libudev.c revision bd75fddbcbc65799bd4a684b3b6f4f04bcd637d8
0N/A/*
430N/A * libudev - interface to udev device information
0N/A *
0N/A * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
0N/A *
0N/A * This library is free software; you can redistribute it and/or
0N/A * modify it under the terms of the GNU Lesser General Public
0N/A * License as published by the Free Software Foundation; either
0N/A * version 2.1 of the License, or (at your option) any later version.
0N/A */
0N/A
0N/A#include <stdio.h>
0N/A#include <stdlib.h>
0N/A#include <stddef.h>
0N/A#include <stdarg.h>
0N/A#include <unistd.h>
0N/A#include <errno.h>
0N/A#include <string.h>
0N/A#include <ctype.h>
0N/A
0N/A#include "libudev.h"
0N/A#include "libudev-private.h"
0N/A
0N/Astruct udev {
0N/A int refcount;
0N/A void (*log_fn)(struct udev *udev,
0N/A int priority, const char *file, int line, const char *fn,
0N/A const char *format, va_list args);
0N/A void *userdata;
430N/A char *sys_path;
430N/A char *dev_path;
0N/A char *rules_path;
0N/A struct udev_list_node properties_list;
430N/A int log_priority;
0N/A int run;
0N/A};
0N/A
0N/Avoid udev_log(struct udev *udev,
0N/A int priority, const char *file, int line, const char *fn,
0N/A const char *format, ...)
0N/A{
0N/A va_list args;
0N/A
0N/A if (priority > udev->log_priority)
430N/A return;
0N/A
0N/A va_start(args, format);
0N/A udev->log_fn(udev, priority, file, line, fn, format, args);
430N/A va_end(args);
430N/A}
0N/A
430N/Astatic void log_stderr(struct udev *udev,
430N/A int priority, const char *file, int line, const char *fn,
430N/A const char *format, va_list args)
430N/A{
430N/A fprintf(stderr, "libudev: %s: ", fn);
430N/A vfprintf(stderr, format, args);
430N/A}
430N/A
430N/Avoid *udev_get_userdata(struct udev *udev)
0N/A{
0N/A if (udev == NULL)
0N/A return NULL;
0N/A return udev->userdata;
0N/A}
0N/A
0N/Avoid udev_set_userdata(struct udev *udev, void *userdata)
0N/A{
0N/A if (udev == NULL)
0N/A return;
430N/A udev->userdata = userdata;
0N/A}
0N/A
0N/A/**
0N/A * udev_new:
0N/A *
0N/A * Create udev library context.
0N/A *
0N/A * The initial refcount is 1, and needs to be decremented to
0N/A * release the resources of the udev library context.
0N/A *
0N/A * Returns: a new udev library context
0N/A **/
0N/Astruct udev *udev_new(void)
430N/A{
0N/A struct udev *udev;
0N/A const char *env;
0N/A char *config_file;
0N/A FILE *f;
430N/A
0N/A udev = calloc(1, sizeof(struct udev));
0N/A if (udev == NULL)
0N/A return NULL;
0N/A udev->refcount = 1;
430N/A udev->log_fn = log_stderr;
430N/A udev->log_priority = LOG_ERR;
0N/A udev_list_init(&udev->properties_list);
0N/A udev->run = 1;
0N/A udev->dev_path = strdup(UDEV_PREFIX "/dev");
0N/A udev->sys_path = strdup("/sys");
0N/A config_file = strdup(SYSCONFDIR "/udev/udev.conf");
0N/A if (udev->dev_path == NULL ||
0N/A udev->sys_path == NULL ||
0N/A config_file == NULL)
0N/A goto err;
0N/A
0N/A /* settings by environment and config file */
0N/A env = getenv("SYSFS_PATH");
0N/A if (env != NULL) {
0N/A free(udev->sys_path);
0N/A udev->sys_path = strdup(env);
0N/A util_remove_trailing_chars(udev->sys_path, '/');
0N/A udev_add_property(udev, "SYSFS_PATH", udev->sys_path);
0N/A }
0N/A
0N/A env = getenv("UDEV_RUN");
0N/A if (env != NULL && strcmp(env, "0") == 0)
430N/A udev->run = 0;
0N/A
0N/A env = getenv("UDEV_CONFIG_FILE");
0N/A if (env != NULL) {
0N/A free(config_file);
0N/A config_file = strdup(env);
0N/A util_remove_trailing_chars(config_file, '/');
0N/A }
0N/A if (config_file == NULL)
0N/A goto err;
0N/A f = fopen(config_file, "r");
0N/A if (f != NULL) {
430N/A char line[UTIL_LINE_SIZE];
430N/A int line_nr = 0;
430N/A
430N/A while (fgets(line, sizeof(line), f)) {
430N/A size_t len;
430N/A char *key;
0N/A char *val;
0N/A
0N/A line_nr++;
0N/A
0N/A /* find key */
0N/A key = line;
0N/A while (isspace(key[0]))
0N/A key++;
430N/A
0N/A /* comment or empty line */
430N/A if (key[0] == '#' || key[0] == '\0')
0N/A continue;
0N/A
0N/A /* split key/value */
0N/A val = strchr(key, '=');
0N/A if (val == NULL) {
0N/A err(udev, "missing <key>=<value> in '%s'[%i], skip line\n", config_file, line_nr);
0N/A continue;
0N/A }
0N/A val[0] = '\0';
0N/A val++;
0N/A
0N/A /* find value */
0N/A while (isspace(val[0]))
0N/A val++;
0N/A
0N/A /* terminate key */
0N/A len = strlen(key);
0N/A if (len == 0)
0N/A continue;
0N/A while (isspace(key[len-1]))
0N/A len--;
0N/A key[len] = '\0';
0N/A
0N/A /* terminate value */
0N/A len = strlen(val);
0N/A if (len == 0)
0N/A continue;
0N/A while (isspace(val[len-1]))
0N/A len--;
0N/A val[len] = '\0';
430N/A
0N/A if (len == 0)
430N/A continue;
0N/A
0N/A /* unquote */
430N/A if (val[0] == '"' || val[0] == '\'') {
0N/A if (val[len-1] != val[0]) {
0N/A err(udev, "inconsistent quoting in '%s'[%i], skip line\n", config_file, line_nr);
0N/A continue;
0N/A }
430N/A val[len-1] = '\0';
430N/A val++;
430N/A }
430N/A
430N/A if (strcmp(key, "udev_log") == 0) {
430N/A udev_set_log_priority(udev, util_log_priority(val));
0N/A continue;
0N/A }
0N/A if (strcmp(key, "udev_root") == 0) {
0N/A free(udev->dev_path);
0N/A udev->dev_path = strdup(val);
0N/A util_remove_trailing_chars(udev->dev_path, '/');
430N/A continue;
430N/A }
0N/A if (strcmp(key, "udev_rules") == 0) {
0N/A free(udev->rules_path);
0N/A udev->rules_path = strdup(val);
430N/A util_remove_trailing_chars(udev->rules_path, '/');
430N/A continue;
430N/A }
430N/A }
430N/A fclose(f);
430N/A }
430N/A
430N/A env = getenv("UDEV_ROOT");
430N/A if (env != NULL) {
430N/A free(udev->dev_path);
430N/A udev->dev_path = strdup(env);
430N/A util_remove_trailing_chars(udev->dev_path, '/');
430N/A udev_add_property(udev, "UDEV_ROOT", udev->dev_path);
430N/A }
430N/A
430N/A env = getenv("UDEV_LOG");
0N/A if (env != NULL)
0N/A udev_set_log_priority(udev, util_log_priority(env));
0N/A
0N/A if (udev->dev_path == NULL || udev->sys_path == NULL)
0N/A goto err;
0N/A dbg(udev, "context %p created\n", udev);
0N/A dbg(udev, "log_priority=%d\n", udev->log_priority);
0N/A dbg(udev, "config_file='%s'\n", config_file);
0N/A dbg(udev, "dev_path='%s'\n", udev->dev_path);
0N/A dbg(udev, "sys_path='%s'\n", udev->sys_path);
0N/A if (udev->rules_path != NULL)
0N/A dbg(udev, "rules_path='%s'\n", udev->rules_path);
0N/A free(config_file);
0N/A return udev;
0N/Aerr:
0N/A free(config_file);
0N/A err(udev, "context creation failed\n");
0N/A udev_unref(udev);
0N/A return NULL;
0N/A}
0N/A
0N/A/**
0N/A * udev_ref:
0N/A * @udev: udev library context
0N/A *
0N/A * Take a reference of the udev library context.
0N/A *
0N/A * Returns: the passed udev library context
0N/A **/
0N/Astruct udev *udev_ref(struct udev *udev)
0N/A{
0N/A if (udev == NULL)
0N/A return NULL;
0N/A udev->refcount++;
0N/A return udev;
0N/A}
0N/A
0N/A/**
0N/A * udev_unref:
0N/A * @udev: udev library context
0N/A *
0N/A * Drop a reference of the udev library context. If the refcount
0N/A * reaches zero, the resources of the context will be released.
0N/A *
0N/A **/
0N/Avoid udev_unref(struct udev *udev)
0N/A{
0N/A if (udev == NULL)
0N/A return;
0N/A udev->refcount--;
0N/A if (udev->refcount > 0)
0N/A return;
0N/A udev_list_cleanup_entries(udev, &udev->properties_list);
0N/A free(udev->dev_path);
0N/A free(udev->sys_path);
0N/A free(udev->rules_path);
0N/A dbg(udev, "context %p released\n", udev);
0N/A free(udev);
0N/A}
0N/A
0N/A/**
0N/A * udev_set_log_fn:
430N/A * @udev: udev library context
430N/A * @log_fn: function to be called for logging messages
430N/A *
430N/A * The built-in logging writes to stderr. It can be
430N/A * overridden by a custom function, to plug log messages
0N/A * into the users' logging functionality.
0N/A *
0N/A **/
0N/Avoid udev_set_log_fn(struct udev *udev,
0N/A void (*log_fn)(struct udev *udev,
0N/A int priority, const char *file, int line, const char *fn,
0N/A const char *format, va_list args))
0N/A{
0N/A udev->log_fn = log_fn;
0N/A info(udev, "custom logging function %p registered\n", udev);
0N/A}
0N/A
0N/Aint udev_get_log_priority(struct udev *udev)
0N/A{
0N/A return udev->log_priority;
0N/A}
0N/A
0N/Avoid udev_set_log_priority(struct udev *udev, int priority)
0N/A{
0N/A char num[32];
0N/A
0N/A udev->log_priority = priority;
0N/A snprintf(num, sizeof(num), "%u", udev->log_priority);
0N/A udev_add_property(udev, "UDEV_LOG", num);
0N/A}
0N/A
0N/Aconst char *udev_get_rules_path(struct udev *udev)
0N/A{
0N/A return udev->rules_path;
0N/A}
0N/A
0N/Aint udev_get_run(struct udev *udev)
0N/A{
0N/A return udev->run;
0N/A}
0N/A
0N/A/**
0N/A * udev_get_sys_path:
0N/A * @udev: udev library context
0N/A *
0N/A * Retrieve the sysfs mount point. The default is "/sys". For
0N/A * testing purposes, it can be overridden with the environment
0N/A * variable SYSFS_PATH.
0N/A *
0N/A * Returns: the sys mount point
0N/A **/
0N/Aconst char *udev_get_sys_path(struct udev *udev)
0N/A{
430N/A if (udev == NULL)
0N/A return NULL;
0N/A return udev->sys_path;
0N/A}
430N/A
430N/A/**
430N/A * udev_get_dev_path:
430N/A * @udev: udev library context
430N/A *
430N/A * Retrieve the device directory path. The default value is "/dev",
430N/A * the actual value may be overridden in the udev configuration
430N/A * file.
430N/A *
430N/A * Returns: the device directory path
430N/A **/
430N/Aconst char *udev_get_dev_path(struct udev *udev)
430N/A{
430N/A if (udev == NULL)
430N/A return NULL;
430N/A return udev->dev_path;
430N/A}
430N/A
430N/Astruct udev_list_entry *udev_add_property(struct udev *udev, const char *key, const char *value)
430N/A{
430N/A if (value == NULL) {
430N/A struct udev_list_entry *list_entry;
430N/A
430N/A list_entry = udev_get_properties_list_entry(udev);
430N/A list_entry = udev_list_entry_get_by_name(list_entry, key);
0N/A if (list_entry != NULL)
0N/A udev_list_entry_delete(list_entry);
0N/A return NULL;
0N/A }
0N/A return udev_list_entry_add(udev, &udev->properties_list, key, value, 1, 0);
0N/A}
0N/A
0N/Astruct udev_list_entry *udev_get_properties_list_entry(struct udev *udev)
0N/A{
0N/A return udev_list_get_entry(&udev->properties_list);
0N/A}
0N/A