blob: f934fc157eb527d493293ba5e5e6e1cab6855992 [file] [log] [blame]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <ctype.h>
#include <errno.h>
#include <sys/inotify.h>
#include <unistd.h>
#include "alloc-util.h"
#include "device-nodes.h"
#include "device-private.h"
#include "device-util.h"
#include "env-file.h"
#include "errno-util.h"
#include "escape.h"
#include "fd-util.h"
#include "log.h"
#include "macro.h"
#include "parse-util.h"
#include "path-util.h"
#include "signal-util.h"
#include "socket-util.h"
#include "string-table.h"
#include "string-util.h"
#include "strxcpyx.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(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_stat_rdev(ret_device, &st);
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, SD_DEVICE_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, sd_device_action_t a) {
sd_device_action_t b;
assert(dev);
if (a < 0)
return false;
if (sd_device_get_action(dev, &b) < 0)
return false;
return a == b;
}
void log_device_uevent(sd_device *device, const char *str) {
sd_device_action_t action = _SD_DEVICE_ACTION_INVALID;
uint64_t seqnum = 0;
if (!DEBUG_LOGGING)
return;
(void) sd_device_get_seqnum(device, &seqnum);
(void) sd_device_get_action(device, &action);
log_device_debug(device, "%s%s(SEQNUM=%"PRIu64", ACTION=%s)",
strempty(str), isempty(str) ? "" : " ",
seqnum, strna(device_action_to_string(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;
}
size_t udev_replace_whitespace(const char *str, char *to, size_t len) {
bool is_space = false;
size_t i, j;
assert(str);
assert(to);
/* Copy from 'str' to 'to', while removing all leading and trailing whitespace, and replacing
* each run of consecutive whitespace with a single underscore. The chars from 'str' are copied
* up to the \0 at the end of the string, or at most 'len' chars. This appends \0 to 'to', at
* the end of the copied characters.
*
* If 'len' chars are copied into 'to', the final \0 is placed at len+1 (i.e. 'to[len] = \0'),
* so the 'to' buffer must have at least len+1 chars available.
*
* Note this may be called with 'str' == 'to', i.e. to replace whitespace in-place in a buffer.
* This function can handle that situation.
*
* Note that only 'len' characters are read from 'str'. */
i = strspn(str, WHITESPACE);
for (j = 0; j < len && i < len && str[i] != '\0'; i++) {
if (isspace(str[i])) {
is_space = true;
continue;
}
if (is_space) {
if (j + 1 >= len)
break;
to[j++] = '_';
is_space = false;
}
to[j++] = str[i];
}
to[j] = '\0';
return j;
}
size_t udev_replace_ifname(char *str) {
size_t replaced = 0;
assert(str);
/* See ifname_valid_full(). */
for (char *p = str; *p != '\0'; p++)
if (!ifname_valid_char(*p)) {
*p = '_';
replaced++;
}
return replaced;
}
size_t udev_replace_chars(char *str, const char *allow) {
size_t i = 0, replaced = 0;
assert(str);
/* allow chars in allow list, plain ascii, hex-escaping and valid utf8. */
while (str[i] != '\0') {
int len;
if (allow_listed_char_for_devnode(str[i], allow)) {
i++;
continue;
}
/* accept hex encoding */
if (str[i] == '\\' && str[i+1] == 'x') {
i += 2;
continue;
}
/* accept valid utf8 */
len = utf8_encoded_valid_unichar(str + i, SIZE_MAX);
if (len > 1) {
i += len;
continue;
}
/* if space is allowed, replace whitespace with ordinary space */
if (isspace(str[i]) && allow && strchr(allow, ' ')) {
str[i] = ' ';
i++;
replaced++;
continue;
}
/* everything else is replaced with '_' */
str[i] = '_';
i++;
replaced++;
}
return replaced;
}
int udev_resolve_subsys_kernel(const char *string, char *result, size_t maxsize, bool read_value) {
_cleanup_(sd_device_unrefp) sd_device *dev = NULL;
_cleanup_free_ char *temp = NULL;
char *subsys, *sysname, *attr;
const char *val;
int r;
assert(string);
assert(result);
/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
if (string[0] != '[')
return -EINVAL;
temp = strdup(string);
if (!temp)
return -ENOMEM;
subsys = &temp[1];
sysname = strchr(subsys, '/');
if (!sysname)
return -EINVAL;
sysname[0] = '\0';
sysname = &sysname[1];
attr = strchr(sysname, ']');
if (!attr)
return -EINVAL;
attr[0] = '\0';
attr = &attr[1];
if (attr[0] == '/')
attr = &attr[1];
if (attr[0] == '\0')
attr = NULL;
if (read_value && !attr)
return -EINVAL;
r = sd_device_new_from_subsystem_sysname(&dev, subsys, sysname);
if (r < 0)
return r;
if (read_value) {
r = sd_device_get_sysattr_value(dev, attr, &val);
if (r < 0 && !ERRNO_IS_PRIVILEGE(r) && r != -ENOENT)
return r;
if (r >= 0)
strscpy(result, maxsize, val);
else
result[0] = '\0';
log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
} else {
r = sd_device_get_syspath(dev, &val);
if (r < 0)
return r;
strscpyl(result, maxsize, val, attr ? "/" : NULL, attr ?: NULL, NULL);
log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, strempty(attr), result);
}
return 0;
}
int udev_queue_is_empty(void) {
return access("/run/udev/queue", F_OK) < 0 ?
(errno == ENOENT ? true : -errno) : false;
}
int udev_queue_init(void) {
_cleanup_close_ int fd = -1;
fd = inotify_init1(IN_CLOEXEC);
if (fd < 0)
return -errno;
if (inotify_add_watch(fd, "/run/udev" , IN_DELETE) < 0)
return -errno;
return TAKE_FD(fd);
}