IB/ipoib: Return IPoIB devices matching connection parameters

Implement the get_net_device_by_port_pkey_ip callback that returns network
device to ib_core according to connection parameters. Check the ipoib
device and iterate over all child devices to look for a match.

For each IPoIB device we iterate through all upper devices when searching
for a matching IP, in order to support bonding.
Signed-off-by: Guy Shapiro <guysh@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Yotam Kenneth <yotamke@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -48,6 +48,9 @@
 
 #include <linux/jhash.h>
 #include <net/arp.h>
+#include <net/addrconf.h>
+#include <linux/inetdevice.h>
+#include <rdma/ib_cache.h>
 
 #define DRV_VERSION "1.0.0"
 
@@ -91,11 +94,16 @@ struct ib_sa_client ipoib_sa_client;
 static void ipoib_add_one(struct ib_device *device);
 static void ipoib_remove_one(struct ib_device *device, void *client_data);
 static void ipoib_neigh_reclaim(struct rcu_head *rp);
+static struct net_device *ipoib_get_net_dev_by_params(
+		struct ib_device *dev, u8 port, u16 pkey,
+		const union ib_gid *gid, const struct sockaddr *addr,
+		void *client_data);
 
 static struct ib_client ipoib_client = {
 	.name   = "ipoib",
 	.add    = ipoib_add_one,
-	.remove = ipoib_remove_one
+	.remove = ipoib_remove_one,
+	.get_net_dev_by_params = ipoib_get_net_dev_by_params,
 };
 
 int ipoib_open(struct net_device *dev)
@@ -222,6 +230,225 @@ static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
 	return 0;
 }
 
+/* Called with an RCU read lock taken */
+static bool ipoib_is_dev_match_addr_rcu(const struct sockaddr *addr,
+					struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+	struct in_device *in_dev;
+	struct sockaddr_in *addr_in = (struct sockaddr_in *)addr;
+	struct sockaddr_in6 *addr_in6 = (struct sockaddr_in6 *)addr;
+	__be32 ret_addr;
+
+	switch (addr->sa_family) {
+	case AF_INET:
+		in_dev = in_dev_get(dev);
+		if (!in_dev)
+			return false;
+
+		ret_addr = inet_confirm_addr(net, in_dev, 0,
+					     addr_in->sin_addr.s_addr,
+					     RT_SCOPE_HOST);
+		in_dev_put(in_dev);
+		if (ret_addr)
+			return true;
+
+		break;
+	case AF_INET6:
+		if (IS_ENABLED(CONFIG_IPV6) &&
+		    ipv6_chk_addr(net, &addr_in6->sin6_addr, dev, 1))
+			return true;
+
+		break;
+	}
+	return false;
+}
+
+/**
+ * Find the master net_device on top of the given net_device.
+ * @dev: base IPoIB net_device
+ *
+ * Returns the master net_device with a reference held, or the same net_device
+ * if no master exists.
+ */
+static struct net_device *ipoib_get_master_net_dev(struct net_device *dev)
+{
+	struct net_device *master;
+
+	rcu_read_lock();
+	master = netdev_master_upper_dev_get_rcu(dev);
+	if (master)
+		dev_hold(master);
+	rcu_read_unlock();
+
+	if (master)
+		return master;
+
+	dev_hold(dev);
+	return dev;
+}
+
+/**
+ * Find a net_device matching the given address, which is an upper device of
+ * the given net_device.
+ * @addr: IP address to look for.
+ * @dev: base IPoIB net_device
+ *
+ * If found, returns the net_device with a reference held. Otherwise return
+ * NULL.
+ */
+static struct net_device *ipoib_get_net_dev_match_addr(
+		const struct sockaddr *addr, struct net_device *dev)
+{
+	struct net_device *upper,
+			  *result = NULL;
+	struct list_head *iter;
+
+	rcu_read_lock();
+	if (ipoib_is_dev_match_addr_rcu(addr, dev)) {
+		dev_hold(dev);
+		result = dev;
+		goto out;
+	}
+
+	netdev_for_each_all_upper_dev_rcu(dev, upper, iter) {
+		if (ipoib_is_dev_match_addr_rcu(addr, upper)) {
+			dev_hold(upper);
+			result = upper;
+			break;
+		}
+	}
+out:
+	rcu_read_unlock();
+	return result;
+}
+
+/* returns the number of IPoIB netdevs on top a given ipoib device matching a
+ * pkey_index and address, if one exists.
+ *
+ * @found_net_dev: contains a matching net_device if the return value >= 1,
+ * with a reference held. */
+static int ipoib_match_gid_pkey_addr(struct ipoib_dev_priv *priv,
+				     const union ib_gid *gid,
+				     u16 pkey_index,
+				     const struct sockaddr *addr,
+				     int nesting,
+				     struct net_device **found_net_dev)
+{
+	struct ipoib_dev_priv *child_priv;
+	struct net_device *net_dev = NULL;
+	int matches = 0;
+
+	if (priv->pkey_index == pkey_index &&
+	    (!gid || !memcmp(gid, &priv->local_gid, sizeof(*gid)))) {
+		if (!addr) {
+			net_dev = ipoib_get_master_net_dev(priv->dev);
+		} else {
+			/* Verify the net_device matches the IP address, as
+			 * IPoIB child devices currently share a GID. */
+			net_dev = ipoib_get_net_dev_match_addr(addr, priv->dev);
+		}
+		if (net_dev) {
+			if (!*found_net_dev)
+				*found_net_dev = net_dev;
+			else
+				dev_put(net_dev);
+			++matches;
+		}
+	}
+
+	/* Check child interfaces */
+	down_read_nested(&priv->vlan_rwsem, nesting);
+	list_for_each_entry(child_priv, &priv->child_intfs, list) {
+		matches += ipoib_match_gid_pkey_addr(child_priv, gid,
+						    pkey_index, addr,
+						    nesting + 1,
+						    found_net_dev);
+		if (matches > 1)
+			break;
+	}
+	up_read(&priv->vlan_rwsem);
+
+	return matches;
+}
+
+/* Returns the number of matching net_devs found (between 0 and 2). Also
+ * return the matching net_device in the @net_dev parameter, holding a
+ * reference to the net_device, if the number of matches >= 1 */
+static int __ipoib_get_net_dev_by_params(struct list_head *dev_list, u8 port,
+					 u16 pkey_index,
+					 const union ib_gid *gid,
+					 const struct sockaddr *addr,
+					 struct net_device **net_dev)
+{
+	struct ipoib_dev_priv *priv;
+	int matches = 0;
+
+	*net_dev = NULL;
+
+	list_for_each_entry(priv, dev_list, list) {
+		if (priv->port != port)
+			continue;
+
+		matches += ipoib_match_gid_pkey_addr(priv, gid, pkey_index,
+						     addr, 0, net_dev);
+		if (matches > 1)
+			break;
+	}
+
+	return matches;
+}
+
+static struct net_device *ipoib_get_net_dev_by_params(
+		struct ib_device *dev, u8 port, u16 pkey,
+		const union ib_gid *gid, const struct sockaddr *addr,
+		void *client_data)
+{
+	struct net_device *net_dev;
+	struct list_head *dev_list = client_data;
+	u16 pkey_index;
+	int matches;
+	int ret;
+
+	if (!rdma_protocol_ib(dev, port))
+		return NULL;
+
+	ret = ib_find_cached_pkey(dev, port, pkey, &pkey_index);
+	if (ret)
+		return NULL;
+
+	if (!dev_list)
+		return NULL;
+
+	/* See if we can find a unique device matching the L2 parameters */
+	matches = __ipoib_get_net_dev_by_params(dev_list, port, pkey_index,
+						gid, NULL, &net_dev);
+
+	switch (matches) {
+	case 0:
+		return NULL;
+	case 1:
+		return net_dev;
+	}
+
+	dev_put(net_dev);
+
+	/* Couldn't find a unique device with L2 parameters only. Use L3
+	 * address to uniquely match the net device */
+	matches = __ipoib_get_net_dev_by_params(dev_list, port, pkey_index,
+						gid, addr, &net_dev);
+	switch (matches) {
+	case 0:
+		return NULL;
+	default:
+		dev_warn_ratelimited(&dev->dev,
+				     "duplicate IP address detected\n");
+		/* Fall through */
+	case 1:
+		return net_dev;
+	}
+}
+
 int ipoib_set_mode(struct net_device *dev, const char *buf)
 {
 	struct ipoib_dev_priv *priv = netdev_priv(dev);