/*
 * ZeroTier One - Network Virtualization Everywhere
 * Copyright (C) 2011-2015  ZeroTier, Inc.
 *
 * 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/>.
 *
 * --
 *
 * ZeroTier may be used and distributed under the terms of the GPLv3, which
 * are available at: http://www.gnu.org/licenses/gpl-3.0.html
 *
 * If you would like to embed ZeroTier into a commercial application or
 * redistribute it in a modified binary form, please contact ZeroTier Networks
 * LLC. Start here: http://www.zerotier.com/
 */

#ifndef ZT_NETCONETHERNETTAP_HPP
#define ZT_NETCONETHERNETTAP_HPP

#ifdef ZT_ENABLE_NETCON

#include <stdio.h>
#include <stdlib.h>

#include <string>
#include <vector>
#include <stdexcept>

#include "../node/Constants.hpp"
#include "../node/MulticastGroup.hpp"
#include "../node/Mutex.hpp"
#include "../node/InetAddress.hpp"
#include "../osdep/Thread.hpp"
#include "../osdep/Phy.hpp"
#include "../osdep/Arp.hpp"

#include "NetconService.hpp"
#include "NetconUtilities.hpp"

#include "netif/etharp.h"

struct tapif {
  struct eth_addr *ethaddr;
  /* Add whatever per-interface state that is needed here. */
  int fd;
};

namespace ZeroTier {

class NetconEthernetTap;

/**
 * Network Containers instance -- emulates an Ethernet tap device as far as OneService knows
 */
class NetconEthernetTap
{
	friend class Phy<NetconEthernetTap *>;

public:
	NetconEthernetTap(
		const char *homePath,
		const MAC &mac,
		unsigned int mtu,
		unsigned int metric,
		uint64_t nwid,
		const char *friendlyName,
		void (*handler)(void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int),
		void *arg);

	~NetconEthernetTap();

	void setEnabled(bool en);
	bool enabled() const;
	bool addIp(const InetAddress &ip);
	bool removeIp(const InetAddress &ip);
	std::vector<InetAddress> ips() const;
	void put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len);
	std::string deviceName() const;
	void setFriendlyName(const char *friendlyName);
	void scanMulticastGroups(std::vector<MulticastGroup> &added,std::vector<MulticastGroup> &removed);

	void threadMain()
		throw();

	LWIPStack *lwipstack;
  uint64_t _nwid;
  void (*_handler)(void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int);
  void *_arg;

private:

	// LWIP callbacks
	static err_t nc_poll(void* arg, struct tcp_pcb *tpcb);
	static err_t nc_accept(void *arg, struct tcp_pcb *newpcb, err_t err);
	static err_t nc_recved(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err);
	static void nc_err(void *arg, err_t err);
	static void nc_close(struct tcp_pcb *tpcb);
	static err_t nc_send(struct tcp_pcb *tpcb);
	static err_t nc_sent(void *arg, struct tcp_pcb *tpcb, u16_t len);
	static err_t nc_connected(void *arg, struct tcp_pcb *tpcb, err_t err);

	// RPC handlers (from NetconIntercept)
	void handle_bind(NetconClient *client, struct bind_st *bind_rpc);
	void handle_listen(NetconClient *client, struct listen_st *listen_rpc);
	void handle_retval(NetconClient *client, unsigned char* buf);
	void handle_socket(NetconClient *client, struct socket_st* socket_rpc);
	void handle_connect(NetconClient *client, struct connect_st* connect_rpc);
	void handle_write(NetconConnection *c);

	void phyOnDatagram(PhySocket *sock,void **uptr,const struct sockaddr *from,void *data,unsigned long len);
	void phyOnTcpConnect(PhySocket *sock,void **uptr,bool success);
	void phyOnTcpAccept(PhySocket *sockL,PhySocket *sockN,void **uptrL,void **uptrN,const struct sockaddr *from);
	void phyOnTcpClose(PhySocket *sock,void **uptr);
	void phyOnTcpData(PhySocket *sock,void **uptr,void *data,unsigned long len);
	void phyOnTcpWritable(PhySocket *sock,void **uptr);
	void phyOnUnixAccept(PhySocket *sockL,PhySocket *sockN,void **uptrL,void **uptrN);
	void phyOnUnixClose(PhySocket *sock,void **uptr);
	void phyOnUnixData(PhySocket *sock,void **uptr,void *data,unsigned long len);
	void phyOnUnixWritable(PhySocket *sock,void **uptr);

	void phyOnSocketPairEndpointClose(PhySocket *sock, void **uptr);
	void phyOnSocketPairEndpointData(PhySocket *sock, void **uptr, void *buf, unsigned long n);
  void phyOnSocketPairEndpointWritable(PhySocket *sock, void **uptr);

	int send_return_value(NetconClient *client, int retval);

	ip_addr_t convert_ip(struct sockaddr_in * addr)
	{
	  ip_addr_t conn_addr;
	  struct sockaddr_in *ipv4 = addr;
	  short a = ip4_addr1(&(ipv4->sin_addr));
	  short b = ip4_addr2(&(ipv4->sin_addr));
	  short c = ip4_addr3(&(ipv4->sin_addr));
	  short d = ip4_addr4(&(ipv4->sin_addr));
	  IP4_ADDR(&conn_addr, a,b,c,d);
	  return conn_addr;
	}

	// Client helpers
	NetconConnection *getConnectionByThisFD(int fd);
	NetconConnection *getConnectionByPCB(struct tcp_pcb *pcb);
	NetconClient *getClientByPCB(struct tcp_pcb *pcb);
	void closeClient(NetconClient *client);
	void closeConnection(NetconConnection *conn);


	Phy<NetconEthernetTap *> _phy;
	PhySocket *_unixListenSocket;

	std::vector<NetconClient*> clients;
	netif interface;


	MAC _mac;
	Thread _thread;
	std::string _homePath;
	std::string _dev; // path to Unix domain socket

	Arp _arp;
	Mutex _arp_m;

	std::vector<MulticastGroup> _multicastGroups;
	Mutex _multicastGroups_m;

	std::vector<InetAddress> _ips;
	Mutex _ips_m;

	unsigned int _mtu;
	volatile bool _enabled;
	volatile bool _run;
};


/*------------------------------------------------------------------------------
------------------------ low-level Interface functions -------------------------
------------------------------------------------------------------------------*/

  static void low_level_init(struct netif *netif)
  {
  }

  static err_t tapif_init(struct netif *netif)
  {
    return ERR_OK;
  }

  static err_t low_level_output(struct netif *netif, struct pbuf *p)
  {
    struct pbuf *q;
    char buf[1514];
    char *bufptr;
    //struct tapif *tapif;
    int tot_len = 0;

    //tapif = (struct tapif *)netif->state;
    ZeroTier::NetconEthernetTap *tap = (ZeroTier::NetconEthernetTap*)netif->state;

  #if 0
      if(((double)rand()/(double)RAND_MAX) < 0.2) {
      printf("drop output\n");
      return ERR_OK;
      }
  #endif
    /* initiate transfer(); */

    bufptr = &buf[0];

    for(q = p; q != NULL; q = q->next) {
      /* Send the data from the pbuf to the interface, one pbuf at a
         time. The size of the data in each pbuf is kept in the ->len
         variable. */
      /* send data from(q->payload, q->len); */
      memcpy(bufptr, q->payload, q->len);
      bufptr += q->len;
      tot_len += q->len;
    }

    // signal that packet should be sent();
    // Split ethernet header and feed into handler
    struct eth_hdr *ethhdr;
    ethhdr = (struct eth_hdr *)p->payload;

    ZeroTier::MAC src_mac;
    ZeroTier::MAC dest_mac;

    src_mac.setTo(ethhdr->src.addr, 6);
    dest_mac.setTo(ethhdr->dest.addr, 6);

    tap->_handler(tap->_arg,tap->_nwid,src_mac,dest_mac,ZT_ETHERTYPE_IPV4,0,buf,p->tot_len);
    return ERR_OK;
  }

} // namespace ZeroTier

#endif // ZT_ENABLE_NETCON

#endif