/src/lib/vio/TCP.cpp

/******************************************************************************
 *  This file is part of vio.                                                 *
 *                                                                            *
 *  Copyright (C) 2012, 2013, 2014  Rouven Spreckels  <n3vu0r@nevux.org>      *
 *                                                                            *
 *  vio is free software: you can redistribute it and/or modify               *
 *  it under the terms of the GNU Affero General Public License version 3 as  *
 *  published by the Free Software Foundation on 19 November 2007.            *
 *                                                                            *
 *  vio 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 Affero General Public License for more details.                       *
 *                                                                            *
 *  You should have received a copy of the GNU Affero General Public License  *
 *  along with vio.  If not, see <http://www.gnu.org/licenses/>.              *
 ******************************************************************************/

#ifndef _VIO_TCP_
#define _VIO_TCP_

#include "TCP.hpp"

#include <cerrno>
#include <cstring>
#include <cstdlib>

#include <unistd.h>

void VIO::TCP::readable() {
	if (state & LISTENING) {
		if (state & ACCEPTING)
			accept();
		else
			state |= ACCEPTABLE;
	}
	else {
		//Data front = destinations.front();
		IO::readable();
		if (!fetched.size)
			state &= ~CONNECTED;
		//else
		//if (!front.size)
		//	if (0 > recv(fd, front.data, fetched.size, 0))
		//		state &= ~CONNECTED;
	}
}

void VIO::TCP::writable() {
	if (state & CONNECTING) {
		int value = 0;
		socklen_t size = sizeof value;
		if (0 > getsockopt(fd, SOL_SOCKET, SO_ERROR, &value, &size))
			throw Error("Cannot get socket options", std::strerror(errno), that, GETSOCKOPT);
		if (value) {
			::close(fd);
			if (address)
				connecting();
			else
				throw Error("No addresses left", 0, that, UNAVAILABLE);
		}
		else {
			freeaddrinfo(address);
			configure();
			select &= ~WRITABLE;
			state &= ~CONNECTING;
			state |= CONNECTED;
		}
	}
	else {
		IO::writable();
		if (!pushed.size)
			state &= ~CONNECTED;
	}
}

void VIO::TCP::timewise() {
	static char byte;
	if (!isConnected())
		throw Error("Timer disconnected", std::strerror(errno), that, TIMER);
	if (!hasToRead()) {
		fetch(&byte, sizeof byte);
		clock_gettime(CLOCK_REALTIME, &last);
		select |= SCHEDULE;
	}
	else
		select &= ~SCHEDULE;
}

void VIO::TCP::timing(TCP* tcp, timespec span) {
	char byte;
	for (bool undone = true; undone; undone = process()) {
		if (!tcp->isConnected())
			break;
		if (!tcp->hasToWrite()) {
			timespec left = span;
			while (-1 == nanosleep(&left, &left) and errno == EINTR);
			tcp->push(&byte, sizeof byte);
		}
	}
}

/*
void VIO::TCP::read() {
	int bytes = recv(fd, destinations.front().data, destinations.front().left, destinations.front().size ? 0 : MSG_PEEK);
	if (0 > bytes)
		bytes = 0;
	fetched.data = destinations.front().data;
	fetched.size = bytes;
	fetched.left = 0;
}

void VIO::TCP::write() {
	int bytes = send(fd, sources.front().data, sources.front().left, 0);
	if (0 > bytes)
		bytes = 0;
	pushed.data = sources.front().data;
	pushed.size = bytes;
	pushed.left = 0;
}
*/

void VIO::TCP::read() {
	try {
		IO::read();
	}
	catch (IO::Error& error) {
		state &= ~CONNECTED;
		//throw error;
	}
}

void VIO::TCP::write() {
	try {
		IO::write();
	}
	catch (IO::Error& error) {
		state &= ~CONNECTED;
		//throw error;
	}
}

void VIO::TCP::connecting() {
	if (!address)
		throw Error("No addresses left", 0, that, UNAVAILABLE);
	for (; address; address = address->ai_next) {
		if (0 > (fd = ::socket(address->ai_family, address->ai_socktype, address->ai_protocol)))
			continue;
		configure();
		if (::connect(fd, address->ai_addr, address->ai_addrlen) < 0) {
			if (errno == EINPROGRESS) {
				address = address->ai_next;
				select |= WRITABLE;
				break;
			}
			::close(fd);
			continue;
		}
		freeaddrinfo(address);
		configure();
		select &= ~WRITABLE;
		state &= ~CONNECTING;
		state |= CONNECTED;
		break;
	}
}

void VIO::TCP::pair(TCP* tcp0, TCP* tcp1) {
	int fd[2];
	if (-1 == socketpair(PF_LOCAL, SOCK_STREAM, 0, fd))
		throw Error("Cannot create socketpair", std::strerror(errno), 0, SOCKETPAIR);
	tcp0->fd = fd[0];
	tcp1->fd = fd[1];
	tcp0->configure();
	tcp1->configure();
	tcp0->state |= CONNECTED;
	tcp1->state |= CONNECTED;
}

void VIO::TCP::forkTimer(TCP* pulse, timespec span) {
	TCP timer;
	TCP::pair(pulse, &timer);
	pulse->select |= TIMEWISE;
	pid_t pid;
	if (-1 == (pid = fork()))
		throw Error("Cannot fork process", std::strerror(errno), 0, FORK);
	if (pid) {
		timer.close();
		timer.clear();
		pulse->timewise();
	}
	else {
		pulse->close();
		pulse->clear();
		timing(&timer, span);
		exit(EXIT_SUCCESS);
	}
}

VIO::TCP::Error::Error(const char* context, const char* message, const void* instance, int code)
: IO::Error(context, message, instance, code) {
}

VIO::TCP::TCP()
: IO() {
	state = 0;
	address = 0;
	addrlen = sizeof (struct sockaddr);
}

void VIO::TCP::listen(std::string service, bool reuse, bool accepting) {
	int value = reuse ? 1 : 0;
	state |= LISTENING;
	if (accepting)
		state |= ACCEPTING;
	select |= READABLE;
	struct addrinfo hints, * address;
	memset(&hints, 0, sizeof hints);
	hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
	hints.ai_socktype = SOCK_STREAM;
	if (int gaino = ::getaddrinfo(0, service.c_str(), &hints, &address))
		throw Error("Cannot resolve address information", gai_strerror(gaino), that, GETADDRINFO);
	for (; address; address = address->ai_next) {
		if (0 > (fd = ::socket(address->ai_family, address->ai_socktype, address->ai_protocol)))
			continue;
		if (reuse and -1 == ::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &value, sizeof (int)))
			throw Error("Cannot set socket option reuse", std::strerror(errno), that, SETSOCKOPT);
		if (::bind(fd, address->ai_addr, address->ai_addrlen) < 0) {
			::close(fd);
			fd = -1;
			continue;
		}
	}
	freeaddrinfo(address);
	if (0 > fd)
		throw Error("Cannot create listening socket", std::strerror(errno), that, BIND);
	if (-1 == ::listen(fd, SOMAXCONN))
		throw Error("Cannot listen to socket", std::strerror(errno), that, LISTEN);
	configure();
}

VIO::TCP::Clients::reverse_iterator VIO::TCP::accept() {
	if (!(state & (ACCEPTING | ACCEPTABLE)))
		return clients.rend();
	TCP* client = new TCP();
	if (-1 == (client->fd = ::accept(fd, (struct sockaddr*)&client->addr, &client->addrlen)))
		return clients.rend();
	if (-1 == getpeername(client->fd, (struct sockaddr*)&client->addr, &client->addrlen))
		throw Error("Cannot get peer name", std::strerror(errno), that, GETPEERNAME);
	state &= ~ACCEPTABLE;
	client->state |= CONNECTED;
	client->select |= ACTIVITY;
	client->activity();
	client->configure();
	clients.push_back(client);
	return clients.rbegin();
}

void VIO::TCP::connect(std::string host, std::string service) {
	struct addrinfo hints;
	memset(&hints, 0, sizeof hints);
	hints.ai_flags = AI_ADDRCONFIG;
	hints.ai_socktype = SOCK_STREAM;
	if(int gaino = ::getaddrinfo(host.c_str(), service.c_str(), &hints, &address))
		throw Error("Cannot resolve address information", gai_strerror(gaino), that, GETADDRINFO);
	state |= CONNECTING;
	connecting();
	select |= ACTIVITY;
	activity();
}

bool VIO::TCP::isConnected() {
	return state & CONNECTED ? true : false;
}

bool VIO::TCP::isConnected(timespec timeout) {
	if (!IO::isActive(timeout)) {
		if (state & CONNECTED) {
			state &= ~CONNECTED;
			::close(fd);
			clear();
		}
		activity();
		throw Error("Inactivity reached timeout", 0, that, TIMEOUT);
	}
	return isConnected();
}

std::string VIO::TCP::host() {
	char host[NI_MAXHOST];
	addrlen = sizeof (struct sockaddr_storage);
	if (int gaino = getnameinfo((struct sockaddr*)&addr, addrlen, host, sizeof host, NULL, 0, 0))
		throw Error("Cannot resolve name information", gai_strerror(gaino), that, GETNAMEINFO);
	return host;
}

void VIO::TCP::clear() {
	IO::clear();
	state &= LISTENING | ACCEPTING;
}

VIO::TCP::~TCP() {
	if (state & LISTENING)
		for (Clients::iterator client = clients.begin(); client != clients.end(); ++client)
			delete *client;
}

#endif