eudev/device.c
2010-03-31 20:08:05 +02:00

395 lines
10 KiB
C

/*-*- Mode: C; c-basic-offset: 8 -*-*/
/***
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"
static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = {
[DEVICE_DEAD] = UNIT_INACTIVE,
[DEVICE_AVAILABLE] = UNIT_ACTIVE
};
static const char* const state_string_table[_DEVICE_STATE_MAX] = {
[DEVICE_DEAD] = "dead",
[DEVICE_AVAILABLE] = "available"
};
static void device_done(Unit *u) {
Device *d = DEVICE(u);
assert(d);
free(d->sysfs);
}
static void device_set_state(Device *d, DeviceState state) {
DeviceState old_state;
assert(d);
old_state = d->state;
d->state = state;
log_debug("%s changed %s → %s", unit_id(UNIT(d)), state_string_table[old_state], state_string_table[state]);
unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state]);
}
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_AVAILABLE);
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, state_string_table[d->state],
prefix, strna(d->sysfs));
}
static UnitActiveState device_active_state(Unit *u) {
assert(u);
return state_translation_table[DEVICE(u)->state];
}
static int device_add_escaped_name(Unit *u, const char *dn, bool make_id) {
char *e;
int r;
assert(u);
assert(dn);
assert(dn[0] == '/');
if (!(e = unit_name_escape_path(dn+1, ".device")))
return -ENOMEM;
r = unit_add_name(u, e);
if (r >= 0 && make_id)
unit_choose_id(u, e);
free(e);
if (r < 0 && r != -EEXIST)
return r;
return 0;
}
static int device_process_new_device(Manager *m, struct udev_device *dev, bool update_state) {
const char *dn, *names, *wants, *sysfs;
Unit *u = NULL;
int r;
char *e, *w, *state;
size_t l;
bool delete;
struct udev_list_entry *item = NULL, *first = NULL;
assert(m);
/* Check whether this entry is even relevant for us. */
dn = udev_device_get_devnode(dev);
names = udev_device_get_property_value(dev, "SYSTEMD_NAMES");
wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS");
if (!dn && !names && !wants)
return 0;
/* Ok, seems kinda interesting. Now, let's see if this one
* already exists. */
if (!(sysfs = udev_device_get_syspath(dev)))
return -ENOMEM;
assert(sysfs[0] == '/');
if (!(e = unit_name_escape_path(sysfs+1, ".device")))
return -ENOMEM;
if (!(u = manager_get_unit(m, e))) {
const char *model;
delete = true;
if (!(u = unit_new(m))) {
free(e);
return -ENOMEM;
}
r = unit_add_name(u, e);
free(e);
if (r < 0)
goto fail;
if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
r = -ENOMEM;
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 (dn)
if ((r = unit_set_description(u, dn)) < 0)
goto fail;
unit_add_to_load_queue(u);
} else {
delete = false;
free(e);
}
if (dn)
if ((r = device_add_escaped_name(u, dn, true)) < 0)
goto fail;
first = udev_device_get_devlinks_list_entry(dev);
udev_list_entry_foreach(item, first)
if ((r = device_add_escaped_name(u, udev_list_entry_get_name(item), false)) < 0)
goto fail;
if (names) {
FOREACH_WORD(w, l, names, state) {
if (!(e = strndup(w, l))) {
r = -ENOMEM;
goto fail;
}
r = unit_add_name(u, e);
free(e);
if (r < 0 && r != -EEXIST)
goto fail;
}
}
if (wants) {
FOREACH_WORD(w, l, wants, state) {
if (!(e = strndup(w, l))) {
r = -ENOMEM;
goto fail;
}
r = unit_add_dependency_by_name(u, UNIT_WANTS, e);
free(e);
if (r < 0)
goto fail;
}
}
if (update_state) {
manager_dispatch_load_queue(u->meta.manager);
device_set_state(DEVICE(u), DEVICE_AVAILABLE);
}
unit_add_to_dbus_queue(u);
return 0;
fail:
if (delete && u)
unit_free(u);
return r;
}
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;
char *e;
Unit *u;
Device *d;
assert(m);
assert(dev);
if (!(sysfs = udev_device_get_syspath(dev)))
return -ENOMEM;
assert(sysfs[0] == '/');
if (!(e = unit_name_escape_path(sysfs+1, ".device")))
return -ENOMEM;
u = manager_get_unit(m, e);
free(e);
if (!u)
return 0;
d = DEVICE(u);
free(d->sysfs);
d->sysfs = NULL;
device_set_state(d, DEVICE_DEAD);
return 0;
}
static void device_shutdown(Manager *m) {
assert(m);
if (m->udev_monitor)
udev_monitor_unref(m->udev_monitor);
if (m->udev)
udev_unref(m->udev);
}
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 = udev_new()))
return -ENOMEM;
if (!(m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev"))) {
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_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;
assert(m);
assert(events == EPOLLIN);
log_debug("got udev event");
if (!(dev = udev_monitor_receive_device(m->udev_monitor))) {
log_error("Failed to receive device.");
return;
}
if (!(action = udev_device_get_action(dev))) {
log_error("Failed to get udev action string.");
goto fail;
}
if (streq(action, "remove")) {
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);
}
const UnitVTable device_vtable = {
.suffix = ".device",
.init = unit_load_fragment_and_dropin,
.done = device_done,
.coldplug = device_coldplug,
.dump = device_dump,
.active_state = device_active_state,
.enumerate = device_enumerate,
.shutdown = device_shutdown
};