NAMESTORE: Allow service-side record set filtering. Fixes #7193

This commit enables zone iteration APIs which allow you to set a record
set filter to determine which records should be returned or not.
In particular filtering of private records and maintenance records
(TOMBSTONE) for zonemaster.

1 files changed, 109 insertions, 3 deletions

diff --git a/src/include/gnunet_namestore_service.h b/src/include/gnunet_namestore_service.h
index 0788bc8b4..dc6aeaa69 100644
--- a/src/include/gnunet_namestore_service.h
+++ b/src/include/gnunet_namestore_service.h
@@ -198,6 +198,27 @@ typedef void
                                    unsigned int rd_count,
                                    const struct GNUNET_GNSRECORD_Data *rd);
 
+/**
+ * Process a record set that was stored in the namestore.
+ * The record set expiration value takes existing TOMBSTONE records
+ * into account even if those are not returned.
+ *
+ * @param cls closure
+ * @param zone private key of the zone
+ * @param label label of the records
+ * @param rd_count number of entries in @a rd array, 0 if label was deleted
+ * @param rd array of records with data to store
+ * @param expiry the expiration of this record set.
+ */
+typedef void
+(*GNUNET_NAMESTORE_RecordSetMonitor) (void *cls,
+                                      const struct
+                                      GNUNET_IDENTITY_PrivateKey *zone,
+                                      const char *label,
+                                      unsigned int rd_count,
+                                      const struct GNUNET_GNSRECORD_Data *rd,
+                                      struct GNUNET_TIME_Absolute expiry);
+
 
 /**
  * Lookup an item in the namestore.
@@ -265,6 +286,9 @@ GNUNET_NAMESTORE_cancel (struct GNUNET_NAMESTORE_QueueEntry *qe);
 
 
 /**
+ * @deprecated since 0.16.7 will be replaced in 0.18
+ * @see GNUNET_NAMESTORE_zone_iteration_start2()
+ *
  * Starts a new zone iteration (used to periodically PUT all of our
  * records into our DHT). This MUST lock the `struct GNUNET_NAMESTORE_Handle`
  * for any other calls than #GNUNET_NAMESTORE_zone_iterator_next() and
@@ -300,6 +324,44 @@ GNUNET_NAMESTORE_zone_iteration_start (struct GNUNET_NAMESTORE_Handle *h,
                                        GNUNET_SCHEDULER_TaskCallback finish_cb,
                                        void *finish_cb_cls);
 
+/**
+ * Starts a new zone iteration (used to periodically PUT all of our
+ * records into our DHT). This MUST lock the `struct GNUNET_NAMESTORE_Handle`
+ * for any other calls than #GNUNET_NAMESTORE_zone_iterator_next() and
+ * #GNUNET_NAMESTORE_zone_iteration_stop. @a proc will be called once
+ * immediately, and then again after
+ * #GNUNET_NAMESTORE_zone_iterator_next() is invoked.
+ *
+ * On error (disconnect), @a error_cb will be invoked.
+ * On normal completion, @a finish_cb proc will be
+ * invoked.
+ *
+ * @param h handle to the namestore
+ * @param zone zone to access, NULL for all zones
+ * @param error_cb function to call on error (i.e. disconnect),
+ *        the handle is afterwards invalid
+ * @param error_cb_cls closure for @a error_cb
+ * @param proc function to call on each name from the zone; it
+ *        will be called repeatedly with a value (if available)
+ * @param proc_cls closure for @a proc
+ * @param finish_cb function to call on completion
+ *        the handle is afterwards invalid
+ * @param finish_cb_cls closure for @a finish_cb
+ * @return an iterator handle to use for iteration
+ */
+struct GNUNET_NAMESTORE_ZoneIterator *
+GNUNET_NAMESTORE_zone_iteration_start2 (struct GNUNET_NAMESTORE_Handle *h,
+                                        const struct
+                                        GNUNET_IDENTITY_PrivateKey *zone,
+                                        GNUNET_SCHEDULER_TaskCallback error_cb,
+                                        void *error_cb_cls,
+                                        GNUNET_NAMESTORE_RecordSetMonitor proc,
+                                        void *proc_cls,
+                                        GNUNET_SCHEDULER_TaskCallback finish_cb,
+                                        void *finish_cb_cls,
+                                        enum GNUNET_GNSRECORD_Filter filter);
+
+
 
 /**
  * Calls the record processor specified in #GNUNET_NAMESTORE_zone_iteration_start
@@ -332,6 +394,9 @@ struct GNUNET_NAMESTORE_ZoneMonitor;
 
 
 /**
+ * @deprecated since 0.16.7 will be replaced in 0.18
+ * @see GNUNET_NAMESTORE_zone_monitor_start2()
+ *
  * Begin monitoring a zone for changes.  Will first call the @a
  * monitor function on all existing records in the selected zone(s) if
  * @a iterate_first is #GNUNET_YES.  In any case, we will then call @a
@@ -370,6 +435,47 @@ GNUNET_NAMESTORE_zone_monitor_start (
   GNUNET_SCHEDULER_TaskCallback sync_cb,
   void *sync_cb_cls);
 
+/**
+ * Begin monitoring a zone for changes.  Will first call the @a
+ * monitor function on all existing records in the selected zone(s) if
+ * @a iterate_first is #GNUNET_YES.  In any case, we will then call @a
+ * sync_cb, and then afterwards call the @a monitor whenever a record
+ * changes.  If the namestore disconnects, the @a error_cb function is
+ * called with a disconnect event. Once the connection is
+ * re-established, the process begins from the start (depending on @a
+ * iterate_first, we will again first do all existing records, then @a
+ * sync, then updates).
+ *
+ * @param cfg configuration to use to connect to namestore
+ * @param zone zone to monitor, NULL for all zones
+ * @param iterate_first #GNUNET_YES to first iterate over all existing records,
+ *                      #GNUNET_NO to only return changes that happen from now on
+ * @param error_cb function to call on error (i.e. disconnect); note that
+ *         unlike the other error callbacks in this API, a call to this
+ *         function does NOT destroy the monitor handle, it merely signals
+ *         that monitoring is down. You need to still explicitly call
+ *         #GNUNET_NAMESTORE_zone_monitor_stop().
+ * @param error_cb_cls closure for @a error_cb
+ * @param monitor function to call on zone changes, with an initial limit of 1
+ * @param monitor_cls closure for @a monitor
+ * @param sync_cb function called when we're in sync with the namestore
+ * @param sync_cb_cls closure for @a sync_cb
+ * @param filter the record set filter to use
+ * @return handle to stop monitoring
+ */
+struct GNUNET_NAMESTORE_ZoneMonitor *
+GNUNET_NAMESTORE_zone_monitor_start2 (
+  const struct GNUNET_CONFIGURATION_Handle *cfg,
+  const struct GNUNET_IDENTITY_PrivateKey *zone,
+  int iterate_first,
+  GNUNET_SCHEDULER_TaskCallback error_cb,
+  void *error_cb_cls,
+  GNUNET_NAMESTORE_RecordSetMonitor monitor,
+  void *monitor_cls,
+  GNUNET_SCHEDULER_TaskCallback sync_cb,
+  void *sync_cb_cls,
+  enum GNUNET_GNSRECORD_Filter filter);
+
 
 /**
  * Calls the monitor processor specified in #GNUNET_NAMESTORE_zone_monitor_start
@@ -435,9 +541,9 @@ GNUNET_NAMESTORE_transaction_begin (struct GNUNET_NAMESTORE_Handle *h,
  */
 struct GNUNET_NAMESTORE_QueueEntry *
 GNUNET_NAMESTORE_transaction_rollback (struct GNUNET_NAMESTORE_Handle *h,
-                                     GNUNET_NAMESTORE_ContinuationWithStatus
-                                     cont,
-                                     void *cont_cls);
+                                       GNUNET_NAMESTORE_ContinuationWithStatus
+                                       cont,
+                                       void *cont_cls);
 /**
  * Commit a namestore transaction.
  * Saves all actions performed since #GNUNET_NAMESTORE_transaction_begin