smLaunchOwner and smLaunchName.
Note, the data type and the range of this object must be
consistent with the definition of smLaunchRunIndexNext
and smLaunchStart."
::= { smRunEntry 1 }
smRunArgument OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The argument supplied to the script when it started."
DEFVAL { ''H }
::= { smRunEntry 2 }
smRunStartTime OBJECT-TYPE
SYNTAX DateAndTime
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The date and time when the execution started. The value
'0000000000000000'H is returned if the script has not
started yet."
DEFVAL { '0000000000000000'H }
::= { smRunEntry 3 }
smRunEndTime OBJECT-TYPE
SYNTAX DateAndTime
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The date and time when the execution terminated. The value
'0000000000000000'H is returned if the script has not
terminated yet."
DEFVAL { '0000000000000000'H }
::= { smRunEntry 4 }
smRunLifeTime OBJECT-TYPE
SYNTAX TimeInterval
UNITS "centi-seconds"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object specifies how long the script can execute.
This object returns the remaining time that the script
may run. The object is initialized with the value of the
associated smLaunchLifeTime object and ticks backwards.
The script is aborted immediately when the value reaches 0.
The value of this object may be set in order to increase or
reduce the remaining time that the script may run. Setting
this value to 0 will abort script execution immediately,
and, if the value of smRunExpireTime is also 0, will remove
this entry from the smRunTable once it has terminated.
The value of smRunLifeTime reflects the real-time execution
time as seen by the outside world. The value of this object
will always be 0 for a script that finished execution, that
is smRunState has the value `terminated'.
The value of smRunLifeTime does not change while a script
is suspended, that is smRunState has the value `suspended'.
Note, this does not affect set operations. It is legal to
modify smRunLifeTime via set operations while a script is
suspended."
::= { smRunEntry 5 }
smRunExpireTime OBJECT-TYPE
SYNTAX TimeInterval
UNITS "centi-seconds"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This value specifies how long this row can exist in the
smRunTable after the script has terminated. This object
returns the remaining time that the row may exist before it
is aged out. The object is initialized with the value of the
associated smLaunchExpireTime object and ticks backwards. The
entry in the smRunTable is destroyed when the value reaches 0
and the smRunState has the value `terminated'.
The value of this object may be set in order to increase or
reduce the remaining time that the row may exist. Setting
the value to 0 will destroy this entry as soon as the
smRunState has the value `terminated'."
::= { smRunEntry 6 }
smRunExitCode OBJECT-TYPE
SYNTAX INTEGER {
noError(1),
halted(2),
lifeTimeExceeded(3),
noResourcesLeft(4),
languageError(5),
runtimeError(6),
invalidArgument(7),
securityViolation(8),
genericError(9)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object indicates the reason why a
script finished execution. The smRunExitCode code may have
one of the following values:
- `noError', which indicates that the script completed
successfully without errors;
- `halted', which indicates that the script was halted
by a request from an authorized manager;
- `lifeTimeExceeded', which indicates that the script
exited because a time limit was exceeded;
- `noResourcesLeft', which indicates that the script
exited because it ran out of resources (e.g. memory);
- `languageError', which indicates that the script exited
because of a language error (e.g. a syntax error in an
interpreted language);
- `runtimeError', which indicates that the script exited
due to a runtime error (e.g. a division by zero);
- `invalidArgument', which indicates that the script could
not be run because of invalid script arguments;
- `securityViolation', which indicates that the script
exited due to a security violation;
- `genericError', which indicates that the script exited
for an unspecified reason.
If the script has not yet begun running, or is currently
running, the value will be `noError'."
DEFVAL { noError }
::= { smRunEntry 7 }
smRunResult OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The result value produced by the running script. Note that
the result may change while the script is executing."
DEFVAL { ''H }
::= { smRunEntry 8 }
smRunControl OBJECT-TYPE
SYNTAX INTEGER {
abort(1),
suspend(2),
resume(3),
nop(4)
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The value of this object indicates the desired status of the
script execution defined by this row.
Setting this object to `abort' will abort execution if the
value of smRunState is `initializing', `executing',
`suspending', `suspended' or `resuming'. Setting this object
to `abort' when the value of smRunState is `aborting' or
`terminated' will result in an inconsistentValue error.
Setting this object to `suspend' will suspend execution
if the value of smRunState is `executing'. Setting this
object to `suspend' will cause an inconsistentValue error
if the value of smRunState is not `executing'.
Setting this object to `resume' will resume execution
if the value of smRunState is `suspending' or
`suspended'. Setting this object to `resume' will cause an
inconsistentValue error if the value of smRunState is
not `suspending' or `suspended'.
Setting this object to nop(4) has no effect."
DEFVAL { nop }
::= { smRunEntry 9 }
smRunState OBJECT-TYPE
SYNTAX INTEGER {
initializing(1),
executing(2),
suspending(3),
suspended(4),
resuming(5),
aborting(6),
terminated(7)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object indicates the script's execution
status. If the script has been invoked but has not yet
begun execution, the value will be `initializing'. If the
script is running, the value will be `executing'. A script
which received a request to suspend execution but which
did not actually suspend execution will be `suspending'.
A script which has suspended execution will be `suspended'.
A script which received a request to resume execution but
which is not yet running is `resuming'. The resuming state
will finally lead to the `executing' state. A script which
received a request to abort execution but which is still
running is `aborting'. A script which stopped execution
is `terminated'."
::= { smRunEntry 10 }
smRunError OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This contains a descriptive error message if the script
terminates in an abnormally. An implementation must store a
descriptive error message in this object if the script exits
with the smRunExitCode `genericError'.
The value of this object is the zero-length string as long
as the smRunExitCode has the value `noError'"
DEFVAL { ''H }
::= { smRunEntry 11 }
--
-- Notifications. The definition of smTraps makes notification
-- registrations reversible (see STD 58, RFC2578).
--
smTraps OBJECT IDENTIFIER ::= { smNotifications 0 }
smScriptAbort NOTIFICATION-TYPE
OBJECTS { smRunExitCode, smRunEndTime, smRunError }
STATUS current
DESCRIPTION
"This notification is generated whenever a running script
terminates with an smRunExitCode unequal to `noError'."
::= { smTraps 1 }
smScriptResult NOTIFICATION-TYPE
OBJECTS { smRunResult }
STATUS current
DESCRIPTION
"This notification can be used by scripts to notify other
management applications about script results. It can be
used to notify managers about a script result.
This notification is not automatically generated by the
script MIB implementation. It is the responsibility of
the executing script to emit this notification where it
is appropriate to do so."
::= { smTraps 2 }
-- conformance information
smCompliances OBJECT IDENTIFIER ::= { smConformance 1 }
smGroups OBJECT IDENTIFIER ::= { smConformance 2 }
-- compliance statements
smCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for SNMP entities which implement
the script MIB."
MODULE -- this module
MANDATORY-GROUPS {
smLanguageGroup, smScriptGroup, smLaunchGroup, smRunGroup
}
GROUP smCodeGroup
DESCRIPTION
"The smCodeGroup is mandatory only for those implementations
that support the downloading of scripts via SNMP."
OBJECT smScriptSource
MIN-ACCESS read-only
DESCRIPTION
"The smScriptSource object is read-only for implementations
that are not able to download script code from a URL."
OBJECT smLaunchArgument
DESCRIPTION
"A compliant implementation has to support a minimum size
for smLaunchArgument of 255 octets."
OBJECT smRunArgument
DESCRIPTION
"A compliant implementation has to support a minimum size
for smRunArgument of 255 octets."
OBJECT smRunResult
DESCRIPTION
"A compliant implementation has to support a minimum size
for smRunResult of 255 octets."
OBJECT smRunState
DESCRIPTION
"A compliant implementation does not have to support script
suspension and the smRunState `suspended'. Such an
implementation will change into the `suspending' state
when the smRunControl is set to `suspend' and remain in this
state until smRunControl is set to `resume' or the script
terminates."
::= { smCompliances 1 }
smLanguageGroup OBJECT-GROUP
OBJECTS {
smLangLanguage,
smLangVersion,
smLangVendor,
smLangRevision,
smLangDescr,
smExtsnExtension,
smExtsnVersion,
smExtsnVendor,
smExtsnRevision,
smExtsnDescr
}
STATUS current
DESCRIPTION
"A collection of objects providing information about the
capabilities of the scripting engine."
::= { smGroups 1 }
smScriptGroup OBJECT-GROUP
OBJECTS {
smScriptDescr,
smScriptLanguage,
smScriptSource,
smScriptAdminStatus,
smScriptOperStatus,
smScriptStorageType,
smScriptRowStatus
}
STATUS current
DESCRIPTION
"A collection of objects providing information about
installed scripts."
::= { smGroups 2 }
smCodeGroup OBJECT-GROUP
OBJECTS {
smCodeText,
smCodeRowStatus
}
STATUS current
DESCRIPTION
"A collection of objects used to download or modify scripts
by using SNMP set requests."
::= { smGroups 3 }
smLaunchGroup OBJECT-GROUP
OBJECTS {
smLaunchScriptOwner,
smLaunchScriptName,
smLaunchArgument,
smLaunchMaxRunning,
smLaunchMaxCompleted,
smLaunchLifeTime,
smLaunchExpireTime,
smLaunchStart,
smLaunchControl,
smLaunchAdminStatus,
smLaunchOperStatus,
smLaunchRunIndexNext,
smLaunchStorageType,
smLaunchRowStatus
}
STATUS current
DESCRIPTION
"A collection of objects providing information about scripts
that can be launched."
::= { smGroups 4 }
smRunGroup OBJECT-GROUP
OBJECTS {
smRunArgument,
smRunStartTime,
smRunEndTime,
smRunLifeTime,
smRunExpireTime,
smRunExitCode,
smRunResult,
smRunState,
smRunControl,
smRunError
}
STATUS current
DESCRIPTION
"A collection of objects providing information about running
scripts."
::= { smGroups 5 }
smNotificationsGroup NOTIFICATION-GROUP
NOTIFICATIONS {
smScriptAbort,
smScriptResult
}
STATUS current
DESCRIPTION
"The notifications emitted by the script MIB."
::= { smGroups 6 }
END
7. Usage Examples
This section presents some examples that explain how a manager can
use the Script MIB defined in this memo. The purpose of these
examples is to explain the steps that are normally used to delegate
management scripts.
7.1. Pushing a script via SNMP
This example explains the steps performed by a manager to push a
script into a distributed manager.
1. The manager first checks the smLanguageTable and the
smExtensionTable in order to select the appropriate script or
language.
2. The manager creates a row in the smScriptTable by issuing an
SNMP set-request. The smScriptRowStatus object is set to
`createAndWait' and the smScriptSource object is set to an empty
string. The smScriptLanguage object is set to the language in
which the script was written. The smScriptStorageType object is
set to `volatile' to indicate that the script will be loaded via
the smCodeTable. The smScriptOwner is set to a string which
identifies the principal who owns the new row. The smScriptName
defines the administratively assigned unique name for the
script.
3. The manager sets the smScriptRowStatus object to `active' and
the smScriptAdminStatus object to `editing'.
4. The manager pushes the script to the distributed manager by
issuing a couple of SNMP set-requests to fill the smCodeTable.
5. Once the whole script has been transferred, the manager sends a
set-request to set the smScriptAdminStatus object to `enabled'.
The Script MIB implementation now makes the script accessible to
the runtime system. This might include the compilation of the
script if the language requires a compilation step.
6. The manager polls the smScriptOperStatus object until the value
is either `enabled' or one of the error status codes. The
script can only be used if the value of smScriptOperStatus is
`enabled'.
7. If the manager wants to store the script in local non-volatile
storage, it should send a set-request which changes the
smScriptStorageType object to `nonVolatile'.
7.2. Pulling a script from a URL
This example explains the steps performed by a manager to cause a
distributed manager to pull a script from a URL.
1. The manager first checks the smLanguageTable and the
smExtensionTable in order to select the appropriate script or
language.
2. The manager creates a row in the smScriptTable by issuing an
SNMP set-request. The smScriptRowStatus object is set to
`createAndWait' and the smScriptSource object is set to the URL
which points to the script source. The smScriptLanguage object
is set to the language in which the script was written. The
smScriptOwner is set to a string which identifies the principal
who owns the new row. The smScriptName defines the
administratively assigned unique name for the script.
3. The manager sets the smScriptRowStatus object to `active'.
4. The manager sends a set-request to set the smScriptAdminStatus
object to `enabled'. The Script MIB implementation now makes the
script accessible to the runtime system. This causes a retrieval
operation to pull the script from the URL stored in
smScriptSource. This retrieval operation might be followed by a
compile operation if the language requires a compilation step.
5. The manager polls the smScriptOperStatus object until the value
is either `enabled' or one of the error status codes. The
script can only be used if the value of smScriptOperStatus is
`enabled'.
6. If the manager wants to store the script in local non-volatile
storage, it should send a set-request which changes the
smScriptStorageType object to `nonVolatile'.
7.3. Modifying an existing script
This section explains how a manager can modify a script by sending
SNMP set-requests.
1. First, the script is de-activated by setting the
smScriptAdminStatus to `disabled'.
2. The manager polls the smScriptOperStatus object until the value
is `disabled'.
3. The manager sets smScriptSource to an empty string and
smScriptAdminStatus to `editing'. This makes the script source
available in the smCodeTable.
4. The manager polls the smScriptOperStatus object until the value
is `editing'.
5. The manager sends SNMP set-requests to modify the script in the
smCodeTable.
6. The manager sends a set-request to set the smScriptAdminStatus
object to `enabled'. The Script MIB implementation now makes the
script accessible to the runtime system. This might include the
compilation of the script if the language requires a compilation
step.
7. The manager polls the smScriptOperStatus object until the value
is either `enabled' or one of the error status codes. The
script can only be used if the value of smScriptOperStatus is
`enabled'.
7.4. Removing an existing script
This section explains how a manager can remove a script from a
distributed manager.
1. First, the manager sets the smScriptAdminStatus to `disabled'.
This will ensure that no new scripts can be started while
running scripts finish their execution.
2. The manager polls the smScriptOperStatus object until the value
is `disabled'.
3. The manager sends an SNMP set-request to change the
smScriptRowStatus object to `destroy'. This will remove the row
and all associated resources from the Script MIB implementation.
7.5. Creating a launch button
This section explains how a manager can create a launch button for
starting a script.
1. The manager, who is identified by an smLaunchOwner value, first
chooses a name for the new row in the smLaunchTable. The manager
sends an SNMP set-request to set the smLaunchRowStatus object
for this smLaunchOwner and smLaunchName to `createAndWait'.
2. The manager fills the new smLaunchTable row with all required
parameters. The smLaunchScriptOwner and smLaunchScriptName
values point to the script that should be started from this
launch button.
3. The manager sends a set-request to change smLaunchAdminStatus to
`enabled' once the new smLaunchTable row is complete.
4. The manager polls the smLaunchOperStatus object until the value
is `enabled'.
7.6. Launching a script
This section explains the suggested way to launch a script from a
given launch button.
1. The manager first retrieves the value of smLaunchRunIndexNext
from the launch button selected to start the script.
2. The manager sends an SNMP set-request to set the smLaunchStart
object to the value obtained in step 1. This will launch the
script if all necessary pre-conditions are satisfied (see the
definition of smLaunchStart for more details). The manager can
also provide the smLaunchArgument in the same set-request that
is used to start the script. Upon successful start, a new row
will be created in the smRunTable indexed by smLaunchOwner,
smLaunchName and the value written to smLaunchStart.
Note, the first step is not required. A manager can also try to guess
an unused value for smRunIndex if he wants to start script in a
single transaction. A manager can also use the special value 0 if he
does not care about the results produced by the script.
7.7. Terminating a script
This section explains two ways to terminate a running script. The
first approach is as follows:
1. The manager sets the smRunControl object of the running script
or the smLaunchControl object of the launch button used to start
the running script to `abort'. Setting smLaunchControl will
abort all running scripts started from the launch button while
smRunControl will only abort the running script associated with
the smRunControl instance.
The second way to terminate a script is to set the smRunLifeTime to
zero which causes the runtime system to terminate the script with a
`lifeTimeExceeded' exit code:
1. The manager changes the value of smRunLifeTime to 0. This causes
the Script MIB implementation to abort the script because the
remaining life time has expired.
Note, changing the smRunLifeTime value can also be used to increase
the permitted lifetime of a running script. For example, a manager
can choose to set smRunLifeTime to a small fixed time interval and
increase the value periodically. This strategy has the nice effect
that scripts terminate automatically if the manager loses contact
with the Script MIB engine.
7.8. Removing a launch button
This section explains how a manager can remove a launch button from a
distributed manager.
1. First, the manager sets the smLaunchAdminStatus to
`disabled'. This will ensure that no new scripts can be started
from this launch button while running script will finish their
execution.
2. The manager polls the smLaunchOperStatus object until the value
is `disabled'.
3. The manager sends an SNMP set-request to change the
smLaunchRowStatus object to `destroy'. This will remove the row
and all associated resources from the Script MIB implementation.
8. VACM Configuration Examples
This section shows how the view-based access control model defined in
RFC2275 [15] can be configured to control access to the script MIB.
8.1. Sandbox for guests
The first example demonstrates how to configure VACM to give the
members of the VACM group "guest" limited access to the script MIB.
The MIB views defined below give the members of the "guest" group a
sandbox where they can install and start their own scripts, but not
access any other scripts maintained by the Script MIB implementation.
vacmAccessReadView."guest"."".usm.authNoPriv = "guestReadView"
vacmAccessWriteView."guest"."".usm.authNoPriv = "guestWriteView"
The guestReadView grants read access to the smLangTable, the
smExtsnTable and to all the table entries owned by "guest":
guestReadView:
smLangTable (included)
smExtsnTable (included)
smScriptObjects.*.*.*."guest" (included)
smRunObjects.*.*.*."guest" (included)
The guestWriteView grants write access to all the table entries owned
by "guest":
guestWriteView:
smScriptObjects.*.*.*."guest" (included)
smRunObjects.*.*.*."guest" (included)
8.2. Sharing scripts
This example demonstrates how VACM can be used to share a repository
of scripts between the members of the "senior" and the members of the
"junior" VACM group:
vacmAccessReadView."junior"."".usm.authNoPriv = "juniorReadView"
vacmAccessWriteView."junior"."".usm.authNoPriv = "juniorWriteView"
juniorReadView:
smLangTable (included)
smExtsnTable (included)
smScriptObjects.*.*.*."junior" (included)
smRunObjects.*.*.*."junior" (included)
smScriptObjects.*.*.*."utils" (included)
juniorWriteView:
smScriptObjects.*.*.*."junior" (included)
smRunObjects.*.*.*."junior" (included)
The definitions above allow the members of the "junior" VACM group to
start the scripts owned by "utils" in addition to the script the
members of the "junior" VACM group installed themself. This is
accomplished by giving the members of "junior" read access to scripts
in "utils". This allows members of "junior" to create entries in the
smLauchTable which refer to scripts in "utils", and to launch those
scripts using these entries in the smLaunchTable.
vacmAccessReadView."senior"."".usm.authNoPriv = "seniorReadView"
vacmAccessWriteView."senior"."".usm.authNoPriv = "seniorWriteView"
seniorReadView:
smLangTable (included)
smExtsnTable (included)
smScriptObjects.*.*.*."senior" (included)
smRunObjects.*.*.*."senior" (included)
smScriptObjects.*.*.*."utils" (included)
seniorWriteView:
smScriptObjects.*.*.*."senior" (included)
smRunObjects.*.*.*."senior" (included)
smScriptObjects.*.*.*."utils" (included)
The definitions for the members of the "senior" VACM group allow to
start the scripts owned by "utils" in addition to the script the
members of the "senior" VACM group installed themself. The third
write access rule in the seniorWriteView also grants the permission
to install scripts owned by "utils". The members of the "senior" VACM
group therefore have the permissions to install and modify scripts
that can be called by the members of the "junior" VACM group.
8.3. Emergency scripts
This example demonstrates how VACM can be used to allow the members
of the "junior" VACM group to launch scripts that are executed with
the permissions associated with the "emergency" owner. This works by
adding the following rules to the juniorReadView and the
juniorWriteView:
juniorReadView:
smScriptObjects.*.*.*."emergency" (included)
smRunObjects.*.*.*."emergency" (included)
juniorWriteView
smLaunchStart."emergency" (included)
smLaunchArgument."emergency" (included)
The rules added to the juniorReadView grant read access to the
scripts, the launch buttons and the results owned by "emergency". The
rules added to the juniorWriteView grant write permissions to the
smLaunchStart and smLaunchArgument variables ownded by "emergency".
Members of the "junior" VACM group can therefore start scripts that
will execute under the owner "emergency".
seniorReadView:
smScriptObjects.*.*.*."emergency" (included)
smRunObjects.*.*.*."emergency" (included)
seniorWriteView:
smScriptObjects.*.*.*."emergency" (included)
smRunObjects.*.*.*."emergency" (included)
The rules added to the seniorReadView and the seniorWriteView will
give the members of the "senior" VACM group the rights to install
emergency scripts and to configure appropriate launch buttons.
9. IANA Considerations
The Internet Assigned Numbers Authority (IANA) is responsible for
maintaining a MIB module which provides OID registrations for well-
known languages. The IANA language registry is intented to reduce
interoperability problems by providing a single list of well-known
languages. However, it is of course still possible to register
languages in private OID spaces. Registering languages in private
spaces is especially attractive if a language is used for
experimentation or if a language is only used in environments where
the distribution of MIB modules with the language registration does
not cause any maintenance problems.
Any additions or changes to the list of languages registered via IANA
require Designated Expert Review as defined in the IANA guidelines
[20]. The Designated Expert will be selected by the IESG Area
Director for the IETF Operations and Management Area.
10. Security Considerations
This MIB provides the ability to distribute applications written in
an arbitrary language to remote systems in a network. The security
features of the languages available in a particular implementation
should be taken into consideration when deploying an implementation
of this MIB.
To facilitate the provisioning of access control by a security
administrator using the View-Based Access Control Model (VACM)
defined in RFC2275 [15] for tables in which multiple users may need
to independently create or modify entries, the initial index is used
as an "owner index". Such an initial index has a syntax of
SnmpAdminString, and can thus be trivially mapped to a securityName
or groupName as defined in VACM, in accordance with a security
policy.
All entries in related tables belonging to a particular user will
have the same value for this initial index. For a given user's
entries in a particular table, the object identifiers for the
information in these entries will have the same subidentifiers
(except for the "column" subidentifier) up to the end of the encoded
owner index. To configure VACM to permit access to this portion of
the table, one would create vacmViewTreeFamilyTable entries with the
value of vacmViewTreeFamilySubtree including the owner index portion,
and vacmViewTreeFamilyMask "wildcarding" the column subidentifier.
More elaborate configurations are possible.
The VACM access control mechanism described above provides control
over SNMP access to Script MIB objects. There are a number of other
access control issues that are outside of the scope of this MIB. For
example, access control on URLs, especially those that use the file
scheme, must be realized by the underlying operating system. A
mapping of the owner index value to a local operating system security
user identity should be used by an implementation of this MIB to
control access to operating system resources when resolving URLs or
executing scripts.
11. Intellectual Property
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementors or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
12. Acknowledgments
This document was produced by the IETF Distributed Management
(DISMAN) working group.
13. References
[1] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
Describing SNMP Management Frameworks", RFC2271, January 1998.
[2] Rose, M. and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based Internets", STD 16, RFC
1155, May 1990.
[3] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
RFC1212, March 1991.
[4] Rose, M., "A Convention for Defining Traps for use with the
SNMP", RFC1215, March 1991.
[5] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
M. and S. Waldbusser, "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC2578, April 1999.
[6] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
M. and S. Waldbusser, "Textual Conventions for SMIv2", STD 58,
RFC2579, April 1999.
[7] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose,
M. and S. Waldbusser, "Conformance Statements for SMIv2", STD
58, RFC2580, April 1999.
[8] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
Network Management Protocol", STD 15, RFC1157, May 1990.
[9] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
"Introduction to Community-based SNMPv2", RFC1901, January
1996.
[10] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Transport
Mappings for Version 2 of the Simple Network Management Protocol
(SNMPv2)", RFC1906, January 1996.
[11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
Processing and Dispatching for the Simple Network Management
Protocol (SNMP)", RFC2272, January 1998.
[12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
for version 3 of the Simple Network Management Protocol
(SNMPv3)", RFC2274, January 1998.
[13] Case, J., McCloghrie, K., Rose, M. and S. Waldbusser, "Protocol
Operations for Version 2 of the Simple Network Management
Protocol (SNMPv2)", RFC1905, January 1996.
[14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
2273, January 1998.
[15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
Control Model (VACM) for the Simple Network Management Protocol
(SNMP)", RFC2275, January 1998.
[16] Hovey, R. and S. Bradner, "The Organizations Involved in the
IETF Standards Process", BCP 11, RFC2028, October 1996.
[17] Berners-Lee, T., Fielding, R. and L. Masinter, " Uniform
Resource Identifiers (URI): Generic Syntax", RFC2396, August
1998.
[18] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9, RFC
959, October 1985.
[19] Fielding, R., Gettys, J., Mogul, J., Frystyk, H. and T.
Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC
2068, January 1997.
[20] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA
Considerations Section in RFCs", BCP 26, RFC2434, October 1998.
[21] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC2119, March 1997.
14. Editors' Addresses
David B. Levi
Nortel Networks
4401 Great America Parkway
Santa Clara, CA 95052-8185
U.S.A.
Phone: +1 423 686 0432
EMail: dlevi@nortelnetworks.com
Juergen Schoenwaelder
TU Braunschweig
Bueltenweg 74/75
38106 Braunschweig
Germany
Phone: +49 531 391-3683
EMail: schoenw@ibr.cs.tu-bs.de
16. Full Copyright Statement
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