1 // SPDX-License-Identifier: GPL-2.0
2 #include <test_progs.h>
3 #include "cgroup_helpers.h"
4 
5 static int prog_attach(struct bpf_object *obj, int cgroup_fd, const char *title)
6 {
7 	enum bpf_attach_type attach_type;
8 	enum bpf_prog_type prog_type;
9 	struct bpf_program *prog;
10 	int err;
11 
12 	err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
13 	if (err) {
14 		log_err("Failed to deduct types for %s BPF program", title);
15 		return -1;
16 	}
17 
18 	prog = bpf_object__find_program_by_title(obj, title);
19 	if (!prog) {
20 		log_err("Failed to find %s BPF program", title);
21 		return -1;
22 	}
23 
24 	err = bpf_prog_attach(bpf_program__fd(prog), cgroup_fd,
25 			      attach_type, BPF_F_ALLOW_MULTI);
26 	if (err) {
27 		log_err("Failed to attach %s BPF program", title);
28 		return -1;
29 	}
30 
31 	return 0;
32 }
33 
34 static int prog_detach(struct bpf_object *obj, int cgroup_fd, const char *title)
35 {
36 	enum bpf_attach_type attach_type;
37 	enum bpf_prog_type prog_type;
38 	struct bpf_program *prog;
39 	int err;
40 
41 	err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
42 	if (err)
43 		return -1;
44 
45 	prog = bpf_object__find_program_by_title(obj, title);
46 	if (!prog)
47 		return -1;
48 
49 	err = bpf_prog_detach2(bpf_program__fd(prog), cgroup_fd,
50 			       attach_type);
51 	if (err)
52 		return -1;
53 
54 	return 0;
55 }
56 
57 static int run_getsockopt_test(struct bpf_object *obj, int cg_parent,
58 			       int cg_child, int sock_fd)
59 {
60 	socklen_t optlen;
61 	__u8 buf;
62 	int err;
63 
64 	/* Set IP_TOS to the expected value (0x80). */
65 
66 	buf = 0x80;
67 	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
68 	if (err < 0) {
69 		log_err("Failed to call setsockopt(IP_TOS)");
70 		goto detach;
71 	}
72 
73 	buf = 0x00;
74 	optlen = 1;
75 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
76 	if (err) {
77 		log_err("Failed to call getsockopt(IP_TOS)");
78 		goto detach;
79 	}
80 
81 	if (buf != 0x80) {
82 		log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
83 		err = -1;
84 		goto detach;
85 	}
86 
87 	/* Attach child program and make sure it returns new value:
88 	 * - kernel:      -> 0x80
89 	 * - child:  0x80 -> 0x90
90 	 */
91 
92 	err = prog_attach(obj, cg_child, "cgroup/getsockopt/child");
93 	if (err)
94 		goto detach;
95 
96 	buf = 0x00;
97 	optlen = 1;
98 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
99 	if (err) {
100 		log_err("Failed to call getsockopt(IP_TOS)");
101 		goto detach;
102 	}
103 
104 	if (buf != 0x90) {
105 		log_err("Unexpected getsockopt 0x%x != 0x90", buf);
106 		err = -1;
107 		goto detach;
108 	}
109 
110 	/* Attach parent program and make sure it returns new value:
111 	 * - kernel:      -> 0x80
112 	 * - child:  0x80 -> 0x90
113 	 * - parent: 0x90 -> 0xA0
114 	 */
115 
116 	err = prog_attach(obj, cg_parent, "cgroup/getsockopt/parent");
117 	if (err)
118 		goto detach;
119 
120 	buf = 0x00;
121 	optlen = 1;
122 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
123 	if (err) {
124 		log_err("Failed to call getsockopt(IP_TOS)");
125 		goto detach;
126 	}
127 
128 	if (buf != 0xA0) {
129 		log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
130 		err = -1;
131 		goto detach;
132 	}
133 
134 	/* Setting unexpected initial sockopt should return EPERM:
135 	 * - kernel: -> 0x40
136 	 * - child:  unexpected 0x40, EPERM
137 	 * - parent: unexpected 0x40, EPERM
138 	 */
139 
140 	buf = 0x40;
141 	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
142 	if (err < 0) {
143 		log_err("Failed to call setsockopt(IP_TOS)");
144 		goto detach;
145 	}
146 
147 	buf = 0x00;
148 	optlen = 1;
149 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
150 	if (!err) {
151 		log_err("Unexpected success from getsockopt(IP_TOS)");
152 		goto detach;
153 	}
154 
155 	/* Detach child program and make sure we still get EPERM:
156 	 * - kernel: -> 0x40
157 	 * - parent: unexpected 0x40, EPERM
158 	 */
159 
160 	err = prog_detach(obj, cg_child, "cgroup/getsockopt/child");
161 	if (err) {
162 		log_err("Failed to detach child program");
163 		goto detach;
164 	}
165 
166 	buf = 0x00;
167 	optlen = 1;
168 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
169 	if (!err) {
170 		log_err("Unexpected success from getsockopt(IP_TOS)");
171 		goto detach;
172 	}
173 
174 	/* Set initial value to the one the parent program expects:
175 	 * - kernel:      -> 0x90
176 	 * - parent: 0x90 -> 0xA0
177 	 */
178 
179 	buf = 0x90;
180 	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
181 	if (err < 0) {
182 		log_err("Failed to call setsockopt(IP_TOS)");
183 		goto detach;
184 	}
185 
186 	buf = 0x00;
187 	optlen = 1;
188 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
189 	if (err) {
190 		log_err("Failed to call getsockopt(IP_TOS)");
191 		goto detach;
192 	}
193 
194 	if (buf != 0xA0) {
195 		log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
196 		err = -1;
197 		goto detach;
198 	}
199 
200 detach:
201 	prog_detach(obj, cg_child, "cgroup/getsockopt/child");
202 	prog_detach(obj, cg_parent, "cgroup/getsockopt/parent");
203 
204 	return err;
205 }
206 
207 static int run_setsockopt_test(struct bpf_object *obj, int cg_parent,
208 			       int cg_child, int sock_fd)
209 {
210 	socklen_t optlen;
211 	__u8 buf;
212 	int err;
213 
214 	/* Set IP_TOS to the expected value (0x80). */
215 
216 	buf = 0x80;
217 	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
218 	if (err < 0) {
219 		log_err("Failed to call setsockopt(IP_TOS)");
220 		goto detach;
221 	}
222 
223 	buf = 0x00;
224 	optlen = 1;
225 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
226 	if (err) {
227 		log_err("Failed to call getsockopt(IP_TOS)");
228 		goto detach;
229 	}
230 
231 	if (buf != 0x80) {
232 		log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
233 		err = -1;
234 		goto detach;
235 	}
236 
237 	/* Attach child program and make sure it adds 0x10. */
238 
239 	err = prog_attach(obj, cg_child, "cgroup/setsockopt");
240 	if (err)
241 		goto detach;
242 
243 	buf = 0x80;
244 	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
245 	if (err < 0) {
246 		log_err("Failed to call setsockopt(IP_TOS)");
247 		goto detach;
248 	}
249 
250 	buf = 0x00;
251 	optlen = 1;
252 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
253 	if (err) {
254 		log_err("Failed to call getsockopt(IP_TOS)");
255 		goto detach;
256 	}
257 
258 	if (buf != 0x80 + 0x10) {
259 		log_err("Unexpected getsockopt 0x%x != 0x80 + 0x10", buf);
260 		err = -1;
261 		goto detach;
262 	}
263 
264 	/* Attach parent program and make sure it adds another 0x10. */
265 
266 	err = prog_attach(obj, cg_parent, "cgroup/setsockopt");
267 	if (err)
268 		goto detach;
269 
270 	buf = 0x80;
271 	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
272 	if (err < 0) {
273 		log_err("Failed to call setsockopt(IP_TOS)");
274 		goto detach;
275 	}
276 
277 	buf = 0x00;
278 	optlen = 1;
279 	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
280 	if (err) {
281 		log_err("Failed to call getsockopt(IP_TOS)");
282 		goto detach;
283 	}
284 
285 	if (buf != 0x80 + 2 * 0x10) {
286 		log_err("Unexpected getsockopt 0x%x != 0x80 + 2 * 0x10", buf);
287 		err = -1;
288 		goto detach;
289 	}
290 
291 detach:
292 	prog_detach(obj, cg_child, "cgroup/setsockopt");
293 	prog_detach(obj, cg_parent, "cgroup/setsockopt");
294 
295 	return err;
296 }
297 
298 void test_sockopt_multi(void)
299 {
300 	struct bpf_prog_load_attr attr = {
301 		.file = "./sockopt_multi.o",
302 	};
303 	int cg_parent = -1, cg_child = -1;
304 	struct bpf_object *obj = NULL;
305 	int sock_fd = -1;
306 	int err = -1;
307 	int ignored;
308 
309 	cg_parent = test__join_cgroup("/parent");
310 	if (CHECK_FAIL(cg_parent < 0))
311 		goto out;
312 
313 	cg_child = test__join_cgroup("/parent/child");
314 	if (CHECK_FAIL(cg_child < 0))
315 		goto out;
316 
317 	err = bpf_prog_load_xattr(&attr, &obj, &ignored);
318 	if (CHECK_FAIL(err))
319 		goto out;
320 
321 	sock_fd = socket(AF_INET, SOCK_STREAM, 0);
322 	if (CHECK_FAIL(sock_fd < 0))
323 		goto out;
324 
325 	CHECK_FAIL(run_getsockopt_test(obj, cg_parent, cg_child, sock_fd));
326 	CHECK_FAIL(run_setsockopt_test(obj, cg_parent, cg_child, sock_fd));
327 
328 out:
329 	close(sock_fd);
330 	bpf_object__close(obj);
331 	close(cg_child);
332 	close(cg_parent);
333 }
334