[PATCH bpf-next 4/7] selftests: bpf: test bpf_skc_to_mptcp_sock

Mat Martineau
2022-04-20T22:25:26Z

From: Geliang Tang <geliang.tang@suse.com>

This patch extends the MPTCP test base, to test the new helper
bpf_skc_to_mptcp_sock().

Define struct mptcp_sock in bpf_tcp_helpers.h, use bpf_skc_to_mptcp_sock
to get the msk socket in progs/mptcp_sock.c and store the infos in
socket_storage_map.

Get the infos from socket_storage_map in prog_tests/mptcp.c. Add a new
function verify_msk() to verify the infos of MPTCP socket, and rename
verify_sk() to verify_tsk() to verify TCP socket only.

Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
MAINTAINERS | 1 +
.../testing/selftests/bpf/bpf_mptcp_helpers.h | 14 ++++++++
.../testing/selftests/bpf/prog_tests/mptcp.c | 36 +++++++++++++++----
.../testing/selftests/bpf/progs/mptcp_sock.c | 22 +++++++++---
4 files changed, 62 insertions(+), 11 deletions(-)
create mode 100644 tools/testing/selftests/bpf/bpf_mptcp_helpers.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 01fbdb0e0180..f31fa73266f9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13764,6 +13764,7 @@ F: include/net/mptcp.h
F: include/trace/events/mptcp.h
F: include/uapi/linux/mptcp.h
F: net/mptcp/
+F: tools/testing/selftests/bpf/bpf_mptcp_helpers.h
F: tools/testing/selftests/bpf/*/*mptcp*.c
F: tools/testing/selftests/net/mptcp/

diff --git a/tools/testing/selftests/bpf/bpf_mptcp_helpers.h b/tools/testing/selftests/bpf/bpf_mptcp_helpers.h
new file mode 100644
index 000000000000..18da4cc65e89
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_mptcp_helpers.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2022, SUSE. */
+
+#ifndef __BPF_MPTCP_HELPERS_H
+#define __BPF_MPTCP_HELPERS_H
+
+#include "bpf_tcp_helpers.h"
+
+struct mptcp_sock {
+ struct inet_connection_sock sk;
+
+} __attribute__((preserve_access_index));
+
+#endif
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index cd548bb2828f..4b40bbdaf91f 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -10,14 +10,12 @@ struct mptcp_storage {
__u32 is_mptcp;
};

-static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
+static int verify_tsk(int map_fd, int client_fd)
{
+ char *msg = "plain TCP socket";
int err = 0, cfd = client_fd;
struct mptcp_storage val;

- if (is_mptcp == 1)
- return 0;
-
if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &cfd, &val) < 0)) {
perror("Failed to read socket storage");
return -1;
@@ -38,6 +36,32 @@ static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
return err;
}

+static int verify_msk(int map_fd, int client_fd)
+{
+ char *msg = "MPTCP subflow socket";
+ int err = 0, cfd = client_fd;
+ struct mptcp_storage val;
+
+ if (CHECK_FAIL(bpf_map_lookup_elem(map_fd, &cfd, &val) < 0)) {
+ perror("Failed to read socket storage");
+ return -1;
+ }
+
+ if (val.invoked != 1) {
+ log_err("%s: unexpected invoked count %d != 1",
+ msg, val.invoked);
+ err++;
+ }
+
+ if (val.is_mptcp != 1) {
+ log_err("%s: unexpected bpf_tcp_sock.is_mptcp %d != 1",
+ msg, val.is_mptcp);
+ err++;
+ }
+
+ return err;
+}
+
static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
{
int client_fd, prog_fd, map_fd, err;
@@ -88,8 +112,8 @@ static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
goto out;
}

- err += is_mptcp ? verify_sk(map_fd, client_fd, "MPTCP subflow socket", 1) :
- verify_sk(map_fd, client_fd, "plain TCP socket", 0);
+ err += is_mptcp ? verify_msk(map_fd, client_fd) :
+ verify_tsk(map_fd, client_fd);

close(client_fd);

diff --git a/tools/testing/selftests/bpf/progs/mptcp_sock.c b/tools/testing/selftests/bpf/progs/mptcp_sock.c
index 0d65fb889d03..5cfaec4e7245 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_sock.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_sock.c
@@ -3,6 +3,7 @@

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
+#include "bpf_mptcp_helpers.h"

char _license[] SEC("license") = "GPL";
__u32 _version SEC("version") = 1;
@@ -24,6 +25,7 @@ int _sockops(struct bpf_sock_ops *ctx)
{
struct mptcp_storage *storage;
struct bpf_tcp_sock *tcp_sk;
+ struct mptcp_sock *msk;
int op = (int)ctx->op;
struct bpf_sock *sk;

@@ -38,11 +40,21 @@ int _sockops(struct bpf_sock_ops *ctx)
if (!tcp_sk)
return 1;

- storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
- BPF_SK_STORAGE_GET_F_CREATE);
- if (!storage)
- return 1;
-
+ if (!tcp_sk->is_mptcp) {
+ storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
+ BPF_SK_STORAGE_GET_F_CREATE);
+ if (!storage)
+ return 1;
+ } else {
+ msk = bpf_skc_to_mptcp_sock(sk);
+ if (!msk)
+ return 1;
+
+ storage = bpf_sk_storage_get(&socket_storage_map, msk, 0,
+ BPF_SK_STORAGE_GET_F_CREATE);
+ if (!storage)
+ return 1;
+ }
storage->invoked++;
storage->is_mptcp = tcp_sk->is_mptcp;

--
2.36.0