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 1.3 2000-07-01 03:39:10 assar 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 #include <netinet/in_systm.h>
  27 #include <netinet/ip.h>
  28 #include <netinet/ip_var.h>
  29 #include <netinet/udp.h>
  30 #include <netinet/udp_var.h>
  31 #include <netinet/tcp.h>
  32 #include <netinet/tcpip.h>
  33
  34 #include <stdlib.h>
  35 #include <stdio.h>
  36 #include <string.h>
  37
  38 #include "interface.h"
  39 #include "addrtoname.h"
  40 #include "extract.h"
  41
  42 static void
  43 stp_print_bridge_id(const u_char *p)
  44 {
  45         printf("%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
  46                p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
  47 }
  48
  49 static void
  50 stp_print_config_bpdu(const u_char *p, u_int length)
  51 {
  52         printf("config ");
  53         if (p[7] & 1)
  54                 printf("TOP_CHANGE ");
  55         if (p[7] & 0x80)
  56                 printf("TOP_CHANGE_ACK ");
  57
  58         stp_print_bridge_id(p+20);
  59         printf(".%.2x%.2x ", p[28], p[29]);
  60
  61         printf("root ");
  62         stp_print_bridge_id(p+8);
  63
  64         printf(" pathcost %i ", (p[16] << 24) | (p[17] << 16) | (p[18] << 8) | p[19]);
  65
  66         printf("age %i ", p[30]);
  67         printf("max %i ", p[32]);
  68         printf("hello %i ", p[34]);
  69         printf("fdelay %i ", p[36]);
  70 }
  71
  72 static void
  73 stp_print_tcn_bpdu(const u_char *p, u_int length)
  74 {
  75         printf("tcn");
  76 }
  77
  78 /*
  79  * Print 802.1d packets.
  80  */
  81 void
  82 stp_print(const u_char *p, u_int length)
  83 {
  84         if (length < 7)
  85                 goto trunc;
  86
  87         printf("802.1d ");
  88         if (p[2] != 0x03 || p[3] || p[4] || p[5]) {
  89                 printf("unknown version");
  90                 return;
  91         }
  92
  93         switch (p[6])
  94         {
  95         case 0:
  96                 if (length < 10)
  97                         goto trunc;
  98                 stp_print_config_bpdu(p, length);
  99                 break;
 100
 101         case 1:
 102                 stp_print_tcn_bpdu(p, length);
 103                 break;
 104
 105         default:
 106                 printf("unknown type %i\n", p[6]);
 107                 break;
 108         }
 109
 110         return;
 111 trunc:
 112         printf("[|stp %d]", length);
 113 }