/* * 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; 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; } /** * 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; 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); f = fopen(SYSCONFDIR "/udev/udev.conf", "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) { udev_err(udev, "missing <key>=<value> in " SYSCONFDIR "/udev/udev.conf[%i]; skip line\n", 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]) { udev_err(udev, "inconsistent quoting in " SYSCONFDIR "/udev/udev.conf[%i]; skip line\n", line_nr); continue; } val[len-1] = '\0'; val++; } if (strcmp(key, "udev_log") == 0) { udev_set_log_priority(udev, util_log_priority(val)); continue; } } fclose(f); } /* environment overrides config */ env = getenv("UDEV_LOG"); if (env != NULL) udev_set_log_priority(udev, util_log_priority(env)); return udev; } /** * 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); } /** * 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; udev_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); } /** * udev_get_sys_path: * @udev: udev library context * * Returns always "/sys"; deprecated, will be removed in a future version. * * Returns: the sys mount point **/ _public_ const char *udev_get_sys_path(struct udev *udev) { if (udev == NULL) return NULL; return "/sys"; } /** * udev_get_dev_path: * @udev: udev library context * * Returns always "/dev"; deprecated, will be removed in a future version. * * Returns: the device directory path **/ _public_ const char *udev_get_dev_path(struct udev *udev) { if (udev == NULL) return NULL; return "/dev"; } /** * udev_get_run_path: * @udev: udev library context * * Returns always "/run/udev"; deprecated, will be removed in a future version. * * Returns: the runtime directory path **/ _public_ const char *udev_get_run_path(struct udev *udev) { if (udev == NULL) return NULL; return "/run/udev"; } 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); }