/*
 * Copyright (c) 1997 - 2006 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "hdb_locl.h"

#if HAVE_DB3

#ifdef HAVE_DBHEADER
#include <db.h>
#elif HAVE_DB5_DB_H
#include <db5/db.h>
#elif HAVE_DB4_DB_H
#include <db4/db.h>
#elif HAVE_DB3_DB_H
#include <db3/db.h>
#else
#include <db.h>
#endif

static krb5_error_code
DB_close(krb5_context context, HDB *db)
{
    DB *d = (DB*)db->hdb_db;
    DBC *dbcp = (DBC*)db->hdb_dbc;

    (*dbcp->c_close)(dbcp);
    db->hdb_dbc = 0;
    (*d->close)(d, 0);
    return 0;
}

static krb5_error_code
DB_destroy(krb5_context context, HDB *db)
{
    krb5_error_code ret;

    ret = hdb_clear_master_key (context, db);
    free(db->hdb_name);
    free(db);
    return ret;
}

static krb5_error_code
DB_lock(krb5_context context, HDB *db, int operation)
{
    DB *d = (DB*)db->hdb_db;
    int fd;
    krb5_error_code ret;

    if (db->lock_count > 1) {
	db->lock_count++;
	if (db->lock_count == HDB_WLOCK || db->lock_count == operation)
	    return 0;
    }

    if ((*d->fd)(d, &fd))
	return HDB_ERR_CANT_LOCK_DB;
    ret = hdb_lock(fd, operation);
    if (ret)
	return ret;
    db->lock_count++;
    return 0;
}

static krb5_error_code
DB_unlock(krb5_context context, HDB *db)
{
    DB *d = (DB*)db->hdb_db;
    int fd;

    if (db->lock_count > 1) {
	db->lock_count--;
	return 0;
    }
    heim_assert(db->lock_count == 1, "HDB lock/unlock sequence does not match");
    db->lock_count--;

    if ((*d->fd)(d, &fd))
	return HDB_ERR_CANT_LOCK_DB;
    return hdb_unlock(fd);
}


static krb5_error_code
DB_seq(krb5_context context, HDB *db,
       unsigned flags, hdb_entry_ex *entry, int flag)
{
    DBT key, value;
    DBC *dbcp = db->hdb_dbc;
    krb5_data key_data, data;
    int code;

    memset(&key, 0, sizeof(DBT));
    memset(&value, 0, sizeof(DBT));
    if ((*db->hdb_lock)(context, db, HDB_RLOCK))
	return HDB_ERR_DB_INUSE;
    code = (*dbcp->c_get)(dbcp, &key, &value, flag);
    (*db->hdb_unlock)(context, db); /* XXX check value */
    if (code == DB_NOTFOUND)
	return HDB_ERR_NOENTRY;
    if (code)
	return code;

    key_data.data = key.data;
    key_data.length = key.size;
    data.data = value.data;
    data.length = value.size;
    memset(entry, 0, sizeof(*entry));
    if (hdb_value2entry(context, &data, &entry->entry))
	return DB_seq(context, db, flags, entry, DB_NEXT);
    if (db->hdb_master_key_set && (flags & HDB_F_DECRYPT)) {
	code = hdb_unseal_keys (context, db, &entry->entry);
	if (code)
	    hdb_free_entry (context, entry);
    }
    if (entry->entry.principal == NULL) {
	entry->entry.principal = malloc(sizeof(*entry->entry.principal));
	if (entry->entry.principal == NULL) {
	    hdb_free_entry (context, entry);
	    krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
	    return ENOMEM;
	} else {
	    hdb_key2principal(context, &key_data, entry->entry.principal);
	}
    }
    return 0;
}


static krb5_error_code
DB_firstkey(krb5_context context, HDB *db, unsigned flags, hdb_entry_ex *entry)
{
    return DB_seq(context, db, flags, entry, DB_FIRST);
}


static krb5_error_code
DB_nextkey(krb5_context context, HDB *db, unsigned flags, hdb_entry_ex *entry)
{
    return DB_seq(context, db, flags, entry, DB_NEXT);
}

static krb5_error_code
DB_rename(krb5_context context, HDB *db, const char *new_name)
{
    int ret;
    char *old, *new;

    ret = asprintf(&old, "%s.db", db->hdb_name);
    if (ret == -1)
	return ENOMEM;
    ret = asprintf(&new, "%s.db", new_name);
    if (ret == -1) {
	free(old);
	return ENOMEM;
    }
    ret = rename(old, new);
    free(old);
    if(ret) {
	free(new);
	return errno;
    }

    free(db->hdb_name);
    new[strlen(new) - 3] = '\0';
    db->hdb_name = new;
    return 0;
}

static krb5_error_code
DB__get(krb5_context context, HDB *db, krb5_data key, krb5_data *reply)
{
    DB *d = (DB*)db->hdb_db;
    DBT k, v;
    int code;

    memset(&k, 0, sizeof(DBT));
    memset(&v, 0, sizeof(DBT));
    k.data = key.data;
    k.size = key.length;
    k.flags = 0;
    if ((code = (*db->hdb_lock)(context, db, HDB_RLOCK)))
	return code;
    code = (*d->get)(d, NULL, &k, &v, 0);
    (*db->hdb_unlock)(context, db);
    if(code == DB_NOTFOUND)
	return HDB_ERR_NOENTRY;
    if(code)
	return code;

    krb5_data_copy(reply, v.data, v.size);
    return 0;
}

static krb5_error_code
DB__put(krb5_context context, HDB *db, int replace,
	krb5_data key, krb5_data value)
{
    DB *d = (DB*)db->hdb_db;
    DBT k, v;
    int code;

    memset(&k, 0, sizeof(DBT));
    memset(&v, 0, sizeof(DBT));
    k.data = key.data;
    k.size = key.length;
    k.flags = 0;
    v.data = value.data;
    v.size = value.length;
    v.flags = 0;
    if ((code = (*db->hdb_lock)(context, db, HDB_WLOCK)))
	return code;
    code = (*d->put)(d, NULL, &k, &v, replace ? 0 : DB_NOOVERWRITE);
    (*db->hdb_unlock)(context, db);
    if(code == DB_KEYEXIST)
	return HDB_ERR_EXISTS;
    if(code)
	return errno;
    return 0;
}

static krb5_error_code
DB__del(krb5_context context, HDB *db, krb5_data key)
{
    DB *d = (DB*)db->hdb_db;
    DBT k;
    krb5_error_code code;
    memset(&k, 0, sizeof(DBT));
    k.data = key.data;
    k.size = key.length;
    k.flags = 0;
    code = (*db->hdb_lock)(context, db, HDB_WLOCK);
    if(code)
	return code;
    code = (*d->del)(d, NULL, &k, 0);
    (*db->hdb_unlock)(context, db);
    if(code == DB_NOTFOUND)
	return HDB_ERR_NOENTRY;
    if(code)
	return code;
    return 0;
}

static krb5_error_code
DB_open(krb5_context context, HDB *db, int flags, mode_t mode)
{
    DBC *dbc = NULL;
    char *fn;
    krb5_error_code ret;
    DB *d;
    int myflags = 0;
    int aret;

    if (flags & O_CREAT)
      myflags |= DB_CREATE;

    if (flags & O_EXCL)
      myflags |= DB_EXCL;

    if((flags & O_ACCMODE) == O_RDONLY)
      myflags |= DB_RDONLY;

    if (flags & O_TRUNC)
      myflags |= DB_TRUNCATE;

    aret = asprintf(&fn, "%s.db", db->hdb_name);
    if (aret == -1) {
	krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
	return ENOMEM;
    }
    if (db_create(&d, NULL, 0) != 0) {
	free(fn);
	krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
	return ENOMEM;
    }
    db->hdb_db = d;

#if (DB_VERSION_MAJOR >= 4) && (DB_VERSION_MINOR >= 1)
    ret = (*d->open)(db->hdb_db, NULL, fn, NULL, DB_BTREE, myflags, mode);
#else
    ret = (*d->open)(db->hdb_db, fn, NULL, DB_BTREE, myflags, mode);
#endif

    if (ret == ENOENT) {
	/* try to open without .db extension */
#if (DB_VERSION_MAJOR >= 4) && (DB_VERSION_MINOR >= 1)
	ret = (*d->open)(db->hdb_db, NULL, db->hdb_name, NULL, DB_BTREE,
			 myflags, mode);
#else
	ret = (*d->open)(db->hdb_db, db->hdb_name, NULL, DB_BTREE,
			 myflags, mode);
#endif
    }

    if (ret) {
	free(fn);
	krb5_set_error_message(context, ret, "opening %s: %s",
			      db->hdb_name, strerror(ret));
	return ret;
    }
    free(fn);

    ret = (*d->cursor)(d, NULL, &dbc, 0);
    if (ret) {
	krb5_set_error_message(context, ret, "d->cursor: %s", strerror(ret));
        return ret;
    }
    db->hdb_dbc = dbc;

    if((flags & O_ACCMODE) == O_RDONLY)
	ret = hdb_check_db_format(context, db);
    else
	ret = hdb_init_db(context, db);
    if(ret == HDB_ERR_NOENTRY)
	return 0;
    if (ret) {
	DB_close(context, db);
	krb5_set_error_message(context, ret, "hdb_open: failed %s database %s",
			       (flags & O_ACCMODE) == O_RDONLY ?
			       "checking format of" : "initialize",
			       db->hdb_name);
    }

    return ret;
}

krb5_error_code
hdb_db_create(krb5_context context, HDB **db,
	      const char *filename)
{
    *db = calloc(1, sizeof(**db));
    if (*db == NULL) {
	krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
	return ENOMEM;
    }

    (*db)->hdb_db = NULL;
    (*db)->hdb_name = strdup(filename);
    if ((*db)->hdb_name == NULL) {
	free(*db);
	*db = NULL;
	krb5_set_error_message(context, ENOMEM, "malloc: out of memory");
	return ENOMEM;
    }
    (*db)->hdb_master_key_set = 0;
    (*db)->hdb_openp = 0;
    (*db)->hdb_capability_flags = HDB_CAP_F_HANDLE_ENTERPRISE_PRINCIPAL;
    (*db)->hdb_open  = DB_open;
    (*db)->hdb_close = DB_close;
    (*db)->hdb_fetch_kvno = _hdb_fetch_kvno;
    (*db)->hdb_store = _hdb_store;
    (*db)->hdb_remove = _hdb_remove;
    (*db)->hdb_firstkey = DB_firstkey;
    (*db)->hdb_nextkey= DB_nextkey;
    (*db)->hdb_lock = DB_lock;
    (*db)->hdb_unlock = DB_unlock;
    (*db)->hdb_rename = DB_rename;
    (*db)->hdb__get = DB__get;
    (*db)->hdb__put = DB__put;
    (*db)->hdb__del = DB__del;
    (*db)->hdb_destroy = DB_destroy;
    return 0;
}
#endif /* HAVE_DB3 */