/* * udev-add.c * * Userspace devfs * * Copyright (C) 2003 Greg Kroah-Hartman * * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation version 2 of the License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include #include #include #include #include "udev.h" #include "udev_version.h" #include "namedev.h" #include "udevdb.h" #include "libsysfs/libsysfs.h" /* * Right now the major/minor of a device is stored in a file called * "dev" in sysfs. * The number is stored as: * MM:mm * MM is the major * mm is the minor * The value is in decimal. */ static int get_major_minor(struct sysfs_class_device *class_dev, int *major, int *minor) { int retval = -ENODEV; char *dev; dev = sysfs_get_value_from_attributes(class_dev->directory->attributes, "dev"); if (dev == NULL) goto exit; dbg("dev = %s", dev); if (sscanf(dev, "%u:%u", major, minor) != 2) goto exit; dbg("found major = %d, minor = %d", *major, *minor); retval = 0; exit: return retval; } /* * We also want to add some permissions here, and possibly some symlinks */ static int create_node(struct udevice *dev) { char filename[255]; int retval = 0; strncpy(filename, udev_root, sizeof(filename)); strncat(filename, dev->name, sizeof(filename)); switch (dev->type) { case 'b': dev->mode |= S_IFBLK; break; case 'c': case 'u': dev->mode |= S_IFCHR; break; case 'p': dev->mode |= S_IFIFO; break; default: dbg("unknown node type %c\n", dev->type); return -EINVAL; } dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor); retval = mknod(filename, dev->mode, makedev(dev->major, dev->minor)); if (retval) dbg("mknod(%s, %#o, %u, %u) failed with error '%s'", filename, dev->mode, dev->major, dev->minor, strerror(errno)); // FIXME set the ownership of the node return retval; } static struct sysfs_class_device *get_class_dev(char *device_name) { char dev_path[SYSFS_PATH_MAX]; struct sysfs_class_device *class_dev = NULL; strcpy(dev_path, sysfs_path); strcat(dev_path, device_name); dbg("looking at %s", dev_path); /* open up the sysfs class device for this thing... */ class_dev = sysfs_open_class_device(dev_path); if (class_dev == NULL) { dbg ("sysfs_open_class_device failed"); goto exit; } dbg("class_dev->name = %s", class_dev->name); exit: return class_dev; } /* wait for the "dev" file to show up in the directory in sysfs. * If it doesn't happen in about 10 seconds, give up. */ #define SECONDS_TO_WAIT_FOR_DEV 10 int sleep_for_dev(char *path) { char filename[SYSFS_PATH_MAX + 6]; struct stat buf; int loop = 0; int retval = -ENODEV; strcpy(filename, sysfs_path); strcat(filename, path); strcat(filename, "/dev"); while (loop < SECONDS_TO_WAIT_FOR_DEV) { dbg("looking for %s", filename); retval = stat(filename, &buf); if (retval == 0) { retval = 0; goto exit; } /* sleep for a second or two to give the kernel a chance to * create the dev file */ sleep(1); ++loop; } retval = -ENODEV; exit: return retval; } int udev_add_device(char *path, char *subsystem) { struct sysfs_class_device *class_dev; struct udevice dev; struct device_attr attr; int retval = -EINVAL; /* for now, the block layer is the only place where block devices are */ if (strcmp(subsystem, "block") == 0) dev.type = 'b'; else dev.type = 'c'; retval = sleep_for_dev(path); if (retval) goto exit; class_dev = get_class_dev(path); if (class_dev == NULL) goto exit; retval = namedev_name_device(class_dev, &attr); if (retval) return retval; retval = get_major_minor(class_dev, &dev.major, &dev.minor); if (retval) { dbg("get_major_minor failed"); goto exit; } strcpy(dev.name, attr.name); strcpy(dev.owner, attr.owner); strcpy(dev.group, attr.group); dev.mode = attr.mode; retval = udevdb_add_dev(path, &dev); if (retval != 0) dbg("udevdb_add_dev failed, but we are going to try to create the node anyway. " "But remove might not work properly for this device."); sysfs_close_class_device(class_dev); dbg("name = %s", dev.name); retval = create_node(&dev); exit: return retval; }