prop224: Add a client intro point state cache

This cache keeps track of the state of intro points which is needed when we
have failures when using them. It is similar to the failure cache of the
legacy system.

At this commit, it is unused but initialized, cleanup and freed.

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

1 files changed, 35 insertions, 0 deletions

diff --git a/src/or/hs_cache.h b/src/or/hs_cache.h
index 79456f69c8..2a4d2dbb2f 100644
--- a/src/or/hs_cache.h
+++ b/src/or/hs_cache.h
@@ -15,8 +15,34 @@
 #include "crypto_ed25519.h"
 #include "hs_common.h"
 #include "hs_descriptor.h"
+#include "rendcommon.h"
 #include "torcert.h"
 
+/* This is the maximum time an introduction point state object can stay in the
+ * client cache in seconds (2 mins or 120 seconds). */
+#define HS_CACHE_CLIENT_INTRO_STATE_MAX_AGE (2 * 60)
+
+/* Introduction point state. */
+typedef struct hs_cache_intro_state_t {
+  /* When this entry was created and put in the cache. */
+  time_t created_ts;
+
+  /* Did it suffered a generic error? */
+  unsigned int error : 1;
+
+  /* Did it timed out? */
+  unsigned int timed_out : 1;
+
+  /* How many times we tried to reached it and it was unreachable. */
+  uint32_t unreachable_count;
+} hs_cache_intro_state_t;
+
+typedef struct hs_cache_client_intro_state_t {
+  /* Contains hs_cache_intro_state_t object indexed by introduction point
+   * authentication key. */
+  digest256map_t *intro_points;
+} hs_cache_client_intro_state_t;
+
 /* Descriptor representation on the directory side which is a subset of
  * information that the HSDir can decode and serve it. */
 typedef struct hs_cache_dir_descriptor_t {
@@ -59,6 +85,15 @@ int hs_cache_store_as_client(const char *desc_str,
                              const ed25519_public_key_t *identity_pk);
 void hs_cache_clean_as_client(time_t now);
 
+/* Client failure cache. */
+void hs_cache_client_intro_state_note(const ed25519_public_key_t *service_pk,
+                                      const ed25519_public_key_t *auth_key,
+                                      rend_intro_point_failure_t failure);
+const hs_cache_intro_state_t *hs_cache_client_intro_state_find(
+                                       const ed25519_public_key_t *service_pk,
+                                       const ed25519_public_key_t *auth_key);
+void hs_cache_client_intro_state_clean(time_t now);
+
 #ifdef HS_CACHE_PRIVATE
 
 /** Represents a locally cached HS descriptor on a hidden service client. */