/*
   Copyright (C) 1993, 1994 Free Software Foundation

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 the GNU Hurd; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/* Written by Michael I. Bushnell.  */

#include "priv.h"
#include "fsys_S.h"
#include "fsys_reply_U.h"
#include <assert.h>
#include <fcntl.h>
#include <string.h>

struct pending_open 
{
  struct trivfs_protid *cred;
  mach_port_t reply_port;
  mach_msg_type_name_t reply_port_type;
  struct pending_open *next;
};

kern_return_t
trivfs_S_fsys_getroot (struct trivfs_control *cntl,
		       mach_port_t reply_port,
		       mach_msg_type_name_t reply_port_type,
		       mach_port_t dotdot,
		       uid_t *uids, u_int nuids,
		       uid_t *gids, u_int ngids,
		       int flags,
		       retry_type *do_retry,
		       char *retry_name,
		       mach_port_t *newpt,
		       mach_msg_type_name_t *newpttype)
{
  struct trivfs_protid *cred;
  mach_port_t new_realnode;
  error_t err = 0;
  int perms;
  int i;

  if (!cntl)
    return EOPNOTSUPP;

  if ((flags & (O_READ|O_WRITE|O_EXEC) & trivfs_allow_open)
      != (flags & (O_READ|O_WRITE|O_EXEC)))
    return EOPNOTSUPP;

  /* O_CREAT and O_EXCL are not meaningful here; O_NOLINK and O_NOTRANS
     will only be useful when trivfs supports translators (which it doesn't 
     now). */
  flags &= O_HURD;
  flags &= ~(O_CREAT|O_EXCL|O_NOLINK|O_NOTRANS);

  io_restrict_auth (cntl->underlying, &new_realnode,
		    uids, nuids, gids, ngids);
  file_check_access (new_realnode, &perms);
  if ((flags & (O_READ|O_WRITE|O_EXEC) & perms)
      != (flags & (O_READ|O_WRITE|O_EXEC)))
    {
      mach_port_deallocate (mach_task_self (), new_realnode);
      return EACCES;
    }

  if (trivfs_check_open_hook)
    {
      err = (*trivfs_check_open_hook) (cntl, uids, nuids, gids, ngids, flags);
      assert (err != EWOULDBLOCK);
      if (err && (err != EWOULDBLOCK 
		  || (err == EWOULDBLOCK && (flags & O_NONBLOCK))))
	{
	  mach_port_deallocate (mach_task_self (), new_realnode);
	  return err;
	}
    }
  
  cred = ports_allocate_port (sizeof (struct trivfs_protid),
			      cntl->protidtypes);
  cred->isroot = 0;
  for (i = 0; i < nuids; i++)
    if (uids[i] == 0)
      cred->isroot = 1;
  cred->uids = malloc (nuids * sizeof (uid_t));
  cred->gids = malloc (ngids * sizeof (uid_t));
  bcopy (uids, cred->uids, nuids * sizeof (uid_t));
  bcopy (gids, cred->gids, ngids * sizeof (uid_t));
  cred->nuids = nuids;
  cred->ngids = ngids;
  cred->hook = 0;

  cred->po = malloc (sizeof (struct trivfs_peropen));
  cred->po->refcnt = 1;
  cred->po->cntl = cntl;
  cred->po->openmodes = (flags & ~O_NONBLOCK);
  cred->po->hook = 0;
  ports_port_ref (cntl);
  if (trivfs_peropen_create_hook)
    (*trivfs_peropen_create_hook) (cred->po);

  cred->realnode = new_realnode;
  if (trivfs_protid_create_hook)
    (*trivfs_protid_create_hook) (cred);

  if (err == EWOULDBLOCK)
    {
      /* This open request must block. */
      struct pending_open *pendo;
      pendo = malloc (sizeof (struct pending_open));
      ports_port_ref (cred);
      pendo->cred = cred;
      pendo->reply_port = reply_port;
      pendo->reply_port_type = reply_port_type;
      pendo->next = 0;
      if (cntl->openstail)
	cntl->openstail->next = pendo;
      else
	cntl->openshead = pendo;
      cntl->openstail = pendo;
      
      ports_done_with_port (cntl);
      mach_port_deallocate (mach_task_self (), dotdot);
      return MIG_NO_REPLY;
    }
  else
    {
      *do_retry = FS_RETRY_NORMAL;
      *retry_name = '\0';
      *newpt = ports_get_right (cred);
      *newpttype = MACH_MSG_TYPE_MAKE_SEND;
      mach_port_deallocate (mach_task_self (), dotdot);
      return 0;
    }
}

void
trivfs_complete_open (struct trivfs_control *cntl,
		      int multi,
		      error_t err)
{
  struct pending_open *pendo, *nxt;

  if (!multi)
    {
      pendo = cntl->openshead;
      cntl->openshead = pendo->next;
      if (!cntl->openshead)
	cntl->openstail = 0;
      
      if (!err)
	fsys_getroot_reply (pendo->reply_port, pendo->reply_port_type, 0,
			    FS_RETRY_NORMAL, "", ports_get_right (pendo->cred),
			    MACH_MSG_TYPE_MAKE_SEND);
      else
	fsys_getroot_reply (pendo->reply_port, pendo->reply_port_type, err,
			    FS_RETRY_NORMAL, "", MACH_PORT_NULL,
			    MACH_MSG_TYPE_COPY_SEND);
      ports_done_with_port (pendo->cred);
      free (pendo);
    }
  else
    {
      for (pendo = cntl->openshead; pendo; pendo = nxt)
	{
	  if (!err)
	    fsys_getroot_reply (pendo->reply_port, pendo->reply_port_type, 0,
				FS_RETRY_NORMAL, "", 
				ports_get_right (pendo->cred),
				MACH_MSG_TYPE_MAKE_SEND);
	  else
	    fsys_getroot_reply (pendo->reply_port, pendo->reply_port_type, err,
				FS_RETRY_NORMAL, "", MACH_PORT_NULL,
				MACH_MSG_TYPE_COPY_SEND);
	  nxt = pendo->next;
	  ports_done_with_port (pendo->cred);
	  free (pendo);
	}
      cntl->openshead = cntl->openstail = 0;
    }
}