sendmail/libsmdb/smndbm.c

/*
** Copyright (c) 1999-2002 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.
*/

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sm/gen.h>
SM_RCSID("@(#)$Id: smndbm.c,v 8.52 2002/05/21 22:30:30 gshapiro Exp $")

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

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

#ifdef NDBM

# define SMNDB_DIR_FILE_EXTENSION "dir"
# define SMNDB_PAG_FILE_EXTENSION "pag"

struct smdb_dbm_database_struct
{
    DBM *smndbm_dbm;
    int smndbm_lock_fd;
    bool    smndbm_cursor_in_use;
};
typedef struct smdb_dbm_database_struct SMDB_DBM_DATABASE;

struct smdb_dbm_cursor_struct
{
    SMDB_DBM_DATABASE   *smndbmc_db;
    datum           smndbmc_current_key;
};
typedef struct smdb_dbm_cursor_struct SMDB_DBM_CURSOR;

/*
**  SMDB_PUT_FLAGS_TO_NDBM_FLAGS -- Translates smdb put flags to ndbm put flags.
**
**  Parameters:
**      flags -- The flags to translate.
**
**  Returns:
**      The ndbm flags that are equivalent to the smdb flags.
**
**  Notes:
**      Any invalid flags are ignored.
**
*/

int
smdb_put_flags_to_ndbm_flags(flags)
    SMDB_FLAG flags;
{
    int return_flags;

    return_flags = 0;
    if (bitset(SMDBF_NO_OVERWRITE, flags))
        return_flags = DBM_INSERT;
    else
        return_flags = DBM_REPLACE;

    return return_flags;
}

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

SMDB_DBM_DATABASE *
smdbm_malloc_database()
{
    SMDB_DBM_DATABASE *db;

    db = (SMDB_DBM_DATABASE *) malloc(sizeof(SMDB_DBM_DATABASE));
    if (db != NULL)
    {
        db->smndbm_dbm = NULL;
        db->smndbm_lock_fd = -1;
        db->smndbm_cursor_in_use = false;
    }

    return db;
}

int
smdbm_close(database)
    SMDB_DATABASE *database;
{
    SMDB_DBM_DATABASE *db = (SMDB_DBM_DATABASE *) database->smdb_impl;
    DBM *dbm = ((SMDB_DBM_DATABASE *) database->smdb_impl)->smndbm_dbm;

    dbm_close(dbm);
    if (db->smndbm_lock_fd != -1)
        close(db->smndbm_lock_fd);

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

    return SMDBE_OK;
}

int
smdbm_del(database, key, flags)
    SMDB_DATABASE *database;
    SMDB_DBENT *key;
    unsigned int flags;
{
    int result;
    DBM *dbm = ((SMDB_DBM_DATABASE *) database->smdb_impl)->smndbm_dbm;
    datum dbkey;

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

    errno = 0;
    result = dbm_delete(dbm, dbkey);
    if (result != 0)
    {
        int save_errno = errno;

        if (dbm_error(dbm))
            return SMDBE_IO_ERROR;

        if (save_errno != 0)
            return save_errno;

        return SMDBE_NOT_FOUND;
    }
    return SMDBE_OK;
}

int
smdbm_fd(database, fd)
    SMDB_DATABASE *database;
    int *fd;
{
    DBM *dbm = ((SMDB_DBM_DATABASE *) database->smdb_impl)->smndbm_dbm;

    *fd = dbm_dirfno(dbm);
    if (*fd <= 0)
        return EINVAL;

    return SMDBE_OK;
}

int
smdbm_lockfd(database)
    SMDB_DATABASE *database;
{
    SMDB_DBM_DATABASE *db = (SMDB_DBM_DATABASE *) database->smdb_impl;

    return db->smndbm_lock_fd;
}

int
smdbm_get(database, key, data, flags)
    SMDB_DATABASE *database;
    SMDB_DBENT *key;
    SMDB_DBENT *data;
    unsigned int flags;
{
    DBM *dbm = ((SMDB_DBM_DATABASE *) database->smdb_impl)->smndbm_dbm;
    datum dbkey, dbdata;

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

    errno = 0;
    dbdata = dbm_fetch(dbm, dbkey);
    if (dbdata.dptr == NULL)
    {
        int save_errno = errno;

        if (dbm_error(dbm))
            return SMDBE_IO_ERROR;

        if (save_errno != 0)
            return save_errno;

        return SMDBE_NOT_FOUND;
    }
    data->data = dbdata.dptr;
    data->size = dbdata.dsize;
    return SMDBE_OK;
}

int
smdbm_put(database, key, data, flags)
    SMDB_DATABASE *database;
    SMDB_DBENT *key;
    SMDB_DBENT *data;
    unsigned int flags;
{
    int result;
    int save_errno;
    DBM *dbm = ((SMDB_DBM_DATABASE *) database->smdb_impl)->smndbm_dbm;
    datum dbkey, dbdata;

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

    errno = 0;
    result = dbm_store(dbm, dbkey, dbdata,
               smdb_put_flags_to_ndbm_flags(flags));
    switch (result)
    {
      case 1:
        return SMDBE_DUPLICATE;

      case 0:
        return SMDBE_OK;

      default:
        save_errno = errno;

        if (dbm_error(dbm))
            return SMDBE_IO_ERROR;

        if (save_errno != 0)
            return save_errno;

        return SMDBE_IO_ERROR;
    }
    /* NOTREACHED */
}

int
smndbm_set_owner(database, uid, gid)
    SMDB_DATABASE *database;
    uid_t uid;
    gid_t gid;
{
# if HASFCHOWN
    int fd;
    int result;
    DBM *dbm = ((SMDB_DBM_DATABASE *) database->smdb_impl)->smndbm_dbm;

    fd = dbm_dirfno(dbm);
    if (fd <= 0)
        return EINVAL;

    result = fchown(fd, uid, gid);
    if (result < 0)
        return errno;

    fd = dbm_pagfno(dbm);
    if (fd <= 0)
        return EINVAL;

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

    return SMDBE_OK;
}

int
smdbm_sync(database, flags)
    SMDB_DATABASE *database;
    unsigned int flags;
{
    return SMDBE_UNSUPPORTED;
}

int
smdbm_cursor_close(cursor)
    SMDB_CURSOR *cursor;
{
    SMDB_DBM_CURSOR *dbm_cursor = (SMDB_DBM_CURSOR *) cursor->smdbc_impl;
    SMDB_DBM_DATABASE *db = dbm_cursor->smndbmc_db;

    if (!db->smndbm_cursor_in_use)
        return SMDBE_NOT_A_VALID_CURSOR;

    db->smndbm_cursor_in_use = false;
    free(dbm_cursor);
    free(cursor);

    return SMDBE_OK;
}

int
smdbm_cursor_del(cursor, flags)
    SMDB_CURSOR *cursor;
    unsigned int flags;
{
    int result;
    SMDB_DBM_CURSOR *dbm_cursor = (SMDB_DBM_CURSOR *) cursor->smdbc_impl;
    SMDB_DBM_DATABASE *db = dbm_cursor->smndbmc_db;
    DBM *dbm = db->smndbm_dbm;

    errno = 0;
    result = dbm_delete(dbm, dbm_cursor->smndbmc_current_key);
    if (result != 0)
    {
        int save_errno = errno;

        if (dbm_error(dbm))
            return SMDBE_IO_ERROR;

        if (save_errno != 0)
            return save_errno;

        return SMDBE_NOT_FOUND;
    }
    return SMDBE_OK;
}

int
smdbm_cursor_get(cursor, key, value, flags)
    SMDB_CURSOR *cursor;
    SMDB_DBENT *key;
    SMDB_DBENT *value;
    SMDB_FLAG flags;
{
    SMDB_DBM_CURSOR *dbm_cursor = (SMDB_DBM_CURSOR *) cursor->smdbc_impl;
    SMDB_DBM_DATABASE *db = dbm_cursor->smndbmc_db;
    DBM *dbm = db->smndbm_dbm;
    datum dbkey, dbdata;

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

    if (flags == SMDB_CURSOR_GET_RANGE)
        return SMDBE_UNSUPPORTED;

    if (dbm_cursor->smndbmc_current_key.dptr == NULL)
    {
        dbm_cursor->smndbmc_current_key = dbm_firstkey(dbm);
        if (dbm_cursor->smndbmc_current_key.dptr == NULL)
        {
            if (dbm_error(dbm))
                return SMDBE_IO_ERROR;
            return SMDBE_LAST_ENTRY;
        }
    }
    else
    {
        dbm_cursor->smndbmc_current_key = dbm_nextkey(dbm);
        if (dbm_cursor->smndbmc_current_key.dptr == NULL)
        {
            if (dbm_error(dbm))
                return SMDBE_IO_ERROR;
            return SMDBE_LAST_ENTRY;
        }
    }

    errno = 0;
    dbdata = dbm_fetch(dbm, dbm_cursor->smndbmc_current_key);
    if (dbdata.dptr == NULL)
    {
        int save_errno = errno;

        if (dbm_error(dbm))
            return SMDBE_IO_ERROR;

        if (save_errno != 0)
            return save_errno;

        return SMDBE_NOT_FOUND;
    }
    value->data = dbdata.dptr;
    value->size = dbdata.dsize;
    key->data = dbm_cursor->smndbmc_current_key.dptr;
    key->size = dbm_cursor->smndbmc_current_key.dsize;

    return SMDBE_OK;
}

int
smdbm_cursor_put(cursor, key, value, flags)
    SMDB_CURSOR *cursor;
    SMDB_DBENT *key;
    SMDB_DBENT *value;
    SMDB_FLAG flags;
{
    int result;
    int save_errno;
    SMDB_DBM_CURSOR *dbm_cursor = (SMDB_DBM_CURSOR *) cursor->smdbc_impl;
    SMDB_DBM_DATABASE *db = dbm_cursor->smndbmc_db;
    DBM *dbm = db->smndbm_dbm;
    datum dbdata;

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

    errno = 0;
    result = dbm_store(dbm, dbm_cursor->smndbmc_current_key, dbdata,
               smdb_put_flags_to_ndbm_flags(flags));
    switch (result)
    {
      case 1:
        return SMDBE_DUPLICATE;

      case 0:
        return SMDBE_OK;

      default:
        save_errno = errno;

        if (dbm_error(dbm))
            return SMDBE_IO_ERROR;

        if (save_errno != 0)
            return save_errno;

        return SMDBE_IO_ERROR;
    }
    /* NOTREACHED */
}

int
smdbm_cursor(database, cursor, flags)
    SMDB_DATABASE *database;
    SMDB_CURSOR **cursor;
    SMDB_FLAG flags;
{
    SMDB_DBM_DATABASE *db = (SMDB_DBM_DATABASE *) database->smdb_impl;
    SMDB_CURSOR *cur;
    SMDB_DBM_CURSOR *dbm_cursor;

    if (db->smndbm_cursor_in_use)
        return SMDBE_ONLY_SUPPORTS_ONE_CURSOR;

    db->smndbm_cursor_in_use = true;
    dbm_cursor = (SMDB_DBM_CURSOR *) malloc(sizeof(SMDB_DBM_CURSOR));
    dbm_cursor->smndbmc_db = db;
    dbm_cursor->smndbmc_current_key.dptr = NULL;
    dbm_cursor->smndbmc_current_key.dsize = 0;

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

    cur->smdbc_impl = dbm_cursor;
    cur->smdbc_close = smdbm_cursor_close;
    cur->smdbc_del = smdbm_cursor_del;
    cur->smdbc_get = smdbm_cursor_get;
    cur->smdbc_put = smdbm_cursor_put;
    *cursor = cur;

    return SMDBE_OK;
}
/*
**  SMDB_NDBM_OPEN -- Opens a ndbm database.
**
**  Parameters:
**      database -- An unallocated database pointer to a pointer.
**      db_name -- The name of the database without extension.
**      mode -- File permisions on a created database.
**      mode_mask -- Mode bits that much match on an opened database.
**      sff -- Flags to safefile.
**      type -- The type of database to open.
**          Only SMDB_NDBM is supported.
**      user_info -- Information on the user to use for file
**              permissions.
**      db_params -- No params are supported.
**
**  Returns:
**      SMDBE_OK -- Success, otherwise errno:
**      SMDBE_MALLOC -- Cannot allocate memory.
**      SMDBE_UNSUPPORTED -- The type is not supported.
**      SMDBE_GDBM_IS_BAD -- We have detected GDBM and we don't
**                  like it.
**      SMDBE_BAD_OPEN -- dbm_open failed and errno was not set.
**      Anything else: errno
*/

int
smdb_ndbm_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 lock_fd;
    SMDB_DATABASE *smdb_db;
    SMDB_DBM_DATABASE *db;
    DBM *dbm = NULL;
    struct stat dir_stat_info;
    struct stat pag_stat_info;

    result = SMDBE_OK;
    *database = NULL;

    if (type == NULL)
        return SMDBE_UNKNOWN_DB_TYPE;

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

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

    if ((dir_stat_info.st_mode == ST_MODE_NOFILE ||
         pag_stat_info.st_mode == ST_MODE_NOFILE) &&
        bitset(mode, O_CREAT))
        lockcreated = true;

    lock_fd = -1;
    result = smdb_lock_file(&lock_fd, db_name, mode, sff,
                SMNDB_DIR_FILE_EXTENSION);
    if (result != SMDBE_OK)
        return result;

    if (lockcreated)
    {
        int pag_fd;

        /* Need to pre-open the .pag file as well with O_EXCL */
        result = smdb_lock_file(&pag_fd, db_name, mode, sff,
                    SMNDB_PAG_FILE_EXTENSION);
        if (result != SMDBE_OK)
        {
            (void) close(lock_fd);
            return result;
        }
        (void) close(pag_fd);

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

    smdb_db = smdb_malloc_database();
    if (smdb_db == NULL)
        result = SMDBE_MALLOC;

    db = smdbm_malloc_database();
    if (db == NULL)
        result = SMDBE_MALLOC;

    /* Try to open database */
    if (result == SMDBE_OK)
    {
        db->smndbm_lock_fd = lock_fd;

        errno = 0;
        dbm = dbm_open(db_name, mode, DBMMODE);
        if (dbm == NULL)
        {
            if (errno == 0)
                result = SMDBE_BAD_OPEN;
            else
                result = errno;
        }
        db->smndbm_dbm = dbm;
    }

    /* Check for GDBM */
    if (result == SMDBE_OK)
    {
        if (dbm_dirfno(dbm) == dbm_pagfno(dbm))
            result = SMDBE_GDBM_IS_BAD;
    }

    /* Check for filechanged */
    if (result == SMDBE_OK)
    {
        result = smdb_filechanged(db_name, SMNDB_DIR_FILE_EXTENSION,
                      dbm_dirfno(dbm), &dir_stat_info);
        if (result == SMDBE_OK)
        {
            result = smdb_filechanged(db_name,
                          SMNDB_PAG_FILE_EXTENSION,
                          dbm_pagfno(dbm),
                          &pag_stat_info);
        }
    }

    /* XXX Got to get fchown stuff in here */

    /* Setup driver if everything is ok */
    if (result == SMDBE_OK)
    {
        *database = smdb_db;

        smdb_db->smdb_close = smdbm_close;
        smdb_db->smdb_del = smdbm_del;
        smdb_db->smdb_fd = smdbm_fd;
        smdb_db->smdb_lockfd = smdbm_lockfd;
        smdb_db->smdb_get = smdbm_get;
        smdb_db->smdb_put = smdbm_put;
        smdb_db->smdb_set_owner = smndbm_set_owner;
        smdb_db->smdb_sync = smdbm_sync;
        smdb_db->smdb_cursor = smdbm_cursor;

        smdb_db->smdb_impl = db;

        return SMDBE_OK;
    }

    /* If we're here, something bad happened, clean up */
    if (dbm != NULL)
        dbm_close(dbm);

    smdb_unlock_file(db->smndbm_lock_fd);
    free(db);
    smdb_free_database(smdb_db);

    return result;
}
#endif /* NDBM */