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2 * Copyright (C) 2020 NVIDIA Corporation
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; either version 2 of the License, or (at your option)
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along
16 * with this program; see the file COPYING; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 #ifndef __FRRSCRIPT_H__
20 #define __FRRSCRIPT_H__
28 #include "bgpd/bgp_script.h" // for peer and attr encoders/decoders
34 typedef void (*encoder_func
)(lua_State
*, const void *);
35 typedef void *(*decoder_func
)(lua_State
*, int);
37 struct frrscript_codec
{
43 struct lua_function_state
{
52 /* Hash of Lua function name to Lua function state */
53 struct hash
*lua_function_hash
;
58 * Hash related functions for lua_function_hash
61 void *lua_function_alloc(void *arg
);
63 unsigned int lua_function_hash_key(const void *data
);
65 bool lua_function_hash_cmp(const void *d1
, const void *d2
);
67 struct frrscript_env
{
79 * Create new struct frrscript for a Lua script.
80 * This will hold the states for the Lua functions in this script.
83 * Name of the Lua script file, without the .lua
85 struct frrscript
*frrscript_new(const char *scriptname
);
88 * Load a function into frrscript, run callback if any
90 int frrscript_load(struct frrscript
*fs
, const char *function_name
,
91 int (*load_cb
)(struct frrscript
*));
94 * Delete Lua function states and frrscript
96 void frrscript_delete(struct frrscript
*fs
);
99 * Register a Lua codec for a type.
102 * Name of type; e.g., "peer", "ospf_interface", etc. Chosen at will.
105 * Function pointer to codec struct. Encoder function should push a Lua
106 * table representing the passed argument - which will have the C type
107 * associated with the chosen 'tname' to the provided stack. The decoder
108 * function should pop a value from the top of the stack and return a heap
109 * chunk containing that value. Allocations should be made with MTYPE_TMP.
111 * If using the plural function variant, pass a NULL-terminated array.
114 void frrscript_register_type_codec(struct frrscript_codec
*codec
);
115 void frrscript_register_type_codecs(struct frrscript_codec
*codecs
);
118 * Initialize scripting subsystem. Call this before anything else.
121 * Directory in which to look for scripts
123 void frrscript_init(const char *scriptdir
);
126 * This macro is mapped to every (name, value) in frrscript_call,
127 * so this in turn maps them onto their encoders
129 #define ENCODE_ARGS(name, value) ENCODE_ARGS_WITH_STATE(lfs->L, (value))
132 * This macro is also mapped to every (name, value) in frrscript_call, but
133 * not every value can be mapped to its decoder - only those that appear
134 * in the returned table will. To find out if they appear in the returned
135 * table, first pop the value and check if its nil. Only call the decoder
138 * At the end, the only thing left on the stack should be the
141 #define DECODE_ARGS(name, value) \
143 lua_getfield(lfs->L, 1, (name)); \
144 if (lua_isnil(lfs->L, 2)) { \
145 lua_pop(lfs->L, 1); \
147 DECODE_ARGS_WITH_STATE(lfs->L, (value)); \
149 assert(lua_gettop(lfs->L) == 1); \
153 * Maps the type of value to its encoder/decoder.
154 * Add new mappings here.
159 * Directory in which to look for scripts
161 #define ENCODE_ARGS_WITH_STATE(L, value) \
163 int : lua_pushinteger, \
164 long long * : lua_pushintegerp, \
165 struct prefix * : lua_pushprefix, \
166 struct interface * : lua_pushinterface, \
167 struct in_addr * : lua_pushinaddr, \
168 struct in6_addr * : lua_pushin6addr, \
169 union sockunion * : lua_pushsockunion, \
170 time_t * : lua_pushtimet, \
171 char * : lua_pushstring_wrapper, \
172 struct attr * : lua_pushattr, \
173 struct peer * : lua_pushpeer, \
174 const struct prefix * : lua_pushprefix \
177 #define DECODE_ARGS_WITH_STATE(L, value) \
179 int : lua_decode_integer_noop, \
180 long long * : lua_decode_integerp, \
181 struct prefix * : lua_decode_prefix, \
182 struct interface * : lua_decode_interface, \
183 struct in_addr * : lua_decode_inaddr, \
184 struct in6_addr * : lua_decode_in6addr, \
185 union sockunion * : lua_decode_sockunion, \
186 time_t * : lua_decode_timet, \
187 char * : lua_decode_stringp, \
188 struct attr * : lua_decode_attr, \
189 struct peer * : lua_decode_noop, \
190 const struct prefix * : lua_decode_noop \
194 * Call Lua function state (abstraction for a single Lua function)
197 * The Lua function to call; this should have been loaded in by
198 * frrscript_load(). nargs Number of arguments the function accepts
201 * 0 if the script ran successfully, nonzero otherwise.
203 int _frrscript_call_lua(struct lua_function_state
*lfs
, int nargs
);
206 * Wrapper for calling Lua function state.
208 * The Lua function name (f) to run should have already been checked by
209 * frrscript_load. So this wrapper will:
210 * 1) Find the Lua function state, which contains the Lua state
211 * 2) Clear the Lua state (there may be leftovers items from previous call)
212 * 3) Push the Lua function (f)
213 * 4) Map frrscript_call arguments onto their encoder and decoders, push those
214 * 5) Call _frrscript_call_lua (Lua execution takes place)
215 * 6) Write back to frrscript_call arguments using their decoders
217 * This wrapper can be called multiple times (after one frrscript_load).
220 * The struct frrscript in which the Lua fuction was loaded into
222 * Name of the Lua function.
225 * 0 if the script ran successfully, nonzero otherwise.
227 #define frrscript_call(fs, f, ...) \
229 struct lua_function_state lookup = {.name = (f)}; \
230 struct lua_function_state *lfs; \
231 lfs = hash_lookup((fs)->lua_function_hash, &lookup); \
234 "frrscript: '%s.lua': '%s': tried to call this function but it was not loaded", \
239 lua_settop(lfs->L, 0); \
240 lua_getglobal(lfs->L, f); \
241 MAP_LISTS(ENCODE_ARGS, ##__VA_ARGS__); \
242 _frrscript_call_lua( \
243 lfs, PP_NARG(__VA_ARGS__)); \
247 "frrscript: '%s.lua': '%s': this function called but returned non-zero exit code. No variables modified.", \
252 MAP_LISTS(DECODE_ARGS, \
259 * Get result from finished function
262 * The script. This script must have been run already.
264 * Name of the Lua function.
266 * Name of the result.
267 * This will be used as a string key to retrieve from the table that the
268 * Lua function returns.
269 * The name here should *not* appear in frrscript_call.
271 * Function pointer to a lua_to decoder function.
272 * This function should allocate and decode a value from the Lua state.
275 * A pointer to the decoded value from the Lua state, or NULL if no such
278 void *frrscript_get_result(struct frrscript
*fs
, const char *function_name
,
280 void *(*lua_to
)(lua_State
*L
, int idx
));
284 #endif /* __cplusplus */
286 #endif /* HAVE_SCRIPTING */
288 #endif /* __FRRSCRIPT_H__ */