selftests/bpf: Calls bpf_setsockopt() on a ktls enabled socket.

Ensures that whenever bpf_setsockopt() is called with the SOL_TCP
option on a ktls enabled socket, the call will be accepted by the
system. The provided test makes sure of this by performing an
examination when the server side socket is in the CLOSE_WAIT state. At
this stage, ktls is still enabled on the server socket and can be used
to test if bpf_setsockopt() works correctly with linux.
Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
Link: https://lore.kernel.org/r/20230125201608.908230-3-kuifeng@meta.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

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

@@ -4,6 +4,7 @@
 #define _GNU_SOURCE
 #include <sched.h>
 #include <linux/socket.h>
+#include <linux/tls.h>
 #include <net/if.h>
 
 #include "test_progs.h"
@@ -83,6 +84,76 @@ static void test_udp(int family)
 	ASSERT_EQ(bss->nr_binddev, 1, "nr_bind");
 }
 
+static void test_ktls(int family)
+{
+	struct tls12_crypto_info_aes_gcm_128 aes128;
+	struct setget_sockopt__bss *bss = skel->bss;
+	int cfd = -1, sfd = -1, fd = -1, ret;
+	char buf;
+
+	memset(bss, 0, sizeof(*bss));
+
+	sfd = start_server(family, SOCK_STREAM,
+			   family == AF_INET6 ? addr6_str : addr4_str, 0, 0);
+	if (!ASSERT_GE(sfd, 0, "start_server"))
+		return;
+	fd = connect_to_fd(sfd, 0);
+	if (!ASSERT_GE(fd, 0, "connect_to_fd"))
+		goto err_out;
+
+	cfd = accept(sfd, NULL, 0);
+	if (!ASSERT_GE(cfd, 0, "accept"))
+		goto err_out;
+
+	close(sfd);
+	sfd = -1;
+
+	/* Setup KTLS */
+	ret = setsockopt(fd, IPPROTO_TCP, TCP_ULP, "tls", sizeof("tls"));
+	if (!ASSERT_OK(ret, "setsockopt"))
+		goto err_out;
+	ret = setsockopt(cfd, IPPROTO_TCP, TCP_ULP, "tls", sizeof("tls"));
+	if (!ASSERT_OK(ret, "setsockopt"))
+		goto err_out;
+
+	memset(&aes128, 0, sizeof(aes128));
+	aes128.info.version = TLS_1_2_VERSION;
+	aes128.info.cipher_type = TLS_CIPHER_AES_GCM_128;
+
+	ret = setsockopt(fd, SOL_TLS, TLS_TX, &aes128, sizeof(aes128));
+	if (!ASSERT_OK(ret, "setsockopt"))
+		goto err_out;
+
+	ret = setsockopt(cfd, SOL_TLS, TLS_RX, &aes128, sizeof(aes128));
+	if (!ASSERT_OK(ret, "setsockopt"))
+		goto err_out;
+
+	/* KTLS is enabled */
+
+	close(fd);
+	/* At this point, the cfd socket is at the CLOSE_WAIT state
+	 * and still run TLS protocol.  The test for
+	 * BPF_TCP_CLOSE_WAIT should be run at this point.
+	 */
+	ret = read(cfd, &buf, sizeof(buf));
+	ASSERT_EQ(ret, 0, "read");
+	close(cfd);
+
+	ASSERT_EQ(bss->nr_listen, 1, "nr_listen");
+	ASSERT_EQ(bss->nr_connect, 1, "nr_connect");
+	ASSERT_EQ(bss->nr_active, 1, "nr_active");
+	ASSERT_EQ(bss->nr_passive, 1, "nr_passive");
+	ASSERT_EQ(bss->nr_socket_post_create, 2, "nr_socket_post_create");
+	ASSERT_EQ(bss->nr_binddev, 2, "nr_bind");
+	ASSERT_EQ(bss->nr_fin_wait1, 1, "nr_fin_wait1");
+	return;
+
+err_out:
+	close(fd);
+	close(cfd);
+	close(sfd);
+}
+
 void test_setget_sockopt(void)
 {
 	cg_fd = test__join_cgroup(CG_NAME);
@@ -118,6 +189,8 @@ void test_setget_sockopt(void)
 	test_tcp(AF_INET);
 	test_udp(AF_INET6);
 	test_udp(AF_INET);
+	test_ktls(AF_INET6);
+	test_ktls(AF_INET);
 
 done:
 	setget_sockopt__destroy(skel);

tools/testing/selftests/bpf/progs/setget_sockopt.c

@@ -22,6 +22,7 @@ int nr_active;
 int nr_connect;
 int nr_binddev;
 int nr_socket_post_create;
+int nr_fin_wait1;
 
 struct sockopt_test {
 	int opt;
@@ -386,6 +387,13 @@ int skops_sockopt(struct bpf_sock_ops *skops)
 		nr_passive += !(bpf_test_sockopt(skops, sk) ||
 				test_tcp_maxseg(skops, sk) ||
 				test_tcp_saved_syn(skops, sk));
+		bpf_sock_ops_cb_flags_set(skops,
+					  skops->bpf_sock_ops_cb_flags |
+					  BPF_SOCK_OPS_STATE_CB_FLAG);
+		break;
+	case BPF_SOCK_OPS_STATE_CB:
+		if (skops->args[1] == BPF_TCP_CLOSE_WAIT)
+			nr_fin_wait1 += !bpf_test_sockopt(skops, sk);
 		break;
 	}