/*
 *
 * Copyright CEA/DAM/DIF  (2008)
 * contributeur : Philippe DENIEL   philippe.deniel@cea.fr
 *                Thomas LEIBOVICI  thomas.leibovici@cea.fr
 *
 *
 * This program 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 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
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * ---------------------------------------
 */

/**
 * @file nfs_filehandle_mgmt.c
 * @brief Some tools for managing the file handles
 *
 */

#include "config.h"
#include "log.h"
#include "nfs_core.h"
#include "nfs23.h"
#include "nfs4.h"
#include "fsal.h"
#include "nfs_exports.h"
#include "nfs_file_handle.h"
#include "nfs_proto_functions.h"
#include "nfs_proto_tools.h"
#include "nfs_convert.h"
#include "export_mgr.h"
#include "fsal_convert.h"

#ifdef _USE_NFS3
/**
 *
 *  nfs3_FhandleToCache: gets the FSAL obj from the NFSv3 file handle.
 *
 * Validates and Converts a V3 file handle and then gets the FSAL obj.
 *
 * @param fh3 [IN] pointer to the file handle to be converted
 * @param status [OUT] protocol status
 * @param rc [OUT] operation status
 *
 * @return FSAL obj or NULL on failure
 *
 */
struct fsal_obj_handle *nfs3_FhandleToCache(nfs_fh3 *fh3,
				   nfsstat3 *status,
				   int *rc)
{
	fsal_status_t fsal_status;
	file_handle_v3_t *v3_handle;
	struct fsal_export *export;
	struct fsal_obj_handle *obj = NULL;
	struct gsh_buffdesc fh_desc;
	char fhbuf[NFS3_FHSIZE];

	/* Default behaviour */
	*rc = NFS_REQ_OK;

	/* validate the filehandle  */
	*status = nfs3_Is_Fh_Invalid(fh3);

	if (*status != NFS3_OK)
		goto badhdl;

	/* Cast the fh as a non opaque structure */
	v3_handle = (file_handle_v3_t *) (fh3->data.data_val);

	assert(ntohs(v3_handle->exportid) == op_ctx->ctx_export->export_id);

	export = op_ctx->fsal_export;

	/*
	 * FIXME: the wire handle can obviously be no larger than NFS4_FHSIZE,
	 * but there is no such limit on a host handle. Here, we assume that as
	 * the size limit. Eventually it might be nice to call into the FSAL to
	 * ask how large a buffer it needs for a host handle.
	 */
	memcpy(fhbuf, &v3_handle->fsopaque, v3_handle->fs_len);
	fh_desc.len = v3_handle->fs_len;
	fh_desc.addr = fhbuf;

	/* adjust the wire handle opaque into a host-handle */
	fsal_status =
	    export->exp_ops.wire_to_host(export, FSAL_DIGEST_NFSV3,
					 &fh_desc,
					 v3_handle->fhflags1);

	if (!FSAL_IS_ERROR(fsal_status))
		fsal_status = export->exp_ops.create_handle(export, &fh_desc,
							    &obj, NULL);

	if (FSAL_IS_ERROR(fsal_status)) {
		*status = nfs3_Errno_status(fsal_status);
		if (nfs_RetryableError(fsal_status.major))
			*rc = NFS_REQ_DROP;
	}

 badhdl:
	return obj;
}
#endif /* _USE_NFS3 */

/**
 * @brief Converts an FSAL object to an NFSv4 file handle
 *
 * @param[out] fh4        The extracted file handle
 * @param[in]  fsalhandle The FSAL handle to be converted
 *
 * @return true if successful, false otherwise
 */
bool nfs4_FSALToFhandle(bool allocate,
			nfs_fh4 *fh4,
			const struct fsal_obj_handle *fsalhandle,
			struct gsh_export *exp)
{
	file_handle_v4_t *file_handle;
	struct gsh_buffdesc fh_desc;

	if (allocate) {
		/* Allocating the filehandle in memory */
		nfs4_AllocateFH(fh4);
	} else {
		/* reset the buffer to be used as handle */
		fh4->nfs_fh4_len = NFS4_FHSIZE;
		memset(fh4->nfs_fh4_val, 0, NFS4_FHSIZE);
	}

	file_handle = (file_handle_v4_t *) fh4->nfs_fh4_val;

	/* Fill in the fs opaque part */
	fh_desc.addr = &file_handle->fsopaque;
	fh_desc.len = fh4->nfs_fh4_len - offsetof(file_handle_v4_t, fsopaque);

	if (FSAL_IS_ERROR(fsalhandle->obj_ops->handle_to_wire(fsalhandle,
							    FSAL_DIGEST_NFSV4,
							    &fh_desc))) {
		LogDebug(COMPONENT_FILEHANDLE,
			 "handle_to_wire FSAL_DIGEST_NFSV4 failed");
		if (allocate)
			nfs4_freeFH(fh4);
		return false;
	}

	file_handle->fhversion = GANESHA_FH_VERSION;
#if (BYTE_ORDER == BIG_ENDIAN)
	file_handle->fhflags1 = FH_FSAL_BIG_ENDIAN;
#endif
	file_handle->fs_len = fh_desc.len;	/* set the actual size */
	/* keep track of the export id network byte order for nfs_fh4*/
	file_handle->id.exports = htons(exp->export_id);

	/* Set the len */
	fh4->nfs_fh4_len = nfs4_sizeof_handle(file_handle);

	LogFullDebugOpaque(COMPONENT_FILEHANDLE, "NFS4 Handle %s", LEN_FH_STR,
			   fh4->nfs_fh4_val, fh4->nfs_fh4_len);

	return true;
}

/**
 * @brief Converts an FSAL object to an NFSv3 file handle
 *
 * @param[out] fh3        The extracted file handle
 * @param[in]  fsalhandle The FSAL handle to be converted
 * @param[in]  exp        The gsh_export that this handle belongs to
 *
 * @return true if successful, false otherwise
 *
 * @todo Do we have to worry about buffer alignment and memcpy to
 * compensate??
 */
bool nfs3_FSALToFhandle(bool allocate,
			nfs_fh3 *fh3,
			const struct fsal_obj_handle *fsalhandle,
			struct gsh_export *exp)
{
	file_handle_v3_t *file_handle;
	struct gsh_buffdesc fh_desc;

	if (allocate) {
		/* Allocating the filehandle in memory */
		nfs3_AllocateFH(fh3);
	} else {
		/* reset the buffer to be used as handle */
		fh3->data.data_len = NFS3_FHSIZE;
		memset(fh3->data.data_val, 0, NFS3_FHSIZE);
	}

	file_handle = (file_handle_v3_t *) fh3->data.data_val;

	/* Fill in the fs opaque part */
	fh_desc.addr = &file_handle->fsopaque;
	fh_desc.len = NFS3_FHSIZE - offsetof(file_handle_v3_t, fsopaque);

	if (FSAL_IS_ERROR(fsalhandle->obj_ops->handle_to_wire(fsalhandle,
							    FSAL_DIGEST_NFSV3,
							    &fh_desc))) {
		LogDebug(COMPONENT_FILEHANDLE,
			 "handle_to_wire FSAL_DIGEST_NFSV3 failed");
		if (allocate)
			nfs3_freeFH(fh3);
		return false;
	}

	file_handle->fhversion = GANESHA_FH_VERSION;
#if (BYTE_ORDER == BIG_ENDIAN)
	file_handle->fhflags1 = FH_FSAL_BIG_ENDIAN;
#endif
	file_handle->fs_len = fh_desc.len;	/* set the actual size */
	/* keep track of the export id in network byte order*/
	file_handle->exportid = htons(exp->export_id);

	/* Set the len */
	/* re-adjust to as built */
	fh3->data.data_len = nfs3_sizeof_handle(file_handle);

	LogFullDebugOpaque(COMPONENT_FILEHANDLE, "NFS3 Handle %s", LEN_FH_STR,
			   fh3->data.data_val, fh3->data.data_len);

	/* Check VMware NFSv3 client's 56 byte file handle size restriction */
	if (nfs_param.core_param.short_file_handle && fh3->data.data_len > 56)
		LogWarnOnce(COMPONENT_FILEHANDLE,
			    "Short file handle option is enabled but file handle size computed is: %d",
			fh3->data.data_len);

	return true;
}

/**
 *
 * nfs4_Is_Fh_DSHandle
 *
 * This routine is used to test if a fh is a DS fh
 *
 * @param fh [IN] file handle to test.
 *
 * @return true if DS fh, false otherwise
 *
 */
int nfs4_Is_Fh_DSHandle(nfs_fh4 *fh)
{
	file_handle_v4_t *fhandle4;

	if (fh == NULL)
		return 0;

	fhandle4 = (file_handle_v4_t *) (fh->nfs_fh4_val);

	return (fhandle4->fhflags1 & FILE_HANDLE_V4_FLAG_DS) != 0;
}

/**
 * @brief Test if a filehandle is invalid
 *
 * @param[in] fh File handle to test.
 *
 * @return NFS4_OK if successfull.
 */

int nfs4_Is_Fh_Invalid(nfs_fh4 *fh)
{
	file_handle_v4_t *pfile_handle;

	if (fh == NULL) {
		LogMajor(COMPONENT_FILEHANDLE, "INVALID HANDLE: fh==NULL");
		return NFS4ERR_BADHANDLE;
	}

	LogFullDebugOpaque(COMPONENT_FILEHANDLE, "NFS4 Handle %s", LEN_FH_STR,
			   fh->nfs_fh4_val, fh->nfs_fh4_len);

	/* Cast the fh as a non opaque structure */
	pfile_handle = (file_handle_v4_t *) (fh->nfs_fh4_val);

	/* validate the filehandle  */
	if (pfile_handle == NULL || fh->nfs_fh4_len == 0
	    || pfile_handle->fhversion != GANESHA_FH_VERSION
	    || fh->nfs_fh4_len < offsetof(struct file_handle_v4, fsopaque)
	    || fh->nfs_fh4_len > NFS4_FHSIZE
	    || fh->nfs_fh4_len != nfs4_sizeof_handle(pfile_handle)) {
		if (isInfo(COMPONENT_FILEHANDLE)) {
			if (pfile_handle == NULL) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: nfs_fh4_val=NULL");
			} else if (fh->nfs_fh4_len == 0) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: zero length handle");
			} else if (pfile_handle->fhversion !=
				   GANESHA_FH_VERSION) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: not a Ganesha handle, fhversion=%d",
					pfile_handle->fhversion);
			} else if (fh->nfs_fh4_len <
				   offsetof(struct file_handle_v4, fsopaque)) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: data.data_len=%d is less than %d",
					fh->nfs_fh4_len,
					(int)offsetof(struct file_handle_v4,
						      fsopaque));
			} else if (fh->nfs_fh4_len >
				   NFS4_FHSIZE) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: data.data_len=%d is greater than %d",
					fh->nfs_fh4_len,
					(int)NFS4_FHSIZE);
			} else if (fh->nfs_fh4_len !=
				   nfs4_sizeof_handle(pfile_handle)) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: nfs_fh4_len=%d, should be %d",
					fh->nfs_fh4_len,
					(int)nfs4_sizeof_handle(pfile_handle));
			} else {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: is_pseudofs=%d",
					ntohs(pfile_handle->id.exports) == 0);
			}
		}

		return NFS4ERR_BADHANDLE;	/* Bad FH */
	}

	return NFS4_OK;
}				/* nfs4_Is_Fh_Invalid */

/**
 * @brief Test if a filehandle is invalid.
 *
 * @param[in] fh3 File handle to test.
 *
 * @return NFS4_OK if successfull.
 *
 */
int nfs3_Is_Fh_Invalid(nfs_fh3 *fh3)
{
	file_handle_v3_t *pfile_handle;

	if (fh3 == NULL) {
		LogMajor(COMPONENT_FILEHANDLE, "INVALID HANDLE: fh3==NULL");
		return NFS3ERR_BADHANDLE;
	}

	LogFullDebugOpaque(COMPONENT_FILEHANDLE, "NFS3 Handle %s", LEN_FH_STR,
			   fh3->data.data_val, fh3->data.data_len);

	/* Cast the fh as a non opaque structure */
	pfile_handle = (file_handle_v3_t *) (fh3->data.data_val);

	/* validate the filehandle  */
	if (pfile_handle == NULL || fh3->data.data_len == 0
	    || pfile_handle->fhversion != GANESHA_FH_VERSION
	    || fh3->data.data_len < offsetof(file_handle_v3_t, fsopaque)
	    || fh3->data.data_len > NFS3_FHSIZE
	    || fh3->data.data_len != nfs3_sizeof_handle(pfile_handle)) {
		if (isInfo(COMPONENT_FILEHANDLE)) {
			if (pfile_handle == NULL) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: data.data_val=NULL");
			} else if (fh3->data.data_len == 0) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: zero length handle");
			} else if (pfile_handle->fhversion !=
				   GANESHA_FH_VERSION) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: not a Ganesha handle, fhversion=%d",
					pfile_handle->fhversion);
			} else if (fh3->data.data_len <
				   sizeof(file_handle_v3_t)) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: data.data_len=%d is less than %d",
					fh3->data.data_len,
					(int)offsetof(file_handle_v3_t,
						      fsopaque));
			} else if (fh3->data.data_len >
				   NFS3_FHSIZE) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: data.data_len=%d is greater than %d",
					fh3->data.data_len,
					(int)NFS3_FHSIZE);
			} else if (fh3->data.data_len !=
				   nfs3_sizeof_handle(pfile_handle)) {
				LogInfo(COMPONENT_FILEHANDLE,
					"INVALID HANDLE: data.data_len=%d, should be %d",
					fh3->data.data_len,
					(int)nfs3_sizeof_handle(pfile_handle));
			}
		}

		return NFS3ERR_BADHANDLE;	/* Bad FH */
	}

	return NFS3_OK;
}				/* nfs3_Is_Fh_Invalid */

/**
 * @brief Do basic checks on the CurrentFH
 *
 * This function performs basic checks to make sure the supplied
 * filehandle is sane for a given operation.
 *
 * @param data          [IN] Compound_data_t for the operation to check
 * @param required_type [IN] The file type this operation requires.
 *                           Set to 0 to allow any type.
 * @param ds_allowed    [IN] true if DS handles are allowed.
 *
 * @return NFSv4.1 status codes
 */

nfsstat4 nfs4_sanity_check_FH(compound_data_t *data,
			      object_file_type_t required_type,
			      bool ds_allowed)
{
	int fh_status;

	/* If there is no FH */
	fh_status = nfs4_Is_Fh_Empty(&data->currentFH);

	if (fh_status != NFS4_OK)
		return fh_status;

	assert(data->current_obj != NULL &&
	       data->current_filetype != NO_FILE_TYPE);

	/* If the filehandle is invalid */
	fh_status = nfs4_Is_Fh_Invalid(&data->currentFH);

	if (fh_status != NFS4_OK)
		return fh_status;


	/* Check for the correct file type */
	if (required_type != NO_FILE_TYPE &&
	    data->current_filetype != required_type) {
		LogDebug(COMPONENT_NFS_V4,
			 "Wrong file type expected %s actual %s",
			 object_file_type_to_str(required_type),
			 object_file_type_to_str(data->current_filetype));

		if (required_type == DIRECTORY) {
			if (data->current_filetype == SYMBOLIC_LINK)
				return NFS4ERR_SYMLINK;
			else
				return NFS4ERR_NOTDIR;
		} else if (required_type == SYMBOLIC_LINK)
			return NFS4ERR_INVAL;

		switch (data->current_filetype) {
		case DIRECTORY:
			return NFS4ERR_ISDIR;
		default:
			return NFS4ERR_INVAL;
		}
	}

	if (nfs4_Is_Fh_DSHandle(&data->currentFH) && !ds_allowed) {
		LogDebug(COMPONENT_NFS_V4, "DS Handle");
		return NFS4ERR_INVAL;
	}

	return NFS4_OK;
}				/* nfs4_sanity_check_FH */

/**
 * @brief Do basic checks on the SavedFH
 *
 * This function performs basic checks to make sure the supplied
 * filehandle is sane for a given operation.
 *
 * @param data          [IN] Compound_data_t for the operation to check
 * @param required_type [IN] The file type this operation requires.
 *                           Set to 0 to allow any type. A negative value
 *                           indicates any type BUT that type is allowed.
 * @param ds_allowed    [IN] true if DS handles are allowed.
 *
 * @return NFSv4.1 status codes
 */

nfsstat4 nfs4_sanity_check_saved_FH(compound_data_t *data, int required_type,
				    bool ds_allowed)
{
	int fh_status;

	/* If there is no FH */
	fh_status = nfs4_Is_Fh_Empty(&data->savedFH);

	if (fh_status != NFS4_OK)
		return fh_status;

	/* If the filehandle is invalid */
	fh_status = nfs4_Is_Fh_Invalid(&data->savedFH);
	if (fh_status != NFS4_OK)
		return fh_status;

	if (nfs4_Is_Fh_DSHandle(&data->savedFH) && !ds_allowed) {
		LogDebug(COMPONENT_NFS_V4, "DS Handle");
		return NFS4ERR_INVAL;
	}

	/* Check for the correct file type */
	if (required_type < 0) {
		if (-required_type == data->saved_filetype) {
			LogDebug(COMPONENT_NFS_V4,
				 "Wrong file type expected not to be %s was %s",
				 object_file_type_to_str((object_file_type_t)
							 -required_type),
				 object_file_type_to_str(
						data->current_filetype));
			if (-required_type == DIRECTORY) {
				return NFS4ERR_ISDIR;
			}
		}
	} else if (required_type != NO_FILE_TYPE &&
		   data->saved_filetype != required_type) {
		LogDebug(COMPONENT_NFS_V4,
			 "Wrong file type expected %s was %s",
			 object_file_type_to_str((object_file_type_t)
						 required_type),
			 object_file_type_to_str(data->current_filetype));

		if (required_type == DIRECTORY) {
			if (data->current_filetype == SYMBOLIC_LINK)
				return NFS4ERR_SYMLINK;
			else
				return NFS4ERR_NOTDIR;
		} else if (required_type == SYMBOLIC_LINK)
			return NFS4ERR_INVAL;

		switch (data->saved_filetype) {
		case DIRECTORY:
			return NFS4ERR_ISDIR;
		default:
			return NFS4ERR_INVAL;
		}
	}

	return NFS4_OK;
}				/* nfs4_sanity_check_saved_FH */
