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mirror of https://gitlab.isc.org/isc-projects/bind9 synced 2025-08-22 10:10:06 +00:00
bind/lib/ns/tests/nstest.c

930 lines
20 KiB
C

/*
* 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.
*/
/*! \file */
#include <config.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <isc/app.h>
#include <isc/buffer.h>
#include <isc/entropy.h>
#include <isc/file.h>
#include <isc/hash.h>
#include <isc/mem.h>
#include <isc/os.h>
#include <isc/print.h>
#include <isc/random.h>
#include <isc/string.h>
#include <isc/socket.h>
#include <isc/stdio.h>
#include <isc/task.h>
#include <isc/timer.h>
#include <isc/util.h>
#include <dns/cache.h>
#include <dns/db.h>
#include <dns/dispatch.h>
#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/name.h>
#include <dns/result.h>
#include <dns/view.h>
#include <dns/zone.h>
#include <ns/client.h>
#include <ns/interfacemgr.h>
#include <ns/server.h>
#include "../hooks.h"
#include "nstest.h"
isc_mem_t *mctx = NULL;
isc_entropy_t *ectx = NULL;
isc_log_t *lctx = NULL;
isc_taskmgr_t *taskmgr = NULL;
isc_task_t *maintask = NULL;
isc_timermgr_t *timermgr = NULL;
isc_socketmgr_t *socketmgr = NULL;
dns_zonemgr_t *zonemgr = NULL;
dns_dispatchmgr_t *dispatchmgr = NULL;
ns_clientmgr_t *clientmgr = NULL;
ns_interfacemgr_t *interfacemgr = NULL;
ns_server_t *sctx = NULL;
isc_boolean_t app_running = ISC_FALSE;
int ncpus;
isc_boolean_t debug_mem_record = ISC_TRUE;
isc_boolean_t run_managers = ISC_FALSE;
static isc_boolean_t dst_active = ISC_FALSE;
static dns_zone_t *served_zone = NULL;
/*
* Logging categories: this needs to match the list in lib/ns/log.c.
*/
static isc_logcategory_t categories[] = {
{ "", 0 },
{ "client", 0 },
{ "network", 0 },
{ "update", 0 },
{ "queries", 0 },
{ "unmatched", 0 },
{ "update-security", 0 },
{ "query-errors", 0 },
{ NULL, 0 }
};
static isc_result_t
matchview(isc_netaddr_t *srcaddr, isc_netaddr_t *destaddr,
dns_message_t *message, dns_aclenv_t *env, dns_ecs_t *ecs,
isc_result_t *sigresultp, dns_view_t **viewp)
{
UNUSED(srcaddr);
UNUSED(destaddr);
UNUSED(message);
UNUSED(env);
UNUSED(ecs);
UNUSED(sigresultp);
UNUSED(viewp);
return (ISC_R_NOTIMPLEMENTED);
}
/*
* These need to be shut down from a running task.
*/
isc_boolean_t shutdown_done = ISC_FALSE;
static void
shutdown_managers(isc_task_t *task, isc_event_t *event) {
UNUSED(task);
if (clientmgr != NULL) {
ns_clientmgr_destroy(&clientmgr);
}
if (interfacemgr != NULL) {
ns_interfacemgr_shutdown(interfacemgr);
ns_interfacemgr_detach(&interfacemgr);
}
if (dispatchmgr != NULL) {
dns_dispatchmgr_destroy(&dispatchmgr);
}
shutdown_done = ISC_TRUE;
run_managers = ISC_FALSE;
isc_event_free(&event);
}
static void
cleanup_managers(void) {
if (app_running)
isc_app_finish();
shutdown_done = ISC_FALSE;
if (maintask != NULL) {
isc_task_shutdown(maintask);
isc_task_destroy(&maintask);
}
while (run_managers && !shutdown_done) {
#ifndef ISC_PLATFORM_USETHREADS
while (isc__taskmgr_ready(taskmgr))
isc__taskmgr_dispatch(taskmgr);
#else
/*
* There's no straightforward way to determine
* whether all the clients have shut down, so
* we'll just sleep for a bit and hope.
*/
ns_test_nap(500000);
#endif
}
if (sctx != NULL)
ns_server_detach(&sctx);
if (socketmgr != NULL)
isc_socketmgr_destroy(&socketmgr);
if (taskmgr != NULL)
isc_taskmgr_destroy(&taskmgr);
if (timermgr != NULL)
isc_timermgr_destroy(&timermgr);
}
static void
scan_interfaces(isc_task_t *task, isc_event_t *event) {
UNUSED(task);
ns_interfacemgr_scan(interfacemgr, ISC_TRUE);
isc_event_free(&event);
}
static isc_result_t
create_managers(void) {
isc_result_t result;
ns_listenlist_t *listenon = NULL;
isc_event_t *event = NULL;
#ifdef ISC_PLATFORM_USETHREADS
ncpus = isc_os_ncpus();
#else
ncpus = 1;
#endif
CHECK(isc_taskmgr_create(mctx, ncpus, 0, &taskmgr));
CHECK(isc_task_create(taskmgr, 0, &maintask));
isc_taskmgr_setexcltask(taskmgr, maintask);
CHECK(isc_task_onshutdown(maintask, shutdown_managers, NULL));
CHECK(isc_timermgr_create(mctx, &timermgr));
CHECK(isc_socketmgr_create(mctx, &socketmgr));
CHECK(ns_server_create(mctx, ectx, matchview, &sctx));
CHECK(dns_dispatchmgr_create(mctx, ectx, &dispatchmgr));
CHECK(ns_interfacemgr_create(mctx, sctx, taskmgr, timermgr,
socketmgr, dispatchmgr, maintask,
ncpus, NULL, &interfacemgr));
CHECK(ns_clientmgr_create(mctx, sctx, taskmgr, timermgr,
&clientmgr));
CHECK(ns_listenlist_default(mctx, 5300, -1, ISC_TRUE, &listenon));
ns_interfacemgr_setlistenon4(interfacemgr, listenon);
ns_listenlist_detach(&listenon);
event = isc_event_allocate(mctx, maintask, ISC_TASKEVENT_TEST,
scan_interfaces, NULL,
sizeof (isc_event_t));
isc_task_send(maintask, &event);
#ifndef ISC_PLATFORM_USETHREADS
while (isc__taskmgr_ready(taskmgr))
isc__taskmgr_dispatch(taskmgr);
#else
/*
* There's no straightforward way to determine
* whether the interfaces have been scanned,
* we'll just sleep for a bit and hope.
*/
ns_test_nap(500000);
#endif
run_managers = ISC_TRUE;
return (ISC_R_SUCCESS);
cleanup:
cleanup_managers();
return (result);
}
isc_result_t
ns_test_begin(FILE *logfile, isc_boolean_t start_managers) {
isc_result_t result;
if (start_managers)
CHECK(isc_app_start());
if (debug_mem_record)
isc_mem_debugging |= ISC_MEM_DEBUGRECORD;
CHECK(isc_mem_create(0, 0, &mctx));
CHECK(isc_entropy_create(mctx, &ectx));
CHECK(dst_lib_init(mctx, ectx, ISC_ENTROPY_BLOCKING));
dst_active = ISC_TRUE;
if (logfile != NULL) {
isc_logdestination_t destination;
isc_logconfig_t *logconfig = NULL;
CHECK(isc_log_create(mctx, &lctx, &logconfig));
isc_log_registercategories(lctx, categories);
isc_log_setcontext(lctx);
dns_log_init(lctx);
dns_log_setcontext(lctx);
destination.file.stream = logfile;
destination.file.name = NULL;
destination.file.versions = ISC_LOG_ROLLNEVER;
destination.file.maximum_size = 0;
CHECK(isc_log_createchannel(logconfig, "stderr",
ISC_LOG_TOFILEDESC,
ISC_LOG_DYNAMIC,
&destination, 0));
CHECK(isc_log_usechannel(logconfig, "stderr", NULL, NULL));
}
dns_result_register();
if (start_managers)
CHECK(create_managers());
/*
* atf-run changes us to a /tmp directory, so tests
* that access test data files must first chdir to the proper
* location.
*/
if (chdir(TESTS) == -1)
CHECK(ISC_R_FAILURE);
ns__hook_table = NULL;
return (ISC_R_SUCCESS);
cleanup:
ns_test_end();
return (result);
}
void
ns_test_end(void) {
if (dst_active) {
dst_lib_destroy();
dst_active = ISC_FALSE;
}
cleanup_managers();
if (ectx != NULL)
isc_entropy_detach(&ectx);
if (lctx != NULL)
isc_log_destroy(&lctx);
if (mctx != NULL)
isc_mem_destroy(&mctx);
}
isc_result_t
ns_test_makeview(const char *name, isc_boolean_t with_cache,
dns_view_t **viewp)
{
dns_cache_t *cache = NULL;
dns_view_t *view = NULL;
isc_result_t result;
CHECK(dns_view_create(mctx, dns_rdataclass_in, name, &view));
if (with_cache) {
CHECK(dns_cache_create(mctx, mctx, taskmgr, timermgr,
dns_rdataclass_in, "", "rbt", 0, NULL,
&cache));
dns_view_setcache(view, cache);
/*
* Reference count for "cache" is now at 2, so decrement it in
* order for the cache to be automatically freed when "view"
* gets freed.
*/
dns_cache_detach(&cache);
}
*viewp = view;
return (ISC_R_SUCCESS);
cleanup:
if (view != NULL)
dns_view_detach(&view);
return (result);
}
/*
* Create a zone with origin 'name', return a pointer to the zone object in
* 'zonep'. If 'view' is set, add the zone to that view; otherwise, create
* a new view for the purpose.
*
* If the created view is going to be needed by the caller subsequently,
* then 'keepview' should be set to true; this will prevent the view
* from being detached. In this case, the caller is responsible for
* detaching the view.
*/
isc_result_t
ns_test_makezone(const char *name, dns_zone_t **zonep, dns_view_t *view,
isc_boolean_t keepview)
{
isc_result_t result;
dns_zone_t *zone = NULL;
isc_buffer_t buffer;
dns_fixedname_t fixorigin;
dns_name_t *origin;
if (view == NULL)
CHECK(dns_view_create(mctx, dns_rdataclass_in, "view", &view));
else if (!keepview)
keepview = ISC_TRUE;
zone = *zonep;
if (zone == NULL)
CHECK(dns_zone_create(&zone, mctx));
isc_buffer_constinit(&buffer, name, strlen(name));
isc_buffer_add(&buffer, strlen(name));
dns_fixedname_init(&fixorigin);
origin = dns_fixedname_name(&fixorigin);
CHECK(dns_name_fromtext(origin, &buffer, dns_rootname, 0, NULL));
CHECK(dns_zone_setorigin(zone, origin));
dns_zone_setview(zone, view);
dns_zone_settype(zone, dns_zone_master);
dns_zone_setclass(zone, view->rdclass);
dns_view_addzone(view, zone);
if (!keepview)
dns_view_detach(&view);
*zonep = zone;
return (ISC_R_SUCCESS);
cleanup:
if (zone != NULL)
dns_zone_detach(&zone);
if (view != NULL)
dns_view_detach(&view);
return (result);
}
isc_result_t
ns_test_setupzonemgr(void) {
isc_result_t result;
REQUIRE(zonemgr == NULL);
result = dns_zonemgr_create(mctx, taskmgr, timermgr, socketmgr,
&zonemgr);
return (result);
}
isc_result_t
ns_test_managezone(dns_zone_t *zone) {
isc_result_t result;
REQUIRE(zonemgr != NULL);
result = dns_zonemgr_setsize(zonemgr, 1);
if (result != ISC_R_SUCCESS)
return (result);
result = dns_zonemgr_managezone(zonemgr, zone);
return (result);
}
void
ns_test_releasezone(dns_zone_t *zone) {
REQUIRE(zonemgr != NULL);
dns_zonemgr_releasezone(zonemgr, zone);
}
void
ns_test_closezonemgr(void) {
REQUIRE(zonemgr != NULL);
dns_zonemgr_shutdown(zonemgr);
dns_zonemgr_detach(&zonemgr);
}
isc_result_t
ns_test_serve_zone(const char *zonename, const char *filename,
dns_view_t *view)
{
isc_result_t result;
dns_db_t *db = NULL;
/*
* Prepare zone structure for further processing.
*/
result = ns_test_makezone(zonename, &served_zone, view, ISC_TRUE);
if (result != ISC_R_SUCCESS) {
return (result);
}
/*
* Start zone manager.
*/
result = ns_test_setupzonemgr();
if (result != ISC_R_SUCCESS) {
goto free_zone;
}
/*
* Add the zone to the zone manager.
*/
result = ns_test_managezone(served_zone);
if (result != ISC_R_SUCCESS) {
goto close_zonemgr;
}
view->nocookieudp = 512;
/*
* Set path to the master file for the zone and then load it.
*/
dns_zone_setfile(served_zone, filename, dns_masterformat_text,
&dns_master_style_default);
result = dns_zone_load(served_zone);
if (result != ISC_R_SUCCESS) {
goto release_zone;
}
/*
* The zone should now be loaded; test it.
*/
result = dns_zone_getdb(served_zone, &db);
if (result != ISC_R_SUCCESS) {
goto release_zone;
}
if (db != NULL) {
dns_db_detach(&db);
}
return (ISC_R_SUCCESS);
release_zone:
ns_test_releasezone(served_zone);
close_zonemgr:
ns_test_closezonemgr();
free_zone:
dns_zone_detach(&served_zone);
return (result);
}
void
ns_test_cleanup_zone(void) {
ns_test_releasezone(served_zone);
ns_test_closezonemgr();
dns_zone_detach(&served_zone);
}
isc_result_t
ns_test_getclient(ns_interface_t *ifp0, isc_boolean_t tcp,
ns_client_t **clientp)
{
isc_result_t result;
ns_interface_t *ifp = ifp0;
if (ifp == NULL) {
ifp = ns__interfacemgr_getif(interfacemgr);
}
if (ifp == NULL) {
return (ISC_R_FAILURE);
}
result = ns__clientmgr_getclient(clientmgr, ifp, tcp, clientp);
return (result);
}
/*%
* Synthesize a DNS message based on supplied QNAME, QTYPE and flags, then
* parse it and store the results in client->message.
*/
static isc_result_t
attach_query_msg_to_client(ns_client_t *client, const char *qnamestr,
dns_rdatatype_t qtype, unsigned int qflags)
{
dns_rdataset_t *qrdataset = NULL;
dns_message_t *message = NULL;
unsigned char query[65536];
dns_name_t *qname = NULL;
isc_buffer_t querybuf;
dns_compress_t cctx;
isc_result_t result;
isc_uint32_t qid;
REQUIRE(client != NULL);
REQUIRE(qnamestr != NULL);
/*
* Create a new DNS message holding a query.
*/
result = dns_message_create(mctx, DNS_MESSAGE_INTENTRENDER, &message);
if (result != ISC_R_SUCCESS) {
return (result);
}
/*
* Set query ID to a random value.
*/
isc_random_get(&qid);
message->id = (dns_messageid_t)(qid & 0xffff);
/*
* Set query flags as requested by the caller.
*/
message->flags = qflags;
/*
* Allocate structures required to construct the query.
*/
result = dns_message_gettemprdataset(message, &qrdataset);
if (result != ISC_R_SUCCESS) {
goto destroy_message;
}
result = dns_message_gettempname(message, &qname);
if (result != ISC_R_SUCCESS) {
goto put_rdataset;
}
/*
* Convert "qnamestr" to a DNS name, create a question rdataset of
* class IN and type "qtype", link the two and add the result to the
* QUESTION section of the query.
*/
result = dns_name_fromstring(qname, qnamestr, 0, mctx);
if (result != ISC_R_SUCCESS) {
goto put_name;
}
dns_rdataset_makequestion(qrdataset, dns_rdataclass_in, qtype);
ISC_LIST_APPEND(qname->list, qrdataset, link);
dns_message_addname(message, qname, DNS_SECTION_QUESTION);
/*
* Render the query.
*/
dns_compress_init(&cctx, -1, mctx);
isc_buffer_init(&querybuf, query, sizeof(query));
result = dns_message_renderbegin(message, &cctx, &querybuf);
if (result != ISC_R_SUCCESS) {
goto destroy_message;
}
result = dns_message_rendersection(message, DNS_SECTION_QUESTION, 0);
if (result != ISC_R_SUCCESS) {
goto destroy_message;
}
result = dns_message_renderend(message);
if (result != ISC_R_SUCCESS) {
goto destroy_message;
}
dns_compress_invalidate(&cctx);
/*
* Destroy the created message as it was rendered into "querybuf" and
* the latter is all we are going to need from now on.
*/
dns_message_destroy(&message);
/*
* Parse the rendered query, storing results in client->message.
*/
isc_buffer_first(&querybuf);
return (dns_message_parse(client->message, &querybuf, 0));
put_name:
dns_message_puttempname(message, &qname);
put_rdataset:
dns_message_puttemprdataset(message, &qrdataset);
destroy_message:
dns_message_destroy(&message);
return (result);
}
/*%
* A hook callback which stores the query context pointed to by "hook_data" at
* "callback_data". Causes execution to be interrupted at hook insertion
* point.
*/
static isc_boolean_t
extract_qctx(void *hook_data, void *callback_data, isc_result_t *resultp) {
query_ctx_t **qctxp;
query_ctx_t *qctx;
REQUIRE(hook_data != NULL);
REQUIRE(callback_data != NULL);
REQUIRE(resultp != NULL);
/*
* qctx is a stack variable in lib/ns/query.c. Its contents need to be
* duplicated or otherwise they will become invalidated once the stack
* gets unwound.
*/
qctx = isc_mem_get(mctx, sizeof(*qctx));
if (qctx != NULL) {
memmove(qctx, (query_ctx_t *)hook_data, sizeof(*qctx));
}
qctxp = (query_ctx_t **)callback_data;
/*
* If memory allocation failed, the supplied pointer will simply be set
* to NULL. We rely on the user of this hook to react properly.
*/
*qctxp = qctx;
*resultp = ISC_R_UNSET;
return (ISC_TRUE);
}
/*%
* Initialize a query context for "client" and store it in "qctxp".
*
* Requires:
*
* \li "client->message" to hold a parsed DNS query.
*/
static isc_result_t
create_qctx_for_client(ns_client_t *client, query_ctx_t **qctxp) {
ns_hook_t *saved_hook_table;
ns_hook_t query_hooks[NS_QUERY_HOOKS_COUNT + 1] = {
[NS_QUERY_SETUP_QCTX_INITIALIZED] = {
.callback = extract_qctx,
.callback_data = qctxp,
},
};
REQUIRE(client != NULL);
REQUIRE(qctxp != NULL);
REQUIRE(*qctxp == NULL);
/*
* Call ns_query_start() to initialize a query context for given
* client, but first hook into query_setup() so that we can just
* extract an initialized query context, without kicking off any
* further processing. Make sure we do not overwrite any previously
* set hooks.
*/
saved_hook_table = ns__hook_table;
ns__hook_table = query_hooks;
ns_query_start(client);
ns__hook_table = saved_hook_table;
if (*qctxp == NULL) {
return (ISC_R_NOMEMORY);
} else {
return (ISC_R_SUCCESS);
}
}
isc_result_t
ns_test_qctx_create(const ns_test_qctx_create_params_t *params,
query_ctx_t **qctxp)
{
ns_client_t *client = NULL;
isc_result_t result;
REQUIRE(params != NULL);
REQUIRE(params->qname != NULL);
REQUIRE(qctxp != NULL);
REQUIRE(*qctxp == NULL);
/*
* Allocate and initialize a client structure.
*/
result = ns_test_getclient(NULL, ISC_FALSE, &client);
if (result != ISC_R_SUCCESS) {
return (result);
}
TIME_NOW(&client->tnow);
/*
* Every client needs to belong to a view.
*/
result = ns_test_makeview("view", params->with_cache, &client->view);
if (result != ISC_R_SUCCESS) {
goto detach_client;
}
/*
* Synthesize a DNS query using given QNAME, QTYPE and flags, storing
* it in client->message.
*/
result = attach_query_msg_to_client(client, params->qname,
params->qtype, params->qflags);
if (result != ISC_R_SUCCESS) {
goto detach_client;
}
/*
* Allow recursion for the client. As NS_CLIENTATTR_RA normally gets
* set in ns__client_request(), i.e. earlier than the unit tests hook
* into the call chain, just set it manually.
*/
client->attributes |= NS_CLIENTATTR_RA;
/*
* Create a query context for a client sending the previously
* synthesized query.
*/
result = create_qctx_for_client(client, qctxp);
if (result != ISC_R_SUCCESS) {
goto destroy_query;
}
/*
* Reference count for "client" is now at 2, so decrement it in order
* for it to drop to zero when "qctx" gets destroyed.
*/
ns_client_detach(&client);
return (ISC_R_SUCCESS);
destroy_query:
dns_message_destroy(&client->message);
detach_client:
ns_client_detach(&client);
return (result);
}
void
ns_test_qctx_destroy(query_ctx_t **qctxp) {
query_ctx_t *qctx;
REQUIRE(qctxp != NULL);
REQUIRE(*qctxp != NULL);
qctx = *qctxp;
ns_client_detach(&qctx->client);
if (qctx->zone != NULL) {
dns_zone_detach(&qctx->zone);
}
if (qctx->db != NULL) {
dns_db_detach(&qctx->db);
}
isc_mem_put(mctx, qctx, sizeof(*qctx));
*qctxp = NULL;
}
isc_boolean_t
ns_test_hook_catch_call(void *hook_data, void *callback_data,
isc_result_t *resultp)
{
UNUSED(hook_data);
UNUSED(callback_data);
*resultp = ISC_R_UNSET;
return (ISC_TRUE);
}
/*
* Sleep for 'usec' microseconds.
*/
void
ns_test_nap(isc_uint32_t usec) {
#ifdef HAVE_NANOSLEEP
struct timespec ts;
ts.tv_sec = usec / 1000000;
ts.tv_nsec = (usec % 1000000) * 1000;
nanosleep(&ts, NULL);
#elif HAVE_USLEEP
usleep(usec);
#else
/*
* No fractional-second sleep function is available, so we
* round up to the nearest second and sleep instead
*/
sleep((usec / 1000000) + 1);
#endif
}
isc_result_t
ns_test_loaddb(dns_db_t **db, dns_dbtype_t dbtype, const char *origin,
const char *testfile)
{
isc_result_t result;
dns_fixedname_t fixed;
dns_name_t *name;
dns_fixedname_init(&fixed);
name = dns_fixedname_name(&fixed);
result = dns_name_fromstring(name, origin, 0, NULL);
if (result != ISC_R_SUCCESS)
return(result);
result = dns_db_create(mctx, "rbt", name, dbtype, dns_rdataclass_in,
0, NULL, db);
if (result != ISC_R_SUCCESS)
return (result);
result = dns_db_load(*db, testfile, dns_masterformat_text, 0);
return (result);
}
static int
fromhex(char c) {
if (c >= '0' && c <= '9')
return (c - '0');
else if (c >= 'a' && c <= 'f')
return (c - 'a' + 10);
else if (c >= 'A' && c <= 'F')
return (c - 'A' + 10);
printf("bad input format: %02x\n", c);
exit(3);
/* NOTREACHED */
}
isc_result_t
ns_test_getdata(const char *file, unsigned char *buf,
size_t bufsiz, size_t *sizep)
{
isc_result_t result;
unsigned char *bp;
char *rp, *wp;
char s[BUFSIZ];
size_t len, i;
FILE *f = NULL;
int n;
result = isc_stdio_open(file, "r", &f);
if (result != ISC_R_SUCCESS)
return (result);
bp = buf;
while (fgets(s, sizeof(s), f) != NULL) {
rp = s;
wp = s;
len = 0;
while (*rp != '\0') {
if (*rp == '#')
break;
if (*rp != ' ' && *rp != '\t' &&
*rp != '\r' && *rp != '\n') {
*wp++ = *rp;
len++;
}
rp++;
}
if (len == 0U)
continue;
if (len % 2 != 0U)
CHECK(ISC_R_UNEXPECTEDEND);
if (len > bufsiz * 2)
CHECK(ISC_R_NOSPACE);
rp = s;
for (i = 0; i < len; i += 2) {
n = fromhex(*rp++);
n *= 16;
n += fromhex(*rp++);
*bp++ = n;
}
}
*sizep = bp - buf;
result = ISC_R_SUCCESS;
cleanup:
isc_stdio_close(f);
return (result);
}