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Diffstat (limited to 'daemon/bindings/impl.h')
| -rw-r--r-- | daemon/bindings/impl.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/daemon/bindings/impl.h b/daemon/bindings/impl.h new file mode 100644 index 0000000..d522756 --- /dev/null +++ b/daemon/bindings/impl.h @@ -0,0 +1,90 @@ +/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz> + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#pragma once + +#include "daemon/engine.h" +#include "daemon/worker.h" /* the_worker is often useful */ + +#include <lua.h> +#include <lauxlib.h> +/* It may happen that include files are messed up and we're hitting a header + * e.g. from vanilla Lua. Even 5.1 won't work due to missing luaL_traceback() in <lauxlib.h>. */ +#if (LUA_VERSION_NUM) != 501 || !defined(LUA_LJDIR) + #error "Incorrect Lua version in #include <lua.h> - LuaJIT compatible with Lua 5.1 is required" +#endif + + +/** Useful to stringify macros into error strings. */ +#define STR(s) STRINGIFY_TOKEN(s) +#define STRINGIFY_TOKEN(s) #s + + +/** Check lua table at the top of the stack for allowed keys. + * \param keys NULL-terminated array of 0-terminated strings + * \return NULL if passed or the offending string (pushed on top of lua stack) + * \note Future work: if non-NULL is returned, there's extra stuff on the lua stack. + * \note Brute-force complexity: table length * summed length of keys. + */ +const char * lua_table_checkindices(lua_State *L, const char *keys[]); + +/** If the value at the top of the stack isn't a table, make it a single-element list. */ +static inline void lua_listify(lua_State *L) +{ + if (lua_istable(L, -1)) + return; + lua_createtable(L, 1, 0); + lua_insert(L, lua_gettop(L) - 1); /* swap the top two stack elements */ + lua_pushinteger(L, 1); + lua_insert(L, lua_gettop(L) - 1); /* swap the top two stack elements */ + lua_settable(L, -3); +} + + +/** Throw a formatted lua error. + * + * The message will get prefixed by "ERROR: " and supplemented by stack trace. + * \return never! It calls lua_error(). + * + * Example: + ERROR: not a valid pin_sha256: 'a1Z/3ek=', raw length 5 instead of 32 + stack traceback: + [C]: in function 'tls_client' + /PathToPREFIX/lib/kdns_modules/policy.lua:175: in function 'TLS_FORWARD' + /PathToConfig.lua:46: in main chunk + */ +KR_PRINTF(2) KR_NORETURN KR_COLD +void lua_error_p(lua_State *L, const char *fmt, ...); +/** @internal Annotate for static checkers. */ +KR_NORETURN int lua_error(lua_State *L); + +/** Shortcut for common case. */ +static inline void lua_error_maybe(lua_State *L, int err) +{ + if (err) lua_error_p(L, "%s", kr_strerror(err)); +} + +static inline int execute_callback(lua_State *L, int argc) +{ + int ret = engine_pcall(L, argc); + if (ret != 0) { + kr_log_error(SYSTEM, "error: %s\n", lua_tostring(L, -1)); + } + /* Clear the stack, there may be event a/o anything returned */ + lua_settop(L, 0); + return ret; +} + +/** Push a pointer as heavy/full userdata. + * + * It's useful as a replacement of lua_pushlightuserdata(), + * but note that it behaves differently in lua (converts to pointer-to-pointer). + */ +static inline void lua_pushpointer(lua_State *L, void *p) +{ + void **addr = lua_newuserdata(L, sizeof(void *)); + kr_require(addr); + memcpy(addr, &p, sizeof(void *)); +} + |