allowing cancellation of resolver requests

2 files changed, 44 insertions, 15 deletions

diff --git a/src/include/gnunet_client_lib.h b/src/include/gnunet_client_lib.h
index c78df41c7..2ba9e135f 100644
--- a/src/include/gnunet_client_lib.h
+++ b/src/include/gnunet_client_lib.h
@@ -64,10 +64,15 @@ struct GNUNET_CLIENT_Connection *GNUNET_CLIENT_connect (struct
                                                         *cfg);
 
 /**
- * Destroy connection with the service.  This will
- * automatically cancel any pending "receive" request
- * (however, the handler will *NOT* be called, not
- * even with a NULL message).
+ * Destroy connection with the service.  This will automatically
+ * cancel any pending "receive" request (however, the handler will
+ * *NOT* be called, not even with a NULL message).  Any pending
+ * transmission request will also be cancelled UNLESS the callback for
+ * the transmission request has already been called, in which case the
+ * transmission is guaranteed to complete before the socket is fully
+ * destroyed.
+ *
+ * @param sock handle to the service connection
  */
 void GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *sock);
 
diff --git a/src/include/gnunet_resolver_service.h b/src/include/gnunet_resolver_service.h
index b7fb1532a..f8b1e79c7 100644
--- a/src/include/gnunet_resolver_service.h
+++ b/src/include/gnunet_resolver_service.h
@@ -53,6 +53,13 @@ typedef void (*GNUNET_RESOLVER_AddressCallback) (void *cls,
 
 
 /**
+ * Handle to a request given to the resolver.  Can be used to cancel
+ * the request prior to the timeout or successful execution.
+ */
+struct GNUNET_RESOLVER_RequestHandle;
+
+
+/**
  * Convert a string to one or more IP addresses.
  *
  * @param sched scheduler to use
@@ -62,8 +69,9 @@ typedef void (*GNUNET_RESOLVER_AddressCallback) (void *cls,
  * @param callback function to call with addresses
  * @param callback_cls closure for callback
  * @param timeout how long to try resolving
+ * @return handle that can be used to cancel the request, NULL on error
  */
-void
+struct GNUNET_RESOLVER_RequestHandle *
 GNUNET_RESOLVER_ip_get (struct GNUNET_SCHEDULER_Handle *sched,
                         const struct GNUNET_CONFIGURATION_Handle *cfg,
                         const char *hostname,
@@ -82,8 +90,9 @@ GNUNET_RESOLVER_ip_get (struct GNUNET_SCHEDULER_Handle *sched,
  * @param callback function to call with addresses
  * @param cls closure for callback
  * @param timeout how long to try resolving
+ * @return handle that can be used to cancel the request, NULL on error
  */
-void
+struct GNUNET_RESOLVER_RequestHandle *
 GNUNET_RESOLVER_hostname_resolve (struct GNUNET_SCHEDULER_Handle *sched,
                                   const struct GNUNET_CONFIGURATION_Handle *cfg,
                                   int domain,
@@ -104,7 +113,7 @@ typedef void (*GNUNET_RESOLVER_HostnameCallback) (void *cls,
 
 
 /**
- * Get an IP address as a string.
+ * Perform a reverse DNS lookup.
  *
  * @param sched scheduler to use
  * @param cfg configuration to use
@@ -114,15 +123,30 @@ typedef void (*GNUNET_RESOLVER_HostnameCallback) (void *cls,
  * @param timeout how long to try resolving
  * @param callback function to call with hostnames
  * @param cls closure for callback
+ * @return handle that can be used to cancel the request, NULL on error
  */
-void GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched,
-                                   const struct GNUNET_CONFIGURATION_Handle *cfg,
-                                   const struct sockaddr *sa,
-                                   socklen_t salen,
-                                   int do_resolve,
-                                   struct GNUNET_TIME_Relative timeout,
-                                   GNUNET_RESOLVER_HostnameCallback callback,
-                                   void *cls);
+struct GNUNET_RESOLVER_RequestHandle * 
+GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched,
+                              const struct GNUNET_CONFIGURATION_Handle *cfg,
+                              const struct sockaddr *sa,
+                              socklen_t salen,
+                              int do_resolve,
+                              struct GNUNET_TIME_Relative timeout,
+                              GNUNET_RESOLVER_HostnameCallback callback,
+                              void *cls);
+
+
+/**
+ * Cancel a request that is still pending with the resolver.
+ * Note that a client MUST NOT cancel a request that has
+ * been completed (i.e, the callback has been called to
+ * signal timeout or the final result).
+ *
+ * @param h handle of request to cancel
+ */
+void
+GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *h);
+
 
 #if 0                           /* keep Emacsens' auto-indent happy */
 {