wiretap/lanalyzer.c

   1 /* lanalyzer.c
   2  *
   3  * $Id: lanalyzer.c,v 1.8 1999/01/29 17:06:56 gram Exp $
   4  *
   5  * Wiretap Library
   6  * Copyright (c) 1998 by Gilbert Ramirez <gram@verdict.uthscsa.edu>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version 2
  11  * of the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21  *
  22  */
  23 #include <stdlib.h>
  24 #include <time.h>
  25 #include "wtap.h"
  26 #include "lanalyzer.h"
  27
  28 int lanalyzer_open(wtap *wth)
  29 {
  30         int bytes_read;
  31         char record_type[2];
  32         char record_length[2];
  33         char summary[210];
  34         guint16 board_type, mxslc;
  35         guint16 type, length;
  36         guint8 cr_day, cr_month, cr_year;
  37         struct tm tm;
  38
  39         fseek(wth->fh, 0, SEEK_SET);
  40         bytes_read = fread(record_type, 1, 2, wth->fh);
  41         bytes_read += fread(record_length, 1, 2, wth->fh);
  42         type = pletohs(record_type);
  43         length = pletohs(record_length); /* make sure to do this for while() loop */
  44
  45         if (bytes_read != 4) {
  46                 return WTAP_FILE_UNKNOWN;
  47         }
  48
  49         if (type != 0x1001 && type != 0x1007) {
  50                 return WTAP_FILE_UNKNOWN;
  51         }
  52
  53         /* If we made it this far, then the file is a LANAlyzer file.
  54          * Let's get some info from it */
  55         wth->capture.lanalyzer = g_malloc(sizeof(lanalyzer_t));
  56         wth->subtype_read = lanalyzer_read;
  57 /*      wth->snapshot_length = 16384; */ /* available in header as 'mxslc' */
  58
  59         /* Read records until we find the start of packets */
  60
  61         while (1) {
  62                 fseek(wth->fh, length, SEEK_CUR);
  63                 bytes_read = fread(record_type, 1, 2, wth->fh);
  64                 bytes_read += fread(record_length, 1, 2, wth->fh);
  65                 if (bytes_read != 4) {
  66                         free(wth->capture.lanalyzer);
  67                         return WTAP_FILE_UNKNOWN;
  68                 }
  69
  70                 type = pletohs(record_type);
  71                 length = pletohs(record_length);
  72
  73 /*              g_message("Record 0x%04X Length %d", type, length);*/
  74                 switch (type) {
  75                         /* Trace Summary Record */
  76                         case 0x1002:
  77                                 fread(summary, 1, 210, wth->fh);
  78
  79                                 /* Assume that the date of the creation of the trace file
  80                                  * is the same date of the trace. Lanalyzer doesn't
  81                                  * store the creation date/time of the trace, but only of
  82                                  * the file. Unless you traced at 11:55 PM and saved at 00:05
  83                                  * AM, the assumption that trace.date == file.date is true.
  84                                  */
  85                                 cr_day = summary[0];
  86                                 cr_month = summary[1];
  87                                 cr_year = pletohs(&summary[2]);
  88                                 /*g_message("Day %d Month %d Year %d (%04X)", cr_day, cr_month,
  89                                                 cr_year, cr_year);*/
  90
  91                                 /* Get capture start time. I learned how to do
  92                                  * this from Guy's code in ngsniffer.c
  93                                  */
  94                                 /* this strange year offset is not in the
  95                                  * lanalyzer file format documentation, but it
  96                                  * works. */
  97                                 tm.tm_year = cr_year - (1900 - 1792);
  98                                 tm.tm_mon = cr_month - 1;
  99                                 tm.tm_mday = cr_day;
 100                                 tm.tm_hour = 0;
 101                                 tm.tm_min = 0;
 102                                 tm.tm_sec = 0;
 103                                 tm.tm_isdst = -1;
 104                                 wth->capture.lanalyzer->start = mktime(&tm);
 105                                 /*g_message("Day %d Month %d Year %d", tm.tm_mday,
 106                                                 tm.tm_mon, tm.tm_year);*/
 107                                 mxslc = pletohs(&summary[30]);
 108                                 wth->snapshot_length = mxslc;
 109
 110                                 length = 0; /* to fake the next iteration of while() */
 111                                 board_type = pletohs(&summary[188]);
 112                                 switch (board_type) {
 113                                         case 226:
 114                                                 wth->encapsulation = WTAP_ENCAP_ETHERNET;
 115                                                 break;
 116                                         case 227:
 117                                                 wth->encapsulation = WTAP_ENCAP_TR;
 118                                                 break;
 119                                         default:
 120                                                 wth->encapsulation = WTAP_ENCAP_NONE;
 121                                 }
 122                                 break;
 123
 124                         /* Trace Packet Data Record */
 125                         case 0x1005:
 126                                 wth->capture.lanalyzer->pkt_len = length - 32;
 127                                 return WTAP_FILE_LANALYZER;
 128
 129                 /*      default: no default action */
 130                 /*              printf("Record 0x%04X Length %d\n", type, length);*/
 131                 }
 132         }
 133
 134         /* never gets here */
 135         return WTAP_FILE_LANALYZER;
 136 }
 137
 138 /* Read the next packet */
 139 int lanalyzer_read(wtap *wth)
 140 {
 141         int packet_size = wth->capture.lanalyzer->pkt_len; /* slice, really */
 142         int bytes_read;
 143         char record_type[2];
 144         char record_length[2];
 145         guint16 type, length;
 146         gchar descriptor[32];
 147         int     data_offset;
 148         guint16 time_low, time_med, time_high, true_size;
 149         double t;
 150
 151         /* If this is the very first packet, then the fh cursor will already
 152          * be at the start of the packet data instead of at the start of the Trace
 153          * Packet Data Record. Check for this */
 154         if (!packet_size) {
 155
 156                 /* Increment fh cursor to next record */
 157                 bytes_read = fread(record_type, 1, 2, wth->fh);
 158                 bytes_read += fread(record_length, 1, 2, wth->fh);
 159                 if (bytes_read != 4) {
 160                         return 0;
 161                 }
 162
 163                 type = pletohs(record_type);
 164                 length = pletohs(record_length);
 165
 166                 if (type != 0x1005) {
 167                         return 0;
 168                 }
 169                 else {
 170                         packet_size = length - 32;
 171                 }
 172         }
 173         else {
 174                 wth->capture.lanalyzer->pkt_len = 0;
 175         }
 176
 177         /* Read the descriptor data */
 178         bytes_read = fread(descriptor, 1, 32, wth->fh);
 179         if (bytes_read != 32) {
 180                 g_error("lanalyzer_read: not enough descriptor data (%d bytes)",
 181                                 bytes_read);
 182                 return 0;
 183         }
 184
 185         /* Read the packet data */
 186         buffer_assure_space(&wth->frame_buffer, packet_size);
 187         data_offset = ftell(wth->fh);
 188         bytes_read = fread(buffer_start_ptr(&wth->frame_buffer), 1,
 189                 packet_size, wth->fh);
 190
 191         if (bytes_read != packet_size) {
 192                 if (ferror(wth->fh)) {
 193                         g_error("lanalyzer_read: fread for data: read error\n");
 194                 } else {
 195                         g_error("lanalyzer_read: fread for data: %d bytes out of %d read",
 196                                 bytes_read, packet_size);
 197                 }
 198                 return -1;
 199         }
 200
 201         true_size = pletohs(&descriptor[4]);
 202         time_low = pletohs(&descriptor[8]);
 203         time_med = pletohs(&descriptor[10]);
 204         time_high = pletohs(&descriptor[12]);
 205
 206         t = (double)time_low+(double)(time_med)*65536.0 +
 207                 (double)time_high*4294967296.0;
 208         t = t/1000000.0 * 0.5; /* t = # of secs */
 209         t += wth->capture.lanalyzer->start;
 210
 211         wth->phdr.ts.tv_sec = (long)t;
 212         wth->phdr.ts.tv_usec = (unsigned long)((t-(double)(wth->phdr.ts.tv_sec))
 213                         *1.0e6);
 214
 215         wth->phdr.len = true_size - 4;
 216         wth->phdr.caplen = packet_size;
 217         wth->phdr.pkt_encap = wth->encapsulation;
 218
 219         return data_offset;
 220 }