Add tests for new_route_len()

src/or/circuitbuild.c

@@ -73,7 +73,6 @@ static int circuit_deliver_create_cell(circuit_t *circ,
 static int onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit);
 static crypt_path_t *onion_next_hop_in_cpath(crypt_path_t *cpath);
 static int onion_extend_cpath(origin_circuit_t *circ);
-static int count_acceptable_nodes(smartlist_t *routers);
 static int onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice);
 
 /** This function tries to get a channel to the specified endpoint,
@@ -1552,7 +1551,7 @@ onionskin_answer(or_circuit_t *circ,
  * If the routerlist <b>nodes</b> doesn't have enough routers
  * to handle the desired path length, return -1.
  */
-static int
+STATIC int
 new_route_len(uint8_t purpose, extend_info_t *exit_ei, smartlist_t *nodes)
 {
   int num_acceptable_routers;
@@ -2188,8 +2187,8 @@ circuit_extend_to_new_exit(origin_circuit_t *circ, extend_info_t *exit_ei)
 /** Return the number of routers in <b>routers</b> that are currently up
  * and available for building circuits through.
  */
-static int
+MOCK_IMPL(STATIC int,
-count_acceptable_nodes(smartlist_t *nodes)
+count_acceptable_nodes, (smartlist_t *nodes))
 {
   int num=0;
 

src/or/circuitbuild.h

@@ -77,6 +77,9 @@ void circuit_upgrade_circuits_from_guard_wait(void);
 
 #ifdef CIRCUITBUILD_PRIVATE
 STATIC circid_t get_unique_circ_id_by_chan(channel_t *chan);
+STATIC int new_route_len(uint8_t purpose, extend_info_t *exit_ei,
+                         smartlist_t *nodes);
+MOCK_DECL(STATIC int, count_acceptable_nodes, (smartlist_t *nodes));
 #if defined(ENABLE_TOR2WEB_MODE) || defined(TOR_UNIT_TESTS)
 STATIC const node_t *pick_tor2web_rendezvous_node(router_crn_flags_t flags,
                                                   const or_options_t *options);

src/test/include.am

@@ -82,6 +82,7 @@ src_test_test_SOURCES = \
 	src/test/test_checkdir.c \
 	src/test/test_circuitlist.c \
 	src/test/test_circuitmux.c \
+	src/test/test_circuitbuild.c \
 	src/test/test_circuituse.c \
 	src/test/test_compat_libevent.c \
 	src/test/test_config.c \

src/test/test.c

@@ -1188,6 +1188,7 @@ struct testgroup_t testgroups[] = {
   { "channel/", channel_tests },
   { "channeltls/", channeltls_tests },
   { "checkdir/", checkdir_tests },
+  { "circuitbuild/", circuitbuild_tests },
   { "circuitlist/", circuitlist_tests },
   { "circuitmux/", circuitmux_tests },
   { "circuituse/", circuituse_tests },

src/test/test.h

@@ -183,6 +183,7 @@ extern struct testcase_t cell_queue_tests[];
 extern struct testcase_t channel_tests[];
 extern struct testcase_t channeltls_tests[];
 extern struct testcase_t checkdir_tests[];
+extern struct testcase_t circuitbuild_tests[];
 extern struct testcase_t circuitlist_tests[];
 extern struct testcase_t circuitmux_tests[];
 extern struct testcase_t circuituse_tests[];

src/test/test_circuitbuild.c

@@ -0,0 +1,105 @@
+/* Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2016, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#define CIRCUITBUILD_PRIVATE
+
+#include "or.h"
+#include "test.h"
+#include "test_helpers.h"
+#include "config.h"
+#include "circuitbuild.h"
+
+/* Dummy nodes smartlist for testing */
+static smartlist_t dummy_nodes;
+/* Dummy exit extend_info for testing */
+static extend_info_t dummy_ei;
+
+static int
+mock_count_acceptable_nodes(smartlist_t *nodes)
+{
+  (void)nodes;
+
+  return DEFAULT_ROUTE_LEN + 1;
+}
+
+/* Test route lengths when the caller of new_route_len() doesn't
+ * specify exit_ei. */
+static void
+test_new_route_len_noexit(void *arg)
+{
+  int r;
+
+  (void)arg;
+  MOCK(count_acceptable_nodes, mock_count_acceptable_nodes);
+
+  r = new_route_len(CIRCUIT_PURPOSE_C_GENERAL, NULL, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN, OP_EQ, r);
+
+  r = new_route_len(CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT, NULL, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN, OP_EQ, r);
+
+  r = new_route_len(CIRCUIT_PURPOSE_S_CONNECT_REND, NULL, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN, OP_EQ, r);
+
+ done:
+  UNMOCK(count_acceptable_nodes);
+}
+
+/* Test route lengths where someone else chose the "exit" node, which
+ * require an extra hop for safety. */
+static void
+test_new_route_len_unsafe_exit(void *arg)
+{
+  int r;
+
+  (void)arg;
+  MOCK(count_acceptable_nodes, mock_count_acceptable_nodes);
+
+  /* connecting to hidden service directory */
+  r = new_route_len(CIRCUIT_PURPOSE_C_GENERAL, &dummy_ei, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN + 1, OP_EQ, r);
+
+  /* client connecting to introduction point */
+  r = new_route_len(CIRCUIT_PURPOSE_C_INTRODUCING, &dummy_ei, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN + 1, OP_EQ, r);
+
+  /* hidden service connecting to rendezvous point */
+  r = new_route_len(CIRCUIT_PURPOSE_S_CONNECT_REND, &dummy_ei, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN + 1, OP_EQ, r);
+
+ done:
+  UNMOCK(count_acceptable_nodes);
+}
+
+/* Test route lengths where we chose the "exit" node, which don't
+ * require an extra hop for safety. */
+static void
+test_new_route_len_safe_exit(void *arg)
+{
+  int r;
+
+  (void)arg;
+  MOCK(count_acceptable_nodes, mock_count_acceptable_nodes);
+
+  /* hidden service connecting to introduction point */
+  r = new_route_len(CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, &dummy_ei,
+                    &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN, OP_EQ, r);
+
+  /* router testing its own reachability */
+  r = new_route_len(CIRCUIT_PURPOSE_TESTING, &dummy_ei, &dummy_nodes);
+  tt_int_op(DEFAULT_ROUTE_LEN, OP_EQ, r);
+
+ done:
+  UNMOCK(count_acceptable_nodes);
+}
+
+struct testcase_t circuitbuild_tests[] = {
+  { "noexit", test_new_route_len_noexit, 0, NULL, NULL },
+  { "safe_exit", test_new_route_len_safe_exit, 0, NULL, NULL },
+  { "unsafe_exit", test_new_route_len_unsafe_exit, 0, NULL, NULL },
+  END_OF_TESTCASES
+};
+