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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/*
* A simple database driver that calls a Tcl procedure to define
* the contents of the DNS namespace. The procedure is loaded
* from the file lookup.tcl; look at the comments there for
* more information.
*/
#include <config.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <isc/mem.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/util.h>
#include <dns/log.h>
#include <dns/sdb.h>
#include <named/globals.h>
#include <tcl.h>
#include <tcldb.h>
#define CHECK(op) \
do { result = (op); \
if (result != ISC_R_SUCCESS) return (result); \
} while (0)
typedef struct tcldb_driver {
isc_mem_t *mctx;
Tcl_Interp *interp;
} tcldb_driver_t;
static tcldb_driver_t *the_driver = NULL;
static dns_sdbimplementation_t *tcldb = NULL;
static isc_result_t
tcldb_driver_create(isc_mem_t *mctx, tcldb_driver_t **driverp) {
int tclres;
isc_result_t result = ISC_R_SUCCESS;
tcldb_driver_t *driver = isc_mem_get(mctx, sizeof(tcldb_driver_t));
if (driver == NULL)
return (ISC_R_NOMEMORY);
driver->mctx = mctx;
driver->interp = Tcl_CreateInterp();
tclres = Tcl_EvalFile(driver->interp, (char *) "lookup.tcl");
if (tclres != TCL_OK) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_SDB, ISC_LOG_ERROR,
"initializing tcldb: "
"loading 'lookup.tcl' failed: %s",
driver->interp->result);
result = ISC_R_FAILURE;
goto cleanup;
}
*driverp = driver;
return (ISC_R_SUCCESS);
cleanup:
isc_mem_put(mctx, driver, sizeof(tcldb_driver_t));
return (result);
}
static void
tcldb_driver_destroy(tcldb_driver_t **driverp) {
tcldb_driver_t *driver = *driverp;
Tcl_DeleteInterp(driver->interp);
isc_mem_put(driver->mctx, driver, sizeof(tcldb_driver_t));
}
/*
* Perform a lookup, by invoking the Tcl procedure "lookup".
*/
#ifdef DNS_CLIENTINFO_VERSION
static isc_result_t
tcldb_lookup(const char *zone, const char *name, void *dbdata,
dns_sdblookup_t *lookup, dns_clientinfomethods_t *methods,
dns_clientinfo_t *clientinfo)
#else
static isc_result_t
tcldb_lookup(const char *zone, const char *name, void *dbdata,
dns_sdblookup_t *lookup)
#endif /* DNS_CLIENTINFO_VERSION */
{
isc_result_t result = ISC_R_SUCCESS;
int tclres;
int rrc; /* RR count */
char **rrv; /* RR vector */
int i;
char *cmdv[3];
char *cmd;
#ifdef DNS_CLIENTINFO_VERSION
UNUSED(methods);
UNUSED(clientinfo);
#endif /* DNS_CLIENTINFO_VERSION */
tcldb_driver_t *driver = (tcldb_driver_t *) dbdata;
cmdv[0] = "lookup";
cmdv[1] = zone;
cmdv[2] = name;
cmd = Tcl_Merge(3, cmdv);
tclres = Tcl_Eval(driver->interp, cmd);
Tcl_Free(cmd);
if (tclres != TCL_OK) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_SDB, ISC_LOG_ERROR,
"zone '%s': tcl lookup function failed: %s",
zone, driver->interp->result);
return (ISC_R_FAILURE);
}
if (strcmp(driver->interp->result, "NXDOMAIN") == 0) {
result = ISC_R_NOTFOUND;
goto fail;
}
tclres = Tcl_SplitList(driver->interp, driver->interp->result,
&rrc, &rrv);
if (tclres != TCL_OK)
goto malformed;
for (i = 0; i < rrc; i++) {
isc_result_t tmpres;
int fieldc; /* Field count */
char **fieldv; /* Field vector */
tclres = Tcl_SplitList(driver->interp, rrv[i],
&fieldc, &fieldv);
if (tclres != TCL_OK) {
tmpres = ISC_R_FAILURE;
goto failrr;
}
if (fieldc != 3)
goto malformed;
tmpres = dns_sdb_putrr(lookup, fieldv[0], atoi(fieldv[1]),
fieldv[2]);
Tcl_Free((char *) fieldv);
failrr:
if (tmpres != ISC_R_SUCCESS)
result = tmpres;
}
Tcl_Free((char *) rrv);
if (result == ISC_R_SUCCESS)
return (result);
malformed:
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_SDB, ISC_LOG_ERROR,
"zone '%s': "
"malformed return value from tcl lookup function: %s",
zone, driver->interp->result);
result = ISC_R_FAILURE;
fail:
return (result);
}
/*
* Set up per-zone state. In our case, the database arguments of the
* zone are collected into a Tcl list and assigned to an element of
* the global array "dbargs".
*/
static isc_result_t
tcldb_create(const char *zone, int argc, char **argv,
void *driverdata, void **dbdata)
{
tcldb_driver_t *driver = (tcldb_driver_t *) driverdata;
char *list = Tcl_Merge(argc, argv);
Tcl_SetVar2(driver->interp, (char *) "dbargs", (char *) zone, list, 0);
Tcl_Free(list);
*dbdata = driverdata;
return (ISC_R_SUCCESS);
}
/*
* This driver does not support zone transfer, so allnodes() is NULL.
*/
static dns_sdbmethods_t tcldb_methods = {
tcldb_lookup,
NULL, /* authority */
NULL, /* allnodes */
tcldb_create,
NULL, /* destroy */
NULL /* lookup2 */
};
/*
* Initialize the tcldb driver.
*/
isc_result_t
tcldb_init(void) {
isc_result_t result;
int flags = DNS_SDBFLAG_RELATIVEOWNER | DNS_SDBFLAG_RELATIVERDATA;
result = tcldb_driver_create(ns_g_mctx, &the_driver);
if (result != ISC_R_SUCCESS)
return (result);
return (dns_sdb_register("tcl", &tcldb_methods, the_driver, flags,
ns_g_mctx, &tcldb));
}
/*
* Wrapper around dns_sdb_unregister().
*/
void
tcldb_clear(void) {
if (tcldb != NULL)
dns_sdb_unregister(&tcldb);
if (the_driver != NULL)
tcldb_driver_destroy(&the_driver);
}
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