Add suppor to loader.efi to load files off hte network. For this we need

to open the device in exclusive mode as, without this, the firmware may
also be reading packets off the interface leading to a race.

Reviewed by:	emaste
Sponsored by:	ABT Systems Ltd
Differential Revision:	https://reviews.freebsd.org/D4132

1 files changed, 27 insertions, 3 deletions

diff --git a/sys/boot/efi/libefi/efinet.c b/sys/boot/efi/libefi/efinet.c
index f1e6143..d9ecdcc 100644
--- a/sys/boot/efi/libefi/efinet.c
+++ b/sys/boot/efi/libefi/efinet.c
@@ -184,11 +184,16 @@ efinet_init(struct iodesc *desc, void *machdep_hint)
 	EFI_HANDLE h;
 	EFI_STATUS status;
 
+	if (nif->nif_driver->netif_ifs[nif->nif_unit].dif_unit < 0) {
+		printf("Invalid network interface %d\n", nif->nif_unit);
+		return;
+	}
+
 	h = nif->nif_driver->netif_ifs[nif->nif_unit].dif_private;
 	status = BS->HandleProtocol(h, &sn_guid, (VOID **)&nif->nif_devdata);
 	if (status != EFI_SUCCESS) {
-		printf("net%d: cannot start interface (status=%ld)\n",
-		    nif->nif_unit, (long)status);
+		printf("net%d: cannot start interface (status=%lu)\n",
+		    nif->nif_unit, EFI_ERROR_CODE(status));
 		return;
 	}
 
@@ -288,11 +293,30 @@ efinet_dev_init()
 	stats = calloc(nifs, sizeof(struct netif_stats));
 
 	for (i = 0; i < nifs; i++) {
+		EFI_SIMPLE_NETWORK *net;
+		EFI_HANDLE h;
+
 		dif = &efinetif.netif_ifs[i];
+		dif->dif_unit = -1;
+
+		h = efi_find_handle(&efinet_dev, i);
+
+		/*
+		 * Open the network device in exclusive mode. Without this
+		 * we will be racing with the UEFI network stack. It will
+		 * pull packets off the network leading to lost packets.
+		 */
+		status = BS->OpenProtocol(h, &sn_guid, (void **)&net,
+		    IH, 0, EFI_OPEN_PROTOCOL_EXCLUSIVE);
+		if (status != EFI_SUCCESS) {
+			printf("Unable to open network interface %d\n", i);
+			continue;
+		}
+
 		dif->dif_unit = i;
 		dif->dif_nsel = 1;
 		dif->dif_stats = &stats[i];
-		dif->dif_private = efi_find_handle(&efinet_dev, i);
+		dif->dif_private = h;
 	}
 
 	return (0);