[master] Optimized if and when DNS client context and ports are initted

    Merges in rt45290.

1 files changed, 51 insertions, 29 deletions

diff --git a/omapip/isclib.c b/omapip/isclib.c
index 781db848..3c9c3590 100644
--- a/omapip/isclib.c
+++ b/omapip/isclib.c
@@ -1,5 +1,5 @@
 /*
- * Copyright(c) 2009-2010,2013-2014 by Internet Systems Consortium, Inc.("ISC")
+ * Copyright(c) 2009-2017 by Internet Systems Consortium, Inc.("ISC")
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -226,39 +226,24 @@ dhcp_context_create(int flags,
 
 #if defined (NSUPDATE)
 	if ((flags & DHCP_CONTEXT_POST_DB) != 0) {
-		isc_sockaddr_t localaddr4, *localaddr4_ptr = NULL;
-		isc_sockaddr_t localaddr6, *localaddr6_ptr = NULL;
+		/* Setting addresses only.
+		 * All real work will be done later on if needed to avoid
+		 * listening on ddns port if client/server was compiled with
+		 * ddns support but not using it. */
 		if (local4 != NULL) {
-			isc_sockaddr_fromin(&localaddr4, local4, 0);
-			localaddr4_ptr = &localaddr4;
+			dhcp_gbl_ctx.use_local4 = 1;
+			isc_sockaddr_fromin(&dhcp_gbl_ctx.local4_sockaddr,
+					    local4, 0);
 		}
+
 		if (local6 != NULL) {
-			isc_sockaddr_fromin6(&localaddr6, local6, 0);
-			localaddr6_ptr = &localaddr6;
+			dhcp_gbl_ctx.use_local6 = 1;
+			isc_sockaddr_fromin6(&dhcp_gbl_ctx.local6_sockaddr,
+					     local6, 0);
 		}
 
-		result = dns_client_createx2(dhcp_gbl_ctx.mctx,
-					     dhcp_gbl_ctx.actx,
-					     dhcp_gbl_ctx.taskmgr,
-					     dhcp_gbl_ctx.socketmgr,
-					     dhcp_gbl_ctx.timermgr,
-					     0,
-					     &dhcp_gbl_ctx.dnsclient,
-					     localaddr4_ptr,
-					     localaddr6_ptr);
-		if (result != ISC_R_SUCCESS)
-			goto cleanup;
-
-		/*
-		 * If we can't set up the servers we may not be able to
-		 * do DDNS but we should continue to try and perform
-		 * our basic functions and let the user sort it out.
-		 */
-		result = dhcp_dns_client_setservers();
-		if (result != ISC_R_SUCCESS) {
-			log_error("Unable to set resolver from resolv.conf; "
-				  "startup continuing but DDNS support "
-				  "may be affected");
+		if (!(flags & DHCP_DNS_CLIENT_LAZY_INIT)) {
+			result = dns_client_init();
 		}
 	}
 #endif
@@ -365,3 +350,40 @@ void dhcp_signal_handler(int signal) {
 		(void) isc_app_ctxsuspend(ctx);
 	}
 }
+
+isc_result_t dns_client_init() {
+	isc_result_t result;
+	if (dhcp_gbl_ctx.dnsclient == NULL) {
+		result = dns_client_createx2(dhcp_gbl_ctx.mctx,
+					     dhcp_gbl_ctx.actx,
+					     dhcp_gbl_ctx.taskmgr,
+					     dhcp_gbl_ctx.socketmgr,
+					     dhcp_gbl_ctx.timermgr,
+					     0,
+					     &dhcp_gbl_ctx.dnsclient,
+					     (dhcp_gbl_ctx.use_local4 ?
+					      &dhcp_gbl_ctx.local4_sockaddr
+					      : NULL),
+					     (dhcp_gbl_ctx.use_local6 ?
+					      &dhcp_gbl_ctx.local6_sockaddr
+					      : NULL));
+
+		if (result != ISC_R_SUCCESS) {
+			log_error("Unable to create DNS client context:"
+				  " result: %d", result);
+			return result;
+		}
+
+		/* If we can't set up the servers we may not be able to
+		 * do DDNS but we should continue to try and perform
+		 * our basic functions and let the user sort it out. */
+		result = dhcp_dns_client_setservers();
+		if (result != ISC_R_SUCCESS) {
+			log_error("Unable to set resolver from resolv.conf; "
+				  "startup continuing but DDNS support "
+				  "may be affected: result %d", result);
+		}
+	}
+
+	return ISC_R_SUCCESS;
+}