packet-llc.c

   1 /* packet-llc.c
   2  * Routines for IEEE 802.2 LLC layer
   3  * Gilbert Ramirez <gram@verdict.uthscsa.edu>
   4  *
   5  * $Id: packet-llc.c,v 1.8 1998/10/10 03:32:12 gerald Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@unicom.net>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #ifdef HAVE_SYS_TYPES_H
  32 # include <sys/types.h>
  33 #endif
  34
  35 #include <pcap.h>
  36
  37 #include <gtk/gtk.h>
  38
  39 #include <stdio.h>
  40
  41 #include "ethereal.h"
  42 #include "packet.h"
  43 #include "etypes.h"
  44
  45 struct sap_info {
  46         guint8  sap;
  47         void    (*func) (const u_char *, int, frame_data *, GtkTree *);
  48         char    *text;
  49 };
  50
  51 static struct sap_info  saps[] = {
  52         { 0x00, NULL,           "NULL LSAP" },
  53         { 0x02, NULL,           "LLC Sub-Layer Management Individual" },
  54         { 0x03, NULL,           "LLC Sub-Layer Management Group" },
  55         { 0x04, NULL,           "SNA Path Control Individual" },
  56         { 0x05, NULL,           "SNA Path Control Group" },
  57         { 0x06, dissect_ip,     "TCP/IP" },
  58         { 0x08, NULL,           "SNA" },
  59         { 0x0C, NULL,           "SNA" },
  60         { 0x42, NULL,           "Spanning Tree BPDU" },
  61         { 0x7F, NULL,           "ISO 802.2" },
  62         { 0x80, NULL,           "XNS" },
  63         { 0xAA, NULL,           "SNAP" },
  64         /*{ 0xBA, dissect_vines,        "Banyan Vines" },
  65         { 0xBC, dissect_vines,  "Banyan Vines" },*/
  66         { 0xBA, NULL,           "Banyan Vines" },
  67         { 0xBC, NULL,           "Banyan Vines" },
  68         { 0xE0, dissect_ipx,    "NetWare" },
  69         { 0xF0, NULL,           "NetBIOS" },
  70         { 0xF4, NULL,           "IBM Net Management Individual" },
  71         { 0xF5, NULL,           "IBM Net Management Group" },
  72         { 0xF8, NULL,           "Remote Program Load" },
  73         { 0xFC, NULL,           "Remote Program Load" },
  74         { 0xFE, dissect_osi,    "ISO Network Layer" },
  75         { 0xFF, NULL,           "Global LSAP" },
  76         { 0x00, NULL,           NULL }
  77 };
  78
  79
  80 static char*
  81 sap_text(u_char sap) {
  82         int i=0;
  83
  84         while (saps[i].text != NULL) {
  85                 if (saps[i].sap == sap) {
  86                         return saps[i].text;
  87                 }
  88                 i++;
  89         }
  90         return "Unknown";
  91 }
  92
  93 static void*
  94 sap_func(u_char sap) {
  95         int i=0;
  96
  97         while (saps[i].text != NULL) {
  98                 if (saps[i].sap == sap) {
  99                         return saps[i].func;
 100                 }
 101                 i++;
 102         }
 103         return dissect_data;
 104 }
 105
 106 static char*
 107 llc_org(const u_char *ptr) {
 108
 109         unsigned long org = (ptr[0] << 16) | (ptr[1] << 8) | ptr[2];
 110         char *llc_org[1] = {
 111                 "Encapsulated Ethernet"};
 112
 113         if (org > 0) {
 114                 return "Unknown";
 115         }
 116         else {
 117                 return llc_org[org];
 118         }
 119 }
 120
 121 void
 122 dissect_llc(const u_char *pd, int offset, frame_data *fd, GtkTree *tree) {
 123
 124         GtkWidget       *llc_tree = NULL, *ti;
 125         guint16         etype;
 126         int             is_snap;
 127         void            (*dissect) (const u_char *, int, frame_data *, GtkTree *);
 128
 129         /* LLC Strings */
 130         char *llc_ctrl[4] = {
 131                 "Information Transfer", "Supervisory",
 132                 "", "Unnumbered Information" };
 133
 134         is_snap = (pd[offset] == 0xAA) && (pd[offset+1] == 0xAA);
 135
 136         if (fd->win_info[COL_NUM]) {
 137                 strcpy(fd->win_info[COL_PROTOCOL], "LLC");
 138         }
 139
 140         if (tree) {
 141                 ti = add_item_to_tree(GTK_WIDGET(tree), offset, (is_snap ? 8 : 3),
 142                         "Logical-Link Control");
 143                 llc_tree = gtk_tree_new();
 144                 add_subtree(ti, llc_tree, ETT_LLC);
 145                 add_item_to_tree(llc_tree, offset,      1, "DSAP: %s (0x%02X)",
 146                         sap_text(pd[offset]), pd[offset]);
 147                 add_item_to_tree(llc_tree, offset+1,    1, "SSAP: %s (0x%02X)",
 148                         sap_text(pd[offset+1]), pd[offset+1]);
 149                 add_item_to_tree(llc_tree, offset+2,    1, "Control: %s",
 150                         llc_ctrl[pd[offset+2] & 3]);
 151         }
 152
 153         if (is_snap) {
 154                 if (fd->win_info[COL_NUM]) {
 155                         strcpy(fd->win_info[COL_INFO], "802.2 LLC (SNAP)");
 156                 }
 157                 if (tree) {
 158                         add_item_to_tree(llc_tree, offset+3,    3,
 159                                 "Organization Code: %s (%02X-%02X-%02X)",
 160                                 llc_org(&pd[offset+3]),
 161                                 pd[offset+3], pd[offset+4], pd[offset+5]);
 162                 }
 163                 etype  = (pd[offset+6] << 8) | pd[offset+7];
 164                 offset += 8;
 165                 ethertype(etype, offset, pd, fd, tree, llc_tree);
 166         }
 167         else {
 168                 if (fd->win_info[COL_NUM]) {
 169                         sprintf(fd->win_info[COL_INFO], "802.2 LLC (%s)", sap_text(pd[offset]));
 170                 }
 171
 172                 dissect = sap_func(pd[offset]);
 173
 174                 /* non-SNAP */
 175                 offset += 3;
 176
 177                 if (dissect) {
 178                         dissect(pd, offset, fd, tree);
 179                 }
 180                 else {
 181                         dissect_data(pd, offset, fd, tree);
 182                 }
 183
 184         }
 185 }