[pseudo] [PATCH v3 5/6] test: Add open_tree_attr syscall test

[frezidok1@gmail.com]

From: Dmitry Sakhonchik <frezidok1@gmail.com>

[YOCTO #16379]

Covers basic wrapper functionality when using syscall(SYS_open_tree_attr, ...), also tests AT_EMPTY_PATH flag and related paths using dirfd != AT_FDCWD.
The test uses attr == NULL, because using mount_attr in this call starts mount-specific privilege checks which end up with EPERM.

Signed-off-by: Dmitry Sakhonchik <frezidok1@gmail.com>
---
 test/test-open_tree_attr-syscall.c  | 165 ++++++++++++++++++++++++++++
 test/test-open_tree_attr-syscall.sh |   5 +
 2 files changed, 170 insertions(+)
 create mode 100644 test/test-open_tree_attr-syscall.c
 create mode 100755 test/test-open_tree_attr-syscall.sh

diff --git a/test/test-open_tree_attr-syscall.c b/test/test-open_tree_attr-syscall.c
new file mode 100644
index 0000000..4b656cb
--- /dev/null
+++ b/test/test-open_tree_attr-syscall.c
@@ -0,0 +1,165 @@
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <linux/mount.h>
+#include <sys/stat.h>
+
+#ifndef SYS_open_tree_attr
+
+#ifndef __NR_open_tree_attr
+#define __NR_open_tree_attr 467
+#endif
+
+#define SYS_open_tree_attr __NR_open_tree_attr
+#endif
+
+#define TEST_DIR "test-open-tree-dir"
+#define TEST_FILE "test-open-tree-file"
+
+static int do_open_tree_attr_syscall(int dirfd, const char *path,
+                unsigned int flags)
+{
+    /* Using mount_attr in this call starts mount-specific privilege checks
+     * which end up with EPERM.
+     * The functionality when using attr == NULL is equivalent to open_tree() */
+#ifdef SYS_open_tree_attr
+    return syscall(SYS_open_tree_attr, dirfd, path, flags, NULL, 0);
+#elif defined(__NR_open_tree_attr)
+    return syscall(__NR_open_tree_attr, dirfd, path, flags, NULL, 0);
+#else
+    errno = ENOSYS;
+    return -1;
+#endif
+}
+
+static int test_no_flags(void) {
+    int treefd = -1;
+    int fd = -1;
+    int rc = 1;
+
+    treefd = do_open_tree_attr_syscall(AT_FDCWD, TEST_DIR, 0);
+    if (treefd == -1) {
+        perror("open_tree_attr");
+        goto out;
+    }
+
+    fd = openat(treefd, TEST_FILE, O_CREAT | O_RDWR, 0666);
+    if (fd < 0) {
+        perror("openat");
+        goto out;
+    }
+
+    rc = 0;
+out:
+    if (treefd != -1) {
+        close(treefd);
+    }
+    if (fd != -1) {
+        close(fd);
+    }
+    return rc;
+}
+
+static int test_relative_dirfd(void) {
+    int basefd = -1;
+    int treefd = -1;
+    int fd = -1;
+    int rc = 1;
+
+    basefd = open(".", O_PATH | O_DIRECTORY);
+    if (basefd < 0) {
+        perror("open");
+        goto out;
+    }
+
+    treefd = do_open_tree_attr_syscall(basefd, TEST_DIR, 0);
+    if (treefd < 0) {
+        perror("open_tree_attr");
+        goto out;
+    }
+
+    fd = openat(treefd, TEST_FILE, O_CREAT | O_RDWR, 0666);
+    if (fd < 0) {
+        perror("openat");
+        goto out;
+    }
+
+    rc = 0;
+    out:
+        if (basefd != -1) {
+            close(basefd);
+        }
+    if (treefd != -1) {
+        close(treefd);
+    }
+    if (fd != -1) {
+        close(fd);
+    }
+    return rc;
+}
+
+static int test_at_empty_path(void) {
+    int treefd = -1;
+    int dirfd = -1;
+    int fd = -1;
+    int rc = 1;
+
+    dirfd = open(TEST_DIR, O_PATH | O_DIRECTORY);
+    if (dirfd < 0) {
+        perror("open");
+        goto out;
+    }
+
+    treefd = do_open_tree_attr_syscall(dirfd, "", AT_EMPTY_PATH);
+    if (treefd == -1) {
+        perror("open_tree_attr");
+        goto out;
+    }
+
+    fd = openat(treefd, TEST_FILE, O_CREAT | O_RDWR, 0666);
+    if (fd < 0) {
+        perror("openat");
+        goto out;
+    }
+
+    rc = 0;
+out:
+    if (dirfd != -1) {
+        close(dirfd);
+    }
+    if (treefd != -1) {
+        close(treefd);
+    }
+    if (fd != -1) {
+        close(fd);
+    }
+    return rc;
+}
+
+static void cleanup(void) {
+    if (unlink(TEST_DIR "/" TEST_FILE) == -1 && errno != ENOENT) {
+        perror("unlink");
+    }
+    if (rmdir(TEST_DIR) == -1 && errno != ENOENT) {
+        perror("rmdir");
+    }
+}
+
+int main(void) {
+    cleanup();
+
+    if (mkdir(TEST_DIR, 0777) == -1) {
+        perror("mkdir");
+        return 1;
+    }
+
+    int rc = test_no_flags() || test_at_empty_path() || test_relative_dirfd();
+
+    cleanup();
+
+    return rc;
+}
diff --git a/test/test-open_tree_attr-syscall.sh b/test/test-open_tree_attr-syscall.sh
new file mode 100755
index 0000000..3e50ebe
--- /dev/null
+++ b/test/test-open_tree_attr-syscall.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+./test/test-open_tree_attr-syscall
+
+PSEUDO_IGNORE_PATHS=/ ./test/test-open_tree_attr-syscall