[PATCH bpf-next v14 4/4] selftests/bpf: Add mptcpify test

Geliang Tang posted 4 patches 1 year, 2 months ago
[PATCH bpf-next v14 4/4] selftests/bpf: Add mptcpify test
Posted by Geliang Tang 1 year, 2 months ago
Implement a new test program mptcpify: if the family is AF_INET or
AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
update_socket_protocol().

Extend the MPTCP test base, add a selftest test_mptcpify() for the
mptcpify case. Open and load the mptcpify test prog to mptcpify the
TCP sockets dynamically, then use start_server() and connect_to_fd()
to create a TCP socket, but actually what's created is an MPTCP
socket, which can be verified through 'getsockopt(SOL_PROTOCOL)'
and 'getsockopt(MPTCP_INFO)'.

Acked-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 116 ++++++++++++++++++
 tools/testing/selftests/bpf/progs/mptcpify.c  |  20 +++
 2 files changed, 136 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c

diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 3d3999067e27..68ebf9735e16 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -2,13 +2,30 @@
 /* Copyright (c) 2020, Tessares SA. */
 /* Copyright (c) 2022, SUSE. */
 
+#include <linux/mptcp.h>
+#include <netinet/in.h>
 #include <test_progs.h>
 #include "cgroup_helpers.h"
 #include "network_helpers.h"
 #include "mptcp_sock.skel.h"
+#include "mptcpify.skel.h"
 
 #define NS_TEST "mptcp_ns"
 
+#ifndef IPPROTO_MPTCP
+#define IPPROTO_MPTCP 262
+#endif
+
+#ifndef MPTCP_INFO
+#define MPTCP_INFO		1
+#endif
+#ifndef MPTCP_INFO_FLAG_FALLBACK
+#define MPTCP_INFO_FLAG_FALLBACK		_BITUL(0)
+#endif
+#ifndef MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED
+#define MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED	_BITUL(1)
+#endif
+
 #ifndef TCP_CA_NAME_MAX
 #define TCP_CA_NAME_MAX	16
 #endif
@@ -183,8 +200,107 @@ static void test_base(void)
 	close(cgroup_fd);
 }
 
+static void send_byte(int fd)
+{
+	char b = 0x55;
+
+	ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
+}
+
+static int verify_mptcpify(int server_fd, int client_fd)
+{
+	struct mptcp_info info;
+	socklen_t optlen;
+	int protocol;
+	int err = 0;
+
+	optlen = sizeof(protocol);
+	if (!ASSERT_OK(getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen),
+		       "getsockopt(SOL_PROTOCOL)"))
+		return -1;
+
+	if (!ASSERT_EQ(protocol, IPPROTO_MPTCP, "protocol isn't MPTCP"))
+		err++;
+
+	optlen = sizeof(info);
+	if (!ASSERT_OK(getsockopt(client_fd, SOL_MPTCP, MPTCP_INFO, &info, &optlen),
+		       "getsockopt(MPTCP_INFO)"))
+		return -1;
+
+	if (!ASSERT_GE(info.mptcpi_flags, 0, "unexpected mptcpi_flags"))
+		err++;
+	if (!ASSERT_FALSE(info.mptcpi_flags & MPTCP_INFO_FLAG_FALLBACK,
+			  "MPTCP fallback"))
+		err++;
+	if (!ASSERT_TRUE(info.mptcpi_flags & MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED,
+			 "no remote key received"))
+		err++;
+
+	return err;
+}
+
+static int run_mptcpify(int cgroup_fd)
+{
+	int server_fd, client_fd, err = 0;
+	struct mptcpify *mptcpify_skel;
+
+	mptcpify_skel = mptcpify__open_and_load();
+	if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
+		return libbpf_get_error(mptcpify_skel);
+
+	err = mptcpify__attach(mptcpify_skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto out;
+
+	/* without MPTCP */
+	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
+	if (!ASSERT_GE(server_fd, 0, "start_server")) {
+		err = -EIO;
+		goto out;
+	}
+
+	client_fd = connect_to_fd(server_fd, 0);
+	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
+		err = -EIO;
+		goto close_server;
+	}
+
+	send_byte(client_fd);
+
+	err = verify_mptcpify(server_fd, client_fd);
+
+	close(client_fd);
+close_server:
+	close(server_fd);
+out:
+	mptcpify__destroy(mptcpify_skel);
+	return err;
+}
+
+static void test_mptcpify(void)
+{
+	struct nstoken *nstoken = NULL;
+	int cgroup_fd;
+
+	cgroup_fd = test__join_cgroup("/mptcpify");
+	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
+		return;
+
+	nstoken = create_netns();
+	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
+		goto fail;
+
+	ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
+
+fail:
+	cleanup_netns(nstoken);
+	close(cgroup_fd);
+}
+
 void test_mptcp(void)
 {
 	if (test__start_subtest("base"))
 		test_base();
+	if (test__start_subtest("mptcpify"))
+		test_mptcpify();
 }
diff --git a/tools/testing/selftests/bpf/progs/mptcpify.c b/tools/testing/selftests/bpf/progs/mptcpify.c
new file mode 100644
index 000000000000..53301ae8a8f7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/mptcpify.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023, SUSE. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+#include "bpf_tracing_net.h"
+
+char _license[] SEC("license") = "GPL";
+
+SEC("fmod_ret/update_socket_protocol")
+int BPF_PROG(mptcpify, int family, int type, int protocol)
+{
+	if ((family == AF_INET || family == AF_INET6) &&
+	    type == SOCK_STREAM &&
+	    (!protocol || protocol == IPPROTO_TCP)) {
+		return IPPROTO_MPTCP;
+	}
+
+	return protocol;
+}
-- 
2.35.3
Re: [PATCH bpf-next v14 4/4] selftests/bpf: Add mptcpify test
Posted by Martin KaFai Lau 1 year, 2 months ago
On 8/15/23 6:11 PM, Geliang Tang wrote:
> Implement a new test program mptcpify: if the family is AF_INET or
> AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
> IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
> update_socket_protocol().
> 
> Extend the MPTCP test base, add a selftest test_mptcpify() for the
> mptcpify case. Open and load the mptcpify test prog to mptcpify the
> TCP sockets dynamically, then use start_server() and connect_to_fd()
> to create a TCP socket, but actually what's created is an MPTCP
> socket, which can be verified through 'getsockopt(SOL_PROTOCOL)'
> and 'getsockopt(MPTCP_INFO)'.
> 
> Acked-by: Yonghong Song <yonghong.song@linux.dev>
> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> ---
>   .../testing/selftests/bpf/prog_tests/mptcp.c  | 116 ++++++++++++++++++
>   tools/testing/selftests/bpf/progs/mptcpify.c  |  20 +++
>   2 files changed, 136 insertions(+)
>   create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> index 3d3999067e27..68ebf9735e16 100644
> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -2,13 +2,30 @@
>   /* Copyright (c) 2020, Tessares SA. */
>   /* Copyright (c) 2022, SUSE. */
>   
> +#include <linux/mptcp.h>
bpf CI failed 
(https://github.com/kernel-patches/bpf/actions/runs/5882006207/job/15951617063):

   /tmp/work/bpf/bpf/tools/testing/selftests/bpf/prog_tests/mptcp.c:5:10: fatal 
error: 'linux/mptcp.h' file not found
   #include <linux/mptcp.h>

I fixed that by copying the 'struct mptcp_info' but renamed to 'struct 
__mptcp_info' just in case any fallout in the future.

My environment also does not have SOL_MPTCP, so I do an ifndef for it also.

> +#include <netinet/in.h>
>   #include <test_progs.h>
>   #include "cgroup_helpers.h"
>   #include "network_helpers.h"
>   #include "mptcp_sock.skel.h"
> +#include "mptcpify.skel.h"
>   
>   #define NS_TEST "mptcp_ns"
>   
> +#ifndef IPPROTO_MPTCP
> +#define IPPROTO_MPTCP 262
> +#endif
> +
> +#ifndef MPTCP_INFO
> +#define MPTCP_INFO		1
> +#endif
> +#ifndef MPTCP_INFO_FLAG_FALLBACK
> +#define MPTCP_INFO_FLAG_FALLBACK		_BITUL(0)

I have to add '#include <linux/const.h>' for the _BITUL() here also....

The set is applied. Please follow up if I make mistake on those fixes.