Lua filters: connected with no exported vars

Makefile.in

@@ -7,10 +7,10 @@ MAKEFLAGS += -r
 
 # Variable definitions
 CPPFLAGS=-I$(objdir) -I$(srcdir) @CPPFLAGS@
-CFLAGS=$(CPPFLAGS) @CFLAGS@
+CFLAGS=$(CPPFLAGS) @CFLAGS@ @LUA_INCLUDE@
 LDFLAGS=@LDFLAGS@
 LIBS=@LIBS@
-DAEMON_LIBS=@DAEMON_LIBS@
+DAEMON_LIBS=@DAEMON_LIBS@ @LUA_LIB@
 CLIENT_LIBS=@CLIENT_LIBS@
 CC=@CC@
 M4=@M4@
@@ -67,7 +67,7 @@ cli: $(client)
 $(daemon): LIBS += $(DAEMON_LIBS)
 
 # Include directories
-dirs := client conf doc filter lib nest test $(addprefix proto/,$(protocols)) @sysdep_dirs@
+dirs := client conf doc filter lib lua nest test $(addprefix proto/,$(protocols)) @sysdep_dirs@
 
 conf-y-targets := $(addprefix $(objdir)/conf/,cf-parse.y keywords.h commands.h)
 cf-local = $(conf-y-targets): $(s)config.Y

aclocal.m4

@@ -110,3 +110,483 @@ AC_DEFUN([BIRD_CHECK_PROG_FLAVOR_GNU],
   )
   esac
 ])
+
+dnl =========================================================================
+dnl AX_PROG_LUA([MINIMUM-VERSION], [TOO-BIG-VERSION],
+dnl             [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_PROG_LUA],
+[
+  dnl Check for required tools.
+  AC_REQUIRE([AC_PROG_GREP])
+  AC_REQUIRE([AC_PROG_SED])
+
+  dnl Make LUA a precious variable.
+  AC_ARG_VAR([LUA], [The Lua interpreter, e.g. /usr/bin/lua5.1])
+
+  dnl Find a Lua interpreter.
+  m4_define_default([_AX_LUA_INTERPRETER_LIST],
+    [lua lua5.3 lua53 lua5.2 lua52 lua5.1 lua51 lua50])
+
+  m4_if([$1], [],
+  [ dnl No version check is needed. Find any Lua interpreter.
+    AS_IF([test "x$LUA" = 'x'],
+      [AC_PATH_PROGS([LUA], [_AX_LUA_INTERPRETER_LIST], [:])])
+    ax_display_LUA='lua'
+
+    AS_IF([test "x$LUA" != 'x:'],
+      [ dnl At least check if this is a Lua interpreter.
+        AC_MSG_CHECKING([if $LUA is a Lua interpreter])
+        _AX_LUA_CHK_IS_INTRP([$LUA],
+          [AC_MSG_RESULT([yes])],
+          [ AC_MSG_RESULT([no])
+            AC_MSG_ERROR([not a Lua interpreter])
+          ])
+      ])
+  ],
+  [ dnl A version check is needed.
+    AS_IF([test "x$LUA" != 'x'],
+    [ dnl Check if this is a Lua interpreter.
+      AC_MSG_CHECKING([if $LUA is a Lua interpreter])
+      _AX_LUA_CHK_IS_INTRP([$LUA],
+        [AC_MSG_RESULT([yes])],
+        [ AC_MSG_RESULT([no])
+          AC_MSG_ERROR([not a Lua interpreter])
+        ])
+      dnl Check the version.
+      m4_if([$2], [],
+        [_ax_check_text="whether $LUA version >= $1"],
+        [_ax_check_text="whether $LUA version >= $1, < $2"])
+      AC_MSG_CHECKING([$_ax_check_text])
+      _AX_LUA_CHK_VER([$LUA], [$1], [$2],
+        [AC_MSG_RESULT([yes])],
+        [ AC_MSG_RESULT([no])
+          AC_MSG_ERROR([version is out of range for specified LUA])])
+      ax_display_LUA=$LUA
+    ],
+    [ dnl Try each interpreter until we find one that satisfies VERSION.
+      m4_if([$2], [],
+        [_ax_check_text="for a Lua interpreter with version >= $1"],
+        [_ax_check_text="for a Lua interpreter with version >= $1, < $2"])
+      AC_CACHE_CHECK([$_ax_check_text],
+        [ax_cv_pathless_LUA],
+        [ for ax_cv_pathless_LUA in _AX_LUA_INTERPRETER_LIST none; do
+            test "x$ax_cv_pathless_LUA" = 'xnone' && break
+            _AX_LUA_CHK_IS_INTRP([$ax_cv_pathless_LUA], [], [continue])
+            _AX_LUA_CHK_VER([$ax_cv_pathless_LUA], [$1], [$2], [break])
+          done
+        ])
+      dnl Set $LUA to the absolute path of $ax_cv_pathless_LUA.
+      AS_IF([test "x$ax_cv_pathless_LUA" = 'xnone'],
+        [LUA=':'],
+        [AC_PATH_PROG([LUA], [$ax_cv_pathless_LUA])])
+      ax_display_LUA=$ax_cv_pathless_LUA
+    ])
+  ])
+
+  AS_IF([test "x$LUA" = 'x:'],
+  [ dnl Run any user-specified action, or abort.
+    m4_default([$4], [AC_MSG_ERROR([cannot find suitable Lua interpreter])])
+  ],
+  [ dnl Query Lua for its version number.
+    AC_CACHE_CHECK([for $ax_display_LUA version],
+      [ax_cv_lua_version],
+      [ dnl Get the interpreter version in X.Y format. This should work for
+        dnl interpreters version 5.0 and beyond.
+        ax_cv_lua_version=[`$LUA -e '
+          -- return a version number in X.Y format
+          local _, _, ver = string.find(_VERSION, "^Lua (%d+%.%d+)")
+          print(ver)'`]
+      ])
+    AS_IF([test "x$ax_cv_lua_version" = 'x'],
+      [AC_MSG_ERROR([invalid Lua version number])])
+    AC_SUBST([LUA_VERSION], [$ax_cv_lua_version])
+    AC_SUBST([LUA_SHORT_VERSION], [`echo "$LUA_VERSION" | $SED 's|\.||'`])
+
+    dnl The following check is not supported:
+    dnl At times (like when building shared libraries) you may want to know
+    dnl which OS platform Lua thinks this is.
+    AC_CACHE_CHECK([for $ax_display_LUA platform],
+      [ax_cv_lua_platform],
+      [ax_cv_lua_platform=[`$LUA -e 'print("unknown")'`]])
+    AC_SUBST([LUA_PLATFORM], [$ax_cv_lua_platform])
+
+    dnl Use the values of $prefix and $exec_prefix for the corresponding
+    dnl values of LUA_PREFIX and LUA_EXEC_PREFIX. These are made distinct
+    dnl variables so they can be overridden if need be. However, the general
+    dnl consensus is that you shouldn't need this ability.
+    AC_SUBST([LUA_PREFIX], ['${prefix}'])
+    AC_SUBST([LUA_EXEC_PREFIX], ['${exec_prefix}'])
+
+    dnl Lua provides no way to query the script directory, and instead
+    dnl provides LUA_PATH. However, we should be able to make a safe educated
+    dnl guess. If the built-in search path contains a directory which is
+    dnl prefixed by $prefix, then we can store scripts there. The first
+    dnl matching path will be used.
+    AC_CACHE_CHECK([for $ax_display_LUA script directory],
+      [ax_cv_lua_luadir],
+      [ AS_IF([test "x$prefix" = 'xNONE'],
+          [ax_lua_prefix=$ac_default_prefix],
+          [ax_lua_prefix=$prefix])
+
+        dnl Initialize to the default path.
+        ax_cv_lua_luadir="$LUA_PREFIX/share/lua/$LUA_VERSION"
+
+        dnl Try to find a path with the prefix.
+        _AX_LUA_FND_PRFX_PTH([$LUA], [$ax_lua_prefix], [script])
+        AS_IF([test "x$ax_lua_prefixed_path" != 'x'],
+        [ dnl Fix the prefix.
+          _ax_strip_prefix=`echo "$ax_lua_prefix" | $SED 's|.|.|g'`
+          ax_cv_lua_luadir=`echo "$ax_lua_prefixed_path" | \
+            $SED "s|^$_ax_strip_prefix|$LUA_PREFIX|"`
+        ])
+      ])
+    AC_SUBST([luadir], [$ax_cv_lua_luadir])
+    AC_SUBST([pkgluadir], [\${luadir}/$PACKAGE])
+
+    dnl Lua provides no way to query the module directory, and instead
+    dnl provides LUA_PATH. However, we should be able to make a safe educated
+    dnl guess. If the built-in search path contains a directory which is
+    dnl prefixed by $exec_prefix, then we can store modules there. The first
+    dnl matching path will be used.
+    AC_CACHE_CHECK([for $ax_display_LUA module directory],
+      [ax_cv_lua_luaexecdir],
+      [ AS_IF([test "x$exec_prefix" = 'xNONE'],
+          [ax_lua_exec_prefix=$ax_lua_prefix],
+          [ax_lua_exec_prefix=$exec_prefix])
+
+        dnl Initialize to the default path.
+        ax_cv_lua_luaexecdir="$LUA_EXEC_PREFIX/lib/lua/$LUA_VERSION"
+
+        dnl Try to find a path with the prefix.
+        _AX_LUA_FND_PRFX_PTH([$LUA],
+          [$ax_lua_exec_prefix], [module])
+        AS_IF([test "x$ax_lua_prefixed_path" != 'x'],
+        [ dnl Fix the prefix.
+          _ax_strip_prefix=`echo "$ax_lua_exec_prefix" | $SED 's|.|.|g'`
+          ax_cv_lua_luaexecdir=`echo "$ax_lua_prefixed_path" | \
+            $SED "s|^$_ax_strip_prefix|$LUA_EXEC_PREFIX|"`
+        ])
+      ])
+    AC_SUBST([luaexecdir], [$ax_cv_lua_luaexecdir])
+    AC_SUBST([pkgluaexecdir], [\${luaexecdir}/$PACKAGE])
+
+    dnl Run any user specified action.
+    $3
+  ])
+])
+
+dnl AX_WITH_LUA is now the same thing as AX_PROG_LUA.
+AC_DEFUN([AX_WITH_LUA],
+[
+  AC_MSG_WARN([[$0 is deprecated, please use AX_PROG_LUA instead]])
+  AX_PROG_LUA
+])
+
+
+dnl =========================================================================
+dnl _AX_LUA_CHK_IS_INTRP(PROG, [ACTION-IF-TRUE], [ACTION-IF-FALSE])
+dnl =========================================================================
+AC_DEFUN([_AX_LUA_CHK_IS_INTRP],
+[
+  dnl A minimal Lua factorial to prove this is an interpreter. This should work
+  dnl for Lua interpreters version 5.0 and beyond.
+  _ax_lua_factorial=[`$1 2>/dev/null -e '
+    -- a simple factorial
+    function fact (n)
+      if n == 0 then
+        return 1
+      else
+        return n * fact(n-1)
+      end
+    end
+    print("fact(5) is " .. fact(5))'`]
+  AS_IF([test "$_ax_lua_factorial" = 'fact(5) is 120'],
+    [$2], [$3])
+])
+
+
+dnl =========================================================================
+dnl _AX_LUA_CHK_VER(PROG, MINIMUM-VERSION, [TOO-BIG-VERSION],
+dnl                 [ACTION-IF-TRUE], [ACTION-IF-FALSE])
+dnl =========================================================================
+AC_DEFUN([_AX_LUA_CHK_VER],
+[
+  dnl Check that the Lua version is within the bounds. Only the major and minor
+  dnl version numbers are considered. This should work for Lua interpreters
+  dnl version 5.0 and beyond.
+  _ax_lua_good_version=[`$1 -e '
+    -- a script to compare versions
+    function verstr2num(verstr)
+      local _, _, majorver, minorver = string.find(verstr, "^(%d+)%.(%d+)")
+      if majorver and minorver then
+        return tonumber(majorver) * 100 + tonumber(minorver)
+      end
+    end
+    local minver = verstr2num("$2")
+    local _, _, trimver = string.find(_VERSION, "^Lua (.*)")
+    local ver = verstr2num(trimver)
+    local maxver = verstr2num("$3") or 1e9
+    if minver <= ver and ver < maxver then
+      print("yes")
+    else
+      print("no")
+    end'`]
+    AS_IF([test "x$_ax_lua_good_version" = "xyes"],
+      [$4], [$5])
+])
+
+
+dnl =========================================================================
+dnl _AX_LUA_FND_PRFX_PTH(PROG, PREFIX, SCRIPT-OR-MODULE-DIR)
+dnl =========================================================================
+AC_DEFUN([_AX_LUA_FND_PRFX_PTH],
+[
+  dnl Get the script or module directory by querying the Lua interpreter,
+  dnl filtering on the given prefix, and selecting the shallowest path. If no
+  dnl path is found matching the prefix, the result will be an empty string.
+  dnl The third argument determines the type of search, it can be 'script' or
+  dnl 'module'. Supplying 'script' will perform the search with package.path
+  dnl and LUA_PATH, and supplying 'module' will search with package.cpath and
+  dnl LUA_CPATH. This is done for compatibility with Lua 5.0.
+
+  ax_lua_prefixed_path=[`$1 -e '
+    -- get the path based on search type
+    local searchtype = "$3"
+    local paths = ""
+    if searchtype == "script" then
+      paths = (package and package.path) or LUA_PATH
+    elseif searchtype == "module" then
+      paths = (package and package.cpath) or LUA_CPATH
+    end
+    -- search for the prefix
+    local prefix = "'$2'"
+    local minpath = ""
+    local mindepth = 1e9
+    string.gsub(paths, "(@<:@^;@:>@+)",
+      function (path)
+        path = string.gsub(path, "%?.*$", "")
+        path = string.gsub(path, "/@<:@^/@:>@*$", "")
+        if string.find(path, prefix) then
+          local depth = string.len(string.gsub(path, "@<:@^/@:>@", ""))
+          if depth < mindepth then
+            minpath = path
+            mindepth = depth
+          end
+        end
+      end)
+    print(minpath)'`]
+])
+
+
+dnl =========================================================================
+dnl AX_LUA_HEADERS([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_LUA_HEADERS],
+[
+  dnl Check for LUA_VERSION.
+  AC_MSG_CHECKING([if LUA_VERSION is defined])
+  AS_IF([test "x$LUA_VERSION" != 'x'],
+    [AC_MSG_RESULT([yes])],
+    [ AC_MSG_RESULT([no])
+      AC_MSG_ERROR([cannot check Lua headers without knowing LUA_VERSION])
+    ])
+
+  dnl Make LUA_INCLUDE a precious variable.
+  AC_ARG_VAR([LUA_INCLUDE], [The Lua includes, e.g. -I/usr/include/lua5.1])
+
+  dnl Some default directories to search.
+  LUA_SHORT_VERSION=`echo "$LUA_VERSION" | $SED 's|\.||'`
+  m4_define_default([_AX_LUA_INCLUDE_LIST],
+    [ /usr/include/lua$LUA_VERSION \
+      /usr/include/lua-$LUA_VERSION \
+      /usr/include/lua/$LUA_VERSION \
+      /usr/include/lua$LUA_SHORT_VERSION \
+      /usr/local/include/lua$LUA_VERSION \
+      /usr/local/include/lua-$LUA_VERSION \
+      /usr/local/include/lua/$LUA_VERSION \
+      /usr/local/include/lua$LUA_SHORT_VERSION \
+    ])
+
+  dnl Try to find the headers.
+  _ax_lua_saved_cppflags=$CPPFLAGS
+  CPPFLAGS="$CPPFLAGS $LUA_INCLUDE"
+  AC_CHECK_HEADERS([lua.h lualib.h lauxlib.h luaconf.h])
+  CPPFLAGS=$_ax_lua_saved_cppflags
+
+  dnl Try some other directories if LUA_INCLUDE was not set.
+  AS_IF([test "x$LUA_INCLUDE" = 'x' &&
+         test "x$ac_cv_header_lua_h" != 'xyes'],
+    [ dnl Try some common include paths.
+      for _ax_include_path in _AX_LUA_INCLUDE_LIST; do
+        test ! -d "$_ax_include_path" && continue
+
+        AC_MSG_CHECKING([for Lua headers in])
+        AC_MSG_RESULT([$_ax_include_path])
+
+        AS_UNSET([ac_cv_header_lua_h])
+        AS_UNSET([ac_cv_header_lualib_h])
+        AS_UNSET([ac_cv_header_lauxlib_h])
+        AS_UNSET([ac_cv_header_luaconf_h])
+
+        _ax_lua_saved_cppflags=$CPPFLAGS
+        CPPFLAGS="$CPPFLAGS -I$_ax_include_path"
+        AC_CHECK_HEADERS([lua.h lualib.h lauxlib.h luaconf.h])
+        CPPFLAGS=$_ax_lua_saved_cppflags
+
+        AS_IF([test "x$ac_cv_header_lua_h" = 'xyes'],
+          [ LUA_INCLUDE="-I$_ax_include_path"
+            break
+          ])
+      done
+    ])
+
+  AS_IF([test "x$ac_cv_header_lua_h" = 'xyes'],
+    [ dnl Make a program to print LUA_VERSION defined in the header.
+      dnl TODO It would be really nice if we could do this without compiling a
+      dnl program, then it would work when cross compiling. But I'm not sure how
+      dnl to do this reliably. For now, assume versions match when cross compiling.
+
+      AS_IF([test "x$cross_compiling" != 'xyes'],
+        [ AC_CACHE_CHECK([for Lua header version],
+            [ax_cv_lua_header_version],
+            [ _ax_lua_saved_cppflags=$CPPFLAGS
+              CPPFLAGS="$CPPFLAGS $LUA_INCLUDE"
+              AC_RUN_IFELSE(
+                [ AC_LANG_SOURCE([[
+#include <lua.h>
+#include <stdlib.h>
+#include <stdio.h>
+int main(int argc, char ** argv)
+{
+  if(argc > 1) printf("%s", LUA_VERSION);
+  exit(EXIT_SUCCESS);
+}
+]])
+                ],
+                [ ax_cv_lua_header_version=`./conftest$EXEEXT p | \
+                    $SED -n "s|^Lua \(@<:@0-9@:>@\{1,\}\.@<:@0-9@:>@\{1,\}\).\{0,\}|\1|p"`
+                ],
+                [ax_cv_lua_header_version='unknown'])
+              CPPFLAGS=$_ax_lua_saved_cppflags
+            ])
+
+          dnl Compare this to the previously found LUA_VERSION.
+          AC_MSG_CHECKING([if Lua header version matches $LUA_VERSION])
+          AS_IF([test "x$ax_cv_lua_header_version" = "x$LUA_VERSION"],
+            [ AC_MSG_RESULT([yes])
+              ax_header_version_match='yes'
+            ],
+            [ AC_MSG_RESULT([no])
+              ax_header_version_match='no'
+            ])
+        ],
+        [ AC_MSG_WARN([cross compiling so assuming header version number matches])
+          ax_header_version_match='yes'
+        ])
+    ])
+
+  dnl Was LUA_INCLUDE specified?
+  AS_IF([test "x$ax_header_version_match" != 'xyes' &&
+         test "x$LUA_INCLUDE" != 'x'],
+    [AC_MSG_ERROR([cannot find headers for specified LUA_INCLUDE])])
+
+  dnl Test the final result and run user code.
+  AS_IF([test "x$ax_header_version_match" = 'xyes'], [$1],
+    [m4_default([$2], [AC_MSG_ERROR([cannot find Lua includes])])])
+])
+
+dnl AX_LUA_HEADERS_VERSION no longer exists, use AX_LUA_HEADERS.
+AC_DEFUN([AX_LUA_HEADERS_VERSION],
+[
+  AC_MSG_WARN([[$0 is deprecated, please use AX_LUA_HEADERS instead]])
+])
+
+
+dnl =========================================================================
+dnl AX_LUA_LIBS([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_LUA_LIBS],
+[
+  dnl TODO Should this macro also check various -L flags?
+
+  dnl Check for LUA_VERSION.
+  AC_MSG_CHECKING([if LUA_VERSION is defined])
+  AS_IF([test "x$LUA_VERSION" != 'x'],
+    [AC_MSG_RESULT([yes])],
+    [ AC_MSG_RESULT([no])
+      AC_MSG_ERROR([cannot check Lua libs without knowing LUA_VERSION])
+    ])
+
+  dnl Make LUA_LIB a precious variable.
+  AC_ARG_VAR([LUA_LIB], [The Lua library, e.g. -llua5.1])
+
+  AS_IF([test "x$LUA_LIB" != 'x'],
+  [ dnl Check that LUA_LIBS works.
+    _ax_lua_saved_libs=$LIBS
+    LIBS="$LIBS $LUA_LIB"
+    AC_SEARCH_LIBS([lua_load], [],
+      [_ax_found_lua_libs='yes'],
+      [_ax_found_lua_libs='no'])
+    LIBS=$_ax_lua_saved_libs
+
+    dnl Check the result.
+    AS_IF([test "x$_ax_found_lua_libs" != 'xyes'],
+      [AC_MSG_ERROR([cannot find libs for specified LUA_LIB])])
+  ],
+  [ dnl First search for extra libs.
+    _ax_lua_extra_libs=''
+
+    _ax_lua_saved_libs=$LIBS
+    LIBS="$LIBS $LUA_LIB"
+    AC_SEARCH_LIBS([exp], [m])
+    AC_SEARCH_LIBS([dlopen], [dl])
+    LIBS=$_ax_lua_saved_libs
+
+    AS_IF([test "x$ac_cv_search_exp" != 'xno' &&
+           test "x$ac_cv_search_exp" != 'xnone required'],
+      [_ax_lua_extra_libs="$_ax_lua_extra_libs $ac_cv_search_exp"])
+
+    AS_IF([test "x$ac_cv_search_dlopen" != 'xno' &&
+           test "x$ac_cv_search_dlopen" != 'xnone required'],
+      [_ax_lua_extra_libs="$_ax_lua_extra_libs $ac_cv_search_dlopen"])
+
+    dnl Try to find the Lua libs.
+    _ax_lua_saved_libs=$LIBS
+    LIBS="$LIBS $LUA_LIB"
+    AC_SEARCH_LIBS([lua_load],
+      [ lua$LUA_VERSION \
+        lua$LUA_SHORT_VERSION \
+        lua-$LUA_VERSION \
+        lua-$LUA_SHORT_VERSION \
+        lua \
+      ],
+      [_ax_found_lua_libs='yes'],
+      [_ax_found_lua_libs='no'],
+      [$_ax_lua_extra_libs])
+    LIBS=$_ax_lua_saved_libs
+
+    AS_IF([test "x$ac_cv_search_lua_load" != 'xno' &&
+           test "x$ac_cv_search_lua_load" != 'xnone required'],
+      [LUA_LIB="$ac_cv_search_lua_load $_ax_lua_extra_libs"])
+  ])
+
+  dnl Test the result and run user code.
+  AS_IF([test "x$_ax_found_lua_libs" = 'xyes'], [$1],
+    [m4_default([$2], [AC_MSG_ERROR([cannot find Lua libs])])])
+])
+
+
+dnl =========================================================================
+dnl AX_LUA_READLINE([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl =========================================================================
+AC_DEFUN([AX_LUA_READLINE],
+[
+  AX_LIB_READLINE
+  AS_IF([test "x$ac_cv_header_readline_readline_h" != 'x' &&
+         test "x$ac_cv_header_readline_history_h" != 'x'],
+    [ LUA_LIBS_CFLAGS="-DLUA_USE_READLINE $LUA_LIBS_CFLAGS"
+      $1
+    ],
+    [$2])
+])

configure.ac

@@ -315,6 +315,12 @@ AC_C_BIGENDIAN(
   [AC_MSG_ERROR([Cannot determine CPU endianity.])]
 )
 
+AX_PROG_LUA(5.3)
+AX_LUA_HEADERS
+AX_LUA_LIBS
+AC_SUBST(LUA_INCLUDE)
+AC_SUBST(LUA_LIBS)
+
 if test "$enable_debug" = yes ; then
   AC_DEFINE([DEBUGGING], [1], [Define to 1 if debugging is enabled])
   LDFLAGS="$LDFLAGS -rdynamic"

filter/filter.c

@@ -1575,6 +1575,15 @@ interpret(struct f_inst *what)
     CALL(bt_assert_hook, res.val.i, what);
     break;
 
+  case P('L','C'):	/* Lua include */
+    ONEARG;
+    if (v1.type != T_STRING)
+      runtime("Lua code should be a string argument");
+
+    res.type = T_RETURN;
+    res.val.i = filter_lua_chunk(v1.val.s, f_rte, f_old_rta, f_tmp_attrs, f_pool);
+    break;
+
   default:
     bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
   }

filter/filter.h

@@ -220,4 +220,7 @@ struct f_bt_test_suite {
 /* Hook for call bt_assert() function in configuration */
 extern void (*bt_assert_hook)(int result, struct f_inst *assert);
 
+/* Lua */
+int filter_lua_chunk(const char *chunk, struct rte **e, struct rta *a, struct ea_list **ea, struct linpool *lp);
+
 #endif

lua/Makefile

@@ -0,0 +1,4 @@
+src := filter.c
+obj := $(src-o-files)
+$(all-daemon)
+#$(cf-local)

lua/filter.c

@@ -0,0 +1,25 @@
+#include "nest/bird.h"
+#include "filter/filter.h"
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+int filter_lua_chunk(const char *chunk, struct rte **e, struct rta *a, struct ea_list **ea, struct linpool *lp) {
+  lua_State *L = luaL_newstate();
+  luaL_openlibs(L);
+  int le = luaL_dostring(L, chunk);
+  int out;
+  if (le) {
+    log(L_WARN "bad lua: %s", lua_tostring(L, -1));
+    out = F_ERROR;
+  } else if (lua_isnumber(L, -1)) {
+    out = lua_tonumber(L, -1);
+  } else {
+    log(L_WARN "lua return value is not a number: %s", lua_tostring(L, -1));
+    out = F_ERROR;
+  }
+
+  lua_close(L);
+  return out;
+}

nest/config.Y

@@ -65,7 +65,7 @@ proto_postconfig(void)
 CF_DECLS
 
 CF_KEYWORDS(ROUTER, ID, PROTOCOL, TEMPLATE, PREFERENCE, DISABLED, DEBUG, ALL, OFF, DIRECT)
-CF_KEYWORDS(INTERFACE, IMPORT, EXPORT, FILTER, NONE, VRF, TABLE, STATES, ROUTES, FILTERS)
+CF_KEYWORDS(INTERFACE, IMPORT, EXPORT, FILTER, LUA, NONE, VRF, TABLE, STATES, ROUTES, FILTERS)
 CF_KEYWORDS(IPV4, IPV6, VPN4, VPN6, ROA4, ROA6)
 CF_KEYWORDS(RECEIVE, LIMIT, ACTION, WARN, BLOCK, RESTART, DISABLE, KEEP, FILTERED)
 CF_KEYWORDS(PASSWORD, FROM, PASSIVE, TO, ID, EVENTS, PACKETS, PROTOCOLS, INTERFACES)
@@ -262,6 +262,14 @@ rtable:
 
 imexport:
    FILTER filter { $$ = $2; }
+ | LUA constant {
+    $$ = cfg_alloc(sizeof(struct filter));
+    $$->name = NULL;
+    $$->root = f_new_inst();
+    $$->root->code = P('L','C');
+    $$->root->a1.p = $2;
+    $$->root->next = NULL;
+  }
  | where_filter
  | ALL { $$ = FILTER_ACCEPT; }
  | NONE { $$ = FILTER_REJECT; }