epan/xdlc.h

   1 /* xdlc.h
   2  * Define *DLC frame types, and routine to dissect the control field of
   3  * a *DLC frame.
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  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.
  15  *
  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.
  20  *
  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #ifndef __XDLC_H__
  27 #define __XDLC_H__
  28
  29 #include "ws_symbol_export.h"
  30
  31 /** @file
  32  * Define *DLC frame types, and routine to dissect the control field of
  33  * a *DLC frame.
  34  */
  35 /*
  36  * Low-order bits of first (extended) or only (basic) octet of control
  37  * field, specifying the frame type.
  38  */
  39 #define XDLC_I_MASK             0x01    /**< Mask to test for I or not I */
  40 #define XDLC_I                  0x00    /**< Information frames */
  41 #define XDLC_S_U_MASK   0x03    /**< Mask to test for S or U */
  42 #define XDLC_S                  0x01    /**< Supervisory frames */
  43 #define XDLC_U                  0x03    /**< Unnumbered frames */
  44
  45 /*
  46  * N(S) and N(R) fields, in basic and extended operation.
  47  */
  48 #define XDLC_N_R_MASK           0xE0    /**< basic */
  49 #define XDLC_N_R_SHIFT          5
  50 #define XDLC_N_R_EXT_MASK       0xFE00  /**< extended */
  51 #define XDLC_N_R_EXT_SHIFT      9
  52 #define XDLC_N_S_MASK           0x0E    /**< basic */
  53 #define XDLC_N_S_SHIFT          1
  54 #define XDLC_N_S_EXT_MASK       0x00FE  /**< extended */
  55 #define XDLC_N_S_EXT_SHIFT      1
  56
  57 /*
  58  * Poll/Final bit, in basic and extended operation.
  59  */
  60 #define XDLC_P_F                0x10    /**< basic */
  61 #define XDLC_P_F_EXT    0x0100  /**< extended */
  62
  63 /*
  64  * S-format frame types.
  65  */
  66 #define XDLC_S_FTYPE_MASK       0x0C
  67 #define XDLC_RR                 0x00    /**< Receiver ready */
  68 #define XDLC_RNR                0x04    /**< Receiver not ready */
  69 #define XDLC_REJ                0x08    /**< Reject */
  70 #define XDLC_SREJ               0x0C    /**< Selective reject */
  71
  72 /*
  73  * U-format modifiers.
  74  */
  75 #define XDLC_U_MODIFIER_MASK    0xEC
  76 #define XDLC_UI         0x00    /**< Unnumbered Information */
  77 #define XDLC_UP         0x20    /**< Unnumbered Poll */
  78 #define XDLC_DISC       0x40    /**< Disconnect (command) */
  79 #define XDLC_RD         0x40    /**< Request Disconnect (response) */
  80 #define XDLC_UA         0x60    /**< Unnumbered Acknowledge */
  81 #define XDLC_SNRM       0x80    /**< Set Normal Response Mode */
  82 #define XDLC_TEST       0xE0    /**< Test */
  83 #define XDLC_SIM        0x04    /**< Set Initialization Mode (command) */
  84 #define XDLC_RIM        0x04    /**< Request Initialization Mode (response) */
  85 #define XDLC_FRMR       0x84    /**< Frame reject */
  86 #define XDLC_CFGR       0xC4    /**< Configure */
  87 #define XDLC_SARM       0x0C    /**< Set Asynchronous Response Mode (command) */
  88 #define XDLC_DM         0x0C    /**< Disconnected mode (response) */
  89 #define XDLC_SABM       0x2C    /**< Set Asynchronous Balanced Mode */
  90 #define XDLC_SARME      0x4C    /**< Set Asynchronous Response Mode Extended */
  91 #define XDLC_SABME      0x6C    /**< Set Asynchronous Balanced Mode Extended */
  92 #define XDLC_RESET      0x8C    /**< Reset */
  93 #define XDLC_XID        0xAC    /**< Exchange identification */
  94 #define XDLC_SNRME      0xCC    /**< Set Normal Response Mode Extended */
  95 #define XDLC_BCN        0xEC    /**< Beacon */
  96
  97 /**
  98  * This macro takes the control field of an xDLC frame, as returned by
  99  * "get_xdlc_control()" or "dissect_xdlc_control()", and evaluates to
 100  * TRUE if the frame is an "information" frame and FALSE if it isn't.
 101  * Note that frames other than information frames can have data in them,
 102  * e.g. TEST frames.
 103  */
 104 #define XDLC_IS_INFORMATION(control) \
 105         (((control) & XDLC_I_MASK) == XDLC_I || (control) == (XDLC_UI|XDLC_U))
 106
 107 /**
 108  * This macro takes the control field of an xDLC frame, and a flag saying
 109  * whether we're doing basic or extended operation, and evaluates to
 110  * the length of that field (if it's an Unnumbered frame, or we're not
 111  * in extended mode, it's 1 byte long, otherwise it's 2 bytes long).
 112  */
 113 #define XDLC_CONTROL_LEN(control, is_extended) \
 114         ((((control) & XDLC_S_U_MASK) == XDLC_U || !(is_extended)) ? 1 : 2)
 115
 116 /**
 117  * Structure containing pointers to hf_ values for various subfields of
 118  * the control field.
 119  */
 120 typedef struct {
 121         int     *hf_xdlc_n_r;
 122         int     *hf_xdlc_n_s;
 123         int     *hf_xdlc_p;
 124         int     *hf_xdlc_f;
 125         int     *hf_xdlc_s_ftype;
 126         int     *hf_xdlc_u_modifier_cmd;
 127         int     *hf_xdlc_u_modifier_resp;
 128         int     *hf_xdlc_ftype_i;
 129         int     *hf_xdlc_ftype_s_u;
 130 } xdlc_cf_items;
 131
 132 extern const value_string ftype_vals[];
 133 extern const value_string stype_vals[];
 134 extern const value_string modifier_vals_cmd[];
 135 extern const value_string modifier_vals_resp[];
 136
 137 extern int get_xdlc_control(const guchar *pd, int offset, gboolean is_extended);
 138
 139 /**
 140  * Check whether the control field of the packet looks valid.
 141  */
 142 WS_DLL_PUBLIC gboolean check_xdlc_control(tvbuff_t *tvb, int offset,
 143   const value_string *u_modifier_short_vals_cmd,
 144   const value_string *u_modifier_short_vals_resp, gboolean is_response,
 145   gboolean is_extended _U_);
 146
 147 WS_DLL_PUBLIC int dissect_xdlc_control(tvbuff_t *tvb, int offset, packet_info *pinfo,
 148   proto_tree *xdlc_tree, int hf_xdlc_control, gint ett_xdlc_control,
 149   const xdlc_cf_items *cf_items_nonext, const xdlc_cf_items *cf_items_ext,
 150   const value_string *u_modifier_short_vals_cmd,
 151   const value_string *u_modifier_short_vals_resp, gboolean is_response,
 152   gboolean is_extended, gboolean append_info);
 153
 154 #endif