hs-v3: Implement HS_DESC FAILED event

A new v3 specific function has been added named
control_event_hsv3_descriptor_failed().

The HS v3 subsystem now uses it.

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

src/or/control.c

@@ -7296,6 +7296,7 @@ control_event_hs_descriptor_upload(const char *onion_address,
  * NOTE: this is an internal function used by following functions:
  * control_event_hsv2_descriptor_received
  * control_event_hsv2_descriptor_failed
+ * control_event_hsv3_descriptor_failed
  *
  * So do not call this function directly.
  */
@@ -7447,6 +7448,32 @@ control_event_hsv2_descriptor_failed(const rend_data_t *rend_data,
   tor_free(desc_id_field);
 }
 
+/** Send HS_DESC event to inform controller that the query to
+ * <b>onion_address</b> failed to retrieve hidden service descriptor
+ * <b>desc_id</b> from directory identified by <b>hsdir_id_digest</b>. If
+ * NULL, "UNKNOWN" is used.  If <b>reason</b> is not NULL, add it to REASON=
+ * field. */
+void
+control_event_hsv3_descriptor_failed(const char *onion_address,
+                                     const char *desc_id,
+                                     const char *hsdir_id_digest,
+                                     const char *reason)
+{
+  char *desc_id_field = NULL;
+
+  if (BUG(!onion_address || !desc_id || !reason)) {
+    return;
+  }
+
+  /* Because DescriptorID is an optional positional value, we need to add a
+   * whitespace before in order to not be next to the HsDir value. */
+  tor_asprintf(&desc_id_field, " %s", desc_id);
+
+  event_hs_descriptor_receive_end("FAILED", onion_address, desc_id_field,
+                                  REND_NO_AUTH, hsdir_id_digest, reason);
+  tor_free(desc_id_field);
+}
+
 /** Send HS_DESC_CONTENT event after completion of a successful fetch from hs
  * directory. If <b>hsdir_id_digest</b> is NULL, it is replaced by "UNKNOWN".
  * If <b>content</b> is NULL, it is replaced by an empty string. The

src/or/control.h

@@ -139,6 +139,11 @@ void control_event_hsv2_descriptor_failed(const rend_data_t *rend_data,
 void control_event_hsv2_descriptor_received(const char *onion_address,
                                             const rend_data_t *rend_data,
                                             const char *id_digest);
+/* Hidden service v3 HS_DESC specific. */
+void control_event_hsv3_descriptor_failed(const char *onion_address,
+                                          const char *desc_id,
+                                          const char *hsdir_id_digest,
+                                          const char *reason);
 void control_event_hs_descriptor_upload_failed(const char *hs_dir,
                                                const char *onion_address,
                                                const char *reason);

src/or/directory.c

@@ -25,6 +25,7 @@
 #include "geoip.h"
 #include "hs_cache.h"
 #include "hs_common.h"
+#include "hs_control.h"
 #include "hs_client.h"
 #include "main.h"
 #include "microdesc.h"
@@ -3090,6 +3091,9 @@ handle_response_fetch_hsdesc_v3(dir_connection_t *conn,
     /* We got something: Try storing it in the cache. */
     if (hs_cache_store_as_client(body, &conn->hs_ident->identity_pk) < 0) {
       log_warn(LD_REND, "Failed to store hidden service descriptor");
+      /* Fire control port FAILED event. */
+      hs_control_desc_event_failed(conn->hs_ident, conn->identity_digest,
+                                   "BAD_DESC");
     } else {
       log_info(LD_REND, "Stored hidden service descriptor successfully.");
       TO_CONN(conn)->purpose = DIR_PURPOSE_HAS_FETCHED_HSDESC;
@@ -3101,13 +3105,18 @@ handle_response_fetch_hsdesc_v3(dir_connection_t *conn,
      * tries to clean this conn up. */
     log_info(LD_REND, "Fetching hidden service v3 descriptor not found: "
                       "Retrying at another directory.");
-    /* TODO: Inform the control port */
+    /* Fire control port FAILED event. */
+    hs_control_desc_event_failed(conn->hs_ident, conn->identity_digest,
+                                 "NOT_FOUND");
     break;
   case 400:
     log_warn(LD_REND, "Fetching v3 hidden service descriptor failed: "
                       "http status 400 (%s). Dirserver didn't like our "
                       "query? Retrying at another directory.",
              escaped(reason));
+    /* Fire control port FAILED event. */
+    hs_control_desc_event_failed(conn->hs_ident, conn->identity_digest,
+                                 "QUERY_REJECTED");
     break;
   default:
     log_warn(LD_REND, "Fetching v3 hidden service descriptor failed: "
@@ -3115,6 +3124,9 @@ handle_response_fetch_hsdesc_v3(dir_connection_t *conn,
              "'%s:%d'. Retrying at another directory.",
              status_code, escaped(reason), TO_CONN(conn)->address,
              TO_CONN(conn)->port);
+    /* Fire control port FAILED event. */
+    hs_control_desc_event_failed(conn->hs_ident, conn->identity_digest,
+                                 "UNEXPECTED");
     break;
   }
 

src/or/hs_control.c

@@ -50,3 +50,30 @@ hs_control_desc_event_requested(const ed25519_public_key_t *onion_pk,
   memwipe(onion_address, 0, sizeof(onion_address));
 }
 
+/* Send on the control port the "HS_DESC FAILED [...]" event.
+ *
+ * Using a directory connection identifier, the HSDir identity digest and a
+ * reason for the failure. None can be NULL. */
+void
+hs_control_desc_event_failed(const hs_ident_dir_conn_t *ident,
+                             const char *hsdir_id_digest,
+                             const char *reason)
+{
+  char onion_address[HS_SERVICE_ADDR_LEN_BASE32 + 1];
+  char base64_blinded_pk[ED25519_BASE64_LEN + 1];
+
+  tor_assert(ident);
+  tor_assert(hsdir_id_digest);
+  tor_assert(reason);
+
+  /* Build onion address and encoded blinded key. */
+  IF_BUG_ONCE(ed25519_public_to_base64(base64_blinded_pk,
+                                       &ident->blinded_pk) < 0) {
+    return;
+  }
+  hs_build_address(&ident->identity_pk, HS_VERSION_THREE, onion_address);
+
+  control_event_hsv3_descriptor_failed(onion_address, base64_blinded_pk,
+                                       hsdir_id_digest, reason);
+}
+

src/or/hs_control.h

@@ -9,10 +9,17 @@
 #ifndef TOR_HS_CONTROL_H
 #define TOR_HS_CONTROL_H
 
+#include "hs_ident.h"
+
 /* Event "HS_DESC REQUESTED [...]" */
 void hs_control_desc_event_requested(const ed25519_public_key_t *onion_pk,
                                      const char *base64_blinded_pk,
                                      const routerstatus_t *hsdir_rs);
 
+/* Event "HS_DESC FAILED [...]" */
+void hs_control_desc_event_failed(const hs_ident_dir_conn_t *ident,
+                                  const char *hsdir_id_digest,
+                                  const char *reason);
+
 #endif /* !defined(TOR_HS_CONTROL_H) */