Use circuitmux_t in channels and when relaying cells

1 files changed, 135 insertions, 148 deletions

diff --git a/src/or/relay.c b/src/or/relay.c
index 60f696cd47..f0792437c3 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -1779,10 +1779,10 @@ circuit_consider_sending_sendme(circuit_t *circ, crypt_path_t *layer_hint)
 }
 
 #ifdef ACTIVE_CIRCUITS_PARANOIA
-#define assert_active_circuits_ok_paranoid(conn) \
-     assert_active_circuits_ok(conn)
+#define assert_cmux_ok_paranoid(chan) \
+     assert_cmux_okay(chan)
 #else
-#define assert_active_circuits_ok_paranoid(conn)
+#define assert_cmux_ok_paranoid(chan)
 #endif
 
 /** The total number of cells we have allocated from the memory pool. */
@@ -2004,6 +2004,7 @@ prev_circ_on_chan_p(circuit_t *circ, channel_t *chan)
   }
 }
 
+#if 0
 /** Helper for sorting cell_ewma_t values in their priority queue. */
 static int
 compare_cell_ewma_counts(const void *p1, const void *p2)
@@ -2240,122 +2241,61 @@ pop_first_cell_ewma_from_chan(channel_t *chan)
                               compare_cell_ewma_counts,
                               STRUCT_OFFSET(cell_ewma_t, heap_index));
 }
+#endif
 
-/** Add <b>circ</b> to the list of circuits with pending cells on
- * <b>chan</b>.  No effect if <b>circ</b> is already linked. */
+/**
+ * Update the number of cells available on the circuit's n_chan or p_chan's
+ * circuit mux.
+ */
 void
-make_circuit_active_on_chan(circuit_t *circ, channel_t *chan)
+update_circuit_on_cmux(circuit_t *circ, cell_direction_t direction)
 {
-  circuit_t **nextp = NULL, **prevp = NULL;
+  channel_t *chan = NULL;
+  or_circuit_t *or_circ = NULL;
+  circuitmux_t *cmux = NULL;
 
-  tor_assert(chan);
   tor_assert(circ);
 
-  nextp = next_circ_on_chan_p(circ, chan);
-  prevp = prev_circ_on_chan_p(circ, chan);
-
-  if (*nextp && *prevp) {
-    /* Already active. */
-    return;
-  }
-
-  assert_active_circuits_ok_paranoid(chan);
-
-  if (!(chan->active_circuits)) {
-    chan->active_circuits = circ;
-    *prevp = *nextp = circ;
-  } else {
-    circuit_t *head = chan->active_circuits;
-    circuit_t *old_tail = *prev_circ_on_chan_p(head, chan);
-    *next_circ_on_chan_p(old_tail, chan) = circ;
-    *nextp = head;
-    *prev_circ_on_chan_p(head, chan) = circ;
-    *prevp = old_tail;
-  }
-
-  if (circ->n_chan == chan) {
-    add_cell_ewma_to_chan(chan, &circ->n_cell_ewma);
+  /* Okay, get the channel */
+  if (direction == CELL_DIRECTION_OUT) {
+    chan = circ->n_chan;
   } else {
-    or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
-    tor_assert(chan == orcirc->p_chan);
-    add_cell_ewma_to_chan(chan, &orcirc->p_cell_ewma);
+    or_circ = TO_OR_CIRCUIT(circ);
+    chan = or_circ->p_chan;
   }
 
-  assert_active_circuits_ok_paranoid(chan);
-}
-
-/** Remove <b>circ</b> from the list of circuits with pending cells on
- * <b>chan</b>.  No effect if <b>circ</b> is already unlinked. */
-void
-make_circuit_inactive_on_chan(circuit_t *circ, channel_t *chan)
-{
-  circuit_t **nextp = NULL, **prevp = NULL;
-  circuit_t *next = NULL, *prev = NULL;
-
   tor_assert(chan);
-  tor_assert(circ);
+  tor_assert(chan->cmux);
 
-  nextp = next_circ_on_chan_p(circ, chan);
-  prevp = prev_circ_on_chan_p(circ, chan);
-  next = *nextp;
-  prev = *prevp;
+  /* Now get the cmux */
+  cmux = chan->cmux;
 
-  if (!next && !prev) {
-    /* Already inactive. */
-    return;
-  }
-
-  assert_active_circuits_ok_paranoid(chan);
-
-  tor_assert(next && prev);
-  tor_assert(*prev_circ_on_chan_p(next, chan) == circ);
-  tor_assert(*next_circ_on_chan_p(prev, chan) == circ);
+  /* Cmux sanity check */
+  tor_assert(circuitmux_is_circuit_attached(cmux, circ));
+  tor_assert(circuitmux_attached_circuit_direction(cmux, circ) == direction);
 
-  if (next == circ) {
-    chan->active_circuits = NULL;
-  } else {
-    *prev_circ_on_chan_p(next, chan) = prev;
-    *next_circ_on_chan_p(prev, chan) = next;
-    if (chan->active_circuits == circ)
-      chan->active_circuits = next;
-  }
-  *prevp = *nextp = NULL;
+  assert_cmux_ok_paranoid(chan);
 
-  if (circ->n_chan == chan) {
-    remove_cell_ewma_from_chan(chan, &circ->n_cell_ewma);
+  /* Update the number of cells we have for the circuit mux */
+  if (direction == CELL_DIRECTION_OUT) {
+    circuitmux_set_num_cells(cmux, circ, circ->n_chan_cells.n);
   } else {
-    or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
-    tor_assert(chan == orcirc->p_chan);
-    remove_cell_ewma_from_chan(chan, &orcirc->p_cell_ewma);
+    circuitmux_set_num_cells(cmux, circ, or_circ->p_chan_cells.n);
   }
 
-  assert_active_circuits_ok_paranoid(chan);
+  assert_cmux_ok_paranoid(chan);
 }
 
-/** Remove all circuits from the list of circuits with pending cells on
- * <b>chan</b>. */
+/** Remove all circuits from the cmux on <b>chan</b>. */
 void
-channel_unlink_all_active_circs(channel_t *chan)
+channel_unlink_all_circuits(channel_t *chan)
 {
-  circuit_t *head = NULL, *cur = NULL;
-
   tor_assert(chan);
+  tor_assert(chan->cmux);
 
-  cur = head = chan->active_circuits;
-  if (! head)
-    return;
-  do {
-    circuit_t *next = *next_circ_on_chan_p(cur, chan);
-    *prev_circ_on_chan_p(cur, chan) = NULL;
-    *next_circ_on_chan_p(cur, chan) = NULL;
-    cur = next;
-  } while (cur != head);
-  chan->active_circuits = NULL;
-
-  SMARTLIST_FOREACH(chan->active_circuit_pqueue,
-                    cell_ewma_t *, e,
-                    e->heap_index = -1);
-  smartlist_clear(chan->active_circuit_pqueue);
+  circuitmux_detach_all_circuits(chan->cmux);
+  chan->num_n_circuits = 0;
+  chan->num_p_circuits = 0;
 }
 
 /** Block (if <b>block</b> is true) or unblock (if <b>block</b> is false)
@@ -2419,53 +2359,71 @@ set_streams_blocked_on_circ(circuit_t *circ, channel_t *chan,
 int
 channel_flush_from_first_active_circuit(channel_t *chan, int max)
 {
-  int n_flushed;
+  circuitmux_t *cmux = NULL;
+  int n_flushed = 0;
   cell_queue_t *queue;
   circuit_t *circ;
+  or_circuit_t *or_circ;
   int streams_blocked;
+  packed_cell_t *cell;
 
+#if 0
   /* The current (hi-res) time */
   struct timeval now_hires;
 
   /* The EWMA cell counter for the circuit we're flushing. */
   cell_ewma_t *cell_ewma = NULL;
   double ewma_increment = -1;
+#endif
 
+  /* Get the cmux */
   tor_assert(chan);
+  tor_assert(chan->cmux);
+  cmux = chan->cmux;
+
+  /* Main loop: pick a circuit, send a cell, update the cmux */
+  while (n_flushed < max) {
+    circ = circuitmux_get_first_active_circuit(cmux);
+    /* If it returns NULL, no cells left to send */
+    if (!circ) break;
+    assert_cmux_ok_paranoid(chan);
+
+#if 0
+    /* This will go in circuitmux_get_first_active_circuit() */
+    /* See if we're doing the ewma circuit selection algorithm. */
+    if (ewma_enabled) {
+      unsigned tick;
+      double fractional_tick;
+      tor_gettimeofday_cached(&now_hires);
+      tick = cell_ewma_tick_from_timeval(&now_hires, &fractional_tick);
+
+      if (tick != chan->active_circuit_pqueue_last_recalibrated) {
+        scale_active_circuits(chan, tick);
+      }
 
-  circ = chan->active_circuits;
-  if (!circ) return 0;
-  assert_active_circuits_ok_paranoid(chan);
-
-  /* See if we're doing the ewma circuit selection algorithm. */
-  if (ewma_enabled) {
-    unsigned tick;
-    double fractional_tick;
-    tor_gettimeofday_cached(&now_hires);
-    tick = cell_ewma_tick_from_timeval(&now_hires, &fractional_tick);
+      ewma_increment = pow(ewma_scale_factor, -fractional_tick);
 
-    if (tick != chan->active_circuit_pqueue_last_recalibrated) {
-      scale_active_circuits(chan, tick);
+      cell_ewma = smartlist_get(chan->active_circuit_pqueue, 0);
+      circ = cell_ewma_to_circuit(cell_ewma);
     }
+#endif
 
-    ewma_increment = pow(ewma_scale_factor, -fractional_tick);
-
-    cell_ewma = smartlist_get(chan->active_circuit_pqueue, 0);
-    circ = cell_ewma_to_circuit(cell_ewma);
-  }
-
-  if (circ->n_chan == chan) {
-    queue = &circ->n_chan_cells;
-    streams_blocked = circ->streams_blocked_on_n_chan;
-  } else {
-    queue = &TO_OR_CIRCUIT(circ)->p_chan_cells;
-    streams_blocked = circ->streams_blocked_on_p_chan;
-  }
-  tor_assert(*next_circ_on_chan_p(circ, chan));
+    if (circ->n_chan == chan) {
+      queue = &circ->n_chan_cells;
+      streams_blocked = circ->streams_blocked_on_n_chan;
+    } else {
+      or_circ = TO_OR_CIRCUIT(circ);
+      tor_assert(or_circ->p_chan == chan);
+      queue = &TO_OR_CIRCUIT(circ)->p_chan_cells;
+      streams_blocked = circ->streams_blocked_on_p_chan;
+    }
 
-  for (n_flushed = 0; n_flushed < max && queue->head; ) {
-    packed_cell_t *cell = cell_queue_pop(queue);
-    tor_assert(*next_circ_on_chan_p(circ, chan));
+    /*
+     * Get just one cell here; once we've sent it, that can change the circuit
+     * selection, so we have to loop around for another even if this circuit
+     * has more than one.
+     */
+    cell = cell_queue_pop(queue);
 
     /* Calculate the exact time that this cell has spent in the queue. */
     if (get_options()->CellStatistics && !CIRCUIT_IS_ORIGIN(circ)) {
@@ -2481,8 +2439,8 @@ channel_flush_from_first_active_circuit(channel_t *chan, int max)
                              "Looks like the CellStatistics option was "
                              "recently enabled.");
       } else {
-        or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
         insertion_time_elem_t *elem = it_queue->first;
+        or_circ = TO_OR_CIRCUIT(circ);
         cell_waiting_time =
             (uint32_t)((flushed * 10L + SECONDS_IN_A_DAY * 1000L -
                         elem->insertion_time * 10L) %
@@ -2495,8 +2453,8 @@ channel_flush_from_first_active_circuit(channel_t *chan, int max)
             it_queue->last = NULL;
           mp_pool_release(elem);
         }
-        orcirc->total_cell_waiting_time += cell_waiting_time;
-        orcirc->processed_cells++;
+        or_circ->total_cell_waiting_time += cell_waiting_time;
+        or_circ->processed_cells++;
       }
     }
 
@@ -2507,14 +2465,34 @@ channel_flush_from_first_active_circuit(channel_t *chan, int max)
                                 DIRREQ_TUNNELED,
                                 DIRREQ_CIRC_QUEUE_FLUSHED);
 
+    /* Now send the cell */
     channel_write_packed_cell(chan, cell);
+    cell = NULL;
+
     /*
      * Don't packed_cell_free_unchecked(cell) here because the channel will
      * do so when it gets out of the channel queue (probably already did, in
      * which case that was an immediate double-free bug).
      */
 
+    /* Update the counter */
     ++n_flushed;
+
+    /*
+     * Now update the cmux; tell it we've just sent a cell, and how many
+     * we have left.
+     */
+    circuitmux_notify_xmit_cells(cmux, circ, 1);
+    circuitmux_set_num_cells(cmux, circ, queue->n);
+    if (queue->n == 0)
+      log_debug(LD_GENERAL, "Made a circuit inactive.");
+
+    /* Is the cell queue low enough to unblock all the streams that are waiting
+     * to write to this circuit? */
+    if (streams_blocked && queue->n <= CELL_QUEUE_LOWWATER_SIZE)
+      set_streams_blocked_on_circ(circ, chan, 0, 0); /* unblock streams */
+
+#if 0
     if (cell_ewma) {
       cell_ewma_t *tmp;
       cell_ewma->cell_count += ewma_increment;
@@ -2534,22 +2512,13 @@ channel_flush_from_first_active_circuit(channel_t *chan, int max)
       assert_active_circuits_ok_paranoid(chan);
       goto done;
     }
-  }
-  tor_assert(*next_circ_on_chan_p(circ, chan));
-  assert_active_circuits_ok_paranoid(chan);
-  chan->active_circuits = *next_circ_on_chan_p(circ, chan);
-
-  /* Is the cell queue low enough to unblock all the streams that are waiting
-   * to write to this circuit? */
-  if (streams_blocked && queue->n <= CELL_QUEUE_LOWWATER_SIZE)
-    set_streams_blocked_on_circ(circ, chan, 0, 0); /* unblock streams */
+#endif
 
-  /* Did we just run out of cells on this circuit's queue? */
-  if (queue->n == 0) {
-    log_debug(LD_GENERAL, "Made a circuit inactive.");
-    make_circuit_inactive_on_chan(circ, chan);
+    /* If n_flushed < max still, loop around and pick another circuit */
   }
- done:
+
+  /* Okay, we're done sending now */
+  assert_cmux_ok_paranoid(chan);
 
   return n_flushed;
 }
@@ -2587,11 +2556,11 @@ append_cell_to_circuit_queue(circuit_t *circ, channel_t *chan,
     set_streams_blocked_on_circ(circ, chan, 1, fromstream);
   }
 
+  update_circuit_on_cmux(circ, direction);
   if (queue->n == 1) {
-    /* This was the first cell added to the queue.  We need to make this
+    /* This was the first cell added to the queue.  We just made this
      * circuit active. */
     log_debug(LD_GENERAL, "Made a circuit active.");
-    make_circuit_active_on_chan(circ, chan);
   }
 
   if (!channel_has_queued_writes(chan)) {
@@ -2669,20 +2638,37 @@ void
 circuit_clear_cell_queue(circuit_t *circ, channel_t *chan)
 {
   cell_queue_t *queue;
+  cell_direction_t direction;
+
   if (circ->n_chan == chan) {
     queue = &circ->n_chan_cells;
+    direction = CELL_DIRECTION_OUT;
   } else {
     or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
     tor_assert(orcirc->p_chan == chan);
     queue = &orcirc->p_chan_cells;
+    direction = CELL_DIRECTION_IN;
   }
 
-  if (queue->n)
-    make_circuit_inactive_on_chan(circ, chan);
-
+  /* Clear the queue */
   cell_queue_clear(queue);
+
+  /* Update the cell counter in the cmux */
+  update_circuit_on_cmux(circ, direction);
+}
+
+/** Fail with an assert if the circuit mux on chan is corrupt
+ */
+void
+assert_circuit_mux_okay(channel_t *chan)
+{
+  tor_assert(chan);
+  tor_assert(chan->cmux);
+
+  circuitmux_assert_okay(chan->cmux);
 }
 
+#if 0
 /** Fail with an assert if the active circuits ring on <b>orconn</b> is
  * corrupt.  */
 void
@@ -2721,6 +2707,7 @@ assert_active_circuits_ok(channel_t *chan)
 
   tor_assert(n == smartlist_len(chan->active_circuit_pqueue));
 }
+#endif
 
 /** Return 1 if we shouldn't restart reading on this circuit, even if
  * we get a SENDME.  Else return 0.