Commit b722fe7e authored by Ondřej Zajíček's avatar Ondřej Zajíček
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
......@@ -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;
}
......
......@@ -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);
......
......@@ -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)
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment