IB/core: Find the network device matching connection parameters

In the case of IPoIB, and maybe in other cases, the network device is
managed by an upper-layer protocol (ULP). In order to expose this
network device to other users of the IB device, let ULPs implement
a callback that returns network device according to connection parameters.

The IB device and port, together with the P_Key and the GID should
be enough to uniquely identify the ULP net device. However, in current
kernels there can be multiple IPoIB interfaces created with the same GID.
Furthermore, such configuration may be desireable to support ipvlan-like
configurations for RDMA CM with IPoIB.  To resolve the device in these
cases the code will also take the IP address as an additional input.

Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.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: Guy Shapiro <guysh@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index ce317e623862..a9a27816991a 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -38,6 +38,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
+#include <linux/netdevice.h>
 #include <rdma/rdma_netlink.h>
 
 #include "core_priv.h"
@@ -780,6 +781,51 @@ int ib_find_pkey(struct ib_device *device,
 }
 EXPORT_SYMBOL(ib_find_pkey);
 
+/**
+ * ib_get_net_dev_by_params() - Return the appropriate net_dev
+ * for a received CM request
+ * @dev:	An RDMA device on which the request has been received.
+ * @port:	Port number on the RDMA device.
+ * @pkey:	The Pkey the request came on.
+ * @gid:	A GID that the net_dev uses to communicate.
+ * @addr:	Contains the IP address that the request specified as its
+ *		destination.
+ */
+struct net_device *ib_get_net_dev_by_params(struct ib_device *dev,
+					    u8 port,
+					    u16 pkey,
+					    const union ib_gid *gid,
+					    const struct sockaddr *addr)
+{
+	struct net_device *net_dev = NULL;
+	struct ib_client_data *context;
+
+	if (!rdma_protocol_ib(dev, port))
+		return NULL;
+
+	down_read(&lists_rwsem);
+
+	list_for_each_entry(context, &dev->client_data_list, list) {
+		struct ib_client *client = context->client;
+
+		if (context->going_down)
+			continue;
+
+		if (client->get_net_dev_by_params) {
+			net_dev = client->get_net_dev_by_params(dev, port, pkey,
+								gid, addr,
+								context->data);
+			if (net_dev)
+				break;
+		}
+	}
+
+	up_read(&lists_rwsem);
+
+	return net_dev;
+}
+EXPORT_SYMBOL(ib_get_net_dev_by_params);
+
 static int __init ib_core_init(void)
 {
 	int ret;