Update unit tests for fascist_firewall_choose_address*

Check that clients, bridge clients, and relays choose addresses
as expected.

1 files changed, 347 insertions, 175 deletions

diff --git a/src/test/test_policy.c b/src/test/test_policy.c
index 3688909acb..84a7081588 100644
--- a/src/test/test_policy.c
+++ b/src/test/test_policy.c
@@ -1374,6 +1374,51 @@ test_policies_fascist_firewall_allows_address(void *arg)
 #define TEST_IPV6_OR_PORT  61234
 #define TEST_IPV6_DIR_PORT 62345
 
+/* Check that fascist_firewall_choose_address_rs() returns the expected
+ * results. */
+#define CHECK_CHOSEN_ADDR_RS(fake_rs, fw_connection, pref_only, expect_rv, \
+                             expect_ap) \
+  STMT_BEGIN \
+    tor_addr_port_t chosen_rs_ap; \
+    tor_addr_make_null(&chosen_rs_ap.addr, AF_INET); \
+    chosen_rs_ap.port = 0; \
+    tt_int_op(fascist_firewall_choose_address_rs(&(fake_rs), \
+                                                 (fw_connection), \
+                                                 (pref_only), \
+                                                 &chosen_rs_ap), \
+              OP_EQ, (expect_rv)); \
+    tt_assert(tor_addr_eq(&(expect_ap).addr, &chosen_rs_ap.addr)); \
+    tt_int_op((expect_ap).port, OP_EQ, chosen_rs_ap.port); \
+  STMT_END
+
+/* Check that fascist_firewall_choose_address_node() returns the expected
+ * results. */
+#define CHECK_CHOSEN_ADDR_NODE(fake_node, fw_connection, pref_only, \
+                               expect_rv, expect_ap) \
+  STMT_BEGIN \
+    tor_addr_port_t chosen_node_ap; \
+    tor_addr_make_null(&chosen_node_ap.addr, AF_INET); \
+    chosen_node_ap.port = 0; \
+    tt_int_op(fascist_firewall_choose_address_node(&(fake_node), \
+                                                   (fw_connection), \
+                                                   (pref_only), \
+                                                   &chosen_node_ap), \
+              OP_EQ, (expect_rv)); \
+    tt_assert(tor_addr_eq(&(expect_ap).addr, &chosen_node_ap.addr)); \
+    tt_int_op((expect_ap).port, OP_EQ, chosen_node_ap.port); \
+  STMT_END
+
+/* Check that fascist_firewall_choose_address_rs and
+ * fascist_firewall_choose_address_node() both return the expected results. */
+#define CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, fw_connection, pref_only, \
+                             expect_rv, expect_ap) \
+  STMT_BEGIN \
+    CHECK_CHOSEN_ADDR_RS(fake_rs, fw_connection, pref_only, expect_rv, \
+                         expect_ap); \
+    CHECK_CHOSEN_ADDR_NODE(fake_node, fw_connection, pref_only, expect_rv, \
+                           expect_ap); \
+  STMT_END
+
 /** Run unit tests for fascist_firewall_choose_address */
 static void
 test_policies_fascist_firewall_choose_address(void *arg)
@@ -1402,91 +1447,196 @@ test_policies_fascist_firewall_choose_address(void *arg)
   tor_addr_make_null(&n_ipv6_ap.addr, AF_INET6);
   n_ipv6_ap.port = 0;
 
-  /* Choose an address with IPv4 and IPv6 on */
+  /* Sanity check fascist_firewall_choose_address with IPv4 and IPv6 on */
   memset(&mock_options, 0, sizeof(or_options_t));
   mock_options.ClientUseIPv4 = 1;
   mock_options.ClientUseIPv6 = 1;
   mock_options.UseBridges = 0;
 
-  /* Preferring IPv4 */
-  mock_options.ClientPreferIPv6ORPort = 0;
-  mock_options.ClientPreferIPv6DirPort = 0;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
+  /* Prefer IPv4 */
+  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 1,
+                                            FIREWALL_OR_CONNECTION, 0, 0)
             == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
+  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 1,
+                                            FIREWALL_OR_CONNECTION, 1, 0)
             == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
+  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 1,
+                                            FIREWALL_DIR_CONNECTION, 0, 0)
             == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
+  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 1,
+                                            FIREWALL_DIR_CONNECTION, 1, 0)
             == &ipv4_dir_ap);
 
-  /* Auto (Preferring IPv4) */
-  mock_options.ClientPreferIPv6ORPort = -1;
-  mock_options.ClientPreferIPv6DirPort = -1;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 0)
-            == &ipv4_or_ap);
+  /* Prefer IPv6 */
   tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 1)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 1)
-            == &ipv4_dir_ap);
-
-  /* Preferring IPv6 */
-  mock_options.ClientPreferIPv6ORPort = 1;
-  mock_options.ClientPreferIPv6DirPort = 1;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
+                                            FIREWALL_OR_CONNECTION, 0, 1)
             == &ipv6_or_ap);
   tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
+                                            FIREWALL_OR_CONNECTION, 1, 1)
             == &ipv6_or_ap);
   tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
+                                            FIREWALL_DIR_CONNECTION, 0, 1)
             == &ipv6_dir_ap);
   tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
+                                            FIREWALL_DIR_CONNECTION, 1, 1)
             == &ipv6_dir_ap);
 
-  /* Preferring IPv4 OR / IPv6 Dir */
-  mock_options.ClientPreferIPv6ORPort = 0;
-  mock_options.ClientPreferIPv6DirPort = 1;
+  /* Unusual inputs */
+
+  /* null preferred OR addresses */
+  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &n_ipv6_ap, 0,
+                                            FIREWALL_OR_CONNECTION, 0, 1)
+            == &ipv4_or_ap);
+  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &ipv6_or_ap, 1,
+                                            FIREWALL_OR_CONNECTION, 0, 0)
+            == &ipv6_or_ap);
+
+  /* null both OR addresses */
+  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &n_ipv6_ap, 0,
+                                            FIREWALL_OR_CONNECTION, 0, 1)
+            == NULL);
+  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &n_ipv6_ap, 1,
+                                            FIREWALL_OR_CONNECTION, 0, 0)
+            == NULL);
+
+  /* null preferred Dir addresses */
+  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &n_ipv6_ap, 0,
+                                            FIREWALL_DIR_CONNECTION, 0, 1)
+            == &ipv4_dir_ap);
+  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &ipv6_dir_ap, 1,
+                                            FIREWALL_DIR_CONNECTION, 0, 0)
+            == &ipv6_dir_ap);
+
+  /* null both Dir addresses */
+  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &n_ipv6_ap, 0,
+                                            FIREWALL_DIR_CONNECTION, 0, 1)
+            == NULL);
+  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &n_ipv6_ap, 1,
+                                            FIREWALL_DIR_CONNECTION, 0, 0)
+            == NULL);
+
+  /* Prefer IPv4 but want IPv6 (contradictory) */
   tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
+                                            FIREWALL_OR_CONNECTION, 0, 0)
             == &ipv4_or_ap);
   tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
+                                            FIREWALL_OR_CONNECTION, 1, 0)
             == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv6_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
-            == &ipv6_dir_ap);
+
+  /* Prefer IPv6 but want IPv4 (contradictory) */
+  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 1,
+                                            FIREWALL_OR_CONNECTION, 0, 1)
+            == &ipv6_or_ap);
+  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 1,
+                                            FIREWALL_OR_CONNECTION, 1, 1)
+            == &ipv6_or_ap);
+
+  /* Make a fake rs. There will be no corresponding node.
+   * This is what happens when there's no consensus and we're bootstrapping
+   * from authorities / fallbacks. */
+  routerstatus_t fake_rs;
+  memset(&fake_rs, 0, sizeof(routerstatus_t));
+  /* In a routerstatus, the OR and Dir addresses are the same */
+  fake_rs.addr = tor_addr_to_ipv4h(&ipv4_or_ap.addr);
+  fake_rs.or_port = ipv4_or_ap.port;
+  fake_rs.dir_port = ipv4_dir_ap.port;
+
+  tor_addr_copy(&fake_rs.ipv6_addr, &ipv6_or_ap.addr);
+  fake_rs.ipv6_orport = ipv6_or_ap.port;
+  /* In a routerstatus, the IPv4 and IPv6 DirPorts are the same.*/
+  ipv6_dir_ap.port = TEST_IPV4_DIR_PORT;
+
+  /* Make a fake node. Even though it contains the fake_rs, a lookup won't
+  * find the node from the rs, because they're not in the hash table. */
+  node_t fake_node;
+  memset(&fake_node, 0, sizeof(node_t));
+  fake_node.rs = &fake_rs;
+
+  /* Choose an address with IPv4 and IPv6 on */
+  memset(&mock_options, 0, sizeof(or_options_t));
+  mock_options.ClientUseIPv4 = 1;
+  mock_options.ClientUseIPv6 = 1;
+  mock_options.UseBridges = 0;
+
+  /* Preferring IPv4 */
+  mock_options.ClientPreferIPv6ORPort = 0;
+  mock_options.ClientPreferIPv6DirPort = 0;
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv4_dir_ap);
+
+  /* Auto (Preferring IPv4) */
+  mock_options.ClientPreferIPv6ORPort = -1;
+  mock_options.ClientPreferIPv6DirPort = -1;
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv4_dir_ap);
+
+  /* Preferring IPv6 */
+  mock_options.ClientPreferIPv6ORPort = 1;
+  mock_options.ClientPreferIPv6DirPort = 1;
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv6_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv6_dir_ap);
+
+  /* Preferring IPv4 OR / IPv6 Dir */
+  mock_options.ClientPreferIPv6ORPort = 0;
+  mock_options.ClientPreferIPv6DirPort = 1;
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv6_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv6_dir_ap);
 
   /* Preferring IPv6 OR / IPv4 Dir */
   mock_options.ClientPreferIPv6ORPort = 1;
   mock_options.ClientPreferIPv6DirPort = 0;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
-            == &ipv4_dir_ap);
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv4_dir_ap);
 
   /* Choose an address with UseBridges on */
   memset(&mock_options, 0, sizeof(or_options_t));
@@ -1497,157 +1647,175 @@ test_policies_fascist_firewall_choose_address(void *arg)
   /* Preferring IPv4 */
   mock_options.ClientPreferIPv6ORPort = 0;
   mock_options.ClientPreferIPv6DirPort = 0;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 0)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 1)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 1)
-            == &ipv4_dir_ap);
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv4_dir_ap);
 
   /* Auto:
-   * - bridge clients prefer the configured bridge OR address,
-   * - other clients prefer IPv4 OR by default,
-   * - all clients prefer IPv4 Dir by default.
+   * - bridge clients prefer the configured bridge OR address from the node,
+   *   (the configured address family sets node.ipv6_preferred)
+   * - other clients prefer IPv4 OR by default (see above),
+   * - all clients, including bridge clients, prefer IPv4 Dir by default.
    */
   mock_options.ClientPreferIPv6ORPort = -1;
   mock_options.ClientPreferIPv6DirPort = -1;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 0)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 1)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 1)
-            == &ipv4_dir_ap);
+
+  /* Simulate the initialisation of fake_node.ipv6_preferred with a bridge
+   * configured with an IPv4 address */
+  fake_node.ipv6_preferred = 0;
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 0, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 1, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                         ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                         ipv4_dir_ap);
+
+  /* Simulate the initialisation of fake_node.ipv6_preferred with a bridge
+   * configured with an IPv6 address */
+  fake_node.ipv6_preferred = 1;
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 0, 1, ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 1, 1, ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                         ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                         ipv4_dir_ap);
+
+  /* When a rs has no node, it defaults to IPv4 under auto. */
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_OR_CONNECTION, 0, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_OR_CONNECTION, 1, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_DIR_CONNECTION, 0, 1, ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_DIR_CONNECTION, 1, 1, ipv4_dir_ap);
 
   /* Preferring IPv6 */
   mock_options.ClientPreferIPv6ORPort = 1;
   mock_options.ClientPreferIPv6DirPort = 1;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 0)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 1)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 0)
-            == &ipv6_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 1)
-            == &ipv6_dir_ap);
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv6_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv6_dir_ap);
 
   /* In the default configuration (Auto / IPv6 off), bridge clients should
-   * still use IPv6, and only prefer it for bridges configured with an IPv6
-   * address, regardless of ClientUseIPv6. */
+   * use both IPv4 and IPv6, but only prefer IPv6 for bridges configured with
+   * an IPv6 address, regardless of ClientUseIPv6. (See above.) */
   mock_options.ClientUseIPv6 = 0;
   mock_options.ClientPreferIPv6ORPort = -1;
   mock_options.ClientPreferIPv6DirPort = -1;
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 0)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                            FIREWALL_OR_CONNECTION, 1)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                            FIREWALL_DIR_CONNECTION, 1)
-            == &ipv4_dir_ap);
+  /* Simulate the initialisation of fake_node.ipv6_preferred with a bridge
+   * configured with an IPv4 address */
+  fake_node.ipv6_preferred = 0;
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 0, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 1, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                         ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                         ipv4_dir_ap);
+
+  /* Simulate the initialisation of fake_node.ipv6_preferred with a bridge
+   * configured with an IPv6 address */
+  fake_node.ipv6_preferred = 1;
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 0, 1, ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_OR_CONNECTION, 1, 1, ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                         ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_NODE(fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                         ipv4_dir_ap);
+
+  /* When a rs has no node, it defaults to IPv4 under auto. */
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_OR_CONNECTION, 0, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_OR_CONNECTION, 1, 1, ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_DIR_CONNECTION, 0, 1, ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RS(fake_rs, FIREWALL_DIR_CONNECTION, 1, 1, ipv4_dir_ap);
 
   /* Choose an address with IPv4 on */
   memset(&mock_options, 0, sizeof(or_options_t));
   mock_options.ClientUseIPv4 = 1;
   mock_options.ClientUseIPv6 = 0;
-  mock_options.UseBridges = 0;
-
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
-            == &ipv4_dir_ap);
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv4_dir_ap);
 
   /* Choose an address with IPv6 on */
   memset(&mock_options, 0, sizeof(or_options_t));
   mock_options.ClientUseIPv4 = 0;
   mock_options.ClientUseIPv6 = 1;
-  mock_options.UseBridges = 0;
-
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv6_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
-            == &ipv6_dir_ap);
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv6_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv6_dir_ap);
 
   /* Choose an address with ClientUseIPv4 0.
    * This means "use IPv6" regardless of the other settings. */
   memset(&mock_options, 0, sizeof(or_options_t));
   mock_options.ClientUseIPv4 = 0;
   mock_options.ClientUseIPv6 = 0;
-  mock_options.UseBridges = 0;
-
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 1)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv6_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 1)
-            == &ipv6_dir_ap);
-
-  /* Choose from unusual inputs */
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
+
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv6_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv6_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv6_dir_ap);
+
+  /* Choose an address with ORPort_set 1 (server mode).
+   * This means "use IPv4" regardless of the other settings. */
   memset(&mock_options, 0, sizeof(or_options_t));
-  mock_options.ClientUseIPv4 = 1;
+  mock_options.ORPort_set = 1;
+  mock_options.ClientUseIPv4 = 0;
   mock_options.ClientUseIPv6 = 1;
-  mock_options.UseBridges = 1;
+  mock_options.ClientPreferIPv6ORPort = 1;
+  mock_options.ClientPreferIPv6DirPort = 1;
 
-  tt_assert(fascist_firewall_choose_address(&ipv4_or_ap, &n_ipv6_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == &ipv4_or_ap);
-  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &ipv6_or_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == &ipv6_or_ap);
-  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &n_ipv6_ap, 0,
-                                                 FIREWALL_OR_CONNECTION, 0)
-            == NULL);
+  /* Simulate the initialisation of fake_node.ipv6_preferred */
+  fake_node.ipv6_preferred = fascist_firewall_prefer_ipv6_orport(
+                                                                &mock_options);
 
-  tt_assert(fascist_firewall_choose_address(&ipv4_dir_ap, &n_ipv6_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv4_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &ipv6_dir_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == &ipv6_dir_ap);
-  tt_assert(fascist_firewall_choose_address(&n_ipv4_ap, &n_ipv6_ap, 0,
-                                                 FIREWALL_DIR_CONNECTION, 0)
-            == NULL);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 0, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_OR_CONNECTION, 1, 1,
+                       ipv4_or_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 0, 1,
+                       ipv4_dir_ap);
+  CHECK_CHOSEN_ADDR_RN(fake_rs, fake_node, FIREWALL_DIR_CONNECTION, 1, 1,
+                       ipv4_dir_ap);
 
  done:
   UNMOCK(get_options);
@@ -1660,6 +1828,10 @@ test_policies_fascist_firewall_choose_address(void *arg)
 #undef TEST_IPV6_OR_PORT
 #undef TEST_IPV6_DIR_PORT
 
+#undef CHECK_CHOSEN_ADDR_RS
+#undef CHECK_CHOSEN_ADDR_NODE
+#undef CHECK_CHOSEN_ADDR_RN
+
 struct testcase_t policy_tests[] = {
   { "router_dump_exit_policy_to_string", test_dump_exit_policy_to_string, 0,
     NULL, NULL },