hs-v2: Lookup intro failure cache when picking an intro from descriptor

When picking an intro point from the service descriptor, the client failed to
lookup the failure cache.

It made an HS v2 client re-pick bad intro points for which we already know it
won't work in the first place.

Based on Neel Chauhan original patch.

Fixes #25568

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

1 files changed, 2 insertions, 0 deletions

diff --git a/src/feature/rend/rendcache.h b/src/feature/rend/rendcache.h
index aec97eabb8..c83f36d189 100644
--- a/src/feature/rend/rendcache.h
+++ b/src/feature/rend/rendcache.h
@@ -80,6 +80,8 @@ int rend_cache_store_v2_desc_as_client(const char *desc,
                                        rend_cache_entry_t **entry);
 size_t rend_cache_get_total_allocation(void);
 
+bool rend_cache_intro_failure_exists(const char *service_id,
+                                     const uint8_t *intro_identity);
 void rend_cache_intro_failure_note(rend_intro_point_failure_t failure,
                                    const uint8_t *identity,
                                    const char *service_id);