From 2b13d8192f0d7a08bb16a3e488e772d54b10d81a Mon Sep 17 00:00:00 2001
From: Jakub Hrozek <jhrozek@redhat.com>
Date: Wed, 12 Aug 2015 12:41:44 +0200
Subject: [PATCH 56/57] UTIL: Provide a common interface to safely create
temporary files
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
---
src/tests/cmocka/test_utils.c | 175 ++++++++++++++++++++++++++++++++++++++++++
src/util/util.c | 127 ++++++++++++++++++++++++++++++
src/util/util.h | 21 +++++
3 files changed, 323 insertions(+)
diff --git a/src/tests/cmocka/test_utils.c b/src/tests/cmocka/test_utils.c
index d3d00feda0bdd4048519f90ba48ae9d1042a95a1..c7ebe0997ec00197e8852bedbcf26ef1f6394fc3 100644
--- a/src/tests/cmocka/test_utils.c
+++ b/src/tests/cmocka/test_utils.c
@@ -1212,6 +1212,168 @@ void test_fix_domain_in_name_list(void **state)
talloc_free(dom);
}
+struct unique_file_test_ctx {
+ char *filename;
+};
+
+static int unique_file_test_setup(void **state)
+{
+ struct unique_file_test_ctx *test_ctx;
+
+ assert_true(leak_check_setup());
+ check_leaks_push(global_talloc_context);
+
+ test_ctx = talloc_zero(global_talloc_context, struct unique_file_test_ctx);
+ assert_non_null(test_ctx);
+
+ test_ctx->filename = talloc_strdup(test_ctx, "test_unique_file_XXXXXX");
+ assert_non_null(test_ctx);
+
+ *state = test_ctx;
+ return 0;
+}
+
+static int unique_file_test_teardown(void **state)
+{
+ struct unique_file_test_ctx *test_ctx;
+ errno_t ret;
+
+ test_ctx = talloc_get_type(*state, struct unique_file_test_ctx);
+
+ errno = 0;
+ ret = unlink(test_ctx->filename);
+ if (ret != 0 && errno != ENOENT) {
+ fail();
+ }
+
+ talloc_free(test_ctx);
+ assert_true(check_leaks_pop(global_talloc_context) == true);
+ assert_true(leak_check_teardown());
+ return 0;
+}
+
+static void assert_destructor(TALLOC_CTX *owner,
+ struct unique_file_test_ctx *test_ctx)
+{
+ int fd;
+ errno_t ret;
+ char *check_filename;
+
+ /* Test that the destructor works */
+ if (owner == NULL) {
+ return;
+ }
+
+ check_filename = talloc_strdup(test_ctx, test_ctx->filename);
+ assert_non_null(check_filename);
+
+ talloc_free(owner);
+
+ ret = check_and_open_readonly(test_ctx->filename, &fd,
+ geteuid(), getegid(),
+ (S_IRUSR | S_IWUSR | S_IFREG), 0);
+ close(fd);
+ assert_int_not_equal(ret, EOK);
+}
+
+static void sss_unique_file_test(struct unique_file_test_ctx *test_ctx,
+ bool test_destructor)
+{
+ int fd;
+ errno_t ret;
+ struct stat sb;
+ TALLOC_CTX *owner = NULL;
+
+ if (test_destructor) {
+ owner = talloc_new(test_ctx);
+ assert_non_null(owner);
+ }
+
+ fd = sss_unique_file(owner, test_ctx->filename, &ret);
+ assert_int_not_equal(fd, -1);
+ assert_int_equal(ret, EOK);
+
+ ret = check_fd(fd, geteuid(), getegid(),
+ (S_IRUSR | S_IWUSR | S_IFREG), 0, &sb);
+ close(fd);
+ assert_int_equal(ret, EOK);
+
+ assert_destructor(owner, test_ctx);
+}
+
+static void test_sss_unique_file(void **state)
+{
+ struct unique_file_test_ctx *test_ctx;
+ test_ctx = talloc_get_type(*state, struct unique_file_test_ctx);
+ sss_unique_file_test(test_ctx, false);
+}
+
+static void test_sss_unique_file_destruct(void **state)
+{
+ struct unique_file_test_ctx *test_ctx;
+ test_ctx = talloc_get_type(*state, struct unique_file_test_ctx);
+ sss_unique_file_test(test_ctx, true);
+}
+
+static void test_sss_unique_file_neg(void **state)
+{
+ int fd;
+ errno_t ret;
+
+ fd = sss_unique_file(NULL, discard_const("badpattern"), &ret);
+ assert_int_equal(fd, -1);
+ assert_int_equal(ret, EINVAL);
+}
+
+static void sss_unique_filename_test(struct unique_file_test_ctx *test_ctx,
+ bool test_destructor)
+{
+ int fd;
+ errno_t ret;
+ char *tmp_filename;
+ TALLOC_CTX *owner = NULL;
+
+ tmp_filename = talloc_strdup(test_ctx, test_ctx->filename);
+ assert_non_null(tmp_filename);
+
+ if (test_destructor) {
+ owner = talloc_new(test_ctx);
+ assert_non_null(owner);
+ }
+
+ ret = sss_unique_filename(owner, test_ctx->filename);
+ assert_int_equal(ret, EOK);
+
+ assert_int_equal(strncmp(test_ctx->filename,
+ tmp_filename,
+ strlen(tmp_filename) - sizeof("XXXXXX")),
+ 0);
+
+ ret = check_and_open_readonly(test_ctx->filename, &fd,
+ geteuid(), getegid(),
+ (S_IRUSR | S_IWUSR | S_IFREG), 0);
+ close(fd);
+ assert_int_equal(ret, EOK);
+
+ assert_destructor(owner, test_ctx);
+}
+
+static void test_sss_unique_filename(void **state)
+{
+ struct unique_file_test_ctx *test_ctx;
+
+ test_ctx = talloc_get_type(*state, struct unique_file_test_ctx);
+ sss_unique_filename_test(test_ctx, false);
+}
+
+static void test_sss_unique_filename_destruct(void **state)
+{
+ struct unique_file_test_ctx *test_ctx;
+
+ test_ctx = talloc_get_type(*state, struct unique_file_test_ctx);
+ sss_unique_filename_test(test_ctx, true);
+}
+
int main(int argc, const char *argv[])
{
poptContext pc;
@@ -1275,6 +1437,19 @@ int main(int argc, const char *argv[])
cmocka_unit_test_setup_teardown(test_fix_domain_in_name_list,
confdb_test_setup,
confdb_test_teardown),
+ cmocka_unit_test_setup_teardown(test_sss_unique_file,
+ unique_file_test_setup,
+ unique_file_test_teardown),
+ cmocka_unit_test_setup_teardown(test_sss_unique_file_destruct,
+ unique_file_test_setup,
+ unique_file_test_teardown),
+ cmocka_unit_test(test_sss_unique_file_neg),
+ cmocka_unit_test_setup_teardown(test_sss_unique_filename,
+ unique_file_test_setup,
+ unique_file_test_teardown),
+ cmocka_unit_test_setup_teardown(test_sss_unique_filename_destruct,
+ unique_file_test_setup,
+ unique_file_test_teardown),
};
/* Set debug level to invalid value so we can deside if -d 0 was used. */
diff --git a/src/util/util.c b/src/util/util.c
index 782cd026b7928e607a8980fb5f333c794feb5b1a..f0925051a08970b191f61a533cd49dd53ae128e0 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -979,3 +979,130 @@ errno_t sss_utc_to_time_t(const char *str, const char *format, time_t *_unix_tim
*_unix_time = ut;
return EOK;
}
+
+struct tmpfile_watch {
+ const char *filename;
+};
+
+static int unlink_dbg(const char *filename)
+{
+ errno_t ret;
+
+ ret = unlink(filename);
+ if (ret != 0) {
+ if (errno == 2) {
+ DEBUG(SSSDBG_TRACE_INTERNAL,
+ "File already removed: [%s]\n", filename);
+ return 0;
+ } else {
+ DEBUG(SSSDBG_CRIT_FAILURE,
+ "Cannot remove temporary file [%s]\n", filename);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int unique_filename_destructor(void *memptr)
+{
+ struct tmpfile_watch *tw = talloc_get_type(memptr, struct tmpfile_watch);
+
+ if (tw == NULL || tw->filename == NULL) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "BUG: Wrong private pointer\n");
+ return -1;
+ }
+
+ DEBUG(SSSDBG_TRACE_INTERNAL, "Unlinking [%s]\n", tw->filename);
+
+ return unlink_dbg(tw->filename);
+}
+
+static struct tmpfile_watch *tmpfile_watch_set(TALLOC_CTX *owner,
+ const char *filename)
+{
+ struct tmpfile_watch *tw = NULL;
+
+ tw = talloc_zero(owner, struct tmpfile_watch);
+ if (tw == NULL) {
+ return NULL;
+ }
+
+ tw->filename = talloc_strdup(tw, filename);
+ if (tw->filename == NULL) {
+ talloc_free(tw);
+ return NULL;
+ }
+
+ talloc_set_destructor((TALLOC_CTX *) tw,
+ unique_filename_destructor);
+ return tw;
+}
+
+int sss_unique_file_ex(TALLOC_CTX *owner,
+ char *path_tmpl,
+ mode_t file_umask,
+ errno_t *_err)
+{
+ size_t tmpl_len;
+ errno_t ret;
+ int fd = -1;
+ mode_t old_umask;
+ struct tmpfile_watch *tw = NULL;
+
+ tmpl_len = strlen(path_tmpl);
+ if (tmpl_len < 6 || strcmp(path_tmpl + (tmpl_len - 6), "XXXXXX") != 0) {
+ DEBUG(SSSDBG_OP_FAILURE,
+ "Template too short or doesn't end with XXXXXX!\n");
+ ret = EINVAL;
+ goto done;
+ }
+
+ old_umask = umask(file_umask);
+ fd = mkstemp(path_tmpl);
+ umask(old_umask);
+ if (fd == -1) {
+ ret = errno;
+ DEBUG(SSSDBG_OP_FAILURE,
+ "mkstemp(\"%s\") failed [%d]: %s!\n",
+ path_tmpl, ret, strerror(ret));
+ goto done;
+ }
+
+ if (owner != NULL) {
+ tw = tmpfile_watch_set(owner, path_tmpl);
+ if (tw == NULL) {
+ unlink_dbg(path_tmpl);
+ ret = ENOMEM;
+ goto done;
+ }
+ }
+
+ ret = EOK;
+done:
+ if (_err) {
+ *_err = ret;
+ }
+ return fd;
+}
+
+int sss_unique_file(TALLOC_CTX *owner,
+ char *path_tmpl,
+ errno_t *_err)
+{
+ return sss_unique_file_ex(owner, path_tmpl, 077, _err);
+}
+
+errno_t sss_unique_filename(TALLOC_CTX *owner, char *path_tmpl)
+{
+ int fd;
+ errno_t ret;
+
+ fd = sss_unique_file(owner, path_tmpl, &ret);
+ /* We only care about a unique file name */
+ if (fd >= 0) {
+ close(fd);
+ }
+
+ return ret;
+}
diff --git a/src/util/util.h b/src/util/util.h
index 94a3ddea839f0998cb7796f1d2fe13f743de3aaf..a20d1d82eb8f10dac515ad25e7e424713bb1c099 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -658,4 +658,25 @@ int get_seuser(TALLOC_CTX *mem_ctx, const char *login_name,
/* convert time from generalized form to unix time */
errno_t sss_utc_to_time_t(const char *str, const char *format, time_t *unix_time);
+/* Creates a unique file using mkstemp with provided umask. The template
+ * must end with XXXXXX. Returns the fd, sets _err to an errno value on error.
+ *
+ * Prefer using sss_unique_file() as it uses a secure umask internally.
+ */
+int sss_unique_file_ex(TALLOC_CTX *mem_ctx,
+ char *path_tmpl,
+ mode_t file_umask,
+ errno_t *_err);
+int sss_unique_file(TALLOC_CTX *owner,
+ char *path_tmpl,
+ errno_t *_err);
+
+/* Creates a unique filename using mkstemp with secure umask. The template
+ * must end with XXXXXX
+ *
+ * path_tmpl must be a talloc context. Destructor would be set on the filename
+ * so that it's guaranteed the file is removed.
+ */
+int sss_unique_filename(TALLOC_CTX *owner, char *path_tmpl);
+
#endif /* __SSSD_UTIL_H__ */
--
2.4.3