eigrpd/eigrp_reply.c

   1 /*
   2  * EIGRP Sending and Receiving EIGRP Reply Packets.
   3  * Copyright (C) 2013-2016
   4  * Authors:
   5  *   Donnie Savage
   6  *   Jan Janovic
   7  *   Matej Perina
   8  *   Peter Orsag
   9  *   Peter Paluch
  10  *   Frantisek Gazo
  11  *   Tomas Hvorkovy
  12  *   Martin Kontsek
  13  *   Lukas Koribsky
  14  *
  15  * This file is part of GNU Zebra.
  16  *
  17  * GNU Zebra is free software; you can redistribute it and/or modify it
  18  * under the terms of the GNU General Public License as published by the
  19  * Free Software Foundation; either version 2, or (at your option) any
  20  * later version.
  21  *
  22  * GNU Zebra is distributed in the hope that it will be useful, but
  23  * WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  * General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License along
  28  * with this program; see the file COPYING; if not, write to the Free Software
  29  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  30  */
  31
  32 #include <zebra.h>
  33
  34 #include "thread.h"
  35 #include "memory.h"
  36 #include "linklist.h"
  37 #include "prefix.h"
  38 #include "if.h"
  39 #include "table.h"
  40 #include "sockunion.h"
  41 #include "stream.h"
  42 #include "log.h"
  43 #include "sockopt.h"
  44 #include "checksum.h"
  45 #include "md5.h"
  46 #include "vty.h"
  47 #include "keychain.h"
  48 #include "plist.h"
  49
  50 #include "eigrpd/eigrp_structs.h"
  51 #include "eigrpd/eigrpd.h"
  52 #include "eigrpd/eigrp_interface.h"
  53 #include "eigrpd/eigrp_neighbor.h"
  54 #include "eigrpd/eigrp_packet.h"
  55 #include "eigrpd/eigrp_zebra.h"
  56 #include "eigrpd/eigrp_vty.h"
  57 #include "eigrpd/eigrp_dump.h"
  58 #include "eigrpd/eigrp_macros.h"
  59 #include "eigrpd/eigrp_topology.h"
  60 #include "eigrpd/eigrp_fsm.h"
  61 #include "eigrpd/eigrp_memory.h"
  62
  63 void eigrp_send_reply(struct eigrp_neighbor *nbr, struct eigrp_prefix_entry *pe)
  64 {
  65         struct eigrp_packet *ep;
  66         u_int16_t length = EIGRP_HEADER_LEN;
  67
  68         struct access_list *alist;
  69         struct prefix_list *plist;
  70         struct access_list *alist_i;
  71         struct prefix_list *plist_i;
  72         struct eigrp *e;
  73         struct eigrp_prefix_entry *pe2;
  74
  75         // TODO: Work in progress
  76         /* Filtering */
  77         /* get list from eigrp process */
  78         e = eigrp_lookup();
  79         pe2 = XCALLOC(MTYPE_EIGRP_PREFIX_ENTRY,
  80                       sizeof(struct eigrp_prefix_entry));
  81         memcpy(pe2, pe, sizeof(struct eigrp_prefix_entry));
  82         /* Get access-lists and prefix-lists from process and interface */
  83         alist = e->list[EIGRP_FILTER_OUT];
  84         plist = e->prefix[EIGRP_FILTER_OUT];
  85         alist_i = nbr->ei->list[EIGRP_FILTER_OUT];
  86         plist_i = nbr->ei->prefix[EIGRP_FILTER_OUT];
  87
  88         /* Check if any list fits */
  89         if ((alist
  90              && access_list_apply(alist, pe2->destination)
  91                         == FILTER_DENY)
  92             || (plist
  93                 && prefix_list_apply(plist,
  94                                      pe2->destination)
  95                            == PREFIX_DENY)
  96             || (alist_i
  97                 && access_list_apply(alist_i,
  98                                      pe2->destination)
  99                            == FILTER_DENY)
 100             || (plist_i
 101                 && prefix_list_apply(plist_i,
 102                                      pe2->destination)
 103                            == PREFIX_DENY)) {
 104                 zlog_info("REPLY SEND: Setting Metric to max");
 105                 pe2->reported_metric.delay = EIGRP_MAX_METRIC;
 106
 107         }
 108
 109         /*
 110          * End of filtering
 111          */
 112
 113         ep = eigrp_packet_new(nbr->ei->ifp->mtu, nbr);
 114
 115         /* Prepare EIGRP INIT UPDATE header */
 116         eigrp_packet_header_init(EIGRP_OPC_REPLY, e, ep->s, 0,
 117                                  nbr->ei->eigrp->sequence_number, 0);
 118
 119         // encode Authentication TLV, if needed
 120         if ((IF_DEF_PARAMS(nbr->ei->ifp)->auth_type == EIGRP_AUTH_TYPE_MD5)
 121             && (IF_DEF_PARAMS(nbr->ei->ifp)->auth_keychain != NULL)) {
 122                 length += eigrp_add_authTLV_MD5_to_stream(ep->s, nbr->ei);
 123         }
 124
 125
 126         length += eigrp_add_internalTLV_to_stream(ep->s, pe2);
 127
 128         if ((IF_DEF_PARAMS(nbr->ei->ifp)->auth_type == EIGRP_AUTH_TYPE_MD5)
 129             && (IF_DEF_PARAMS(nbr->ei->ifp)->auth_keychain != NULL)) {
 130                 eigrp_make_md5_digest(nbr->ei, ep->s, EIGRP_AUTH_UPDATE_FLAG);
 131         }
 132
 133         /* EIGRP Checksum */
 134         eigrp_packet_checksum(nbr->ei, ep->s, length);
 135
 136         ep->length = length;
 137         ep->dst.s_addr = nbr->src.s_addr;
 138
 139         /*This ack number we await from neighbor*/
 140         ep->sequence_number = nbr->ei->eigrp->sequence_number;
 141
 142         /*Put packet to retransmission queue*/
 143         eigrp_fifo_push(nbr->retrans_queue, ep);
 144
 145         if (nbr->retrans_queue->count == 1) {
 146                 eigrp_send_packet_reliably(nbr);
 147         }
 148
 149         XFREE(MTYPE_EIGRP_PREFIX_ENTRY, pe2);
 150 }
 151
 152 /*EIGRP REPLY read function*/
 153 void eigrp_reply_receive(struct eigrp *eigrp, struct ip *iph,
 154                          struct eigrp_header *eigrph, struct stream *s,
 155                          struct eigrp_interface *ei, int size)
 156 {
 157         struct eigrp_neighbor *nbr;
 158         struct TLV_IPv4_Internal_type *tlv;
 159
 160         struct access_list *alist;
 161         struct prefix_list *plist;
 162         struct access_list *alist_i;
 163         struct prefix_list *plist_i;
 164         struct eigrp *e;
 165
 166         u_int16_t type;
 167
 168         /* increment statistics. */
 169         ei->reply_in++;
 170
 171         /* get neighbor struct */
 172         nbr = eigrp_nbr_get(ei, eigrph, iph);
 173
 174         /* neighbor must be valid, eigrp_nbr_get creates if none existed */
 175         assert(nbr);
 176
 177         nbr->recv_sequence_number = ntohl(eigrph->sequence);
 178
 179         while (s->endp > s->getp) {
 180                 type = stream_getw(s);
 181                 if (type == EIGRP_TLV_IPv4_INT) {
 182                         struct prefix dest_addr;
 183
 184                         stream_set_getp(s, s->getp - sizeof(u_int16_t));
 185
 186                         tlv = eigrp_read_ipv4_tlv(s);
 187
 188                         dest_addr.family = AF_INET;
 189                         dest_addr.u.prefix4 = tlv->destination;
 190                         dest_addr.prefixlen = tlv->prefix_length;
 191                         struct eigrp_prefix_entry *dest =
 192                                 eigrp_topology_table_lookup_ipv4(
 193                                         eigrp->topology_table, &dest_addr);
 194                         /*
 195                          * Destination must exists
 196                          */
 197                         assert(dest);
 198
 199                         struct eigrp_fsm_action_message msg;
 200                         struct eigrp_neighbor_entry *entry =
 201                                 eigrp_prefix_entry_lookup(dest->entries, nbr);
 202
 203                         /*
 204                          * Filtering
 205                          */
 206                         // TODO: Work in progress
 207                         /* get list from eigrp process */
 208                         e = eigrp_lookup();
 209                         /* Get access-lists and prefix-lists from process and
 210                          * interface */
 211                         alist = e->list[EIGRP_FILTER_IN];
 212                         plist = e->prefix[EIGRP_FILTER_IN];
 213                         alist_i = ei->list[EIGRP_FILTER_IN];
 214                         plist_i = ei->prefix[EIGRP_FILTER_IN];
 215                         /* Check if any list fits */
 216                         if ((alist
 217                              && access_list_apply(alist,
 218                                                   (struct prefix *)&dest_addr)
 219                                         == FILTER_DENY)
 220                             || (plist
 221                                 && prefix_list_apply(
 222                                            plist, (struct prefix *)&dest_addr)
 223                                            == PREFIX_DENY)
 224                             || (alist_i
 225                                 && access_list_apply(
 226                                            alist_i, (struct prefix *)&dest_addr)
 227                                            == FILTER_DENY)
 228                             || (plist_i
 229                                 && prefix_list_apply(
 230                                            plist_i, (struct prefix *)&dest_addr)
 231                                            == PREFIX_DENY)) {
 232                                 tlv->metric.delay = EIGRP_MAX_METRIC;
 233                         }
 234                         /*
 235                          * End of filtering
 236                          */
 237
 238                         msg.packet_type = EIGRP_OPC_REPLY;
 239                         msg.eigrp = eigrp;
 240                         msg.data_type = EIGRP_INT;
 241                         msg.adv_router = nbr;
 242                         msg.metrics = tlv->metric;
 243                         msg.entry = entry;
 244                         msg.prefix = dest;
 245                         eigrp_fsm_event(&msg);
 246
 247
 248                         eigrp_IPv4_InternalTLV_free(tlv);
 249                 }
 250         }
 251         eigrp_hello_send_ack(nbr);
 252 }