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-rw-r--r--tools/testing/selftests/openat2/helpers.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/tools/testing/selftests/openat2/helpers.c b/tools/testing/selftests/openat2/helpers.c
new file mode 100644
index 0000000000..5074681ffd
--- /dev/null
+++ b/tools/testing/selftests/openat2/helpers.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author: Aleksa Sarai <cyphar@cyphar.com>
+ * Copyright (C) 2018-2019 SUSE LLC.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <string.h>
+#include <syscall.h>
+#include <limits.h>
+
+#include "helpers.h"
+
+bool needs_openat2(const struct open_how *how)
+{
+ return how->resolve != 0;
+}
+
+int raw_openat2(int dfd, const char *path, void *how, size_t size)
+{
+ int ret = syscall(__NR_openat2, dfd, path, how, size);
+ return ret >= 0 ? ret : -errno;
+}
+
+int sys_openat2(int dfd, const char *path, struct open_how *how)
+{
+ return raw_openat2(dfd, path, how, sizeof(*how));
+}
+
+int sys_openat(int dfd, const char *path, struct open_how *how)
+{
+ int ret = openat(dfd, path, how->flags, how->mode);
+ return ret >= 0 ? ret : -errno;
+}
+
+int sys_renameat2(int olddirfd, const char *oldpath,
+ int newdirfd, const char *newpath, unsigned int flags)
+{
+ int ret = syscall(__NR_renameat2, olddirfd, oldpath,
+ newdirfd, newpath, flags);
+ return ret >= 0 ? ret : -errno;
+}
+
+int touchat(int dfd, const char *path)
+{
+ int fd = openat(dfd, path, O_CREAT, 0700);
+ if (fd >= 0)
+ close(fd);
+ return fd;
+}
+
+char *fdreadlink(int fd)
+{
+ char *target, *tmp;
+
+ E_asprintf(&tmp, "/proc/self/fd/%d", fd);
+
+ target = malloc(PATH_MAX);
+ if (!target)
+ ksft_exit_fail_msg("fdreadlink: malloc failed\n");
+ memset(target, 0, PATH_MAX);
+
+ E_readlink(tmp, target, PATH_MAX);
+ free(tmp);
+ return target;
+}
+
+bool fdequal(int fd, int dfd, const char *path)
+{
+ char *fdpath, *dfdpath, *other;
+ bool cmp;
+
+ fdpath = fdreadlink(fd);
+ dfdpath = fdreadlink(dfd);
+
+ if (!path)
+ E_asprintf(&other, "%s", dfdpath);
+ else if (*path == '/')
+ E_asprintf(&other, "%s", path);
+ else
+ E_asprintf(&other, "%s/%s", dfdpath, path);
+
+ cmp = !strcmp(fdpath, other);
+
+ free(fdpath);
+ free(dfdpath);
+ free(other);
+ return cmp;
+}
+
+bool openat2_supported = false;
+
+void __attribute__((constructor)) init(void)
+{
+ struct open_how how = {};
+ int fd;
+
+ BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_VER0);
+
+ /* Check openat2(2) support. */
+ fd = sys_openat2(AT_FDCWD, ".", &how);
+ openat2_supported = (fd >= 0);
+
+ if (fd >= 0)
+ close(fd);
+}