build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/github.com/cyphar/filepath-securejoin/openat_linux.go

@@ -0,0 +1,59 @@
+//go:build linux
+
+// Copyright (C) 2024 SUSE LLC. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package securejoin
+
+import (
+	"os"
+	"path/filepath"
+
+	"golang.org/x/sys/unix"
+)
+
+func dupFile(f *os.File) (*os.File, error) {
+	fd, err := unix.FcntlInt(f.Fd(), unix.F_DUPFD_CLOEXEC, 0)
+	if err != nil {
+		return nil, os.NewSyscallError("fcntl(F_DUPFD_CLOEXEC)", err)
+	}
+	return os.NewFile(uintptr(fd), f.Name()), nil
+}
+
+func openatFile(dir *os.File, path string, flags int, mode int) (*os.File, error) {
+	// Make sure we always set O_CLOEXEC.
+	flags |= unix.O_CLOEXEC
+	fd, err := unix.Openat(int(dir.Fd()), path, flags, uint32(mode))
+	if err != nil {
+		return nil, &os.PathError{Op: "openat", Path: dir.Name() + "/" + path, Err: err}
+	}
+	// All of the paths we use with openatFile(2) are guaranteed to be
+	// lexically safe, so we can use path.Join here.
+	fullPath := filepath.Join(dir.Name(), path)
+	return os.NewFile(uintptr(fd), fullPath), nil
+}
+
+func fstatatFile(dir *os.File, path string, flags int) (unix.Stat_t, error) {
+	var stat unix.Stat_t
+	if err := unix.Fstatat(int(dir.Fd()), path, &stat, flags); err != nil {
+		return stat, &os.PathError{Op: "fstatat", Path: dir.Name() + "/" + path, Err: err}
+	}
+	return stat, nil
+}
+
+func readlinkatFile(dir *os.File, path string) (string, error) {
+	size := 4096
+	for {
+		linkBuf := make([]byte, size)
+		n, err := unix.Readlinkat(int(dir.Fd()), path, linkBuf)
+		if err != nil {
+			return "", &os.PathError{Op: "readlinkat", Path: dir.Name() + "/" + path, Err: err}
+		}
+		if n != size {
+			return string(linkBuf[:n]), nil
+		}
+		// Possible truncation, resize the buffer.
+		size *= 2
+	}
+}