K 10
svn:author
V 5
andre
K 8
svn:date
V 27
2012-10-23T19:26:49.192251Z
K 7
svn:log
V 1597
Extend PFIL hooks with explicit hook ordering and reinjecting of
packets into the chain after a particular hook.

Add pfil_add_hook_order() taking a numerical value between 0-255
to specify the relative position of this hook in the list of all
hooks.  Lower numbers have higher ordering (ie. will run first).
Within a particular order value the last added will be the first
to run.  Three fixed positions are defined:
 PFIL_ORDER_FIRST	  0
 PFIL_ORDER_DEFAULT	200
 PFIL_ORDER_LAST	255

Previously the order was non-deterministic and dependent on the
ordering of the add hook calls.  The last added would always
become the first to run.

Non-ordering aware pfil consumers using the pfil_add_hook() call
get PFIL_ORDER_DEFAULT assigned resulting in the previous ordering.

The ordering is determined at hookup time by the pfil consumer
and no tool for later manual re-ordering is provided.  Most well
known pfil consumers are expected to have a predetermined preferred
position in the order.  A tool or sysctl reporting the order of
hooked pfil consumers will be provided later.

Add pfil_run_inject() taking an opaque cookie value obtained with
pfil_get_cookie() after the hook is added.  Processing of the hook
chain skips all hooks until after the one with the same cookie.
The cookie is valid as long as this hook remains hooked.  If no
cookie is found processing is started with the first hook again.
If the cookie is invalid processing of all hooks is effectively
skipped.

With this pfil hooks consumers can dequeue packets for further
processing and later re-inject them with the next hook.

END