//
// Route_BSD.cpp
//
// $Id: //poco/1.4/Foundation/src/Route_BSD.cpp#2 $
//
// Library: Net
// Package: NetCore
// Module:  Route
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <sys/sysctl.h>
#include <netinet/in.h>
#include <string>


#define RTMSG_LEN	(sizeof(struct rt_msghdr) + 512)
#define ROUNDUP(a)	((a) > 0 ? (((a) + sizeof(uint32_t) - 1) & ~(sizeof(uint32_t) - 1)) : sizeof(long))
#define NEXTADDR(w, u) \
					if (rtm_addrs & (w)) {\
						int l = ROUNDUP(u.sin_len); memmove(cp, &(u), l); cp += l;\
					}
#define ADVANCE(x, n)	(x += ROUNDUP((n)->sa_len))

#define SIN_OFFSET  (offsetof(sockaddr_in,sin_addr))
#define SIN_LENGTH  (sizeof(struct in_addr))
#define SIN6_OFFSET (offsetof(sockaddr_in6,sin6_addr))
#define SIN6_LENGTH (sizeof(struct in6_addr))



namespace Poco {
namespace Net {
		
		
static int seq = rand();

	
static void get_rtaddrs(unsigned addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
	for (unsigned i = 0; i < RTAX_MAX; i++) {
		if (addrs & (1 << i)) {
			rti_info[i] = sa;
			sa = (struct sockaddr *)((char *)sa + ROUNDUP(sa->sa_len));
		} else {
			rti_info[i] = NULL;
		}
	}
}

	
static IPAddress unpack_sockaddr_inX(struct sockaddr *sa, bool ipv4)
{
	const unsigned offset = (ipv4 ? SIN_OFFSET : SIN6_OFFSET);
	unsigned char *addr = (unsigned char*)sa + offset;

	// return wildcard
	if (sa->sa_len == 0)
		return IPAddress(ipv4 ? IPAddress::IPv4 : IPAddress::IPv6);

	struct in6_addr buf;
	memset(&buf, 0, sizeof(buf));
	memcpy(&buf, addr, sa->sa_len - offset);

	IPAddress ip(&buf, (ipv4 ? SIN_LENGTH : SIN6_LENGTH));

	return ip;
}
	

static Route createRoute(struct rt_msghdr2 *rtm, struct sockaddr **rti_info)
{
	IPAddress dest, netmask, nexthop;
	int ifIndex = rtm->rtm_index;
	bool adjacent = false;
	sa_family_t family = AF_MAX;
	char macaddr[16];

	for (unsigned i = 0; i < RTAX_MAX; i++)
	{
		sockaddr* sa = (struct sockaddr*)rti_info[i];

		if (sa == 0) continue;

		switch (i)
		{
		case RTAX_DST:
			poco_assert(sa->sa_family == AF_INET || sa->sa_family == AF_INET6);
			family = sa->sa_family;
			if (family == AF_INET)
			{
				struct sockaddr_in *sin = (struct sockaddr_in *)sa;
				dest = IPAddress(&sin->sin_addr, SIN_LENGTH);
			}
			else
			{
				struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
				dest = IPAddress(&sin6->sin6_addr, SIN6_LENGTH, rtm->rtm_index);
			}
			break;

		case RTAX_GATEWAY:
			poco_assert((sa->sa_family == family || sa->sa_family == AF_LINK));
			switch (sa->sa_family)
			{
			case AF_INET:
				{
					struct sockaddr_in *sin = (struct sockaddr_in *)sa;
					nexthop = IPAddress(&sin->sin_addr, SIN_LENGTH);
					break;
				}
			case AF_INET6:
				{
					struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
					nexthop = IPAddress(&sin6->sin6_addr, SIN6_LENGTH, rtm->rtm_index);
					break;
				}
			case AF_LINK:
				{
					struct sockaddr_dl *sdl = (struct sockaddr_dl *)sa;
					adjacent = true;
					ifIndex = sdl->sdl_index;
					memcpy(macaddr, sdl->sdl_data, sdl->sdl_alen);
					break;
				}
			default:
				break;
			}
			break;

		case RTAX_NETMASK:
			netmask = unpack_sockaddr_inX(sa, (family == AF_INET));
			break;

		case RTAX_GENMASK:
			// IPAddress genmask = unpack_sockaddr_inX(sa, (family == AF_INET));
			break;

		default:
			// do something?
			break;
		}
	}

	if (rtm->rtm_flags & RTF_HOST)
	{
		poco_assert(!(rtm->rtm_addrs & RTA_NETMASK));
		if (family == AF_INET)
			netmask = IPAddress(32, IPAddress::IPv4);
		else
			netmask = IPAddress(128, IPAddress::IPv6);
	}

	if (adjacent)
	{
		Route route(dest, netmask, ifIndex, Route::ROUTE_DIRECT);
		route.setMTU(rtm->rtm_rmx.rmx_mtu);
		route.setHops(rtm->rtm_rmx.rmx_hopcount);
		route.setUsage(rtm->rtm_use);
		// OSX uses expire, not metric; we reuse metric member here
		if (rtm->rtm_rmx.rmx_expire)
		{
			time_t expTime;
			if ((expTime = rtm->rtm_rmx.rmx_expire - ::time(0)) > 0)
				route.setMetric(expTime);
			else route.setMetric(Route::ROUTE_METRIC_UNKNOWN);
		}
		else route.setMetric(Route::ROUTE_METRIC_UNKNOWN);
		return route;
	}
	else
	{
		Route route(dest, netmask, nexthop, ifIndex, Route::ROUTE_INDIRECT);
		route.setMTU(rtm->rtm_rmx.rmx_mtu);
		route.setHops(rtm->rtm_rmx.rmx_hopcount);
		route.setUsage(rtm->rtm_use);
		// OSX uses expire, not metric; we reuse metric member here
		if (rtm->rtm_rmx.rmx_expire)
		{
			time_t expTime;
			if ((expTime = rtm->rtm_rmx.rmx_expire - ::time(0)) > 0)
				route.setMetric(expTime);
			else route.setMetric(Route::ROUTE_METRIC_UNKNOWN);
		}
		else route.setMetric(Route::ROUTE_METRIC_UNKNOWN);
		return route;
	}
}

	
Route::RouteList Route::list(IPAddress::Family family)
{
	Route::RouteList routes;
	int mib[6];

	mib[0] = CTL_NET;
	mib[1] = PF_ROUTE;
	mib[2] = mib[3] = 0;
	mib[4] = NET_RT_DUMP2;
	mib[5] = 0;

	size_t needed = 0;
	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
		throw std::runtime_error("sysctl failed to return routing table size");;

	char *buf = new char[needed];

	if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
		throw std::runtime_error("sysctl failed to populate routing table");

	struct rt_msghdr2 *rtm = NULL;
	for (char *next = buf, *lim = &buf[needed]; next < lim; next += rtm->rtm_msglen)
	{
		rtm = (struct rt_msghdr2 *)next;

		struct sockaddr_in *sin = (struct sockaddr_in*)(rtm + 1);

		if (sin->sin_family != ((family == IPAddress::IPv4) ? AF_INET : AF_INET6)) continue;

		// skip cloned routes
		if (rtm->rtm_parentflags & RTF_PRCLONING) continue;

		struct sockaddr* rti_info[RTAX_MAX];
		get_rtaddrs(rtm->rtm_addrs, (struct sockaddr *)sin, rti_info);

		// RTF_IFSCOPE?

		routes.push_back(createRoute(rtm, rti_info));
	}

	delete[] buf;

	return routes;
}
	

}} // namespace Poco::Net