Re: Sandboxing and thread environments

[William Ahern <wahern@...>]

On Fri, 2006-08-11 at 13:37 +1000, D Burgess wrote:
> The following works OK /for what I am doing/
> L1 is the thread state.
> 
>     lua_newtable(L1); /* the env, */
>     lua_createtable(L1,0,1); /* the meta table */
>     lua_pushvalue(L1,LUA_GLOBALSINDEX);
>     lua_setfield(L1,-2, "__index");
>     lua_setmetatable(L1, -2); /* setmetatable(env, {_index = _G }) */
>     lua_pushvalue(L1,-1);
>     lua_replace(L1, LUA_GLOBALSINDEX);

Yes. I'm doing exactly that (well, that and also trying an alternative
approach; notice the ifdef's). Actually, you may have pasted this same
code (from whence I got mine), to a similar e-mail I posted about 8
months ago ;)


lua_pushthread(L);

lua_newtable(L);
lua_newtable(L);

lua_pushstring(L, "__index");
lua_pushvalue(L, LUA_GLOBALSINDEX);
lua_settable(L, -3);

if (1 != lua_setmetatable(L, -2))
                goto luafail;

#if 0
        lua_pushstring(L, "_G");
        lua_pushvalue(L, -2);
        lua_settable(L, -3);
#endif

#if 1
        if (1 != lua_setfenv(L, -2))
                goto luafail;
#else
        lua_replace(L, LUA_GLOBALSINDEX);
#endif

#if 1
        lua_pop(L, 1);
#endif

-- 
William Ahern <wahern@barracudanetworks.com>


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