Add missing descriptor ID to HS_DESC control event

For FAILED and RECEIVED action of the HS_DESC event, we now sends back the
descriptor ID at the end like specified in the control-spec section 4.1.25.

Fixes #15881

Signed-off-by: David Goulet <dgoulet@ev0ke.net>

changes/bug15881

@@ -0,0 +1,3 @@
+  o Controller fixes:
+    - Add the descriptor ID in each HS_DESC control event. It was missing
+      but specified in control-spec.txt. Fixes ticket 15881.

src/or/control.c

@@ -5904,6 +5904,44 @@ control_event_hs_descriptor_requested(const rend_data_t *rend_query,
                      desc_id_base32);
 }
 
+/** For an HS descriptor query <b>rend_data</b>, using the
+ * <b>onion_address</b> and HSDir fingerprint <b>hsdir_fp</b>, find out
+ * which descriptor ID in the query is the right one.
+ *
+ * Return a pointer of the binary descriptor ID found in the query's object
+ * or NULL if not found. */
+static const char *
+get_desc_id_from_query(const rend_data_t *rend_data, const char *hsdir_fp)
+{
+  int replica;
+  const char *desc_id = NULL;
+
+  /* Possible if the fetch was done using a descriptor ID. This means that
+   * the HSFETCH command was used. */
+  if (!tor_digest_is_zero(rend_data->desc_id_fetch)) {
+    desc_id = rend_data->desc_id_fetch;
+    goto end;
+  }
+
+  /* OK, we have an onion address so now let's find which descriptor ID
+   * is the one associated with the HSDir fingerprint. */
+  for (replica = 0; replica < REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS;
+       replica++) {
+    const char *digest = rend_data->descriptor_id[replica];
+
+    SMARTLIST_FOREACH_BEGIN(rend_data->hsdirs_fp, char *, fingerprint) {
+      if (tor_memcmp(fingerprint, hsdir_fp, DIGEST_LEN) == 0) {
+        /* Found it! This descriptor ID is the right one. */
+        desc_id = digest;
+        goto end;
+      }
+    } SMARTLIST_FOREACH_END(fingerprint);
+  }
+
+end:
+  return desc_id;
+}
+
 /** send HS_DESC upload event.
  *
  * <b>service_id</b> is the descriptor onion address.
@@ -5940,30 +5978,45 @@ control_event_hs_descriptor_upload(const char *service_id,
 void
 control_event_hs_descriptor_receive_end(const char *action,
                                         const char *onion_address,
-                                        rend_auth_type_t auth_type,
+                                        const rend_data_t *rend_data,
                                         const char *id_digest,
                                         const char *reason)
 {
+  char *desc_id_field = NULL;
   char *reason_field = NULL;
+  char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
+  const char *desc_id = NULL;
 
-  if (!action || !id_digest || !onion_address) {
-    log_warn(LD_BUG, "Called with action==%p, id_digest==%p "
-             "onion_address==%p", action, id_digest, onion_address);
+  if (!action || !id_digest || !rend_data || !onion_address) {
+    log_warn(LD_BUG, "Called with action==%p, id_digest==%p, "
+             "rend_data==%p, onion_address==%p", action, id_digest,
+             rend_data, onion_address);
     return;
   }
 
+  desc_id = get_desc_id_from_query(rend_data, id_digest);
+  if (desc_id != NULL) {
+    /* Set the descriptor ID digest to base32 so we can send it. */
+    base32_encode(desc_id_base32, sizeof(desc_id_base32), desc_id,
+                  DIGEST_LEN);
+    /* Extra whitespace is needed before the value. */
+    tor_asprintf(&desc_id_field, " %s", desc_id_base32);
+  }
+
   if (reason) {
     tor_asprintf(&reason_field, " REASON=%s", reason);
   }
 
   send_control_event(EVENT_HS_DESC, ALL_FORMATS,
-                     "650 HS_DESC %s %s %s %s%s\r\n",
+                     "650 HS_DESC %s %s %s %s%s%s\r\n",
                      action,
                      rend_hsaddress_str_or_unknown(onion_address),
-                     rend_auth_type_to_string(auth_type),
+                     rend_auth_type_to_string(rend_data->auth_type),
                      node_describe_longname_by_id(id_digest),
+                     desc_id_field ? desc_id_field : "",
                      reason_field ? reason_field : "");
 
+  tor_free(desc_id_field);
   tor_free(reason_field);
 }
 
@@ -6007,15 +6060,16 @@ control_event_hs_descriptor_upload_end(const char *action,
  */
 void
 control_event_hs_descriptor_received(const char *onion_address,
-                                     rend_auth_type_t auth_type,
+                                     const rend_data_t *rend_data,
                                      const char *id_digest)
 {
-  if (!id_digest) {
-    log_warn(LD_BUG, "Called with id_digest==%p", id_digest);
+  if (!rend_data || !id_digest || !onion_address) {
+    log_warn(LD_BUG, "Called with rend_data==%p, id_digest==%p, "
+             "onion_address==%p", rend_data, id_digest, onion_address);
     return;
   }
   control_event_hs_descriptor_receive_end("RECEIVED", onion_address,
-                                          auth_type, id_digest, NULL);
+                                          rend_data, id_digest, NULL);
 }
 
 /** send HS_DESC UPLOADED event
@@ -6039,17 +6093,18 @@ control_event_hs_descriptor_uploaded(const char *id_digest)
  * field.
  */
 void
-control_event_hs_descriptor_failed(const char *onion_address,
-                                   rend_auth_type_t auth_type,
+control_event_hs_descriptor_failed(const rend_data_t *rend_data,
                                    const char *id_digest,
                                    const char *reason)
 {
-  if (!id_digest) {
-    log_warn(LD_BUG, "Called with id_digest==%p", id_digest);
+  if (!rend_data || !id_digest) {
+    log_warn(LD_BUG, "Called with rend_data==%p, id_digest==%p",
+             rend_data, id_digest);
     return;
   }
-  control_event_hs_descriptor_receive_end("FAILED", onion_address, auth_type,
-                                          id_digest, reason);
+  control_event_hs_descriptor_receive_end("FAILED",
+                                          rend_data->onion_address,
+                                          rend_data, id_digest, reason);
 }
 
 /** send HS_DESC_CONTENT event after completion of a successful fetch from

src/or/control.h

@@ -111,18 +111,17 @@ void control_event_hs_descriptor_upload(const char *service_id,
                                         const char *hs_dir);
 void control_event_hs_descriptor_receive_end(const char *action,
                                              const char *onion_address,
-                                             rend_auth_type_t auth_type,
+                                             const rend_data_t *rend_data,
                                              const char *id_digest,
                                              const char *reason);
 void control_event_hs_descriptor_upload_end(const char *action,
                                             const char *hs_dir,
                                             const char *reason);
 void control_event_hs_descriptor_received(const char *onion_address,
-                                          rend_auth_type_t auth_type,
+                                          const rend_data_t *rend_data,
                                           const char *id_digest);
 void control_event_hs_descriptor_uploaded(const char *hs_dir);
-void control_event_hs_descriptor_failed(const char *onion_address,
-                                        rend_auth_type_t auth_type,
+void control_event_hs_descriptor_failed(const rend_data_t *rend_data,
                                         const char *id_digest,
                                         const char *reason);
 void control_event_hs_descriptor_upload_failed(const char *hs_dir,

src/or/directory.c

@@ -2099,8 +2099,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
 
   if (conn->base_.purpose == DIR_PURPOSE_FETCH_RENDDESC_V2) {
     #define SEND_HS_DESC_FAILED_EVENT(reason) ( \
-      control_event_hs_descriptor_failed(conn->rend_data->onion_address, \
-                                         conn->rend_data->auth_type, \
+      control_event_hs_descriptor_failed(conn->rend_data, \
                                          conn->identity_digest, \
                                          reason) )
     #define SEND_HS_DESC_FAILED_CONTENT() ( \
@@ -2141,7 +2140,7 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
             log_info(LD_REND, "Successfully fetched v2 rendezvous "
                      "descriptor.");
             control_event_hs_descriptor_received(service_id,
-                                                 conn->rend_data->auth_type,
+                                                 conn->rend_data,
                                                  conn->identity_digest);
             control_event_hs_descriptor_content(service_id,
                                                 conn->requested_resource,

src/or/or.h

@@ -814,6 +814,10 @@ typedef struct rend_data_t {
 
   /** Rendezvous cookie used by both, client and service. */
   char rend_cookie[REND_COOKIE_LEN];
+
+  /** List of HSDir fingerprints on which this request has been sent to.
+   * This contains binary identity digest of the directory. */
+  smartlist_t *hsdirs_fp;
 } rend_data_t;
 
 /** Time interval for tracking replays of DH public keys received in

src/or/rendclient.c

@@ -686,6 +686,7 @@ directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query,
                           routerstatus_t *rs_hsdir)
 {
   routerstatus_t *hs_dir = rs_hsdir;
+  char *hsdir_fp;
   char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
   char descriptor_cookie_base64[3*REND_DESC_COOKIE_LEN_BASE64];
 #ifdef ENABLE_TOR2WEB_MODE
@@ -709,6 +710,12 @@ directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query,
     }
   }
 
+  /* Add a copy of the HSDir identity digest to the query so we can track it
+   * on the control port. */
+  hsdir_fp = tor_memdup(hs_dir->identity_digest,
+                        sizeof(hs_dir->identity_digest));
+  smartlist_add(rend_query->hsdirs_fp, hsdir_fp);
+
   /* Encode descriptor cookie for logging purposes. Also, if the cookie is
    * malformed, no fetch is triggered thus this needs to be done before the
    * fetch request. */

src/or/rendcommon.c

@@ -1400,8 +1400,14 @@ rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint,
 rend_data_t *
 rend_data_dup(const rend_data_t *data)
 {
+  rend_data_t *data_dup;
   tor_assert(data);
-  return tor_memdup(data, sizeof(rend_data_t));
+  data_dup = tor_memdup(data, sizeof(rend_data_t));
+  data_dup->hsdirs_fp = smartlist_new();
+  SMARTLIST_FOREACH(data->hsdirs_fp, char *, fp,
+                    smartlist_add(data_dup->hsdirs_fp,
+                                  tor_memdup(fp, DIGEST_LEN)));
+  return data_dup;
 }
 
 /** Compute descriptor ID for each replicas and save them. A valid onion
@@ -1495,6 +1501,7 @@ rend_data_client_create(const char *onion_address, const char *desc_id,
   }
 
   rend_data->auth_type = auth_type;
+  rend_data->hsdirs_fp = smartlist_new();
 
   return rend_data;
 

src/or/rendcommon.h

@@ -16,6 +16,12 @@
 static INLINE void
 rend_data_free(rend_data_t *data)
 {
+  if (!data) {
+    return;
+  }
+  /* Cleanup the HSDir identity digest. */
+  SMARTLIST_FOREACH(data->hsdirs_fp, char *, d, tor_free(d));
+  smartlist_free(data->hsdirs_fp);
   tor_free(data);
 }
 

src/test/test_hs.c

@@ -160,7 +160,7 @@ test_hs_desc_event(void *arg)
   /* test received event */
   rend_query.auth_type = 1;
   control_event_hs_descriptor_received(rend_query.onion_address,
-                                       rend_query.auth_type, HSDIR_EXIST_ID);
+                                       &rend_query, HSDIR_EXIST_ID);
   expected_msg = "650 HS_DESC RECEIVED "STR_HS_ADDR" BASIC_AUTH "\
                   STR_HSDIR_EXIST_LONGNAME"\r\n";
   tt_assert(received_msg);
@@ -169,8 +169,8 @@ test_hs_desc_event(void *arg)
 
   /* test failed event */
   rend_query.auth_type = 2;
-  control_event_hs_descriptor_failed(rend_query.onion_address,
-                                     rend_query.auth_type, HSDIR_NONE_EXIST_ID,
+  control_event_hs_descriptor_failed(&rend_query,
+                                     HSDIR_NONE_EXIST_ID,
                                      "QUERY_REJECTED");
   expected_msg = "650 HS_DESC FAILED "STR_HS_ADDR" STEALTH_AUTH "\
                   STR_HSDIR_NONE_EXIST_LONGNAME" REASON=QUERY_REJECTED\r\n";
@@ -180,8 +180,8 @@ test_hs_desc_event(void *arg)
 
   /* test invalid auth type */
   rend_query.auth_type = 999;
-  control_event_hs_descriptor_failed(rend_query.onion_address,
-                                     rend_query.auth_type, HSDIR_EXIST_ID,
+  control_event_hs_descriptor_failed(&rend_query,
+                                     HSDIR_EXIST_ID,
                                      "QUERY_REJECTED");
   expected_msg = "650 HS_DESC FAILED "STR_HS_ADDR" UNKNOWN "\
                   STR_HSDIR_EXIST_LONGNAME" REASON=QUERY_REJECTED\r\n";