[LTP] [PATCH 8/8] syscalls/fanotify: New test to validate unprivileged listener events
Amir Goldstein
amir73il@gmail.com
Thu Mar 18 14:11:34 CET 2021
Defined test cases that are responsible for validating that the events
returned to an unprivileged event listener contain the correct values.
Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
runtest/syscalls | 1 +
testcases/kernel/syscalls/fanotify/.gitignore | 1 +
.../kernel/syscalls/fanotify/fanotify19.c | 253 ++++++++++++++++++
3 files changed, 255 insertions(+)
create mode 100644 testcases/kernel/syscalls/fanotify/fanotify19.c
diff --git a/runtest/syscalls b/runtest/syscalls
index 9caa3cf7a..2d1e7b648 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -592,6 +592,7 @@ fanotify15 fanotify15
fanotify16 fanotify16
fanotify17 fanotify17
fanotify18 fanotify18
+fanotify19 fanotify19
ioperm01 ioperm01
ioperm02 ioperm02
diff --git a/testcases/kernel/syscalls/fanotify/.gitignore b/testcases/kernel/syscalls/fanotify/.gitignore
index 175e68ca3..9554b16b1 100644
--- a/testcases/kernel/syscalls/fanotify/.gitignore
+++ b/testcases/kernel/syscalls/fanotify/.gitignore
@@ -16,4 +16,5 @@
/fanotify16
/fanotify17
/fanotify18
+/fanotify19
/fanotify_child
diff --git a/testcases/kernel/syscalls/fanotify/fanotify19.c b/testcases/kernel/syscalls/fanotify/fanotify19.c
new file mode 100644
index 000000000..83a9aaa98
--- /dev/null
+++ b/testcases/kernel/syscalls/fanotify/fanotify19.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2018 Matthew Bobrowski. All Rights Reserved.
+ *
+ * Started by Matthew Bobrowski <mbobrowski@mbobrowski.org>
+ *
+ * DESCRIPTION
+ * This set of tests is to ensure that the unprivileged listener feature of
+ * fanotify is functioning as expected. The objective of this test file is
+ * to generate a sequence of events and ensure that the returned events
+ * contain the limited values that an unprivileged listener is expected
+ * to receive.
+ */
+#define _GNU_SOURCE
+#include "config.h"
+
+#include <pwd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+
+#include "tst_test.h"
+#include "fanotify.h"
+
+#if defined(HAVE_SYS_FANOTIFY_H)
+#include <sys/fanotify.h>
+
+#define EVENT_MAX 1024
+#define EVENT_SIZE (sizeof (struct fanotify_event_metadata))
+#define EVENT_BUF_LEN (EVENT_MAX * EVENT_SIZE)
+#define EVENT_SET_MAX 48
+
+#define BUF_SIZE 256
+
+#define MOUNT_PATH "fs_mnt"
+#define TEST_FILE MOUNT_PATH "/testfile"
+
+static int fd_notify;
+static char buf[BUF_SIZE];
+static struct fanotify_event_metadata event_buf[EVENT_BUF_LEN];
+
+static struct test_case_t {
+ const char *name;
+ unsigned int fork;
+ unsigned int event_count;
+ unsigned long long event_set[EVENT_SET_MAX];
+} test_cases[] = {
+ {
+ "unprivileged listener - events by self",
+ 0,
+ 4,
+ {
+ FAN_OPEN,
+ FAN_ACCESS,
+ FAN_MODIFY,
+ FAN_CLOSE,
+ }
+ },
+ {
+ "unprivileged lisneter - events by child",
+ 1,
+ 4,
+ {
+ FAN_OPEN,
+ FAN_ACCESS,
+ FAN_MODIFY,
+ FAN_CLOSE,
+ }
+ }
+};
+
+static void generate_events(void)
+{
+ int fd;
+
+ /* FAN_OPEN */
+ fd = SAFE_OPEN(TEST_FILE, O_RDWR);
+
+ /* FAN_ACCESS */
+ SAFE_READ(0, fd, buf, BUF_SIZE);
+
+ /* FAN_MODIFY */
+ SAFE_WRITE(1, fd, TEST_FILE, 1);
+
+ /* FAN_CLOSE */
+ SAFE_CLOSE(fd);
+}
+
+static void do_fork(void)
+{
+ int status;
+ pid_t child;
+
+ child = SAFE_FORK();
+
+ if (child == 0) {
+ SAFE_CLOSE(fd_notify);
+ generate_events();
+ exit(0);
+ }
+
+ SAFE_WAITPID(child, &status, 0);
+
+ if (WIFEXITED(child) && WEXITSTATUS(child) != 0)
+ tst_brk(TBROK, "Child process terminated incorrectly. Aborting");
+}
+
+static void test_fanotify(unsigned int n)
+{
+ int len = 0;
+ pid_t pid = getpid();
+ unsigned int test_number = 0;
+ struct fanotify_event_metadata *event;
+ struct test_case_t *tc = &test_cases[n];
+
+ tst_res(TINFO, "Test #%d %s", n, tc->name);
+
+ /* Initialize fanotify */
+ fd_notify = fanotify_init(FANOTIFY_REQUIRED_USER_INIT_FLAGS, O_RDONLY);
+
+ if (fd_notify < 0) {
+ if (errno == EPERM || errno == EINVAL) {
+ tst_res(TCONF,
+ "unprivileged fanotify not supported by kernel?");
+ return;
+ } else {
+ tst_brk(TBROK | TERRNO,
+ "fanotify_init(FAN_CLASS_NOTIF, O_RDONLY) failed");
+ }
+ }
+
+ /* Place mark on object */
+ if (fanotify_mark(fd_notify, FAN_MARK_ADD, FAN_ALL_EVENTS,
+ AT_FDCWD, TEST_FILE) < 0) {
+ tst_brk(TBROK | TERRNO,
+ "fanotify_mark(%d, FAN_MARK_ADD, %d, "
+ "AT_FDCWD, %s) failed",
+ fd_notify,
+ FAN_ALL_EVENTS,
+ TEST_FILE);
+ }
+
+ /* Generate events in either child or listening process */
+ if (tc->fork)
+ do_fork();
+ else
+ generate_events();
+
+ /* Read events from queue */
+ len = SAFE_READ(0, fd_notify, event_buf + len, EVENT_BUF_LEN - len);
+
+ event = event_buf;
+
+ /* Iterate over and validate events against expected result set */
+ while (FAN_EVENT_OK(event, len) && test_number < tc->event_count) {
+ if (!(event->mask & tc->event_set[test_number])) {
+ tst_res(TFAIL,
+ "Received unexpected event mask: mask=%llx "
+ "pid=%u fd=%d",
+ (unsigned long long) event->mask,
+ (unsigned) event->pid,
+ event->fd);
+ } else if ((!tc->fork && event->pid != pid) ||
+ (tc->fork && event->pid != 0)) {
+ tst_res(TFAIL,
+ "Received unexpected pid in event: "
+ "mask=%llx pid=%u (expected %u) fd=%d",
+ (unsigned long long) event->mask,
+ (unsigned) event->pid,
+ (tc->fork ? 0 : pid),
+ event->fd);
+ } else if (event->fd != FAN_NOFD) {
+ tst_res(TFAIL,
+ "Received unexpected file descriptor: "
+ "mask=%llx pid=%u fd=%d (expected %d)",
+ (unsigned long long) event->pid,
+ (unsigned) event->pid,
+ event->fd,
+ FAN_NOFD);
+ SAFE_CLOSE(event->fd);
+ } else {
+ tst_res(TPASS,
+ "Received event: mask=%llx, pid=%u fd=%d",
+ (unsigned long long) event->mask,
+ (unsigned) event->pid,
+ event->fd);
+ }
+
+ /* Non-permission events can be merged into a single event. */
+ event->mask &= ~tc->event_set[test_number];
+
+ if (event->mask == 0)
+ event = FAN_EVENT_NEXT(event, len);
+ test_number++;
+ }
+
+ /*
+ * Determine whether there is still unprocessed events remaining in the
+ * buffer. This is to cover the basis whereby the event processing loop
+ * terminates prematurely. In that case, we need to ensure that any
+ * event file descriptor that is open is closed so that the temporary
+ * filesystem can be unmounted.
+ */
+ if (FAN_EVENT_OK(event, len)) {
+ tst_res(TFAIL,
+ "Event processing loop exited prematurely. Did NOT "
+ "finish processing events in buffer. Cleaning up.");
+ while (FAN_EVENT_OK(event, len)) {
+ if (event->fd != FAN_NOFD)
+ SAFE_CLOSE(event->fd);
+ event = FAN_EVENT_NEXT(event, len);
+ }
+ }
+}
+
+static void setup(void)
+{
+ SAFE_FILE_PRINTF(TEST_FILE, "1");
+ SAFE_CHMOD(TEST_FILE, 0666);
+
+ /* Check for kernel fanotify support */
+ REQUIRE_FANOTIFY_INIT_FLAGS_SUPPORTED_ON_FS(FAN_REPORT_FID, TEST_FILE);
+
+ /* Relinquish privileged user */
+ if (geteuid() == 0) {
+ tst_res(TINFO,
+ "Running as privileged user, revoking.");
+ struct passwd *nobody = SAFE_GETPWNAM("nobody");
+ SAFE_SETUID(nobody->pw_uid);
+ }
+}
+
+static void cleanup(void)
+{
+ if (fd_notify > 0)
+ SAFE_CLOSE(fd_notify);
+}
+
+static struct tst_test test = {
+ .test = test_fanotify,
+ .tcnt = ARRAY_SIZE(test_cases),
+ .setup = setup,
+ .cleanup = cleanup,
+ .forks_child = 1,
+ .needs_root = 1,
+ .mount_device = 1,
+ .mntpoint = MOUNT_PATH,
+};
+
+#else
+ TST_TEST_CONF("System does not have required fanotify support");
+#endif
--
2.25.1
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