relay: Avoid a directory early fetch

The directory_fetches_from_authorities() is used to know if a client or relay
should fetch data from an authority early in the boot process.

We had a condition in that function that made a relay trigger that fetch if it
didn't know its address (so we can learn it). However, when this is called,
the address discovery has not been done yet so it would always return true for
a relay.

Furthermore, it would always trigger a log notice that the IPv4 couldn't be
found which was inevitable because the address discovery process has not been
done yet (done when building our first descriptor).

It is also important to point out that starting in 0.4.5.1-alpha, asking an
authority for an address is done during address discovery time using a one-hop
circuit thus independent from the relay deciding to fetch or not documents
from an authority.

Small fix also is to reverse the "IPv(4|6)Only" flag in the notice so that if
we can't find IPv6 it would output to use IPv4Only.

Fixes #40300

Signed-off-by: David Goulet <dgoulet@torproject.org>

changes/ticket40300

@@ -2,4 +2,7 @@
     - Remove a spammy log notice that should not have been indicating the
       operator that its IPv4/v6 was missing but it was not. Fixes bug 40300;
       bugfix on 0.4.5.1-alpha.
-
+    - Do not query the address cache early in the boot process when deciding
+      if we a relay needs to fetch early directory information from an
+      authority. This resulted in a relay falsely believing it didn't have an
+      address and thus triggering an authority fetch at each boot.

src/feature/dirclient/dirclient_modes.c

@@ -45,14 +45,6 @@ dirclient_fetches_from_authorities(const or_options_t *options)
     return 1;
   if (options->BridgeRelay == 1)
     return 0;
-  /* We don't know our IP address; ask an authority. IPv4 is still mandatory
-   * to have thus if we don't have it, we ought to learn it from an authority
-   * through the NETINFO cell or the HTTP header it sends us back.
-   *
-   * Note that at the moment, relay do a direct connection so no NETINFO cell
-   * for now. */
-  if (server_mode(options) && !relay_has_address_set(AF_INET))
-    return 1;
   refuseunknown = ! router_my_exit_policy_is_reject_star() &&
     should_refuse_unknown_exits(options);
   if (!dir_server_mode(options) && !refuseunknown)

src/feature/relay/relay_find_addr.c

@@ -162,7 +162,8 @@ relay_find_addr_to_publish, (const or_options_t *options, int family,
                  "explicit address or set Address.",
                  fmt_af_family(family),
                  routerconf_find_or_port(options, family),
-                 fmt_af_family(family));
+                 (family == AF_INET) ? fmt_af_family(AF_INET6) :
+                                       fmt_af_family(AF_INET));
 
   /* Not found. */
   return false;
@@ -171,18 +172,6 @@ relay_find_addr_to_publish, (const or_options_t *options, int family,
   return true;
 }
 
-/** Return true iff this relay has an address set for the given family.
- *
- * This only checks the caches so it will not trigger a full discovery of the
- * address. */
-bool
-relay_has_address_set(int family)
-{
-  tor_addr_t addr;
-  return relay_find_addr_to_publish(get_options(), family,
-                                    RELAY_FIND_ADDR_CACHE_ONLY, &addr);
-}
-
 /** How often should we launch a circuit to an authority to be sure of getting
  * a guess for our IP? */
 #define DUMMY_DOWNLOAD_INTERVAL (20*60)

src/feature/relay/relay_find_addr.h

@@ -22,8 +22,6 @@ MOCK_DECL(bool, relay_find_addr_to_publish,
           (const or_options_t *options, int family, int flags,
            tor_addr_t *addr_out));
 
-bool relay_has_address_set(int family);
-
 void relay_addr_learn_from_dirauth(void);
 
 #ifdef RELAY_FIND_ADDR_PRIVATE

src/test/test_config.c

@@ -3982,27 +3982,6 @@ test_config_directory_fetch(void *arg)
   tt_int_op(networkstatus_consensus_can_use_multiple_directories(options),
             OP_EQ, 1);
 
-  /* OR servers only fetch the consensus from the authorities when they don't
-   * know their own address, but never use multiple directories for bootstrap
-   */
-  or_options_free(options);
-  options = options_new();
-  options->ORPort_set = 1;
-
-  mock_relay_find_addr_to_publish_result = false;
-  tt_assert(server_mode(options) == 1);
-  tt_assert(public_server_mode(options) == 1);
-  tt_int_op(dirclient_fetches_from_authorities(options), OP_EQ, 1);
-  tt_int_op(networkstatus_consensus_can_use_multiple_directories(options),
-            OP_EQ, 0);
-
-  mock_relay_find_addr_to_publish_result = true;
-  tt_assert(server_mode(options) == 1);
-  tt_assert(public_server_mode(options) == 1);
-  tt_int_op(dirclient_fetches_from_authorities(options), OP_EQ, 0);
-  tt_int_op(networkstatus_consensus_can_use_multiple_directories(options),
-            OP_EQ, 0);
-
   /* Exit OR servers only fetch the consensus from the authorities when they
    * refuse unknown exits, but never use multiple directories for bootstrap
    */