/* 
   Unix SMB/CIFS implementation.

   POSIX NTVFS backend - open and close

   Copyright (C) Andrew Tridgell 2004

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "include/includes.h"
#include "vfs_posix.h"


/*
  find open file handle given fnum
*/
struct pvfs_file *pvfs_find_fd(struct pvfs_state *pvfs,
			       struct smbsrv_request *req, uint16_t fnum)
{
	struct pvfs_file *f;
	for (f=pvfs->open_files;f;f=f->next) {
		if (f->fnum == fnum) {
			if (req->session != f->session) {
				DEBUG(2,("pvfs_find_fd: attempt to use wrong session for fnum %d\n", fnum));
				return NULL;
			}
			return f;
		}
	}
	return NULL;
}

/*
  by using a destructor we make sure that abnormal cleanup will not 
  leak file descriptors (assuming at least the top level pointer is freed, which
  will cascade down to here)
*/
static int pvfs_fd_destructor(void *p)
{
	struct pvfs_file *f = p;
	if (f->fd != -1) {
		close(f->fd);
		f->fd = -1;
	}
	return 0;
}

/*
  open a file
  TODO: this is a temporary implementation derived from the simple backend
  its purpose is to allow other tests to run 
*/
NTSTATUS pvfs_open(struct ntvfs_module_context *ntvfs,
		   struct smbsrv_request *req, union smb_open *io)
{
	struct pvfs_state *pvfs = ntvfs->private_data;
	int fd, flags;
	struct pvfs_filename *name;
	struct pvfs_file *f;
	NTSTATUS status;

	if (io->generic.level != RAW_OPEN_GENERIC) {
		return ntvfs_map_open(req, io, ntvfs);
	}

	/* resolve the cifs name to a posix name */
	status = pvfs_resolve_name(pvfs, req, io->ntcreatex.in.fname,
				   PVFS_RESOLVE_NO_WILDCARD, &name);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	switch (io->generic.in.open_disposition) {
	case NTCREATEX_DISP_SUPERSEDE:
	case NTCREATEX_DISP_OVERWRITE_IF:
		flags = O_CREAT | O_TRUNC;
		break;
	case NTCREATEX_DISP_OPEN:
	case NTCREATEX_DISP_OVERWRITE:
		flags = 0;
		break;
	case NTCREATEX_DISP_CREATE:
		flags = O_CREAT | O_EXCL;
		break;
	case NTCREATEX_DISP_OPEN_IF:
		flags = O_CREAT;
		break;
	default:
		flags = 0;
		break;
	}
	
	flags |= O_RDWR;

/* we need to do this differently to support systems without O_DIRECTORY */
#ifndef O_DIRECTORY
#define O_DIRECTORY 0
#endif

	if (io->generic.in.create_options & NTCREATEX_OPTIONS_DIRECTORY) {
		flags = O_RDONLY | O_DIRECTORY;
		if (pvfs->flags & PVFS_FLAG_READONLY) {
			goto do_open;
		}
		switch (io->generic.in.open_disposition) {
		case NTCREATEX_DISP_CREATE:
			if (mkdir(name->full_name, 0755) == -1) {
				return pvfs_map_errno(pvfs,errno);
			}
			break;
		case NTCREATEX_DISP_OPEN_IF:
			if (mkdir(name->full_name, 0755) == -1 && errno != EEXIST) {
				return pvfs_map_errno(pvfs,errno);
			}
			break;
		}
	}

do_open:
	fd = open(name->full_name, flags, 0644);
	if (fd == -1) {
		if (errno == 0)
			errno = ENOENT;
		return pvfs_map_errno(pvfs,errno);
	}

	f = talloc_p(pvfs, struct pvfs_file);
	if (f == NULL) {
		close(fd);
		return NT_STATUS_NO_MEMORY;
	}

	/* re-resolve the open fd */
	status = pvfs_resolve_name_fd(pvfs, fd, name);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	f->fnum = fd;
	f->fd = fd;
	f->name = talloc_steal(f, name);
	f->session = req->session;
	f->smbpid = req->smbpid;

	/* setup a destructor to avoid file descriptor leaks on
	   abnormal termination */
	talloc_set_destructor(f, pvfs_fd_destructor);

	DLIST_ADD(pvfs->open_files, f);

	ZERO_STRUCT(io->generic.out);
	
	io->generic.out.create_time = name->dos.create_time;
	io->generic.out.access_time = name->dos.access_time;
	io->generic.out.write_time = name->dos.write_time;
	io->generic.out.change_time = name->dos.change_time;
	io->generic.out.fnum = f->fnum;
	io->generic.out.alloc_size = name->dos.alloc_size;
	io->generic.out.size = name->st.st_size;
	io->generic.out.attrib = name->dos.attrib;
	io->generic.out.is_directory = (name->dos.attrib & FILE_ATTRIBUTE_DIRECTORY)?1:0;

	return NT_STATUS_OK;
}


/*
  close a file
*/
NTSTATUS pvfs_close(struct ntvfs_module_context *ntvfs,
		    struct smbsrv_request *req, union smb_close *io)
{
	struct pvfs_state *pvfs = ntvfs->private_data;
	struct pvfs_file *f;
	NTSTATUS status;

	if (io->generic.level != RAW_CLOSE_CLOSE) {
		/* we need a mapping function */
		return NT_STATUS_INVALID_LEVEL;
	}

	f = pvfs_find_fd(pvfs, req, io->close.in.fnum);
	if (!f) {
		return NT_STATUS_INVALID_HANDLE;
	}

	if (close(f->fd) != 0) {
		status = pvfs_map_errno(pvfs, errno);
	} else {
		status = NT_STATUS_OK;
	}

	talloc_set_destructor(f, NULL);

	DLIST_REMOVE(pvfs->open_files, f);
	talloc_free(f);

	return status;
}


/*
  logoff - close all file descriptors open by a vuid
*/
NTSTATUS pvfs_logoff(struct ntvfs_module_context *ntvfs,
		     struct smbsrv_request *req)
{
	struct pvfs_state *pvfs = ntvfs->private_data;
	struct pvfs_file *f, *next;

	for (f=pvfs->open_files;f;f=next) {
		next = f->next;
		if (f->session == req->session) {
			talloc_set_destructor(f, NULL);
			DLIST_REMOVE(pvfs->open_files, f);
			talloc_free(f);
		}
	}

	return NT_STATUS_OK;
}


/*
  exit - close files for the current pid
*/
NTSTATUS pvfs_exit(struct ntvfs_module_context *ntvfs,
		   struct smbsrv_request *req)
{
	struct pvfs_state *pvfs = ntvfs->private_data;
	struct pvfs_file *f, *next;

	for (f=pvfs->open_files;f;f=next) {
		next = f->next;
		if (f->smbpid == req->smbpid) {
			talloc_set_destructor(f, NULL);
			DLIST_REMOVE(pvfs->open_files, f);
			talloc_free(f);
		}
	}

	return NT_STATUS_OK;
}