This patch adds a base for MPTCP specific tests.
It is currently limited to the is_mptcp field in case of plain TCP
connection because for the moment there is no easy way to get the subflow
sk from a msk in userspace. This implies that we cannot lookup the
sk_storage attached to the subflow sk in the sockops program.
Acked-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Nicolas Rybowski <nicolas.rybowski@xxxxxxxxxxxx>
---
Notes:
v2 -> v3:
- remove useless close_client_fd label (Song)
- remove error count increment (Song)
v1 -> v2:
- new patch: mandatory selftests (Alexei)
tools/testing/selftests/bpf/config | 1 +
tools/testing/selftests/bpf/network_helpers.c | 37 +++++-
tools/testing/selftests/bpf/network_helpers.h | 3 +
.../testing/selftests/bpf/prog_tests/mptcp.c | 118 ++++++++++++++++++
tools/testing/selftests/bpf/progs/mptcp.c | 48 +++++++
5 files changed, 202 insertions(+), 5 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/mptcp.c
create mode 100644 tools/testing/selftests/bpf/progs/mptcp.c
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index 2118e23ac07a..8377836ea976 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -39,3 +39,4 @@ CONFIG_BPF_JIT=y
CONFIG_BPF_LSM=y
CONFIG_SECURITY=y
CONFIG_LIRC=y
+CONFIG_MPTCP=y
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index 12ee40284da0..85cbb683965c 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -14,6 +14,10 @@
#include "bpf_util.h"
#include "network_helpers.h"
+#ifndef IPPROTO_MPTCP
+#define IPPROTO_MPTCP 262
+#endif
+
#define clean_errno() (errno == 0 ? "None" : strerror(errno))
#define log_err(MSG, ...) ({ \
int __save = errno; \
@@ -66,8 +70,8 @@ static int settimeo(int fd, int timeout_ms)
#define save_errno_close(fd) ({ int __save = errno; close(fd); errno = __save; })
-int start_server(int family, int type, const char *addr_str, __u16 port,
- int timeout_ms)
+static int start_server_proto(int family, int type, int protocol,
+ const char *addr_str, __u16 port, int timeout_ms)
{
struct sockaddr_storage addr = {};
socklen_t len;
@@ -76,7 +80,7 @@ int start_server(int family, int type, const char *addr_str, __u16 port,
if (make_sockaddr(family, addr_str, port, &addr, &len))
return -1;
- fd = socket(family, type, 0);
+ fd = socket(family, type, protocol);
if (fd < 0) {
log_err("Failed to create server socket");
return -1;
@@ -104,6 +108,19 @@ int start_server(int family, int type, const char *addr_str, __u16 port,
return -1;
}
+int start_server(int family, int type, const char *addr_str, __u16 port,
+ int timeout_ms)
+{
+ return start_server_proto(family, type, 0, addr_str, port, timeout_ms);
+}
+
+int start_mptcp_server(int family, const char *addr_str, __u16 port,
+ int timeout_ms)
+{
+ return start_server_proto(family, SOCK_STREAM, IPPROTO_MPTCP, addr_str,
+ port, timeout_ms);
+}
+
int fastopen_connect(int server_fd, const char *data, unsigned int data_len,
int timeout_ms)
{
@@ -153,7 +170,7 @@ static int connect_fd_to_addr(int fd,
return 0;
}
-int connect_to_fd(int server_fd, int timeout_ms)
+static int connect_to_fd_proto(int server_fd, int protocol, int timeout_ms)
{
struct sockaddr_storage addr;
struct sockaddr_in *addr_in;
@@ -173,7 +190,7 @@ int connect_to_fd(int server_fd, int timeout_ms)
}
addr_in = (struct sockaddr_in *)&addr;
- fd = socket(addr_in->sin_family, type, 0);
+ fd = socket(addr_in->sin_family, type, protocol);
if (fd < 0) {
log_err("Failed to create client socket");
return -1;
@@ -192,6 +209,16 @@ int connect_to_fd(int server_fd, int timeout_ms)
return -1;
}
+int connect_to_fd(int server_fd, int timeout_ms)
+{
+ return connect_to_fd_proto(server_fd, 0, timeout_ms);
+}
+
+int connect_to_mptcp_fd(int server_fd, int timeout_ms)
+{
+ return connect_to_fd_proto(server_fd, IPPROTO_MPTCP, timeout_ms);
+}
+
int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms)
{
struct sockaddr_storage addr;
diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h
index 7205f8afdba1..336423a789e9 100644
--- a/tools/testing/selftests/bpf/network_helpers.h
+++ b/tools/testing/selftests/bpf/network_helpers.h
@@ -35,7 +35,10 @@ extern struct ipv6_packet pkt_v6;
int start_server(int family, int type, const char *addr, __u16 port,
int timeout_ms);
+int start_mptcp_server(int family, const char *addr, __u16 port,
+ int timeout_ms);
int connect_to_fd(int server_fd, int timeout_ms);
+int connect_to_mptcp_fd(int server_fd, int timeout_ms);
int connect_fd_to_fd(int client_fd, int server_fd, int timeout_ms);
int fastopen_connect(int server_fd, const char *data, unsigned int data_len,
int timeout_ms);
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
new file mode 100644
index 000000000000..9accf2cfce36
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include "cgroup_helpers.h"
+#include "network_helpers.h"
+
+struct mptcp_storage {
+ __u32 invoked;
+ __u32 is_mptcp;
+};
+
+static int verify_sk(int map_fd, int client_fd, const char *msg, __u32 is_mptcp)
+{
+ int err = 0, cfd = client_fd;
+ struct mptcp_storage val;
+
+ /* Currently there is no easy way to get back the subflow sk from the MPTCP
+ * sk, thus we cannot access here the sk_storage associated to the subflow
+ * sk. Also, there is no sk_storage associated with the MPTCP sk since it
+ * does not trigger sockops events.
+ * We silently pass this situation at the moment.
+ */
+ 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;
+ }
+
+ if (val.invoked != 1) {
+ log_err("%s: unexpected invoked count %d != %d",
+ msg, val.invoked, 1);
+ err++;
+ }
+
+ if (val.is_mptcp != is_mptcp) {
+ log_err("%s: unexpected bpf_tcp_sock.is_mptcp %d != %d",
+ msg, val.is_mptcp, 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;
+ struct bpf_object *obj;
+ struct bpf_map *map;
+
+ struct bpf_prog_load_attr attr = {
+ .prog_type = BPF_PROG_TYPE_SOCK_OPS,
+ .file = "./mptcp.o",
+ .expected_attach_type = BPF_CGROUP_SOCK_OPS,
+ };
+
+ err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
+ if (err) {
+ log_err("Failed to load BPF object");
+ return -1;
+ }
+
+ map = bpf_map__next(NULL, obj);
+ map_fd = bpf_map__fd(map);
+
+ err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
+ if (err) {
+ log_err("Failed to attach BPF program");
+ goto close_bpf_object;
+ }
+
+ client_fd = is_mptcp ? connect_to_mptcp_fd(server_fd, 0) :
+ connect_to_fd(server_fd, 0);
+ if (client_fd < 0) {
+ err = -1;
+ goto close_bpf_object;
+ }
+
+ err = is_mptcp ? verify_sk(map_fd, client_fd, "MPTCP subflow socket", 1) :
+ verify_sk(map_fd, client_fd, "plain TCP socket", 0);
+
+ close(client_fd);
+
+close_bpf_object:
+ bpf_object__close(obj);
+ return err;
+}
+
+void test_mptcp(void)
+{
+ int server_fd, cgroup_fd;
+
+ cgroup_fd = test__join_cgroup("/mptcp");
+ if (CHECK_FAIL(cgroup_fd < 0))
+ return;
+
+ /* without MPTCP */
+ server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
+ if (CHECK_FAIL(server_fd < 0))
+ goto with_mptcp;
+
+ CHECK_FAIL(run_test(cgroup_fd, server_fd, false));
+
+ close(server_fd);
+
+with_mptcp:
+ /* with MPTCP */
+ server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
+ if (CHECK_FAIL(server_fd < 0))
+ goto close_cgroup_fd;
+
+ CHECK_FAIL(run_test(cgroup_fd, server_fd, true));
+
+ close(server_fd);
+
+close_cgroup_fd:
+ close(cgroup_fd);
+}
diff --git a/tools/testing/selftests/bpf/progs/mptcp.c b/tools/testing/selftests/bpf/progs/mptcp.c
new file mode 100644
index 000000000000..be5ee8dac2b3
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/mptcp.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1;
+
+struct mptcp_storage {
+ __u32 invoked;
+ __u32 is_mptcp;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_SK_STORAGE);
+ __uint(map_flags, BPF_F_NO_PREALLOC);
+ __type(key, int);
+ __type(value, struct mptcp_storage);
+} socket_storage_map SEC(".maps");
+
+SEC("sockops")
+int _sockops(struct bpf_sock_ops *ctx)
+{
+ struct mptcp_storage *storage;
+ struct bpf_tcp_sock *tcp_sk;
+ int op = (int)ctx->op;
+ struct bpf_sock *sk;
+
+ sk = ctx->sk;
+ if (!sk)
+ return 1;
+
+ storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
+ BPF_SK_STORAGE_GET_F_CREATE);
+ if (!storage)
+ return 1;
+
+ if (op != BPF_SOCK_OPS_TCP_CONNECT_CB)
+ return 1;
+
+ tcp_sk = bpf_tcp_sock(sk);
+ if (!tcp_sk)
+ return 1;
+
+ storage->invoked++;
+ storage->is_mptcp = tcp_sk->is_mptcp;
+
+ return 1;
+}
--
2.28.0
