File

util-src/net.c @ 11707:61759372be26

mod_s2s: Clone 'extra' data to let resolvers add more to it This way 'extra' is unique for each connect() instance, making it safer to mutate it, while inheriting the global settings. See 926d53af9a7a for some more context.
author Kim Alvefur <zash@zash.se>
date Sun, 18 Jul 2021 21:53:26 +0200
parent 10921:6eb5d2bb11af
child 12575:1f6f05a98fcd
line wrap: on
line source

/* Prosody IM
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
-- Copyright (C) 2012 Paul Aurich
-- Copyright (C) 2013 Matthew Wild
-- Copyright (C) 2013 Florian Zeitz
--
*/

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <stddef.h>
#include <string.h>
#include <errno.h>

#ifndef _WIN32
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#endif

#include <lua.h>
#include <lauxlib.h>

#if (LUA_VERSION_NUM == 501)
#define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
#endif
#if (LUA_VERSION_NUM < 504)
#define luaL_pushfail lua_pushnil
#endif

/* Enumerate all locally configured IP addresses */

static const char *const type_strings[] = {
	"both",
	"ipv4",
	"ipv6",
	NULL
};

static int lc_local_addresses(lua_State *L) {
#ifndef _WIN32
	/* Link-local IPv4 addresses; see RFC 3927 and RFC 5735 */
	const uint32_t ip4_linklocal = htonl(0xa9fe0000); /* 169.254.0.0 */
	const uint32_t ip4_mask      = htonl(0xffff0000);
	struct ifaddrs *addr = NULL, *a;
#endif
	int n = 1;
	int type = luaL_checkoption(L, 1, "both", type_strings);
	const char link_local = lua_toboolean(L, 2); /* defaults to 0 (false) */
	const char ipv4 = (type == 0 || type == 1);
	const char ipv6 = (type == 0 || type == 2);

#ifndef _WIN32

	if(getifaddrs(&addr) < 0) {
		luaL_pushfail(L);
		lua_pushfstring(L, "getifaddrs failed (%d): %s", errno,
		                strerror(errno));
		return 2;
	}

#endif
	lua_newtable(L);

#ifndef _WIN32

	for(a = addr; a; a = a->ifa_next) {
		int family;
		char ipaddr[INET6_ADDRSTRLEN];
		const char *tmp = NULL;

		if(a->ifa_addr == NULL || a->ifa_flags & IFF_LOOPBACK) {
			continue;
		}

		family = a->ifa_addr->sa_family;

		if(ipv4 && family == AF_INET) {
			struct sockaddr_in *sa = (struct sockaddr_in *)a->ifa_addr;

			if(!link_local && ((sa->sin_addr.s_addr & ip4_mask) == ip4_linklocal)) {
				continue;
			}

			tmp = inet_ntop(family, &sa->sin_addr, ipaddr, sizeof(ipaddr));
		} else if(ipv6 && family == AF_INET6) {
			struct sockaddr_in6 *sa = (struct sockaddr_in6 *)a->ifa_addr;

			if(!link_local && IN6_IS_ADDR_LINKLOCAL(&sa->sin6_addr)) {
				continue;
			}

			if(IN6_IS_ADDR_V4MAPPED(&sa->sin6_addr) || IN6_IS_ADDR_V4COMPAT(&sa->sin6_addr)) {
				continue;
			}

			tmp = inet_ntop(family, &sa->sin6_addr, ipaddr, sizeof(ipaddr));
		}

		if(tmp != NULL) {
			lua_pushstring(L, tmp);
			lua_rawseti(L, -2, n++);
		}

		/* TODO: Error reporting? */
	}

	freeifaddrs(addr);
#else

	if(ipv4) {
		lua_pushstring(L, "0.0.0.0");
		lua_rawseti(L, -2, n++);
	}

	if(ipv6) {
		lua_pushstring(L, "::");
		lua_rawseti(L, -2, n++);
	}

#endif
	return 1;
}

static int lc_pton(lua_State *L) {
	char buf[16];
	const char *ipaddr = luaL_checkstring(L, 1);
	int errno_ = 0;
	int family = strchr(ipaddr, ':') ? AF_INET6 : AF_INET;

	switch(inet_pton(family, ipaddr, &buf)) {
		case 1:
			lua_pushlstring(L, buf, family == AF_INET6 ? 16 : 4);
			return 1;

		case -1:
			errno_ = errno;
			luaL_pushfail(L);
			lua_pushstring(L, strerror(errno_));
			lua_pushinteger(L, errno_);
			return 3;

		default:
		case 0:
			luaL_pushfail(L);
			lua_pushstring(L, strerror(EINVAL));
			lua_pushinteger(L, EINVAL);
			return 3;
	}

}

static int lc_ntop(lua_State *L) {
	char buf[INET6_ADDRSTRLEN];
	int family;
	int errno_;
	size_t l;
	const char *ipaddr = luaL_checklstring(L, 1, &l);

	if(l == 16) {
		family = AF_INET6;
	}
	else if(l == 4) {
		family = AF_INET;
	}
	else {
		luaL_pushfail(L);
		lua_pushstring(L, strerror(EAFNOSUPPORT));
		lua_pushinteger(L, EAFNOSUPPORT);
		return 3;
	}

	if(!inet_ntop(family, ipaddr, buf, INET6_ADDRSTRLEN))
	{
		errno_ = errno;
		luaL_pushfail(L);
		lua_pushstring(L, strerror(errno_));
		lua_pushinteger(L, errno_);
		return 3;
	}

	lua_pushstring(L, (const char *)(&buf));
	return 1;
}

int luaopen_util_net(lua_State *L) {
#if (LUA_VERSION_NUM > 501)
	luaL_checkversion(L);
#endif
	luaL_Reg exports[] = {
		{ "local_addresses", lc_local_addresses },
		{ "pton", lc_pton },
		{ "ntop", lc_ntop },
		{ NULL, NULL }
	};

	lua_createtable(L, 0, 1);
	luaL_setfuncs(L, exports, 0);
	return 1;
}