/*
 * uhub - A tiny ADC p2p connection hub
 * Copyright (C) 2007-2009, Jan Vidar Krey
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "uhub.h"

#define NET_WANT_READ             NET_EVENT_READ
#define NET_WANT_WRITE            NET_EVENT_WRITE
#define NET_WANT_ACCEPT           0x0008
#define NET_WANT_SSL_READ         0x0010
#define NET_WANT_SSL_WRITE        0x0020
#define NET_WANT_SSL_ACCEPT       0x0040
#define NET_WANT_SSL_CONNECT      0x0080
#define NET_WANT_SSL_X509_LOOKUP  0x0100

#define NET_PROCESSING_BUSY       0x8000
#define NET_CLEANUP               0x4000
#define NET_INITIALIZED           0x2000
#define NET_TIMER_ENABLED         0x1000

/* FIXME: Meant for debugging */
#define NET_EVENT_SET             0x0800

extern struct hub_info* g_hub;

static inline int net_con_flag_get(struct net_connection* con, unsigned int flag)
{
    return con->flags & flag;
}

static inline void net_con_flag_set(struct net_connection* con, unsigned int flag)
{
    con->flags |= flag;
}

static inline void net_con_flag_unset(struct net_connection* con, unsigned int flag)
{
    con->flags &= ~flag;
}

#ifdef USE_LIBEVENT
static inline int net_con_convert_to_libevent_mask(int ev)
{
	int events = 0;
	if (ev & NET_EVENT_READ)  events |= EV_READ;
	if (ev & NET_EVENT_WRITE) events |= EV_WRITE;
	return events;
}

static inline int net_con_convert_from_libevent_mask(int ev)
{
	int events = 0;
	if (ev & EV_TIMEOUT)    events |= NET_EVENT_TIMEOUT;
	if (ev & EV_READ)       events |= NET_EVENT_READ;
	if (ev & EV_WRITE)      events |= NET_EVENT_WRITE;
	return events;
}
#endif

static void net_con_event(int fd, short ev, void *arg);

void net_con_set(struct net_connection* con)
{
	uhub_assert(con);

	int ev = 0;
	if (net_con_flag_get(con, NET_WANT_READ | NET_WANT_SSL_READ))   ev |= EV_READ;
	if (net_con_flag_get(con, NET_WANT_WRITE | NET_WANT_SSL_WRITE)) ev |= EV_WRITE;

	if (net_con_flag_get(con, NET_EVENT_SET) != 0)
	{
		event_del(&con->event);
	}
	net_con_flag_set(con, NET_EVENT_SET);

	LOG_MEMORY("SET: set+add: CON={ %p, %p, %d, %d}", con, &con->event, con->sd, ev);
	event_set(&con->event, con->sd, ev, net_con_event, con);
	event_add(&con->event, 0);
	net_con_flag_set(con, NET_INITIALIZED);
}

static void net_con_after_close(struct net_connection* con)
{
	if (net_con_flag_get(con, NET_INITIALIZED))
	{
		LOG_MEMORY("DEL:   close: CON={ %p, %p, %d, %d}", con, &con->event, con->sd, -1);
		net_con_flag_unset(con, NET_EVENT_SET);

		event_del(&con->event);
		net_con_flag_unset(con, NET_INITIALIZED);
	}

	net_con_clear_timeout(con);
	net_close(con->sd);
	con->sd = -1;

	hub_free(con);
}

#define CALLBACK(CON, EVENTS) \
	if (CON->callback) \
		CON->callback(con, EVENTS, CON->ptr);

static void net_con_event(int fd, short ev, void *arg)
{
	struct net_connection* con = (struct net_connection*) arg;
	int events = net_con_convert_from_libevent_mask(ev);

	if (!net_con_flag_get(con, NET_INITIALIZED))
	{
		return;
	}

	if (net_con_flag_get(con, NET_CLEANUP))
	{
		net_con_after_close(con);
		return;
	}

	net_con_flag_set(con, NET_PROCESSING_BUSY);

// 	uhub_assert(net_con_flag_get(con, NET_EVENT_SET) != 0);
	net_con_flag_unset(con, NET_EVENT_SET);

	LOG_MEMORY("EVT: process: CON={ %p, %p, %d, %d}", con, &con->event, con->sd, (int) ev);

#ifdef SSL_SUPPORT
	if (!con->ssl)
	{
#endif
		CALLBACK(con, events);
#ifdef SSL_SUPPORT
	}
	else
	{
#ifdef NETWORK_DUMP_DEBUG
		LOG_PROTO("net_con_event: events=%d, con=%p", ev, con);
#endif
		if (ev & (EV_READ | EV_WRITE))
		{
			if (net_con_flag_get(con, NET_WANT_SSL_ACCEPT))
			{
				if (net_con_ssl_accept(con) < 0)
					CALLBACK(con, NET_EVENT_SOCKERROR);
			}
			else if (net_con_flag_get(con, NET_WANT_SSL_CONNECT))
			{
				if (net_con_ssl_connect(con) < 0)
					CALLBACK(con, NET_EVENT_SOCKERROR);
			}
			else if (ev == EV_READ && net_con_flag_get(con, NET_WANT_SSL_READ))
			{
				CALLBACK(con, NET_EVENT_WRITE);
			}
			else if (ev == EV_WRITE && net_con_flag_get(con, NET_WANT_SSL_WRITE))
			{
				CALLBACK(con, events & NET_EVENT_READ);
			}
			else
			{
				CALLBACK(con, events);
			}
		}
		else
		{
			CALLBACK(con, events);
		}
	}
#endif
	net_con_flag_unset(con, NET_PROCESSING_BUSY);

	if (net_con_flag_get(con, NET_CLEANUP))
	{
		net_con_after_close(con);
	}
	else
	{
		net_con_set(con);
	}
}


void net_con_initialize(struct net_connection* con, int sd, net_connection_cb callback, const void* ptr, int ev)
{
	uhub_assert(con);

	int events = net_con_convert_to_libevent_mask(ev);
	if (ev & NET_EVENT_READ)  net_con_flag_set(con, NET_WANT_READ);
	if (ev & NET_EVENT_WRITE) net_con_flag_set(con, NET_WANT_WRITE);

	con->sd = sd;
	con->flags = 0;
	con->ptr = (void*) ptr;
	con->callback = callback;
	con->last_send = time(0);
	con->last_recv = con->last_send;

	if (ev)
	{
		uhub_assert(net_con_flag_get(con, NET_EVENT_SET) == 0);
		net_con_flag_set(con, NET_EVENT_SET);

		LOG_MEMORY("SET:    init: CON={ %p, %p, %d, %d}", con, &con->event, con->sd, ev);
		event_set(&con->event, con->sd, events, net_con_event, con);
		event_add(&con->event, 0);
		net_con_flag_set(con, NET_INITIALIZED);
	}

	net_set_nonblocking(sd, 1);
	net_set_nosigpipe(sd, 1);

#ifdef SSL_SUPPORT
	con->ssl = NULL;
	con->write_len = 0;
#endif
}

void net_con_reinitialize(struct net_connection* con, net_connection_cb callback, const void* ptr, int events)
{
	uhub_assert(con);
	con->callback = callback;
	con->ptr = (void*) ptr;
	net_con_update(con, events);
}

void net_con_update(struct net_connection* con, int ev)
{
	uhub_assert(con);

	if (ev & NET_EVENT_READ)
		net_con_flag_set(con, NET_EVENT_READ);
	else
		net_con_flag_unset(con, NET_EVENT_READ);

	if (ev & NET_EVENT_WRITE)
		net_con_flag_set(con, NET_EVENT_WRITE);
	else
		net_con_flag_unset(con, NET_EVENT_WRITE);

	if (!net_con_flag_get(con, NET_PROCESSING_BUSY))
	{
		net_con_set(con);
	}
}

int net_con_close(struct net_connection* con)
{
	uhub_assert(con);

	con->ptr = 0;

	if (net_con_flag_get(con, NET_CLEANUP))
		return 0;

	if (net_con_flag_get(con, NET_PROCESSING_BUSY))
	{
		net_con_flag_set(con, NET_CLEANUP);
		return 0;
	}

	net_con_after_close(con);
	return 1;
}

#ifdef SSL_SUPPORT
static int handle_openssl_error(struct net_connection* con, int ret)
{
	uhub_assert(con);

	int error = SSL_get_error(con->ssl, ret);
	switch (error)
	{
		case SSL_ERROR_ZERO_RETURN:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_ZERO_RETURN", ret, error);
			return -1;

		case SSL_ERROR_WANT_READ:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_WANT_READ", ret, error);
			net_con_update(con, EV_READ);
			net_con_flag_set(con, NET_WANT_SSL_READ);
			return 0;

		case SSL_ERROR_WANT_WRITE:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_WANT_WRITE", ret, error);
			net_con_update(con, EV_READ | EV_WRITE);
			net_con_flag_set(con, NET_WANT_SSL_WRITE);
			return 0;

		case SSL_ERROR_WANT_CONNECT:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_WANT_CONNECT", ret, error);
			net_con_update(con, EV_READ | EV_WRITE);
			net_con_flag_set(con, NET_WANT_SSL_CONNECT);
			return 0;

		case SSL_ERROR_WANT_ACCEPT:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_WANT_ACCEPT", ret, error);
			net_con_update(con, EV_READ | EV_WRITE);
			net_con_flag_set(con, NET_WANT_SSL_ACCEPT);
			return 0;

		case SSL_ERROR_WANT_X509_LOOKUP:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_WANT_X509_LOOKUP", ret, error);
			return 0;

		case SSL_ERROR_SYSCALL:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_SYSCALL", ret, error);
			/* if ret == 0, connection closed, if ret == -1, check with errno */
			if (ret == 0)
				return -1;
			else
				return -net_error();

		case SSL_ERROR_SSL:
			LOG_PROTO("SSL_get_error: ret=%d, error=%d: SSL_ERROR_SSL", ret, error);
			/* internal openssl error */
			return -1;
	}

	return -1;
}
#endif


ssize_t net_con_send(struct net_connection* con, const void* buf, size_t len)
{
	uhub_assert(con);

#ifdef SSL_SUPPORT
	if (!con->ssl)
	{
#endif
		int ret = net_send(con->sd, buf, len, UHUB_SEND_SIGNAL);
#ifdef NETWORK_DUMP_DEBUG
		LOG_PROTO("net_send: ret=%d", ret);
#endif
		if (ret > 0)
		{
			con->last_send = time(0);
		}
		else if (ret == -1 && (net_error() == EWOULDBLOCK || net_error() == EINTR))
		{
			return 0;
		}
		else
		{
			return -1;
		}
		return ret;
#ifdef SSL_SUPPORT
	}
	else
	{
		if (net_con_flag_get(con, NET_WANT_SSL_READ) && con->write_len)
			len = con->write_len;

		int ret = SSL_write(con->ssl, buf, len);
#ifdef NETWORK_DUMP_DEBUG
		LOG_PROTO("net_send: ret=%d", ret);
#endif
		if (ret > 0)
		{
			con->last_send = time(0);
			net_con_flag_unset(con, NET_WANT_SSL_READ);
			con->write_len = 0;
		}
		else
		{
			con->write_len = len;
			return handle_openssl_error(con, ret);
		}
		return ret;
	}
#endif


}

ssize_t net_con_recv(struct net_connection* con, void* buf, size_t len)
{
	uhub_assert(con);

#ifdef SSL_SUPPORT
	if (!con->ssl)
	{
#endif
		int ret = net_recv(con->sd, buf, len, 0);
#ifdef NETWORK_DUMP_DEBUG
		LOG_PROTO("net_recv: ret=%d", ret);
#endif
		if (ret > 0)
		{
			con->last_recv = time(0);
		}
		else if (ret == -1 && (net_error() == EWOULDBLOCK || net_error() == EINTR))
		{
			return 0;
		}
		else
		{
			return -1;
		}
		return ret;
#ifdef SSL_SUPPORT
	}
	else
	{
		int ret = SSL_read(con->ssl, buf, len);
#ifdef NETWORK_DUMP_DEBUG
		LOG_PROTO("net_recv: ret=%d", ret);
#endif
		if (ret > 0)
		{
			con->last_recv = time(0);
			net_con_flag_unset(con, NET_WANT_SSL_WRITE);
		}
		else
		{
			return handle_openssl_error(con, ret);
		}
		return ret;
	}
#endif
}

ssize_t net_con_peek(struct net_connection* con, void* buf, size_t len)
{
	uhub_assert(con);

#ifdef SSL_SUPPORT
	if (!con->ssl)
	{
#endif
		int ret = net_recv(con->sd, buf, len, MSG_PEEK);
#ifdef NETWORK_DUMP_DEBUG
		LOG_PROTO("net_recv: ret=%d (MSG_PEEK)", ret);
#endif
		if (ret > 0)
		{
			con->last_recv = time(0);
		}
		else if (ret == -1 && (net_error() == EWOULDBLOCK || net_error() == EINTR))
		{
			return 0;
		}
		else
		{
			return -1;
		}
		return ret;
#ifdef SSL_SUPPORT
	}
	else
	{
		// FIXME: Not able to do this!
		return 0;
	}
#endif
}

void net_con_set_timeout(struct net_connection* con, int seconds)
{
	uhub_assert(con);

	struct timeval timeout = { seconds, 0 };
	net_con_clear_timeout(con);

	evtimer_set(&con->timeout, net_con_event, con);
	evtimer_add(&con->timeout, &timeout);
	net_con_flag_set(con, NET_TIMER_ENABLED);
}

void net_con_clear_timeout(struct net_connection* con)
{
	uhub_assert(con);

	if (net_con_flag_get(con, NET_TIMER_ENABLED))
	{
		evtimer_del(&con->timeout);
		net_con_flag_unset(con, NET_TIMER_ENABLED);
	}
}


#ifdef SSL_SUPPORT
ssize_t net_con_ssl_accept(struct net_connection* con)
{
	uhub_assert(con);

	net_con_flag_set(con, NET_WANT_SSL_ACCEPT);
	ssize_t ret = SSL_accept(con->ssl);
#ifdef NETWORK_DUMP_DEBUG
	LOG_PROTO("SSL_accept() ret=%d", ret);
#endif
	if (ret > 0)
	{
		net_con_flag_unset(con, NET_WANT_SSL_ACCEPT);
		net_con_flag_unset(con, NET_WANT_SSL_READ);
	}
	else
	{
		return handle_openssl_error(con, ret);
	}
	return ret;
}

ssize_t net_con_ssl_connect(struct net_connection* con)
{
	uhub_assert(con);

	net_con_flag_set(con, NET_WANT_SSL_CONNECT);
	ssize_t ret = SSL_connect(con->ssl);
#ifdef NETWORK_DUMP_DEBUG
	LOG_PROTO("SSL_connect() ret=%d", ret);
#endif
	if (ret > 0)
	{
		net_con_flag_unset(con, NET_WANT_SSL_CONNECT);
		net_con_flag_unset(con, NET_WANT_SSL_WRITE);
	}
	else
	{
		return handle_openssl_error(con, ret);
	}
	return ret;
}

ssize_t net_con_ssl_handshake(struct net_connection* con, int ssl_mode)
{
	uhub_assert(con);

	if (ssl_mode == NET_CON_SSL_MODE_SERVER)
	{
		con->ssl = SSL_new(g_hub->ssl_ctx);
		SSL_set_fd(con->ssl, con->sd);
		return net_con_ssl_accept(con);
	}
	else
	{
		con->ssl = SSL_new(SSL_CTX_new(TLSv1_method()));
		SSL_set_fd(con->ssl, con->sd);
		return net_con_ssl_connect(con);
	}
}
#endif /* SSL_SUPPORT */

static void net_timer_event(int fd, short ev, void *arg)
{
	struct net_timer* timer = (struct net_timer*) arg;
	timer->callback(timer, timer->ptr);
}

void net_timer_initialize(struct net_timer* timer, net_timeout_cb callback, void* ptr)
{
	timer->initialized = 0;
	timer->callback = callback;
	timer->ptr = ptr;
}

void net_timer_reset(struct net_timer* timer, int seconds)
{
	struct timeval timeout = { seconds, 0 };
	if (timer->initialized)
	{
		evtimer_del(&timer->timeout);
		timer->initialized = 0;
	}
	evtimer_set(&timer->timeout, net_timer_event, timer);
	evtimer_add(&timer->timeout, &timeout);
}

void net_timer_shutdown(struct net_timer* timer)
{
	if (timer->initialized)
	{
		evtimer_del(&timer->timeout);
		timer->initialized = 0;
	}
	timer->callback = 0;
	timer->ptr = 0;
}