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SiLK - Documentation - rwcut
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NAME

rwcut - Print selected fields of binary SiLK Flow records


SYNOPSIS

  rwcut [--fields=FIELDS] [--all-fields] [--plugin=PLUGIN]
        [--start-rec-num=NUM] [--end-rec-num=NUM] [--num-recs=NUM]
        [--dry-run] [--icmp-type-and-code] [--epoch-time]
        [{--integer-ips | --zero-pad-ips}] [--integer-sensors]
        [--no-titles] [--no-columns] [--column-separator=CHAR]
        [--no-final-delimiter] [{--delimited | --delimited=CHAR}]
        [--print-filenames] [--copy-input=PATH] [--output-path=PATH]
        [--pager=PAGER_PROG] [--site-config-file=FILENAME]
        [--ipv6-policy={ignore,asv4,mix,force,only}]
        [{--legacy-timestamps | --legacy-timestamps=NUM}]
        [--pmap-file=MAPNAME:PATH [--pmap-file=MAPNAME:PATH ...]]
        [--pmap-column-width=NUM] [--python-file=PATH ...]
        [FILES...]
  rwcut [--pmap-file=MAPNAME:PATH [--pmap-file=MAPNAME:PATH ...]]
        [--plugin=PLUGIN ...] [--python-file=PATH ...] --help
  rwcut --version


DESCRIPTION

rwcut reads binary SiLK Flow records from files listed on the command line or from the standard input and prints the records to the screen in a textual, bar (|) delimited format. See the EXAMPLES section below for sample output.


OPTIONS

Option names may be abbreviated if the abbreviation is unique or is an exact match for an option. A parameter to an option may be specified as --arg=param or --arg param, though the first form is required for options that take optional parameters.

--fields=FIELDS

FIELDS contains the list of flow attributes (a.k.a. fields or columns) to print. The columns will be displayed in the order the fields are specified. Fields may be repeated. FIELDS is a comma separated list of field-names, field-integers, and ranges of field-integers; a range is specified by separating the start and end of the range with a hyphen (-). Field-names are case-insensitive. Example:

 --fields=stime,10,1-5

If the --fields switch is not given, FIELDS defaults to:

 sIP,dIP,sPort,dPort,protocol,packets,bytes,flags,sTime,dur,eTime,sensor

The complete list of built-in fields that the SiLK tool suite supports follows, though note that not all fields are present in all SiLK file formats; when a field is not present, its value is 0.

sIP,1

source IP address

dIP,2

destination IP address

sPort,3

source port for TCP and UDP, or equivalent

dPort,4

destination port for TCP and UDP, or equivalent

protocol,5

IP protocol

packets,pkts,6

packet count

bytes,7

byte count

flags,8

bit-wise OR of TCP flags over all packets

sTime,9

starting time of flow (millisecond resolution unless the --legacy-timestamps switch is specified)

dur,10

duration of flow (millisecond resolution unless the --legacy-timestamps switch is specified)

eTime,11

end time of flow (millisecond resolution unless the --legacy-timestamps switch is specified)

sensor,12

name or ID of sensor at the collection point

class,20

class of sensor at the collection point

type,21

type of sensor at the collection point

sTime+msec,22

starting time of flow including milliseconds (milliseconds are always displayed)

eTime+msec,23

end time of flow including milliseconds (milliseconds are always displayed)

dur+msec,24

duration of flow including milliseconds (milliseconds are always displayed)

icmpTypeCode,25

include two columns, iType and iCode that contain the ICMP type and code for ICMP flows; for non-ICMP flows, these columns are empty

Many SiLK file formats do not store the following fields and their values will always be 0; they are listed here for completeness:

in,13

router SNMP input interface

out,14

router SNMP output interface

nhIP,15

router next hop IP

SiLK can store flows generated by enhanced collection software that provides more information than NetFlow v5. These flows may support some or all of these additional fields; for flows without this additional information, the field's value is always 0.

initialFlags,26

TCP flags on first packet in the flow

sessionFlags,27

bit-wise OR of TCP flags over all packets except the first in the flow

attributes,28

flow attributes set by the flow generator:

F

flow generator saw additional packets in this flow following a packet with a FIN flag (excluding ACK packets)

T

flow generator prematurely created a record for a long-running connection due to a timeout. (When the flow generator yaf(1) is run with the --silk switch, it will prematurely create a flow and mark it with T if the byte count of the flow cannot be stored in a 32-bit value.)

C

flow generator created this flow as a continuation of long-running connection, where the previous flow for this connection met a timeout (or a byte threshold in the case of yaf).

Consider a long-running ssh session that exceeds the flow generator's active timeout. (This is the active timeout since the flow generator creates a flow for a connection that still has activity). The flow generator will create multiple flow records for this ssh session, each spanning some portion of the total session. The first flow record will be marked with a T indicating that it hit the timeout. The second through next-to-last records will be marked with TC indicating that this flow both timed out and is a continuation of a flow that timed out. The final flow will be marked with a C, indicating that it was created as a continuation of an active flow.

application,29

guess as to the content the flow. Some software that generates flow records from packet data, such as yaf, will inspect the contents of the packets that make up a flow and use traffic signatures to label the content of the flow. SiLK calls this label the application; yaf refers to it as the appLabel. The application is the port number that is traditionally used for that type of traffic (see the /etc/services file on most UNIX systems). For example, traffic that the flow generator recognizes as FTP will have a value of 21, even if that traffic is being routed through the standard HTTP/web port (80).

The list of built-in fields may be augmented by run-time loading of plug-ins (shared object files or dynamic libraries) when the plug-in is available. rwcut automatically looks for the following plug-ins:

ADDRESS TYPE (addrtype.so)

stype,16

for the source IP address, the value 0 if the address is non-routable, 1 if it is internal, or 2 if it is routable and external. See addrtype(3).

dtype,17

as stype for the destination IP address

COUNTRY CODE (ccfilter.so)

scc,18

for the source IP, a two-letter country code abbreviation denoting the country who owns that IP address. See ccfilter(3).

dcc,19

as scc for the destination IP

PREFIX MAP (pmapfilter.so)

src-MAPNAME

value determined by passing the source IP or the protocol/source-port to the user-defined mapping defined in the prefix map associated with MAPNAME. See the description of the --pmap-file switch and the pmapfilter(3) manual page.

dst-MAPNAME

as src-MAPNAME for the destination IP or protocol/destination-port.

sval
dval

These are deprecated field names created by pmapfilter that correspond to src-MAPNAME and dst-MAPNAME, respectively. These fields are available when a prefix map is used that is not associated with a MAPNAME.

--all-fields

Instruct rwcut to print all known fields. This switch cannot be combined with the --fields switch. This switch suppresses error messages from the plug-ins.

--plugin=PLUGIN

Augment the list of fields by using run-time loading of the plug-in (shared object) whose path is PLUGIN. The creation of these plug-ins is beyond the scope of this manual page. When PLUGIN contains a slash (/), rwcut assumes the path to PLUGIN is correct. Otherwise, rwcut will attempt to find the file in $SILK_PATH/lib/silk, $SILK_PATH/share/lib, $SILK_PATH/lib, and in these directories parallel to the application's directory: lib/silk, share/lib, and lib. If rwcut does not find the file, it assumes the plug-in is in the current directory. To force rwcut to look in the current directory first, specify --plugin=./PLUGIN. When the SILK_PLUGIN_DEBUG environment variable is non-empty, rwcut prints status messages to the standard error as it tries to open each of its plug-ins.

--start-rec-num=START_NUM

Begin printing with the START_NUM'th record by skipping the first START_NUM-1 records. The default is 1; that is, to start printing at the first record; START_NUM must be a positive integer. If START_NUM is greater than the number of input records, the only output will be the title. This parameter does not affect the records written to the stream specified by --copy-input.

--end-rec-num=END_NUM

Stop printing after the END_NUM'th record. When END_NUM is 0, the default, printing stops once all input records have been printed; that is, END_NUM is effectively infinity. If this value is non-zero, it must not be less than START_NUM. This parameter does not affect the records written to the stream specified by --copy-input.

--num-recs=REC_COUNT

Print no more than REC_COUNT records; however, if both --start-rec-num and --end-rec-num are specified or if END_NUM is less than REC_COUNT, this switch is ignored. Specifying a REC_COUNT of 0 will print all records, which is the default.

--dry-run

Causes rwcut to print the column headers and exit. Useful for testing.

--icmp-type-and-code

Unlike TCP or UDP, ICMP messages do not use ports, but instead have types and codes. Specifying this switch will cause rwcut to print, for ICMP records, the message's type and code in the sPort and dPort columns, respectively. The use of this switch is discouraged; use the icmpTypeCode field instead.

--epoch-time

Print timestamps as epoch time (number of seconds since midnight GMT on 1970-01-01).

--integer-ips

Print IPs as integers. By default, IP addresses are printed in their canonical form.

--zero-pad-ips

Print IP addresses in their canonical form, but add zeros to the IP address so it fully fills the width of column. For IPv4, use three digits per octet, e.g, 127.000.000.001. For IPv6, use four digits per hexadectet and expand empty hexadectets, e.g.; 0000:0000:0000:0000:0000:FFFF:FF00:0001.

--integer-sensors

Print the integer ID of the sensor rather than its name.

--no-titles

Turn off column titles. By default, titles are printed.

--no-columns

Disable fixed-width columnar output.

--column-separator=C

Use specified character between columns and after the final column. When this switch is not specified, the default of '|' is used.

--no-final-delimiter

Do not print the column separator after the final column. Normally a delimiter is printed.

--delimited
--delimited=C

Run as if --no-columns --no-final-delimiter --column-sep=C had been specified. That is, disable fixed-width columnar output; if character C is provided, it is used as the delimiter between columns instead of the default '|'.

--print-filenames

Print to the standard error the names of input files as they are opened.

--copy-input=PATH

Copy all binary input to the specified file or named pipe. PATH can be stdout to print flows to the standard output as long as the --output-path switch has been used to redirect rwcut's ASCII output.

--output-path=PATH

Determines where the output of rwcut (ASCII text) is written. If this option is not given, output is written to the standard output.

--pager=PAGER_PROG

When output is to a terminal, invoke the program PAGER_PROG to view the output one screen full at a time. This switch overrides the SILK_PAGER environment variable, which in turn overrides the PAGER variable. If the value of the pager is determined to be the empty string, no paging will be performed and all output will be printed to the terminal.

--ipv6-policy=POLICY

Determine how IPv4 and IPv6 flows are handled when SiLK has been compiled with IPv6 support. When the switch is not provided, the SILK_IPV6_POLICY environment variable is checked for a policy. If it is also unset or contains an invalid policy, the POLICY is mixed. When SiLK has not been compiled with IPv6 support; IPv6 flows are always ignored, regardless of the value passed to this switch or in the SILK_IPV6_POLICY variable. The supported values for POLICY are:

ignore

Completely ignore IPv6 flows. Only IPv4 flows will be printed.

asv4

Convert IPv6 addresses to IPv4 if possible, otherwise ignore the IPv6 flows.

mix

Process the input as a mixture of IPv4 and IPv6 flows.

force

Force IPv4 flows to be converted to IPv6.

only

Only process flows that were marked as IPv6 and completely ignore IPv4 flows.

--site-config-file=FILENAME

Read the SiLK site configuration from the named file FILENAME. When this switch is not provided, the location specified by the SILK_CONFIG_FILE environment variable is used if that variable is not empty. The value of SILK_CONFIG_FILE should include the name of the file. Otherwise, the application looks for a file named silk.conf in the following directories: the directory specified in the SILK_DATA_ROOTDIR environment variable; the data root directory that is compiled into SiLK (use the --version switch to view this value); the directories $SILK_PATH/share/silk/ and $SILK_PATH/share/; and the share/silk/ and share/ directories parallel to the application's directory.

--legacy-timestamps
--legacy-timestamps=NUM

Specify the format for human readable timestamps, either the default (new) style, YYYY/MM/DDThh:mm:ss.sss, or the legacy style, MM/DD/YYYY hh:mm:ss. When this switch is not present, the timestamps will be in the default format. When this switch is present and no argument is given, timestamps are in the legacy format. When an argument is supplied, timestamps will be in the new format if the argument begins with 0, and in the old format if the argument begins with 1. Any other argument to the switch is an error.

This switch also controls whether fractional seconds are displayed in the sTime and eTime fields when --epoch-time is requested. If the --legacy-timestamps switch is present with no value or with a value of 1, milliseconds will not be displayed; when not present or specified with a value of 0, milliseconds will be displayed.

--help

Print the available options and exit. Options that add fields can be specified before --help so that the new options appear in the output.

--version

Print the version number and information about how SiLK was configured, then exit the application.

--dynamic-library=PLUGIN

This switch is deprecated. It is an alias for --plugin.

--pmap-file=MAPNAME:PATH
--pmap-file=PATH

When the prefix map plug-in is used, rwcut reads the mapping file located at PATH. When MAPNAME is provided, it will be used to refer to the fields specific to that prefix map. If MAPNAME is not provided, rwcut will check the prefix map file to see if a map-name was specified when the file was created. Using multiple --prefix-map switches allows additional prefix map files to be read as long as each uses a unique map-name. For more information, see pmapfilter(3).

--pmap-column-width=NUM

When the pmapfilter plug-in is used, this switch gives the maximum number of characters to use when displaying the textual value of any field.

--python-file=PATH

When the SiLK Python plug-in is used, rwcut reads the Python code from the file PATH to define additional fields for possible output. This file should call register_plugin_field() for each field it wishes to define. For details and examples, see the silkpython(3) and pysilk(3) manual pages.


EXAMPLES

A standard rwcut output will look like this (with the text wrapped for readability):

            sIP|            dIP|sPort|dPort|pro|\
    10.30.30.31|    10.70.70.71|   80|36761|  6|\
        packets|     bytes|          flags|\
              7|      3227|      FS PA    |\
                    sTime|      dur|                  eTime|senso|
  2003/01/01T00:00:14.625|    3.959|2003/01/01T00:00:18.584|EDGE1|

The first line of the output is the title line--this line shows what the selected fields are; the --no-titles switch will disable the printing of that line. The second line onwards will contain data.

The most basic use of rwcut is by being directly connected to rwfilter(1). For example, to see representative TCP traffic:

 rwfilter --start-date=2002/01/19:00 --end-date=2002/01/19:01 \
      --proto=6 --pass=stdout | rwcut

To see only limited field, use the --fields switch. For example, to see only the protocols, use:

 rwcut --fields=5

The silkpython(3) manual page provides examples that use PySiLK to create and print arbitrary fields for rwcut.

The order of the FIELDS is significant, and fields can be repeated. For example, here is a case where in addition to the default fields of 1-12, you also to prefix each row with an integer form of the destination IP and the start time to make processing by another tool easier. However, within the default fields of 1-12, you want to see dotted-decimal IP addresses.

 rwfilter ... --pass=stdout | \
       rwcut --integer-ip --fields=2,9,1-12 --epoch-time | \
       num2dot --ip-field=3,4


ENVIRONMENT

SILK_IPV6_POLICY

This environment variable is used as the value for the --ipv6-policy when that switch is not provided.

SILK_PAGER

When set to a non-empty string, rwcut automatically invokes this program to display its output a screen at a time. If set to an empty string, rwcut does not automatically page its output.

PAGER

When set and SILK_PAGER is not set, rwcut automatically invokes this program to display its output a screen at a time.

PYTHONPATH

This environment variable is used by Python to locate modules. When --python-file is specified, rwcut loads Python which in turn loads the PySiLK module which is comprised of several files (silk/pysilk_nl.so, silk/__init__.py, etc). If this silk/ directory is located outside Python's normal search path (for example, in the SiLK installation tree), it may be necessary to set or modify the PYTHONPATH environment variable to include the parent directory of silk/ so that Python can find the PySiLK module.

SILK_PYTHON_TRACEBACK

When set, Python plug-ins will output traceback information on Python errors to the standard error.

SILK_COUNTRY_CODES

This environment variable allows the user to specify the country code mapping file that the ccfilter(3) plug-in will use. The value may be a complete path or a file relative to the SILK_PATH. If the variable is not specified, the code looks for a file named country_codes.pmap in the location specified by SILK_PATH.

SILK_CONFIG_FILE

This environment variable is used as the value for the --site-config-file when that switch is not provided.

SILK_DATA_ROOTDIR

When the --site-config-file switch is not provided and the SILK_CONFIG_FILE environment variable is not set, rwcut looks for the site configuration file in $SILK_DATA_ROOTDIR/silk.conf.

SILK_PATH

This environment variable gives the root of the install tree. As part of its search for the SiLK site configuration file, rwcut checks for a file named silk.conf in the directories $SILK_PATH/share/silk and $SILK_PATH/share. These directories are also searched when any other configuration file is required (e.g., the country code map). In addition, rwcut looks for plug-ins in $SILK_PATH/lib/silk, $SILK_PATH/share/lib and $SILK_PATH/lib.

SILK_PLUGIN_DEBUG

When set to 1, rwcut prints status messages to the standard error as it tries to open each of its plug-ins.


NOTES

The ordering of the field numbers in --fields is significant, specifying --fields=2,1 will print destination IP, then source IP.

If you are interested in only a few fields, use the --fields option to reduce the volume of data to be processed. For example, if you are checking to see which internal host got hit with the slammer worm (signature: UDP, destPort 1434, pkt size 404), then the following rwfilter, rwcut combination will be much faster than simply using default values:

  rwfilter --proto-17 --dport=1434 --bytes-per-packet=404-404 \
        | rwcut --fields=2

To get a mapping from the integer representing a sensor to its name, use the mapsid(1) command.


SEE ALSO

rwfilter(1), mapsid(1), num2dot(1), addrtype(3), ccfilter(3), pmapfilter(3), silkpython(3), pysilk(3), yaf(1)