Merge branch 'bug29085_rebase'

1 files changed, 238 insertions, 57 deletions

diff --git a/src/test/test_circuitpadding.c b/src/test/test_circuitpadding.c
index db175fecee..b2ae659a60 100644
--- a/src/test/test_circuitpadding.c
+++ b/src/test/test_circuitpadding.c
@@ -55,6 +55,7 @@ void test_circuitpadding_conditions(void *arg);
 void test_circuitpadding_serialize(void *arg);
 void test_circuitpadding_rtt(void *arg);
 void test_circuitpadding_tokens(void *arg);
+void test_circuitpadding_state_length(void *arg);
 
 static void
 simulate_single_hop_extend(circuit_t *client, circuit_t *mid_relay,
@@ -329,12 +330,12 @@ test_circuitpadding_rtt(void *arg)
   relay_side->padding_info[0] = circpad_circuit_machineinfo_new(client_side,0);
 
   /* Test 1: Test measuring RTT */
-  circpad_cell_event_nonpadding_received((circuit_t*)relay_side);
+  circpad_cell_event_nonpadding_received(relay_side);
   tt_u64_op(relay_side->padding_info[0]->last_received_time_usec, OP_NE, 0);
 
   timers_advance_and_run(20);
 
-  circpad_cell_event_nonpadding_sent((circuit_t*)relay_side);
+  circpad_cell_event_nonpadding_sent(relay_side);
   tt_u64_op(relay_side->padding_info[0]->last_received_time_usec, OP_EQ, 0);
 
   tt_int_op(relay_side->padding_info[0]->rtt_estimate_usec, OP_GE, 19000);
@@ -345,12 +346,12 @@ test_circuitpadding_rtt(void *arg)
             circpad_machine_current_state(
              relay_side->padding_info[0])->histogram_edges[0]);
 
-  circpad_cell_event_nonpadding_received((circuit_t*)relay_side);
-  circpad_cell_event_nonpadding_received((circuit_t*)relay_side);
+  circpad_cell_event_nonpadding_received(relay_side);
+  circpad_cell_event_nonpadding_received(relay_side);
   tt_u64_op(relay_side->padding_info[0]->last_received_time_usec, OP_NE, 0);
   timers_advance_and_run(20);
-  circpad_cell_event_nonpadding_sent((circuit_t*)relay_side);
-  circpad_cell_event_nonpadding_sent((circuit_t*)relay_side);
+  circpad_cell_event_nonpadding_sent(relay_side);
+  circpad_cell_event_nonpadding_sent(relay_side);
   tt_u64_op(relay_side->padding_info[0]->last_received_time_usec, OP_EQ, 0);
 
   tt_int_op(relay_side->padding_info[0]->rtt_estimate_usec, OP_GE, 20000);
@@ -365,9 +366,9 @@ test_circuitpadding_rtt(void *arg)
   tt_int_op(relay_side->padding_info[0]->stop_rtt_update, OP_EQ, 1);
   rtt_estimate = relay_side->padding_info[0]->rtt_estimate_usec;
 
-  circpad_cell_event_nonpadding_received((circuit_t*)relay_side);
+  circpad_cell_event_nonpadding_received(relay_side);
   timers_advance_and_run(4);
-  circpad_cell_event_nonpadding_sent((circuit_t*)relay_side);
+  circpad_cell_event_nonpadding_sent(relay_side);
 
   tt_int_op(relay_side->padding_info[0]->rtt_estimate_usec, OP_EQ,
             rtt_estimate);
@@ -380,11 +381,11 @@ test_circuitpadding_rtt(void *arg)
              relay_side->padding_info[0])->histogram_edges[0]);
 
   /* Test 3: Make sure client side machine properly ignores RTT */
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
   tt_u64_op(client_side->padding_info[0]->last_received_time_usec, OP_EQ, 0);
 
   timers_advance_and_run(20);
-  circpad_cell_event_nonpadding_sent((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_u64_op(client_side->padding_info[0]->last_received_time_usec, OP_EQ, 0);
 
   tt_int_op(client_side->padding_info[0]->rtt_estimate_usec, OP_EQ, 0);
@@ -415,6 +416,7 @@ helper_create_basic_machine(void)
 
   circ_client_machine.states[CIRCPAD_STATE_START].
       next_state[CIRCPAD_EVENT_NONPADDING_RECV] = CIRCPAD_STATE_BURST;
+  circ_client_machine.states[CIRCPAD_STATE_START].use_rtt_estimate = 1;
 
   circ_client_machine.states[CIRCPAD_STATE_BURST].
       next_state[CIRCPAD_EVENT_PADDING_RECV] = CIRCPAD_STATE_BURST;
@@ -526,7 +528,7 @@ test_circuitpadding_token_removal_higher(void *arg)
   MOCK(circpad_machine_schedule_padding,circpad_machine_schedule_padding_mock);
 
   /* Setup test environment (time etc.) */
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
   monotime_enable_test_mocking();
 
@@ -537,7 +539,7 @@ test_circuitpadding_token_removal_higher(void *arg)
     circpad_circuit_machineinfo_new(client_side, 0);
 
   /* move the machine to the right state */
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
   tt_int_op(client_side->padding_info[0]->current_state, OP_EQ,
             CIRCPAD_STATE_BURST);
 
@@ -586,12 +588,12 @@ test_circuitpadding_token_removal_higher(void *arg)
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 2);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 1);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     /* Test that we cleaned out this bin. Don't do this in the case of the last
        bin since the tokens will get refilled */
@@ -610,7 +612,7 @@ test_circuitpadding_token_removal_higher(void *arg)
             CIRCPAD_STATE_BURST);
   circ_client_machine.states[CIRCPAD_STATE_BURST].histogram_edges[0] = 100;
   mi->padding_scheduled_at_usec = current_time;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[0], OP_EQ, 1);
 
  done:
@@ -631,7 +633,7 @@ test_circuitpadding_token_removal_lower(void *arg)
   MOCK(circpad_machine_schedule_padding,circpad_machine_schedule_padding_mock);
 
   /* Setup test environment (time etc.) */
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
   monotime_enable_test_mocking();
 
@@ -642,7 +644,7 @@ test_circuitpadding_token_removal_lower(void *arg)
     circpad_circuit_machineinfo_new(client_side, 0);
 
   /* move the machine to the right state */
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
   tt_int_op(client_side->padding_info[0]->current_state, OP_EQ,
             CIRCPAD_STATE_BURST);
 
@@ -683,12 +685,12 @@ test_circuitpadding_token_removal_lower(void *arg)
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 2);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 1);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     /* Test that we cleaned out this bin. Don't do this in the case of the last
        bin since the tokens will get refilled */
@@ -708,7 +710,7 @@ test_circuitpadding_token_removal_lower(void *arg)
   circ_client_machine.states[CIRCPAD_STATE_BURST].
     histogram_edges[BIG_HISTOGRAM_LEN-2] = 100;
   mi->padding_scheduled_at_usec = current_time - 29202;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[BIG_HISTOGRAM_LEN-2], OP_EQ, 1);
 
  done:
@@ -729,7 +731,7 @@ test_circuitpadding_closest_token_removal(void *arg)
   MOCK(circpad_machine_schedule_padding,circpad_machine_schedule_padding_mock);
 
   /* Setup test environment (time etc.) */
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
   monotime_enable_test_mocking();
 
@@ -740,7 +742,7 @@ test_circuitpadding_closest_token_removal(void *arg)
     circpad_circuit_machineinfo_new(client_side, 0);
 
   /* move the machine to the right state */
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
   tt_int_op(client_side->padding_info[0]->current_state, OP_EQ,
             CIRCPAD_STATE_BURST);
 
@@ -780,12 +782,12 @@ test_circuitpadding_closest_token_removal(void *arg)
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 2);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 1);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     /* Test that we cleaned out this bin. Don't do this in the case of the last
        bin since the tokens will get refilled */
@@ -807,14 +809,14 @@ test_circuitpadding_closest_token_removal(void *arg)
   circ_client_machine.states[CIRCPAD_STATE_BURST].histogram_edges[2] = 120;
   mi->padding_scheduled_at_usec = current_time - 102;
   mi->histogram[0] = 0;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[1], OP_EQ, 1);
 
   /* Test above the highest bin, for coverage */
   tt_int_op(client_side->padding_info[0]->current_state, OP_EQ,
             CIRCPAD_STATE_BURST);
   mi->padding_scheduled_at_usec = current_time - 29202;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[BIG_HISTOGRAM_LEN-2], OP_EQ, 1);
 
  done:
@@ -835,7 +837,7 @@ test_circuitpadding_closest_token_removal_usec(void *arg)
   MOCK(circpad_machine_schedule_padding,circpad_machine_schedule_padding_mock);
 
   /* Setup test environment (time etc.) */
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
   monotime_enable_test_mocking();
 
@@ -846,7 +848,7 @@ test_circuitpadding_closest_token_removal_usec(void *arg)
     circpad_circuit_machineinfo_new(client_side, 0);
 
   /* move the machine to the right state */
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
   tt_int_op(client_side->padding_info[0]->current_state, OP_EQ,
             CIRCPAD_STATE_BURST);
 
@@ -889,12 +891,12 @@ test_circuitpadding_closest_token_removal_usec(void *arg)
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 2);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     tt_int_op(mi->histogram[bin_to_remove], OP_EQ, 1);
 
     mi->padding_scheduled_at_usec = current_time - 57;
-    circpad_machine_remove_token(mi);
+    circpad_cell_event_nonpadding_sent(client_side);
 
     /* Test that we cleaned out this bin. Don't do this in the case of the last
        bin since the tokens will get refilled */
@@ -916,7 +918,7 @@ test_circuitpadding_closest_token_removal_usec(void *arg)
   circ_client_machine.states[CIRCPAD_STATE_BURST].histogram_edges[2] = 120;
   mi->padding_scheduled_at_usec = current_time - 102;
   mi->histogram[0] = 0;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[1], OP_EQ, 1);
 
   /* Test above the highest bin, for coverage */
@@ -925,7 +927,7 @@ test_circuitpadding_closest_token_removal_usec(void *arg)
   circ_client_machine.states[CIRCPAD_STATE_BURST].
     histogram_edges[BIG_HISTOGRAM_LEN-2] = 100;
   mi->padding_scheduled_at_usec = current_time - 29202;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[BIG_HISTOGRAM_LEN-2], OP_EQ, 1);
 
  done:
@@ -946,7 +948,7 @@ test_circuitpadding_token_removal_exact(void *arg)
   MOCK(circpad_machine_schedule_padding,circpad_machine_schedule_padding_mock);
 
   /* Setup test environment (time etc.) */
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
   monotime_enable_test_mocking();
 
@@ -957,7 +959,7 @@ test_circuitpadding_token_removal_exact(void *arg)
     circpad_circuit_machineinfo_new(client_side, 0);
 
   /* move the machine to the right state */
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
   tt_int_op(client_side->padding_info[0]->current_state, OP_EQ,
             CIRCPAD_STATE_BURST);
 
@@ -971,16 +973,16 @@ test_circuitpadding_token_removal_exact(void *arg)
   /* Ensure that we will clear out bin #4 with this usec */
   mi->padding_scheduled_at_usec = current_time - 57;
   tt_int_op(mi->histogram[4], OP_EQ, 2);
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   mi->padding_scheduled_at_usec = current_time - 57;
   tt_int_op(mi->histogram[4], OP_EQ, 1);
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   tt_int_op(mi->histogram[4], OP_EQ, 0);
 
   /* Ensure that we will not remove any other tokens even tho we try to, since
    * this is what the exact strategy dictates */
   mi->padding_scheduled_at_usec = current_time - 57;
-  circpad_machine_remove_token(mi);
+  circpad_cell_event_nonpadding_sent(client_side);
   for (int i = 0; i < BIG_HISTOGRAM_LEN ; i++) {
     if (i != 4) {
       tt_int_op(mi->histogram[i], OP_EQ, 2);
@@ -1046,8 +1048,8 @@ test_circuitpadding_tokens(void *arg)
   mi = client_side->padding_info[0];
 
   // Pretend a non-padding cell was sent
-  circpad_cell_event_nonpadding_received((circuit_t*)client_side);
-  circpad_cell_event_nonpadding_sent((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_received(client_side);
+  circpad_cell_event_nonpadding_sent(client_side);
   /* We have to save the infinity bin because one inf delay
    * could have been chosen when we transition to burst */
   circpad_hist_token_t inf_bin = mi->histogram[4];
@@ -1156,11 +1158,11 @@ test_circuitpadding_tokens(void *arg)
   /* Drain the infinity bin and cause a refill */
   while (inf_bin != 0) {
     tt_int_op(mi->histogram[4], OP_EQ, inf_bin);
-    circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+    circpad_cell_event_nonpadding_received(client_side);
     inf_bin--;
   }
 
-  circpad_cell_event_nonpadding_sent((circuit_t*)client_side);
+  circpad_cell_event_nonpadding_sent(client_side);
 
   // We should have refilled here.
   tt_int_op(mi->histogram[4], OP_EQ, 2);
@@ -1284,10 +1286,10 @@ test_circuitpadding_wronghop(void *arg)
    * padding that gets sent by scheduled timers. */
   MOCK(circpad_machine_schedule_padding,circpad_machine_schedule_padding_mock);
 
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   dummy_channel.cmux = circuitmux_alloc();
-  relay_side = (circuit_t *)new_fake_orcirc(&dummy_channel,
-                                            &dummy_channel);
+  relay_side = TO_CIRCUIT(new_fake_orcirc(&dummy_channel,
+                                            &dummy_channel));
   orig_client = TO_ORIGIN_CIRCUIT(client_side);
 
   relay_side->purpose = CIRCUIT_PURPOSE_OR;
@@ -1405,9 +1407,9 @@ test_circuitpadding_wronghop(void *arg)
   free_fake_origin_circuit(TO_ORIGIN_CIRCUIT(client_side));
   free_fake_orcirc(relay_side);
 
-  client_side = (circuit_t *)origin_circuit_new();
-  relay_side = (circuit_t *)new_fake_orcirc(&dummy_channel,
-                                            &dummy_channel);
+  client_side = TO_CIRCUIT(origin_circuit_new());
+  relay_side = TO_CIRCUIT(new_fake_orcirc(&dummy_channel,
+                                            &dummy_channel));
   relay_side->purpose = CIRCUIT_PURPOSE_OR;
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
 
@@ -1601,10 +1603,10 @@ simulate_single_hop_extend(circuit_t *client, circuit_t *mid_relay,
   tor_addr_t addr;
 
   // Pretend a non-padding cell was sent
-  circpad_cell_event_nonpadding_sent((circuit_t*)client);
+  circpad_cell_event_nonpadding_sent(client);
 
   // Receive extend cell at middle
-  circpad_cell_event_nonpadding_received((circuit_t*)mid_relay);
+  circpad_cell_event_nonpadding_received(mid_relay);
 
   // Advance time a tiny bit so we can calculate an RTT
   curr_mocked_time += 10 * TOR_NSEC_PER_MSEC;
@@ -1612,10 +1614,10 @@ simulate_single_hop_extend(circuit_t *client, circuit_t *mid_relay,
   monotime_set_mock_time_nsec(curr_mocked_time);
 
   // Receive extended cell at middle
-  circpad_cell_event_nonpadding_sent((circuit_t*)mid_relay);
+  circpad_cell_event_nonpadding_sent(mid_relay);
 
   // Receive extended cell at first hop
-  circpad_cell_event_nonpadding_received((circuit_t*)client);
+  circpad_cell_event_nonpadding_received(client);
 
   // Add a hop to cpath
   crypt_path_t *hop = tor_malloc_zero(sizeof(crypt_path_t));
@@ -1643,6 +1645,55 @@ simulate_single_hop_extend(circuit_t *client, circuit_t *mid_relay,
 }
 
 static circpad_machine_spec_t *
+helper_create_length_machine(void)
+{
+  circpad_machine_spec_t *ret =
+    tor_malloc_zero(sizeof(circpad_machine_spec_t));
+
+  /* Start, burst */
+  circpad_machine_states_init(ret, 2);
+
+  ret->states[CIRCPAD_STATE_START].
+      next_state[CIRCPAD_EVENT_PADDING_SENT] = CIRCPAD_STATE_BURST;
+
+  ret->states[CIRCPAD_STATE_BURST].
+      next_state[CIRCPAD_EVENT_PADDING_SENT] = CIRCPAD_STATE_BURST;
+
+  ret->states[CIRCPAD_STATE_BURST].
+      next_state[CIRCPAD_EVENT_LENGTH_COUNT] = CIRCPAD_STATE_END;
+
+  ret->states[CIRCPAD_STATE_BURST].
+      next_state[CIRCPAD_EVENT_BINS_EMPTY] = CIRCPAD_STATE_END;
+
+  /* No token removal.. end via state_length only */
+  ret->states[CIRCPAD_STATE_BURST].token_removal =
+      CIRCPAD_TOKEN_REMOVAL_NONE;
+
+  /* Let's have this one end after 12 packets */
+  ret->states[CIRCPAD_STATE_BURST].length_dist.type = CIRCPAD_DIST_UNIFORM;
+  ret->states[CIRCPAD_STATE_BURST].length_dist.param1 = 12;
+  ret->states[CIRCPAD_STATE_BURST].length_dist.param2 = 13;
+  ret->states[CIRCPAD_STATE_BURST].max_length = 12;
+
+  ret->states[CIRCPAD_STATE_BURST].histogram_len = 4;
+
+  ret->states[CIRCPAD_STATE_BURST].histogram_edges[0] = 0;
+  ret->states[CIRCPAD_STATE_BURST].histogram_edges[1] = 1;
+  ret->states[CIRCPAD_STATE_BURST].histogram_edges[2] = 1000000;
+  ret->states[CIRCPAD_STATE_BURST].histogram_edges[3] = 10000000;
+
+  ret->states[CIRCPAD_STATE_BURST].histogram[0] = 0;
+  ret->states[CIRCPAD_STATE_BURST].histogram[1] = 0;
+  ret->states[CIRCPAD_STATE_BURST].histogram[2] = 6;
+
+  ret->states[CIRCPAD_STATE_BURST].histogram_total_tokens = 6;
+  ret->states[CIRCPAD_STATE_BURST].use_rtt_estimate = 0;
+  ret->states[CIRCPAD_STATE_BURST].length_includes_nonpadding = 0;
+
+  return ret;
+}
+
+static circpad_machine_spec_t *
 helper_create_conditional_machine(void)
 {
   circpad_machine_spec_t *ret =
@@ -1738,6 +1789,135 @@ helper_create_conditional_machines(void)
 }
 
 void
+test_circuitpadding_state_length(void *arg)
+{
+  /**
+   * Test plan:
+   *  * Explicitly test that with no token removal enabled, we hit
+   *    the state length limit due to either padding, or non-padding.
+   *  * Repeat test with an arbitrary token removal strategy, and
+   *    verify that if we run out of tokens due to padding before we
+   *    hit the state length, we still go to state end (all our
+   *    token removal tests only test nonpadding token removal).
+   */
+  int64_t actual_mocked_monotime_start;
+  (void)arg;
+  MOCK(circuitmux_attach_circuit, circuitmux_attach_circuit_mock);
+  MOCK(circpad_send_command_to_hop, circpad_send_command_to_hop_mock);
+
+  nodes_init();
+  dummy_channel.cmux = circuitmux_alloc();
+  relay_side = TO_CIRCUIT(new_fake_orcirc(&dummy_channel,
+                                            &dummy_channel));
+  client_side = TO_CIRCUIT(origin_circuit_new());
+  relay_side->purpose = CIRCUIT_PURPOSE_OR;
+  client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
+
+  monotime_init();
+  monotime_enable_test_mocking();
+  actual_mocked_monotime_start = MONOTIME_MOCK_START;
+  monotime_set_mock_time_nsec(actual_mocked_monotime_start);
+  monotime_coarse_set_mock_time_nsec(actual_mocked_monotime_start);
+  curr_mocked_time = actual_mocked_monotime_start;
+
+  /* This is needed so that we are not considered to be dormant */
+  note_user_activity(20);
+
+  timers_initialize();
+  circpad_machine_spec_t *client_machine =
+      helper_create_length_machine();
+
+  MOCK(circuit_package_relay_cell,
+       circuit_package_relay_cell_mock);
+  MOCK(node_get_by_id,
+       node_get_by_id_mock);
+
+  client_side->padding_machine[0] = client_machine;
+  client_side->padding_info[0] =
+    circpad_circuit_machineinfo_new(client_side, 0);
+  circpad_machine_runtime_t *mi = client_side->padding_info[0];
+
+  circpad_cell_event_padding_sent(client_side);
+  tt_int_op(mi->state_length, OP_EQ, 12);
+  tt_ptr_op(mi->histogram, OP_EQ, NULL);
+
+  /* Verify that non-padding does not change our state length */
+  circpad_cell_event_nonpadding_sent(client_side);
+  tt_int_op(mi->state_length, OP_EQ, 12);
+
+  /* verify that sending padding changes our state length */
+  for (uint64_t i = mi->state_length-1; i > 0; i--) {
+    circpad_send_padding_cell_for_callback(mi);
+    tt_int_op(mi->state_length, OP_EQ, i);
+  }
+  circpad_send_padding_cell_for_callback(mi);
+
+  tt_int_op(mi->state_length, OP_EQ, -1);
+  tt_int_op(mi->current_state, OP_EQ, CIRCPAD_STATE_END);
+
+  /* Restart machine */
+  mi->current_state = CIRCPAD_STATE_START;
+
+  /* Now, count nonpadding as part of the state length */
+  client_machine->states[CIRCPAD_STATE_BURST].length_includes_nonpadding = 1;
+
+  circpad_cell_event_padding_sent(client_side);
+  tt_int_op(mi->state_length, OP_EQ, 12);
+
+  /* Verify that non-padding does change our state length now */
+  for (uint64_t i = mi->state_length-1; i > 0; i--) {
+    circpad_cell_event_nonpadding_sent(client_side);
+    tt_int_op(mi->state_length, OP_EQ, i);
+  }
+
+  circpad_cell_event_nonpadding_sent(client_side);
+  tt_int_op(mi->state_length, OP_EQ, -1);
+  tt_int_op(mi->current_state, OP_EQ, CIRCPAD_STATE_END);
+
+  /* Now, just test token removal when we send padding */
+  client_machine->states[CIRCPAD_STATE_BURST].token_removal =
+      CIRCPAD_TOKEN_REMOVAL_EXACT;
+
+  /* Restart machine */
+  mi->current_state = CIRCPAD_STATE_START;
+  circpad_cell_event_padding_sent(client_side);
+  tt_int_op(mi->state_length, OP_EQ, 12);
+  tt_ptr_op(mi->histogram, OP_NE, NULL);
+  tt_int_op(mi->chosen_bin, OP_EQ, 2);
+
+  /* verify that sending padding changes our state length and
+   * our histogram now */
+  for (uint32_t i = mi->histogram[2]-1; i > 0; i--) {
+    circpad_send_padding_cell_for_callback(mi);
+    tt_int_op(mi->chosen_bin, OP_EQ, 2);
+    tt_int_op(mi->histogram[2], OP_EQ, i);
+  }
+
+  tt_int_op(mi->state_length, OP_EQ, 7);
+  tt_int_op(mi->histogram[2], OP_EQ, 1);
+
+  circpad_send_padding_cell_for_callback(mi);
+  tt_int_op(mi->current_state, OP_EQ, CIRCPAD_STATE_END);
+
+ done:
+  tor_free(client_machine->states);
+  tor_free(client_machine);
+
+  free_fake_origin_circuit(TO_ORIGIN_CIRCUIT(client_side));
+  free_fake_orcirc(relay_side);
+
+  circuitmux_detach_all_circuits(dummy_channel.cmux, NULL);
+  circuitmux_free(dummy_channel.cmux);
+  timers_shutdown();
+  monotime_disable_test_mocking();
+  UNMOCK(circuit_package_relay_cell);
+  UNMOCK(circuitmux_attach_circuit);
+  UNMOCK(node_get_by_id);
+
+  return;
+}
+
+void
 test_circuitpadding_conditions(void *arg)
 {
   /**
@@ -1761,9 +1941,9 @@ test_circuitpadding_conditions(void *arg)
 
   nodes_init();
   dummy_channel.cmux = circuitmux_alloc();
-  relay_side = (circuit_t *)new_fake_orcirc(&dummy_channel,
-                                            &dummy_channel);
-  client_side = (circuit_t *)origin_circuit_new();
+  relay_side = TO_CIRCUIT(new_fake_orcirc(&dummy_channel,
+                                            &dummy_channel));
+  client_side = TO_CIRCUIT(origin_circuit_new());
   relay_side->purpose = CIRCUIT_PURPOSE_OR;
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
 
@@ -2217,7 +2397,7 @@ test_circuitpadding_sample_distribution(void *arg)
     }
 
     /* send a non-padding cell to move to the next machine state */
-    circpad_cell_event_nonpadding_received((circuit_t*)client_side);
+    circpad_cell_event_nonpadding_received(client_side);
   }
 
  done:
@@ -2329,12 +2509,12 @@ test_circuitpadding_global_rate_limiting(void *arg)
   curr_mocked_time = actual_mocked_monotime_start;
   timers_initialize();
 
-  client_side = (circuit_t *)origin_circuit_new();
+  client_side = TO_CIRCUIT(origin_circuit_new());
   client_side->purpose = CIRCUIT_PURPOSE_C_GENERAL;
   dummy_channel.cmux = circuitmux_alloc();
 
   /* Setup machine and circuits */
-  relay_side = (circuit_t *)new_fake_orcirc(&dummy_channel, &dummy_channel);
+  relay_side = TO_CIRCUIT(new_fake_orcirc(&dummy_channel, &dummy_channel));
   relay_side->purpose = CIRCUIT_PURPOSE_OR;
   helper_create_basic_machine();
   relay_side->padding_machine[0] = &circ_client_machine;
@@ -2555,6 +2735,7 @@ test_circuitpadding_reduce_disable(void *arg)
 
 struct testcase_t circuitpadding_tests[] = {
   TEST_CIRCUITPADDING(circuitpadding_tokens, TT_FORK),
+  TEST_CIRCUITPADDING(circuitpadding_state_length, TT_FORK),
   TEST_CIRCUITPADDING(circuitpadding_negotiation, TT_FORK),
   TEST_CIRCUITPADDING(circuitpadding_wronghop, TT_FORK),
   /** Disabled unstable test until #29298 is implemented (see #29122) */