/*
** Copyright (c) 1999-2003, 2009 Sendmail, Inc. and its suppliers.
**      All rights reserved.
**
** By using this file, you agree to the terms and conditions set
** forth in the LICENSE file which can be found at the top level of
** the sendmail distribution.
*/

#include <sm/gen.h>
SM_RCSID("@(#)$Id: smdb2.c,v 8.80 2009/11/12 23:07:49 ca Exp $")

#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>


#include <sendmail/sendmail.h>
#include <libsmdb/smdb.h>

#if (DB_VERSION_MAJOR >= 2)

# define SMDB2_FILE_EXTENSION "db"

struct smdb_db2_database
{
        DB      *smdb2_db;
        int     smdb2_lock_fd;
};
typedef struct smdb_db2_database SMDB_DB2_DATABASE;

/*
**  SMDB_TYPE_TO_DB2_TYPE -- Translates smdb database type to db2 type.
**
**      Parameters:
**              type -- The type to translate.
**
**      Returns:
**              The DB2 type that corresponsds to the passed in SMDB type.
**              Returns -1 if there is no equivalent type.
**
*/

DBTYPE
smdb_type_to_db2_type(type)
        SMDB_DBTYPE type;
{
        if (type == SMDB_TYPE_DEFAULT)
                return DB_HASH;

        if (strncmp(type, SMDB_TYPE_HASH, SMDB_TYPE_HASH_LEN) == 0)
                return DB_HASH;

        if (strncmp(type, SMDB_TYPE_BTREE, SMDB_TYPE_BTREE_LEN) == 0)
                return DB_BTREE;

        return DB_UNKNOWN;
}
/*
**  DB2_ERROR_TO_SMDB -- Translates db2 errors to smdbe errors
**
**      Parameters:
**              error -- The error to translate.
**
**      Returns:
**              The SMDBE error corresponding to the db2 error.
**              If we don't have a corresponding error, it returs errno.
**
*/

int
db2_error_to_smdb(error)
        int error;
{
        int result;

        switch (error)
        {
# ifdef DB_INCOMPLETE
                case DB_INCOMPLETE:
                        result = SMDBE_INCOMPLETE;
                        break;
# endif /* DB_INCOMPLETE */

# ifdef DB_NOTFOUND
                case DB_NOTFOUND:
                        result = SMDBE_NOT_FOUND;
                        break;
# endif /* DB_NOTFOUND */

# ifdef DB_KEYEMPTY
                case DB_KEYEMPTY:
                        result = SMDBE_KEY_EMPTY;
                        break;
# endif /* DB_KEYEMPTY */

# ifdef DB_KEYEXIST
                case DB_KEYEXIST:
                        result = SMDBE_KEY_EXIST;
                        break;
# endif /* DB_KEYEXIST */

# ifdef DB_LOCK_DEADLOCK
                case DB_LOCK_DEADLOCK:
                        result = SMDBE_LOCK_DEADLOCK;
                        break;
# endif /* DB_LOCK_DEADLOCK */

# ifdef DB_LOCK_NOTGRANTED
                case DB_LOCK_NOTGRANTED:
                        result = SMDBE_LOCK_NOT_GRANTED;
                        break;
# endif /* DB_LOCK_NOTGRANTED */

# ifdef DB_LOCK_NOTHELD
                case DB_LOCK_NOTHELD:
                        result = SMDBE_LOCK_NOT_HELD;
                        break;
# endif /* DB_LOCK_NOTHELD */

# ifdef DB_RUNRECOVERY
                case DB_RUNRECOVERY:
                        result = SMDBE_RUN_RECOVERY;
                        break;
# endif /* DB_RUNRECOVERY */

# ifdef DB_OLD_VERSION
                case DB_OLD_VERSION:
                        result = SMDBE_OLD_VERSION;
                        break;
# endif /* DB_OLD_VERSION */

                case 0:
                        result = SMDBE_OK;
                        break;

                default:
                        result = error;
        }
        return result;
}
/*
**  SMDB_PUT_FLAGS_TO_DB2_FLAGS -- Translates smdb put flags to db2 put flags.
**
**      Parameters:
**              flags -- The flags to translate.
**
**      Returns:
**              The db2 flags that are equivalent to the smdb flags.
**
**      Notes:
**              Any invalid flags are ignored.
**
*/

unsigned int
smdb_put_flags_to_db2_flags(flags)
        SMDB_FLAG flags;
{
        int return_flags;

        return_flags = 0;

        if (bitset(SMDBF_NO_OVERWRITE, flags))
                return_flags |= DB_NOOVERWRITE;

        return return_flags;
}
/*
**  SMDB_CURSOR_GET_FLAGS_TO_DB2 -- Translates smdb cursor get flags to db2
**      getflags.
**
**      Parameters:
**              flags -- The flags to translate.
**
**      Returns:
**              The db2 flags that are equivalent to the smdb flags.
**
**      Notes:
**              -1 is returned if flag is unknown.
**
*/

int
smdb_cursor_get_flags_to_db2(flags)
        SMDB_FLAG flags;
{
        switch (flags)
        {
                case SMDB_CURSOR_GET_FIRST:
                        return DB_FIRST;

                case SMDB_CURSOR_GET_LAST:
                        return DB_LAST;

                case SMDB_CURSOR_GET_NEXT:
                        return DB_NEXT;

                case SMDB_CURSOR_GET_RANGE:
                        return DB_SET_RANGE;

                default:
                        return -1;
        }
}

/*
**  Except for smdb_db_open, the rest of these functions correspond to the
**  interface laid out in smdb.h.
*/

SMDB_DB2_DATABASE *
smdb2_malloc_database()
{
        SMDB_DB2_DATABASE *db2;

        db2 = (SMDB_DB2_DATABASE *) malloc(sizeof(SMDB_DB2_DATABASE));
        if (db2 != NULL)
                db2->smdb2_lock_fd = -1;

        return db2;
}

int
smdb2_close(database)
        SMDB_DATABASE *database;
{
        int result;
        SMDB_DB2_DATABASE *db2 = (SMDB_DB2_DATABASE *) database->smdb_impl;
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;

        result = db2_error_to_smdb(db->close(db, 0));
        if (db2->smdb2_lock_fd != -1)
                close(db2->smdb2_lock_fd);

        free(db2);
        database->smdb_impl = NULL;

        return result;
}

int
smdb2_del(database, key, flags)
        SMDB_DATABASE *database;
        SMDB_DBENT *key;
        unsigned int flags;
{
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;
        DBT dbkey;

        (void) memset(&dbkey, '\0', sizeof dbkey);
        dbkey.data = key->data;
        dbkey.size = key->size;
        return db2_error_to_smdb(db->del(db, NULL, &dbkey, flags));
}

int
smdb2_fd(database, fd)
        SMDB_DATABASE *database;
        int *fd;
{
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;

        return db2_error_to_smdb(db->fd(db, fd));
}

int
smdb2_lockfd(database)
        SMDB_DATABASE *database;
{
        SMDB_DB2_DATABASE *db2 = (SMDB_DB2_DATABASE *) database->smdb_impl;

        return db2->smdb2_lock_fd;
}

int
smdb2_get(database, key, data, flags)
        SMDB_DATABASE *database;
        SMDB_DBENT *key;
        SMDB_DBENT *data;
        unsigned int flags;
{
        int result;
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;
        DBT dbkey, dbdata;

        (void) memset(&dbdata, '\0', sizeof dbdata);
        (void) memset(&dbkey, '\0', sizeof dbkey);
        dbkey.data = key->data;
        dbkey.size = key->size;

        result = db->get(db, NULL, &dbkey, &dbdata, flags);
        data->data = dbdata.data;
        data->size = dbdata.size;
        return db2_error_to_smdb(result);
}

int
smdb2_put(database, key, data, flags)
        SMDB_DATABASE *database;
        SMDB_DBENT *key;
        SMDB_DBENT *data;
        unsigned int flags;
{
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;
        DBT dbkey, dbdata;

        (void) memset(&dbdata, '\0', sizeof dbdata);
        (void) memset(&dbkey, '\0', sizeof dbkey);
        dbkey.data = key->data;
        dbkey.size = key->size;
        dbdata.data = data->data;
        dbdata.size = data->size;

        return db2_error_to_smdb(db->put(db, NULL, &dbkey, &dbdata,
                                         smdb_put_flags_to_db2_flags(flags)));
}


int
smdb2_set_owner(database, uid, gid)
        SMDB_DATABASE *database;
        uid_t uid;
        gid_t gid;
{
# if HASFCHOWN
        int fd;
        int result;
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;

        result = db->fd(db, &fd);
        if (result != 0)
                return result;

        result = fchown(fd, uid, gid);
        if (result < 0)
                return errno;
# endif /* HASFCHOWN */

        return SMDBE_OK;
}

int
smdb2_sync(database, flags)
        SMDB_DATABASE *database;
        unsigned int flags;
{
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;

        return db2_error_to_smdb(db->sync(db, flags));
}

int
smdb2_cursor_close(cursor)
        SMDB_CURSOR *cursor;
{
        int ret;
        DBC *dbc = (DBC *) cursor->smdbc_impl;

        ret = db2_error_to_smdb(dbc->c_close(dbc));
        free(cursor);
        return ret;
}

int
smdb2_cursor_del(cursor, flags)
        SMDB_CURSOR *cursor;
        SMDB_FLAG flags;
{
        DBC *dbc = (DBC *) cursor->smdbc_impl;

        return db2_error_to_smdb(dbc->c_del(dbc, 0));
}

int
smdb2_cursor_get(cursor, key, value, flags)
        SMDB_CURSOR *cursor;
        SMDB_DBENT *key;
        SMDB_DBENT *value;
        SMDB_FLAG flags;
{
        int db2_flags;
        int result;
        DBC *dbc = (DBC *) cursor->smdbc_impl;
        DBT dbkey, dbdata;

        (void) memset(&dbdata, '\0', sizeof dbdata);
        (void) memset(&dbkey, '\0', sizeof dbkey);

        db2_flags = smdb_cursor_get_flags_to_db2(flags);
        result = dbc->c_get(dbc, &dbkey, &dbdata, db2_flags);
        if (result == DB_NOTFOUND)
                return SMDBE_LAST_ENTRY;
        key->data = dbkey.data;
        key->size = dbkey.size;
        value->data = dbdata.data;
        value->size = dbdata.size;
        return db2_error_to_smdb(result);
}

int
smdb2_cursor_put(cursor, key, value, flags)
        SMDB_CURSOR *cursor;
        SMDB_DBENT *key;
        SMDB_DBENT *value;
        SMDB_FLAG flags;
{
        DBC *dbc = (DBC *) cursor->smdbc_impl;
        DBT dbkey, dbdata;

        (void) memset(&dbdata, '\0', sizeof dbdata);
        (void) memset(&dbkey, '\0', sizeof dbkey);
        dbkey.data = key->data;
        dbkey.size = key->size;
        dbdata.data = value->data;
        dbdata.size = value->size;

        return db2_error_to_smdb(dbc->c_put(dbc, &dbkey, &dbdata, 0));
}

int
smdb2_cursor(database, cursor, flags)
        SMDB_DATABASE *database;
        SMDB_CURSOR **cursor;
        SMDB_FLAG flags;
{
        int result;
        DB *db = ((SMDB_DB2_DATABASE *) database->smdb_impl)->smdb2_db;
        DBC *db2_cursor;

# if DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6
        result = db->cursor(db, NULL, &db2_cursor, 0);
# else /* DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6 */
        result = db->cursor(db, NULL, &db2_cursor);
# endif /* DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6 */
        if (result != 0)
                return db2_error_to_smdb(result);

        *cursor = (SMDB_CURSOR *) malloc(sizeof(SMDB_CURSOR));
        if (*cursor == NULL)
                return SMDBE_MALLOC;

        (*cursor)->smdbc_close = smdb2_cursor_close;
        (*cursor)->smdbc_del = smdb2_cursor_del;
        (*cursor)->smdbc_get = smdb2_cursor_get;
        (*cursor)->smdbc_put = smdb2_cursor_put;
        (*cursor)->smdbc_impl = db2_cursor;

        return SMDBE_OK;
}

# if DB_VERSION_MAJOR == 2
static int
smdb_db_open_internal(db_name, db_type, db_flags, db_params, db)
        char *db_name;
        DBTYPE db_type;
        int db_flags;
        SMDB_DBPARAMS *db_params;
        DB **db;
{
        void *params;
        DB_INFO db_info;

        params = NULL;
        (void) memset(&db_info, '\0', sizeof db_info);
        if (db_params != NULL)
        {
                db_info.db_cachesize = db_params->smdbp_cache_size;
                if (db_type == DB_HASH)
                        db_info.h_nelem = db_params->smdbp_num_elements;
                if (db_params->smdbp_allow_dup)
                        db_info.flags |= DB_DUP;
                params = &db_info;
        }
        return db_open(db_name, db_type, db_flags, DBMMODE, NULL, params, db);
}
# endif /* DB_VERSION_MAJOR == 2 */

# if DB_VERSION_MAJOR > 2
static int
smdb_db_open_internal(db_name, db_type, db_flags, db_params, db)
        char *db_name;
        DBTYPE db_type;
        int db_flags;
        SMDB_DBPARAMS *db_params;
        DB **db;
{
        int result;

        result = db_create(db, NULL, 0);
        if (result != 0 || *db == NULL)
                return result;

        if (db_params != NULL)
        {
                result = (*db)->set_cachesize(*db, 0,
                                              db_params->smdbp_cache_size, 0);
                if (result != 0)
                {
                        (void) (*db)->close((*db), 0);
                        *db = NULL;
                        return db2_error_to_smdb(result);
                }
                if (db_type == DB_HASH)
                {
                        result = (*db)->set_h_nelem(*db, db_params->smdbp_num_elements);
                        if (result != 0)
                        {
                                (void) (*db)->close(*db, 0);
                                *db = NULL;
                                return db2_error_to_smdb(result);
                        }
                }
                if (db_params->smdbp_allow_dup)
                {
                        result = (*db)->set_flags(*db, DB_DUP);
                        if (result != 0)
                        {
                                (void) (*db)->close(*db, 0);
                                *db = NULL;
                                return db2_error_to_smdb(result);
                        }
                }
        }

        result = (*db)->open(*db,
                             DBTXN      /* transaction for DB 4.1 */
                             db_name, NULL, db_type, db_flags, DBMMODE);
        if (result != 0)
        {
                (void) (*db)->close(*db, 0);
                *db = NULL;
        }
        return db2_error_to_smdb(result);
}
# endif /* DB_VERSION_MAJOR > 2 */
/*
**  SMDB_DB_OPEN -- Opens a db database.
**
**      Parameters:
**              database -- An unallocated database pointer to a pointer.
**              db_name -- The name of the database without extension.
**              mode -- File permisions for a created database.
**              mode_mask -- Mode bits that must match on an opened database.
**              sff -- Flags for safefile.
**              type -- The type of database to open
**                      See smdb_type_to_db2_type for valid types.
**              user_info -- User information for file permissions.
**              db_params --
**                      An SMDB_DBPARAMS struct including params. These
**                      are processed according to the type of the
**                      database. Currently supported params (only for
**                      HASH type) are:
**                         num_elements
**                         cache_size
**
**      Returns:
**              SMDBE_OK -- Success, other errno:
**              SMDBE_MALLOC -- Cannot allocate memory.
**              SMDBE_BAD_OPEN -- db_open didn't return an error, but
**                               somehow the DB pointer is NULL.
**              Anything else: translated error from db2
*/

int
smdb_db_open(database, db_name, mode, mode_mask, sff, type, user_info, db_params)
        SMDB_DATABASE **database;
        char *db_name;
        int mode;
        int mode_mask;
        long sff;
        SMDB_DBTYPE type;
        SMDB_USER_INFO *user_info;
        SMDB_DBPARAMS *db_params;
{
        bool lockcreated = false;
        int result;
        int db_flags;
        int lock_fd;
        int db_fd;
        int major_v, minor_v, patch_v;
        SMDB_DATABASE *smdb_db;
        SMDB_DB2_DATABASE *db2;
        DB *db;
        DBTYPE db_type;
        struct stat stat_info;
        char db_file_name[MAXPATHLEN];

        (void) db_version(&major_v, &minor_v, &patch_v);
        if (major_v != DB_VERSION_MAJOR || minor_v != DB_VERSION_MINOR)
                return SMDBE_VERSION_MISMATCH;

        *database = NULL;

        result = smdb_add_extension(db_file_name, sizeof db_file_name,
                                    db_name, SMDB2_FILE_EXTENSION);
        if (result != SMDBE_OK)
                return result;

        result = smdb_setup_file(db_name, SMDB2_FILE_EXTENSION,
                                 mode_mask, sff, user_info, &stat_info);
        if (result != SMDBE_OK)
                return result;

        lock_fd = -1;

        if (stat_info.st_mode == ST_MODE_NOFILE &&
            bitset(mode, O_CREAT))
                lockcreated = true;

        result = smdb_lock_file(&lock_fd, db_name, mode, sff,
                                SMDB2_FILE_EXTENSION);
        if (result != SMDBE_OK)
                return result;

        if (lockcreated)
        {
                mode |= O_TRUNC;
                mode &= ~(O_CREAT|O_EXCL);
        }

        smdb_db = smdb_malloc_database();
        db2 = smdb2_malloc_database();
        if (db2 == NULL || smdb_db == NULL)
        {
                smdb_unlock_file(lock_fd);
                smdb_free_database(smdb_db);    /* ok to be NULL */
                return SMDBE_MALLOC;
        }

        db2->smdb2_lock_fd = lock_fd;

        db_type = smdb_type_to_db2_type(type);

        db = NULL;

        db_flags = 0;
        if (bitset(O_CREAT, mode))
                db_flags |= DB_CREATE;
        if (bitset(O_TRUNC, mode))
                db_flags |= DB_TRUNCATE;
        if (mode == O_RDONLY)
                db_flags |= DB_RDONLY;
        SM_DB_FLAG_ADD(db_flags);

        result = smdb_db_open_internal(db_file_name, db_type,
                                       db_flags, db_params, &db);

        if (result == 0 && db != NULL)
        {
                result = db->fd(db, &db_fd);
                if (result == 0)
                        result = SMDBE_OK;
        }
        else
        {
                /* Try and narrow down on the problem */
                if (result != 0)
                        result = db2_error_to_smdb(result);
                else
                        result = SMDBE_BAD_OPEN;
        }

        if (result == SMDBE_OK)
                result = smdb_filechanged(db_name, SMDB2_FILE_EXTENSION, db_fd,
                                          &stat_info);

        if (result == SMDBE_OK)
        {
                /* Everything is ok. Setup driver */
                db2->smdb2_db = db;

                smdb_db->smdb_close = smdb2_close;
                smdb_db->smdb_del = smdb2_del;
                smdb_db->smdb_fd = smdb2_fd;
                smdb_db->smdb_lockfd = smdb2_lockfd;
                smdb_db->smdb_get = smdb2_get;
                smdb_db->smdb_put = smdb2_put;
                smdb_db->smdb_set_owner = smdb2_set_owner;
                smdb_db->smdb_sync = smdb2_sync;
                smdb_db->smdb_cursor = smdb2_cursor;
                smdb_db->smdb_impl = db2;

                *database = smdb_db;

                return SMDBE_OK;
        }

        if (db != NULL)
                db->close(db, 0);

        smdb_unlock_file(db2->smdb2_lock_fd);
        free(db2);
        smdb_free_database(smdb_db);

        return result;
}

#endif /* (DB_VERSION_MAJOR >= 2) */