/*
 * Convert ZFS/NFSv4 acls to NT acls and vice versa.
 *
 * Copyright (C) Jiri Sasek, 2007
 * based on the foobar.c module which is copyrighted by Volker Lendecke
 *
 * Many thanks to Axel Apitz for help to fix the special ace's handling
 * issues.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "includes.h"
#include "nfs4_acls.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS

#define ZFSACL_MODULE_NAME "zfsacl"

/* zfs_get_nt_acl()
 * read the local file's acls and return it in NT form
 * using the NFSv4 format conversion
 */
static NTSTATUS zfs_get_nt_acl_common(const char *name,
				      uint32 security_info,
				      SMB4ACL_T **ppacl)
{
	int naces, i;
	ace_t *acebuf;
	SMB4ACL_T *pacl;
	TALLOC_CTX	*mem_ctx;

	/* read the number of file aces */
	if((naces = acl(name, ACE_GETACLCNT, 0, NULL)) == -1) {
		if(errno == ENOSYS) {
			DEBUG(9, ("acl(ACE_GETACLCNT, %s): Operation is not "
				  "supported on the filesystem where the file "
				  "reside", name));
		} else {
			DEBUG(9, ("acl(ACE_GETACLCNT, %s): %s ", name,
					strerror(errno)));
		}
		return map_nt_error_from_unix(errno);
	}
	/* allocate the field of ZFS aces */
	mem_ctx = talloc_tos();
	acebuf = (ace_t *) talloc_size(mem_ctx, sizeof(ace_t)*naces);
	if(acebuf == NULL) {
		return NT_STATUS_NO_MEMORY;
	}
	/* read the aces into the field */
	if(acl(name, ACE_GETACL, naces, acebuf) < 0) {
		DEBUG(9, ("acl(ACE_GETACL, %s): %s ", name,
				strerror(errno)));
		return map_nt_error_from_unix(errno);
	}
	/* create SMB4ACL data */
	if((pacl = smb_create_smb4acl()) == NULL) {
		return NT_STATUS_NO_MEMORY;
	}
	for(i=0; i<naces; i++) {
		SMB_ACE4PROP_T aceprop;

		aceprop.aceType  = (uint32) acebuf[i].a_type;
		aceprop.aceFlags = (uint32) acebuf[i].a_flags;
		aceprop.aceMask  = (uint32) acebuf[i].a_access_mask;
		aceprop.who.id   = (uint32) acebuf[i].a_who;

		if(aceprop.aceFlags & ACE_OWNER) {
			aceprop.flags = SMB_ACE4_ID_SPECIAL;
			aceprop.who.special_id = SMB_ACE4_WHO_OWNER;
		} else if(aceprop.aceFlags & ACE_GROUP) {
			aceprop.flags = SMB_ACE4_ID_SPECIAL;
			aceprop.who.special_id = SMB_ACE4_WHO_GROUP;
		} else if(aceprop.aceFlags & ACE_EVERYONE) {
			aceprop.flags = SMB_ACE4_ID_SPECIAL;
			aceprop.who.special_id = SMB_ACE4_WHO_EVERYONE;
		} else {
			aceprop.flags	= 0;
		}
		if(smb_add_ace4(pacl, &aceprop) == NULL)
			return NT_STATUS_NO_MEMORY;
	}

	*ppacl = pacl;
	return NT_STATUS_OK;
}

/* call-back function processing the NT acl -> ZFS acl using NFSv4 conv. */
static bool zfs_process_smbacl(files_struct *fsp, SMB4ACL_T *smbacl)
{
	int naces = smb_get_naces(smbacl), i;
	ace_t *acebuf;
	SMB4ACE_T *smbace;
	TALLOC_CTX	*mem_ctx;

	/* allocate the field of ZFS aces */
	mem_ctx = talloc_tos();
	acebuf = (ace_t *) talloc_size(mem_ctx, sizeof(ace_t)*naces);
	if(acebuf == NULL) {
		errno = ENOMEM;
		return False;
	}
	/* handle all aces */
	for(smbace = smb_first_ace4(smbacl), i = 0;
			smbace!=NULL;
			smbace = smb_next_ace4(smbace), i++) {
		SMB_ACE4PROP_T *aceprop = smb_get_ace4(smbace);

		acebuf[i].a_type        = aceprop->aceType;
		acebuf[i].a_flags       = aceprop->aceFlags;
		acebuf[i].a_access_mask = aceprop->aceMask;
		acebuf[i].a_who         = aceprop->who.id;
		if(aceprop->flags & SMB_ACE4_ID_SPECIAL) {
			switch(aceprop->who.special_id) {
			case SMB_ACE4_WHO_EVERYONE:
				acebuf[i].a_flags |= ACE_EVERYONE;
				break;
			case SMB_ACE4_WHO_OWNER:
				acebuf[i].a_flags |= ACE_OWNER;
				break;
			case SMB_ACE4_WHO_GROUP:
				acebuf[i].a_flags |= ACE_GROUP;
				break;
			default:
				DEBUG(8, ("unsupported special_id %d\n", \
					aceprop->who.special_id));
				continue; /* don't add it !!! */
			}
		}
	}
	SMB_ASSERT(i == naces);

	/* store acl */
	if(acl(fsp->fsp_name, ACE_SETACL, naces, acebuf)) {
		if(errno == ENOSYS) {
			DEBUG(9, ("acl(ACE_SETACL, %s): Operation is not "
				  "supported on the filesystem where the file "
				  "reside", fsp->fsp_name));
		} else {
			DEBUG(9, ("acl(ACE_SETACL, %s): %s ", fsp->fsp_name,
					strerror(errno)));
		}
		return 0;
	}

	return True;
}

/* zfs_set_nt_acl()
 * set the local file's acls obtaining it in NT form
 * using the NFSv4 format conversion
 */
static NTSTATUS zfs_set_nt_acl(vfs_handle_struct *handle, files_struct *fsp,
			   uint32 security_info_sent,
			   struct security_descriptor *psd)
{
	return smb_set_nt_acl_nfs4(fsp, security_info_sent, psd,
			zfs_process_smbacl);
}

static NTSTATUS zfsacl_fget_nt_acl(struct vfs_handle_struct *handle,
				 struct files_struct *fsp,
				 uint32 security_info,
				 struct security_descriptor **ppdesc)
{
	SMB4ACL_T *pacl;
	NTSTATUS status;

	status = zfs_get_nt_acl_common(fsp->fsp_name, security_info, &pacl);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	return smb_fget_nt_acl_nfs4(fsp, security_info, ppdesc, pacl);
}

static NTSTATUS zfsacl_get_nt_acl(struct vfs_handle_struct *handle,
				const char *name,  uint32 security_info,
				struct security_descriptor **ppdesc)
{
	SMB4ACL_T *pacl;
	NTSTATUS status;

	status = zfs_get_nt_acl_common(name, security_info, &pacl);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	return smb_get_nt_acl_nfs4(handle->conn, name, security_info, ppdesc,
				   pacl);
}

static NTSTATUS zfsacl_fset_nt_acl(vfs_handle_struct *handle,
			 files_struct *fsp,
			 uint32 security_info_sent,
			 SEC_DESC *psd)
{
	return zfs_set_nt_acl(handle, fsp, security_info_sent, psd);
}

/* VFS operations structure */

static vfs_op_tuple zfsacl_ops[] = {
	{SMB_VFS_OP(zfsacl_fget_nt_acl), SMB_VFS_OP_FGET_NT_ACL,
	 SMB_VFS_LAYER_OPAQUE},
	{SMB_VFS_OP(zfsacl_get_nt_acl), SMB_VFS_OP_GET_NT_ACL,
	 SMB_VFS_LAYER_OPAQUE},
	{SMB_VFS_OP(zfsacl_fset_nt_acl), SMB_VFS_OP_FSET_NT_ACL,
	 SMB_VFS_LAYER_OPAQUE},
	{SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
};

/* != 0 if this module will be compiled as static */

#define STATIC 0

#if STATIC
NTSTATUS vfs_zfsacl_init(void);
#else
NTSTATUS init_module(void);
#endif

NTSTATUS
#if STATIC
	vfs_zfsacl_init
#else
	init_module
#endif
		(void)
{
	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "zfsacl",
				zfsacl_ops);
}