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#include <stdio.h>
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
#include "conn.h"
#include "lua-privsep.h"
#ifndef PRIVSEP_PATH
#define PRIVSEP_PATH "./"
#endif
static int traceback (lua_State *L) {
if (!lua_isstring(L, 1)) /* 'message' not a string? */
return 1; /* keep it intact */
fprintf(stderr, "traceback\n");
lua_getfield(L, LUA_GLOBALSINDEX, "debug");
if (!lua_istable(L, -1)) {
fprintf(stderr, "traceback: debug\n");
lua_pop(L, 1);
return 1;
}
lua_getfield(L, -1, "traceback");
if (!lua_isfunction(L, -1)) {
fprintf(stderr, "traceback: traceback\n");
lua_pop(L, 2);
return 1;
}
lua_pushvalue(L, 1); /* pass error message */
lua_pushinteger(L, 2); /* skip this function and traceback */
lua_call(L, 2, 1); /* call debug.traceback */
return 1;
}
int call_lua(int fd, const char *msg, size_t msglen)
{
const char *luamain = PRIVSEP_PATH "privileged-main.lua";
int traceback_index;
const char *retbuf;
size_t retsize;
lua_State *L = luaL_newstate();
luaL_openlibs(L);
lua_pushcfunction(L, traceback);
traceback_index = lua_gettop(L);
if (luaL_loadfile(L, luamain))
return luaL_error(L, "%s", luamain);
lua_pushlstring(L, msg, msglen);
if (lua_pcall(L, 1, 1, traceback_index))
return luaL_error(L, "error");
if (!lua_isstring(L, -1))
error(L, "function must return string");
retbuf = lua_tolstring(L, -1, &retsize);
return write(fd, retbuf, retsize);
}
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