diff options
Diffstat (limited to 'src/shared/udev-util.c')
| -rw-r--r-- | src/shared/udev-util.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/src/shared/udev-util.c b/src/shared/udev-util.c new file mode 100644 index 0000000..4200032 --- /dev/null +++ b/src/shared/udev-util.c @@ -0,0 +1,171 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <errno.h> +#include <string.h> + +#include "alloc-util.h" +#include "env-file.h" +#include "log.h" +#include "parse-util.h" +#include "string-table.h" +#include "string-util.h" +#include "udev-util.h" +#include "udev.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) { + + _cleanup_free_ char *log_val = NULL, *children_max = NULL, *exec_delay = NULL, *event_timeout = NULL, *resolve_names = 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); + 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_debug_errno(r, "/etc/udev/udev.conf: 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_notice_errno(r, "/etc/udev/udev.conf: failed to set 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_notice_errno(r, "/etc/udev/udev.conf: failed to set 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_notice_errno(r, "/etc/udev/udev.conf: failed to set 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_notice("/etc/udev/udev.conf: failed to set parse resolve_names=%s, ignoring.", resolve_names); + else + *ret_resolve_name_timing = t; + } + + return 0; +} + +struct DeviceMonitorData { + const char *sysname; + sd_device *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); + assert(!data->device); + + if (sd_device_get_sysname(device, &sysname) >= 0 && streq(sysname, data->sysname)) { + data->device = sd_device_ref(device); + return sd_event_exit(sd_device_monitor_get_event(monitor), 0); + } + + return 0; +} + +int device_wait_for_initialization(sd_device *device, const char *subsystem, sd_device **ret) { + _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL; + _cleanup_(sd_event_unrefp) sd_event *event = NULL; + struct DeviceMonitorData data = {}; + int r; + + assert(device); + assert(subsystem); + + if (sd_device_get_is_initialized(device) > 0) { + if (ret) + *ret = sd_device_ref(device); + return 0; + } + + assert_se(sd_device_get_sysname(device, &data.sysname) >= 0); + + /* Wait until the device is initialized, so that we can get access to the ID_PATH property */ + + r = sd_event_default(&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"); + + 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"); + + /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized + * yet. */ + if (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, "Event loop failed: %m"); + + if (ret) + *ret = TAKE_PTR(data.device); + return 0; +} |