RDMA/ucma: Allow user space to pass AF_IB into resolve

Allow user space applications to call resolve_addr using AF_IB.  To
support sockaddr_ib, we need to define a new structure capable of
handling the larger address size.

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 22ed97e..00ce990 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -577,6 +577,33 @@
 	return ret;
 }
 
+static ssize_t ucma_resolve_addr(struct ucma_file *file,
+				 const char __user *inbuf,
+				 int in_len, int out_len)
+{
+	struct rdma_ucm_resolve_addr cmd;
+	struct sockaddr *src, *dst;
+	struct ucma_context *ctx;
+	int ret;
+
+	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+		return -EFAULT;
+
+	src = (struct sockaddr *) &cmd.src_addr;
+	dst = (struct sockaddr *) &cmd.dst_addr;
+	if (cmd.reserved || (cmd.src_size && (cmd.src_size != rdma_addr_size(src))) ||
+	    !cmd.dst_size || (cmd.dst_size != rdma_addr_size(dst)))
+		return -EINVAL;
+
+	ctx = ucma_get_ctx(file, cmd.id);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	ret = rdma_resolve_addr(ctx->cm_id, src, dst, cmd.timeout_ms);
+	ucma_put_ctx(ctx);
+	return ret;
+}
+
 static ssize_t ucma_resolve_route(struct ucma_file *file,
 				  const char __user *inbuf,
 				  int in_len, int out_len)
@@ -1423,7 +1450,8 @@
 	[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_BIND]		 = ucma_bind
+	[RDMA_USER_CM_CMD_BIND]		 = ucma_bind,
+	[RDMA_USER_CM_CMD_RESOLVE_ADDR]	 = ucma_resolve_addr
 };
 
 static ssize_t ucma_write(struct file *filp, const char __user *buf,