/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2003       Renzo Davoli
//  Copyright (C) 2003-2021  The Bochs Project
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library 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
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
//
/////////////////////////////////////////////////////////////////////////

// eth_vde.cc  - Virtual Distributed Ethernet interface by Renzo Davoli <renzo@cs.unibo.it>
//

// Define BX_PLUGGABLE in files that can be compiled into plugins.  For
// platforms that require a special tag on exported symbols, BX_PLUGGABLE
// is used to know when we are exporting symbols and when we are importing.
#define BX_PLUGGABLE

#include "iodev.h"
#include "netmod.h"

#if BX_NETWORKING && BX_NETMOD_VDE

// network driver plugin entry point

PLUGIN_ENTRY_FOR_NET_MODULE(vde)
{
  // Nothing here yet
  return 0; // Success
}

// network driver implementation

#define LOG_THIS netdev->

#include <signal.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/socket.h>
#if defined(__linux__)
#include <asm/types.h>
#include <linux/netlink.h>
#include <linux/if.h>
#elif BX_HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <sys/uio.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <assert.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <inttypes.h>

#define SWITCH_MAGIC 0xfeedface

#define BX_ETH_VDE_LOGGING 0

int vde_alloc(char *dev,int *fdp,struct sockaddr_un *pdataout);

//
//  Define the class. This is private to this module
//
class bx_vde_pktmover_c : public eth_pktmover_c {
public:
  bx_vde_pktmover_c(const char *netif, const char *macaddr,
                    eth_rx_handler_t rxh, eth_rx_status_t rxstat,
                    bx_devmodel_c *dev, const char *script);
  virtual ~bx_vde_pktmover_c();
  void sendpkt(void *buf, unsigned io_len);
private:
  int fd;
  int rx_timer_index;
  static void rx_timer_handler(void *);
  void rx_timer();
#if BX_ETH_VDE_LOGGING
  FILE *txlog, *txlog_txt, *rxlog, *rxlog_txt;
#endif
  int fddata;
  struct sockaddr_un dataout;
};


//
//  Define the static class that registers the derived pktmover class,
// and allocates one on request.
//
class bx_vde_locator_c : public eth_locator_c {
public:
  bx_vde_locator_c(void) : eth_locator_c("vde") {}
protected:
  eth_pktmover_c *allocate(const char *netif, const char *macaddr,
                           eth_rx_handler_t rxh, eth_rx_status_t rxstat,
                           bx_devmodel_c *dev, const char *script) {
    return (new bx_vde_pktmover_c(netif, macaddr, rxh, rxstat, dev, script));
  }
} bx_vde_match;


//
// Define the methods for the bx_vde_pktmover derived class
//

// the constructor
bx_vde_pktmover_c::bx_vde_pktmover_c(const char *netif,
                                     const char *macaddr,
                                     eth_rx_handler_t rxh,
                                     eth_rx_status_t rxstat,
                                     bx_devmodel_c *dev,
                                     const char *script)
{
  int flags;

  this->netdev = dev;
  //if (strncmp (netif, "vde", 3) != 0) {
   // BX_PANIC (("eth_vde: interface name (%s) must be vde", netif));
  //}
  char intname[IFNAMSIZ];
  if (netif == NULL || strcmp(netif,"") == 0)
    strcpy(intname,"/tmp/vde.ctl");
  else
    strcpy(intname,netif);
  fd=vde_alloc(intname,&fddata,&dataout);
  if (fd < 0) {
    BX_PANIC(("open failed on %s: %s", netif, strerror (errno)));
    return;
  }

  /* set O_ASYNC flag so that we can poll with read() */
  if ((flags = fcntl(fd, F_GETFL)) < 0) {
    BX_PANIC(("getflags on vde device: %s", strerror (errno)));
  }
  flags |= O_NONBLOCK;
  if (fcntl(fd, F_SETFL, flags) < 0) {
    BX_PANIC(("set vde device flags: %s", strerror (errno)));
  }

  BX_INFO(("eth_vde: opened %s device", netif));

  /* Execute the configuration script */
  if((script != NULL) && (strcmp(script, "") != 0) && (strcmp(script, "none") != 0))
  {
    if (execute_script(this->netdev, script, intname) < 0)
      BX_ERROR(("execute script '%s' on %s failed", script, intname));
  }

  // Start the rx poll
  this->rx_timer_index =
    DEV_register_timer(this, this->rx_timer_handler, 1000, 1, 1,
                       "eth_vde"); // continuous, active
  this->rxh    = rxh;
  this->rxstat = rxstat;
#if BX_ETH_VDE_LOGGING
  // eventually Bryce wants txlog to dump in pcap format so that
  // tcpdump -r FILE can read it and interpret packets.
  txlog = fopen("eth_vde-tx.log", "wb");
  if (!txlog) BX_PANIC(("open eth_vde-tx.log failed"));
  txlog_txt = fopen("eth_vde-txdump.txt", "wb");
  if (!txlog_txt) BX_PANIC(("open eth_vde-txdump.txt failed"));
  fprintf(txlog_txt, "vde packetmover readable log file\n");
  fprintf(txlog_txt, "net IF = %s\n", netif);
  fprintf(txlog_txt, "MAC address = ");
  for (int i=0; i<6; i++)
    fprintf(txlog_txt, "%02x%s", 0xff & macaddr[i], i<5?":" : "");
  fprintf(txlog_txt, "\n--\n");
  fflush(txlog_txt);

  rxlog = fopen("eth_vde-rx.log", "wb");
  if (!rxlog) BX_PANIC(("open eth_vde-rx.log failed"));
  rxlog_txt = fopen("eth_vde-rxdump.txt", "wb");
  if (!rxlog_txt) BX_PANIC(("open eth_vde-rxdump.txt failed"));
  fprintf(rxlog_txt, "vde packetmover readable log file\n");
  fprintf(rxlog_txt, "net IF = %s\n", netif);
  fprintf(rxlog_txt, "MAC address = ");
  for (int i=0; i<6; i++)
    fprintf(rxlog_txt, "%02x%s", 0xff & macaddr[i], i<5?":" : "");
  fprintf(rxlog_txt, "\n--\n");
  fflush(rxlog_txt);

#endif
}

bx_vde_pktmover_c::~bx_vde_pktmover_c()
{
#if BX_ETH_VDE_LOGGING
  fclose(txlog);
  fclose(txlog_txt);
  fclose(rxlog);
  fclose(rxlog_txt);
#endif
}

void bx_vde_pktmover_c::sendpkt(void *buf, unsigned io_len)
{
  unsigned int size;
  //size = write (fd, buf, io_len);
  //size=send(fd,buf,io_len,0);
  size=sendto(fddata,buf,io_len,0,(struct sockaddr *) &dataout, sizeof(struct sockaddr_un));
  if (size != io_len) {
    BX_PANIC(("write on vde device: %s", strerror (errno)));
  } else {
    BX_INFO(("wrote %d bytes on vde", io_len));
  }
#if BX_ETH_VDE_LOGGING
  BX_DEBUG(("sendpkt length %u", io_len));
  // dump raw bytes to a file, eventually dump in pcap format so that
  // tcpdump -r FILE can interpret them for us.
  int n = fwrite(buf, io_len, 1, txlog);
  if (n != 1) BX_ERROR(("fwrite to txlog failed"));
  // dump packet in hex into an ascii log file
  write_pktlog_txt(txlog_txt, (const Bit8u *)buf, io_len, 0);
  // flush log so that we see the packets as they arrive w/o buffering
  fflush(txlog);
#endif
}

void bx_vde_pktmover_c::rx_timer_handler(void *this_ptr)
{
  bx_vde_pktmover_c *class_ptr = (bx_vde_pktmover_c *) this_ptr;
  class_ptr->rx_timer();
}

void bx_vde_pktmover_c::rx_timer()
{
  int nbytes;
  Bit8u buf[BX_PACKET_BUFSIZE];
  Bit8u *rxbuf;
  struct sockaddr_un datain;
  socklen_t datainsize;

  if (fd<0) return;
  //nbytes = read (fd, buf, sizeof(buf));
  nbytes=recvfrom(fddata,buf,sizeof(buf),MSG_DONTWAIT|MSG_WAITALL,(struct sockaddr *) &datain, &datainsize);

  rxbuf=buf;

  if (nbytes>0)
    BX_INFO(("vde read returned %d bytes", nbytes));
  if (nbytes<0) {
    if (errno != EAGAIN)
      BX_ERROR(("vde read error: %s", strerror(errno)));
    return;
  }
#if BX_ETH_VDE_LOGGING
  if (nbytes > 0) {
    BX_DEBUG(("receive packet length %u", nbytes));
    // dump raw bytes to a file, eventually dump in pcap format so that
    // tcpdump -r FILE can interpret them for us.
    int n = fwrite(rxbuf, nbytes, 1, rxlog);
    if (n != 1) BX_ERROR(("fwrite to rxlog failed"));
    // dump packet in hex into an ascii log file
    write_pktlog_txt(rxlog_txt, rxbuf, nbytes, 1);

    // flush log so that we see the packets as they arrive w/o buffering
    fflush(rxlog);
  }
#endif
  BX_DEBUG(("eth_vde: got packet: %d bytes, dst=%x:%x:%x:%x:%x:%x, src=%x:%x:%x:%x:%x:%x\n", nbytes, rxbuf[0], rxbuf[1], rxbuf[2], rxbuf[3], rxbuf[4], rxbuf[5], rxbuf[6], rxbuf[7], rxbuf[8], rxbuf[9], rxbuf[10], rxbuf[11]));
  if (nbytes < MIN_RX_PACKET_LEN) {
    BX_INFO(("packet too short (%d), padding to %d", nbytes, MIN_RX_PACKET_LEN));
    nbytes = MIN_RX_PACKET_LEN;
  }
  if (this->rxstat(this->netdev) & BX_NETDEV_RXREADY) {
    this->rxh(this->netdev, rxbuf, nbytes);
  } else {
    BX_ERROR(("device not ready to receive data"));
  }
}

//enum request_type { REQ_NEW_CONTROL };
#define REQ_NEW_CONTROL 0

struct request_v3 {
  Bit32u magic;
  Bit32u version;
  //enum request_type type;
  int type;
  struct sockaddr_un sock;
};

static int send_fd(char *name, int fddata, struct sockaddr_un *datasock, int group)
{
  int pid = getpid();
  struct request_v3 req;
  int fdctl;
  struct sockaddr_un sock;

  if((fdctl = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
    perror("socket");
    return(-1);
  }
  sock.sun_family = AF_UNIX;
  snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
  if(connect(fdctl, (struct sockaddr *) &sock, sizeof(sock))) {
    perror("connect");
    return(-1);
  }

  req.magic=SWITCH_MAGIC;
  req.version=3;
  req.type=((int)REQ_NEW_CONTROL)+((group > 0)?((geteuid()<<8) + group) << 8:0);
  req.sock.sun_family=AF_UNIX;
  memset(req.sock.sun_path, 0, sizeof(req.sock.sun_path));
  sprintf(&req.sock.sun_path[1], "%5d", pid);

  if(bind(fddata, (struct sockaddr *) &req.sock, sizeof(req.sock)) < 0) {
    perror("bind");
    return(-1);
  }
  if (send(fdctl,&req,sizeof(req),0) < 0) {
    perror("send");
    return(-1);
  }
  if (recv(fdctl,datasock,sizeof(struct sockaddr_un),0) < 0) {
    perror("recv");
    return(-1);
  }
  return fdctl;
}

int vde_alloc(char *dev, int *fdp, struct sockaddr_un *pdataout)
{
  //struct ifreq ifr;
  //int err;
  int fd, fddata;

  if ((fddata = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
    return -1;

  if ((fd = send_fd(dev, fddata, pdataout, 0)) < 0)
    return -1;

  //memset(&ifr, 0, sizeof(ifr));
  *fdp=fddata;

  return fd;
}

#endif /* if BX_NETWORKING && BX_NETMOD_VDE */