diff options
Diffstat (limited to 'src/libudev/libudev.c')
| -rw-r--r-- | src/libudev/libudev.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/src/libudev/libudev.c b/src/libudev/libudev.c new file mode 100644 index 0000000000..74b53cbf1b --- /dev/null +++ b/src/libudev/libudev.c @@ -0,0 +1,449 @@ +/* + * libudev - interface to udev device information + * + * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <stdarg.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <ctype.h> +#include <time.h> + +#include "libudev.h" +#include "libudev-private.h" + +/** + * SECTION:libudev + * @short_description: libudev context + * + * The context contains the default values read from the udev config file, + * and is passed to all library operations. + */ + +/** + * udev: + * + * Opaque object representing the library context. + */ +struct udev { + int refcount; + void (*log_fn)(struct udev *udev, + int priority, const char *file, int line, const char *fn, + const char *format, va_list args); + void *userdata; + char *sys_path; + char *dev_path; + char *rules_path[4]; + unsigned long long rules_path_ts[4]; + int rules_path_count; + char *run_path; + struct udev_list properties_list; + int log_priority; +}; + +void udev_log(struct udev *udev, + int priority, const char *file, int line, const char *fn, + const char *format, ...) +{ + va_list args; + + va_start(args, format); + udev->log_fn(udev, priority, file, line, fn, format, args); + va_end(args); +} + +static void log_stderr(struct udev *udev, + int priority, const char *file, int line, const char *fn, + const char *format, va_list args) +{ + fprintf(stderr, "libudev: %s: ", fn); + vfprintf(stderr, format, args); +} + +/** + * udev_get_userdata: + * @udev: udev library context + * + * Retrieve stored data pointer from library context. This might be useful + * to access from callbacks like a custom logging function. + * + * Returns: stored userdata + **/ +_public_ void *udev_get_userdata(struct udev *udev) +{ + if (udev == NULL) + return NULL; + return udev->userdata; +} + +/** + * udev_set_userdata: + * @udev: udev library context + * @userdata: data pointer + * + * Store custom @userdata in the library context. + **/ +_public_ void udev_set_userdata(struct udev *udev, void *userdata) +{ + if (udev == NULL) + return; + udev->userdata = userdata; +} + +static char *set_value(char **s, const char *v) +{ + free(*s); + *s = strdup(v); + util_remove_trailing_chars(*s, '/'); + return *s; +} + +/** + * udev_new: + * + * Create udev library context. This reads the udev configuration + * file, and fills in the default values. + * + * The initial refcount is 1, and needs to be decremented to + * release the resources of the udev library context. + * + * Returns: a new udev library context + **/ +_public_ struct udev *udev_new(void) +{ + struct udev *udev; + const char *env; + char *config_file = NULL; + FILE *f; + + udev = calloc(1, sizeof(struct udev)); + if (udev == NULL) + return NULL; + udev->refcount = 1; + udev->log_fn = log_stderr; + udev->log_priority = LOG_ERR; + udev_list_init(udev, &udev->properties_list, true); + + /* custom config file */ + env = getenv("UDEV_CONFIG_FILE"); + if (env != NULL) { + if (set_value(&config_file, env) == NULL) + goto err; + udev_add_property(udev, "UDEV_CONFIG_FILE", config_file); + } + + /* default config file */ + if (config_file == NULL) + config_file = strdup(SYSCONFDIR "/udev/udev.conf"); + if (config_file == NULL) + goto err; + + f = fopen(config_file, "re"); + if (f != NULL) { + char line[UTIL_LINE_SIZE]; + int line_nr = 0; + + while (fgets(line, sizeof(line), f)) { + size_t len; + char *key; + char *val; + + line_nr++; + + /* find key */ + key = line; + while (isspace(key[0])) + key++; + + /* comment or empty line */ + if (key[0] == '#' || key[0] == '\0') + continue; + + /* split key/value */ + val = strchr(key, '='); + if (val == NULL) { + err(udev, "missing <key>=<value> in '%s'[%i], skip line\n", config_file, line_nr); + continue; + } + val[0] = '\0'; + val++; + + /* find value */ + while (isspace(val[0])) + val++; + + /* terminate key */ + len = strlen(key); + if (len == 0) + continue; + while (isspace(key[len-1])) + len--; + key[len] = '\0'; + + /* terminate value */ + len = strlen(val); + if (len == 0) + continue; + while (isspace(val[len-1])) + len--; + val[len] = '\0'; + + if (len == 0) + continue; + + /* unquote */ + if (val[0] == '"' || val[0] == '\'') { + if (val[len-1] != val[0]) { + err(udev, "inconsistent quoting in '%s'[%i], skip line\n", config_file, line_nr); + continue; + } + val[len-1] = '\0'; + val++; + } + + if (strcmp(key, "udev_log") == 0) { + udev_set_log_priority(udev, util_log_priority(val)); + continue; + } + if (strcmp(key, "udev_root") == 0) { + set_value(&udev->dev_path, val); + continue; + } + if (strcmp(key, "udev_run") == 0) { + set_value(&udev->run_path, val); + continue; + } + if (strcmp(key, "udev_sys") == 0) { + set_value(&udev->sys_path, val); + continue; + } + if (strcmp(key, "udev_rules") == 0) { + set_value(&udev->rules_path[0], val); + udev->rules_path_count = 1; + continue; + } + } + fclose(f); + } + + /* environment overrides config */ + env = getenv("UDEV_LOG"); + if (env != NULL) + udev_set_log_priority(udev, util_log_priority(env)); + + /* set defaults */ + if (udev->dev_path == NULL) + if (set_value(&udev->dev_path, "/dev") == NULL) + goto err; + + if (udev->sys_path == NULL) + if (set_value(&udev->sys_path, "/sys") == NULL) + goto err; + + if (udev->run_path == NULL) + if (set_value(&udev->run_path, "/run/udev") == NULL) + goto err; + + if (udev->rules_path[0] == NULL) { + /* /usr/lib/udev -- system rules */ + udev->rules_path[0] = strdup(UDEVLIBEXECDIR "/rules.d"); + if (!udev->rules_path[0]) + goto err; + + /* /run/udev -- runtime rules */ + if (asprintf(&udev->rules_path[1], "%s/rules.d", udev->run_path) < 0) + goto err; + + /* /etc/udev -- local administration rules */ + udev->rules_path[2] = strdup(SYSCONFDIR "/udev/rules.d"); + if (!udev->rules_path[2]) + goto err; + + udev->rules_path_count = 3; + } + + free(config_file); + return udev; +err: + free(config_file); + err(udev, "context creation failed\n"); + udev_unref(udev); + return NULL; +} + +/** + * udev_ref: + * @udev: udev library context + * + * Take a reference of the udev library context. + * + * Returns: the passed udev library context + **/ +_public_ struct udev *udev_ref(struct udev *udev) +{ + if (udev == NULL) + return NULL; + udev->refcount++; + return udev; +} + +/** + * udev_unref: + * @udev: udev library context + * + * Drop a reference of the udev library context. If the refcount + * reaches zero, the resources of the context will be released. + * + **/ +_public_ void udev_unref(struct udev *udev) +{ + if (udev == NULL) + return; + udev->refcount--; + if (udev->refcount > 0) + return; + udev_list_cleanup(&udev->properties_list); + free(udev->dev_path); + free(udev->sys_path); + free(udev->rules_path[0]); + free(udev->rules_path[1]); + free(udev->rules_path[2]); + free(udev->run_path); + free(udev); +} + +/** + * udev_set_log_fn: + * @udev: udev library context + * @log_fn: function to be called for logging messages + * + * The built-in logging writes to stderr. It can be + * overridden by a custom function, to plug log messages + * into the users' logging functionality. + * + **/ +_public_ void udev_set_log_fn(struct udev *udev, + void (*log_fn)(struct udev *udev, + int priority, const char *file, int line, const char *fn, + const char *format, va_list args)) +{ + udev->log_fn = log_fn; + dbg(udev, "custom logging function %p registered\n", log_fn); +} + +/** + * udev_get_log_priority: + * @udev: udev library context + * + * The initial logging priority is read from the udev config file + * at startup. + * + * Returns: the current logging priority + **/ +_public_ int udev_get_log_priority(struct udev *udev) +{ + return udev->log_priority; +} + +/** + * udev_set_log_priority: + * @udev: udev library context + * @priority: the new logging priority + * + * Set the current logging priority. The value controls which messages + * are logged. + **/ +_public_ void udev_set_log_priority(struct udev *udev, int priority) +{ + char num[32]; + + udev->log_priority = priority; + snprintf(num, sizeof(num), "%u", udev->log_priority); + udev_add_property(udev, "UDEV_LOG", num); +} + +int udev_get_rules_path(struct udev *udev, char **path[], unsigned long long *stamp_usec[]) +{ + *path = udev->rules_path; + if (stamp_usec) + *stamp_usec = udev->rules_path_ts; + return udev->rules_path_count; +} + +/** + * udev_get_sys_path: + * @udev: udev library context + * + * Retrieve the sysfs mount point. The default is "/sys". For + * testing purposes, it can be overridden with udev_sys= + * in the udev configuration file. + * + * Returns: the sys mount point + **/ +_public_ const char *udev_get_sys_path(struct udev *udev) +{ + if (udev == NULL) + return NULL; + return udev->sys_path; +} + +/** + * udev_get_dev_path: + * @udev: udev library context + * + * Retrieve the device directory path. The default value is "/dev", + * the actual value may be overridden in the udev configuration + * file. + * + * Returns: the device directory path + **/ +_public_ const char *udev_get_dev_path(struct udev *udev) +{ + if (udev == NULL) + return NULL; + return udev->dev_path; +} + +/** + * udev_get_run_path: + * @udev: udev library context + * + * Retrieve the udev runtime directory path. The default is "/run/udev". + * + * Returns: the runtime directory path + **/ +_public_ const char *udev_get_run_path(struct udev *udev) +{ + if (udev == NULL) + return NULL; + return udev->run_path; +} + +struct udev_list_entry *udev_add_property(struct udev *udev, const char *key, const char *value) +{ + if (value == NULL) { + struct udev_list_entry *list_entry; + + list_entry = udev_get_properties_list_entry(udev); + list_entry = udev_list_entry_get_by_name(list_entry, key); + if (list_entry != NULL) + udev_list_entry_delete(list_entry); + return NULL; + } + return udev_list_entry_add(&udev->properties_list, key, value); +} + +struct udev_list_entry *udev_get_properties_list_entry(struct udev *udev) +{ + return udev_list_get_entry(&udev->properties_list); +} |