/* * libudev - interface to udev device information * * Copyright (C) 2008-2010 Kay Sievers * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "libudev.h" #include "libudev-private.h" /** * SECTION:libudev-device * @short_description: kernel sys devices * * Representation of kernel sys devices. Devices are uniquely identified * by their syspath, every device has exactly one path in the kernel sys * filesystem. Devices usually belong to a kernel subsystem, and and have * a unique name inside that subsystem. */ /** * udev_device: * * Opaque object representing one kernel sys device. */ struct udev_device { struct udev *udev; struct udev_device *parent_device; char *syspath; const char *devpath; char *sysname; const char *sysnum; char *devnode; mode_t devnode_mode; char *subsystem; char *devtype; char *driver; char *action; char *devpath_old; char *id_filename; char **envp; char *monitor_buf; size_t monitor_buf_len; struct udev_list devlinks_list; struct udev_list properties_list; struct udev_list sysattr_value_list; struct udev_list sysattr_list; struct udev_list tags_list; unsigned long long int seqnum; unsigned long long int usec_initialized; int devlink_priority; int refcount; dev_t devnum; int ifindex; int watch_handle; int maj, min; bool parent_set; bool subsystem_set; bool devtype_set; bool devlinks_uptodate; bool envp_uptodate; bool tags_uptodate; bool driver_set; bool info_loaded; bool db_loaded; bool uevent_loaded; bool is_initialized; bool sysattr_list_read; bool db_persist; }; /** * udev_device_get_seqnum: * @udev_device: udev device * * This is only valid if the device was received through a monitor. Devices read from * sys do not have a sequence number. * * Returns: the kernel event sequence number, or 0 if there is no sequence number available. **/ UDEV_EXPORT unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device) { if (udev_device == NULL) return 0; return udev_device->seqnum; } static int udev_device_set_seqnum(struct udev_device *udev_device, unsigned long long int seqnum) { char num[32]; udev_device->seqnum = seqnum; snprintf(num, sizeof(num), "%llu", seqnum); udev_device_add_property(udev_device, "SEQNUM", num); return 0; } int udev_device_get_ifindex(struct udev_device *udev_device) { if (!udev_device->info_loaded) udev_device_read_uevent_file(udev_device); return udev_device->ifindex; } static int udev_device_set_ifindex(struct udev_device *udev_device, int ifindex) { char num[32]; udev_device->ifindex = ifindex; snprintf(num, sizeof(num), "%u", ifindex); udev_device_add_property(udev_device, "IFINDEX", num); return 0; } /** * udev_device_get_devnum: * @udev_device: udev device * * Returns: the device major/minor number. **/ UDEV_EXPORT dev_t udev_device_get_devnum(struct udev_device *udev_device) { if (udev_device == NULL) return makedev(0, 0); if (!udev_device->info_loaded) udev_device_read_uevent_file(udev_device); return udev_device->devnum; } static int udev_device_set_devnum(struct udev_device *udev_device, dev_t devnum) { char num[32]; udev_device->devnum = devnum; snprintf(num, sizeof(num), "%u", major(devnum)); udev_device_add_property(udev_device, "MAJOR", num); snprintf(num, sizeof(num), "%u", minor(devnum)); udev_device_add_property(udev_device, "MINOR", num); return 0; } const char *udev_device_get_devpath_old(struct udev_device *udev_device) { return udev_device->devpath_old; } static int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old) { const char *pos; free(udev_device->devpath_old); udev_device->devpath_old = strdup(devpath_old); if (udev_device->devpath_old == NULL) return -ENOMEM; udev_device_add_property(udev_device, "DEVPATH_OLD", udev_device->devpath_old); pos = strrchr(udev_device->devpath_old, '/'); if (pos == NULL) return -EINVAL; return 0; } /** * udev_device_get_driver: * @udev_device: udev device * * Returns: the driver string, or #NULL if there is no driver attached. **/ UDEV_EXPORT 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_set) { udev_device->driver_set = true; if (util_get_sys_core_link_value(udev_device->udev, "driver", udev_device->syspath, driver, sizeof(driver)) > 0) udev_device->driver = strdup(driver); } return udev_device->driver; } static int udev_device_set_driver(struct udev_device *udev_device, const char *driver) { free(udev_device->driver); udev_device->driver = strdup(driver); if (udev_device->driver == NULL) return -ENOMEM; udev_device->driver_set = true; udev_device_add_property(udev_device, "DRIVER", udev_device->driver); return 0; } /** * udev_device_get_devtype: * @udev_device: udev device * * Retrieve the devtype string of the udev device. * * Returns: the devtype name of the udev device, or #NULL if it can not be determined **/ UDEV_EXPORT const char *udev_device_get_devtype(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (!udev_device->devtype_set) { udev_device->devtype_set = true; udev_device_read_uevent_file(udev_device); } return udev_device->devtype; } static int udev_device_set_devtype(struct udev_device *udev_device, const char *devtype) { free(udev_device->devtype); udev_device->devtype = strdup(devtype); if (udev_device->devtype == NULL) return -ENOMEM; udev_device->devtype_set = true; udev_device_add_property(udev_device, "DEVTYPE", udev_device->devtype); return 0; } static int udev_device_set_subsystem(struct udev_device *udev_device, const char *subsystem) { free(udev_device->subsystem); udev_device->subsystem = strdup(subsystem); if (udev_device->subsystem == NULL) return -ENOMEM; udev_device->subsystem_set = true; udev_device_add_property(udev_device, "SUBSYSTEM", udev_device->subsystem); return 0; } /** * 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 **/ UDEV_EXPORT 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_set) { udev_device->subsystem_set = true; /* read "subsystem" link */ if (util_get_sys_core_link_value(udev_device->udev, "subsystem", udev_device->syspath, subsystem, sizeof(subsystem)) > 0) { udev_device_set_subsystem(udev_device, subsystem); return udev_device->subsystem; } /* implicit names */ if (strncmp(udev_device->devpath, "/module/", 8) == 0) { udev_device_set_subsystem(udev_device, "module"); return udev_device->subsystem; } if (strstr(udev_device->devpath, "/drivers/") != NULL) { udev_device_set_subsystem(udev_device, "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_set_subsystem(udev_device, "subsystem"); return udev_device->subsystem; } } return udev_device->subsystem; } mode_t udev_device_get_devnode_mode(struct udev_device *udev_device) { if (!udev_device->info_loaded) udev_device_read_uevent_file(udev_device); return udev_device->devnode_mode; } static int udev_device_set_devnode_mode(struct udev_device *udev_device, mode_t mode) { char num[32]; udev_device->devnode_mode = mode; snprintf(num, sizeof(num), "%#o", mode); udev_device_add_property(udev_device, "DEVMODE", num); return 0; } struct udev_list_entry *udev_device_add_property(struct udev_device *udev_device, const char *key, const char *value) { udev_device->envp_uptodate = false; if (value == NULL) { struct udev_list_entry *list_entry; list_entry = udev_device_get_properties_list_entry(udev_device); list_entry = udev_list_entry_get_by_name(list_entry, key); if (list_entry != NULL) udev_list_entry_delete(list_entry); return NULL; } return udev_list_entry_add(&udev_device->properties_list, key, value); } static struct udev_list_entry *udev_device_add_property_from_string(struct udev_device *udev_device, const char *property) { char name[UTIL_LINE_SIZE]; char *val; util_strscpy(name, sizeof(name), property); val = strchr(name, '='); if (val == NULL) return NULL; val[0] = '\0'; val = &val[1]; if (val[0] == '\0') val = NULL; return udev_device_add_property(udev_device, name, val); } /* * parse property string, and if needed, update internal values accordingly * * udev_device_add_property_from_string_parse_finish() needs to be * called after adding properties, and its return value checked * * udev_device_set_info_loaded() needs to be set, to avoid trying * to use a device without a DEVPATH set */ void udev_device_add_property_from_string_parse(struct udev_device *udev_device, const char *property) { if (strncmp(property, "DEVPATH=", 8) == 0) { char path[UTIL_PATH_SIZE]; util_strscpyl(path, sizeof(path), udev_get_sys_path(udev_device->udev), &property[8], NULL); udev_device_set_syspath(udev_device, path); } else if (strncmp(property, "SUBSYSTEM=", 10) == 0) { udev_device_set_subsystem(udev_device, &property[10]); } else if (strncmp(property, "DEVTYPE=", 8) == 0) { udev_device_set_devtype(udev_device, &property[8]); } else if (strncmp(property, "DEVNAME=", 8) == 0) { udev_device_set_devnode(udev_device, &property[8]); } else if (strncmp(property, "DEVLINKS=", 9) == 0) { char devlinks[UTIL_PATH_SIZE]; char *slink; char *next; util_strscpy(devlinks, sizeof(devlinks), &property[9]); slink = devlinks; next = strchr(slink, ' '); while (next != NULL) { next[0] = '\0'; udev_device_add_devlink(udev_device, slink, 0); slink = &next[1]; next = strchr(slink, ' '); } if (slink[0] != '\0') udev_device_add_devlink(udev_device, slink, 0); } else if (strncmp(property, "TAGS=", 5) == 0) { char tags[UTIL_PATH_SIZE]; char *next; util_strscpy(tags, sizeof(tags), &property[5]); next = strchr(tags, ':'); if (next != NULL) { next++; while (next[0] != '\0') { char *tag; tag = next; next = strchr(tag, ':'); if (next == NULL) break; next[0] = '\0'; next++; udev_device_add_tag(udev_device, tag); } } } else if (strncmp(property, "USEC_INITIALIZED=", 19) == 0) { udev_device_set_usec_initialized(udev_device, strtoull(&property[19], NULL, 10)); } else if (strncmp(property, "DRIVER=", 7) == 0) { udev_device_set_driver(udev_device, &property[7]); } else if (strncmp(property, "ACTION=", 7) == 0) { udev_device_set_action(udev_device, &property[7]); } else if (strncmp(property, "MAJOR=", 6) == 0) { udev_device->maj = strtoull(&property[6], NULL, 10); } else if (strncmp(property, "MINOR=", 6) == 0) { udev_device->min = strtoull(&property[6], NULL, 10); } else if (strncmp(property, "DEVPATH_OLD=", 12) == 0) { udev_device_set_devpath_old(udev_device, &property[12]); } else if (strncmp(property, "SEQNUM=", 7) == 0) { udev_device_set_seqnum(udev_device, strtoull(&property[7], NULL, 10)); } else if (strncmp(property, "IFINDEX=", 8) == 0) { udev_device_set_ifindex(udev_device, strtoull(&property[8], NULL, 10)); } else if (strncmp(property, "DEVMODE=", 8) == 0) { udev_device_set_devnode_mode(udev_device, strtoul(&property[8], NULL, 8)); } else { udev_device_add_property_from_string(udev_device, property); } } int udev_device_add_property_from_string_parse_finish(struct udev_device *udev_device) { if (udev_device->maj > 0) udev_device_set_devnum(udev_device, makedev(udev_device->maj, udev_device->min)); udev_device->maj = 0; udev_device->min = 0; if (udev_device->devpath == NULL || udev_device->subsystem == NULL) return -EINVAL; return 0; } /** * udev_device_get_property_value: * @udev_device: udev device * @key: property name * * Returns: the value of a device property, or #NULL if there is no such property. **/ UDEV_EXPORT const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key) { struct udev_list_entry *list_entry; if (udev_device == NULL) return NULL; if (key == NULL) return NULL; list_entry = udev_device_get_properties_list_entry(udev_device); list_entry = udev_list_entry_get_by_name(list_entry, key); return udev_list_entry_get_value(list_entry); } int udev_device_read_db(struct udev_device *udev_device, const char *dbfile) { char filename[UTIL_PATH_SIZE]; char line[UTIL_LINE_SIZE]; FILE *f; /* providing a database file will always force-load it */ if (dbfile == NULL) { const char *id; if (udev_device->db_loaded) return 0; udev_device->db_loaded = true; id = udev_device_get_id_filename(udev_device); if (id == NULL) return -1; util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev_device->udev), "/data/", id, NULL); dbfile = filename; } f = fopen(dbfile, "re"); if (f == NULL) { info(udev_device->udev, "no db file to read %s: %m\n", dbfile); return -1; } udev_device->is_initialized = true; while (fgets(line, sizeof(line), f)) { ssize_t len; const char *val; struct udev_list_entry *entry; len = strlen(line); if (len < 4) break; line[len-1] = '\0'; val = &line[2]; switch(line[0]) { case 'S': util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_device->udev), "/", val, NULL); udev_device_add_devlink(udev_device, filename, 0); break; case 'L': udev_device_set_devlink_priority(udev_device, atoi(val)); break; case 'E': entry = udev_device_add_property_from_string(udev_device, val); udev_list_entry_set_num(entry, true); break; case 'G': udev_device_add_tag(udev_device, val); break; case 'W': udev_device_set_watch_handle(udev_device, atoi(val)); break; case 'I': udev_device_set_usec_initialized(udev_device, strtoull(val, NULL, 10)); break; } } fclose(f); info(udev_device->udev, "device %p filled with db file data\n", udev_device); return 0; } int udev_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; if (udev_device->uevent_loaded) return 0; util_strscpyl(filename, sizeof(filename), udev_device->syspath, "/uevent", NULL); f = fopen(filename, "re"); if (f == NULL) return -1; udev_device->uevent_loaded = true; while (fgets(line, sizeof(line), f)) { char *pos; pos = strchr(line, '\n'); if (pos == NULL) continue; pos[0] = '\0'; if (strncmp(line, "DEVTYPE=", 8) == 0) { udev_device_set_devtype(udev_device, &line[8]); continue; } if (strncmp(line, "IFINDEX=", 8) == 0) { udev_device_set_ifindex(udev_device, strtoull(&line[8], NULL, 10)); continue; } if (strncmp(line, "DEVNAME=", 8) == 0) { udev_device_set_devnode(udev_device, &line[8]); continue; } 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); else if (strncmp(line, "DEVMODE=", 8) == 0) udev_device->devnode_mode = strtoul(&line[8], NULL, 8); udev_device_add_property_from_string(udev_device, line); } udev_device->devnum = makedev(maj, min); fclose(f); return 0; } void udev_device_set_info_loaded(struct udev_device *device) { device->info_loaded = true; } struct udev_device *udev_device_new(struct udev *udev) { struct udev_device *udev_device; struct udev_list_entry *list_entry; if (udev == NULL) return NULL; udev_device = calloc(1, sizeof(struct udev_device)); if (udev_device == NULL) return NULL; udev_device->refcount = 1; udev_device->udev = udev; udev_list_init(udev, &udev_device->devlinks_list, true); udev_list_init(udev, &udev_device->properties_list, true); udev_list_init(udev, &udev_device->sysattr_value_list, true); udev_list_init(udev, &udev_device->sysattr_list, false); udev_list_init(udev, &udev_device->tags_list, true); udev_device->watch_handle = -1; /* copy global properties */ udev_list_entry_foreach(list_entry, udev_get_properties_list_entry(udev)) udev_device_add_property(udev_device, udev_list_entry_get_name(list_entry), udev_list_entry_get_value(list_entry)); dbg(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 syspath 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 resources of the udev device. * * Returns: a new udev device, or #NULL, if it does not exist **/ UDEV_EXPORT struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath) { size_t len; const char *subdir; char path[UTIL_PATH_SIZE]; char *pos; 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[1] == '\0' || pos < &subdir[2]) { dbg(udev, "not a subdir :%s\n", syspath); return NULL; } /* resolve possible symlink to real path */ util_strscpy(path, sizeof(path), syspath); util_resolve_sys_link(udev, path, sizeof(path)); if (strncmp(&path[len], "/devices/", 9) == 0) { char file[UTIL_PATH_SIZE]; /* all "devices" require a "uevent" file */ util_strscpyl(file, sizeof(file), path, "/uevent", NULL); if (stat(file, &statbuf) != 0) { dbg(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)) { dbg(udev, "directory not found: %s\n", syspath); return NULL; } } udev_device = udev_device_new(udev); if (udev_device == NULL) return NULL; udev_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; } /** * udev_device_new_from_devnum: * @udev: udev library context * @type: char or block device * @devnum: device major/minor number * * Create new udev device, and fill in information from the sys * device and the udev database entry. The device is looked-up * by its major/minor number and type. Character and block device * numbers are not unique across the two types. * * The initial refcount is 1, and needs to be decremented to * release the resources of the udev device. * * Returns: a new udev device, or #NULL, if it does not exist **/ UDEV_EXPORT 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; if (type == 'b') type_str = "block"; else if (type == 'c') type_str = "char"; else return NULL; /* use /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)); return udev_device_new_from_syspath(udev, path); } struct udev_device *udev_device_new_from_id_filename(struct udev *udev, char *id) { char type; int maj, min; char subsys[UTIL_PATH_SIZE]; char *sysname; switch(id[0]) { case 'b': case 'c': if (sscanf(id, "%c%i:%i", &type, &maj, &min) != 3) return NULL; return udev_device_new_from_devnum(udev, type, makedev(maj, min)); case 'n': { int sk; struct ifreq ifr; struct udev_device *dev; int ifindex; ifindex = strtoul(&id[1], NULL, 10); if (ifindex <= 0) return NULL; sk = socket(PF_INET, SOCK_DGRAM, 0); if (sk < 0) return NULL; memset(&ifr, 0x00, sizeof(struct ifreq)); ifr.ifr_ifindex = ifindex; if (ioctl(sk, SIOCGIFNAME, &ifr) != 0) { close(sk); return NULL; } close(sk); dev = udev_device_new_from_subsystem_sysname(udev, "net", ifr.ifr_name); if (dev == NULL) return NULL; if (udev_device_get_ifindex(dev) == ifindex) return dev; udev_device_unref(dev); return NULL; } case '+': util_strscpy(subsys, sizeof(subsys), &id[1]); sysname = strchr(subsys, ':'); if (sysname == NULL) return NULL; sysname[0] = '\0'; sysname = &sysname[1]; return udev_device_new_from_subsystem_sysname(udev, subsys, sysname); default: return NULL; } } /** * udev_device_new_from_subsystem_sysname: * @udev: udev library context * @subsystem: the subsystem of the device * @sysname: the name of the device * * Create new udev device, and fill in information from the sys device * and the udev database entry. The device is looked up by the subsystem * and name string of the device, like "mem" / "zero", or "block" / "sda". * * The initial refcount is 1, and needs to be decremented to * release the resources of the udev device. * * Returns: a new udev device, or #NULL, if it does not exist **/ UDEV_EXPORT struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname) { char path_full[UTIL_PATH_SIZE]; char *path; size_t l; struct stat statbuf; path = path_full; l = util_strpcpyl(&path, sizeof(path_full), udev_get_sys_path(udev), NULL); if (strcmp(subsystem, "subsystem") == 0) { util_strscpyl(path, l, "/subsystem/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; util_strscpyl(path, l, "/bus/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; util_strscpyl(path, l, "/class/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; goto out; } if (strcmp(subsystem, "module") == 0) { util_strscpyl(path, l, "/module/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; goto out; } if (strcmp(subsystem, "drivers") == 0) { char subsys[UTIL_NAME_SIZE]; char *driver; util_strscpy(subsys, sizeof(subsys), sysname); driver = strchr(subsys, ':'); if (driver != NULL) { driver[0] = '\0'; driver = &driver[1]; util_strscpyl(path, l, "/subsystem/", subsys, "/drivers/", driver, NULL); if (stat(path_full, &statbuf) == 0) goto found; util_strscpyl(path, l, "/bus/", subsys, "/drivers/", driver, NULL); if (stat(path_full, &statbuf) == 0) goto found; } goto out; } util_strscpyl(path, l, "/subsystem/", subsystem, "/devices/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; util_strscpyl(path, l, "/bus/", subsystem, "/devices/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; util_strscpyl(path, l, "/class/", subsystem, "/", sysname, NULL); if (stat(path_full, &statbuf) == 0) goto found; out: return NULL; found: return udev_device_new_from_syspath(udev, path_full); } /** * udev_device_new_from_environment * @udev: udev library context * * Create new udev device, and fill in information from the * current process environment. This only works reliable if * the process is called from a udev rule. It is usually used * for tools executed from IMPORT= rules. * * The initial refcount is 1, and needs to be decremented to * release the resources of the udev device. * * Returns: a new udev device, or #NULL, if it does not exist **/ UDEV_EXPORT struct udev_device *udev_device_new_from_environment(struct udev *udev) { int i; struct udev_device *udev_device; udev_device = udev_device_new(udev); if (udev_device == NULL) return NULL; udev_device_set_info_loaded(udev_device); for (i = 0; environ[i] != NULL; i++) udev_device_add_property_from_string_parse(udev_device, environ[i]); if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) { info(udev, "missing values, invalid device\n"); udev_device_unref(udev_device); udev_device = NULL; } return udev_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; util_strscpy(path, sizeof(path), udev_device->syspath); subdir = &path[strlen(udev_get_sys_path(udev_device->udev))+1]; for (;;) { 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; } /** * udev_device_get_parent: * @udev_device: the device to start searching from * * Find the next parent device, and fill in information from the sys * device and the udev database entry. * * The returned the device is not referenced. It is attached to the * child device, and will be cleaned up when the child device * is cleaned up. * * It is not necessarily just the upper level directory, empty or not * recognized sys directories are ignored. * * It can be called as many times as needed, without caring about * references. * * Returns: a new udev device, or #NULL, if it no parent exist. **/ UDEV_EXPORT struct udev_device *udev_device_get_parent(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (!udev_device->parent_set) { udev_device->parent_set = true; udev_device->parent_device = device_new_from_parent(udev_device); } if (udev_device->parent_device != NULL) dbg(udev_device->udev, "returning existing parent %p\n", udev_device->parent_device); return udev_device->parent_device; } /** * udev_device_get_parent_with_subsystem_devtype: * @udev_device: udev device to start searching from * @subsystem: the subsystem of the device * @devtype: the type (DEVTYPE) of the device * * Find the next parent device, with a matching subsystem and devtype * value, and fill in information from the sys device and the udev * database entry. * * If devtype is #NULL, only subsystem is checked, and any devtype will * match. * * The returned the device is not referenced. It is attached to the * child device, and will be cleaned up when the child device * is cleaned up. * * It can be called as many times as needed, without caring about * references. * * Returns: a new udev device, or #NULL if no matching parent exists. **/ UDEV_EXPORT struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype) { struct udev_device *parent; if (subsystem == NULL) return NULL; parent = udev_device_get_parent(udev_device); while (parent != NULL) { const char *parent_subsystem; const char *parent_devtype; parent_subsystem = udev_device_get_subsystem(parent); if (parent_subsystem != NULL && strcmp(parent_subsystem, subsystem) == 0) { if (devtype == NULL) break; parent_devtype = udev_device_get_devtype(parent); if (parent_devtype != NULL && strcmp(parent_devtype, devtype) == 0) break; } parent = udev_device_get_parent(parent); } return parent; } /** * udev_device_get_udev: * @udev_device: udev device * * Retrieve the udev library context the device was created with. * * Returns: the udev library context **/ UDEV_EXPORT 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 **/ UDEV_EXPORT 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 resources of the device will be released. * **/ UDEV_EXPORT 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->sysname); free(udev_device->devnode); free(udev_device->subsystem); free(udev_device->devtype); udev_list_cleanup(&udev_device->devlinks_list); udev_list_cleanup(&udev_device->properties_list); udev_list_cleanup(&udev_device->sysattr_value_list); udev_list_cleanup(&udev_device->sysattr_list); udev_list_cleanup(&udev_device->tags_list); free(udev_device->action); free(udev_device->driver); free(udev_device->devpath_old); free(udev_device->id_filename); free(udev_device->envp); free(udev_device->monitor_buf); dbg(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 **/ UDEV_EXPORT 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 **/ UDEV_EXPORT const char *udev_device_get_syspath(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->syspath; } /** * udev_device_get_sysname: * @udev_device: udev device * * Returns: the sys name of the device device **/ UDEV_EXPORT const char *udev_device_get_sysname(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->sysname; } /** * udev_device_get_sysnum: * @udev_device: udev device * * Returns: the trailing number of of the device name **/ UDEV_EXPORT const char *udev_device_get_sysnum(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->sysnum; } /** * 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 **/ UDEV_EXPORT const char *udev_device_get_devnode(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (udev_device->devnode != NULL) return udev_device->devnode; if (!udev_device->info_loaded) udev_device_read_uevent_file(udev_device); return udev_device->devnode; } /** * 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 **/ UDEV_EXPORT 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) udev_device_read_db(udev_device, NULL); return udev_list_get_entry(&udev_device->devlinks_list); } void udev_device_cleanup_devlinks_list(struct udev_device *udev_device) { udev_device->devlinks_uptodate = false; udev_list_cleanup(&udev_device->devlinks_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 **/ UDEV_EXPORT 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) { udev_device_read_uevent_file(udev_device); udev_device_read_db(udev_device, NULL); } if (!udev_device->devlinks_uptodate) { char symlinks[UTIL_PATH_SIZE]; struct udev_list_entry *list_entry; udev_device->devlinks_uptodate = true; list_entry = udev_device_get_devlinks_list_entry(udev_device); if (list_entry != NULL) { char *s; size_t l; s = symlinks; l = util_strpcpyl(&s, sizeof(symlinks), udev_list_entry_get_name(list_entry), NULL); udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry)) l = util_strpcpyl(&s, l, " ", udev_list_entry_get_name(list_entry), NULL); udev_device_add_property(udev_device, "DEVLINKS", symlinks); } } if (!udev_device->tags_uptodate) { udev_device->tags_uptodate = true; if (udev_device_get_tags_list_entry(udev_device) != NULL) { char tags[UTIL_PATH_SIZE]; struct udev_list_entry *list_entry; char *s; size_t l; s = tags; l = util_strpcpyl(&s, sizeof(tags), ":", NULL); udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device)) l = util_strpcpyl(&s, l, udev_list_entry_get_name(list_entry), ":", NULL); udev_device_add_property(udev_device, "TAGS", tags); } } return udev_list_get_entry(&udev_device->properties_list); } /** * udev_device_get_action: * @udev_device: udev device * * This is only valid if the device was received through a monitor. Devices read from * sys do not have an action string. Usual actions are: add, remove, change, online, * offline. * * Returns: the kernel action value, or #NULL if there is no action value available. **/ UDEV_EXPORT const char *udev_device_get_action(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; return udev_device->action; } /** * udev_device_get_usec_since_initialized: * @udev_device: udev device * * Return the number of microseconds passed since udev set up the * device for the first time. * * This is only implemented for devices with need to store properties * in the udev database. All other devices return 0 here. * * Returns: the number of microseconds since the device was first seen. **/ UDEV_EXPORT unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device) { unsigned long long now; if (udev_device == NULL) return 0; if (!udev_device->info_loaded) udev_device_read_db(udev_device, NULL); if (udev_device->usec_initialized == 0) return 0; now = now_usec(); if (now == 0) return 0; return now - udev_device->usec_initialized; } unsigned long long udev_device_get_usec_initialized(struct udev_device *udev_device) { return udev_device->usec_initialized; } void udev_device_set_usec_initialized(struct udev_device *udev_device, unsigned long long usec_initialized) { char num[32]; udev_device->usec_initialized = usec_initialized; snprintf(num, sizeof(num), "%llu", usec_initialized); udev_device_add_property(udev_device, "USEC_INITIALIZED", num); } /** * udev_device_get_sysattr_value: * @udev_device: udev device * @sysattr: attribute name * * The retrieved value is cached in the device. Repeated calls will return the same * value and not open the attribute again. * * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value. **/ UDEV_EXPORT const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr) { struct udev_list_entry *list_entry; char path[UTIL_PATH_SIZE]; char value[4096]; struct stat statbuf; int fd; ssize_t size; const char *val = NULL; if (udev_device == NULL) return NULL; if (sysattr == NULL) return NULL; /* look for possibly already cached result */ list_entry = udev_list_get_entry(&udev_device->sysattr_value_list); list_entry = udev_list_entry_get_by_name(list_entry, sysattr); if (list_entry != NULL) { dbg(udev_device->udev, "got '%s' (%s) from cache\n", sysattr, udev_list_entry_get_value(list_entry)); return udev_list_entry_get_value(list_entry); } util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", sysattr, NULL); if (lstat(path, &statbuf) != 0) { dbg(udev_device->udev, "no attribute '%s', keep negative entry\n", path); udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, NULL); goto out; } if (S_ISLNK(statbuf.st_mode)) { struct udev_device *dev; /* * Some core links return only the last element of the target path, * these are just values, the paths should not be exposed. */ if (strcmp(sysattr, "driver") == 0 || strcmp(sysattr, "subsystem") == 0 || strcmp(sysattr, "module") == 0) { if (util_get_sys_core_link_value(udev_device->udev, sysattr, udev_device->syspath, value, sizeof(value)) < 0) return NULL; dbg(udev_device->udev, "cache '%s' with link value '%s'\n", sysattr, value); list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value); val = udev_list_entry_get_value(list_entry); goto out; } /* resolve link to a device and return its syspath */ util_strscpyl(path, sizeof(path), udev_device->syspath, "/", sysattr, NULL); dev = udev_device_new_from_syspath(udev_device->udev, path); if (dev != NULL) { list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, udev_device_get_syspath(dev)); val = udev_list_entry_get_value(list_entry); udev_device_unref(dev); } 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|O_CLOEXEC); if (fd < 0) { dbg(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'); dbg(udev_device->udev, "'%s' has attribute value '%s'\n", path, value); list_entry = udev_list_entry_add(&udev_device->sysattr_value_list, sysattr, value); val = udev_list_entry_get_value(list_entry); out: return val; } static int udev_device_sysattr_list_read(struct udev_device *udev_device) { struct dirent *dent; DIR *dir; int num = 0; if (udev_device == NULL) return -1; if (udev_device->sysattr_list_read) return 0; dir = opendir(udev_device_get_syspath(udev_device)); if (!dir) { dbg(udev_device->udev, "sysfs dir '%s' can not be opened\n", udev_device_get_syspath(udev_device)); return -1; } for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { char path[UTIL_PATH_SIZE]; struct stat statbuf; /* only handle symlinks and regular files */ if (dent->d_type != DT_LNK && dent->d_type != DT_REG) continue; util_strscpyl(path, sizeof(path), udev_device_get_syspath(udev_device), "/", dent->d_name, NULL); if (lstat(path, &statbuf) != 0) continue; if ((statbuf.st_mode & S_IRUSR) == 0) continue; udev_list_entry_add(&udev_device->sysattr_list, dent->d_name, NULL); num++; } closedir(dir); dbg(udev_device->udev, "found %d sysattrs for '%s'\n", num, udev_device_get_syspath(udev_device)); udev_device->sysattr_list_read = true; return num; } /** * udev_device_get_sysattr_list_entry: * @udev_device: udev device * * Retrieve the list of available sysattrs, with value being empty; * This just return all available sysfs attributes for a particular * device without reading their values. * * Returns: the first entry of the property list **/ UDEV_EXPORT struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device) { if (!udev_device->sysattr_list_read) { int ret; ret = udev_device_sysattr_list_read(udev_device); if (0 > ret) return NULL; } return udev_list_get_entry(&udev_device->sysattr_list); } int udev_device_set_syspath(struct udev_device *udev_device, const char *syspath) { const char *pos; size_t len; free(udev_device->syspath); 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))]; udev_device_add_property(udev_device, "DEVPATH", udev_device->devpath); pos = strrchr(udev_device->syspath, '/'); if (pos == NULL) return -EINVAL; udev_device->sysname = strdup(&pos[1]); if (udev_device->sysname == NULL) return -ENOMEM; /* some devices have '!' in their name, change that to '/' */ len = 0; while (udev_device->sysname[len] != '\0') { if (udev_device->sysname[len] == '!') udev_device->sysname[len] = '/'; len++; } /* trailing number */ while (len > 0 && isdigit(udev_device->sysname[--len])) udev_device->sysnum = &udev_device->sysname[len]; /* sysname is completely numeric */ if (len == 0) udev_device->sysnum = NULL; return 0; } int udev_device_set_devnode(struct udev_device *udev_device, const char *devnode) { free(udev_device->devnode); if (devnode[0] != '/') { if (asprintf(&udev_device->devnode, "%s/%s", udev_get_dev_path(udev_device->udev), devnode) < 0) udev_device->devnode = NULL; } else { udev_device->devnode = strdup(devnode); } if (udev_device->devnode == NULL) return -ENOMEM; udev_device_add_property(udev_device, "DEVNAME", udev_device->devnode); return 0; } int udev_device_add_devlink(struct udev_device *udev_device, const char *devlink, int unique) { struct udev_list_entry *list_entry; udev_device->devlinks_uptodate = false; list_entry = udev_list_entry_add(&udev_device->devlinks_list, devlink, NULL); if (list_entry == NULL) return -ENOMEM; if (unique) udev_list_entry_set_num(list_entry, true); return 0; } const char *udev_device_get_id_filename(struct udev_device *udev_device) { if (udev_device->id_filename == NULL) { if (udev_device_get_subsystem(udev_device) == NULL) return NULL; if (major(udev_device_get_devnum(udev_device)) > 0) { /* use dev_t -- b259:131072, c254:0 */ if (asprintf(&udev_device->id_filename, "%c%u:%u", strcmp(udev_device_get_subsystem(udev_device), "block") == 0 ? 'b' : 'c', major(udev_device_get_devnum(udev_device)), minor(udev_device_get_devnum(udev_device))) < 0) udev_device->id_filename = NULL; } else if (udev_device_get_ifindex(udev_device) > 0) { /* use netdev ifindex -- n3 */ if (asprintf(&udev_device->id_filename, "n%u", udev_device_get_ifindex(udev_device)) < 0) udev_device->id_filename = NULL; } else { /* * use $subsys:$syname -- pci:0000:00:1f.2 * sysname() has '!' translated, get it from devpath */ const char *sysname; sysname = strrchr(udev_device->devpath, '/'); if (sysname == NULL) return NULL; sysname = &sysname[1]; if (asprintf(&udev_device->id_filename, "+%s:%s", udev_device_get_subsystem(udev_device), sysname) < 0) udev_device->id_filename = NULL; } } return udev_device->id_filename; } /** * udev_device_get_is_initialized: * @udev_device: udev device * * Check if udev has already handled the device and has set up * device node permissions and context, or has renamed a network * device. * * This is only implemented for devices with a device node * or network interfaces. All other devices return 1 here. * * Returns: 1 if the device is set up. 0 otherwise. **/ UDEV_EXPORT int udev_device_get_is_initialized(struct udev_device *udev_device) { if (!udev_device->info_loaded) udev_device_read_db(udev_device, NULL); return udev_device->is_initialized; } void udev_device_set_is_initialized(struct udev_device *udev_device) { udev_device->is_initialized = true; } int udev_device_add_tag(struct udev_device *udev_device, const char *tag) { if (strchr(tag, ':') != NULL || strchr(tag, ' ') != NULL) return -EINVAL; udev_device->tags_uptodate = false; if (udev_list_entry_add(&udev_device->tags_list, tag, NULL) != NULL) return 0; return -ENOMEM; } void udev_device_cleanup_tags_list(struct udev_device *udev_device) { udev_device->tags_uptodate = false; udev_list_cleanup(&udev_device->tags_list); } /** * udev_device_get_tags_list_entry: * @udev_device: udev device * * Retrieve the list of tags attached to the udev device. The next * list entry can be retrieved with udev_list_entry_next(), * which returns #NULL if no more entries exist. The tag string * can be retrieved from the list entry by udev_list_get_name(). * * Returns: the first entry of the tag list **/ UDEV_EXPORT struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device) { if (udev_device == NULL) return NULL; if (!udev_device->info_loaded) udev_device_read_db(udev_device, NULL); return udev_list_get_entry(&udev_device->tags_list); } UDEV_EXPORT int udev_device_has_tag(struct udev_device *udev_device, const char *tag) { struct udev_list_entry *list_entry; if (udev_device == NULL) return false; if (!udev_device->info_loaded) udev_device_read_db(udev_device, NULL); list_entry = udev_device_get_tags_list_entry(udev_device); if (udev_list_entry_get_by_name(list_entry, tag) != NULL) return true; return false; } #define ENVP_SIZE 128 #define MONITOR_BUF_SIZE 4096 static int update_envp_monitor_buf(struct udev_device *udev_device) { struct udev_list_entry *list_entry; char *s; size_t l; unsigned int i; /* monitor buffer of property strings */ free(udev_device->monitor_buf); udev_device->monitor_buf_len = 0; udev_device->monitor_buf = malloc(MONITOR_BUF_SIZE); if (udev_device->monitor_buf == NULL) return -ENOMEM; /* envp array, strings will point into monitor buffer */ if (udev_device->envp == NULL) udev_device->envp = malloc(sizeof(char *) * ENVP_SIZE); if (udev_device->envp == NULL) return -ENOMEM; i = 0; s = udev_device->monitor_buf; l = MONITOR_BUF_SIZE; udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) { const char *key; key = udev_list_entry_get_name(list_entry); /* skip private variables */ if (key[0] == '.') continue; /* add string to envp array */ udev_device->envp[i++] = s; if (i+1 >= ENVP_SIZE) return -EINVAL; /* add property string to monitor buffer */ l = util_strpcpyl(&s, l, key, "=", udev_list_entry_get_value(list_entry), NULL); if (l == 0) return -EINVAL; /* advance past the trailing '\0' that util_strpcpyl() guarantees */ s++; l--; } udev_device->envp[i] = NULL; udev_device->monitor_buf_len = s - udev_device->monitor_buf; udev_device->envp_uptodate = true; dbg(udev_device->udev, "filled envp/monitor buffer, %u properties, %zu bytes\n", i, udev_device->monitor_buf_len); return 0; } char **udev_device_get_properties_envp(struct udev_device *udev_device) { if (!udev_device->envp_uptodate) if (update_envp_monitor_buf(udev_device) != 0) return NULL; return udev_device->envp; } ssize_t udev_device_get_properties_monitor_buf(struct udev_device *udev_device, const char **buf) { if (!udev_device->envp_uptodate) if (update_envp_monitor_buf(udev_device) != 0) return -EINVAL; *buf = udev_device->monitor_buf; return udev_device->monitor_buf_len; } int udev_device_set_action(struct udev_device *udev_device, const char *action) { free(udev_device->action); udev_device->action = strdup(action); if (udev_device->action == NULL) return -ENOMEM; udev_device_add_property(udev_device, "ACTION", udev_device->action); return 0; } int udev_device_get_devlink_priority(struct udev_device *udev_device) { if (!udev_device->info_loaded) udev_device_read_db(udev_device, NULL); return udev_device->devlink_priority; } int udev_device_set_devlink_priority(struct udev_device *udev_device, int prio) { udev_device->devlink_priority = prio; return 0; } int udev_device_get_watch_handle(struct udev_device *udev_device) { if (!udev_device->info_loaded) udev_device_read_db(udev_device, NULL); return udev_device->watch_handle; } int udev_device_set_watch_handle(struct udev_device *udev_device, int handle) { udev_device->watch_handle = handle; return 0; } bool udev_device_get_db_persist(struct udev_device *udev_device) { return udev_device->db_persist; } void udev_device_set_db_persist(struct udev_device *udev_device) { udev_device->db_persist = true; }