/* 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 <sys/un.h>

#include <hurd.h>

#include <hurd/fd.h>

#include <hurd/ifsock.h>

#include <hurd/socket.h>

#include "hurd/hurdsocket.h"

/* Send a message described MESSAGE on socket FD.

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

ssize_t

__libc_sendmsg (int fd, const struct msghdr *message, int flags)

{

  error_t err = 0;

  struct sockaddr_un *addr = message->msg_name;

  socklen_t addr_len = message->msg_namelen;

  addr_port_t aport = MACH_PORT_NULL;

  union

  {

    char *ptr;

    vm_address_t addr;

  } data = { .ptr = NULL };

  char data_buf[2048];

  mach_msg_type_number_t len;

  mach_msg_type_number_t amount;

  int dealloc = 0;

  int i;

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

  len = 0;

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

    {

      if (message->msg_iov[i].iov_len > 0)

	{

	  /* As an optimization, if we only have a single non-empty

             iovec, we set DATA and LEN from it.  */

	  if (len == 0)

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

	  else

	    data.ptr = NULL;

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

	}

    }

  if (data.ptr == NULL)

    {

      size_t to_copy;

      char *buf;

      /* Allocate a temporary buffer to hold the data.  For small

         amounts of data, we allocate a buffer on the stack.  Larger

         amounts of data are stored in a page-aligned buffer.  The

         limit of 2048 bytes is inspired by the MiG stubs.  */

      if (len > 2048)

	{

	  err = __vm_allocate (__mach_task_self (), &data.addr, len, 1);

	  if (err)

	    {

	      __set_errno (err);

	      return -1;

	    }

	  dealloc = 1;

	}

      else

	data.ptr = data_buf;

      /* Copy the data into DATA.  */

      to_copy = len;

      buf = data.ptr;

      for (i = 0; i < len; i++)

	{

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

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

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

	  to_copy -= copy;

	  if (to_copy == 0)

	    break;

	}

    }

  if (addr)

    {

      if (addr->sun_family == AF_LOCAL)

	{

	  char *name = _hurd_sun_path_dupa (addr, addr_len);

	  /* For the local domain, we must look up the name as a file

	     and talk to it with the ifsock protocol.  */

	  file_t file = __file_name_lookup (name, 0, 0);

	  if (file == MACH_PORT_NULL)

	    {

	      if (dealloc)

		__vm_deallocate (__mach_task_self (), data.addr, len);

	      return -1;

	    }

	  err = __ifsock_getsockaddr (file, &aport);

	  __mach_port_deallocate (__mach_task_self (), file);

	  if (err == MIG_BAD_ID || err == EOPNOTSUPP)

	    /* The file did not grok the ifsock protocol.  */

	    err = ENOTSOCK;

	  if (err)

	    {

	      if (dealloc)

		__vm_deallocate (__mach_task_self (), data.addr, len);

	      return __hurd_fail (err);

	    }

	}

      else

	err = EIEIO;

    }

  err = HURD_DPORT_USE (fd,

			({

			  if (err)

			    err = __socket_create_address (port,

							   addr->sun_family,

							   (char *) addr,

							   addr_len,

							   &aport);

			  if (! err)

			    {

			      /* Send the data.  */

			      err = __socket_send (port, aport,

						   flags, data.ptr, len,

						   NULL,

						   MACH_MSG_TYPE_COPY_SEND, 0,

						   message->msg_control,

						   message->msg_controllen,

						   &amount);

			      __mach_port_deallocate (__mach_task_self (),

						      aport);

			    }

			  err;

			}));

  if (dealloc)

    __vm_deallocate (__mach_task_self (), data.addr, len);

  return err ? __hurd_sockfail (fd, flags, err) : amount;

}

weak_alias (__libc_sendmsg, sendmsg)

weak_alias (__libc_sendmsg, __sendmsg)