path: root/xlators/encryption/crypt/src/crypt.h

/*
  Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  This file is licensed to you under your choice of the GNU Lesser
  General Public License, version 3 or any later version (LGPLv3 or
  later), or the GNU General Public License, version 2 (GPLv2), in all
  cases as published by the Free Software Foundation.
*/

#ifndef __CRYPT_H__
#define __CRYPT_H__

#include <openssl/aes.h>
#include <openssl/evp.h>
#include <openssl/sha.h>
#include <openssl/hmac.h>
#include <openssl/cmac.h>
#include <openssl/modes.h>
#include "crypt-mem-types.h"
#include "compat.h"

#define CRYPT_XLATOR_ID (0)

#define MAX_IOVEC_BITS (3)
#define MAX_IOVEC (1 << MAX_IOVEC_BITS)
#define KEY_FACTOR_BITS (6)

#define DEBUG_CRYPT (0)
#define TRIVIAL_TFM (0)

#define CRYPT_MIN_BLOCK_BITS (9)
#define CRYPT_MAX_BLOCK_BITS (12)

#define MASTER_VOL_KEY_SIZE (32)
#define NMTD_VOL_KEY_SIZE (16)

#if !defined(GF_LINUX_HOST_OS)
typedef off_t loff_t;
#endif

struct crypt_key {
    uint32_t len;
    const char *label;
};

/*
 * Add new key types to the end of this
 * enumeration but before LAST_KEY_TYPE
 */
typedef enum {
    MASTER_VOL_KEY,
    NMTD_VOL_KEY,
    NMTD_LINK_KEY,
    EMTD_FILE_KEY,
    DATA_FILE_KEY_256,
    DATA_FILE_KEY_512,
    LAST_KEY_TYPE
} crypt_key_type;

struct kderive_context {
    const unsigned char *pkey; /* parent key */
    uint32_t pkey_len;         /* parent key size, bits */
    uint32_t ckey_len;         /* child key size, bits */
    unsigned char *fid;        /* fixed input data, NIST 800-108, 5.1 */
    uint32_t fid_len;          /* fid len, bytes */
    unsigned char *out;        /* contains child keying material */
    uint32_t out_len;          /* out len, bytes */
};

typedef enum { DATA_ATOM, HOLE_ATOM, LAST_DATA_TYPE } atom_data_type;

typedef enum {
    HEAD_ATOM,
    TAIL_ATOM,
    FULL_ATOM,
    LAST_LOCALITY_TYPE
} atom_locality_type;

typedef enum {
    MTD_CREATE,
    MTD_APPEND,
    MTD_OVERWRITE,
    MTD_CUT,
    MTD_LAST_OP
} mtd_op_t;

struct xts128_context {
    void *key1, *key2;
    block128_f block1, block2;
};

struct object_cipher_info {
    cipher_alg_t o_alg;
    cipher_mode_t o_mode;
    uint32_t o_block_bits;
    uint32_t o_dkey_size; /* raw data key size in bits */
    union {
        struct {
            unsigned char ivec[16];
            AES_KEY dkey[2];
            AES_KEY tkey; /* key used for tweaking */
            XTS128_CONTEXT xts;
        } aes_xts;
    } u;
};

struct master_cipher_info {
    /*
     * attributes inherited by newly created regular files
     */
    cipher_alg_t m_alg;
    cipher_mode_t m_mode;
    uint32_t m_block_bits;
    uint32_t m_dkey_size; /* raw key size in bits */
    /*
     * master key
     */
    unsigned char m_key[MASTER_VOL_KEY_SIZE];
    /*
     * volume key for oid authentication
     */
    unsigned char m_nmtd_key[NMTD_VOL_KEY_SIZE];
};

/*
 * This info is not changed during file's life
 */
struct crypt_inode_info {
#if DEBUG_CRYPT
    loc_t *loc; /* pathname that the file has been
                   opened, or created with */
#endif
    uint16_t nr_minor;
    uuid_t oid;
    struct object_cipher_info cinfo;
};

/*
 * this should locate in secure memory
 */
typedef struct {
    struct master_cipher_info master;
} crypt_private_t;

static inline struct master_cipher_info *
get_master_cinfo(crypt_private_t *priv)
{
    return &priv->master;
}

static inline struct object_cipher_info *
get_object_cinfo(struct crypt_inode_info *info)
{
    return &info->cinfo;
}

/*
 * this describes layouts and properties
 * of atoms in an aligned vector
 */
struct avec_config {
    uint32_t atom_size;
    atom_data_type type;
    size_t orig_size;
    off_t orig_offset;
    size_t expanded_size;
    off_t aligned_offset;

    uint32_t off_in_head;
    uint32_t off_in_tail;
    uint32_t gap_in_tail;
    uint32_t nr_full_blocks;

    struct iovec *avec; /* aligned vector */
    uint32_t acount;    /* number of avec components. The same
                         * as number of occupied logical blocks */
    char **pool;
    uint32_t blocks_in_pool;
    uint32_t cursor; /* makes sense only for ordered writes,
                      * so there is no races on this counter.
                      *
                      * Cursor is per-config object, we don't
                      * reset cursor for atoms of different
                      * localities (head, tail, full)
                      */
};

typedef struct {
    glusterfs_fop_t fop; /* code of FOP this local info built for */
    fd_t *fd;
    inode_t *inode;
    loc_t *loc;
    int32_t mac_idx;
    loc_t *newloc;
    int32_t flags;
    int32_t wbflags;
    struct crypt_inode_info *info;
    struct iobref *iobref;
    struct iobref *iobref_data;
    off_t offset;

    uint64_t old_file_size; /* per FOP, retrieved under lock held */
    uint64_t cur_file_size; /* per iteration, before issuing IOs */
    uint64_t new_file_size; /* per iteration, after issuing IOs */

    uint64_t io_offset;        /* offset of IOs issued per iteration */
    uint64_t io_offset_nopad;  /* offset of user's data in the atom */
    uint32_t io_size;          /* size of IOs issued per iteration */
    uint32_t io_size_nopad;    /* size of user's data in the IOs */
    uint32_t eof_padding_size; /* size od EOF padding in the IOs */

    gf_lock_t call_lock; /* protect nr_calls from many cbks */
    int32_t nr_calls;

    atom_data_type active_setup; /* which setup (hole or date)
                                    is currently active */
    /* data setup */
    struct avec_config data_conf;

    /* hole setup */
    int hole_conv_in_proggress;
    gf_lock_t hole_lock; /* protect hole config from many cbks */
    int hole_handled;
    struct avec_config hole_conf;
    struct iatt buf;
    struct iatt prebuf;
    struct iatt postbuf;
    struct iatt *prenewparent;
    struct iatt *postnewparent;
    int32_t op_ret;
    int32_t op_errno;
    int32_t rw_count;        /* total read or written */
    gf_lock_t rw_count_lock; /* protect the counter above */
    unsigned char *format;   /* for create, update format string */
    uint32_t format_size;
    uint32_t msgflags; /* messages for crypt_open() */
    dict_t *xdata;
    dict_t *xattr;
    struct iovec vec; /* contains last file's atom for
                         read-prune-write sequence */
    gf_boolean_t custom_mtd;
    /*
     * the next 3 fields are used by readdir and friends
     */
    gf_dirent_t *de;        /* directory entry */
    char *de_path;          /* pathname of directory entry */
    uint32_t de_prefix_len; /* length of the parent's pathname */
    gf_dirent_t *entries;

    uint32_t update_disk_file_size : 1;
} crypt_local_t;

/* This represents a (read)modify-write atom */
struct rmw_atom {
    atom_locality_type locality;
    /*
     * read-modify-write sequence of the atom
     */
    int32_t (*rmw)(call_frame_t *frame, void *cookie, xlator_t *this,
                   int32_t op_ret, int32_t op_errno, struct iovec *vec,
                   int32_t count, struct iatt *stbuf, struct iobref *iobref,
                   dict_t *xdata);
    /*
     * offset of the logical block in a file
     */
    loff_t (*offset_at)(call_frame_t *frame, struct object_cipher_info *object);
    /*
     * IO offset in an atom
     */
    uint32_t (*offset_in)(call_frame_t *frame,
                          struct object_cipher_info *object);
    /*
     * number of bytes of plain text of this atom that user
     * wants to read/write.
     * It can be smaller than atom_size in the case of head
     * or tail atoms.
     */
    uint32_t (*io_size_nopad)(call_frame_t *frame,
                              struct object_cipher_info *object);
    /*
     * which iovec represents the atom
     */
    struct iovec *(*get_iovec)(call_frame_t *frame, uint32_t count);
    /*
     * how many bytes of partial block should be uptodated by
     * reading from disk.
     * This is used to perform a read component of RMW (read-modify-write).
     */
    uint32_t (*count_to_uptodate)(call_frame_t *frame,
                                  struct object_cipher_info *object);
    struct avec_config *(*get_config)(call_frame_t *frame);
};

struct data_cipher_alg {
    gf_boolean_t atomic;     /* true means that algorithm requires
                                to pad data before cipher transform */
    gf_boolean_t should_pad; /* true means that algorithm requires
                                to pad the end of file with extra-data */
    uint32_t blkbits;        /* blksize = 1 << blkbits */
    /*
     * any preliminary sanity checks goes here
     */
    int32_t (*init)(void);
    /*
     * set alg-mode specific inode info
     */
    int32_t (*set_private)(struct crypt_inode_info *info,
                           struct master_cipher_info *master);
    /*
     * check alg-mode specific data key
     */
    int32_t (*check_key)(uint32_t key_size);
    void (*set_iv)(off_t offset, struct object_cipher_info *object);
    int32_t (*encrypt)(const unsigned char *from, unsigned char *to,
                       size_t length, off_t offset, const int enc,
                       struct object_cipher_info *object);
};

/*
 * version-dependent metadata loader
 */
struct crypt_mtd_loader {
    /*
     * return core format size
     */
    size_t (*format_size)(mtd_op_t op, size_t old_size);
    /*
     * pack version-specific metadata of an object
     * at ->create()
     */
    int32_t (*create_format)(unsigned char *wire, loc_t *loc,
                             struct crypt_inode_info *info,
                             struct master_cipher_info *master);
    /*
     * extract version-specific metadata of an object
     * at ->open() time
     */
    int32_t (*open_format)(unsigned char *wire, int32_t len, loc_t *loc,
                           struct crypt_inode_info *info,
                           struct master_cipher_info *master,
                           crypt_local_t *local, gf_boolean_t load_info);
    int32_t (*update_format)(unsigned char *new, unsigned char *old,
                             size_t old_len, int32_t mac_idx, mtd_op_t op,
                             loc_t *loc, struct crypt_inode_info *info,
                             struct master_cipher_info *master,
                             crypt_local_t *local);
};

typedef int32_t (*end_writeback_handler_t)(call_frame_t *frame, void *cookie,
                                           xlator_t *this, int32_t op_ret,
                                           int32_t op_errno,
                                           struct iatt *prebuf,
                                           struct iatt *postbuf, dict_t *xdata);
typedef void (*linkop_wind_handler_t)(call_frame_t *frame, xlator_t *this);
typedef void (*linkop_unwind_handler_t)(call_frame_t *frame);

/* Declarations */

/* keys.c */
extern struct crypt_key crypt_keys[LAST_KEY_TYPE];
int32_t
get_nmtd_vol_key(struct master_cipher_info *master);
int32_t
get_nmtd_link_key(loc_t *loc, struct master_cipher_info *master,
                  unsigned char *result);
int32_t
get_emtd_file_key(struct crypt_inode_info *info,
                  struct master_cipher_info *master, unsigned char *result);
int32_t
get_data_file_key(struct crypt_inode_info *info,
                  struct master_cipher_info *master, uint32_t keysize,
                  unsigned char *key);
/* data.c */
extern struct data_cipher_alg data_cipher_algs[LAST_CIPHER_ALG]
                                              [LAST_CIPHER_MODE];
void
encrypt_aligned_iov(struct object_cipher_info *object, struct iovec *vec,
                    int count, off_t off);
void
decrypt_aligned_iov(struct object_cipher_info *object, struct iovec *vec,
                    int count, off_t off);
int32_t
align_iov_by_atoms(xlator_t *this, crypt_local_t *local,
                   struct object_cipher_info *object,
                   struct iovec *vec /* input vector */,
                   int32_t count /* number of vec components */,
                   struct iovec *avec /* aligned vector */,
                   char **blocks /* pool of blocks */,
                   uint32_t *blocks_allocated, struct avec_config *conf);
int32_t
set_config_avec_data(xlator_t *this, crypt_local_t *local,
                     struct avec_config *conf,
                     struct object_cipher_info *object, struct iovec *vec,
                     int32_t vec_count);
int32_t
set_config_avec_hole(xlator_t *this, crypt_local_t *local,
                     struct avec_config *conf,
                     struct object_cipher_info *object, glusterfs_fop_t fop);
void
set_gap_at_end(call_frame_t *frame, struct object_cipher_info *object,
               struct avec_config *conf, atom_data_type dtype);
void
set_config_offsets(call_frame_t *frame, xlator_t *this, uint64_t offset,
                   uint64_t count, atom_data_type dtype,
                   int32_t setup_gap_in_tail);

/* metadata.c */
extern struct crypt_mtd_loader mtd_loaders[LAST_MTD_LOADER];

int32_t
alloc_format(crypt_local_t *local, size_t size);
int32_t
alloc_format_create(crypt_local_t *local);
void
free_format(crypt_local_t *local);
size_t
format_size(mtd_op_t op, size_t old_size);
size_t
new_format_size(void);
int32_t
open_format(unsigned char *str, int32_t len, loc_t *loc,
            struct crypt_inode_info *info, struct master_cipher_info *master,
            crypt_local_t *local, gf_boolean_t load_info);
int32_t
update_format(unsigned char *new, unsigned char *old, size_t old_len,
              int32_t mac_idx, mtd_op_t op, loc_t *loc,
              struct crypt_inode_info *info, struct master_cipher_info *master,
              crypt_local_t *local);
int32_t
create_format(unsigned char *wire, loc_t *loc, struct crypt_inode_info *info,
              struct master_cipher_info *master);

/* atom.c */
struct rmw_atom *
atom_by_types(atom_data_type data, atom_locality_type locality);
void
submit_partial(call_frame_t *frame, xlator_t *this, fd_t *fd,
               atom_locality_type ltype);
void
submit_full(call_frame_t *frame, xlator_t *this);

/* crypt.c */

end_writeback_handler_t
dispatch_end_writeback(glusterfs_fop_t fop);
void
set_local_io_params_writev(call_frame_t *frame,
                           struct object_cipher_info *object,
                           struct rmw_atom *atom, off_t io_offset,
                           uint32_t io_size);
void
link_wind(call_frame_t *frame, xlator_t *this);
void
unlink_wind(call_frame_t *frame, xlator_t *this);
void
link_unwind(call_frame_t *frame);
void
unlink_unwind(call_frame_t *frame);
void
rename_wind(call_frame_t *frame, xlator_t *this);
void
rename_unwind(call_frame_t *frame);

/* Inline functions */

static inline int32_t
crypt_xlator_id(void)
{
    return CRYPT_XLATOR_ID;
}

static inline mtd_loader_id
current_mtd_loader(void)
{
    return MTD_LOADER_V1;
}

static inline uint32_t
master_key_size(void)
{
    return crypt_keys[MASTER_VOL_KEY].len >> 3;
}

static inline uint32_t
nmtd_vol_key_size(void)
{
    return crypt_keys[NMTD_VOL_KEY].len >> 3;
}

static inline uint32_t
alg_mode_blkbits(cipher_alg_t alg, cipher_mode_t mode)
{
    return data_cipher_algs[alg][mode].blkbits;
}

static inline uint32_t
alg_mode_blksize(cipher_alg_t alg, cipher_mode_t mode)
{
    return 1 << alg_mode_blkbits(alg, mode);
}

static inline gf_boolean_t
alg_mode_atomic(cipher_alg_t alg, cipher_mode_t mode)
{
    return data_cipher_algs[alg][mode].atomic;
}

static inline gf_boolean_t
alg_mode_should_pad(cipher_alg_t alg, cipher_mode_t mode)
{
    return data_cipher_algs[alg][mode].should_pad;
}

static inline uint32_t
master_alg_blksize(struct master_cipher_info *mr)
{
    return alg_mode_blksize(mr->m_alg, mr->m_mode);
}

static inline uint32_t
master_alg_blkbits(struct master_cipher_info *mr)
{
    return alg_mode_blkbits(mr->m_alg, mr->m_mode);
}

static inline gf_boolean_t
master_alg_atomic(struct master_cipher_info *mr)
{
    return alg_mode_atomic(mr->m_alg, mr->m_mode);
}

static inline gf_boolean_t
master_alg_should_pad(struct master_cipher_info *mr)
{
    return alg_mode_should_pad(mr->m_alg, mr->m_mode);
}

static inline uint32_t
object_alg_blksize(struct object_cipher_info *ob)
{
    return alg_mode_blksize(ob->o_alg, ob->o_mode);
}

static inline uint32_t
object_alg_blkbits(struct object_cipher_info *ob)
{
    return alg_mode_blkbits(ob->o_alg, ob->o_mode);
}

static inline gf_boolean_t
object_alg_atomic(struct object_cipher_info *ob)
{
    return alg_mode_atomic(ob->o_alg, ob->o_mode);
}

static inline gf_boolean_t
object_alg_should_pad(struct object_cipher_info *ob)
{
    return alg_mode_should_pad(ob->o_alg, ob->o_mode);
}

static inline uint32_t
aes_raw_key_size(struct master_cipher_info *master)
{
    return master->m_dkey_size >> 3;
}

static inline struct avec_config *
get_hole_conf(call_frame_t *frame)
{
    return &(((crypt_local_t *)frame->local)->hole_conf);
}

static inline struct avec_config *
get_data_conf(call_frame_t *frame)
{
    return &(((crypt_local_t *)frame->local)->data_conf);
}

static inline int32_t
get_atom_bits(struct object_cipher_info *object)
{
    return object->o_block_bits;
}

static inline int32_t
get_atom_size(struct object_cipher_info *object)
{
    return 1 << get_atom_bits(object);
}

static inline int32_t
has_head_block(struct avec_config *conf)
{
    return conf->off_in_head || (conf->acount == 1 && conf->off_in_tail);
}

static inline int32_t
has_tail_block(struct avec_config *conf)
{
    return conf->off_in_tail && conf->acount > 1;
}

static inline int32_t
has_full_blocks(struct avec_config *conf)
{
    return conf->nr_full_blocks;
}

static inline int32_t
should_submit_head_block(struct avec_config *conf)
{
    return has_head_block(conf) && (conf->cursor == 0);
}

static inline int32_t
should_submit_tail_block(struct avec_config *conf)
{
    return has_tail_block(conf) && (conf->cursor == conf->acount - 1);
}

static inline int32_t
should_submit_full_block(struct avec_config *conf)
{
    uint32_t start = has_head_block(conf) ? 1 : 0;

    return has_full_blocks(conf) && conf->cursor >= start &&
           conf->cursor < start + conf->nr_full_blocks;
}

#if DEBUG_CRYPT
static inline void
crypt_check_input_len(size_t len, struct object_cipher_info *object)
{
    if (object_alg_should_pad(object) &&
        (len & (object_alg_blksize(object) - 1)))
        gf_log("crypt", GF_LOG_DEBUG, "bad input len: %d", (int)len);
}

static inline void
check_head_block(struct avec_config *conf)
{
    if (!has_head_block(conf))
        gf_log("crypt", GF_LOG_DEBUG, "not a head atom");
}

static inline void
check_tail_block(struct avec_config *conf)
{
    if (!has_tail_block(conf))
        gf_log("crypt", GF_LOG_DEBUG, "not a tail atom");
}

static inline void
check_full_block(struct avec_config *conf)
{
    if (!has_full_blocks(conf))
        gf_log("crypt", GF_LOG_DEBUG, "not a full atom");
}

static inline void
check_cursor_head(struct avec_config *conf)
{
    if (!has_head_block(conf))
        gf_log("crypt", GF_LOG_DEBUG, "Illegal call of head atom method");
    else if (conf->cursor != 0)
        gf_log("crypt", GF_LOG_DEBUG, "Cursor (%d) is not at head atom",
               conf->cursor);
}

static inline void
check_cursor_full(struct avec_config *conf)
{
    if (!has_full_blocks(conf))
        gf_log("crypt", GF_LOG_DEBUG, "Illegal call of full atom method");
    if (has_head_block(conf) && (conf->cursor == 0))
        gf_log("crypt", GF_LOG_DEBUG, "Cursor is not at full atom");
}

/*
 * FIXME: use avec->iov_len to check setup
 */
static inline int
data_local_invariant(crypt_local_t *local)
{
    return 0;
}

#else
#define crypt_check_input_len(len, object) noop
#define check_head_block(conf) noop
#define check_tail_block(conf) noop
#define check_full_block(conf) noop
#define check_cursor_head(conf) noop
#define check_cursor_full(conf) noop

#endif /* DEBUG_CRYPT */

static inline struct avec_config *
conf_by_type(call_frame_t *frame, atom_data_type dtype)
{
    struct avec_config *conf = NULL;

    switch (dtype) {
        case HOLE_ATOM:
            conf = get_hole_conf(frame);
            break;
        case DATA_ATOM:
            conf = get_data_conf(frame);
            break;
        default:
            gf_log("crypt", GF_LOG_DEBUG, "bad atom type");
    }
    return conf;
}

static inline uint32_t
nr_calls_head(struct avec_config *conf)
{
    return has_head_block(conf) ? 1 : 0;
}

static inline uint32_t
nr_calls_tail(struct avec_config *conf)
{
    return has_tail_block(conf) ? 1 : 0;
}

static inline uint32_t
nr_calls_full(struct avec_config *conf)
{
    switch (conf->type) {
        case HOLE_ATOM:
            return has_full_blocks(conf);
        case DATA_ATOM:
            return has_full_blocks(conf)
                       ? logical_blocks_occupied(0, conf->nr_full_blocks,
                                                 MAX_IOVEC_BITS)
                       : 0;
        default:
            gf_log("crypt", GF_LOG_DEBUG, "bad atom data type");
            return 0;
    }
}

static inline uint32_t
nr_calls(struct avec_config *conf)
{
    return nr_calls_head(conf) + nr_calls_tail(conf) + nr_calls_full(conf);
}

static inline uint32_t
nr_calls_data(call_frame_t *frame)
{
    return nr_calls(get_data_conf(frame));
}

static inline uint32_t
nr_calls_hole(call_frame_t *frame)
{
    return nr_calls(get_hole_conf(frame));
}

static inline void
get_one_call_nolock(call_frame_t *frame)
{
    crypt_local_t *local = frame->local;

    ++local->nr_calls;

    // gf_log("crypt", GF_LOG_DEBUG, "get %d calls", 1);
}

static inline void
get_one_call(call_frame_t *frame)
{
    crypt_local_t *local = frame->local;

    LOCK(&local->call_lock);
    get_one_call_nolock(frame);
    UNLOCK(&local->call_lock);
}

static inline void
get_nr_calls_nolock(call_frame_t *frame, int32_t nr)
{
    crypt_local_t *local = frame->local;

    local->nr_calls += nr;

    // gf_log("crypt", GF_LOG_DEBUG, "get %d calls", nr);
}

static inline void
get_nr_calls(call_frame_t *frame, int32_t nr)
{
    crypt_local_t *local = frame->local;

    LOCK(&local->call_lock);
    get_nr_calls_nolock(frame, nr);
    UNLOCK(&local->call_lock);
}

static inline int
put_one_call(crypt_local_t *local)
{
    uint32_t last = 0;

    LOCK(&local->call_lock);
    if (--local->nr_calls == 0)
        last = 1;

    // gf_log("crypt", GF_LOG_DEBUG, "put %d calls", 1);

    UNLOCK(&local->call_lock);
    return last;
}

static inline int
is_appended_write(call_frame_t *frame)
{
    crypt_local_t *local = frame->local;
    struct avec_config *conf = get_data_conf(frame);

    return conf->orig_offset + conf->orig_size > local->old_file_size;
}

static inline int
is_ordered_mode(call_frame_t *frame)
{
#if 0
	crypt_local_t *local = frame->local;
	return local->fop == GF_FOP_FTRUNCATE ||
		(local->fop == GF_FOP_WRITE && is_appended_write(frame));
#endif
    return 1;
}

static inline int32_t
hole_conv_completed(crypt_local_t *local)
{
    struct avec_config *conf = &local->hole_conf;
    return conf->cursor == conf->acount;
}

static inline int32_t
data_write_in_progress(crypt_local_t *local)
{
    return local->active_setup == DATA_ATOM;
}

static inline int32_t
parent_is_crypt_xlator(call_frame_t *frame, xlator_t *this)
{
    return frame->parent->this == this;
}

static inline linkop_wind_handler_t
linkop_wind_dispatch(glusterfs_fop_t fop)
{
    switch (fop) {
        case GF_FOP_LINK:
            return link_wind;
        case GF_FOP_UNLINK:
            return unlink_wind;
        case GF_FOP_RENAME:
            return rename_wind;
        default:
            gf_log("crypt", GF_LOG_ERROR, "Bad link operation %d", fop);
            return NULL;
    }
}

static inline linkop_unwind_handler_t
linkop_unwind_dispatch(glusterfs_fop_t fop)
{
    switch (fop) {
        case GF_FOP_LINK:
            return link_unwind;
        case GF_FOP_UNLINK:
            return unlink_unwind;
        case GF_FOP_RENAME:
            return rename_unwind;
        default:
            gf_log("crypt", GF_LOG_ERROR, "Bad link operation %d", fop);
            return NULL;
    }
}

static inline mtd_op_t
linkop_mtdop_dispatch(glusterfs_fop_t fop)
{
    switch (fop) {
        case GF_FOP_LINK:
            return MTD_APPEND;
        case GF_FOP_UNLINK:
            return MTD_CUT;
        case GF_FOP_RENAME:
            return MTD_OVERWRITE;
        default:
            gf_log("crypt", GF_LOG_WARNING, "Bad link operation %d", fop);
            return MTD_LAST_OP;
    }
}

#define CRYPT_STACK_UNWIND(fop, frame, params...)                              \
    do {                                                                       \
        crypt_local_t *__local = NULL;                                         \
        if (frame) {                                                           \
            __local = frame->local;                                            \
            frame->local = NULL;                                               \
        }                                                                      \
        STACK_UNWIND_STRICT(fop, frame, params);                               \
        if (__local) {                                                         \
            GF_FREE(__local);                                                  \
        }                                                                      \
    } while (0)

#endif /* __CRYPT_H__ */

/*
  Local variables:
  c-indentation-style: "K&R"
  mode-name: "LC"
  c-basic-offset: 8
  tab-width: 8
  fill-column: 80
  scroll-step: 1
  End:
*/