/* Serial interface for raw TCP connections on Un*x like systems.

   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2001, 2005, 2006,
   2007, 2008 Free Software Foundation, Inc.

   This file is part of GDB.

   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 "defs.h"
#include "serial.h"
#include "ser-base.h"
#include "ser-tcp.h"

#include <sys/types.h>

#ifdef HAVE_SYS_FILIO_H
#include <sys/filio.h>  /* For FIONBIO. */
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>  /* For FIONBIO. */
#endif

#include <sys/time.h>

#ifdef USE_WIN32API
#include <winsock2.h>
#define ETIMEDOUT WSAETIMEDOUT
#define close(fd) closesocket (fd)
#define ioctl ioctlsocket
#else
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#endif

#include <signal.h>
#include "gdb_string.h"

#ifndef HAVE_SOCKLEN_T
typedef int socklen_t;
#endif

void _initialize_ser_tcp (void);

/* seconds to wait for connect */
#define TIMEOUT 15
/* how many times per second to poll deprecated_ui_loop_hook */
#define POLL_INTERVAL 2

/* Open a tcp socket */

int
net_open (struct serial *scb, const char *name)
{
  char *port_str, hostname[100];
  int n, port, tmp;
  int use_udp;
  struct hostent *hostent;
  struct sockaddr_in sockaddr;
#ifdef USE_WIN32API
  u_long ioarg;
#else
  int ioarg;
#endif

  use_udp = 0;
  if (strncmp (name, "udp:", 4) == 0)
    {
      use_udp = 1;
      name = name + 4;
    }
  else if (strncmp (name, "tcp:", 4) == 0)
    name = name + 4;

  port_str = strchr (name, ':');

  if (!port_str)
    error (_("net_open: No colon in host name!"));	   /* Shouldn't ever happen */

  tmp = min (port_str - name, (int) sizeof hostname - 1);
  strncpy (hostname, name, tmp);	/* Don't want colon */
  hostname[tmp] = '\000';	/* Tie off host name */
  port = atoi (port_str + 1);

  /* default hostname is localhost */
  if (!hostname[0])
    strcpy (hostname, "localhost");

  hostent = gethostbyname (hostname);
  if (!hostent)
    {
      fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
      errno = ENOENT;
      return -1;
    }

  if (use_udp)
    scb->fd = socket (PF_INET, SOCK_DGRAM, 0);
  else
    scb->fd = socket (PF_INET, SOCK_STREAM, 0);

  if (scb->fd < 0)
    return -1;
  
  sockaddr.sin_family = PF_INET;
  sockaddr.sin_port = htons (port);
  memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
	  sizeof (struct in_addr));

  /* set socket nonblocking */
  ioarg = 1;
  ioctl (scb->fd, FIONBIO, &ioarg);

  /* Use Non-blocking connect.  connect() will return 0 if connected already. */
  n = connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr));

  if (n < 0
#ifdef USE_WIN32API
      /* Under Windows, calling "connect" with a non-blocking socket
	 results in WSAEWOULDBLOCK, not WSAEINPROGRESS.  */
      && WSAGetLastError() != WSAEWOULDBLOCK
#else
      && errno != EINPROGRESS
#endif
      )
    {
#ifdef USE_WIN32API
      errno = WSAGetLastError();
#endif
      net_close (scb);
      return -1;
    }

  if (n)
    {
      /* looks like we need to wait for the connect */
      struct timeval t;
      fd_set rset, wset, eset;
      int polls = 0;
      FD_ZERO (&rset);

      do 
	{
	  /* While we wait for the connect to complete, 
	     poll the UI so it can update or the user can 
	     interrupt.  */
	  if (deprecated_ui_loop_hook)
	    {
	      if (deprecated_ui_loop_hook (0))
		{
		  errno = EINTR;
		  net_close (scb);
		  return -1;
		}
	    }
	  
	  FD_SET (scb->fd, &rset);
	  wset = rset;
	  eset = rset;
	  t.tv_sec = 0;
	  t.tv_usec = 1000000 / POLL_INTERVAL;
	  
	  /* POSIX systems return connection success or failure by signalling
	     wset.  Windows systems return success in wset and failure in
	     eset.

	     We must call select here, rather than gdb_select, because
	     the serial structure has not yet been initialized - the
	     MinGW select wrapper will not know that this FD refers
	     to a socket.  */
	  n = select (scb->fd + 1, &rset, &wset, &eset, &t);
	  polls++;
	} 
      while (n == 0 && polls <= TIMEOUT * POLL_INTERVAL);
      if (n < 0 || polls > TIMEOUT * POLL_INTERVAL)
	{
	  if (polls > TIMEOUT * POLL_INTERVAL)
	    errno = ETIMEDOUT;
	  net_close (scb);
	  return -1;
	}
    }

  /* Got something.  Is it an error? */
  {
    int res, err;
    socklen_t len;
    len = sizeof (err);
    /* On Windows, the fourth parameter to getsockopt is a "char *";
       on UNIX systems it is generally "void *".  The cast to "void *"
       is OK everywhere, since in C "void *" can be implicitly
       converted to any pointer type.  */
    res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len);
    if (res < 0 || err)
      {
	if (err)
	  errno = err;
	net_close (scb);
	return -1;
      }
  } 

  /* turn off nonblocking */
  ioarg = 0;
  ioctl (scb->fd, FIONBIO, &ioarg);

  if (use_udp == 0)
    {
      /* Disable Nagle algorithm. Needed in some cases. */
      tmp = 1;
      setsockopt (scb->fd, IPPROTO_TCP, TCP_NODELAY,
		  (char *)&tmp, sizeof (tmp));
    }

#ifdef SIGPIPE
  /* If we don't do this, then GDB simply exits
     when the remote side dies.  */
  signal (SIGPIPE, SIG_IGN);
#endif

  return 0;
}

void
net_close (struct serial *scb)
{
  if (scb->fd < 0)
    return;

  close (scb->fd);
  scb->fd = -1;
}

int
net_read_prim (struct serial *scb, size_t count)
{
  return recv (scb->fd, scb->buf, count, 0);
}

int
net_write_prim (struct serial *scb, const void *buf, size_t count)
{
  return send (scb->fd, buf, count, 0);
}

void
_initialize_ser_tcp (void)
{
#ifdef USE_WIN32API
  /* Do nothing; the TCP serial operations will be initialized in
     ser-mingw.c.  */
  return;
#else
  struct serial_ops *ops;
  ops = XMALLOC (struct serial_ops);
  memset (ops, 0, sizeof (struct serial_ops));
  ops->name = "tcp";
  ops->next = 0;
  ops->open = net_open;
  ops->close = net_close;
  ops->readchar = ser_base_readchar;
  ops->write = ser_base_write;
  ops->flush_output = ser_base_flush_output;
  ops->flush_input = ser_base_flush_input;
  ops->send_break = ser_base_send_break;
  ops->go_raw = ser_base_raw;
  ops->get_tty_state = ser_base_get_tty_state;
  ops->set_tty_state = ser_base_set_tty_state;
  ops->print_tty_state = ser_base_print_tty_state;
  ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
  ops->setbaudrate = ser_base_setbaudrate;
  ops->setstopbits = ser_base_setstopbits;
  ops->drain_output = ser_base_drain_output;
  ops->async = ser_base_async;
  ops->read_prim = net_read_prim;
  ops->write_prim = net_write_prim;
  serial_add_interface (ops);
#endif /* USE_WIN32API */
}