/*
 * Copyright (C) 2006  Justin Karneges
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301  USA
 *
 */

// this code assumes the following ioctls work:
//   SIOCGIFCONF  - get list of devices
//   SIOCGIFFLAGS - get flags about a device

// gateway detection currently only works on linux

#include "irisnetplugin.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <errno.h>
#include <unistd.h>

// for solaris
#ifndef SIOCGIFCONF
# include<sys/sockio.h>
#endif

#ifdef Q_OS_LINUX
static QStringList read_proc_as_lines(const char *procfile)
{
	QStringList out;

	FILE *f = fopen(procfile, "r");
	if(!f)
		return out;

	QByteArray buf;
	while(!feof(f))
	{
		// max read on a proc is 4K
		QByteArray block(4096, 0);
		int ret = fread(block.data(), 1, block.size(), f);
		if(ret <= 0)
			break;
		block.resize(ret);
		buf += block;
	}
	fclose(f);

	QString str = QString::fromLocal8Bit(buf);
	out = str.split('\n', QString::SkipEmptyParts);
	return out;
}

static QHostAddress linux_ipv6_to_qaddr(const QString &in)
{
	QHostAddress out;
	if(in.length() != 32)
		return out;
	quint8 raw[16];
	for(int n = 0; n < 16; ++n)
	{
		bool ok;
		int x = in.mid(n * 2, 2).toInt(&ok, 16);
		if(!ok)
			return out;
		raw[n] = (quint8)x;
	}
	out.setAddress(raw);
	return out;
}

static QHostAddress linux_ipv4_to_qaddr(const QString &in)
{
	QHostAddress out;
	if(in.length() != 8)
		return out;
	quint32 raw;
	unsigned char *rawp = (unsigned char *)&raw;
	for(int n = 0; n < 4; ++n)
	{
		bool ok;
		int x = in.mid(n * 2, 2).toInt(&ok, 16);
		if(!ok)
			return out;
		rawp[n] = (unsigned char )x;
	}
	out.setAddress(raw);
	return out;
}

static QList<XMPP::NetGatewayProvider::Info> get_linux_gateways()
{
	QList<XMPP::NetGatewayProvider::Info> out;

	QStringList lines = read_proc_as_lines("/proc/net/route");
	// skip the first line, so we start at 1
	for(int n = 1; n < lines.count(); ++n)
	{
		const QString &line = lines[n];
		QStringList parts = line.simplified().split(' ', QString::SkipEmptyParts);
		if(parts.count() < 10) // net-tools does 10, but why not 11?
			continue;

		QHostAddress addr = linux_ipv4_to_qaddr(parts[2]);
		if(addr.isNull())
			continue;

		int iflags = parts[3].toInt(0, 16);
		if(!(iflags & RTF_UP))
			continue;

		if(!(iflags & RTF_GATEWAY))
			continue;

		XMPP::NetGatewayProvider::Info g;
		g.ifaceId = parts[0];
		g.gateway = addr;
		out += g;
	}

	lines = read_proc_as_lines("/proc/net/ipv6_route");
	for(int n = 0; n < lines.count(); ++n)
	{
		const QString &line = lines[n];
		QStringList parts = line.simplified().split(' ', QString::SkipEmptyParts);
		if(parts.count() < 10)
			continue;

		QHostAddress addr = linux_ipv6_to_qaddr(parts[4]);
		if(addr.isNull())
			continue;

		int iflags = parts[8].toInt(0, 16);
		if(!(iflags & RTF_UP))
			continue;

		if(!(iflags & RTF_GATEWAY))
			continue;

		XMPP::NetGatewayProvider::Info g;
		g.ifaceId = parts[9];
		g.gateway = addr;
		out += g;
	}

	return out;
}
#endif

static QList<XMPP::NetGatewayProvider::Info> get_unix_gateways()
{
	// support other platforms here
	QList<XMPP::NetGatewayProvider::Info> out;
#ifdef Q_OS_LINUX
	out = get_linux_gateways();
#endif
	return out;
}

namespace XMPP {

class UnixGateway : public NetGatewayProvider
{
	Q_OBJECT
	Q_INTERFACES(XMPP::NetGatewayProvider)
public:
	QList<Info> info;
	//QTimer t;

	UnixGateway() //: t(this)
	{
		//connect(&t, SIGNAL(timeout()), SLOT(check()));
		// TODO track changes without timers
	}

	void start()
	{
		//t.start(5000);
		poll();
	}

	QList<Info> gateways() const
	{
		return info;
	}

	void poll()
	{
		info = get_unix_gateways();
	}

public slots:
	void check()
	{
		poll();
		emit updated();
	}
};

class UnixNetProvider : public IrisNetProvider
{
	Q_OBJECT
	Q_INTERFACES(XMPP::IrisNetProvider)
public:
	virtual NetGatewayProvider *createNetGatewayProvider()
	{
		return new UnixGateway;
	}
};

IrisNetProvider *irisnet_createUnixNetProvider()
{
	return new UnixNetProvider;
}

}

#include "netinterface_unix.moc"
