relay: Deciding to fetch from authority, use new find address API

Use the new relay_has_address_set() interface when deciding if we need to
fetch directory information from an authority as a relay.

If no IPv4 address is found, we'll proceed with a fetch so we can learn our
address in the HTTP header or NETINFO cell that a trusted authority will send
us back.

Related to #40025

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

2 files changed, 13 insertions, 0 deletions

diff --git a/src/feature/relay/relay_find_addr.c b/src/feature/relay/relay_find_addr.c
index dabf985751..d685145934 100644
--- a/src/feature/relay/relay_find_addr.c
+++ b/src/feature/relay/relay_find_addr.c
@@ -254,3 +254,14 @@ router_pick_published_address, (const or_options_t *options, uint32_t *addr,
   /* We have no useful cached answers. Return failure. */
   return -1;
 }
+
+/** 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, 1, &addr);
+}
diff --git a/src/feature/relay/relay_find_addr.h b/src/feature/relay/relay_find_addr.h
index e28ceb933a..399ac8dc44 100644
--- a/src/feature/relay/relay_find_addr.h
+++ b/src/feature/relay/relay_find_addr.h
@@ -22,6 +22,8 @@ void relay_address_new_suggestion(const tor_addr_t *suggested_addr,
 bool relay_find_addr_to_publish(const or_options_t *options, int family,
                                 bool cache_only, tor_addr_t *addr_out);
 
+bool relay_has_address_set(int family);
+
 #ifdef RELAY_FIND_ADDR_PRIVATE
 
 #endif /* RELAY_FIND_ADDR_PRIVATE */