mirror of
https://git.proxmox.com/git/mirror_frr
synced 2025-04-29 18:10:23 +00:00
f869ab17a7
This implements the ability to get results out from lua scripts after they've run. For each C type we support passing to Lua, there is a corresponding `struct frrscript_codec`. This struct contains a typename field - just a string identifying the type - and two function pointers. The first function pointer, encode, takes a lua_State and a pointer to the C value and pushes some corresponding Lua representation onto the stack. The second, decode, assumes there is some Lua value on the stack and decodes it into the corresponding C value. Each supported type's `struct frrscript_codec` is registered with the scripting stuff in the library, which creates a mapping between the type name (string) and the `struct frrscript_codec`. When calling a script, you specify arguments by passing an array of `struct frrscript_env`. Each of these structs has a void *, a type name, and a desired binding name. The type names are used to look up the appropriate function to encode the pointed-at value onto the Lua stack, then bind the pushed value to the provided binding name, so that the converted value is accessible by that name within the script. Results work in a similar way. After a script runs, call frrscript_get_result() with the script and a `struct frrscript_env`. The typename and name fields are used to fetch the Lua value from the script's environment and use the registered decoder for the typename to convert the Lua value back into a C value, which is returned from the function. The caller is responsible for freeing these. frrscript_call()'s macro foo has been stripped, as the underlying function now takes fixed arrays. varargs have awful performance characteristics, they're hard to read, and structs are more defined than an order sensitive list. Signed-off-by: Quentin Young <qlyoung@nvidia.com>
132 lines
3.3 KiB
C
132 lines
3.3 KiB
C
/* Scripting foo
|
|
* Copyright (C) 2020 NVIDIA Corporation
|
|
* Quentin Young
|
|
*
|
|
* This program 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 of the License, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program 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 this program; see the file COPYING; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#ifndef __FRRSCRIPT_H__
|
|
#define __FRRSCRIPT_H__
|
|
|
|
#include <lua.h>
|
|
#include "frrlua.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
#define FRRSCRIPT_PATH "/etc/frr/scripts"
|
|
|
|
typedef void (*encoder_func)(lua_State *, const void *);
|
|
typedef void *(*decoder_func)(lua_State *, int);
|
|
|
|
struct frrscript_codec {
|
|
const char *typename;
|
|
encoder_func encoder;
|
|
decoder_func decoder;
|
|
};
|
|
|
|
struct frrscript {
|
|
/* Script name */
|
|
char *name;
|
|
|
|
/* Lua state */
|
|
struct lua_State *L;
|
|
};
|
|
|
|
struct frrscript_env {
|
|
/* Value type */
|
|
const char *typename;
|
|
|
|
/* Binding name */
|
|
const char *name;
|
|
|
|
/* Value */
|
|
const void *val;
|
|
};
|
|
|
|
/*
|
|
* Create new FRR script.
|
|
*/
|
|
struct frrscript *frrscript_load(const char *name,
|
|
int (*load_cb)(struct frrscript *));
|
|
|
|
/*
|
|
* Destroy FRR script.
|
|
*/
|
|
void frrscript_unload(struct frrscript *fs);
|
|
|
|
/*
|
|
* Register a Lua codec for a type.
|
|
*
|
|
* tname
|
|
* Name of type; e.g., "peer", "ospf_interface", etc. Chosen at will.
|
|
*
|
|
* codec(s)
|
|
* Function pointer to codec struct. Encoder function should push a Lua
|
|
* table representing the passed argument - which will have the C type
|
|
* associated with the chosen 'tname' to the provided stack. The decoder
|
|
* function should pop a value from the top of the stack and return a heap
|
|
* chunk containing that value. Allocations should be made with MTYPE_TMP.
|
|
*
|
|
* If using the plural function variant, pass a NULL-terminated array.
|
|
*
|
|
*/
|
|
void frrscript_register_type_codec(struct frrscript_codec *codec);
|
|
void frrscript_register_type_codecs(struct frrscript_codec *codecs);
|
|
|
|
/*
|
|
* Initialize scripting subsystem. Call this before anything else.
|
|
*/
|
|
void frrscript_init(void);
|
|
|
|
|
|
/*
|
|
* Call script.
|
|
*
|
|
* fs
|
|
* The script to call; this is obtained from frrscript_load().
|
|
*
|
|
* env
|
|
* The script's environment. Specify this as an array of frrscript_env.
|
|
*
|
|
* Returns:
|
|
* 0 if the script ran successfully, nonzero otherwise.
|
|
*/
|
|
int frrscript_call(struct frrscript *fs, struct frrscript_env *env);
|
|
|
|
|
|
/*
|
|
* Get result from finished script.
|
|
*
|
|
* fs
|
|
* The script. This script must have been run already.
|
|
*
|
|
* result
|
|
* The result to extract from the script.
|
|
* This reuses the frrscript_env type, but only the typename and name fields
|
|
* need to be set. The value is returned directly.
|
|
*
|
|
* Returns:
|
|
* The script result of the specified name and type, or NULL.
|
|
*/
|
|
void *frrscript_get_result(struct frrscript *fs,
|
|
const struct frrscript_env *result);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /* __cplusplus */
|
|
|
|
#endif /* __FRRSCRIPT_H__ */
|