src/mops_ext_bpdu.c

   1 /*
   2  * Mausezahn - A fast versatile traffic generator
   3  * Copyright (C) 2008-2010 Herbert Haas
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License version 2 as published by the
   7  * Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  11  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
  12  * details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, see http://www.gnu.org/licenses/gpl-2.0.html
  16  *
  17 */
  18
  19
  20
  21 #include "mz.h"
  22 #include "mops.h"
  23
  24
  25 // Initialization function - specify defaults here!
  26 //
  27 int mops_init_pdesc_bpdu(struct mops *mp)
  28 {
  29         struct mops_ext_bpdu * pd;
  30         int i;
  31
  32
  33         if (mp->p_desc == NULL) return 1;  // p_desc not properly assigned
  34         pd = mp->p_desc;
  35
  36         // 1. - Initialize Ethernet header
  37         str2hex("01:80:C2:00:00:00",mp->eth_dst, 6);
  38
  39         // 2. - Initialize BPDU fields
  40         pd->id = 0;
  41         pd->version = 0;           // 0=802.1D, 2=RSTP(802.1w)
  42         pd->bpdu_type = 0x80;      // 0=conf, 0x80=topology change, 2=RSTP/MSTP
  43         pd->flags = 0;             // X... .... = TCN ACK
  44                               // .X.. .... = Agreement
  45                               // ..X. .... = Forwarding
  46                               // ...X .... = Learning
  47                               // .... XX.. = Port Role (e. g. 11=Desgn)
  48                               // .... ..X. = Proposal
  49                               // .... ...X = TCN
  50
  51         i = mops_get_device_index(tx.device);
  52         if (i!=-1) { // found
  53                 memcpy((void*) &pd->root_id[2], (void*) device_list[i].mac_mops, 6);
  54                 memcpy((void*) &pd->bridge_id[2], (void*) device_list[i].mac_mops, 6);
  55         } else {
  56                 str2hex("00:00:00:00:00:00", &pd->root_id[2], 6);
  57                 str2hex("00:00:00:00:00:00", &pd->bridge_id[2], 6);
  58         }
  59
  60         pd->root_id[0] = 0x00;
  61         pd->root_id[1] = 0x00;
  62
  63         pd->bridge_id[0] = 0x00;
  64         pd->bridge_id[1] = 0x00;
  65
  66         pd->root_pc = 0;       // Root Path Cost
  67         pd->port_id = 0;       // Port Identifier
  68         pd->message_age = 0;   // All timers are multiples of 1/256 sec. Thus times range from 0 to 256 seconds.
  69         pd->max_age = 5120;    // 20 seconds
  70         pd->hello_time = 512;
  71         pd->f_delay = 3840;
  72
  73         str2hex("00:00:00:00:00:00:00:00", pd->trailer, 8);
  74         // either all-zero or 00:00:00:00:02:VLAN(16bit) when PVST+
  75         pd->rstp = 0; // 1 = RSTP
  76         pd->pvst = 0; // 1=PVST+ , 0 = 802.1D
  77         pd->mstp = 0; // 1 = Multiple Instance STP
  78
  79         return 0;
  80 }
  81
  82
  83 /////////////////////////////////////////////////////////////////////////////////
  84 /////////////////////////////// Update functions ////////////////////////////////
  85 //
  86 // **** Here is a summary of mops tool functions: ****
  87 //
  88 // Adds single byte to msg
  89 // int mops_msg_add_byte (struct mops *mp, u_int8_t data);
  90 //
  91 // Adds bit field in *previous* msg-byte using optional left-shift
  92 // int mops_msg_add_field (struct mops *mp, u_int8_t data, int shift);
  93 //
  94 // Adds two bytes in network byte order to msg
  95 // int mops_msg_add_2bytes (struct mops *mp, u_int16_t data);
  96 //
  97 // Adds four bytes in network byte order to msg
  98 // int mops_msg_add_4bytes (struct mops *mp, u_int32_t data);
  99 //
 100 // Adds string of bytes with lenght len
 101 // int mops_msg_add_string (struct mops *mp, u_int8_t *str, int len);
 102
 103 int mops_update_bpdu(struct mops * mp)
 104 {
 105
 106    struct mops_ext_bpdu * pd;
 107
 108    pd = mp->p_desc;
 109    if (pd==NULL) return 1;  // no valid pointer to a p_desc
 110    mp->msg_s = 0; // important! Otherwise the msg would get longer and longer after each call!
 111
 112
 113    // NOTE: the length field does not include the trailer!
 114    if (pd->pvst)
 115      {
 116         str2hex("01:00:0C:CC:CC:CD", mp->eth_dst, 6);
 117         mp->eth_len=50;
 118         str2hex("aa:aa:03:00:00:0c:01:0b",mp->eth_snap, 8);
 119         mp->eth_snap_s = 8;
 120      }
 121    else
 122      {
 123         str2hex("01:80:C2:00:00:00",mp->eth_dst, 6);
 124         mp->eth_len=38;
 125         str2hex("42:42:03",mp->eth_snap, 3);
 126         mp->eth_snap_s = 3;
 127      }
 128
 129    mops_msg_add_2bytes (mp, pd->id);
 130    mops_msg_add_byte (mp, pd->version);
 131    mops_msg_add_byte (mp, pd->bpdu_type);
 132
 133    if (pd->bpdu_type & 0x80) // if TCN then don't add more fields
 134      {
 135            if (pd->pvst) mp->eth_len=12; else mp->eth_len=7;
 136      }
 137    else
 138      {
 139         mops_msg_add_byte (mp, pd->flags);
 140         mops_msg_add_string (mp, pd->root_id, 8);
 141         mops_msg_add_4bytes (mp, pd->root_pc);
 142         mops_msg_add_string (mp, pd->bridge_id, 8);
 143         mops_msg_add_2bytes (mp, pd->port_id);
 144         mops_msg_add_2bytes (mp, pd->message_age);
 145         mops_msg_add_2bytes (mp, pd->max_age);
 146         mops_msg_add_2bytes (mp, pd->hello_time);
 147         mops_msg_add_2bytes (mp, pd->f_delay);
 148      }
 149
 150    // we always add the trailer
 151    mops_msg_add_string (mp, pd->trailer, 8);
 152
 153    return 0;
 154 }
 155
 156
 157
 158 // Create RID or BID based on priority, ext-sys-id, and MAC address.
 159 // The last parameter selects BID (0) or RID (1)
 160 //
 161 // pri .... 0-15
 162 // esi .... 0-4095
 163 // mac .... XX:XX:XX:XX:XX:XX or interface name
 164 //
 165 // NOTE: Invalid parameters will result in default values
 166 //
 167 // RETURN VALUE: Only informational; identifies which parameter
 168 // was errourness, using the following values:
 169 //
 170 //   0 ... all parameters valid
 171 //   1 ... priority exceeded range
 172 //   2 ... ext-sys-id exceeded range
 173 //   3 ... invalid MAC address or invalid interface
 174 //   4 ... other
 175
 176 int mops_create_bpdu_bid(struct mops * mp, int pri, int esi, char *mac, int bid_or_rid)
 177 {
 178         int i;
 179         struct mops_ext_bpdu * pd = mp->p_desc;
 180         u_int8_t rid[8];
 181         u_int16_t p16;
 182
 183         if ((pri<0)||(pri>15)) return 1;
 184         if ((esi<0)||(esi>4095)) return 2;
 185
 186         if (mac!=NULL) {
 187                 // first check if an interface is specified:
 188                 i = mops_get_device_index(mac);
 189                 if (i!=-1) { // found
 190                         memcpy((void*) &rid[2], (void*) device_list[i].mac_mops, 6);
 191                 }
 192                 else { // MAC address given?
 193                         if (mops_pdesc_mac(&rid[2], mac)) {
 194                                 return 3;
 195                         }
 196                 }
 197         } else { // mac==NULL
 198                 // use MAC of default interface!
 199                 i = mops_get_device_index(tx.device);
 200                 if (i!=-1) { // found
 201                         memcpy((void*) &rid[2], (void*) device_list[i].mac_mops, 6);
 202                 }
 203                 else {
 204                         str2hex("00:00:00:00:00:00", &rid[2], 6);
 205                         return 4;
 206                 }
 207         }
 208
 209         // now prepend pri, esi
 210
 211         p16 = pri;
 212         p16 <<= 12;
 213         p16 |= esi;
 214
 215         mops_hton2 (&p16, &rid[0]);
 216         if (bid_or_rid)
 217                 memcpy((void*) pd->root_id, (void*) rid, 8);
 218         else
 219                 memcpy((void*) pd->bridge_id, (void*) rid, 8);
 220         return 0;
 221 }
 222
 223
 224 int mops_create_bpdu_trailer (struct mops * mp, u_int16_t vlan)
 225 {
 226         struct mops_ext_bpdu * pd = mp->p_desc;
 227
 228         // PVST+ requires a trailer with either all-zero
 229         // or 00:00:00:00:02:VLAN(16bit)
 230
 231         // trailer already initialized with zeroes
 232         pd->trailer[0]=0x00;
 233         pd->trailer[1]=0x00;
 234         pd->trailer[2]=0x00;
 235         pd->trailer[3]=0x00;
 236         pd->trailer[4]=0x02;
 237         pd->trailer[5]=0x00;
 238         pd->trailer[6]=0x00;
 239         mops_hton2 (&vlan, &pd->trailer[5]);
 240
 241    return 0;
 242 }