Internet on FIRE

/*

 *        BIRD -- OSPF

 *

 *        (c) 2000--2004 Ondrej Filip <feela@network.cz>

 *        (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>

 *        (c) 2009--2014 CZ.NIC z.s.p.o.

 *

 *        Can be freely distributed and used under the terms of the GNU GPL.

 */

#include "ospf.h"

/*

struct ospf_lsack_packet

{

  struct ospf_packet hdr;

  // union ospf_auth auth;

  struct ospf_lsa_header lsas[];

};

*/

struct lsa_node

{

  node n;

  struct ospf_lsa_header lsa;

};

static inline void

ospf_lsack_body(struct ospf_proto *p, struct ospf_packet *pkt,

                struct ospf_lsa_header **body, uint *count)

{

  uint plen = ntohs(pkt->length);

  uint hlen = ospf_pkt_hdrlen(p);

  *body = ((void *) pkt) + hlen;

  *count = (plen - hlen) / sizeof(struct ospf_lsa_header);

}

static void

ospf_dump_lsack(struct ospf_proto *p, struct ospf_packet *pkt)

{

  struct ospf_lsa_header *lsas;

  uint i, lsa_count;

  ASSERT(pkt->type == LSACK_P);

  ospf_dump_common(p, pkt);

  ospf_lsack_body(p, pkt, &lsas, &lsa_count);

  for (i = 0; i < lsa_count; i++)

    ospf_dump_lsahdr(p, lsas + i);

}

void

ospf_enqueue_lsack(struct ospf_neighbor *n, struct ospf_lsa_header *h_n, int queue)

{

  /* Note that h_n is in network endianity */

  struct lsa_node *no = mb_alloc(n->pool, sizeof(struct lsa_node));

  memcpy(&no->lsa, h_n, sizeof(struct ospf_lsa_header));

  add_tail(&n->ackl[queue], NODE no);

  DBG("Adding %s ack for %R, ID: %R, RT: %R, Type: %u\n",

      (queue == ACKL_DIRECT) ? "direct" : "delayed",

      n->rid, ntohl(h_n->id), ntohl(h_n->rt), h_n->type);

}

void

ospf_reset_lsack_queue(struct ospf_neighbor *n)

{

  struct lsa_node *no;

  WALK_LIST_FIRST(no, n->ackl[ACKL_DELAY])

  {

    rem_node(NODE no);

    mb_free(no);

  }

}

static inline void

ospf_send_lsack_(struct ospf_proto *p, struct ospf_neighbor *n, int queue)

{

  struct ospf_iface *ifa = n->ifa;

  struct ospf_lsa_header *lsas;

  struct ospf_packet *pkt;

  struct lsa_node *no;

  uint i, lsa_max, length;

  /* RFC 2328 13.5 */

  pkt = ospf_tx_buffer(ifa);

  ospf_pkt_fill_hdr(ifa, pkt, LSACK_P);

  ospf_lsack_body(p, pkt, &lsas, &lsa_max);

  for (i = 0; i < lsa_max && !EMPTY_LIST(n->ackl[queue]); i++)

  {

    no = (struct lsa_node *) HEAD(n->ackl[queue]);

    memcpy(&lsas[i], &no->lsa, sizeof(struct ospf_lsa_header));

    DBG("Iter %u ID: %R, RT: %R, Type: %04x\n",

        i, ntohl(lsas[i].id), ntohl(lsas[i].rt), lsas[i].type);

    rem_node(NODE no);

    mb_free(no);

  }

  length = ospf_pkt_hdrlen(p) + i * sizeof(struct ospf_lsa_header);

  pkt->length = htons(length);

  OSPF_PACKET(ospf_dump_lsack, pkt, "LSACK packet sent via %s", ifa->ifname);

  if (ifa->type == OSPF_IT_BCAST)

  {

    if ((ifa->state == OSPF_IS_DR) || (ifa->state == OSPF_IS_BACKUP))

      ospf_send_to_all(ifa);

    else

      ospf_send_to_des(ifa);

  }

  else

    ospf_send_to_agt(ifa, NEIGHBOR_EXCHANGE);

}

void

ospf_send_lsack(struct ospf_proto *p, struct ospf_neighbor *n, int queue)

{

  while (!EMPTY_LIST(n->ackl[queue]))

    ospf_send_lsack_(p, n, queue);

}

void

ospf_receive_lsack(struct ospf_packet *pkt, struct ospf_iface *ifa,

                   struct ospf_neighbor *n)

{

  struct ospf_proto *p = ifa->oa->po;

  struct ospf_lsa_header lsa, *lsas;

  struct top_hash_entry *ret, *en;

  uint i, lsa_count;

  u32 lsa_type, lsa_domain;

  /* RFC 2328 13.7 */

  /* No need to check length, lsack has only basic header */

  OSPF_PACKET(ospf_dump_lsack, pkt, "LSACK packet received from %I via %s", n->ip, ifa->ifname);

  if (n->state < NEIGHBOR_EXCHANGE)

    return;

  ospf_neigh_sm(n, INM_HELLOREC);        /* Not in RFC */

  ospf_lsack_body(p, pkt, &lsas, &lsa_count);

  for (i = 0; i < lsa_count; i++)

  {

    lsa_ntoh_hdr(&lsas[i], &lsa);

    lsa_get_type_domain(&lsa, n->ifa, &lsa_type, &lsa_domain);

    ret = ospf_hash_find(n->lsrth, lsa_domain, lsa.id, lsa.rt, lsa_type);

    if (!ret)

      continue;

    if (lsa_comp(&lsa, &ret->lsa) != CMP_SAME)

    {

      OSPF_TRACE(D_PACKETS, "Strange LSACK from %I", n->ip);

      OSPF_TRACE(D_PACKETS, "Type: %04x, Id: %R, Rt: %R",

                 lsa_type, lsa.id, lsa.rt);

      OSPF_TRACE(D_PACKETS, "I have: Age: %4u, Seq: %08x, Sum: %04x",

                 ret->lsa.age, ret->lsa.sn, ret->lsa.checksum);

      OSPF_TRACE(D_PACKETS, "He has: Age: %4u, Seq: %08x, Sum: %04x",

                 lsa.age, lsa.sn, lsa.checksum);

      continue;

    }

    en = ospf_hash_find_entry(p->gr, ret);

    if (en)

      en->ret_count--;

    DBG("Deleting LSA (Type: %04x Id: %R Rt: %R) from lsrtl for neighbor %R\n",

        lsa_type, lsa.id, lsa.rt, n->rid);

    s_rem_node(SNODE ret);

    ospf_hash_delete(n->lsrth, ret);

  }

}