void
reliable_mark_active_incoming (struct reliable *rel, struct buffer *buf,
packet_id_type pid, int opcode)
{
int i;
for (i = 0; i < rel->size; ++i)
{
struct reliable_entry *e = &rel->array[i];
if (buf == &e->buf)
{
e->active = true;
/* packets may not arrive in sequential order */
e->packet_id = pid;
/* check for replay */
ASSERT (!reliable_pid_min (pid, rel->packet_id));
e->opcode = opcode;
e->next_try = 0;
e->timeout = 0;
dmsg (D_REL_DEBUG, "ACK mark active incoming ID " packet_id_format, (packet_id_print_type)e->packet_id);
return;
}
}
ASSERT (0); /* buf not found in rel */
}
/* grab a free buffer, fail if buffer clogged by unacknowledged low packet IDs */
struct buffer *
reliable_get_buf_output_sequenced (struct reliable *rel)
{
struct gc_arena gc = gc_new ();
int i;
packet_id_type min_id = 0;
bool min_id_defined = false;
struct buffer *ret = NULL;
/* find minimum active packet_id */
for (i = 0; i < rel->size; ++i)
{
const struct reliable_entry *e = &rel->array[i];
if (e->active)
{
if (!min_id_defined || reliable_pid_min (e->packet_id, min_id))
{
min_id_defined = true;
min_id = e->packet_id;
}
}
}
if (!min_id_defined || reliable_pid_in_range1 (rel->packet_id, min_id, rel->size))
{
ret = reliable_get_buf (rel);
}
else
{
dmsg (D_REL_LOW, "ACK output sequence broken: %s", reliable_print_ids (rel, &gc));
}
gc_free (&gc);
return ret;
}
/* return next buffer to send to remote */
struct buffer *
reliable_send (struct reliable *rel, int *opcode)
{
int i;
struct reliable_entry *best = NULL;
const time_t local_now = now;
for (i = 0; i < rel->size; ++i)
{
struct reliable_entry *e = &rel->array[i];
if (e->active && local_now >= e->next_try)
{
if (!best || reliable_pid_min (e->packet_id, best->packet_id))
best = e;
}
}
if (best)
{
#ifdef EXPONENTIAL_BACKOFF
/* exponential backoff */
best->next_try = reliable_unique_retry (rel, local_now + best->timeout);
best->timeout *= 2;
#else
/* constant timeout, no backoff */
best->next_try = local_now + best->timeout;
#endif
*opcode = best->opcode;
dmsg (D_REL_DEBUG, "ACK reliable_send ID " packet_id_format " (size=%d to=%d)",
(packet_id_print_type)best->packet_id, best->buf.len,
(int)(best->next_try - local_now));
return &best->buf;
}
return NULL;
}
/* make sure that incoming packet ID isn't a replay */
bool
reliable_not_replay(const struct reliable *rel, packet_id_type id)
{
struct gc_arena gc = gc_new();
int i;
if (reliable_pid_min(id, rel->packet_id))
{
goto bad;
}
for (i = 0; i < rel->size; ++i)
{
const struct reliable_entry *e = &rel->array[i];
if (e->active && e->packet_id == id)
{
goto bad;
}
}
gc_free(&gc);
return true;
bad:
dmsg(D_REL_DEBUG, "ACK " packet_id_format " is a replay: %s", (packet_id_print_type)id, reliable_print_ids(rel, &gc));
gc_free(&gc);
return false;
}