selftests/bpf: Move test_dev_cgroup to prog_tests

Move test_dev_cgroup to prog_tests to be able to run it with test_progs.
Replace dev_cgroup.bpf.o with skel header file, dev_cgroup.skel.h and
load program from it accourdingly.

  ./test_progs -t test_dev_cgroup
  mknod: /tmp/test_dev_cgroup_null: Operation not permitted
  64+0 records in
  64+0 records out
  32768 bytes (33 kB, 32 KiB) copied, 0.000856684 s, 38.2 MB/s
  dd: failed to open '/dev/full': Operation not permitted
  dd: failed to open '/dev/random': Operation not permitted
  #365     test_dev_cgroup:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Muhammad Usama Anjum <[email protected]>

Author: musamaanjum

tools/testing/selftests/bpf/prog_tests/test_dev_cgroup.c

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+
+#include <test_progs.h>
+#include <time.h>
+#include "cgroup_helpers.h"
+#include "dev_cgroup.skel.h"
+
+#define TEST_CGROUP "/test-bpf-based-device-cgroup/"
+
+void test_test_dev_cgroup(void)
+{
+	int cgroup_fd, err, duration = 0;
+	struct dev_cgroup *skel;
+	__u32 prog_cnt;
+
+	skel = dev_cgroup__open_and_load();
+	if (CHECK(!skel, "skel_open_and_load", "failed\n"))
+		goto cleanup;
+
+	cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);
+	if (CHECK(cgroup_fd < 0, "cgroup_setup_and_join", "failed: %d\n", cgroup_fd))
+		goto cleanup;
+
+	err = bpf_prog_attach(bpf_program__fd(skel->progs.bpf_prog1), cgroup_fd,
+			      BPF_CGROUP_DEVICE, 0);
+	if (CHECK(err, "bpf_attach", "failed: %d\n", err))
+		goto cleanup;
+
+	err = bpf_prog_query(cgroup_fd, BPF_CGROUP_DEVICE, 0, NULL, NULL, &prog_cnt);
+	if (CHECK(err || prog_cnt != 1, "bpf_query", "failed: %d %d\n", err, prog_cnt))
+		goto cleanup;
+
+	/* All operations with /dev/zero and /dev/urandom are allowed,
+	 * everything else is forbidden.
+	 */
+	CHECK(system("rm -f /tmp/test_dev_cgroup_null"), "rm",
+	      "unexpected rm on _null\n");
+	CHECK(!system("mknod /tmp/test_dev_cgroup_null c 1 3"),
+	      "mknod", "unexpected mknod on _null\n");
+	CHECK(system("rm -f /tmp/test_dev_cgroup_null"), "rm",
+	      "unexpected rm on _null\n");
+
+	/* /dev/zero is whitelisted */
+	CHECK(system("rm -f /tmp/test_dev_cgroup_zero"), "rm",
+	      "unexpected rm on _zero\n");
+	CHECK(system("mknod /tmp/test_dev_cgroup_zero c 1 5"),
+	      "mknod", "unexpected mknod on _zero\n");
+	CHECK(system("rm -f /tmp/test_dev_cgroup_zero"), "rm",
+	      "unexpected rm on _zero\n");
+
+	CHECK(system("dd if=/dev/urandom of=/dev/zero count=64"), "dd",
+	      "unexpected dd on /dev/zero\n");
+
+	/* src is allowed, target is forbidden */
+	CHECK(!system("dd if=/dev/urandom of=/dev/full count=64"), "dd",
+	      "unexpected dd on /dev/full\n");
+
+	/* src is forbidden, target is allowed */
+	CHECK(!system("dd if=/dev/random of=/dev/zero count=64"), "dd",
+	      "unexpected dd on /dev/zero\n");
+
+cleanup:
+	cleanup_cgroup_environment();
+	dev_cgroup__destroy(skel);
+}