When running as grand master, the attributes of the local clock are not
known by the ptp4l program. Since these attributes may change over time,
for example when losing signal from GPS satellites, we need to have a
way to provide updated information at run time. This patch provides a
new TLV intended for local IPC that contains the required settings.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Many of the single field management messages have just two bytes, one for
the data value and one for padding. This patch adds a structure that can
be used for all of these management IDs.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Modifies existing structs changing Octet *foo -> Octet foo[0] and
marks them PACKED so the message buffer can be cast to the structs.
Signed-off-by: Geoff Salmon <gsalmon@se-instruments.com>
These flexible TLVs don't need to be represented as a single packed
struct directly in the message buffer. Instead a separate struct
contains pointers to the individual parts of the TLV in the message
buffer. The flexible TLV can only be the last TLV in a message.
Signed-off-by: Geoff Salmon <gsalmon@se-instruments.com>
The function, tlv_post_recv, and the functions it calls don't check
the length of the tlv before flipping the byte order of fields. An
attacker (or a really buggy client) can craft a message causing the
byte order of data outside the received message to be flipped.
None of the supported tlvs are large enough to flip bytes outside the
ptp_message struct, which could corrupt the heap. However, it's easy
to mess up the message's refcnt field, leading to memory leaks.
The fix is to check that the tlv length is what is expected when
receiving, and tlv_post_recv needs to return an int to signal when a
tlv is invalid.
Signed-off-by: Geoff Salmon <gsalmon@se-instruments.com>
This non-portable, implementation specific message is designed to inform
external programs about the relationship between the local clock and the
remote master clock.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Richard Cochran
Dale P. Smith
Geoff Salmon