[PATCH V2 net 01/10] net: hns: bug fix about ping6

[Yisen Zhuang <Yisen.Zhuang@huawei.com>]

From: Kejian Yan <yankejian@huawei.com>

The current upstreaming code fails to ping other IPv6 net device, because
the enet receives the multicast packets with the src mac addr which is the
same as its mac addr. These packets need to be dropped.

Signed-off-by: Kejian Yan <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
---
change log:
 PATCH v2:
 - modifies the wrong charator "whick" to "which" in commit log
 - use the "eth_hdr()" help to get source mac of packets

 PATCH v1:
 - first submit

 Link: https://lkml.org/lkml/2016/3/21/215
---
---
 drivers/net/ethernet/hisilicon/hns/hns_enet.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.c b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
index 3f77ff7..ef84bd7 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
@@ -564,6 +564,7 @@ static int hns_nic_poll_rx_skb(struct hns_nic_ring_data *ring_data,
 	struct sk_buff *skb;
 	struct hnae_desc *desc;
 	struct hnae_desc_cb *desc_cb;
+	struct ethhdr *eh;
 	unsigned char *va;
 	int bnum, length, i;
 	int pull_len;
@@ -670,6 +671,14 @@ out_bnum_err:
 		return -EFAULT;
 	}
 
+	/* filter out multicast pkt with the same src mac as this port */
+	eh = eth_hdr(skb);
+	if (unlikely(is_multicast_ether_addr(eh->h_dest) &&
+		     ether_addr_equal(ndev->dev_addr, eh->h_source))) {
+		dev_kfree_skb_any(skb);
+		return -EFAULT;
+	}
+
 	ring->stats.rx_pkts++;
 	ring->stats.rx_bytes += skb->len;
 
-- 
1.9.1