File

util-src/windows.c @ 12995:e385f3a06673

moduleapi: Add 'peek' to :may() and new :could() helper to suppress logging The current method logs scary "access denied" messages on failure - this is generally very useful when debugging access control stuff, but in some cases the call is simply a check to see if someone *could* perform an action, even if they haven't requested it yet. One example is determining whether to show the user as an admin in disco. The 'peek' parameter, if true, will suppress such logging. The :could() method is just a simple helper that can make the calling code a bit more readable (suggested by Zash).
author Matthew Wild <mwild1@gmail.com>
date Sun, 26 Mar 2023 14:06:04 +0100
parent 12575:1f6f05a98fcd
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/* 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 < 504)
#define luaL_pushfail lua_pushnil
#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 {
		luaL_pushfail(L);
		lua_pushfstring(L, "DnsQueryConfig returned %d", status);
		return 2;
	}
}

static int lerror(lua_State *L, char *string) {
	luaL_pushfail(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) {
	luaL_checkversion(L);
	lua_newtable(L);
	luaL_setfuncs(L, Reg, 0);
	lua_pushliteral(L, "-3.14");
	lua_setfield(L, -2, "version");
	return 1;
}