/*
 * 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) 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/include/lustre_capa.h
 *
 * Author: Lai Siyao <lsy@clusterfs.com>
 */

#ifndef __LINUX_CAPA_H_
#define __LINUX_CAPA_H_

/** \defgroup capa capa
 *
 * @{
 */

/*
 * capability
 */
#include <linux/crypto.h>
#include "lustre/lustre_idl.h"

#define CAPA_TIMEOUT 1800               /* sec, == 30 min */
#define CAPA_KEY_TIMEOUT (24 * 60 * 60)  /* sec, == 1 days */

struct capa_hmac_alg {
        const char     *ha_name;
        int          ha_len;
        int          ha_keylen;
};

#define DEF_CAPA_HMAC_ALG(name, type, len, keylen)      \
[CAPA_HMAC_ALG_ ## type] = {                        \
        .ha_name         = name,                        \
        .ha_len   = len,                         \
        .ha_keylen       = keylen,                    \
}

struct client_capa {
        struct inode         *inode;
        struct list_head                lli_list;     /* link to lli_oss_capas */
};

struct target_capa {
        struct hlist_node         c_hash;       /* link to capa hash */
};

struct obd_capa {
        struct list_head                c_list;       /* link to capa_list */

        struct lustre_capa      c_capa;       /* capa */
        atomic_t              c_refc;       /* ref count */
        unsigned long           c_expiry;     /* jiffies */
        spinlock_t              c_lock; /* protect capa content */
        int                     c_site;

        union {
                struct client_capa      cli;
                struct target_capa      tgt;
        } u;
};

enum {
        CAPA_SITE_CLIENT = 0,
        CAPA_SITE_SERVER,
        CAPA_SITE_MAX
};

static inline struct lu_fid *capa_fid(struct lustre_capa *capa)
{
        return &capa->lc_fid;
}

static inline __u64 capa_opc(struct lustre_capa *capa)
{
        return capa->lc_opc;
}

static inline __u64 capa_uid(struct lustre_capa *capa)
{
        return capa->lc_uid;
}

static inline __u64 capa_gid(struct lustre_capa *capa)
{
        return capa->lc_gid;
}

static inline __u32 capa_flags(struct lustre_capa *capa)
{
        return capa->lc_flags & 0xffffff;
}

static inline __u32 capa_alg(struct lustre_capa *capa)
{
        return (capa->lc_flags >> 24);
}

static inline __u32 capa_keyid(struct lustre_capa *capa)
{
        return capa->lc_keyid;
}

static inline __u64 capa_key_seq(struct lustre_capa_key *key)
{
        return key->lk_seq;
}

static inline __u32 capa_key_keyid(struct lustre_capa_key *key)
{
        return key->lk_keyid;
}

static inline __u32 capa_timeout(struct lustre_capa *capa)
{
        return capa->lc_timeout;
}

static inline __u32 capa_expiry(struct lustre_capa *capa)
{
        return capa->lc_expiry;
}

void _debug_capa(struct lustre_capa *, struct libcfs_debug_msg_data *,
                 const char *fmt, ...);
#define DEBUG_CAPA(level, capa, fmt, args...)                             \
do {                                                                       \
        if (((level) & D_CANTMASK) != 0 ||                                   \
            ((libcfs_debug & (level)) != 0 &&                             \
             (libcfs_subsystem_debug & DEBUG_SUBSYSTEM) != 0)) {               \
                LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, level, NULL);             \
                _debug_capa((capa), &msgdata, fmt, ##args);                 \
        }                                                                     \
} while (0)

#define DEBUG_CAPA_KEY(level, k, fmt, args...)                           \
do {                                                                       \
CDEBUG(level, fmt " capability key@%p seq %llu keyid %u\n",              \
       ##args, k, capa_key_seq(k), capa_key_keyid(k));                   \
} while (0)

typedef int (* renew_capa_cb_t)(struct obd_capa *, struct lustre_capa *);

/* obdclass/capa.c */
extern struct list_head capa_list[];
extern spinlock_t capa_lock;
extern int capa_count[];
extern struct kmem_cache *capa_cachep;

struct hlist_head *init_capa_hash(void);
void cleanup_capa_hash(struct hlist_head *hash);

struct obd_capa *capa_add(struct hlist_head *hash,
                          struct lustre_capa *capa);
struct obd_capa *capa_lookup(struct hlist_head *hash,
                             struct lustre_capa *capa, int alive);

int capa_hmac(__u8 *hmac, struct lustre_capa *capa, __u8 *key);
int capa_encrypt_id(__u32 *d, __u32 *s, __u8 *key, int keylen);
int capa_decrypt_id(__u32 *d, __u32 *s, __u8 *key, int keylen);
void capa_cpy(void *dst, struct obd_capa *ocapa);
static inline struct obd_capa *alloc_capa(int site)
{
        struct obd_capa *ocapa;

        if (unlikely(site != CAPA_SITE_CLIENT && site != CAPA_SITE_SERVER))
                return ERR_PTR(-EINVAL);

        OBD_SLAB_ALLOC_PTR(ocapa, capa_cachep);
        if (unlikely(!ocapa))
                return ERR_PTR(-ENOMEM);

        INIT_LIST_HEAD(&ocapa->c_list);
        atomic_set(&ocapa->c_refc, 1);
        spin_lock_init(&ocapa->c_lock);
        ocapa->c_site = site;
        if (ocapa->c_site == CAPA_SITE_CLIENT)
                INIT_LIST_HEAD(&ocapa->u.cli.lli_list);
        else
                INIT_HLIST_NODE(&ocapa->u.tgt.c_hash);

        return ocapa;
}

static inline struct obd_capa *capa_get(struct obd_capa *ocapa)
{
        if (!ocapa)
                return NULL;

        atomic_inc(&ocapa->c_refc);
        return ocapa;
}

static inline void capa_put(struct obd_capa *ocapa)
{
        if (!ocapa)
                return;

        if (atomic_read(&ocapa->c_refc) == 0) {
                DEBUG_CAPA(D_ERROR, &ocapa->c_capa, "refc is 0 for");
                LBUG();
        }

        if (atomic_dec_and_test(&ocapa->c_refc)) {
                LASSERT(list_empty(&ocapa->c_list));
                if (ocapa->c_site == CAPA_SITE_CLIENT) {
                        LASSERT(list_empty(&ocapa->u.cli.lli_list));
                } else {
                        struct hlist_node *hnode;

                        hnode = &ocapa->u.tgt.c_hash;
                        LASSERT(!hnode->next && !hnode->pprev);
                }
                OBD_SLAB_FREE(ocapa, capa_cachep, sizeof(*ocapa));
        }
}

static inline int open_flags_to_accmode(int flags)
{
        int mode = flags;

        if ((mode + 1) & O_ACCMODE)
                mode++;
        if (mode & O_TRUNC)
                mode |= 2;

        return mode;
}

static inline __u64 capa_open_opc(int mode)
{
        return mode & FMODE_WRITE ? CAPA_OPC_OSS_WRITE : CAPA_OPC_OSS_READ;
}

static inline void set_capa_expiry(struct obd_capa *ocapa)
{
        unsigned long expiry = cfs_time_sub((unsigned long)ocapa->c_capa.lc_expiry,
                                         get_seconds());
        ocapa->c_expiry = cfs_time_add(cfs_time_current(),
                                       cfs_time_seconds(expiry));
}

static inline int capa_is_expired_sec(struct lustre_capa *capa)
{
        return (capa->lc_expiry - get_seconds() <= 0);
}

static inline int capa_is_expired(struct obd_capa *ocapa)
{
        return time_before_eq(ocapa->c_expiry, cfs_time_current());
}

static inline int capa_opc_supported(struct lustre_capa *capa, __u64 opc)
{
        return (capa_opc(capa) & opc) == opc;
}

struct filter_capa_key {
        struct list_head              k_list;
        struct lustre_capa_key  k_key;
};

enum {
        LC_ID_NONE      = 0,
        LC_ID_PLAIN     = 1,
        LC_ID_CONVERT   = 2
};

#define BYPASS_CAPA (struct lustre_capa *)ERR_PTR(-ENOENT)

/** @} capa */

#endif /* __LINUX_CAPA_H_ */