diff options
Diffstat (limited to 'src/libsystemd/libsystemd-internal/sd-device/device-enumerator.c')
| -rw-r--r-- | src/libsystemd/libsystemd-internal/sd-device/device-enumerator.c | 986 |
1 files changed, 986 insertions, 0 deletions
diff --git a/src/libsystemd/libsystemd-internal/sd-device/device-enumerator.c b/src/libsystemd/libsystemd-internal/sd-device/device-enumerator.c new file mode 100644 index 0000000000..796728ee0e --- /dev/null +++ b/src/libsystemd/libsystemd-internal/sd-device/device-enumerator.c @@ -0,0 +1,986 @@ +/*** + 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 <systemd/sd-device.h> + +#include "alloc-util.h" +#include "device-enumerator-private.h" +#include "device-util.h" +#include "dirent-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_(sd_device_enumerator_unrefp) 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_(sd_device_unrefp) 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_(sd_device_unrefp) 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_(sd_device_unrefp) 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); +} |