sources/network/ipaddress.cpp

/*
	Copyright 2014 - 2021 Teemu Piippo
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions of source code must retain the above copyright
	   notice, this list of conditions and the following disclaimer.
	2. Redistributions in binary form must reproduce the above copyright
	   notice, this list of conditions and the following disclaimer in the
	   documentation and/or other materials provided with the distribution.
	3. Neither the name of the copyright holder nor the names of its
	   contributors may be used to endorse or promote products derived from
	   this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
	TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
	PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
	OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include "ipaddress.h"

#ifndef _WIN32
# include <netinet/in.h>
# include <netdb.h>
#else
# include <winsock2.h>
# include <ws2tcpip.h>
#endif

BEGIN_ZFC_NAMESPACE

#ifdef _WIN32
typedef ADDRINFOA AddrInfo;
#else
typedef struct addrinfo AddrInfo;
#endif

net::octet_t net::ip_octet(const net::ip_address& address, unsigned char n)
{
	assert(n < 4);
	return (address.host >> ((3 - n) * 8)) & 0xFF;
}

void net::ip_set_octet(net::ip_address* address, unsigned char n, net::octet_t octet)
{
	// TODO: make a big-endian version
	assert(n < 4);
	address->host &= ~(0xFF << (3 - n) * 8);
	address->host |= octet << ((3 - n) * 8);
}

std::string net::ip_address_to_string(const net::ip_address& address)
{
	const auto octet = [&](unsigned char n) { return ip_octet(address, n); };
	std::string val = sprintf ("%u.%u.%u.%u:%u", octet(0), octet(1), octet(2), octet(3), address.port);
	return val;
}

int net::ip_compare(const net::ip_address &one, const net::ip_address &other)
{
	if (one.host != other.host)
	{
		return one.host - other.host;
	}
	return one.port - other.port;
}

bool net::ip_address::operator<(const ip_address& other) const
{
	return ip_compare(*this, other) < 0;
}

bool net::ip_address::operator==(const net::ip_address &other) const
{
	return this->host == other.host and this->port == other.port;
}

// -----------------------------------------------------------------------------
//
sockaddr_in net::ip_address_to_sockaddr_in(const net::ip_address& address)
{
	sockaddr_in claddr;
	memset (&claddr, 0, sizeof claddr);
	claddr.sin_addr.s_addr = htonl(address.host);
	claddr.sin_port = htons(address.port);
	claddr.sin_family = AF_INET;
	return claddr;
}

std::optional<unsigned short> net::ip_parse_port(const char* port_string, std::ostream& errorStream)
{
	std::optional<long> opt = to_int(port_string);
	if (opt.has_value())
	{
		if (*opt >= 0 and *opt < 65536)
		{
			return static_cast<unsigned short>(opt.value());
		}
		else
		{
			return {};
			errorStream << "port is not in range"s;
		}
	}
	else
	{
		return {};
		errorStream << "could not parse port"s;
	}
}

std::optional<net::ip_address> net::ip_resolve_hostname(const std::string& node, std::ostream& errorStream)
{
	AddrInfo hints;
	AddrInfo* lookup;
	memset(&hints, 0, sizeof hints);
	hints.ai_family = AF_INET;
	std::optional<net::ip_address> result = {};
	if (::getaddrinfo(node.data(), nullptr, &hints, &lookup) != 0)
	{
		errorStream << "unknown host "s + node;
	}
	else
	{
		assert (lookup != nullptr);
		sockaddr_in* addr = reinterpret_cast<sockaddr_in*>(lookup[0].ai_addr);
		result = net::ip_address{ntohl(addr->sin_addr.s_addr), ntohs(addr->sin_port)};
		::freeaddrinfo(lookup);
	}
	return result;
}

std::optional<net::ip_address> net::ip_resolve(const std::string& input_string, std::ostream& errorStream)
{
	int colonpos = input_string.find(":");
	std::string addressString = colonpos == -1 ? input_string : mid(input_string, 0, colonpos);
	std::optional<net::ip_address> value;
	// Try scanf the IPv4 host first
	int parts[4];
	if (std::sscanf(addressString.data(), "%d.%d.%d.%d", &parts[0], &parts[1], &parts[2], &parts[3]))
	{
		value = net::ip_address{};
		for (unsigned char i = 0; i < 4; i += 1)
		{
			if (parts[i] >= 0 and parts[i] < 256)
			{
				ip_set_octet(&*value, i, parts[i]);
			}
			else
			{
				value.reset();
				errorStream << "IP address value out of range";
				break;
			}
		}
	}
	else
	{
		// Possibly a hostname, try resolve it
		value = ip_resolve_hostname(addressString, errorStream);
	}
	if (value.has_value() and colonpos != -1)
	{
		std::optional<unsigned short> port_opt = ip_parse_port(&input_string.data()[colonpos + 1], errorStream);
		if (port_opt.has_value())
		{
			value->port = *port_opt;
		}
		else
		{
			value.reset();
		}
	}
	return value;
}

END_ZFC_NAMESPACE