2 * Define *DLC frame types, and routine to dissect the control field of
5 * Wireshark - Network traffic analyzer
6 * By Gerald Combs <gerald@wireshark.org>
7 * Copyright 1998 Gerald Combs
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version 2
12 * of the License, or (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
27 #include "ws_symbol_export.h"
30 * Define *DLC frame types, and routine to dissect the control field of
34 * Low-order bits of first (extended) or only (basic) octet of control
35 * field, specifying the frame type.
37 #define XDLC_I_MASK 0x01 /**< Mask to test for I or not I */
38 #define XDLC_I 0x00 /**< Information frames */
39 #define XDLC_S_U_MASK 0x03 /**< Mask to test for S or U */
40 #define XDLC_S 0x01 /**< Supervisory frames */
41 #define XDLC_U 0x03 /**< Unnumbered frames */
44 * N(S) and N(R) fields, in basic and extended operation.
46 #define XDLC_N_R_MASK 0xE0 /**< basic */
47 #define XDLC_N_R_SHIFT 5
48 #define XDLC_N_R_EXT_MASK 0xFE00 /**< extended */
49 #define XDLC_N_R_EXT_SHIFT 9
50 #define XDLC_N_S_MASK 0x0E /**< basic */
51 #define XDLC_N_S_SHIFT 1
52 #define XDLC_N_S_EXT_MASK 0x00FE /**< extended */
53 #define XDLC_N_S_EXT_SHIFT 1
56 * Poll/Final bit, in basic and extended operation.
58 #define XDLC_P_F 0x10 /**< basic */
59 #define XDLC_P_F_EXT 0x0100 /**< extended */
62 * S-format frame types.
64 #define XDLC_S_FTYPE_MASK 0x0C
65 #define XDLC_RR 0x00 /**< Receiver ready */
66 #define XDLC_RNR 0x04 /**< Receiver not ready */
67 #define XDLC_REJ 0x08 /**< Reject */
68 #define XDLC_SREJ 0x0C /**< Selective reject */
73 #define XDLC_U_MODIFIER_MASK 0xEC
74 #define XDLC_UI 0x00 /**< Unnumbered Information */
75 #define XDLC_UP 0x20 /**< Unnumbered Poll */
76 #define XDLC_DISC 0x40 /**< Disconnect (command) */
77 #define XDLC_RD 0x40 /**< Request Disconnect (response) */
78 #define XDLC_UA 0x60 /**< Unnumbered Acknowledge */
79 #define XDLC_SNRM 0x80 /**< Set Normal Response Mode */
80 #define XDLC_TEST 0xE0 /**< Test */
81 #define XDLC_SIM 0x04 /**< Set Initialization Mode (command) */
82 #define XDLC_RIM 0x04 /**< Request Initialization Mode (response) */
83 #define XDLC_FRMR 0x84 /**< Frame reject */
84 #define XDLC_CFGR 0xC4 /**< Configure */
85 #define XDLC_SARM 0x0C /**< Set Asynchronous Response Mode (command) */
86 #define XDLC_DM 0x0C /**< Disconnected mode (response) */
87 #define XDLC_SABM 0x2C /**< Set Asynchronous Balanced Mode */
88 #define XDLC_SARME 0x4C /**< Set Asynchronous Response Mode Extended */
89 #define XDLC_SABME 0x6C /**< Set Asynchronous Balanced Mode Extended */
90 #define XDLC_RESET 0x8C /**< Reset */
91 #define XDLC_XID 0xAC /**< Exchange identification */
92 #define XDLC_SNRME 0xCC /**< Set Normal Response Mode Extended */
93 #define XDLC_BCN 0xEC /**< Beacon */
96 * This macro takes the control field of an xDLC frame, as returned by
97 * "get_xdlc_control()" or "dissect_xdlc_control()", and evaluates to
98 * TRUE if the frame is an "information" frame and FALSE if it isn't.
99 * Note that frames other than information frames can have data in them,
102 #define XDLC_IS_INFORMATION(control) \
103 (((control) & XDLC_I_MASK) == XDLC_I || (control) == (XDLC_UI|XDLC_U))
106 * This macro takes the control field of an xDLC frame, and a flag saying
107 * whether we're doing basic or extended operation, and evaluates to
108 * the length of that field (if it's an Unnumbered frame, or we're not
109 * in extended mode, it's 1 byte long, otherwise it's 2 bytes long).
111 #define XDLC_CONTROL_LEN(control, is_extended) \
112 ((((control) & XDLC_S_U_MASK) == XDLC_U || !(is_extended)) ? 1 : 2)
115 * Structure containing pointers to hf_ values for various subfields of
123 int *hf_xdlc_s_ftype;
124 int *hf_xdlc_u_modifier_cmd;
125 int *hf_xdlc_u_modifier_resp;
126 int *hf_xdlc_ftype_i;
127 int *hf_xdlc_ftype_s_u;
130 extern const value_string ftype_vals[];
131 extern const value_string stype_vals[];
132 extern const value_string modifier_vals_cmd[];
133 extern const value_string modifier_vals_resp[];
135 extern int get_xdlc_control(const guchar *pd, int offset, gboolean is_extended);
138 * Check whether the control field of the packet looks valid.
140 WS_DLL_PUBLIC gboolean check_xdlc_control(tvbuff_t *tvb, int offset,
141 const value_string *u_modifier_short_vals_cmd,
142 const value_string *u_modifier_short_vals_resp, gboolean is_response,
143 gboolean is_extended _U_);
145 WS_DLL_PUBLIC int dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo,
146 proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control,
147 const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext,
148 const value_string *u_modifier_short_vals_cmd,
149 const value_string *u_modifier_short_vals_resp, gboolean is_response,
150 gboolean is_extended, gboolean append_info);