util-src/windows.c
author Jonas Schäfer <jonas@wielicki.name>
Mon, 10 Jan 2022 18:23:54 +0100
branch0.11
changeset 12185 783056b4e448
parent 7892 b8d694646597
child 10925 6eb5d2bb11af
permissions -rw-r--r--
util.xml: Do not allow doctypes, comments or processing instructions Yes. This is as bad as it sounds. CVE pending. In Prosody itself, this only affects mod_websocket, which uses util.xml to parse the <open/> frame, thus allowing unauthenticated remote DoS using Billion Laughs. However, third-party modules using util.xml may also be affected by this. This commit installs handlers which disallow the use of doctype declarations and processing instructions without any escape hatch. It, by default, also introduces such a handler for comments, however, there is a way to enable comments nontheless. This is because util.xml is used to parse human-facing data, where comments are generally a desirable feature, and also because comments are generally harmless.

/* Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
*/

/*
* windows.c
* Windows support functions for Lua
*/

#include <stdio.h>
#include <windows.h>
#include <windns.h>

#include "lua.h"
#include "lauxlib.h"

#if (LUA_VERSION_NUM == 501)
#define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
#endif

static int Lget_nameservers(lua_State *L) {
	char stack_buffer[1024]; // stack allocated buffer
	IP4_ARRAY *ips = (IP4_ARRAY *) stack_buffer;
	DWORD len = sizeof(stack_buffer);
	DNS_STATUS status;

	status = DnsQueryConfig(DnsConfigDnsServerList, FALSE, NULL, NULL, ips, &len);

	if(status == 0) {
		DWORD i;
		lua_createtable(L, ips->AddrCount, 0);

		for(i = 0; i < ips->AddrCount; i++) {
			DWORD ip = ips->AddrArray[i];
			char ip_str[16] = "";
			sprintf_s(ip_str, sizeof(ip_str), "%d.%d.%d.%d", (ip >> 0) & 255, (ip >> 8) & 255, (ip >> 16) & 255, (ip >> 24) & 255);
			lua_pushstring(L, ip_str);
			lua_rawseti(L, -2, i + 1);
		}

		return 1;
	} else {
		lua_pushnil(L);
		lua_pushfstring(L, "DnsQueryConfig returned %d", status);
		return 2;
	}
}

static int lerror(lua_State *L, char *string) {
	lua_pushnil(L);
	lua_pushfstring(L, "%s: %d", string, GetLastError());
	return 2;
}

static int Lget_consolecolor(lua_State *L) {
	HWND console = GetStdHandle(STD_OUTPUT_HANDLE);
	WORD color;
	DWORD read_len;

	CONSOLE_SCREEN_BUFFER_INFO info;

	if(console == INVALID_HANDLE_VALUE) {
		return lerror(L, "GetStdHandle");
	}

	if(!GetConsoleScreenBufferInfo(console, &info)) {
		return lerror(L, "GetConsoleScreenBufferInfo");
	}

	if(!ReadConsoleOutputAttribute(console, &color, 1, info.dwCursorPosition, &read_len)) {
		return lerror(L, "ReadConsoleOutputAttribute");
	}

	lua_pushnumber(L, color);
	return 1;
}
static int Lset_consolecolor(lua_State *L) {
	int color = luaL_checkint(L, 1);
	HWND console = GetStdHandle(STD_OUTPUT_HANDLE);

	if(console == INVALID_HANDLE_VALUE) {
		return lerror(L, "GetStdHandle");
	}

	if(!SetConsoleTextAttribute(console, color)) {
		return lerror(L, "SetConsoleTextAttribute");
	}

	lua_pushboolean(L, 1);
	return 1;
}

static const luaL_Reg Reg[] = {
	{ "get_nameservers",	Lget_nameservers	},
	{ "get_consolecolor",	Lget_consolecolor	},
	{ "set_consolecolor",	Lset_consolecolor	},
	{ NULL,		NULL	}
};

LUALIB_API int luaopen_util_windows(lua_State *L) {
#if (LUA_VERSION_NUM > 501)
	luaL_checkversion(L);
#endif
	lua_newtable(L);
	luaL_setfuncs(L, Reg, 0);
	lua_pushliteral(L, "-3.14");
	lua_setfield(L, -2, "version");
	return 1;
}