Commit b722fe7e authored by Ondrej Zajicek's avatar Ondrej Zajicek
Browse files

Fixes bug in OSPF packet retransmission. 

If a DBDES packet from a master to a slave is lost, then the old code
does not retransmit it and instead send a next one with the same
sequence number. That leads to silent desynchronization of LSA
databases.
parent 8298d780

proto/ospf/dbdes.c

+9 −9
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ static void ospf_dump_dbdes(struct proto *p, struct ospf_dbdes_packet *pkt) 
/**

 * 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 10.6 of RFC 2328.

 * Reception of each packet is acknowledged in the sequence number of another.
@@ -43,7 +44,7 @@ static void ospf_dump_dbdes(struct proto *p, struct ospf_dbdes_packet *pkt) 
 * of the buffer.

 */

void

ospf_dbdes_send(struct ospf_neighbor *n)

ospf_dbdes_send(struct ospf_neighbor *n, int next)

{

  struct ospf_dbdes_packet *pkt;

  struct ospf_packet *op;
@@ -77,10 +78,9 @@ ospf_dbdes_send(struct ospf_neighbor *n) 
  case NEIGHBOR_EXCHANGE:

    n->myimms.bit.i = 0;



    if (((n->myimms.bit.ms) && (n->dds == n->ddr + 1)) ||

	((!(n->myimms.bit.ms)) && (n->dds == n->ddr)))

    if (next)

    {

      snode *sn;		/* Send next */

      snode *sn;

      struct ospf_lsa_header *lsa;



      pkt = n->ldbdes;
@@ -254,7 +254,7 @@ ospf_dbdes_receive(struct ospf_dbdes_packet *ps, 
      n->imms.byte = ps->imms.byte;

      OSPF_TRACE(D_PACKETS, "I'm slave to %I.", n->ip);

      ospf_neigh_sm(n, INM_NEGDONE);

      ospf_dbdes_send(n);

      ospf_dbdes_send(n, 1);

      break;

    }
@@ -283,7 +283,7 @@ ospf_dbdes_receive(struct ospf_dbdes_packet *ps, 
      if (n->myimms.bit.ms == 0)

      {

	/* Slave should retransmit dbdes packet */

	ospf_dbdes_send(n);

	ospf_dbdes_send(n, 0);

      }

      return;

    }
@@ -334,7 +334,7 @@ ospf_dbdes_receive(struct ospf_dbdes_packet *ps, 
      }

      else

      {

	ospf_dbdes_send(n);

	ospf_dbdes_send(n, 1);

      }



    }
@@ -350,7 +350,7 @@ ospf_dbdes_receive(struct ospf_dbdes_packet *ps, 
      n->ddr = ntohl(ps->ddseq);

      n->dds = ntohl(ps->ddseq);

      ospf_dbdes_reqladd(ps, n);

      ospf_dbdes_send(n);

      ospf_dbdes_send(n, 1);

    }



    break;
@@ -364,7 +364,7 @@ ospf_dbdes_receive(struct ospf_dbdes_packet *ps, 
      if (n->myimms.bit.ms == 0)

      {

	/* Slave should retransmit dbdes packet */

	ospf_dbdes_send(n);

	ospf_dbdes_send(n, 0);

      }

      return;

    }

proto/ospf/dbdes.h

+1 −1
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ 
#ifndef _BIRD_OSPF_DBDES_H_

#define _BIRD_OSPF_DBDES_H_



void ospf_dbdes_send(struct ospf_neighbor *n);

void ospf_dbdes_send(struct ospf_neighbor *n, int next);

void ospf_dbdes_receive(struct ospf_dbdes_packet *ps,

			struct ospf_iface *ifa, struct ospf_neighbor *n);

proto/ospf/neighbor.c

+2 −2
Original line number Diff line number Diff line
@@ -643,12 +643,12 @@ rxmt_timer_hook(timer * timer) 


  if (n->state == NEIGHBOR_EXSTART)

  {

    ospf_dbdes_send(n);

    ospf_dbdes_send(n, 1);

    return;

  }



  if ((n->state == NEIGHBOR_EXCHANGE) && n->myimms.bit.ms)	/* I'm master */

    ospf_dbdes_send(n);

    ospf_dbdes_send(n, 0);





  if (n->state < NEIGHBOR_FULL)

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