From: Gary Leshner <Gary.S.Leshner@intel.com>
Date: Mon, 11 May 2020 12:06:55 -0400
Subject: IB/{hfi1, ipoib, rdma}: Broadcast ping sent packets which exceeded
 mtu size
Patch-mainline: v5.8-rc1
Git-commit: b7e159eb008eb8b0bb83c09990b648bd2c4081df
References: jsc#SLE-13208

When in connected mode ipoib sent broadcast pings which exceeded the mtu
size for broadcast addresses.

Add an mtu attribute to the rdma_netdev structure which ipoib sets to its
mcast mtu size.

The RDMA netdev uses this value to determine if the skb length is too long
for the mtu specified and if it is, drops the packet and logs an error
about the errant packet.

Link: https://lore.kernel.org/r/20200511160655.173205.14546.stgit@awfm-01.aw.intel.com
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Gary Leshner <Gary.S.Leshner@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/ulp/ipoib/ipoib_main.c      |    2 ++
 drivers/infiniband/ulp/ipoib/ipoib_multicast.c |    1 +
 drivers/infiniband/ulp/ipoib/ipoib_vlan.c      |    3 +++
 3 files changed, 6 insertions(+)

--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1902,6 +1902,7 @@ static int ipoib_ndo_init(struct net_dev
 {
 	struct ipoib_dev_priv *priv = ipoib_priv(ndev);
 	int rc;
+	struct rdma_netdev *rn = netdev_priv(ndev);
 
 	if (priv->parent) {
 		ipoib_child_init(ndev);
@@ -1914,6 +1915,7 @@ static int ipoib_ndo_init(struct net_dev
 	/* MTU will be reset when mcast join happens */
 	ndev->mtu = IPOIB_UD_MTU(priv->max_ib_mtu);
 	priv->mcast_mtu = priv->admin_mtu = ndev->mtu;
+	rn->mtu = priv->mcast_mtu;
 	ndev->max_mtu = IPOIB_CM_MTU;
 
 	ndev->neigh_priv_len = sizeof(struct ipoib_neigh);
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -246,6 +246,7 @@ static int ipoib_mcast_join_finish(struc
 		if (priv->mcast_mtu == priv->admin_mtu)
 			priv->admin_mtu = IPOIB_UD_MTU(mtu);
 		priv->mcast_mtu = IPOIB_UD_MTU(mtu);
+		rn->mtu = priv->mcast_mtu;
 
 		priv->qkey = be32_to_cpu(priv->broadcast->mcmember.qkey);
 		spin_unlock_irq(&priv->lock);
--- a/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_vlan.c
@@ -97,6 +97,7 @@ int __ipoib_vlan_add(struct ipoib_dev_pr
 {
 	struct net_device *ndev = priv->dev;
 	int result;
+	struct rdma_netdev *rn = netdev_priv(ndev);
 
 	ASSERT_RTNL();
 
@@ -117,6 +118,8 @@ int __ipoib_vlan_add(struct ipoib_dev_pr
 		goto out_early;
 	}
 
+	rn->mtu = priv->mcast_mtu;
+
 	priv->parent = ppriv->dev;
 	priv->pkey = pkey;
 	priv->child_type = type;