[PATCH 15/40] e1000x: Take CRC into consideration for size check

[Akihiko Odaki]

Section 13.7.15 Receive Length Error Count says:
>  Packets over 1522 bytes are oversized if LongPacketEnable is 0b
> (RCTL.LPE). If LongPacketEnable (LPE) is 1b, then an incoming packet
> is considered oversized if it exceeds 16384 bytes.

> These lengths are based on bytes in the received packet from
> <Destination Address> through <CRC>, inclusively.

As QEMU processes packets without CRC, the number of bytes for CRC
need to be subtracted.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 hw/net/e1000x_common.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/net/e1000x_common.c b/hw/net/e1000x_common.c
index 6cc23138a8..b4dfc74b66 100644
--- a/hw/net/e1000x_common.c
+++ b/hw/net/e1000x_common.c
@@ -142,10 +142,10 @@ bool e1000x_is_oversized(uint32_t *mac, size_t size)
 {
     /* this is the size past which hardware will
        drop packets when setting LPE=0 */
-    static const int maximum_ethernet_vlan_size = 1522;
+    static const int maximum_ethernet_vlan_size = 1522 - 4;
     /* this is the size past which hardware will
        drop packets when setting LPE=1 */
-    static const int maximum_ethernet_lpe_size = 16 * KiB;
+    static const int maximum_ethernet_lpe_size = 16 * KiB - 4;
 
     if ((size > maximum_ethernet_lpe_size ||
         (size > maximum_ethernet_vlan_size
-- 
2.40.0