libudev: docs - add udev_get_run_path()

[elogind.git] / libudev / libudev.c

diff --git a/libudev/libudev.c b/libudev/libudev.c
index cd418709f0336b32468bc8aafc2b079d6c5c7936..edc24e2fcab42e3f1d5210f8e31d37c819b670d0 100644 (file)
--- a/libudev/libudev.c
+++ b/libudev/libudev.c
@@ -43,6 +43,8 @@ struct udev {
        char *sys_path;
        char *dev_path;
        char *rules_path;
+       char *run_config_path;
+       char *run_path;
        struct udev_list_node properties_list;
        int log_priority;
 };
@@ -96,6 +98,14 @@ void udev_set_userdata(struct udev *udev, void *userdata)
        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:
  *
@@ -111,7 +121,7 @@ struct udev *udev_new(void)
 {
        struct udev *udev;
        const char *env;
-       char *config_file;
+       char *config_file = NULL;
        FILE *f;
 
        udev = calloc(1, sizeof(struct udev));
@@ -121,31 +131,21 @@ struct udev *udev_new(void)
        udev->log_fn = log_stderr;
        udev->log_priority = LOG_ERR;
        udev_list_init(&udev->properties_list);
-       udev->dev_path = strdup("/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);
-       }
 
+       /* custom config file */
        env = getenv("UDEV_CONFIG_FILE");
        if (env != NULL) {
-               free(config_file);
-               config_file = strdup(env);
-               util_remove_trailing_chars(config_file, '/');
+               udev_add_property(udev, "UDEV_CONFIG_FILE", udev->dev_path);
+               if (set_value(&config_file, env) == NULL)
+                       goto err;
        }
+
+       /* 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];
@@ -214,40 +214,57 @@ struct udev *udev_new(void)
                                continue;
                        }
                        if (strcmp(key, "udev_root") == 0) {
-                               free(udev->dev_path);
-                               udev->dev_path = strdup(val);
-                               util_remove_trailing_chars(udev->dev_path, '/');
+                               set_value(&udev->dev_path, val);
+                               continue;
+                       }
+                       if (strcmp(key, "udev_run") == 0) {
+                               set_value(&udev->run_config_path, val);
                                continue;
                        }
                        if (strcmp(key, "udev_rules") == 0) {
-                               free(udev->rules_path);
-                               udev->rules_path = strdup(val);
-                               util_remove_trailing_chars(udev->rules_path, '/');
+                               set_value(&udev->rules_path, val);
                                continue;
                        }
                }
                fclose(f);
        }
 
+       /* environment overwrites config */
+       env = getenv("UDEV_LOG");
+       if (env != NULL)
+               udev_set_log_priority(udev, util_log_priority(env));
+
        env = getenv("UDEV_ROOT");
        if (env != NULL) {
-               free(udev->dev_path);
-               udev->dev_path = strdup(env);
-               util_remove_trailing_chars(udev->dev_path, '/');
+               set_value(&udev->dev_path, env);
                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));
+       env = getenv("SYSFS_PATH");
+       if (env != NULL) {
+               set_value(&udev->sys_path, env);
+               udev_add_property(udev, "SYSFS_PATH", udev->sys_path);
+       }
+
+       /* 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_config_path == NULL)
+               if (set_value(&udev->run_config_path, "/run/udev") == NULL)
+                       goto err;
 
-       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);
+       dbg(udev, "run_path='%s'\n", udev->run_config_path);
        if (udev->rules_path != NULL)
                dbg(udev, "rules_path='%s'\n", udev->rules_path);
        free(config_file);
@@ -294,6 +311,8 @@ void udev_unref(struct udev *udev)
        free(udev->dev_path);
        free(udev->sys_path);
        free(udev->rules_path);
+       free(udev->run_path);
+       free(udev->run_config_path);
        dbg(udev, "context %p released\n", udev);
        free(udev);
 }
@@ -387,6 +406,47 @@ const char *udev_get_dev_path(struct udev *udev)
        return udev->dev_path;
 }
 
+const char *udev_get_run_config_path(struct udev *udev)
+{
+       return udev->run_config_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
+ **/
+const char *udev_get_run_path(struct udev *udev)
+{
+       if (udev->run_path != NULL)
+               return udev->run_path;
+
+       /* check if configured path exists */
+       if (access(udev->run_config_path, F_OK) < 0) {
+               char filename[UTIL_PATH_SIZE];
+
+               /* fall back to /dev/.udev if that exists */
+               util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev", NULL);
+               if (access(filename, F_OK) >= 0)
+                       if (set_value(&udev->run_path, filename) != NULL)
+                               return udev->run_path;
+       }
+
+       /* use default path */
+       set_value(&udev->run_path, udev->run_config_path);
+       if (udev->run_path == NULL)
+               return udev->run_config_path;
+       return udev->run_path;
+}
+
+const char *udev_set_run_path(struct udev *udev, const char *path)
+{
+       return set_value(&udev->run_path, path);
+}
+
 struct udev_list_entry *udev_add_property(struct udev *udev, const char *key, const char *value)
 {
        if (value == NULL) {