Internet Draft Policy-Based Management MIB June 11, 2001
Policy Based Management MIB
draft-ietf-snmpconf-pm-06.txt
June 11, 2001
Steve Waldbusser
Jon Saperia
Thippanna Hongal
Status of this Memo
This document is an Internet-Draft and is in full conformance
with all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet
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Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
1. Abstract
This memo defines a portion of the Management Information Base
(MIB) for use with network management protocols in TCP/IP-
based internets. In particular, this MIB defines objects that
enable policy-based configuration management of SNMP
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infrastructures.
2. The SNMP Management Framework
The SNMP Management Framework presently consists of five
major components:
o An overall architecture, described in RFC 2571 [1].
o Mechanisms for describing and naming objects and
events for the purpose of management. The first
version of this Structure of Management Information
(SMI) is called SMIv1 and described in STD 16, RFC
1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4]. The
second version, called SMIv2, is described in STD 58,
RFC 2578 [5], RFC 2579 [6] and RFC 2580 [7].
o Message protocols for transferring management
information. The first version of the SNMP message
protocol is called SNMPv1 and described in STD 15, RFC
1157 [8]. A second version of the SNMP message
protocol, which is not an Internet standards track
protocol, is called SNMPv2c and described in RFC 1901
[9] and RFC 1906 [10]. The third version of the
message protocol is called SNMPv3 and described in RFC
1906 [10], RFC 2572 [11] and RFC 2574 [12].
o Protocol operations for accessing management
information. The first set of protocol operations and
associated PDU formats is described in STD 15, RFC
1157 [8]. A second set of protocol operations and
associated PDU formats is described in RFC 1905 [13].
o A set of fundamental applications described in RFC
2573 [14] and the view-based access control mechanism
described in RFC 2575 [15].
A more detailed introduction to the current SNMP Management
Framework can be found in RFC 2570 [18].
Managed objects are accessed via a virtual information
store, termed the Management Information Base or MIB.
Objects in the MIB are defined using the mechanisms defined
in the SMI.
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This memo specifies a MIB module that is compliant to the
SMIv2. A MIB conforming to the SMIv1 can be produced
through the appropriate translations. The resulting
translated MIB must be semantically equivalent, except
where objects or events are omitted because no translation
is possible (use of Counter64). Some machine readable
information in SMIv2 will be converted into textual
descriptions in SMIv1 during the translation process.
However, this loss of machine readable information is not
considered to change the semantics of the MIB.
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3. Overview
Large IT organizations have developed management strategies to cope
with the extraordinarily large scale and complexity inherent in
today's networks. In particular, they try to configure the network as
a whole by describing and implementing high-level business policies,
rather than managing device by device, where orders of magnitude more
decisions (and mistakes) may be made.
Following this management practice results in the following benefits:
- Reduced training needs (fewer details to learn)
- Reduced documentation costs (fewer details to document)
- Reduced impact of turnover (less ad-hoc knowledge goes out the door)
- Greater testability (a greater percentage of fielded
configurations may be tested in the lab)
- Higher reliability (combination of factors above)
- Lower cost of changes (changes can be simpler and operate over a
wider extent)
- Lower cost of corporate mergers (less knowledge to transfer; fewer
policies to integrate)
- Lower cost of ownership (combination of factors above)
To illustrate the concept of "business policies", some examples are:
- All routers will run code version 6.2
- On-site contractors will all have special security restrictions on
their ports
- All voice over cable ports in California must provide free local
calling
- Apply special forwarding to all ports whose customers have paid
for premium service.
Each of these policies could represent an action applied to hundreds
of thousands of configuration variables.
In order to automate this practice, customers need software tools that
will implement business policies across their network, as well as
a standard protocol that will ensure that it can be applied to all of
their devices, regardless of the vendor.
This practice is called Policy-Based Management. This document
defines standard managed objects for the Simple Network Management
Protocol that are used to distribute policies in a standard form
throughout the network.
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4. Policy-Based Management Architecture
Policy-based management is the practice of applying management
operations globally on all managed elements that share certain
attributes.
Policies are intended to express a notion of:
if (an element has certain characteristics) then (apply operation to
that element)
Policies take the following normal form:
if (policyCondition) then (policyAction)
A policyCondition is program code which results in a boolean
to determine whether or not an element is a member of a set of
elements upon which an action is to be performed.
A policyAction is an operation performed on an element or a set of
elements.
These policies are most often executed on or near managed devices,
where the elements live (and thus their characteristics may be easily
inspected), and where operations on those elements will be performed.
A management station is responsible for distributing an organization's
policies to all of the managed devices in the infrastructure. The
pmPolicyTable provides managed objects for representing a policy on a
managed device.
An element is an instance of a physical or logical entity and is
embodied by a group of related MIB variables such as all the variables
for interface #7. This enables policies to be expressed more
efficiently and concisely. Elements can also model circuits, CPUs,
queues, processes, systems, etc.
Conceptually, policies are executed in the following manner:
foreach element for which policyCondition returns true
execute policyAction on that element
For example:
If (interface is fast ethernet) then (apply full-duplex mode)
If (interface is access) then (apply security filters)
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If (circuit w/gold service paid for) then (apply special queuing)
Each unique combination of policy and element is called an execution
context. Within a particular execution context, the phrase "this
element" is often used to refer to the associated element, as most
policy operations will be applied to "this element". The address of
"this element" contains the index of the element, the context the
element was discovered in, and the address of the system on which the
element was discovered.
PolicyConditions have the capability of performing comparison operations
on SNMP variables, logical expressions, and other functions. Many
device characteristics are already defined in MIBs and are
easy to include in policyCondition expressions (ifType == ethernet,
frCircuitCommittedBurst < 128K, etc). However, there are
important characteristics that aren't currently in MIB objects, and
worse, it is not current practice to store this information on managed
devices. Therefore, this document defines MIB objects for this
information. To meet today's needs there are three missing areas:
roles, capabilities and time.
Roles
A role is an administratively specified characteristic of a managed
element. It is a selector for policies, to determine the applicability
of the policy to a particular managed element.
Some examples of roles are political, financial, legal,
geographical, or architectural characteristics, typically not directly
derivable from information stored on the managed system. For example,
"paid for premium service" or "is plugged into a UPS" are examples of
roles, whereas the "percent utilization of a link" would not be.
Some types of information one would put into a role include:
political - describes the role of a person or group of people, or of
a service that a group of people use. Examples:
executive, sales, outside-contractor, customer.
If (attached user is executive) then (apply higher bandwidth)
If (attached user is outside-contractor) then (restrict access)
financial/legal - describes what financial consideration was
received. Could also include contractual or legal
considerations. Examples:
paid, gold, free, trial, demo, lifeline
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If (gold service paid for) then (apply special queuing)
geographical - describes the location of an element. Examples:
California, Headquarters, insecure conduit.
If (interface leaves the building) then (apply special security)
architectural - describes the network architects "intent" for an
element. For example: backup, trunk.
If (interface is backup) then (set ifAdminStatus = down)
Roles in this model are human defined strings that can be referenced
by policy code. Roles may be assigned to elements by the role group
in this MIB as well as through implementation-dependent
means. Multiple roles may be assigned to each element. Because
policy code has access to data in MIB objects that represent the
current state of the system and (in contrast) role strings are more
static, it is recommended that role strings not duplicate
information that is available in MIB objects. Role strings generally
should be used to describe information not accessible in MIB objects.
The roleMatch accessor function allows policy code to make
decisions based on whether or not an element has a particular role
assigned to it.
The role group allows a management station to learn what roles exist
on a managed system. The management station may choose not to
install policies that depend on a role that does not exist on any
elements in the system. The management station can then register for
notifications of new roles. Upon receipt of a pmNewRoleNotification,
it may choose to install new policies that make use of that new
role.
Capabilities
Some actions are inappropriate for certain elements or are simply
unsupported because a capability doesn't exist or because it is
restricted. One must be able to define policy conditions so that a
policy can be applied only to elements that have the proper
capability. The capabilities table provides MIB objects that
describe the capabilities of the system.
The capMatch accessor function allows policy code to make
decisions based on whether or not an element has certain
capabilities.
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The capabilities table allows a management station to learn what
capabilities exist on a managed system. The management station may
choose not to install policies that depend on a capability that
does not exist on any elements in the system. The management station
can then register for notifications of new capabilities. Upon
receipt of a pmNewCapabilityNotification, it may choose to install
new policies that make use of that new capability.
Time
Managers may wish to define policies that are intended to apply for
certain periods of time. This might mean that a policy is installed
and is dormant for a period of time, becomes active, and then later
becomes inactive. Sometimes these time periods will be regular (M-F
9-5) and sometimes ad-hoc. This MIB provides MIB objects that allow
policies to be dependent on time.
5. Policy Based Management Execution Environment
5.1. Terminology
Run-Time Exception (RTE) - A run-time exception is a fatal
error caused in PolicyScript language processing or in the
processing of accessor functions. If, during the invocation of
a script, a run-time exception occurs, execution of that
script is immediately terminated. If a policyCondition
experiences a run-time exception while processing an element,
the element is not matched by the condition and the associated
action will not be run on that element. A run-time exception
can cause an entry to be added to the pmDebuggingTable and
will be reflected in the pmTrackingPEInfo object. The phrase
run-time exception will be commonly abbreviated to RTE.
There are several steps performed in order to execute policies
in this environment:
- Element Discovery
- Element Filtering
- Policy Enforcement
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5.2. Element Discovery
An element is an instance of a physical or logical entity.
Examples of elements include interfaces, circuits, queues,
CPUs, and processes. Sometimes various attributes of an entity
will be described through tables in several standard and
proprietary MIBs - as long as the indexing is consistent
between these tables, the entity can be modeled as 1 element.
For example, the ifTable and the dot3Stats table both contain
attributes of interfaces and share the same index (ifIndex),
therefore they can be modeled in this model as one element
type.
The Element Type Registration table is used by the manager to
learn what element types are being managed by the system and
to register new types if necessary. An element type is
registered by providing the OID of an SNMP object (i.e.,
without the instance). Each SNMP instance that exists under
that object is a distinct element. The index part of the
discovered OID will be supplied to policy conditions and
actions so that this code can inspect and configure the
element.
For each element that is discovered, the policy condition is
called with the element's index as an argument to see if the
element is a member of the set that the policy acts upon.
Note that agents may automatically configure entries in this
table for frequently used element types (interfaces, circuits,
etc.). In particular, it may configure elements for whom
discovery is optimized in one or both of the following ways:
1. The agent may discover elements by scanning internal data
structures as opposed to issuing local SNMP requests. It is
possible to recreate the exact semantics described in this
table even if local SNMP requests are not issued.
2. The agent may receive asynchronous notification of new
elements (for example, "card inserted") and use that
information to instantly create elements rather than
through polling. A similar feature might be available for
the deletion of elements.
Note that the disposition of agent-installed entries is
described by the pmPolicyStorageType object.
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A special element type "0.0" exists. "0.0" represents the
single instance of the system itself and provides an execution
context for policies to operate on "the system" as well as on
MIB objects modeled as scalars. For example, "0.0" gives an
execution context for policy-based selection of the operating
system code version (likely modeled as a scalar MIB object).
The element type "0.0" always exists - as a consequence, no
actual discovery will take place and the
pmElementTypeRegMaxLatency object will have no effect for the
"0.0" element type. However, if the "0.0" element type is not
registered in the table, policies will not be executed on the
"0.0" element.
If the agent is discovering elements by polling, it should
check for new elements no less frequently than
pmElementTypeRegMaxLatency would dictate. When an element is
first discovered all policyConditions are run immediately and
policyConditions that match will have the associated
policyAction run immediately. Subsequently, the
policyCondition will be run regularly for the element with no
more than pmPolicyConditionMaxLatency milliseconds elapsing
between each invocation. Note that if an implementation has
the ability to be alerted immediately when a particular type
of element is created, it is urged to discover that type of
element in this fashion rather than through polling, resulting
in immediate configuration of the discovered element.
5.2.1. Implementation Notes
Note that while the external behavior of this registration
process is defined in terms of the walking of MIB tables,
implementation strategies may differ. For example, commonly-
used element types (like interface) may have purpose-built
element discovery capability built-in and advertised to
managers through an entry in the pmElementTypeRegTable.
Before registering an element type, it is the responsibility
of a manager to inspect the table and see if it is already
registered (by the agent or another manager). Note that
entries that differ only in the last subid (which specifies
which object in an entry) are effectively duplicates and
should be treated as such by the manager.
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The system which implements the Policy-Based Management MIB
may not have knowledge of the format of object identifiers in
other MIBs. Therefore it is inappropriate for it to check
these OIDs for errors. It is the responsibility of the
management station to register well-formed object-identifiers.
For example, if an extra sub-identifier is supplied when
registering the ifTable, no elements will be discovered.
Similarly, if a sub-identifier is missing, every element will
be discovered numerous times (once per column) and none of the
element addresses will be well-formed.
5.3. Element Filtering
The first step in executing a policy is to see which elements
match the policy condition. To evaluate a policy, the policy
condition is called once for each element and runs to
completion. The element's index is the only argument that is
passed to the condition code for each invocation. Except for
state accessible through accessor functions, no state is
remembered from the previous invocation of this element nor
from the previous invocation of the policy condition. If any
run-time exception occurs, the condition will terminate
immediately for this element. If the condition returns non-
zero, the corresponding policy action will be executed for
this element.
If an element matches a condition and it had not matched that
condition the last time it was checked (or it is a newly-
discovered element), the associated policyAction will be
executed immediately. If the element had matched the condition
at the last check, it will remain in the set of elements whose
policyAction will be run within the policyActionMaxLatency.
5.3.1. Implementation Notes
It is an implementation-dependent matter as to how policy
conditions are scheduled. Each condition/element combination
is conceptually its own process and can be scheduled
sequentially or two or more could be run simultaneously.
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5.4. Policy Enforcement
For each element that has returned non-zero from the policy
condition, the corresponding policy action is called. The
element's index is the only argument that is passed to the
policy action for each invocation. Except for state
accessible from accessor functions, no state is remembered
from the policy condition evaluation, nor from the previous
condition/action invocation of this element nor from the
previous invocation of the policy condition or action on any
other element. If any run-time exception occurs, the action
will terminate immediately for this element.
5.4.1. Implementation Notes
It is an implementation-dependent matter as to how policy
actions are scheduled. Each condition/element combination is
conceptually its own process and can be scheduled sequentially
or two or more could be run simultaneously.
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6. The PolicyScript Language
Policy conditions and policy actions are expressed with the
PolicyScript language. The PolicyScript language is designed
to be a small interpreted language that is simple to
understand and implement; it is designed to be appropriate for
writing small scripts that make up policy conditions and
actions.
PolicyScript is intended to be familiar to programmers in a
variety of languages, including Perl and C. PolicyScript is
nominally a subset of the C language - however it was
desirable to have access to C++'s operator overloading (solely
to aid in documenting the language - operator overloading is
not a feature of PolicyScript). Therefore, PolicyScript is
defined formally as a subset of the C++ language. A subset was
used to provide for easy development of low-cost interpreters
of PolicyScript and to take away language constructs that are
peculiar to the C/C++ languages. For example, it is expected
that both C and Perl programmers will understand the
constructs allowed in PolicyScript.
Some examples of the features that have been removed from the
C/C++ language are: function definitions, pointer variables,
structures, enums, typedefs, floating point and pre-processor
functions (except for comments).
This language is formally defined as a subset of ISO C++ [19],
but only allows those constructs that may be expressed in the
Extended Backus-Naur Form (EBNF) documented here. This is done
because while EBNF doesn't fully specify syntactical rules (it
allows constructs that are invalid) and doesn't specify
semantic rules, it can successfully be used to define the
subset of the language that is required for conformance to
this specification. Unless explicitly described herein, the
meaning of any construct expressed in the EBNF can be found by
reference to the ISO C++ standard.
The use of comments and newlines are allowed and encouraged in
order to promote readability of PolicyScript code. Comments
begin with '/*' and end with '*/' or begin with '//' and go
until the end of the line.
One subset is not expressible in the EBNF syntax: all
variables within a PolicyScript program are within the same
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scope.
PolicyScript code must be expressed in the UTF8 character set.
In the EBNF used here, terminals are character set members
(singly or in a sequence) that are enclosed between two
single-quote characters or described as a phrase between '<'
and '>' characters. Nonterminals are a sequence of letters
and underscore characters. A colon (:) following a
nonterminal introduces its definition, a production. In a
production, a '|' character separates alternatives. The '('
and ')' symbols group the enclosed items. The '[' and ']'
symbols indicate that the enclosed items are optional. The '?'
symbol following an item indicates that the item is optional.
The '*' symbol following an item indicates that the item is
repeated zero, one, or more times. The '+' symbol following an
item indicates that the item is repeated one or more times.
The symbol '--' begins a comment that ends at the end of the
line.
6.1. Formal Definition
The PolicyScript language follows the syntax and semantics of
ISO C++ [19], but is limited to that which can be expressed in
the EBNF below.
The following keywords are reserved words and cannot be used
in any policy script. This prevents someone from using a word
that is a common keyword in other languages as an identifier
in a program and thus make the meaning of the program
confusing. The reserved words are:
auto, case, char, const, default, do, double, enum,
extern, float, goto, inline, int, long, register, short,
signed, sizeof, static, struct, switch, typedef, union,
unsigned, void, and volatile.
Any syntax error, use of a reserved keyword, reference of an
unknown identifier, improper number of function arguments,
error in coercing an argument to the proper type, exceeding
local limitations on string length or exceeding local
limitations on the total amount of storage used by local
variables will cause a RTE.
PolicyScript permits comments using the comment delimiters,
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'/*' to '*/' or the start of comment symbol '//'.
-- Lexical Grammar
letter: '_' | 'a' | 'b' | 'c' | 'd' | 'e' | 'f'
| 'g' | 'h' | 'i' | 'j' | 'k' | 'l' | 'm'
| 'n' | 'o' | 'p' | 'q' | 'r' | 's' | 't'
| 'u' | 'v' | 'w' | 'x' | 'y' | 'z'
| 'A' | 'B' | 'C' | 'D' | 'E' | 'F'
| 'G' | 'H' | 'I' | 'J' | 'K' | 'L' | 'M'
| 'N' | 'O' | 'P' | 'Q' | 'R' | 'S' | 'T'
| 'U' | 'V' | 'W' | 'X' | 'Y' | 'Z'
digit: '0' | '1' | '2' | '3' | '4'
| '5' | '6' | '7' | '8' | '9'
non_zero: '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
oct_digit: '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7'
hex_digit: digit | 'a' | 'b' | 'c' | 'd' | 'e' | 'f'
| 'A' | 'B' | 'C' | 'D' | 'E' | 'F'
escape_seq: '\'' | '\"' | '\?' | '\\'
| '\a' | '\b' | '\f' | '\n'
| '\r' | '\t' | '\v'
| '\' oct_digit+ | '\x' hex_digit+
non_quote: Any character in the UTF-8 character set
except single quote ('), double quote ("),
backslash ('\') or newline.
c_char: non_quote | '"' | escape_seq
string_literal: '"' s_char* '"'
s_char: non_quote | ''' | escape_seq
char_constant: ''' c_char '''
decimal_constant: non_zero digit*
octal_constant: '0' oct_digit*
hex_constant: ( '0x' | '0X' ) hex_digit+
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integer_constant: decimal_constant | octal_constant | hex_constant
identifier: letter ( letter | digit )*
-- Phrase Structure Grammar
-- Expressions
primary_expr: identifier | integer_constant | char_constant
| string_literal | '(' expression ')'
postfix_expr: primary_expr
| postfix_expr '(' argument_expression_list? ')'
| postfix_expr '++'
| postfix_expr '--'
| postfix_expr '[' expression ']'
argument_expression_list:
assignment_expr
| argument_expression_list ',' assignment_expr
unary_expr: postfix_expr | unary_op unary_expr
unary_op: '+' | '-' | '~' | '!' | '++' | '--'
binary_expr: unary_expr | binary_expr binary_op unary_expr
binary_op: '||' | '&&' | '|' | '^' | '&' | '!='
| '==' | '>=' | '<=' | '>' | '<' | '>>'
| '<<' | '-' | '+' | '%' | '/' | '*'
assignment_expr: binary_expr
| unary_expr assignment_op assignment_expr
assignment_op: '=' | '*=' | '/=' | '%=' | '+=' | '-='
| '<<=' | '>>=' | '&=' | '^=' | '|='
expression: assignment_expr | expression ',' assignment_expr
-- Declarations
declaration: 'var' declarator_list ';'
declarator_list: init_declarator
| declarator_list ',' init_declarator
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init_declarator: identifier [ '=' assignment_expr ]
-- Statements
statement: declaration
| compound_statement
| expression_statement
| selection_statement
| iteration_statement
| jump_statement
compound_statement: '{' statement* '}'
expression_statement: expression? ';'
selection_statement:
'if' '(' expression ')' statement
| 'if' '(' expression ')' statement 'else' statement
iteration_statement:
'while' '(' expression ')' statement
| 'for' '(' expression? ';' expression? ';' expression? ')'
statement
jump_statement: 'continue' ';'
| 'break' ';'
| 'return' expression? ';'
-- Root production
PolicyScript: statement*
6.2. Variables
To promote shorter scripts and ease in writing scripts,
PolicyScript provides a loosely-typed data class, "var", that
can store both integer and string values. The native C++
types (char, int, etc.) are thus unnecessary and have not been
carried into the subset that comprises this language. The
semantics of the "var" type are modeled after those of
ECMAScript[20].
For example:
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var number = 0, name = "IETF";
This language will be executed in an environment where the
following typedef is declared. (Note that this typedef will
not be visible in the policyCondition or policyAction code.)
typedef ... var;
While this declaration is expressed here as a typedef, the
'typedef' keyword itself is not available to be used inside of
PolicyScript code.
6.2.1. The var class
A value is an entity that takes on one of two types: string or
integer.
The String type is the set of all finite ordered sequences of
zero or more 8-bit unsigned integer values ("elements"). The
string type can store textual data as well as binary data
sequences. Each element is regarded as occupying a position
within the sequence. These positions are indexed with
nonnegative integers. The first element (if any) is at
position 0, the next element (if any) at position 1, and so
on. The length of a string is the number of elements (i.e.,
8-bit values) within it. The empty string has length zero and
therefore contains no elements.
The integer type is the set of all integer values in the range
-9223372036854775808 (-2^63) to 18446744073709551615 (2^64-1).
If an integer operation would cause a (positive) overflow,
then the result is returned modulo 2^64. If an integer
operation would cause a (negative) underflow, then the result
is undefined.
Prior to initialization, a var object has type String and a
length of zero.
The policy script runtime system performs automatic type
conversion as needed. To clarify the semantics of certain
constructs it is useful to define a set of conversion
operators. These operators are not a part of the language;
they are defined here to aid the specification of the
semantics of the language. The conversion operators are
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polymorphic; that is, they can accept a value of any standard
type.
ToInteger
The operator ToInteger converts its argument to a value of
type Integer according to the following table:
Integer The result equals the input argument
(no conversion).
String See grammar and note below
integer_constant The result equals the input argument
(no conversion).
string_literal See grammar and note below
char_constant See grammar and note below
ToInteger Applied to strings
ToInteger applied to the String Type, string_literal and
char_constants applies the following grammar to the input. If
the grammar cannot interpret the string as an expansion of
numeric_string, then an RTE is generated. Note that a
numeric_string that is empty or contains only white space is
converted to 0.
-- EBNF for numeric_string
numeric_string : white_space* numeric white_space*
white_space : <TAB> | <SP> | <NBSP> | <FF> | <VT>
| <CR> | <LF> | <LS> | <PS> | <USP>
numeric : signed_decimal | hex_constant | octal_constant
signed_decimal: [ '-' | '+' ] decimal_constant
-- decimal_constant, hex_constant, octal_constant are defined in the
-- PolicyScript EBNF described earlier
ToString
The operator ToString converts its argument to a value of type String
according to the following table:
Integer Return the string containing the decimal
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representation of the input argument in
the form of signed_decimal except that
no leading '+' will be used.
String Return the input argument (no conversion)
integer_constant Return the string containing the decimal
representation of the input argument in the
form of signed_decimal except that no
leading '+' will be used.
string_literal Return the input argument (no conversion)
char_constant Return the string of length one containing
the value of the input argument.
ToBoolean
The operator ToBoolean converts its argument to a value of type
Integer according to the following table:
Integer The result is 0 if the argument is 0.
Otherwise the result is 1.
String The results is 0 if the argument is the
empty string. Otherwise the result is 1.
integer_constant The result is 0 if the argument is 0.
Otherwise the result is 1.
string_literal The result is 0 if the argument is the
empty string. Otherwise the result is 1.
char_constant The result is 1.
Operators
A++, A--, ++A, --A:
A = ToInteger(A); OP;
+A: ToInteger(A);
-A: -1 * ToInteger(A);
~A: ~ToInteger(A);
!A: !ToBoolean(A);
A * B, A - B, A & B, A ^ B , A | B, A << B, A >> B:
ToInteger(A) OP ToInteger(B)
A / B, A % B:
if (ToInteger(B) == 0)
RTE, terminate;
else
ToInteger(A) OP ToInteger(B)
A + B:
if (Type(A) == String || Type(B) == String)
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ToString(A) concatenated with ToString(B)
else
A + B
Compound Assignment (op=):
Simply follow rules above. Note that type of LHS may be
changed as a result.
A < B, A > B, A <= B, A >= B, A == B, A != B:
if (Type(A) == String && Type(B) == String)
lexically compare strings with strcmp() logic
else
ToInteger(A) OP ToInteger(B)
A && B:
if (ToBoolean(A))
ToBoolean(B);
else
false;
A || B:
if (ToBoolean(A))
true;
else
ToBoolean(B);
if(A):
if (ToBoolean(A))
while(A):
while(ToBoolean(A)
for(...; A; ...):
for(...; ToBoolean(A); ...)
A[B] as a RHS value:
if (Type(A) != String
|| ToInteger(B) >= strlen(A))
RTE, terminate;
A[ ToInteger(B) ]
The contents are returned as a string of length one
A[B] = C as a LHS value:
if (Type(A) != String
|| ToInteger(B) >= strlen(A))
RTE, terminate;
if (strlen(ToString(C)) == 0)
RTE, terminate
A[ ToInteger(B) ] = First octet of ToString(C)
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Note that this is only applicable in a simple assignment.
6.3. PolicyScript QuickStart Guide
PolicyScript is designed so that programmers fluent in other
languages can quickly begin to write scripts.
One way to become familiar with a language is to see it in
action. The following nonsensical program exercises most of
the PolicyScript constructs (though it skips some usage
options and many arithmetic operators).
var x, index = 7, str = "Hello World", oid = "ifSpeed.";
x = 0;
while(x < 10){
if (str < "Goodbye") /* string comparison */
continue;
else
break;
x++;
}
if (oidlen(oid) == 10)
oid += "." + index; // append index to oid
for(x = 0; x < 7; x++){
str += "a";
var y = 12;
index = ((x * 7) + y) % 3;
if (str[6] == 'W')
return index;
}
return;
A few examples that are more practical are:
For a condition:
// Return 1 if this is an interface and it is tagged
// with the role "gold"
return (inSubtree(elementName(), "ifEntry")
&& roleMatch("gold"))
A condition/action pair:
First, register the Host Resources MIB hrSWRunEntry as a new element
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in the pmElementTypeRegTable. This will cause the policy to run for
every process on the system and $0 will be the process index.
The condition:
// if it's a process and it's an application and it's
// consumed more than 5 minutes of CPU time
return (inSubtree(elementName(), "hrSWRunEntry")
&& getVar("hrSWRunType.$0") == 4 // app, not OS or driver
&& getVar("hrSWRunPerfCPU.$0") > 30000) // 300 seconds
The action:
// Kill it
setVar("hrSWRunStatus.$0", 4, Integer); // invalid(4) kills it
A more substantial action to start an RMON2 host table on interfaces
that match the condition:
var index, pdu;
pdu = newPDU();
// setRowStatus finds an empty row and creates it
if (!(index = setRowStatus("hlHostControlStatus.*", 20)))
return; /* couldn't find a free row */
writeVar(pdu, 0, "hlHostControlDataSource." + index,
"ifIndex." + ev(0), Oid);
writeVar(pdu, 1, "hlHostControlNlMaxDesiredEntries." + index,
1000, Integer);
writeVar(pdu, 2, "hlHostControlAlMaxDesiredEntries." + index,
1000, Integer);
writeVar(pdu, 3, "hlHostControlOwner." + index, "policy", String);
writeVar(pdu, 4, "hlHostControlStatus." + index, 1, Integer);
snmpSend(pdu, 5, OP_SET);
Because PolicyScript is a least common denominator, it
contains nothing that would astonish programmers familiar with
C, C++, Perl, Tcl, JavaScript or Python. While a new
programmer may attempt to use language constructs that aren't
available in PolicyScript, they should be able to understand
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any existing PolicyScript and will likely know how to use
anything that is valid in PolicyScript. The lists below
quickly enumerate the changes of note for programmers coming
some particular languages. These lists won't describe the
unavailable constructs but it is easy to see from the
definition above what is available.
6.3.1. Quickstart for C Programmers
- Character constants (i.e. 'c') are treated as one-character
strings, not integers. So operations like ('M' - 'A') or (x + 'A')
will not perform as expected.
- Accessor functions can change the value of arguments even though
they are not pointers (or called like '&arg').
- All variables are in the same scope
6.3.2. Quickstart for Perl Programmers
- Comments are '/* comment */' and '// till end of line', not '#'
- No need to put a '$' in front of variables
- Strings are compared with ==, <=, < etc. (Details in Sec. 6.2.1)
- Strings are concatenated with '+'. (Details in Sec. 6.2.1)
- No variable substitution in "" strings. '' strings are 1 char only.
- Variables must be declared before use (but no type is necessary)
- All variables are in the same scope
6.3.3. Quickstart for TCL Programmers
- Comments are '/* comment */' and '// till end of line', not '#'
- No need to put a '$' in front of variables
- Function calls are func-name(arg1, arg2, ...)
- Square braces [] don't interpret their contents
- Double quotes "" surround a string but no substitutions are
performed ("" is like { } in TCL )
- Statements are terminated by a semicolon;
- Instead of "Set a b", use "b = a;"
- Strings are concatenated with '+'. (Details in Sec. 6.2.1)
- All variables are in the same scope
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6.3.4. Quickstart for Python Programmers
- Comments are '/* comment */' and '// till end of line', not '#'
- Single quotes can be used only for single-character strings ('a')
- Indentation doesn't matter. Braces {} define blocks.
- Variables must be declared before use (but no type is necessary)
- The expression for if and while is always surrounded by
parenthesis, like "if (x < 5)".
- 'for' syntax is "for(expression; expression; expression)" (see EBNF).
- All variables are in the same scope
6.3.5. Quickstart for JavaScript/ECMAScript/JScript
Programmers
- Variables must be declared before use.
- Accessor functions can change the value of arguments
- All variables are in the same scope
7. Index information for `this element'
PolicyScript code needs a convenient way to get the components
of the index for "this element" so that they can perform SNMP
operations on it or on related elements.
Two mechanisms are provided.
1. For all oid input parameters to all SNMP Accessor Functions (but
not oid utility functions), the token "$n" ('$' followed by an
integer between 0 and 128) can be used in place of any decimal
sub-identifier. This token is expanded by the agent at execution
time to contain the n'th subid of the index for the current
element. For example, if the element is interface #7, and the
objectIdentifier is "1.3.6.1.2.1.2.2.1.3.$0", it will be expanded
to "1.3.6.1.2.1.2.2.1.3.7". The special token "$*" is expanded to
contain all of the subidentifiers of the index of the current
element, separated by '.' characters.
It is an RTE if a token is specified that is beyond the length of
the index for the current element.
2. The ec() and ev() functions allow access to the components of the
index for "this element". ec() takes no argument and returns the
number of index components that exist. ev() takes an integer
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argument specifying which component of the index (numbered starting
at 0) and returns an integer containing the value of the n'th
subidentifier. Refer to the accessor functions section for the
complete definition of ec() and ev().
For example, if "this element" is frCircuitDLCI.5.57
(ifIndex = 5, DLCI = 57)
then ec() returns 2
ev(0) returns 5
ev(1) returns 57
This is helpful when wishing to address a related element.
Extending the previous example, to find the port speed of the port
the circuit (above) runs over:
portSpeed = getVar("ifSpeed." + ev(0));
8. Accessor Functions
Accessor functions are built-in functions available primarily
to provide access to information on the local system or to
more efficiently manipulate this information. A group of
functions is organized into a library, the unit of conformance
for function implementation. In order to claim conformance to
a library, an implementation must implement all functions in a
library to the specifications of the library.
In order for a management station or a condition or action to
understand if a certain library of functions is implemented,
each library will have a registration OID that it registers in
this MIB's capabilities table. Thus, conformance to a library
can be tested with the capMatch library function (in the base
library) or by inspecting the pmCapabilitiesType objects in
the pmCapabilitiesTable.
9. Base Accessor Function Library
A standard base library of accessor functions is available to
all systems that implement this specification. This library is
known by the capability OID of:
pmBaseFunctionLibrary ::= { pmMib pmConformance pmGroups 4 }
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This library contains four types of functions:
- SNMP Accessor functions
- Policy Accessor functions
- Utility functions
- Library Functions
Note that in the descriptions of these functions below, the
function prototype describes the type of argument expected.
Even though variables are not declared with a particular type,
their contents must be as appropriate for each function
argument. If the type is variable, the keyword 'var' will be
used. If only a string is appropriate, the keyword 'string'
will be used. If only an integer is appropriate, the keyword
'integer' will be used. If the argument is declared as
'string' or 'integer' and a value of a different type is
passed, the argument will be coerced with ToInteger() or
ToString(). Any failure on this coercion will cause an RTE (in
particular for ToInteger(), which will fail if its string-
valued argument is not a well-formed integer).
In the function prototype, if the '&' character precedes the
identifier for an argument, that argument may be modified by
the function (e.g., "integer &result, ...)"). Arguments
without the '&' character cannot be modified by the function.
In the function prototype, the '[' and ']' characters surround
arguments that are optional. In PolicyScript code, the
optional argument may only be included if all optional
arguments to the left of it are included. The function may
place restrictions on when an optional argument must, or must
not, be included.
9.1. SNMP Accessor Functions
Two sets of SNMP Accessor functions are available with
different situations in mind:
- Convenience SNMP Functions
In an effort to keep simple things simple, these functions are
easy to use and promote easy to understand code. These functions
will suffice for the majority of situations where a single
variable is referenced and the desired error recovery is to simply
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(and immediately) give up (and move to the next policy-element
combination). In more complex cases, the General SNMP Functions
can be used at the cost of several times the code complexity.
The convenience SNMP functions are getVar, exists,
setVar, setRowStatus, and searchColumn.
- General SNMP Functions
The General SNMP functions allow nearly any legal SNMP Message to
be generated, including those with multiple varbinds, getNext
operations, notifications, and messages with explicit addressing
or security specifications.
The general SNMP functions are writeVar, readVar, and snmpSend.
9.1.1. SNMP Operations on Non-Local Systems
From time to time, a script may need to perform an operation
on a different SNMP system than that which "this element"
resides on. Scripts may also need to specify the use of
alternate security parameters. In order to do this, the
following optional arguments are provided for the SNMP
accessor functions:
function(...[, integer mPModel,
string tDomain, string tAddress,
integer secModel, string secName,
integer secLevel])
'mPModel' is the integer value of the SnmpMessageProcessingModel
to use for this operation.
'tDomain' is a string containing an ASCII dotted-decimal
object identifier representing the transport domain to use for
this operation.
'tAddress' is a string containing the transport address according
formatted according to the 'tDomain' argument.
'secModel' is the integer value of the SnmpSecurityModel to use
for this operation.
'secName' is a string value representing the SnmpSecurityName to
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use for this operation.
'secLevel' is the integer value of the SnmpSecurityLevel to use
for this operation.
For convenience, constants for 'mPModel', 'secModel' and
'secLevel' are defined in the "Constants" section below.
In order for PolicyScript code to use any of these arguments, all
optional arguments to the left must be included. These arguments
must be used as a group - if one is specified, they must all be
specified.
The use of these arguments is denoted in the function definitions
below by the keyword 'NonLocalArgs'.
9.1.2. Form of SNMP Values
Many of the accessor functions have input or output parameters
that may be one of the many SMI data types. The actual type is
not encoded in the value, but rather is specified elsewhere,
possibly by nature of the context in which it is used. The
exact usage for input and output is:
Any Integer value
(INTEGER, Integer32, Counter32, Counter64, Gauge32, Unsigned32,
TimeTicks, Counter64):
On input:
An Integer or a String that can be successfully coerced to an
Integer with the ToInteger() function. It is an RTE if
a string argument in this context cannot be converted by
ToInteger() into an integer.
On output:
An Integer containing the returned value.
Octet String
On input:
Either a String or an Integer. If an Integer, it will be coerced
to a String with the ToString() function. This string will be
used as an unencoded representation of the octet string value.
On output:
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A String containing the unencoded value of the octet string.
Object Identifier
On input and on output:
A String containing a decimal ascii encoded object identifier
of the following form:
oid: subid [ '.' subid ]* [ '.' ]
subid: '0' | decimal_constant
It is an RTE if an Object Identifier argument is not in the form
above. Note that a trailing '.' is acceptable and will simply be
ignored.
Note that ascii descriptors (e.g. "ifIndex") are never used in
these encodings "over the wire". They are never returned from
accessor functions nor are they ever accepted by them. NMS user
interfaces are encouraged to allow humans to view object
identifiers with ascii descriptors, but they must translate those
descriptors to dotted-decimal format before sending them in MIB
objects to policy agents.
9.1.3. Convenience SNMP Functions
9.1.3.1. getVar()
The getVar() function is used to retrieve the value of an SNMP
MIB instance.
string getVar(string oid [, string context, NonLocalArgs])
'Oid' is a string containing an ASCII dotted-decimal
representation of an object identifier
(e.g. "1.3.6.1.2.1.1.1.0").
The optional 'context' argument contains the context to
operate on. If this argument is not present, the context of
"this element" will be used. If this argument is the zero
length string, the default context is used.
The optional 'NonLocalArgs' provide addressing and security
information to perform an SNMP operation on a different system
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than "this element".
It is an RTE if the queried object identifier value does not
exist.
This function returns a string containing the returned value,
encoded according to the returned type. Note that no actual
SNMP PDU needs to be generated and parsed when the policy MIB
agent resides on the same system as the managed elements.
It is recommended that NMS user interfaces display and allow
input of MIB object names by their descriptor values followed
by the index in dotted-decimal form (e.g., "ifType.7").
9.1.3.2. exists()
The exists() function is used to verify the existence of an
SNMP MIB instance.
integer exists(string oid [, string context, NonLocalArgs])
'oid' is a string containing an ASCII dotted-decimal
representation of an object identifier
(e.g. "1.3.6.1.2.1.1.1.0").
The optional 'context' argument contains the context to
operate on. If this argument is not present, the context of
"this element" will be used. If this argument is the zero
length string, the default context is used.
The optional 'NonLocalArgs' provide addressing and security
information to perform an SNMP operation on a different system
than "this element".
This function returns the value 1 if the SNMP instance exists
and 0 if it doesn't exist. Note that no actual SNMP PDU needs
to be generated and parsed when the policy MIB agent resides
on the same system as the managed elements.
It is recommended that NMS user interfaces display and allow
input of MIB object names by their descriptor values followed
by the index in dotted-decimal form (e.g., "ifType.7").
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9.1.3.3. setVar()
The setVar() function is used to set a MIB instance to a
certain value. The setVar() function is only valid in
policyActions.
integer setVar(string oid, var value, integer type
[, string context, NonLocalArgs] )
'oid' is a string containing an ASCII dotted-decimal
representation of an object identifier
(e.g. "1.3.6.1.2.1.1.1.0").
'value' is a string encoded in the format appropriate to
the 'type' parameter. The agent will set the variable
specified by 'oid' to the value specified by 'value'.
'type' will be the type of the 'value'' parameter and will
be set to one of the values for DataType Constants.
The optional 'context' argument contains the context to
operate on. If this argument is not present, the context of
"this element" will be used. If this argument is the zero
length string, the default context is used.
The optional 'NonLocalArgs' provide addressing and security
information to perform an SNMP operation on a different system
than "this element". Note that no actual SNMP PDU needs
to be generated and parsed when the policy MIB agent resides
on the same system as the managed elements.
If the set encounters any error, 0 is returned. If successful,
1 is returned.
It is recommended that NMS user interfaces display and allow
input of MIB object names by their descriptor values followed
by the index in dotted-decimal form (e.g., "ifType.7").
9.1.3.4. searchColumn()
integer searchColumn(string columnoid, string &oid,
string pattern, integer mode
[, string context, NonLocalArgs])
searchColumn performs an SNMP walk on a portion of the MIB
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searching for objects with values equal to the `pattern'
parameter.
'columnoid' constrains the search to only those variables that
share the same OID prefix (i.e. are beneath it in the OID
tree).
A getnext request will be sent requesting the object
identifier 'oid'. If 'oid' is an empty string, the value of
'columnoid' will be sent.
The value returned in each response packet will be transformed
to a string representation of the value of the returned
variable. The string representation of the value will be
formed by putting the value in the form dictated by the "Form
of SNMP Values" rules, and then performing the ToString()
function on this value, forming 'SearchString'.
The 'mode' value controls what type of match to perform on
this 'SearchString' value. There are 6 possibilities for mode:
mode Search Action
0 Case sensitive exact match of 'pattern'
and 'SearchString'
1 Case insensitive exact match of 'pattern'
and 'SearchString'
2 Case sensitive substring match, finding
'pattern' in 'SearchString'
3 Case insensitive substring match, finding
'pattern' in 'SearchString'
4 Case sensitive regular expression match,
searching 'SearchString' for the regular
expression given in 'pattern'.
5 Case insensitive regular expression match,
searching 'SearchString' for the regular
expression given in 'pattern'.
searchColumn uses the POSIX extended regular expressions
defined in POSIX 1003.2.
The optional 'context' argument contains the context to
operate on. If this argument is not present, the context of
"this element" will be used. If this argument is the zero
length string, the default context is used.
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The optional 'NonLocalArgs' provide addressing and security
information to perform SNMP operations on a different system
than "this element".
If a match is found, 'oid' is set to the oid of the matched
value and 1 is returned. If the search traverses beyond
columnoid or returns an error without finding a match, zero is
returned and 'oid' isn't modified.
To find the first match, the caller should set 'oid' to the
empty string. To find additional matches, subsequent calls to
searchColumn should have 'oid' set to the oid of the last
match, an operation than searchColumn performs automatically.
For example:
To find an ethernet interface
oid = "";
searchColumn("ifType", oid, "6", 0);
This sends a getnext request for ifType and continues to walk
the tree until a value matching 6 is found or a variable
returns that is not in the 'ifType' subtree.
To find the next ethernet interface, assuming interface #3
was discovered to be the first:
oid = "ifType.3";
searchColumn("ifType", oid, "6", 0);
In a loop, this looks simply like:
oid = "";
while(searchColumn("ifType", oid, "6", 0)){
/* Do something with oid */
}
Note that in the preceding examples, "ifType" is used as a
notational convenience and the actual code downloaded to the
policy MIB agent must use the string "1.3.6.1.2.1.2.2.1.3" as
there may be no MIB compiler (or MIB) available on the policy
MIB agent.
Note that if the value of 'columnoid' is too short and thus
references too much of the object identifier tree
(e.g. "1.3.6"), 'columnoid' could end up searching a huge
number of variables (if it was "1.3.6", it would search ALL
variables on the agent). It is the responsibility of the
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caller to make sure that 'columnoid' is set appropriately.
9.1.3.5. setRowStatus()
integer setRowStatus(string oid, integer maxTries
[, integer freeOnException , integer seed
, string context, NonLocalArgs])
setRowStatus is used to automate the process of finding an
unused row in a read-create table that uses RowStatus.
'oid' is a string containing an ASCII dotted-decimal
representation of an object identifier, with one of
the subids replaced with a '*' character
(e.g. "1.3.6.1.3.1.99.1.2.1.9.*"). 'oid' must reference an
'instance' of the RowStatus object and the '*' must replace
any integer index item that may be set to some random value.
setRowStatus will come up with a number for the selected index
item and will attempt to create the instance with the
createAndWait state. If the attempt fails, it will retry with
a different random index value. It will attempt this no more
than 'maxTries' times.
If the optional 'freeOnException' argument is present and
equal to 1, the agent will free this row by setting RowStatus
to 'destroy' if later in the same script invocation this
script dies with a run-time exception or by a call to die().
Note that this does not apply to subsequent invocations of
the script.
If the optional 'seed' argument is present, the initial index
will be set to 'seed'. Otherwise it will be random. The 'seed'
argument may not be present if the 'freeOnException' argument
is not present.
The optional 'context' argument contains the context to
operate on. If this argument is not present, the context of
"this element" will be used. If this argument is the zero
length string, the default context is used.
The optional 'NonLocalArgs' provide addressing and security
information to perform an SNMP operation on a different system
than "this element".
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setRowStatus returns the successful integer value for the
index. If unsuccessful after 'maxTries' or if more than one
'*' is in oid, -1 will be returned.
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9.1.3.6. counterRate()
When a policy wishes to make a decision based on the rate of a
counter, it faces a couple of problems:
1. It may need to run every X minutes, but need to make
decisions on rates calculated over at least Y minutes
where Y > X. This would require the complexity of managing
a queue of old counter values.
2. The policy script has no control over exactly when it
will run
The counterRate() function is designed to easily surmount
these problems.
integer counterRate(string oid, integer minInterval [, integer 64bit])
counterRate retrieves the variable specified by oid once per
invocation. It keeps track of timestamped values retrieved on
previous invocations by this execution context so that it can
calculate a rate over a longer period than since the last
invocation.
'oid' is the object identifier that will be retrieved.
A previously-saved value of the same object identifier that is
older than 'minInterval' seconds old will be subtracted from
the newly-retrieved value, yielding a delta. This delta will
be divided by the number of seconds elapsed between the two
retrievals and the integer-valued result will be returned.
If there was no previously-saved retrieval older than
'minInterval' seconds, then -1 will be returned.
The delta calculation will allow for 32-bit counter semantics
if it encounters rollover between the two retrievals unless
the optional argument '64bit' is present and equal to 1,
in which case it will allow for 64-bit counter semantics.
The implementation will need to store a number of timestamped
counter values. The implementation is free to throw away
old values as long as it retains at least one value that is
older than minInterval seconds.
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9.1.3.7. counter32Delta()
If a (single) counter overflow occurs between successive
retrievals of a Counter32 object, the delta can still be
retrieved accurately but it has to be done consistent with 32
bit unsigned rollover semantics. This function is useful to
simplify that process in an environment where all counters are
64 bits.
integer counter32Delta(integer old, integer new)
counter32Delta returns the delta between 'new' and 'old'
compensating for the potential 32-bit unsigned rollover of the
counter between the sampling of 'new' and 'old'.
Example:
var counter, lastcounter, delta;
counter = getVar("ifInOctets.$0");
if (getScratchpad(PolicyElement, "inOctets", lastcounter)){
// if returns 0, no value was stored, so punt to next iteration
delta = counter32Delta(lastcounter, counter);
}
setScratchpad(PolicyElement, "inOctets", counter);
/*
* delta now contains the 32bit delta of ifInOctets since the last
* iteration.
*/
9.1.4. General SNMP Functions
It is desirable for a general SNMP interface have the ability
to perform SNMP operations on multiple variables at once and
for it to allow multiple varbind lists to exist at once. The
newPdu, readVar and writeVar functions exist in order to
provide these facilities in a language without pointers,
arrays and memory allocators.
newPDU is called to allocate a PDU and return an integer
handle to it. Since PDUs are automatically freed when the
script exits and because they can be reused during execution,
there is no freePDU().
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readVar and writeVar access a variable length varbindlist for
a PDU. The PDU handle and the index of the variable within
that PDU are specified in every readVar and writeVar
operation. Once a PDU has been fully specified by one or more
calls to writeVar, it is passed to snmpSend (by referencing
the PDU handle) and the number of varbinds to be included in
the operation. When a response is returned, the contents of
the response are in the same PDU (i.e. the same PDU handle is
used) and may be read by one or more calls to readVar.
Varbinds in this data store are created automatically whenever
they are written by any writeVar, readVar, or snmpSend
operation. It is an RTE to read a varbind that has not been
previously written.
For example:
var pdu = newPDU();
writeVar(pdu, 0, "sysDescr.0", ...);
writeVar(pdu, 1, "sysOID.0", ...);
writeVar(pdu, 2, "ifNumber.0", ...);
if (snmpSend(pdu, 3, Get, ...))
return;
readVar(pdu, 0, iKnowItsSysDescr, iKnowItsaString, value);
readVar(pdu, 1, ...)
readVar(pdu, 2, ...)
...
or,
var pdu = newPDU();
writeVar(pdu, 0, "ifIndex", ...);
writeVar(pdu, 1, "ifType", ...);
while(!done){
if (snmpSend(pdu, 2, Getnext, ...))
continue;
readVar(pdu, 0, oid1, ...);
readVar(pdu, 1, oid2, ...);
/* leave OIDs alone, now PDU #0 is set up for next step
in table walk. */
if (oidncmp(oid1, "ifIndex", oidlen("ifIndex")))
done = 0;
...
}
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Note that in the preceding examples, descriptors such as
ifType and sysDescr are used in object identifiers solely as a
notational convenience and the actual code downloaded to the
policy MIB agent must use a dotted decimal notation only as
there may be no MIB compiler (or MIB) available on the policy
MIB agent.
It is suggested that implementations limit the total number of
PDUs per invocation to protect other script invocations from a
malfunctioning script (e.g. a script that calls newPDU() in a
loop). To be conformant to this specification, implementations
must allow each policy script invocation to allocate at least
5 PDUs with at least 32 varbinds per list.
9.1.4.1. newPDU()
integer newPDU()
newPDU will allocate a new PDU and return a handle to the
PDU. If no PDU could be allocated, -1 will be returned.
9.1.4.2. writeVar()
writeVar(integer pdu, integer varBindIndex,
string oid, var value, integer type)
writeVar will store 'oid', 'value' and 'type' in
the specified varbind.
'pdu' is the handle to a PDU allocated by newPDU().
'varBindIndex' is a non-negative integer that identifies the
varbind within the specified PDU modified by this call. The
first varbind is number 0.
'oid' is a string containing an ASCII dotted-decimal
representation of an object identifier
(e.g. "1.3.6.1.2.1.1.1.0").
'value' is the value to be stored, of a type appropriate to the
'type' parameter.
'type' will be the type of the value parameter and will be set
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to one of the values for DataType Constants.
9.1.4.3. readVar()
readVar(integer pdu, integer varBindIndex,
string &oid, var &value, integer &type)
readVar will retrieve the oid, the value and it's type
from the specified varbind.
'pdu' is the handle to a PDU allocated by newPDU().
'varBindIndex' is a non-negative integer that identifies the
varbind within the specified PDU read by this call. The
first varbind is number 0.
The object identifier value of the referenced varbind will be
copied into the 'oid' parameter, formatted in an ASCII
dotted-decimal representation (e.g. "1.3.6.1.2.1.1.1.0").
'value' is the value retrieved, of a type appropriate to the
'type' parameter.
'type' is the type of the value parameter and will be set to
one of the values for DataType Constants.
If 'pdu' doesn't reference a valid PDU or 'varBindIndex'
doesn't reference a valid varbind, the function returns
without modifying 'oid', 'value' or 'type'.
9.1.4.4. snmpSend()
integer snmpSend(integer pdu, integer numVarbinds, integer opcode
[, string context , NonLocalArgs] )
snmpSend will perform an SNMP operation using the specified
PDU. Note that no actual SNMP PDU needs to be
generated and parsed when the policy MIB agent
resides on the same system as the managed elements.
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The optional 'context' argument contains the context to
operate on. If this argument is not present, the context of
"this element" will be used. If this argument is the zero
length string, the default context is used.
The optional 'NonLocalArgs' provide addressing and security
information to perform an SNMP operation on a different system
than "this element".
The results of the operation will be placed in the same
PDU. If an error occurred, the PDU will remain
unmodified except for the following:
1) If the response PDU had a nonzero error-index, the
varbind specified by the error-index will have its type
field replaced with associated error-status constant.
2) If the response PDU contained varbinds with exceptions,
the type field of those varbinds will be replaced with
the appropriate exception (Nosuchobject,
NosuchInstance, or Endofmibview).
3) If the error-status was zero and there were no
exceptions, the PDU will remain unmodified. (some
examples of situations where this will apply are timeout
and authentication failure).
This function returns zero unless an error occurs in which
case it returns the proper SNMP Error Constant.
'pdu' is the handle to a PDU allocated by newPDU().
'numVarbinds' is a integer greater than zero that specified
which varbinds in the PDU will be used in this
operation. The first N varbinds in the PDU are used.
'opcode' is the type of SNMP operation to perform and must be
one of the values for SNMP Operation Constants.
9.2. Constants
The following constants are defined for use in all SNMP
Accessor Functions. Policy code will be executed in an
environment where the following constants are declared. (Note
that these constant declarations will not be visible in the
policyCondition or policyAction code.)
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While these declarations are expressed here as C 'const's, the
'const' construct itself is not available to be used inside of
policy code.
// Datatype Constants
const int Integer = 1;
const int String = 2;
const int Oid = 3;
const int Integer32 = 4;
const int Ipaddress = 5;
const int Counter32 = 6;
const int Gauge32 = 7;
const int Unsigned32 = 8;
const int Timeticks = 9;
const int Opaque = 10;
const int Counter64 = 11;
// SNMP Error Constants
const int Nosuchobject = 21;
const int Nosuchinstance = 22;
const int Endofmibview = 23;
const int Noerror = 24;
const int Toobig = 25;
const int Nosuchname = 26;
const int Badvalue = 27;
const int Readonly = 28;
const int Generr = 29;
const int Noaccess = 30;
const int Wrongtype = 31;
const int Wronglength = 32;
const int Wrongencoding = 33;
const int Wrongvalue = 34;
const int Nocreation = 35;
const int Inconsistentvalue = 36;
const int Resourceunavailable = 37;
const int Commitfailed = 38;
const int Undofailed = 39;
const int Authorizationerror = 40;
const int Notwritable = 41;
const int Badparameter = 42;
const int Toolong = 43;
const int Parseerror = 44;
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const int Authfailure = 45;
const int Timeout = 46;
// SNMP Operation Constants
const int Get = 0;
const int Getnext = 1;
const int Set = 3;
const int Trap = 4;
const int Inform = 6;
const int V2trap = 7;
// Constants for SnmpMessageProcessingModel and SnmpSecurityModel
const int SNMPv1 = 0;
const int SNMPv2c = 1;
const int SNMPv3 = 3;
// SnmpSecurityLevel Constants
const int noAuthNoPriv = 1;
const int authNoPriv = 2;
const int authPriv = 3;
9.3. Policy Accessor Functions
Policy Accessor Functions provide access to information
specifically related to the execution of policies.
9.3.1. roleMatch()
The roleMatch() function is used to check to see if an element
has been assigned a particular role.
integer roleMatch(string roleString [, string element,
string context, string contextEngineID])
Argument 'roleString' is a string. The optional argument
'element' contains the OID name of an element, defaulting
to the current element if this argument is not supplied.
If roleString exactly matches (content and length) any role
assigned to the specified element, the function returns 1. If
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no roles match, the function returns 0.
The 'context' argument contains the context of 'element'. If
this argument is not present, the context of "this element"
will be used. This argument may only be present if the
'element' argument is present. If this argument is the zero
length string, the default context is specified.
The 'contextEngineID' argument contains the contextEngineID of
the remote system that 'element' resides on. It is encoded as
a pair of hex digits (upper and lower case are valid) for each
octet of the contextEngineID. If this argument is not present,
the local system will be used. This argument may only be
present if the 'element' and 'context' arguments are present.
9.3.2. capMatch()
The capMatch() function is used to check to see if an element
has a certain capability.
integer capMatch(string capOid [, string element])
Argument 'capOid' is a string containing a
ASCII dotted-decimal representation of an object identifier
that describes a capability as would be found in the
pmCapabilitiesTable. The optional argument 'element'
contains the OID name of an element, defaulting to the
current element if this argument is not supplied.
If the specified element has the capability described by
capOid, this function returns 1, otherwise it returns 0.
9.3.3. elementName()
The elementName() function is used to determine what the
current element is and can be used to provide information
about the type of element as well as how it is indexed.
string elementName()
elementName returns a string containing an ASCII
dotted-decimal representation of an object identifier
(e.g. 1.3.6.1.2.1.1.1.0). This object identifier identifies an
instance of a MIB object that is an attribute of this element.
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9.3.4. ec()
The ec() and ev() functions provide convenient access to the
components of the index for "this element". Typical uses will
be in creating the index to other, related elements.
integer ec()
ec() returns an integer count of the number index subidentifiers
exist in the index for "this element".
9.3.5. ev()
The ec() and ev() functions provide convenient access to the
components of the index for "this element". Typical uses will
be in creating the index to other, related elements.
integer ev(integer n)
ev() returns the value of the n'th subidentifier in the index
for 'this element". The first subidentifier is indexed at
0. It is an RTE if 'n' specifies a subidentifier beyond the
last subidentifier.
9.3.6. context()
string elementContext()
elementContext() returns a string containing the context of
"this element".
9.3.7. elementAddress()
elementAddress(&tDomain, &tAddress)
elementAddress modifies the 'tDomain' and 'tAddress' arguments
to contain a domain/address pair that can be used to access
"this element".
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9.3.8. setScratchpad()
setScratchpad(integer scope, string varName [, string value,
integer storageType])
Every maxLatency time period, every policy runs once for each
element. When the setScratchpad function executes, it stores a
value that can be retrieved even after this policy execution
code exits. This allows sharing of data between a condition and
an action, two conditions executing on different elements, or
even different policies altogether. The value of 'scope'
controls which policy/element combinations can retrieve this
'varName'/'value' pair. The options for 'scope' are:
Global
The 'varName'/'value' combination will be available in the
condition or action of any policy while executing on any
element.
Policy
The 'varName'/'value' combination will be available in any
future execution of the condition or action of the current
policy (regardless of what element the policy is executing
on). If a policy is ever deleted or its condition or action
code is modified, all values in its 'Policy' scope will be
deleted.
PolicyElement
The 'varName'/'value' combination will be available in
future executions of the condition or action of the current
policy but only when the policy is executing on the
current element. If a policy is ever deleted or its
condition or action code is modified, all values in its
'PolicyElement' scope will be deleted.
'varName' is a string used to identify the value. Subsequent
retrievals of the same 'varName' in the proper scope will
return the value stored. Note that the namespace for 'varName'
is distinct for each scope. 'varName' is case sensitive.
'value' is a string containing the value to be stored.
ToString(value) is called on this argument to convert it
to a string before storage.
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If the 'value' argument this missing, the effect will be to
delete 'varName' in scope 'scope' if it exists.
If the optional 'storageType' argument is present and is equal
to the constant 'volatile', then this variable must be deleted
on a reboot. If it is equal to 'nonVolatile', then this
variable should be stored in non-volatile storage where it
will be available after a reboot. If it is equal to
'freeOnException', the agent will free this variable if later
in the same script invocation this script dies with a run-time
exception or by a call to die() (note that this does not apply
to subsequent invocations of the script). If the 'storageType'
argument is not present, the variable will volatile and will
be erased on reboot. The 'storageType'' argument may not be
present if the 'value' argument is not present.
Note that there may be implementation-specific limits on the
number of scratchpad variables that can be allocated. The
limit of unique scratchpad variables may be different for each
scope or storageType.
Contents of the scratchpad are erased on reboot.
9.3.9. getScratchpad()
integer getScratchpad(integer scope, string varName,
string &value)
The getScratchpad function allows the retrieval of values that
were stored previously in this execution context or in
other execution contexts. The value of 'scope' controls which
execution contexts can pass a value to this execution context.
Refer to the definition of setScratchpad to see which values
of 'scope' can pass a value to which execution contexts.
'varName' is a string used to identify the value. Subsequent
retrievals of the same 'varName' in the proper scope will return
the value stored. Note that the namespace for varName is
distinct for each scope. As a result, getScratchpad cannot
force access to a variable in an inaccessible scope - it can
only retrieve variables by referencing the proper scope in
which they were set. 'varName' is case sensitive.
On successful return, 'value' will be set to the value that was
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previously stored, otherwise 'value' will not be modified.
This function returns 1 if a value was previously stored and 0
otherwise.
Scratchpad Usage Examples
Policy Element Action
A ifIndex.1 setScratchpad(Global, "foo", "55")
A ifIndex.1 getScratchpad(Global, "foo", val) == 55
A ifIndex.2 getScratchpad(Global, "foo", val) == 55
B ifIndex.2 getScratchpad(Global, "foo", val) == 55
B ifIndex.2 setScratchpad(Global, "foo", "16")
A ifIndex.1 getScratchpad(Global, "foo", val) == 16
Policy Element Action
A ifIndex.1 setScratchpad(Policy, "bar", "75")
A ifIndex.1 getScratchpad(Policy, "bar", val) == 75
A ifIndex.2 getScratchpad(Policy, "bar", val) == 75
B ifIndex.1 getScratchpad(Policy, "bar", val) not found
B ifIndex.1 setScratchpad(Policy, "bar", "20")
A ifIndex.2 getScratchpad(Policy, "bar", val) == 75
B ifIndex.2 getScratchpad(Policy, "bar", val) == 20
Policy Element Action
A ifIndex.1 setScratchpad(PolicyElement, "baz", "43")
A ifIndex.1 getScratchpad(PolicyElement, "baz", val) == 43
A ifIndex.2 getScratchpad(PolicyElement, "baz", val) not found
B ifIndex.1 getScratchpad(PolicyElement, "baz", val) not found
A ifIndex.2 setScratchpad(PolicyElement, "baz", "54")
B ifIndex.1 setScratchpad(PolicyElement, "baz", "65")
A ifIndex.1 getScratchpad(PolicyElement, "baz", val) == 43
A ifIndex.2 getScratchpad(PolicyElement, "baz", val) == 54
B ifIndex.1 getScratchpad(PolicyElement, "baz", val) == 65
Policy Element Action
A ifIndex.1 setScratchpad(PolicyElement, "foo", "11")
A ifIndex.1 setScratchpad(Global, "foo", "22")
A ifIndex.1 getScratchpad(PolicyElement, "foo", val) == 11
A ifIndex.1 getScratchpad(Global, "foo", val) == 22
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9.3.10. Constants
The following constants are defined for use for the scratchpad
functions. Policy code will be executed in an environment
where the following constants are declared. (Note that these
constant declarations will not be visible in the
policyCondition or policyAction MIB objects.)
While these declarations are expressed here as C 'const's, the
'const' construct itself is not available to be used inside of
policy code.
// Scratchpad Constants
// Values of scope
const int Global = 0;
const int Policy = 1;
const int PolicyElement = 2;
// Values of storageType
const int volatile = 0;
const int nonVolatile = 1;
const int freeOnException = 2;
9.3.11. signalError()
The signalError() function is used to by the script to
indicate to a management station that it is experiencing
abnormal behavior. signalError() turns on the
conditionUserSignal(3) or actionUserSignal(5) bit in the
associated pmTrackingPEInfo object (subsequent calls to
signalError() have no additional effect). This bit is
initially cleared at the beginning of each execution, so if
upon a subsequent execution, a script no longer calls this
function, the bit will be cleared.
signalError()
The signalException function takes no arguments and returns no
value.
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9.3.12. defer()
Policies can be associated in groups with the behavior that
for each element, of the policies that match the condition,
only the one the highest precedence value will be active. For
example if there is a default bronze policy that applies to
any interface and a special policy for gold interfaces, the
higher precedence of the gold policy will ensure that it is
run on gold ports and the bronze policy isn't.
Unfortunately, once the winning policy has been selected and
the action begins running, situations can occur where the code
determines that it cannot complete its task. In many such
cases, it is desirable that the next runner-up policy be
executed. In the previous example it would be desirable that
at least bronze behavior be configured if gold is appropriate
but isn't possible.
When a policy defers it exits and the condition-matching
policy with the next-highest precedence is immediately run.
Because it's possible that might defer as well, the execution
environment must remember where it is in the precedence chain
so that it can continue going down the chain until an action
completes without deferring or no policies are left in the
group. Once a policy completes successfully, the next
iteration will begin at the top of the precedence chain.
There are two ways to defer. A script can exit by calling
die() and specify that it should defer. Alternately, a script
can instruct the execution environment to cause it to defer if
it experiences a run-time exception.
defer(integer defer)
The defer function changes the run-time exception behavior of a
script. By default, a script will not defer when it encounters
an RTE. If defer(1) is called, the exit behavior is changed so
the script will defer when it is terminated due to an RTE.
won't defer when it is terminated due to an RTE.
9.3.13. die()
die(integer defer, integer free [, string message] )
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The die function causes the script to optionally perform
certain functions and then exit.
If the 'defer' argument is 1, this script will defer to the
next lower precedence policy in the same group who's condition
matches. If the 'defer' argument isn't 1, it won't defer.
Note that if a condition defers, it is functionally equivalent to
the condition returning false.
If the 'free' argument is 1, certain registered resources will
be freed. If earlier in this script invocation any rows were
created by createRow with the 'freeOnException' option, the
execution environment will set the RowStatus of each row to
'destroy' to delete the row. Further, if earlier in this script
invocation any scratchpad variables were created or modified
with the 'freeOnException' option, they will be deleted.
If the optional 'message' argument is present, it will be
logged to the debugging table if pmPolicyDebugging is turned on
for this policy.
Finally, the script will terminate.
9.3.14. getParameters()
From time to time, policy scripts may desire one or more
parameters (e.g., site-specific constants). These parameters
may be installed with the script in this object and are
accessible to the script via the getParameters() accessor
function. If it is necessary for multiple parameters to be
passed to the script, the script can choose whatever
encoding/delimiting mechanism is most appropriate.
string getParameters()
The getParameters function takes no arguments. It returns a
string containing the value of the pmPolicyParameters object
for the running policy.
9.4. Utility Accessor Functions
Utility Accessor Functions are provided to enable more
efficient use of the other accessor functions.
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9.4.1. regexp()
integer regexp(string pattern, string str,
integer case [, string &match])
regexp searches 'str' for matches to the regular expression
given in `pattern`. regexp uses the POSIX extended regular
expressions defined in POSIX 1003.2.
If the `case` argument is 0, the search will be case
insensitive, otherwise it will be case sensitive.
If a match is found, 1 is returned, otherwise 0 is returned.
If the optional argument 'match' is provided and a match is
found, the text of the first substring of 'str' that matches
'pattern' will be copied to 'match'. If no match is found it
will be unchanged.
9.4.2. regexpReplace()
string regexpReplace(string pattern, string replacement,
string str, integer case)
regexpReplace searches 'str' for matches to the regular expression
given in `pattern`, replacing the matched text with
'replacement'. regexpReplace uses the POSIX extended regular
expressions defined in POSIX 1003.2.
If the `case` argument is 0, the search will be case
insensitive, otherwise it will be case sensitive.
The modified string is returned (which could be the same as
the original string if no matches were found).
9.4.3. oidlen()
integer oidlen(string oid)
oidlen returns the number of subidentifiers in 'oid'. 'oid' is
a string containing an ASCII dotted-decimal representation of
an object identifier (e.g. "1.3.6.1.2.1.1.1.0").
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9.4.4. oidncmp()
integer oidncmp(string oid1, string oid2, integer n)
Arguments 'oid1' and 'oid2' are strings containing
ASCII dotted-decimal representations of object identifiers
(e.g. "1.3.6.1.2.1.1.1.0").
oidcmp compares not more than 'n' subidentifiers of 'oid1' and
'oid2' and returns -1 if 'oid1' is less than 'oid2', 0 if they
are equal, and 1 if 'oid1' is greater than 'oid2'.
9.4.5. inSubtree()
integer inSubtree(string oid, string prefix)
Arguments 'oid' and 'prefix' are strings containing
ASCII dotted-decimal representations of object identifiers
(e.g. "1.3.6.1.2.1.1.1.0").
inSubtree returns 1 if every subidentifier in 'prefix' equals
the corresponding subidentifier in 'oid', otherwise it returns
0. The is equivalent to oidncmp(oid1, prefix, oidlen(prefix))
is provided because this is an idiom and because it avoids
evaluating 'prefix' twice if is an expression.
9.4.6. subid()
integer subid(string oid, integer n)
subid returns the value of the 'n'th (starting at zero)
subidentifier of 'oid'. 'oid' is a string containing an ASCII
dotted-decimal representation of an object identifier
(e.g. "1.3.6.1.2.1.1.1.0").
If 'n' specifies a subidentifier beyond the length of 'oid', a
value of -1 is returned.
9.4.7. subidWrite()
integer subidWrite(string oid, integer n, integer subid)
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subidWrite sets the value of the 'n'th (starting at zero)
subidentifier of 'oid' to `subid'. 'oid' is a string
containing an ASCII dotted-decimal representation of an object
identifier (e.g. "1.3.6.1.2.1.1.1.0").
If 'n' specifies a subidentifier beyond the length of 'oid',
a value of -1 is returned. Note that appending subidentifiers
can be accomplished with the string concatenation '+'
operator.
9.4.8. oidSplice()
string oidSplice(string oid1, integer offset, integer len, string oid2)
oidSplice replaces 'len' subidentifiers in 'oid1' with all of
the subidentifiers from 'oid2', starting at 'offset' in 'oid1'
(the first subidentifier is at offset 0). The oid length will
be extended if necessary if 'offset' + 'len' extends beyond
the end of 'oid1'.
The resulting oid is returned.
For example:
oidSplice("1.3.6.1.2.1", 5, 1, "7") => "1.3.6.1.2.7"
oidSplice("1.3.6.1.2.1", 4, 2, "7.7") => "1.3.6.1.7.7"
oidSplice("1.3.6.1.2.1", 4, 3, "7.7.7") => "1.3.6.1.7.7.7"
9.4.9. parseIndex()
ParseIndex is provided to make it easy to pull index values
from OIDs into variables.
var parseIndex(string oid, integer &index, integer type,
integer len)
parseIndex pulls values from the instance identification
portion of 'oid', encoded as per Section 7.7 "Mapping of the
INDEX clause" of the SMIv2[5].
'oid' is the oid to be parsed.
'index' describes which subid to begin parsing at. 'index'
will be modified to indicate the subid after the last one
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parsed (even if this points past the last subid). The first
subid is index 0. If any error occurs, 'index' will set to -1
on return. If the input index refers past the end of the oid,
'index' will be set to -1 on return.
If 'type' is Integer, 'len' will not be consulted. The return
value is the integer value of the next subid.
If 'type' is String and 'len' is greater than zero, 'len'
subids will be parsed. For each subid parsed, the chr() value
of the subid will be appended to the returned string. If any
subid is greater than 255, the 'index' argument will be set to
-1 on return and an empty string will be returned. If there
are fewer than 'len' subids left in 'oid', 'index' will be
set to -1 on return but a string will be returned containing a
character for each subid that was left.
If 'type' is String and 'len' is zero, the next subid will be
parsed to find 'N', the length of the string. Then this many
subids will be parsed. For each subid parsed, the chr() value
of the subid will be appended to the returned string. If any
subid is greater than 255, the 'index' argument will be set to
-1 on return and an empty string will be returned. If there
are fewer than 'N' subids left in 'oid', 'index' will be set
to -1 on return but a string will be returned containing a
character for each subid that was left.
If 'type' is String and 'len' is -1, subids will be parsed
until the end of 'oid'. For each subid parsed, the chr()
value of the subid will be appended to the returned string. If
any subid is greater than 255, the 'index' argument will be
set to -1 on return and an empty string will be returned.
If 'type' is Oid and 'len' is greater than zero, 'len' subids
will be parsed. For each subid parsed, the decimal-encoded
value of the subid will be appended to the returned string,
with a '.' character appended between each output subid but
not after the last subid. If there are fewer than 'len' subids
left in 'oid', 'index' will be set to -1 on return but a
string will be returned containing an encoding for each subid
that was left.
If 'type' is Oid and 'len' is zero, the next subid will be
parsed to find 'N', the number of subids to parse. For each
subid parsed, the decimal-encoded value of the subid will be
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appended to the returned string, with a '.' character appended
between each output subid but not after the last subid. If
there are fewer than 'N' subids left in 'oid', 'index' will be
set to -1 on return but a string will be returned containing
an encoding for each subid that was left.
If 'type' is Oid and 'len' is -1, subids will be parsed until
the end of 'oid'. For each subid parsed, the decimal-encoded
value of the subid will be appended to the returned string,
with a '.' character appended between each output subid but
not after the last subid.
9.4.10. stringToDotted()
stringToDotted() is provided to encode strings suitable for
the index portion of an oid or to convert the binary encoding
of an ip address to a dotted-decimal encoding.
string stringToDotted(string value)
If 'value' is the zero length string, the zero length string
is returned.
The decimal encoding of the first byte of 'value' is appended
to the output string. Then for each additional byte in
'value', a '.' is appended to the output string followed by
the decimal encoding of the additional byte.
9.4.11. integer()
integer integer(var input)
integer converts 'input' into an integer by using the rules
specified for ToInteger(), returning the integer-typed
results.
9.4.12. string()
string string(var input)
string converts 'input' into a string by using the rules
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specified for ToString(), returning the string-typed
results.
9.4.13. type()
string type(var variable)
type returns the type of its argument as either the string
'String' or the string 'Integer'.
9.4.14. chr()
string chr(integer utf8)
Returns a one-character string containing the character
specified by the UTF8 code contained in 'utf8'. Note that a
property of UTF8 is that 7-bit ASCII characters are
represented by the same UTF8 code-points as their ascii
equivalents.
9.4.15. ord()
integer ord(string str)
Returns the UTF8 code-point value of the first character of
'str'. This function complements chr(). Note that a property of
UTF8 is that 7-bit ASCII characters are represented by the
same UTF8 code-points as their ascii equivalents.
9.4.16. substr()
string substr(string &str, integer offset,
integer len [, string replacement])
Extracts a substring out of 'str' and returns it. The first
octet is at offset 0. If offset is negative, the returned
string starts that far from the end of 'str'. If 'len' is
positive, the returned string contains up to 'len' octets,
up to the end of the string. If 'len' is omitted, the returned
string includes everything to the end of 'str'. If 'len' is
negative, abs(len) octets are left off the end of the
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string.
If you specify a substring that is partly outside the string,
the part within the string is returned. If the substring is
totally outside the string, a zero-length string is produced.
If the optional replacement argument is included, 'str' is
modified. 'offset' and 'len' act as above to select a range of
octets in 'str'. These octets are replaced with
octets from 'replacement'. If the replacement string is
shorter or longer than the number of octets selected,
'str' will shrink or grow respectively.
9.5. Library Accessor Functions
The following POSIX standard library accessor functions are
provided:
strncmp()
strncasecmp()
strlen()
random()
sprintf()
sscanf()
10. Schedule Table
This table is an adapted form of the policyTimePeriodCondition
class defined in the Policy Core Information Model, RFC 3090
[21].
The policy schedule table allows control over when a policy
will be active based on the date and time. Note that the use
of the term active in this context does not refer to the
'active' state of the pmPolicyRowStatus object, although it is
necessary for a the RowStatus to be active for the policy to
run. It is also necessary for the pmPolicyAdminStatus to be in
an enabled mode.
A policy's pmPolicySchedule variable refers to a group of one
or more schedules in the schedule table. At any given point in
time, if any of these schedules are active, the policy will be
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active (assuming that it is enabled) and it's conditions and
actions will be executed as appropriate. At times when none
of these schedules are active, the policy won't be active and
will have no effect. A policy will always be active if it's
pmPolicySchedule variable is 0 or doesn't refer to an existing
schedule group.
A policy that is controlled by a schedule group immediately
executes its policy condition (and conditionally the
policyAction) when the schedule group becomes active,
periodically re-executing these scripts as appropriate until
the schedule group becomes inactive (i.e. all schedules are
inactive).
An individual schedule item is active at those times that
match all of the variables that define the schedule:
pmSchedTimePeriod, pmSchedMonth, pmSchedDay, pmSchedWeekDay,
and pmSchedTimeOfDay. It is possible to specify multiple
values for each schedule item. This provides a mechanism for
defining complex schedules. For example, a schedule could be
defined which is active the entire workday each weekday.
Months, days and weekdays are specified using the objects
pmSchedMonth, pmSchedDay and pmSchedWeekDay of type BITS.
Setting multiple bits in these objects causes an OR operation.
For example, setting the bits monday(1) and friday(5) in
pmSchedWeekDay restricts the schedule to Mondays and Fridays.
The matched times for pmSchedTimePeriod, pmSchedMonth,
pmSchedDay pmSchedWeekDay, and pmSchedTimeOfDay are ANDed
together to determine the time periods that the schedule will
be active; in other words, the schedule is only active for
those times that ALL of these schedule attributes match. For
example, a schedule with an overall validity range of January
1, 2000 through December 31, 2000; a month mask that selects
March and April; a day-of-the-week mask that selects Fridays;
and a time of day range of 0800 through 1600 would represent
the following time periods:
Friday, March 5, 2000, from 0800 through 1600;
Friday, March 12, 2000, from 0800 through 1600;
Friday, March 19, 2000, from 0800 through 1600;
Friday, March 26, 2000, from 0800 through 1600;
Friday, April 2, 2000, from 0800 through 1600;
Friday, April 9, 2000, from 0800 through 1600;
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Friday, April 16, 2000, from 0800 through 1600;
Friday, April 23, 2000, from 0800 through 1600;
Friday, April 30, 2000, from 0800 through 1600.
Wildcarding of schedule attributes of type BITS is achieved by
setting all bits to one.
It is possible to define schedules that will never cause a
policy to be activated. For example, one can define a schedule
which should be active on February 31st.
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11. Definitions
POLICY-BASED-MANAGEMENT-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
Counter32, Integer32, Gauge32, Unsigned32,
experimental FROM SNMPv2-SMI
RowStatus, RowPointer, TEXTUAL-CONVENTION,
DateAndTime, StorageType FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP,
NOTIFICATION-GROUP FROM SNMPv2-CONF
SnmpAdminString FROM SNMP-FRAMEWORK-MIB;
-- Policy-Based Management MIB
pmMib MODULE-IDENTITY
LAST-UPDATED "200106110000Z" -- June 11, 2001
ORGANIZATION "IETF SNMP Configuration Working Group"
CONTACT-INFO
"
Steve Waldbusser
Phone: +1-650-948-6500
Fax: +1-650-745-0671
Email: waldbusser@nextbeacon.com
Jon Saperia (WG Co-chair)
JDS Consulting, Inc.
174 Chapman St.
Watertown MA 02472-3063
USA
Phone: +1-617-744-1079
Fax: +1-617-249-0874
Email: saperia@jdscons.com
Thippanna Hongal
Riverstone Networks, Inc.
5200 Great America Parkway
Santa Clara, CA, 95054
USA
Phone: +1-408-878-6562
Fax: +1-408-878-6501
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Email: hongal@riverstonenet.com
David Partain (WG Co-chair)
Postal: Ericsson Radio Systems
P.O. Box 1248
SE-581 12 Linkoping
Sweden
Tel: +46 13 28 41 44
E-mail: David.Partain@ericsson.com
Any questions or comments about this document can also be
directed to the working group at snmpconf@snmp.com."
DESCRIPTION
"The MIB module for policy-based configuration of SNMP
infrastructures."
REVISION "200106110000Z" -- June 11, 2001
DESCRIPTION
"The original version of this MIB, published as RFCXXXX."
::= { experimental 107 }
UTF8String ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"An octet string containing information typically in
human-readable form.
To facilitate internationalization, this
information is represented using the ISO/IEC
IS 10646-1 character set, encoded as an octet
string using the UTF-8 transformation format
described in [RFC2279].
Since additional code points are added by
amendments to the 10646 standard from time
to time, implementations must be prepared to
encounter any code point from 0x00000000 to
0x7fffffff. Byte sequences that do not
correspond to the valid UTF-8 encoding of a
code point or are outside this range are
prohibited.
The use of control codes should be avoided.
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When it is necessary to represent a newline,
the control code sequence CR LF should be used.
For code points not directly supported by user
interface hardware or software, an alternative
means of entry and display, such as hexadecimal,
may be provided.
For information encoded in 7-bit US-ASCII,
the UTF-8 encoding is identical to the
US-ASCII encoding.
UTF-8 may require multiple bytes to represent a
single character / code point; thus the length
of this object in octets may be different from
the number of characters encoded. Similarly,
size constraints refer to the number of encoded
octets, not the number of characters represented
by an encoding.
Note that when this TC is used for an object that
is used or envisioned to be used as an index, then
a SIZE restriction MUST be specified so that the
number of sub-identifiers for any object instance
does not exceed the limit of 128, as defined by
[RFC1905].
Note that the size of an UTF8String object is
measured in octets, not characters."
SYNTAX OCTET STRING
-- The policy group
pmPolicyTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmPolicyEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The policy table. A policy is a pairing of a
policyCondition and a policyAction which is used to apply the
action to a selected set of elements."
::= { pmMib 1 }
pmPolicyEntry OBJECT-TYPE
SYNTAX PmPolicyEntry
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MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the policy table representing one policy."
INDEX { pmPolicyIndex }
::= { pmPolicyTable 1 }
PmPolicyEntry ::= SEQUENCE {
pmPolicyIndex Unsigned32,
pmPolicyGroup UTF8String,
pmPolicyPrecedence Unsigned32,
pmPolicySchedule Unsigned32,
pmPolicyElementTypeFilter UTF8String,
pmPolicyConditionProgramIndex Unsigned32,
pmPolicyActionProgramIndex Unsigned32,
pmPolicyParameters OCTET STRING,
pmPolicyConditionMaxLatency Unsigned32,
pmPolicyActionMaxLatency Unsigned32,
pmPolicyMaxIterations Unsigned32,
pmPolicyDescription UTF8String,
pmPolicyMatches Gauge32,
pmPolicyAbnormalTerminations Gauge32,
pmPolicyExecutionErrors Counter32,
pmPolicyDebugging INTEGER,
pmPolicyAdminStatus INTEGER,
pmPolicyStorageType StorageType,
pmPolicyRowStatus RowStatus
}
pmPolicyIndex OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique index for this policy entry."
::= { pmPolicyEntry 1 }
pmPolicyGroup OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..32))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An administratively assigned string that is used to group
policies. For each element, only one policy in the same group
may be active on that element. If multiple policies would be
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active on an element (because their conditions return non-zero),
the execution environment will only allow the policy with the
highest value of pmPolicyPrecedence to be active."
::= { pmPolicyEntry 2 }
pmPolicyPrecedence OBJECT-TYPE
SYNTAX Unsigned32 (0..65535)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"If while checking to see which policy conditions match an
element, 2 or more policies in the same group match the same
element, the pmPolicyPrecedence object provides the rule to
arbitrate which single policy action will be executed on this
element. Of policies in the same group, only the matching
policy with the highest precedence value (i.e. 2 is higher
than 1) will have its policy action periodically executed on
this element.
When a policy condition no longer matches an element, the
condition-matching policy with the next-highest precedence is
immediately run. If a policy condition suddenly begins matching
an element, it will immediately be run and any
lower-precedence matching policies will not run anymore.
In the case where multiple policies share the
highest value, it is an implementation-dependent matter as to
which single policy action will be chosen.
Note that if it is necessary to take certain actions after a
policy is no longer active on an element, these actions should
be included in a lower-precedence policy that is in the same
policy group."
::= { pmPolicyEntry 3 }
pmPolicySchedule OBJECT-TYPE
SYNTAX Unsigned32 (0..65535)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"If this object refers to a valid pmSchedGroupIndex, this
policy will be activated as specified by the associated
schedule entries. Whenever any schedule in the group is
active, this policy will be active.
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A valid pmSchedGroupIndex is one that refers to a
pmSchedGroup that contains at least one running schedule with
its RowStatus set to 'active'.
If the value of this object is 0, this policy is always
active."
::= { pmPolicyEntry 4 }
pmPolicyElementTypeFilter OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..128))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object specifies the element types for which this policy
will be executed. When this policy is active, it will be
executed on all elements of these types.
The format of this object will be a sequence of
pmElementTypeRegOIDPrefix values, encoded in the following
form:
elementTypeFilter: oid [ ';' oid ]*
oid: subid [ '.' subid ]*
subid: '0' | decimal_constant
For example, to register for the policy to be run on all
interface elements, the 'ifEntry' element type will be
registered as '1.3.6.1.2.1.2.2.1'.
If a value is registered that does not represent a registered
pmElementTypeRegOIDPrefix, then that value will be ignored."
::= { pmPolicyEntry 5 }
pmPolicyConditionProgramIndex OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A pointer to the row or rows in the pmPolicyCodeTable that
contain the condition code for this policy. When a policy entry
is created, an unused pmPolicyCodeIndex value will be
assigned to this object.
A policy condition is one or more PolicyScript statements
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which results in a boolean value that represents whether or
not an element is a member of a set of elements upon which an
action is to be performed.
Condition evaluation stops immediately when any run-time
exception is detected and the policyAction is not executed.
The policyCondition is evaluated for various elements. Any
element for which the policyCondition returns any nonzero value
will match the condition and will have the associated
policyAction executed on that element unless a
higher-precedence policy in the same policy group also
matches this element.
If the condition object is empty (contains no code) or otherwise
does not return a value, the element will not be matched.
When executing this condition, if SNMP requests are made to the
local system, access to objects is under the security
credentials of the requester who modified the most
recently modified pmPolicyCodeEntry associated with either
the pmPolicyConditionProgramIndex value or
pmPolicyActionProgramIndex value. In other words,
modification of any part of a policy's condition or action will
change the credentials stored for the policy.
These credentials are the input parameters for
isAccessAllowed from the Architecture for Describing SNMP
Management Frameworks[1]."
::= { pmPolicyEntry 6 }
pmPolicyActionProgramIndex OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A pointer to the row or rows in the pmPolicyCodeTable that
contain the action code for this policy. When a policy entry
is created, an unused pmPolicyCodeIndex value will be
assigned to this object.
A pmPolicyAction is an operation performed on a
set of elements.
Action evaluation stops immediately when any run-time
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exception is detected.
When executing this action, if SNMP requests are made to the
local system, access to objects is under the security
credentials of the requester who modified the most
recently modified pmPolicyCodeEntry associated with either
the pmPolicyConditionProgramIndex value or
pmPolicyActionProgramIndex value. In other words,
modification of any part of a policy's condition or action will
change the credentials stored for the policy.
These credentials are the input parameters for
isAccessAllowed from the Architecture for Describing SNMP
Management Frameworks[1]."
::= { pmPolicyEntry 7 }
pmPolicyParameters OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"From time to time, policy scripts may desire one or more
parameters (e.g., site-specific constants). These parameters
may be installed with the script in this object and are
accessible to the script via the getParameters() accessor
function. If it is necessary for multiple parameters to be
passed to the script, the script can choose whatever
encoding/delimiting mechanism is most appropriate."
::= { pmPolicyEntry 8 }
pmPolicyConditionMaxLatency OBJECT-TYPE
SYNTAX Unsigned32 (0..2147483647)
UNITS "milliseconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Every element under the control of this agent is
re-checked periodically to see if it is under control of this
policy by re-running the condition for this policy.
This object lets the manager control the maximum amount of
time that may pass before an element is re-checked.
In other words, in any given interval of this duration, all
elements must be re-checked. Note that it is an
implementation-dependent matter as to how the policy agent
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schedules the checking of various elements within this
interval. Implementations may wish to re-run a condition more
quickly if they note a change to the role strings for an
element."
::= { pmPolicyEntry 9 }
pmPolicyActionMaxLatency OBJECT-TYPE
SYNTAX Unsigned32 (0..2147483647)
UNITS "milliseconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Every element that matches this policy's condition and is
therefore under control of this policy will have this policy's
action executed periodically to ensure that the element
remains in the state dictated by the policy.
This object lets the manager control the maximum amount of
time that may pass before an element has the action run on
it.
In other words, in any given interval of this duration, all
elements under control of this policy must have the action run
on them. Note that it is an implementation-dependent matter as
to how the policy agent schedules the policy action on various
elements within this interval."
::= { pmPolicyEntry 10 }
pmPolicyMaxIterations OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"If a condition or action script iterates in loops too many
times in one invocation, it may be considered by the execution
environment to be in an infinite loop or otherwise not acting
as intended and may be terminated by the execution
environment. The execution environment will count the
cumulative number of times all 'for' or 'while' loops iterated
and will apply a threshold to determine when to terminate the
script. It is an implementation-dependent manner as to what
threshold the execution environment uses, but the value of
this object SHOULD be the basis for choosing the threshold for
each script. The value of this object represents a
policy-specific threshold and can be tuned for policies of
varying workloads. If this value is zero, no
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threshold will be enforced except for any
implementation-dependent maximum.
Note that the condition and action invocations are tracked
separately."
::= { pmPolicyEntry 11 }
pmPolicyDescription OBJECT-TYPE
SYNTAX UTF8String
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A description of this rule and its significance, typically
provided by a human."
::= { pmPolicyEntry 12 }
pmPolicyMatches OBJECT-TYPE
SYNTAX Gauge32
UNITS "elements"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of elements that, in their most recent execution
of the associated condition, were matched by the condition."
::= { pmPolicyEntry 13 }
pmPolicyAbnormalTerminations OBJECT-TYPE
SYNTAX Gauge32
UNITS "elements"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of elements that, in their most recent execution
of the associated condition or action, have experienced a
run-time exception and terminated abnormally. Note that if a
policy was experiencing a run-time exception while processing
a particular element but on a subsequent invocation it runs
normally, this number can decline."
::= { pmPolicyEntry 14 }
pmPolicyExecutionErrors OBJECT-TYPE
SYNTAX Counter32
UNITS "errors"
MAX-ACCESS read-only
STATUS current
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DESCRIPTION
"The total number of times that execution of this policy's
condition or action has been terminated due to run-time
exceptions."
::= { pmPolicyEntry 15 }
pmPolicyDebugging OBJECT-TYPE
SYNTAX INTEGER {
off(0),
on(1)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of debugging for this policy. If this is turned
on(1), log entries will be created in the pmDebuggingTable
for each run-time exception that is experienced by this
policy."
DEFVAL { off }
::= { pmPolicyEntry 16 }
pmPolicyAdminStatus OBJECT-TYPE
SYNTAX INTEGER {
disabled(0),
enabled(1),
enabledAutoRemove(2)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The administrative status of this policy.
The policy will be runnable only if the associated
pmPolicyRowStatus is set to active(1) and this object is set
to enabled(1) or enabledAutoRemove(2).
If this object is set to enabledAutoRemove(2), the next time
the associated schedule moves from the active state to the
inactive state, this policy will immediately be deleted,
including any associated entries in the pmPolicyCodeTable.
[Note to reader: This object exists because a row cannot sit
for extended periods of time with it's rowstatus set to
inactive (it is subject to garbage collection). This object
allows policies to be downloaded but not run except at the
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convenience of the management station.]"
::= { pmPolicyEntry 17 }
pmPolicyStorageType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object defines whether this policy and any associated
entries in the pmPolicyCodeTable are kept in volatile storage
and lost upon reboot or if this row is backed up by
non-volatile or permanent storage."
::= { pmPolicyEntry 18 }
pmPolicyRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The row status of this pmPolicyEntry.
The status may not be set to active if any of the related
entries in the pmPolicyCode table do not have a status of
active or if any of the objects in this row are not set to
valid values.
If this row is deleted, any associated entries in the
pmPolicyCodeTable will be deleted as well."
::= { pmPolicyEntry 19 }
-- Policy Code Table
pmPolicyCodeTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmPolicyCodeEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The pmPolicyCodeTable stores the code for policy conditions and
actions."
::= { pmMib 2 }
pmPolicyCodeEntry OBJECT-TYPE
SYNTAX PmPolicyCodeEntry
MAX-ACCESS not-accessible
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STATUS current
DESCRIPTION
"An entry in the policy code table representing one code
segment. Entries that share a common ProgramIndex value make
up a single script. Valid values of ProgramIndex are retrieved
from pmPolicyConditionProgramIndex and pmPolicyActionProgramIndex
after a pmPolicyEntry is created. Segments of code can then be
written to this table using the learned ProgramIndex values."
INDEX { pmPolicyCodeProgramIndex, pmPolicyCodeSegment }
::= { pmPolicyCodeTable 1 }
PmPolicyCodeEntry ::= SEQUENCE {
pmPolicyCodeProgramIndex Unsigned32,
pmPolicyCodeSegment Unsigned32,
pmPolicyCodeText UTF8String,
pmPolicyCodeStatus RowStatus
}
pmPolicyCodeProgramIndex OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique index for each policy condition or action. The code
for each such condition or action may be composed of multiple
entries in this table if the code cannot fit in one entry.
Values of pmPolicyCodeProgramIndex may not be used unless
they have previously been assigned in the
pmPolicyConditionProgramIndex or pmPolicyActionProgramIndex
objects."
::= { pmPolicyCodeEntry 1 }
pmPolicyCodeSegment OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique index for each segment of a policy condition or
action.
When a policy condition or action spans multiple entries in this
table, the code of that policy starts from the
lowest-numbered segment and continues with increasing segment
values until ending with the highest-numbered segment."
::= { pmPolicyCodeEntry 2 }
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pmPolicyCodeText OBJECT-TYPE
SYNTAX UTF8String (SIZE (1..1024))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A segment of policy code (condition or action). Lengthy Policy
conditions or actions may be stored in multiple segments in this
table that share the same value of pmPolicyCodeProgramIndex.
When multiple segments are used, it is recommended that each
segment be as large as practical.
Entries in this table are associated with policies by values
of the pmPolicyConditionProgramIndex and
pmPolicyActionProgramIndex objects. If the status of the
related policy is active, then this object may not be
modified."
::= { pmPolicyCodeEntry 3 }
pmPolicyCodeStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this code entry.
Entries in this table are associated with policies by values
of the pmPolicyConditionProgramIndex and
pmPolicyActionProgramIndex objects. If the status of the
related policy is active, then this object can not be
modified (I.E., deleted or set to notInService) nor may new
entries be created."
::= { pmPolicyCodeEntry 4 }
-- Element Type Registration Table
-- The Element Type Registration table is used by the manager to learn
-- what element types are being managed by the system and to register
-- new types if necessary. An element type is registered by providing
-- the OID of an SNMP entry (i.e., the xxxEntry object) Each row that
-- exists under that object is a distinct element. The index of the
-- element is the index part of the discovered OID. This index will be
-- supplied to policy conditions and actions so that this code can
-- inspect and configure the element.
pmElementTypeRegTable OBJECT-TYPE
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SYNTAX SEQUENCE OF PmElementTypeRegEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A registration table for element types managed by this
system.
Note that agents may automatically configure elements in this
table for frequently used element types (interfaces, circuits,
etc.). In particular, it may configure elements for whom
discovery is optimized in one or both of the following ways:
1. The agent may discover elements by scanning internal data
structures as opposed to issuing local SNMP requests. It is
possible to recreate the exact semantics described in this
table even if local SNMP requests are not issued.
2. The agent may receive asynchronous notification of new
elements (for example, 'card inserted') and use that
information to instantly create elements rather than
through polling. A similar feature might be available for
the deletion of elements.
Note that the disposition of agent-installed entries is
described by the pmPolicyStorageType object."
::= { pmMib 3 }
pmElementTypeRegEntry OBJECT-TYPE
SYNTAX PmElementTypeRegEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A registration of an element type."
INDEX { pmElementTypeRegOIDPrefix }
::= { pmElementTypeRegTable 1 }
PmElementTypeRegEntry ::= SEQUENCE {
pmElementTypeRegOIDPrefix OBJECT IDENTIFIER,
pmElementTypeRegMaxLatency Unsigned32,
pmElementTypeRegDescription UTF8String,
pmElementTypeRegStorageType StorageType,
pmElementTypeRegRowStatus RowStatus
}
pmElementTypeRegOIDPrefix OBJECT-TYPE
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SYNTAX OBJECT IDENTIFIER
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This OBJECT IDENTIFIER value identifies a table in which all
elements of this type will be found. Every row in the
referenced table will be treated as an element for the
period of time that it remains in the table. The agent will
then execute policy conditions and actions as appropriate on each
of these elements.
This object identifier value is specified down to the 'entry'
component (i.e. ifEntry) of the identifier.
The index of each discovered row will be passed to each
invocation of the policy condition and policy action.
The actual mechanism by which instances are discovered is
implementation-dependent. Periodic walks of the table to
discover the rows in the table is one such mechanism. This
mechanism has the advantage that it can be performed by an
agent with no knowledge of the names, syntax or semantics
of the MIB objects in the table. This mechanism also serves as
the reference design. Other implementation-dependent
mechanisms may be implemented that are more efficient (perhaps
because they are hard-coded) or that don't require polling.
These mechanisms must discover the same elements as the
table-walking reference design.
A special OBJECT IDENTIFIER '0.0' can be written to this
object. '0.0' represents the single instance of the system
itself and provides an execution context for policies to
operate on 'the system' as well as on MIB objects modeled as
scalars. For example, '0.0' gives an execution context for
policy-based selection of the operating system code version
(likely modeled as a scalar MIB object). The element type
'0.0' always exists - as a consequence, no actual discovery
will take place and the pmElementTypeRegMaxLatency object will
have no effect for the '0.0' element type. However, if the
'0.0' element type is not registered in the table, policies
will not be executed on the '0.0' element.
When a policy is invoked on behalf of a '0.0' entry in this
table, the element name will be '0.0' and there is no index
of 'this element' (in other words it has zero length)."
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::= { pmElementTypeRegEntry 2 }
pmElementTypeRegMaxLatency OBJECT-TYPE
SYNTAX Unsigned32
UNITS "milliseconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The PM agent is responsible for discovering new elements of
types that are registered. This object lets the manager
control the maximum amount of time that may pass between the
time an element is created and when it is discovered.
In other words, in any given interval of this duration, all
new elements must be discovered. Note that it is an
implementation-dependent matter as to how the policy agent
schedules the checking of various elements within this
interval."
::= { pmElementTypeRegEntry 3 }
pmElementTypeRegDescription OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..32))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A descriptive label for this registered type."
::= { pmElementTypeRegEntry 4 }
pmElementTypeRegStorageType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object defines whether this row is kept
in volatile storage and lost upon reboot or if this row is
backed up by non-volatile or permanent storage."
::= { pmElementTypeRegEntry 5 }
pmElementTypeRegRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this registration entry."
::= { pmElementTypeRegEntry 6 }
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-- Role Table
-- The pmRoleTable is a read-create table that organizes role
-- strings sorted by element. This table is used to create and modify
-- role strings and their associations as well as to allow a
-- management station to learn about the existence of roles and their
-- associations.
--
-- It is the responsibility of the agent to keep track of any
-- re-indexing of the underlying SNMP elements and to continue to
-- associate role strings with the element with which they were
-- initially configured.
--
-- Policy MIB agents that have elements in multiple local contexts
-- need to allow some roles to be assigned to elements in particular
-- contexts. This is particularly true when some elements have the
-- same names in different contexts and the context is required to
-- disambiguate them. In those situations, a value for the
-- pmRoleContextName may be provided. When a pmRoleContextName value
-- is not provided, the assignment is to the element in the default
-- context.
--
-- Policy MIB agents that discover elements on other systems and
-- execute policies on their behalf need to have access to role
-- information for these remote elements. In such situations, role
-- assignments for other systems can be stored in this table by
-- providing values for the pmRoleContextEngineID parameters.
--
-- For example:
-- Example:
-- element role context ctxEngineID #comment
-- ifindex.1 gold local, default context
-- ifindex.2 gold local, default context
-- repeaterid.1 foo rptr1 local, rptr1 context
-- repeaterid.1 bar rptr2 local, rptr2 context
-- ifindex.1 gold "" A different system
-- ifindex.1 gold "" B different system
pmRoleTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmRoleEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The role string table.
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The agent must store role string associations in nonvolatile
storage."
::= { pmMib 4 }
pmRoleEntry OBJECT-TYPE
SYNTAX PmRoleEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A role string entry associates a role string with an
individual element."
INDEX { pmRoleElement, pmRoleContextName,
pmRoleContextEngineID, pmRoleString }
::= { pmRoleTable 1 }
PmRoleEntry ::= SEQUENCE {
pmRoleElement RowPointer,
pmRoleContextName SnmpAdminString,
pmRoleContextEngineID OCTET STRING,
pmRoleString UTF8String,
pmRoleStatus RowStatus
}
pmRoleElement OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The element to which this role string is associated.
If the agent assigns new indexes in the MIB table to
represent the same underlying element (re-indexing), the
agent will modify this value to contain the new index for the
underlying element."
::= { pmRoleEntry 1 }
pmRoleContextName OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is not in the default context for
the target system, this object is used to identify the
context. If the element is in the default context, this object
is equal to the empty string."
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::= { pmRoleEntry 2 }
pmRoleContextEngineID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..32))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is on a remote system, this object
is used to identify the remote system. This object contains
the contextEngineID of the system that this role string
assignment is valid for. If the element is on the local system
this object will be the empty string."
::= { pmRoleEntry 3 }
pmRoleString OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..64))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The role string that is associated with an element through
this table.
A role string is an administratively specified characteristic
of a managed element (for example, an interface). It is a
selector for policy rules, to determine the applicability of
the rule to a particular managed element."
::= { pmRoleEntry 4 }
pmRoleStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this role string."
::= { pmRoleEntry 5 }
-- Capabilities table
-- The pmCapabilitiesTable contains a description of
-- the inherent capabilities of the system so that scripts can
-- differentially apply code based on the capabilities and so that
-- management stations can learn of an agent's capabilities and
-- differentially install policies based on the capabilities.
pmCapabilitiesTable OBJECT-TYPE
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SYNTAX SEQUENCE OF PmCapabilitiesEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The pmCapabilitiesTable contains a description of
the inherent capabilities of the system.
Note that it is not necessary to list all
OIDs that a mechanism specific MIB Module supports, just the
base OID if the implementation is a fully compliant one. If
the implementation is not, then additional rows will exist in
the table that list the limitations or enhancements."
::= { pmMib 6 }
pmCapabilitiesEntry OBJECT-TYPE
SYNTAX PmCapabilitiesEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The description of a capability or limitation of a
capability of the system. An entry will exist for each
domain and mechanism specific ability the system has. In
the case of a domain specific capability with no mechanism
specific parameters, the pmCapabilitiesSubType and all other
columns may be null. Entries will exist that contain
values for the pmCapabilitiesRestrictOID,
pmCapabilitiesRestrictType, pmCapabilitiesRestrictValue
and pmCapabilitiesRestrictString objects only when
an implementation is reporting a mechanism specific
restriction. Multiple entries are possible when more
than one restriction for a type or subtype are needed."
INDEX { pmCapabilitiesIndex }
::= { pmCapabilitiesTable 1 }
PmCapabilitiesEntry ::= SEQUENCE {
pmCapabilitiesIndex Unsigned32,
pmCapabilitiesType OBJECT IDENTIFIER,
pmCapabilitiesSubType OBJECT IDENTIFIER,
pmCapabilitiesModificationOID OBJECT IDENTIFIER,
pmCapabilitiesModificationType INTEGER,
pmCapabilitiesModificationValue Integer32,
pmCapabilitiesModificationString OCTET STRING
}
pmCapabilitiesIndex OBJECT-TYPE
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SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique index for this entry."
::= { pmCapabilitiesEntry 1 }
pmCapabilitiesType OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The type of the capability represented by this entry.
The IANA will publish the list of identifiers that are valid
values for this object."
::= { pmCapabilitiesEntry 2 }
pmCapabilitiesSubType OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The sub type of capability is a pointer to a mechanism specific
set of capabilities supporting a base technology. In the case of
DIFFSERV, the OID value here would be the base OID of the
Differentiated Services Policy MIB Module."
::= { pmCapabilitiesEntry 3 }
pmCapabilitiesModificationOID OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The OID of the object that is either not supported, supported
with one or more limitations, or expanded by an implementation
specific module. If this columnar object is other than null then
there must be at least an entry in pmCapabilitiesModificationType.
Note that this need not be a leaf node or scalar object. If
an entire table is not supported, this value can be the base OID
for the table."
::= { pmCapabilitiesEntry 4 }
pmCapabilitiesModificationType OBJECT-TYPE
SYNTAX INTEGER {
unsupported(0),
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restricted(1),
additional(2),
addvalue(3),
maxlimit(4),
minlimit(5)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An unsupported value indicates that the OID in
pmCapabilitiesModificationOID is not supported on
this system. A value of 1 indicates that the OID
is supported but with restricted values
These constraints are described in the
pmCapabilitiesModificationValue and
pmCapabilitiesModificationString objects. A value of
2 indicates a vendor specific extension to a standard.
The OID of the new object is pmCapabilitiesModificationOID.
For some implementations, additional functions may be
provided. addvalue indicates that this row of the table
describes an additional value that the object can take.
The specific value is in the pmCapabilitiesModificationValue.
The values of 4 and 5 indicate restrictions or the removal
of restrictions for the object identified."
::= { pmCapabilitiesEntry 5 }
pmCapabilitiesModificationValue OBJECT-TYPE
SYNTAX Integer32 (0..2147483647)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"If the value of pmCapabilitiesModificationType is 0, this
object will be null since 0 indicates no support for the
object at all. A value of 1 in the
pmCapabilitiesModificationType will be further modified by a
single integer value in this object that corresponds to
enumerated integer values that are not supported by the
system for the object that is identified in this row. This
value can also represent the limit values in the
pmCapabilitiesModificationType object."
::= { pmCapabilitiesEntry 6 }
pmCapabilitiesModificationString OBJECT-TYPE
SYNTAX OCTET STRING
MAX-ACCESS read-only
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STATUS current
DESCRIPTION
"Any additional details or description or parameters needed."
::= { pmCapabilitiesEntry 7 }
-- The Schedule Group
pmSchedLocalTime OBJECT-TYPE
SYNTAX DateAndTime (SIZE (11))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The local time used by the scheduler. Schedules which
refer to calendar time will use the local time indicated
by this object. An implementation MUST return all 11 bytes
of the DateAndTime textual-convention so that a manager
may retrieve the offset from GMT time."
::= { pmMib 7 }
--
-- The schedule table which controls the scheduler.
--
pmSchedTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmSchedEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table defines schedules for policies."
::= { pmMib 8 }
pmSchedEntry OBJECT-TYPE
SYNTAX PmSchedEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry describing a particular schedule.
Unless noted otherwise, writable objects of this row can be
modified independent of the current value of pmSchedRowStatus,
pmSchedAdminStatus and pmSchedOperStatus. In particular, it
is legal to modify pmSchedWeekDay, pmSchedMonth, pmSchedDay,
pmSchedHour, and pmSchedMinute when pmSchedRowStatus is
active."
INDEX { pmSchedIndex }
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::= { pmSchedTable 1 }
PmSchedEntry ::= SEQUENCE {
pmSchedIndex Unsigned32,
pmSchedGroupIndex Unsigned32,
pmSchedDescr UTF8String,
pmSchedTimePeriod UTF8String,
pmSchedMonth BITS,
pmSchedDay BITS,
pmSchedWeekDay BITS,
pmSchedTimeOfDay UTF8String,
pmSchedLocalOrUtc INTEGER,
pmSchedStorageType StorageType,
pmSchedRowStatus RowStatus
}
pmSchedIndex OBJECT-TYPE
SYNTAX Unsigned32 (1..65535)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The locally-unique, administratively assigned index for this
scheduling entry."
::= { pmSchedEntry 1 }
pmSchedGroupIndex OBJECT-TYPE
SYNTAX Unsigned32 (1..65535)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The locally-unique, administratively assigned index for the
group that this scheduling entry belongs to.
To assign multiple schedule entries to the same group, the
pmSchedGroupIndex of each entry in the group will be set to
the same value. This pmSchedGroupIndex value must be equal to
the pmSchedIndex of one of the entries in the group. If the
entry is deleted whose pmSchedIndex equals the
pmSchedGroupIndex for the group, the agent will assign a new
pmSchedGroupIndex to all remaining members of the group.
If an entry is not a member of a group, its pmSchedGroupIndex
must be assigned to the value of its pmSchedIndex.
Policies that are controlled by a group of schedule entries
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are active when any schedule in the group is active."
::= { pmSchedEntry 2 }
pmSchedDescr OBJECT-TYPE
SYNTAX UTF8String
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The human readable description of the purpose of this
scheduling entry."
DEFVAL { ''H }
::= { pmSchedEntry 3 }
pmSchedTimePeriod OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..31))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The overall range of calendar dates and times over which this
schedule is valid. It is stored in a slightly extended version
of the format for a 'period-explicit' defined in RFC 2445
[22]. This format is expressed as a string representing the
starting date and time, in which the character 'T' indicates
the beginning of the time portion, followed by the solidus
character '/', followed by a similar string representing an
end date and time. The start of the period MUST be before the
end of the period. Date-Time values are expressed as
substrings of the form 'yyyymmddThhmmss'. For example:
20000101T080000/20000131T120000
January 1, 2000, 0800 through January 31, 2000, noon
The 'Date with UTC time' format defined in RFC 2445 in which
the Date-Time string ends with the character 'Z' is not
allowed.
This 'period-explicit' format is also extended to allow two
special cases in which one of the Date-Time strings is
replaced with a special string defined in RFC 2445:
1. If the first Date-Time value is replaced with the string
'THISANDPRIOR', then the value indicates that the schedule
is valid at any time prior to the Date-Time that appears
after the '/'.
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2. If the second Date-Time is replaced with the string
'THISANDFUTURE', then the value indicates that the schedule
is valid at any time after the Date-Time that appears
before the '/'.
Note that while RFC 2445 defines these two strings, they are
not specified for use in the 'period-explicit' format. The use
of these strings represents an extension to the
'period-explicit' format."
::= { pmSchedEntry 4 }
pmSchedMonth OBJECT-TYPE
SYNTAX BITS {
january(0),
february(1),
march(2),
april(3),
may(4),
june(5),
july(6),
august(7),
september(8),
october(9),
november(10),
december(11)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Within the overall time period specified in the
pmSchedTimePeriod object, the value of this object specifies
the specific months within that time period that the schedule
is active. Setting all bits will cause the schedule to act
independently of the month."
DEFVAL { { january, february, march, april, may, june, july,
august, september, october, november, december } }
::= { pmSchedEntry 5 }
pmSchedDay OBJECT-TYPE
SYNTAX BITS {
d1(0), d2(1), d3(2), d4(3), d5(4),
d6(5), d7(6), d8(7), d9(8), d10(9),
d11(10), d12(11), d13(12), d14(13), d15(14),
d16(15), d17(16), d18(17), d19(18), d20(19),
d21(20), d22(21), d23(22), d24(23), d25(24),
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d26(25), d27(26), d28(27), d29(28), d30(29),
d31(30),
r1(31), r2(32), r3(33), r4(34), r5(35),
r6(36), r7(37), r8(38), r9(39), r10(40),
r11(41), r12(42), r13(43), r14(44), r15(45),
r16(46), r17(47), r18(48), r19(49), r20(50),
r21(51), r22(52), r23(53), r24(54), r25(55),
r26(56), r27(57), r28(58), r29(59), r30(60),
r31(61)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Within the overall time period specified in the
pmSchedTimePeriod object, the value of this object specifies
the specific days of the month within that time period that
the schedule is active.
There are two sets of bits one can use to define the day
within a month:
Enumerations starting with the letter 'd' indicate a
day in a month relative to the first day of a month.
The first day of the month can therefore be specified
by setting the bit d1(0) and d31(30) means the last
day of a month with 31 days.
Enumerations starting with the letter 'r' indicate a
day in a month in reverse order, relative to the last
day of a month. The last day in the month can therefore
be specified by setting the bit r1(31), and r31(61) means
the first day of a month with 31 days.
Setting multiple bits will include several days in the set
of possible days for this schedule. Setting all bits starting
with the letter 'd' or all bits starting with the letter 'r'
will cause the schedule to act independently of the day of the
month."
DEFVAL { { d1, d2, d3, d4, d5, d6, d7, d8, d9, d10,
d11, d12, d13, d14, d15, d16, d17, d18, d19, d20,
d21, d22, d23, d24, d25, d26, d27, d28, d29, d30,
d31, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10,
r11, r12, r13, r14, r15, r16, r17, r18, r19, r20,
r21, r22, r23, r24, r25, r26, r27, r28, r29, r30,
r31 } }
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::= { pmSchedEntry 6 }
pmSchedWeekDay OBJECT-TYPE
SYNTAX BITS {
sunday(0),
monday(1),
tuesday(2),
wednesday(3),
thursday(4),
friday(5),
saturday(6)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Within the overall time period specified in the
pmSchedTimePeriod object, the value of this object specifies
the specific days of the week within that time period that
the schedule is active. Setting all bits will cause the
schedule to act independently of the day of the week."
DEFVAL { { sunday, monday, tuesday, wednesday, thursday,
friday, saturday } }
::= { pmSchedEntry 7 }
pmSchedTimeOfDay OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..15))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Within the overall time period specified in the
pmSchedTimePeriod object, the value of this object specifies
the range of times in a day that the schedule is active.
This value is stored in a format based on the RFC 2445 format
for 'time': The character 'T' followed by a 'time' string ,
followed by the solidus character '/', followed by the
character 'T' followed by a second time string. The first time
indicates the beginning of the range, while the second time
indicates the end. Thus, this value takes the form:
'Thhmmss/Thhmmss'.
The second substring always identifies a later time than the
first substring. To allow for ranges that span midnight,
however, the value of the second string may be smaller than
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the value of the first substring. Thus, 'T080000/T210000'
identifies the range from 0800 until 2100, while
'T210000/T080000' identifies the range from 2100 until 0800 of
the following day.
When a range spans midnight, it by definition includes parts
of two successive days. When one of these days is also
selected by either the MonthOfYearMask, DayOfMonthMask, and/or
DayOfWeekMask, but the other day is not, then the policy is
active only during the portion of the range that falls on the
selected day. For example, if the range extends from 2100
until 0800, and the day of week mask selects Monday and
Tuesday, then the policy is active during the following three
intervals:
From midnight Sunday until 0800 Monday;
From 2100 Monday until 0800 Tuesday;
From 2100 Tuesday until 23:59:59 Tuesday.
Setting this value to 'T000000/T235959' will cause the
schedule to act independently of the time of day."
DEFVAL { '543030303030302F54323335393539'H } -- T000000/T235959
::= { pmSchedEntry 8 }
pmSchedLocalOrUtc OBJECT-TYPE
SYNTAX INTEGER {
localTime(1),
utcTime(2)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object indicates whether the times represented in the
TimePeriod object and in the various Mask objects represent
local times or UTC times."
DEFVAL { utcTime }
::= { pmSchedEntry 9 }
pmSchedStorageType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object defines whether this schedule entry is kept
in volatile storage and lost upon reboot or if this row is
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backed up by non-volatile or permanent storage.
Conceptual rows having the value `permanent' must allow write
access to the columnar objects pmSchedDescr, pmSchedWeekDay,
pmSchedMonth, pmSchedDay, pmSchedHour, and pmSchedMinute."
DEFVAL { volatile }
::= { pmSchedEntry 10 }
pmSchedRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this schedule entry."
::= { pmSchedEntry 11 }
-- Policy Tracking
-- The "policy to element" (PE) table and the "element to policy" (EP)
-- table track the status of execution contexts grouped by policy and
-- element respectively.
pmTrackingPETable OBJECT-TYPE
SYNTAX SEQUENCE OF PmTrackingPEEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The pmTrackingPETable describes what elements
are under control of a policy. This table is indexed in
order to optimize retrieval of the entire status for a given
policy."
::= { pmMib 9 }
pmTrackingPEEntry OBJECT-TYPE
SYNTAX PmTrackingPEEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the pmTrackingPETable. The pmPolicyIndex in
the index specifies the policy tracked by this entry."
INDEX { pmPolicyIndex, pmTrackingPEElement,
pmTrackingPEContextName, pmTrackingPEContextEngineID }
::= { pmTrackingPETable 1 }
PmTrackingPEEntry ::= SEQUENCE {
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pmTrackingPEElement RowPointer,
pmTrackingPEContextName SnmpAdminString,
pmTrackingPEContextEngineID OCTET STRING,
pmTrackingPEInfo BITS
}
pmTrackingPEElement OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The element that is acted upon by the associated policy."
::= { pmTrackingPEEntry 1 }
pmTrackingPEContextName OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is not in the default context for
the target system, this object is used to identify the
context. If the element is in the default context, this object
is equal to the empty string."
::= { pmTrackingPEEntry 2 }
pmTrackingPEContextEngineID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..32))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is on a remote system, this object
is used to identify the remote system. This object contains
the contextEngineID of the system on which the associated
element resides. If the element is on the local system
this object will be the empty string."
::= { pmTrackingPEEntry 3 }
pmTrackingPEInfo OBJECT-TYPE
SYNTAX BITS {
conditionMatched(0),
actionSkippedDueToPrecedence(1),
conditionRunTimeException(2),
conditionUserSignal(3),
actionRunTimeException(4),
actionUserSignal(5)
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}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object returns information about the previous policy
script executions.
If the conditionMatched(0) bit is set, the last execution of the
associated policy condition returned non-zero.
If the actionSkippedDueToPrecedence(1) bit is set, the last
execution of the associated policy condition returned non-zero
but the action is not active because it was trumped by a
matching policy condition in the same policy group with a higher
precedence value.
If the conditionRunTimeException(2) bit is set, the last
execution of the associated policy condition encountered a
run-time exception and aborted.
If the conditionUserSignal(3) bit is set, the last
execution of the associated policy condition called the
signalError() function.
If the actionRunTimeException(4) bit is set, the last
execution of the associated policy action encountered a
run-time exception and aborted.
If the actionUserSignal(5) bit is set, the last
execution of the associated policy action called the
signalError() function.
Entries will only exist in this table of one or more bits are
set. In particular, if an entry does not exist for a
particular policy/element combination, it can be assumed that
the policy's condition did not match this element."
::= { pmTrackingPEEntry 4 }
-- Element to Policy Table
pmTrackingEPTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmTrackingEPEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
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"The pmTrackingEPTable describes what policies
are controlling an element. This table is indexed in
order to optimize retrieval of the status of all policies
active for a given element."
::= { pmMib 10 }
pmTrackingEPEntry OBJECT-TYPE
SYNTAX PmTrackingEPEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the pmTrackingEPTable. Entries exist for all
element/policy combinations for which the policy's condition
matches and only if the schedule for the policy is active.
The pmPolicyIndex in the index specifies the policy
tracked by this entry."
INDEX { pmTrackingEPElement, pmTrackingEPContextName,
pmTrackingEPContextEngineID, pmPolicyIndex }
::= { pmTrackingEPTable 1 }
PmTrackingEPEntry ::= SEQUENCE {
pmTrackingEPElement RowPointer,
pmTrackingEPContextName SnmpAdminString,
pmTrackingEPContextEngineID OCTET STRING,
pmTrackingEPStatus INTEGER
}
pmTrackingEPElement OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The element acted upon by the associated policy."
::= { pmTrackingEPEntry 1 }
pmTrackingEPContextName OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is not in the default context for
the target system, this object is used to identify the
context. If the element is in the default context, this object
is equal to the empty string."
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::= { pmTrackingEPEntry 2 }
pmTrackingEPContextEngineID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..32))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is on a remote system, this object
is used to identify the remote system. This object contains
the contextEngineID of the system on which the associated
element resides. If the element is on the local system
this object will be the empty string."
::= { pmTrackingEPEntry 3 }
pmTrackingEPStatus OBJECT-TYPE
SYNTAX INTEGER {
on(0),
forceOff(1)
}
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This entry will only exist if the calendar for the policy is
active and if the associated policyCondition returned 1 for this
element.
A policy can be forcibly disabled on a particular element
by setting this value to forceOff(1). The agent should then
act as if the policyCondition failed for this element. The
forceOff(1) state will persist (even across reboots) until
this value is set to on(0) by a management request. The
forceOff(1) state may be set even if the entry does not
previously exist so that future policy invocations can be
avoided.
Unless forcibly disabled, if this value exists it's value
will be on(0)."
::= { pmTrackingEPEntry 4 }
-- Policy Debugging Table
-- Policies that have debugging turned on will generate a log entry in
-- the policy debugging table for every runtime exception that occurs
-- in either the condition or action code.
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pmDebuggingTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmDebuggingEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The pmDebuggingTable logs debugging messages when
policies experience run-time exceptions in either the condition
or action code and the associated pmPolicyDebugging object
has been turned on.
It is an implementation-dependent manner as to the maximum
number of debugging entries that will be stored and the
maximum length of time an entry will be kept. If entries must
be discarded to make room for new entries, the oldest entries
must be discarded first."
::= { pmMib 11 }
pmDebuggingEntry OBJECT-TYPE
SYNTAX PmDebuggingEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the pmDebuggingTable. The pmPolicyIndex in the
index specifies the policy that encountered the exception
that led to this log entry."
INDEX { pmPolicyIndex, pmDebuggingElement,
pmDebuggingContextName, pmDebuggingContextEngineID,
pmDebuggingLogIndex }
::= { pmDebuggingTable 1 }
PmDebuggingEntry ::= SEQUENCE {
pmDebuggingElement RowPointer,
pmDebuggingContextName SnmpAdminString,
pmDebuggingContextEngineID OCTET STRING,
pmDebuggingLogIndex Unsigned32,
pmDebuggingMessage UTF8String
}
pmDebuggingElement OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The element the policy was executing on when it encountered
the error that led to this log entry."
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::= { pmDebuggingEntry 1 }
pmDebuggingContextName OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is not in the default context for
the target system, this object is used to identify the
context. If the element is in the default context, this object
is equal to the empty string."
::= { pmDebuggingEntry 2 }
pmDebuggingContextEngineID OBJECT-TYPE
SYNTAX OCTET STRING (SIZE (0..32))
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"If the associated element is on a remote system, this object
is used to identify the remote system. This object contains
the contextEngineID of the system on which the associated
element resides. If the element is on the local system
this object will be the empty string."
::= { pmDebuggingEntry 3 }
pmDebuggingLogIndex OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A unique index for this log entry amongst other log entries
for this policy/element combination."
::= { pmDebuggingEntry 4 }
pmDebuggingMessage OBJECT-TYPE
SYNTAX UTF8String (SIZE (0..128))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An error message generated by the policy execution
environment. It's recommended that this message include the
time of day that the message was generated, if known."
::= { pmDebuggingEntry 5 }
-- Notification Registration Table
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-- A management station may choose not to install policies to a
-- system that depend on roles or capabilities that don't exist on any
-- elements in the system. However, the management station must be able
-- to quickly learn if new roles or capabilities are added to the
-- system so that it can immediately install the policies that make
-- use of that new role or capability. This table allows a management
-- station to register itself so that it will receive
-- pmNewRoleNotifications and pmNewCapabilityNotifications whenever a
-- role or capability first appears on the system.
--
-- pmNewRoleNotifications and pmNewCapabilityNotifications are sent in
-- Inform PDU's so they are automatically retransmitted if they are
-- not acknowledged.
--
-- The procedure to guarantee accurate knowledge of roles and
-- capabilities is as follows:
--
-- Step 1: The NMS registers itself in the pmNotificationRegTable
-- Whenever it receives a notification, it adds the new role
-- or capability to its internal database for that system.
-- Followed immediately by:
-- Step 2: The NMS retrieves the roles and capabilities from the
-- system from the pmRoleTable and the
-- pmCapabilitiesTable, adding this information to its
-- internal database.
-- Followed immediately by:
-- Step 3: The NMS installs policies on the system, potentially
-- skipping policies that depend on roles or capabilities
-- that haven't been inserted into the internal database.
-- Followed immediately by:
-- Step 4: Whenever a notification indicates a new role or
-- capability that requires new policies to be installed,
-- it will immediately install such policies. The NMS will
-- continue this step indefinitely.
--
-- Note that using this algorithm to avoid installing "unnecessary"
-- policies may result in delays in having the policy available when
-- the policy becomes necessary. This delay could become extensive if
-- an interruption of communications prevents the notification from
-- being delivered and/or the policy from being installed, causing
-- the system to not be in compliance with policy for a period of
-- time. In particular, if the policy is enforcing security rules,
-- this could open up security vulnerabilities during this period of
-- time.
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pmNotificationRegTable OBJECT-TYPE
SYNTAX SEQUENCE OF PmNotificationRegEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A manager that wishes to receive notifications about new
roles or capabilities on an agent places an entry in the
notification registration table. pmNewRoleNotifications and
pmNewCapabilityNotifications will then be sent to the target
specified in the associated snmpTargetAddr entry. These
notifications will be sent until the entry is removed from
this table."
::= { pmMib 12 }
pmNotificationRegEntry OBJECT-TYPE
SYNTAX PmNotificationRegEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the pmNotificationRegTable."
INDEX { pmNotificationRegIndex }
::= { pmNotificationRegTable 1 }
PmNotificationRegEntry ::= SEQUENCE {
pmNotificationRegIndex Unsigned32,
pmNotificationRegSnmpTargetAddrName SnmpAdminString,
pmNotificationRegStorageType StorageType,
pmNotificationRegStatus RowStatus
}
pmNotificationRegIndex OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique index for this entry."
::= { pmNotificationRegEntry 1 }
pmNotificationRegSnmpTargetAddrName OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The snmpTargetAddrName of an associated
snmpTargetAddrEntry. When the following conditions are true,
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pmNewRoleNotifications and pmNewCapabilityNotifications
should be sent to the specified target:
1) The pmNotificationRegEntry is active
2) The associated snmpTargetAddr entry is fully
configured and active.
3) The associated snmpTargetParams entry is fully
configured and active."
::= { pmNotificationRegEntry 2 }
pmNotificationRegStorageType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object defines whether this row is kept
in volatile storage and lost upon reboot or if this row is
backed up by non-volatile or permanent storage."
::= { pmNotificationRegEntry 3 }
pmNotificationRegStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this entry."
::= { pmNotificationRegEntry 4 }
-- Notifications
pmNotifications OBJECT IDENTIFIER ::= { pmMib 13 }
pmNewRoleNotification NOTIFICATION-TYPE
OBJECTS { pmRoleStatus }
STATUS current
DESCRIPTION
"The pmNewRoleNotification is sent when an agent is configured with
its first instance of a previously unused role string (not
every time a new element is given a particular role).
An instance of the pmRoleStatus object is sent containing
the new roleString in it's index. In the event that two or
more elements are given the same role simultaneously, it is an
implementation-dependent matter as to which pmRoleTable
instance will be included in the notification."
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::= { pmNotifications 1 }
pmNewCapabilityNotification NOTIFICATION-TYPE
OBJECTS { pmCapabilitiesType }
STATUS current
DESCRIPTION
"The pmNewCapabilityNotification is sent when an agent
gains a new capability that did not previously exist in any
element on the system (not every time an element gains a
particular role).
An instance of the pmCapabilitiesType object is sent containing
the identity of the new capability. In the event that two or
more elements gain the same capability simultaneously, it is an
implementation-dependent matter as to which pmCapabilitiesType
instance will be included in the notification."
::= { pmNotifications 2 }
pmAbnormalTerminationNotification NOTIFICATION-TYPE
OBJECTS { pmTrackingPEInfo }
STATUS current
DESCRIPTION
"The pmAbnormalTerminationNotification is sent when a policy's
pmPolicyAbnormalTerminations gauge changes value from zero to
any value greater than zero and no such notification has been
sent for that policy in the last 5 minutes.
The notification contains an instance of the pmTrackingPEInfo
object where the pmPolicyIndex component of the index
identifies the associated policy and the rest of the index
identifies an element on which the policy failed."
::= { pmNotifications 3 }
-- Compliance Statements
pmConformance OBJECT IDENTIFIER ::= { pmMib 20 }
pmCompliances OBJECT IDENTIFIER ::= { pmConformance 1 }
pmGroups OBJECT IDENTIFIER ::= { pmConformance 2 }
pmCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"Describes the requirements for conformance to
the Policy-Based Management MIB"
MODULE -- this module
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MANDATORY-GROUPS { pmPolicyManagementGroup, pmSchedGroup,
pmNotificationGroup }
::= { pmCompliances 1 }
pmPolicyManagementGroup OBJECT-GROUP
OBJECTS { pmPolicyGroup, pmPolicyPrecedence,
pmPolicySchedule, pmPolicyElementTypeFilter,
pmPolicyConditionProgramIndex, pmPolicyActionProgramIndex,
pmPolicyParameters,
pmPolicyConditionMaxLatency, pmPolicyActionMaxLatency,
pmPolicyMaxIterations,
pmPolicyDescription, pmPolicyMatches,
pmPolicyAbnormalTerminations,
pmPolicyExecutionErrors, pmPolicyDebugging,
pmPolicyStorageType, pmPolicyAdminStatus,
pmPolicyRowStatus, pmPolicyCodeText, pmPolicyCodeStatus,
pmElementTypeRegMaxLatency, pmElementTypeRegDescription,
pmElementTypeRegStorageType, pmElementTypeRegRowStatus,
pmRoleStatus,
pmCapabilitiesType, pmCapabilitiesSubType,
pmCapabilitiesModificationOID,
pmCapabilitiesModificationType,
pmCapabilitiesModificationValue,
pmCapabilitiesModificationString,
pmTrackingPEInfo,
pmTrackingEPStatus,
pmDebuggingElement, pmDebuggingLogIndex,
pmDebuggingMessage,
pmNotificationRegSnmpTargetAddrName,
pmNotificationRegStorageType, pmNotificationRegStatus }
STATUS current
DESCRIPTION
"Objects that allow for the creation and management of
configuration policies."
::= { pmGroups 1 }
pmSchedGroup OBJECT-GROUP
OBJECTS { pmSchedLocalTime, pmSchedGroupIndex,
pmSchedDescr, pmSchedTimePeriod,
pmSchedMonth, pmSchedDay, pmSchedWeekDay,
pmSchedTimeOfDay, pmSchedLocalOrUtc, pmSchedStorageType,
pmSchedRowStatus
}
STATUS current
DESCRIPTION
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"Objects that allow for the scheduling of policies."
::= { pmGroups 2 }
pmNotificationGroup NOTIFICATION-GROUP
NOTIFICATIONS { pmNewRoleNotification,
pmNewCapabilityNotification,
pmAbnormalTerminationNotification }
STATUS current
DESCRIPTION
"Notifications sent by an Policy MIB agent."
::= { pmGroups 3 }
pmBaseFunctionLibrary OBJECT IDENTIFIER ::= { pmGroups 4 }
END
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12. Security Considerations
There are a number of management objects defined in this MIB
that have a MAX-ACCESS clause of read-write and/or read-
create. Such objects may be considered sensitive or
vulnerable in some network environments. The support for SET
operations in a non-secure environment without proper
protection can have a negative effect on network operations.
SNMPv1 by itself is not a secure environment. Even if the
network itself is secure (for example by using IPSec), even
then, there is no control as to who on the secure network is
allowed to access and GET/SET (read/change/create/delete) the
objects in this MIB.
It is recommended that the implementers consider the security
features as provided by the SNMPv3 framework. Specifically,
the use of the User-based Security Model RFC 2574 [12] and the
View-based Access Control Model RFC 2575 [15] is recommended.
It is then a customer/user responsibility to ensure that the
SNMP entity giving access to an instance of this MIB, is
properly configured to give access to the objects only to
those principals (users) that have legitimate rights to indeed
GET or SET (change/create/delete) them.
Access control for SNMP requests made to the local system
depends on the security credentials of the last entity to
modify any object in the condition or action for a policy.
These security credentials are the input parameters for
isAccessAllowed from the Architecture for Describing SNMP
Management Frameworks[1].
Some policies may be designed to ensure the security of a
network. If these policies have not been installed pending the
appearance of a role or capability, some delay will occur in
the activation of these policies when the role or capability
appears because a responsible manager must notice the change
and install the policy. This delay may expose the device or
the network to unacceptable security vulnerabilities during
this delay. If the role or capability appears during a time of
network stress or when the management station is unavailable,
this delay could be extensive, further increasing the
exposure. It is recommended that management stations install
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any security-related policies that might ever be needed on a
particular managed device, even if a nonexistent role or
capability suggests it is not needed at a given time.
13. Acknowledgements
The authors gratefully acknowledge the significant
contributions to this work made by Jeff Case, Joel Halpern,
Pablo Halpern, and David Partain.
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14. References
[1] Harrington, D., Presuhn, R., and B. Wijnen, "An
Architecture for Describing SNMP Management Frameworks",
RFC 2571, April 1999.
[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, RFC 1212, March 1991.
[4] Rose, M., "A Convention for Defining Traps for use with
the SNMP", RFC 1215, 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, RFC 2578, April
1999.
[6] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M., and S. Waldbusser, "Textual Conventions for
SMIv2", STD 58, RFC 2579, April 1999.
[7] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
Rose, M., and S. Waldbusser, "Conformance Statements for
SMIv2", STD 58, RFC 2580, April 1999.
[8] Case, J., Fedor, M., Schoffstall, M., and J. Davin,
"Simple Network Management Protocol", STD 15, RFC 1157,
May 1990.
[9] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
"Introduction to Community-based SNMPv2", RFC 1901,
January 1996.
[10] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
"Transport Mappings for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC 1906, January 1996.
[11] Case, J., Harrington D., Presuhn R., and B. Wijnen,
"Message Processing and Dispatching for the Simple
Network Management Protocol (SNMP)", RFC 2572, April
1999.
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[12] Blumenthal, U., and B. Wijnen, "User-based Security Model
(USM) for version 3 of the Simple Network Management
Protocol (SNMPv3)", RFC 2574, April 1999.
[13] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
"Protocol Operations for Version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC 1905, January 1996.
[14] Levi, D., Meyer, P., and B. Stewart, "SNMPv3
Applications", RFC 2573, April 1999.
[15] Wijnen, B., Presuhn, R., and K. McCloghrie, "View-based
Access Control Model (VACM) for the Simple Network
Management Protocol (SNMP)", RFC 2575, April 1999.
[16] McCloghrie, K. and M. Rose, Editors, "Management
Information Base for Network Management of TCP/IP-based
internets: MIB-II", STD 17, RFC 1213, Hughes LAN Systems,
Performance Systems International, March 1991.
[17] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
MIB using SMIv2", RFC 2233, Cisco Systems, FTP Software,
November 1997.
[18] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction to Version 3 of the Internet-standard
Network Management Framework", RFC 2570, April 1999.
[19] International Standards Organization, "Information
Technology - Programming Languages - C++", ISO/IEC
14882-1998
[20] ECMA, "ECMAScript Language Specification", ECMA-262,
December 1999
[21] Moore, B., Ellesson, E., Strassner, J., and A.
Westerinen, "Policy Core Information Model -- Version 1
Specification", RFC 3060, February 2001.
[22] Dawson, F. and D. Stenerson, "Internet Calendaring and
Scheduling Core Object Specification (iCalendar)", RFC
2445, November 1998
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15. 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.
16. Full Copyright Statement
Copyright (C) The Internet Society (2001). All Rights Reserved.
This document and translations of it may be copied and
furnished to others, and derivative works that comment on or
otherwise explain it or assist in its implementation may be
prepared, copied, published and distributed, in whole or in
part, without restriction of any kind, provided that the above
copyright notice and this paragraph are included on all such
copies and derivative works. However, this document itself
may not be modified in any way, such as by removing the
copyright notice or references to the Internet Society or
other Internet organizations, except as needed for the
purpose of developing Internet standards in which case the
procedures for copyrights defined in the Internet Standards
process must be followed, or as required to translate it into
languages other than English.
The limited permissions granted above are perpetual and will
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not be revoked by the Internet Society or its successors or
assigns.
This document and the information contained herein is provided
on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE
USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR
ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE.
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Internet Draft Policy-Based Management MIB June 11, 2001
Table of Contents
1 Abstract .............................................. 1
2 The SNMP Management Framework ......................... 2
3 Overview .............................................. 4
4 Policy-Based Management Architecture .................. 5
5 Policy Based Management Execution Environment ......... 8
5.1 Terminology ......................................... 8
5.2 Element Discovery ................................... 9
5.2.1 Implementation Notes .............................. 10
5.3 Element Filtering ................................... 11
5.3.1 Implementation Notes .............................. 11
5.4 Policy Enforcement .................................. 12
5.4.1 Implementation Notes .............................. 12
6 The PolicyScript Language ............................. 13
6.1 Formal Definition ................................... 14
6.2 Variables ........................................... 17
6.2.1 The var class ..................................... 18
6.3 PolicyScript QuickStart Guide ....................... 22
6.3.1 Quickstart for C Programmers ...................... 24
6.3.2 Quickstart for Perl Programmers ................... 24
6.3.3 Quickstart for TCL Programmers .................... 24
6.3.4 Quickstart for Python Programmers ................. 25
6.3.5 Quickstart for JavaScript/ECMAScript/JScript
Programmers ........................................ 25
7 Index information for `this element' .................. 25
8 Accessor Functions .................................... 26
9 Base Accessor Function Library ........................ 26
9.1 SNMP Accessor Functions ............................. 27
9.1.1 SNMP Operations on Non-Local Systems .............. 28
9.1.2 Form of SNMP Values ............................... 29
9.1.3 Convenience SNMP Functions ........................ 30
9.1.3.1 getVar() ........................................ 30
9.1.3.2 exists() ........................................ 31
9.1.3.3 setVar() ........................................ 32
9.1.3.4 searchColumn() .................................. 32
9.1.3.5 setRowStatus() .................................. 35
9.1.3.6 counterRate() ................................... 37
9.1.3.7 counter32Delta() ................................ 38
9.1.4 General SNMP Functions ............................ 38
9.1.4.1 newPDU() ........................................ 40
9.1.4.2 writeVar() ...................................... 40
9.1.4.3 readVar() ....................................... 41
9.1.4.4 snmpSend() ...................................... 41
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9.2 Constants ........................................... 42
9.3 Policy Accessor Functions ........................... 44
9.3.1 roleMatch() ....................................... 44
9.3.2 capMatch() ........................................ 45
9.3.3 elementName() ..................................... 45
9.3.4 ec() .............................................. 46
9.3.5 ev() .............................................. 46
9.3.6 context() ......................................... 46
9.3.7 elementAddress() .................................. 46
9.3.8 setScratchpad() ................................... 47
9.3.9 getScratchpad() ................................... 48
9.3.10 Constants ........................................ 50
9.3.11 signalError() .................................... 50
9.3.12 defer() .......................................... 51
9.3.13 die() ............................................ 51
9.3.14 getParameters() .................................. 52
9.4 Utility Accessor Functions .......................... 52
9.4.1 regexp() .......................................... 53
9.4.2 regexpReplace() ................................... 53
9.4.3 oidlen() .......................................... 53
9.4.4 oidncmp() ......................................... 54
9.4.5 inSubtree() ....................................... 54
9.4.6 subid() ........................................... 54
9.4.7 subidWrite() ...................................... 54
9.4.8 oidSplice() ....................................... 55
9.4.9 parseIndex() ...................................... 55
9.4.10 stringToDotted() ................................. 57
9.4.11 integer() ........................................ 57
9.4.12 string() ......................................... 57
9.4.13 type() ........................................... 58
9.4.14 chr() ............................................ 58
9.4.15 ord() ............................................ 58
9.4.16 substr() ......................................... 58
9.5 Library Accessor Functions .......................... 59
10 Schedule Table ....................................... 59
11 Definitions .......................................... 62
12 Security Considerations .............................. 105
13 Acknowledgements ..................................... 106
14 References ........................................... 107
15 Intellectual Property ................................ 109
16 Full Copyright Statement ............................. 109
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