[thirdparty/bird.git] / proto / ospf / dbdes.c

/*
 *	BIRD -- OSPF
 *
 *	(c) 1999--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_dbdes2_packet
{
  struct ospf_packet hdr;
  union ospf_auth2 auth;

  u16 iface_mtu;
  u8 options;
  u8 imms;			/* I, M, MS bits */
  u32 ddseq;

  struct ospf_lsa_header lsas[];
};

struct ospf_dbdes3_packet
{
  struct ospf_packet hdr;

  u32 options;
  u16 iface_mtu;
  u8 padding;
  u8 imms;			/* I, M, MS bits */
  u32 ddseq;

  struct ospf_lsa_header lsas[];
};


uint
ospf_dbdes3_options(struct ospf_packet *pkt)
{
  struct ospf_dbdes3_packet *ps = (void *) pkt;
  return ntohl(ps->options);
}

static inline uint
ospf_dbdes_hdrlen(struct ospf_proto *p)
{
  return ospf_is_v2(p) ?
    sizeof(struct ospf_dbdes2_packet) : sizeof(struct ospf_dbdes3_packet);
}

static void
ospf_dbdes_body(struct ospf_proto *p, struct ospf_packet *pkt,
		struct ospf_lsa_header **body, uint *count)
{
  uint plen = ntohs(pkt->length);
  uint hlen = ospf_dbdes_hdrlen(p);

  *body = ((void *) pkt) + hlen;
  *count = (plen - hlen) / sizeof(struct ospf_lsa_header);
}

static void
ospf_dump_dbdes(struct ospf_proto *p, struct ospf_packet *pkt)
{
  struct ospf_lsa_header *lsas;
  uint i, lsa_count;
  u32 pkt_ddseq;
  u16 pkt_iface_mtu;
  u8 pkt_imms;

  ASSERT(pkt->type == DBDES_P);
  ospf_dump_common(p, pkt);

  if (ospf_is_v2(p))
  {
    struct ospf_dbdes2_packet *ps = (void *) pkt;
    pkt_iface_mtu = ntohs(ps->iface_mtu);
    pkt_imms = ps->imms;
    pkt_ddseq = ntohl(ps->ddseq);
  }
  else /* OSPFv3 */
  {
    struct ospf_dbdes3_packet *ps = (void *) pkt;
    pkt_iface_mtu = ntohs(ps->iface_mtu);
    pkt_imms = ps->imms;
    pkt_ddseq = ntohl(ps->ddseq);
  }

  log(L_TRACE "%s:     mtu      %u", p->p.name, pkt_iface_mtu);
  log(L_TRACE "%s:     imms     %s%s%s", p->p.name,
      (pkt_imms & DBDES_I) ? "I " : "",
      (pkt_imms & DBDES_M) ? "M " : "",
      (pkt_imms & DBDES_MS) ? "MS" : "");
  log(L_TRACE "%s:     ddseq    %u", p->p.name, pkt_ddseq);

  ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
  for (i = 0; i < lsa_count; i++)
    ospf_dump_lsahdr(p, lsas + i);
}


static void
ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
  struct ospf_iface *ifa = n->ifa;
  struct ospf_packet *pkt;
  uint length;

  u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu;

  /* Update DBDES buffer */
  if (n->ldd_bsize != ifa->tx_length)
  {
    mb_free(n->ldd_buffer);
    n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length);
    n->ldd_bsize = ifa->tx_length;
  }

  pkt = n->ldd_buffer;
  ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);

  if (ospf_is_v2(p))
  {
    struct ospf_dbdes2_packet *ps = (void *) pkt;
    ps->iface_mtu = htons(iface_mtu);
    ps->options = ifa->oa->options | OPT_O;
    ps->imms = 0;	/* Will be set later */
    ps->ddseq = htonl(n->dds);
    length = sizeof(struct ospf_dbdes2_packet);
  }
  else /* OSPFv3 */
  {
    struct ospf_dbdes3_packet *ps = (void *) pkt;
    ps->options = htonl(ifa->oa->options | (ifa->autype == OSPF_AUTH_CRYPT ? OPT_AT : 0));
    ps->iface_mtu = htons(iface_mtu);
    ps->padding = 0;
    ps->imms = 0;	/* Will be set later */
    ps->ddseq = htonl(n->dds);
    length = sizeof(struct ospf_dbdes3_packet);
  }

  /* Prepare DBDES body */
  if (!(n->myimms & DBDES_I) && (n->myimms & DBDES_M))
  {
    struct ospf_lsa_header *lsas;
    struct top_hash_entry *en;
    uint i = 0, lsa_max;

    ospf_dbdes_body(p, pkt, &lsas, &lsa_max);
    en = (void *) s_get(&(n->dbsi));

    while (i < lsa_max)
    {
      if (!SNODE_VALID(en))
      {
	n->myimms &= ~DBDES_M;	/* Unset More bit */
	break;
      }

      if ((en->lsa.age < LSA_MAXAGE) &&
	  lsa_flooding_allowed(en->lsa_type, en->domain, ifa) &&
	  lsa_is_acceptable(en->lsa_type, n, p))
      {
	lsa_hton_hdr(&(en->lsa), lsas + i);
	i++;
      }

      en = SNODE_NEXT(en);
    }

    s_put(&(n->dbsi), SNODE en);

    length += i * sizeof(struct ospf_lsa_header);
  }

  if (ospf_is_v2(p))
    ((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms;
  else
    ((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms;

  pkt->length = htons(length);
}

static void
ospf_do_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
  struct ospf_iface *ifa = n->ifa;

  OSPF_PACKET(ospf_dump_dbdes, n->ldd_buffer,
	      "DBDES packet sent to nbr %R on %s", n->rid, ifa->ifname);
  sk_set_tbuf(ifa->sk, n->ldd_buffer);
  ospf_send_to(ifa, n->ip);
  sk_set_tbuf(ifa->sk, NULL);
}

/**
 * ospf_send_dbdes - transmit database description packet
 * @p: OSPF protocol instance
 * @n: neighbor
 *
 * Sending of a database description packet is described in 10.8 of RFC 2328.
 * Reception of each packet is acknowledged in the sequence number of another.
 * When I send a packet to a neighbor I keep a copy in a buffer. If the neighbor
 * does not reply, I don't create a new packet but just send the content
 * of the buffer.
 */
void
ospf_send_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
  /* RFC 2328 10.8 */

  ASSERT((n->state == NEIGHBOR_EXSTART) || (n->state == NEIGHBOR_EXCHANGE));

  if (n->ifa->oa->rt == NULL)
    return;

  ospf_prepare_dbdes(p, n);
  ospf_do_send_dbdes(p, n);
}

void
ospf_rxmt_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
{
  ASSERT(n->state > NEIGHBOR_EXSTART);

  if (!n->ldd_buffer)
  {
    log(L_WARN "%s: No DBDES packet for retransmit", p->p.name);
    ospf_neigh_sm(n, INM_SEQMIS);
    return;
  }

  /* Send last packet */
  ospf_do_send_dbdes(p, n);
}

static int
ospf_process_dbdes(struct ospf_proto *p, struct ospf_packet *pkt, struct ospf_neighbor *n)
{
  struct ospf_iface *ifa = n->ifa;
  struct ospf_lsa_header *lsas, lsa;
  struct top_hash_entry *en, *req;
  const char *err_dsc = NULL;
  u32 lsa_type, lsa_domain;
  uint i, lsa_count;

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

  for (i = 0; i < lsa_count; i++)
  {
    lsa_ntoh_hdr(lsas + i, &lsa);
    lsa_get_type_domain(&lsa, ifa, &lsa_type, &lsa_domain);

    /* RFC 2328 10.6 and RFC 5340 4.2.2 */

    if (!lsa_type)
      DROP1("LSA of unknown type");

    if (!oa_is_ext(ifa->oa) && (LSA_SCOPE(lsa_type) == LSA_SCOPE_AS))
      DROP1("LSA with AS scope in stub area");

    /* Errata 3746 to RFC 2328 - rt-summary-LSAs forbidden in stub areas */
    if (!oa_is_ext(ifa->oa) && (lsa_type == LSA_T_SUM_RT))
      DROP1("rt-summary-LSA in stub area");

    /* Not explicitly mentioned in RFC 5340 4.2.2 but makes sense */
    if (LSA_SCOPE(lsa_type) == LSA_SCOPE_RES)
      DROP1("LSA with invalid scope");

    en = ospf_hash_find(p->gr, lsa_domain, lsa.id, lsa.rt, lsa_type);
    if (!en || (lsa_comp(&lsa, &(en->lsa)) == CMP_NEWER))
    {
      /* This should be splitted to ospf_lsa_lsrq_up() */
      req = ospf_hash_get(n->lsrqh, lsa_domain, lsa.id, lsa.rt, lsa_type);

      if (!SNODE_VALID(req))
	s_add_tail(&n->lsrql, SNODE req);

      if (!SNODE_VALID(n->lsrqi))
	n->lsrqi = req;

      req->lsa = lsa;
      req->lsa_body = LSA_BODY_DUMMY;

      if (!tm_active(n->lsrq_timer))
	tm_start(n->lsrq_timer, 0);
    }
  }

  return 0;

drop:
  LOG_LSA1("Bad LSA (Type: %04x, Id: %R, Rt: %R) in DBDES", lsa_type, lsa.id, lsa.rt);
  LOG_LSA2("  received from nbr %R on %s - %s", n->rid, ifa->ifname, err_dsc);

  ospf_neigh_sm(n, INM_SEQMIS);
  return -1;
}

void
ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
		   struct ospf_neighbor *n)
{
  struct ospf_proto *p = ifa->oa->po;
  const char *err_dsc = NULL;
  u32 rcv_ddseq, rcv_options;
  u16 rcv_iface_mtu;
  u8 rcv_imms;
  uint plen, err_val = 0;

  /* RFC 2328 10.6 */

  plen = ntohs(pkt->length);
  if (plen < ospf_dbdes_hdrlen(p))
  {
    LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen);
    return;
  }

  OSPF_PACKET(ospf_dump_dbdes, pkt, "DBDES packet received from nbr %R on %s", n->rid, ifa->ifname);

  ospf_neigh_sm(n, INM_HELLOREC);

  if (ospf_is_v2(p))
  {
    struct ospf_dbdes2_packet *ps = (void *) pkt;
    rcv_iface_mtu = ntohs(ps->iface_mtu);
    rcv_options = ps->options;
    rcv_imms = ps->imms;
    rcv_ddseq = ntohl(ps->ddseq);
  }
  else /* OSPFv3 */
  {
    struct ospf_dbdes3_packet *ps = (void *) pkt;
    rcv_options = ntohl(ps->options);
    rcv_iface_mtu = ntohs(ps->iface_mtu);
    rcv_imms = ps->imms;
    rcv_ddseq = ntohl(ps->ddseq);
  }

  /* Reject packets with non-matching MTU */
  if ((ifa->type != OSPF_IT_VLINK) &&
      (rcv_iface_mtu != ifa->iface->mtu) &&
      (rcv_iface_mtu != 0) && (ifa->iface->mtu != 0))
  {
    LOG_PKT("MTU mismatch with nbr %R on %s (remote %d, local %d)",
	    n->rid, ifa->ifname, rcv_iface_mtu, ifa->iface->mtu);
    return;
  }

  switch (n->state)
  {
  case NEIGHBOR_DOWN:
  case NEIGHBOR_ATTEMPT:
  case NEIGHBOR_2WAY:
    OSPF_TRACE(D_PACKETS, "DBDES packet ignored - lesser state than ExStart");
    return;

  case NEIGHBOR_INIT:
    ospf_neigh_sm(n, INM_2WAYREC);
    if (n->state != NEIGHBOR_EXSTART)
      return;
    /* fallthrough */

  case NEIGHBOR_EXSTART:
    if (((rcv_imms & DBDES_IMMS) == DBDES_IMMS) &&
	(n->rid > p->router_id) &&
	(plen == ospf_dbdes_hdrlen(p)))
    {
      /* I'm slave! */
      n->dds = rcv_ddseq;
      n->ddr = rcv_ddseq;
      n->options = rcv_options;
      n->myimms &= ~DBDES_MS;
      n->imms = rcv_imms;
      tm_stop(n->dbdes_timer);
      ospf_neigh_sm(n, INM_NEGDONE);
      ospf_send_dbdes(p, n);
      break;
    }

    if (!(rcv_imms & DBDES_I) &&
	!(rcv_imms & DBDES_MS) &&
	(n->rid < p->router_id) &&
	(n->dds == rcv_ddseq))
    {
      /* I'm master! */
      n->options = rcv_options;
      n->ddr = rcv_ddseq - 1;	/* It will be set corectly a few lines down */
      n->imms = rcv_imms;
      ospf_neigh_sm(n, INM_NEGDONE);
      /* Continue to the NEIGHBOR_EXCHANGE case */
    }
    else
    {
      DBG("%s: Nothing happend to %I (imms=%d)\n", p->name, n->ip, rcv_imms);
      break;
    }

  case NEIGHBOR_EXCHANGE:
    if ((rcv_imms == n->imms) &&
	(rcv_options == n->options) &&
	(rcv_ddseq == n->ddr))
      goto duplicate;

    if ((rcv_imms & DBDES_MS) != (n->imms & DBDES_MS))
      DROP("MS-bit mismatch", rcv_imms);

    if (rcv_imms & DBDES_I)
      DROP("I-bit mismatch", rcv_imms);

    if (rcv_options != n->options)
      DROP("options mismatch", rcv_options);

    n->ddr = rcv_ddseq;
    n->imms = rcv_imms;

    if (n->myimms & DBDES_MS)
    {
      /* MASTER */

      if (rcv_ddseq != n->dds)
	DROP("DD sequence number mismatch", rcv_ddseq);

      n->dds++;

      if (ospf_process_dbdes(p, pkt, n) < 0)
	return;

      if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
      {
	tm_stop(n->dbdes_timer);
	ospf_neigh_sm(n, INM_EXDONE);
	break;
      }

      ospf_send_dbdes(p, n);
      tm_start(n->dbdes_timer, n->ifa->rxmtint S);
    }
    else
    {
      /* SLAVE */

      if (rcv_ddseq != (n->dds + 1))
	DROP("DD sequence number mismatch", rcv_ddseq);

      n->ddr = rcv_ddseq;
      n->dds = rcv_ddseq;

      if (ospf_process_dbdes(p, pkt, n) < 0)
	return;

      ospf_send_dbdes(p, n);

      if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
	ospf_neigh_sm(n, INM_EXDONE);
    }
    break;

  case NEIGHBOR_LOADING:
  case NEIGHBOR_FULL:
    if ((rcv_imms == n->imms) &&
	(rcv_options == n->options) &&
	(rcv_ddseq == n->ddr))
      goto duplicate;

    DROP("too late for DD exchange", n->state);

  default:
    bug("Undefined interface state");
  }
  return;

duplicate:
  OSPF_TRACE(D_PACKETS, "DBDES packet is duplicate");

  /* Slave should retransmit DBDES packet */
  if (!(n->myimms & DBDES_MS))
    ospf_rxmt_dbdes(p, n);
  return;

drop:
  LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)",
	  n->rid, ifa->ifname, err_dsc, err_val);

  ospf_neigh_sm(n, INM_SEQMIS);
  return;
}
Commit	Line	Data
4364b47e OF	1	/*
	2	* BIRD -- OSPF
	3	*
f158bb71	4	* (c) 1999--2004 Ondrej Filip <feela@network.cz>
70945cb6 OZ	5	* (c) 2009--2014 Ondrej Zajicek <santiago@crfreenet.org>
70945cb6 OZ	6	* (c) 2009--2014 CZ.NIC z.s.p.o.
4364b47e OF	7	*
	8	* Can be freely distributed and used under the terms of the GNU GPL.
	9	*/
	10
	11	#include "ospf.h"
	12
c3226991	13
70945cb6	14	struct ospf_dbdes2_packet
c3226991	15	{
70945cb6	16	struct ospf_packet hdr;
4727d1db	17	union ospf_auth2 auth;
70945cb6	18
c3226991 OZ	19	u16 iface_mtu;
c3226991 OZ	20	u8 options;
70945cb6	21	u8 imms; /* I, M, MS bits */
c3226991	22	u32 ddseq;
c3226991	23
70945cb6 OZ	24	struct ospf_lsa_header lsas[];
70945cb6 OZ	25	};
c3226991	26
70945cb6	27	struct ospf_dbdes3_packet
c3226991	28	{
70945cb6 OZ	29	struct ospf_packet hdr;
70945cb6 OZ	30
c3226991 OZ	31	u32 options;
	32	u16 iface_mtu;
	33	u8 padding;
70945cb6	34	u8 imms; /* I, M, MS bits */
c3226991	35	u32 ddseq;
70945cb6 OZ	36
70945cb6 OZ	37	struct ospf_lsa_header lsas[];
c3226991 OZ	38	};
c3226991 OZ	39
c3226991	40
4727d1db OZ	41	uint
	42	ospf_dbdes3_options(struct ospf_packet *pkt)
	43	{
	44	struct ospf_dbdes3_packet ps = (void ) pkt;
	45	return ntohl(ps->options);
	46	}
	47
70945cb6 OZ	48	static inline uint
	49	ospf_dbdes_hdrlen(struct ospf_proto *p)
	50	{
	51	return ospf_is_v2(p) ?
	52	sizeof(struct ospf_dbdes2_packet) : sizeof(struct ospf_dbdes3_packet);
	53	}
	54
70945cb6 OZ	55	static void
	56	ospf_dbdes_body(struct ospf_proto p, struct ospf_packet pkt,
	57	struct ospf_lsa_header *body, uint count)
	58	{
	59	uint plen = ntohs(pkt->length);
	60	uint hlen = ospf_dbdes_hdrlen(p);
	61
	62	body = ((void ) pkt) + hlen;
	63	*count = (plen - hlen) / sizeof(struct ospf_lsa_header);
	64	}
742029eb	65
70945cb6 OZ	66	static void
70945cb6 OZ	67	ospf_dump_dbdes(struct ospf_proto p, struct ospf_packet pkt)
8298d780	68	{
70945cb6 OZ	69	struct ospf_lsa_header *lsas;
	70	uint i, lsa_count;
	71	u32 pkt_ddseq;
	72	u16 pkt_iface_mtu;
	73	u8 pkt_imms;
8298d780	74
70945cb6 OZ	75	ASSERT(pkt->type == DBDES_P);
70945cb6 OZ	76	ospf_dump_common(p, pkt);
8298d780	77
70945cb6 OZ	78	if (ospf_is_v2(p))
	79	{
	80	struct ospf_dbdes2_packet ps = (void ) pkt;
	81	pkt_iface_mtu = ntohs(ps->iface_mtu);
	82	pkt_imms = ps->imms;
	83	pkt_ddseq = ntohl(ps->ddseq);
	84	}
	85	else /* OSPFv3 */
	86	{
	87	struct ospf_dbdes3_packet ps = (void ) pkt;
	88	pkt_iface_mtu = ntohs(ps->iface_mtu);
	89	pkt_imms = ps->imms;
	90	pkt_ddseq = ntohl(ps->ddseq);
	91	}
8298d780	92
70945cb6 OZ	93	log(L_TRACE "%s: mtu %u", p->p.name, pkt_iface_mtu);
	94	log(L_TRACE "%s: imms %s%s%s", p->p.name,
	95	(pkt_imms & DBDES_I) ? "I " : "",
	96	(pkt_imms & DBDES_M) ? "M " : "",
	97	(pkt_imms & DBDES_MS) ? "MS" : "");
	98	log(L_TRACE "%s: ddseq %u", p->p.name, pkt_ddseq);
8298d780	99
70945cb6 OZ	100	ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
	101	for (i = 0; i < lsa_count; i++)
	102	ospf_dump_lsahdr(p, lsas + i);
8298d780 OZ	103	}
	104
	105
70945cb6	106	static void
f8fefde3	107	ospf_prepare_dbdes(struct ospf_proto p, struct ospf_neighbor n)
70945cb6 OZ	108	{
	109	struct ospf_iface *ifa = n->ifa;
	110	struct ospf_packet *pkt;
	111	uint length;
	112
	113	u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu;
	114
f8fefde3	115	/* Update DBDES buffer */
70945cb6 OZ	116	if (n->ldd_bsize != ifa->tx_length)
	117	{
	118	mb_free(n->ldd_buffer);
	119	n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length);
	120	n->ldd_bsize = ifa->tx_length;
	121	}
	122
	123	pkt = n->ldd_buffer;
	124	ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);
	125
	126	if (ospf_is_v2(p))
	127	{
	128	struct ospf_dbdes2_packet ps = (void ) pkt;
	129	ps->iface_mtu = htons(iface_mtu);
5a50a989	130	ps->options = ifa->oa->options \| OPT_O;
70945cb6 OZ	131	ps->imms = 0; /* Will be set later */
	132	ps->ddseq = htonl(n->dds);
	133	length = sizeof(struct ospf_dbdes2_packet);
	134	}
	135	else /* OSPFv3 */
	136	{
	137	struct ospf_dbdes3_packet ps = (void ) pkt;
4727d1db	138	ps->options = htonl(ifa->oa->options \| (ifa->autype == OSPF_AUTH_CRYPT ? OPT_AT : 0));
70945cb6 OZ	139	ps->iface_mtu = htons(iface_mtu);
	140	ps->padding = 0;
	141	ps->imms = 0; /* Will be set later */
	142	ps->ddseq = htonl(n->dds);
	143	length = sizeof(struct ospf_dbdes3_packet);
	144	}
	145
f8fefde3 OZ	146	/* Prepare DBDES body */
f8fefde3 OZ	147	if (!(n->myimms & DBDES_I) && (n->myimms & DBDES_M))
70945cb6 OZ	148	{
	149	struct ospf_lsa_header *lsas;
	150	struct top_hash_entry *en;
	151	uint i = 0, lsa_max;
	152
	153	ospf_dbdes_body(p, pkt, &lsas, &lsa_max);
	154	en = (void *) s_get(&(n->dbsi));
	155
	156	while (i < lsa_max)
	157	{
	158	if (!SNODE_VALID(en))
	159	{
	160	n->myimms &= ~DBDES_M; /* Unset More bit */
	161	break;
	162	}
	163
	164	if ((en->lsa.age < LSA_MAXAGE) &&
5a50a989 OZ	165	lsa_flooding_allowed(en->lsa_type, en->domain, ifa) &&
5a50a989 OZ	166	lsa_is_acceptable(en->lsa_type, n, p))
70945cb6 OZ	167	{
	168	lsa_hton_hdr(&(en->lsa), lsas + i);
	169	i++;
	170	}
	171
	172	en = SNODE_NEXT(en);
	173	}
	174
	175	s_put(&(n->dbsi), SNODE en);
	176
	177	length += i * sizeof(struct ospf_lsa_header);
	178	}
	179
	180	if (ospf_is_v2(p))
	181	((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms;
	182	else
	183	((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms;
	184
	185	pkt->length = htons(length);
	186	}
	187
	188	static void
	189	ospf_do_send_dbdes(struct ospf_proto p, struct ospf_neighbor n)
	190	{
	191	struct ospf_iface *ifa = n->ifa;
	192
	193	OSPF_PACKET(ospf_dump_dbdes, n->ldd_buffer,
f8fefde3	194	"DBDES packet sent to nbr %R on %s", n->rid, ifa->ifname);
70945cb6 OZ	195	sk_set_tbuf(ifa->sk, n->ldd_buffer);
	196	ospf_send_to(ifa, n->ip);
	197	sk_set_tbuf(ifa->sk, NULL);
	198	}
	199
eee9cefd	200	/**
70945cb6	201	* ospf_send_dbdes - transmit database description packet
8e433d6a	202	* @p: OSPF protocol instance
eee9cefd OF	203	* @n: neighbor
eee9cefd OF	204	*
c3226991	205	* Sending of a database description packet is described in 10.8 of RFC 2328.
baa5dd6c OF	206	* Reception of each packet is acknowledged in the sequence number of another.
	207	* When I send a packet to a neighbor I keep a copy in a buffer. If the neighbor
	208	* does not reply, I don't create a new packet but just send the content
	209	* of the buffer.
eee9cefd	210	*/
4364b47e	211	void
f8fefde3	212	ospf_send_dbdes(struct ospf_proto p, struct ospf_neighbor n)
4364b47e	213	{
70945cb6	214	/* RFC 2328 10.8 */
4364b47e	215
f8fefde3 OZ	216	ASSERT((n->state == NEIGHBOR_EXSTART) \|\| (n->state == NEIGHBOR_EXCHANGE));
f8fefde3 OZ	217
a7a7372a	218	if (n->ifa->oa->rt == NULL)
70945cb6	219	return;
054a3524	220
f8fefde3 OZ	221	ospf_prepare_dbdes(p, n);
f8fefde3 OZ	222	ospf_do_send_dbdes(p, n);
f8fefde3	223	}
12bed559	224
f8fefde3 OZ	225	void
	226	ospf_rxmt_dbdes(struct ospf_proto p, struct ospf_neighbor n)
	227	{
	228	ASSERT(n->state > NEIGHBOR_EXSTART);
e7ef86a5	229
f8fefde3 OZ	230	if (!n->ldd_buffer)
	231	{
	232	log(L_WARN "%s: No DBDES packet for retransmit", p->p.name);
	233	ospf_neigh_sm(n, INM_SEQMIS);
	234	return;
70945cb6	235	}
04c6319a	236
f8fefde3 OZ	237	/* Send last packet */
	238	ospf_do_send_dbdes(p, n);
	239	}
48e5f32d	240
70945cb6 OZ	241	static int
	242	ospf_process_dbdes(struct ospf_proto p, struct ospf_packet pkt, struct ospf_neighbor *n)
	243	{
	244	struct ospf_iface *ifa = n->ifa;
f8fefde3 OZ	245	struct ospf_lsa_header *lsas, lsa;
	246	struct top_hash_entry en, req;
	247	const char *err_dsc = NULL;
	248	u32 lsa_type, lsa_domain;
70945cb6 OZ	249	uint i, lsa_count;
	250
	251	ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
	252
	253	for (i = 0; i < lsa_count; i++)
	254	{
70945cb6 OZ	255	lsa_ntoh_hdr(lsas + i, &lsa);
70945cb6 OZ	256	lsa_get_type_domain(&lsa, ifa, &lsa_type, &lsa_domain);
b1f7229a	257
70945cb6	258	/* RFC 2328 10.6 and RFC 5340 4.2.2 */
b1f7229a	259
70945cb6	260	if (!lsa_type)
f8fefde3	261	DROP1("LSA of unknown type");
4364b47e	262
70945cb6	263	if (!oa_is_ext(ifa->oa) && (LSA_SCOPE(lsa_type) == LSA_SCOPE_AS))
f8fefde3	264	DROP1("LSA with AS scope in stub area");
4364b47e	265
70945cb6 OZ	266	/* Errata 3746 to RFC 2328 - rt-summary-LSAs forbidden in stub areas */
70945cb6 OZ	267	if (!oa_is_ext(ifa->oa) && (lsa_type == LSA_T_SUM_RT))
f8fefde3	268	DROP1("rt-summary-LSA in stub area");
910e557b	269
70945cb6 OZ	270	/* Not explicitly mentioned in RFC 5340 4.2.2 but makes sense */
70945cb6 OZ	271	if (LSA_SCOPE(lsa_type) == LSA_SCOPE_RES)
f8fefde3	272	DROP1("LSA with invalid scope");
910e557b	273
70945cb6 OZ	274	en = ospf_hash_find(p->gr, lsa_domain, lsa.id, lsa.rt, lsa_type);
	275	if (!en \|\| (lsa_comp(&lsa, &(en->lsa)) == CMP_NEWER))
	276	{
6f8bbaa1	277	/* This should be splitted to ospf_lsa_lsrq_up() */
70945cb6	278	req = ospf_hash_get(n->lsrqh, lsa_domain, lsa.id, lsa.rt, lsa_type);
6d2b3211	279
70945cb6 OZ	280	if (!SNODE_VALID(req))
70945cb6 OZ	281	s_add_tail(&n->lsrql, SNODE req);
6d2b3211	282
6f8bbaa1 OZ	283	if (!SNODE_VALID(n->lsrqi))
	284	n->lsrqi = req;
	285
70945cb6	286	req->lsa = lsa;
a7a7372a	287	req->lsa_body = LSA_BODY_DUMMY;
6f8bbaa1	288
a6f79ca5 OZ	289	if (!tm_active(n->lsrq_timer))
a6f79ca5 OZ	290	tm_start(n->lsrq_timer, 0);
95eb1dba	291	}
6d2b3211	292	}
70945cb6 OZ	293
	294	return 0;
	295
f8fefde3 OZ	296	drop:
	297	LOG_LSA1("Bad LSA (Type: %04x, Id: %R, Rt: %R) in DBDES", lsa_type, lsa.id, lsa.rt);
	298	LOG_LSA2(" received from nbr %R on %s - %s", n->rid, ifa->ifname, err_dsc);
	299
70945cb6 OZ	300	ospf_neigh_sm(n, INM_SEQMIS);
70945cb6 OZ	301	return -1;
4364b47e OF	302	}
	303
	304	void
70945cb6	305	ospf_receive_dbdes(struct ospf_packet pkt, struct ospf_iface ifa,
c3226991	306	struct ospf_neighbor *n)
4364b47e	307	{
70945cb6	308	struct ospf_proto *p = ifa->oa->po;
f8fefde3	309	const char *err_dsc = NULL;
70945cb6 OZ	310	u32 rcv_ddseq, rcv_options;
	311	u16 rcv_iface_mtu;
	312	u8 rcv_imms;
6f8bbaa1	313	uint plen, err_val = 0;
4364b47e	314
70945cb6 OZ	315	/* RFC 2328 10.6 */
	316
	317	plen = ntohs(pkt->length);
	318	if (plen < ospf_dbdes_hdrlen(p))
6f8bbaa1 OZ	319	{
	320	LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen);
	321	return;
	322	}
a6bc04d5	323
f8fefde3	324	OSPF_PACKET(ospf_dump_dbdes, pkt, "DBDES packet received from nbr %R on %s", n->rid, ifa->ifname);
b1f7229a	325
4bb9ce56	326	ospf_neigh_sm(n, INM_HELLOREC);
353f3261	327
70945cb6 OZ	328	if (ospf_is_v2(p))
	329	{
	330	struct ospf_dbdes2_packet ps = (void ) pkt;
	331	rcv_iface_mtu = ntohs(ps->iface_mtu);
	332	rcv_options = ps->options;
	333	rcv_imms = ps->imms;
	334	rcv_ddseq = ntohl(ps->ddseq);
	335	}
	336	else /* OSPFv3 */
	337	{
	338	struct ospf_dbdes3_packet ps = (void ) pkt;
	339	rcv_options = ntohl(ps->options);
	340	rcv_iface_mtu = ntohs(ps->iface_mtu);
	341	rcv_imms = ps->imms;
	342	rcv_ddseq = ntohl(ps->ddseq);
	343	}
742029eb	344
267da813 OZ	345	/* Reject packets with non-matching MTU */
	346	if ((ifa->type != OSPF_IT_VLINK) &&
	347	(rcv_iface_mtu != ifa->iface->mtu) &&
	348	(rcv_iface_mtu != 0) && (ifa->iface->mtu != 0))
	349	{
	350	LOG_PKT("MTU mismatch with nbr %R on %s (remote %d, local %d)",
	351	n->rid, ifa->ifname, rcv_iface_mtu, ifa->iface->mtu);
	352	return;
	353	}
	354
12bed559	355	switch (n->state)
4364b47e	356	{
12bed559 OF	357	case NEIGHBOR_DOWN:
	358	case NEIGHBOR_ATTEMPT:
	359	case NEIGHBOR_2WAY:
f8fefde3	360	OSPF_TRACE(D_PACKETS, "DBDES packet ignored - lesser state than ExStart");
12bed559	361	return;
70945cb6	362
12bed559 OF	363	case NEIGHBOR_INIT:
	364	ospf_neigh_sm(n, INM_2WAYREC);
	365	if (n->state != NEIGHBOR_EXSTART)
	366	return;
d4cebc6b	367	/* fallthrough */
9f1500f5	368
70945cb6	369	case NEIGHBOR_EXSTART:
d3f4f92b	370	if (((rcv_imms & DBDES_IMMS) == DBDES_IMMS) &&
70945cb6 OZ	371	(n->rid > p->router_id) &&
70945cb6 OZ	372	(plen == ospf_dbdes_hdrlen(p)))
12bed559 OF	373	{
12bed559 OF	374	/* I'm slave! */
70945cb6 OZ	375	n->dds = rcv_ddseq;
	376	n->ddr = rcv_ddseq;
	377	n->options = rcv_options;
	378	n->myimms &= ~DBDES_MS;
	379	n->imms = rcv_imms;
a6f79ca5	380	tm_stop(n->dbdes_timer);
12bed559	381	ospf_neigh_sm(n, INM_NEGDONE);
f8fefde3	382	ospf_send_dbdes(p, n);
4364b47e	383	break;
12bed559	384	}
b1f7229a	385
70945cb6 OZ	386	if (!(rcv_imms & DBDES_I) &&
70945cb6 OZ	387	!(rcv_imms & DBDES_MS) &&
742029eb	388	(n->rid < p->router_id) &&
70945cb6	389	(n->dds == rcv_ddseq))
12bed559	390	{
b1f7229a	391	/* I'm master! */
70945cb6 OZ	392	n->options = rcv_options;
	393	n->ddr = rcv_ddseq - 1; /* It will be set corectly a few lines down */
	394	n->imms = rcv_imms;
b1f7229a	395	ospf_neigh_sm(n, INM_NEGDONE);
6f8bbaa1	396	/* Continue to the NEIGHBOR_EXCHANGE case */
12bed559	397	}
b1f7229a OF	398	else
b1f7229a OF	399	{
70945cb6	400	DBG("%s: Nothing happend to %I (imms=%d)\n", p->name, n->ip, rcv_imms);
12bed559	401	break;
b1f7229a	402	}
70945cb6	403
12bed559	404	case NEIGHBOR_EXCHANGE:
70945cb6 OZ	405	if ((rcv_imms == n->imms) &&
	406	(rcv_options == n->options) &&
	407	(rcv_ddseq == n->ddr))
f8fefde3	408	goto duplicate;
910e557b	409
f8fefde3 OZ	410	if ((rcv_imms & DBDES_MS) != (n->imms & DBDES_MS))
f8fefde3 OZ	411	DROP("MS-bit mismatch", rcv_imms);
12bed559	412
f8fefde3 OZ	413	if (rcv_imms & DBDES_I)
	414	DROP("I-bit mismatch", rcv_imms);
	415
	416	if (rcv_options != n->options)
	417	DROP("options mismatch", rcv_options);
4364b47e	418
70945cb6 OZ	419	n->ddr = rcv_ddseq;
	420	n->imms = rcv_imms;
	421
	422	if (n->myimms & DBDES_MS)
12bed559	423	{
f8fefde3 OZ	424	/* MASTER */
	425
	426	if (rcv_ddseq != n->dds)
	427	DROP("DD sequence number mismatch", rcv_ddseq);
70945cb6	428
12bed559	429	n->dds++;
70945cb6 OZ	430
	431	if (ospf_process_dbdes(p, pkt, n) < 0)
	432	return;
	433
	434	if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
6f8bbaa1	435	{
a6f79ca5	436	tm_stop(n->dbdes_timer);
12bed559	437	ospf_neigh_sm(n, INM_EXDONE);
6f8bbaa1 OZ	438	break;
	439	}
	440
	441	ospf_send_dbdes(p, n);
a6f79ca5	442	tm_start(n->dbdes_timer, n->ifa->rxmtint S);
12bed559 OF	443	}
	444	else
	445	{
f8fefde3 OZ	446	/* SLAVE */
	447
	448	if (rcv_ddseq != (n->dds + 1))
	449	DROP("DD sequence number mismatch", rcv_ddseq);
12bed559	450
70945cb6 OZ	451	n->ddr = rcv_ddseq;
	452	n->dds = rcv_ddseq;
	453
	454	if (ospf_process_dbdes(p, pkt, n) < 0)
	455	return;
	456
f8fefde3	457	ospf_send_dbdes(p, n);
6f8bbaa1 OZ	458
	459	if (!(n->myimms & DBDES_M) && !(n->imms & DBDES_M))
	460	ospf_neigh_sm(n, INM_EXDONE);
70945cb6	461	}
12bed559	462	break;
70945cb6	463
12bed559 OF	464	case NEIGHBOR_LOADING:
12bed559 OF	465	case NEIGHBOR_FULL:
70945cb6 OZ	466	if ((rcv_imms == n->imms) &&
	467	(rcv_options == n->options) &&
	468	(rcv_ddseq == n->ddr))
f8fefde3 OZ	469	goto duplicate;
f8fefde3 OZ	470
f8fefde3	471	DROP("too late for DD exchange", n->state);
70945cb6	472
189dab54	473	default:
f8fefde3	474	bug("Undefined interface state");
12bed559	475	}
f8fefde3 OZ	476	return;
	477
	478	duplicate:
	479	OSPF_TRACE(D_PACKETS, "DBDES packet is duplicate");
	480
	481	/* Slave should retransmit DBDES packet */
	482	if (!(n->myimms & DBDES_MS))
	483	ospf_rxmt_dbdes(p, n);
	484	return;
	485
	486	drop:
	487	LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)",
	488	n->rid, ifa->ifname, err_dsc, err_val);
	489
6f8bbaa1	490	ospf_neigh_sm(n, INM_SEQMIS);
f8fefde3	491	return;
12bed559	492	}