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  *
  34  *      last edit-date: [Mon Dec 13 21:50:41 1999]
  35  *
  36  *---------------------------------------------------------------------------*/
  37
  38 #include "decode.h"
  39
  40 /*---------------------------------------------------------------------------*
  41  *      decode poll bit
  42  *---------------------------------------------------------------------------*/
  43 static void
  44 poll(int layer, char *buffer, int cnt, unsigned char value, unsigned char mask)
  45 {
  46         sprintline(layer, buffer, cnt, value, mask, "P/F, Poll = %s", (value & mask) ? "Immediate Response Required" : "No Immediate Response Required");
  47 }
  48
  49 /*---------------------------------------------------------------------------*
  50  *      decode final bit
  51  *---------------------------------------------------------------------------*/
  52 static void
  53 final(int layer, char *buffer, int cnt, unsigned char value, unsigned char mask)
  54 {
  55         sprintline(layer, buffer, cnt, value, mask, "P/F, Final = %s", (value & mask) ? "Result of Poll" : "No Result of Poll");
  56 }
  57
  58 /*---------------------------------------------------------------------------*
  59  *      decode protocol specified in Q.921
  60  *---------------------------------------------------------------------------*/
  61 int
  62 layer2(char *pbuf, unsigned char *buf, int dir, int printit)
  63 {
  64         int sap, tei, cmd;
  65         int cnt = 0;
  66         char locbuf[32000];
  67         char *lbufp = &locbuf[0];
  68         char buffer[80];
  69
  70         *lbufp = '\0';
  71         *pbuf = '\0';
  72
  73         /* address high */
  74
  75         sap = (buf[0] >> 2) & 0x3f;
  76
  77         if(sap == 0)
  78                 strcpy(buffer, "Call Control");
  79         else if((sap >= 1) && (sap <= 15))
  80                 strcpy(buffer, "Reserved");
  81         else if(sap == 16)
  82                 strcpy(buffer, "X.25");
  83         else if((sap >= 17) && (sap <= 31))
  84                 strcpy(buffer, "Reserved");
  85         else if(sap == 63)
  86                 strcpy(buffer, "Layer 2 Management");
  87         else
  88                 strcpy(buffer, "Not available for Q.921");
  89         sprintline(2, lbufp+strlen(lbufp), cnt, buf[0], 0xfc, "SAPI = %d (%s)", sap, buffer);
  90
  91         if(dir == FROM_TE)
  92                 cmd = !(buf[0] & 0x02);
  93         else
  94                 cmd = buf[0] & 0x02;
  95
  96         sprintline(2, lbufp+strlen(lbufp), cnt, buf[0], 0x02, "C/R = %s", cmd ? "Command" : "Response");
  97         extension(2, lbufp+strlen(lbufp), cnt, buf[0], 0x01);
  98         cnt++;
  99
 100         /* address low */
 101
 102         tei = buf[1] >> 1;
 103
 104         if((tei >= 0) && (tei <= 63))
 105                 strcpy(buffer, "Non-automatic TEI");
 106         else if((tei >= 64) && (tei <= 126))
 107                 strcpy(buffer, "Automatic TEI");
 108         if(tei == 127)
 109                 strcpy(buffer, "Group TEI");
 110
 111         sprintline(2, lbufp+strlen(lbufp), cnt, buf[1], 0xfe, "TEI = %d (%s)", tei, buffer);
 112         extension(2, lbufp+strlen(lbufp), cnt, buf[1], 0x01);
 113         cnt++;
 114
 115         /* control 1 */
 116
 117         if((buf[2] & 0x03) == 0x03)
 118         {
 119                 /* U-frame */
 120
 121                 if((buf[2] & 0xef) == 0x6f)
 122                 {
 123                         /* SABME */
 124
 125                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: SABME (Set Asynchonous Balanced Mode)");
 126                         poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 127                         cnt++;
 128                 }
 129                 else if((buf[2] & 0xef) == 0x0f)
 130                 {
 131                         /* DM */
 132
 133                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: DM (Disconnected Mode)");
 134                         final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 135                         cnt++;
 136                 }
 137                 else if((buf[2] & 0xef) == 0x03)
 138                 {
 139                         /* UI */
 140
 141                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: UI (Unnumbered Information)");
 142                         poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 143                         cnt++;
 144
 145                         if(sap == 63 && (buf[3] == 0x0f))       /* TEI management */
 146                         {
 147                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[3], 0xff, "MEI (Management Entity Identifier)");
 148                                 cnt++;
 149                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[4], 0xff, "Ri = 0x%04x (Reference number high)", (buf[4] << 8) | buf[5]);
 150                                 cnt++;
 151                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[5], 0xff, "Ri (Reference Number low)");
 152                                 cnt++;
 153
 154                                 switch(buf[6])
 155                                 {
 156                                         case 0x01:
 157                                                 strcpy(buffer, "Identity Request");
 158                                                 break;
 159                                         case 0x02:
 160                                                 strcpy(buffer, "Identity Assigned");
 161                                                 break;
 162                                         case 0x03:
 163                                                 strcpy(buffer, "Identity denied");
 164                                                 break;
 165                                         case 0x04:
 166                                                 strcpy(buffer, "Identity Check Request");
 167                                                 break;
 168                                         case 0x05:
 169                                                 strcpy(buffer, "Identity Check Response");
 170                                                 break;
 171                                         case 0x06:
 172                                                 strcpy(buffer, "Identity Remove");
 173                                                 break;
 174                                         case 0x07:
 175                                                 strcpy(buffer, "Identity Verify");
 176                                                 break;
 177                                         default:
 178                                                 strcpy(buffer, "undefined");
 179                                                 break;
 180                                 }
 181
 182                                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[6], 0xff, "TEI %s (Message Type %d)", buffer, buf[6]);
 183                                 cnt++;
 184
 185                                 switch(buf[6])
 186                                 {
 187                                         case 0x01:
 188                                                 strcpy(buffer, "Any TEI value acceptable");
 189                                                 break;
 190                                         case 0x02:
 191                                                 strcpy(buffer, "");
 192                                                 break;
 193                                         case 0x03:
 194                                                 strcpy(buffer, "No TEI Value available");
 195                                                 break;
 196                                         case 0x04:
 197                                                 strcpy(buffer, "Check all TEI values");
 198                                                 break;
 199                                         case 0x05:
 200                                                 strcpy(buffer, "");
 201                                                 break;
 202                                         case 0x06:
 203                                                 strcpy(buffer, "Request for removal of all TEI values");
 204                                                 break;
 205                                         case 0x07:
 206                                                 strcpy(buffer, "");
 207                                                 break;
 208                                         default:
 209                                                 strcpy(buffer, "");
 210                                                 break;
 211                                 }
 212                                 if(((buf[7] >> 1) & 0x7f) == 127)
 213                                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[7], 0xfe, "Ai = %d (Action Indicator = %s)", (buf[7] >> 1) & 0x7f, buffer);
 214                                 else
 215                                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[7], 0xfe, "Ai = %d (Action Indicator)", (buf[7] >> 1) & 0x7f);
 216                                 extension(2, lbufp+strlen(lbufp), cnt, buf[7], 0x01);
 217                                 cnt++;
 218                         }
 219                 }
 220                 else if((buf[2] & 0xef) == 0x43)
 221                 {
 222                         /* DISC */
 223
 224                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: DISC (Disconnect)");
 225                         poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 226                         cnt++;
 227                 }
 228                 else if((buf[2] & 0xef) == 0x63)
 229                 {
 230                         /* UA */
 231
 232                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: UA (Unnumbered Acknowledge)");
 233                         final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 234                         cnt++;
 235                 }
 236                 else if((buf[2] & 0xef) == 0x87)
 237                 {
 238                         /* FRMR */
 239
 240                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: FRMR (Frame Reject)");
 241                         final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 242                         cnt++;
 243                 }
 244                 else if((buf[2] & 0xef) == 0x9f)
 245                 {
 246                         /* XID */
 247
 248                         sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xef, "U-Frame: XID (Exchange Identification)");
 249                         if(cmd)
 250                                 poll(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 251                         else
 252                                 final(2, lbufp+strlen(lbufp), cnt, buf[2], 0x10);
 253                         cnt++;
 254                 }
 255
 256         }
 257         else if((buf[2] & 0x03) == 0x01)
 258         {
 259                 /* S-frame */
 260
 261                 if(buf[2] == 0x01)
 262                         strcpy(buffer, "RR (Receiver Ready)");
 263                 else if(buf[2] == 0x05)
 264                         strcpy(buffer, "RNR (Receiver Not Ready)");
 265                 else if(buf[2] == 0x09)
 266                         strcpy(buffer, "REJ (Reject)");
 267                 else
 268                         strcpy(buffer, "Unknown");
 269
 270                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xff, "S-Frame: %s", buffer);
 271                 cnt++;
 272
 273                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[3], 0xfe, "N(R) = %d (receive sequence number)", (buf[3] >> 1) & 0x7f);
 274                 if(cmd)
 275                         poll(2, lbufp+strlen(lbufp), cnt, buf[3], 0x01);
 276                 else
 277                         final(2, lbufp+strlen(lbufp), cnt, buf[3], 0x01);
 278                 cnt++;
 279
 280         }
 281         else if((buf[2] & 0x01) == 0x00)
 282         {
 283                 /* I-frame */
 284
 285                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0xfe, "N(S) = %d (send sequence number)", (buf[2] >> 1) & 0x7f);
 286                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[2], 0x01, "I-Frame: Information transfer");
 287                 cnt++;
 288
 289                 sprintf(buffer, "N(R) = %d", (buf[3] >> 1) & 0x7f);
 290                 sprintline(2, lbufp+strlen(lbufp), cnt, buf[3], 0xfe, "N(R) = %d (receive sequence number)", (buf[3] >> 1) & 0x7f);
 291                 poll(2, lbufp+strlen(lbufp), cnt, buf[3], 0x01);
 292                 cnt++;
 293
 294         }
 295
 296         sprintf((pbuf+strlen(pbuf)),"%s", &locbuf[0]);
 297         return (cnt);
 298 }
 299
 300 /* EOF */