iPXE has never supported SEEK_END; the usage of "whence" offers only
the options of SEEK_SET and SEEK_CUR and so is effectively a boolean
flag. Further flags will be required to support additional metadata
required by the Fibre Channel network model, so repurpose the "whence"
field as a generic "flags" field.
xfer_seek() has always been used with SEEK_SET, so remove the "whence"
field altogether from its argument list.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Remove data-xfer as an interface type, and replace data-xfer
interfaces with generic interfaces supporting the data-xfer methods.
Filter interfaces (as used by the TLS layer) are handled using the
generic pass-through interface capability. A side-effect of this is
that deliver_raw() no longer exists as a data-xfer method. (In
practice this doesn't lose any efficiency, since there are no
instances within the current codebase where xfer_deliver_raw() is used
to pass data to an interface supporting the deliver_raw() method.)
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Standardise on using timer_init() to initialise an embedded retry
timer, to match the coding style used by other embedded objects.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Standardise on using ref_init() to initialise an embedded reference
count, to match the coding style used by other embedded objects.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Access to the gpxe.org and etherboot.org domains and associated
resources has been revoked by the registrant of the domain. Work
around this problem by renaming project from gPXE to iPXE, and
updating URLs to match.
Also update README, LOG and COPYRIGHTS to remove obsolete information.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add the definition of SLAM_MAX_BLOCKS_PER_NACK, which is roughly
equivalent to a TCP window size; it represents the maximum number of
packets that will be requested in a single NACK.
Note that, to keep the code size down, we still limit ourselves to
requesting only a single range per NACK; if the missing-block list is
discontiguous then we may request fewer than SLAM_MAX_BLOCKS_PER_NACK
blocks.
On any fast network, or with any driver that may drop packets
(e.g. Infiniband, which has very small RX rings), the traditional
usage of the SLAM protocol will result in enormous numbers of packet
drops and a consequent large number of retransmissions.
By adapting the client behaviour, we can force the server to act more
like a multicast TFTP server, with flow control provided by a single
master client.
This behaviour should interoperate with any traditional SLAM client
(e.g. Etherboot 5.4) on the network. The SLAM protocol isn't actually
documented anywhere, so it's hard to define either behaviour as
compliant or otherwise.
In a SLAM NACK packet, if we run out of space to represent the
missing-block list, then indicate all remaining blocks as missing.
This avoids the need to wait for the one-second timeout before
receiving the blocks that otherwise wouldn't have been requested due
to running out of space.
Shorter NACK packets take less time to construct and spew out less
debug output, and there's a limit to how useful it is to send a
complete missing-block list anyway; if the loss rate is high then
we're going to have to retransmit an updated missing-block list
anyway.
Also add pretty debugging output to show the list of requested blocks.
