1 files changed, 150 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c b/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c
new file mode 100644
index 000000000000..eaf441dc7e79
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright Amazon.com Inc. or its affiliates. */
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdlib.h>
+#include <net/if.h>
+
+#include "test_progs.h"
+#include "cgroup_helpers.h"
+#include "network_helpers.h"
+#include "test_tcp_custom_syncookie.skel.h"
+
+static struct test_tcp_custom_syncookie_case {
+	int family, type;
+	char addr[16];
+	char name[10];
+} test_cases[] = {
+	{
+		.name = "IPv4 TCP",
+		.family = AF_INET,
+		.type = SOCK_STREAM,
+		.addr = "127.0.0.1",
+	},
+	{
+		.name = "IPv6 TCP",
+		.family = AF_INET6,
+		.type = SOCK_STREAM,
+		.addr = "::1",
+	},
+};
+
+static int setup_netns(void)
+{
+	if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
+		return -1;
+
+	if (!ASSERT_OK(system("ip link set dev lo up"), "ip"))
+		goto err;
+
+	if (!ASSERT_OK(write_sysctl("/proc/sys/net/ipv4/tcp_ecn", "1"),
+		       "write_sysctl"))
+		goto err;
+
+	return 0;
+err:
+	return -1;
+}
+
+static int setup_tc(struct test_tcp_custom_syncookie *skel)
+{
+	LIBBPF_OPTS(bpf_tc_hook, qdisc_lo, .attach_point = BPF_TC_INGRESS);
+	LIBBPF_OPTS(bpf_tc_opts, tc_attach,
+		    .prog_fd = bpf_program__fd(skel->progs.tcp_custom_syncookie));
+
+	qdisc_lo.ifindex = if_nametoindex("lo");
+	if (!ASSERT_OK(bpf_tc_hook_create(&qdisc_lo), "qdisc add dev lo clsact"))
+		goto err;
+
+	if (!ASSERT_OK(bpf_tc_attach(&qdisc_lo, &tc_attach),
+		       "filter add dev lo ingress"))
+		goto err;
+
+	return 0;
+err:
+	return -1;
+}
+
+#define msg "Hello World"
+#define msglen 11
+
+static void transfer_message(int sender, int receiver)
+{
+	char buf[msglen];
+	int ret;
+
+	ret = send(sender, msg, msglen, 0);
+	if (!ASSERT_EQ(ret, msglen, "send"))
+		return;
+
+	memset(buf, 0, sizeof(buf));
+
+	ret = recv(receiver, buf, msglen, 0);
+	if (!ASSERT_EQ(ret, msglen, "recv"))
+		return;
+
+	ret = strncmp(buf, msg, msglen);
+	if (!ASSERT_EQ(ret, 0, "strncmp"))
+		return;
+}
+
+static void create_connection(struct test_tcp_custom_syncookie_case *test_case)
+{
+	int server, client, child;
+
+	server = start_server(test_case->family, test_case->type, test_case->addr, 0, 0);
+	if (!ASSERT_NEQ(server, -1, "start_server"))
+		return;
+
+	client = connect_to_fd(server, 0);
+	if (!ASSERT_NEQ(client, -1, "connect_to_fd"))
+		goto close_server;
+
+	child = accept(server, NULL, 0);
+	if (!ASSERT_NEQ(child, -1, "accept"))
+		goto close_client;
+
+	transfer_message(client, child);
+	transfer_message(child, client);
+
+	close(child);
+close_client:
+	close(client);
+close_server:
+	close(server);
+}
+
+void test_tcp_custom_syncookie(void)
+{
+	struct test_tcp_custom_syncookie *skel;
+	int i;
+
+	if (setup_netns())
+		return;
+
+	skel = test_tcp_custom_syncookie__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+
+	if (setup_tc(skel))
+		goto destroy_skel;
+
+	for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
+		if (!test__start_subtest(test_cases[i].name))
+			continue;
+
+		skel->bss->handled_syn = false;
+		skel->bss->handled_ack = false;
+
+		create_connection(&test_cases[i]);
+
+		ASSERT_EQ(skel->bss->handled_syn, true, "SYN is not handled at tc.");
+		ASSERT_EQ(skel->bss->handled_ack, true, "ACK is not handled at tc");
+	}
+
+destroy_skel:
+	system("tc qdisc del dev lo clsact");
+
+	test_tcp_custom_syncookie__destroy(skel);
+}