Commit a4400952 authored by Roger Dingledine's avatar Roger Dingledine
Browse files

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.
parent a6679123

src/or/onion.c

+27 −4
Original line number Diff line number Diff line
@@ -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",