/* Copyright (C) 2001-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C 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 2.1 of the

   License, or (at your option) any later version.

   The GNU C 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 the GNU C Library; see the file COPYING.LIB.  If

   not, see <http://www.gnu.org/licenses/>.  */

#include <errno.h>

#include <string.h>

#include <sys/socket.h>

#include <hurd.h>

#include <hurd/fd.h>

#include <hurd/socket.h>

/* Receive a message as described by MESSAGE from socket FD.

   Returns the number of bytes read or -1 for errors.  */

ssize_t

__libc_recvmsg (int fd, struct msghdr *message, int flags)

{

  error_t err;

  addr_port_t aport;

  char *data = NULL;

  mach_msg_type_number_t len = 0;

  mach_port_t *ports;

  mach_msg_type_number_t nports = 0;

  char *cdata = NULL;

  mach_msg_type_number_t clen = 0;

  size_t amount;

  char *buf;

  int i;

  /* Find the total number of bytes to be read.  */

  amount = 0;

  for (i = 0; i < message->msg_iovlen; i++)

    {

      amount += message->msg_iov[i].iov_len;

      /* As an optimization, we set the initial values of DATA and LEN

         from the first non-empty iovec.  This kicks-in in the case

         where the whole packet fits into that iovec buffer.  */

      if (data == NULL && message->msg_iov[i].iov_len > 0)

	{

	  data = message->msg_iov[i].iov_base;

	  len = message->msg_iov[i].iov_len;

	}

    }

  buf = data;

  if (err = HURD_DPORT_USE (fd, __socket_recv (port, &aport,

					       flags, &data, &len,

					       &ports, &nports,

					       &cdata, &clen,

					       &message->msg_flags, amount)))

    return __hurd_sockfail (fd, flags, err);

  if (message->msg_name != NULL && aport != MACH_PORT_NULL)

    {

      char *buf = message->msg_name;

      mach_msg_type_number_t buflen = message->msg_namelen;

      int type;

      err = __socket_whatis_address (aport, &type, &buf, &buflen);

      if (err == EOPNOTSUPP)

	/* If the protocol server can't tell us the address, just return a

	   zero-length one.  */

	{

	  buf = message->msg_name;

	  buflen = 0;

	  err = 0;

	}

      if (err)

	{

	  __mach_port_deallocate (__mach_task_self (), aport);

	  return __hurd_sockfail (fd, flags, err);

	}

      if (message->msg_namelen > buflen)

	message->msg_namelen = buflen;

      if (buf != message->msg_name)

	{

	  memcpy (message->msg_name, buf, message->msg_namelen);

	  __vm_deallocate (__mach_task_self (), (vm_address_t) buf, buflen);

	}

      if (buflen > 0)

	((struct sockaddr *) message->msg_name)->sa_family = type;

    }

  else if (message->msg_name != NULL)

    message->msg_namelen = 0;

  __mach_port_deallocate (__mach_task_self (), aport);

  if (buf == data)

    buf += len;

  else

    {

      /* Copy the data into MSG.  */

      if (len > amount)

	message->msg_flags |= MSG_TRUNC;

      else

	amount = len;

      buf = data;

      for (i = 0; i < message->msg_iovlen; i++)

	{

#define min(a, b)	((a) > (b) ? (b) : (a))

	  size_t copy = min (message->msg_iov[i].iov_len, amount);

	  memcpy (message->msg_iov[i].iov_base, buf, copy);

	  buf += copy;

	  amount -= copy;

	  if (len == 0)

	    break;

	}

      __vm_deallocate (__mach_task_self (), (vm_address_t) data, len);

    }

  /* Copy the control message into MSG.  */

  if (clen > message->msg_controllen)

    message->msg_flags |= MSG_CTRUNC;

  else

    message->msg_controllen = clen;

  memcpy (message->msg_control, cdata, message->msg_controllen);

  __vm_deallocate (__mach_task_self (), (vm_address_t) cdata, clen);

  return (buf - data);

}

weak_alias (__libc_recvmsg, recvmsg)

weak_alias (__libc_recvmsg, __recvmsg)