docs: update ppp_generic.rst to document new ioctls

Add documentation of the newly-added PPPIOCBRIDGECHAN and
PPPIOCUNBRIDGECHAN ioctls.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Parkin 2020-12-10 15:50:58 +00:00 committed by David S. Miller
parent 4cf476ced4
commit 563b603bd6

View File

@ -314,6 +314,22 @@ channel are:
it is connected to. It will return an EINVAL error if the channel
is not connected to an interface.
* PPPIOCBRIDGECHAN bridges a channel with another. The argument should
point to an int containing the channel number of the channel to bridge
to. Once two channels are bridged, frames presented to one channel by
ppp_input() are passed to the bridge instance for onward transmission.
This allows frames to be switched from one channel into another: for
example, to pass PPPoE frames into a PPPoL2TP session. Since channel
bridging interrupts the normal ppp_input() path, a given channel may
not be part of a bridge at the same time as being part of a unit.
This ioctl will return an EALREADY error if the channel is already
part of a bridge or unit, or ENXIO if the requested channel does not
exist.
* PPPIOCUNBRIDGECHAN performs the inverse of PPPIOCBRIDGECHAN, unbridging
a channel pair. This ioctl will return an EINVAL error if the channel
does not form part of a bridge.
* All other ioctl commands are passed to the channel ioctl() function.
The ioctl calls that are available on an instance that is attached to