/*** This file is part of systemd. Copyright 2008-2012 Kay Sievers <kay@vrfy.org> Copyright 2015 Tom Gundersen <teg@jklm.no> systemd 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. systemd 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <ctype.h> #include <dirent.h> #include <errno.h> #include <fcntl.h> #include <linux/sockios.h> #include <net/if.h> #include <stdbool.h> #include <stddef.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <sys/ioctl.h> #include <sys/socket.h> #include <sys/stat.h> #include <unistd.h> #include "libudev.h" #include "sd-device.h" #include "alloc-util.h" #include "device-private.h" #include "device-util.h" #include "libudev-device-internal.h" #include "libudev-private.h" #include "parse-util.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 have * a unique name inside that subsystem. */ /** * 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. **/ _public_ unsigned long long int udev_device_get_seqnum(struct udev_device *udev_device) { const char *seqnum; unsigned long long ret; int r; assert_return_errno(udev_device, 0, EINVAL); r = sd_device_get_property_value(udev_device->device, "SEQNUM", &seqnum); if (r == -ENOENT) return 0; else if (r < 0) { errno = -r; return 0; } r = safe_atollu(seqnum, &ret); if (r < 0) { errno = -r; return 0; } return ret; } /** * udev_device_get_devnum: * @udev_device: udev device * * Get the device major/minor number. * * Returns: the dev_t number. **/ _public_ dev_t udev_device_get_devnum(struct udev_device *udev_device) { dev_t devnum; int r; assert_return_errno(udev_device, makedev(0, 0), EINVAL); r = sd_device_get_devnum(udev_device->device, &devnum); if (r < 0) { errno = -r; return makedev(0, 0); } return devnum; } /** * udev_device_get_driver: * @udev_device: udev device * * Get the kernel driver name. * * Returns: the driver name string, or #NULL if there is no driver attached. **/ _public_ const char *udev_device_get_driver(struct udev_device *udev_device) { const char *driver; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_driver(udev_device->device, &driver); if (r < 0) { errno = -r; return NULL; } return driver; } /** * 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 **/ _public_ const char *udev_device_get_devtype(struct udev_device *udev_device) { const char *devtype; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_devtype(udev_device->device, &devtype); if (r < 0) { errno = -r; return NULL; } return devtype; } /** * 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 **/ _public_ const char *udev_device_get_subsystem(struct udev_device *udev_device) { const char *subsystem; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_subsystem(udev_device->device, &subsystem); if (r < 0) { errno = -r; return NULL; } else if (!subsystem) errno = ENODATA; return subsystem; } /** * udev_device_get_property_value: * @udev_device: udev device * @key: property name * * Get the value of a given property. * * Returns: the property string, or #NULL if there is no such property. **/ _public_ const char *udev_device_get_property_value(struct udev_device *udev_device, const char *key) { const char *value = NULL; int r; assert_return_errno(udev_device && key, NULL, EINVAL); r = sd_device_get_property_value(udev_device->device, key, &value); if (r < 0) { errno = -r; return NULL; } return value; } struct udev_device *udev_device_new(struct udev *udev) { struct udev_device *udev_device; assert_return_errno(udev, NULL, EINVAL); udev_device = new0(struct udev_device, 1); if (!udev_device) { errno = ENOMEM; return NULL; } udev_device->refcount = 1; udev_device->udev = udev; udev_list_init(udev, &udev_device->properties, true); udev_list_init(udev, &udev_device->tags, true); udev_list_init(udev, &udev_device->sysattrs, true); udev_list_init(udev, &udev_device->devlinks, true); 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 **/ _public_ struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath) { struct udev_device *udev_device; int r; udev_device = udev_device_new(udev); if (!udev_device) return NULL; r = sd_device_new_from_syspath(&udev_device->device, syspath); if (r < 0) { errno = -r; udev_device_unref(udev_device); return NULL; } 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 **/ _public_ struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum) { struct udev_device *udev_device; int r; udev_device = udev_device_new(udev); if (!udev_device) return NULL; r = sd_device_new_from_devnum(&udev_device->device, type, devnum); if (r < 0) { errno = -r; udev_device_unref(udev_device); return NULL; } return udev_device; } /** * udev_device_new_from_device_id: * @udev: udev library context * @id: text string identifying a kernel device * * Create new udev device, and fill in information from the sys * device and the udev database entry. The device is looked-up * by a special string: * b8:2 - block device major:minor * c128:1 - char device major:minor * n3 - network device ifindex * +sound:card29 - kernel driver core subsystem:device name * * 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 **/ _public_ struct udev_device *udev_device_new_from_device_id(struct udev *udev, const char *id) { struct udev_device *udev_device; int r; udev_device = udev_device_new(udev); if (!udev_device) return NULL; r = sd_device_new_from_device_id(&udev_device->device, id); if (r < 0) { errno = -r; udev_device_unref(udev_device); return NULL; } return udev_device; } /** * 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 **/ _public_ struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname) { struct udev_device *udev_device; int r; udev_device = udev_device_new(udev); if (!udev_device) return NULL; r = sd_device_new_from_subsystem_sysname(&udev_device->device, subsystem, sysname); if (r < 0) { errno = -r; udev_device_unref(udev_device); return NULL; } return udev_device; } /** * 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 **/ _public_ struct udev_device *udev_device_new_from_environment(struct udev *udev) { struct udev_device *udev_device; int r; udev_device = udev_device_new(udev); if (!udev_device) return NULL; r = device_new_from_strv(&udev_device->device, environ); if (r < 0) { errno = -r; udev_device_unref(udev_device); return NULL; } return udev_device; } static struct udev_device *device_new_from_parent(struct udev_device *child) { struct udev_device *parent; int r; assert_return_errno(child, NULL, EINVAL); parent = udev_device_new(child->udev); if (!parent) return NULL; r = sd_device_get_parent(child->device, &parent->device); if (r < 0) { errno = -r; udev_device_unref(parent); return NULL; } /* the parent is unref'ed with the child, so take a ref from libudev as well */ sd_device_ref(parent->device); return parent; } /** * 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. * * Returned 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. **/ _public_ struct udev_device *udev_device_get_parent(struct udev_device *udev_device) { assert_return_errno(udev_device, NULL, EINVAL); if (!udev_device->parent_set) { udev_device->parent_set = true; udev_device->parent = device_new_from_parent(udev_device); } /* TODO: errno will differ here in case parent == NULL */ return udev_device->parent; } /** * 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. * * Returned 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. **/ _public_ struct udev_device *udev_device_get_parent_with_subsystem_devtype(struct udev_device *udev_device, const char *subsystem, const char *devtype) { sd_device *parent; int r; assert_return_errno(udev_device, NULL, EINVAL); /* this relies on the fact that finding the subdevice of a parent or the parent of a subdevice commute */ /* first find the correct sd_device */ r = sd_device_get_parent_with_subsystem_devtype(udev_device->device, subsystem, devtype, &parent); if (r < 0) { errno = -r; return NULL; } /* then walk the chain of udev_device parents until the corresponding one is found */ while ((udev_device = udev_device_get_parent(udev_device))) { if (udev_device->device == parent) return udev_device; } errno = ENOENT; return NULL; } /** * udev_device_get_udev: * @udev_device: udev device * * Retrieve the udev library context the device was created with. * * Returns: the udev library context **/ _public_ struct udev *udev_device_get_udev(struct udev_device *udev_device) { assert_return_errno(udev_device, NULL, EINVAL); return udev_device->udev; } /** * udev_device_ref: * @udev_device: udev device * * Take a reference of a udev device. * * Returns: the passed udev device **/ _public_ struct udev_device *udev_device_ref(struct udev_device *udev_device) { if (udev_device) 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. * * Returns: #NULL **/ _public_ struct udev_device *udev_device_unref(struct udev_device *udev_device) { if (udev_device && (-- udev_device->refcount) == 0) { sd_device_unref(udev_device->device); udev_device_unref(udev_device->parent); udev_list_cleanup(&udev_device->properties); udev_list_cleanup(&udev_device->sysattrs); udev_list_cleanup(&udev_device->tags); udev_list_cleanup(&udev_device->devlinks); free(udev_device); } return NULL; } /** * 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 **/ _public_ const char *udev_device_get_devpath(struct udev_device *udev_device) { const char *devpath; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_devpath(udev_device->device, &devpath); if (r < 0) { errno = -r; return NULL; } return 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 **/ _public_ const char *udev_device_get_syspath(struct udev_device *udev_device) { const char *syspath; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_syspath(udev_device->device, &syspath); if (r < 0) { errno = -r; return NULL; } return syspath; } /** * udev_device_get_sysname: * @udev_device: udev device * * Get the kernel device name in /sys. * * Returns: the name string of the device **/ _public_ const char *udev_device_get_sysname(struct udev_device *udev_device) { const char *sysname; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_sysname(udev_device->device, &sysname); if (r < 0) { errno = -r; return NULL; } return sysname; } /** * udev_device_get_sysnum: * @udev_device: udev device * * Get the instance number of the device. * * Returns: the trailing number string of the device name **/ _public_ const char *udev_device_get_sysnum(struct udev_device *udev_device) { const char *sysnum; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_sysnum(udev_device->device, &sysnum); if (r < 0) { errno = -r; return NULL; } return 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 **/ _public_ const char *udev_device_get_devnode(struct udev_device *udev_device) { const char *devnode; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_devname(udev_device->device, &devnode); if (r < 0) { errno = -r; return NULL; } return 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_get_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 **/ _public_ struct udev_list_entry *udev_device_get_devlinks_list_entry(struct udev_device *udev_device) { assert_return_errno(udev_device, NULL, EINVAL); if (device_get_devlinks_generation(udev_device->device) != udev_device->devlinks_generation || !udev_device->devlinks_read) { const char *devlink; udev_list_cleanup(&udev_device->devlinks); FOREACH_DEVICE_DEVLINK(udev_device->device, devlink) udev_list_entry_add(&udev_device->devlinks, devlink, NULL); udev_device->devlinks_read = true; udev_device->devlinks_generation = device_get_devlinks_generation(udev_device->device); } return udev_list_get_entry(&udev_device->devlinks); } /** * udev_device_get_event_properties_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_get_next(), * which returns #NULL if no more entries exist. The property name * can be retrieved from the list entry by udev_list_entry_get_name(), * the property value by udev_list_entry_get_value(). * * Returns: the first entry of the property list **/ _public_ struct udev_list_entry *udev_device_get_properties_list_entry(struct udev_device *udev_device) { assert_return_errno(udev_device, NULL, EINVAL); if (device_get_properties_generation(udev_device->device) != udev_device->properties_generation || !udev_device->properties_read) { const char *key, *value; udev_list_cleanup(&udev_device->properties); FOREACH_DEVICE_PROPERTY(udev_device->device, key, value) udev_list_entry_add(&udev_device->properties, key, value); udev_device->properties_read = true; udev_device->properties_generation = device_get_properties_generation(udev_device->device); } return udev_list_get_entry(&udev_device->properties); } /** * 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. **/ _public_ const char *udev_device_get_action(struct udev_device *udev_device) { const char *action = NULL; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_property_value(udev_device->device, "ACTION", &action); if (r < 0 && r != -ENOENT) { errno = -r; return NULL; } return 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. **/ _public_ unsigned long long int udev_device_get_usec_since_initialized(struct udev_device *udev_device) { usec_t ts; int r; assert_return(udev_device, -EINVAL); r = sd_device_get_usec_since_initialized(udev_device->device, &ts); if (r < 0) { errno = EINVAL; return 0; } return ts; } /** * 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. **/ _public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr) { const char *value; int r; assert_return_errno(udev_device, NULL, EINVAL); r = sd_device_get_sysattr_value(udev_device->device, sysattr, &value); if (r < 0) { errno = -r; return NULL; } return value; } /** * udev_device_set_sysattr_value: * @udev_device: udev device * @sysattr: attribute name * @value: new value to be set * * Update the contents of the sys attribute and the cached value of the device. * * Returns: Negative error code on failure or 0 on success. **/ _public_ int udev_device_set_sysattr_value(struct udev_device *udev_device, const char *sysattr, char *value) { int r; assert_return(udev_device, -EINVAL); r = sd_device_set_sysattr_value(udev_device->device, sysattr, value); if (r < 0) return r; return 0; } /** * 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 **/ _public_ struct udev_list_entry *udev_device_get_sysattr_list_entry(struct udev_device *udev_device) { assert_return_errno(udev_device, NULL, EINVAL); if (!udev_device->sysattrs_read) { const char *sysattr; udev_list_cleanup(&udev_device->sysattrs); FOREACH_DEVICE_SYSATTR(udev_device->device, sysattr) udev_list_entry_add(&udev_device->sysattrs, sysattr, NULL); udev_device->sysattrs_read = true; } return udev_list_get_entry(&udev_device->sysattrs); } /** * 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. **/ _public_ int udev_device_get_is_initialized(struct udev_device *udev_device) { int r, initialized; assert_return(udev_device, -EINVAL); r = sd_device_get_is_initialized(udev_device->device, &initialized); if (r < 0) { errno = -r; return 0; } return initialized; } /** * 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_get_next(), * which returns #NULL if no more entries exist. The tag string * can be retrieved from the list entry by udev_list_entry_get_name(). * * Returns: the first entry of the tag list **/ _public_ struct udev_list_entry *udev_device_get_tags_list_entry(struct udev_device *udev_device) { assert_return_errno(udev_device, NULL, EINVAL); if (device_get_tags_generation(udev_device->device) != udev_device->tags_generation || !udev_device->tags_read) { const char *tag; udev_list_cleanup(&udev_device->tags); FOREACH_DEVICE_TAG(udev_device->device, tag) udev_list_entry_add(&udev_device->tags, tag, NULL); udev_device->tags_read = true; udev_device->tags_generation = device_get_tags_generation(udev_device->device); } return udev_list_get_entry(&udev_device->tags); } /** * udev_device_has_tag: * @udev_device: udev device * @tag: tag name * * Check if a given device has a certain tag associated. * * Returns: 1 if the tag is found. 0 otherwise. **/ _public_ int udev_device_has_tag(struct udev_device *udev_device, const char *tag) { assert_return(udev_device, 0); return sd_device_has_tag(udev_device->device, tag); }