separate xfer method.

Add missing .alloc_iob entries to several xfer_interface_operations
structures.

xfer_window() function, which can return a scalar rather than a
boolean.

structures.

DHCP still broken and #if 0'd out.

present; DHCP is broken).

Achieved via Perl using:

perl -pi -e 's/pk_buff/io_buffer/g; s/Packet buffer/I\/O buffer/ig; ' \
	-e 's/pkbuff\.h/iobuf.h/g; s/pkb_/iob_/g; s/_pkb/_iob/g; ' \
	-e 's/pkb/iobuf/g; s/PKB/IOB/g;'

connections might break things. Only-sending applications like syslog()
do not need a newdata() handler, so added a check if that handler exists.

it as a fallback network device rather than an explicitly forced network
device.

Clear routing table entries before re-attempting DHCP.

udp_senddata() callback.  This will simplify any UDP protocols that don't
need the temporary buffer.

to set up dummy routing entries.

transmissions.

skb_tailroom().  Add pkb_headroom().

Simplify checksum generation on the TX datapath.

defined in vsprintf.h.  (This may change, since vsprintf.h is a
non-standard name, but for now it's the one to use.)

There should be no need to include vsprintf.h just for DBG() statements,
since include/compiler.h forces it in for a debug build anyway.

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.

udp_connect() now follows the standard BSD sockets semantics and simply
sets the default address for outgoing packets; it doesn't filter incoming
packets.

Updated PXE API dispatcher to use copy_{to,from}_user, and moved to
arch/i386 since the implementation is quite architecture-dependent.
(The individual PXE API calls can be largely
architecture-independent.)

Introduced struct sockaddr_tcpip, to simplify code that deals with
both IPv4 and IPv6 addresses.

Reorganised parts of tcpip.c and udp.c.

the TCP/IP protocol suite (rather than being general transport-layer
functions).

if the application wants to send data then it will have to use the normal
senddata() mechanism.

against value in header.

Temporarily disable RX checksumming; it's broken and is holding up
work on higher-layer protocols
.

a pointer).

Use pkb_available() rather than pkb_len() (which will always return 0
on a freshly allocated buffer).

udp_send() should assume that the buffer has already been allocated.

1. Updated UDP send data code\
2. Corrected internet checksum\
3. Moved udp_buffer() and udp_buflen() to udp.c from udp.h