diff options
Diffstat (limited to 'tools/blktap2/control/tap-ctl-major.c')
-rw-r--r-- | tools/blktap2/control/tap-ctl-major.c | 69 |
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; +} |