/* * libudev - interface to udev device information * * Copyright (C) 2008 Kay Sievers * * 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, either version 2 of the License, or * (at your option) any later version. * * 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, see . */ #include #include #include #include #include #include #include #include #include #include "libudev.h" #include "libudev-private.h" struct udev_device { int refcount; struct udev *udev; struct udev_device *parent_device; char *syspath; const char *devpath; const char *sysname; char *devnode; char *subsystem; struct list_node devlink_list; struct list_node properties_list; char *action; int event_timeout; char *driver; char *devpath_old; char *physdevpath; int timeout; dev_t devnum; unsigned long long int seqnum; int num_fake_partitions; int devlink_priority; int ignore_remove; struct list_node attr_list; int info_loaded; }; static size_t syspath_to_db_path(struct udev_device *udev_device, char *filename, size_t len) { size_t start; /* translate to location of db file */ util_strlcpy(filename, udev_get_dev_path(udev_device->udev), len); start = util_strlcat(filename, "/.udev/db/", len); util_strlcat(filename, udev_device->devpath, len); return util_path_encode(&filename[start], len - start); } static int device_read_db(struct udev_device *udev_device) { struct stat stats; char filename[UTIL_PATH_SIZE]; char line[UTIL_LINE_SIZE]; FILE *f; syspath_to_db_path(udev_device, filename, sizeof(filename)); if (lstat(filename, &stats) != 0) { info(udev_device->udev, "no db file to read %s: %s\n", filename, strerror(errno)); return -1; } if ((stats.st_mode & S_IFMT) == S_IFLNK) { char target[UTIL_PATH_SIZE]; int target_len; target_len = readlink(filename, target, sizeof(target)); if (target_len > 0) target[target_len] = '\0'; else { info(udev_device->udev, "error reading db link %s: %s\n", filename, strerror(errno)); return -1; } if (asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), target) < 0) return -ENOMEM; info(udev_device->udev, "device %p filled with db symlink data '%s'\n", udev_device, udev_device->devnode); return 0; } f = fopen(filename, "r"); if (f == NULL) { info(udev_device->udev, "error reading db file %s: %s\n", filename, strerror(errno)); return -1; } while (fgets(line, sizeof(line), f)) { ssize_t len; const char *val; len = strlen(line); if (len < 4) break; line[len-1] = '\0'; val = &line[2]; switch(line[0]) { case 'N': asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), val); break; case 'S': util_strlcpy(filename, udev_get_dev_path(udev_device->udev), sizeof(filename)); util_strlcat(filename, "/", sizeof(filename)); util_strlcat(filename, val, sizeof(filename)); device_add_devlink(udev_device, filename); break; case 'L': device_set_devlink_priority(udev_device, atoi(val)); break; case 'T': device_set_event_timeout(udev_device, atoi(val)); break; case 'A': device_set_num_fake_partitions(udev_device, atoi(val)); break; case 'R': device_set_ignore_remove(udev_device, atoi(val)); break; case 'E': device_add_property_from_string(udev_device, val); break; } } fclose(f); info(udev_device->udev, "device %p filled with db file data\n", udev_device); return 0; } static int device_read_uevent_file(struct udev_device *udev_device) { char filename[UTIL_PATH_SIZE]; FILE *f; char line[UTIL_LINE_SIZE]; int maj = 0; int min = 0; util_strlcpy(filename, udev_device->syspath, sizeof(filename)); util_strlcat(filename, "/uevent", sizeof(filename)); f = fopen(filename, "r"); if (f == NULL) return -1; while (fgets(line, sizeof(line), f)) { char *pos; pos = strchr(line, '\n'); if (pos == NULL) continue; pos[0] = '\0'; if (strncmp(line, "MAJOR=", 6) == 0) maj = strtoull(&line[6], NULL, 10); else if (strncmp(line, "MINOR=", 6) == 0) min = strtoull(&line[6], NULL, 10); device_add_property_from_string(udev_device, line); } udev_device->devnum = makedev(maj, min); fclose(f); return 0; } static void device_load_info(struct udev_device *device) { device_read_uevent_file(device); device_read_db(device); device->info_loaded = 1; } void device_set_info_loaded(struct udev_device *device) { device->info_loaded = 1; } struct udev_device *device_init(struct udev *udev) { struct udev_device *udev_device; if (udev == NULL) return NULL; udev_device = malloc(sizeof(struct udev_device)); if (udev_device == NULL) return NULL; memset(udev_device, 0x00, sizeof(struct udev_device)); udev_device->refcount = 1; udev_device->udev = udev; list_init(&udev_device->devlink_list); list_init(&udev_device->properties_list); list_init(&udev_device->attr_list); info(udev_device->udev, "udev_device: %p created\n", udev_device); return udev_device; } /** * udev_device_new_from_syspath: * @udev: udev library context * @syspath: sys device path including sys directory * * Create new udev device, and fill in information from the sys * device and the udev database entry. The sypath is the absolute * path to the device, including the sys mount point. * * The initial refcount is 1, and needs to be decremented to * release the ressources of the udev device. * * Returns: a new udev device, or #NULL, if it does not exist **/ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath) { size_t len; const char *subdir; const char *pos; char path[UTIL_PATH_SIZE]; struct stat statbuf; struct udev_device *udev_device; if (udev == NULL) return NULL; if (syspath == NULL) return NULL; /* path starts in sys */ len = strlen(udev_get_sys_path(udev)); if (strncmp(syspath, udev_get_sys_path(udev), len) != 0) { info(udev, "not in sys :%s\n", syspath); return NULL; } /* path is not a root directory */ subdir = &syspath[len+1]; pos = strrchr(subdir, '/'); if (pos == NULL || pos < &subdir[2]) { info(udev, "not a subdir :%s\n", syspath); return NULL; } /* resolve possible symlink to real path */ util_strlcpy(path, syspath, sizeof(path)); util_resolve_sys_link(udev, path, sizeof(path)); /* path exists in sys */ if (strncmp(&syspath[len], "/devices/", 9) == 0 || strncmp(&syspath[len], "/class/", 7) == 0 || strncmp(&syspath[len], "/block/", 7) == 0) { char file[UTIL_PATH_SIZE]; /* all "devices" require a "uevent" file */ util_strlcpy(file, path, sizeof(file)); util_strlcat(file, "/uevent", sizeof(file)); if (stat(file, &statbuf) != 0) { info(udev, "not a device: %s\n", syspath); return NULL; } } else { /* everything else just needs to be a directory */ if (stat(path, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode)) { info(udev, "directory not found: %s\n", syspath); return NULL; } } udev_device = device_init(udev); if (udev_device == NULL) return NULL; device_set_syspath(udev_device, path); info(udev, "device %p has devpath '%s'\n", udev_device, udev_device_get_devpath(udev_device)); return udev_device; } struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum) { char path[UTIL_PATH_SIZE]; const char *type_str; struct udev_enumerate *udev_enumerate; struct udev_list_entry *list_entry; struct udev_device *device = NULL; if (type == 'b') type_str = "block"; else if (type == 'c') type_str = "char"; else return NULL; /* /sys/dev/{block,char}/: link */ snprintf(path, sizeof(path), "%s/dev/%s/%u:%u", udev_get_sys_path(udev), type_str, major(devnum), minor(devnum)); if (util_resolve_sys_link(udev, path, sizeof(path)) == 0) return udev_device_new_from_syspath(udev, path); udev_enumerate = udev_enumerate_new(udev); if (udev_enumerate == NULL) return NULL; /* fallback to search sys devices for the major/minor */ if (type == 'b') udev_enumerate_scan_devices(udev_enumerate, "block", NULL); else if (type == 'c') udev_enumerate_scan_devices(udev_enumerate, "!block", NULL); udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) { struct udev_device *device_loop; device_loop = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry)); if (device_loop != NULL) { if (udev_device_get_devnum(device_loop) == devnum) { const char *subsystem; subsystem = udev_device_get_subsystem(device_loop); if (type == 'b' && strcmp(subsystem, "block") != 0) continue; if (type == 'c' && strcmp(subsystem, "block") == 0) continue; device = device_loop; break; } udev_device_unref(device_loop); } } udev_enumerate_unref(udev_enumerate); return device; } static struct udev_device *device_new_from_parent(struct udev_device *udev_device) { struct udev_device *udev_device_parent = NULL; char path[UTIL_PATH_SIZE]; const char *subdir; /* follow "device" link in deprecated sys layout */ if (strncmp(udev_device->devpath, "/class/", 7) == 0 || strncmp(udev_device->devpath, "/block/", 7) == 0) { util_strlcpy(path, udev_device->syspath, sizeof(path)); util_strlcat(path, "/device", sizeof(path)); if (util_resolve_sys_link(udev_device->udev, path, sizeof(path)) == 0) udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path); return udev_device_parent; } util_strlcpy(path, udev_device->syspath, sizeof(path)); subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1]; while (1) { char *pos; pos = strrchr(subdir, '/'); if (pos == NULL || pos < &subdir[2]) break; pos[0] = '\0'; udev_device_parent = udev_device_new_from_syspath(udev_device->udev, path); if (udev_device_parent != NULL) return udev_device_parent; } return NULL; } struct udev_device *udev_device_get_parent(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (udev_device->parent_device != NULL) { info(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device); return udev_device->parent_device; } udev_device->parent_device = device_new_from_parent(udev_device); return udev_device->parent_device; } /** * udev_device_get_udev: * @udev_device: udev device * * Retrieve the udev library context the device was created with. * * Returns: the udev library context **/ struct udev *udev_device_get_udev(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->udev; } /** * udev_device_ref: * @udev_device: udev device * * Take a reference of a udev device. * * Returns: the passed udev device **/ struct udev_device *udev_device_ref(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; udev_device->refcount++; return udev_device; } /** * udev_device_unref: * @udev_device: udev device * * Drop a reference of a udev device. If the refcount reaches zero, * the ressources of the device will be released. * **/ void udev_device_unref(struct udev_device *udev_device) { if (udev_device == NULL) return; udev_device->refcount--; if (udev_device->refcount > 0) return; if (udev_device->parent_device != NULL) udev_device_unref(udev_device->parent_device); free(udev_device->syspath); free(udev_device->devnode); free(udev_device->subsystem); list_cleanup(udev_device->udev, &udev_device->devlink_list); list_cleanup(udev_device->udev, &udev_device->properties_list); free(udev_device->action); free(udev_device->driver); free(udev_device->devpath_old); free(udev_device->physdevpath); list_cleanup(udev_device->udev, &udev_device->attr_list); info(udev_device->udev, "udev_device: %p released\n", udev_device); free(udev_device); } /** * udev_device_get_devpath: * @udev_device: udev device * * Retrieve the kernel devpath value of the udev device. The path * does not contain the sys mount point, and starts with a '/'. * * Returns: the devpath of the udev device **/ const char *udev_device_get_devpath(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->devpath; } /** * udev_device_get_syspath: * @udev_device: udev device * * Retrieve the sys path of the udev device. The path is an * absolute path and starts with the sys mount point. * * Returns: the sys path of the udev device **/ const char *udev_device_get_syspath(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->syspath; } const char *udev_device_get_sysname(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->sysname; } /** * udev_device_get_devnode: * @udev_device: udev device * * Retrieve the device node file name belonging to the udev device. * The path is an absolute path, and starts with the device directory. * * Returns: the device node file name of the udev device, or #NULL if no device node exists **/ const char *udev_device_get_devnode(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (!udev_device->info_loaded) device_load_info(udev_device); return udev_device->devnode; } /** * udev_device_get_subsystem: * @udev_device: udev device * * Retrieve the subsystem string of the udev device. The string does not * contain any "/". * * Returns: the subsystem name of the udev device, or #NULL if it can not be determined **/ const char *udev_device_get_subsystem(struct udev_device *udev_device) { char subsystem[UTIL_NAME_SIZE]; if (udev_device == NULL) return NULL; if (udev_device->subsystem != NULL) return udev_device->subsystem; /* read "subsytem" link */ if (util_get_sys_subsystem(udev_device->udev, udev_device->syspath, subsystem, sizeof(subsystem)) > 0) { udev_device->subsystem = strdup(subsystem); return udev_device->subsystem; } /* implicit names */ if (strncmp(udev_device->devpath, "/module/", 8) == 0) { udev_device->subsystem = strdup("module"); return udev_device->subsystem; } if (strstr(udev_device->devpath, "/drivers/") != NULL) { udev_device->subsystem = strdup("drivers"); return udev_device->subsystem; } if (strncmp(udev_device->devpath, "/subsystem/", 11) == 0 || strncmp(udev_device->devpath, "/class/", 7) == 0 || strncmp(udev_device->devpath, "/bus/", 5) == 0) { udev_device->subsystem = strdup("subsystem"); return udev_device->subsystem; } return NULL; } /** * udev_device_get_devlinks_list_entry: * @udev_device: udev device * * Retrieve the list of device links pointing to the device file of * the udev device. The next list entry can be retrieved with * udev_list_entry_next(), which returns #NULL if no more entries exist. * The devlink path can be retrieved from the list entry by * udev_list_entry_get_name(). The path is an absolute path, and starts with * the device directory. * * Returns: the first entry of the device node link list **/ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (!udev_device->info_loaded) device_load_info(udev_device); return list_get_entry(&udev_device->devlink_list); } /** * udev_device_get_properties_list_entry: * @udev_device: udev device * * Retrieve the list of key/value device properties of the udev * device. The next list entry can be retrieved with udev_list_entry_next(), * which returns #NULL if no more entries exist. The property name * can be retrieved from the list entry by udev_list_get_name(), * the property value by udev_list_get_value(). * * Returns: the first entry of the property list **/ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (!udev_device->info_loaded) device_load_info(udev_device); return list_get_entry(&udev_device->properties_list); } const char *udev_device_get_driver(struct udev_device *udev_device) { char driver[UTIL_NAME_SIZE]; if (udev_device == NULL) return NULL; if (udev_device->driver != NULL) return udev_device->driver; if (util_get_sys_driver(udev_device->udev, udev_device->syspath, driver, sizeof(driver)) < 2) return NULL; udev_device->driver = strdup(driver); return udev_device->driver; } dev_t udev_device_get_devnum(struct udev_device *udev_device) { if (udev_device == NULL) return makedev(0, 0); if (!udev_device->info_loaded) device_load_info(udev_device); return udev_device->devnum; } const char *udev_device_get_action(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->action; } unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device) { if (udev_device == NULL) return 0; return udev_device->seqnum; } const char *udev_device_get_attr_value(struct udev_device *udev_device, const char *attr) { struct udev_list_entry *list_entry; char path[UTIL_PATH_SIZE]; char value[UTIL_NAME_SIZE]; struct stat statbuf; int fd; ssize_t size; const char *val = NULL; /* look for possibly already cached result */ udev_list_entry_foreach(list_entry, list_get_entry(&udev_device->attr_list)) { if (strcmp(udev_list_entry_get_name(list_entry), attr) == 0) { info(udev_device->udev, "got '%s' (%s) from cache\n", attr, udev_list_entry_get_value(list_entry)); return udev_list_entry_get_value(list_entry); } } util_strlcpy(path, udev_device_get_syspath(udev_device), sizeof(path)); util_strlcat(path, "/", sizeof(path)); util_strlcat(path, attr, sizeof(path)); if (lstat(path, &statbuf) != 0) { info(udev_device->udev, "stat '%s' failed: %s\n", path, strerror(errno)); goto out; } if (S_ISLNK(statbuf.st_mode)) { /* links return the last element of the target path */ char target[UTIL_NAME_SIZE]; int len; char *pos; len = readlink(path, target, sizeof(target)); if (len > 0) { target[len] = '\0'; pos = strrchr(target, '/'); if (pos != NULL) { pos = &pos[1]; info(udev_device->udev, "cache '%s' with link value '%s'\n", attr, pos); list_entry = list_entry_add(udev_device->udev, &udev_device->attr_list, attr, pos, 0, 0); val = udev_list_entry_get_value(list_entry); } } goto out; } /* skip directories */ if (S_ISDIR(statbuf.st_mode)) goto out; /* skip non-readable files */ if ((statbuf.st_mode & S_IRUSR) == 0) goto out; /* read attribute value */ fd = open(path, O_RDONLY); if (fd < 0) { info(udev_device->udev, "attribute '%s' can not be opened\n", path); goto out; } size = read(fd, value, sizeof(value)); close(fd); if (size < 0) goto out; if (size == sizeof(value)) goto out; /* got a valid value, store it in cache and return it */ value[size] = '\0'; util_remove_trailing_chars(value, '\n'); info(udev_device->udev, "'%s' has attribute value '%s'\n", path, value); list_entry = list_entry_add(udev_device->udev, &udev_device->attr_list, attr, value, 0, 0); val = udev_list_entry_get_value(list_entry); out: return val; } int device_set_syspath(struct udev_device *udev_device, const char *syspath) { const char *pos; udev_device->syspath = strdup(syspath); if (udev_device->syspath == NULL) return -ENOMEM; udev_device->devpath = &udev_device->syspath[strlen(udev_get_sys_path(udev_device->udev))]; pos = strrchr(udev_device->syspath, '/'); if (pos == NULL) return -EINVAL; udev_device->sysname = &pos[1]; return 0; } int device_set_subsystem(struct udev_device *udev_device, const char *subsystem) { udev_device->subsystem = strdup(subsystem); if (udev_device->subsystem == NULL) return -1; return 0; } int device_set_devnode(struct udev_device *udev_device, const char *devnode) { udev_device->devnode = strdup(devnode); if (udev_device->devnode == NULL) return -ENOMEM; return 0; } int device_add_devlink(struct udev_device *udev_device, const char *devlink) { if (list_entry_add(udev_device->udev, &udev_device->devlink_list, devlink, NULL, 1, 0) == NULL) return -ENOMEM; return 0; } int device_add_property(struct udev_device *udev_device, const char *key, const char *value) { if (list_entry_add(udev_device->udev, &udev_device->properties_list, key, value, 1, 0) == NULL) return -ENOMEM; return 0; } int device_add_property_from_string(struct udev_device *udev_device, const char *property) { char name[UTIL_PATH_SIZE]; char *val; strncpy(name, property, sizeof(name)); val = strchr(name, '='); if (val == NULL) return -1; val[0] = '\0'; val = &val[1]; if (val[0] == '\0') val = NULL; device_add_property(udev_device, name, val); return 0; } int device_set_action(struct udev_device *udev_device, const char *action) { udev_device->action = strdup(action); if (udev_device->action == NULL) return -ENOMEM; return 0; } int device_set_driver(struct udev_device *udev_device, const char *driver) { udev_device->driver = strdup(driver); if (udev_device->driver == NULL) return -ENOMEM; return 0; } const char *device_get_devpath_old(struct udev_device *udev_device) { return udev_device->devpath_old; } int device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old) { udev_device->devpath_old = strdup(devpath_old); if (udev_device->devpath_old == NULL) return -ENOMEM; return 0; } const char *device_get_physdevpath(struct udev_device *udev_device) { return udev_device->physdevpath; } int device_set_physdevpath(struct udev_device *udev_device, const char *physdevpath) { udev_device->physdevpath = strdup(physdevpath); if (udev_device->physdevpath == NULL) return -ENOMEM; return 0; } int device_get_timeout(struct udev_device *udev_device) { return udev_device->timeout; } int device_set_timeout(struct udev_device *udev_device, int timeout) { udev_device->timeout = timeout; return 0; } int device_get_event_timeout(struct udev_device *udev_device) { if (!udev_device->info_loaded) device_load_info(udev_device); return udev_device->event_timeout; } int device_set_event_timeout(struct udev_device *udev_device, int event_timeout) { udev_device->event_timeout = event_timeout; return 0; } int device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum) { udev_device->seqnum = seqnum; return 0; } int device_set_devnum(struct udev_device *udev_device, dev_t devnum) { udev_device->devnum = devnum; return 0; } int device_get_num_fake_partitions(struct udev_device *udev_device) { if (!udev_device->info_loaded) device_load_info(udev_device); return udev_device->num_fake_partitions; } int device_set_num_fake_partitions(struct udev_device *udev_device, int num) { udev_device->num_fake_partitions = num; return 0; } int device_get_devlink_priority(struct udev_device *udev_device) { if (!udev_device->info_loaded) device_load_info(udev_device); return udev_device->devlink_priority; } int device_set_devlink_priority(struct udev_device *udev_device, int prio) { udev_device->devlink_priority = prio; return 0; } int device_get_ignore_remove(struct udev_device *udev_device) { if (!udev_device->info_loaded) device_load_info(udev_device); return udev_device->ignore_remove; } int device_set_ignore_remove(struct udev_device *udev_device, int ignore) { udev_device->ignore_remove = ignore; return 0; }