1 files changed, 95 insertions, 124 deletions

diff --git a/src/core/or/circuitlist.c b/src/core/or/circuitlist.c
index ccf3041bb4..384835667d 100644
--- a/src/core/or/circuitlist.c
+++ b/src/core/or/circuitlist.c
@@ -1,7 +1,7 @@
 /* Copyright 2001 Matej Pfajfar.
  * Copyright (c) 2001-2004, Roger Dingledine.
  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2019, The Tor Project, Inc. */
+ * Copyright (c) 2007-2020, The Tor Project, Inc. */
 /* See LICENSE for licensing information */
 
 /**
@@ -51,6 +51,7 @@
  * logic, which was originally circuit-focused.
  **/
 #define CIRCUITLIST_PRIVATE
+#define OCIRC_EVENT_PRIVATE
 #include "lib/cc/torint.h"  /* TOR_PRIuSZ */
 
 #include "core/or/or.h"
@@ -61,11 +62,13 @@
 #include "core/or/circuitlist.h"
 #include "core/or/circuituse.h"
 #include "core/or/circuitstats.h"
+#include "core/or/circuitpadding.h"
+#include "core/or/crypt_path.h"
 #include "core/mainloop/connection.h"
 #include "app/config/config.h"
 #include "core/or/connection_edge.h"
 #include "core/or/connection_or.h"
-#include "feature/control/control.h"
+#include "feature/control/control_events.h"
 #include "lib/crypt_ops/crypto_rand.h"
 #include "lib/crypt_ops/crypto_util.h"
 #include "lib/crypt_ops/crypto_dh.h"
@@ -94,7 +97,9 @@
 #include "lib/compress/compress_lzma.h"
 #include "lib/compress/compress_zlib.h"
 #include "lib/compress/compress_zstd.h"
-#include "lib/container/buffers.h"
+#include "lib/buf/buffers.h"
+
+#include "core/or/ocirc_event.h"
 
 #include "ht.h"
 
@@ -127,7 +132,6 @@ static smartlist_t *circuits_pending_other_guards = NULL;
  * circuit_mark_for_close and which are waiting for circuit_about_to_free. */
 static smartlist_t *circuits_pending_close = NULL;
 
-static void circuit_free_cpath_node(crypt_path_t *victim);
 static void cpath_ref_decref(crypt_path_reference_t *cpath_ref);
 static void circuit_about_to_free_atexit(circuit_t *circ);
 static void circuit_about_to_free(circuit_t *circ);
@@ -142,6 +146,9 @@ static int any_opened_circs_cached_val = 0;
 
 /********* END VARIABLES ************/
 
+/* Implement circuit handle helpers. */
+HANDLE_IMPL(circuit, circuit_t,)
+
 or_circuit_t *
 TO_OR_CIRCUIT(circuit_t *x)
 {
@@ -208,10 +215,10 @@ chan_circid_entry_hash_(chan_circid_circuit_map_t *a)
 static HT_HEAD(chan_circid_map, chan_circid_circuit_map_t)
      chan_circid_map = HT_INITIALIZER();
 HT_PROTOTYPE(chan_circid_map, chan_circid_circuit_map_t, node,
-             chan_circid_entry_hash_, chan_circid_entries_eq_)
+             chan_circid_entry_hash_, chan_circid_entries_eq_);
 HT_GENERATE2(chan_circid_map, chan_circid_circuit_map_t, node,
              chan_circid_entry_hash_, chan_circid_entries_eq_, 0.6,
-             tor_reallocarray_, tor_free_)
+             tor_reallocarray_, tor_free_);
 
 /** The most recently returned entry from circuit_get_by_circid_chan;
  * used to improve performance when many cells arrive in a row from the
@@ -481,6 +488,54 @@ circuit_set_n_circid_chan(circuit_t *circ, circid_t id,
   }
 }
 
+/**
+ * Helper function to publish a message about events on an origin circuit
+ *
+ * Publishes a message to subscribers of origin circuit events, and
+ * sends the control event.
+ **/
+int
+circuit_event_status(origin_circuit_t *circ, circuit_status_event_t tp,
+                     int reason_code)
+{
+  ocirc_cevent_msg_t *msg = tor_malloc(sizeof(*msg));
+
+  tor_assert(circ);
+
+  msg->gid = circ->global_identifier;
+  msg->evtype = tp;
+  msg->reason = reason_code;
+  msg->onehop = circ->build_state->onehop_tunnel;
+
+  ocirc_cevent_publish(msg);
+  return control_event_circuit_status(circ, tp, reason_code);
+}
+
+/**
+ * Helper function to publish a state change message
+ *
+ * circuit_set_state() calls this to notify subscribers about a change
+ * of the state of an origin circuit.  @a circ must be an origin
+ * circuit.
+ **/
+static void
+circuit_state_publish(const circuit_t *circ)
+{
+  ocirc_state_msg_t *msg = tor_malloc(sizeof(*msg));
+  const origin_circuit_t *ocirc;
+
+  tor_assert(CIRCUIT_IS_ORIGIN(circ));
+  ocirc = CONST_TO_ORIGIN_CIRCUIT(circ);
+  /* Only inbound OR circuits can be in this state, not origin circuits. */
+  tor_assert(circ->state != CIRCUIT_STATE_ONIONSKIN_PENDING);
+
+  msg->gid = ocirc->global_identifier;
+  msg->state = circ->state;
+  msg->onehop = ocirc->build_state->onehop_tunnel;
+
+  ocirc_state_publish(msg);
+}
+
 /** Change the state of <b>circ</b> to <b>state</b>, adding it to or removing
  * it from lists as appropriate. */
 void
@@ -510,6 +565,8 @@ circuit_set_state(circuit_t *circ, uint8_t state)
   if (state == CIRCUIT_STATE_GUARD_WAIT || state == CIRCUIT_STATE_OPEN)
     tor_assert(!circ->n_chan_create_cell);
   circ->state = state;
+  if (CIRCUIT_IS_ORIGIN(circ))
+    circuit_state_publish(circ);
 }
 
 /** Append to <b>out</b> all circuits in state CHAN_WAIT waiting for
@@ -767,6 +824,8 @@ circuit_purpose_to_controller_string(uint8_t purpose)
       return "PATH_BIAS_TESTING";
     case CIRCUIT_PURPOSE_HS_VANGUARDS:
       return "HS_VANGUARDS";
+    case CIRCUIT_PURPOSE_C_CIRCUIT_PADDING:
+      return "CIRCUIT_PADDING";
 
     default:
       tor_snprintf(buf, sizeof(buf), "UNKNOWN_%d", (int)purpose);
@@ -796,6 +855,7 @@ circuit_purpose_to_controller_hs_state_string(uint8_t purpose)
     case CIRCUIT_PURPOSE_CONTROLLER:
     case CIRCUIT_PURPOSE_PATH_BIAS_TESTING:
     case CIRCUIT_PURPOSE_HS_VANGUARDS:
+    case CIRCUIT_PURPOSE_C_CIRCUIT_PADDING:
       return NULL;
 
     case CIRCUIT_PURPOSE_INTRO_POINT:
@@ -896,6 +956,9 @@ circuit_purpose_to_string(uint8_t purpose)
     case CIRCUIT_PURPOSE_HS_VANGUARDS:
       return "Hidden service: Pre-built vanguard circuit";
 
+    case CIRCUIT_PURPOSE_C_CIRCUIT_PADDING:
+      return "Circuit kept open for padding";
+
     default:
       tor_snprintf(buf, sizeof(buf), "UNKNOWN_%d", (int)purpose);
       return buf;
@@ -931,6 +994,7 @@ init_circuit_base(circuit_t *circ)
 
   circ->package_window = circuit_initial_package_window();
   circ->deliver_window = CIRCWINDOW_START;
+  circuit_reset_sendme_randomness(circ);
   cell_queue_init(&circ->n_chan_cells);
 
   smartlist_add(circuit_get_global_list(), circ);
@@ -1072,7 +1136,7 @@ circuit_free_(circuit_t *circ)
    * circuit is closed. This is to avoid any code path that free registered
    * circuits without closing them before. This needs to be done before the
    * hs identifier is freed. */
-  hs_circ_cleanup(circ);
+  hs_circ_cleanup_on_free(circ);
 
   if (CIRCUIT_IS_ORIGIN(circ)) {
     origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
@@ -1092,7 +1156,7 @@ circuit_free_(circuit_t *circ)
 
     if (ocirc->build_state) {
         extend_info_free(ocirc->build_state->chosen_exit);
-        circuit_free_cpath_node(ocirc->build_state->pending_final_cpath);
+        cpath_free(ocirc->build_state->pending_final_cpath);
         cpath_ref_decref(ocirc->build_state->service_pending_final_cpath_ref);
     }
     tor_free(ocirc->build_state);
@@ -1171,11 +1235,23 @@ circuit_free_(circuit_t *circ)
    * "active" checks will be violated. */
   cell_queue_clear(&circ->n_chan_cells);
 
+  /* Cleanup possible SENDME state. */
+  if (circ->sendme_last_digests) {
+    SMARTLIST_FOREACH(circ->sendme_last_digests, uint8_t *, d, tor_free(d));
+    smartlist_free(circ->sendme_last_digests);
+  }
+
   log_info(LD_CIRC, "Circuit %u (id: %" PRIu32 ") has been freed.",
            n_circ_id,
            CIRCUIT_IS_ORIGIN(circ) ?
               TO_ORIGIN_CIRCUIT(circ)->global_identifier : 0);
 
+  /* Free any circuit padding structures */
+  circpad_circuit_free_all_machineinfos(circ);
+
+  /* Clear all dangling handle references. */
+  circuit_handles_clear(circ);
+
   if (should_free) {
     memwipe(mem, 0xAA, memlen); /* poison memory */
     tor_free(mem);
@@ -1207,10 +1283,10 @@ circuit_clear_cpath(origin_circuit_t *circ)
   while (cpath->next && cpath->next != head) {
     victim = cpath;
     cpath = victim->next;
-    circuit_free_cpath_node(victim);
+    cpath_free(victim);
   }
 
-  circuit_free_cpath_node(cpath);
+  cpath_free(cpath);
 
   circ->cpath = NULL;
 }
@@ -1267,29 +1343,13 @@ circuit_free_all(void)
   HT_CLEAR(chan_circid_map, &chan_circid_map);
 }
 
-/** Deallocate space associated with the cpath node <b>victim</b>. */
-static void
-circuit_free_cpath_node(crypt_path_t *victim)
-{
-  if (!victim)
-    return;
-
-  relay_crypto_clear(&victim->crypto);
-  onion_handshake_state_release(&victim->handshake_state);
-  crypto_dh_free(victim->rend_dh_handshake_state);
-  extend_info_free(victim->extend_info);
-
-  memwipe(victim, 0xBB, sizeof(crypt_path_t)); /* poison memory */
-  tor_free(victim);
-}
-
 /** Release a crypt_path_reference_t*, which may be NULL. */
 static void
 cpath_ref_decref(crypt_path_reference_t *cpath_ref)
 {
   if (cpath_ref != NULL) {
     if (--(cpath_ref->refcount) == 0) {
-      circuit_free_cpath_node(cpath_ref->cpath);
+      cpath_free(cpath_ref->cpath);
       tor_free(cpath_ref);
     }
   }
@@ -2140,6 +2200,11 @@ circuit_mark_for_close_, (circuit_t *circ, int reason, int line,
   tor_assert(line);
   tor_assert(file);
 
+  /* Check whether the circuitpadding subsystem wants to block this close */
+  if (circpad_marked_circuit_for_padding(circ, reason)) {
+    return;
+  }
+
   if (circ->marked_for_close) {
     log_warn(LD_BUG,
         "Duplicate call to circuit_mark_for_close at %s:%d"
@@ -2195,7 +2260,7 @@ circuit_mark_for_close_, (circuit_t *circ, int reason, int line,
   }
 
   /* Notify the HS subsystem that this circuit is closing. */
-  hs_circ_cleanup(circ);
+  hs_circ_cleanup_on_close(circ);
 
   if (circuits_pending_close == NULL)
     circuits_pending_close = smartlist_new();
@@ -2270,50 +2335,13 @@ circuit_about_to_free(circuit_t *circ)
     smartlist_remove(circuits_pending_other_guards, circ);
   }
   if (CIRCUIT_IS_ORIGIN(circ)) {
-    control_event_circuit_status(TO_ORIGIN_CIRCUIT(circ),
+    circuit_event_status(TO_ORIGIN_CIRCUIT(circ),
      (circ->state == CIRCUIT_STATE_OPEN ||
       circ->state == CIRCUIT_STATE_GUARD_WAIT) ?
                                  CIRC_EVENT_CLOSED:CIRC_EVENT_FAILED,
      orig_reason);
   }
 
-  if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
-    origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
-    int timed_out = (reason == END_CIRC_REASON_TIMEOUT);
-    tor_assert(circ->state == CIRCUIT_STATE_OPEN);
-    tor_assert(ocirc->build_state->chosen_exit);
-    if (orig_reason != END_CIRC_REASON_IP_NOW_REDUNDANT &&
-        ocirc->rend_data) {
-      /* treat this like getting a nack from it */
-      log_info(LD_REND, "Failed intro circ %s to %s (awaiting ack). %s",
-          safe_str_client(rend_data_get_address(ocirc->rend_data)),
-          safe_str_client(build_state_get_exit_nickname(ocirc->build_state)),
-          timed_out ? "Recording timeout." : "Removing from descriptor.");
-      rend_client_report_intro_point_failure(ocirc->build_state->chosen_exit,
-                                             ocirc->rend_data,
-                                             timed_out ?
-                                             INTRO_POINT_FAILURE_TIMEOUT :
-                                             INTRO_POINT_FAILURE_GENERIC);
-    }
-  } else if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCING &&
-             reason != END_CIRC_REASON_TIMEOUT) {
-    origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
-    if (ocirc->build_state->chosen_exit && ocirc->rend_data) {
-      if (orig_reason != END_CIRC_REASON_IP_NOW_REDUNDANT &&
-          ocirc->rend_data) {
-        log_info(LD_REND, "Failed intro circ %s to %s "
-            "(building circuit to intro point). "
-            "Marking intro point as possibly unreachable.",
-            safe_str_client(rend_data_get_address(ocirc->rend_data)),
-            safe_str_client(build_state_get_exit_nickname(
-                                              ocirc->build_state)));
-        rend_client_report_intro_point_failure(ocirc->build_state->chosen_exit,
-                                              ocirc->rend_data,
-                                              INTRO_POINT_FAILURE_UNREACHABLE);
-      }
-    }
-  }
-
   if (circ->n_chan) {
     circuit_clear_cell_queue(circ, circ->n_chan);
     /* Only send destroy if the channel isn't closing anyway */
@@ -2374,13 +2402,9 @@ marked_circuit_free_cells(circuit_t *circ)
     return;
   }
   cell_queue_clear(&circ->n_chan_cells);
-  if (circ->n_mux)
-    circuitmux_clear_num_cells(circ->n_mux, circ);
   if (! CIRCUIT_IS_ORIGIN(circ)) {
     or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
     cell_queue_clear(&orcirc->p_chan_cells);
-    if (orcirc->p_mux)
-      circuitmux_clear_num_cells(orcirc->p_mux, circ);
   }
 }
 
@@ -2724,59 +2748,6 @@ circuits_handle_oom(size_t current_allocation)
              n_dirconns_killed);
 }
 
-/** Verify that cpath layer <b>cp</b> has all of its invariants
- * correct. Trigger an assert if anything is invalid.
- */
-void
-assert_cpath_layer_ok(const crypt_path_t *cp)
-{
-//  tor_assert(cp->addr); /* these are zero for rendezvous extra-hops */
-//  tor_assert(cp->port);
-  tor_assert(cp);
-  tor_assert(cp->magic == CRYPT_PATH_MAGIC);
-  switch (cp->state)
-    {
-    case CPATH_STATE_OPEN:
-      relay_crypto_assert_ok(&cp->crypto);
-      FALLTHROUGH;
-    case CPATH_STATE_CLOSED:
-      /*XXXX Assert that there's no handshake_state either. */
-      tor_assert(!cp->rend_dh_handshake_state);
-      break;
-    case CPATH_STATE_AWAITING_KEYS:
-      /* tor_assert(cp->dh_handshake_state); */
-      break;
-    default:
-      log_fn(LOG_ERR, LD_BUG, "Unexpected state %d", cp->state);
-      tor_assert(0);
-    }
-  tor_assert(cp->package_window >= 0);
-  tor_assert(cp->deliver_window >= 0);
-}
-
-/** Verify that cpath <b>cp</b> has all of its invariants
- * correct. Trigger an assert if anything is invalid.
- */
-static void
-assert_cpath_ok(const crypt_path_t *cp)
-{
-  const crypt_path_t *start = cp;
-
-  do {
-    assert_cpath_layer_ok(cp);
-    /* layers must be in sequence of: "open* awaiting? closed*" */
-    if (cp != start) {
-      if (cp->state == CPATH_STATE_AWAITING_KEYS) {
-        tor_assert(cp->prev->state == CPATH_STATE_OPEN);
-      } else if (cp->state == CPATH_STATE_OPEN) {
-        tor_assert(cp->prev->state == CPATH_STATE_OPEN);
-      }
-    }
-    cp = cp->next;
-    tor_assert(cp);
-  } while (cp != start);
-}
-
 /** Verify that circuit <b>c</b> has all of its invariants
  * correct. Trigger an assert if anything is invalid.
  */
@@ -2838,7 +2809,7 @@ assert_circuit_ok,(const circuit_t *c))
                !smartlist_contains(circuits_pending_chans, c));
   }
   if (origin_circ && origin_circ->cpath) {
-    assert_cpath_ok(origin_circ->cpath);
+    cpath_assert_ok(origin_circ->cpath);
   }
   if (c->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED) {
     tor_assert(or_circ);