[netdevice] Add the concept of an "Ethernet-compatible" MAC address
The iBFT is Ethernet-centric in providing only six bytes for a MAC
address. This is most probably an indirect consequence of a similar
design flaw in the Windows NDIS stack. (The WinOF IPoIB stack
performs all sorts of contortions in order to pretend to the NDIS
layer that it is dealing with six-byte MAC addresses.)
There is no sensible way in which to extend the iBFT without breaking
compatibility with programs that expect to parse it. Add the notion
of an "Ethernet-compatible" MAC address to our link layer abstraction,
so that link layers can provide their own workarounds for this
limitation.
802.11 multicast hashing is the same as standard Ethernet hashing, so
just expose and use eth_mc_hash().
Signed-off-by: Joshua Oreman <oremanj@rwcr.net>
[netdevice] Allow the hardware and link-layer addresses to differ in size
IPoIB has a 20-byte link-layer address, of which only eight bytes
represent anything relating to a "hardware address".
The PXE and EFI SNP APIs expect the permanent address to be the same
size as the link-layer address, so fill in the "permanent address"
field with the initial link layer address (as generated by
register_netdev() based upon the real hardware address).
[netdevice] Make ll_broadcast per-netdevice rather than per-ll_protocol
IPoIB has a link-layer broadcast address that varies according to the
partition key. We currently go through several contortions to pretend
that the link-layer address is a fixed constant; by making the
broadcast address a property of the network device rather than the
link-layer protocol it will be possible to simplify IPoIB's broadcast
handling.
Kill off the static single net device and move to proper dynamic
registration (which we need with the new device model).
Break the (flawed) assumption that all network-layer protocols can use
ARP; such network-layer protocols (i.e. IPv4) must now register as an ARP
protocol using ARP_NET_PROTOCOL() and provide a single method for checking
the existence of a local network-layer address.
Network API now allows for multiple network devices (although the
implementation allows for only one, and does so without compromising on
the efficiency of static allocation).
Link-layer protocols are cleanly separated from the device drivers.
Network-layer protocols are cleanly separated from individual network
devices.
Link-layer and network-layer protocols are cleanly separated from each
other.