From: Grigorii Demidov <grigorii.demidov@nic.cz>
Date: Mon, 19 Mar 2018 16:42:31 +0000 (+0100)
Subject: daemon: time period which determines how long NS non-reachabilty will be cached made... 
X-Git-Tag: v2.2.0~1^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb338c2a8046fc2c06325342dd5bea641af6d777;p=thirdparty%2Fknot-resolver.git

daemon: time period which determines how long NS non-reachabilty will be cached made configurable
---

diff --git a/daemon/bindings.c b/daemon/bindings.c
index bdde5dfa5..361b66cc7 100644
--- a/daemon/bindings.c
+++ b/daemon/bindings.c
@@ -1117,6 +1117,39 @@ static int cache_get(lua_State *L)
 	return 1;
 }
 
+/** Set time interval for cleaning rtt cache.
+ * Servers with score >= KR_NS_TIMEOUTED will be cleaned after
+ * this interval ended up, so that they will be able to participate
+ * in NS elections again. */
+static int cache_touted_ns_clean_interval(lua_State *L)
+{
+	struct engine *engine = engine_luaget(L);
+	struct kr_context *ctx = &engine->resolver;
+
+	/* Check parameters */
+	int n = lua_gettop(L);
+	if (n < 1) {
+		lua_pushinteger(L, ctx->cache_rtt_tout_retry_interval);
+		return 1;
+	}
+
+	if (!lua_isnumber(L, 1)) {
+		format_error(L, "expected 'cache.ns_tout(interval in ms)'");
+		lua_error(L);
+	}
+
+	lua_Number interval_lua = lua_tonumber(L, 1);
+	if (!(interval_lua >= 0 && interval_lua < UINT_MAX)) {
+		format_error(L, "invalid interval specified, it must be in range > 0, < " xstr(UINT_MAX));
+		lua_error(L);
+	}
+
+	ctx->cache_rtt_tout_retry_interval = interval_lua;
+	lua_pushinteger(L, ctx->cache_rtt_tout_retry_interval);
+	return 1;
+}
+
+
 int lib_cache(lua_State *L)
 {
 	static const luaL_Reg lib[] = {
@@ -1131,6 +1164,7 @@ int lib_cache(lua_State *L)
 		{ "get",    cache_get },
 		{ "max_ttl", cache_max_ttl },
 		{ "min_ttl", cache_min_ttl },
+		{ "ns_tout", cache_touted_ns_clean_interval },
 		{ NULL, NULL }
 	};
 
diff --git a/daemon/engine.c b/daemon/engine.c
index a32b18d6f..e62d71135 100644
--- a/daemon/engine.c
+++ b/daemon/engine.c
@@ -585,6 +585,7 @@ static int init_resolver(struct engine *engine)
 	engine->resolver.negative_anchors = map_make(NULL);
 	engine->resolver.pool = engine->pool;
 	engine->resolver.modules = &engine->modules;
+	engine->resolver.cache_rtt_tout_retry_interval = KR_NS_TIMEOUT_RETRY_INTERVAL;
 	/* Create OPT RR */
 	engine->resolver.opt_rr = mm_alloc(engine->pool, sizeof(knot_rrset_t));
 	if (!engine->resolver.opt_rr) {
diff --git a/lib/nsrep.c b/lib/nsrep.c
index 9be90e46a..f7aae0d98 100644
--- a/lib/nsrep.c
+++ b/lib/nsrep.c
@@ -82,9 +82,11 @@ static void update_nsrep_set(struct kr_nsrep *ns, const knot_dname_t *name, uint
 
 #undef ADDR_SET
 
-static unsigned eval_addr_set(pack_t *addr_set, kr_nsrep_rtt_lru_t *rtt_cache,
-			      unsigned score, uint8_t *addr[], struct kr_qflags opts)
+static unsigned eval_addr_set(pack_t *addr_set, struct kr_context *ctx,
+			      unsigned score, uint8_t *addr[])
 {
+	kr_nsrep_rtt_lru_t *rtt_cache = ctx->cache_rtt;
+	struct kr_qflags opts = ctx->options;
 	/* Name server is better candidate if it has address record. */
 	uint8_t *it = pack_head(*addr_set);
 	while (it != pack_tail(*addr_set)) {
@@ -110,10 +112,10 @@ static unsigned eval_addr_set(pack_t *addr_set, kr_nsrep_rtt_lru_t *rtt_cache,
 				elapsed = elapsed > UINT_MAX ? UINT_MAX : elapsed;
 				/* If NS once was marked as "timeouted",
 				 * it won't participate in NS elections
-				 * at least KR_NS_TIMEOUT_RETRY_INTERVAL milliseconds. */
+				 * at least ctx->cache_rtt_tout_retry_interval milliseconds. */
 				addr_score = cached->score;
 				if (cached->score >= KR_NS_TIMEOUT &&
-				    elapsed > KR_NS_TIMEOUT_RETRY_INTERVAL) {
+				    elapsed > ctx->cache_rtt_tout_retry_interval) {
 					addr_score = KR_NS_LONG - 1;
 					cached->score = addr_score;
 					cached->tout_timestamp = 0;
@@ -171,7 +173,7 @@ static int eval_nsrep(const char *k, void *v, void *baton)
 			}
 		}
 	} else {
-		score = eval_addr_set(addr_set, ctx->cache_rtt, score, addr_choice, ctx->options);
+		score = eval_addr_set(addr_set, ctx, score, addr_choice);
 	}
 
 	/* Probabilistic bee foraging strategy (naive).
@@ -286,7 +288,7 @@ int kr_nsrep_elect_addr(struct kr_query *qry, struct kr_context *ctx)
 	}
 	/* Evaluate addr list */
 	uint8_t *addr_choice[KR_NSREP_MAXADDR] = { NULL, };
-	unsigned score = eval_addr_set(addr_set, ctx->cache_rtt, ns->score, addr_choice, ctx->options);
+	unsigned score = eval_addr_set(addr_set, ctx, ns->score, addr_choice);
 	update_nsrep_set(ns, ns->name, addr_choice, score);
 	return kr_ok();
 }
diff --git a/lib/resolve.h b/lib/resolve.h
index 5ff492730..011679ec6 100644
--- a/lib/resolve.h
+++ b/lib/resolve.h
@@ -163,6 +163,7 @@ struct kr_context
 	struct kr_zonecut root_hints;
 	struct kr_cache cache;
 	kr_nsrep_rtt_lru_t *cache_rtt;
+	unsigned cache_rtt_tout_retry_interval;
 	kr_nsrep_lru_t *cache_rep;
 	module_array_t *modules;
 	/* The cookie context structure should not be held within the cookies