device-enumerator.c revision 3ffd4af22052963e7a29431721ee204e634bea75
/***
This file is part of systemd.
Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
Copyright 2014-2015 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 "sd-device.h"
#include "device-enumerator-private.h"
#include "device-util.h"
#include "fd-util.h"
#include "prioq.h"
#include "set.h"
#include "string-util.h"
#include "strv.h"
#include "util.h"
#define DEVICE_ENUMERATE_MAX_DEPTH 256
typedef enum DeviceEnumerationType {
DEVICE_ENUMERATION_TYPE_DEVICES,
DEVICE_ENUMERATION_TYPE_SUBSYSTEMS,
_DEVICE_ENUMERATION_TYPE_MAX,
_DEVICE_ENUMERATION_TYPE_INVALID = -1,
} DeviceEnumerationType;
struct sd_device_enumerator {
unsigned n_ref;
DeviceEnumerationType type;
Prioq *devices;
bool scan_uptodate;
Set *match_subsystem;
Set *nomatch_subsystem;
Hashmap *match_sysattr;
Hashmap *nomatch_sysattr;
Hashmap *match_property;
Set *match_sysname;
Set *match_tag;
sd_device *match_parent;
bool match_allow_uninitialized;
};
_public_ int sd_device_enumerator_new(sd_device_enumerator **ret) {
_cleanup_device_enumerator_unref_ sd_device_enumerator *enumerator = NULL;
assert(ret);
enumerator = new0(sd_device_enumerator, 1);
if (!enumerator)
return -ENOMEM;
enumerator->n_ref = 1;
enumerator->type = _DEVICE_ENUMERATION_TYPE_INVALID;
*ret = enumerator;
enumerator = NULL;
return 0;
}
_public_ sd_device_enumerator *sd_device_enumerator_ref(sd_device_enumerator *enumerator) {
assert_return(enumerator, NULL);
assert_se((++ enumerator->n_ref) >= 2);
return enumerator;
}
_public_ sd_device_enumerator *sd_device_enumerator_unref(sd_device_enumerator *enumerator) {
if (enumerator && (-- enumerator->n_ref) == 0) {
sd_device *device;
while ((device = prioq_pop(enumerator->devices)))
sd_device_unref(device);
prioq_free(enumerator->devices);
set_free_free(enumerator->match_subsystem);
set_free_free(enumerator->nomatch_subsystem);
hashmap_free_free_free(enumerator->match_sysattr);
hashmap_free_free_free(enumerator->nomatch_sysattr);
hashmap_free_free_free(enumerator->match_property);
set_free_free(enumerator->match_sysname);
set_free_free(enumerator->match_tag);
sd_device_unref(enumerator->match_parent);
free(enumerator);
}
return NULL;
}
_public_ int sd_device_enumerator_add_match_subsystem(sd_device_enumerator *enumerator, const char *subsystem, int match) {
Set **set;
int r;
assert_return(enumerator, -EINVAL);
assert_return(subsystem, -EINVAL);
if (match)
set = &enumerator->match_subsystem;
else
set = &enumerator->nomatch_subsystem;
r = set_ensure_allocated(set, NULL);
if (r < 0)
return r;
r = set_put_strdup(*set, subsystem);
if (r < 0)
return r;
enumerator->scan_uptodate = false;
return 0;
}
_public_ int sd_device_enumerator_add_match_sysattr(sd_device_enumerator *enumerator, const char *_sysattr, const char *_value, int match) {
_cleanup_free_ char *sysattr = NULL, *value = NULL;
Hashmap **hashmap;
int r;
assert_return(enumerator, -EINVAL);
assert_return(_sysattr, -EINVAL);
if (match)
hashmap = &enumerator->match_sysattr;
else
hashmap = &enumerator->nomatch_sysattr;
r = hashmap_ensure_allocated(hashmap, NULL);
if (r < 0)
return r;
sysattr = strdup(_sysattr);
if (!sysattr)
return -ENOMEM;
if (_value) {
value = strdup(_value);
if (!value)
return -ENOMEM;
}
r = hashmap_put(*hashmap, sysattr, value);
if (r < 0)
return r;
sysattr = NULL;
value = NULL;
enumerator->scan_uptodate = false;
return 0;
}
_public_ int sd_device_enumerator_add_match_property(sd_device_enumerator *enumerator, const char *_property, const char *_value) {
_cleanup_free_ char *property = NULL, *value = NULL;
int r;
assert_return(enumerator, -EINVAL);
assert_return(_property, -EINVAL);
r = hashmap_ensure_allocated(&enumerator->match_property, NULL);
if (r < 0)
return r;
property = strdup(_property);
if (!property)
return -ENOMEM;
if (_value) {
value = strdup(_value);
if (!value)
return -ENOMEM;
}
r = hashmap_put(enumerator->match_property, property, value);
if (r < 0)
return r;
property = NULL;
value = NULL;
enumerator->scan_uptodate = false;
return 0;
}
_public_ int sd_device_enumerator_add_match_sysname(sd_device_enumerator *enumerator, const char *sysname) {
int r;
assert_return(enumerator, -EINVAL);
assert_return(sysname, -EINVAL);
r = set_ensure_allocated(&enumerator->match_sysname, NULL);
if (r < 0)
return r;
r = set_put_strdup(enumerator->match_sysname, sysname);
if (r < 0)
return r;
enumerator->scan_uptodate = false;
return 0;
}
_public_ int sd_device_enumerator_add_match_tag(sd_device_enumerator *enumerator, const char *tag) {
int r;
assert_return(enumerator, -EINVAL);
assert_return(tag, -EINVAL);
r = set_ensure_allocated(&enumerator->match_tag, NULL);
if (r < 0)
return r;
r = set_put_strdup(enumerator->match_tag, tag);
if (r < 0)
return r;
enumerator->scan_uptodate = false;
return 0;
}
_public_ int sd_device_enumerator_add_match_parent(sd_device_enumerator *enumerator, sd_device *parent) {
assert_return(enumerator, -EINVAL);
assert_return(parent, -EINVAL);
sd_device_unref(enumerator->match_parent);
enumerator->match_parent = sd_device_ref(parent);
enumerator->scan_uptodate = false;
return 0;
}
_public_ int sd_device_enumerator_allow_uninitialized(sd_device_enumerator *enumerator) {
assert_return(enumerator, -EINVAL);
enumerator->match_allow_uninitialized = true;
enumerator->scan_uptodate = false;
return 0;
}
int device_enumerator_add_match_is_initialized(sd_device_enumerator *enumerator) {
assert_return(enumerator, -EINVAL);
enumerator->match_allow_uninitialized = false;
enumerator->scan_uptodate = false;
return 0;
}
static int device_compare(const void *_a, const void *_b) {
sd_device *a = (sd_device *)_a, *b = (sd_device *)_b;
const char *devpath_a, *devpath_b, *sound_a;
bool delay_a, delay_b;
assert_se(sd_device_get_devpath(a, &devpath_a) >= 0);
assert_se(sd_device_get_devpath(b, &devpath_b) >= 0);
sound_a = strstr(devpath_a, "/sound/card");
if (sound_a) {
/* For sound cards the control device must be enumerated last to
* make sure it's the final device node that gets ACLs applied.
* Applications rely on this fact and use ACL changes on the
* control node as an indicator that the ACL change of the
* entire sound card completed. The kernel makes this guarantee
* when creating those devices, and hence we should too when
* enumerating them. */
sound_a += strlen("/sound/card");
sound_a = strchr(sound_a, '/');
if (sound_a) {
unsigned prefix_len;
prefix_len = sound_a - devpath_a;
if (strncmp(devpath_a, devpath_b, prefix_len) == 0) {
const char *sound_b;
sound_b = devpath_b + prefix_len;
if (startswith(sound_a, "/controlC") &&
!startswith(sound_b, "/contolC"))
return 1;
if (!startswith(sound_a, "/controlC") &&
startswith(sound_b, "/controlC"))
return -1;
}
}
}
/* md and dm devices are enumerated after all other devices */
delay_a = strstr(devpath_a, "/block/md") || strstr(devpath_a, "/block/dm-");
delay_b = strstr(devpath_b, "/block/md") || strstr(devpath_b, "/block/dm-");
if (delay_a != delay_b)
return delay_a - delay_b;
return strcmp(devpath_a, devpath_b);
}
int device_enumerator_add_device(sd_device_enumerator *enumerator, sd_device *device) {
int r;
assert_return(enumerator, -EINVAL);
assert_return(device, -EINVAL);
r = prioq_ensure_allocated(&enumerator->devices, device_compare);
if (r < 0)
return r;
r = prioq_put(enumerator->devices, device, NULL);
if (r < 0)
return r;
sd_device_ref(device);
return 0;
}
static bool match_sysattr_value(sd_device *device, const char *sysattr, const char *match_value) {
const char *value;
int r;
assert(device);
assert(sysattr);
r = sd_device_get_sysattr_value(device, sysattr, &value);
if (r < 0)
return false;
if (!match_value)
return true;
if (fnmatch(match_value, value, 0) == 0)
return true;
return false;
}
static bool match_sysattr(sd_device_enumerator *enumerator, sd_device *device) {
const char *sysattr;
const char *value;
Iterator i;
assert(enumerator);
assert(device);
HASHMAP_FOREACH_KEY(value, sysattr, enumerator->nomatch_sysattr, i)
if (match_sysattr_value(device, sysattr, value))
return false;
HASHMAP_FOREACH_KEY(value, sysattr, enumerator->match_sysattr, i)
if (!match_sysattr_value(device, sysattr, value))
return false;
return true;
}
static bool match_property(sd_device_enumerator *enumerator, sd_device *device) {
const char *property;
const char *value;
Iterator i;
assert(enumerator);
assert(device);
if (hashmap_isempty(enumerator->match_property))
return true;
HASHMAP_FOREACH_KEY(value, property, enumerator->match_property, i) {
const char *property_dev, *value_dev;
FOREACH_DEVICE_PROPERTY(device, property_dev, value_dev) {
if (fnmatch(property, property_dev, 0) != 0)
continue;
if (!value && !value_dev)
return true;
if (!value || !value_dev)
continue;
if (fnmatch(value, value_dev, 0) == 0)
return true;
}
}
return false;
}
static bool match_tag(sd_device_enumerator *enumerator, sd_device *device) {
const char *tag;
Iterator i;
assert(enumerator);
assert(device);
SET_FOREACH(tag, enumerator->match_tag, i)
if (!sd_device_has_tag(device, tag))
return false;
return true;
}
static bool match_parent(sd_device_enumerator *enumerator, sd_device *device) {
const char *devpath, *devpath_dev;
int r;
assert(enumerator);
assert(device);
if (!enumerator->match_parent)
return true;
r = sd_device_get_devpath(enumerator->match_parent, &devpath);
assert(r >= 0);
r = sd_device_get_devpath(device, &devpath_dev);
assert(r >= 0);
return startswith(devpath_dev, devpath);
}
static bool match_sysname(sd_device_enumerator *enumerator, const char *sysname) {
const char *sysname_match;
Iterator i;
assert(enumerator);
assert(sysname);
if (set_isempty(enumerator->match_sysname))
return true;
SET_FOREACH(sysname_match, enumerator->match_sysname, i)
if (fnmatch(sysname_match, sysname, 0) == 0)
return true;
return false;
}
static int enumerator_scan_dir_and_add_devices(sd_device_enumerator *enumerator, const char *basedir, const char *subdir1, const char *subdir2) {
_cleanup_closedir_ DIR *dir = NULL;
char *path;
struct dirent *dent;
int r = 0;
assert(enumerator);
assert(basedir);
path = strjoina("/sys/", basedir, "/");
if (subdir1)
path = strjoina(path, subdir1, "/");
if (subdir2)
path = strjoina(path, subdir2, "/");
dir = opendir(path);
if (!dir)
return -errno;
FOREACH_DIRENT_ALL(dent, dir, return -errno) {
_cleanup_device_unref_ sd_device *device = NULL;
char syspath[strlen(path) + 1 + strlen(dent->d_name) + 1];
dev_t devnum;
int ifindex, initialized, k;
if (dent->d_name[0] == '.')
continue;
if (!match_sysname(enumerator, dent->d_name))
continue;
(void)sprintf(syspath, "%s%s", path, dent->d_name);
k = sd_device_new_from_syspath(&device, syspath);
if (k < 0) {
if (k != -ENODEV)
/* this is necessarily racey, so ignore missing devices */
r = k;
continue;
}
k = sd_device_get_devnum(device, &devnum);
if (k < 0) {
r = k;
continue;
}
k = sd_device_get_ifindex(device, &ifindex);
if (k < 0) {
r = k;
continue;
}
k = sd_device_get_is_initialized(device, &initialized);
if (k < 0) {
r = k;
continue;
}
/*
* All devices with a device node or network interfaces
* possibly need udev to adjust the device node permission
* or context, or rename the interface before it can be
* reliably used from other processes.
*
* For now, we can only check these types of devices, we
* might not store a database, and have no way to find out
* for all other types of devices.
*/
if (!enumerator->match_allow_uninitialized &&
!initialized &&
(major(devnum) > 0 || ifindex > 0))
continue;
if (!match_parent(enumerator, device))
continue;
if (!match_tag(enumerator, device))
continue;
if (!match_property(enumerator, device))
continue;
if (!match_sysattr(enumerator, device))
continue;
k = device_enumerator_add_device(enumerator, device);
if (k < 0)
r = k;
}
return r;
}
static bool match_subsystem(sd_device_enumerator *enumerator, const char *subsystem) {
const char *subsystem_match;
Iterator i;
assert(enumerator);
if (!subsystem)
return false;
SET_FOREACH(subsystem_match, enumerator->nomatch_subsystem, i)
if (fnmatch(subsystem_match, subsystem, 0) == 0)
return false;
if (set_isempty(enumerator->match_subsystem))
return true;
SET_FOREACH(subsystem_match, enumerator->match_subsystem, i)
if (fnmatch(subsystem_match, subsystem, 0) == 0)
return true;
return false;
}
static int enumerator_scan_dir(sd_device_enumerator *enumerator, const char *basedir, const char *subdir, const char *subsystem) {
_cleanup_closedir_ DIR *dir = NULL;
char *path;
struct dirent *dent;
int r = 0;
path = strjoina("/sys/", basedir);
dir = opendir(path);
if (!dir)
return -errno;
log_debug(" device-enumerator: scanning %s", path);
FOREACH_DIRENT_ALL(dent, dir, return -errno) {
int k;
if (dent->d_name[0] == '.')
continue;
if (!match_subsystem(enumerator, subsystem ? : dent->d_name))
continue;
k = enumerator_scan_dir_and_add_devices(enumerator, basedir, dent->d_name, subdir);
if (k < 0)
r = k;
}
return r;
}
static int enumerator_scan_devices_tag(sd_device_enumerator *enumerator, const char *tag) {
_cleanup_closedir_ DIR *dir = NULL;
char *path;
struct dirent *dent;
int r = 0;
assert(enumerator);
assert(tag);
path = strjoina("/run/udev/tags/", tag);
dir = opendir(path);
if (!dir) {
if (errno == ENOENT)
return 0;
else {
log_error("sd-device-enumerator: could not open tags directory %s: %m", path);
return -errno;
}
}
/* TODO: filter away subsystems? */
FOREACH_DIRENT_ALL(dent, dir, return -errno) {
_cleanup_device_unref_ sd_device *device = NULL;
const char *subsystem, *sysname;
int k;
if (dent->d_name[0] == '.')
continue;
k = sd_device_new_from_device_id(&device, dent->d_name);
if (k < 0) {
if (k != -ENODEV)
/* this is necessarily racy, so ignore missing devices */
r = k;
continue;
}
k = sd_device_get_subsystem(device, &subsystem);
if (k < 0) {
r = k;
continue;
}
if (!match_subsystem(enumerator, subsystem))
continue;
k = sd_device_get_sysname(device, &sysname);
if (k < 0) {
r = k;
continue;
}
if (!match_sysname(enumerator, sysname))
continue;
if (!match_parent(enumerator, device))
continue;
if (!match_property(enumerator, device))
continue;
if (!match_sysattr(enumerator, device))
continue;
k = device_enumerator_add_device(enumerator, device);
if (k < 0) {
r = k;
continue;
}
}
return r;
}
static int enumerator_scan_devices_tags(sd_device_enumerator *enumerator) {
const char *tag;
Iterator i;
int r;
assert(enumerator);
SET_FOREACH(tag, enumerator->match_tag, i) {
r = enumerator_scan_devices_tag(enumerator, tag);
if (r < 0)
return r;
}
return 0;
}
static int parent_add_child(sd_device_enumerator *enumerator, const char *path) {
_cleanup_device_unref_ sd_device *device = NULL;
const char *subsystem, *sysname;
int r;
r = sd_device_new_from_syspath(&device, path);
if (r == -ENODEV)
/* this is necessarily racy, so ignore missing devices */
return 0;
else if (r < 0)
return r;
r = sd_device_get_subsystem(device, &subsystem);
if (r == -ENOENT)
return 0;
if (r < 0)
return r;
if (!match_subsystem(enumerator, subsystem))
return 0;
r = sd_device_get_sysname(device, &sysname);
if (r < 0)
return r;
if (!match_sysname(enumerator, sysname))
return 0;
if (!match_property(enumerator, device))
return 0;
if (!match_sysattr(enumerator, device))
return 0;
r = device_enumerator_add_device(enumerator, device);
if (r < 0)
return r;
return 1;
}
static int parent_crawl_children(sd_device_enumerator *enumerator, const char *path, unsigned maxdepth) {
_cleanup_closedir_ DIR *dir = NULL;
struct dirent *dent;
int r = 0;
dir = opendir(path);
if (!dir) {
log_debug("sd-device-enumerate: could not open parent directory %s: %m", path);
return -errno;
}
FOREACH_DIRENT_ALL(dent, dir, return -errno) {
_cleanup_free_ char *child = NULL;
int k;
if (dent->d_name[0] == '.')
continue;
if (dent->d_type != DT_DIR)
continue;
child = strjoin(path, "/", dent->d_name, NULL);
if (!child)
return -ENOMEM;
k = parent_add_child(enumerator, child);
if (k < 0)
r = k;
if (maxdepth > 0)
parent_crawl_children(enumerator, child, maxdepth - 1);
else
log_debug("device-enumerate: max depth reached, %s: ignoring devices", child);
}
return r;
}
static int enumerator_scan_devices_children(sd_device_enumerator *enumerator) {
const char *path;
int r = 0, k;
r = sd_device_get_syspath(enumerator->match_parent, &path);
if (r < 0)
return r;
k = parent_add_child(enumerator, path);
if (k < 0)
r = k;
k = parent_crawl_children(enumerator, path, DEVICE_ENUMERATE_MAX_DEPTH);
if (k < 0)
r = k;
return r;
}
static int enumerator_scan_devices_all(sd_device_enumerator *enumerator) {
int r = 0;
log_debug("device-enumerator: scan all dirs");
if (access("/sys/subsystem", F_OK) >= 0) {
/* we have /subsystem/, forget all the old stuff */
r = enumerator_scan_dir(enumerator, "subsystem", "devices", NULL);
if (r < 0)
return log_debug_errno(r, "device-enumerator: failed to scan /sys/subsystem: %m");
} else {
int k;
k = enumerator_scan_dir(enumerator, "bus", "devices", NULL);
if (k < 0) {
log_debug_errno(k, "device-enumerator: failed to scan /sys/bus: %m");
r = k;
}
k = enumerator_scan_dir(enumerator, "class", NULL, NULL);
if (k < 0) {
log_debug_errno(k, "device-enumerator: failed to scan /sys/class: %m");
r = k;
}
}
return r;
}
int device_enumerator_scan_devices(sd_device_enumerator *enumerator) {
sd_device *device;
int r;
assert(enumerator);
if (enumerator->scan_uptodate &&
enumerator->type == DEVICE_ENUMERATION_TYPE_DEVICES)
return 0;
while ((device = prioq_pop(enumerator->devices)))
sd_device_unref(device);
if (!set_isempty(enumerator->match_tag)) {
r = enumerator_scan_devices_tags(enumerator);
if (r < 0)
return r;
} else if (enumerator->match_parent) {
r = enumerator_scan_devices_children(enumerator);
if (r < 0)
return r;
} else {
r = enumerator_scan_devices_all(enumerator);
if (r < 0)
return r;
}
enumerator->scan_uptodate = true;
return 0;
}
_public_ sd_device *sd_device_enumerator_get_device_first(sd_device_enumerator *enumerator) {
int r;
assert_return(enumerator, NULL);
r = device_enumerator_scan_devices(enumerator);
if (r < 0)
return NULL;
enumerator->type = DEVICE_ENUMERATION_TYPE_DEVICES;
return prioq_peek(enumerator->devices);
}
_public_ sd_device *sd_device_enumerator_get_device_next(sd_device_enumerator *enumerator) {
assert_return(enumerator, NULL);
if (!enumerator->scan_uptodate ||
enumerator->type != DEVICE_ENUMERATION_TYPE_DEVICES)
return NULL;
sd_device_unref(prioq_pop(enumerator->devices));
return prioq_peek(enumerator->devices);
}
int device_enumerator_scan_subsystems(sd_device_enumerator *enumerator) {
sd_device *device;
const char *subsysdir;
int r = 0, k;
assert(enumerator);
if (enumerator->scan_uptodate &&
enumerator->type == DEVICE_ENUMERATION_TYPE_SUBSYSTEMS)
return 0;
while ((device = prioq_pop(enumerator->devices)))
sd_device_unref(device);
/* modules */
if (match_subsystem(enumerator, "module")) {
k = enumerator_scan_dir_and_add_devices(enumerator, "module", NULL, NULL);
if (k < 0) {
log_debug_errno(k, "device-enumerator: failed to scan modules: %m");
r = k;
}
}
if (access("/sys/subsystem", F_OK) >= 0)
subsysdir = "subsystem";
else
subsysdir = "bus";
/* subsystems (only buses support coldplug) */
if (match_subsystem(enumerator, "subsystem")) {
k = enumerator_scan_dir_and_add_devices(enumerator, subsysdir, NULL, NULL);
if (k < 0) {
log_debug_errno(k, "device-enumerator: failed to scan subsystems: %m");
r = k;
}
}
/* subsystem drivers */
if (match_subsystem(enumerator, "drivers")) {
k = enumerator_scan_dir(enumerator, subsysdir, "drivers", "drivers");
if (k < 0) {
log_debug_errno(k, "device-enumerator: failed to scan drivers: %m");
r = k;
}
}
enumerator->scan_uptodate = true;
return r;
}
_public_ sd_device *sd_device_enumerator_get_subsystem_first(sd_device_enumerator *enumerator) {
int r;
assert_return(enumerator, NULL);
r = device_enumerator_scan_subsystems(enumerator);
if (r < 0)
return NULL;
enumerator->type = DEVICE_ENUMERATION_TYPE_SUBSYSTEMS;
return prioq_peek(enumerator->devices);
}
_public_ sd_device *sd_device_enumerator_get_subsystem_next(sd_device_enumerator *enumerator) {
assert_return(enumerator, NULL);
if (enumerator->scan_uptodate ||
enumerator->type != DEVICE_ENUMERATION_TYPE_SUBSYSTEMS)
return NULL;
sd_device_unref(prioq_pop(enumerator->devices));
return prioq_peek(enumerator->devices);
}
sd_device *device_enumerator_get_first(sd_device_enumerator *enumerator) {
assert_return(enumerator, NULL);
return prioq_peek(enumerator->devices);
}
sd_device *device_enumerator_get_next(sd_device_enumerator *enumerator) {
assert_return(enumerator, NULL);
sd_device_unref(prioq_pop(enumerator->devices));
return prioq_peek(enumerator->devices);
}