Commit a4b7193d authored by Xu Kuohai's avatar Xu Kuohai Committed by Martin KaFai Lau
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selftests/bpf: Add sockmap test for redirecting partial skb data 



Add a test case to check whether sockmap redirection works correctly
when data length returned by stream_parser is less than skb->len.

In addition, this test checks whether strp_done is called correctly.
The reason is that we returns skb->len - 1 from the stream_parser, so
the last byte in the skb will be held by strp->skb_head. Therefore,
if strp_done is not called to free strp->skb_head, we'll get a memleak
warning.

Signed-off-by: default avatarXu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20230804073740.194770-5-xukuohai@huaweicloud.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent 90f0074c

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

+72 −0
Original line number Diff line number Diff line
@@ -869,6 +869,77 @@ static void test_msg_redir_to_listening(struct test_sockmap_listen *skel, 
	xbpf_prog_detach2(verdict, sock_map, BPF_SK_MSG_VERDICT);

}



static void redir_partial(int family, int sotype, int sock_map, int parser_map)

{

	int s, c0, c1, p0, p1;

	int err, n, key, value;

	char buf[] = "abc";



	key = 0;

	value = sizeof(buf) - 1;

	err = xbpf_map_update_elem(parser_map, &key, &value, 0);

	if (err)

		return;



	s = socket_loopback(family, sotype | SOCK_NONBLOCK);

	if (s < 0)

		goto clean_parser_map;



	err = create_socket_pairs(s, family, sotype, &c0, &c1, &p0, &p1);

	if (err)

		goto close_srv;



	err = add_to_sockmap(sock_map, p0, p1);

	if (err)

		goto close;



	n = xsend(c1, buf, sizeof(buf), 0);

	if (n < sizeof(buf))

		FAIL("incomplete write");



	n = xrecv_nonblock(c0, buf, sizeof(buf), 0);

	if (n != sizeof(buf) - 1)

		FAIL("expect %zu, received %d", sizeof(buf) - 1, n);



close:

	xclose(c0);

	xclose(p0);

	xclose(c1);

	xclose(p1);

close_srv:

	xclose(s);



clean_parser_map:

	key = 0;

	value = 0;

	xbpf_map_update_elem(parser_map, &key, &value, 0);

}



static void test_skb_redir_partial(struct test_sockmap_listen *skel,

				   struct bpf_map *inner_map, int family,

				   int sotype)

{

	int verdict = bpf_program__fd(skel->progs.prog_stream_verdict);

	int parser = bpf_program__fd(skel->progs.prog_stream_parser);

	int parser_map = bpf_map__fd(skel->maps.parser_map);

	int sock_map = bpf_map__fd(inner_map);

	int err;



	err = xbpf_prog_attach(parser, sock_map, BPF_SK_SKB_STREAM_PARSER, 0);

	if (err)

		return;



	err = xbpf_prog_attach(verdict, sock_map, BPF_SK_SKB_STREAM_VERDICT, 0);

	if (err)

		goto detach;



	redir_partial(family, sotype, sock_map, parser_map);



	xbpf_prog_detach2(verdict, sock_map, BPF_SK_SKB_STREAM_VERDICT);

detach:

	xbpf_prog_detach2(parser, sock_map, BPF_SK_SKB_STREAM_PARSER);

}



static void test_reuseport_select_listening(int family, int sotype,

					    int sock_map, int verd_map,

					    int reuseport_prog)
@@ -1243,6 +1314,7 @@ static void test_redir(struct test_sockmap_listen *skel, struct bpf_map *map, 
	} tests[] = {

		TEST(test_skb_redir_to_connected),

		TEST(test_skb_redir_to_listening),

		TEST(test_skb_redir_partial),

		TEST(test_msg_redir_to_connected),

		TEST(test_msg_redir_to_listening),

	};

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

+14 −0
Original line number Diff line number Diff line
@@ -28,12 +28,26 @@ struct { 
	__type(value, unsigned int);

} verdict_map SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_ARRAY);

	__uint(max_entries, 1);

	__type(key, int);

	__type(value, int);

} parser_map SEC(".maps");



bool test_sockmap = false; /* toggled by user-space */

bool test_ingress = false; /* toggled by user-space */



SEC("sk_skb/stream_parser")

int prog_stream_parser(struct __sk_buff *skb)

{

	int *value;

	__u32 key = 0;



	value = bpf_map_lookup_elem(&parser_map, &key);

	if (value && *value)

		return *value;



	return skb->len;

}