X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/c3d6f1ff09458b3e7619f9bc4799aec0ab5fc2f2..0cc804c87799fb5902e66d5bd537a762f786dc2a:/src/src/hintsdb.h

diff --git a/src/src/hintsdb.h b/src/src/hintsdb.h
new file mode 100644
index 000000000..de3e6e4aa
--- /dev/null
+++ b/src/src/hintsdb.h
@@ -0,0 +1,805 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 - 2022 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* This header file contains macro definitions so that a variety of DBM
+libraries can be used by Exim. Nigel Metheringham provided the original set for
+Berkeley DB 1.x in native mode and ndbm. Subsequently, versions for Berkeley DB
+2.x and 3.x were added. Later still, support for tdb was added, courtesy of
+James Antill. Most recently, support for native mode gdbm was added, with code
+from Pierre A. Humblet, so Exim could be made to work with Cygwin.
+
+For convenience, the definitions of the structures used in the various hints
+databases are also kept in this file, which is used by the maintenance
+utilities as well as the main Exim binary. */
+
+#ifndef HINTSDB_H
+#define HINTSDB_H
+
+
+#if defined(USE_TDB)
+
+/* ************************* tdb interface ************************ */
+/*XXX https://manpages.org/tdb/3 mentions concurrent writes.
+Could we lose the file lock? */
+
+# include <tdb.h>
+
+/* Basic DB type */
+# define EXIM_DB TDB_CONTEXT
+
+/* Cursor type: tdb uses the previous "key" in _nextkey() (really it wants
+tdb_traverse to be called) */
+# define EXIM_CURSOR TDB_DATA
+
+/* The datum type used for queries */
+# define EXIM_DATUM TDB_DATA
+
+/* Some text for messages */
+# define EXIM_DBTYPE "tdb"
+
+/* Access functions */
+
+/* EXIM_DBOPEN - return pointer to an EXIM_DB, NULL if failed */
+static EXIM_DB *
+exim_dbopen__(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+return tdb_open(CS name, 0, TDB_DEFAULT, flags, mode);
+}
+
+/* EXIM_DBGET - returns TRUE if successful, FALSE otherwise */
+static BOOL
+exim_dbget(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * res)
+{
+*res = tdb_fetch(dbp, *key);	/* A struct arg and return!! */
+return res->dptr != NULL;
+}
+
+/* EXIM_DBPUT - returns nothing useful, assumes replace mode */
+static int
+exim_dbput(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return tdb_store(dbp, *key, *data, TDB_REPLACE); }
+
+/* EXIM_DBPUTB - non-overwriting for use by dbmbuild */
+static int
+exim_dbputb(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return tdb_store(dbp, *key, *data, TDB_INSERT); }
+
+/* Returns from EXIM_DBPUTB */
+
+# define EXIM_DBPUTB_OK  0
+# define EXIM_DBPUTB_DUP (-1)
+
+/* EXIM_DBDEL */
+static int
+exim_dbdel(EXIM_DB * dbp, EXIM_DATUM * key)
+{ return tdb_delete(dbp, *key); }
+
+/* EXIM_DBCREATE_CURSOR - initialize for scanning operation */
+static EXIM_CURSOR *
+exim_dbcreate_cursor(EXIM_DB * dbp)
+{
+EXIM_CURSOR * c = store_malloc(sizeof(TDB_DATA));
+c->dptr = NULL;
+return c;
+}
+
+/* EXIM_DBSCAN - This is complicated because we have to free the last datum
+free() must not die when passed NULL */
+
+static BOOL
+exim_dbscan(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * res, BOOL first,
+  EXIM_CURSOR * cursor)
+{
+*key = first ? tdb_firstkey(dbp) : tdb_nextkey(dbp, *cursor);
+free(cursor->dptr);
+*cursor = *key;
+return key->dptr != NULL;
+}
+
+/* EXIM_DBDELETE_CURSOR - terminate scanning operation. */
+static void
+exim_dbdelete_cursor(EXIM_CURSOR * cursor)
+{ store_free(cursor); }
+
+/* EXIM_DBCLOSE */
+static void
+exim_dbclose__(EXIM_DB * db)
+{ tdb_close(db); }
+
+/* Datum access */
+
+static uschar *
+exim_datum_data_get(EXIM_DATUM * dp)
+{ return US dp->dptr; }
+static void
+exim_datum_data_set(EXIM_DATUM * dp, void * s)
+{ dp->dptr = s; }
+
+static unsigned
+exim_datum_size_get(EXIM_DATUM * dp)
+{ return dp->dsize; }
+static void
+exim_datum_size_set(EXIM_DATUM * dp, unsigned n)
+{ dp->dsize = n; }
+
+/* No initialization is needed. */
+
+static void
+exim_datum_init(EXIM_DATUM * d)
+{ }
+
+/* Free the stuff inside the datum. */
+
+static void
+exim_datum_free(EXIM_DATUM * d)
+{
+free(d->dptr);
+d->dptr = NULL;
+}
+
+/* size limit */
+
+# define EXIM_DB_RLIMIT	150
+
+
+
+
+
+
+/********************* Berkeley db native definitions **********************/
+
+#elif defined USE_DB
+
+# include <db.h>
+
+/* 1.x did no locking
+   2.x had facilities, but exim does it's own
+   3.x+ unknown
+*/
+
+/* We can distinguish between versions 1.x and 2.x/3.x by looking for a
+definition of DB_VERSION_STRING, which is present in versions 2.x onwards. */
+
+# ifdef DB_VERSION_STRING
+
+#  if DB_VERSION_MAJOR >= 6
+#   error Version 6 and later BDB API is not supported
+#  endif
+
+/* The API changed (again!) between the 2.x and 3.x versions */
+
+# if DB_VERSION_MAJOR >= 3
+
+/***************** Berkeley db 3.x/4.x native definitions ******************/
+
+/* Basic DB type */
+#  if DB_VERSION_MAJOR > 4 || (DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR >= 1)
+#   define EXIM_DB       DB_ENV
+/* Cursor type, for scanning */
+#   define EXIM_CURSOR   DBC
+
+/* The datum type used for queries */
+#   define EXIM_DATUM    DBT
+
+/* Some text for messages */
+#   define EXIM_DBTYPE   "db (v4.1+)"
+
+/* Only more-recent versions.  5+ ? */
+#   ifndef DB_FORCESYNC
+#    define DB_FORCESYNC 0
+#   endif
+
+/* Error callback */
+/* For Berkeley DB >= 2, we can define a function to be called in case of DB
+errors. This should help with debugging strange DB problems, e.g. getting "File
+exists" when you try to open a db file. The API for this function was changed
+at DB release 4.3. */
+
+static void
+dbfn_bdb_error_callback(const DB_ENV * dbenv, const char * pfx, const char * msg)
+{ log_write(0, LOG_MAIN, "Berkeley DB error: %s", msg); }
+
+
+
+/* Access functions */
+
+/* EXIM_DBOPEN - return pointer to an EXIM_DB, NULL if failed */
+/* The API changed for DB 4.1. - and we also starting using the "env" with a
+specified working dir, to avoid the DBCONFIG file trap. */
+
+#   define ENV_TO_DB(env) ((DB *)(((EXIM_DB *)env)->app_private))
+
+static EXIM_DB *
+exim_dbopen__(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+EXIM_DB * dbp;
+DB * b;
+if (  db_env_create(&dbp, 0) != 0
+   || (dbp->set_errcall(dbp, dbfn_bdb_error_callback), 0)
+   || dbp->open(dbp, CS dirname, DB_CREATE|DB_INIT_MPOOL|DB_PRIVATE, 0) != 0
+   )
+  return NULL;
+if (db_create(&b, dbp, 0) == 0)
+  {
+  dbp->app_private = b;
+  if (b->open(b, NULL, CS name, NULL,
+	      flags == O_RDONLY ? DB_UNKNOWN : DB_HASH,
+	      flags == O_RDONLY ? DB_RDONLY : DB_CREATE,
+	      mode) == 0
+	  )
+    return dbp;
+
+  b->close(b, 0);
+  }
+dbp->close(dbp, 0);
+return NULL;
+}
+
+/* EXIM_DBGET - returns TRUE if successful, FALSE otherwise */
+static BOOL
+exim_dbget(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * res)
+{
+DB * b = ENV_TO_DB(dbp);
+return b->get(b, NULL, key, res, 0) == 0;
+}
+
+/* EXIM_DBPUT - returns nothing useful, assumes replace mode */
+static int
+exim_dbput(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{
+DB * b = ENV_TO_DB(dbp);
+return b->put(b, NULL, key, data, 0);
+}
+
+/* EXIM_DBPUTB - non-overwriting for use by dbmbuild */
+static int
+exim_dbputb(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{
+DB * b = ENV_TO_DB(dbp);
+return b->put(b, NULL, key, data, DB_NOOVERWRITE);
+}
+
+/* Return values from EXIM_DBPUTB */
+
+#   define EXIM_DBPUTB_OK  0
+#   define EXIM_DBPUTB_DUP DB_KEYEXIST
+
+/* EXIM_DBDEL */
+static int
+exim_dbdel(EXIM_DB * dbp, EXIM_DATUM * key)
+{
+DB * b = ENV_TO_DB(dbp);
+return b->del(b, NULL, key, 0);
+}
+
+/* EXIM_DBCREATE_CURSOR - initialize for scanning operation */
+
+static EXIM_CURSOR *
+exim_dbcreate_cursor(EXIM_DB * dbp)
+{
+DB * b = ENV_TO_DB(dbp);
+EXIM_CURSOR * c;
+b->cursor(b, NULL, &c, 0);
+return c;
+}
+
+/* EXIM_DBSCAN - returns TRUE if data is returned, FALSE at end */
+static BOOL
+exim_dbscan(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data, BOOL first,
+  EXIM_CURSOR * cursor)
+{
+return cursor->c_get(cursor, key, data, first ? DB_FIRST : DB_NEXT) == 0;
+}
+
+/* EXIM_DBDELETE_CURSOR - terminate scanning operation */
+static void
+exim_dbdelete_cursor(EXIM_CURSOR * cursor)
+{ cursor->c_close(cursor); }
+
+/* EXIM_DBCLOSE */
+static void
+exim_dbclose__(EXIM_DB * dbp_o)
+{
+DB_ENV * dbp = dbp_o;
+DB * b = ENV_TO_DB(dbp);
+b->close(b, 0);
+dbp->close(dbp, DB_FORCESYNC);
+}
+
+/* Datum access */
+
+static uschar *
+exim_datum_data_get(EXIM_DATUM * dp)
+{ return dp->data; }
+static void
+exim_datum_data_set(EXIM_DATUM * dp, void * s)
+{ dp->data = s; }
+
+static unsigned
+exim_datum_size_get(EXIM_DATUM * dp)
+{ return dp->size; }
+static void
+exim_datum_size_set(EXIM_DATUM * dp, unsigned n)
+{ dp->size = n; }
+
+/* The whole datum structure contains other fields that must be cleared
+before use, but we don't have to free anything after reading data. */
+
+static void
+exim_datum_init(EXIM_DATUM * d)
+{ memset(d, 0, sizeof(*d)); }
+
+static void
+exim_datum_free(EXIM_DATUM * d)
+{ }
+
+#  else	/* pre- 4.1 */
+
+#   define EXIM_DB       DB
+
+/* Cursor type, for scanning */
+#   define EXIM_CURSOR   DBC
+
+/* The datum type used for queries */
+#   define EXIM_DATUM    DBT
+
+/* Some text for messages */
+#   define EXIM_DBTYPE   "db (v3/4)"
+
+/* Access functions */
+
+/* EXIM_DBOPEN - return pointer to an EXIM_DB, NULL if failed */
+static EXIM_DB *
+exim_dbopen__(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+EXIM_DB * dbp;
+return db_create(&dbp, NULL, 0) == 0
+  && (  dbp->set_errcall(dbp, dbfn_bdb_error_callback),
+	dbp->open(dbp, CS name, NULL,
+	  flags == O_RDONLY ? DB_UNKNOWN : DB_HASH,
+	  flags == O_RDONLY ? DB_RDONLY : DB_CREATE,
+	  mode)
+     ) == 0
+  ? dbp : NULL;
+}
+
+/* EXIM_DBGET - returns TRUE if successful, FALSE otherwise */
+static BOOL
+exim_dbget(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * res)
+{ return dbp->get(dbp, NULL, key, res, 0) == 0; }
+
+/* EXIM_DBPUT - returns nothing useful, assumes replace mode */
+static int
+exim_dbput(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return dbp->put(dbp, NULL, key, data, 0); }
+
+/* EXIM_DBPUTB - non-overwriting for use by dbmbuild */
+static int
+exim_dbputb(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return dbp->put(dbp, NULL, key, data, DB_NOOVERWRITE); }
+
+/* Return values from EXIM_DBPUTB */
+
+#   define EXIM_DBPUTB_OK  0
+#   define EXIM_DBPUTB_DUP DB_KEYEXIST
+
+/* EXIM_DBDEL */
+static int
+exim_dbdel(EXIM_DB * dbp, EXIM_DATUM * key)
+{ return dbp->del(dbp, NULL, key, 0); }
+
+/* EXIM_DBCREATE_CURSOR - initialize for scanning operation */
+
+static EXIM_CURSOR *
+exim_dbcreate_cursor(EXIM_DB * dbp)
+{
+EXIM_CURSOR * c;
+dbp->cursor(dbp, NULL, &c, 0);
+return c;
+}
+
+/* EXIM_DBSCAN - returns TRUE if data is returned, FALSE at end */
+static BOOL
+exim_dbscan(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data, BOOL first,
+  EXIM_CURSOR * cursor)
+{
+return cursor->c_get(cursor, key, data, first ? DB_FIRST : DB_NEXT) == 0;
+}
+
+/* EXIM_DBDELETE_CURSOR - terminate scanning operation */
+static void
+exim_dbdelete_cursor(EXIM_CURSOR * cursor)
+{ cursor->c_close(cursor); }
+
+/* EXIM_DBCLOSE */
+static void
+exim_dbclose__(EXIM_DB * dbp)
+{ dbp->close(dbp, 0); }
+
+/* Datum access */
+
+static uschar *
+exim_datum_data_get(EXIM_DATUM * dp)
+{ return US dp->dptr; }
+static void
+exim_datum_data_set(EXIM_DATUM * dp, void * s)
+{ dp->dptr = s; }
+
+static uschar *
+exim_datum_size_get(EXIM_DATUM * dp)
+{ return US dp->size; }
+static void
+exim_datum_size_set(EXIM_DATUM * dp, uschar * s)
+{ dp->size = CS s; }
+
+/* The whole datum structure contains other fields that must be cleared
+before use, but we don't have to free anything after reading data. */
+
+static void
+exim_datum_init(EXIM_DATUM * d)
+{ memset(d, 0, sizeof(*d)); }
+
+static void
+exim_datum_free(EXIM_DATUM * d)
+{ }
+
+#  endif
+
+
+#  else /* DB_VERSION_MAJOR >= 3 */
+#   error Berkeley DB versions earlier than 3 are not supported */
+#  endif /* DB_VERSION_MAJOR */
+# else
+#  error Berkeley DB version 1 is no longer supported
+# endif /* DB_VERSION_STRING */
+
+
+/* all BDB versions */
+/* size limit */
+
+# define EXIM_DB_RLIMIT	150
+
+
+
+
+
+
+/********************* gdbm interface definitions **********************/
+
+#elif defined USE_GDBM
+/*XXX TODO: exim's locfile not needed */
+
+# include <gdbm.h>
+
+/* Basic DB type */
+typedef struct {
+       GDBM_FILE gdbm;  /* Database */
+       datum lkey;      /* Last key, for scans */
+} EXIM_DB;
+
+/* Cursor type, not used with gdbm: just set up a dummy */
+# define EXIM_CURSOR int
+
+/* The datum type used for queries */
+# define EXIM_DATUM datum
+
+/* Some text for messages */
+
+# define EXIM_DBTYPE "gdbm"
+
+/* Access functions */
+
+/* EXIM_DBOPEN - return pointer to an EXIM_DB, NULL if failed */
+static EXIM_DB *
+exim_dbopen__(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+EXIM_DB * dbp = malloc(sizeof(EXIM_DB));	/*XXX why not exim mem-mgmt? */
+if (dbp)
+  {
+  dbp->lkey.dptr = NULL;
+  dbp->gdbm = gdbm_open(CS name, 0,
+    flags & O_CREAT ? GDBM_WRCREAT
+    : flags & (O_RDWR|O_WRONLY) ? GDBM_WRITER
+    : GDBM_READER,
+    mode, 0);
+  if (dbp->gdbm) return dbp;
+  free(dbp);
+  }
+return NULL;
+}
+
+/* EXIM_DBGET - returns TRUE if successful, FALSE otherwise */
+static BOOL
+exim_dbget(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * res)
+{
+*res = gdbm_fetch(dbp->gdbm, *key);	/* A struct arg & return! */
+return res->dptr != NULL;
+}
+
+/* EXIM_DBPUT - returns nothing useful, assumes replace mode */
+static int
+exim_dbput(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return gdbm_store(dbp->gdbm, *key, *data, GDBM_REPLACE); }
+
+/* EXIM_DBPUTB - non-overwriting for use by dbmbuild */
+static int
+exim_dbputb(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return gdbm_store(dbp->gdbm, *key, *data, GDBM_INSERT); }
+
+/* Returns from EXIM_DBPUTB */
+
+# define EXIM_DBPUTB_OK  0
+# define EXIM_DBPUTB_DUP 1
+
+/* EXIM_DBDEL */
+static int
+exim_dbdel(EXIM_DB * dbp, EXIM_DATUM * key)
+{ return gdbm_delete(dbp->gdbm, *key); }
+
+/* EXIM_DBCREATE_CURSOR - initialize for scanning operation (null) */
+static EXIM_CURSOR *
+exim_dbcreate_cursor(EXIM_DB * dbp)
+{ return NULL; }
+
+/* EXIM_DBSCAN */
+static BOOL
+exim_dbscan(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data, BOOL first,
+  EXIM_CURSOR * cursor)
+{
+char * s;
+*key = first ? gdbm_firstkey(dbp->gdbm) : gdbm_nextkey(dbp->gdbm, dbp->lkey);
+if ((s = dbp->lkey.dptr)) free(s);
+dbp->lkey = *key;
+return key->dptr != NULL;
+}
+
+/* EXIM_DBDELETE_CURSOR - terminate scanning operation (null). */
+static void
+exim_dbdelete_cursor(EXIM_CURSOR * cursor)
+{ }
+
+/* EXIM_DBCLOSE */
+static void
+exim_dbclose__(EXIM_DB * dbp)
+{
+char * s;
+gdbm_close(dbp->gdbm);
+if ((s = dbp->lkey.dptr)) free(s);
+free(dbp);
+}
+
+/* Datum access types */
+
+static uschar *
+exim_datum_data_get(EXIM_DATUM * dp)
+{ return US dp->dptr; }
+static void
+exim_datum_data_set(EXIM_DATUM * dp, void * s)
+{ dp->dptr = s; }
+
+static unsigned
+exim_datum_size_get(EXIM_DATUM * dp)
+{ return dp->dsize; }
+static void
+exim_datum_size_set(EXIM_DATUM * dp, unsigned n)
+{ dp->dsize = n; }
+
+/* There's no clearing required before use, but we have to free the dptr
+after reading data. */
+
+static void
+exim_datum_init(EXIM_DATUM * d)
+{ }
+
+static void
+exim_datum_free(EXIM_DATUM * d)
+{ free(d->dptr); }
+
+/* size limit */
+
+# define EXIM_DB_RLIMIT	150
+
+#else  /* USE_GDBM */
+
+
+
+
+
+
+/* If none of USE_DB, USG_GDBM, or USE_TDB are set, the default is the NDBM
+interface */
+
+
+/********************* ndbm interface definitions **********************/
+
+# include <ndbm.h>
+
+/* Basic DB type */
+# define EXIM_DB DBM
+
+/* Cursor type, not used with ndbm: just set up a dummy */
+# define EXIM_CURSOR int
+
+/* The datum type used for queries */
+# define EXIM_DATUM datum
+
+/* Some text for messages */
+
+# define EXIM_DBTYPE "ndbm"
+
+/* Access functions */
+
+/* EXIM_DBOPEN - returns a EXIM_DB *, NULL if failed */
+/* Check that the name given is not present. This catches
+a directory name; otherwise we would create the name.pag and
+name.dir files in the directory's parent. */
+
+static EXIM_DB *
+exim_dbopen__(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+struct stat st;
+if (!(flags & O_CREAT) || lstat(CCS name, &st) != 0 && errno == ENOENT)
+  return dbm_open(CS name, flags, mode);
+#ifndef COMPILE_UTILITY
+debug_printf("%s %d errno %s\n", __FUNCTION__, __LINE__, strerror(errno));
+#endif
+errno = (st.st_mode & S_IFMT) == S_IFDIR ? EISDIR : EEXIST;
+return NULL;
+}
+
+/* EXIM_DBGET - returns TRUE if successful, FALSE otherwise */
+static BOOL
+exim_dbget(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * res)
+{
+*res = dbm_fetch(dbp, *key);	/* A struct arg & return! */
+return res->dptr != NULL;
+}
+
+/* EXIM_DBPUT - returns nothing useful, assumes replace mode */
+static int
+exim_dbput(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return dbm_store(dbp, *key, *data, DBM_REPLACE); }
+
+/* EXIM_DBPUTB - non-overwriting for use by dbmbuild */
+static int
+exim_dbputb(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data)
+{ return dbm_store(dbp, *key, *data, DBM_INSERT); }
+
+/* Returns from EXIM_DBPUTB */
+
+# define EXIM_DBPUTB_OK  0
+# define EXIM_DBPUTB_DUP 1
+
+/* EXIM_DBDEL */
+static int
+exim_dbdel(EXIM_DB * dbp, EXIM_DATUM * key)
+{ return dbm_delete(dbp, *key); }
+
+/* EXIM_DBCREATE_CURSOR - initialize for scanning operation (null) */
+static EXIM_CURSOR *
+exim_dbcreate_cursor(EXIM_DB * dbp)
+{ return NULL; }
+
+/* EXIM_DBSCAN */
+static BOOL
+exim_dbscan(EXIM_DB * dbp, EXIM_DATUM * key, EXIM_DATUM * data, BOOL first,
+  EXIM_CURSOR * cursor)
+{
+*key = first ? dbm_firstkey(dbp) : dbm_nextkey(dbp);
+return key->dptr != NULL;
+}
+
+/* EXIM_DBDELETE_CURSOR - terminate scanning operation (null). */
+static void
+exim_dbdelete_cursor(EXIM_CURSOR * cursor)
+{ }
+
+/* EXIM_DBCLOSE */
+static void
+exim_dbclose__(EXIM_DB * dbp)
+{ dbm_close(dbp); }
+
+/* Datum access types */
+
+static uschar *
+exim_datum_data_get(EXIM_DATUM * dp)
+{ return US dp->dptr; }
+static void
+exim_datum_data_set(EXIM_DATUM * dp, void * s)
+{ dp->dptr = s; }
+
+static unsigned
+exim_datum_size_get(EXIM_DATUM * dp)
+{ return dp->dsize; }
+static void
+exim_datum_size_set(EXIM_DATUM * dp, unsigned n)
+{ dp->dsize = n; }
+
+/* There's no clearing required before use, and we don't have to free anything
+after reading data. */
+
+static void
+exim_datum_init(EXIM_DATUM * d)
+{ }
+
+static void
+exim_datum_free(EXIM_DATUM * d)
+{ }
+
+/* size limit */
+
+# define EXIM_DB_RLIMIT	150
+
+#endif /* USE_GDBM */
+
+
+
+
+
+#if defined(COMPILE_UTILITY) || defined(MACRO_PREDEF)
+
+static EXIM_DB *
+exim_dbopen(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+return exim_dbopen__(name, dirname, flags, mode);
+}
+
+static void
+exim_dbclose(EXIM_DB * dbp)
+{ exim_dbclose__(dbp); }
+
+#else
+/* Wrappers for open/close with debug tracing */
+
+extern void debug_printf_indent(const char *, ...);
+static BOOL is_tainted(const void *);
+
+static EXIM_DB *
+exim_dbopen(const uschar * name, const uschar * dirname, int flags,
+  unsigned mode)
+{
+void * dbp;
+DEBUG(D_hints_lookup)
+  debug_printf_indent("EXIM_DBOPEN: file <%s> dir <%s> flags=%s\n",
+    name, dirname,
+    flags == O_RDONLY ? "O_RDONLY"
+    : flags == O_RDWR ? "O_RDWR"
+    : flags == (O_RDWR|O_CREAT) ? "O_RDWR|O_CREAT"
+    : "??");
+if (is_tainted(name) || is_tainted(dirname))
+  {
+  log_write(0, LOG_MAIN|LOG_PANIC, "Tainted name for DB file not permitted");
+  dbp = NULL;
+  }
+else
+  dbp = exim_dbopen__(name, dirname, flags, mode);
+
+DEBUG(D_hints_lookup) debug_printf_indent("returned from EXIM_DBOPEN: %p\n", dbp);
+return dbp;
+}
+
+static void
+exim_dbclose(EXIM_DB * dbp)
+{
+DEBUG(D_hints_lookup) debug_printf_indent("EXIM_DBCLOSE(%p)\n", dbp);
+exim_dbclose__(dbp);
+}
+
+# endif
+
+/********************* End of dbm library definitions **********************/
+
+
+#endif	/* whole file */
+/* End of hintsdb.h */