nl-pktloc-lookup (8)

nl-pktloc-lookup name

nl-pktloc-lookup --list

nl-pktloc-lookup searches the packet location database for a matching entry. It is used to resolve packet location aliases to their definition, i.e. alignment, layer, offset, and mask.

-\^h or --help

Print help text to console and exit.

-\^v or --version

Print versioning information to console and exit.

-\^l or --list

List all packet location definitions.

--u32=VALUE

Prints the packet location definition in a special format that is understood by iproute2's u32 selector parser. It will output a u32 selector which will compare the provided value with the value specified by the packet location.

Please note that due to the limitation of u32, it is not possible to use packet locations based on the link layer. nl-pktloc-lookup will print an error message in this case.

Example:

  selector=$(nl-pktloc-lookup --u32 22 tcp.sport)
  tc filter add [...] u32 match $(selector) flowid 1:2

/etc/libnl/pktloc

Thomas Graf is the original author and current maintainer of libnl and libnl tools. Many people have contributed to it since.