xref: /linux/tools/testing/selftests/bpf/prog_tests/mptcp.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
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 
create_netns(void)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 
cleanup_netns(struct nstoken * nstoken)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 
start_mptcp_server(int family,const char * addr_str,__u16 port,int timeout_ms)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 
93 	return start_server_str(family, SOCK_STREAM, addr_str, port, &opts);
94 }
95 
verify_tsk(int map_fd,int client_fd)96 static int verify_tsk(int map_fd, int client_fd)
97 {
98 	int err, cfd = client_fd;
99 	struct mptcp_storage val;
100 
101 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
102 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
103 		return err;
104 
105 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
106 		err++;
107 
108 	if (!ASSERT_EQ(val.is_mptcp, 0, "unexpected is_mptcp"))
109 		err++;
110 
111 	return err;
112 }
113 
get_msk_ca_name(char ca_name[])114 static void get_msk_ca_name(char ca_name[])
115 {
116 	size_t len;
117 	int fd;
118 
119 	fd = open("/proc/sys/net/ipv4/tcp_congestion_control", O_RDONLY);
120 	if (!ASSERT_GE(fd, 0, "failed to open tcp_congestion_control"))
121 		return;
122 
123 	len = read(fd, ca_name, TCP_CA_NAME_MAX);
124 	if (!ASSERT_GT(len, 0, "failed to read ca_name"))
125 		goto err;
126 
127 	if (len > 0 && ca_name[len - 1] == '\n')
128 		ca_name[len - 1] = '\0';
129 
130 err:
131 	close(fd);
132 }
133 
verify_msk(int map_fd,int client_fd,__u32 token)134 static int verify_msk(int map_fd, int client_fd, __u32 token)
135 {
136 	char ca_name[TCP_CA_NAME_MAX];
137 	int err, cfd = client_fd;
138 	struct mptcp_storage val;
139 
140 	if (!ASSERT_GT(token, 0, "invalid token"))
141 		return -1;
142 
143 	get_msk_ca_name(ca_name);
144 
145 	err = bpf_map_lookup_elem(map_fd, &cfd, &val);
146 	if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
147 		return err;
148 
149 	if (!ASSERT_EQ(val.invoked, 1, "unexpected invoked count"))
150 		err++;
151 
152 	if (!ASSERT_EQ(val.is_mptcp, 1, "unexpected is_mptcp"))
153 		err++;
154 
155 	if (!ASSERT_EQ(val.token, token, "unexpected token"))
156 		err++;
157 
158 	if (!ASSERT_EQ(val.first, val.sk, "unexpected first"))
159 		err++;
160 
161 	if (!ASSERT_STRNEQ(val.ca_name, ca_name, TCP_CA_NAME_MAX, "unexpected ca_name"))
162 		err++;
163 
164 	return err;
165 }
166 
run_test(int cgroup_fd,int server_fd,bool is_mptcp)167 static int run_test(int cgroup_fd, int server_fd, bool is_mptcp)
168 {
169 	int client_fd, prog_fd, map_fd, err;
170 	struct mptcp_sock *sock_skel;
171 
172 	sock_skel = mptcp_sock__open_and_load();
173 	if (!ASSERT_OK_PTR(sock_skel, "skel_open_load"))
174 		return libbpf_get_error(sock_skel);
175 
176 	err = mptcp_sock__attach(sock_skel);
177 	if (!ASSERT_OK(err, "skel_attach"))
178 		goto out;
179 
180 	prog_fd = bpf_program__fd(sock_skel->progs._sockops);
181 	map_fd = bpf_map__fd(sock_skel->maps.socket_storage_map);
182 	err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_SOCK_OPS, 0);
183 	if (!ASSERT_OK(err, "bpf_prog_attach"))
184 		goto out;
185 
186 	client_fd = connect_to_fd(server_fd, 0);
187 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
188 		err = -EIO;
189 		goto out;
190 	}
191 
192 	err += is_mptcp ? verify_msk(map_fd, client_fd, sock_skel->bss->token) :
193 			  verify_tsk(map_fd, client_fd);
194 
195 	close(client_fd);
196 
197 out:
198 	mptcp_sock__destroy(sock_skel);
199 	return err;
200 }
201 
test_base(void)202 static void test_base(void)
203 {
204 	struct nstoken *nstoken = NULL;
205 	int server_fd, cgroup_fd;
206 
207 	cgroup_fd = test__join_cgroup("/mptcp");
208 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
209 		return;
210 
211 	nstoken = create_netns();
212 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
213 		goto fail;
214 
215 	/* without MPTCP */
216 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
217 	if (!ASSERT_GE(server_fd, 0, "start_server"))
218 		goto with_mptcp;
219 
220 	ASSERT_OK(run_test(cgroup_fd, server_fd, false), "run_test tcp");
221 
222 	close(server_fd);
223 
224 with_mptcp:
225 	/* with MPTCP */
226 	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
227 	if (!ASSERT_GE(server_fd, 0, "start_mptcp_server"))
228 		goto fail;
229 
230 	ASSERT_OK(run_test(cgroup_fd, server_fd, true), "run_test mptcp");
231 
232 	close(server_fd);
233 
234 fail:
235 	cleanup_netns(nstoken);
236 	close(cgroup_fd);
237 }
238 
send_byte(int fd)239 static void send_byte(int fd)
240 {
241 	char b = 0x55;
242 
243 	ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
244 }
245 
verify_mptcpify(int server_fd,int client_fd)246 static int verify_mptcpify(int server_fd, int client_fd)
247 {
248 	struct __mptcp_info info;
249 	socklen_t optlen;
250 	int protocol;
251 	int err = 0;
252 
253 	optlen = sizeof(protocol);
254 	if (!ASSERT_OK(getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen),
255 		       "getsockopt(SOL_PROTOCOL)"))
256 		return -1;
257 
258 	if (!ASSERT_EQ(protocol, IPPROTO_MPTCP, "protocol isn't MPTCP"))
259 		err++;
260 
261 	optlen = sizeof(info);
262 	if (!ASSERT_OK(getsockopt(client_fd, SOL_MPTCP, MPTCP_INFO, &info, &optlen),
263 		       "getsockopt(MPTCP_INFO)"))
264 		return -1;
265 
266 	if (!ASSERT_GE(info.mptcpi_flags, 0, "unexpected mptcpi_flags"))
267 		err++;
268 	if (!ASSERT_FALSE(info.mptcpi_flags & MPTCP_INFO_FLAG_FALLBACK,
269 			  "MPTCP fallback"))
270 		err++;
271 	if (!ASSERT_TRUE(info.mptcpi_flags & MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED,
272 			 "no remote key received"))
273 		err++;
274 
275 	return err;
276 }
277 
run_mptcpify(int cgroup_fd)278 static int run_mptcpify(int cgroup_fd)
279 {
280 	int server_fd, client_fd, err = 0;
281 	struct mptcpify *mptcpify_skel;
282 
283 	mptcpify_skel = mptcpify__open_and_load();
284 	if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
285 		return libbpf_get_error(mptcpify_skel);
286 
287 	mptcpify_skel->bss->pid = getpid();
288 
289 	err = mptcpify__attach(mptcpify_skel);
290 	if (!ASSERT_OK(err, "skel_attach"))
291 		goto out;
292 
293 	/* without MPTCP */
294 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
295 	if (!ASSERT_GE(server_fd, 0, "start_server")) {
296 		err = -EIO;
297 		goto out;
298 	}
299 
300 	client_fd = connect_to_fd(server_fd, 0);
301 	if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
302 		err = -EIO;
303 		goto close_server;
304 	}
305 
306 	send_byte(client_fd);
307 
308 	err = verify_mptcpify(server_fd, client_fd);
309 
310 	close(client_fd);
311 close_server:
312 	close(server_fd);
313 out:
314 	mptcpify__destroy(mptcpify_skel);
315 	return err;
316 }
317 
test_mptcpify(void)318 static void test_mptcpify(void)
319 {
320 	struct nstoken *nstoken = NULL;
321 	int cgroup_fd;
322 
323 	cgroup_fd = test__join_cgroup("/mptcpify");
324 	if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
325 		return;
326 
327 	nstoken = create_netns();
328 	if (!ASSERT_OK_PTR(nstoken, "create_netns"))
329 		goto fail;
330 
331 	ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
332 
333 fail:
334 	cleanup_netns(nstoken);
335 	close(cgroup_fd);
336 }
337 
test_mptcp(void)338 void test_mptcp(void)
339 {
340 	if (test__start_subtest("base"))
341 		test_base();
342 	if (test__start_subtest("mptcpify"))
343 		test_mptcpify();
344 }
345