Because of packet reordering that can occur in the network, in the
hardware, or in the networking stack, a follow up message can appear
to arrive in the application before the matching sync message. As this
is a normal occurrence, and the sequenceID message field ensures
proper matching, the ptp4l program accepts out of order packets.
This patch adds an additional check using the software time stamps
from the networking stack to verify that the sync message did arrive
first. This check is only useful if the sequence IDs generated by
the master might possibly be incorrect.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
This means no conversion is necessary between the transport_type and
the networkProtocol field of the PortAddress struct. Not currently an
issue, but will be needed for implementing the CLOCK_DESCRIPTION
management TLV.
The Linux kernel supports a hardware time stamping mode that allows
sending a one step sync message. This commit adds support for this mode
by expanding the time stamp type enumeration. In order to enable this
mode, the configuration must specify both hardware time stamping and set
the twoStepFlag to false.
We still do not support the one step peer delay request mechanism since
there is neither kernel nor hardware support for it at this time.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Although the UDP/IPv4 layer does not need any state per instance (other
than the two file descriptors), the raw Ethernet layer will need this.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Stephan Gatzka
Richard Cochran
Geoff Salmon