Commit e727f57 ("[efi] Include a copy of the device path within struct
efi_device") neglected to delete the closure of the parent's device
path from the success code path in efi_snp_probe().
Reduce confusion by removing this (harmless) additional close.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow network upper-layer drivers (such as LLDP, which attaches to
each network device in order to provide a corresponding LLDP settings
block) to specify a size for private data, which will be allocated as
part of the network device structure (as with the existing private
data allocated for the underlying device driver).
This will allow network upper-layer drivers to be simplified by
omitting memory allocation and freeing code. If the upper-layer
driver requires a reference counter (e.g. for interface
initialisation), then it may use the network device's existing
reference counter, since this is now the reference counter for the
containing block of memory.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The network device index currently serves two purposes: acting as a
sequential index for network device names ("net0", "net1", etc), and
acting as an opaque unique integer identifier used in socket address
scope IDs.
There is no particular need for these usages to be linked, and it can
lead to situations in which devices are named unexpectedly. For
example: if a system has two network devices "net0" and "net1", a VLAN
is created as "net1-42", and then a USB NIC is connected, then the USB
NIC will be named "net3" rather than the expected "net2" since the
VLAN device "net1-42" will have consumed an index.
Separate the usages: rename the "index" field to "scope_id" (matching
its one and only use case), and assign the name without reference to
the scope ID by finding the first unused name. For consistency,
assign the scope ID by similarly finding the first unused scope ID.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
UEFI implements VLAN support within the Managed Network Protocol (MNP)
driver, which may create child VLAN devices automatically based on
stored UEFI variables. These child devices do not themselves provide
a raw-packet interface via EFI_SIMPLE_NETWORK_PROTOCOL, and may be
consumed only via the EFI_MANAGED_NETWORK_PROTOCOL interface.
The device paths constructed for these child devices may conflict with
those for the EFI_SIMPLE_NETWORK_PROTOCOL instances that iPXE attempts
to install for its own VLAN devices. The upshot is that creating an
iPXE VLAN device (e.g. via the "vcreate" command) will fail if the
UEFI Managed Network Protocol has already created a device for the
same VLAN tag.
Fix by providing our own EFI_VLAN_CONFIG_PROTOCOL instance on the same
device handle as EFI_SIMPLE_NETWORK_PROTOCOL. This causes the MNP
driver to treat iPXE's device as supporting hardware VLAN offload, and
it will therefore not attempt to install its own instance of the
protocol.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE seems to be almost alone in the UEFI world in attempting to shut
down cleanly, free resources, and leave hardware in a well-defined
reset state before handing over to the booted operating system.
The UEFI driver model does allow for graceful shutdown via
uninstallation of protocol interfaces. However, virtually no other
UEFI drivers do this, and the external code paths that react to
uninstallation are consequently poorly tested. This leads to a
proliferation of bugs found in UEFI implementations in the wild, as
described in commits such as 1295b4a ("[efi] Allow initialisation via
SNP interface even while claimed") or b6e2ea0 ("[efi] Veto the HP
XhciDxe Driver").
Try to avoid triggering such bugs by unconditionally skipping the
protocol interface uninstallation during UEFI boot services shutdown,
leaving the interfaces present but nullified and deliberately leaking
the containing memory.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE will currently fail all SNP interface methods with EFI_NOT_READY
while the network devices are claimed for use by iPXE's own network
stack.
As of commit c70b3e0 ("[efi] Always enable recursion when calling
ConnectController()"), this exposes latent UEFI firmware bugs on some
systems at the point of calling ExitBootServices().
With recursion enabled, the MnpDxe driver will immediately attempt to
consume the SNP protocol instance provided by iPXE. Since the network
devices are claimed by iPXE at this point, the calls by MnpDxe to
Start() and Initialize() will both fail with EFI_NOT_READY.
This unfortunately triggers a broken error-handling code path in the
Ip6Dxe driver. Specifically: Ip6DriverBindingStart() will call
Ip6CreateService(), which will call Ip6ServiceConfigMnp(), which will
return an error. The subsequent error handling code path in
Ip6CreateService() simply calls Ip6CleanService(). The code in
Ip6CleanService() will attempt to leave the all-nodes multicast group,
which will fail since the group was never joined. This will result in
Ip6CleanService() returning an error and omitting most of the required
clean-up operations. In particular, the MNP protocol instance will
remain opened with BY_DRIVER attributes even though the Ip6Dxe driver
start method has failed.
When ExitBootServices() is eventually called, iPXE will attempt to
uninstall the SNP protocol instance. This results in the UEFI core
calling Ip6DriverBindingStop(), which will fail since there is no
EFI_IP6_SERVICE_BINDING_PROTOCOL instance installed on the handle.
A failure during a call to UninstallMultipleProtocolInterfaces() will
result in the UEFI core attempting to reinstall any successfully
uninstalled protocols. This is an intrinsically unsafe operation, and
represents a fundamental design flaw in UEFI. Failure code paths
cannot be required to themselves handle failures, since there is no
well-defined correct outcome of such a situation.
With a current build of OVMF, this results in some unexpected debug
messages occurring at the time that the loaded operating system calls
ExitBootServices(). With the UEFI firmware in Hyper-V, the result is
an immediate reboot.
Work around these UEFI design and implementation flaws by allowing the
calls to our EFI_SIMPLE_NETWORK_PROTOCOL instance's Start() and
Initialize() methods to return success even when the network devices
are claimed for exclusive use by iPXE. This is sufficient to allow
MnpDxe to believe that it has successfully initialised the device, and
thereby avoids the problematic failure code paths in Ip6Dxe.
Debugged-by: Aaron Heusser <aaron_heusser@hotmail.com>
Debugged-by: Pico Mitchell <pico@randomapplications.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE will currently drop to TPL_APPLICATION whenever the current
system time is obtained via currticks(), since the system time
mechanism relies on a timer that can fire only when the TPL is below
TPL_CALLBACK.
This can cause unexpected behaviour if the system time is obtained in
the middle of an API call into iPXE by external code. For example,
MnpDxe sets up a 10ms periodic timer running at TPL_CALLBACK to poll
the underling EFI_SIMPLE_NETWORK_PROTOCOL device for received packets.
If the resulting poll within iPXE happens to hit a code path that
requires obtaining the current system time (e.g. due to reception of
an STP packet, which affects iPXE's blocked link timer), then iPXE
will end up temporarily dropping to TPL_APPLICATION. This can
potentially result in retriggering the MnpDxe periodic timer, causing
code to be unexpectedly re-entered.
Fix by recording the external TPL at any entry point into iPXE and
dropping only as far as this external TPL, rather than dropping
unconditionally to TPL_APPLICATION.
The side effect of this change is that iPXE's view of the current
system time will be frozen for the duration of any API calls made into
iPXE by external code at TPL_CALLBACK or above. Since any such
external code is already responsible for allowing execution at
TPL_APPLICATION to occur, then this should not cause a problem in
practice.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The UEFI specification allows uninstallation of a protocol interface
to fail. There is no sensible way for code to react to this, since
uninstallation is likely to be taking place on a code path that cannot
itself fail (e.g. a code path that is itself a failure path).
Where the protocol structure exists within a dynamically allocated
block of memory, this leads to possible use-after-free bugs. Work
around this unfortunate design choice by nullifying the protocol
(i.e. overwriting the method pointers with no-ops) and leaking the
memory containing the protocol structure.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Provide efi_netdev_path() as a standalone function, to allow for reuse
when constructing child device paths.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Current (simplified):
1. InstallMultipleProtocolInterfaces
if err goto err_install_protocol_interface;
2. OpenProtocol(efi_nii_protocol_guid)
if err goto err_open_nii;
3. OpenProtocol(efi_nii31_protocol_guid)
if err goto err_open_nii31;
4. efi_child_add
if err goto err_efi_child_add;
...
err_efi_child_add:
CloseProtocol(efi_nii_protocol_guid) <= should be efi_nii31_protocol_guid
err_open_nii: <= should be err_open_nii31
CloseProtocol(efi_nii31_protocol_guid) <= should be efi_nii_protocol_guid
err_open_nii31: <= should be err_open_nii
UninstallMultipleProtocolInterfaces
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
As noted in the comments, UEFI manages to combines the all of the
worst aspects of both a polling design (inefficiency and inability to
sleep until something interesting happens) and of an interrupt-driven
design (the complexity of code that could be preempted at any time,
thanks to UEFI timers).
This causes problems in particular for UEFI USB keyboards: the
keyboard driver calls UsbAsyncInterruptTransfer() to set up a periodic
timer which is used to poll the USB bus. This poll may interrupt a
critical section within iPXE, typically resulting in list corruption
and either a hang or reboot.
Work around this problem by mirroring the BIOS design, in which we run
with interrupts disabled almost all of the time.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The UEFI specification does not state whether or not a return value of
EFI_BUFFER_TOO_SMALL from the SNP Receive() method should follow the
usual EFI API behaviour of allowing the caller to retry the request
with an increased buffer size.
Examination of the SnpDxe driver in EDK2 suggests that Receive() will
just return the truncated packet (complete with any requested
link-layer header fields), so match this behaviour.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We do not currently check the length of the caller's buffer for
received packets. This creates a potential buffer overrun when iPXE
is being used via the SNP or UNDI protocols.
Fix by checking the buffer length and correctly returning the required
length and an EFI_BUFFER_TOO_SMALL error.
Reported-by: Paul McMillan <paul.mcmillan@oracle.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The SNP device path includes the network device's MAC address within
the MAC_ADDR_DEVICE_PATH.MacAddress field. We check that the
link-layer address will fit within this field, and then perform the
copy using the length of the destination buffer.
At 32 bytes, the MacAddress field is actually larger than the current
maximum iPXE link-layer address. The copy therefore overflows the
source buffer, resulting in trailing garbage bytes being appended to
the device path's MacAddress. This is invisible in debug messages,
since the DevicePathToText protocol will render only the length
implied by the interface type.
Fix by copying only the actual length of the link-layer address (which
we have already verified will not overflow the destination buffer).
Debugged-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
UEFI UNDI is a hideously ugly lump of poorly specified garbage bolted
on as an appendix of the UEFI specification. My personal favourite
line from the UNDI 'specification' is section E.2.2, which states
"Basically, the rule is: Do it right, or don't do it at all". The
author appears to believe that such exhortations are a viable
substitute for documenting what it is that the wretched reader is
supposed to, in fact, do.
(Second favourite is the section listing the pros and cons of various
driver types. This fails to identify a single con for the mythical
"Hardware UNDI", a design so insanely intrinsically slow that it
appears to have been the inspiration for the EFI_USB_IO_PROTOCOL.)
UNDI is functionally isomorphic to the substantially less preposterous
EFI_SIMPLE_NETWORK_PROTOCOL. Provide an UNDI interface (as a thin
wrapper around the existing SNP interface) to allow for use by
third-party software that has made poor life choices.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Our SNP ReceiveFilters() method is a no-op, since we always (if
possible) use promiscuous mode for all network cards. The method
currently returns EFI_NOT_READY if the SNP interfaces are claimed for
use by iPXE, as with all other SNP methods.
The WDS bootstrap wdsmgfw.efi attempts to use both the PXE Base Code
protocol and the Simple Network Protocol simultaneously. This is
fundamentally broken, since use of the PXE Base Code protocol requires
us to disable the use of SNP (by claiming the interfaces for use by
iPXE), otherwise MnpDxe swallows all of the received packets before
our PXE Base Code's UdpRead() method is able to return them.
The root cause of this problem is that, as with BIOS PXE, the network
booting portions of the UEFI specification are less of a specification
and more of an application note sketchily describing how the original
hacked-together Intel implementation works. No sane design would ever
have included the UdpWrite() and UdpRead() methods.
Work around these fundamental conceptual flaws by unconditionally
returning success from efi_snp_receive_filters().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
The raw EFI_HANDLE value is almost never useful to know, and simply
adds noise to the already verbose debug messages. Improve the
legibility of debug messages by using only the name generated by
efi_handle_name().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Allow the return status from an embedded image to propagate out to the
eventual return status from main(). When running under Linux, this
allows the pass/fail result of unit tests to be observable without
having to visually inspect the console output.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
UEFI platforms may provide a watchdog timer, which will reboot the
machine if an operating system takes more than five minutes to load.
This can cause long-lived iPXE downloads (or interactive shell
sessions) to unexpectedly reboot.
Fix by resetting the watchdog timer every ten seconds while the iPXE
main processing loop continues to run.
Reported-by: Bradley B Williams <bradleybwilliams@swbell.net>
Reported-by: John Clark <john.r.clark.3@gmail.com>
Reported-by: wdriever@gmail.com
Reported-by: Charlie Beima <cbeima@indiana.edu>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
iPXE does not currently provide EFI_PXE_BASE_CODE_PROTOCOL: this
causes failures when chainloading bootloaders such as shim.efi which
assume that this protocol will be present.
Provide the ability to work around these problems via the build
configuration option EFI_DOWNGRADE_UX. If this option is enabled,
then we will not install our usual EFI_LOAD_FILE_PROTOCOL
implementation, thereby allowing the platform firmware to install its
own EFI_PXE_BASE_CODE_PROTOCOL implementation on top of our
EFI_SIMPLE_NETWORK_PROTOCOL handle.
A somewhat major side-effect of this workaround is that almost all
iPXE features will be disabled.
This configuration option will be removed in future when support for
EFI_PXE_BASE_CODE_PROTOCOL is added.
Requested-by: Laszlo Ersek <lersek@redhat.com>
Requested-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Fix the TxBuf value filled in by GetStatus() to report the transmit
buffer address as required by the (now clarified) specification.
Simplify "interrupt" handling in GetStatus() to report only that one
or more packets have been transmitted or received; there is no need to
report one GetStatus() "interrupt" per packet.
Simplify receive handling to dequeue received packets immediately from
the network device into an internal list (thereby avoiding the hacks
previously used to determine when to report new packet arrivals).
Originally-fixed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some EFI 1.10 systems (observed on an Apple iMac) do not allow us to
open the device path protocol with an attribute of
EFI_OPEN_PROTOCOL_BY_DRIVER and so we cannot maintain a safe,
long-lived pointer to the device path. Work around this by instead
opening the device path protocol with an attribute of
EFI_OPEN_PROTOCOL_GET_PROTOCOL whenever we need to use it.
Debugged-by: Curtis Larsen <larsen@dixie.edu>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Using efi_devpath_text() is marginally more efficient if we already
have the device path protocol available, but the mild increase in
efficiency is not worth compromising the clarity of the pattern:
DBGC ( device, "THING %p %s ...", device, efi_handle_name ( device ) );
Signed-off-by: Michael Brown <mcb30@ipxe.org>
HII seems to fail on several systems. Since it is non-essential,
treat HII problems as non-fatal.
Debugged-by: Curtis Larsen <larsen@dixie.edu>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
We currently treat network devices as available for use via the SNP
API only if RX queue processing has been frozen. (This is similar in
spirit to the way that RX queue processing is frozen for the network
device currently exposed via the PXE API.)
The default state of a freshly created network device is for the RX
queue to not be frozen, and thus to be unavailable for use via SNP.
This causes problems when devices are added through code paths other
than _efidrv_start() (which explicitly releases devices for use via
SNP).
We don't actually need to freeze RX queue processing, since calls via
the SNP API will always use netdev_poll() rather than net_poll(), and
so will never trigger the RX queue processing code path anyway.
We can therefore simplify the code to use a single global flag to
indicate whether network devices are claimed for use by iPXE or
available for use via SNP. Using a global flag allows the default
state for dynamically created network devices to behave sensibly.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Expose the build timestamp (measured in seconds since the Epoch) and
the build name (e.g. "rtl8139.rom" or "ipxe.efi"), and provide the
product name and product short name in a single centralised location.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Some UEFI builds will set up a timer to continuously poll any SNP
devices. This can drain packets from the network device's receive
queue before iPXE gets a chance to process them.
Use netdev_rx_[un]freeze() to explicitly indicate when we expect our
network devices to be driven via the external SNP API (as we do with
the UNDI API on the standard BIOS build), and disable the SNP API
except when receive queue processing is frozen.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Exploit the redefinition of iPXE error codes to include a "platform
error code" to allow for meaningful conversion of EFI_STATUS values to
iPXE errors and vice versa.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
When iPXE is used as a UEFI driver, the UEFI PXE base code currently
provides the TCP/IP stack, network protocols, and user interface.
This represents a substantial downgrade from the standard BIOS iPXE
user experience.
Fix by installing our own EFI_LOAD_FILE_PROTOCOL implementation which
initiates the standard iPXE boot procedure. This upgrades the UEFI
iPXE user experience to match the standard BIOS iPXE user experience.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
eIPoIB requires space to expand a transmitted ARP packet. This
guarantee is met by ensuring that a transmitted packet consists of at
least MAX_LL_HEADER_LEN bytes from the start of the I/O buffer up to
the end of the link-layer header, and at least IOB_ZLEN bytes
thereafter.
Adjust the I/O buffer allocation for SNP transmitted packets to ensure
that this guarantee is met.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown
Ignat Korchagin
Rob Taglang