In function efi_http_service_binding_destroy_child() phandler is created as
as a local variable. If efi_search_protocol() fails, phandler will hold a
random value from the stack. Even it is not zero, we must not use it.

If efi_search_protocol() succeeds, the pointer has already be dereferenced,
so checking against NULL makes not sense here.

If ChildHandle is not a valid UEFI handle, we must return
EFI_INVALID_PARAMETER.

Use a single location for EFI_EXIT().

Addresses-Coverity-ID: CID 531974 (Unchecked return value)
Fixes: 5753dc3f6572 ("efi_loader: Prevent dereference of uninitialised variable")
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

If phandler is returned as NULL from efi_search_protocol then
protocol_interface is never assigned to. Instead return
EFI_UNSUPPORTED as per the spec.

This issue found by Smatch.

Also eliminate the use of the variable protocol_interface as it is not
needed.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Add support for multiple efi_net_obj structs in efi_net.c. This comes
in preparation for an EFI network driver supporting multiple network
interfaces. For now the EFI network stack still registers a single ethernet
udevice as an EFI network device even if multiple are present, namely
the one that was the current device at the moment of EFI initialization.

Signed-off-by: Adriano Cordova <adriano.cordova@canonical.com>

In preparation to support mutiple efi net udevices. Add a device path
cache to support device paths from multiple ethernet udevices.
The device paths can be added to the cache before EFI gets initialized and
the protocols get installed.

Signed-off-by: Adriano Cordova <adriano.cordova@canonical.com>

The log category should be LOGC_EFI all over the EFI sub-system.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Add an EFI HTTP driver. This commit implements the
EFI_HTTP_PROTOCOL and the EFI_HTTP_SERVICE_BINDING_PROTOCOL.
The latter is attached to the handle of th efi network
device. This is the same handle where snp, pxe, and ipconfig
are attached to.

Signed-off-by: Adriano Cordova <adrianox@gmail.com>