/* 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

--

*/

#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>

/* Enumerate all locally configured IP addresses */

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 long ip4_linklocal = htonl(0xa9fe0000); /* 169.254.0.0 */

	const long 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) {

		lua_pushnil(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;

}

int luaopen_util_net(lua_State* L)

{

	luaL_Reg exports[] = {

		{ "local_addresses", lc_local_addresses },

		{ NULL, NULL }

	};

	lua_newtable(L);

	luaL_register(L, NULL,  exports);

	return 1;

}