For IPoIB, the chaddr field is too small (16 bytes) to contain the
20-byte IPoIB link-layer address.  RFC4390 mandates that we should
pass an empty chaddr field and rely on the DHCP client identifier
instead.  This has many problems, not least of which is that a client
identifier containing an IPoIB link-layer address is not very useful
from the point of view of creating DHCP reservations, since the QPN
component is assigned at runtime and may vary between boots.

Leave the DHCP client identifier as-is, to avoid breaking existing
setups as far as possible, but expose the real hardware address (the
port GUID) via the DHCP chaddr field, using the broadcast flag to
instruct the DHCP server not to use this chaddr value as a link-layer
address.

This makes it possible (at least with ISC dhcpd) to create DHCP
reservations using host declarations such as:

    host duckling {
        fixed-address 10.252.252.99;
        hardware unknown-32 00:02:c9:02:00:25:a1:b5;
    }

IPoIB has a 20-byte link-layer address, of which only eight bytes
represent anything relating to a "hardware address".

The PXE and EFI SNP APIs expect the permanent address to be the same
size as the link-layer address, so fill in the "permanent address"
field with the initial link layer address (as generated by
register_netdev() based upon the real hardware address).

The hardware address is an intrinsic property of the hardware, while
the link-layer address can be changed at runtime.  This separation is
exposed via APIs such as PXE and EFI, but is currently elided by gPXE.

Expose the hardware and link-layer addresses as separate properties
within a net device.  Drivers should now fill in hw_addr, which will
be used to initialise ll_addr at the time of calling
register_netdev().

The option ROM header contains a one-byte field indicating the number
of 512-byte sectors in the ROM image.  Currently it is linked to
contain the number of uncompressed sectors, with an instruction to the
compressor to correct it.  This causes link failure when the
uncompressed size of the ROM image is over 128k.

Fix by replacing the SUBx compressor fixup with an ADDx fixup that
adds the total compressed output length, scaled as requested, to an
addend stored in the field where the final length value will be
placed.  This is similar to the behavior of ELF relocations, and
ensures that an overflow error will not be generated unless the
compressed size is still too large for the field.

This also allows us to do away with the _filesz_pgh and _filesz_sect
calculations exported by the linker script.

Output tested bitwise identical to the old SUBx mechanism on hd, dsk,
lkrn, and rom prefixes, on both 32-bit and 64-bit processors.

Modified-by: Michael Brown <mcb30@etherboot.org>
Signed-off-by: Michael Brown <mcb30@etherboot.org>

The SRP Boot Firmware Table serves a similar role to the iSCSI and AoE
Boot Firmware Tables; it provides information required by the loaded
OS in order to establish a connection back to the SRP boot device.

There is diagnostic value in being able to disambiguate between the
various reasons why an IB CM has rejected a connection attempt.  In
particular, reason 8 "invalid service ID" can be used to identify an
incorrect SRP service_id root-path component, and reason 28 "consumer
reject" corresponds to a genuine SRP login rejection IU, which can be
passed up to the SRP layer.

For rejection reasons other than "consumer reject", we should not pass
through the private data, since it is most likely generated by the CM
without any protocol-specific knowledge.

With iSCSI, connection attempts are expensive; it may take many
seconds to determine that a connection will fail.  SRP connection
attempts are much less expensive, so we may as well avoid the
"optimisation" of declaring a state of permanent failure after a
certain number of attempts.  This allows a gPXE SRP initiator to
resume operations after an arbitrary amount of SRP target downtime.

Generate errors within individual MAD transaction consumers such as
ib_pathrec.c and ib_mcast.c, rather than within ib_mi.c.  This allows
for more meaningful error messages to eventually be displayed to the
user.

SRP is the SCSI RDMA Protocol.  It allows for a method of SAN booting
whereby the target is responsible for reading and writing data using
Remote DMA directly to the initiator's memory.  The software initiator
merely sends and receives SCSI commands; it never has to touch the
actual data.

The minimal-surprise behaviour, when no explicit SRP initiator device
is specified, will probably be to use the most recently opened
Infiniband device.  This matches our behaviour with using the most
recently opened net device for PXE, iSCSI, AoE, NBI, etc.

SRP over Infiniband uses a protocol whereby data is sent via a
combination of the CM private data fields and the RC queue pair
itself.  This seems sufficiently generic that it's worth having
available as a separate protocol.

The ACK timeout determines how long we take to notice a failed
Reliable Connection.  Reducing it from the arbitrary value of 19 down
to 14 reduces the individual ACK timeout from around 2.1s to 67ms;
this in turn reduces the time to tear down and re-establish a broken
SRP session from around 30s to around 1s.

The Infiniband Communication Manager will refuse to establish a
connection if it believes the connection is already established.
There is no immediately obvious way to ask it to tear down the
existing connection and replace it; to issue a DREP we would need to
know the local and remote communication IDs used for the previous
connection setup.

We can work around this by randomising the high-order bits of the
queue pair number; these have no significance to the hardware, but are
sufficient to convince the IB CM that this is a different connection.

Nothing within the SCSI core actually refers to the LUN, so we can
simplify matters by treating it as purely a property of the backend.

We will terminate our transaction as soon as we receive the first CM
REP, since that provides all the state that we need.  However, the
peer may resend the REP if it didn't see our RTU, and if we don't
respond with another RTU we risk being disconnected.  (This protocol
appears not to handle retries gracefully.)

Fix by adding a management agent that will listen for these duplicate
REPs and send back an RTU.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

Signed-off-by: Michael Brown <mcb30@etherboot.org>

When a probe found no results, the list head of beacons would not be
freed, leaking 16 bytes of memory per probe.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

Previously the maximum packet length was computed using an erroneous
understanding of the role of the MIC field in TKIP-encrypted packets.
The field is actually considered to be part of the MSDU (encrypted and
fragmented data), not the MPDU (container for each encrypted
fragment). As such its size does not contribute to cryptographic
overhead outside the data field's size limitations. The net result is
that the previous maximum packet length value was 4 bytes too long;
fix it to the correct value of 2352.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

Some cards (such as ath5k) always need to tune to a particular channel
when they are reset; the reset may happen upon open(), which is before
the channels array would be set up (in prepare_probe()). Avoid tuning
the card to an inconsistent state by copying the hardware
supported-channels array to the 802.11 device's allowable-channels
array even before channels are "properly" set up.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

The prior net80211 model of physical-layer behavior for drivers was
overly simplistic and limited the drivers that could be written.  To
be more flexible, split the driver-provided list of supported rates by
band, and add a means for specifying a list of supported channels.
Allow drivers to specify a hardware channel value that will be tied to
uses of the channel.

Expose net80211_duration() to drivers, and make the rate it uses in
its computations configurable, so that it can be used in calculating
durations that must be set in hardware for ACK and CTS packets. Add
net80211_cts_duration() for the common case of calculating the
duration for a CTS packet.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

If isolinux.bin is not installed in the expected location the error
message shown is slightly misleading.

Signed-off-by: Vibi Sreenivasan <vibi_sreenivasan@cms.com>
Signed-off-by: Michael Brown <mcb30@etherboot.org>

A management interface is the component through which both local and
remote management agents are accessed.

This new implementation of a management interface allows for the user
to react to timed-out transactions, and also allows for cancellation
of in-progress transactions.

Some BIOSes support the BIOS Boot Specification (BBS) but fail to set
%es:%di correctly when calling the option ROM initialisation entry
point.  This causes gPXE to identify the BIOS as non-PnP (and so
non-BBS), leaving the user unable to control the boot order.

Fix by scanning for the $PnP signature ourselves, rather than relying
on the BIOS having passed in %es:%di correctly.

Tested-by: Helmut Adrigan <helmut.adrigan@chello.at>

Originally-fixed-by: Itay Gazit <itaygazit@gmail.com>

The IBA specification refers to management "interfaces" and "agents".
The interface is the component that connects to the queue pair and
sends and receives MADs; the agent is the component that constructs
the reply to the MAD.

Rename the IB_{QPN,QKEY,QPT} constants as a first step towards making
this separation in gPXE.

The function __intel_new_proc_init() (called implicitly when building
using icc) is marked with __attribute__((cdecl)).  This breaks
building on x86_64, where cdecl is meaningless.

Fix by replacing with the existing __libgcc macro, which is already
defined to be "__attribute__((cdecl))" for i386 builds and empty for
x86_64 builds.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

Signed-off-by: Michael Brown <mcb30@etherboot.org>

The MIT and ISC licenses are legally equivalent to the bsd2 license,
but with slightly different verbiage.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Michael Brown <mcb30@etherboot.org>

pxe_api.h is just a description of API functions, it's actively
undesirable to have more implementations than necessary.  Allowing it
under the MIT license lets the Syslinux libraries use it.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Michael Brown <mcb30@etherboot.org>

The commands bring in UNDI and thus real-mode code, so they cannot be
used on EFI.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

Tested-by: Joshua Oreman <oremanj@xenon.get-linux.org>

In several places, we currently use size_t to represent a difference
between TCP sequence numbers.  This can cause compiler warnings
relating to printf format specifiers, since the result of
(uint32_t+size_t) may be an unsigned long on some compilers.

Fix by using uint32_t for all variables that represent a difference
between TCP sequence numbers.

Tested-by: Joshua Oreman <oremanj@xenon.get-linux.org>

The geniso, genliso and gensdsk scripts contain hard-coded temporary
directory names, and so could potentially collide with each other when
run as part of a concurrent build (e.g. "make -j 4").

Fix by using mktemp to generate suitable temporary directory names.

We add a syslinux floppy disk type using parts of the genliso script.
This floppy image cat be dd'ed to a physical floppy or used in
instances where a virtual floppy with an mountable DOS filesystem is
useful.

We also modify the genliso script to only generate .liso images
rather than creating images depending on how it is called.

Signed-off-by: Michael Brown <mcb30@etherboot.org>

This is required for all modern 802.11 devices, and allows drivers
to be written for them with minimally more effort than is required
for a wired NIC.

Signed-off-by: Michael Brown <mcb30@etherboot.org>
Modified-by: Michael Brown <mcb30@etherboot.org>

The Linux IB Communication Manager will always send MADs to QP1,
rather than back to the originating QP.  On Hermon, QP1 is by default
handled by the embedded firmware.  We can change this, but the cost is
that we have to handle both QP0 and QP1 (i.e. we have to provide SMA
as well as GMA service in software), and we have to use MLX queues
rather than standard UD queues (i.e. we have to construct the UD
datagrams by hand).

There doesn't seem to be any viable way around this situation, ugly
though it is.