tree 473f9131b9e641d803bfbea174cf1dfc45aea3ca
parent ddab05568eaa70fc92b2aae957136f188f724e9c
author Tomasz Grobelny <tomasz@grobelny.oswiecenia.net> 1220506219 +0200
committer Gerrit Renker <gerrit@erg.abdn.ac.uk> 1220507139 +0200

dccp: Policy-based packet dequeueing infrastructure

This patch adds a generic infrastructure for policy-based dequeueing of 
TX packets and provides two policies:
 * a simple FIFO policy (which is the default) and
 * a priority based policy (set via socket options).
Both policies honour the tx_qlen sysctl for the maximum size of the write
queue (can be overridden via socket options). 

The priority policy uses skb->priority internally to assign an u32 priority
identifier, using the same ranking as SO_PRIORITY. The skb->priority field
is set to 0 when the packet leaves DCCP. The priority is supplied as ancillary
data using cmsg(3), the patch also provides the requisite parsing routines.

Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>