commit a4400952ee477ac6fb5a2743f14df0dcd1cb8424 Author: Roger Dingledine arma@torproject.org Date: Tue Sep 3 22:15:33 2013 -0400

Be more general in calculating expected onion queue processing time

Now we consider the TAP cells we'll process while draining the NTor queue, and vice versa. --- src/or/onion.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/or/onion.c b/src/or/onion.c index 4ea2061..cabd055 100644 --- a/src/or/onion.c +++ b/src/or/onion.c @@ -49,6 +49,7 @@ TOR_TAILQ_HEAD(onion_queue_head_t, onion_queue_t) /** Number of entries of each type currently in each element of ol_list[]. */ static int ol_entries[MAX_ONION_HANDSHAKE_TYPE+1];

+static int num_ntors_per_tap(void); static void onion_queue_entry_remove(onion_queue_t *victim);

/* XXXX024 Check lengths vs MAX_ONIONSKIN_{CHALLENGE,REPLY}_LEN. @@ -66,27 +67,49 @@ have_room_for_onionskin(uint16_t type) const or_options_t *options = get_options(); int num_cpus; uint64_t tap_usec, ntor_usec; + uint64_t ntor_during_tap_usec, tap_during_ntor_usec; + /* If we've got fewer than 50 entries, we always have room for one more. */ if (ol_entries[type] < 50) return 1; num_cpus = get_num_cpus(options); /* Compute how many microseconds we'd expect to need to clear all - * onionskins in the current queue. */ + * onionskins in various combinations of the queues. */ + + /* How long would it take to process all the TAP cells in the queue? */ tap_usec = estimated_usec_for_onionskins( ol_entries[ONION_HANDSHAKE_TYPE_TAP], ONION_HANDSHAKE_TYPE_TAP) / num_cpus; + + /* How long would it take to process all the NTor cells in the queue? */ ntor_usec = estimated_usec_for_onionskins( ol_entries[ONION_HANDSHAKE_TYPE_NTOR], ONION_HANDSHAKE_TYPE_NTOR) / num_cpus;

+ /* How long would it take to process the tap cells that we expect to + * process while draining the ntor queue? */ + tap_during_ntor_usec = estimated_usec_for_onionskins( + MIN(ol_entries[ONION_HANDSHAKE_TYPE_TAP], + ol_entries[ONION_HANDSHAKE_TYPE_NTOR] / num_ntors_per_tap()), + ONION_HANDSHAKE_TYPE_TAP) / num_cpus; + + /* How long would it take to process the ntor cells that we expect to + * process while draining the tap queue? */ + ntor_during_tap_usec = estimated_usec_for_onionskins( + MIN(ol_entries[ONION_HANDSHAKE_TYPE_NTOR], + ol_entries[ONION_HANDSHAKE_TYPE_TAP] * num_ntors_per_tap()), + ONION_HANDSHAKE_TYPE_NTOR) / num_cpus; + /* See whether that exceeds MaxOnionQueueDelay. If so, we can't queue * this. */ if (type == ONION_HANDSHAKE_TYPE_NTOR && - ntor_usec / 1000 > (uint64_t)options->MaxOnionQueueDelay) + (ntor_usec + tap_during_ntor_usec) / 1000 > + (uint64_t)options->MaxOnionQueueDelay) return 0;

if (type == ONION_HANDSHAKE_TYPE_TAP && - (tap_usec + ntor_usec) / 1000 > (uint64_t)options->MaxOnionQueueDelay) + (tap_usec + ntor_during_tap_usec) / 1000 > + (uint64_t)options->MaxOnionQueueDelay) return 0;

#ifdef CURVE25519_ENABLED @@ -173,7 +196,7 @@ static int num_ntors_per_tap(void) { #define DEFAULT_NUM_NTORS_PER_TAP 10 -#define MIN_NUM_NTORS_PER_TAP 0 +#define MIN_NUM_NTORS_PER_TAP 1 #define MAX_NUM_NTORS_PER_TAP 100000

return networkstatus_get_param(NULL, "NumNTorsPerTAP",