tree cc59c4609144ce9ff36f226ceb8ae06a56c438b2
parent f0645dce4f4db48d3b763f5fc4f68de76f89b278
author Willy Tarreau <w@1wt.eu> 1470753978 +0200
committer Willy Tarreau <w@1wt.eu> 1470754208 +0200
encoding latin1

MINOR: tcp: add dst_is_local and src_is_local

It is sometimes needed in application server environments to easily tell
if a source is local to the machine or a remote one, without necessarily
knowing all the local addresses (dhcp, vrrp, etc). Similarly in transparent
proxy configurations it is sometimes desired to tell the difference between
local and remote destination addresses.

This patch adds two new sample fetch functions for this :

dst_is_local : boolean
  Returns true if the destination address of the incoming connection is local
  to the system, or false if the address doesn't exist on the system, meaning
  that it was intercepted in transparent mode. It can be useful to apply
  certain rules by default to forwarded traffic and other rules to the traffic
  targetting the real address of the machine. For example the stats page could
  be delivered only on this address, or SSH access could be locally redirected.
  Please note that the check involves a few system calls, so it's better to do
  it only once per connection.

src_is_local : boolean
  Returns true if the source address of the incoming connection is local to the
  system, or false if the address doesn't exist on the system, meaning that it
  comes from a remote machine. Note that UNIX addresses are considered local.
  It can be useful to apply certain access restrictions based on where the
  client comes from (eg: require auth or https for remote machines). Please
  note that the check involves a few system calls, so it's better to do it only
  once per connection.