# NAME

extcap - Extcap grammar elements

# DESCRIPTION

Grammar elements:

arg (options)

  argument for CLI calling

number

  Reference # of argument for other values, display order

call

  Literal argument to call (--call=...)

display

  Displayed name

default

  Default value, in proper form for type

range

  Range of valid values for UI checking (min,max) in proper form

type

  Argument type for UI filtering for raw, or UI type for selector:

          integer
          unsigned
          long (may include scientific / special notation)
          float
          selector (display selector table, all values as strings)
          boolean (display checkbox)
          radio (display group of radio buttons with provided values, all values as strings)
          fileselect (display a dialog to select a file from the filesystem, value as string)
          multicheck (display a textbox for selecting multiple options, values as strings)
          password (display a textbox with masked text)

value (options)

          Values for argument selection
          arg     Argument # this value applies to

# EXAMPLES

Example 1:

        arg {number=0}{call=--channel}{display=Wi-Fi Channel}{type=integer}{required=true}
        arg {number=1}{call=--chanflags}{display=Channel Flags}{type=radio}
        arg {number=2}{call=--interface}{display=Interface}{type=selector}
        value {arg=0}{range=1,11}
        value {arg=1}{value=ht40p}{display=HT40+}
        value {arg=1}{value=ht40m}{display=HT40-}
        value {arg=1}{value=ht20}{display=HT20}
        value {arg=2}{value=wlan0}{display=wlan0}

Example 2:

        arg {number=0}{call=--usbdevice}{USB Device}{type=selector}
        value {arg=0}{call=/dev/sysfs/usb/foo/123}{display=Ubertooth One sn 1234}
        value {arg=0}{call=/dev/sysfs/usb/foo/456}{display=Ubertooth One sn 8901}

Example 3:

        arg {number=0}{call=--usbdevice}{USB Device}{type=selector}
        arg {number=1}{call=--server}{display=IP address for log server}{type=string}{validation=(?:\d{1,3}\.){3}\d{1,3}}
        flag {failure=Permission denied opening Ubertooth device}

Example 4: arg {number=0}{call=--username}{display=Username}{type=string} arg {number=1}{call=--password}{display=Password}{type=password}

# Security awareness

- Users running wireshark as root, we can't save you
- Dumpcap retains suid/setgid and group+x permissions to allow users in wireshark group only
- Third-party capture programs run w/ whatever privs they're installed with
- If an attacker can write to a system binary directory, we're game over anyhow
- Reference the folders tab in the wireshark->about information, to see from which directory extcap is being run

# SEE ALSO

wireshark(1), tshark(1), dumpcap(1), androiddump(1), sshdump(1), randpktdump(1)

# NOTES

Extcap is feature of Wireshark. The latest version of Wireshark can be found at https://www.wireshark.org.

HTML versions of the Wireshark project man pages are available at: https://www.wireshark.org/docs/man-pages.