Mate/Reference

MATE Reference Manual

Attribute Value Pairs

MATE uses AVPs for almost everything: to keep the data it has extracted from the frames' trees as well as to keep the elements of the configuration.

These "pairs" (actually tuples) are made of a name, a value and, in case of configuration AVPs, an operator. Names and values are strings. AVPs with operators other than '=' are used only in the configuration and are used for matching AVPs of Pdus, GoPs and GoGs in the analysis phase.

Name

The name is a string used to refer to a class of AVPs. Two attributes won't match unless their names are identical. Capitalized names are reserved for keywords (you can use them for your elements if you want but I think it's not the case). MATE attribute names can be used in Wireshark's display filters the same way like names of protocol fields provided by dissectors, but they are not just references to (or aliases of) protocol fields.

Value

The value is a string. It is either set in the configuration (for configuration AVPs) or by MATE while extracting interesting fields from a dissection tree and/or manipulating them later. The values extracted from fields use the same representation as they do in filter strings.

Operators

Currently only match operators are defined (there are plans to (re)add transform attributes but some internal issues have to be solved before that). The match operations are always performed between two operands: the value of an AVP stated in the configuration and the value of an AVP (or several AVPs with the same name) extracted from packet data (called "data AVPs"). It is not possible to match data AVPs to each other.

The defined match operators are:

Equal AVP Operator

This operator tests whether the values of the operator and the operand AVP are equal.

Example

Not equal AVP operator

This operator matches if the value strings of two AVPs are not equal.

Examples

"One of" AVP operator

The "one of" operator matches if the data AVP value is equal to one of the values listed in the "one of" AVP.

Examples

"Starts with" AVP operator

The "starts with" operator matches if the first characters of the data AVP value are identical to the configuration AVP value.

Examples

"Ends with" operator

The ends with operator will match if the last bytes of the data AVP value are equal to the configuration AVP value.

Examples

Contains operator

The "contains" operator will match if the data AVP value contains a string identical to the configuration AVP value.

Example

"Lower than" operator

The "lower than" operator will match if the data AVP value is semantically lower than the configuration AVP value.

Examples
BUGS

It should check whether the values are numbers and compare them numerically

"Higher than" operator

The "higher than" operator will match if the data AVP value is semantically higher than the configuration AVP value.

Examples
BUGS

It should check whether the values are numbers and compare them numerically

Exists operator

The exists operator will always match as far as the two operands have the same name.

Examples

Attribute/Value Pair List (AVPL)

Pdus, GoPs and GoGs use an AVPL to contain the tracing information. An AVPL is an unsorted set of AVPs that can be matched against other AVPLs.

Operations between AVPLs

Loose Match

Loose Match Examples

Every Match

"Every" Match Examples

Strict Match

Examples

AVPL Merge

Examples

Transforms

A Transform is a sequence of Match rules optionally followed by an instruction how to modify the match result using an additional AVPL. Such modification may be an Insert (merge) or a Replace. The syntax is as follows:

    Transform name {
      Match [Strict|Every|Loose] match_avpl [[Insert|Replace] modify_avpl] ; // may occur multiple times, at least once
    };

Configuration AVPLs

Pdu's configuration actions

The following configuration AVPLs deal with PDU creation and data extraction.

Pdu declaration block header

    Pdu name Proto proto_name Transport proto1[/proto2/proto3[/...]]] {
      Payload proto; //optional, no default value
      Extract attribute From proto.field ; //may occur multiple times, at least once
      Transform (transform1[, transform2[, ...]]); //optional
      Criteria [{Accept|Reject}] [{Strict|Every|Loose} match_avpl];
      DropUnassigned {true|false}; //optional, default=false
      DiscardPduData {true|false}; //optional, default=false
      LastExtracted {true|false}; //optional, default=false
    };

Pdu name

Proto and Transport clauses

Payload clause

Other than the Pdu's Proto and its Transport protocols, there is also a Payload attribute to tell MATE from which ranges of Proto's payload to extract fields of a frame into the Pdu. In order to extract an attribute from a frame's tree the highlighted area of the field in the hex display must be within the area of the Proto's relative payload(s). Payloads are choosen moving forward from the protocol area, in the order they are given. Proto http Transport tcp/ip Payload mmse will select the first mmse range after the current http range. Once we've selected the Payload ranges, MATE will fetch those protocol fields belonging to them whose extraction is declared using the Extract clauses for the Pdu type.

Extract clause

Each Extract clause tells MATE which protocol field value to extract as an AVP value and what string to use as the AVP name. The protocol fields are referred to using the names used in Wireshark display filters. If there is more than one such protocol field in the frame, each instance that fulfills the criteria stated above is extracted into its own AVP. The AVP names may be chosen arbitrarily, but to be able to match values originally coming from different Pdus (e.g., hostname from DNS query and a hostname from HTTP GET request) later in the analysis, identical AVP names must be assigned to them and the dissectors must provide the field values in identical format (which is not always the case).

Transform clause

The Transform clause specifies a list of previously declared Transforms to be performed on the Pdu's AVPL after all protocol fields have been extracted to it. The list is always executed completely, left to right. On the contrary, the list of Match clauses inside each individual Transform is executed only until the first match succeeds.

Criteria clause

This clause tells MATE whether to use the Pdu for analysis. It specifies a match AVPL, an AVPL match type (Strict, Every, or Loose) and the action to be performed (Accept or Reject) if the match succeeds. Once every attribute has been extracted and eventual transform list has been executed, and if the Criteria clause is present, the Pdu's AVPL is matched against the match AVPL; if the match succeeds, the action specified is executed, i.e. the Pdu is accepted or rejected. The default behaviours used if the respective keywords are omitted are Strict and Accept. Accordingly, if the clause is omitted, all Pdus are accepted.

DropUnassigned clause

If set to TRUE, MATE will destroy the Pdu if it cannot assign it to a Gop. If set to FALSE (the default if not given), MATE will keep them.

DiscardPduData clause

If set to TRUE, MATE will delete the Pdu's AVPL once it has analyzed it and eventually extracted some AVPs from it into the Gop's AVPL. This is useful to save memory (of which MATE uses a lot). If set to FALSE (the default if not given), MATE will keep the Pdu attributes.

LastExtracted clause

If set to FALSE (the default if not given), MATE will continue to look for Pdus of other types in the frame. If set to TRUE, it will not try to create Pdus of other types from the current frame, yet it will continue to try for the current type.

Gop's configuration actions

Gop declaration block header

Declares a Gop type and its prematch candidate key.

    Gop name On pduname Match key {
      Start match_avpl; // optional
      Stop match_avpl; // optional
      Extra match_avpl; // optional
      Transform transform_list; // optional
      Expiration time; // optional
      IdleTimeout time; // optional
      Lifetime time; // optional
      DropUnassigned [TRUE|FALSE]; //optional
      ShowTree [NoTree|PduTree|FrameTree|BasicTree]; //optional
      ShowTimes [TRUE|FALSE]; //optional, default TRUE
    };

Gop name

The name is a mandatory attribute of a Gop declaration. It is chosen arbitrarily, except that each name may only be used once in MATE's configuration, regardless the class of an item it is used for. The name is used to distinguish between different types of Pdus, Gops, and Gogs. The name is also used as part of the filterable fields' names related to this type of Gop which MATE creates.

On clause

The name of Pdus which this type of Gop is supposed to be groupping. It is mandatory.

Match clause

Defines what AVPs form up the key part of the Gop's AVPL (the Gop's key AVPL or simply the Gop's key). All Pdus matching the key AVPL of an active Gop are assigned to that Gop; a Pdu which contains the AVPs whose attribute names are listed in the Gop's key AVPL, but they do not strictly match any active Gop's key AVPL, will create a new Gop (unless a Start clause is given). When a Gop is created, the elements of its key AVPL are copied from the creating Pdu.

Start clause

If given, it tells MATE what match_avpl must a Pdu's AVPL match, in addition to matching the Gop's key, in order to start a Gop. If not given, any Pdu whose AVPL matches the Gop's Key AVPL will act as a start for a Gop. The Pdu's AVPs matching the match_avpl are not automatically copied into the Gop's AVPL.

Stop clause

If given, it tells MATE what match_avpl must a Pdu's AVPL match, in addition to matching the Gop's key, in order to stop a Gop. If omitted, the Gop is "auto-stopped" - that is, the Gop is marked as stopped as soon as it is created. The Pdu's AVPs matching the match_avpl are not automatically copied into the Gop's AVPL.

Extra clause

If given, tells MATE which AVPs from the Pdu's AVPL are to be copied into the Gop's AVPL in addition to the Gop's key.

Transform clause

The Transform clause specifies a list of previously declared Transforms to be performed on the Gop's AVPL after the AVPs from each new Pdu, specified by the key AVPL and the Extra clause's match_avpl, have been merged into it. The list is always executed completely, left to right. On the contrary, the list of Match clauses inside each individual Transform is executed only until the first match succeeds.

Expiration clause

A (floating) number of seconds after a Gop is Stopped during which further Pdus matching the Stopped Gop's key but not the Start condition will still be assigned to that Gop. The default value of zero has an actual meaning of infinity, as it disables this timer, so all Pdus matching the Stopped Gop's key will be assigned to that Gop unless they match the Start condition.

IdleTimeout clause

A (floating) number of seconds elapsed from the last Pdu assigned to the Gop after which the Gop will be considered released. The default value of zero has an actual meaning of infinity, as it disables this timer, so the Gop won't be released even if no Pdus arrive - unless the Lifetime timer expires.

Lifetime clause

A (floating) of seconds after the Gop Start after which the Gop will be considered released regardless anything else. The default value of zero has an actual meaning of infinity.

DropUnassigned clause

Whether or not a Gop that has not being assigned to any Gog should be discarded. If TRUE, the Gop is discarded right after creation. If FALSE, the default, the unassigned Gop is kept. Setting it to TRUE helps save memory and speed up filtering.

TreeMode clause

Controls the display of Pdus subtree of the Gop:

ShowTimes clause

Whether or not to show the times subtree of the Gop. If TRUE, the default, the subtree with the timers is added to the Gop's tree. If FALSE, the subtree is suppressed.

Gog's configuration actions

Gop declaration block header

Declares a Gog type and its prematch candidate key.

    Gog name {
      Member gopname (key); // mandatory, at least one
      Extra match_avpl; // optional
      Transform transform_list; // optional
      Expiration time; // optional, default 2.0
      GopTree [NoTree|PduTree|FrameTree|BasicTree]; // optional
      ShowTimes [TRUE|FALSE]; // optional, default TRUE
    };

Gop name

The name is a mandatory attribute of a Gog declaration. It is chosen arbitrarily, except that each name may only be used once in MATE's configuration, regardless the class of an item it is used for. The name is used to distinguish between different types of Pdus, Gops, and Gogs. The name is also used as part of the filterable fields' names related to this type of Gop which MATE creates.

Member clause

Extra clause

If given, tells MATE which AVPs from any of the Gop's AVPL are to be copied into the Gog's AVPL in addition to the Gog's key.

Expiration clause

A (floating) number of seconds after all the Gops assigned to a Gog have been released during which new Gops matching any of the session keys should still be assigned to the existing Gog instead of creating a new one. Its value can range from 0.0 to infinite. Defaults to 2.0 seconds.

Transform clause

The Transform clause specifies a list of previously declared Transforms to be performed on the Gog's AVPL after the AVPs from each new Gop, specified by the key AVPL and the Extra clause's match_avpl, have been merged into it. The list is always executed completely, left to right. On the contrary, the list of Match clauses inside each individual Transform is executed only until the first match succeeds.

TreeMode clause

Controls the display of Gops subtree of the Gog:

ShowTimes clause

Whether or not to show the times subtree of the Gog. If TRUE, the default, the subtree with the timers is added to the Gog's tree. If FALSE, the subtree is suppressed.

Settings Config AVPL

The Settings config element is used to pass to MATE various operational parameters. the possible parameters are

GogExpiration

How long in seconds after all the gops assigned to a gog have been released new gops matching any of the session keys should create a new gog instead of being assigned to the previous one. Its value can range from 0.0 to infinite. Defaults to 2.0 seconds.

DiscardPduData

Whether or not the AVPL of every Pdu should be deleted after it was being processed (saves memory). It can be either TRUE or FALSE. Defaults to TRUE. Setting it to FALSE can save you from a headache if your config does not work.

DiscardUnassignedPdu

Whether Pdus should be deleted if they are not assigned to any Gop. It can be either TRUE or FALSE. Defaults to FALSE. Set it to TRUE to save memory if unassigned Pdus are useless.

DiscardUnassignedGop

Whether GoPs should be deleted if they are not assigned to any session. It can be either TRUE or FALSE. Defaults to FALSE. Setting it to TRUE saves memory.

ShowPduTree
ShowGopTimes

Debugging stuff

The following settings are used to debug MATE and its configuration. All levels are integers ranging from 0 (print only errors) to 9 (flood me with junk), defaulting to 0.

Debug declaration block header

    Debug {
      Filename "path/name"; //optional, no default value
      Level [0-9]; //optional, generic debug level
      Pdu Level [0-9]; //optional, specific debug level for Pdu handling
      Gop Level [0-9]; //optional, specific debug level for Gop handling
      Gog Level [0-9]; //optional, specific debug level for Gog handling
    };

Filename clause

The path/name is a full path to the file to which debug output is to be written. Non-existent file will be created, existing file will be overwritten at each opening of a capture file. If the statement is missing, debug messages are written to console, which means they are invisible on Windows.

Level clause

Sets the level of debugging for generic debug messages. It is an integer ranging from 0 (print only errors) to 9 (flood me with junk).

Pdu Level clause

Sets the level of debugging for messages regarding Pdu creation. It is an integer ranging from 0 (print only errors) to 9 (flood me with junk).

Gop Level clause

Sets the level of debugging for messages regarding Pdu analysis (that is how do they fit into GoPs). It is an integer ranging from 0 (print only errors) to 9 (flood me with junk).

Gog Level clause

Sets the level of debugging for messages regarding GoP analysis (that is how do they fit into GoGs). It is an integer ranging from 0 (print only errors) to 9 (flood me with junk).

Settings Example

 Action=Settings; SessionExpiration=3.5; DiscardPduData=FALSE; 

Action=Include

Will include a file to the configuration.

        Action=Include; {Filename=filename;|Lib=libname;}

Filename

The filename of the file to include. If it does not beging with '/' it will look for the file in the current path.

Lib

The name of the lib config to include. will look for libname.mate in wiresharks_dir/matelib .

Include Example

Action=Include; Filename=rtsp.mate; This will include the file called "rtsp.mate" into the current config.

Imported from https://wiki.wireshark.org/Mate/Reference on 2020-08-11 23:16:35 UTC