RDMA/ucma: Allow user space to bind to AF_IB

Support user space binding to addresses using AF_IB.  Since
sockaddr_ib is larger than sockaddr_in6, we need to define a larger
structure when binding using AF_IB.  This time we use sockaddr_storage
to cover future cases.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 82fb1e6..22ed97e 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -531,6 +531,30 @@
 	return ret;
 }
 
+static ssize_t ucma_bind(struct ucma_file *file, const char __user *inbuf,
+			 int in_len, int out_len)
+{
+	struct rdma_ucm_bind cmd;
+	struct sockaddr *addr;
+	struct ucma_context *ctx;
+	int ret;
+
+	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+		return -EFAULT;
+
+	addr = (struct sockaddr *) &cmd.addr;
+	if (cmd.reserved || !cmd.addr_size || (cmd.addr_size != rdma_addr_size(addr)))
+		return -EINVAL;
+
+	ctx = ucma_get_ctx(file, cmd.id);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	ret = rdma_bind_addr(ctx->cm_id, addr);
+	ucma_put_ctx(ctx);
+	return ret;
+}
+
 static ssize_t ucma_resolve_ip(struct ucma_file *file,
 			       const char __user *inbuf,
 			       int in_len, int out_len)
@@ -1398,7 +1422,8 @@
 	[RDMA_USER_CM_CMD_JOIN_IP_MCAST] = ucma_join_ip_multicast,
 	[RDMA_USER_CM_CMD_LEAVE_MCAST]	 = ucma_leave_multicast,
 	[RDMA_USER_CM_CMD_MIGRATE_ID]	 = ucma_migrate_id,
-	[RDMA_USER_CM_CMD_QUERY]	 = ucma_query
+	[RDMA_USER_CM_CMD_QUERY]	 = ucma_query,
+	[RDMA_USER_CM_CMD_BIND]		 = ucma_bind
 };
 
 static ssize_t ucma_write(struct file *filp, const char __user *buf,