blob: 030922eca931b2a8db6eb17fe5eeb9bed642625a [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <unistd.h>
#include "alloc-util.h"
#include "device-util.h"
#include "env-file.h"
#include "escape.h"
#include "log.h"
#include "macro.h"
#include "parse-util.h"
#include "path-util.h"
#include "signal-util.h"
#include "string-table.h"
#include "string-util.h"
#include "udev-util.h"
#include "utf8.h"
static const char* const resolve_name_timing_table[_RESOLVE_NAME_TIMING_MAX] = {
[RESOLVE_NAME_NEVER] = "never",
[RESOLVE_NAME_LATE] = "late",
[RESOLVE_NAME_EARLY] = "early",
};
DEFINE_STRING_TABLE_LOOKUP(resolve_name_timing, ResolveNameTiming);
int udev_parse_config_full(
unsigned *ret_children_max,
usec_t *ret_exec_delay_usec,
usec_t *ret_event_timeout_usec,
ResolveNameTiming *ret_resolve_name_timing,
int *ret_timeout_signal) {
_cleanup_free_ char *log_val = NULL, *children_max = NULL, *exec_delay = NULL, *event_timeout = NULL, *resolve_names = NULL, *timeout_signal = NULL;
int r;
r = parse_env_file(NULL, "/etc/udev/udev.conf",
"udev_log", &log_val,
"children_max", &children_max,
"exec_delay", &exec_delay,
"event_timeout", &event_timeout,
"resolve_names", &resolve_names,
"timeout_signal", &timeout_signal);
if (r == -ENOENT)
return 0;
if (r < 0)
return r;
if (log_val) {
const char *log;
size_t n;
/* unquote */
n = strlen(log_val);
if (n >= 2 &&
((log_val[0] == '"' && log_val[n-1] == '"') ||
(log_val[0] == '\'' && log_val[n-1] == '\''))) {
log_val[n - 1] = '\0';
log = log_val + 1;
} else
log = log_val;
/* we set the udev log level here explicitly, this is supposed
* to regulate the code in libudev/ and udev/. */
r = log_set_max_level_from_string_realm(LOG_REALM_UDEV, log);
if (r < 0)
log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
"failed to set udev log level '%s', ignoring: %m", log);
}
if (ret_children_max && children_max) {
r = safe_atou(children_max, ret_children_max);
if (r < 0)
log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
"failed to parse children_max=%s, ignoring: %m", children_max);
}
if (ret_exec_delay_usec && exec_delay) {
r = parse_sec(exec_delay, ret_exec_delay_usec);
if (r < 0)
log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
"failed to parse exec_delay=%s, ignoring: %m", exec_delay);
}
if (ret_event_timeout_usec && event_timeout) {
r = parse_sec(event_timeout, ret_event_timeout_usec);
if (r < 0)
log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
"failed to parse event_timeout=%s, ignoring: %m", event_timeout);
}
if (ret_resolve_name_timing && resolve_names) {
ResolveNameTiming t;
t = resolve_name_timing_from_string(resolve_names);
if (t < 0)
log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
"failed to parse resolve_names=%s, ignoring.", resolve_names);
else
*ret_resolve_name_timing = t;
}
if (ret_timeout_signal && timeout_signal) {
r = signal_from_string(timeout_signal);
if (r < 0)
log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
"failed to parse timeout_signal=%s, ignoring: %m", timeout_signal);
else
*ret_timeout_signal = r;
}
return 0;
}
/* Note that if -ENOENT is returned, it will be logged at debug level rather than error,
* because it's an expected, common occurrence that the caller will handle with a fallback */
static int device_new_from_dev_path(const char *devlink, sd_device **ret_device) {
struct stat st;
int r;
assert(devlink);
if (stat(devlink, &st) < 0)
return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno,
"Failed to stat() %s: %m", devlink);
if (!S_ISBLK(st.st_mode))
return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK),
"%s does not point to a block device: %m", devlink);
r = sd_device_new_from_devnum(ret_device, 'b', st.st_rdev);
if (r < 0)
return log_error_errno(r, "Failed to initialize device from %s: %m", devlink);
return 0;
}
struct DeviceMonitorData {
const char *sysname;
const char *devlink;
sd_device *device;
};
static void device_monitor_data_free(struct DeviceMonitorData *d) {
assert(d);
sd_device_unref(d->device);
}
static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
struct DeviceMonitorData *data = userdata;
const char *sysname;
assert(device);
assert(data);
assert(data->sysname || data->devlink);
assert(!data->device);
/* Ignore REMOVE events here. We are waiting for initialization after all, not de-initialization. We
* might see a REMOVE event from an earlier use of the device (devices by the same name are recycled
* by the kernel after all), which we should not get confused by. After all we cannot distinguish use
* cycles of the devices, as the udev queue is entirely asynchronous.
*
* If we see a REMOVE event here for the use cycle we actually care about then we won't notice of
* course, but that should be OK, given the timeout logic used on the wait loop: this will be noticed
* by means of -ETIMEDOUT. Thus we won't notice immediately, but eventually, and that should be
* sufficient for an error path that should regularly not happen.
*
* (And yes, we only need to special case REMOVE. It's the only "negative" event type, where a device
* ceases to exist. All other event types are "positive": the device exists and is registered in the
* udev database, thus whenever we see the event, we can consider it initialized.) */
if (device_for_action(device, DEVICE_ACTION_REMOVE))
return 0;
if (data->sysname && sd_device_get_sysname(device, &sysname) >= 0 && streq(sysname, data->sysname))
goto found;
if (data->devlink) {
const char *devlink;
FOREACH_DEVICE_DEVLINK(device, devlink)
if (path_equal(devlink, data->devlink))
goto found;
if (sd_device_get_devname(device, &devlink) >= 0 && path_equal(devlink, data->devlink))
goto found;
}
return 0;
found:
data->device = sd_device_ref(device);
return sd_event_exit(sd_device_monitor_get_event(monitor), 0);
}
static int device_wait_for_initialization_internal(
sd_device *_device,
const char *devlink,
const char *subsystem,
usec_t deadline,
sd_device **ret) {
_cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
_cleanup_(sd_event_source_unrefp) sd_event_source *timeout_source = NULL;
_cleanup_(sd_event_unrefp) sd_event *event = NULL;
/* Ensure that if !_device && devlink, device gets unrefd on errors since it will be new */
_cleanup_(sd_device_unrefp) sd_device *device = sd_device_ref(_device);
_cleanup_(device_monitor_data_free) struct DeviceMonitorData data = {
.devlink = devlink,
};
int r;
assert(device || (subsystem && devlink));
/* Devlink might already exist, if it does get the device to use the sysname filtering */
if (!device && devlink) {
r = device_new_from_dev_path(devlink, &device);
if (r < 0 && r != -ENOENT)
return r;
}
if (device) {
if (sd_device_get_is_initialized(device) > 0) {
if (ret)
*ret = sd_device_ref(device);
return 0;
}
/* We need either the sysname or the devlink for filtering */
assert_se(sd_device_get_sysname(device, &data.sysname) >= 0 || devlink);
}
/* Wait until the device is initialized, so that we can get access to the ID_PATH property */
r = sd_event_new(&event);
if (r < 0)
return log_error_errno(r, "Failed to get default event: %m");
r = sd_device_monitor_new(&monitor);
if (r < 0)
return log_error_errno(r, "Failed to acquire monitor: %m");
if (device && !subsystem) {
r = sd_device_get_subsystem(device, &subsystem);
if (r < 0 && r != -ENOENT)
return log_device_error_errno(device, r, "Failed to get subsystem: %m");
}
if (subsystem) {
r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
if (r < 0)
return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);
}
r = sd_device_monitor_attach_event(monitor, event);
if (r < 0)
return log_error_errno(r, "Failed to attach event to device monitor: %m");
r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
if (r < 0)
return log_error_errno(r, "Failed to start device monitor: %m");
if (deadline != USEC_INFINITY) {
r = sd_event_add_time(
event, &timeout_source,
CLOCK_MONOTONIC, deadline, 0,
NULL, INT_TO_PTR(-ETIMEDOUT));
if (r < 0)
return log_error_errno(r, "Failed to add timeout event source: %m");
}
/* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
* yet. */
if (!device && devlink) {
r = device_new_from_dev_path(devlink, &device);
if (r < 0 && r != -ENOENT)
return r;
}
if (device && sd_device_get_is_initialized(device) > 0) {
if (ret)
*ret = sd_device_ref(device);
return 0;
}
r = sd_event_loop(event);
if (r < 0)
return log_error_errno(r, "Failed to wait for device to be initialized: %m");
if (ret)
*ret = TAKE_PTR(data.device);
return 0;
}
int device_wait_for_initialization(sd_device *device, const char *subsystem, usec_t deadline, sd_device **ret) {
return device_wait_for_initialization_internal(device, NULL, subsystem, deadline, ret);
}
int device_wait_for_devlink(const char *devlink, const char *subsystem, usec_t deadline, sd_device **ret) {
return device_wait_for_initialization_internal(NULL, devlink, subsystem, deadline, ret);
}
int device_is_renaming(sd_device *dev) {
int r;
assert(dev);
r = sd_device_get_property_value(dev, "ID_RENAMING", NULL);
if (r == -ENOENT)
return false;
if (r < 0)
return r;
return true;
}
bool device_for_action(sd_device *dev, DeviceAction action) {
DeviceAction a;
assert(dev);
if (device_get_action(dev, &a) < 0)
return false;
return a == action;
}
int udev_rule_parse_value(char *str, char **ret_value, char **ret_endpos) {
char *i, *j;
int r;
bool is_escaped;
/* value must be double quotated */
is_escaped = str[0] == 'e';
str += is_escaped;
if (str[0] != '"')
return -EINVAL;
str++;
if (!is_escaped) {
/* unescape double quotation '\"'->'"' */
for (i = j = str; *i != '"'; i++, j++) {
if (*i == '\0')
return -EINVAL;
if (i[0] == '\\' && i[1] == '"')
i++;
*j = *i;
}
j[0] = '\0';
} else {
_cleanup_free_ char *unescaped = NULL;
/* find the end position of value */
for (i = str; *i != '"'; i++) {
if (i[0] == '\\')
i++;
if (*i == '\0')
return -EINVAL;
}
i[0] = '\0';
r = cunescape_length(str, i - str, 0, &unescaped);
if (r < 0)
return r;
assert(r <= i - str);
memcpy(str, unescaped, r + 1);
}
*ret_value = str;
*ret_endpos = i + 1;
return 0;
}