From e0043c18d6c5280d8dbc999700454fafee04baec Mon Sep 17 00:00:00 2001
From: Alaa Hleihel <ahleihel@redhat.com>
Date: Mon, 1 Jun 2020 15:40:45 -0400
Subject: [PATCH 292/312] [netdrv] net/mlx5e: IPoIB, Drop multicast packets
 that this interface sent

Message-id: <20200601154102.25980-23-ahleihel@redhat.com>
Patchwork-id: 315726
Patchwork-instance: patchwork
O-Subject: [RHEL8.3 BZ 1842258 22/39] net/mlx5e: IPoIB, Drop multicast packets that this interface sent
Bugzilla: 1842258
RH-Acked-by: Honggang Li <honli@redhat.com>
RH-Acked-by: Kamal Heib <kheib@redhat.com>
RH-Acked-by: Marcelo Leitner <mleitner@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>

Bugzilla: http://bugzilla.redhat.com/1842258
Upstream: git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git , branch: master

commit 8b46d424a743ddfef8056d5167f13ee7ebd1dcad
Author: Erez Shitrit <erezsh@mellanox.com>
Date:   Mon May 4 11:46:25 2020 +0300

    net/mlx5e: IPoIB, Drop multicast packets that this interface sent

    After enabled loopback packets for IPoIB, we need to drop these packets
    that this HCA has replicated and came back to the same interface that
    sent them.

    Fixes: 4c6c615e3f30 ("net/mlx5e: IPoIB, Add PKEY child interface nic profile")
    Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
    Reviewed-by: Alex Vesker <valex@mellanox.com>
    Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Signed-off-by: Alaa Hleihel <ahleihel@redhat.com>
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 7aad59376ff4..aee120af6e1f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -1496,6 +1496,7 @@ int mlx5e_poll_rx_cq(struct mlx5e_cq *cq, int budget)
 
 #ifdef CONFIG_MLX5_CORE_IPOIB
 
+#define MLX5_IB_GRH_SGID_OFFSET 8
 #define MLX5_IB_GRH_DGID_OFFSET 24
 #define MLX5_GID_SIZE           16
 
@@ -1509,6 +1510,7 @@ static inline void mlx5i_complete_rx_cqe(struct mlx5e_rq *rq,
 	struct net_device *netdev;
 	struct mlx5e_priv *priv;
 	char *pseudo_header;
+	u32 flags_rqpn;
 	u32 qpn;
 	u8 *dgid;
 	u8 g;
@@ -1530,7 +1532,8 @@ static inline void mlx5i_complete_rx_cqe(struct mlx5e_rq *rq,
 	tstamp = &priv->tstamp;
 	stats = &priv->channel_stats[rq->ix].rq;
 
-	g = (be32_to_cpu(cqe->flags_rqpn) >> 28) & 3;
+	flags_rqpn = be32_to_cpu(cqe->flags_rqpn);
+	g = (flags_rqpn >> 28) & 3;
 	dgid = skb->data + MLX5_IB_GRH_DGID_OFFSET;
 	if ((!g) || dgid[0] != 0xff)
 		skb->pkt_type = PACKET_HOST;
@@ -1539,9 +1542,15 @@ static inline void mlx5i_complete_rx_cqe(struct mlx5e_rq *rq,
 	else
 		skb->pkt_type = PACKET_MULTICAST;
 
-	/* TODO: IB/ipoib: Allow mcast packets from other VFs
-	 * 68996a6e760e5c74654723eeb57bf65628ae87f4
+	/* Drop packets that this interface sent, ie multicast packets
+	 * that the HCA has replicated.
 	 */
+	if (g && (qpn == (flags_rqpn & 0xffffff)) &&
+	    (memcmp(netdev->dev_addr + 4, skb->data + MLX5_IB_GRH_SGID_OFFSET,
+		    MLX5_GID_SIZE) == 0)) {
+		skb->dev = NULL;
+		return;
+	}
 
 	skb_pull(skb, MLX5_IB_GRH_BYTES);
 
-- 
2.13.6