// SPDX-License-Identifier: LGPL-3.0-or-later
/*
 * vim:noexpandtab:shiftwidth=8:tabstop=8:
 *
 * 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    mnt_Mnt.c
 * brief   MOUNTPROC_MNT for Mount protocol v1 and v3.
 *
 * mnt_Null.c : MOUNTPROC_EXPORT in V1, V3.
 *
 */
#include "config.h"
#include "log.h"
#include "nfs_core.h"
#include "nfs_exports.h"
#include "fsal.h"
#include "nfs_file_handle.h"
#include "nfs_proto_functions.h"
#include "client_mgr.h"
#include "export_mgr.h"

/**
 * @brief The Mount proc mount function for MOUNT_V3 version
 *
 * The MOUNT proc function for MOUNT_V3 version
 *
 * @param[in]  arg     The export path to be mounted
 * @param[in]  req     ignored
 * @param[out] res     Result structure.
 *
 */

int mnt_Mnt(nfs_arg_t *arg, struct svc_req *req, nfs_res_t *res)
{
	struct gsh_export *export = NULL;
	int auth_flavor[NB_AUTH_FLAVOR];
	int index_auth = 0;
	int i = 0;
	int retval = NFS_REQ_OK;
	nfs_fh3 *fh3 = (nfs_fh3 *)&res->res_mnt3.mountres3_u.mountinfo.fhandle;
	struct fsal_obj_handle *obj = NULL;
	mountres3_ok *const RES_MOUNTINFO =
		&res->res_mnt3.mountres3_u.mountinfo;

	LogDebug(COMPONENT_NFSPROTO,
		 "REQUEST PROCESSING: Calling MNT_MNT path=%s", arg->arg_mnt);

	/* Paranoid command to clean the result struct. */
	memset(res, 0, sizeof(nfs_res_t));

	/* Quick escape if an unsupported MOUNT version */
	if (req->rq_msg.cb_vers != MOUNT_V3) {
		res->res_mnt1.status = NFSERR_ACCES;
		goto out;
	}

	if (arg->arg_mnt == NULL) {
		LogCrit(COMPONENT_NFSPROTO,
			"NULL path passed as Mount argument !!!");
		retval = NFS_REQ_DROP;
		goto out;
	}

	/* If the path ends with a '/', get rid of it */
	/** @todo: should it be a while()?? */
	if ((strlen(arg->arg_mnt) > 1) &&
	    (arg->arg_mnt[strlen(arg->arg_mnt) - 1] == '/'))
		arg->arg_mnt[strlen(arg->arg_mnt) - 1] = '\0';

	/*  Find the export for the dirname (using as well Path, Pseudo, or Tag)
	 */
	if (arg->arg_mnt[0] != '/') {
		LogFullDebug(COMPONENT_NFSPROTO,
			     "Searching for export by tag for %s",
			     arg->arg_mnt);
		export = get_gsh_export_by_tag(arg->arg_mnt);
	} else if (nfs_param.core_param.mount_path_pseudo) {
		LogFullDebug(COMPONENT_NFSPROTO,
			     "Searching for export by pseudo for %s",
			     arg->arg_mnt);
		export = get_gsh_export_by_pseudo(arg->arg_mnt, false);
	} else {
		LogFullDebug(COMPONENT_NFSPROTO,
			     "Searching for export by path for %s",
			     arg->arg_mnt);
		export = get_gsh_export_by_path(arg->arg_mnt, false);
	}

	if (export == NULL) {
		/* No export found, return ACCESS error. */
		LogEvent(COMPONENT_NFSPROTO,
			 "MOUNT: Export entry for %s not found", arg->arg_mnt);

		/* entry not found. */
		/* @todo : not MNT3ERR_NOENT => ok */
		res->res_mnt3.fhs_status = MNT3ERR_ACCES;
		goto out;
	}

	/* set the export in the context */
	set_op_context_export(export);

	/* Check access based on client. Don't bother checking TCP/UDP as some
	 * clients use UDP for MOUNT even when they will use TCP for NFS.
	 */
	export_check_access();

	if ((op_ctx->export_perms.options & EXPORT_OPTION_NFSV3) == 0) {
		LogInfoAlt(
			COMPONENT_NFSPROTO, COMPONENT_EXPORT,
			"MOUNT: Export entry %s does not support NFS v3 for client %s",
			ctx_export_path(op_ctx),
			op_ctx->client ? op_ctx->client->hostaddr_str
				       : "unknown client");
		res->res_mnt3.fhs_status = MNT3ERR_ACCES;
		goto out;
	}

	if ((op_ctx->export_perms.options & EXPORT_OPTION_ACCESS_MASK) == 0) {
		LogInfoAlt(
			COMPONENT_NFSPROTO, COMPONENT_EXPORT,
			"MOUNT: Export entry %s does not allow access for client %s",
			ctx_export_path(op_ctx),
			op_ctx->client ? op_ctx->client->hostaddr_str
				       : "unknown client");
		res->res_mnt3.fhs_status = MNT3ERR_ACCES;
		goto out;
	}

	/* retrieve the associated NFS handle */
	if (arg->arg_mnt[0] != '/') {
		/* We found the export by tag. Use the root entry of the
		 * export.
		 */
		if (FSAL_IS_ERROR(nfs_export_get_root_entry(export, &obj))) {
			res->res_mnt3.fhs_status = MNT3ERR_ACCES;
			goto out;
		}
	} else {
		/* Note that we call this even if arg_mnt is just the path to
		 * the export. It resolves that efficiently.
		 */
		if (FSAL_IS_ERROR(fsal_lookup_path(arg->arg_mnt, &obj))) {
			res->res_mnt3.fhs_status = MNT3ERR_ACCES;
			goto out;
		}
	}

	/* convert the fsal_handle to a file handle */
	/** @todo:
	 * The mountinfo.fhandle definition is an overlay on/of nfs_fh3.
	 * redefine and eliminate one or the other.
	 */
	if (!nfs3_FSALToFhandle(true, fh3, obj, export))
		res->res_mnt3.fhs_status = MNT3ERR_INVAL;
	else
		res->res_mnt3.fhs_status = MNT3_OK;

	/* Release the fsal_obj_handle created for the path */
	LogFullDebug(COMPONENT_FSAL, "Releasing %p", obj);
	obj->obj_ops->put_ref(obj);

	/* Return the supported authentication flavor in V3 based
	 * on the client's export permissions. These should be listed
	 * in a preferred order.
	 */
#ifdef _HAVE_GSSAPI
	if (nfs_param.krb5_param.active_krb5 == true) {
		if (op_ctx->export_perms.options &
		    EXPORT_OPTION_RPCSEC_GSS_PRIV)
			auth_flavor[index_auth++] = MNT_RPC_GSS_PRIVACY;
		if (op_ctx->export_perms.options &
		    EXPORT_OPTION_RPCSEC_GSS_INTG)
			auth_flavor[index_auth++] = MNT_RPC_GSS_INTEGRITY;
		if (op_ctx->export_perms.options &
		    EXPORT_OPTION_RPCSEC_GSS_NONE)
			auth_flavor[index_auth++] = MNT_RPC_GSS_NONE;
	}
#endif
	if (op_ctx->export_perms.options & EXPORT_OPTION_AUTH_UNIX)
		auth_flavor[index_auth++] = AUTH_UNIX;
	if (op_ctx->export_perms.options & EXPORT_OPTION_AUTH_NONE)
		auth_flavor[index_auth++] = AUTH_NONE;

	if (isDebug(COMPONENT_NFSPROTO)) {
		char str[LEN_FH_STR];
		struct display_buffer dspbuf = { sizeof(str), str, str };

		display_opaque_bytes(&dspbuf, fh3->data.data_val,
				     fh3->data.data_len);

		LogDebug(
			COMPONENT_NFSPROTO,
			"MOUNT: Entry supports %d different flavours handle=%s for client %s",
			index_auth, str,
			op_ctx->client ? op_ctx->client->hostaddr_str
				       : "unknown client");
	}

	RES_MOUNTINFO->auth_flavors.auth_flavors_val =
		gsh_calloc(index_auth, sizeof(int));

	RES_MOUNTINFO->auth_flavors.auth_flavors_len = index_auth;
	for (i = 0; i < index_auth; i++)
		RES_MOUNTINFO->auth_flavors.auth_flavors_val[i] =
			auth_flavor[i];

out:
	if (export != NULL)
		clear_op_context_export();

	return retval;

} /* mnt_Mnt */

/**
 * mnt_Mnt_Free: Frees the result structure allocated for mnt_Mnt.
 *
 * Frees the result structure allocated for mnt_Mnt.
 *
 * @param res        [INOUT]   Pointer to the result structure.
 *
 */

void mnt1_Mnt_Free(nfs_res_t *res)
{
	/* return */
}

void mnt3_Mnt_Free(nfs_res_t *res)
{
	mountres3_ok *resok = &res->res_mnt3.mountres3_u.mountinfo;

	if (res->res_mnt3.fhs_status == MNT3_OK) {
		gsh_free(resok->auth_flavors.auth_flavors_val);
		gsh_free(resok->fhandle.fhandle3_val);
	}
}
