/* 
   Copyright (C) 1995 Free Software Foundation, Inc.
   Written by Michael I. Bushnell, p/BSG.

   This file is part of the GNU Hurd.

   The GNU Hurd 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 2, or (at
   your option) any later version.

   The GNU Hurd 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */

error_t
S_io_write (struct sock_user *user,
	    char *data,
	    u_int datalen,
	    off_t offset,
	    mach_msg_type_number_t *amount)
{
  error_t err;
  
  if (!user)
    return EOPNOTSUPP;

  mutex_lock (&global_lock);
  become_task (user);
  /* O_NONBLOCK for fourth arg? XXX */
  err = - (*user->sock->ops->write) (user->sock, data, datalen, 0);
  mutex_unlock (&global_lock);
  
  return err;
}

error_t
S_io_read (struct sock_user *user,
	   char **data,
	   u_int *datalen,
	   off_t offset,
	   mach_msg_type_number_t amount)
{
  error_t err;
  int alloced = 0;

  if (!user)
    return EOPNOTSUPP;
  
  /* Instead of this, we should peek and the socket and only
     allocate as much as necessary. */
  if (amount > *datalen)
    {
      vm_allocate (mach_task_self (), (vm_address_t *)data, amount, 1);
      alloced = 1;
    }
  
  mutex_lock (&global_lock);
  become_task (user);
  /* O_NONBLOCK for fourth arg? XXX */
  err = (*user->sock->ops->read) (user->sock, *data, amount, 0);
  mutex_unlock (&global_lock);
  
  if (err < 0)
    err = -err;
  else
    {
      *datalen = err;
      if (alloced && page_round (*datalen) < page_round (amount))
	vm_deallocate (mach_task_self (), *data + page_round (*datalen),
		       page_round (amount) - page_round (*datalen));
      err = 0;
    }
  return err;
}

error_t
S_io_seek (struct sock_user *user,
	   off_t offset,
	   int whence,
	   off_t *newp)
{
  return user ? ESPIPE : EOPNOTSUPP;
}

error_t
S_io_readable (struct sock_user *user,
	       mach_msg_type_number_t *amount)
{
  struct sock *sk;
  error_t err;
  
  if (!user)
    return EOPNOTSUPP;
  
  mutex_lock (&global_lock);
  become_task (user);
  
  /* We need to avoid calling the Linux ioctl routines,
     so here is a rather ugly break of modularity. */

  sk = (struct sock *) user->sock->data;
  err = 0;
  
  /* Linux's af_inet.c ioctl routine just calls the protocol-specific
     ioctl routine; it's those routines that we need to simulate.  So
     this switch corresponds to the initialization of SK->prot in
     af_inet.c:inet_create. */
  switch (sock->type)
    {
    case SOCK_STREAM:
    case SOCK_SEQPACKET:
      /* These guts are copied from tcp.c:tcp_ioctl. */
      if (sk->state == TCP_LISTEN)
	err = EINVAL;
      else
	{
	  sk->inuse = 1;
	  *amount = tcp_readable (sk);
	  release_sock (sk);
	}
      break;
      
    case SOCK_DGRAM:
      /* These guts are copied from udp.c:udp_ioctl (TIOCINQ). */
      if (sk->state == TCP_LISTEN)
	err = EINVAL;
      else
	/* Boy, I really love the C language. */
	*amount = (skb_peek (&sk->receive_queue)
		   ? : &((struct sk_buff){}))->len;
      break;
      
    case SOCK_RAW:
    default:
      err = EOPNOTSUPP;
      break;
    }

  mutex_unlock (&global_lock);
  return err;
}