lua: Initial Lua import

This code sets up the ability to use lua inside of FRR.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

configure.ac

@@ -203,7 +203,15 @@ elif test "x${enable_dev_build}" = "xyes"; then
       AC_C_FLAG([-g3])
       AC_C_FLAG([-O0])
    fi
+   if test "x${enable_lua}" = "xyes"; then
+      AC_CHECK_LIB([lua], [lua_newstate],
+      [LIBS="$LIBS -llua"])
+      AC_DEFINE(HAVE_LUA,,Lua enabled for development)
+   fi
 else
+   if test "x${enable_lua}" = "xyes"; then
+      AC_MSG_ERROR([Lua is not meant to be built/used outside of development at this time])
+   fi
    if test "z$orig_cflags" = "z"; then
       AC_C_FLAG([-g])
       AC_C_FLAG([-Os], [
@@ -454,6 +462,9 @@ fi
 AC_ARG_ENABLE([dev_build],
     AS_HELP_STRING([--enable-dev-build], [build for development]))
 
+AC_ARG_ENABLE([lua],
+    AS_HELP_STRING([--enable-lua], [Build Lua scripting]))
+
 if test x"${enable_time_check}" != x"no" ; then
   if test x"${enable_time_check}" = x"yes" -o x"${enable_time_check}" = x ; then
     AC_DEFINE(CONSUMED_TIME_CHECK,5000000,Consumed Time Check)
@@ -1126,6 +1137,7 @@ if test x"$LIBM" = x ; then
   AC_MSG_WARN([Unable to find working pow function - bgpd may not link])
 fi
 LIBS="$TMPLIBS"
+
 AC_SUBST(LIBM)
 
 AC_CHECK_FUNCS([ppoll], [

lib/lua.c

@@ -0,0 +1,130 @@
+/*
+ * This file defines the lua interface into
+ * FRRouting.
+ *
+ * Copyright (C) 2016 Cumulus Networks, Inc.
+ * Donald Sharp
+ *
+ * This file is part of FreeRangeRouting (FRR).
+ *
+ * FRR is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2, or (at your option) any later version.
+ *
+ * FRR is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with FRR; see the file COPYING.  If not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <stdio.h>
+
+#include <zebra.h>
+
+#if defined(HAVE_LUA)
+#include "prefix.h"
+#include "lua.h"
+#include "log.h"
+
+static int lua_zlog_debug(lua_State *L)
+{
+	int debug_lua = 1;
+	const char *string = lua_tostring(L, 1);
+
+	if (debug_lua)
+		zlog_debug("%s", string);
+
+	return 0;
+}
+
+const char *get_string(lua_State *L, const char *key)
+{
+	const char *str;
+
+	lua_pushstring(L, key);
+	lua_gettable(L, -2);
+
+	str = (const char *)lua_tostring(L, -1);
+	lua_pop(L, 1);
+
+	return str;
+}
+
+int get_integer(lua_State *L, const char *key)
+{
+	int result;
+
+	lua_pushstring(L, key);
+	lua_gettable(L, -2);
+
+	result = lua_tointeger(L, -1);
+	lua_pop(L, 1);
+
+	return result;
+}
+
+static void *lua_alloc(void *ud, void *ptr, size_t osize,
+		       size_t nsize)
+{
+	(void)ud;  (void)osize;  /* not used */
+	if (nsize == 0) {
+		free(ptr);
+		return NULL;
+	} else
+		return realloc(ptr, nsize);
+}
+
+lua_State *lua_initialize(const char *file)
+{
+	int status;
+	lua_State *L = lua_newstate(lua_alloc, NULL);
+
+	zlog_debug("Newstate: %p", L);
+	luaL_openlibs(L);
+	zlog_debug("Opened lib");
+	status = luaL_loadfile(L, file);
+	if (status) {
+		zlog_debug("Failure to open %s %d", file, status);
+		lua_close(L);
+		return NULL;
+	}
+
+	lua_pcall(L, 0, LUA_MULTRET, 0);
+	zlog_debug("Setting global function");
+	lua_pushcfunction(L, lua_zlog_debug);
+	lua_setglobal(L, "zlog_debug");
+
+	return L;
+}
+
+void lua_setup_prefix_table(lua_State *L, const struct prefix *prefix)
+{
+	char buffer[100];
+
+	lua_newtable(L);
+	lua_pushstring(L, prefix2str(prefix, buffer, 100));
+	lua_setfield(L, -2, "route");
+	lua_pushinteger(L, prefix->family);
+	lua_setfield(L, -2, "family");
+	lua_setglobal(L, "prefix");
+}
+
+enum lua_rm_status lua_run_rm_rule(lua_State *L, const char *rule)
+{
+	int status;
+
+	lua_getglobal(L, rule);
+	status = lua_pcall(L, 0, 1, 0);
+	if (status) {
+		zlog_debug("Executing Failure with function: %s: %d",
+			   rule, status);
+		return LUA_RM_FAILURE;
+	}
+
+	status = lua_tonumber(L, -1);
+	return status;
+}
+#endif

lib/lua.h

@@ -0,0 +1,79 @@
+/*
+ * This file defines the lua interface into
+ * FRRouting.
+ *
+ * Copyright (C) 2016 Cumulus Networks, Inc.
+ * Donald Sharp
+ *
+ * This file is part of FreeRangeRouting (FRR).
+ *
+ * FRR is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2, or (at your option) any later version.
+ *
+ * FRR is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with FRR; see the file COPYING.  If not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#ifndef __LUA_H__
+#define __LUA_H__
+
+#if defined(HAVE_LUA)
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+/*
+ * These functions are helper functions that
+ * try to glom some of the lua_XXX functionality
+ * into what we actually need, instead of having
+ * to make multiple calls to set up what
+ * we want
+ */
+enum lua_rm_status {
+	/*
+	 * Script function run failure.  This will translate into a
+	 * deny
+	 */
+	LUA_RM_FAILURE = 0,
+	/*
+	 * No Match was found for the route map function
+	 */
+	LUA_RM_NOMATCH,
+	/*
+	 * Match was found but no changes were made to the
+	 * incoming data.
+	 */
+	LUA_RM_MATCH,
+	/*
+	 * Match was found and data was modified, so
+	 * figure out what changed
+	 */
+	LUA_RM_MATCH_AND_CHANGE,
+};
+
+/*
+ * Open up the lua.scr file and parse
+ * initial global values, if any.
+ */
+lua_State *lua_initialize(const char *file);
+
+void lua_setup_prefix_table(lua_State *L, const struct prefix *prefix);
+
+enum lua_rm_status lua_run_rm_rule(lua_State *L, const char *rule);
+
+/*
+ * Get particular string/integer information
+ * from a table.  It is *assumed* that
+ * the table has already been selected
+ */
+const char *get_string(lua_State *L, const char *key);
+int get_integer(lua_State *L, const char *key);
+#endif
+#endif

lib/subdir.am

@@ -82,6 +82,7 @@ lib_libfrr_la_SOURCES = \
 	lib/workqueue.c \
 	lib/zclient.c \
 	lib/logicalrouter.c \
+	lib/lua.c \
 	# end
 
 vtysh_scan += \
@@ -190,6 +191,7 @@ pkginclude_HEADERS += \
 	lib/zclient.h \
 	lib/zebra.h \
 	lib/logicalrouter.h \
+	lib/lua.h \
 	lib/pbr.h \
 	# end