hostapd/src/utils/state_machine.h
2009-01-04 15:07:54 +02:00

144 lines
5.5 KiB
C

/*
* wpa_supplicant/hostapd - State machine definitions
* Copyright (c) 2002-2005, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*
* This file includes a set of pre-processor macros that can be used to
* implement a state machine. In addition to including this header file, each
* file implementing a state machine must define STATE_MACHINE_DATA to be the
* data structure including state variables (enum machine_state,
* Boolean changed), and STATE_MACHINE_DEBUG_PREFIX to be a string that is used
* as a prefix for all debug messages. If SM_ENTRY_MA macro is used to define
* a group of state machines with shared data structure, STATE_MACHINE_ADDR
* needs to be defined to point to the MAC address used in debug output.
* SM_ENTRY_M macro can be used to define similar group of state machines
* without this additional debug info.
*/
#ifndef STATE_MACHINE_H
#define STATE_MACHINE_H
/**
* SM_STATE - Declaration of a state machine function
* @machine: State machine name
* @state: State machine state
*
* This macro is used to declare a state machine function. It is used in place
* of a C function definition to declare functions to be run when the state is
* entered by calling SM_ENTER or SM_ENTER_GLOBAL.
*/
#define SM_STATE(machine, state) \
static void sm_ ## machine ## _ ## state ## _Enter(STATE_MACHINE_DATA *sm, \
int global)
/**
* SM_ENTRY - State machine function entry point
* @machine: State machine name
* @state: State machine state
*
* This macro is used inside each state machine function declared with
* SM_STATE. SM_ENTRY should be in the beginning of the function body, but
* after declaration of possible local variables. This macro prints debug
* information about state transition and update the state machine state.
*/
#define SM_ENTRY(machine, state) \
if (!global || sm->machine ## _state != machine ## _ ## state) { \
sm->changed = TRUE; \
wpa_printf(MSG_DEBUG, STATE_MACHINE_DEBUG_PREFIX ": " #machine \
" entering state " #state); \
} \
sm->machine ## _state = machine ## _ ## state;
/**
* SM_ENTRY_M - State machine function entry point for state machine group
* @machine: State machine name
* @_state: State machine state
* @data: State variable prefix (full variable: prefix_state)
*
* This macro is like SM_ENTRY, but for state machine groups that use a shared
* data structure for more than one state machine. Both machine and prefix
* parameters are set to "sub-state machine" name. prefix is used to allow more
* than one state variable to be stored in the same data structure.
*/
#define SM_ENTRY_M(machine, _state, data) \
if (!global || sm->data ## _ ## state != machine ## _ ## _state) { \
sm->changed = TRUE; \
wpa_printf(MSG_DEBUG, STATE_MACHINE_DEBUG_PREFIX ": " \
#machine " entering state " #_state); \
} \
sm->data ## _ ## state = machine ## _ ## _state;
/**
* SM_ENTRY_MA - State machine function entry point for state machine group
* @machine: State machine name
* @_state: State machine state
* @data: State variable prefix (full variable: prefix_state)
*
* This macro is like SM_ENTRY_M, but a MAC address is included in debug
* output. STATE_MACHINE_ADDR has to be defined to point to the MAC address to
* be included in debug.
*/
#define SM_ENTRY_MA(machine, _state, data) \
if (!global || sm->data ## _ ## state != machine ## _ ## _state) { \
sm->changed = TRUE; \
wpa_printf(MSG_DEBUG, STATE_MACHINE_DEBUG_PREFIX ": " MACSTR " " \
#machine " entering state " #_state, \
MAC2STR(STATE_MACHINE_ADDR)); \
} \
sm->data ## _ ## state = machine ## _ ## _state;
/**
* SM_ENTER - Enter a new state machine state
* @machine: State machine name
* @state: State machine state
*
* This macro expands to a function call to a state machine function defined
* with SM_STATE macro. SM_ENTER is used in a state machine step function to
* move the state machine to a new state.
*/
#define SM_ENTER(machine, state) \
sm_ ## machine ## _ ## state ## _Enter(sm, 0)
/**
* SM_ENTER_GLOBAL - Enter a new state machine state based on global rule
* @machine: State machine name
* @state: State machine state
*
* This macro is like SM_ENTER, but this is used when entering a new state
* based on a global (not specific to any particular state) rule. A separate
* macro is used to avoid unwanted debug message floods when the same global
* rule is forcing a state machine to remain in on state.
*/
#define SM_ENTER_GLOBAL(machine, state) \
sm_ ## machine ## _ ## state ## _Enter(sm, 1)
/**
* SM_STEP - Declaration of a state machine step function
* @machine: State machine name
*
* This macro is used to declare a state machine step function. It is used in
* place of a C function definition to declare a function that is used to move
* state machine to a new state based on state variables. This function uses
* SM_ENTER and SM_ENTER_GLOBAL macros to enter new state.
*/
#define SM_STEP(machine) \
static void sm_ ## machine ## _Step(STATE_MACHINE_DATA *sm)
/**
* SM_STEP_RUN - Call the state machine step function
* @machine: State machine name
*
* This macro expands to a function call to a state machine step function
* defined with SM_STEP macro.
*/
#define SM_STEP_RUN(machine) sm_ ## machine ## _Step(sm)
#endif /* STATE_MACHINE_H */