--- /dev/null
+/*
+ * Copyright (c) - 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by as
+ * published by the Free Software Foundation; only version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <stdlib.h>
+#include <inttypes.h>
+#include <stdbool.h>
+#include <assert.h>
+#include <string.h>
+#include <stdarg.h>
+#include <tap/tap.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+#include <urcu.h>
+
+#include <common/fd-tracker/fd-tracker.h>
+#include <common/error.h>
+
+/* For error.h */
+int lttng_opt_quiet = 1;
+int lttng_opt_verbose;
+int lttng_opt_mi;
+
+/* Number of TAP tests in this file */
+#define NUM_TESTS 35
+/* 3 for stdin, stdout, and stderr */
+#define STDIO_FD_COUNT 3
+#define TRACKER_FD_LIMIT 50
+#define TMP_DIR_PATTERN "/tmp/fd-tracker-XXXXXX"
+
+/*
+ * Count of fds, beyond stdin, stderr, stdout that were open
+ * at the launch of the test. This allows the test to succeed when
+ * run by automake's test runner or valgrind which both open
+ * fds behind our back.
+ */
+int unknown_fds_count;
+
+const char file_contents[] = "Bacon ipsum dolor amet jerky drumstick sirloin "
+ "strip steak venison boudin filet mignon picanha doner shoulder. "
+ "Strip steak brisket alcatra, venison beef chuck cupim pastrami. "
+ "Landjaeger tri-tip salami leberkas ball tip, ham hock chuck sausage "
+ "flank jerky cupim. Pig bacon chuck pancetta andouille.";
+
+int fd_count(void)
+{
+ DIR *dir;
+ struct dirent *entry;
+ int count = 0;
+
+ dir = opendir("/proc/self/fd");
+ if (!dir) {
+ perror("# Failed to enumerate /proc/self/fd/ to count the number of used file descriptors");
+ count = -1;
+ goto end;
+ }
+
+ while ((entry = readdir(dir)) != NULL) {
+ if (!strcmp(entry->d_name, ".") || !strcmp(entry->d_name, "..")) {
+ continue;
+ }
+ count++;
+ }
+ /* Don't account for the file descriptor opened by opendir(). */
+ count--;
+ closedir(dir);
+end:
+ return count;
+}
+
+static
+void check_fd_count(int expected_count)
+{
+ int count = 0;
+
+ count = fd_count();
+ ok(count == expected_count, "Expected %d open file descriptors (%d are open)",
+ expected_count, count);
+}
+
+static
+int noop_open(void *data, int *fds)
+{
+ *fds = *((int *) data);
+ return 0;
+}
+
+static
+int noop_close(void *data, int *fds)
+{
+ return 0;
+}
+
+static
+void track_std_fds(struct fd_tracker *tracker)
+{
+ int i;
+ struct { int fd; const char *name; } files[] = {
+ { .fd = fileno(stdin), .name = "stdin" },
+ { .fd = fileno(stdout), .name = "stdout" },
+ { .fd = fileno(stderr), .name = "stderr" },
+ };
+
+ for (i = 0; i < sizeof(files) / sizeof(*files); i++) {
+ int out_fd, ret;
+
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ &files[i].name, 1, noop_open, &files[i].fd);
+ assert(out_fd == files[i].fd);
+
+ ok(ret == 0, "Track unsuspendable fd %d (%s)", files[i].fd,
+ files[i].name);
+ }
+}
+
+static
+void untrack_std_fds(struct fd_tracker *tracker)
+{
+ int i;
+ struct { int fd; const char *name; } files[] = {
+ { .fd = fileno(stdin), .name = "stdin" },
+ { .fd = fileno(stdout), .name = "stdout" },
+ { .fd = fileno(stderr), .name = "stderr" },
+ };
+ unsigned int fds_set_to_minus_1 = 0;
+
+ for (i = 0; i < sizeof(files) / sizeof(*files); i++) {
+ int fd = files[i].fd;
+ int ret = fd_tracker_close_unsuspendable_fd(tracker,
+ &files[i].fd, 1, noop_close, NULL);
+
+ ok(ret == 0, "Untrack unsuspendable fd %d (%s)", fd,
+ files[i].name);
+ fds_set_to_minus_1 += (files[i].fd == -1);
+ }
+}
+
+/*
+ * Basic test opening and closing three unsuspendable fds.
+ */
+static
+void test_unsuspendable_basic(void)
+{
+ struct fd_tracker *tracker;
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ ok(tracker, "Created an fd tracker with a limit of %d simulateously opened file descriptors",
+ TRACKER_FD_LIMIT);
+ if (!tracker) {
+ return;
+ }
+
+ track_std_fds(tracker);
+ untrack_std_fds(tracker);
+
+ fd_tracker_destroy(tracker);
+}
+
+static
+int error_open(void *data, int *fds)
+{
+ return *((int *) data);
+}
+
+static
+int error_close(void *data, int *fds)
+{
+ return *((int *) data);
+}
+
+/*
+ * Validate that user callback return values are returned to the
+ * caller of the fd tracker.
+ */
+static
+void test_unsuspendable_cb_return(void)
+{
+ int ret, stdout_fd = fileno(stdout), out_fd = 42;
+ struct fd_tracker *tracker;
+ int expected_error = -ENETDOWN;
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ assert(tracker);
+
+ /* The error_open callback should fail and return 'expected_error'. */
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ NULL, 1, error_open, &expected_error);
+ ok(ret == expected_error, "fd_tracker_open_unsuspendable_fd() forwards the user callback's error code");
+ ok(out_fd == 42, "Output fd parameter is unaffected on error of fd_tracker_open_unsuspendable_fd()");
+
+ /*
+ * Track a valid fd since we don't want the tracker to fail with an
+ * invalid fd error for this test.
+ */
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ NULL, 1, noop_open, &stdout_fd);
+ ok(out_fd == stdout_fd, "fd_tracker_open_unsuspendable_fd() sets the output fd parameter to the newly-tracked fd's value");
+ assert(!ret);
+
+ ret = fd_tracker_close_unsuspendable_fd(tracker,
+ &stdout_fd, 1, error_close, &expected_error);
+ ok(ret == expected_error, "fd_tracker_close_unsuspendable_fd() forwards the user callback's error code");
+ ret = fd_tracker_close_unsuspendable_fd(tracker,
+ &stdout_fd, 1, noop_close, &expected_error);
+ assert(!ret);
+
+ fd_tracker_destroy(tracker);
+}
+
+/*
+ * Validate that the tracker refuses to track two identical unsuspendable
+ * file descriptors.
+ */
+static
+void test_unsuspendable_duplicate(void)
+{
+ int ret, stdout_fd = fileno(stdout), out_fd;
+ struct fd_tracker *tracker;
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ assert(tracker);
+
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ NULL, 1, noop_open, &stdout_fd);
+ assert(!ret);
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ NULL, 1, noop_open, &stdout_fd);
+ ok(ret == -EEXIST, "EEXIST reported on open of an already tracked file descriptor");
+
+ ret = fd_tracker_close_unsuspendable_fd(tracker,
+ &stdout_fd, 1, noop_close, NULL);
+ assert(!ret);
+
+ fd_tracker_destroy(tracker);
+}
+
+static
+int open_pipes(void *data, int *out_fds)
+{
+ unsigned int i;
+ const unsigned int pipe_count = TRACKER_FD_LIMIT / 2;
+
+ for (i = 0; i < pipe_count; i++) {
+ int ret = pipe(&out_fds[i * 2]);
+
+ if (ret) {
+ return -errno;
+ }
+ }
+ return 0;
+}
+
+static
+int close_pipes(void *data, int *fds)
+{
+ int i;
+ int *pipes = fds;
+
+ for (i = 0; i < TRACKER_FD_LIMIT; i++) {
+ int ret = close(pipes[i]);
+
+ if (ret) {
+ return -errno;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Validate that the tracker enforces the open file descriptor limit
+ * when unsuspendable file descritptors are being opened.
+ */
+static
+void test_unsuspendable_limit(void)
+{
+ struct fd_tracker *tracker;
+ int ret, stdout_fd = fileno(stdout), out_fd;
+ int fds[TRACKER_FD_LIMIT];
+
+ /* This test assumes TRACKER_FD_LIMIT is a multiple of 2. */
+ assert((TRACKER_FD_LIMIT % 2 == 0) && TRACKER_FD_LIMIT);
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ assert(tracker);
+
+ ret = fd_tracker_open_unsuspendable_fd(tracker, fds,
+ NULL, TRACKER_FD_LIMIT, open_pipes, NULL);
+ ok(ret == 0, "File descriptor tracker allowed the user to meet its limit with unsuspendable file descritptors (%d)",
+ TRACKER_FD_LIMIT);
+
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ NULL, 1, noop_open, &stdout_fd);
+ ok(ret == -EMFILE, "EMFILE reported when exceeding the file descriptor limit while opening an unsuspendable fd");
+
+ ret = fd_tracker_close_unsuspendable_fd(tracker,
+ fds, TRACKER_FD_LIMIT, close_pipes, NULL);
+ assert(!ret);
+
+ fd_tracker_destroy(tracker);
+}
+
+/*
+ * Validate that the tracker refuses to track two identical unsuspendable
+ * file descriptors.
+ */
+static
+void test_unsuspendable_close_untracked(void)
+{
+ int ret, stdout_fd = fileno(stdout), unknown_fds[2], out_fd;
+ struct fd_tracker *tracker;
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ if (!tracker) {
+ return;
+ }
+
+ ret = pipe(unknown_fds);
+ assert(!ret);
+ assert(close(unknown_fds[0]) == 0);
+ assert(close(unknown_fds[1]) == 0);
+
+ ret = fd_tracker_open_unsuspendable_fd(tracker, &out_fd,
+ NULL, 1, noop_open, &stdout_fd);
+ assert(!ret);
+
+ ret = fd_tracker_close_unsuspendable_fd(tracker,
+ unknown_fds, 1, noop_close, NULL);
+ ok(ret == -EINVAL, "EINVAL reported on close of an untracked file descriptor");
+
+ ret = fd_tracker_close_unsuspendable_fd(tracker,
+ &stdout_fd, 1, noop_close, NULL);
+ assert(!ret);
+
+ fd_tracker_destroy(tracker);
+}
+
+static
+int open_files(struct fd_tracker *tracker, const char *dir, unsigned int count,
+ struct fs_handle **handles, char **file_paths)
+{
+ int ret = 0;
+ unsigned int i;
+
+ for (i = 0; i < count; i++) {
+ int ret;
+ char *file_path;
+ struct fs_handle *handle;
+ mode_t mode = S_IWUSR | S_IRUSR;
+
+ ret = asprintf(&file_path, "%s/file-%u", dir, i);
+ assert(ret >= 0);
+ file_paths[i] = file_path;
+
+ handle = fd_tracker_open_fs_handle(tracker, file_path,
+ O_RDWR | O_CREAT, &mode);
+ if (!handle) {
+ ret = -1;
+ break;
+ }
+ handles[i] = handle;
+ }
+ return ret;
+}
+
+static
+int cleanup_files(struct fd_tracker *tracker, const char *dir,
+ unsigned int count, struct fs_handle **handles,
+ char **file_paths)
+{
+ int ret = 0;
+ unsigned int i;
+
+ for (i = 0; i < count; i++) {
+ char *file_path = file_paths[i];
+
+ if (!file_path) {
+ break;
+ }
+ (void) unlink(file_path);
+ free(file_path);
+ if (fs_handle_close(handles[i])) {
+ ret = -1;
+ }
+ }
+ return ret;
+}
+
+static
+void test_suspendable_limit(void)
+{
+ int ret;
+ const int files_to_create = TRACKER_FD_LIMIT * 10;
+ struct fd_tracker *tracker;
+ char tmp_path_pattern[] = TMP_DIR_PATTERN;
+ const char *output_dir;
+ char *output_files[files_to_create];
+ struct fs_handle *handles[files_to_create];
+
+ memset(output_files, 0, sizeof(output_files));
+ memset(handles, 0, sizeof(handles));
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ if (!tracker) {
+ return;
+ }
+
+ output_dir = mkdtemp(tmp_path_pattern);
+ if (!output_dir) {
+ diag("Failed to create temporary path of the form %s",
+ TMP_DIR_PATTERN);
+ assert(0);
+ }
+
+ ret = open_files(tracker, output_dir, files_to_create, handles,
+ output_files);
+ ok(!ret, "Created %d files with a limit of %d simultaneously-opened file descriptor",
+ files_to_create, TRACKER_FD_LIMIT);
+ check_fd_count(TRACKER_FD_LIMIT + STDIO_FD_COUNT + unknown_fds_count);
+
+ ret = cleanup_files(tracker, output_dir, files_to_create, handles,
+ output_files);
+ ok(!ret, "Close all opened filesystem handles");
+ (void) rmdir(output_dir);
+ fd_tracker_destroy(tracker);
+}
+
+static
+void test_mixed_limit(void)
+{
+ int ret;
+ const int files_to_create = TRACKER_FD_LIMIT;
+ struct fd_tracker *tracker;
+ char tmp_path_pattern[] = TMP_DIR_PATTERN;
+ const char *output_dir;
+ char *output_files[files_to_create];
+ struct fs_handle *handles[files_to_create];
+
+ memset(output_files, 0, sizeof(output_files));
+ memset(handles, 0, sizeof(handles));
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ if (!tracker) {
+ return;
+ }
+
+ output_dir = mkdtemp(tmp_path_pattern);
+ if (!output_dir) {
+ diag("Failed to create temporary path of the form %s",
+ TMP_DIR_PATTERN);
+ assert(0);
+ }
+
+ ret = open_files(tracker, output_dir, files_to_create, handles,
+ output_files);
+ ok(!ret, "Created %d files with a limit of %d simultaneously-opened file descriptor",
+ files_to_create, TRACKER_FD_LIMIT);
+ diag("Check file descriptor count after opening %u files", files_to_create);
+ check_fd_count(TRACKER_FD_LIMIT + STDIO_FD_COUNT + unknown_fds_count);
+
+ /*
+ * Open unsuspendable fds (stdin, stdout, stderr) and verify that the fd
+ * cap is still respected.
+ */
+ diag("Check file descriptor count after adding %d unsuspendable fds",
+ STDIO_FD_COUNT);
+ track_std_fds(tracker);
+ check_fd_count(TRACKER_FD_LIMIT + unknown_fds_count);
+ diag("Untrack unsuspendable file descriptors");
+ untrack_std_fds(tracker);
+ check_fd_count(TRACKER_FD_LIMIT + unknown_fds_count);
+
+ ret = cleanup_files(tracker, output_dir, files_to_create, handles,
+ output_files);
+ ok(!ret, "Close all opened filesystem handles");
+ (void) rmdir(output_dir);
+ fd_tracker_destroy(tracker);
+}
+
+/*
+ * Open more files than allowed by the fd tracker's cap and write,
+ * byte-by-byte, and in round-robin, a string. The goal is to force
+ * the fd tracker to suspend and resume the fs_handles often and
+ * verify that the fd cap is always respected.
+ *
+ * The content of the files is also verified at the end.
+ */
+static
+void test_suspendable_restore(void)
+{
+ int ret;
+ const int files_to_create = TRACKER_FD_LIMIT * 10;
+ struct fd_tracker *tracker;
+ char tmp_path_pattern[] = TMP_DIR_PATTERN;
+ const char *output_dir;
+ char *output_files[files_to_create];
+ struct fs_handle *handles[files_to_create];
+ size_t content_index;
+ int handle_index;
+ bool write_success = true;
+ bool fd_cap_respected = true;
+ bool content_ok = true;
+
+ memset(output_files, 0, sizeof(output_files));
+ memset(handles, 0, sizeof(handles));
+
+ tracker = fd_tracker_create(TRACKER_FD_LIMIT);
+ if (!tracker) {
+ return;
+ }
+
+ output_dir = mkdtemp(tmp_path_pattern);
+ if (!output_dir) {
+ diag("Failed to create temporary path of the form %s",
+ TMP_DIR_PATTERN);
+ assert(0);
+ }
+
+ ret = open_files(tracker, output_dir, files_to_create, handles,
+ output_files);
+ ok(!ret, "Created %d files with a limit of %d simultaneously-opened file descriptor",
+ files_to_create, TRACKER_FD_LIMIT);
+ diag("Check file descriptor count after opening %u files", files_to_create);
+ check_fd_count(TRACKER_FD_LIMIT + STDIO_FD_COUNT + unknown_fds_count);
+
+ for (content_index = 0; content_index < sizeof(file_contents); content_index++) {
+ for (handle_index = 0; handle_index < files_to_create; handle_index++) {
+ int fd;
+ struct fs_handle *handle = handles[handle_index];
+ const char *path = output_files[handle_index];
+
+ fd = fs_handle_get_fd(handle);
+ if (fd < 0) {
+ write_success = false;
+ diag("Failed to restore fs_handle to %s",
+ path);
+ goto skip_write;
+ }
+
+ do {
+ ret = write(fd, file_contents + content_index, 1);
+ } while (ret < 0 && errno == EINTR);
+
+ if (ret != 1) {
+ write_success = false;
+ PERROR("write() to %s failed", path);
+ goto skip_write;
+ }
+
+ if (fd_count() >
+ (TRACKER_FD_LIMIT + STDIO_FD_COUNT +
+ unknown_fds_count)) {
+ fd_cap_respected = false;
+ }
+
+ fs_handle_put_fd(handle);
+ }
+ }
+skip_write:
+ ok(write_success, "Wrote reference string to %d files",
+ files_to_create);
+ ok(fd_cap_respected, "FD tracker enforced the file descriptor cap");
+
+ /* Validate the contents of the files. */
+ for (handle_index = 0; handle_index < files_to_create; handle_index++) {
+ struct stat fd_stat;
+ const char *path = output_files[handle_index];
+ char read_buf[sizeof(file_contents)];
+ char *read_pos;
+ size_t to_read = sizeof(read_buf);
+ int fd;
+
+ fd = open(path, O_RDONLY);
+ assert(fd >= 0);
+ ret = fstat(fd, &fd_stat);
+ assert(!ret);
+ if (fd_stat.st_size != sizeof(file_contents)) {
+ diag("Content size of file %s doesn't match, got %" PRId64 ", expected %zu",
+ path, (int64_t) fd_stat.st_size,
+ sizeof(file_contents));
+ content_ok = false;
+ (void) close(fd);
+ break;
+ }
+
+ read_pos = read_buf;
+ do {
+ ret = read(fd, read_pos, to_read);
+ if (ret > 0) {
+ to_read -= ret;
+ read_pos += ret;
+ }
+ } while (to_read && (ret < 0 && errno == EINTR));
+ if (ret < 0) {
+ content_ok = false;
+ PERROR("Failed to read file %s", path);
+ (void) close(fd);
+ break;
+ }
+
+ if (strcmp(file_contents, read_buf)) {
+ content_ok = false;
+ diag("File content doesn't match the expectated string");
+ (void) close(fd);
+ break;
+ }
+ (void) close(fd);
+ }
+ ok(content_ok, "Files contain the expected content");
+ ret = cleanup_files(tracker, output_dir, files_to_create, handles,
+ output_files);
+ ok(!ret, "Close all opened filesystem handles");
+ (void) rmdir(output_dir);
+ fd_tracker_destroy(tracker);
+}
+
+int main(int argc, char **argv)
+{
+ plan_tests(NUM_TESTS);
+ diag("File descriptor tracker unit tests");
+
+ rcu_register_thread();
+
+ unknown_fds_count = fd_count() - STDIO_FD_COUNT;
+ assert(unknown_fds_count >= 0);
+
+ diag("Unsuspendable - basic");
+ test_unsuspendable_basic();
+ diag("Unsuspendable - callback return values");
+ test_unsuspendable_cb_return();
+ diag("Unsuspendable - duplicate file descriptors");
+ test_unsuspendable_duplicate();
+ diag("Unsuspendable - closing an untracked file descriptor");
+ test_unsuspendable_close_untracked();
+ diag("Unsuspendable - check that file descritptor limit is enforced");
+ test_unsuspendable_limit();
+
+ diag("Suspendable - check that file descritptor limit is enforced");
+ test_suspendable_limit();
+ diag("Suspendable - restoration test");
+ test_suspendable_restore();
+
+ diag("Mixed - check that file descritptor limit is enforced");
+ test_mixed_limit();
+
+ rcu_unregister_thread();
+ return exit_status();
+}
projects / lttng-tools.git / commitdiff
