1 /* 2 * wpa_supplicant/hostapd - State machine definitions 3 * Copyright (c) 2002-2005, Jouni Malinen <j@w1.fi> 4 * 5 * This software may be distributed under the terms of the BSD license. 6 * See README for more details. 7 * 8 * This file includes a set of pre-processor macros that can be used to 9 * implement a state machine. In addition to including this header file, each 10 * file implementing a state machine must define STATE_MACHINE_DATA to be the 11 * data structure including state variables (enum machine_state, 12 * bool changed), and STATE_MACHINE_DEBUG_PREFIX to be a string that is used 13 * as a prefix for all debug messages. If SM_ENTRY_MA macro is used to define 14 * a group of state machines with shared data structure, STATE_MACHINE_ADDR 15 * needs to be defined to point to the MAC address used in debug output. 16 * SM_ENTRY_M macro can be used to define similar group of state machines 17 * without this additional debug info. 18 */ 19 20 #ifndef STATE_MACHINE_H 21 #define STATE_MACHINE_H 22 23 /** 24 * SM_STATE - Declaration of a state machine function 25 * @machine: State machine name 26 * @state: State machine state 27 * 28 * This macro is used to declare a state machine function. It is used in place 29 * of a C function definition to declare functions to be run when the state is 30 * entered by calling SM_ENTER or SM_ENTER_GLOBAL. 31 */ 32 #define SM_STATE(machine, state) \ 33 static void sm_ ## machine ## _ ## state ## _Enter(STATE_MACHINE_DATA *sm, \ 34 int global) 35 36 /** 37 * SM_ENTRY - State machine function entry point 38 * @machine: State machine name 39 * @state: State machine state 40 * 41 * This macro is used inside each state machine function declared with 42 * SM_STATE. SM_ENTRY should be in the beginning of the function body, but 43 * after declaration of possible local variables. This macro prints debug 44 * information about state transition and update the state machine state. 45 */ 46 #define SM_ENTRY(machine, state) \ 47 if (!global || sm->machine ## _state != machine ## _ ## state) { \ 48 sm->changed = true; \ 49 wpa_printf(MSG_DEBUG, STATE_MACHINE_DEBUG_PREFIX ": " #machine \ 50 " entering state " #state); \ 51 } \ 52 sm->machine ## _state = machine ## _ ## state; 53 54 /** 55 * SM_ENTRY_M - State machine function entry point for state machine group 56 * @machine: State machine name 57 * @_state: State machine state 58 * @data: State variable prefix (full variable: prefix_state) 59 * 60 * This macro is like SM_ENTRY, but for state machine groups that use a shared 61 * data structure for more than one state machine. Both machine and prefix 62 * parameters are set to "sub-state machine" name. prefix is used to allow more 63 * than one state variable to be stored in the same data structure. 64 */ 65 #define SM_ENTRY_M(machine, _state, data) \ 66 if (!global || sm->data ## _ ## state != machine ## _ ## _state) { \ 67 sm->changed = true; \ 68 wpa_printf(MSG_DEBUG, STATE_MACHINE_DEBUG_PREFIX ": " \ 69 #machine " entering state " #_state); \ 70 } \ 71 sm->data ## _ ## state = machine ## _ ## _state; 72 73 /** 74 * SM_ENTRY_MA - State machine function entry point for state machine group 75 * @machine: State machine name 76 * @_state: State machine state 77 * @data: State variable prefix (full variable: prefix_state) 78 * 79 * This macro is like SM_ENTRY_M, but a MAC address is included in debug 80 * output. STATE_MACHINE_ADDR has to be defined to point to the MAC address to 81 * be included in debug. 82 */ 83 #define SM_ENTRY_MA(machine, _state, data) \ 84 if (!global || sm->data ## _ ## state != machine ## _ ## _state) { \ 85 sm->changed = true; \ 86 wpa_printf(MSG_DEBUG, STATE_MACHINE_DEBUG_PREFIX ": " MACSTR " " \ 87 #machine " entering state " #_state, \ 88 MAC2STR(STATE_MACHINE_ADDR)); \ 89 } \ 90 sm->data ## _ ## state = machine ## _ ## _state; 91 92 /** 93 * SM_ENTER - Enter a new state machine state 94 * @machine: State machine name 95 * @state: State machine state 96 * 97 * This macro expands to a function call to a state machine function defined 98 * with SM_STATE macro. SM_ENTER is used in a state machine step function to 99 * move the state machine to a new state. 100 */ 101 #define SM_ENTER(machine, state) \ 102 sm_ ## machine ## _ ## state ## _Enter(sm, 0) 103 104 /** 105 * SM_ENTER_GLOBAL - Enter a new state machine state based on global rule 106 * @machine: State machine name 107 * @state: State machine state 108 * 109 * This macro is like SM_ENTER, but this is used when entering a new state 110 * based on a global (not specific to any particular state) rule. A separate 111 * macro is used to avoid unwanted debug message floods when the same global 112 * rule is forcing a state machine to remain in on state. 113 */ 114 #define SM_ENTER_GLOBAL(machine, state) \ 115 sm_ ## machine ## _ ## state ## _Enter(sm, 1) 116 117 /** 118 * SM_STEP - Declaration of a state machine step function 119 * @machine: State machine name 120 * 121 * This macro is used to declare a state machine step function. It is used in 122 * place of a C function definition to declare a function that is used to move 123 * state machine to a new state based on state variables. This function uses 124 * SM_ENTER and SM_ENTER_GLOBAL macros to enter new state. 125 */ 126 #define SM_STEP(machine) \ 127 static void sm_ ## machine ## _Step(STATE_MACHINE_DATA *sm) 128 129 /** 130 * SM_STEP_RUN - Call the state machine step function 131 * @machine: State machine name 132 * 133 * This macro expands to a function call to a state machine step function 134 * defined with SM_STEP macro. 135 */ 136 #define SM_STEP_RUN(machine) sm_ ## machine ## _Step(sm) 137 138 #endif /* STATE_MACHINE_H */ 139