selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca

This patch uses connect_to_fd_opts() instead of using connect_fd_to_fd()
and settcpca() in do_test() in prog_tests/bpf_tcp_ca.c to accept a struct
network_helper_opts argument.

Then define a dctcp dedicated post_socket_cb callback stg_post_socket_cb(),
invoking both settcpca() and bpf_map_update_elem() in it, and set it in
test_dctcp(). For passing map_fd into stg_post_socket_cb() callback, a new
member map_fd is added in struct cb_opts.

Add another "const struct network_helper_opts *cli_opts" to do_test() to
separate it from the server "opts".
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/876ec90430865bc468e3b7f6fb2648420b075548.1717054461.git.tanggeliang@kylinos.cn

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

@@ -25,6 +25,7 @@ static int expected_stg = 0xeB9F;
 
 struct cb_opts {
 	const char *cc;
+	int map_fd;
 };
 
 static int settcpca(int fd, const char *tcp_ca)
@@ -39,9 +40,9 @@ static int settcpca(int fd, const char *tcp_ca)
 }
 
 static void do_test(const struct network_helper_opts *opts,
+		    const struct network_helper_opts *cli_opts,
 		    const struct bpf_map *sk_stg_map)
 {
-	struct cb_opts *cb_opts = (struct cb_opts *)opts->cb_opts;
 	int lfd = -1, fd = -1;
 	int err;
 
@@ -49,25 +50,9 @@ static void do_test(const struct network_helper_opts *opts,
 	if (!ASSERT_NEQ(lfd, -1, "socket"))
 		return;
 
-	fd = socket(AF_INET6, SOCK_STREAM, 0);
-	if (!ASSERT_NEQ(fd, -1, "socket")) {
-		close(lfd);
-		return;
-	}
-
-	if (settcpca(fd, cb_opts->cc))
-		goto done;
-
-	if (sk_stg_map) {
-		err = bpf_map_update_elem(bpf_map__fd(sk_stg_map), &fd,
-					  &expected_stg, BPF_NOEXIST);
-		if (!ASSERT_OK(err, "bpf_map_update_elem(sk_stg_map)"))
-			goto done;
-	}
-
 	/* connect to server */
-	err = connect_fd_to_fd(fd, lfd, 0);
-	if (!ASSERT_NEQ(err, -1, "connect"))
+	fd = connect_to_fd_opts(lfd, cli_opts);
+	if (!ASSERT_NEQ(fd, -1, "connect_to_fd_opts"))
 		goto done;
 
 	if (sk_stg_map) {
@@ -116,7 +101,7 @@ static void test_cubic(void)
 		return;
 	}
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 
 	ASSERT_EQ(cubic_skel->bss->bpf_cubic_acked_called, 1, "pkts_acked called");
 
@@ -124,6 +109,23 @@ static void test_cubic(void)
 	bpf_cubic__destroy(cubic_skel);
 }
 
+static int stg_post_socket_cb(int fd, void *opts)
+{
+	struct cb_opts *cb_opts = (struct cb_opts *)opts;
+	int err;
+
+	err = settcpca(fd, cb_opts->cc);
+	if (err)
+		return err;
+
+	err = bpf_map_update_elem(cb_opts->map_fd, &fd,
+				  &expected_stg, BPF_NOEXIST);
+	if (!ASSERT_OK(err, "bpf_map_update_elem(sk_stg_map)"))
+		return err;
+
+	return 0;
+}
+
 static void test_dctcp(void)
 {
 	struct cb_opts cb_opts = {
@@ -133,6 +135,10 @@ static void test_dctcp(void)
 		.post_socket_cb	= cc_cb,
 		.cb_opts	= &cb_opts,
 	};
+	struct network_helper_opts cli_opts = {
+		.post_socket_cb	= stg_post_socket_cb,
+		.cb_opts	= &cb_opts,
+	};
 	struct bpf_dctcp *dctcp_skel;
 	struct bpf_link *link;
 
@@ -146,7 +152,8 @@ static void test_dctcp(void)
 		return;
 	}
 
-	do_test(&opts, dctcp_skel->maps.sk_stg_map);
+	cb_opts.map_fd = bpf_map__fd(dctcp_skel->maps.sk_stg_map);
+	do_test(&opts, &cli_opts, dctcp_skel->maps.sk_stg_map);
 	ASSERT_EQ(dctcp_skel->bss->stg_result, expected_stg, "stg_result");
 
 	bpf_link__destroy(link);
@@ -350,14 +357,14 @@ static void test_update_ca(void)
 	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
 	ASSERT_OK_PTR(link, "attach_struct_ops");
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 	saved_ca1_cnt = skel->bss->ca1_cnt;
 	ASSERT_GT(saved_ca1_cnt, 0, "ca1_ca1_cnt");
 
 	err = bpf_link__update_map(link, skel->maps.ca_update_2);
 	ASSERT_OK(err, "update_map");
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 	ASSERT_EQ(skel->bss->ca1_cnt, saved_ca1_cnt, "ca2_ca1_cnt");
 	ASSERT_GT(skel->bss->ca2_cnt, 0, "ca2_ca2_cnt");
 
@@ -386,14 +393,14 @@ static void test_update_wrong(void)
 	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
 	ASSERT_OK_PTR(link, "attach_struct_ops");
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 	saved_ca1_cnt = skel->bss->ca1_cnt;
 	ASSERT_GT(saved_ca1_cnt, 0, "ca1_ca1_cnt");
 
 	err = bpf_link__update_map(link, skel->maps.ca_wrong);
 	ASSERT_ERR(err, "update_map");
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 	ASSERT_GT(skel->bss->ca1_cnt, saved_ca1_cnt, "ca2_ca1_cnt");
 
 	bpf_link__destroy(link);
@@ -423,7 +430,7 @@ static void test_mixed_links(void)
 	link = bpf_map__attach_struct_ops(skel->maps.ca_update_1);
 	ASSERT_OK_PTR(link, "attach_struct_ops");
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 	ASSERT_GT(skel->bss->ca1_cnt, 0, "ca1_ca1_cnt");
 
 	err = bpf_link__update_map(link, skel->maps.ca_no_link);
@@ -530,7 +537,7 @@ static void test_cc_cubic(void)
 		return;
 	}
 
-	do_test(&opts, NULL);
+	do_test(&opts, &opts, NULL);
 
 	bpf_link__destroy(link);
 	bpf_cc_cubic__destroy(cc_cubic_skel);