draft-ietf-rtfm-ruleset-language-03.txt   draft-ietf-rtfm-ruleset-language-04.txt 
Internet Engineering Task Force Nevil Brownlee Internet Engineering Task Force Nevil Brownlee
INTERNET-DRAFT The University of Auckland INTERNET-DRAFT The University of Auckland
September 1998 Expires October 1999
SRL: A Language for Describing Traffic Flows SRL: A Language for Describing Traffic Flows
and Specifying Actions for Flow Groups and Specifying Actions for Flow Groups
<draft-ietf-rtfm-ruleset-language-03.txt> <draft-ietf-rtfm-ruleset-language-04.txt>
Status of this Memo Status of this Memo
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Realtime Traffic Flow Measurement Working Group of the IETF.
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Abstract Abstract
This document describes a language for specifying rulesets, i.e. This document describes a language for specifying rulesets, i.e.
configuration files which may be loaded into a traffic flow meter so as configuration files which may be loaded into a traffic flow meter so as
to specify which traffic flows are measured by the meter, and the to specify which traffic flows are measured by the meter, and the
information it will store for each flow. Although the language is information it will store for each flow.
primarily intended for RTFM traffic flows, it should also be useful in
other areas as a general way of specifying flows to be measured or
collected.
Contents Contents
1 Purpose and Scope 3 1 Purpose and Scope 3
1.1 RTFM Meters and Traffic Flows . . . . . . . . . . . . . . . . 3 1.1 RTFM Meters and Traffic Flows . . . . . . . . . . . . . . . . 3
1.2 SRL Overview . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2 SRL Overview . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 SRL Language Description 5 2 SRL Language Description 5
2.1 Define Directive . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Define Directive . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Program . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 Program . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.3 Declaration . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Declaration . . . . . . . . . . . . . . . . . . . . . . . . . 6
3 Statement 6 3 Statement 6
3.1 IF_statement . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 IF_statement . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.1expression . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.1expression . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.2term . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.2term . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.3factor . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.3factor . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.4operand_list . . . . . . . . . . . . . . . . . . . . . . . 7 3.1.4operand_list . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.5operand . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.5 operand . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.6Test Part . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.6 Test Part . . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.7Action Part . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1.7 Action Part . . . . . . . . . . . . . . . . . . . . . . . 9
3.1.8ELSE Clause . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1.8 ELSE Clause . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Compound_statement . . . . . . . . . . . . . . . . . . . . . . 9 3.2 Compound_statement . . . . . . . . . . . . . . . . . . . . . . 9
3.3 Imperative_statement . . . . . . . . . . . . . . . . . . . . . 10 3.3 Imperative_statement . . . . . . . . . . . . . . . . . . . . . 10
3.3.1SAVE Statement . . . . . . . . . . . . . . . . . . . . . . 10 3.3.1SAVE Statement . . . . . . . . . . . . . . . . . . . . . . 10
3.3.2COUNT Statement . . . . . . . . . . . . . . . . . . . . . . 11 3.3.2 COUNT Statement . . . . . . . . . . . . . . . . . . . . . 11
3.3.3EXIT Statement . . . . . . . . . . . . . . . . . . . . . . 11 3.3.3EXIT Statement . . . . . . . . . . . . . . . . . . . . . . 11
3.3.4IGNORE Statement . . . . . . . . . . . . . . . . . . . . . 11 3.3.4 IGNORE Statement . . . . . . . . . . . . . . . . . . . . . 12
3.3.5NOMATCH Statement . . . . . . . . . . . . . . . . . . . . . 12 3.3.5 NOMATCH Statement . . . . . . . . . . . . . . . . . . . . 12
3.3.6STORE Statement . . . . . . . . . . . . . . . . . . . . . . 12 3.3.6 STORE Statement . . . . . . . . . . . . . . . . . . . . . 12
3.3.7RETURN Statement . . . . . . . . . . . . . . . . . . . . . 12 3.3.7RETURN Statement . . . . . . . . . . . . . . . . . . . . . 12
3.4 Subroutine_declaration . . . . . . . . . . . . . . . . . . . . 12 3.4 Subroutine_declaration . . . . . . . . . . . . . . . . . . . . 13
3.5 CALL_statement . . . . . . . . . . . . . . . . . . . . . . . . 13 3.5 CALL_statement . . . . . . . . . . . . . . . . . . . . . . . . 13
4 Example Programs 14 4 Example Programs 14
4.1 Classify IP Port Numbers . . . . . . . . . . . . . . . . . . . 14 4.1 Classify IP Port Numbers . . . . . . . . . . . . . . . . . . . 14
4.2 Classify Traffic into Groups of Networks . . . . . . . . . . . 15 4.2 Classify Traffic into Groups of Networks . . . . . . . . . . . 15
5 APPENDICES 16 5 IANA Considerations 16
5.1 Appendix A: SRL Syntax in BNF . . . . . . . . . . . . . . . . 16
5.2 Appendix B: Syntax for Values and Masks . . . . . . . . . . . 18
5.3 Appendix C: RTFM Attribute Information . . . . . . . . . . . . 19
6 Acknowledgments 20 6 APPENDICES 17
6.1 Appendix A: SRL Syntax in BNF . . . . . . . . . . . . . . . . 17
6.2 Appendix B: Syntax for Values and Masks . . . . . . . . . . . 19
6.3 Appendix C: RTFM Attribute Information . . . . . . . . . . . . 19
7 References 20 7 Acknowledgments 21
8 Author's Address 20 8 References 21
9 Author's Address 21
1 Purpose and Scope 1 Purpose and Scope
A ruleset for an RTFM Meter is a sequence of instructions to be executed A ruleset for an RTFM Meter is a sequence of instructions to be executed
by the meter's Pattern Matching Engine (PME). The form of these by the meter's Pattern Matching Engine (PME). The form of these
instructions is described in detail in the 'RTFM Architecture' and 'RTFM instructions is described in detail in the 'RTFM Architecture' and 'RTFM
Meter MIB' documents [1], [2], but most users - at least inititially - Meter MIB' documents [1], [2], but most users - at least initially -
find them confusing and difficult to write, mainly because the effect of find them confusing and difficult to write, mainly because the effect of
each instruction is strongly dependent on the state of the meter's each instruction is strongly dependent on the state of the meter's
Packet Matching Engine at the moment of its execution. Packet Matching Engine at the moment of its execution.
SRL is a procedural language for creating RTFM rulesets. It has been SRL (the Simple Ruleset Language) is a procedural language for creating
designed to be simple for people to understand, using statements which RTFM rulesets. It has been designed to be simple for people to
help to clarify the execution context in which they operate. SRL understand, using statements which help to clarify the execution context
programs will be compiled into rulesets which can then be downloaded to in which they operate. SRL programs will be compiled into rulesets
RTFM meters. which can then be downloaded to RTFM meters.
An SRL compiler is available as part of NeTraMet (a free-software An SRL compiler is available as part of NeTraMet (a free-software
implementation of the RTFM meter and manager), version 4.2 [3]. implementation of the RTFM meter and manager), version 4.2 [3].
1.1 RTFM Meters and Traffic Flows 1.1 RTFM Meters and Traffic Flows
The RTFM Architecture [1] defines a set of 'attributes' which apply to The RTFM Architecture [1] defines a set of 'attributes' which apply to
network traffic. Among the attributes are 'address attributes,' such as network traffic. Among the attributes are 'address attributes,' such as
PeerType, PeerAddress, TransType and TransAddress, which have meaning PeerType, PeerAddress, TransType and TransAddress, which have meaning
for many protocols, e.g. for IP traffic (PeerType == IP) PeerAddress is for many protocols, e.g. for IP traffic (PeerType == IP) PeerAddress is
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'Packet Matching Engine (PME),' which is described in detail in [1]. An 'Packet Matching Engine (PME),' which is described in detail in [1]. An
RTFM meter may run multiple rule sets, with every passing packet being RTFM meter may run multiple rule sets, with every passing packet being
processed by each of the rulesets. The rule 'actions' in this document processed by each of the rulesets. The rule 'actions' in this document
are described as though only a single ruleset were running. are described as though only a single ruleset were running.
In the past creating a ruleset has meant writing machine code for the In the past creating a ruleset has meant writing machine code for the
PME, which has proved rather difficult to do. SRL provides a high-level PME, which has proved rather difficult to do. SRL provides a high-level
language which should enable users to create effective rulesets without language which should enable users to create effective rulesets without
having to understand the details of the PME. having to understand the details of the PME.
The language could easily be adapted to other uses, being suitable for The language may be useful in other applications, being suitable for any
any application area which involves selecting traffic flows from a application area which involves selecting traffic flows from a stream of
stream of packets. packets.
1.2 SRL Overview 1.2 SRL Overview
An SRL program is executed from the beginning for each new packet An SRL program is executed from the beginning for each new packet
arriving at the meter. It has two essential goals. arriving at the meter. It has two essential goals.
(a) Decide whether the current packet is part of a flow which is of (a) Decide whether the current packet is part of a flow which is of
interest and, if necessary, determine its direction (i.e. decide interest and, if necessary, determine its direction (i.e. decide
which of its end-points is considered to be its source). Other which of its end-points is considered to be its source). Other
packets will be ignored. packets will be ignored.
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using one or more SAVE statements to store the flow's identification using one or more SAVE statements to store the flow's identification
attributes; a COUNT statement then increments the statistical data attributes; a COUNT statement then increments the statistical data
accumulating for it. accumulating for it.
2 SRL Language Description 2 SRL Language Description
The SRL language is explained below using 'railway diagrams' to describe The SRL language is explained below using 'railway diagrams' to describe
the syntax. Flow through a diagram is from left to right. The only the syntax. Flow through a diagram is from left to right. The only
exception to this is that lines carrying a left arrow may only be exception to this is that lines carrying a left arrow may only be
traversed right to left. In the diagrams, keywords are written in traversed right to left. In the diagrams, keywords are written in
capital letters; in practice an SRL compiler will be insensitive to capital letters; in practice an SRL compiler must be insensitive to
case. Lower-case identifiers are explained in the text, or they refer case. Lower-case identifiers are explained in the text, or they refer
to another diagram. to another diagram.
The tokens of an SRL program obey the following rules: The tokens of an SRL program obey the following rules:
- Comments may appear on any line of an SRL program, following a # - Comments may appear on any line of an SRL program, following a #
- White space is used to separate tokens - White space is used to separate tokens
- Semicolon is used as the terminator for most statements - Semicolon is used as the terminator for most statements
- Identifiers (e.g. for defines and labels) must start with a letter - Identifiers (e.g. for defines and labels) must start with a letter
- Identifiers may contain letters, digits and underscores - Identifiers may contain letters, digits and underscores
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than one attribute, the masks and values are saved for all the matched than one attribute, the masks and values are saved for all the matched
attributes. For each value_list in the statement the value saved is the attributes. For each value_list in the statement the value saved is the
one which the packet actually matched. See below for further one which the packet actually matched. See below for further
description of SAVE statements. description of SAVE statements.
Other actions are described in detail under "Imperative statements" Other actions are described in detail under "Imperative statements"
below. Note that the RETURN action is valid only within subroutines. below. Note that the RETURN action is valid only within subroutines.
3.1.8 ELSE Clause 3.1.8 ELSE Clause
An Else Clause provides a statement which will be executed if the IF's An ELSE Clause provides a statement which will be executed if the IF's
test fails. The statement following ELSE will often be another IF test fails. The statement following ELSE will often be another IF
statement, providing SRL's version of a 'select' statement. Note that statement, providing SRL's version of a 'select' statement. Note that
an ELSE clause always matches the immediately preceding IF. an ELSE clause always matches the immediately preceding IF.
3.2 Compound_statement 3.2 Compound_statement
-------+-------------+----- { ---+---- Statement ----+--- } ------- -------+-------------+----- { ---+---- Statement ----+--- } -------
| | | | | | | |
+-- label : --+ +--------<----------+ +-- label : --+ +--------<----------+
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instructs the PME to build the flow identifier from the attributes which instructs the PME to build the flow identifier from the attributes which
have been SAVEd, find it in the meter's flow table (creating a new entry have been SAVEd, find it in the meter's flow table (creating a new entry
if this is the first packet observed for the flow), and increment its if this is the first packet observed for the flow), and increment its
counters. The meter then moves on to examine the next incoming packet. counters. The meter then moves on to examine the next incoming packet.
3.3.3 EXIT Statement 3.3.3 EXIT Statement
The EXIT statement exits a labelled compound statement. The next The EXIT statement exits a labelled compound statement. The next
statement to be executed will be the one following that compound statement to be executed will be the one following that compound
statement. This provides a well-defined way to jump to a clearly statement. This provides a well-defined way to jump to a clearly
identified point in a program. identified point in a program. For example
outer: {
...
if SourcePeerAddress == 192.168/16
exit outer; # exits the statement labelled 'outer'
...
}
# execution resumes here
In practice the language provides sufficient logical structure that one
seldom - if ever - needs to use the EXIT statement.
3.3.4 IGNORE Statement 3.3.4 IGNORE Statement
The IGNORE statement terminates examination of the current packet The IGNORE statement terminates examination of the current packet
without saving any information from it. The meter then moves on to without saving any information from it. The meter then moves on to
examine the next incoming packet, beginning again at the first statement examine the next incoming packet, beginning again at the first statement
of its program. of its program.
3.3.5 NOMATCH Statement 3.3.5 NOMATCH Statement
The NOMATCH statement indicates that matching has failed for this The NOMATCH statement indicates that matching has failed for this
execution of the program. If it is executed when a packet is being execution of the program. If it is executed when a packet is being
processed with its addresses in 'on the wire' order, the PME will processed with its addresses in 'on the wire' order, the PME will
perform the program again from the beginning with source and destination perform the program again from the beginning with source and destination
addresses interchanged. If it is executed following such an addresses interchanged. If it is executed following such an
interchange, the packet will be IGNOREd. NOMATCH is illustrated in the interchange, the packet will be IGNOREd.
above example, where it is used to ensure that flows having 130.216/16
as an end-point are counted as though 130.216 had been those flows' NOMATCH is illustrated in the SAVE example (section 3.3.1), where it is
source peer (IP) address. used to ensure that flows having 130.216/16 as an end-point are counted
as though 130.216 had been those flows' source peer (IP) address.
3.3.6 STORE Statement 3.3.6 STORE Statement
The STORE statement assigns a value to an SRL variable and SAVEs it. The STORE statement assigns a value to an SRL variable and SAVEs it.
There are six SRL variables: There are six SRL variables:
SourceClass SourceKind SourceClass SourceKind
DestClass DestKind DestClass DestKind
FlowClass FlowKind FlowClass FlowKind
Their names have no particular significance; they were arbitrarily Their names have no particular significance; they were arbitrarily
chosen as likely RTFM attributes but can be used to store any chosen as likely RTFM attributes but can be used to store any
single-byte integer values. Their values are set to zero each time single-byte integer values. Their values are set to zero each time
examination of a new packet begins. examination of a new packet begins. For example
STORE SourceClass := 3;
STORE FlowKind := 'W'
3.3.7 RETURN Statement 3.3.7 RETURN Statement
The RETURN statement is used to return from subroutines and can be used The RETURN statement is used to return from subroutines and can be used
only within the context of a subroutine. It is described in detail only within the context of a subroutine. It is described in detail
below (CALL statement). below (CALL statement).
3.4 Subroutine_declaration 3.4 Subroutine_declaration
-- SUBROUTINE subname ( --+-----------------------------+-- ) --> -- SUBROUTINE subname ( --+-----------------------------+-- ) -->
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3.4 Subroutine_declaration 3.4 Subroutine_declaration
-- SUBROUTINE subname ( --+-----------------------------+-- ) --> -- SUBROUTINE subname ( --+-----------------------------+-- ) -->
| | | |
+--+-- ADDRESS --- pname --+--+ +--+-- ADDRESS --- pname --+--+
| | | |
+-- VARIABLE -- pname --+ +-- VARIABLE -- pname --+
| | | |
+------<------- , ------+ +------<------- , ------+
>------+-------- Statement ---------+----- ENDSUB -------- ; >------+-------- Statement ---------+----- ENDSUB -------- ;
| | | |
+-------------<--------------+ +-------------<--------------+
A Subroutine declaration has three parts: A Subroutine declaration has three parts:
the subname is an indentifier, used to name the subroutine. the subname is an identifier, used to name the subroutine.
the parameter list specifies the subroutine's parameters. the parameter list specifies the subroutine's parameters.
Each parameter is preceded with a keyword indicating its Each parameter is preceded with a keyword indicating its
type - VARIABLE indicates an SRL variable (see the STORE type - VARIABLE indicates an SRL variable (see the STORE
statement above), ADDRESS indicates any other RTFM attribute. statement above), ADDRESS indicates any other RTFM attribute.
A parameter name may be any identifier, and its scope is A parameter name may be any identifier, and its scope is
limited to the subroutine's body. limited to the subroutine's body.
the body specifies what processing the subroutine will perform. the body specifies what processing the subroutine will perform.
This is simply a sequence of Statements, terminated by the This is simply a sequence of Statements, terminated by the
skipping to change at page 15, line 40 skipping to change at page 16, line 4
else if addr == k_nets save, { else if addr == k_nets save, {
store net := 20; return 2; store net := 20; return 2;
} }
save addr/24; # Not my_net or in k_nets save addr/24; # Not my_net or in k_nets
store net := 30; return 3; store net := 30; return 3;
endsub; endsub;
# #
The net_kind subroutine determines whether addr is my network (130.216), The net_kind subroutine determines whether addr is my network (130.216),
one of the Kawaihiko networks (in the k_nets list), or some other one of the Kawaihiko networks (in the k_nets list), or some other
network. It saves the network address from addr (16 bits for my_net and network. It saves the network address from addr (16 bits for my_net and
the k_net networks, 24 bits for others), stores a value of 10, 20 or 30 the k_net networks, 24 bits for others), stores a value of 10, 20 or 30
in net, and returns to 1:, 2: or 3:. Note that the network numbers in net, and returns to 1:, 2: or 3:. Note that the network numbers
used are contained within the two DEFINEs, making them easy to change. used are contained within the two DEFINEs, making them easy to change.
net_kind is called twice, saving Source- and DestPeerAddress and Source- net_kind is called twice, saving Source- and DestPeerAddress and Source-
and DestKind; the COUNT statement produces flows identified by these and DestKind; the COUNT statement produces flows identified by these
four RTFM attributes, with no particular source-dest ordering. four RTFM attributes, with no particular source-dest ordering.
In the program no use is made of return numbers amd they could have been In the program no use is made of return numbers and they could have been
omitted. However, we might wish to re-use the subroutine in another omitted. However, we might wish to re-use the subroutine in another
program doing different things for different return numbers, as in the program doing different things for different return numbers, as in the
version below. version below.
call net_kind (DestPeerAddress, DestKind) call net_kind (DestPeerAddress, DestKind)
1: nomatch; # We want my_net as source 1: nomatch; # We want my_net as source
endcall; endcall;
call net_kind (SourcePeerAddress, SourceKind) call net_kind (SourcePeerAddress, SourceKind)
1: count; # my_net -> other networks 1: count; # my_net -> other networks
endcall; endcall;
save SourcePeerAddress /24; save SourcePeerAddress /24;
save DestPeerAddress /24; save DestPeerAddress /24;
count; count;
This version uses a NOMATCH statement to ensure that its resulting flows This version uses a NOMATCH statement to ensure that its resulting flows
have my_net as their source. The NOMATCH also rejects my_net -> my_net have my_net as their source. The NOMATCH also rejects my_net -> my_net
traffic. Traffic which doesn't have my_net as source or destination traffic. Traffic which doesn't have my_net as source or destination
saves 24 bits of its peer addresses (the subroutine might only have saves 24 bits of its peer addresses (the subroutine might only have
saved 16) before counting such an unusual flow. saved 16) before counting such an unusual flow.
5 APPENDICES 5 IANA Considerations
5.1 Appendix A: SRL Syntax in BNF Appendix C below lists the RTFM attributes by name. Since SRL only
refers to attributes by name, SRL users do not have to know the
attribute numbers.
The size (in bytes) of the various attribute values is also listed in
Appendix C. These sizes reflect the object sizes for the attribute
values as they are stored in the RTFM Meter MIB [2].
IANA considerations for allocating new attributes are discussed in
detail in the RTFM Architecture document [1].
6 APPENDICES
6.1 Appendix A: SRL Syntax in BNF
<SRL program> ::= <S or D> | <SRL program> <S or D> <SRL program> ::= <S or D> | <SRL program> <S or D>
<S or D> ::= <statement> | <declaration> <S or D> ::= <statement> | <declaration>
<declaration> ::= <Subroutine declaration> <declaration> ::= <Subroutine declaration>
<statement> ::= <IF statement> | <statement> ::= <IF statement> |
<Compound statement> | <Compound statement> |
<Imperative statement> | <Imperative statement> |
skipping to change at page 17, line 4 skipping to change at page 17, line 30
<IF statement> ::= IF <expression> <if action> <opt else> <IF statement> ::= IF <expression> <if action> <opt else>
<if action> ::= SAVE ; | <if action> ::= SAVE ; |
SAVE , <statement> | SAVE , <statement> |
<statement> <statement>
<opt else> ::= <null> | <opt else> ::= <null> |
ELSE <statement> ELSE <statement>
<expression> ::= <term> | <term> || <term> <expression> ::= <term> | <term> || <term>
<term> ::= <factor> | <factor> && <factor> <term> ::= <factor> | <factor> && <factor>
<factor> ::= <attrib> == <operand list> | ( <expression> ) <factor> ::= <attribute> == <operand list> |
( <expression> )
<operand list> ::= <operand> | ( <actual operand list> ) <operand list> ::= <operand> | ( <actual operand list> )
<actual operand list> ::= <operand> | <actual operand list> ::= <operand> |
<actual operand list> , <operand> <actual operand list> , <operand>
<operand> ::= <value> | <operand> ::= <value> |
<value> / <width> | <value> / <width> |
<value> & <mask> <value> & <mask>
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<opt call body> ::= <null> | <opt call body> ::= <null> |
<actual call body> <actual call body>
<actual call body> ::= <numbered statement> | <actual call body> ::= <numbered statement> |
<actual call body> <numbered statement> <actual call body> <numbered statement>
<numbered statement> ::= <int label seq> <statement> <numbered statement> ::= <int label seq> <statement>
<int label seq> ::= <integer> : | <int label seq> <integer> : <int label seq> ::= <integer> : | <int label seq> <integer> :
5.2 Appendix B: Syntax for Values and Masks The following are terminals, recognised by the scanner:
<identifier> Described in section 2
<integer> A decimal integer
<value>, <mask> Described in section 5.2
<width> ::= <integer>
<label> ::= <identifier>
<variable> ::= SourceClass _ DestClass _ FlowClass _
SourceKind _ DestKind _ FlowKind
6.2 Appendix B: Syntax for Values and Masks
Values and masks consist of sequences of numeric fields, each of one or Values and masks consist of sequences of numeric fields, each of one or
more bytes. The non-blank character following a field indicates the more bytes. The non-blank character following a field indicates the
field width, and whether the number is decimal or hexadecimal. These field width, and whether the number is decimal or hexadecimal. These
'field type' characters may be: 'field type' characters may be:
. period decimal, single byte . period decimal, single byte
- minus hex, single byte - minus hex, single byte
! exclaim decimal, two bytes ! exclaim decimal, two bytes
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and 1.3.0.10.0.50 are two different ways to specify the same value. and 1.3.0.10.0.50 are two different ways to specify the same value.
Unspecified fields (at the right-hand side of a value or mask) are set Unspecified fields (at the right-hand side of a value or mask) are set
to zero, i.e. 130.216 is the same as 130.216.0.0. to zero, i.e. 130.216 is the same as 130.216.0.0.
If only a single field is specified (no field width character), the If only a single field is specified (no field width character), the
value given fills the whole field. For example, 23 and 0.23 specify the value given fills the whole field. For example, 23 and 0.23 specify the
same value for a SourceTransAddress operand. For variables (which have same value for a SourceTransAddress operand. For variables (which have
one-byte values) a C-style character constant may also be used. one-byte values) a C-style character constant may also be used.
5.3 Appendix C: RTFM Attribute Information In addition, addresses and masks may also use the conventions set
out in the IP Version 6 Addressing Architecture RFC [4].
6.3 Appendix C: RTFM Attribute Information
The following attributes may be tested in an IF statement, and their The following attributes may be tested in an IF statement, and their
values may be SAVEd (except for MatchingStoD). Their size (in bytes) is values may be SAVEd (except for MatchingStoD). Their size (in bytes) is
shown to the left, and a brief description is given for each. shown to the left, and a brief description is given for each.
1 SourceInterface, DestInterface 1 SourceInterface, DestInterface
Interface(s) on which the flow was observed Interface(s) on which the flow was observed
1 SourceAdjacentType, DestAdjacentType 1 SourceAdjacentType, DestAdjacentType
Indicates the interface type(s) Indicates the interface type(s)
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8 ToPDUs, FromPDUs 8 ToPDUs, FromPDUs
Total number of PDUs seen for each direction of the flow Total number of PDUs seen for each direction of the flow
4 FirstTime, LastTime 4 FirstTime, LastTime
Time (in centiseconds) that first and last PDUs were seen Time (in centiseconds) that first and last PDUs were seen
for the flow for the flow
Other attributes will be defined by the RTFM working group from time to Other attributes will be defined by the RTFM working group from time to
time. time.
6 Acknowledgments 7 Acknowledgments
The SRL language is part of the RTFM Working Group's efforts to make the The SRL language is part of the RTFM Working Group's efforts to make the
RTFM traffic measurement system easier to use. Initial work on the RTFM traffic measurement system easier to use. Initial work on the
language was done by Cyndi Mills and Brad Frazee in Boston. SRL was language was done by Cyndi Mills and Brad Frazee in Boston. SRL was
developed in Auckland; it was greatly assisted by detailed discussion developed in Auckland; it was greatly assisted by detailed discussion
with John White and Russell Fulton. Discussion has continued on the with John White and Russell Fulton. Discussion has continued on the
RTFM mailing list. RTFM and NeTraMet mailing lists.
7 References 8 References
[1] Brownlee, N., Mills, C., and G. Ruth, "Traffic Flow [1] Brownlee, N., Mills, C., and G. Ruth, "Traffic Flow
Measurement: Architecture", RFC 2063, The University of Measurement: Architecture", RFC 2063, The University of
Auckland, Bolt Beranek and Newman Inc., GTE Laboratories, Inc, Auckland, GTE Laboratories, Inc, January 1997.
January 1997.
[2] Brownlee, N., "Traffic Flow Measurement: Meter MIB", [2] Brownlee, N., "Traffic Flow Measurement: Meter MIB", RFC
RFC 2064, The University of Auckland, January 1997. 2064, The University of Auckland, January 1997.
[3] Brownlee, N., NeTraMet home page, [3] Brownlee, N., NeTraMet home page,
http://www.auckland.ac.nz/net/NeTraMet http://www.auckland.ac.nz/net/NeTraMet
8 Author's Address [4] Hinden, R., and Deering, S., "IP Version 6 Addressing
Architecture", RFC 2373, Nokia, Cisco Systems, July 1998.
9 Author's Address
Nevil Brownlee Nevil Brownlee
Information Technology Systems & Services Information Technology Systems & Services
The University of Auckland The University of Auckland
Phone: +64 9 373 7599 x8941 Phone: +64 9 373 7599 x8941
E-mail: n.brownlee@auckland.ac.nz E-mail: n.brownlee@auckland.ac.nz
Expires October 1999
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