/*
   *   fs/cifs/xattr.c
   *

   *   Copyright (c) International Business Machines  Corp., 2003, 2007

   *   Author(s): Steve French (sfrench@us.ibm.com)
   *
   *   This 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.
   *
   *   This 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 this library; if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  #include <linux/fs.h>
  #include <linux/posix_acl_xattr.h>

  #include <linux/slab.h>

  #include "cifsfs.h"
  #include "cifspdu.h"
  #include "cifsglob.h"
  #include "cifsproto.h"
  #include "cifs_debug.h"
  
  #define MAX_EA_VALUE_SIZE 65535
  #define CIFS_XATTR_DOS_ATTRIB "user.DosAttrib"
  #define CIFS_XATTR_USER_PREFIX "user."
  #define CIFS_XATTR_SYSTEM_PREFIX "system."
  #define CIFS_XATTR_OS2_PREFIX "os2."
  #define CIFS_XATTR_SECURITY_PREFIX ".security"
  #define CIFS_XATTR_TRUSTED_PREFIX "trusted."
  #define XATTR_TRUSTED_PREFIX_LEN  8
  #define XATTR_SECURITY_PREFIX_LEN 9
  /* BB need to add server (Samba e.g) support for security and trusted prefix */

  int cifs_removexattr(struct dentry *direntry, const char *ea_name)

  {
  	int rc = -EOPNOTSUPP;
  #ifdef CONFIG_CIFS_XATTR
  	int xid;
  	struct cifs_sb_info *cifs_sb;
  	struct cifsTconInfo *pTcon;

  	struct super_block *sb;
  	char *full_path;
  
  	if (direntry == NULL)

  		return -EIO;

  	if (direntry->d_inode == NULL)

  		return -EIO;
  	sb = direntry->d_inode->i_sb;

  	if (sb == NULL)

  		return -EIO;
  	xid = GetXid();

  	cifs_sb = CIFS_SB(sb);
  	pTcon = cifs_sb->tcon;

  	full_path = build_path_from_dentry(direntry);

  	if (full_path == NULL) {

  		rc = -ENOMEM;

  		FreeXid(xid);

  		return rc;

  	}

  	if (ea_name == NULL) {

  		cFYI(1, "Null xattr names not supported");

  	} else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5)
  		&& (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4))) {
  		cFYI(1,

  		     "illegal xattr request %s (only user namespace supported)",
  		     ea_name);

  		/* BB what if no namespace prefix? */
  		/* Should we just pass them to server, except for
  		system and perhaps security prefixes? */
  	} else {

  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)

  			goto remove_ea_exit;

  		ea_name += 5; /* skip past user. prefix */
  		rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, NULL,

  			(__u16)0, cifs_sb->local_nls,
  			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

  	}
  remove_ea_exit:

  	kfree(full_path);

  	FreeXid(xid);
  #endif
  	return rc;
  }

  int cifs_setxattr(struct dentry *direntry, const char *ea_name,
  		  const void *ea_value, size_t value_size, int flags)

  {
  	int rc = -EOPNOTSUPP;
  #ifdef CONFIG_CIFS_XATTR
  	int xid;
  	struct cifs_sb_info *cifs_sb;
  	struct cifsTconInfo *pTcon;

  	struct super_block *sb;
  	char *full_path;

  	if (direntry == NULL)

  		return -EIO;

  	if (direntry->d_inode == NULL)

  		return -EIO;
  	sb = direntry->d_inode->i_sb;

  	if (sb == NULL)

  		return -EIO;
  	xid = GetXid();
  
  	cifs_sb = CIFS_SB(sb);
  	pTcon = cifs_sb->tcon;

  	full_path = build_path_from_dentry(direntry);

  	if (full_path == NULL) {

  		rc = -ENOMEM;

  		FreeXid(xid);

  		return rc;

  	}
  	/* return dos attributes as pseudo xattr */
  	/* return alt name if available as pseudo attr */
  
  	/* if proc/fs/cifs/streamstoxattr is set then

  		search server for EAs or streams to

  		returns as xattrs */

  	if (value_size > MAX_EA_VALUE_SIZE) {

  		cFYI(1, "size of EA value too large");

  		kfree(full_path);

  		FreeXid(xid);
  		return -EOPNOTSUPP;
  	}

  	if (ea_name == NULL) {

  		cFYI(1, "Null xattr names not supported");

  	} else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5) == 0) {
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)

  			goto set_ea_exit;

  		if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0)

  			cFYI(1, "attempt to set cifs inode metadata");

  		ea_name += 5; /* skip past user. prefix */

  		rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,

  			(__u16)value_size, cifs_sb->local_nls,
  			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

  	} else if (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4) == 0) {
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)

  			goto set_ea_exit;
  
  		ea_name += 4; /* skip past os2. prefix */

  		rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,

  			(__u16)value_size, cifs_sb->local_nls,
  			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

  	} else {

  		int temp;
  		temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,

  			strlen(POSIX_ACL_XATTR_ACCESS));
  		if (temp == 0) {
  #ifdef CONFIG_CIFS_POSIX

  			if (sb->s_flags & MS_POSIXACL)
  				rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
  					ea_value, (const int)value_size,
  					ACL_TYPE_ACCESS, cifs_sb->local_nls,
  					cifs_sb->mnt_cifs_flags &

  						CIFS_MOUNT_MAP_SPECIAL_CHR);

  			cFYI(1, "set POSIX ACL rc %d", rc);

  #else

  			cFYI(1, "set POSIX ACL not supported");

  #endif

  		} else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,
  				   strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {

  #ifdef CONFIG_CIFS_POSIX

  			if (sb->s_flags & MS_POSIXACL)
  				rc = CIFSSMBSetPosixACL(xid, pTcon, full_path,
  					ea_value, (const int)value_size,

  					ACL_TYPE_DEFAULT, cifs_sb->local_nls,

  					cifs_sb->mnt_cifs_flags &

  						CIFS_MOUNT_MAP_SPECIAL_CHR);

  			cFYI(1, "set POSIX default ACL rc %d", rc);

  #else

  			cFYI(1, "set default POSIX ACL not supported");

  #endif
  		} else {

  			cFYI(1, "illegal xattr request %s (only user namespace"
  				" supported)", ea_name);

  		  /* BB what if no namespace prefix? */

  		  /* Should we just pass them to server, except for

  		  system and perhaps security prefixes? */
  		}
  	}
  
  set_ea_exit:

  	kfree(full_path);

  	FreeXid(xid);
  #endif
  	return rc;
  }

  ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
  	void *ea_value, size_t buf_size)

  {
  	ssize_t rc = -EOPNOTSUPP;
  #ifdef CONFIG_CIFS_XATTR
  	int xid;
  	struct cifs_sb_info *cifs_sb;
  	struct cifsTconInfo *pTcon;

  	struct super_block *sb;
  	char *full_path;

  	if (direntry == NULL)

  		return -EIO;

  	if (direntry->d_inode == NULL)

  		return -EIO;
  	sb = direntry->d_inode->i_sb;

  	if (sb == NULL)

  		return -EIO;
  
  	xid = GetXid();
  
  	cifs_sb = CIFS_SB(sb);
  	pTcon = cifs_sb->tcon;

  	full_path = build_path_from_dentry(direntry);

  	if (full_path == NULL) {

  		rc = -ENOMEM;

  		FreeXid(xid);

  		return rc;

  	}
  	/* return dos attributes as pseudo xattr */
  	/* return alt name if available as pseudo attr */

  	if (ea_name == NULL) {

  		cFYI(1, "Null xattr names not supported");

  	} else if (strncmp(ea_name, CIFS_XATTR_USER_PREFIX, 5) == 0) {
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)

  			goto get_ea_exit;

  		if (strncmp(ea_name, CIFS_XATTR_DOS_ATTRIB, 14) == 0) {

  			cFYI(1, "attempt to query cifs inode metadata");

  			/* revalidate/getattr then populate from inode */
  		} /* BB add else when above is implemented */
  		ea_name += 5; /* skip past user. prefix */

  		rc = CIFSSMBQAllEAs(xid, pTcon, full_path, ea_name, ea_value,

  			buf_size, cifs_sb->local_nls,
  			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

  	} else if (strncmp(ea_name, CIFS_XATTR_OS2_PREFIX, 4) == 0) {
  		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)

  			goto get_ea_exit;
  
  		ea_name += 4; /* skip past os2. prefix */

  		rc = CIFSSMBQAllEAs(xid, pTcon, full_path, ea_name, ea_value,

  			buf_size, cifs_sb->local_nls,
  			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

  	} else if (strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,

  			  strlen(POSIX_ACL_XATTR_ACCESS)) == 0) {

  #ifdef CONFIG_CIFS_POSIX

  		if (sb->s_flags & MS_POSIXACL)

  			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,

  				ea_value, buf_size, ACL_TYPE_ACCESS,

  				cifs_sb->local_nls,

  				cifs_sb->mnt_cifs_flags &

  					CIFS_MOUNT_MAP_SPECIAL_CHR);

  #ifdef CONFIG_CIFS_EXPERIMENTAL

  		else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {

  			__u16 fid;

  			int oplock = 0;

  			struct cifs_ntsd *pacl = NULL;
  			__u32 buflen = 0;

  			if (experimEnabled)

  				rc = CIFSSMBOpen(xid, pTcon, full_path,
  					FILE_OPEN, GENERIC_READ, 0, &fid,
  					&oplock, NULL, cifs_sb->local_nls,
  					cifs_sb->mnt_cifs_flags &
  					CIFS_MOUNT_MAP_SPECIAL_CHR);
  			/* else rc is EOPNOTSUPP from above */

  			if (rc == 0) {

  				rc = CIFSSMBGetCIFSACL(xid, pTcon, fid, &pacl,
  						      &buflen);

  				CIFSSMBClose(xid, pTcon, fid);

  			}

  		}
  #endif /* EXPERIMENTAL */

  #else

  		cFYI(1, "query POSIX ACL not supported yet");

  #endif /* CONFIG_CIFS_POSIX */

  	} else if (strncmp(ea_name, POSIX_ACL_XATTR_DEFAULT,

  			  strlen(POSIX_ACL_XATTR_DEFAULT)) == 0) {

  #ifdef CONFIG_CIFS_POSIX

  		if (sb->s_flags & MS_POSIXACL)

  			rc = CIFSSMBGetPosixACL(xid, pTcon, full_path,

  				ea_value, buf_size, ACL_TYPE_DEFAULT,

  				cifs_sb->local_nls,

  				cifs_sb->mnt_cifs_flags &

  					CIFS_MOUNT_MAP_SPECIAL_CHR);

  #else

  		cFYI(1, "query POSIX default ACL not supported yet");

  #endif

  	} else if (strncmp(ea_name,
  		  CIFS_XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0) {

  		cFYI(1, "Trusted xattr namespace not supported yet");

  	} else if (strncmp(ea_name,
  		  CIFS_XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0) {

  		cFYI(1, "Security xattr namespace not supported yet");

  	} else

  		cFYI(1,

  		    "illegal xattr request %s (only user namespace supported)",
  		     ea_name);

  	/* We could add an additional check for streams ie

  	    if proc/fs/cifs/streamstoxattr is set then

  		search server for EAs or streams to

  		returns as xattrs */

  	if (rc == -EINVAL)
  		rc = -EOPNOTSUPP;

  
  get_ea_exit:

  	kfree(full_path);

  	FreeXid(xid);
  #endif
  	return rc;
  }

  ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)

  {
  	ssize_t rc = -EOPNOTSUPP;
  #ifdef CONFIG_CIFS_XATTR
  	int xid;
  	struct cifs_sb_info *cifs_sb;
  	struct cifsTconInfo *pTcon;

  	struct super_block *sb;
  	char *full_path;

  	if (direntry == NULL)

  		return -EIO;

  	if (direntry->d_inode == NULL)

  		return -EIO;
  	sb = direntry->d_inode->i_sb;

  	if (sb == NULL)

  		return -EIO;

  
  	cifs_sb = CIFS_SB(sb);
  	pTcon = cifs_sb->tcon;

  	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)

  		return -EOPNOTSUPP;
  
  	xid = GetXid();

  	full_path = build_path_from_dentry(direntry);

  	if (full_path == NULL) {

  		rc = -ENOMEM;

  		FreeXid(xid);

  		return rc;

  	}
  	/* return dos attributes as pseudo xattr */
  	/* return alt name if available as pseudo attr */
  
  	/* if proc/fs/cifs/streamstoxattr is set then

  		search server for EAs or streams to

  		returns as xattrs */

  	rc = CIFSSMBQAllEAs(xid, pTcon, full_path, NULL, data,
  				buf_size, cifs_sb->local_nls,

  				cifs_sb->mnt_cifs_flags &

  					CIFS_MOUNT_MAP_SPECIAL_CHR);

  	kfree(full_path);

  	FreeXid(xid);
  #endif
  	return rc;
  }