summaryrefslogtreecommitdiff
path: root/src/udev/libudev.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/udev/libudev.c')
-rw-r--r--src/udev/libudev.c457
1 files changed, 457 insertions, 0 deletions
diff --git a/src/udev/libudev.c b/src/udev/libudev.c
new file mode 100644
index 000000000..dcba15de4
--- /dev/null
+++ b/src/udev/libudev.c
@@ -0,0 +1,457 @@
+/*
+ * 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
+ **/
+UDEV_EXPORT 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.
+ **/
+UDEV_EXPORT 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
+ **/
+UDEV_EXPORT 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[2], "%s/rules.d", udev->run_path) < 0)
+ goto err;
+
+ /* /etc/udev -- local administration rules */
+ udev->rules_path[1] = strdup(SYSCONFDIR "/udev/rules.d");
+ if (!udev->rules_path[1])
+ goto err;
+
+ udev->rules_path_count = 3;
+ }
+
+ 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);
+ dbg(udev, "run_path='%s'\n", udev->run_path);
+ dbg(udev, "rules_path='%s':'%s':'%s'\n", udev->rules_path[0], udev->rules_path[1], udev->rules_path[2]);
+ 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
+ **/
+UDEV_EXPORT 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.
+ *
+ **/
+UDEV_EXPORT 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);
+ 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.
+ *
+ **/
+UDEV_EXPORT 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", 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
+ **/
+UDEV_EXPORT 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.
+ **/
+UDEV_EXPORT 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
+ **/
+UDEV_EXPORT 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
+ **/
+UDEV_EXPORT 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
+ **/
+UDEV_EXPORT 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);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 20:38:57 +0000