bpf: Add selftests for local_storage

inode_local_storage:

* Hook to the file_open and inode_unlink LSM hooks.
* Create and unlink a temporary file.
* Store some information in the inode's bpf_local_storage during
  file_open.
* Verify that this information exists when the file is unlinked.

sk_local_storage:

* Hook to the socket_post_create and socket_bind LSM hooks.
* Open and bind a socket and set the sk_storage in the
  socket_post_create hook using the start_server helper.
* Verify if the information is set in the socket_bind hook.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825182919.1118197-8-kpsingh@chromium.org

1 files changed, 60 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/test_local_storage.c b/tools/testing/selftests/bpf/prog_tests/test_local_storage.c
new file mode 100644
index 000000000000..91cd6f357246
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/test_local_storage.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2020 Google LLC.
+ */
+
+#include <test_progs.h>
+#include <linux/limits.h>
+
+#include "local_storage.skel.h"
+#include "network_helpers.h"
+
+int create_and_unlink_file(void)
+{
+	char fname[PATH_MAX] = "/tmp/fileXXXXXX";
+	int fd;
+
+	fd = mkstemp(fname);
+	if (fd < 0)
+		return fd;
+
+	close(fd);
+	unlink(fname);
+	return 0;
+}
+
+void test_test_local_storage(void)
+{
+	struct local_storage *skel = NULL;
+	int err, duration = 0, serv_sk = -1;
+
+	skel = local_storage__open_and_load();
+	if (CHECK(!skel, "skel_load", "lsm skeleton failed\n"))
+		goto close_prog;
+
+	err = local_storage__attach(skel);
+	if (CHECK(err, "attach", "lsm attach failed: %d\n", err))
+		goto close_prog;
+
+	skel->bss->monitored_pid = getpid();
+
+	err = create_and_unlink_file();
+	if (CHECK(err < 0, "exec_cmd", "err %d errno %d\n", err, errno))
+		goto close_prog;
+
+	CHECK(skel->data->inode_storage_result != 0, "inode_storage_result",
+	      "inode_local_storage not set\n");
+
+	serv_sk = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
+	if (CHECK(serv_sk < 0, "start_server", "failed to start server\n"))
+		goto close_prog;
+
+	CHECK(skel->data->sk_storage_result != 0, "sk_storage_result",
+	      "sk_local_storage not set\n");
+
+	close(serv_sk);
+
+close_prog:
+	local_storage__destroy(skel);
+}