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#include "nest/bird.h"
#include "conf/conf.h"
#include "filter/filter.h"
#include "lua.h"
#include <lua.h>
#include <lualib.h>
#include <lauxlib.h>
/* Docs: http://pgl.yoyo.org/luai/i/luaL_dostring */
static lua_State *global_lua_state = NULL;
static inline lua_State * luaB_getstate(void) {
if (!global_lua_state) {
lua_State *L = luaL_newstate();
luaL_openlibs(L);
global_lua_state = L;
}
return lua_newthread(global_lua_state);
}
static inline void luaB_close(lua_State *L UNUSED) {
lua_pop(global_lua_state, 1);
}
struct lua_new_filter_writer_data {
struct lua_filter_chunk *first, *last;
};
static int lua_new_filter_writer(lua_State *L UNUSED, const void *p, size_t sz, void *ud) {
struct lua_new_filter_writer_data *d = ud;
struct lua_filter_chunk *cur = cfg_allocz(sizeof(struct lua_filter_chunk));
cur->size = sz;
cur->chunk = cfg_alloc(sz);
memcpy(cur->chunk, p, sz);
if (d->last)
d->last = d->last->next = cur;
else
d->last = d->first = cur;
return 0;
}
struct filter * lua_new_filter(struct f_inst *inst) {
struct filter *f = cfg_alloc(sizeof(struct filter));
f->name = NULL;
f->type = FILTER_LUA;
struct f_val string = f_eval(inst, cfg_mem);
if (string.type != T_STRING) {
cf_error("Lua filter must be a string");
return NULL;
}
lua_State *L = luaB_getstate();
int loadres = luaL_loadstring(L, string.val.s);
switch (loadres) {
case LUA_ERRMEM:
luaB_close(L);
cf_error("Memory allocation error occured when loading lua chunk");
return NULL;
case LUA_ERRSYNTAX:
{
const char *e = lua_tostring(L, -1);
char *ec = cfg_alloc(strlen(e) + 1);
strcpy(ec, e);
luaB_close(L);
cf_error("Lua syntax error: %s", ec);
return NULL;
}
case 0: /* Everything OK */
break;
}
struct lua_new_filter_writer_data lnfwd = {};
lua_dump(L, lua_new_filter_writer, &lnfwd, 0); /* No error to handle */
luaB_close(L);
f->lua_chunk = lnfwd.first;
return f;
}
static const char *lua_interpret_reader(lua_State *L UNUSED, void *ud, size_t *sz) {
struct lua_filter_chunk **cptr = ud;
if ((*cptr) == NULL)
return NULL;
*sz = (*cptr)->size;
void *out = (*cptr)->chunk;
*cptr = (*cptr)->next;
return out;
}
static inline void f_rte_cow(struct rte **e, struct rta **a)
{
if (!((*e)->flags & REF_COW))
return;
*e = rte_do_cow(*e);
}
static void
f_rta_cow(struct rte **e, struct rta **old_rta, struct linpool *lp)
{
if (!rta_is_cached((*e)->attrs))
return;
/* Prepare to modify rte */
f_rte_cow(e, old_rta);
/* Store old rta to free it later, it stores reference from rte_cow() */
*old_rta = (*e)->attrs;
/*
* Get shallow copy of rta. Fields eattrs and nexthops of rta are shared
* with f_old_rta (they will be copied when the cached rta will be obtained
* at the end of f_run()), also the lock of hostentry is inherited (we
* suppose hostentry is not changed by filters).
*/
(*e)->attrs = rta_do_cow((*e)->attrs, lp);
/* Re-cache the ea_list */
/* f_cache_eattrs(); */
}
struct f_val lua_interpret(struct lua_filter_chunk *chunk, struct rte **e, struct rta **a, struct ea_list **ea UNUSED, struct linpool *lp, int flags UNUSED) {
f_rta_cow(e, a, lp);
lua_State *L = luaB_getstate();
lua_bird_state *lbs = luaB_init(L, lp);
luaB_push_route(L, *e);
luaB_push_eattrs(L, *ea);
struct lua_filter_chunk **rptr = &chunk;
lua_load(L, lua_interpret_reader, rptr, "", "b");
int le = lua_pcall(L, 0, LUA_MULTRET, 0);
struct f_val out = F_VAL_VOID;
if (le && lbs->exception) {
out = F_VAL(T_RETURN, i, lbs->exception);
} else if (le) {
log(L_ERR "bad lua: %s", lua_tostring(L, -1));
out = F_VAL(T_RETURN, i, F_ERROR);
} else if (lua_isnumber(L, -1)) {
out = F_VAL(T_INT, i, lua_tonumber(L, -1));
} else {
log(L_WARN "lua return value is not a number (unimplemented): %s", lua_tostring(L, -1));
out = F_VAL(T_RETURN, i, F_ERROR);
}
luaB_close(L);
return out;
}
int lua_filter_same(struct lua_filter_chunk *new, struct lua_filter_chunk *old) {
size_t npos = 0, opos = 0;
while (new && old) {
size_t nrem = new->size - npos;
size_t orem = old->size - opos;
size_t rem = MIN(nrem, orem);
if (memcmp(new->chunk + npos, old->chunk + opos, rem))
return 0;
npos += rem;
opos += rem;
if (npos == new->size) {
new = new->next;
npos = 0;
}
if (opos == old->size) {
old = old->next;
opos = 0;
}
}
if (!new && !old)
return 1;
else
return 0;
}
uint lua_eval(struct f_inst *inst)
{
struct f_val string = f_eval(inst, cfg_mem);
if (string.type != T_STRING) {
cf_error("Lua filter must be a string");
return -1;
}
lua_State *L = luaB_getstate();
int dores = luaL_dostring(L, string.val.s);
log(L_WARN "lua_eval dores '%s' %d", string.val.s, dores);
switch (dores) {
case LUA_ERRMEM:
luaB_close(L);
cf_error("Memory allocation error occured when loading lua chunk");
return -1;
case LUA_ERRSYNTAX:
{
const char *e = lua_tostring(L, -1);
char *ec = cfg_alloc(strlen(e) + 1);
strcpy(ec, e);
luaB_close(L);
cf_error("Lua syntax error: %s", ec);
return -1;
}
case 0: /* Everything OK */
break;
}
luaB_close(L);
return 0;
}
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