1 files changed, 351 insertions, 301 deletions

diff --git a/proto/ospf/dbdes.c b/proto/ospf/dbdes.c
index 6b291344..65bdb3ec 100644
--- a/proto/ospf/dbdes.c
+++ b/proto/ospf/dbdes.c
@@ -2,6 +2,8 @@
  *	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.
  */
@@ -9,422 +11,470 @@
 #include "ospf.h"
 
 
-#ifdef OSPFv2
-struct ospf_dbdes_packet
+struct ospf_dbdes2_packet
 {
-  struct ospf_packet ospf_packet;
+  struct ospf_packet hdr;
+  union ospf_auth auth;
+
   u16 iface_mtu;
   u8 options;
-  union imms imms;		/* I, M, MS bits */
+  u8 imms;			/* I, M, MS bits */
   u32 ddseq;
-};
-
-#define hton_opt(X) X
-#define ntoh_opt(X) X
-#endif
 
+  struct ospf_lsa_header lsas[];
+};
 
-#ifdef OSPFv3
-struct ospf_dbdes_packet
+struct ospf_dbdes3_packet
 {
-  struct ospf_packet ospf_packet;
+  struct ospf_packet hdr;
+
   u32 options;
   u16 iface_mtu;
   u8 padding;
-  union imms imms;		/* I, M, MS bits */
+  u8 imms;			/* I, M, MS bits */
   u32 ddseq;
+
+  struct ospf_lsa_header lsas[];
 };
 
-#define hton_opt(X) htonl(X)
-#define ntoh_opt(X) ntohl(X)
-#endif
 
-  
-static void ospf_dump_dbdes(struct proto *p, struct ospf_dbdes_packet *pkt)
+static inline uint
+ospf_dbdes_hdrlen(struct ospf_proto *p)
 {
-  struct ospf_packet *op = &pkt->ospf_packet;
+  return ospf_is_v2(p) ?
+    sizeof(struct ospf_dbdes2_packet) : sizeof(struct ospf_dbdes3_packet);
+}
 
-  ASSERT(op->type == DBDES_P);
-  ospf_dump_common(p, op);
-  log(L_TRACE "%s:     imms     %s%s%s",
-      p->name, pkt->imms.bit.ms ? "MS " : "",
-      pkt->imms.bit.m ? "M " : "",
-      pkt->imms.bit.i ? "I " : "" );
-  log(L_TRACE "%s:     ddseq    %u", p->name, ntohl(pkt->ddseq));
 
-  struct ospf_lsa_header *plsa = (void *) (pkt + 1);
-  unsigned int i, j;
+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);
 
-  j = (ntohs(op->length) - sizeof(struct ospf_dbdes_packet)) /
-    sizeof(struct ospf_lsa_header);
+  *body = ((void *) pkt) + hlen;
+  *count = (plen - hlen) / sizeof(struct ospf_lsa_header);
+}
 
-  for (i = 0; i < j; i++)
-    ospf_dump_lsahdr(p, plsa + i);
+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);
 }
 
 
-/**
- * ospf_dbdes_send - transmit database description packet
- * @n: neighbor
- * @next: whether to send a next packet in a sequence (1) or to retransmit the old one (0)
- *
- * 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_dbdes_send(struct ospf_neighbor *n, int next)
+static void
+ospf_prepare_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
 {
-  struct ospf_dbdes_packet *pkt;
-  struct ospf_packet *op;
   struct ospf_iface *ifa = n->ifa;
-  struct ospf_area *oa = ifa->oa;
-  struct proto_ospf *po = oa->po;
-  struct proto *p = &po->proto;
-  u16 length, i, j;
+  struct ospf_packet *pkt;
+  uint length;
 
-  /* FIXME ??? */
-  if ((oa->rt == NULL) || (EMPTY_LIST(po->lsal)))
-    update_rt_lsa(oa);
+  u16 iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : ifa->iface->mtu;
 
-  switch (n->state)
+  /* Update DBDES buffer */
+  if (n->ldd_bsize != ifa->tx_length)
   {
-  case NEIGHBOR_EXSTART:	/* Send empty packets */
-    n->myimms.bit.i = 1;
-    pkt = ospf_tx_buffer(ifa);
-    op = &pkt->ospf_packet;
-    ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);
-    pkt->iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : htons(ifa->iface->mtu);
-    pkt->options = hton_opt(oa->options);
-    pkt->imms = n->myimms;
-    pkt->ddseq = htonl(n->dds);
-    length = sizeof(struct ospf_dbdes_packet);
-    op->length = htons(length);
-
-    OSPF_PACKET(ospf_dump_dbdes, pkt, "DBDES packet sent to %I via %s", n->ip, ifa->ifname);
-    ospf_send_to(ifa, n->ip);
-    break;
-
-  case NEIGHBOR_EXCHANGE:
-    n->myimms.bit.i = 0;
+    mb_free(n->ldd_buffer);
+    n->ldd_buffer = mb_allocz(n->pool, ifa->tx_length);
+    n->ldd_bsize = ifa->tx_length;
+  }
 
-    if (next)
-    {
-      snode *sn;
-      struct ospf_lsa_header *lsa;
+  pkt = n->ldd_buffer;
+  ospf_pkt_fill_hdr(ifa, pkt, DBDES_P);
 
-      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;
-      }
+  if (ospf_is_v2(p))
+  {
+    struct ospf_dbdes2_packet *ps = (void *) pkt;
+    ps->iface_mtu = htons(iface_mtu);
+    ps->options = ifa->oa->options;
+    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);
+    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);
+  }
 
-      pkt = n->ldd_buffer;
-      op = (struct ospf_packet *) pkt;
+  /* 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_pkt_fill_hdr(ifa, pkt, DBDES_P);
-      pkt->iface_mtu = (ifa->type == OSPF_IT_VLINK) ? 0 : htons(ifa->iface->mtu);
-      pkt->ddseq = htonl(n->dds);
-      pkt->options = hton_opt(oa->options);
+    ospf_dbdes_body(p, pkt, &lsas, &lsa_max);
+    en = (void *) s_get(&(n->dbsi));
 
-      j = i = (ospf_pkt_maxsize(ifa) - sizeof(struct ospf_dbdes_packet)) / sizeof(struct ospf_lsa_header);	/* Number of possible lsaheaders to send */
-      lsa = (n->ldd_buffer + sizeof(struct ospf_dbdes_packet));
+    while (i < lsa_max)
+    {
+      if (!SNODE_VALID(en))
+      {
+	n->myimms &= ~DBDES_M;	/* Unset More bit */
+	break;
+      }
 
-      if (n->myimms.bit.m)
+      if ((en->lsa.age < LSA_MAXAGE) &&
+	  lsa_flooding_allowed(en->lsa_type, en->domain, ifa))
       {
-	sn = s_get(&(n->dbsi));
-
-	DBG("Number of LSA: %d\n", j);
-	for (; i > 0; i--)
-	{
-	  struct top_hash_entry *en= (struct top_hash_entry *) sn;
-
-          if (ospf_lsa_flooding_allowed(&en->lsa, en->domain, ifa))
-          {
-	    htonlsah(&(en->lsa), lsa);
-	    DBG("Working on: %d\n", i);
-	    DBG("\tX%01x %-1R %-1R %p\n", en->lsa.type, en->lsa.id, en->lsa.rt, en->lsa_body);
-
-	    lsa++;
-          }
-          else i++;	/* No lsa added */
-
-	  if (sn == STAIL(po->lsal))
-          {
-            i--;
-	    break;
-          }
-
-	  sn = sn->next;
-	}
-
-	if (sn == STAIL(po->lsal))
-	{
-	  DBG("Number of LSA NOT sent: %d\n", i);
-	  DBG("M bit unset.\n");
-	  n->myimms.bit.m = 0;	/* Unset more bit */
-	}
-
-	s_put(&(n->dbsi), sn);
+	lsa_hton_hdr(&(en->lsa), lsas + i);
+	i++;
       }
 
-      pkt->imms.byte = n->myimms.byte;
+      en = SNODE_NEXT(en);
+    }
 
-      length = (j - i) * sizeof(struct ospf_lsa_header) +
-	sizeof(struct ospf_dbdes_packet);
-      op->length = htons(length);
+    s_put(&(n->dbsi), SNODE en);
 
-      DBG("%s: DB_DES (M) prepared for %I.\n", p->name, n->ip);
-    }
+    length += i * sizeof(struct ospf_lsa_header);
+  }
 
-  case NEIGHBOR_LOADING:
-  case NEIGHBOR_FULL:
-    length = n->ldd_buffer ? ntohs(((struct ospf_packet *) n->ldd_buffer)->length) : 0;
+  if (ospf_is_v2(p))
+    ((struct ospf_dbdes2_packet *) pkt)->imms = n->myimms;
+  else
+    ((struct ospf_dbdes3_packet *) pkt)->imms = n->myimms;
 
-    if (!length)
-    {
-      OSPF_TRACE(D_PACKETS, "No packet in my buffer for repeating");
-      ospf_neigh_sm(n, INM_KILLNBR);
-      return;
-    }
+  pkt->length = htons(length);
+}
 
-    /* Send last packet from ldd buffer */
+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 %I via %s", n->ip, ifa->ifname);
+  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);
+}
 
-    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
+ * @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 */
 
-    if(n->myimms.bit.ms) tm_start(n->rxmt_timer, n->ifa->rxmtint);		/* Restart timer */
+  ASSERT((n->state == NEIGHBOR_EXSTART) || (n->state == NEIGHBOR_EXCHANGE));
 
-    if (!n->myimms.bit.ms)
-    {
-      if ((n->myimms.bit.m == 0) && (n->imms.bit.m == 0) &&
-	  (n->state == NEIGHBOR_EXCHANGE))
-      {
-	ospf_neigh_sm(n, INM_EXDONE);
-      }
-    }
-    break;
+  if (n->ifa->oa->rt == NULL)
+    return;
 
-  default:			/* Ignore it */
-    break;
-  }
+  ospf_prepare_dbdes(p, n);
+  ospf_do_send_dbdes(p, n);
 }
 
-static void
-ospf_dbdes_reqladd(struct ospf_dbdes_packet *ps, struct ospf_neighbor *n)
+void
+ospf_rxmt_dbdes(struct ospf_proto *p, struct ospf_neighbor *n)
 {
-  struct ospf_lsa_header *plsa, lsa;
-  struct top_hash_entry *he, *sn;
-  struct ospf_area *oa = n->ifa->oa;
-  struct top_graph *gr = oa->po->gr;
-  struct ospf_packet *op;
-  int i, j;
+  ASSERT(n->state > NEIGHBOR_EXSTART);
 
-  op = (struct ospf_packet *) ps;
+  if (!n->ldd_buffer)
+  {
+    log(L_WARN "%s: No DBDES packet for retransmit", p->p.name);
+    ospf_neigh_sm(n, INM_SEQMIS);
+    return;
+  }
 
-  plsa = (void *) (ps + 1);
+  /* Send last packet */
+  ospf_do_send_dbdes(p, n);
+}
 
-  j = (ntohs(op->length) - sizeof(struct ospf_dbdes_packet)) /
-    sizeof(struct ospf_lsa_header);
+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;
 
-  for (i = 0; i < j; i++)
+  ospf_dbdes_body(p, pkt, &lsas, &lsa_count);
+
+  for (i = 0; i < lsa_count; i++)
   {
-    ntohlsah(plsa + i, &lsa);
-    u32 dom = ospf_lsa_domain(lsa.type, n->ifa);
-    if (((he = ospf_hash_find_header(gr, dom, &lsa)) == NULL) ||
-	(lsa_comp(&lsa, &(he->lsa)) == 1))
+    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))
     {
-      /* Is this condition necessary? */
-      if (ospf_hash_find_header(n->lsrqh, dom, &lsa) == NULL)
-      {
-	sn = ospf_hash_get_header(n->lsrqh, dom, &lsa);
-	ntohlsah(plsa + i, &(sn->lsa));
-	s_add_tail(&(n->lsrql), SNODE sn);
-      }
+      /* 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_dbdes_receive(struct ospf_packet *ps_i, struct ospf_iface *ifa,
+ospf_receive_dbdes(struct ospf_packet *pkt, struct ospf_iface *ifa,
 		   struct ospf_neighbor *n)
 {
-  struct proto_ospf *po = ifa->oa->po;
-  struct proto *p = &po->proto;
+  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 */
 
-  unsigned int size = ntohs(ps_i->length);
-  if (size < sizeof(struct ospf_dbdes_packet))
+  plen = ntohs(pkt->length);
+  if (plen < ospf_dbdes_hdrlen(p))
   {
-    log(L_ERR "Bad OSPF DBDES packet from %I -  too short (%u B)", n->ip, size);
+    LOG_PKT("Bad DBDES packet from nbr %R on %s - %s (%u)", n->rid, ifa->ifname, "too short", plen);
     return;
   }
 
-  struct ospf_dbdes_packet *ps = (void *) ps_i;
-  u32 ps_ddseq = ntohl(ps->ddseq);
-  u32 ps_options = ntoh_opt(ps->options);
-  u16 ps_iface_mtu = ntohs(ps->iface_mtu);
-  
-  OSPF_PACKET(ospf_dump_dbdes, ps, "DBDES packet received from %I via %s", n->ip, ifa->ifname);
+  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);
+  }
+
   switch (n->state)
   {
   case NEIGHBOR_DOWN:
   case NEIGHBOR_ATTEMPT:
   case NEIGHBOR_2WAY:
+    OSPF_TRACE(D_PACKETS, "DBDES packet ignored - lesser state than ExStart");
     return;
-    break;
+
   case NEIGHBOR_INIT:
     ospf_neigh_sm(n, INM_2WAYREC);
     if (n->state != NEIGHBOR_EXSTART)
       return;
-  case NEIGHBOR_EXSTART:
-
-    if ((ifa->type != OSPF_IT_VLINK) && (ps_iface_mtu != ifa->iface->mtu)
-	&& (ps_iface_mtu != 0) && (ifa->iface->mtu != 0))
-      log(L_WARN "OSPF: MTU mismatch with neighbour %I on interface %s (remote %d, local %d)",
-	  n->ip, ifa->ifname, ps_iface_mtu, ifa->iface->mtu);
 
-    if ((ps->imms.bit.m && ps->imms.bit.ms && ps->imms.bit.i)
-	&& (n->rid > po->router_id) && (size == sizeof(struct ospf_dbdes_packet)))
+  case NEIGHBOR_EXSTART:
+    if ((ifa->type != OSPF_IT_VLINK) &&
+	(rcv_iface_mtu != ifa->iface->mtu) &&
+	(rcv_iface_mtu != 0) &&
+	(ifa->iface->mtu != 0))
+      LOG_PKT_WARN("MTU mismatch with nbr %R on %s (remote %d, local %d)",
+		   n->rid, ifa->ifname, rcv_iface_mtu, ifa->iface->mtu);
+
+    if ((rcv_imms == DBDES_IMMS) &&
+	(n->rid > p->router_id) &&
+	(plen == ospf_dbdes_hdrlen(p)))
     {
       /* I'm slave! */
-      n->dds = ps_ddseq;
-      n->ddr = ps_ddseq;
-      n->options = ps_options;
-      n->myimms.bit.ms = 0;
-      n->imms.byte = ps->imms.byte;
-      OSPF_TRACE(D_PACKETS, "I'm slave to %I.", n->ip);
+      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_dbdes_send(n, 1);
+      ospf_send_dbdes(p, n);
       break;
     }
 
-    if (((ps->imms.bit.i == 0) && (ps->imms.bit.ms == 0)) &&
-        (n->rid < po->router_id) && (n->dds == ps_ddseq))
+    if (!(rcv_imms & DBDES_I) &&
+	!(rcv_imms & DBDES_MS) &&
+	(n->rid < p->router_id) &&
+	(n->dds == rcv_ddseq))
     {
       /* I'm master! */
-      n->options = ps_options;
-      n->ddr = ps_ddseq - 1;	/* It will be set corectly a few lines down */
-      n->imms.byte = ps->imms.byte;
-      OSPF_TRACE(D_PACKETS, "I'm master to %I.", n->ip);
+      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=%u)\n", p->name, n->ip,
-          ps->imms.byte);
+      DBG("%s: Nothing happend to %I (imms=%d)\n", p->name, n->ip, rcv_imms);
       break;
     }
+
   case NEIGHBOR_EXCHANGE:
-    if ((ps->imms.byte == n->imms.byte) && (ps_options == n->options) &&
-	(ps_ddseq == n->ddr))
-    {
-      /* Duplicate packet */
-      OSPF_TRACE(D_PACKETS, "Received duplicate dbdes from %I.", n->ip);
-      if (n->myimms.bit.ms == 0)
-      {
-	/* Slave should retransmit dbdes packet */
-	ospf_dbdes_send(n, 0);
-      }
-      return;
-    }
+    if ((rcv_imms == n->imms) &&
+	(rcv_options == n->options) &&
+	(rcv_ddseq == n->ddr))
+      goto duplicate;
 
-    n->ddr = ps_ddseq;
+    if ((rcv_imms & DBDES_MS) != (n->imms & DBDES_MS))
+      DROP("MS-bit mismatch", rcv_imms);
 
-    if (ps->imms.bit.ms != n->imms.bit.ms)	/* M/S bit differs */
-    {
-      OSPF_TRACE(D_PACKETS, "dbdes - sequence mismatch neighbor %I (bit MS)",
-		 n->ip);
-      ospf_neigh_sm(n, INM_SEQMIS);
-      break;
-    }
+    if (rcv_imms & DBDES_I)
+      DROP("I-bit mismatch", rcv_imms);
 
-    if (ps->imms.bit.i)		/* I bit is set */
-    {
-      OSPF_TRACE(D_PACKETS, "dbdes - sequence mismatch neighbor %I (bit I)",
-		 n->ip);
-      ospf_neigh_sm(n, INM_SEQMIS);
-      break;
-    }
+    if (rcv_options != n->options)
+      DROP("options mismatch", rcv_options);
 
-    n->imms.byte = ps->imms.byte;
+    n->ddr = rcv_ddseq;
+    n->imms = rcv_imms;
 
-    if (ps_options != n->options)	/* Options differs */
+    if (n->myimms & DBDES_MS)
     {
-      OSPF_TRACE(D_PACKETS, "dbdes - sequence mismatch neighbor %I (options)",
-		 n->ip);
-      ospf_neigh_sm(n, INM_SEQMIS);
-      break;
-    }
+      /* MASTER */
+
+      if (rcv_ddseq != n->dds)
+	DROP("DD sequence number mismatch", rcv_ddseq);
 
-    if (n->myimms.bit.ms)
-    {
-      if (ps_ddseq != n->dds)	/* MASTER */
-      {
-	OSPF_TRACE(D_PACKETS, "dbdes - sequence mismatch neighbor %I (master)",
-		   n->ip);
-	ospf_neigh_sm(n, INM_SEQMIS);
-	break;
-      }
       n->dds++;
-      DBG("Incrementing dds\n");
-      ospf_dbdes_reqladd(ps, n);
-      if ((n->myimms.bit.m == 0) && (ps->imms.bit.m == 0))
+
+      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);
-      }
-      else
-      {
-	ospf_dbdes_send(n, 1);
+	break;
       }
 
+      ospf_send_dbdes(p, n);
+      tm_start(n->dbdes_timer, n->ifa->rxmtint);
     }
     else
     {
-      if (ps_ddseq != (n->dds + 1))	/* SLAVE */
-      {
-	OSPF_TRACE(D_PACKETS, "dbdes - sequence mismatch neighbor %I (slave)", n->ip);
-	ospf_neigh_sm(n, INM_SEQMIS);
-	break;
-      }
-      n->ddr = ps_ddseq;
-      n->dds = ps_ddseq;
-      ospf_dbdes_reqladd(ps, n);
-      ospf_dbdes_send(n, 1);
-    }
+      /* 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 ((ps->imms.byte == n->imms.byte) && (ps_options == n->options)
-	&& (ps_ddseq == n->ddr))
-      /* Only duplicate are accepted */
-    {
-      OSPF_TRACE(D_PACKETS, "Received duplicate dbdes from %I.", n->ip);
-      if (n->myimms.bit.ms == 0)
-      {
-	/* Slave should retransmit dbdes packet */
-	ospf_dbdes_send(n, 0);
-      }
-      return;
-    }
-    else
-    {
-      OSPF_TRACE(D_PACKETS, "dbdes - sequence mismatch neighbor %I (full)",
-		 n->ip);
-      DBG("PS=%u, DDR=%u, DDS=%u\n", ps_ddseq, n->ddr, n->dds);
-      ospf_neigh_sm(n, INM_SEQMIS);
-    }
-    break;
+    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("Received dbdes from %I in undefined state.", n->ip);
+    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;
 }