The
tee
node type has a purpose similar to the
tee(1)
command.
Tee
nodes are useful for debugging or
``snooping''
on a connection
between two netgraph nodes.
Tee
nodes have four hooks,
rightleftright2left
and
left2right
All data received on
right
is sent unmodified to
both
hooks
left
and
right2left
Similarly, all data received on
left
is sent unmodified to both
right
and
left2right
Packets may also be received on
right2left
and
left2right
if so, they are forwarded unchanged out hooks
right
and
left
respectively.
HOOKS
This node type supports the following hooks:
right
The connection to the node on the right.
left
The connection to the node on the left.
right2left
Tap for right to left traffic.
left2right
Tap for left to right traffic.
CONTROL MESSAGES
This node type supports the generic control messages, plus the following.
NGM_TEE_GET_STATS
Get statistics, returned as a
struct ng_tee_stats
NGM_TEE_CLR_STATS
Clear statistics.
SHUTDOWN
This node shuts down upon receipt of an
NGM_SHUTDOWN
control message, or when all hooks have been disconnected.
If both
right
and
left
hooks are present, node removes itself from the chain gently,
connecting
right
and
left
together.
