1 /* xdlc.h 2 * Define *DLC frame types, and routine to dissect the control field of 3 * a *DLC frame. 4 * 5 * Wireshark - Network traffic analyzer 6 * By Gerald Combs <gerald@wireshark.org> 7 * Copyright 1998 Gerald Combs 8 * 9 * SPDX-License-Identifier: GPL-2.0-or-later 10 */ 11 12 #ifndef __XDLC_H__ 13 #define __XDLC_H__ 14 15 #include "ws_symbol_export.h" 16 17 /** @file 18 * Define *DLC frame types, and routine to dissect the control field of 19 * a *DLC frame. 20 */ 21 /* 22 * Low-order bits of first (extended) or only (basic) octet of control 23 * field, specifying the frame type. 24 */ 25 #define XDLC_I_MASK 0x01 /**< Mask to test for I or not I */ 26 #define XDLC_I 0x00 /**< Information frames */ 27 #define XDLC_S_U_MASK 0x03 /**< Mask to test for S or U */ 28 #define XDLC_S 0x01 /**< Supervisory frames */ 29 #define XDLC_U 0x03 /**< Unnumbered frames */ 30 31 /* 32 * N(S) and N(R) fields, in basic and extended operation. 33 */ 34 #define XDLC_N_R_MASK 0xE0 /**< basic */ 35 #define XDLC_N_R_SHIFT 5 36 #define XDLC_N_R_EXT_MASK 0xFE00 /**< extended */ 37 #define XDLC_N_R_EXT_SHIFT 9 38 #define XDLC_N_S_MASK 0x0E /**< basic */ 39 #define XDLC_N_S_SHIFT 1 40 #define XDLC_N_S_EXT_MASK 0x00FE /**< extended */ 41 #define XDLC_N_S_EXT_SHIFT 1 42 43 /* 44 * Poll/Final bit, in basic and extended operation. 45 */ 46 #define XDLC_P_F 0x10 /**< basic */ 47 #define XDLC_P_F_EXT 0x0100 /**< extended */ 48 49 /* 50 * S-format frame types. 51 */ 52 #define XDLC_S_FTYPE_MASK 0x0C 53 #define XDLC_RR 0x00 /**< Receiver ready */ 54 #define XDLC_RNR 0x04 /**< Receiver not ready */ 55 #define XDLC_REJ 0x08 /**< Reject */ 56 #define XDLC_SREJ 0x0C /**< Selective reject */ 57 58 /* 59 * U-format modifiers. 60 */ 61 #define XDLC_U_MODIFIER_MASK 0xEC 62 #define XDLC_UI 0x00 /**< Unnumbered Information */ 63 #define XDLC_UP 0x20 /**< Unnumbered Poll */ 64 #define XDLC_DISC 0x40 /**< Disconnect (command) */ 65 #define XDLC_RD 0x40 /**< Request Disconnect (response) */ 66 #define XDLC_UA 0x60 /**< Unnumbered Acknowledge */ 67 #define XDLC_SNRM 0x80 /**< Set Normal Response Mode */ 68 #define XDLC_TEST 0xE0 /**< Test */ 69 #define XDLC_SIM 0x04 /**< Set Initialization Mode (command) */ 70 #define XDLC_RIM 0x04 /**< Request Initialization Mode (response) */ 71 #define XDLC_FRMR 0x84 /**< Frame reject */ 72 #define XDLC_CFGR 0xC4 /**< Configure */ 73 #define XDLC_SARM 0x0C /**< Set Asynchronous Response Mode (command) */ 74 #define XDLC_DM 0x0C /**< Disconnected mode (response) */ 75 #define XDLC_SABM 0x2C /**< Set Asynchronous Balanced Mode */ 76 #define XDLC_SARME 0x4C /**< Set Asynchronous Response Mode Extended */ 77 #define XDLC_SABME 0x6C /**< Set Asynchronous Balanced Mode Extended */ 78 #define XDLC_RESET 0x8C /**< Reset */ 79 #define XDLC_XID 0xAC /**< Exchange identification */ 80 #define XDLC_SNRME 0xCC /**< Set Normal Response Mode Extended */ 81 #define XDLC_BCN 0xEC /**< Beacon */ 82 83 /** 84 * This macro takes the control field of an xDLC frame, as returned by 85 * "get_xdlc_control()" or "dissect_xdlc_control()", and evaluates to 86 * TRUE if the frame is an "information" frame and FALSE if it isn't. 87 * Note that frames other than information frames can have data in them, 88 * e.g. TEST frames. 89 */ 90 #define XDLC_IS_INFORMATION(control) \ 91 (((control) & XDLC_I_MASK) == XDLC_I || (control) == (XDLC_UI|XDLC_U)) 92 93 /** 94 * This macro takes the control field of an xDLC frame, and a flag saying 95 * whether we're doing basic or extended operation, and evaluates to 96 * the length of that field (if it's an Unnumbered frame, or we're not 97 * in extended mode, it's 1 byte long, otherwise it's 2 bytes long). 98 */ 99 #define XDLC_CONTROL_LEN(control, is_extended) \ 100 ((((control) & XDLC_S_U_MASK) == XDLC_U || !(is_extended)) ? 1 : 2) 101 102 /** 103 * Structure containing pointers to hf_ values for various subfields of 104 * the control field. 105 */ 106 typedef struct { 107 int *hf_xdlc_n_r; 108 int *hf_xdlc_n_s; 109 int *hf_xdlc_p; 110 int *hf_xdlc_f; 111 int *hf_xdlc_s_ftype; 112 int *hf_xdlc_u_modifier_cmd; 113 int *hf_xdlc_u_modifier_resp; 114 int *hf_xdlc_ftype_i; 115 int *hf_xdlc_ftype_s_u; 116 } xdlc_cf_items; 117 118 extern const value_string ftype_vals[]; 119 extern const value_string stype_vals[]; 120 extern const value_string modifier_vals_cmd[]; 121 extern const value_string modifier_vals_resp[]; 122 123 extern int get_xdlc_control(const guint8 *pd, int offset, gboolean is_extended); 124 125 WS_DLL_PUBLIC int dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo, 126 proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control, 127 const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext, 128 const value_string *u_modifier_short_vals_cmd, 129 const value_string *u_modifier_short_vals_resp, gboolean is_response, 130 gboolean is_extended, gboolean append_info); 131 132 #endif 133