Avoid over-filling cell queues when we receive a SENDME

Do not start reading on exit streams when we get a SENDME unless we
have space in the appropriate circuit's cell queue.

Draft fix for bug 1653.

(commit message by nickm)
This commit is contained in:
yetonetime 2010-08-18 13:55:01 -04:00 committed by Nick Mathewson
parent d72edc4b78
commit 4dd3245abb

View File

@ -52,6 +52,8 @@ circuit_resume_edge_reading_helper(edge_connection_t *conn,
crypt_path_t *layer_hint);
static int
circuit_consider_stop_edge_reading(circuit_t *circ, crypt_path_t *layer_hint);
static int
circuit_queue_high(circuit_t *circ);
/** Cache the current hi-res time; the cache gets reset when libevent
* calls us. */
@ -1236,6 +1238,9 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
conn->package_window += STREAMWINDOW_INCREMENT;
log_debug(domain,"stream-level sendme, packagewindow now %d.",
conn->package_window);
if (circuit_queue_high(circ)) { /* Too high, don't touch conn */
return 0;
}
connection_start_reading(TO_CONN(conn));
/* handle whatever might still be on the inbuf */
if (connection_edge_package_raw_inbuf(conn, 1) < 0) {
@ -1437,6 +1442,10 @@ static void
circuit_resume_edge_reading(circuit_t *circ, crypt_path_t *layer_hint)
{
if (circuit_queue_high(circ)) {
log_debug(layer_hint?LD_APP:LD_EXIT,"Too big queue, no resuming");
return;
}
log_debug(layer_hint?LD_APP:LD_EXIT,"resuming");
if (CIRCUIT_IS_ORIGIN(circ))
@ -2405,3 +2414,24 @@ assert_active_circuits_ok(or_connection_t *orconn)
tor_assert(n == smartlist_len(orconn->active_circuit_pqueue));
}
/** Return 1 if the number of cells waiting on the queue
* more than a watermark or equal it. Else return 0.
* XXXY: Only for edges: origin and exit. Middles out of luck for such,
* need the proposal.
*/
static int
circuit_queue_high(circuit_t *circ)
{
cell_queue_t *queue;
if (CIRCUIT_IS_ORIGIN(circ)) {
queue = &circ->n_conn_cells;
} else {
or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
queue = &orcirc->p_conn_cells;
}
if (queue->n >= CELL_QUEUE_HIGHWATER_SIZE)
return 1;
return 0;
}