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-rw-r--r--daemon/bindings/cache.c382
1 files changed, 382 insertions, 0 deletions
diff --git a/daemon/bindings/cache.c b/daemon/bindings/cache.c
new file mode 100644
index 0000000..d42ff62
--- /dev/null
+++ b/daemon/bindings/cache.c
@@ -0,0 +1,382 @@
+/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "daemon/bindings/impl.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;
+ if (kr_fails_assert(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 > TTL_MAX_MAX) {
+ lua_error_p(L,
+ "max_ttl must be larger than minimum TTL, and in range <1, "
+ STR(TTL_MAX_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 > TTL_MAX_MAX) {
+ lua_error_p(L,
+ "min_ttl must be smaller than maximum TTL, and in range <0, "
+ STR(TTL_MAX_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));
+ if (kr_fails_assert(!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;
+}
+
+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 },
+ { NULL, NULL }
+ };
+
+ luaL_register(L, "cache", lib);
+ return 1;
+}
+