The Tcpdump Group git mirrors - tcpdump/blob - print-stp.c

   1 /*
   2  * Copyright (c) 2000 Lennert Buytenhek
   3  *
   4  * This software may be distributed either under the terms of the
   5  * BSD-style license that accompanies tcpdump or the GNU General
   6  * Public License
   7  *
   8  * Format and print IEEE 802.1d spanning tree protocol packets.
   9  * Contributed by Lennert Buytenhek <buytenh@gnu.org>
  10  */
  11
  12 #ifndef lint
  13 static const char rcsid[] =
  14     "@(#) $Header: /tcpdump/master/tcpdump/print-stp.c,v 1.7 2002-05-29 09:59:12 guy Exp $";
  15 #endif
  16
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <sys/param.h>
  22 #include <sys/time.h>
  23 #include <sys/socket.h>
  24
  25 #include <netinet/in.h>
  26
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <string.h>
  30
  31 #include "interface.h"
  32 #include "addrtoname.h"
  33 #include "extract.h"
  34
  35 static void
  36 stp_print_bridge_id(const u_char *p)
  37 {
  38         printf("%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
  39                p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
  40 }
  41
  42 static void
  43 stp_print_config_bpdu(const u_char *p, u_int length)
  44 {
  45         printf("config ");
  46         if (p[7] & 1)
  47                 printf("TOP_CHANGE ");
  48         if (p[7] & 0x80)
  49                 printf("TOP_CHANGE_ACK ");
  50
  51         stp_print_bridge_id(p+20);
  52         printf(".%.2x%.2x ", p[28], p[29]);
  53
  54         printf("root ");
  55         stp_print_bridge_id(p+8);
  56
  57         printf(" pathcost %i ", (p[16] << 24) | (p[17] << 16) | (p[18] << 8) | p[19]);
  58
  59         printf("age %i ", p[30]);
  60         printf("max %i ", p[32]);
  61         printf("hello %i ", p[34]);
  62         printf("fdelay %i ", p[36]);
  63 }
  64
  65 static void
  66 stp_print_tcn_bpdu(const u_char *p, u_int length)
  67 {
  68         printf("tcn");
  69 }
  70
  71 /*
  72  * Print 802.1d packets.
  73  */
  74 void
  75 stp_print(const u_char *p, u_int length)
  76 {
  77         if (length < 7)
  78                 goto trunc;
  79
  80         printf("802.1d ");
  81         if (p[2] != 0x03 || p[3] || p[4] || p[5]) {
  82                 printf("unknown version");
  83                 return;
  84         }
  85
  86         switch (p[6])
  87         {
  88         case 0:
  89                 if (length < 10)
  90                         goto trunc;
  91                 stp_print_config_bpdu(p, length);
  92                 break;
  93
  94         case 1:
  95                 stp_print_tcn_bpdu(p, length);
  96                 break;
  97
  98         default:
  99                 printf("unknown type %i", p[6]);
 100                 break;
 101         }
 102
 103         return;
 104 trunc:
 105         printf("[|stp %d]", length);
 106 }