Commit 02662234 authored by Geliang Tang's avatar Geliang Tang Committed by Andrii Nakryiko
Browse files

selftests/bpf: Verify token of struct mptcp_sock 



This patch verifies the struct member token of struct mptcp_sock. Add a
new member token in struct mptcp_storage to store the token value of the
msk socket got by bpf_skc_to_mptcp_sock(). Trace the kernel function
mptcp_pm_new_connection() by using bpf fentry prog to obtain the msk token
and save it in a global bpf variable. Pass the variable to verify_msk() to
verify it with the token saved in socket_storage_map.

v4:
 - use ASSERT_* instead of CHECK_FAIL (Andrii)
 - skip the test if 'ip mptcp monitor' is not supported (Mat)

v5:
 - Drop 'ip mptcp monitor', trace mptcp_pm_new_connection instead (Martin)
 - Use ASSERT_EQ (Andrii)

Signed-off-by: default avatarGeliang Tang <geliang.tang@suse.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/bpf/20220519233016.105670-6-mathew.j.martineau@linux.intel.com
parent 3bc48b56

tools/testing/selftests/bpf/bpf_tcp_helpers.h

+2 −0
Original line number Diff line number Diff line
@@ -228,6 +228,8 @@ extern void tcp_cong_avoid_ai(struct tcp_sock *tp, __u32 w, __u32 acked) __ksym; 


struct mptcp_sock {

	struct inet_connection_sock	sk;



	__u32		token;

} __attribute__((preserve_access_index));



#endif

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

+13 −2
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
struct mptcp_storage {

	__u32 invoked;

	__u32 is_mptcp;

	__u32 token;

};



static int verify_tsk(int map_fd, int client_fd)
@@ -30,11 +31,14 @@ static int verify_tsk(int map_fd, int client_fd) 
	return err;

}



static int verify_msk(int map_fd, int client_fd)

static int verify_msk(int map_fd, int client_fd, __u32 token)

{

	int err, cfd = client_fd;

	struct mptcp_storage val;



	if (!ASSERT_GT(token, 0, "invalid token"))

		return -1;



	err = bpf_map_lookup_elem(map_fd, &cfd, &val);

	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))

		return err;
@@ -45,6 +49,9 @@ static int verify_msk(int map_fd, int client_fd) 
	if (!ASSERT_EQ(val.is_mptcp, 1, "unexpected is_mptcp"))

		err++;



	if (!ASSERT_EQ(val.token, token, "unexpected token"))

		err++;



	return err;

}
@@ -57,6 +64,10 @@ static int run_test(int cgroup_fd, int server_fd, bool is_mptcp) 
	if (!ASSERT_OK_PTR(sock_skel, "skel_open_load"))

		return -EIO;



	err = mptcp_sock__attach(sock_skel);

	if (!ASSERT_OK(err, "skel_attach"))

		goto out;



	prog_fd = bpf_program__fd(sock_skel->progs._sockops);

	if (!ASSERT_GE(prog_fd, 0, "bpf_program__fd")) {

		err = -EIO;
@@ -79,7 +90,7 @@ static int run_test(int cgroup_fd, int server_fd, bool is_mptcp) 
		goto out;

	}



	err += is_mptcp ? verify_msk(map_fd, client_fd) :

	err += is_mptcp ? verify_msk(map_fd, client_fd, sock_skel->bss->token) :

			  verify_tsk(map_fd, client_fd);



	close(client_fd);

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

+16 −0
Original line number Diff line number Diff line
@@ -7,10 +7,12 @@ 
#include "bpf_tcp_helpers.h"



char _license[] SEC("license") = "GPL";

__u32 token = 0;



struct mptcp_storage {

	__u32 invoked;

	__u32 is_mptcp;

	__u32 token;

};



struct {
@@ -47,6 +49,8 @@ int _sockops(struct bpf_sock_ops *ctx) 
					     BPF_SK_STORAGE_GET_F_CREATE);

		if (!storage)

			return 1;



		storage->token = 0;

	} else {

		msk = bpf_skc_to_mptcp_sock(sk);

		if (!msk)
@@ -56,9 +60,21 @@ int _sockops(struct bpf_sock_ops *ctx) 
					     BPF_SK_STORAGE_GET_F_CREATE);

		if (!storage)

			return 1;



		storage->token = msk->token;

	}

	storage->invoked++;

	storage->is_mptcp = is_mptcp;



	return 1;

}



SEC("fentry/mptcp_pm_new_connection")

int BPF_PROG(trace_mptcp_pm_new_connection, struct mptcp_sock *msk,

	     const struct sock *ssk, int server_side)

{

	if (!server_side)

		token = msk->token;



	return 0;

}