2 * Define *DLC frame types, and routine to dissect the control field of
7 * Ethereal - Network traffic analyzer
8 * By Gerald Combs <gerald@ethereal.com>
9 * Copyright 1998 Gerald Combs
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30 * Low-order bits of first (extended) or only (basic) octet of control
31 * field, specifying the frame type.
33 #define XDLC_I_MASK 0x01 /* Mask to test for I or not I */
34 #define XDLC_I 0x00 /* Information frames */
35 #define XDLC_S_U_MASK 0x03 /* Mask to test for S or U */
36 #define XDLC_S 0x01 /* Supervisory frames */
37 #define XDLC_U 0x03 /* Unnumbered frames */
40 * N(S) and N(R) fields, in basic and extended operation.
42 #define XDLC_N_R_MASK 0xE0 /* basic */
43 #define XDLC_N_R_SHIFT 5
44 #define XDLC_N_R_EXT_MASK 0xFE00 /* extended */
45 #define XDLC_N_R_EXT_SHIFT 9
46 #define XDLC_N_S_MASK 0x0E /* basic */
47 #define XDLC_N_S_SHIFT 1
48 #define XDLC_N_S_EXT_MASK 0x00FE /* extended */
49 #define XDLC_N_S_EXT_SHIFT 1
52 * Poll/Final bit, in basic and extended operation.
54 #define XDLC_P_F 0x10 /* basic */
55 #define XDLC_P_F_EXT 0x0100 /* extended */
58 * S-format frame types.
60 #define XDLC_S_FTYPE_MASK 0x0C
61 #define XDLC_RR 0x00 /* Receiver ready */
62 #define XDLC_RNR 0x04 /* Receiver not ready */
63 #define XDLC_REJ 0x08 /* Reject */
64 #define XDLC_SREJ 0x0C /* Selective reject */
69 #define XDLC_U_MODIFIER_MASK 0xEC
70 #define XDLC_UI 0x00 /* Unnumbered Information */
71 #define XDLC_UP 0x20 /* Unnumbered Poll */
72 #define XDLC_DISC 0x40 /* Disconnect (command) */
73 #define XDLC_RD 0x40 /* Request Disconnect (response) */
74 #define XDLC_UA 0x60 /* Unnumbered Acknowledge */
75 #define XDLC_SNRM 0x80 /* Set Normal Response Mode */
76 #define XDLC_TEST 0xE0 /* Test */
77 #define XDLC_SIM 0x04 /* Set Initialization Mode (command) */
78 #define XDLC_RIM 0x04 /* Request Initialization Mode (response) */
79 #define XDLC_FRMR 0x84 /* Frame reject */
80 #define XDLC_CFGR 0xC4 /* Configure */
81 #define XDLC_SARM 0x0C /* Set Asynchronous Response Mode (command) */
82 #define XDLC_DM 0x0C /* Disconnected mode (response) */
83 #define XDLC_SABM 0x2C /* Set Asynchronous Balanced Mode */
84 #define XDLC_SARME 0x4C /* Set Asynchronous Response Mode Extended */
85 #define XDLC_SABME 0x6C /* Set Asynchronous Balanced Mode Extended */
86 #define XDLC_RESET 0x8C /* Reset */
87 #define XDLC_XID 0xAC /* Exchange identification */
88 #define XDLC_SNRME 0xCC /* Set Normal Response Mode Extended */
89 #define XDLC_BCN 0xEC /* Beacon */
92 * This macro takes the control field of an xDLC frame, as returned by
93 * "get_xdlc_control()" or "dissect_xdlc_control()", and evaluates to
94 * TRUE if the frame is an "information" frame and FALSE if it isn't.
95 * Note that frames other than information frames can have data in them,
98 #define XDLC_IS_INFORMATION(control) \
99 (((control) & XDLC_I_MASK) == XDLC_I || (control) == (XDLC_UI|XDLC_U))
102 * This macro takes the control field of an xDLC frame, and a flag saying
103 * whether we're doing basic or extended operation, and evaluates to
104 * the length of that field (if it's an Unnumbered frame, or we're not
105 * in extended mode, it's 1 byte long, otherwise it's 2 bytes long).
107 #define XDLC_CONTROL_LEN(control, is_extended) \
108 ((((control) & XDLC_S_U_MASK) == XDLC_U || !(is_extended)) ? 1 : 2)
111 * Structure containing pointers to hf_ values for various subfields of
119 int *hf_xdlc_s_ftype;
120 int *hf_xdlc_u_modifier_cmd;
121 int *hf_xdlc_u_modifier_resp;
122 int *hf_xdlc_ftype_i;
123 int *hf_xdlc_ftype_s_u;
126 extern const value_string ftype_vals[];
127 extern const value_string stype_vals[];
128 extern const value_string modifier_vals_cmd[];
129 extern const value_string modifier_vals_resp[];
131 extern int get_xdlc_control(const guchar *pd, int offset, int extended);
133 extern int dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo,
134 proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control,
135 const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext,
136 const value_string *u_modifier_short_vals_cmd,
137 const value_string *u_modifier_short_vals_resp, int is_response,
138 int is_extended, int append_info);