Commit d181c28c authored by Michał Kępień's avatar Michał Kępień Committed by Evan Hunt
Browse files

Add ns_plugin_expandpath()

Implement a helper function which, given an input string:

  - copies it verbatim if it contains at least one path separator,
  - prepends the named plugin installation directory to it otherwise.

This function will allow configuration parsing code to conveniently
determine the full path to a plugin module given either a path or a
filename.

While other, simpler ways exist for making sure filenames passed to
dlopen() cause the latter to look for shared objects in a specific
directory, they are very platform-specific.  Using full paths is thus
likely the most portable and reliable solution.

Also added unit tests for ns_plugin_expandpath() to ensure it behaves
as expected for absolute paths, relative paths, and filenames, for
various target buffer sizes.

(Note: plugins share a directory with named on Windows; there is no
default plugin path. Therefore the source path is copied to the
destination path with no modification.)
parent c527b7fd
......@@ -28,7 +28,7 @@ CINCLUDES = -I. -I${top_srcdir}/lib/ns -Iinclude \
${NS_INCLUDES} ${DNS_INCLUDES} ${ISC_INCLUDES} \
@OPENSSL_INCLUDES@ @DST_GSSAPI_INC@
CDEFINES =
CDEFINES = -DNAMED_PLUGINDIR=\"${plugindir}\"
CWARNINGS =
......
......@@ -13,6 +13,8 @@
#include <config.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#if HAVE_DLFCN_H
......@@ -21,10 +23,12 @@
#include <windows.h>
#endif
#include <isc/errno.h>
#include <isc/list.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/platform.h>
#include <isc/util.h>
......@@ -58,6 +62,41 @@ struct ns_plugin {
static ns_hooklist_t default_hooktable[NS_HOOKPOINTS_COUNT];
LIBNS_EXTERNAL_DATA ns_hooktable_t *ns__hook_table = &default_hooktable;
isc_result_t
ns_plugin_expandpath(const char *src, char *dst, size_t dstsize) {
int result;
#ifndef WIN32
/*
* On Unix systems, differentiate between paths and filenames.
*/
if (strchr(src, '/') != NULL) {
/*
* 'src' is an absolute or relative path. Copy it verbatim.
*/
result = snprintf(dst, dstsize, "%s", src);
} else {
/*
* 'src' is a filename. Prepend default plugin directory path.
*/
result = snprintf(dst, dstsize, "%s/%s", NAMED_PLUGINDIR, src);
}
#else
/*
* On Windows, always copy 'src' do 'dst'.
*/
result = snprintf(dst, dstsize, "%s", src);
#endif
if (result < 0) {
return (isc_errno_toresult(errno));
} else if ((size_t)result >= dstsize) {
return (ISC_R_NOSPACE);
} else {
return (ISC_R_SUCCESS);
}
}
#if HAVE_DLFCN_H && HAVE_DLOPEN
static isc_result_t
load_symbol(void *handle, const char *modpath,
......@@ -253,7 +292,7 @@ load_plugin(isc_mem_t *mctx, const char *modpath, ns_plugin_t **pluginp) {
CHECK(load_symbol(handle, modpath, "plugin_version",
(void **)&version_func));
version = version_func(NULL);
version = version_func();
if (version < (NS_PLUGIN_VERSION - NS_PLUGIN_AGE) ||
version > NS_PLUGIN_VERSION)
{
......
......@@ -315,6 +315,30 @@ ns_plugin_destroy_t plugin_destroy;
ns_plugin_register_t plugin_register;
ns_plugin_version_t plugin_version;
isc_result_t
ns_plugin_expandpath(const char *src, char *dst, size_t dstsize);
/*%<
* Prepare the plugin location to be passed to dlopen() based on the plugin
* path or filename found in the configuration file ('src'). Store the result
* in 'dst', which is 'dstsize' bytes large.
*
* On Unix systems, two classes of 'src' are recognized:
*
* - If 'src' is an absolute or relative path, it will be copied to 'dst'
* verbatim.
*
* - If 'src' is a filename (i.e. does not contain a path separator), the
* path to the directory into which named plugins are installed will be
* prepended to it and the result will be stored in 'dst'.
*
* On Windows, 'src' is always copied to 'dst' verbatim.
*
* Returns:
*\li #ISC_R_SUCCESS Success
*\li #ISC_R_NOSPACE 'dst' is not large enough to hold the output string
*\li Other result snprintf() returned a negative value
*/
isc_result_t
ns_plugin_register(const char *modpath, const char *parameters,
const void *cfg, const char *cfg_file,
......
......@@ -3,4 +3,5 @@ test_suite('bind9')
tap_test_program{name='listenlist_test'}
tap_test_program{name='notify_test'}
tap_test_program{name='plugin_test'}
tap_test_program{name='query_test'}
......@@ -17,7 +17,7 @@ VERSION=@BIND9_VERSION@
CINCLUDES = -I. -Iinclude ${NS_INCLUDES} ${DNS_INCLUDES} ${ISC_INCLUDES} \
@OPENSSL_INCLUDES@ @CMOCKA_CFLAGS@
CDEFINES = -DTESTS="\"${top_builddir}/lib/ns/tests/\""
CDEFINES = -DTESTS="\"${top_builddir}/lib/ns/tests/\"" -DNAMED_PLUGINDIR=\"${plugindir}\"
ISCLIBS = ../../isc/libisc.@A@ @OPENSSL_LIBS@
ISCDEPLIBS = ../../isc/libisc.@A@
......@@ -33,12 +33,14 @@ OBJS = nstest.@O@
SRCS = nstest.c \
listenlist_test.c \
notify_test.c \
plugin_test.c \
query_test.c
SUBDIRS =
TARGETS = listenlist_test@EXEEXT@ \
notify_test@EXEEXT@ \
query_test
plugin_test@EXEEXT@ \
query_test@EXEEXT@
@BIND9_MAKE_RULES@
......@@ -52,6 +54,11 @@ notify_test@EXEEXT@: notify_test.@O@ nstest.@O@ ${NSDEPLIBS} ${ISCDEPLIBS} ${DNS
${LDFLAGS} -o $@ notify_test.@O@ nstest.@O@ \
${NSLIBS} ${DNSLIBS} ${ISCLIBS} ${LIBS}
plugin_test@EXEEXT@: plugin_test.@O@ nstest.@O@ ${NSDEPLIBS} ${ISCDEPLIBS} ${DNSDEPLIBS}
${LIBTOOL_MODE_LINK} ${PURIFY} ${CC} ${CFLAGS} \
${LDFLAGS} -o $@ plugin_test.@O@ nstest.@O@ \
${NSLIBS} ${DNSLIBS} ${ISCLIBS} ${LIBS}
query_test@EXEEXT@: query_test.@O@ nstest.@O@ ${NSDEPLIBS} ${ISCDEPLIBS} ${DNSDEPLIBS}
${LIBTOOL_MODE_LINK} ${PURIFY} ${CC} ${CFLAGS} \
${LDFLAGS} -o $@ query_test.@O@ nstest.@O@ \
......
/*
* 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.
*/
#include <config.h>
#if HAVE_CMOCKA
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <setjmp.h>
#define UNIT_TESTING
#include <cmocka.h>
#include <limits.h>
#include <stdbool.h>
#include <string.h>
#include <isc/mem.h>
#include <isc/result.h>
#include <isc/types.h>
#include <isc/util.h>
#include <ns/hooks.h>
#include "nstest.h"
static int
_setup(void **state) {
isc_result_t result;
UNUSED(state);
result = ns_test_begin(NULL, false);
assert_int_equal(result, ISC_R_SUCCESS);
return (0);
}
static int
_teardown(void **state) {
if (*state != NULL) {
isc_mem_free(mctx, *state);
}
ns_test_end();
return (0);
}
/*%
* Structure containing parameters for run_full_path_test().
*/
typedef struct {
const ns_test_id_t id; /* libns test identifier */
const char *input; /* source string - plugin name or path */
size_t output_size; /* size of target char array to allocate */
isc_result_t result; /* expected return value */
const char *output; /* expected output string */
} ns_plugin_expandpath_test_params_t;
/*%
* Perform a single ns_plugin_expandpath() check using given parameters.
*/
static void
run_full_path_test(const ns_plugin_expandpath_test_params_t *test,
void **state)
{
char **target = (char **)state;
isc_result_t result;
REQUIRE(test != NULL);
REQUIRE(test->id.description != NULL);
REQUIRE(test->input != NULL);
REQUIRE(test->result != ISC_R_SUCCESS || test->output != NULL);
/*
* Prepare a target buffer of given size. Store it in 'state' so that
* it can get cleaned up by _teardown() if the test fails.
*/
*target = isc_mem_allocate(mctx, test->output_size);
/*
* Call ns_plugin_expandpath().
*/
result = ns_plugin_expandpath(test->input,
*target, test->output_size);
/*
* Check return value.
*/
if (result != test->result) {
fail_msg("# test \"%s\" on line %d: "
"expected result %d (%s), got %d (%s)",
test->id.description, test->id.lineno,
test->result, isc_result_totext(test->result),
result, isc_result_totext(result));
}
/*
* Check output string if return value indicates success.
*/
if (result == ISC_R_SUCCESS && strcmp(*target, test->output) != 0) {
fail_msg("# test \"%s\" on line %d: "
"expected output \"%s\", got \"%s\"",
test->id.description, test->id.lineno,
test->output, *target);
}
isc_mem_free(mctx, *target);
}
/* test ns_plugin_expandpath() */
static void
ns_plugin_expandpath_test(void **state) {
size_t i;
const ns_plugin_expandpath_test_params_t tests[] = {
{
NS_TEST_ID("correct use with an absolute path"),
.input = "/usr/lib/named/foo.so",
.output_size = PATH_MAX,
.result = ISC_R_SUCCESS,
.output = "/usr/lib/named/foo.so",
},
{
NS_TEST_ID("correct use with a relative path"),
.input = "../../foo.so",
.output_size = PATH_MAX,
.result = ISC_R_SUCCESS,
.output = "../../foo.so",
},
{
NS_TEST_ID("correct use with a filename"),
.input = "foo.so",
.output_size = PATH_MAX,
.result = ISC_R_SUCCESS,
#ifndef WIN32
.output = NAMED_PLUGINDIR "/foo.so",
#else
.output = "foo.so",
#endif
},
{
NS_TEST_ID("no space at all in target buffer"),
.input = "/usr/lib/named/foo.so",
.output_size = 0,
.result = ISC_R_NOSPACE,
},
{
NS_TEST_ID("target buffer too small to fit input"),
.input = "/usr/lib/named/foo.so",
.output_size = 1,
.result = ISC_R_NOSPACE,
},
{
NS_TEST_ID("target buffer too small to fit NULL byte"),
.input = "/foo.so",
.output_size = 7,
.result = ISC_R_NOSPACE,
},
#ifndef WIN32
{
NS_TEST_ID("target buffer too small to fit full path"),
.input = "foo.so",
.output_size = 7,
.result = ISC_R_NOSPACE,
},
#endif
};
for (i = 0; i < sizeof(tests) / sizeof(tests[0]); i++) {
run_full_path_test(&tests[i], state);
}
}
int
main(void) {
const struct CMUnitTest tests[] = {
cmocka_unit_test_setup_teardown(ns_plugin_expandpath_test,
_setup, _teardown),
};
return (cmocka_run_group_tests(tests, NULL, NULL));
}
#else /* HAVE_CMOCKA */
#include <stdio.h>
int
main(void) {
printf("1..0 # Skipped: cmocka not available\n");
return (0);
}
#endif
......@@ -75,6 +75,7 @@ ns_log_init
ns_log_setcontext
ns_notify_start
ns_plugin_check
ns_plugin_expandpath
ns_plugin_register
ns_plugins_create
ns_plugins_free
......
......@@ -2510,6 +2510,7 @@
./lib/ns/tests/notify_test.c C 2017,2018,2019
./lib/ns/tests/nstest.c C 2017,2018,2019
./lib/ns/tests/nstest.h C 2017,2018,2019
./lib/ns/tests/plugin_test.c C 2019
./lib/ns/tests/query_test.c C 2017,2018,2019
./lib/ns/tests/testdata/notify/notify1.msg X 2017,2018,2019
./lib/ns/update.c C 2017,2018,2019
......
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