Commit 6fdd671b authored by Florent Revest's avatar Florent Revest Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add a selftest for the tracing bpf_get_socket_cookie 



This builds up on the existing socket cookie test which checks whether
the bpf_get_socket_cookie helpers provide the same value in
cgroup/connect6 and sockops programs for a socket created by the
userspace part of the test.

Instead of having an update_cookie sockops program tag a socket local
storage with 0xFF, this uses both an update_cookie_sockops program and
an update_cookie_tracing program which succesively tag the socket with
0x0F and then 0xF0.

Signed-off-by: default avatarFlorent Revest <revest@chromium.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarKP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210210111406.785541-5-revest@chromium.org
parent 6cd4dcc3

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

+8 −3
Original line number Diff line number Diff line
@@ -35,9 +35,14 @@ void test_socket_cookie(void) 
	if (!ASSERT_OK_PTR(skel->links.set_cookie, "prog_attach"))

		goto close_cgroup_fd;



	skel->links.update_cookie = bpf_program__attach_cgroup(

		skel->progs.update_cookie, cgroup_fd);

	if (!ASSERT_OK_PTR(skel->links.update_cookie, "prog_attach"))

	skel->links.update_cookie_sockops = bpf_program__attach_cgroup(

		skel->progs.update_cookie_sockops, cgroup_fd);

	if (!ASSERT_OK_PTR(skel->links.update_cookie_sockops, "prog_attach"))

		goto close_cgroup_fd;



	skel->links.update_cookie_tracing = bpf_program__attach(

		skel->progs.update_cookie_tracing);

	if (!ASSERT_OK_PTR(skel->links.update_cookie_tracing, "prog_attach"))

		goto close_cgroup_fd;



	server_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);

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

+33 −3
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 


#include <bpf/bpf_helpers.h>

#include <bpf/bpf_endian.h>

#include <bpf/bpf_tracing.h>



#define AF_INET6 10
@@ -20,6 +21,14 @@ struct { 
	__type(value, struct socket_cookie);

} socket_cookies SEC(".maps");



/*

 * These three programs get executed in a row on connect() syscalls. The

 * userspace side of the test creates a client socket, issues a connect() on it

 * and then checks that the local storage associated with this socket has:

 * cookie_value == local_port << 8 | 0xFF

 * The different parts of this cookie_value are appended by those hooks if they

 * all agree on the output of bpf_get_socket_cookie().

 */

SEC("cgroup/connect6")

int set_cookie(struct bpf_sock_addr *ctx)

{
@@ -33,14 +42,14 @@ int set_cookie(struct bpf_sock_addr *ctx) 
	if (!p)

		return 1;



	p->cookie_value = 0xFF;

	p->cookie_value = 0xF;

	p->cookie_key = bpf_get_socket_cookie(ctx);



	return 1;

}



SEC("sockops")

int update_cookie(struct bpf_sock_ops *ctx)

int update_cookie_sockops(struct bpf_sock_ops *ctx)

{

	struct bpf_sock *sk = ctx->sk;

	struct socket_cookie *p;
@@ -61,9 +70,30 @@ int update_cookie(struct bpf_sock_ops *ctx) 
	if (p->cookie_key != bpf_get_socket_cookie(ctx))

		return 1;



	p->cookie_value = (ctx->local_port << 8) | p->cookie_value;

	p->cookie_value |= (ctx->local_port << 8);



	return 1;

}



SEC("fexit/inet_stream_connect")

int BPF_PROG(update_cookie_tracing, struct socket *sock,

	     struct sockaddr *uaddr, int addr_len, int flags)

{

	struct socket_cookie *p;



	if (uaddr->sa_family != AF_INET6)

		return 0;



	p = bpf_sk_storage_get(&socket_cookies, sock->sk, 0, 0);

	if (!p)

		return 0;



	if (p->cookie_key != bpf_get_socket_cookie(sock->sk))

		return 0;



	p->cookie_value |= 0xF0;



	return 0;

}



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