xref: /linux/tools/testing/selftests/bpf/prog_tests/mptcp.c (revision 71dfa617ea9f18e4585fe78364217cd32b1fc382)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020, Tessares SA. */
3 /* Copyright (c) 2022, SUSE. */
4 
5 #include <linux/const.h>
6 #include <netinet/in.h>
7 #include <test_progs.h>
8 #include "cgroup_helpers.h"
9 #include "network_helpers.h"
10 #include "mptcp_sock.skel.h"
11 #include "mptcpify.skel.h"
12 
13 #define NS_TEST "mptcp_ns"
14 
15 #ifndef IPPROTO_MPTCP
16 #define IPPROTO_MPTCP 262
17 #endif
18 
19 #ifndef SOL_MPTCP
20 #define SOL_MPTCP 284
21 #endif
22 #ifndef MPTCP_INFO
23 #define MPTCP_INFO		1
24 #endif
25 #ifndef MPTCP_INFO_FLAG_FALLBACK
26 #define MPTCP_INFO_FLAG_FALLBACK		_BITUL(0)
27 #endif
28 #ifndef MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED
29 #define MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED	_BITUL(1)
30 #endif
31 
32 #ifndef TCP_CA_NAME_MAX
33 #define TCP_CA_NAME_MAX	16
34 #endif
35 
36 struct __mptcp_info {
37 	__u8	mptcpi_subflows;
38 	__u8	mptcpi_add_addr_signal;
39 	__u8	mptcpi_add_addr_accepted;
40 	__u8	mptcpi_subflows_max;
41 	__u8	mptcpi_add_addr_signal_max;
42 	__u8	mptcpi_add_addr_accepted_max;
43 	__u32	mptcpi_flags;
44 	__u32	mptcpi_token;
45 	__u64	mptcpi_write_seq;
46 	__u64	mptcpi_snd_una;
47 	__u64	mptcpi_rcv_nxt;
48 	__u8	mptcpi_local_addr_used;
49 	__u8	mptcpi_local_addr_max;
50 	__u8	mptcpi_csum_enabled;
51 	__u32	mptcpi_retransmits;
52 	__u64	mptcpi_bytes_retrans;
53 	__u64	mptcpi_bytes_sent;
54 	__u64	mptcpi_bytes_received;
55 	__u64	mptcpi_bytes_acked;
56 };
57 
58 struct mptcp_storage {
59 	__u32 invoked;
60 	__u32 is_mptcp;
61 	struct sock *sk;
62 	__u32 token;
63 	struct sock *first;
64 	char ca_name[TCP_CA_NAME_MAX];
65 };
66 
67 static struct nstoken *create_netns(void)
68 {
69 	SYS(fail, "ip netns add %s", NS_TEST);
70 	SYS(fail, "ip -net %s link set dev lo up", NS_TEST);
71 
72 	return open_netns(NS_TEST);
73 fail:
74 	return NULL;
75 }
76 
77 static void cleanup_netns(struct nstoken *nstoken)
78 {
79 	if (nstoken)
80 		close_netns(nstoken);
81 
82 	SYS_NOFAIL("ip netns del %s", NS_TEST);
83 }
84 
85 static int verify_tsk(int map_fd, int client_fd)
86 {
87 	int err, cfd = client_fd;
88 	struct mptcp_storage val;
89 
90 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
91 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
92 		return err;
93 
94 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
95 		err++;
96 
97 	if (!ASSERT_EQ(val.is_mptcp, 0, "unexpected is_mptcp"))
98 		err++;
99 
100 	return err;
101 }
102 
103 static void get_msk_ca_name(char ca_name[])
104 {
105 	size_t len;
106 	int fd;
107 
108 	fd = open("/proc/sys/net/ipv4/tcp_congestion_control", O_RDONLY);
109 	if (!ASSERT_GE(fd, 0, "failed to open tcp_congestion_control"))
110 		return;
111 
112 	len = read(fd, ca_name, TCP_CA_NAME_MAX);
113 	if (!ASSERT_GT(len, 0, "failed to read ca_name"))
114 		goto err;
115 
116 	if (len > 0 && ca_name[len - 1] == '\n')
117 		ca_name[len - 1] = '\0';
118 
119 err:
120 	close(fd);
121 }
122 
123 static int verify_msk(int map_fd, int client_fd, __u32 token)
124 {
125 	char ca_name[TCP_CA_NAME_MAX];
126 	int err, cfd = client_fd;
127 	struct mptcp_storage val;
128 
129 	if (!ASSERT_GT(token, 0, "invalid token"))
130 		return -1;
131 
132 	get_msk_ca_name(ca_name);
133 
134 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
135 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
136 		return err;
137 
138 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
139 		err++;
140 
141 	if (!ASSERT_EQ(val.is_mptcp, 1, "unexpected is_mptcp"))
142 		err++;
143 
144 	if (!ASSERT_EQ(val.token, token, "unexpected token"))
145 		err++;
146 
147 	if (!ASSERT_EQ(val.first, val.sk, "unexpected first"))
148 		err++;
149 
150 	if (!ASSERT_STRNEQ(val.ca_name, ca_name, TCP_CA_NAME_MAX, "unexpected ca_name"))
151 		err++;
152 
153 	return err;
154 }
155 
156 static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
157 {
158 	int client_fd, prog_fd, map_fd, err;
159 	struct mptcp_sock *sock_skel;
160 
161 	sock_skel = mptcp_sock__open_and_load();
162 	if (!ASSERT_OK_PTR(sock_skel, "skel_open_load"))
163 		return libbpf_get_error(sock_skel);
164 
165 	err = mptcp_sock__attach(sock_skel);
166 	if (!ASSERT_OK(err, "skel_attach"))
167 		goto out;
168 
169 	prog_fd = bpf_program__fd(sock_skel->progs._sockops);
170 	map_fd = bpf_map__fd(sock_skel->maps.socket_storage_map);
171 	err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
172 	if (!ASSERT_OK(err, "bpf_prog_attach"))
173 		goto out;
174 
175 	client_fd = connect_to_fd(server_fd, 0);
176 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
177 		err = -EIO;
178 		goto out;
179 	}
180 
181 	err += is_mptcp ? verify_msk(map_fd, client_fd, sock_skel->bss->token) :
182 			  verify_tsk(map_fd, client_fd);
183 
184 	close(client_fd);
185 
186 out:
187 	mptcp_sock__destroy(sock_skel);
188 	return err;
189 }
190 
191 static void test_base(void)
192 {
193 	struct nstoken *nstoken = NULL;
194 	int server_fd, cgroup_fd;
195 
196 	cgroup_fd = test__join_cgroup("/mptcp");
197 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
198 		return;
199 
200 	nstoken = create_netns();
201 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
202 		goto fail;
203 
204 	/* without MPTCP */
205 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
206 	if (!ASSERT_GE(server_fd, 0, "start_server"))
207 		goto with_mptcp;
208 
209 	ASSERT_OK(run_test(cgroup_fd, server_fd, false), "run_test tcp");
210 
211 	close(server_fd);
212 
213 with_mptcp:
214 	/* with MPTCP */
215 	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
216 	if (!ASSERT_GE(server_fd, 0, "start_mptcp_server"))
217 		goto fail;
218 
219 	ASSERT_OK(run_test(cgroup_fd, server_fd, true), "run_test mptcp");
220 
221 	close(server_fd);
222 
223 fail:
224 	cleanup_netns(nstoken);
225 	close(cgroup_fd);
226 }
227 
228 static void send_byte(int fd)
229 {
230 	char b = 0x55;
231 
232 	ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
233 }
234 
235 static int verify_mptcpify(int server_fd, int client_fd)
236 {
237 	struct __mptcp_info info;
238 	socklen_t optlen;
239 	int protocol;
240 	int err = 0;
241 
242 	optlen = sizeof(protocol);
243 	if (!ASSERT_OK(getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen),
244 		       "getsockopt(SOL_PROTOCOL)"))
245 		return -1;
246 
247 	if (!ASSERT_EQ(protocol, IPPROTO_MPTCP, "protocol isn't MPTCP"))
248 		err++;
249 
250 	optlen = sizeof(info);
251 	if (!ASSERT_OK(getsockopt(client_fd, SOL_MPTCP, MPTCP_INFO, &info, &optlen),
252 		       "getsockopt(MPTCP_INFO)"))
253 		return -1;
254 
255 	if (!ASSERT_GE(info.mptcpi_flags, 0, "unexpected mptcpi_flags"))
256 		err++;
257 	if (!ASSERT_FALSE(info.mptcpi_flags & MPTCP_INFO_FLAG_FALLBACK,
258 			  "MPTCP fallback"))
259 		err++;
260 	if (!ASSERT_TRUE(info.mptcpi_flags & MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED,
261 			 "no remote key received"))
262 		err++;
263 
264 	return err;
265 }
266 
267 static int run_mptcpify(int cgroup_fd)
268 {
269 	int server_fd, client_fd, err = 0;
270 	struct mptcpify *mptcpify_skel;
271 
272 	mptcpify_skel = mptcpify__open_and_load();
273 	if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
274 		return libbpf_get_error(mptcpify_skel);
275 
276 	err = mptcpify__attach(mptcpify_skel);
277 	if (!ASSERT_OK(err, "skel_attach"))
278 		goto out;
279 
280 	/* without MPTCP */
281 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
282 	if (!ASSERT_GE(server_fd, 0, "start_server")) {
283 		err = -EIO;
284 		goto out;
285 	}
286 
287 	client_fd = connect_to_fd(server_fd, 0);
288 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
289 		err = -EIO;
290 		goto close_server;
291 	}
292 
293 	send_byte(client_fd);
294 
295 	err = verify_mptcpify(server_fd, client_fd);
296 
297 	close(client_fd);
298 close_server:
299 	close(server_fd);
300 out:
301 	mptcpify__destroy(mptcpify_skel);
302 	return err;
303 }
304 
305 static void test_mptcpify(void)
306 {
307 	struct nstoken *nstoken = NULL;
308 	int cgroup_fd;
309 
310 	cgroup_fd = test__join_cgroup("/mptcpify");
311 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
312 		return;
313 
314 	nstoken = create_netns();
315 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
316 		goto fail;
317 
318 	ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
319 
320 fail:
321 	cleanup_netns(nstoken);
322 	close(cgroup_fd);
323 }
324 
325 void test_mptcp(void)
326 {
327 	if (test__start_subtest("base"))
328 		test_base();
329 	if (test__start_subtest("mptcpify"))
330 		test_mptcpify();
331 }
332