Implemented zone refresh on SIGUSR2 signal.

refs #1833

src/knot/main.c

@@ -39,6 +39,7 @@
 /* Signal flags. */
 static volatile short sig_req_stop = 0;
 static volatile short sig_req_reload = 0;
+static volatile short sig_req_refresh = 0;
 static volatile short sig_stopping = 0;
 
 // SIGINT signal handler
@@ -49,7 +50,13 @@ void interrupt_handle(int s)
 		sig_req_reload = 1;
 		return;
 	}
-
+	
+	// Refresh
+	if (s == SIGUSR2) {
+		sig_req_refresh = 1;
+		return;
+	}
+	
 	// Stop server
 	if (s == SIGINT || s == SIGTERM) {
 		if (sig_stopping == 0) {
@@ -288,6 +295,7 @@ int main(int argc, char **argv)
 		sigaction(SIGTERM, &sa, NULL);
 		sigaction(SIGHUP,  &sa, NULL);
 		sigaction(SIGPIPE, &sa, NULL);
+		sigaction(SIGUSR2, &sa, NULL);
 		sa.sa_flags = 0;
 		pthread_sigmask(SIG_BLOCK, &sa.sa_mask, NULL);
 
@@ -324,6 +332,17 @@ int main(int argc, char **argv)
 					break;
 				}
 			}
+			if (sig_req_refresh) {
+				log_server_info("Refreshing slave zones...\n");
+				sig_req_reload = 0;
+				int cf_ret = server_refresh(server);
+				if (cf_ret != KNOTD_EOK) {
+					log_server_error("Couldn't refresh "
+					                 "slave zones - %s",
+					                 knotd_strerror(cf_ret));
+				}
+				
+			}
 
 			/* Events. */
 			if (ret > 0) {

src/knot/server/server.c

@@ -24,17 +24,20 @@
 #include <assert.h>
 #include <grp.h>
 
+
+#include "common/prng.h"
 #include "knot/common.h"
 #include "knot/other/error.h"
 #include "knot/server/server.h"
 #include "knot/server/udp-handler.h"
 #include "knot/server/tcp-handler.h"
 #include "knot/server/xfr-handler.h"
-#include "libknot/nameserver/name-server.h"
+#include "knot/server/zones.h"
+#include "knot/conf/conf.h"
 #include "knot/stat/stat.h"
+#include "libknot/nameserver/name-server.h"
 #include "libknot/zone/zonedb.h"
 #include "libknot/dname.h"
-#include "knot/conf/conf.h"
 
 /*! \brief Event scheduler loop. */
 static int evsched_run(dthread_t *thread)
@@ -610,6 +613,42 @@ int server_wait(server_t *server)
 	return ret;
 }
 
+int server_refresh(server_t *server)
+{
+	if (server == NULL || server->nameserver == NULL) {
+		return KNOTD_EINVAL;
+	}
+	
+	/* Lock RCU and fetch zones. */
+	rcu_read_lock();
+	knot_nameserver_t *ns =  server->nameserver;
+	evsched_t *sch = ((server_t *)knot_ns_get_data(ns))->sched;
+	const knot_zone_t **zones = knot_zonedb_zones(ns->zone_db);
+	if (zones == NULL) {
+		rcu_read_unlock();
+		return KNOTD_ENOMEM;
+	}
+	
+	/* REFRESH zones. */
+	for (unsigned i = 0; i < knot_zonedb_zone_count(ns->zone_db); ++i) {
+		zonedata_t *zd = (zonedata_t *)zones[i]->data;
+		if (zd == NULL) {
+			continue;
+		}
+		/* Expire REFRESH timer. */
+		if (zd->xfr_in.timer) {
+			evsched_cancel(sch, zd->xfr_in.timer);
+			evsched_schedule(sch, zd->xfr_in.timer,
+			                 tls_rand() * 1000);
+		}
+	}
+	
+	/* Unlock RCU. */
+	rcu_read_unlock();
+	free(zones);
+	return KNOTD_EOK;
+}
+
 void server_stop(server_t *server)
 {
 	dbg_server("server: stopping server\n");

src/knot/server/server.h

@@ -178,6 +178,16 @@ int server_start(server_t *server);
  */
 int server_wait(server_t *server);
 
+/*!
+ * \brief Refresh served zones.
+ *
+ * \param server Server structure to be used for operation.
+ *
+ * \retval  0 On success (EOK).
+ * \retval <0 If an error occured (EINVAL).
+ */
+int server_refresh(server_t *server);
+
 /*!
  * \brief Requests server to stop.
  *