tlv_packet_read_bytes() and tlv_packet_read_string() returned the
wrong length when called after other functions which modify the offset
in the container.
In other words, if the TLV data length is X and we do a
tlv_packet_read_u8(), a subsequent tlv_packet_read_bytes() should
return a length of (X - 1).
LLDP TLVs of type 127 are used to carry organizationally specific
information and include additional fields to specify the OUI and
subtype.
Add support for parsing such fields and functions to access the most
common IEEE 802.1 specific TLVs.
It can be useful to know the destination address of a LLDP frame
because it determines the scope of propagation of the frame and thus
this information be used to know whether the neighbor is connected to
the same physical link.
See clause 7.1 of IEEE Std 802.1AB-2009.
like:
src/shared/install.c: In function ‘unit_file_lookup_state’:
src/shared/install.c:1861:16: warning: ‘r’ may be used uninitialized in
this function [-Wmaybe-uninitialized]
return r < 0 ? r : state;
^
src/shared/install.c:1796:13: note: ‘r’ was declared here
int r;
^
This patch introduces LLDP support to networkd. it implements the
receiver side of the protocol.
The Link Layer Discovery Protocol (LLDP) is an industry-standard,
vendor-neutral method to allow networked devices to advertise
capabilities, identity, and other information onto a LAN. The Layer 2
protocol, detailed in IEEE 802.1AB-2005.LLDP allows network devices
that operate at the lower layers of a protocol stack (such as
Layer 2 bridges and switches) to learn some of the capabilities
and characteristics of LAN devices available to higher
layer protocols.
