From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: RHEL Ninjas <example@example.com>
Date: Fri, 25 Sep 2015 16:24:23 +0900
Subject: [PATCH] efinet: add filter for the first exclusive reopen of SNP

---
 grub-core/net/drivers/efi/efinet.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/grub-core/net/drivers/efi/efinet.c b/grub-core/net/drivers/efi/efinet.c
index c3a128cd1dc..d8099a59855 100644
--- a/grub-core/net/drivers/efi/efinet.c
+++ b/grub-core/net/drivers/efi/efinet.c
@@ -407,6 +407,30 @@ grub_efi_net_config_real (grub_efi_handle_t hnd, char **device,
       if (net->mode->state == GRUB_EFI_NETWORK_STARTED
 	  && efi_call_3 (net->initialize, net, 0, 0) != GRUB_EFI_SUCCESS)
 	continue;
+
+      /* Enable hardware receive filters if driver declares support for it.
+	 We need unicast and broadcast and additionaly all nodes and
+	 solicited multicast for IPv6. Solicited multicast is per-IPv6
+	 address and we currently do not have API to do it so simply
+	 try to enable receive of all multicast packets or evertyhing in
+	 the worst case (i386 PXE driver always enables promiscuous too).
+
+	 This does trust firmware to do what it claims to do.
+       */
+      if (net->mode->receive_filter_mask)
+	{
+	  grub_uint32_t filters = GRUB_EFI_SIMPLE_NETWORK_RECEIVE_UNICAST   |
+				  GRUB_EFI_SIMPLE_NETWORK_RECEIVE_BROADCAST |
+				  GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST;
+
+	  filters &= net->mode->receive_filter_mask;
+	  if (!(filters & GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS_MULTICAST))
+	    filters |= (net->mode->receive_filter_mask &
+			GRUB_EFI_SIMPLE_NETWORK_RECEIVE_PROMISCUOUS);
+
+	  efi_call_6 (net->receive_filters, net, filters, 0, 0, 0, NULL);
+	}
+
       card->efi_net = net;
     }
     return;