From: Marek Vavruša <marek.vavrusa@nic.cz>
Date: Wed, 22 Jul 2015 10:47:20 +0000 (+0200)
Subject: lib/resolve: use maximum unfragmented UDP payload for iter as default
X-Git-Tag: v1.0.0-beta1~63
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=926a41fcd14180a308d4029e9e9fa402aff90ee8;p=thirdparty%2Fknot-resolver.git

lib/resolve: use maximum unfragmented UDP payload for iter as default

this is a saner default for large answers. instead of waiting for
probably lost/thrown away fragmented packet, do the query over TCP
instead
---

diff --git a/lib/defines.h b/lib/defines.h
index 9709380c9..d3f3f76fd 100644
--- a/lib/defines.h
+++ b/lib/defines.h
@@ -36,12 +36,12 @@ static inline int __attribute__((__cold__)) kr_error(int x) {
  * @cond internal
  */
 #define KR_CONN_RTT_MAX 3000 /* Timeout for network activity */
-#define KR_ITER_LIMIT 50        /* Built-in iterator limit */
+#define KR_ITER_LIMIT 50     /* Built-in iterator limit */
 
 /*
  * Defines.
  */
 #define KR_DNS_PORT   53
 #define KR_EDNS_VERSION 0
-#define KR_EDNS_PAYLOAD 4096
+#define KR_EDNS_PAYLOAD 1452 /* Maximum payload for unfragmented UDP/v6 */
 /* @endcond */
diff --git a/lib/resolve.c b/lib/resolve.c
index 85b968e7f..75f0d7bb4 100644
--- a/lib/resolve.c
+++ b/lib/resolve.c
@@ -290,7 +290,7 @@ int kr_resolve(struct kr_context* ctx, knot_pkt_t *answer,
 		.ctx = mp_new (KNOT_WIRE_MAX_PKTSIZE),
 		.alloc = (mm_alloc_t) mp_alloc
 	};
-	knot_pkt_t *query = knot_pkt_new(NULL, KNOT_EDNS_MAX_UDP_PAYLOAD, &pool);
+	knot_pkt_t *query = knot_pkt_new(NULL, KR_EDNS_PAYLOAD, &pool);
 	knot_pkt_t *resp = knot_pkt_new(NULL, KNOT_WIRE_MAX_PKTSIZE, &pool);
 	if (!query || !resp) {
 		mp_delete(pool.ctx);