/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/ptlrpc/gss/gss_rawobj.c
 *
 * Author: Eric Mei <ericm@clusterfs.com>
 */

#define DEBUG_SUBSYSTEM S_SEC

#include <linux/mutex.h>

#include <obd.h>
#include <obd_class.h>
#include <obd_support.h>
#include <lustre_sec.h>

#include "gss_internal.h"

int rawobj_empty(rawobj_t *obj)
{
        LASSERT(equi(obj->len, obj->data));
        return (obj->len == 0);
}

int rawobj_alloc(rawobj_t *obj, char *buf, int len)
{
        LASSERT(obj);
        LASSERT(len >= 0);

        obj->len = len;
        if (len) {
                OBD_ALLOC_LARGE(obj->data, len);
                if (!obj->data) {
                        obj->len = 0;
                        RETURN(-ENOMEM);
                }
                memcpy(obj->data, buf, len);
        } else
                obj->data = NULL;
        return 0;
}

void rawobj_free(rawobj_t *obj)
{
        LASSERT(obj);

        if (obj->len) {
                LASSERT(obj->data);
                OBD_FREE_LARGE(obj->data, obj->len);
                obj->len = 0;
                obj->data = NULL;
        } else
                LASSERT(!obj->data);
}

int rawobj_equal(rawobj_t *a, rawobj_t *b)
{
        LASSERT(a && b);

        return (a->len == b->len &&
                (!a->len || !memcmp(a->data, b->data, a->len)));
}

int rawobj_dup(rawobj_t *dest, rawobj_t *src)
{
        LASSERT(src && dest);

        dest->len = src->len;
        if (dest->len) {
                OBD_ALLOC_LARGE(dest->data, dest->len);
                if (!dest->data) {
                        dest->len = 0;
                        return -ENOMEM;
                }
                memcpy(dest->data, src->data, dest->len);
        } else
                dest->data = NULL;
        return 0;
}

int rawobj_serialize(rawobj_t *obj, __u32 **buf, __u32 *buflen)
{
        __u32 len;

        LASSERT(obj);
        LASSERT(buf);
        LASSERT(buflen);

        len = cfs_size_round4(obj->len);

        if (*buflen < 4 + len) {
                CERROR("buflen %u <  %u\n", *buflen, 4 + len);
                return -EINVAL;
        }

        *(*buf)++ = cpu_to_le32(obj->len);
        memcpy(*buf, obj->data, obj->len);
        *buf += (len >> 2);
        *buflen -= (4 + len);

        return 0;
}

static int __rawobj_extract(rawobj_t *obj, __u32 **buf, __u32 *buflen,
                            int alloc, int local)
{
        __u32 len;

        if (*buflen < sizeof(__u32)) {
                CERROR("buflen %u\n", *buflen);
                return -EINVAL;
        }

        obj->len = *(*buf)++;
        if (!local)
                obj->len = le32_to_cpu(obj->len);
        *buflen -= sizeof(__u32);

        if (!obj->len) {
                obj->data = NULL;
                return 0;
        }

        len = local ? obj->len : cfs_size_round4(obj->len);
        if (*buflen < len) {
                CERROR("buflen %u < %u\n", *buflen, len);
                obj->len = 0;
                return -EINVAL;
        }

        if (!alloc)
                obj->data = (__u8 *) *buf;
        else {
                OBD_ALLOC_LARGE(obj->data, obj->len);
                if (!obj->data) {
                        CERROR("fail to alloc %u bytes\n", obj->len);
                        obj->len = 0;
                        return -ENOMEM;
                }
                memcpy(obj->data, *buf, obj->len);
        }

        *((char **)buf) += len;
        *buflen -= len;

        return 0;
}

int rawobj_extract(rawobj_t *obj, __u32 **buf, __u32 *buflen)
{
        return __rawobj_extract(obj, buf, buflen, 0, 0);
}

int rawobj_extract_alloc(rawobj_t *obj, __u32 **buf, __u32 *buflen)
{
        return __rawobj_extract(obj, buf, buflen, 1, 0);
}

int rawobj_extract_local(rawobj_t *obj, __u32 **buf, __u32 *buflen)
{
        return __rawobj_extract(obj, buf, buflen, 0, 1);
}

int rawobj_extract_local_alloc(rawobj_t *obj, __u32 **buf, __u32 *buflen)
{
        return __rawobj_extract(obj, buf, buflen, 1, 1);
}

int rawobj_from_netobj(rawobj_t *rawobj, netobj_t *netobj)
{
        rawobj->len = netobj->len;
        rawobj->data = netobj->data;
        return 0;
}

int rawobj_from_netobj_alloc(rawobj_t *rawobj, netobj_t *netobj)
{
        rawobj->len = 0;
        rawobj->data = NULL;

        if (netobj->len == 0)
                return 0;
                
        OBD_ALLOC_LARGE(rawobj->data, netobj->len);
        if (rawobj->data == NULL)
                return -ENOMEM;

        rawobj->len = netobj->len;
        memcpy(rawobj->data, netobj->data, netobj->len);
        return 0;
}

/****************************************
 * misc more                            *
 ****************************************/

int buffer_extract_bytes(const void **buf, __u32 *buflen,
                         void *res, __u32 reslen)
{
        if (*buflen < reslen) {
                CERROR("buflen %u < %u\n", *buflen, reslen);
                return -EINVAL;
        }

        memcpy(res, *buf, reslen);
        *buf += reslen;
        *buflen -= reslen;
        return 0;
}