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 1.1 2000-06-10 20:57:57 assar Exp $";
  15 #endif
  16
  17 #include <sys/param.h>
  18 #include <sys/time.h>
  19 #include <sys/socket.h>
  20
  21 #include <netinet/in.h>
  22 #include <netinet/in_systm.h>
  23 #include <netinet/ip.h>
  24 #include <netinet/ip_var.h>
  25 #include <netinet/udp.h>
  26 #include <netinet/udp_var.h>
  27 #include <netinet/tcp.h>
  28 #include <netinet/tcpip.h>
  29
  30 #ifdef __STDC__
  31 #include <stdlib.h>
  32 #endif
  33 #include <stdio.h>
  34 #include <string.h>
  35
  36 #include "interface.h"
  37 #include "addrtoname.h"
  38 #include "extract.h"
  39
  40 static void
  41 stp_print_bridge_id(const u_char *p)
  42 {
  43         printf("%.2x%.2x.%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",
  44                p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7]);
  45 }
  46
  47 static void
  48 stp_print_config_bpdu(const u_char *p, u_int length)
  49 {
  50         printf("config ");
  51         if (p[7] & 1)
  52                 printf("TOP_CHANGE ");
  53         if (p[7] & 0x80)
  54                 printf("TOP_CHANGE_ACK ");
  55
  56         stp_print_bridge_id(p+20);
  57         printf(".%.2x%.2x ", p[28], p[29]);
  58
  59         printf("root ");
  60         stp_print_bridge_id(p+8);
  61
  62         printf(" pathcost %i ", (p[16] << 24) | (p[17] << 16) | (p[18] << 8) | p[19]);
  63
  64         printf("age %i ", p[30]);
  65         printf("max %i ", p[32]);
  66         printf("hello %i ", p[34]);
  67         printf("fdelay %i ", p[36]);
  68 }
  69
  70 static void
  71 stp_print_tcn_bpdu(const u_char *p, u_int length)
  72 {
  73         printf("tcn");
  74 }
  75
  76 /*
  77  * Print 802.1d packets.
  78  */
  79 void
  80 stp_print(const u_char *p, u_int length)
  81 {
  82         if (length < 7)
  83                 goto trunc;
  84
  85         printf("802.1d ");
  86         if (p[2] != 0x03 || p[3] || p[4] || p[5]) {
  87                 printf("unknown version");
  88                 return;
  89         }
  90
  91         switch (p[6])
  92         {
  93         case 0:
  94                 if (length < 10)
  95                         goto trunc;
  96                 stp_print_config_bpdu(p, length);
  97                 break;
  98
  99         case 1:
 100                 stp_print_tcn_bpdu(p, length);
 101                 break;
 102
 103         default:
 104                 printf("unknown type %i\n", p[6]);
 105                 break;
 106         }
 107
 108         return;
 109 trunc:
 110         printf("[|stp %d]", length);
 111 }