1 files changed, 69 insertions, 0 deletions
diff --git a/tools/blktap2/control/tap-ctl-major.c b/tools/blktap2/control/tap-ctl-major.c
new file mode 100644
index 0000000000..847af28708
--- /dev/null
+++ b/tools/blktap2/control/tap-ctl-major.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2008, XenSource Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of XenSource Inc. nor the names of its contributors
+ *       may be used to endorse or promote products derived from this software
+ *       without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "tap-ctl.h"
+
+int
+tap_ctl_blk_major(void)
+{
+	FILE *devices;
+	int rv, major;
+
+	devices = fopen("/proc/devices", "r");
+	if (!devices) {
+		rv = -errno;
+		goto out;
+	}
+
+	do {
+		char buf[32], *s;
+		int n, offset;
+
+		s = fgets(buf, sizeof(buf), devices);
+		if (!s)
+			break;
+
+		major  = -ENODEV;
+		offset = 0;
+
+		n = sscanf(buf, "%d tapdev%n", &major, &offset);
+		if (n == 1 && offset)
+			break;
+	} while (1);
+
+	rv = major;
+
+out:
+	if (devices)
+		fclose(devices);
+
+	return rv;
+}