usr.sbin/i4b/isdndecode/layer2.c

   1 /*
   2  * Copyright (c) 1997, 1999 Hellmuth Michaelis. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  *
  25  *---------------------------------------------------------------------------
  26  *
  27  *      layer2.c - decode and print layer 2 (Q.921) information
  28  *      -------------------------------------------------------
  29  *
  30  *      $Id: layer2.c,v 1.5 1999/12/13 21:25:25 hm Exp $
  31  *
  32  * $FreeBSD: src/usr.sbin/i4b/isdndecode/layer2.c,v 1.6.2.1 2001/08/01 17:45:05 obrien Exp $
  33  * $DragonFly: src/usr.sbin/i4b/isdndecode/layer2.c,v 1.2 2003/06/17 04:29:55 dillon Exp $
  34  *
  35  *      last edit-date: [Mon Dec 13 21:50:41 1999]
  36  *
  37  *---------------------------------------------------------------------------*/
  38
  39 #include "decode.h"
  40
  41 /*---------------------------------------------------------------------------*
  42  *      decode poll bit
  43  *---------------------------------------------------------------------------*/
  44 static void
  45 poll(int layer, char *buffer, int cnt, unsigned char value, unsigned char mask)
  46 {
  47         sprintline(layer, buffer, cnt, value, mask, "P/F, Poll = %s", (value & mask) ? "Immediate Response Required" : "No Immediate Response Required");
  48 }
  49
  50 /*---------------------------------------------------------------------------*
  51  *      decode final bit
  52  *---------------------------------------------------------------------------*/
  53 static void
  54 final(int layer, char *buffer, int cnt, unsigned char value, unsigned char mask)
  55 {
  56         sprintline(layer, buffer, cnt, value, mask, "P/F, Final = %s", (value & mask) ? "Result of Poll" : "No Result of Poll");
  57 }
  58
  59 /*---------------------------------------------------------------------------*
  60  *      decode protocol specified in Q.921
  61  *---------------------------------------------------------------------------*/
  62 int
  63 layer2(char *pbuf, unsigned char *buf, int dir, int printit)
  64 {
  65         int sap, tei, cmd;
  66         int cnt = 0;
  67         char locbuf[32000];
  68         char *lbufp = &locbuf[0];
  69         char buffer[80];
  70
  71         *lbufp = '\0';
  72         *pbuf = '\0';
  73
  74         /* address high */
  75
  76         sap = (buf[0] >> 2) & 0x3f;
  77
  78         if(sap == 0)
  79                 strcpy(buffer, "Call Control");
  80         else if((sap >= 1) && (sap <= 15))
  81                 strcpy(buffer, "Reserved");
  82         else if(sap == 16)
  83                 strcpy(buffer, "X.25");
  84         else if((sap >= 17) && (sap <= 31))
  85                 strcpy(buffer, "Reserved");
  86         else if(sap == 63)
  87                 strcpy(buffer, "Layer 2 Management");
  88         else
  89                 strcpy(buffer, "Not available for Q.921");
  90         sprintline(2, lbufp+strlen(lbufp), cnt, buf[0], 0xfc, "SAPI = %d (%s)", sap, buffer);
  91
  92         if(dir == FROM_TE)
  93                 cmd = !(buf[0] & 0x02);
  94         else
  95                 cmd = buf[0] & 0x02;
  96
  97         sprintline(2, lbufp+strlen(lbufp), cnt, buf[0], 0x02, "C/R = %s", cmd ? "Command" : "Response");
  98         extension(2, lbufp+strlen(lbufp), cnt, buf[0], 0x01);
  99         cnt++;
 100
 101         /* address low */
 102
 103         tei = buf[1] >> 1;
 104
 105         if((tei >= 0) && (tei <= 63))
 106                 strcpy(buffer, "Non-automatic TEI");
 107         else if((tei >= 64) && (tei <= 126))
 108                 strcpy(buffer, "Automatic TEI");
 109         if(tei == 127)
 110                 strcpy(buffer, "Group TEI");
 111
 112         sprintline(2, lbufp+strlen(lbufp), cnt, buf[1], 0xfe, "TEI = %d (%s)", tei, buffer);
 113         extension(2, lbufp+strlen(lbufp), cnt, buf[1], 0x01);
 114         cnt++;
 115
 116         /* control 1 */
 117
 118         if((buf[2] & 0x03) == 0x03)
 119         {
 120                 /* U-frame */
 121
 122                 if((buf[2] & 0xef) == 0x6f)
 123                 {
 124                         /* SABME */
 125
 126                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: SABME (Set Asynchonous Balanced Mode)");
 127                         poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 128                         cnt++;
 129                 }
 130                 else if((buf[2] & 0xef) == 0x0f)
 131                 {
 132                         /* DM */
 133
 134                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: DM (Disconnected Mode)");
 135                         final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 136                         cnt++;
 137                 }
 138                 else if((buf[2] & 0xef) == 0x03)
 139                 {
 140                         /* UI */
 141
 142                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: UI (Unnumbered Information)");
 143                         poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 144                         cnt++;
 145
 146                         if(sap == 63 && (buf[3] == 0x0f))       /* TEI management */
 147                         {
 148                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[3], 0xff, "MEI (Management Entity Identifier)");
 149                                 cnt++;
 150                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[4], 0xff, "Ri = 0x%04x (Reference number high)", (buf[4] << 8) | buf[5]);
 151                                 cnt++;
 152                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[5], 0xff, "Ri (Reference Number low)");
 153                                 cnt++;
 154
 155                                 switch(buf[6])
 156                                 {
 157                                         case 0x01:
 158                                                 strcpy(buffer, "Identity Request");
 159                                                 break;
 160                                         case 0x02:
 161                                                 strcpy(buffer, "Identity Assigned");
 162                                                 break;
 163                                         case 0x03:
 164                                                 strcpy(buffer, "Identity denied");
 165                                                 break;
 166                                         case 0x04:
 167                                                 strcpy(buffer, "Identity Check Request");
 168                                                 break;
 169                                         case 0x05:
 170                                                 strcpy(buffer, "Identity Check Response");
 171                                                 break;
 172                                         case 0x06:
 173                                                 strcpy(buffer, "Identity Remove");
 174                                                 break;
 175                                         case 0x07:
 176                                                 strcpy(buffer, "Identity Verify");
 177                                                 break;
 178                                         default:
 179                                                 strcpy(buffer, "undefined");
 180                                                 break;
 181                                 }
 182
 183                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[6], 0xff, "TEI %s (Message Type %d)", buffer, buf[6]);
 184                                 cnt++;
 185
 186                                 switch(buf[6])
 187                                 {
 188                                         case 0x01:
 189                                                 strcpy(buffer, "Any TEI value acceptable");
 190                                                 break;
 191                                         case 0x02:
 192                                                 strcpy(buffer, "");
 193                                                 break;
 194                                         case 0x03:
 195                                                 strcpy(buffer, "No TEI Value available");
 196                                                 break;
 197                                         case 0x04:
 198                                                 strcpy(buffer, "Check all TEI values");
 199                                                 break;
 200                                         case 0x05:
 201                                                 strcpy(buffer, "");
 202                                                 break;
 203                                         case 0x06:
 204                                                 strcpy(buffer, "Request for removal of all TEI values");
 205                                                 break;
 206                                         case 0x07:
 207                                                 strcpy(buffer, "");
 208                                                 break;
 209                                         default:
 210                                                 strcpy(buffer, "");
 211                                                 break;
 212                                 }
 213                                 if(((buf[7] >> 1) & 0x7f) == 127)
 214                                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[7], 0xfe, "Ai = %d (Action Indicator = %s)", (buf[7] >> 1) & 0x7f, buffer);
 215                                 else
 216                                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[7], 0xfe, "Ai = %d (Action Indicator)", (buf[7] >> 1) & 0x7f);
 217                                 extension(2, lbufp+strlen(lbufp), cnt, buf[7], 0x01);
 218                                 cnt++;
 219                         }
 220                 }
 221                 else if((buf[2] & 0xef) == 0x43)
 222                 {
 223                         /* DISC */
 224
 225                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: DISC (Disconnect)");
 226                         poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 227                         cnt++;
 228                 }
 229                 else if((buf[2] & 0xef) == 0x63)
 230                 {
 231                         /* UA */
 232
 233                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: UA (Unnumbered Acknowledge)");
 234                         final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 235                         cnt++;
 236                 }
 237                 else if((buf[2] & 0xef) == 0x87)
 238                 {
 239                         /* FRMR */
 240
 241                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: FRMR (Frame Reject)");
 242                         final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 243                         cnt++;
 244                 }
 245                 else if((buf[2] & 0xef) == 0x9f)
 246                 {
 247                         /* XID */
 248
 249                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: XID (Exchange Identification)");
 250                         if(cmd)
 251                                 poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 252                         else
 253                                 final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 254                         cnt++;
 255                 }
 256
 257         }
 258         else if((buf[2] & 0x03) == 0x01)
 259         {
 260                 /* S-frame */
 261
 262                 if(buf[2] == 0x01)
 263                         strcpy(buffer, "RR (Receiver Ready)");
 264                 else if(buf[2] == 0x05)
 265                         strcpy(buffer, "RNR (Receiver Not Ready)");
 266                 else if(buf[2] == 0x09)
 267                         strcpy(buffer, "REJ (Reject)");
 268                 else
 269                         strcpy(buffer, "Unknown");
 270
 271                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xff, "S-Frame: %s", buffer);
 272                 cnt++;
 273
 274                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[3], 0xfe, "N(R) = %d (receive sequence number)", (buf[3] >> 1) & 0x7f);
 275                 if(cmd)
 276                         poll(2, lbufp+strlen(lbufp), cnt, buf[3], 0x01);
 277                 else
 278                         final(2, lbufp+strlen(lbufp), cnt, buf[3], 0x01);
 279                 cnt++;
 280
 281         }
 282         else if((buf[2] & 0x01) == 0x00)
 283         {
 284                 /* I-frame */
 285
 286                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xfe, "N(S) = %d (send sequence number)", (buf[2] >> 1) & 0x7f);
 287                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0x01, "I-Frame: Information transfer");
 288                 cnt++;
 289
 290                 sprintf(buffer, "N(R) = %d", (buf[3] >> 1) & 0x7f);
 291                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[3], 0xfe, "N(R) = %d (receive sequence number)", (buf[3] >> 1) & 0x7f);
 292                 poll(2, lbufp+strlen(lbufp), cnt, buf[3], 0x01);
 293                 cnt++;
 294
 295         }
 296
 297         sprintf((pbuf+strlen(pbuf)),"%s", &locbuf[0]);
 298         return (cnt);
 299 }
 300
 301 /* EOF */