These files cannot be automatically relicensed by util/relicense.pl
since they either contain unusual but trivial contributions (such as
the addition of __nonnull function attributes), or contain lines
dating back to the initial git revision (and so require manual
knowledge of the code's origin).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE currently advertises a fixed MSS of 1460, which is correct only
for IPv4 over Ethernet. For IPv6 over Ethernet, the value should be
1440 (allowing for the larger IPv6 header). For non-Ethernet link
layers, the value should reflect the MTU of the underlying network
device.
Use tcpip_mtu() to calculate the transport-layer MTU associated with
the peer address, and calculate the MSS to allow for an optionless TCP
header as per RFC 6691.
As a side benefit, we can now fail a connection immediately with a
meaningful error message if we have no route to the destination
address.
Reported-by: Anton D. Kachalov <mouse@yandex-team.ru>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The path MTU is currently hardcoded to 1460 bytes, which fails to
allow space for TCP options. Sending a maximum-sized datagram (which
is viable when using HTTP POST) will therefore fail since the Ethernet
MTU will be exceeded.
Reduce the hardcoded path MTU to produce a maximum datagram of 1280
bytes, which is the size required of data link layers by IPv6. It is
a reasonable assumption that all intermediary data link layers will be
able to convey this packet without fragmentation, even for IPv4.
Note that this reduction has a minimal impact upon download
throughput, since it affects only the transmit data path.
Originally-fixed-by: Suresh Sundriyal <ssundriy@vmware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
A window size of 256kB should be sufficient to allow for
full-bandwidth transfers over a Gigabit LAN, and for acceptable
transfer speeds over other typical links.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The maximum unscaled TCP window (64kB) implies a maximum bandwidth of
around 300kB/s on a WAN link with an RTT of 200ms. Add support for
the TCP window scaling option to remove this upper limit.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
TCP currently neglects to allow sufficient space for its own headers
when allocating I/O buffers. This problem is masked by the fact that
the maximum link-layer header size (802.11) is substantially larger
than the common Ethernet link-layer header.
Fix by allowing sufficient space for any TCP headers, as well as the
network-layer and link-layer headers.
Reported-by: Scott K Logan <logans@cottsay.net>
Debugged-by: Scott K Logan <logans@cottsay.net>
Tested-by: Scott K Logan <logans@cottsay.net>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Declarations without the accompanying __table_entry cause misalignment
of the table entries when using gcc 4.5. Fix by adding the
appropriate __table_entry macro or (where possible) by removing
unnecessary forward declarations.
Signed-off-by: Piotr Jaroszyński <p.jaroszynski@gmail.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Maintain a queue of received packets, so that lost packets need not
result in retransmission of the entire TCP window.
Increase the TCP window to 8kB, in order that we can potentially
transmit enough duplicate ACKs to trigger Fast Retransmission at the
sender.
Using a 10MB HTTP download in qemu-kvm with an artificial drop rate of
1 in 64 packets, this reduces the download time from around 26s to
around 4s.
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>
Michael Brown
Piotr Jaroszyński