[efi] Add support for driving EFI_MANAGED_NETWORK_PROTOCOL devices

We want exclusive access to the network device, both for performance
reasons and because we perform operations such as EAPoL that affect
the entire link.  We currently drive the network card via either a
native hardware driver or via the SNP or NII/UNDI interfaces, both of
which grant us this exclusive access.

Add an alternative driver that drives the network card non-exclusively
via the EFI_MANAGED_NETWORK_PROTOCOL interface.  This can function as
a fallback for situations where neither SNP nor NII/UNDI interfaces
are functional, and also opens up the possibility of non-destructively
installing a temporary network device over which to download the
autoexec.ipxe script.

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

1 files changed, 26 insertions, 0 deletions

diff --git a/src/drivers/net/efi/snponly.c b/src/drivers/net/efi/snponly.c
index 16370463..6786f3e8 100644
--- a/src/drivers/net/efi/snponly.c
+++ b/src/drivers/net/efi/snponly.c
@@ -32,6 +32,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/efi/Protocol/SimpleNetwork.h>
 #include <ipxe/efi/Protocol/NetworkInterfaceIdentifier.h>
 #include "snpnet.h"
+#include "mnpnet.h"
 #include "nii.h"
 
 /** @file
@@ -74,6 +75,11 @@ static struct chained_protocol chained_nii = {
 	.protocol = &efi_nii31_protocol_guid,
 };
 
+/** Chainloaded MNP protocol */
+static struct chained_protocol chained_mnp = {
+	.protocol = &efi_managed_network_service_binding_protocol_guid,
+};
+
 /**
  * Locate chainloaded protocol
  *
@@ -208,6 +214,17 @@ static int niionly_supported ( EFI_HANDLE device ) {
 	return chained_supported ( device, &chained_nii );
 }
 
+/**
+ * Check to see if driver supports a device
+ *
+ * @v device		EFI device handle
+ * @ret rc		Return status code
+ */
+static int mnponly_supported ( EFI_HANDLE device ) {
+
+	return chained_supported ( device, &chained_mnp );
+}
+
 /** EFI SNP chainloading-device-only driver */
 struct efi_driver snponly_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
 	.name = "SNPONLY",
@@ -224,6 +241,14 @@ struct efi_driver niionly_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
 	.stop = nii_stop,
 };
 
+/** EFI MNP chainloading-device-only driver */
+struct efi_driver mnponly_driver __efi_driver ( EFI_DRIVER_NORMAL ) = {
+	.name = "MNPONLY",
+	.supported = mnponly_supported,
+	.start = mnpnet_start,
+	.stop = mnpnet_stop,
+};
+
 /**
  * Initialise EFI chainloaded-device-only driver
  *
@@ -232,6 +257,7 @@ static void chained_init ( void ) {
 
 	chained_locate ( &chained_snp );
 	chained_locate ( &chained_nii );
+	chained_locate ( &chained_mnp );
 }
 
 /** EFI chainloaded-device-only initialisation function */