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-rw-r--r--src/device.c616
1 files changed, 616 insertions, 0 deletions
diff --git a/src/device.c b/src/device.c
new file mode 100644
index 0000000000..0575379d80
--- /dev/null
+++ b/src/device.c
@@ -0,0 +1,616 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ 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
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <sys/epoll.h>
+#include <libudev.h>
+
+#include "unit.h"
+#include "device.h"
+#include "strv.h"
+#include "log.h"
+#include "unit-name.h"
+#include "dbus-device.h"
+#include "def.h"
+
+static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
+ [DEVICE_DEAD] = UNIT_INACTIVE,
+ [DEVICE_PLUGGED] = UNIT_ACTIVE
+};
+
+static void device_unset_sysfs(Device *d) {
+ Device *first;
+
+ assert(d);
+
+ if (!d->sysfs)
+ return;
+
+ /* Remove this unit from the chain of devices which share the
+ * same sysfs path. */
+ first = hashmap_get(UNIT(d)->manager->devices_by_sysfs, d->sysfs);
+ LIST_REMOVE(Device, same_sysfs, first, d);
+
+ if (first)
+ hashmap_remove_and_replace(UNIT(d)->manager->devices_by_sysfs, d->sysfs, first->sysfs, first);
+ else
+ hashmap_remove(UNIT(d)->manager->devices_by_sysfs, d->sysfs);
+
+ free(d->sysfs);
+ d->sysfs = NULL;
+}
+
+static void device_init(Unit *u) {
+ Device *d = DEVICE(u);
+
+ assert(d);
+ assert(UNIT(d)->load_state == UNIT_STUB);
+
+ /* In contrast to all other unit types we timeout jobs waiting
+ * for devices by default. This is because they otherwise wait
+ * indefinitely for plugged in devices, something which cannot
+ * happen for the other units since their operations time out
+ * anyway. */
+ UNIT(d)->job_timeout = DEFAULT_TIMEOUT_USEC;
+
+ UNIT(d)->ignore_on_isolate = true;
+ UNIT(d)->ignore_on_snapshot = true;
+}
+
+static void device_done(Unit *u) {
+ Device *d = DEVICE(u);
+
+ assert(d);
+
+ device_unset_sysfs(d);
+}
+
+static void device_set_state(Device *d, DeviceState state) {
+ DeviceState old_state;
+ assert(d);
+
+ old_state = d->state;
+ d->state = state;
+
+ if (state != old_state)
+ log_debug("%s changed %s -> %s",
+ UNIT(d)->id,
+ device_state_to_string(old_state),
+ device_state_to_string(state));
+
+ unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
+}
+
+static int device_coldplug(Unit *u) {
+ Device *d = DEVICE(u);
+
+ assert(d);
+ assert(d->state == DEVICE_DEAD);
+
+ if (d->sysfs)
+ device_set_state(d, DEVICE_PLUGGED);
+
+ return 0;
+}
+
+static void device_dump(Unit *u, FILE *f, const char *prefix) {
+ Device *d = DEVICE(u);
+
+ assert(d);
+
+ fprintf(f,
+ "%sDevice State: %s\n"
+ "%sSysfs Path: %s\n",
+ prefix, device_state_to_string(d->state),
+ prefix, strna(d->sysfs));
+}
+
+static UnitActiveState device_active_state(Unit *u) {
+ assert(u);
+
+ return state_translation_table[DEVICE(u)->state];
+}
+
+static const char *device_sub_state_to_string(Unit *u) {
+ assert(u);
+
+ return device_state_to_string(DEVICE(u)->state);
+}
+
+static int device_add_escaped_name(Unit *u, const char *dn) {
+ char *e;
+ int r;
+
+ assert(u);
+ assert(dn);
+ assert(dn[0] == '/');
+
+ if (!(e = unit_name_from_path(dn, ".device")))
+ return -ENOMEM;
+
+ r = unit_add_name(u, e);
+ free(e);
+
+ if (r < 0 && r != -EEXIST)
+ return r;
+
+ return 0;
+}
+
+static int device_find_escape_name(Manager *m, const char *dn, Unit **_u) {
+ char *e;
+ Unit *u;
+
+ assert(m);
+ assert(dn);
+ assert(dn[0] == '/');
+ assert(_u);
+
+ if (!(e = unit_name_from_path(dn, ".device")))
+ return -ENOMEM;
+
+ u = manager_get_unit(m, e);
+ free(e);
+
+ if (u) {
+ *_u = u;
+ return 1;
+ }
+
+ return 0;
+}
+
+static int device_update_unit(Manager *m, struct udev_device *dev, const char *path, bool main) {
+ const char *sysfs, *model;
+ Unit *u = NULL;
+ int r;
+ bool delete;
+
+ assert(m);
+
+ if (!(sysfs = udev_device_get_syspath(dev)))
+ return -ENOMEM;
+
+ if ((r = device_find_escape_name(m, path, &u)) < 0)
+ return r;
+
+ if (u && DEVICE(u)->sysfs && !path_equal(DEVICE(u)->sysfs, sysfs))
+ return -EEXIST;
+
+ if (!u) {
+ delete = true;
+
+ u = unit_new(m, sizeof(Device));
+ if (!u)
+ return -ENOMEM;
+
+ r = device_add_escaped_name(u, path);
+ if (r < 0)
+ goto fail;
+
+ unit_add_to_load_queue(u);
+ } else
+ delete = false;
+
+ /* If this was created via some dependency and has not
+ * actually been seen yet ->sysfs will not be
+ * initialized. Hence initialize it if necessary. */
+
+ if (!DEVICE(u)->sysfs) {
+ Device *first;
+
+ if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
+ if (!m->devices_by_sysfs)
+ if (!(m->devices_by_sysfs = hashmap_new(string_hash_func, string_compare_func))) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
+ first = hashmap_get(m->devices_by_sysfs, sysfs);
+ LIST_PREPEND(Device, same_sysfs, first, DEVICE(u));
+
+ if ((r = hashmap_replace(m->devices_by_sysfs, DEVICE(u)->sysfs, first)) < 0)
+ goto fail;
+ }
+
+ if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
+ (model = udev_device_get_property_value(dev, "ID_MODEL"))) {
+ if ((r = unit_set_description(u, model)) < 0)
+ goto fail;
+ } else
+ if ((r = unit_set_description(u, path)) < 0)
+ goto fail;
+
+ if (main) {
+ /* The additional systemd udev properties we only
+ * interpret for the main object */
+ const char *wants, *alias;
+
+ if ((alias = udev_device_get_property_value(dev, "SYSTEMD_ALIAS"))) {
+ if (!is_path(alias))
+ log_warning("SYSTEMD_ALIAS for %s is not a path, ignoring: %s", sysfs, alias);
+ else {
+ if ((r = device_add_escaped_name(u, alias)) < 0)
+ goto fail;
+ }
+ }
+
+ if ((wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS"))) {
+ char *state, *w;
+ size_t l;
+
+ FOREACH_WORD_QUOTED(w, l, wants, state) {
+ char *e;
+
+ if (!(e = strndup(w, l))) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
+ r = unit_add_dependency_by_name(u, UNIT_WANTS, e, NULL, true);
+ free(e);
+
+ if (r < 0)
+ goto fail;
+ }
+ }
+ }
+
+ unit_add_to_dbus_queue(u);
+ return 0;
+
+fail:
+ log_warning("Failed to load device unit: %s", strerror(-r));
+
+ if (delete && u)
+ unit_free(u);
+
+ return r;
+}
+
+static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
+ const char *sysfs, *dn;
+ struct udev_list_entry *item = NULL, *first = NULL;
+
+ assert(m);
+
+ if (!(sysfs = udev_device_get_syspath(dev)))
+ return -ENOMEM;
+
+ /* Add the main unit named after the sysfs path */
+ device_update_unit(m, dev, sysfs, true);
+
+ /* Add an additional unit for the device node */
+ if ((dn = udev_device_get_devnode(dev)))
+ device_update_unit(m, dev, dn, false);
+
+ /* Add additional units for all symlinks */
+ first = udev_device_get_devlinks_list_entry(dev);
+ udev_list_entry_foreach(item, first) {
+ const char *p;
+ struct stat st;
+
+ /* Don't bother with the /dev/block links */
+ p = udev_list_entry_get_name(item);
+
+ if (path_startswith(p, "/dev/block/") ||
+ path_startswith(p, "/dev/char/"))
+ continue;
+
+ /* Verify that the symlink in the FS actually belongs
+ * to this device. This is useful to deal with
+ * conflicting devices, e.g. when two disks want the
+ * same /dev/disk/by-label/xxx link because they have
+ * the same label. We want to make sure that the same
+ * device that won the symlink wins in systemd, so we
+ * check the device node major/minor*/
+ if (stat(p, &st) >= 0)
+ if ((!S_ISBLK(st.st_mode) && !S_ISCHR(st.st_mode)) ||
+ st.st_rdev != udev_device_get_devnum(dev))
+ continue;
+
+ device_update_unit(m, dev, p, false);
+ }
+
+ if (update_state) {
+ Device *d, *l;
+
+ manager_dispatch_load_queue(m);
+
+ l = hashmap_get(m->devices_by_sysfs, sysfs);
+ LIST_FOREACH(same_sysfs, d, l)
+ device_set_state(d, DEVICE_PLUGGED);
+ }
+
+ return 0;
+}
+
+static int device_process_path(Manager *m, const char *path, bool update_state) {
+ int r;
+ struct udev_device *dev;
+
+ assert(m);
+ assert(path);
+
+ if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
+ log_warning("Failed to get udev device object from udev for path %s.", path);
+ return -ENOMEM;
+ }
+
+ r = device_process_new_device(m, dev, update_state);
+ udev_device_unref(dev);
+ return r;
+}
+
+static int device_process_removed_device(Manager *m, struct udev_device *dev) {
+ const char *sysfs;
+ Device *d;
+
+ assert(m);
+ assert(dev);
+
+ if (!(sysfs = udev_device_get_syspath(dev)))
+ return -ENOMEM;
+
+ /* Remove all units of this sysfs path */
+ while ((d = hashmap_get(m->devices_by_sysfs, sysfs))) {
+ device_unset_sysfs(d);
+ device_set_state(d, DEVICE_DEAD);
+ }
+
+ return 0;
+}
+
+static Unit *device_following(Unit *u) {
+ Device *d = DEVICE(u);
+ Device *other, *first = NULL;
+
+ assert(d);
+
+ if (startswith(u->id, "sys-"))
+ return NULL;
+
+ /* Make everybody follow the unit that's named after the sysfs path */
+ for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
+ if (startswith(UNIT(other)->id, "sys-"))
+ return UNIT(other);
+
+ for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev) {
+ if (startswith(UNIT(other)->id, "sys-"))
+ return UNIT(other);
+
+ first = other;
+ }
+
+ return UNIT(first);
+}
+
+static int device_following_set(Unit *u, Set **_s) {
+ Device *d = DEVICE(u);
+ Device *other;
+ Set *s;
+ int r;
+
+ assert(d);
+ assert(_s);
+
+ if (!d->same_sysfs_prev && !d->same_sysfs_next) {
+ *_s = NULL;
+ return 0;
+ }
+
+ if (!(s = set_new(NULL, NULL)))
+ return -ENOMEM;
+
+ for (other = d->same_sysfs_next; other; other = other->same_sysfs_next)
+ if ((r = set_put(s, other)) < 0)
+ goto fail;
+
+ for (other = d->same_sysfs_prev; other; other = other->same_sysfs_prev)
+ if ((r = set_put(s, other)) < 0)
+ goto fail;
+
+ *_s = s;
+ return 1;
+
+fail:
+ set_free(s);
+ return r;
+}
+
+static void device_shutdown(Manager *m) {
+ assert(m);
+
+ if (m->udev_monitor) {
+ udev_monitor_unref(m->udev_monitor);
+ m->udev_monitor = NULL;
+ }
+
+ if (m->udev) {
+ udev_unref(m->udev);
+ m->udev = NULL;
+ }
+
+ hashmap_free(m->devices_by_sysfs);
+ m->devices_by_sysfs = NULL;
+}
+
+static int device_enumerate(Manager *m) {
+ struct epoll_event ev;
+ int r;
+ struct udev_enumerate *e = NULL;
+ struct udev_list_entry *item = NULL, *first = NULL;
+
+ assert(m);
+
+ if (!m->udev) {
+ if (!(m->udev = udev_new()))
+ return -ENOMEM;
+
+ if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
+ /* This will fail if we are unprivileged, but that
+ * should not matter much, as user instances won't run
+ * during boot. */
+ udev_monitor_set_receive_buffer_size(m->udev_monitor, 128*1024*1024);
+
+ if (udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd") < 0) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
+ if (udev_monitor_enable_receiving(m->udev_monitor) < 0) {
+ r = -EIO;
+ goto fail;
+ }
+
+ m->udev_watch.type = WATCH_UDEV;
+ m->udev_watch.fd = udev_monitor_get_fd(m->udev_monitor);
+
+ zero(ev);
+ ev.events = EPOLLIN;
+ ev.data.ptr = &m->udev_watch;
+
+ if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->udev_watch.fd, &ev) < 0)
+ return -errno;
+ }
+
+ if (!(e = udev_enumerate_new(m->udev))) {
+ r = -ENOMEM;
+ goto fail;
+ }
+ if (udev_enumerate_add_match_tag(e, "systemd") < 0) {
+ r = -EIO;
+ goto fail;
+ }
+
+ if (udev_enumerate_scan_devices(e) < 0) {
+ r = -EIO;
+ goto fail;
+ }
+
+ first = udev_enumerate_get_list_entry(e);
+ udev_list_entry_foreach(item, first)
+ device_process_path(m, udev_list_entry_get_name(item), false);
+
+ udev_enumerate_unref(e);
+ return 0;
+
+fail:
+ if (e)
+ udev_enumerate_unref(e);
+
+ device_shutdown(m);
+ return r;
+}
+
+void device_fd_event(Manager *m, int events) {
+ struct udev_device *dev;
+ int r;
+ const char *action, *ready;
+
+ assert(m);
+
+ if (events != EPOLLIN) {
+ static RATELIMIT_DEFINE(limit, 10*USEC_PER_SEC, 5);
+
+ if (!ratelimit_test(&limit))
+ log_error("Failed to get udev event: %m");
+ if (!(events & EPOLLIN))
+ return;
+ }
+
+ if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
+ /*
+ * libudev might filter-out devices which pass the bloom filter,
+ * so getting NULL here is not necessarily an error
+ */
+ return;
+ }
+
+ if (!(action = udev_device_get_action(dev))) {
+ log_error("Failed to get udev action string.");
+ goto fail;
+ }
+
+ ready = udev_device_get_property_value(dev, "SYSTEMD_READY");
+
+ if (streq(action, "remove") || (ready && parse_boolean(ready) == 0)) {
+ if ((r = device_process_removed_device(m, dev)) < 0) {
+ log_error("Failed to process udev device event: %s", strerror(-r));
+ goto fail;
+ }
+ } else {
+ if ((r = device_process_new_device(m, dev, true)) < 0) {
+ log_error("Failed to process udev device event: %s", strerror(-r));
+ goto fail;
+ }
+ }
+
+fail:
+ udev_device_unref(dev);
+}
+
+static const char* const device_state_table[_DEVICE_STATE_MAX] = {
+ [DEVICE_DEAD] = "dead",
+ [DEVICE_PLUGGED] = "plugged"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(device_state, DeviceState);
+
+const UnitVTable device_vtable = {
+ .suffix = ".device",
+ .object_size = sizeof(Device),
+ .sections =
+ "Unit\0"
+ "Device\0"
+ "Install\0",
+
+ .no_instances = true,
+
+ .init = device_init,
+
+ .load = unit_load_fragment_and_dropin_optional,
+ .done = device_done,
+ .coldplug = device_coldplug,
+
+ .dump = device_dump,
+
+ .active_state = device_active_state,
+ .sub_state_to_string = device_sub_state_to_string,
+
+ .bus_interface = "org.freedesktop.systemd1.Device",
+ .bus_message_handler = bus_device_message_handler,
+ .bus_invalidating_properties = bus_device_invalidating_properties,
+
+ .following = device_following,
+ .following_set = device_following_set,
+
+ .enumerate = device_enumerate,
+ .shutdown = device_shutdown
+};