Library to LD_PRELOAD to override the TOS for an app.


Libsettos is a LD_PRELOADable library to set the TOS/DSCP field for
any IP or IPv6 socket created by a dynamically linked binay.
It can be used with:
  env LIBSETTOS_TOS=<tos> <binary> [<arg...>]

Where <tos> is a number between 0 and 255 inclusive with the two
lowest bytes set to 0 (i.e. <tos>%4 == 0).
It correspond to a DSCP code point shifted by two bits to the left
(the two lowest bits of the TOS are reserved for ECN).
<binary> can be any dynamically linked executable (eg. Skype).


License: Public Domain

Vendor: Philippe Troin <>


libsettos-2-1.fif25.src [7 KiB] Changelog by Philippe Troin (2014-02-05):
- Handle IPv6 correctly (IPV6_TFLAGS).