NAME

rwtuc - Text Utility Converter - rwcut output to SiLK flows

SYNOPSIS

rwtuc [--fields=FIELDS] [--column-separator=CHAR]
      [--output-path=PATH] [--bad-input-lines=FILEPATH]
      [--verbose] [--stop-on-error] [--no-titles] [--note-add=TEXT]
      [--note-file-add=FILE] [--compression-method=COMP_METHOD]
      [--site-config-file=FILENAME] [--saddress=IPADDR]
      [--daddress=IPADDR] [--sport=NUM] [--dport=NUM]
      [--protocol=NUM] [--packets=NUM] [--bytes=NUM]
      [--flags-all=TCPFLAGS] [--stime=TIME] [--duration=NUM]
      [--etime=TIME] [--sensor=SID] [--input-index=NUM]
      [--output-index=NUM] [--next-hop-ip=IPADDR]
      [--flags-initial=TCPFLAGS] [--flags-session=TCPFLAGS]
      [--attributes=ATTR] [--application=NUM] [--class=NAME]
      [--type=NAME] [--icmp-type=NUM] [--icmp-code=NUM]
      {[--xargs] | [--xargs=FILENAME] | [FILE [FILE...]]}

rwtuc --help

rwtuc --version

DESCRIPTION

rwtuc reads text files that have a format similar to that produced by rwcut(1) and attempts to create a SiLK Flow record for each line of input.

The fields which make up a single record should be separated by the pipe character ('|'); use the --column-separator switch to change this delimiter. Note that the space character does not work as delimiter since several fields (e.g., time, TCP-flags) may contain embedded spaces.

The fields to be read from each line may be specified with the --fields switch; if the switch is not provided, rwtuc treats the first line as a title and attempts to determine the fields from the title strings.

When --fields is specified, rwtuc still checks whether the first line contains title strings, and rwtuc skips the line if it determines it does. Specify the --no-titles switch to force rwtuc to treat the first line as field values to be parsed.

Command line switches exist which force a field to have a fixed value. These switches cause rwtuc to override the value read from the input file (if any) for those fields. See the "Fixed Values" section below for details.

rwtuc reads the textual input from the files named on the command line or from the standard input when no file names are specified, when --xargs is not present, and when the standard input is not a terminal. To read the standard input in addition to the named files or to force rwfileinfo to read input from a terminal, use - or stdin as a file name. When the --xargs switch is provided, rwtuc reads the names of the files to process from the named text file or from the standard input if no file name argument is provided to the switch. The input to --xargs must contain one file name per line.

When the --output-path switch is not provided, output is sent to the standard output when it is not connected to a terminal.

By default, lines that cannot be parsed are silently ignored (unless rwtuc is attempting to determine the fields from the title line). When the --verbose switch is specified, problems parsing an input line are reported to the standard error, and rwtuc continues to process the input. The --stop-on-error switch is similar to the --verbose switch, except processing stops after the first error. Input lines that cause parse errors may be copied to another output stream with the --bad-input-lines switch. Each bad line has the source file name and line number prepended to it, separated from each other and the source line by colons (':').

Field Constraints

Due to the way SiLK Flow records are stored, certain field combinations cannot be supported, certain fields must appear together, and some fields may only be used on certain occasions:

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 fields (columns) to parse. 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. A field name may not be specified more than once. (As of SiLK 3.15.0, ignore may appear multiple times, allowing multiple input fields to be ignored.)

A field is ignored when its name corresponds to a fixed value switch (e.g. --protocol) given on the command line (see "Fixed Values").

The field names and their descriptions are:

ignore

a field that rwtuc is to skip

sIP,1

source IP address in the canonical form: dotted-quad for IPv4 or hex-encoded for IPv6 (when SiLK has been compiled with IPv6 support). Integers from 0 to 4294967295 are treated as IPv4 addresses.

dIP,2

destination IP address in the same format as sIP,1

sPort,3

source port as a 16-bit integer from 0 to 65,535 inclusive

dPort,4

destination port as a 16-bit integer from 0 to 65,535 inclusive (cf. "Field Constraints")

protocol,5

IP protocol as an 8-bit integer from 0 to 255 inclusive

packets,pkts,6

packet count as a 64-bit integer from 1 to 18,446,744,073,709,551,615 inclusive. Prior to SiLK 3.23, packets was a 32-bit integer from 1 to 4,294,967,295 inclusive.

bytes,7

byte count as a 64-bit integer from 1 to 18,446,744,073,709,551,615 inclusive. Prior to SiLK 3.23, bytes was a 32-bit integer from 1 to 4,294,967,295 inclusive.

flags,8

bit-wise OR of TCP flags over all packets in the flow; the string may contain F, S, R, P, A, U, E, C in upper- or lowercase (cf. "Field Constraints")

sTime,9

starting time of the flow, in the form YYYY/MM/DD[:hh[:mm[:ss[.sss]]]]. The letter T may be used in place of : to separate the day and hour fields. A floating point value between 536870912 and 4294967295 is also allowed and is treated as seconds since the UNIX epoch.

duration,10

duration of flow as a floating point value from 0.0 to 4294967.295

eTime,11

end time of flow in the same form as sTime,9 (cf. "Field Constraints")

sensor,12

router sensor name or ID as given in silk.conf (cf. silk.conf(5))

class

class of router at collection point as given in silk.conf (cf. "Field Constraints")

type

type of router at collection point as given in silk.conf (cf. "Field Constraints")

in,13

router SNMP input (ingress) interface or vlanId; a 32-bit integer from 0 to 4,294,967,295 inclusive. Prior to SiLK 3.23, in was a 16-bit integer from 0 to 65,535 inclusive.

out,14

router SNMP output (egress) interface or postVlanId; a 32-bit integer from 0 to 4,294,967,295 inclusive. Prior to SiLK 3.23, out was a 16-bit integer from 0 to 65,535 inclusive.

nhIP,15

router next hop IP address in the same format as sIP,1

initialFlags,26

TCP flags on first packet in the flow; same form as the flags,8 field (cf. "Field Constraints")

sessionFlags,27

bit-wise OR of TCP flags on the second through final packet in the flow; same form as the flags,8 field (cf. "Field Constraints")

attribute,28

flow attributes set by the flow generator:

S

all the packets in this flow record are exactly the same size

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 prematurely creates 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 of the flow, as a 16-bit integer from 0 to 65,535. 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).

iType

ICMP type as an 8-bit integer from 0 to 255 inclusive (cf. "Field Constraints")

iCode

ICMP code as an 8-bit integer from 0 to 255 inclusive (cf. "Field Constraints")

--column-separator=CHAR

Use the character CHAR as the delimiter between columns (fields) in the input. The default column separator is the vertical pipe ('|'). rwtuc normally ignores whitespace (space and tab) around the column separator; however, using space or tab as the separator causes each space or tab character to be treated as a field delimiter. The newline character is not a valid delimiter character since it is used to denote records.

--output-path=PATH

Write the binary SiLK Flow records to PATH, where PATH is a filename, a named pipe, the keyword stderr to write the output to the standard error, or the keyword stdout or - to write the output to the standard output. If PATH names an existing file, rwtuc exits with an error unless the SILK_CLOBBER environment variable is set, in which case PATH is overwritten. When PATH ends in .gz, the output is compressed using the library associated with gzip(1). If this switch is not given, the output is written to the standard output. Attempting to write the binary output to a terminal causes rwtuc to exit with an error.

--bad-input-lines=FILEPATH

Copy any lines which could not be parsed to FILEPATH. The strings stdout and stderr may be used for the standard output and standard error, respectively. Each bad line is prepended by the source input file, a colon, the line number, and a colon. On exit, rwtuc removes FILEPATH if all input lines were successfully parsed.

--verbose

When an input line fails to parse, print a message to the standard error describing the problem. When this switch is not specified, parsing failures are not reported. rwtuc continues to process the input after printing the message. To stop processing when a parsing error occurs, use --stop-on-error.

--stop-on-error

When an input line fails to parse, print a message to the standard error describing the problem and exit the program. When this occurs, the output file contains any records successfully created prior to reading the bad input line. The default behavior of rwtuc is to silently ignore parsing errors. To report parsing errors and continue processing the input, use --verbose.

--no-titles

Parse the first line of the input as field values. Normally when the --fields switch is specified, rwtuc examines the first line to determine if the line contains the names (titles) of fields and skips the line if it does. rwtuc exits with an error when --no-titles is given but --fields is not.

--note-add=TEXT

Add the specified TEXT to the header of the output file as an annotation. This switch may be repeated to add multiple annotations to a file. To view the annotations, use the rwfileinfo(1) tool.

--note-file-add=FILENAME

Open FILENAME and add the contents of that file to the header of the output file as an annotation. This switch may be repeated to add multiple annotations. Currently the application makes no effort to ensure that FILENAME contains text; be careful that you do not attempt to add a SiLK data file as an annotation.

--compression-method=COMP_METHOD

Specify the compression library to use when writing output files. If this switch is not given, the value in the SILK_COMPRESSION_METHOD environment variable is used if the value names an available compression method. When no compression method is specified, output to the standard output or to named pipes is not compressed, and output to files is compressed using the default chosen when SiLK was compiled. The valid values for COMP_METHOD are determined by which external libraries were found when SiLK was compiled. To see the available compression methods and the default method, use the --help or --version switch. SiLK can support the following COMP_METHOD values when the required libraries are available.

none

Do not compress the output using an external library.

zlib

Use the zlib(3) library for compressing the output, and always compress the output regardless of the destination. Using zlib produces the smallest output files at the cost of speed.

lzo1x

Use the lzo1x algorithm from the LZO real time compression library for compression, and always compress the output regardless of the destination. This compression provides good compression with less memory and CPU overhead.

snappy

Use the snappy library for compression, and always compress the output regardless of the destination. This compression provides good compression with less memory and CPU overhead. Since SiLK 3.13.0.

best

Use lzo1x if available, otherwise use snappy if available, otherwise use zlib if available. Only compress the output when writing to a file.

--site-config-file=FILENAME

Read the SiLK site configuration from the named file FILENAME. When this switch is not provided, rwtuc searches for the site configuration file in the locations specified in the "FILES" section.

--xargs
--xargs=FILENAME

Read the names of the input files from FILENAME or from the standard input if FILENAME is not provided. The input is expected to have one filename per line. rwtuc opens each named file in turn and reads text from it as if the filenames had been listed on the command line. Since SiLK 3.15.0.

--help

Print the available options and exit.

--version

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

Fixed Values

The following switches may be used to set fields to fixed values. A value specified using one these switches overrides the field when it appears in the input, causing that column of input to be completely ignored.

--saddress=IPADDR

Set the source address field to IPADDR for all records. IPADDR may be in canonical notation or an unsigned integer.

--daddress=IPADDR

Set the destination address field to IPADDR for all records. IPADDR may be in canonical notation or an unsigned integer.

--sport=NUM

Set the source port field to NUM for all records; a value between 0 and 65535.

--dport=NUM

Set the destination port field to NUM for all records; a value between 0 and 65535. (cf. "Field Constraints")

--protocol=NUM

Set the protocol field to NUM for all records; a value between 0 and 255.

--packets=NUM

Set the packets field to NUM for all records; the value must be non-zero.

--bytes=NUM

Set the bytes field to NUM for all records; the value must be non-zero.

--flags-all=TCPFLAGS

Set the TCP flags field to TCPFLAGS for all records. (cf. "Field Constraints")

--stime=TIME

Set the start time field to TIME for all records.

--duration=NUM

Set the duration field to NUM for all records.

--etime=TIME

Set the end time field to TIME for all records. (cf. "Field Constraints")

--sensor=SID

Set the sensor field to SID for all records. This may either be a sensor name or sensor ID.

--input-index=NUM

Set the SNMP input index field to NUM for all records; a value between 0 and 4294967295.

--output-index=NUM

Set the SNMP output index field to NUM for all records; a value between 0 and 4294967295.

--next-hop-ip=IPADDR

Set the next-hop-ip field to IPADDR for all records. IPADDR may be in canonical notation or an unsigned integer.

--flags-initial=TCPFLAGS

Set the initial TCP flags field to TCPFLAGS for all records. (cf. "Field Constraints")

--flags-session=TCPFLAGS

Set the session TCP flags field to TCPFLAGS for all records. (cf. "Field Constraints")

--attributes=ATTR

Set the attributes field to ATTR for all records.

--application=NUM

Set the application field to NUM for all records; a value between 0 and 65535.

--class=NAME

Set the class field to NAME for all records. (cf. "Field Constraints")

--type=NAME

Set the type field to NAME for all records. (cf. "Field Constraints")

--icmp-type=NUM

Set the ICMP type field to NUM for all ICMP or ICMPv6 flow records; a value between 0 and 255. (cf. "Field Constraints")

--icmp-code=NUM

Set the ICMP code field to NUM for all ICMP or ICMPv6 flow records; a value between 0 and 255. (cf. "Field Constraints")

EXAMPLES

In the following examples, the dollar sign ($) represents the shell prompt. The text after the dollar sign represents the command line. Lines have been wrapped for improved readability, and the back slash (\) is used to indicate a wrapped line.

Using rwtuc to parse the output of rwcut(1) should produce the same output:

$ rwcut data.rw > cut.txt
$ md5 < cut.txt
7e3d693cd2cba2510803935274e1debd
$ rwtuc < cut.txt | rwcut | md5
7e3d693cd2cba2510803935274e1debd

To swap the source IP and port with the destination IP and port in flows.rw and save the result in reverse.rw:

$ rwcut --fields=dip,dport,sip,sport,5-15,20-29 flows.rw   \
  | rwtuc --fields=1-15,20-29 --output-path=reverse.rw

rwtuc may be used to obfuscate the flow data in myflows.rw to produce obflows.rw. Pipe the output from rwcut into a script that manipulates the IP addresses, then pipe that into rwtuc. Using the sed(1) script in priv.sed, the invocation is:

$ rwcut --fields=1-10,13-15,26-29 myflows.rw               \
  | sed -f priv.sed                                        \
  | rwtuc --sensor=1 > obflows.rw

If the first line of input appears to contain titles, rwtuc ignores it. In the first invocation below, rwtuc treats SP as an abbreviation for sPort and ignores the line. Use the --no-titles switch to force rwtuc to parse the line:

$ echo 'SP' | rwtuc --fields=flags | rwcut --fields=flags
   flags|
$
$ echo 'SP' | rwtuc --fields=flags --no-titles | rwcut --fields=flags
   flags|
 S P    |
$

By default, rwtuc silently ignores lines that it cannot parse. Use the --verbose flag to see error messages:

$ echo sport | rwtuc --fields=flags --no-titles --verbose >/dev/null
rwtuc: stdin:1: Invalid flags 'sport': Unexpected character 'o'

ENVIRONMENT

SILK_CLOBBER

The SiLK tools normally refuse to overwrite existing files. Setting SILK_CLOBBER to a non-empty value removes this restriction.

SILK_COMPRESSION_METHOD

This environment variable is used as the value for --compression-method when that switch is not provided. Since SiLK 3.13.0.

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

This environment variable specifies the root directory of data repository. As described in the "FILES" section, rwtuc may use this environment variable when searching for the SiLK site configuration file.

SILK_PATH

This environment variable gives the root of the install tree. When searching for configuration files, rwtuc may use this environment variable. See the "FILES" section for details.

TZ

When a SiLK installation is built to use the local timezone (to determine if this is the case, check the Timezone support value in the output from rwtuc --version), the value of the TZ environment variable determines the timezone in which rwtuc parses timestamps. If the TZ environment variable is not set, the default timezone is used. Setting TZ to 0 or the empty string causes timestamps to be parsed as UTC. The value of the TZ environment variable is ignored when the SiLK installation uses utc. For system information on the TZ variable, see tzset(3) or environ(7).

FILES

${SILK_CONFIG_FILE}
${SILK_DATA_ROOTDIR}/silk.conf
/data/silk.conf
${SILK_PATH}/share/silk/silk.conf
${SILK_PATH}/share/silk.conf
/usr/share/silk/silk.conf
/usr/share/silk.conf

Possible locations for the SiLK site configuration file which are checked when the --site-config-file switch is not provided.

NOTES

Prior to SiLK 3.23.0, the pkts and bytes fields were limited to 32 bits (0 to 4294967295) and the in and out fields were limited to 16 bits (0 to 65535).

Fields sTime+msec, eTime+msec, dur+msec, and their aliases (22, 23, 24) were removed in SiLK 3.23.0. Use fields sTime, eTime, and duration instead.

SiLK 3.23.0 also removed the --stime+msec, --etime+msec, and --dur+msec options. Use --stime, --etime, and --duration instead.

SEE ALSO

rwcut(1), rwfileinfo(1), rwsiteinfo(1), silk.conf(5), silk(7), yaf(1), gzip(1), sed(1), zlib(3), tzset(3), environ(7)