/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #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 "id128-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 "stat-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; sd_id128_t event_id = SD_ID128_NULL; uint64_t seqnum = 0; if (!DEBUG_LOGGING) return; (void) sd_device_get_seqnum(device, &seqnum); (void) sd_device_get_action(device, &action); (void) sd_device_get_trigger_uuid(device, &event_id); log_device_debug(device, "%s%s(SEQNUM=%"PRIu64", ACTION=%s%s%s)", strempty(str), isempty(str) ? "" : " ", seqnum, strna(device_action_to_string(action)), sd_id128_is_null(event_id) ? "" : ", UUID=", sd_id128_is_null(event_id) ? "" : SD_ID128_TO_UUID_STRING(event_id)); } int udev_rule_parse_value(char *str, char **ret_value, char **ret_endpos) { char *i, *j; 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; ssize_t l; /* find the end position of value */ for (i = str; *i != '"'; i++) { if (i[0] == '\\') i++; if (*i == '\0') return -EINVAL; } i[0] = '\0'; l = cunescape_length(str, i - str, 0, &unescaped); if (l < 0) return l; assert(l <= i - str); memcpy(str, unescaped, l + 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 "[/]" 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; } bool devpath_conflict(const char *a, const char *b) { /* This returns true when two paths are equivalent, or one is a child of another. */ if (!a || !b) return false; for (; *a != '\0' && *b != '\0'; a++, b++) if (*a != *b) return false; return *a == '/' || *b == '/' || *a == *b; } 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); } static int device_is_power_sink(sd_device *device) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; bool found_source = false, found_sink = false; sd_device *parent, *d; int r; assert(device); /* USB-C power supply device has two power roles: source or sink. See, * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-typec */ r = sd_device_enumerator_new(&e); if (r < 0) return r; r = sd_device_enumerator_allow_uninitialized(e); if (r < 0) return r; r = sd_device_enumerator_add_match_subsystem(e, "typec", true); if (r < 0) return r; r = sd_device_get_parent(device, &parent); if (r < 0) return r; r = sd_device_enumerator_add_match_parent(e, parent); if (r < 0) return r; FOREACH_DEVICE(e, d) { const char *val; r = sd_device_get_sysattr_value(d, "power_role", &val); if (r < 0) { if (r != -ENOENT) log_device_debug_errno(d, r, "Failed to read 'power_role' sysfs attribute, ignoring: %m"); continue; } if (strstr(val, "[source]")) { found_source = true; log_device_debug(d, "The USB type-C port is in power source mode."); } else if (strstr(val, "[sink]")) { found_sink = true; log_device_debug(d, "The USB type-C port is in power sink mode."); } } if (found_sink) log_device_debug(device, "The USB type-C device has at least one port in power sink mode."); else if (!found_source) log_device_debug(device, "The USB type-C device has no port in power source mode, assuming the device is in power sink mode."); else log_device_debug(device, "All USB type-C ports are in power source mode."); return found_sink || !found_source; } int on_ac_power(void) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; bool found_offline = false, found_online = false; sd_device *d; int r; r = sd_device_enumerator_new(&e); if (r < 0) return r; r = sd_device_enumerator_allow_uninitialized(e); if (r < 0) return r; r = sd_device_enumerator_add_match_subsystem(e, "power_supply", true); if (r < 0) return r; FOREACH_DEVICE(e, d) { const char *val; unsigned v; r = sd_device_get_sysattr_value(d, "type", &val); if (r < 0) { log_device_debug_errno(d, r, "Failed to read 'type' sysfs attribute, ignoring: %m"); continue; } /* We assume every power source is AC, except for batteries. See * https://github.com/torvalds/linux/blob/4eef766b7d4d88f0b984781bc1bcb574a6eafdc7/include/linux/power_supply.h#L176 * for defined power source types. Also see: * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-power */ if (streq(val, "Battery")) { log_device_debug(d, "The power supply is battery, ignoring."); continue; } /* Ignore USB-C power supply in source mode. See issue #21988. */ if (streq(val, "USB")) { r = device_is_power_sink(d); if (r <= 0) { if (r < 0) log_device_debug_errno(d, r, "Failed to determine the current power role, ignoring: %m"); else log_device_debug(d, "USB power supply is in source mode, ignoring."); continue; } } r = sd_device_get_sysattr_value(d, "online", &val); if (r < 0) { log_device_debug_errno(d, r, "Failed to read 'online' sysfs attribute, ignoring: %m"); continue; } r = safe_atou(val, &v); if (r < 0) { log_device_debug_errno(d, r, "Failed to parse 'online' attribute, ignoring: %m"); continue; } if (v > 0) /* At least 1 and 2 are defined as different types of 'online' */ found_online = true; else found_offline = true; log_device_debug(d, "The power supply is currently %s.", v > 0 ? "online" : "offline"); } if (found_online) log_debug("Found at least one online non-battery power supply, system is running on AC power."); else if (!found_offline) log_debug("Found no offline non-battery power supply, assuming system is running on AC power."); else log_debug("All non-battery power supplies are offline, assuming system is running with battery."); return found_online || !found_offline; } bool udev_available(void) { static int cache = -1; /* The service systemd-udevd is started only when /sys is read write. * See systemd-udevd.service: ConditionPathIsReadWrite=/sys * Also, our container interface (http://systemd.io/CONTAINER_INTERFACE/) states that /sys must * be mounted in read-only mode in containers. */ if (cache >= 0) return cache; return (cache = (path_is_read_only_fs("/sys/") <= 0)); }