eigrpd/eigrp_siareply.c

   1 /*
   2  * EIGRP Sending and Receiving EIGRP SIA-Reply Packets.
   3  * Copyright (C) 2013-2014
   4  * Authors:
   5  *   Donnie Savage
   6  *   Jan Janovic
   7  *   Matej Perina
   8  *   Peter Orsag
   9  *   Peter Paluch
  10  *
  11  * This file is part of GNU Zebra.
  12  *
  13  * GNU Zebra is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License as published by the
  15  * Free Software Foundation; either version 2, or (at your option) any
  16  * later version.
  17  *
  18  * GNU Zebra is distributed in the hope that it will be useful, but
  19  * WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  * General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; see the file COPYING; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  26  */
  27 #include <zebra.h>
  28
  29 #include "thread.h"
  30 #include "memory.h"
  31 #include "linklist.h"
  32 #include "prefix.h"
  33 #include "if.h"
  34 #include "table.h"
  35 #include "sockunion.h"
  36 #include "stream.h"
  37 #include "log.h"
  38 #include "sockopt.h"
  39 #include "checksum.h"
  40 #include "md5.h"
  41 #include "vty.h"
  42
  43 #include "eigrpd/eigrp_structs.h"
  44 #include "eigrpd/eigrpd.h"
  45 #include "eigrpd/eigrp_interface.h"
  46 #include "eigrpd/eigrp_neighbor.h"
  47 #include "eigrpd/eigrp_packet.h"
  48 #include "eigrpd/eigrp_zebra.h"
  49 #include "eigrpd/eigrp_vty.h"
  50 #include "eigrpd/eigrp_dump.h"
  51 #include "eigrpd/eigrp_macros.h"
  52 #include "eigrpd/eigrp_topology.h"
  53 #include "eigrpd/eigrp_fsm.h"
  54 #include "eigrpd/eigrp_memory.h"
  55
  56 /*EIGRP SIA-REPLY read function*/
  57 void
  58 eigrp_siareply_receive (struct eigrp *eigrp, struct ip *iph, struct eigrp_header *eigrph,
  59                         struct stream * s, struct eigrp_interface *ei, int size)
  60 {
  61   struct eigrp_neighbor *nbr;
  62   struct TLV_IPv4_Internal_type *tlv;
  63
  64   u_int16_t type;
  65
  66   /* increment statistics. */
  67   ei->siaReply_in++;
  68
  69   /* get neighbor struct */
  70   nbr = eigrp_nbr_get(ei, eigrph, iph);
  71
  72   /* neighbor must be valid, eigrp_nbr_get creates if none existed */
  73   assert(nbr);
  74
  75   nbr->recv_sequence_number = ntohl(eigrph->sequence);
  76
  77   while (s->endp > s->getp)
  78     {
  79       type = stream_getw(s);
  80       if (type == EIGRP_TLV_IPv4_INT)
  81         {
  82           struct prefix_ipv4 dest_addr;
  83
  84           stream_set_getp(s, s->getp - sizeof(u_int16_t));
  85
  86           tlv = eigrp_read_ipv4_tlv(s);
  87
  88           dest_addr.family = AFI_IP;
  89           dest_addr.prefix = tlv->destination;
  90           dest_addr.prefixlen = tlv->prefix_length;
  91           struct eigrp_prefix_entry *dest =
  92             eigrp_topology_table_lookup_ipv4(eigrp->topology_table, &dest_addr);
  93
  94           /* If the destination exists (it should, but one never know)*/
  95           if (dest != NULL)
  96             {
  97               struct eigrp_fsm_action_message *msg;
  98               msg = XCALLOC(MTYPE_EIGRP_FSM_MSG,
  99                             sizeof(struct eigrp_fsm_action_message));
 100               struct eigrp_neighbor_entry *entry =
 101                 eigrp_prefix_entry_lookup(dest->entries, nbr);
 102               msg->packet_type = EIGRP_OPC_SIAQUERY;
 103               msg->eigrp = eigrp;
 104               msg->data_type = EIGRP_TLV_IPv4_INT;
 105               msg->adv_router = nbr;
 106               msg->data.ipv4_int_type = tlv;
 107               msg->entry = entry;
 108               msg->prefix = dest;
 109               int event = eigrp_get_fsm_event(msg);
 110               eigrp_fsm_event(msg, event);
 111             }
 112           eigrp_IPv4_InternalTLV_free (tlv);
 113         }
 114     }
 115   eigrp_hello_send_ack(nbr);
 116 }
 117
 118 void
 119 eigrp_send_siareply (struct eigrp_neighbor *nbr, struct eigrp_prefix_entry *pe)
 120 {
 121   struct eigrp_packet *ep;
 122   u_int16_t length = EIGRP_HEADER_LEN;
 123
 124   ep = eigrp_packet_new(nbr->ei->ifp->mtu);
 125
 126   /* Prepare EIGRP INIT UPDATE header */
 127   eigrp_packet_header_init(EIGRP_OPC_SIAREPLY, nbr->ei, ep->s, 0,
 128                            nbr->ei->eigrp->sequence_number, 0);
 129
 130   // encode Authentication TLV, if needed
 131   if((IF_DEF_PARAMS (nbr->ei->ifp)->auth_type == EIGRP_AUTH_TYPE_MD5) &&
 132      (IF_DEF_PARAMS (nbr->ei->ifp)->auth_keychain != NULL))
 133     {
 134       length += eigrp_add_authTLV_MD5_to_stream(ep->s,nbr->ei);
 135     }
 136
 137   length += eigrp_add_internalTLV_to_stream(ep->s, pe);
 138
 139   if((IF_DEF_PARAMS (nbr->ei->ifp)->auth_type == EIGRP_AUTH_TYPE_MD5) &&
 140      (IF_DEF_PARAMS (nbr->ei->ifp)->auth_keychain != NULL))
 141     {
 142       eigrp_make_md5_digest(nbr->ei,ep->s, EIGRP_AUTH_UPDATE_FLAG);
 143     }
 144
 145   /* EIGRP Checksum */
 146   eigrp_packet_checksum(nbr->ei, ep->s, length);
 147
 148   ep->length = length;
 149   ep->dst.s_addr = nbr->src.s_addr;
 150
 151   /*This ack number we await from neighbor*/
 152   ep->sequence_number = nbr->ei->eigrp->sequence_number;
 153
 154   if (nbr->state == EIGRP_NEIGHBOR_UP)
 155     {
 156       /*Put packet to retransmission queue*/
 157       eigrp_fifo_push_head(nbr->retrans_queue, ep);
 158
 159       if (nbr->retrans_queue->count == 1)
 160         {
 161           eigrp_send_packet_reliably(nbr);
 162         }
 163     }
 164   else
 165     eigrp_packet_free(ep);
 166 }
 167
 168