[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.
[tcpip] Allow for transmission to multicast IPv4 addresses
When sending to a multicast address, it may be necessary to specify
the source address explicitly, since the multicast destination address
does not provide enough information to deduce the source address via
the miniroute table.
Allow the source address specified via the data-xfer metadata to be
passed down through the TCP/IP stack to the IPv4 layer, which can use
it as a default source address.
[netdevice] Split multicast hashing out into an mc_hash method
Multicast hashing is an ugly overlap between network and link layers.
EFI requires us to provide access to this functionality, so move it
out of ipv4.c and expose it as a method of the link layer.
From: Viswanath Krishnamurthy <viswa.krish@gmail.com>
The current ipv4 incorrectly checks the IP address for multicast address.
This causes valid IPv4 unicast address to be trated as multicast address
For e.g if the PXE/tftp server IP address is 192.168.4.XXX where XXX is
224 or greater, it gets treated as multicast address and a ethernet
multicast address is sent out on the wire causing timeouts
[Settings] Remove assumption that all settings have DHCP tag values
Allow for settings to be described by something other than a DHCP option
tag if desirable. Currently used only for the MAC address setting.
Separate out fake DHCP packet creation code from dhcp.c to fakedhcp.c.
Remove notion of settings from dhcppkt.c.
Rationalise dhcp.c to use settings API only for final registration of the
DHCP options, rather than using {store,fetch}_setting throughout.
Clarified packet ownership transfer between a few functions.
Added a large number of missing calls to free_pkb(). In the case of UDP,
no received packets were ever freed, which lead to memory exhaustion
remarkably quickly once pxelinux started up.
In general, any function with _rx() in its name which accepts a pk_buff
*must* either call free_pkb() or pass the pkb to another _rx() function
(e.g. the next layer up the stack). Since the UDP (and TCP) layers don't
pass packet buffers up to the higher-layer protocols (the
"applications"), they must free the packet buffer after calling the
application's newdata() method.