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authorMichael Contreras <michael@inetric.com>2012-12-02 20:11:22 -0800
committerMichael Roth <mdroth@linux.vnet.ibm.com>2012-12-03 15:02:28 -0600
commite1a0ffb95728304f962ce36b27dcd3a16f04a05d (patch)
treedb9597ca14d9769262ea06685f646068a428847d
parent178ef3a43ad24d074c683e2fe0658e589747c823 (diff)
e1000: Discard packets that are too long if !SBP and !LPE
The e1000_receive function for the e1000 needs to discard packets longer than 1522 bytes if the SBP and LPE flags are disabled. The linux driver assumes this behavior and allocates memory based on this assumption. Signed-off-by: Michael Contreras <michael@inetric.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> (cherry picked from commit b0d9ffcd0251161c7c92f94804dcf599dfa3edeb) Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
-rw-r--r--hw/e1000.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/hw/e1000.c b/hw/e1000.c
index 4d4ac32016..b1d8508880 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -59,6 +59,9 @@ static int debugflags = DBGBIT(TXERR) | DBGBIT(GENERAL);
#define PNPMMIO_SIZE 0x20000
#define MIN_BUF_SIZE 60 /* Min. octets in an ethernet frame sans FCS */
+/* this is the size past which hardware will drop packets when setting LPE=0 */
+#define MAXIMUM_ETHERNET_VLAN_SIZE 1522
+
/*
* HW models:
* E1000_DEV_ID_82540EM works with Windows and Linux
@@ -795,6 +798,13 @@ e1000_receive(NetClientState *nc, const uint8_t *buf, size_t size)
size = sizeof(min_buf);
}
+ /* Discard oversized packets if !LPE and !SBP. */
+ if (size > MAXIMUM_ETHERNET_VLAN_SIZE
+ && !(s->mac_reg[RCTL] & E1000_RCTL_LPE)
+ && !(s->mac_reg[RCTL] & E1000_RCTL_SBP)) {
+ return size;
+ }
+
if (!receive_filter(s, buf, size))
return size;