xref: /linux/tools/testing/selftests/bpf/prog_tests/mptcp.c (revision c34e9ab9a612ee8b18273398ef75c207b01f516d)
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 <unistd.h>
9 #include "cgroup_helpers.h"
10 #include "network_helpers.h"
11 #include "mptcp_sock.skel.h"
12 #include "mptcpify.skel.h"
13 #include "mptcp_subflow.skel.h"
14 
15 #define NS_TEST "mptcp_ns"
16 #define ADDR_1	"10.0.1.1"
17 #define ADDR_2	"10.0.1.2"
18 #define PORT_1	10001
19 
20 #ifndef IPPROTO_MPTCP
21 #define IPPROTO_MPTCP 262
22 #endif
23 
24 #ifndef SOL_MPTCP
25 #define SOL_MPTCP 284
26 #endif
27 #ifndef MPTCP_INFO
28 #define MPTCP_INFO		1
29 #endif
30 #ifndef MPTCP_INFO_FLAG_FALLBACK
31 #define MPTCP_INFO_FLAG_FALLBACK		_BITUL(0)
32 #endif
33 #ifndef MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED
34 #define MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED	_BITUL(1)
35 #endif
36 
37 #ifndef TCP_CA_NAME_MAX
38 #define TCP_CA_NAME_MAX	16
39 #endif
40 
41 struct __mptcp_info {
42 	__u8	mptcpi_subflows;
43 	__u8	mptcpi_add_addr_signal;
44 	__u8	mptcpi_add_addr_accepted;
45 	__u8	mptcpi_subflows_max;
46 	__u8	mptcpi_add_addr_signal_max;
47 	__u8	mptcpi_add_addr_accepted_max;
48 	__u32	mptcpi_flags;
49 	__u32	mptcpi_token;
50 	__u64	mptcpi_write_seq;
51 	__u64	mptcpi_snd_una;
52 	__u64	mptcpi_rcv_nxt;
53 	__u8	mptcpi_local_addr_used;
54 	__u8	mptcpi_local_addr_max;
55 	__u8	mptcpi_csum_enabled;
56 	__u32	mptcpi_retransmits;
57 	__u64	mptcpi_bytes_retrans;
58 	__u64	mptcpi_bytes_sent;
59 	__u64	mptcpi_bytes_received;
60 	__u64	mptcpi_bytes_acked;
61 };
62 
63 struct mptcp_storage {
64 	__u32 invoked;
65 	__u32 is_mptcp;
66 	struct sock *sk;
67 	__u32 token;
68 	struct sock *first;
69 	char ca_name[TCP_CA_NAME_MAX];
70 };
71 
72 static int start_mptcp_server(int family, const char *addr_str, __u16 port,
73 			      int timeout_ms)
74 {
75 	struct network_helper_opts opts = {
76 		.timeout_ms	= timeout_ms,
77 		.proto		= IPPROTO_MPTCP,
78 	};
79 
80 	return start_server_str(family, SOCK_STREAM, addr_str, port, &opts);
81 }
82 
83 static int verify_tsk(int map_fd, int client_fd)
84 {
85 	int err, cfd = client_fd;
86 	struct mptcp_storage val;
87 
88 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
89 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
90 		return err;
91 
92 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
93 		err++;
94 
95 	if (!ASSERT_EQ(val.is_mptcp, 0, "unexpected is_mptcp"))
96 		err++;
97 
98 	return err;
99 }
100 
101 static void get_msk_ca_name(char ca_name[])
102 {
103 	size_t len;
104 	int fd;
105 
106 	fd = open("/proc/sys/net/ipv4/tcp_congestion_control", O_RDONLY);
107 	if (!ASSERT_GE(fd, 0, "failed to open tcp_congestion_control"))
108 		return;
109 
110 	len = read(fd, ca_name, TCP_CA_NAME_MAX);
111 	if (!ASSERT_GT(len, 0, "failed to read ca_name"))
112 		goto err;
113 
114 	if (len > 0 && ca_name[len - 1] == '\n')
115 		ca_name[len - 1] = '\0';
116 
117 err:
118 	close(fd);
119 }
120 
121 static int verify_msk(int map_fd, int client_fd, __u32 token)
122 {
123 	char ca_name[TCP_CA_NAME_MAX];
124 	int err, cfd = client_fd;
125 	struct mptcp_storage val;
126 
127 	if (!ASSERT_GT(token, 0, "invalid token"))
128 		return -1;
129 
130 	get_msk_ca_name(ca_name);
131 
132 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
133 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
134 		return err;
135 
136 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
137 		err++;
138 
139 	if (!ASSERT_EQ(val.is_mptcp, 1, "unexpected is_mptcp"))
140 		err++;
141 
142 	if (!ASSERT_EQ(val.token, token, "unexpected token"))
143 		err++;
144 
145 	if (!ASSERT_EQ(val.first, val.sk, "unexpected first"))
146 		err++;
147 
148 	if (!ASSERT_STRNEQ(val.ca_name, ca_name, TCP_CA_NAME_MAX, "unexpected ca_name"))
149 		err++;
150 
151 	return err;
152 }
153 
154 static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
155 {
156 	int client_fd, prog_fd, map_fd, err;
157 	struct mptcp_sock *sock_skel;
158 
159 	sock_skel = mptcp_sock__open_and_load();
160 	if (!ASSERT_OK_PTR(sock_skel, "skel_open_load"))
161 		return libbpf_get_error(sock_skel);
162 
163 	err = mptcp_sock__attach(sock_skel);
164 	if (!ASSERT_OK(err, "skel_attach"))
165 		goto out;
166 
167 	prog_fd = bpf_program__fd(sock_skel->progs._sockops);
168 	map_fd = bpf_map__fd(sock_skel->maps.socket_storage_map);
169 	err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
170 	if (!ASSERT_OK(err, "bpf_prog_attach"))
171 		goto out;
172 
173 	client_fd = connect_to_fd(server_fd, 0);
174 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
175 		err = -EIO;
176 		goto out;
177 	}
178 
179 	err += is_mptcp ? verify_msk(map_fd, client_fd, sock_skel->bss->token) :
180 			  verify_tsk(map_fd, client_fd);
181 
182 	close(client_fd);
183 
184 out:
185 	mptcp_sock__destroy(sock_skel);
186 	return err;
187 }
188 
189 static void test_base(void)
190 {
191 	struct netns_obj *netns = NULL;
192 	int server_fd, cgroup_fd;
193 
194 	cgroup_fd = test__join_cgroup("/mptcp");
195 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
196 		return;
197 
198 	netns = netns_new(NS_TEST, true);
199 	if (!ASSERT_OK_PTR(netns, "netns_new"))
200 		goto fail;
201 
202 	/* without MPTCP */
203 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
204 	if (!ASSERT_GE(server_fd, 0, "start_server"))
205 		goto with_mptcp;
206 
207 	ASSERT_OK(run_test(cgroup_fd, server_fd, false), "run_test tcp");
208 
209 	close(server_fd);
210 
211 with_mptcp:
212 	/* with MPTCP */
213 	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
214 	if (!ASSERT_GE(server_fd, 0, "start_mptcp_server"))
215 		goto fail;
216 
217 	ASSERT_OK(run_test(cgroup_fd, server_fd, true), "run_test mptcp");
218 
219 	close(server_fd);
220 
221 fail:
222 	netns_free(netns);
223 	close(cgroup_fd);
224 }
225 
226 static void send_byte(int fd)
227 {
228 	char b = 0x55;
229 
230 	ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
231 }
232 
233 static int verify_mptcpify(int server_fd, int client_fd)
234 {
235 	struct __mptcp_info info;
236 	socklen_t optlen;
237 	int protocol;
238 	int err = 0;
239 
240 	optlen = sizeof(protocol);
241 	if (!ASSERT_OK(getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen),
242 		       "getsockopt(SOL_PROTOCOL)"))
243 		return -1;
244 
245 	if (!ASSERT_EQ(protocol, IPPROTO_MPTCP, "protocol isn't MPTCP"))
246 		err++;
247 
248 	optlen = sizeof(info);
249 	if (!ASSERT_OK(getsockopt(client_fd, SOL_MPTCP, MPTCP_INFO, &info, &optlen),
250 		       "getsockopt(MPTCP_INFO)"))
251 		return -1;
252 
253 	if (!ASSERT_GE(info.mptcpi_flags, 0, "unexpected mptcpi_flags"))
254 		err++;
255 	if (!ASSERT_FALSE(info.mptcpi_flags & MPTCP_INFO_FLAG_FALLBACK,
256 			  "MPTCP fallback"))
257 		err++;
258 	if (!ASSERT_TRUE(info.mptcpi_flags & MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED,
259 			 "no remote key received"))
260 		err++;
261 
262 	return err;
263 }
264 
265 static int run_mptcpify(int cgroup_fd)
266 {
267 	int server_fd, client_fd, err = 0;
268 	struct mptcpify *mptcpify_skel;
269 
270 	mptcpify_skel = mptcpify__open_and_load();
271 	if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
272 		return libbpf_get_error(mptcpify_skel);
273 
274 	mptcpify_skel->bss->pid = getpid();
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 netns_obj *netns = 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 	netns = netns_new(NS_TEST, true);
315 	if (!ASSERT_OK_PTR(netns, "netns_new"))
316 		goto fail;
317 
318 	ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
319 
320 fail:
321 	netns_free(netns);
322 	close(cgroup_fd);
323 }
324 
325 static int endpoint_init(char *flags)
326 {
327 	SYS(fail, "ip -net %s link add veth1 type veth peer name veth2", NS_TEST);
328 	SYS(fail, "ip -net %s addr add %s/24 dev veth1", NS_TEST, ADDR_1);
329 	SYS(fail, "ip -net %s link set dev veth1 up", NS_TEST);
330 	SYS(fail, "ip -net %s addr add %s/24 dev veth2", NS_TEST, ADDR_2);
331 	SYS(fail, "ip -net %s link set dev veth2 up", NS_TEST);
332 	if (SYS_NOFAIL("ip -net %s mptcp endpoint add %s %s", NS_TEST, ADDR_2, flags)) {
333 		printf("'ip mptcp' not supported, skip this test.\n");
334 		test__skip();
335 		goto fail;
336 	}
337 
338 	return 0;
339 fail:
340 	return -1;
341 }
342 
343 static void wait_for_new_subflows(int fd)
344 {
345 	socklen_t len;
346 	u8 subflows;
347 	int err, i;
348 
349 	len = sizeof(subflows);
350 	/* Wait max 5 sec for new subflows to be created */
351 	for (i = 0; i < 50; i++) {
352 		err = getsockopt(fd, SOL_MPTCP, MPTCP_INFO, &subflows, &len);
353 		if (!err && subflows > 0)
354 			break;
355 
356 		usleep(100000); /* 0.1s */
357 	}
358 }
359 
360 static void run_subflow(void)
361 {
362 	int server_fd, client_fd, err;
363 	char new[TCP_CA_NAME_MAX];
364 	char cc[TCP_CA_NAME_MAX];
365 	unsigned int mark;
366 	socklen_t len;
367 
368 	server_fd = start_mptcp_server(AF_INET, ADDR_1, PORT_1, 0);
369 	if (!ASSERT_OK_FD(server_fd, "start_mptcp_server"))
370 		return;
371 
372 	client_fd = connect_to_fd(server_fd, 0);
373 	if (!ASSERT_OK_FD(client_fd, "connect_to_fd"))
374 		goto close_server;
375 
376 	send_byte(client_fd);
377 	wait_for_new_subflows(client_fd);
378 
379 	len = sizeof(mark);
380 	err = getsockopt(client_fd, SOL_SOCKET, SO_MARK, &mark, &len);
381 	if (ASSERT_OK(err, "getsockopt(client_fd, SO_MARK)"))
382 		ASSERT_EQ(mark, 0, "mark");
383 
384 	len = sizeof(new);
385 	err = getsockopt(client_fd, SOL_TCP, TCP_CONGESTION, new, &len);
386 	if (ASSERT_OK(err, "getsockopt(client_fd, TCP_CONGESTION)")) {
387 		get_msk_ca_name(cc);
388 		ASSERT_STREQ(new, cc, "cc");
389 	}
390 
391 	close(client_fd);
392 close_server:
393 	close(server_fd);
394 }
395 
396 static void test_subflow(void)
397 {
398 	struct mptcp_subflow *skel;
399 	struct netns_obj *netns;
400 	int cgroup_fd;
401 
402 	cgroup_fd = test__join_cgroup("/mptcp_subflow");
403 	if (!ASSERT_OK_FD(cgroup_fd, "join_cgroup: mptcp_subflow"))
404 		return;
405 
406 	skel = mptcp_subflow__open_and_load();
407 	if (!ASSERT_OK_PTR(skel, "skel_open_load: mptcp_subflow"))
408 		goto close_cgroup;
409 
410 	skel->bss->pid = getpid();
411 
412 	skel->links.mptcp_subflow =
413 		bpf_program__attach_cgroup(skel->progs.mptcp_subflow, cgroup_fd);
414 	if (!ASSERT_OK_PTR(skel->links.mptcp_subflow, "attach mptcp_subflow"))
415 		goto skel_destroy;
416 
417 	skel->links._getsockopt_subflow =
418 		bpf_program__attach_cgroup(skel->progs._getsockopt_subflow, cgroup_fd);
419 	if (!ASSERT_OK_PTR(skel->links._getsockopt_subflow, "attach _getsockopt_subflow"))
420 		goto skel_destroy;
421 
422 	netns = netns_new(NS_TEST, true);
423 	if (!ASSERT_OK_PTR(netns, "netns_new: mptcp_subflow"))
424 		goto skel_destroy;
425 
426 	if (endpoint_init("subflow") < 0)
427 		goto close_netns;
428 
429 	run_subflow();
430 
431 close_netns:
432 	netns_free(netns);
433 skel_destroy:
434 	mptcp_subflow__destroy(skel);
435 close_cgroup:
436 	close(cgroup_fd);
437 }
438 
439 void test_mptcp(void)
440 {
441 	if (test__start_subtest("base"))
442 		test_base();
443 	if (test__start_subtest("mptcpify"))
444 		test_mptcpify();
445 	if (test__start_subtest("subflow"))
446 		test_subflow();
447 }
448