RDMA/cma: Replace net_device pointer with index

Provide the device interface when resolving route information to
ensure that the correct outbound device is used.  This will also
simplify processing of sin6_scope_id for IPv6 support.

Based on work from:
David Wilder <dwilder@us.ibm.com>
Jason Gunthorpe <jgunthrope@obsidianresearch.com>
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

drivers/infiniband/core/addr.c

@@ -107,7 +107,7 @@ int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
 	memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
 	if (dst_dev_addr)
 		memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
-	dev_addr->src_dev = dev;
+	dev_addr->bound_dev_if = dev->ifindex;
 	return 0;
 }
 EXPORT_SYMBOL(rdma_copy_addr);
@@ -117,6 +117,15 @@ int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
 	struct net_device *dev;
 	int ret = -EADDRNOTAVAIL;
 
+	if (dev_addr->bound_dev_if) {
+		dev = dev_get_by_index(&init_net, dev_addr->bound_dev_if);
+		if (!dev)
+			return -ENODEV;
+		ret = rdma_copy_addr(dev_addr, dev, NULL);
+		dev_put(dev);
+		return ret;
+	}
+
 	switch (addr->sa_family) {
 	case AF_INET:
 		dev = ip_dev_find(&init_net,
@@ -231,6 +240,8 @@ static int addr4_resolve_remote(struct sockaddr_in *src_in,
 	memset(&fl, 0, sizeof fl);
 	fl.nl_u.ip4_u.daddr = dst_ip;
 	fl.nl_u.ip4_u.saddr = src_ip;
+	fl.oif = addr->bound_dev_if;
+
 	ret = ip_route_output_key(&init_net, &rt, &fl);
 	if (ret)
 		goto out;
@@ -279,6 +290,7 @@ static int addr6_resolve_remote(struct sockaddr_in6 *src_in,
 	memset(&fl, 0, sizeof fl);
 	fl.nl_u.ip6_u.daddr = dst_in->sin6_addr;
 	fl.nl_u.ip6_u.saddr = src_in->sin6_addr;
+	fl.oif = addr->bound_dev_if;
 
 	dst = ip6_route_output(&init_net, NULL, &fl);
 	if (!dst)

drivers/infiniband/core/cma.c

@@ -2820,7 +2820,7 @@ static int cma_netdev_change(struct net_device *ndev, struct rdma_id_private *id
 
 	dev_addr = &id_priv->id.route.addr.dev_addr;
 
-	if ((dev_addr->src_dev == ndev) &&
+	if ((dev_addr->bound_dev_if == ndev->ifindex) &&
 	    memcmp(dev_addr->src_dev_addr, ndev->dev_addr, ndev->addr_len)) {
 		printk(KERN_INFO "RDMA CM addr change for ndev %s used by id %p\n",
 		       ndev->name, &id_priv->id);

include/rdma/ib_addr.h

@@ -61,7 +61,7 @@ struct rdma_dev_addr {
 	unsigned char dst_dev_addr[MAX_ADDR_LEN];
 	unsigned char broadcast[MAX_ADDR_LEN];
 	enum rdma_node_type dev_type;
-	struct net_device *src_dev;
+	int bound_dev_if;
 };
 
 /**