src/mops_ext_arp.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_arp(struct mops *mp)
  28 {
  29
  30    struct mops_ext_arp * pd;
  31
  32    char tmac[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
  33
  34    if (mp->p_desc == NULL) return 1;  // p_desc not properly assigned
  35
  36    pd = mp->p_desc;
  37
  38    pd->hw_type   = 0x0001;
  39    pd->pr_type   = 0x800;
  40    pd->hw_size   = 6;
  41    pd->pr_size   = 4;
  42    pd->opcode    = 0x0001; // request
  43    memcpy ((void*) pd->sender_mac, (void*) tx.eth_src, 6);
  44    memcpy ((void*) pd->target_mac, (void*) tmac, 6);
  45    memcpy ((void*) pd->sender_ip,  (void*) &tx.ip_src, 4);
  46    memcpy ((void*) pd->target_ip,  (void*) &tx.ip_src, 4);
  47
  48    pd->trailer = 18; // default is 18 byte trailer to get a 60 byte packet (instead of only 42)
  49
  50    return 0;
  51 }
  52
  53
  54
  55
  56
  57
  58
  59
  60 /////////////////////////////////////////////////////////////////////////////////
  61 /////////////////////////////// Update functions ////////////////////////////////
  62 //
  63 // **** Here is a summary of mops tool functions: ****
  64 //
  65 // Adds single byte to msg
  66 // int mops_msg_add_byte (struct mops *mp, u_int8_t data);
  67 //
  68 // Adds bit field in *previous* msg-byte using optional left-shift
  69 // int mops_msg_add_field (struct mops *mp, u_int8_t data, int shift);
  70 //
  71 // Adds two bytes in network byte order to msg
  72 // int mops_msg_add_2bytes (struct mops *mp, u_int16_t data);
  73 //
  74 // Adds four bytes in network byte order to msg
  75 // int mops_msg_add_4bytes (struct mops *mp, u_int32_t data);
  76 //
  77 // Adds string of bytes with lenght len
  78 // int mops_msg_add_string (struct mops *mp, u_int8_t *str, int len);
  79 //
  80 // Add counter to message
  81 // int mops_msg_add_counter (struct mops *mp,
  82 //                        int         random,  // 1=random, 0=use start/stop/step
  83 //                        u_int32_t   start,   // HOST BYTE ORDER
  84 //                        u_int32_t   stop,    // HOST BYTE ORDER
  85 //                        u_int32_t   step,    // HOST BYTE ORDER
  86 //                        int         bytes   // number of bytes used (1|2|4) - selects hton2 or hton4
  87 //                        );
  88 //
  89 //
  90
  91
  92 int mops_update_arp(struct mops * mp)
  93 {
  94
  95    struct mops_ext_arp * pd;
  96    int i;
  97
  98    pd = mp->p_desc;
  99    if (pd==NULL) return 1;  // no valid pointer to a p_desc
 100
 101    mp->msg_s = 0; // important! Otherwise the msg would get longer and longer after each call!
 102
 103    mops_msg_add_2bytes (mp, pd->hw_type);
 104    mops_msg_add_2bytes (mp, pd->pr_type);
 105    mops_msg_add_byte (mp, pd->hw_size);
 106    mops_msg_add_byte (mp, pd->pr_size);
 107    mops_msg_add_2bytes (mp, pd->opcode);
 108    mops_msg_add_string (mp, pd->sender_mac, 6);
 109    mops_msg_add_string (mp, pd->sender_ip, 4);
 110    mops_msg_add_string (mp, pd->target_mac, 6);
 111    mops_msg_add_string (mp, pd->target_ip, 4);
 112
 113    // Avoid buffer problems:
 114    if (pd->trailer>2000)
 115      {
 116         pd->trailer=2000;
 117      }
 118
 119    for (i=0; i<pd->trailer; i++)
 120      {
 121         mops_msg_add_byte (mp, 0x00);
 122      }
 123
 124    return 0;
 125 }
 126
 127
 128
 129 // ARP Service: Resolves MAC address of given IP address and interface
 130 // The result is stored in the last argument 'mac'.
 131 //
 132 // EXAMPLE:
 133 //
 134 //   u_int8_t mymac[6];
 135 //   int ip[4]={192,186,0,1};
 136 //
 137 //   service_arp("eth0", ip, mymac);
 138 //   /* now mymac should contain the MAC address */
 139 //
 140 // RETURN VALUE: 0 upon success
 141 //               1 upon error
 142 //
 143 int service_arp(char *dev, u_int8_t *ip, u_int8_t *mac)
 144 {
 145         int i, devind=0, dev_found=0;
 146         struct mops * mp;
 147         struct mops_ext_arp * pd;
 148         char tmac[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 149         struct arp_table_struct *cur;
 150
 151         // MOPS framework already available?
 152         if (mp_head==NULL) return 1;
 153
 154         // Get list index for that device:
 155         for (i=0; i<device_list_entries; i++) {
 156                 if (strncmp(device_list[i].dev, dev, 16)==0) {
 157                         devind=i;
 158                         dev_found=1;
 159                         break;
 160                 }
 161         }
 162         if (dev_found==0) {
 163                 fprintf(stderr, " Warning: Unknown device (sysARP_service)\n");
 164                 return 1; // ERROR: device name not found !!!!
 165         } else {
 166                 if (verbose) {
 167                         fprintf(stderr, " sysARP_service triggered through interface %s\n", dev);
 168                 }
 169         }
 170
 171         // Look up mops table if already a sysARP packet is available
 172         mp = mops_search_name (mp_head, "sysARP_service");
 173         if (mp!=NULL) { // entry exists...stop if active!
 174                 if (mops_state(mp)==MOPS_STATE_ACTIVE) {
 175                         if (verbose==2) fprintf(stderr, " Warning: Stop active MOPS (sysARP_service)\n");
 176                         mops_destroy_thread(mp);
 177                 }
 178         } else {
 179                 // Allocate a new packet
 180                 if ((mp = mops_alloc_packet(mp_head)) == NULL) {
 181                         fprintf(stderr, " sysARP_service: ERROR -- cannot allocate MOPS\n");
 182                         return 1; // Problem, memory full?
 183                 } else {
 184                         strncpy (mp->packet_name, "sysARP_service", 15);
 185                         mp->mz_system=1; // indicates MZ private packet
 186                         if (mops_ext_add_pdesc (mp, MOPS_ARP)) {
 187                                 return 1; // error
 188                         }
 189                 }
 190         }
 191
 192         // Configure ARP request:
 193         mops_clear_layers(mp, MOPS_ALL);
 194         mops_init_pdesc_arp(mp);
 195
 196         mp->verbose = 0;
 197         mp->use_ETHER = 1;
 198         mp->count = 1;
 199         mp->eth_type = 0x806;
 200         mz_strncpy(mp->device, dev, 16);
 201
 202         pd = mp->p_desc;
 203         memcpy ((void*) pd->sender_mac, (void*) device_list[devind].mac_mops, 6);
 204         memcpy ((void*) pd->target_mac, (void*) tmac, 6);
 205         memcpy ((void*) pd->sender_ip,  (void*) device_list[devind].ip_mops, 4);
 206         pd->target_ip[0]=ip[0];
 207         pd->target_ip[1]=ip[1];
 208         pd->target_ip[2]=ip[2];
 209         pd->target_ip[3]=ip[3];
 210
 211         mops_update_arp(mp);
 212         mops_set_conf(mp);
 213
 214         // Send ARP request
 215
 216         if (mops_tx_simple (mp)) {
 217                 fprintf(stderr, " Warning: sysARP_service failed!\n");
 218                 return 1;
 219         }
 220
 221         usleep(100000); // wait 100 ms
 222         // Now hopefully we got an ARP response;
 223         // look up in ARP cache
 224
 225         cur=device_list[devind].arp_table;
 226         while(cur!=NULL) {
 227                 if ((cur->sip[0]==ip[0]) &&
 228                     (cur->sip[1]==ip[1]) &&
 229                     (cur->sip[2]==ip[2]) &&
 230                     (cur->sip[3]==ip[3])) { // entry found!
 231                         for (i=0; i<6; i++) {
 232                                 mac[i] = cur->smac[i];
 233                         }
 234                 }
 235                 cur=cur->next;
 236         }
 237
 238         return 0;
 239 }