Allow network upper-layer drivers (such as LLDP, which attaches to
each network device in order to provide a corresponding LLDP settings
block) to specify a size for private data, which will be allocated as
part of the network device structure (as with the existing private
data allocated for the underlying device driver).
This will allow network upper-layer drivers to be simplified by
omitting memory allocation and freeing code. If the upper-layer
driver requires a reference counter (e.g. for interface
initialisation), then it may use the network device's existing
reference counter, since this is now the reference counter for the
containing block of memory.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add support for recording LLDP packets and exposing TLV values via the
settings mechanism. LLDP settings are encoded as
${netX.lldp/<prefix>.<type>.<index>.<offset>.<length>}
where
<type> is the TLV type
<offset> is the starting offset within the TLV value
<length> is the length (or zero to read the from <offset> to the end)
<prefix>, if it has a non-zero value, is the subtype byte string of
length <offset> to match at the start of the TLV value, up to a
maximum matched length of 4 bytes
<index> is the index of the entry matching <type> and <prefix> to be
accessed, with zero indicating the first matching entry
The <prefix> is designed to accommodate both matching of the OUI
within an organization-specific TLV (e.g. 0x0080c2 for IEEE 802.1
TLVs) and of a subtype byte as found within many TLVs.
This encoding allows most LLDP values to be extracted easily. For
example
System name: ${netX.lldp/5.0.0.0:string}
System description: ${netX.lldp/6.0.0.0:string}
Port description: ${netX.lldp/4.0.0.0:string}
Port interface name: ${netX.lldp/5.2.0.1.0:string}
Chassis MAC address: ${netX.lldp/4.1.0.1.0:hex}
Management IPv4 address: ${netX.lldp/5.1.8.0.2.4:ipv4}
Port VLAN ID: ${netX.lldp/0x0080c2.1.127.0.4.2:int16}
Port VLAN name: ${netX.lldp/0x0080c2.3.127.0.7.0:string}
Maximum frame size: ${netX.lldp/0x00120f.4.127.0.4.2:uint16}
Originally-implemented-by: Marin Hannache <git@mareo.fr>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown