The assumption in asn1_type() that an ASN.1 cursor will always contain
a type byte is incorrect. A cursor that has been cleanly invalidated
via asn1_invalidate_cursor() will contain a type byte, but there are
other ways in which to arrive at a zero-length cursor.
Fix by explicitly checking the cursor length in asn1_type(). This
allows asn1_invalidate_cursor() to be reduced to simply zeroing the
length field.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some EoIB implementations utilise an EoIB-to-Ethernet gateway device
that does not perform a FullMember join to the multicast group for the
EoIB broadcast domain. This has various exciting side-effects, such
as requiring every EoIB node to send every broadcast packet twice.
As an added bonus, the gateway may also break the EoIB MAC address to
GID mapping protocol by sending Ethernet-sourced packets from the
wrong QPN.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[eoib] Allow the multicast group to be forcefully created
Some EoIB implementations require each individual EoIB node to create
the multicast group for the EoIB broadcast domain.
It is left as an exercise for the interested reader to determine how
such an implementation might ever allow the parameters of such a
multicast group to be changed without requiring a simultaneous upgrade
of every driver on every operating system on every machine currently
attached to the fabric.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
EoIB is a fairly simple protocol in which raw Ethernet frames
(excluding the CRC) are encapsulated within Infiniband Unreliable
Datagrams, with a four-byte fixed EoIB header (which conveys no actual
information). The Ethernet broadcast domain is provided by a
multicast group, similar to the IPoIB IPv4 multicast group.
The mapping from Ethernet MAC addresses to Infiniband address vectors
is achieved by snooping incoming traffic and building a peer cache
which can then be used to map a MAC address into a port GID. The
address vector is completed using a path record lookup, as for IPoIB.
Note that this requires every packet to include a GRH.
Add basic support for EoIB devices. This driver is substantially
derived from the IPoIB driver. There is currently no mechanism for
automatically creating EoIB devices.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipoib] Resimplify test for received broadcast packets
Commit e62e52b ("[ipoib] Simplify test for received broadcast
packets") relies upon the multicast LID being present in the
destination address vector as passed to ipoib_complete_recv().
Unfortunately, this information is not present in many Infiniband
devices' completion queue entries.
Fix by testing instead for the presence of a multicast GID.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Record USB device speed separately from current port speed
Record the speed of a USB device based on the port's speed at the time
that the device was enabled. This allows us to remember the device's
speed even after the device has been disconnected (and so the port's
current speed has changed).
In particular, this allows us to correctly identify the transaction
translator for a low-speed or full-speed device after the device has
been disconnected.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide BIT_QWORD_PTR() to allow for easy extraction of non-endian
fields (e.g. Infiniband GUIDs) without unnecessary byte swapping.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[smsc95xx] Add driver for SMSC/Microchip LAN95xx USB Ethernet NICs
Tested using QEMU and usbredir to expose the LAN9512 chip present on a
Raspberry Pi.
There is a known issue with the LAN9512: an extra two bytes are
appended to every transmitted packet. These two bytes comprise:
{ 0x00, 0x08 } if packet length == 0 (mod 8)
{ CRC[0], 0x00 } if packet length == 7 (mod 8)
{ CRC[0], CRC[1] } otherwise
The extra bytes are appended whether the Ethernet CRC is generated
manually or added automatically by the hardware. The issue occurs
with the Linux kernel driver as well as the iPXE driver. It appears
to be an undocumented hardware errata.
TCP/IP traffic is not affected, since the IP header length field
causes the extraneous bytes to be discarded by the receiver. However,
protocols that rely on the length of the Ethernet frame (such as FCoE
or iPXE's "lotest" protocol) will be unusable on this hardware.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Expose unused USB devices via EFI_USB_IO_PROTOCOL
Allow the UEFI platform firmware to provide drivers for unrecognised
devices, by exposing our own implementation of EFI_USB_IO_PROTOCOL.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Make the class ID a property of the USB driver (rather than a property
of the USB device ID), and allow USB drivers to specify a wildcard ID
for any of the three component IDs (class, subclass, or protocol).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[usb] Select preferred USB device configuration based on driver score
Generate a score for each possible USB device configuration based on
the available driver support, and select the configuration with the
highest score. This will allow us to prefer ECM over RNDIS (for
devices which support both) and will allow us to meaningfully select a
configuration even when we have drivers available for all functions
(e.g. when exposing unused functions via EFI_USB_IO_PROTOCOL).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The decision on whether or not a zero-length packet needs to be
transmitted is independent of the host controller and belongs in the
USB core.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[tcpip] Avoid generating positive zero for transmitted UDP checksums
TCP/IP checksum fields are one's complement values and therefore have
two possible representations of zero: positive zero (0x0000) and
negative zero (0xffff).
In RFC768, UDP over IPv4 exploits this redundancy to repurpose the
positive representation of zero (0x0000) to mean "no checksum
calculated"; checksums are optional for UDP over IPv4.
In RFC2460, checksums are made mandatory for UDP over IPv4. The
wording of the RFC is such that the UDP header is mandated to use only
the negative representation of zero (0xffff), rather than simply
requiring the checksum to be correct but allowing for either
representation of zero to be used.
In RFC1071, an example algorithm is given for calculating the TCP/IP
checksum. This algorithm happens to produce only the positive
representation of zero (0x0000); this is an artifact of the way that
unsigned arithmetic is used to calculate a signed one's complement
sum (and its final negation).
A common misconception has developed (exemplified in RFC1624) that
this artifact is part of the specification. Many people have assumed
that the checksum field should never contain the negative
representation of zero (0xffff).
A sensible receiver will calculate the checksum over the whole packet
and verify that the result is zero (in whichever representation of
zero happens to be generated by the receiver's algorithm). Such a
receiver will not care which representation of zero happens to be used
in the checksum field.
However, there are receivers in existence which will verify the
received checksum the hard way: by calculating the checksum over the
remainder of the packet and comparing the result against the checksum
field. If the representation of zero used by the receiver's algorithm
does not match the representation of zero used by the transmitter (and
so placed in the checksum field), and if the receiver does not
explicitly allow for both representations to compare as equal, then
the receiver may reject packets with a valid checksum.
For UDP, the combined RFCs effectively mandate that we should generate
only the negative representation of zero in the checksum field.
For IP, TCP and ICMP, the RFCs do not mandate which representation of
zero should be used, but the misconceptions which have grown up around
RFC1071 and RFC1624 suggest that it would be least surprising to
generate only the positive representation of zero in the checksum
field.
Fix by ensuring that all of our checksum algorithms generate only the
positive representation of zero, and explicitly inverting this in the
case of transmitted UDP packets.
Reported-by: Wissam Shoukair <wissams@mellanox.com>
Tested-by: Wissam Shoukair <wissams@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[efi] Add a USB host controller driver based on EFI_USB_IO_PROTOCOL
Allow iPXE to coexist with other USB device drivers, by attaching to
the EFI_USB_IO_PROTOCOL instances provided by the UEFI platform
firmware.
The EFI_USB_IO_PROTOCOL is an unsurprisingly badly designed
abstraction of a USB device. The poor design choices intrinsic in the
UEFI specification prevent efficient operation as a network device,
with the result that devices operated using the EFI_USB_IO_PROTOCOL
operate approximately two orders of magnitude slower than devices
operated using our native EHCI or xHCI host controller drivers.
Since the performance is so abysmally slow, and since the underlying
problems are due to fundamental architectural mistakes in the UEFI
specification, support for the EFI_USB_IO_PROTOCOL host controller
driver is left as disabled by default. Users are advised to use the
native iPXE host controller drivers instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Many UEFI NBPs expect to find an EFI_PXE_BASE_CODE_PROTOCOL installed
in addition to the EFI_SIMPLE_NETWORK_PROTOCOL. Most NBPs use the
EFI_PXE_BASE_CODE_PROTOCOL only to retrieve the cached DHCP packets.
This implementation has been tested with grub.efi, shim.efi,
syslinux.efi, and wdsmgfw.efi. Some methods (such as Discover() and
Arp()) are not used by any known NBP and so have not (yet) been
implemented.
Usage notes for the tested bootstraps are:
- grub.efi uses EFI_PXE_BASE_CODE_PROTOCOL only to retrieve the
cached DHCP packet, and uses no other methods.
- shim.efi uses EFI_PXE_BASE_CODE_PROTOCOL to retrieve the cached
DHCP packet and to retrieve the next NBP via the Mtftp() method.
If shim.efi was downloaded via HTTP (or other non-TFTP protocol)
then shim.efi will blindly call Mtftp() with an HTTP URI as the
filename: this allows the next NBP (e.g. grubx64.efi) to also be
transparently retrieved by HTTP.
shim.efi can also use the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL to
retrieve files previously loaded by "imgfetch" or similar commands
in iPXE. The current implementation of shim.efi will use the
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL only if it does not find an
EFI_PXE_BASE_CODE_PROTOCOL; this patch therefore prevents this
usage of our EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. This logic could be
trivially reversed in shim.efi if needed.
- syslinux.efi uses EFI_PXE_BASE_CODE_PROTOCOL only to retrieve the
cached DHCP packet. Versions 6.03 and earlier have a bug which
may cause syslinux.efi to attach to the wrong NIC if there are
multiple NICs in the system (or if the UEFI firmware supports
IPv6).
- wdsmgfw.efi (ab)uses EFI_PXE_BASE_CODE_PROTOCOL to retrieve the
cached DHCP packets, and to send and retrieve UDP packets via the
UdpWrite() and UdpRead() methods. (This was presumably done in
order to minimise the amount of benefit obtainable by switching to
UEFI, by replicating all of the design mistakes present in the
original PXE specification.)
The EFI_DOWNGRADE_UX configuration option remains available for now,
until this implementation has received more widespread testing.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Merge the functionality of parse_next_server_and_filename() and
tftp_uri() into a single pxe_uri(), which takes a server address
(IPv4/IPv6/none) and a filename, and produces a URI using the rule:
- if the filename is a hierarchical absolute URI (i.e. includes a
scheme such as "http://" or "tftp://") then use that URI and ignore
the server address,
- otherwise, if the server address is recognised (according to
sa_family) then construct a TFTP URI based on the server address,
port, and filename
- otherwise fail.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown