rfc2723.txt

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   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 [RTFM-MIB].

   IANA considerations for allocating new attributes are discussed in
   detail in the RTFM Architecture document [RTFM-ARC].






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RFC 2723              SRL: A Traffic Flow Language          October 1999


7  APPENDICES

7.1  Appendix A: SRL Syntax in BNF

      <SRL program>    ::=  <S or D> | <SRL program> <S or D>

      <S or D>         ::=  <statement> | <declaration>

      <declaration>    ::=  <Subroutine declaration>

      <statement>      ::=  <IF statement> |
                            <Compound statement> |
                            <Imperative statement> |
                            <CALL statement>

      <IF statement>   ::=  IF <expression> <if action> <opt else>

      <if action>      ::=  SAVE ; |
                            SAVE , <statement> |
                            <statement>

      <opt else>       ::=  <null> |
                            ELSE <statement>

      <expression>     ::=  <term> | <term> || <term>

      <term>           ::=  <factor> | <factor> && <factor>

      <factor>         ::=  <attribute> == <operand list> |
                            ( <expression> )

      <operand list>   ::=  <operand> | ( <actual operand list> )

      <actual operand list> ::= <operand> |
                            <actual operand list> , <operand>

      <operand>        ::=  <value> |
                            <value> / <width> |
                            <value> & <mask>

      <Compound statement> ::= <opt label> { <statement seq> }

      <opt label>      ::=  <null> |
                            <identifier> :

      <statement seq>  ::=  <statement> | <statement seq> <statement>

      <Imperative statement> ::=  ; |



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                            SAVE <attribute> <opt operand> ; |
                            COUNT ; |
                            EXIT <label> ; |
                            IGNORE ; |
                            NOMATCH ; |
                            RETURN <integer> ; |
                            RETURN ; |
                            STORE <variable> := <value> ;

      <opt operand>    ::=  <null> |
                            <width or mask> |
                            = <operand>

      <width or mask>   ::= / <width> | & <mask>

      <Subroutine declaration> ::=
                            SUBROUTINE <sub header> <sub body> ENDSUB ;

      <sub header>     ::=  <subname> ( ) |
                            <subname> ( <sub param list> )

      <sub param list> ::= <sub param> | <sub param list> , <sub param>

      <sub param>      ::=  ADDRESS <pname> | VARIABLE <pname>

      <pname>          ::=  <identifier>

      <sub body>       ::=  <statement sequence>

      <CALL statement> ::=  CALL <call header> <opt call body> ENDCALL ;

      <call header>    ::=  <subname> ( ) |
                            <subname> ( <call param list> )

      <call param list> ::= <call param> |
                            <call param list> , <call param>

      <call param>     ::=  <attribute> | <variable>

      <opt call body>  ::=  <null> |
                            <actual call body>

      <actual call body> ::=  <numbered statement> |
                            <actual call body> <numbered statement>

      <numbered statement> ::= <int label seq> <statement>

      <int label seq>  ::=  <integer> : | <int label seq> <integer> :



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   The following are terminals, recognised by the scanner:

      <identifier>     Described in section 2
      <integer>        A decimal integer

      <attribute>      Attribute name, as listed in Appendix C

      <value>, <mask>  Described in section 5.2

      <width>     ::= <integer>
      <label>     ::= <identifier>

      <variable>  ::=  SourceClass | DestClass | FlowClass |
                        SourceKind | DestKind | FlowKind

7.2  Appendix B: Syntax for Values and Masks

   Values and masks consist of sequences of numeric fields, each of one
   or more bytes.  The non-blank character following a field indicates
   the field width, and whether the number is decimal or hexadecimal.
   These 'field type' characters may be:

     .  period      decimal, single byte
     -  minus       hex,     single byte
     !  exclaim     decimal, two bytes

   For example, 130.216.0.0 is an IP address (in dotted decimal), and
   FF-FF-00-00 is an IP address in hexadecimal.

   The last field of a value or mask has no field width character.
   Instead it takes the same width as the preceding field.  For example,
   1.3.10!50 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 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
   value given fills the whole field.  For example, 23 and 0.23 specify
   the same value for a SourceTransAddress operand.  For variables
   (which have one-byte values) a C-style character constant may also be
   used.

   IPv6 addresses and masks may also be used, following the conventions
   set out in the IP Version 6 Addressing Architecture RFC [V6-ADR].






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7.3  Appendix C: RTFM Attribute Information

   The following attributes may be tested in an IF statement, and their
   values may be SAVEd (except for MatchingStoD). Their maximum size (in
   bytes) is shown to the left, and a brief description is given for
   each.  The names given here are reserved words in SRL (they are
   <attribute> terminals in the grammar given in Appendix A).

   Note that this table gives only a very brief summary.  The Meter MIB
   [RTFM-MIB] provides the definitive specification of attributes and
   their allowed values.  The MIB variables which represent flow
   attributes have 'flowData' prepended to their names to indicate that
   they belong to the MIB's flowData table.

   1  SourceInterface, DestInterface
         Interface(s) on which the flow was observed

   1  SourceAdjacentType, DestAdjacentType
         Indicates the interface type(s), i.e. an ifType from [ASG-NBR],
         or an Address Family Number (if metering within a tunnel)

   0  SourceAdjacentAddress, DestAdjacentAddress
         For IEEE 802.x interfaces, the MAC addresses for the flow

   1  SourcePeerType, DestPeerType
         Peer protocol types, i.e. Address Family Number from [ASG-NBR],
         such as IPv4, Novell, Ethertalk, ..

   0  SourcePeerAddress, DestPeerAddress
         Peer Addresses (size varies, e.g. 4 for IPv4, 3 for Ethertalk))

   1  SourceTransType, DestTransType
         Transport layer type, i.e. Protocol Number from [ASG-NBR]
         such as tcp(6), udp(17), ospf(89), ..

   2  SourceTransAddress, DestTransAddress
         Transport layer addresses (e.g. port numbers for TCP and UDP)

   1  FlowRuleset
         Rule set number for the flow

   1  MatchingStoD
         Indicates whether the packet is being matched with its
         addresses in 'wire order.'  See [RTFM-ARC] for details.

   The following variables may be tested in an IF, and their values may
   be set by a STORE. They all have one-byte values.




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      SourceClass, DestClass, FlowClass,
      SourceKind,  DestKind,  FlowKind

   The following RTFM attributes are not address attributes - they are
   measured attributes of a flow.  Their values may be read from an RTFM
   meter.  (For example, NeTraMet uses a FORMAT statement to specify
   which attribute values are to be read from the meter.)

   8  ToOctets, FromOctets
         Total number of octets seen for each direction of the flow

   8  ToPDUs, FromPDUs
         Total number of PDUs seen for each direction of the flow

   4  FirstTime, LastActiveTime
         Time (in centiseconds) that first and last PDUs were seen
         for the flow

   Other attributes will be defined by the RTFM working group from time
   to time.

8  Acknowledgments

   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 language was done by Cyndi Mills and Brad Frazee in Boston.  SRL
   was developed in Auckland; it was greatly assisted by detailed
   discussion with John White and Russell Fulton.  Discussion has
   continued on the RTFM and NeTraMet mailing lists.

9  References

   [ASG-NBR]  Reynolds, J. and J. Postel, "Assigned Numbers",
              STD 2, RFC 1700, October 1994.

   [NETRAMET] Brownlee, N., NeTraMet home page,
              http://www.auckland.ac.nz/net/NeTraMet

   [RTFM-ARC] Brownlee, N., Mills, C. and G. Ruth, "Traffic Flow
              Measurement: Architecture", RFC 2722, October 1999.

   [RTFM-MIB] Brownlee, N., "Traffic Flow Measurement: Meter MIB",
              RFC 2720, October 1999.

   [V6-ADDR]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture," RFC 2373, July 1998.





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10  Author's Address

   Nevil Brownlee
   Information Technology Systems & Services
   The University of Auckland
   Private Bag 92-019
   Auckland, New Zealand

   Phone: [phone] x8941
   EMail: [e-mail]









































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11  Full Copyright Statement

   Copyright (C) The Internet Society (1999).  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 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.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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