1 files changed, 463 insertions, 0 deletions
diff --git a/daemon/bindings/cache.c b/daemon/bindings/cache.c
new file mode 100644
index 0000000..4a8afd9
--- /dev/null
+++ b/daemon/bindings/cache.c
@@ -0,0 +1,463 @@
+/*  Copyright (C) 2015-2019 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+ *  SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "daemon/bindings/impl.h"
+
+#include "daemon/zimport.h"
+
+/** @internal return cache, or throw lua error if not open */
+static struct kr_cache * cache_assert_open(lua_State *L)
+{
+	struct kr_cache *cache = &the_worker->engine->resolver.cache;
+	assert(cache);
+	if (!cache || !kr_cache_is_open(cache))
+		lua_error_p(L, "no cache is open yet, use cache.open() or cache.size, etc.");
+	return cache;
+}
+
+/** Return available cached backends. */
+static int cache_backends(lua_State *L)
+{
+	struct engine *engine = the_worker->engine;
+
+	lua_newtable(L);
+	for (unsigned i = 0; i < engine->backends.len; ++i) {
+		const struct kr_cdb_api *api = engine->backends.at[i];
+		lua_pushboolean(L, api == engine->resolver.cache.api);
+		lua_setfield(L, -2, api->name);
+	}
+	return 1;
+}
+
+/** Return number of cached records. */
+static int cache_count(lua_State *L)
+{
+	struct kr_cache *cache = cache_assert_open(L);
+
+	int count = cache->api->count(cache->db, &cache->stats);
+	if (count >= 0) {
+		/* First key is a version counter, omit it if nonempty. */
+		lua_pushinteger(L, count ? count - 1 : 0);
+		return 1;
+	}
+	return 0;
+}
+
+/** Return time of last checkpoint, or re-set it if passed `true`. */
+static int cache_checkpoint(lua_State *L)
+{
+	struct kr_cache *cache = cache_assert_open(L);
+
+	if (lua_gettop(L) == 0) { /* Return the current value. */
+		lua_newtable(L);
+		lua_pushnumber(L, cache->checkpoint_monotime);
+		lua_setfield(L, -2, "monotime");
+		lua_newtable(L);
+		lua_pushnumber(L, cache->checkpoint_walltime.tv_sec);
+		lua_setfield(L, -2, "sec");
+		lua_pushnumber(L, cache->checkpoint_walltime.tv_usec);
+		lua_setfield(L, -2, "usec");
+		lua_setfield(L, -2, "walltime");
+		return 1;
+	}
+
+	if (lua_gettop(L) != 1 || !lua_isboolean(L, 1) || !lua_toboolean(L, 1))
+		lua_error_p(L, "cache.checkpoint() takes no parameters or a true value");
+
+	kr_cache_make_checkpoint(cache);
+	return 1;
+}
+
+/** Return cache statistics. */
+static int cache_stats(lua_State *L)
+{
+	struct kr_cache *cache = cache_assert_open(L);
+	lua_newtable(L);
+#define add_stat(name) \
+	lua_pushinteger(L, (cache->stats.name)); \
+	lua_setfield(L, -2, #name)
+	add_stat(open);
+	add_stat(close);
+	add_stat(count);
+	cache->stats.count_entries = cache->api->count(cache->db, &cache->stats);
+	add_stat(count_entries);
+	add_stat(clear);
+	add_stat(commit);
+	add_stat(read);
+	add_stat(read_miss);
+	add_stat(write);
+	add_stat(remove);
+	add_stat(remove_miss);
+	add_stat(match);
+	add_stat(match_miss);
+	add_stat(read_leq);
+	add_stat(read_leq_miss);
+	/* usage_percent statistics special case - double */
+	cache->stats.usage_percent = cache->api->usage_percent(cache->db);
+	lua_pushnumber(L, cache->stats.usage_percent);
+	lua_setfield(L, -2, "usage_percent");
+#undef add_stat
+
+	return 1;
+}
+
+static const struct kr_cdb_api *cache_select(struct engine *engine, const char **conf)
+{
+	/* Return default backend */
+	if (*conf == NULL || !strstr(*conf, "://")) {
+		return engine->backends.at[0];
+	}
+
+	/* Find storage backend from config prefix */
+	for (unsigned i = 0; i < engine->backends.len; ++i) {
+		const struct kr_cdb_api *api = engine->backends.at[i];
+		if (strncmp(*conf, api->name, strlen(api->name)) == 0) {
+			*conf += strlen(api->name) + strlen("://");
+			return api;
+		}
+	}
+
+	return NULL;
+}
+
+static int cache_max_ttl(lua_State *L)
+{
+	struct kr_cache *cache = cache_assert_open(L);
+
+	int n = lua_gettop(L);
+	if (n > 0) {
+		if (!lua_isnumber(L, 1) || n > 1)
+			lua_error_p(L, "expected 'max_ttl(number ttl)'");
+		uint32_t min = cache->ttl_min;
+		int64_t ttl = lua_tointeger(L, 1);
+		if (ttl < 1 || ttl < min || ttl > UINT32_MAX) {
+			lua_error_p(L,
+				"max_ttl must be larger than minimum TTL, and in range <1, "
+				STR(UINT32_MAX) ">'");
+		}
+		cache->ttl_max = ttl;
+	}
+	lua_pushinteger(L, cache->ttl_max);
+	return 1;
+}
+
+
+static int cache_min_ttl(lua_State *L)
+{
+	struct kr_cache *cache = cache_assert_open(L);
+
+	int n = lua_gettop(L);
+	if (n > 0) {
+		if (!lua_isnumber(L, 1))
+			lua_error_p(L, "expected 'min_ttl(number ttl)'");
+		uint32_t max = cache->ttl_max;
+		int64_t ttl = lua_tointeger(L, 1);
+		if (ttl < 0 || ttl > max || ttl > UINT32_MAX) {
+			lua_error_p(L,
+				"min_ttl must be smaller than maximum TTL, and in range <0, "
+				STR(UINT32_MAX) ">'");
+		}
+		cache->ttl_min = ttl;
+	}
+	lua_pushinteger(L, cache->ttl_min);
+	return 1;
+}
+
+/** Open cache */
+static int cache_open(lua_State *L)
+{
+	/* Check parameters */
+	int n = lua_gettop(L);
+	if (n < 1 || !lua_isnumber(L, 1))
+		lua_error_p(L, "expected 'open(number max_size, string config = \"\")'");
+
+	/* Select cache storage backend */
+	struct engine *engine = the_worker->engine;
+
+	lua_Integer csize_lua = lua_tointeger(L, 1);
+	if (!(csize_lua >= 8192 && csize_lua < SIZE_MAX)) { /* min. is basically arbitrary */
+		lua_error_p(L, "invalid cache size specified, it must be in range <8192, "
+				STR(SIZE_MAX)  ">");
+	}
+	size_t cache_size = csize_lua;
+
+	const char *conf = n > 1 ? lua_tostring(L, 2) : NULL;
+	const char *uri = conf;
+	const struct kr_cdb_api *api = cache_select(engine, &conf);
+	if (!api)
+		lua_error_p(L, "unsupported cache backend");
+
+	/* Close if already open */
+	kr_cache_close(&engine->resolver.cache);
+
+	/* Reopen cache */
+	struct kr_cdb_opts opts = {
+		(conf && strlen(conf)) ? conf : ".",
+		cache_size
+	};
+	int ret = kr_cache_open(&engine->resolver.cache, api, &opts, engine->pool);
+	if (ret != 0) {
+		char cwd[PATH_MAX];
+		get_workdir(cwd, sizeof(cwd));
+		return luaL_error(L, "can't open cache path '%s'; working directory '%s'; %s",
+				  opts.path, cwd, kr_strerror(ret));
+	}
+	/* Let's check_health() every five seconds to avoid keeping old cache alive
+	 * even in case of not having any work to do. */
+	ret = kr_cache_check_health(&engine->resolver.cache, 5000);
+	if (ret != 0) {
+		kr_log_error("[cache] periodic health check failed (ignored): %s\n",
+				kr_strerror(ret));
+	}
+
+	/* Store current configuration */
+	lua_getglobal(L, "cache");
+	lua_pushstring(L, "current_size");
+	lua_pushnumber(L, cache_size);
+	lua_rawset(L, -3);
+	lua_pushstring(L, "current_storage");
+	lua_pushstring(L, uri);
+	lua_rawset(L, -3);
+	lua_pop(L, 1);
+
+	lua_pushboolean(L, 1);
+	return 1;
+}
+
+static int cache_close(lua_State *L)
+{
+	struct kr_cache *cache = &the_worker->engine->resolver.cache;
+	if (!kr_cache_is_open(cache)) {
+		return 0;
+	}
+
+	kr_cache_close(cache);
+	lua_getglobal(L, "cache");
+	lua_pushstring(L, "current_size");
+	lua_pushnumber(L, 0);
+	lua_rawset(L, -3);
+	lua_pop(L, 1);
+	lua_pushboolean(L, 1);
+	return 1;
+}
+
+#if 0
+/** @internal Prefix walk. */
+static int cache_prefixed(struct kr_cache *cache, const char *prefix, bool exact_name,
+			  knot_db_val_t keyval[][2], int maxcount)
+{
+	/* Convert to domain name */
+	uint8_t buf[KNOT_DNAME_MAXLEN];
+	if (!knot_dname_from_str(buf, prefix, sizeof(buf))) {
+		return kr_error(EINVAL);
+	}
+	/* Start prefix search */
+	return kr_cache_match(cache, buf, exact_name, keyval, maxcount);
+}
+#endif
+
+/** Clear everything. */
+static int cache_clear_everything(lua_State *L)
+{
+	struct kr_cache *cache = cache_assert_open(L);
+
+	/* Clear records and packets. */
+	int ret = kr_cache_clear(cache);
+	lua_error_maybe(L, ret);
+
+	/* Clear reputation tables */
+	struct kr_context *ctx = &the_worker->engine->resolver;
+	lru_reset(ctx->cache_cookie);
+	lua_pushboolean(L, true);
+	return 1;
+}
+
+#if 0
+/** @internal Dump cache key into table on Lua stack. */
+static void cache_dump(lua_State *L, knot_db_val_t keyval[])
+{
+	knot_dname_t dname[KNOT_DNAME_MAXLEN];
+	char name[KNOT_DNAME_TXT_MAXLEN];
+	uint16_t type;
+
+	int ret = kr_unpack_cache_key(keyval[0], dname, &type);
+	if (ret < 0) {
+		return;
+	}
+
+	ret = !knot_dname_to_str(name, dname, sizeof(name));
+	assert(!ret);
+	if (ret) return;
+
+	/* If name typemap doesn't exist yet, create it */
+	lua_getfield(L, -1, name);
+	if (lua_isnil(L, -1)) {
+		lua_pop(L, 1);
+		lua_newtable(L);
+	}
+	/* Append to typemap */
+	char type_buf[KR_RRTYPE_STR_MAXLEN] = { '\0' };
+	knot_rrtype_to_string(type, type_buf, sizeof(type_buf));
+	lua_pushboolean(L, true);
+	lua_setfield(L, -2, type_buf);
+	/* Set name typemap */
+	lua_setfield(L, -2, name);
+}
+
+/** Query cached records.  TODO: fix caveats in ./README.rst documentation? */
+static int cache_get(lua_State *L)
+{
+	//struct kr_cache *cache = cache_assert_open(L); // to be fixed soon
+
+	/* Check parameters */
+	int n = lua_gettop(L);
+	if (n < 1 || !lua_isstring(L, 1))
+		lua_error_p(L, "expected 'cache.get(string key)'");
+
+	/* Retrieve set of keys */
+	const char *prefix = lua_tostring(L, 1);
+	knot_db_val_t keyval[100][2];
+	int ret = cache_prefixed(cache, prefix, false/*FIXME*/, keyval, 100);
+	lua_error_maybe(L, ret);
+	/* Format output */
+	lua_newtable(L);
+	for (int i = 0; i < ret; ++i) {
+		cache_dump(L, keyval[i]);
+	}
+	return 1;
+}
+#endif
+static int cache_get(lua_State *L)
+{
+	lua_error_maybe(L, ENOSYS);
+	return kr_error(ENOSYS); /* doesn't happen */
+}
+
+/** Set time interval for cleaning rtt cache.
+ * Servers with score >= KR_NS_TIMEOUT will be cleaned after
+ * this interval ended up, so that they will be able to participate
+ * in NS elections again. */
+static int cache_ns_tout(lua_State *L)
+{
+	struct kr_context *ctx = &the_worker->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))
+		lua_error_p(L, "expected 'cache.ns_tout(interval in ms)'");
+
+	lua_Integer interval_lua = lua_tointeger(L, 1);
+	if (!(interval_lua > 0 && interval_lua < UINT_MAX)) {
+		lua_error_p(L, "invalid interval specified, it must be in range > 0, < "
+				STR(UINT_MAX));
+	}
+
+	ctx->cache_rtt_tout_retry_interval = interval_lua;
+	lua_pushinteger(L, ctx->cache_rtt_tout_retry_interval);
+	return 1;
+}
+
+/** Zone import completion callback.
+ * Deallocates zone import context. */
+static void cache_zone_import_cb(int state, void *param)
+{
+	assert (param);
+	(void)state;
+	struct worker_ctx *worker = (struct worker_ctx *)param;
+	assert (worker->z_import);
+	zi_free(worker->z_import);
+	worker->z_import = NULL;
+}
+
+/** Import zone from file. */
+static int cache_zone_import(lua_State *L)
+{
+	int ret = -1;
+	char msg[128];
+
+	struct worker_ctx *worker = the_worker;
+	if (!worker) {
+		strncpy(msg, "internal error, empty worker pointer", sizeof(msg));
+		goto finish;
+	}
+
+	if (worker->z_import && zi_import_started(worker->z_import)) {
+		strncpy(msg, "import already started", sizeof(msg));
+		goto finish;
+	}
+
+	(void)cache_assert_open(L); /* just check it in advance */
+
+	/* Check parameters */
+	int n = lua_gettop(L);
+	if (n < 1 || !lua_isstring(L, 1)) {
+		strncpy(msg, "expected 'cache.zone_import(path to zone file)'", sizeof(msg));
+		goto finish;
+	}
+
+	/* Parse zone file */
+	const char *zone_file = lua_tostring(L, 1);
+
+	const char *default_origin = NULL; /* TODO */
+	uint16_t default_rclass = 1;
+	uint32_t default_ttl = 0;
+
+	if (worker->z_import == NULL) {
+		worker->z_import = zi_allocate(worker, cache_zone_import_cb, worker);
+		if (worker->z_import == NULL) {
+			strncpy(msg, "can't allocate zone import context", sizeof(msg));
+			goto finish;
+		}
+	}
+
+	ret = zi_zone_import(worker->z_import, zone_file, default_origin,
+			     default_rclass, default_ttl);
+
+	lua_newtable(L);
+	if (ret == 0) {
+		strncpy(msg, "zone file successfully parsed, import started", sizeof(msg));
+	} else if (ret == 1) {
+		strncpy(msg, "TA not found", sizeof(msg));
+	} else {
+		strncpy(msg, "error parsing zone file", sizeof(msg));
+	}
+
+finish:
+	msg[sizeof(msg) - 1] = 0;
+	lua_newtable(L);
+	lua_pushstring(L, msg);
+	lua_setfield(L, -2, "msg");
+	lua_pushnumber(L, ret);
+	lua_setfield(L, -2, "code");
+
+	return 1;
+}
+
+int kr_bindings_cache(lua_State *L)
+{
+	static const luaL_Reg lib[] = {
+		{ "backends", cache_backends },
+		{ "count",  cache_count },
+		{ "stats",  cache_stats },
+		{ "checkpoint", cache_checkpoint },
+		{ "open",   cache_open },
+		{ "close",  cache_close },
+		{ "clear_everything", cache_clear_everything },
+		{ "get",     cache_get },
+		{ "max_ttl", cache_max_ttl },
+		{ "min_ttl", cache_min_ttl },
+		{ "ns_tout", cache_ns_tout },
+		{ "zone_import", cache_zone_import },
+		{ NULL, NULL }
+	};
+
+	luaL_register(L, "cache", lib);
+	return 1;
+}
+