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, 1)) {
82 log_err("Attaching prog to /foo");
86 printf("Attached DROP prog. This ping in cgroup /foo should fail...\n");
87 assert(system(PING_CMD) != 0);
89 /* Create cgroup /foo/bar, get fd, and join it */
90 bar = create_and_get_cgroup(BAR);
97 printf("Attached DROP prog. This ping in cgroup /foo/bar should fail...\n");
98 assert(system(PING_CMD) != 0);
100 if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 1)) {
101 log_err("Attaching prog to /foo/bar");
105 printf("Attached PASS prog. This ping in cgroup /foo/bar should pass...\n");
106 assert(system(PING_CMD) == 0);
108 if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
109 log_err("Detaching program from /foo/bar");
113 printf("Detached PASS from /foo/bar while DROP is attached to /foo.\n"
114 "This ping in cgroup /foo/bar should fail...\n");
115 assert(system(PING_CMD) != 0);
117 if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 1)) {
118 log_err("Attaching prog to /foo/bar");
122 if (bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS)) {
123 log_err("Detaching program from /foo");
127 printf("Attached PASS from /foo/bar and detached DROP from /foo.\n"
128 "This ping in cgroup /foo/bar should pass...\n");
129 assert(system(PING_CMD) == 0);
131 if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 1)) {
132 log_err("Attaching prog to /foo/bar");
136 if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0)) {
138 log_err("Unexpected success attaching prog to /foo/bar");
142 if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
143 log_err("Detaching program from /foo/bar");
147 if (!bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS)) {
149 log_err("Unexpected success in double detach from /foo");
153 if (bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS, 0)) {
154 log_err("Attaching non-overridable prog to /foo");
158 if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0)) {
160 log_err("Unexpected success attaching non-overridable prog to /foo/bar");
164 if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 1)) {
166 log_err("Unexpected success attaching overridable prog to /foo/bar");
170 if (!bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS, 1)) {
172 log_err("Unexpected success attaching overridable prog to /foo");
176 if (bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS, 0)) {
177 log_err("Attaching different non-overridable prog to /foo");
189 cleanup_cgroup_environment();
191 printf("### override:PASS\n");
193 printf("### override:FAIL\n");
197 static int map_fd = -1;
199 static int prog_load_cnt(int verdict, int val)
202 map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
204 printf("failed to create map '%s'\n", strerror(errno));
208 struct bpf_insn prog[] = {
209 BPF_MOV32_IMM(BPF_REG_0, 0),
210 BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
211 BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
212 BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
213 BPF_LD_MAP_FD(BPF_REG_1, map_fd),
214 BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
215 BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
216 BPF_MOV64_IMM(BPF_REG_1, val), /* r1 = 1 */
217 BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
218 BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
221 size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
224 ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
225 prog, insns_cnt, "GPL", 0,
226 bpf_log_buf, BPF_LOG_BUF_SIZE);
229 log_err("Loading program");
230 printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
237 static int test_multiprog(void)
239 __u32 prog_ids[4], prog_cnt = 0, attach_flags, saved_prog_id;
240 int cg1 = 0, cg2 = 0, cg3 = 0, cg4 = 0, cg5 = 0, key = 0;
241 int drop_prog, allow_prog[6] = {}, rc = 0;
242 unsigned long long value;
245 for (i = 0; i < 6; i++) {
246 allow_prog[i] = prog_load_cnt(1, 1 << i);
250 drop_prog = prog_load_cnt(0, 1);
254 if (setup_cgroup_environment())
257 cg1 = create_and_get_cgroup("/cg1");
260 cg2 = create_and_get_cgroup("/cg1/cg2");
263 cg3 = create_and_get_cgroup("/cg1/cg2/cg3");
266 cg4 = create_and_get_cgroup("/cg1/cg2/cg3/cg4");
269 cg5 = create_and_get_cgroup("/cg1/cg2/cg3/cg4/cg5");
273 if (join_cgroup("/cg1/cg2/cg3/cg4/cg5"))
276 if (bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS, 2)) {
277 log_err("Attaching prog to cg1");
280 if (!bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS, 2)) {
281 log_err("Unexpected success attaching the same prog to cg1");
284 if (bpf_prog_attach(allow_prog[1], cg1, BPF_CGROUP_INET_EGRESS, 2)) {
285 log_err("Attaching prog2 to cg1");
288 if (bpf_prog_attach(allow_prog[2], cg2, BPF_CGROUP_INET_EGRESS, 1)) {
289 log_err("Attaching prog to cg2");
292 if (bpf_prog_attach(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS, 2)) {
293 log_err("Attaching prog to cg3");
296 if (bpf_prog_attach(allow_prog[4], cg4, BPF_CGROUP_INET_EGRESS, 1)) {
297 log_err("Attaching prog to cg4");
300 if (bpf_prog_attach(allow_prog[5], cg5, BPF_CGROUP_INET_EGRESS, 0)) {
301 log_err("Attaching prog to cg5");
304 assert(system(PING_CMD) == 0);
305 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
306 assert(value == 1 + 2 + 8 + 32);
308 /* query the number of effective progs in cg5 */
309 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
310 NULL, NULL, &prog_cnt) == 0);
311 assert(prog_cnt == 4);
312 /* retrieve prog_ids of effective progs in cg5 */
313 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
314 &attach_flags, prog_ids, &prog_cnt) == 0);
315 assert(prog_cnt == 4);
316 assert(attach_flags == 0);
317 saved_prog_id = prog_ids[0];
318 /* check enospc handling */
321 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
322 &attach_flags, prog_ids, &prog_cnt) == -1 &&
324 assert(prog_cnt == 4);
325 /* check that prog_ids are returned even when buffer is too small */
326 assert(prog_ids[0] == saved_prog_id);
327 /* retrieve prog_id of single attached prog in cg5 */
329 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
330 NULL, prog_ids, &prog_cnt) == 0);
331 assert(prog_cnt == 1);
332 assert(prog_ids[0] == saved_prog_id);
334 /* detach bottom program and ping again */
335 if (bpf_prog_detach2(-1, cg5, BPF_CGROUP_INET_EGRESS)) {
336 log_err("Detaching prog from cg5");
340 assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
341 assert(system(PING_CMD) == 0);
342 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
343 assert(value == 1 + 2 + 8 + 16);
345 /* detach 3rd from bottom program and ping again */
347 if (!bpf_prog_detach2(0, cg3, BPF_CGROUP_INET_EGRESS)) {
348 log_err("Unexpected success on detach from cg3");
351 if (bpf_prog_detach2(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS)) {
352 log_err("Detaching from cg3");
356 assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
357 assert(system(PING_CMD) == 0);
358 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
359 assert(value == 1 + 2 + 16);
361 /* detach 2nd from bottom program and ping again */
362 if (bpf_prog_detach2(-1, cg4, BPF_CGROUP_INET_EGRESS)) {
363 log_err("Detaching prog from cg4");
367 assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
368 assert(system(PING_CMD) == 0);
369 assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
370 assert(value == 1 + 2 + 4);
373 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
374 &attach_flags, prog_ids, &prog_cnt) == 0);
375 assert(prog_cnt == 3);
376 assert(attach_flags == 0);
377 assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
378 NULL, prog_ids, &prog_cnt) == 0);
379 assert(prog_cnt == 0);
385 for (i = 0; i < 6; i++)
386 if (allow_prog[i] > 0)
387 close(allow_prog[i]);
393 cleanup_cgroup_environment();
395 printf("### multi:PASS\n");
397 printf("### multi:FAIL\n");
401 int main(int argc, char **argv)
409 return test_multiprog();