//=============================================================================
//
//   File : KviNetUtils.cpp
//   Creation date : Sun Jun 18 2000 18:37:27 by Szymon Stefanek
//
//   This file is part of the KVIrc IRC client distribution
//   Copyright (C) 2000-2010 Szymon Stefanek (pragma at kvirc dot net)
//
//   This program is FREE software. You can redistribute it and/or
//   modify it under the terms of the GNU General Public License
//   as published by the Free Software Foundation; either version 2
//   of the License, or (at your option) any later version.
//
//   This program 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 General Public License for more details.
//
//   You should have received a copy of the GNU General Public License
//   along with this program. If not, write to the Free Software Foundation,
//   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
//=============================================================================

#define _KVI_NETUTILS_CPP_

#include "KviNetUtils.h"
#include "KviCString.h"
#include "KviMemory.h"

#include <QString>
#include <QStringList>

#if !defined(COMPILE_ON_WINDOWS) && !defined(COMPILE_ON_MINGW)
#include <sys/time.h> // struct timeval
#include <unistd.h>
#include <netdb.h>
#endif

#ifdef COMPILE_ON_WINDOWS
#include <Ws2tcpip.h>
#endif

#include <sys/types.h>

#if defined(__SVR4) && defined(__sun)
#include <sys/sockio.h>
#endif

#ifdef COMPILE_GET_INTERFACE_ADDRESS
#include <sys/ioctl.h>
#include <net/if.h>
#endif //COMPILE_GET_INTERFACE_ADDRESS

#ifndef HAVE_INET_ATON

// FIXME: #warning "Your system lacks the inet_aton function,"
// FIXME: #warning "you're trying to compile this file without"
// FIXME: #warning "the kvi_sysconfig.h created by the cmake script,"
// FIXME: #warning "Using own internal implementation of inet_aton."

#include <ctype.h>

// Need own inet_aton implementation
//
// Check whether "cp" is a valid ascii representation
// of an Internet address and convert to a binary address.
// Returns 1 if the address is valid, 0 if not.
// This replaces inet_addr, the return value from which
// cannot distinguish between failure and a local broadcast address.
//
// Original code comes from the ircd source.
//

bool kvi_stringIpToBinaryIp(const char * szIp, struct in_addr * address)
{
	unsigned long val;
	int base, n;
	char c;
	unsigned int parts[4];
	unsigned int * pp = parts;
	if(!szIp)
		return false;
	c = *szIp;
	for(;;)
	{
		// Collect number up to ``.''.
		// Values are specified as for C:
		// 0x=hex, 0=octal, isdigit=decimal.
		if(!isdigit(c))
			return false;
		val = 0;
		base = 10;

		if(c == '0')
		{
			c = *++szIp;
			if((c == 'x') || (c == 'X'))
				base = 16, c = *++szIp;
			else
				base = 8;
		}

		for(;;)
		{
			if(isascii(c) && isdigit(c))
			{
				val = (val * base) + (c - '0');
				c = *++szIp;
			}
			else if(base == 16 && isascii(c) && isxdigit(c))
			{
				val = (val << 4) | (c + 10 - (islower(c) ? 'a' : 'A'));
				c = *++szIp;
			}
			else
				break;
		}

		if(c == '.')
		{
			// Internet format:
			//	a.b.c.d
			//	a.b.c	(with c treated as 16 bits)
			//	a.b	(with b treated as 24 bits)

			if(pp >= (parts + 3))
				return false;
			*pp++ = val;
			c = *++szIp;
		}
		else
			break;
	}

	// Check for trailing characters.
	if((c != '\0') && (!isascii(c) || !isspace(c)))
		return false;

	// Concact the address according to
	// the number of parts specified.
	n = pp - parts + 1;

	switch(n)
	{
		case 0:
			return false; // initial nondigit
		case 1:
			break; // a -- 32 bits
		case 2:    // a.b -- 8.24 bits
			if(val > 0xffffff)
				return false;
			val |= parts[0] << 24;
			break;
		case 3: // a.b.c -- 8.8.16 bits
			if(val > 0xffff)
				return false;
			val |= (parts[0] << 24) | (parts[1] << 16);
			break;
		case 4: // a.b.c.d -- 8.8.8.8 bits
			if(val > 0xff)
				return false;
			val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
			break;
	}

	if(address)
		address->s_addr = htonl(val);
	return true;
}

#else  //!HAVE_INET_ATON

bool kvi_stringIpToBinaryIp(const char * szIp, struct in_addr * address)
{
	if(!szIp)
		return false;
	return (inet_aton(szIp, address) != 0);
}
#endif //!HAVE_INET_ATON

#ifndef HAVE_INET_NTOA

// FIXME: #warning "Your system lacks the inet_ntoa function,"
// FIXME: #warning "you're trying to compile this file without"
// FIXME: #warning "the config.h created by the configure script,"
// FIXME: #warning "Using own internal implementation of inet_ntoa."

//
// Original code comes from the ircd source.
//

bool kvi_binaryIpToStringIp(struct in_addr in, QString & szBuffer)
{
	unsigned char * s = (unsigned char *)&in;
	int a, b, c, d;
	a = (int)*s++;
	b = (int)*s++;
	c = (int)*s++;
	d = (int)*s;

	szBuffer = QString("%1.%2.%3.%4").arg(a).arg(b).arg(c).arg(d);
	return true;
}

#else //HAVE_INET_NTOA

bool kvi_binaryIpToStringIp(struct in_addr in, QString & szBuffer)
{
	// FIXME: #warning "This is NOT thread safe!"

	char * ptr = inet_ntoa(in);
	if(!ptr)
		return false;
	szBuffer = ptr;
	return true;
}

#endif //HAVE_INET_NTOA

bool kvi_isValidStringIp(const char * szIp)
{
	struct in_addr address;
	if(!szIp)
		return false;
	if(!isdigit(*szIp))
		return false;
	return kvi_stringIpToBinaryIp(szIp, &address);
}

#ifdef COMPILE_IPV6_SUPPORT

bool kvi_binaryIpToStringIp_V6(struct in6_addr in, QString & szBuffer)
{
	char buf[46];
	bool bRet = inet_ntop(AF_INET6, (void *)&in, buf, 46);

	szBuffer = buf;
	return bRet;
}

#endif

#include <cerrno>

bool kvi_select(int fd, bool * bCanRead, bool * bCanWrite, int iUSecs)
{
	// FIXME: This stuff should DIE!
	fd_set rs;
	fd_set ws;
	FD_ZERO(&rs);
	FD_ZERO(&ws);
	FD_SET(fd, &rs);
	FD_SET(fd, &ws);
	struct timeval tv;

	tv.tv_sec = 0;
	tv.tv_usec = iUSecs;

	int ret = select(fd + 1, &rs, &ws, nullptr, &tv);
	if(ret < 1)
		return false; // EINTR or ENOSTUFFATALL

	*bCanRead = FD_ISSET(fd, &rs);
	*bCanWrite = FD_ISSET(fd, &ws);

	return true;
}

namespace KviNetUtils
{
	bool stringIpToBinaryIp(const QString & szStringIp, struct in_addr * address)
	{
#ifndef HAVE_INET_ATON
		QString szAddr = szStringIp.simplified();
		quint32 iAddr = 0;
		QStringList ipv4 = szAddr.split(".", Qt::KeepEmptyParts, Qt::CaseInsensitive);
		if(ipv4.count() == 4)
		{
			int i = 0;
			bool ok = true;
			while(ok && i < 4)
			{
				uint byteValue = ipv4[i].toUInt(&ok);
				if((byteValue > 255) && ok)
					ok = false;
				if(ok)
					iAddr = (iAddr << 8) + byteValue;
				++i;
			}
			if(ok)
			{
				if(address)
					address->s_addr = htonl(iAddr);
				return true;
			}
		}
		return false;
#else  //HAVE_INET_ATON
		if(szStringIp.isEmpty())
			return false;
		return (inet_aton(szStringIp.toUtf8().data(), address) != 0);
#endif //HAVE_INET_ATON
	}

	bool isValidStringIp(const QString & szIp)
	{
		struct in_addr address;
		if(szIp.isEmpty())
			return false;
		if(!szIp[0].isNumber())
			return false;
		return stringIpToBinaryIp(szIp, &address);
	}

#ifdef COMPILE_IPV6_SUPPORT
	bool stringIpToBinaryIp_V6(const QString & szStringIp, struct in6_addr * address)
	{
		return (inet_pton(AF_INET6, szStringIp.toUtf8().data(), (void *)address) == 1);
	}

	bool isValidStringIPv6(const QString & szIp)
	{
		struct in6_addr address;
		if(szIp.isEmpty())
			return false;
		return stringIpToBinaryIp_V6(szIp, &address);
	}

	bool binaryIpToStringIp_V6(struct in6_addr in, QString & szBuffer)
	{
		char buf[46];
		bool bRet = inet_ntop(AF_INET6, (void *)&in, buf, 46);
		szBuffer = buf;
		return bRet;
	}

#endif //COMPILE_IPV6_SUPPORT

	bool binaryIpToStringIp(struct in_addr in, QString & szBuffer)
	{
		char * ptr = inet_ntoa(in);
		if(!ptr)
			return false;
		szBuffer = ptr;
		return true;
	}

	bool isRoutableIpString(const QString & szIpString)
	{
		struct in_addr a;
		if(szIpString.isEmpty())
			return false;
		stringIpToBinaryIp(szIpString, &a);
		return isRoutableIp((const char *)&a);
	}

	bool isRoutableIp(const char * ipaddr)
	{
		if(!ipaddr)
			return false;
		const unsigned char * ip = (const unsigned char *)ipaddr;
		if(ip[0] == 0)
			return false; // old-style broadcast
		if(ip[0] == 10)
			return false; // Class A VPN
		if(ip[0] == 127)
			return false; // loopback
		if((ip[0] == 172) && (ip[1] >= 16) && (ip[1] <= 31))
			return false; // Class B VPN
		if((ip[0] == 192) && (ip[1] == 168))
			return false; // Class C VPN
		if((ip[0] == 169) && (ip[1] == 254))
			return false; // APIPA
		if((ip[0] == 192) && (ip[1] == 0) && (ip[2] == 2))
			return false; // Class B VPN
		if(ip[0] >= 224)
			return false; // class D multicast and class E reserved

		return true;
	}

#ifdef COMPILE_GET_INTERFACE_ADDRESS
	union sockaddr_union {
		struct sockaddr sa;
		struct sockaddr_in sin;
	};

	bool getInterfaceAddress(const QString & szInterfaceName, QString & szBuffer)
	{
		union sockaddr_union * su;
		struct ifreq ifr;
		int len = szInterfaceName.length();
		if(len > (IFNAMSIZ - 1))
			return false; // invalid interface anyway

		KviMemory::move(ifr.ifr_name, szInterfaceName.toUtf8().data(), len + 1);

		int fd = socket(AF_INET, SOCK_STREAM, 0);
		if(fd < 0)
			return false;

		if(ioctl(fd, SIOCGIFADDR, &ifr) == -1)
			return false; // supports only IPV4 ?

		close(fd);

		su = (union sockaddr_union *)&(ifr.ifr_addr);

		if(su->sa.sa_family != AF_INET)
			return false;

		return binaryIpToStringIp((struct in_addr)su->sin.sin_addr, szBuffer);

// (this seems to work for AF_INET only anyway)
#else  //!COMPILE_GET_INTERFACE_ADDRESS
	bool getInterfaceAddress(const QString &, QString &)
	{
		return false;
#endif //!COMPILE_GET_INTERFACE_ADDRESS
	}

	void formatNetworkBandwidthString(QString & szBuffer, unsigned int uBytesPerSec)
	{
		if(uBytesPerSec > (1024 * 1024))
		{
			unsigned int uMB = uBytesPerSec / (1024 * 1024);
			unsigned int uRem = ((uBytesPerSec % (1024 * 1024)) * 100) / (1024 * 1024);

			szBuffer = QString("%1.%2%3 MiB/s").arg(uMB).arg(uRem / 10).arg(uRem % 10);

			return;
		}

		if(uBytesPerSec >= 1024)
		{
			unsigned int uKB = uBytesPerSec / 1024;
			unsigned int uRem = ((uBytesPerSec % 1024) * 100) / 1024;

			szBuffer = QString("%1.%2%3 KiB/s").arg(uKB).arg(uRem / 10).arg(uRem % 10);

			return;
		}

		szBuffer = QString("%1 B/s").arg(uBytesPerSec);
	}
}

bool kvi_isRoutableIpString(const char * ipstring)
{
	struct in_addr a;
	if(!ipstring)
		return false;
	kvi_stringIpToBinaryIp(ipstring, &a);
	return kvi_isRoutableIp((const char *)&a);
}

bool kvi_isRoutableIp(const char * ipaddr)
{
	if(!ipaddr)
		return false;
	const unsigned char * ip = (const unsigned char *)ipaddr;

	if(ip[0] == 0)
		return false; // old-style broadcast
	if(ip[0] == 10)
		return false; // Class A VPN
	if(ip[0] == 127)
		return false; // loopback
	if((ip[0] == 172) && (ip[1] >= 16) && (ip[1] <= 31))
		return false; // Class B VPN
	if((ip[0] == 192) && (ip[1] == 168))
		return false; // Class C VPN
	if((ip[0] == 169) && (ip[1] == 254))
		return false; // APIPA
	if((ip[0] == 192) && (ip[1] == 0) && (ip[2] == 2))
		return false; // Class B VPN
	if(ip[0] >= 224)
		return false; // class D multicast and class E reserved

	return true;
}

bool kvi_getLocalHostAddress(QString & buffer)
{
	// This will work only on windoze...
	char buf[1024];
	if(gethostname(buf, 1024) != 0)
		return false;
	struct hostent * h = gethostbyname(buf);
	if(!h)
		return false;
	QString tmp;
	int i = 0;
	while(h->h_addr_list[i])
	{
		if(kvi_binaryIpToStringIp(*((struct in_addr *)(h->h_addr_list[i])), tmp))
		{
			if(kvi_isRoutableIp(h->h_addr_list[i]))
			{
				buffer = tmp;
				return true;
			}
		}
		i++;
	}

	buffer = tmp;
	return true;
}

KviSockaddr::KviSockaddr(const char * szIpAddress, kvi_u32_t uPort, bool bIPv6, bool bUdp)
{
	struct addrinfo hints;
	KviMemory::set((void *)&hints, 0, sizeof(hints));
	hints.ai_flags = AI_NUMERICHOST;
#ifdef COMPILE_IPV6_SUPPORT
	hints.ai_family = bIPv6 ? PF_INET6 : PF_INET;
#else
	hints.ai_family = PF_INET;
#endif

	hints.ai_socktype = bUdp ? SOCK_DGRAM : SOCK_STREAM;

	hints.ai_protocol = 0;
	m_pData = nullptr;
	KviCString szPort(KviCString::Format, "%u", uPort);
	getaddrinfo(szIpAddress, szPort.ptr(), &hints, &m_pData);
}

KviSockaddr::KviSockaddr(kvi_u32_t uPort, bool bIPv6, bool bUdp) // passive sockaddr

{
	struct addrinfo hints;
	KviMemory::set((void *)&hints, 0, sizeof(hints));
	hints.ai_flags = AI_NUMERICHOST | AI_PASSIVE;
#ifdef COMPILE_IPV6_SUPPORT
	hints.ai_family = bIPv6 ? PF_INET6 : PF_INET;
#else
	hints.ai_family = PF_INET;
#endif
	hints.ai_socktype = bUdp ? SOCK_DGRAM : SOCK_STREAM;
	hints.ai_protocol = 0;
	m_pData = nullptr;
	KviCString szPort(KviCString::Format, "%u", uPort);
	getaddrinfo(nullptr, szPort.ptr(), &hints, &m_pData);
}

KviSockaddr::~KviSockaddr()
{
	if(m_pData)
	{
		freeaddrinfo(m_pData);
		m_pData = nullptr;
	}
}

struct sockaddr * KviSockaddr::socketAddress()
{
	if(!m_pData)
		return nullptr;
	return (m_pData)->ai_addr;
}

size_t KviSockaddr::addressLength()
{
	if(!m_pData)
		return 0;
	return (m_pData)->ai_addrlen;
}

int KviSockaddr::addressFamily()
{
	if(!m_pData)
		return 0;
	return (m_pData)->ai_family;
}

bool KviSockaddr::isIPv6()
{
	if(!m_pData)
		return false;
#ifdef COMPILE_IPV6_SUPPORT
	return false;
#else
	return (addressFamily() == AF_INET6);
#endif
}

kvi_u32_t KviSockaddr::port()
{
	if(!m_pData)
		return 0;
#ifdef COMPILE_IPV6_SUPPORT
	switch(m_pData->ai_family)
	{
		case AF_INET:
			return ntohs(((struct sockaddr_in *)(m_pData->ai_addr))->sin_port);
			break;
		case AF_INET6:
			return ntohs(((struct sockaddr_in6 *)(m_pData->ai_addr))->sin6_port);
			break;
	}
	return 0;
#else
	return ntohs(((struct sockaddr_in *)(m_pData->ai_addr))->sin_port);
#endif
}

bool KviSockaddr::getStringAddress(QString & szBuffer)
{
	if(!m_pData)
		return false;
#ifdef COMPILE_IPV6_SUPPORT
	switch(((struct addrinfo *)m_pData)->ai_family)
	{
		case AF_INET:
			return kvi_binaryIpToStringIp(((struct sockaddr_in *)(m_pData->ai_addr))->sin_addr, szBuffer);
			break;
		case AF_INET6:
			return kvi_binaryIpToStringIp_V6(((struct sockaddr_in6 *)(m_pData->ai_addr))->sin6_addr, szBuffer);
			break;
	}

	return false;
#else
	return kvi_binaryIpToStringIp(((struct sockaddr_in *)(m_pData->ai_addr))->sin_addr, szBuffer);
#endif
}