[mech_eap.git] / wpa_supplicant / config.h

/*
 * WPA Supplicant / Configuration file structures
 * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
 *
 * This software may be distributed under the terms of the BSD license.
 * See README for more details.
 */

#ifndef CONFIG_H
#define CONFIG_H

#define DEFAULT_EAPOL_VERSION 1
#ifdef CONFIG_NO_SCAN_PROCESSING
#define DEFAULT_AP_SCAN 2
#else /* CONFIG_NO_SCAN_PROCESSING */
#define DEFAULT_AP_SCAN 1
#endif /* CONFIG_NO_SCAN_PROCESSING */
#define DEFAULT_FAST_REAUTH 1
#define DEFAULT_P2P_GO_INTENT 7
#define DEFAULT_P2P_INTRA_BSS 1
#define DEFAULT_BSS_MAX_COUNT 200
#define DEFAULT_BSS_EXPIRATION_AGE 180
#define DEFAULT_BSS_EXPIRATION_SCAN_COUNT 2
#define DEFAULT_MAX_NUM_STA 128
#define DEFAULT_ACCESS_NETWORK_TYPE 15

#include "config_ssid.h"
#include "wps/wps.h"


struct wpa_cred {
        /**
         * next - Next credential in the list
         *
         * This pointer can be used to iterate over all credentials. The head
         * of this list is stored in the cred field of struct wpa_config.
         */
        struct wpa_cred *next;

        /**
         * id - Unique id for the credential
         *
         * This identifier is used as a unique identifier for each credential
         * block when using the control interface. Each credential is allocated
         * an id when it is being created, either when reading the
         * configuration file or when a new credential is added through the
         * control interface.
         */
        int id;

        /**
         * priority - Priority group
         *
         * By default, all networks and credentials get the same priority group
         * (0). This field can be used to give higher priority for credentials
         * (and similarly in struct wpa_ssid for network blocks) to change the
         * Interworking automatic networking selection behavior. The matching
         * network (based on either an enabled network block or a credential)
         * with the highest priority value will be selected.
         */
        int priority;

        /**
         * pcsc - Use PC/SC and SIM/USIM card
         */
        int pcsc;

        /**
         * realm - Home Realm for Interworking
         */
        char *realm;

        /**
         * username - Username for Interworking network selection
         */
        char *username;

        /**
         * password - Password for Interworking network selection
         */
        char *password;

        /**
         * ca_cert - CA certificate for Interworking network selection
         */
        char *ca_cert;

        /**
         * client_cert - File path to client certificate file (PEM/DER)
         *
         * This field is used with Interworking networking selection for a case
         * where client certificate/private key is used for authentication
         * (EAP-TLS). Full path to the file should be used since working
         * directory may change when wpa_supplicant is run in the background.
         *
         * Alternatively, a named configuration blob can be used by setting
         * this to blob://blob_name.
         */
        char *client_cert;

        /**
         * private_key - File path to client private key file (PEM/DER/PFX)
         *
         * When PKCS#12/PFX file (.p12/.pfx) is used, client_cert should be
         * commented out. Both the private key and certificate will be read
         * from the PKCS#12 file in this case. Full path to the file should be
         * used since working directory may change when wpa_supplicant is run
         * in the background.
         *
         * Windows certificate store can be used by leaving client_cert out and
         * configuring private_key in one of the following formats:
         *
         * cert://substring_to_match
         *
         * hash://certificate_thumbprint_in_hex
         *
         * For example: private_key="hash://63093aa9c47f56ae88334c7b65a4"
         *
         * Note that when running wpa_supplicant as an application, the user
         * certificate store (My user account) is used, whereas computer store
         * (Computer account) is used when running wpasvc as a service.
         *
         * Alternatively, a named configuration blob can be used by setting
         * this to blob://blob_name.
         */
        char *private_key;

        /**
         * private_key_passwd - Password for private key file
         */
        char *private_key_passwd;

        /**
         * imsi - IMSI in <MCC> | <MNC> | '-' | <MSIN> format
         */
        char *imsi;

        /**
         * milenage - Milenage parameters for SIM/USIM simulator in
         *      <Ki>:<OPc>:<SQN> format
         */
        char *milenage;

        /**
         * domain - Home service provider FQDN
         *
         * This is used to compare against the Domain Name List to figure out
         * whether the AP is operated by the Home SP.
         */
        char *domain;
};


#define CFG_CHANGED_DEVICE_NAME BIT(0)
#define CFG_CHANGED_CONFIG_METHODS BIT(1)
#define CFG_CHANGED_DEVICE_TYPE BIT(2)
#define CFG_CHANGED_OS_VERSION BIT(3)
#define CFG_CHANGED_UUID BIT(4)
#define CFG_CHANGED_COUNTRY BIT(5)
#define CFG_CHANGED_SEC_DEVICE_TYPE BIT(6)
#define CFG_CHANGED_P2P_SSID_POSTFIX BIT(7)
#define CFG_CHANGED_WPS_STRING BIT(8)
#define CFG_CHANGED_P2P_INTRA_BSS BIT(9)
#define CFG_CHANGED_VENDOR_EXTENSION BIT(10)
#define CFG_CHANGED_P2P_LISTEN_CHANNEL BIT(11)
#define CFG_CHANGED_P2P_OPER_CHANNEL BIT(12)
#define CFG_CHANGED_P2P_PREF_CHAN BIT(13)

/**
 * struct wpa_config - wpa_supplicant configuration data
 *
 * This data structure is presents the per-interface (radio) configuration
 * data. In many cases, there is only one struct wpa_config instance, but if
 * more than one network interface is being controlled, one instance is used
 * for each.
 */
struct wpa_config {
        /**
         * ssid - Head of the global network list
         *
         * This is the head for the list of all the configured networks.
         */
        struct wpa_ssid *ssid;

        /**
         * pssid - Per-priority network lists (in priority order)
         */
        struct wpa_ssid **pssid;

        /**
         * num_prio - Number of different priorities used in the pssid lists
         *
         * This indicates how many per-priority network lists are included in
         * pssid.
         */
        int num_prio;

        /**
         * cred - Head of the credential list
         *
         * This is the head for the list of all the configured credentials.
         */
        struct wpa_cred *cred;

        /**
         * eapol_version - IEEE 802.1X/EAPOL version number
         *
         * wpa_supplicant is implemented based on IEEE Std 802.1X-2004 which
         * defines EAPOL version 2. However, there are many APs that do not
         * handle the new version number correctly (they seem to drop the
         * frames completely). In order to make wpa_supplicant interoperate
         * with these APs, the version number is set to 1 by default. This
         * configuration value can be used to set it to the new version (2).
         */
        int eapol_version;

        /**
         * ap_scan - AP scanning/selection
         *
         * By default, wpa_supplicant requests driver to perform AP
         * scanning and then uses the scan results to select a
         * suitable AP. Another alternative is to allow the driver to
         * take care of AP scanning and selection and use
         * wpa_supplicant just to process EAPOL frames based on IEEE
         * 802.11 association information from the driver.
         *
         * 1: wpa_supplicant initiates scanning and AP selection (default).
         *
         * 0: Driver takes care of scanning, AP selection, and IEEE 802.11
         * association parameters (e.g., WPA IE generation); this mode can
         * also be used with non-WPA drivers when using IEEE 802.1X mode;
         * do not try to associate with APs (i.e., external program needs
         * to control association). This mode must also be used when using
         * wired Ethernet drivers.
         *
         * 2: like 0, but associate with APs using security policy and SSID
         * (but not BSSID); this can be used, e.g., with ndiswrapper and NDIS
         * drivers to enable operation with hidden SSIDs and optimized roaming;
         * in this mode, the network blocks in the configuration are tried
         * one by one until the driver reports successful association; each
         * network block should have explicit security policy (i.e., only one
         * option in the lists) for key_mgmt, pairwise, group, proto variables.
         */
        int ap_scan;

        /**
         * disable_scan_offload - Disable automatic offloading of scan requests
         *
         * By default, %wpa_supplicant tries to offload scanning if the driver
         * indicates support for this (sched_scan). This configuration
         * parameter can be used to disable this offloading mechanism.
         */
        int disable_scan_offload;

        /**
         * ctrl_interface - Parameters for the control interface
         *
         * If this is specified, %wpa_supplicant will open a control interface
         * that is available for external programs to manage %wpa_supplicant.
         * The meaning of this string depends on which control interface
         * mechanism is used. For all cases, the existence of this parameter
         * in configuration is used to determine whether the control interface
         * is enabled.
         *
         * For UNIX domain sockets (default on Linux and BSD): This is a
         * directory that will be created for UNIX domain sockets for listening
         * to requests from external programs (CLI/GUI, etc.) for status
         * information and configuration. The socket file will be named based
         * on the interface name, so multiple %wpa_supplicant processes can be
         * run at the same time if more than one interface is used.
         * /var/run/wpa_supplicant is the recommended directory for sockets and
         * by default, wpa_cli will use it when trying to connect with
         * %wpa_supplicant.
         *
         * Access control for the control interface can be configured
         * by setting the directory to allow only members of a group
         * to use sockets. This way, it is possible to run
         * %wpa_supplicant as root (since it needs to change network
         * configuration and open raw sockets) and still allow GUI/CLI
         * components to be run as non-root users. However, since the
         * control interface can be used to change the network
         * configuration, this access needs to be protected in many
         * cases. By default, %wpa_supplicant is configured to use gid
         * 0 (root). If you want to allow non-root users to use the
         * control interface, add a new group and change this value to
         * match with that group. Add users that should have control
         * interface access to this group.
         *
         * When configuring both the directory and group, use following format:
         * DIR=/var/run/wpa_supplicant GROUP=wheel
         * DIR=/var/run/wpa_supplicant GROUP=0
         * (group can be either group name or gid)
         *
         * For UDP connections (default on Windows): The value will be ignored.
         * This variable is just used to select that the control interface is
         * to be created. The value can be set to, e.g., udp
         * (ctrl_interface=udp).
         *
         * For Windows Named Pipe: This value can be used to set the security
         * descriptor for controlling access to the control interface. Security
         * descriptor can be set using Security Descriptor String Format (see
         * http://msdn.microsoft.com/library/default.asp?url=/library/en-us/secauthz/security/security_descriptor_string_format.asp).
         * The descriptor string needs to be prefixed with SDDL=. For example,
         * ctrl_interface=SDDL=D: would set an empty DACL (which will reject
         * all connections).
         */
        char *ctrl_interface;

        /**
         * ctrl_interface_group - Control interface group (DEPRECATED)
         *
         * This variable is only used for backwards compatibility. Group for
         * UNIX domain sockets should now be specified using GROUP=group in
         * ctrl_interface variable.
         */
        char *ctrl_interface_group;

        /**
         * fast_reauth - EAP fast re-authentication (session resumption)
         *
         * By default, fast re-authentication is enabled for all EAP methods
         * that support it. This variable can be used to disable fast
         * re-authentication (by setting fast_reauth=0). Normally, there is no
         * need to disable fast re-authentication.
         */
        int fast_reauth;

        /**
         * opensc_engine_path - Path to the OpenSSL engine for opensc
         *
         * This is an OpenSSL specific configuration option for loading OpenSC
         * engine (engine_opensc.so); if %NULL, this engine is not loaded.
         */
        char *opensc_engine_path;

        /**
         * pkcs11_engine_path - Path to the OpenSSL engine for PKCS#11
         *
         * This is an OpenSSL specific configuration option for loading PKCS#11
         * engine (engine_pkcs11.so); if %NULL, this engine is not loaded.
         */
        char *pkcs11_engine_path;

        /**
         * pkcs11_module_path - Path to the OpenSSL OpenSC/PKCS#11 module
         *
         * This is an OpenSSL specific configuration option for configuring
         * path to OpenSC/PKCS#11 engine (opensc-pkcs11.so); if %NULL, this
         * module is not loaded.
         */
        char *pkcs11_module_path;

        /**
         * pcsc_reader - PC/SC reader name prefix
         *
         * If not %NULL, PC/SC reader with a name that matches this prefix is
         * initialized for SIM/USIM access. Empty string can be used to match
         * the first available reader.
         */
        char *pcsc_reader;

        /**
         * pcsc_pin - PIN for USIM, GSM SIM, and smartcards
         *
         * This field is used to configure PIN for SIM/USIM for EAP-SIM and
         * EAP-AKA. If left out, this will be asked through control interface.
         */
        char *pcsc_pin;

        /**
         * driver_param - Driver interface parameters
         *
         * This text string is passed to the selected driver interface with the
         * optional struct wpa_driver_ops::set_param() handler. This can be
         * used to configure driver specific options without having to add new
         * driver interface functionality.
         */
        char *driver_param;

        /**
         * dot11RSNAConfigPMKLifetime - Maximum lifetime of a PMK
         *
         * dot11 MIB variable for the maximum lifetime of a PMK in the PMK
         * cache (unit: seconds).
         */
        unsigned int dot11RSNAConfigPMKLifetime;

        /**
         * dot11RSNAConfigPMKReauthThreshold - PMK re-authentication threshold
         *
         * dot11 MIB variable for the percentage of the PMK lifetime
         * that should expire before an IEEE 802.1X reauthentication occurs.
         */
        unsigned int dot11RSNAConfigPMKReauthThreshold;

        /**
         * dot11RSNAConfigSATimeout - Security association timeout
         *
         * dot11 MIB variable for the maximum time a security association
         * shall take to set up (unit: seconds).
         */
        unsigned int dot11RSNAConfigSATimeout;

        /**
         * update_config - Is wpa_supplicant allowed to update configuration
         *
         * This variable control whether wpa_supplicant is allow to re-write
         * its configuration with wpa_config_write(). If this is zero,
         * configuration data is only changed in memory and the external data
         * is not overriden. If this is non-zero, wpa_supplicant will update
         * the configuration data (e.g., a file) whenever configuration is
         * changed. This update may replace the old configuration which can
         * remove comments from it in case of a text file configuration.
         */
        int update_config;

        /**
         * blobs - Configuration blobs
         */
        struct wpa_config_blob *blobs;

        /**
         * uuid - Universally Unique IDentifier (UUID; see RFC 4122) for WPS
         */
        u8 uuid[16];

        /**
         * device_name - Device Name (WPS)
         * User-friendly description of device; up to 32 octets encoded in
         * UTF-8
         */
        char *device_name;

        /**
         * manufacturer - Manufacturer (WPS)
         * The manufacturer of the device (up to 64 ASCII characters)
         */
        char *manufacturer;

        /**
         * model_name - Model Name (WPS)
         * Model of the device (up to 32 ASCII characters)
         */
        char *model_name;

        /**
         * model_number - Model Number (WPS)
         * Additional device description (up to 32 ASCII characters)
         */
        char *model_number;

        /**
         * serial_number - Serial Number (WPS)
         * Serial number of the device (up to 32 characters)
         */
        char *serial_number;

        /**
         * device_type - Primary Device Type (WPS)
         */
        u8 device_type[WPS_DEV_TYPE_LEN];

        /**
         * config_methods - Config Methods
         *
         * This is a space-separated list of supported WPS configuration
         * methods. For example, "label virtual_display virtual_push_button
         * keypad".
         * Available methods: usba ethernet label display ext_nfc_token
         * int_nfc_token nfc_interface push_button keypad
         * virtual_display physical_display
         * virtual_push_button physical_push_button.
         */
        char *config_methods;

        /**
         * os_version - OS Version (WPS)
         * 4-octet operating system version number
         */
        u8 os_version[4];

        /**
         * country - Country code
         *
         * This is the ISO/IEC alpha2 country code for which we are operating
         * in
         */
        char country[2];

        /**
         * wps_cred_processing - Credential processing
         *
         *   0 = process received credentials internally
         *   1 = do not process received credentials; just pass them over
         *      ctrl_iface to external program(s)
         *   2 = process received credentials internally and pass them over
         *      ctrl_iface to external program(s)
         */
        int wps_cred_processing;

#define MAX_SEC_DEVICE_TYPES 5
        /**
         * sec_device_types - Secondary Device Types (P2P)
         */
        u8 sec_device_type[MAX_SEC_DEVICE_TYPES][WPS_DEV_TYPE_LEN];
        int num_sec_device_types;

        int p2p_listen_reg_class;
        int p2p_listen_channel;
        int p2p_oper_reg_class;
        int p2p_oper_channel;
        int p2p_go_intent;
        char *p2p_ssid_postfix;
        int persistent_reconnect;
        int p2p_intra_bss;
        unsigned int num_p2p_pref_chan;
        struct p2p_channel *p2p_pref_chan;

        struct wpabuf *wps_vendor_ext_m1;

#define MAX_WPS_VENDOR_EXT 10
        /**
         * wps_vendor_ext - Vendor extension attributes in WPS
         */
        struct wpabuf *wps_vendor_ext[MAX_WPS_VENDOR_EXT];

        /**
         * p2p_group_idle - Maximum idle time in seconds for P2P group
         *
         * This value controls how long a P2P group is maintained after there
         * is no other members in the group. As a GO, this means no associated
         * stations in the group. As a P2P client, this means no GO seen in
         * scan results. The maximum idle time is specified in seconds with 0
         * indicating no time limit, i.e., the P2P group remains in active
         * state indefinitely until explicitly removed. As a P2P client, the
         * maximum idle time of P2P_MAX_CLIENT_IDLE seconds is enforced, i.e.,
         * this parameter is mainly meant for GO use and for P2P client, it can
         * only be used to reduce the default timeout to smaller value. A
         * special value -1 can be used to configure immediate removal of the
         * group for P2P client role on any disconnection after the data
         * connection has been established.
         */
        int p2p_group_idle;

        /**
         * bss_max_count - Maximum number of BSS entries to keep in memory
         */
        unsigned int bss_max_count;

        /**
         * bss_expiration_age - BSS entry age after which it can be expired
         *
         * This value controls the time in seconds after which a BSS entry
         * gets removed if it has not been updated or is not in use.
         */
        unsigned int bss_expiration_age;

        /**
         * bss_expiration_scan_count - Expire BSS after number of scans
         *
         * If the BSS entry has not been seen in this many scans, it will be
         * removed. A value of 1 means that entry is removed after the first
         * scan in which the BSSID is not seen. Larger values can be used
         * to avoid BSS entries disappearing if they are not visible in
         * every scan (e.g., low signal quality or interference).
         */
        unsigned int bss_expiration_scan_count;

        /**
         * filter_ssids - SSID-based scan result filtering
         *
         *   0 = do not filter scan results
         *   1 = only include configured SSIDs in scan results/BSS table
         */
        int filter_ssids;

        /**
         * filter_rssi - RSSI-based scan result filtering
         *
         * 0 = do not filter scan results
         * -n = filter scan results below -n dBm
         */
        int filter_rssi;

        /**
         * max_num_sta - Maximum number of STAs in an AP/P2P GO
         */
        unsigned int max_num_sta;

        /**
         * changed_parameters - Bitmap of changed parameters since last update
         */
        unsigned int changed_parameters;

        /**
         * disassoc_low_ack - Disassocicate stations with massive packet loss
         */
        int disassoc_low_ack;

        /**
         * interworking - Whether Interworking (IEEE 802.11u) is enabled
         */
        int interworking;

        /**
         * access_network_type - Access Network Type
         *
         * When Interworking is enabled, scans will be limited to APs that
         * advertise the specified Access Network Type (0..15; with 15
         * indicating wildcard match).
         */
        int access_network_type;

        /**
         * hessid - Homogenous ESS identifier
         *
         * If this is set (any octet is non-zero), scans will be used to
         * request response only from BSSes belonging to the specified
         * Homogeneous ESS. This is used only if interworking is enabled.
         */
        u8 hessid[ETH_ALEN];

        /**
         * hs20 - Hotspot 2.0
         */
        int hs20;

        /**
         * pbc_in_m1 - AP mode WPS probing workaround for PBC with Windows 7
         *
         * Windows 7 uses incorrect way of figuring out AP's WPS capabilities
         * by acting as a Registrar and using M1 from the AP. The config
         * methods attribute in that message is supposed to indicate only the
         * configuration method supported by the AP in Enrollee role, i.e., to
         * add an external Registrar. For that case, PBC shall not be used and
         * as such, the PushButton config method is removed from M1 by default.
         * If pbc_in_m1=1 is included in the configuration file, the PushButton
         * config method is left in M1 (if included in config_methods
         * parameter) to allow Windows 7 to use PBC instead of PIN (e.g., from
         * a label in the AP).
         */
        int pbc_in_m1;

        /**
         * autoscan - Automatic scan parameters or %NULL if none
         *
         * This is an optional set of parameters for automatic scanning
         * within an interface in following format:
         * <autoscan module name>:<module parameters>
         */
        char *autoscan;

        /**
         * wps_nfc_dev_pw_id - NFC Device Password ID for password token
         */
        int wps_nfc_dev_pw_id;

        /**
         * wps_nfc_dh_pubkey - NFC DH Public Key for password token
         */
        struct wpabuf *wps_nfc_dh_pubkey;

        /**
         * wps_nfc_dh_pubkey - NFC DH Private Key for password token
         */
        struct wpabuf *wps_nfc_dh_privkey;

        /**
         * wps_nfc_dh_pubkey - NFC Device Password for password token
         */
        struct wpabuf *wps_nfc_dev_pw;
};


/* Prototypes for common functions from config.c */

void wpa_config_free(struct wpa_config *ssid);
void wpa_config_free_ssid(struct wpa_ssid *ssid);
void wpa_config_foreach_network(struct wpa_config *config,
                                void (*func)(void *, struct wpa_ssid *),
                                void *arg);
struct wpa_ssid * wpa_config_get_network(struct wpa_config *config, int id);
struct wpa_ssid * wpa_config_add_network(struct wpa_config *config);
int wpa_config_remove_network(struct wpa_config *config, int id);
void wpa_config_set_network_defaults(struct wpa_ssid *ssid);
int wpa_config_set(struct wpa_ssid *ssid, const char *var, const char *value,
                   int line);
int wpa_config_set_quoted(struct wpa_ssid *ssid, const char *var,
                          const char *value);
char ** wpa_config_get_all(struct wpa_ssid *ssid, int get_keys);
char * wpa_config_get(struct wpa_ssid *ssid, const char *var);
char * wpa_config_get_no_key(struct wpa_ssid *ssid, const char *var);
void wpa_config_update_psk(struct wpa_ssid *ssid);
int wpa_config_add_prio_network(struct wpa_config *config,
                                struct wpa_ssid *ssid);
int wpa_config_update_prio_list(struct wpa_config *config);
const struct wpa_config_blob * wpa_config_get_blob(struct wpa_config *config,
                                                   const char *name);
void wpa_config_set_blob(struct wpa_config *config,
                         struct wpa_config_blob *blob);
void wpa_config_free_blob(struct wpa_config_blob *blob);
int wpa_config_remove_blob(struct wpa_config *config, const char *name);

struct wpa_cred * wpa_config_get_cred(struct wpa_config *config, int id);
struct wpa_cred * wpa_config_add_cred(struct wpa_config *config);
int wpa_config_remove_cred(struct wpa_config *config, int id);
void wpa_config_free_cred(struct wpa_cred *cred);
int wpa_config_set_cred(struct wpa_cred *cred, const char *var,
                        const char *value, int line);

struct wpa_config * wpa_config_alloc_empty(const char *ctrl_interface,
                                           const char *driver_param);
#ifndef CONFIG_NO_STDOUT_DEBUG
void wpa_config_debug_dump_networks(struct wpa_config *config);
#else /* CONFIG_NO_STDOUT_DEBUG */
#define wpa_config_debug_dump_networks(c) do { } while (0)
#endif /* CONFIG_NO_STDOUT_DEBUG */


/* Prototypes for common functions from config.c */
int wpa_config_process_global(struct wpa_config *config, char *pos, int line);


/* Prototypes for backend specific functions from the selected config_*.c */

/**
 * wpa_config_read - Read and parse configuration database
 * @name: Name of the configuration (e.g., path and file name for the
 * configuration file)
 * Returns: Pointer to allocated configuration data or %NULL on failure
 *
 * This function reads configuration data, parses its contents, and allocates
 * data structures needed for storing configuration information. The allocated
 * data can be freed with wpa_config_free().
 *
 * Each configuration backend needs to implement this function.
 */
struct wpa_config * wpa_config_read(const char *name);

/**
 * wpa_config_write - Write or update configuration data
 * @name: Name of the configuration (e.g., path and file name for the
 * configuration file)
 * @config: Configuration data from wpa_config_read()
 * Returns: 0 on success, -1 on failure
 *
 * This function write all configuration data into an external database (e.g.,
 * a text file) in a format that can be read with wpa_config_read(). This can
 * be used to allow wpa_supplicant to update its configuration, e.g., when a
 * new network is added or a password is changed.
 *
 * Each configuration backend needs to implement this function.
 */
int wpa_config_write(const char *name, struct wpa_config *config);

#endif /* CONFIG_H */