/* * udev.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 "libsysfs/libsysfs.h" static char sysfs_path[SYSFS_PATH_MAX]; static char *get_action(void) { char *action; action = getenv("ACTION"); return action; } static char *get_device(void) { char *device; device = getenv("DEVPATH"); return device; } /* * Right now the major/minor of a device is stored in a file called * "dev" in sysfs. * The number is stored as: * MMmm * MM is the major * mm is the minor * The value is in hex. * Yes, this will probably change when we go to a bigger major/minor * range, and will have to be changed at that time. */ static int get_major_minor(struct sysfs_class_device *class_dev, int *major, int *minor) { char temp[3]; int retval = 0; char *dev; dev = sysfs_get_value_from_attributes(class_dev->directory->attributes, "dev"); if (dev == NULL) return -ENODEV; dbg("dev = %s", dev); temp[0] = dev[0]; temp[1] = dev[1]; temp[2] = 0x00; *major = (int)strtol(&temp[0], NULL, 16); temp[0] = dev[2]; temp[1] = dev[3]; temp[2] = 0x00; *minor = (int)strtol(&temp[0], NULL, 16); dbg("found major = %d, minor = %d", *major, *minor); retval = 0; return retval; } /* * Here would go a call to the naming deamon, to get the name we want to have * for this device. But for now, let's just default to whatever the kernel is * calling the device as that will keep the "old-style" naming policy */ static char *get_name(char *dev, int major, int minor) { static char name[100]; char *temp; temp = strrchr(dev, '/'); if (temp == NULL) return NULL; strncpy(name, &temp[1], sizeof(name)); dbg("name is %s", name); return &name[0]; } /* * We also want to add some permissions here, and possibly some symlinks */ static int create_node(char *name, char type, int major, int minor, int mode) { char *argv[7]; char mode_string[100]; char type_string[3]; char major_string[20]; char minor_string[20]; char filename[255]; int retval = 0; strncpy(filename, UDEV_ROOT, sizeof(filename)); strncat(filename, name, sizeof(filename)); snprintf(mode_string, sizeof(mode_string), "--mode=%#o", mode); snprintf(type_string, sizeof(type_string), "%c", type); snprintf(major_string, sizeof(major_string), "%d", major); snprintf(minor_string, sizeof(minor_string), "%d", minor); argv[0] = MKNOD; argv[1] = mode_string; argv[2] = filename; argv[3] = type_string; argv[4] = major_string; argv[5] = minor_string; argv[6] = NULL; dbg ("executing %s %s %s %s %s %s", argv[0], argv[1], argv[2], argv[3], argv[4], argv[5]); switch (fork()) { case 0: /* we are the child, so lets run the program */ execv (MKNOD, argv); exit(0); break; case (-1): dbg ("fork failed."); retval = -EFAULT; break; default: break; } return retval; } /* * We also want to clean up any symlinks that were created in create_node() */ static int delete_node(char *name) { char filename[255]; strncpy(filename, UDEV_ROOT, sizeof(filename)); strncat(filename, name, sizeof(filename)); dbg("unlinking %s", filename); return unlink(filename); } struct sysfs_class_device *get_class_dev(char *device_name) { char dev_path[SYSFS_PATH_MAX]; struct sysfs_class_device *class_dev; 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"); return NULL; } dbg("class_dev->name = %s", class_dev->name); return class_dev; } static int add_device(char *device, char *subsystem) { struct sysfs_class_device *class_dev; struct device_attr attr; //char *name; int major; int minor; char type; //int mode; int retval = -EINVAL; /* for now, the block layer is the only place where block devices are */ if (strcmp(subsystem, "block") == 0) type = 'b'; else type = 'c'; class_dev = get_class_dev(device); if (class_dev == NULL) goto exit; retval = namedev_name_device(class_dev, &attr); if (retval) return retval; retval = get_major_minor(class_dev, &major, &minor); if (retval) { dbg ("get_major_minor failed"); goto exit; } sysfs_close_class_device(class_dev); return create_node(attr.name, type, major, minor, attr.mode); exit: return retval; } static int remove_device(char *device) { char *name; int retval = 0; name = get_name(device, 0, 0); if (name == NULL) { dbg ("get_name failed"); retval = -ENODEV; goto exit; } return delete_node(name); exit: return retval; } static int udev_init(void) { int retval; retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX); dbg("sysfs_path = %s", sysfs_path); return retval; } int main(int argc, char *argv[]) { char *action; char *device; int retval = -EINVAL; if (argc != 2) { dbg ("unknown number of arguments"); goto exit; } device = get_device(); if (!device) { dbg ("no device?"); goto exit; } dbg("looking at %s", device); /* we only care about class devices and block stuff */ if (!strstr(device, "class") && !strstr(device, "block")) { dbg("not block or class"); goto exit; } /* sleep for a second or two to give the kernel a chance to * create the dev file */ sleep(1); udev_init(); namedev_init(); action = get_action(); if (!action) { dbg ("no action?"); goto exit; } if (strcmp(action, "add") == 0) return add_device(device, argv[1]); if (strcmp(action, "remove") == 0) return remove_device(device); dbg("Unknown action: %s", action); return -EINVAL; retval = 0; exit: return retval; }