xref: /linux/tools/testing/selftests/bpf/prog_tests/mptcp.c (revision 001821b0e79716c4e17c71d8e053a23599a7a508)
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 start_mptcp_server(int family, const char *addr_str, __u16 port,
86 			      int timeout_ms)
87 {
88 	struct network_helper_opts opts = {
89 		.timeout_ms	= timeout_ms,
90 		.proto		= IPPROTO_MPTCP,
91 	};
92 	struct sockaddr_storage addr;
93 	socklen_t addrlen;
94 
95 	if (make_sockaddr(family, addr_str, port, &addr, &addrlen))
96 		return -1;
97 
98 	return start_server_addr(SOCK_STREAM, &addr, addrlen, &opts);
99 }
100 
101 static int verify_tsk(int map_fd, int client_fd)
102 {
103 	int err, cfd = client_fd;
104 	struct mptcp_storage val;
105 
106 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
107 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
108 		return err;
109 
110 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
111 		err++;
112 
113 	if (!ASSERT_EQ(val.is_mptcp, 0, "unexpected is_mptcp"))
114 		err++;
115 
116 	return err;
117 }
118 
119 static void get_msk_ca_name(char ca_name[])
120 {
121 	size_t len;
122 	int fd;
123 
124 	fd = open("/proc/sys/net/ipv4/tcp_congestion_control", O_RDONLY);
125 	if (!ASSERT_GE(fd, 0, "failed to open tcp_congestion_control"))
126 		return;
127 
128 	len = read(fd, ca_name, TCP_CA_NAME_MAX);
129 	if (!ASSERT_GT(len, 0, "failed to read ca_name"))
130 		goto err;
131 
132 	if (len > 0 && ca_name[len - 1] == '\n')
133 		ca_name[len - 1] = '\0';
134 
135 err:
136 	close(fd);
137 }
138 
139 static int verify_msk(int map_fd, int client_fd, __u32 token)
140 {
141 	char ca_name[TCP_CA_NAME_MAX];
142 	int err, cfd = client_fd;
143 	struct mptcp_storage val;
144 
145 	if (!ASSERT_GT(token, 0, "invalid token"))
146 		return -1;
147 
148 	get_msk_ca_name(ca_name);
149 
150 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
151 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
152 		return err;
153 
154 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
155 		err++;
156 
157 	if (!ASSERT_EQ(val.is_mptcp, 1, "unexpected is_mptcp"))
158 		err++;
159 
160 	if (!ASSERT_EQ(val.token, token, "unexpected token"))
161 		err++;
162 
163 	if (!ASSERT_EQ(val.first, val.sk, "unexpected first"))
164 		err++;
165 
166 	if (!ASSERT_STRNEQ(val.ca_name, ca_name, TCP_CA_NAME_MAX, "unexpected ca_name"))
167 		err++;
168 
169 	return err;
170 }
171 
172 static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
173 {
174 	int client_fd, prog_fd, map_fd, err;
175 	struct mptcp_sock *sock_skel;
176 
177 	sock_skel = mptcp_sock__open_and_load();
178 	if (!ASSERT_OK_PTR(sock_skel, "skel_open_load"))
179 		return libbpf_get_error(sock_skel);
180 
181 	err = mptcp_sock__attach(sock_skel);
182 	if (!ASSERT_OK(err, "skel_attach"))
183 		goto out;
184 
185 	prog_fd = bpf_program__fd(sock_skel->progs._sockops);
186 	map_fd = bpf_map__fd(sock_skel->maps.socket_storage_map);
187 	err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
188 	if (!ASSERT_OK(err, "bpf_prog_attach"))
189 		goto out;
190 
191 	client_fd = connect_to_fd(server_fd, 0);
192 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
193 		err = -EIO;
194 		goto out;
195 	}
196 
197 	err += is_mptcp ? verify_msk(map_fd, client_fd, sock_skel->bss->token) :
198 			  verify_tsk(map_fd, client_fd);
199 
200 	close(client_fd);
201 
202 out:
203 	mptcp_sock__destroy(sock_skel);
204 	return err;
205 }
206 
207 static void test_base(void)
208 {
209 	struct nstoken *nstoken = NULL;
210 	int server_fd, cgroup_fd;
211 
212 	cgroup_fd = test__join_cgroup("/mptcp");
213 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
214 		return;
215 
216 	nstoken = create_netns();
217 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
218 		goto fail;
219 
220 	/* without MPTCP */
221 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
222 	if (!ASSERT_GE(server_fd, 0, "start_server"))
223 		goto with_mptcp;
224 
225 	ASSERT_OK(run_test(cgroup_fd, server_fd, false), "run_test tcp");
226 
227 	close(server_fd);
228 
229 with_mptcp:
230 	/* with MPTCP */
231 	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
232 	if (!ASSERT_GE(server_fd, 0, "start_mptcp_server"))
233 		goto fail;
234 
235 	ASSERT_OK(run_test(cgroup_fd, server_fd, true), "run_test mptcp");
236 
237 	close(server_fd);
238 
239 fail:
240 	cleanup_netns(nstoken);
241 	close(cgroup_fd);
242 }
243 
244 static void send_byte(int fd)
245 {
246 	char b = 0x55;
247 
248 	ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
249 }
250 
251 static int verify_mptcpify(int server_fd, int client_fd)
252 {
253 	struct __mptcp_info info;
254 	socklen_t optlen;
255 	int protocol;
256 	int err = 0;
257 
258 	optlen = sizeof(protocol);
259 	if (!ASSERT_OK(getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen),
260 		       "getsockopt(SOL_PROTOCOL)"))
261 		return -1;
262 
263 	if (!ASSERT_EQ(protocol, IPPROTO_MPTCP, "protocol isn't MPTCP"))
264 		err++;
265 
266 	optlen = sizeof(info);
267 	if (!ASSERT_OK(getsockopt(client_fd, SOL_MPTCP, MPTCP_INFO, &info, &optlen),
268 		       "getsockopt(MPTCP_INFO)"))
269 		return -1;
270 
271 	if (!ASSERT_GE(info.mptcpi_flags, 0, "unexpected mptcpi_flags"))
272 		err++;
273 	if (!ASSERT_FALSE(info.mptcpi_flags & MPTCP_INFO_FLAG_FALLBACK,
274 			  "MPTCP fallback"))
275 		err++;
276 	if (!ASSERT_TRUE(info.mptcpi_flags & MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED,
277 			 "no remote key received"))
278 		err++;
279 
280 	return err;
281 }
282 
283 static int run_mptcpify(int cgroup_fd)
284 {
285 	int server_fd, client_fd, err = 0;
286 	struct mptcpify *mptcpify_skel;
287 
288 	mptcpify_skel = mptcpify__open_and_load();
289 	if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
290 		return libbpf_get_error(mptcpify_skel);
291 
292 	mptcpify_skel->bss->pid = getpid();
293 
294 	err = mptcpify__attach(mptcpify_skel);
295 	if (!ASSERT_OK(err, "skel_attach"))
296 		goto out;
297 
298 	/* without MPTCP */
299 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
300 	if (!ASSERT_GE(server_fd, 0, "start_server")) {
301 		err = -EIO;
302 		goto out;
303 	}
304 
305 	client_fd = connect_to_fd(server_fd, 0);
306 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
307 		err = -EIO;
308 		goto close_server;
309 	}
310 
311 	send_byte(client_fd);
312 
313 	err = verify_mptcpify(server_fd, client_fd);
314 
315 	close(client_fd);
316 close_server:
317 	close(server_fd);
318 out:
319 	mptcpify__destroy(mptcpify_skel);
320 	return err;
321 }
322 
323 static void test_mptcpify(void)
324 {
325 	struct nstoken *nstoken = NULL;
326 	int cgroup_fd;
327 
328 	cgroup_fd = test__join_cgroup("/mptcpify");
329 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
330 		return;
331 
332 	nstoken = create_netns();
333 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
334 		goto fail;
335 
336 	ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
337 
338 fail:
339 	cleanup_netns(nstoken);
340 	close(cgroup_fd);
341 }
342 
343 void test_mptcp(void)
344 {
345 	if (test__start_subtest("base"))
346 		test_base();
347 	if (test__start_subtest("mptcpify"))
348 		test_mptcpify();
349 }
350