diff options
Diffstat (limited to 'libudev/libudev.c')
-rw-r--r-- | libudev/libudev.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/libudev/libudev.c b/libudev/libudev.c new file mode 100644 index 0000000000..a9baa70799 --- /dev/null +++ b/libudev/libudev.c @@ -0,0 +1,374 @@ +/* + * libudev - interface to udev device information + * + * Copyright (C) 2008 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 "libudev.h" +#include "libudev-private.h" + +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; + struct udev_list_node properties_list; + int log_priority; + int run; +}; + +void udev_log(struct udev *udev, + int priority, const char *file, int line, const char *fn, + const char *format, ...) +{ + va_list args; + + if (priority > udev->log_priority) + return; + + 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); +} + +void *udev_get_userdata(struct udev *udev) +{ + if (udev == NULL) + return NULL; + return udev->userdata; +} + +void udev_set_userdata(struct udev *udev, void *userdata) +{ + if (udev == NULL) + return; + udev->userdata = userdata; +} + +/** + * udev_new: + * + * Create udev library context. + * + * 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 + **/ +struct udev *udev_new(void) +{ + struct udev *udev; + const char *env; + char *config_file; + 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->properties_list); + udev->run = 1; + udev->dev_path = strdup(UDEV_PREFIX "/dev"); + udev->sys_path = strdup("/sys"); + config_file = strdup(SYSCONFDIR "/udev/udev.conf"); + if (udev->dev_path == NULL || + udev->sys_path == NULL || + config_file == NULL) + goto err; + + /* settings by environment and config file */ + env = getenv("SYSFS_PATH"); + if (env != NULL) { + free(udev->sys_path); + udev->sys_path = strdup(env); + util_remove_trailing_chars(udev->sys_path, '/'); + udev_add_property(udev, "SYSFS_PATH", udev->sys_path); + } + + env = getenv("UDEV_RUN"); + if (env != NULL && strcmp(env, "0") == 0) + udev->run = 0; + + env = getenv("UDEV_CONFIG_FILE"); + if (env != NULL) { + free(config_file); + config_file = strdup(env); + util_remove_trailing_chars(config_file, '/'); + } + if (config_file == NULL) + goto err; + f = fopen(config_file, "r"); + 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) { + free(udev->dev_path); + udev->dev_path = strdup(val); + util_remove_trailing_chars(udev->dev_path, '/'); + continue; + } + if (strcmp(key, "udev_rules") == 0) { + free(udev->rules_path); + udev->rules_path = strdup(val); + util_remove_trailing_chars(udev->rules_path, '/'); + continue; + } + } + fclose(f); + } + + env = getenv("UDEV_ROOT"); + if (env != NULL) { + free(udev->dev_path); + udev->dev_path = strdup(env); + util_remove_trailing_chars(udev->dev_path, '/'); + udev_add_property(udev, "UDEV_ROOT", udev->dev_path); + } + + env = getenv("UDEV_LOG"); + if (env != NULL) + udev_set_log_priority(udev, util_log_priority(env)); + + if (udev->dev_path == NULL || udev->sys_path == NULL) + goto err; + dbg(udev, "context %p created\n", udev); + dbg(udev, "log_priority=%d\n", udev->log_priority); + dbg(udev, "config_file='%s'\n", config_file); + dbg(udev, "dev_path='%s'\n", udev->dev_path); + dbg(udev, "sys_path='%s'\n", udev->sys_path); + if (udev->rules_path != NULL) + dbg(udev, "rules_path='%s'\n", udev->rules_path); + 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 + **/ +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. + * + **/ +void udev_unref(struct udev *udev) +{ + if (udev == NULL) + return; + udev->refcount--; + if (udev->refcount > 0) + return; + udev_list_cleanup_entries(udev, &udev->properties_list); + free(udev->dev_path); + free(udev->sys_path); + free(udev->rules_path); + dbg(udev, "context %p released\n", udev); + 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. + * + **/ +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; + info(udev, "custom logging function %p registered\n", udev); +} + +int udev_get_log_priority(struct udev *udev) +{ + return udev->log_priority; +} + +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); +} + +const char *udev_get_rules_path(struct udev *udev) +{ + return udev->rules_path; +} + +int udev_get_run(struct udev *udev) +{ + return udev->run; +} + +/** + * 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 the environment + * variable SYSFS_PATH. + * + * Returns: the sys mount point + **/ +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 + **/ +const char *udev_get_dev_path(struct udev *udev) +{ + if (udev == NULL) + return NULL; + return udev->dev_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, &udev->properties_list, key, value, 1, 0); +} + +struct udev_list_entry *udev_get_properties_list_entry(struct udev *udev) +{ + return udev_list_get_entry(&udev->properties_list); +} |