/*
 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: net.c,v 1.22.2.2.10.7 2004/04/29 01:31:22 marka Exp $ */

#include <config.h>

#include <errno.h>
#include <unistd.h>

#include <isc/net.h>
#include <isc/once.h>
#include <isc/strerror.h>
#include <isc/string.h>
#include <isc/util.h>

#if defined(ISC_PLATFORM_HAVEIPV6) && defined(ISC_PLATFORM_NEEDIN6ADDRANY)
const struct in6_addr isc_net_in6addrany = IN6ADDR_ANY_INIT;
#endif

#if defined(ISC_PLATFORM_HAVEIPV6) && defined(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)
const struct in6_addr isc_net_in6addrloop = IN6ADDR_LOOPBACK_INIT;
#endif

static isc_boolean_t 	once = ISC_FALSE;
static isc_once_t 	once_ipv6only = ISC_ONCE_INIT;
static isc_once_t 	once_ipv6pktinfo = ISC_ONCE_INIT;
static isc_result_t	ipv4_result = ISC_R_NOTFOUND;
static isc_result_t	ipv6_result = ISC_R_NOTFOUND;
static isc_result_t	ipv6only_result = ISC_R_NOTFOUND;
static isc_result_t	ipv6pktinfo_result = ISC_R_NOTFOUND;

static isc_result_t
try_proto(int domain) {
	int s;
	isc_result_t result = ISC_R_SUCCESS;
	char strbuf[ISC_STRERRORSIZE];

	s = socket(domain, SOCK_STREAM, 0);
	if (s == -1) {
		switch (errno) {
#ifdef EAFNOSUPPORT
		case EAFNOSUPPORT:
#endif
#ifdef EPROTONOSUPPORT
		case EPROTONOSUPPORT:
#endif
#ifdef EINVAL
		case EINVAL:
#endif
			return (ISC_R_NOTFOUND);
		default:
			isc__strerror(errno, strbuf, sizeof(strbuf));
			UNEXPECTED_ERROR(__FILE__, __LINE__,
					 "socket() failed: %s",
					 strbuf);
			return (ISC_R_UNEXPECTED);
		}
	}

#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
#ifdef ISC_PLATFORM_HAVEIN6PKTINFO
	if (domain == PF_INET6) {
		struct sockaddr_in6 sin6;
		GETSOCKNAME_SOCKLEN_TYPE len;

		/*
		 * Check to see if IPv6 is broken, as is common on Linux.
		 */
		len = sizeof(sin6);
		if (getsockname(s, (struct sockaddr *)&sin6, &len) < 0)
		{
			result = ISC_R_NOTFOUND;
		} else {
			if (len == sizeof(struct sockaddr_in6))
				result = ISC_R_SUCCESS;
			else {
				result = ISC_R_NOTFOUND;
			}
		}
	}
#endif
#endif
#endif

	(void)close(s);

	return (result);
}

static void
initialize_action(void) {
	ipv4_result = try_proto(PF_INET);
#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
#ifdef ISC_PLATFORM_HAVEIN6PKTINFO
	ipv6_result = try_proto(PF_INET6);
#endif
#endif
#endif
}

static void
initialize(void) {
	if(once == ISC_FALSE) {
		initialize_action();
		once = ISC_TRUE;
	}
}

isc_result_t
isc_net_probeipv4(void) {
	initialize();
	return (ipv4_result);
}

isc_result_t
isc_net_probeipv6(void) {
	initialize();
	return (ipv6_result);
}

#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
static void
try_ipv6only(void) {
#ifdef IPV6_V6ONLY
	int s, on;
	char strbuf[ISC_STRERRORSIZE];
#endif
	isc_result_t result;

	result = isc_net_probeipv6();
	if (result != ISC_R_SUCCESS) {
		ipv6only_result = result;
		return;
	}

#ifndef IPV6_V6ONLY
	ipv6only_result = ISC_R_NOTFOUND;
	return;
#else
	/* check for TCP sockets */
	s = socket(PF_INET6, SOCK_STREAM, 0);
	if (s == -1) {
		isc__strerror(errno, strbuf, sizeof(strbuf));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "socket() failed: %s",
				 strbuf);
		ipv6only_result = ISC_R_UNEXPECTED;
		return;
	}

	on = 1;
	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {
		ipv6only_result = ISC_R_NOTFOUND;
		goto close;
	}

	close(s);

	/* check for UDP sockets */
	s = socket(PF_INET6, SOCK_DGRAM, 0);
	if (s == -1) {
		isc__strerror(errno, strbuf, sizeof(strbuf));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "socket() failed: %s",
				 strbuf);
		ipv6only_result = ISC_R_UNEXPECTED;
		return;
	}

	on = 1;
	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) {
		ipv6only_result = ISC_R_NOTFOUND;
		goto close;
	}

	close(s);

	ipv6only_result = ISC_R_SUCCESS;

close:
	close(s);
	return;
#endif /* IPV6_V6ONLY */
}

static void
initialize_ipv6only(void) {
	RUNTIME_CHECK(isc_once_do(&once_ipv6only,
				  try_ipv6only) == ISC_R_SUCCESS);
}

static void
try_ipv6pktinfo(void) {
	int s, on;
	char strbuf[ISC_STRERRORSIZE];
	isc_result_t result;
	int optname;

	result = isc_net_probeipv6();
	if (result != ISC_R_SUCCESS) {
		ipv6pktinfo_result = result;
		return;
	}

	/* we only use this for UDP sockets */
	s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
	if (s == -1) {
		isc__strerror(errno, strbuf, sizeof(strbuf));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "socket() failed: %s",
				 strbuf);
		ipv6pktinfo_result = ISC_R_UNEXPECTED;
		return;
	}

#ifdef IPV6_RECVPKTINFO
	optname = IPV6_RECVPKTINFO;
#else
	optname = IPV6_PKTINFO;
#endif
	on = 1;
	if (setsockopt(s, IPPROTO_IPV6, optname, &on, sizeof(on)) < 0) {
		ipv6pktinfo_result = ISC_R_NOTFOUND;
		goto close;
	}

	close(s);
	ipv6pktinfo_result = ISC_R_SUCCESS;

close:
	close(s);
	return;
}

static void
initialize_ipv6pktinfo(void) {
	RUNTIME_CHECK(isc_once_do(&once_ipv6pktinfo,
				  try_ipv6pktinfo) == ISC_R_SUCCESS);
}
#endif /* WANT_IPV6 */
#endif /* ISC_PLATFORM_HAVEIPV6 */

isc_result_t
isc_net_probe_ipv6only(void) {
#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
	initialize_ipv6only();
#else
	ipv6only_result = ISC_R_NOTFOUND;
#endif
#endif
	return (ipv6only_result);
}

isc_result_t
isc_net_probe_ipv6pktinfo(void) {
#ifdef ISC_PLATFORM_HAVEIPV6
#ifdef WANT_IPV6
	initialize_ipv6pktinfo();
#else
	ipv6pktinfo_result = ISC_R_NOTFOUND;
#endif
#endif
	return (ipv6pktinfo_result);
}

void
isc_net_disableipv4(void) {
	initialize();
	if (ipv4_result == ISC_R_SUCCESS)
		ipv4_result = ISC_R_DISABLED;
}

void
isc_net_disableipv6(void) {
	initialize();
	if (ipv6_result == ISC_R_SUCCESS)
		ipv6_result = ISC_R_DISABLED;
}

void
isc_net_enableipv4(void) {
	initialize();
	if (ipv4_result == ISC_R_DISABLED)
		ipv4_result = ISC_R_SUCCESS;
}

void
isc_net_enableipv6(void) {
	initialize();
	if (ipv6_result == ISC_R_DISABLED)
		ipv6_result = ISC_R_SUCCESS;
}