1 /* eBPF example program:
3 * - Creates arraymap in kernel with 4 bytes keys and 8 byte values
7 * The eBPF program accesses the map passed in to store two pieces of
8 * information. The number of invocations of the program, which maps
9 * to the number of packets received, is stored to key 0. Key 1 is
10 * incremented on each iteration by the number of bytes stored in
13 * - Attaches the new program to a cgroup using BPF_PROG_ATTACH
15 * - Every second, reads map[0] and map[1] to see how many bytes and
16 * packets were seen on any socket of tasks in the given cgroup.
26 #include <linux/bpf.h>
29 #include "cgroup_helpers.h"
32 #define BAR "/foo/bar/"
33 #define PING_CMD "ping -c1 -w1 127.0.0.1 > /dev/null"
35 char bpf_log_buf[BPF_LOG_BUF_SIZE];
37 static int prog_load(int verdict)
40 struct bpf_insn prog[] = {
41 BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
44 size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
46 ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
47 prog, insns_cnt, "GPL", 0,
48 bpf_log_buf, BPF_LOG_BUF_SIZE);
51 log_err("Loading program");
52 printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
58 static int test_foo_bar(void)
60 int drop_prog, allow_prog, foo = 0, bar = 0, rc = 0;
62 allow_prog = prog_load(1);
66 drop_prog = prog_load(0);
70 if (setup_cgroup_environment())
73 /* Create cgroup /foo, get fd, and join it */
74 foo = create_and_get_cgroup(FOO);
81 if (bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS,
82 BPF_F_ALLOW_OVERRIDE)) {
83 log_err("Attaching prog to /foo");
87 printf("Attached DROP prog. This ping in cgroup /foo should fail...\n");
88 assert(system(PING_CMD) != 0);
90 /* Create cgroup /foo/bar, get fd, and join it */
91 bar = create_and_get_cgroup(BAR);
98 printf("Attached DROP prog. This ping in cgroup /foo/bar should fail...\n");
99 assert(system(PING_CMD) != 0);
101 if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
102 BPF_F_ALLOW_OVERRIDE)) {
103 log_err("Attaching prog to /foo/bar");
107 printf("Attached PASS prog. This ping in cgroup /foo/bar should pass...\n");
108 assert(system(PING_CMD) == 0);
110 if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
111 log_err("Detaching program from /foo/bar");
115 printf("Detached PASS from /foo/bar while DROP is attached to /foo.\n"
116 "This ping in cgroup /foo/bar should fail...\n");
117 assert(system(PING_CMD) != 0);
119 if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
120 BPF_F_ALLOW_OVERRIDE)) {
121 log_err("Attaching prog to /foo/bar");
125 if (bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS)) {
126 log_err("Detaching program from /foo");
130 printf("Attached PASS from /foo/bar and detached DROP from /foo.\n"
131 "This ping in cgroup /foo/bar should pass...\n");
132 assert(system(PING_CMD) == 0);
134 if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
135 BPF_F_ALLOW_OVERRIDE)) {
136 log_err("Attaching prog to /foo/bar");
140 if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0)) {
142 log_err("Unexpected success attaching prog to /foo/bar");
146 if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
147 log_err("Detaching program from /foo/bar");
151 if (!bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS)) {
153 log_err("Unexpected success in double detach from /foo");
157 if (bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS, 0)) {
158 log_err("Attaching non-overridable prog to /foo");
162 if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0)) {
164 log_err("Unexpected success attaching non-overridable prog to /foo/bar");
168 if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
169 BPF_F_ALLOW_OVERRIDE)) {
171 log_err("Unexpected success attaching overridable prog to /foo/bar");
175 if (!bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS,
176 BPF_F_ALLOW_OVERRIDE)) {
178 log_err("Unexpected success attaching overridable prog to /foo");
182 if (bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS, 0)) {
183 log_err("Attaching different non-overridable prog to /foo");
195 cleanup_cgroup_environment();
197 printf("### override:PASS\n");
199 printf("### override:FAIL\n");
203 static int map_fd = -1;
205 static int prog_load_cnt(int verdict, int val)
208 map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
210 printf("failed to create map '%s'\n", strerror(errno));
214 struct bpf_insn prog[] = {
215 BPF_MOV32_IMM(BPF_REG_0, 0),
216 BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
217 BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
218 BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
219 BPF_LD_MAP_FD(BPF_REG_1, map_fd),
220 BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
221 BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
222 BPF_MOV64_IMM(BPF_REG_1, val), /* r1 = 1 */
223 BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
224 BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
227 size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
230 ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
231 prog, insns_cnt, "GPL", 0,
232 bpf_log_buf, BPF_LOG_BUF_SIZE);
235 log_err("Loading program");
236 printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
243 static int test_multiprog(void)
245 __u32 prog_ids[4], prog_cnt = 0, attach_flags, saved_prog_id;
246 int cg1 = 0, cg2 = 0, cg3 = 0, cg4 = 0, cg5 = 0, key = 0;
247 int drop_prog, allow_prog[6] = {}, rc = 0;
248 unsigned long long value;
251 for (i = 0; i < 6; i++) {
252 allow_prog[i] = prog_load_cnt(1, 1 << i);
256 drop_prog = prog_load_cnt(0, 1);
260 if (setup_cgroup_environment())
263 cg1 = create_and_get_cgroup("/cg1");
266 cg2 = create_and_get_cgroup("/cg1/cg2");
269 cg3 = create_and_get_cgroup("/cg1/cg2/cg3");
272 cg4 = create_and_get_cgroup("/cg1/cg2/cg3/cg4");
275 cg5 = create_and_get_cgroup("/cg1/cg2/cg3/cg4/cg5");
279 if (join_cgroup("/cg1/cg2/cg3/cg4/cg5"))
282 if (bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS,
283 BPF_F_ALLOW_MULTI)) {
284 log_err("Attaching prog to cg1");
287 if (!bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS,
288 BPF_F_ALLOW_MULTI)) {
289 log_err("Unexpected success attaching the same prog to cg1");
292 if (bpf_prog_attach(allow_prog[1], cg1, BPF_CGROUP_INET_EGRESS,
293 BPF_F_ALLOW_MULTI)) {
294 log_err("Attaching prog2 to cg1");
297 if (bpf_prog_attach(allow_prog[2], cg2, BPF_CGROUP_INET_EGRESS,
298 BPF_F_ALLOW_OVERRIDE)) {
299 log_err("Attaching prog to cg2");
302 if (bpf_prog_attach(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS,
303 BPF_F_ALLOW_MULTI)) {
304 log_err("Attaching prog to cg3");
307 if (bpf_prog_attach(allow_prog[4], cg4, BPF_CGROUP_INET_EGRESS,
308 BPF_F_ALLOW_OVERRIDE)) {
309 log_err("Attaching prog to cg4");
312 if (bpf_prog_attach(allow_prog[5], cg5, BPF_CGROUP_INET_EGRESS, 0)) {
313 log_err("Attaching prog to cg5");
316 assert(system(PING_CMD) == 0);
317 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
318 assert(value == 1 + 2 + 8 + 32);
320 /* query the number of effective progs in cg5 */
321 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
322 NULL, NULL, &prog_cnt) == 0);
323 assert(prog_cnt == 4);
324 /* retrieve prog_ids of effective progs in cg5 */
325 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
326 &attach_flags, prog_ids, &prog_cnt) == 0);
327 assert(prog_cnt == 4);
328 assert(attach_flags == 0);
329 saved_prog_id = prog_ids[0];
330 /* check enospc handling */
333 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
334 &attach_flags, prog_ids, &prog_cnt) == -1 &&
336 assert(prog_cnt == 4);
337 /* check that prog_ids are returned even when buffer is too small */
338 assert(prog_ids[0] == saved_prog_id);
339 /* retrieve prog_id of single attached prog in cg5 */
341 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
342 NULL, prog_ids, &prog_cnt) == 0);
343 assert(prog_cnt == 1);
344 assert(prog_ids[0] == saved_prog_id);
346 /* detach bottom program and ping again */
347 if (bpf_prog_detach2(-1, cg5, BPF_CGROUP_INET_EGRESS)) {
348 log_err("Detaching prog from cg5");
352 assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
353 assert(system(PING_CMD) == 0);
354 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
355 assert(value == 1 + 2 + 8 + 16);
357 /* detach 3rd from bottom program and ping again */
359 if (!bpf_prog_detach2(0, cg3, BPF_CGROUP_INET_EGRESS)) {
360 log_err("Unexpected success on detach from cg3");
363 if (bpf_prog_detach2(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS)) {
364 log_err("Detaching from cg3");
368 assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
369 assert(system(PING_CMD) == 0);
370 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
371 assert(value == 1 + 2 + 16);
373 /* detach 2nd from bottom program and ping again */
374 if (bpf_prog_detach2(-1, cg4, BPF_CGROUP_INET_EGRESS)) {
375 log_err("Detaching prog from cg4");
379 assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
380 assert(system(PING_CMD) == 0);
381 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
382 assert(value == 1 + 2 + 4);
385 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
386 &attach_flags, prog_ids, &prog_cnt) == 0);
387 assert(prog_cnt == 3);
388 assert(attach_flags == 0);
389 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
390 NULL, prog_ids, &prog_cnt) == 0);
391 assert(prog_cnt == 0);
397 for (i = 0; i < 6; i++)
398 if (allow_prog[i] > 0)
399 close(allow_prog[i]);
405 cleanup_cgroup_environment();
407 printf("### multi:PASS\n");
409 printf("### multi:FAIL\n");
413 int main(int argc, char **argv)
421 return test_multiprog();