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linux/samples/bpf/test_cgrp2_attach2.c
Roman Gushchin 5fcbd29b37 samples/bpf: extend test_cgrp2_attach2 test to use per-cpu cgroup storage 
This commit extends the test_cgrp2_attach2 test to cover per-cpu
cgroup storage. Bpf program will use shared and per-cpu cgroup
storages simultaneously, so a better coverage of corresponding
core code will be achieved.

Expected output:
  $ ./test_cgrp2_attach2
  Attached DROP prog. This ping in cgroup /foo should fail...
  ping: sendmsg: Operation not permitted
  Attached DROP prog. This ping in cgroup /foo/bar should fail...
  ping: sendmsg: Operation not permitted
  Attached PASS prog. This ping in cgroup /foo/bar should pass...
  Detached PASS from /foo/bar while DROP is attached to /foo.
  This ping in cgroup /foo/bar should fail...
  ping: sendmsg: Operation not permitted
  Attached PASS from /foo/bar and detached DROP from /foo.
  This ping in cgroup /foo/bar should pass...
  ### override:PASS
  ### multi:PASS

Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-01 16:18:33 +02:00

460 lines
12 KiB
C
Raw Blame History

/* eBPF example program:
*
* - Creates arraymap in kernel with 4 bytes keys and 8 byte values
*
* - Loads eBPF program
*
* The eBPF program accesses the map passed in to store two pieces of
* information. The number of invocations of the program, which maps
* to the number of packets received, is stored to key 0. Key 1 is
* incremented on each iteration by the number of bytes stored in
* the skb. The program also stores the number of received bytes
* in the cgroup storage.
*
* - Attaches the new program to a cgroup using BPF_PROG_ATTACH
*
* - Every second, reads map[0] and map[1] to see how many bytes and
* packets were seen on any socket of tasks in the given cgroup.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>
#include <linux/bpf.h>
#include <bpf/bpf.h>
#include "bpf_insn.h"
#include "bpf_rlimit.h"
#include "cgroup_helpers.h"
#define FOO "/foo"
#define BAR "/foo/bar/"
#define PING_CMD "ping -c1 -w1 127.0.0.1 > /dev/null"
char bpf_log_buf[BPF_LOG_BUF_SIZE];
static int prog_load(int verdict)
{
int ret;
struct bpf_insn prog[] = {
BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
BPF_EXIT_INSN(),
};
size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
prog, insns_cnt, "GPL", 0,
bpf_log_buf, BPF_LOG_BUF_SIZE);
if (ret < 0) {
log_err("Loading program");
printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
return 0;
}
return ret;
}
static int test_foo_bar(void)
{
int drop_prog, allow_prog, foo = 0, bar = 0, rc = 0;
allow_prog = prog_load(1);
if (!allow_prog)
goto err;
drop_prog = prog_load(0);
if (!drop_prog)
goto err;
if (setup_cgroup_environment())
goto err;
/* Create cgroup /foo, get fd, and join it */
foo = create_and_get_cgroup(FOO);
if (!foo)
goto err;
if (join_cgroup(FOO))
goto err;
if (bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
log_err("Attaching prog to /foo");
goto err;
}
printf("Attached DROP prog. This ping in cgroup /foo should fail...\n");
assert(system(PING_CMD) != 0);
/* Create cgroup /foo/bar, get fd, and join it */
bar = create_and_get_cgroup(BAR);
if (!bar)
goto err;
if (join_cgroup(BAR))
goto err;
printf("Attached DROP prog. This ping in cgroup /foo/bar should fail...\n");
assert(system(PING_CMD) != 0);
if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
log_err("Attaching prog to /foo/bar");
goto err;
}
printf("Attached PASS prog. This ping in cgroup /foo/bar should pass...\n");
assert(system(PING_CMD) == 0);
if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching program from /foo/bar");
goto err;
}
printf("Detached PASS from /foo/bar while DROP is attached to /foo.\n"
"This ping in cgroup /foo/bar should fail...\n");
assert(system(PING_CMD) != 0);
if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
log_err("Attaching prog to /foo/bar");
goto err;
}
if (bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching program from /foo");
goto err;
}
printf("Attached PASS from /foo/bar and detached DROP from /foo.\n"
"This ping in cgroup /foo/bar should pass...\n");
assert(system(PING_CMD) == 0);
if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
log_err("Attaching prog to /foo/bar");
goto err;
}
if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0)) {
errno = 0;
log_err("Unexpected success attaching prog to /foo/bar");
goto err;
}
if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching program from /foo/bar");
goto err;
}
if (!bpf_prog_detach(foo, BPF_CGROUP_INET_EGRESS)) {
errno = 0;
log_err("Unexpected success in double detach from /foo");
goto err;
}
if (bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS, 0)) {
log_err("Attaching non-overridable prog to /foo");
goto err;
}
if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS, 0)) {
errno = 0;
log_err("Unexpected success attaching non-overridable prog to /foo/bar");
goto err;
}
if (!bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
errno = 0;
log_err("Unexpected success attaching overridable prog to /foo/bar");
goto err;
}
if (!bpf_prog_attach(allow_prog, foo, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
errno = 0;
log_err("Unexpected success attaching overridable prog to /foo");
goto err;
}
if (bpf_prog_attach(drop_prog, foo, BPF_CGROUP_INET_EGRESS, 0)) {
log_err("Attaching different non-overridable prog to /foo");
goto err;
}
goto out;
err:
rc = 1;
out:
close(foo);
close(bar);
cleanup_cgroup_environment();
if (!rc)
printf("### override:PASS\n");
else
printf("### override:FAIL\n");
return rc;
}
static int map_fd = -1;
static int prog_load_cnt(int verdict, int val)
{
int cgroup_storage_fd, percpu_cgroup_storage_fd;
if (map_fd < 0)
map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
if (map_fd < 0) {
printf("failed to create map '%s'\n", strerror(errno));
return -1;
}
cgroup_storage_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE,
sizeof(struct bpf_cgroup_storage_key), 8, 0, 0);
if (cgroup_storage_fd < 0) {
printf("failed to create map '%s'\n", strerror(errno));
return -1;
}
percpu_cgroup_storage_fd = bpf_create_map(
BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
sizeof(struct bpf_cgroup_storage_key), 8, 0, 0);
if (percpu_cgroup_storage_fd < 0) {
printf("failed to create map '%s'\n", strerror(errno));
return -1;
}
struct bpf_insn prog[] = {
BPF_MOV32_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
BPF_LD_MAP_FD(BPF_REG_1, map_fd),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
BPF_MOV64_IMM(BPF_REG_1, val), /* r1 = 1 */
BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
BPF_LD_MAP_FD(BPF_REG_1, cgroup_storage_fd),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_local_storage),
BPF_MOV64_IMM(BPF_REG_1, val),
BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_W, BPF_REG_0, BPF_REG_1, 0, 0),
BPF_LD_MAP_FD(BPF_REG_1, percpu_cgroup_storage_fd),
BPF_MOV64_IMM(BPF_REG_2, 0),
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_local_storage),
BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 0x1),
BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_3, 0),
BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
BPF_EXIT_INSN(),
};
size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
int ret;
ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
prog, insns_cnt, "GPL", 0,
bpf_log_buf, BPF_LOG_BUF_SIZE);
if (ret < 0) {
log_err("Loading program");
printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
return 0;
}
close(cgroup_storage_fd);
return ret;
}
static int test_multiprog(void)
{
__u32 prog_ids[4], prog_cnt = 0, attach_flags, saved_prog_id;
int cg1 = 0, cg2 = 0, cg3 = 0, cg4 = 0, cg5 = 0, key = 0;
int drop_prog, allow_prog[6] = {}, rc = 0;
unsigned long long value;
int i = 0;
for (i = 0; i < 6; i++) {
allow_prog[i] = prog_load_cnt(1, 1 << i);
if (!allow_prog[i])
goto err;
}
drop_prog = prog_load_cnt(0, 1);
if (!drop_prog)
goto err;
if (setup_cgroup_environment())
goto err;
cg1 = create_and_get_cgroup("/cg1");
if (!cg1)
goto err;
cg2 = create_and_get_cgroup("/cg1/cg2");
if (!cg2)
goto err;
cg3 = create_and_get_cgroup("/cg1/cg2/cg3");
if (!cg3)
goto err;
cg4 = create_and_get_cgroup("/cg1/cg2/cg3/cg4");
if (!cg4)
goto err;
cg5 = create_and_get_cgroup("/cg1/cg2/cg3/cg4/cg5");
if (!cg5)
goto err;
if (join_cgroup("/cg1/cg2/cg3/cg4/cg5"))
goto err;
if (bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_MULTI)) {
log_err("Attaching prog to cg1");
goto err;
}
if (!bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_MULTI)) {
log_err("Unexpected success attaching the same prog to cg1");
goto err;
}
if (bpf_prog_attach(allow_prog[1], cg1, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_MULTI)) {
log_err("Attaching prog2 to cg1");
goto err;
}
if (bpf_prog_attach(allow_prog[2], cg2, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
log_err("Attaching prog to cg2");
goto err;
}
if (bpf_prog_attach(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_MULTI)) {
log_err("Attaching prog to cg3");
goto err;
}
if (bpf_prog_attach(allow_prog[4], cg4, BPF_CGROUP_INET_EGRESS,
BPF_F_ALLOW_OVERRIDE)) {
log_err("Attaching prog to cg4");
goto err;
}
if (bpf_prog_attach(allow_prog[5], cg5, BPF_CGROUP_INET_EGRESS, 0)) {
log_err("Attaching prog to cg5");
goto err;
}
assert(system(PING_CMD) == 0);
assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
assert(value == 1 + 2 + 8 + 32);
/* query the number of effective progs in cg5 */
assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
NULL, NULL, &prog_cnt) == 0);
assert(prog_cnt == 4);
/* retrieve prog_ids of effective progs in cg5 */
assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
&attach_flags, prog_ids, &prog_cnt) == 0);
assert(prog_cnt == 4);
assert(attach_flags == 0);
saved_prog_id = prog_ids[0];
/* check enospc handling */
prog_ids[0] = 0;
prog_cnt = 2;
assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
&attach_flags, prog_ids, &prog_cnt) == -1 &&
errno == ENOSPC);
assert(prog_cnt == 4);
/* check that prog_ids are returned even when buffer is too small */
assert(prog_ids[0] == saved_prog_id);
/* retrieve prog_id of single attached prog in cg5 */
prog_ids[0] = 0;
assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
NULL, prog_ids, &prog_cnt) == 0);
assert(prog_cnt == 1);
assert(prog_ids[0] == saved_prog_id);
/* detach bottom program and ping again */
if (bpf_prog_detach2(-1, cg5, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching prog from cg5");
goto err;
}
value = 0;
assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
assert(system(PING_CMD) == 0);
assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
assert(value == 1 + 2 + 8 + 16);
/* detach 3rd from bottom program and ping again */
errno = 0;
if (!bpf_prog_detach2(0, cg3, BPF_CGROUP_INET_EGRESS)) {
log_err("Unexpected success on detach from cg3");
goto err;
}
if (bpf_prog_detach2(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching from cg3");
goto err;
}
value = 0;
assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
assert(system(PING_CMD) == 0);
assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
assert(value == 1 + 2 + 16);
/* detach 2nd from bottom program and ping again */
if (bpf_prog_detach2(-1, cg4, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching prog from cg4");
goto err;
}
value = 0;
assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
assert(system(PING_CMD) == 0);
assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
assert(value == 1 + 2 + 4);
prog_cnt = 4;
assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
&attach_flags, prog_ids, &prog_cnt) == 0);
assert(prog_cnt == 3);
assert(attach_flags == 0);
assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
NULL, prog_ids, &prog_cnt) == 0);
assert(prog_cnt == 0);
goto out;
err:
rc = 1;
out:
for (i = 0; i < 6; i++)
if (allow_prog[i] > 0)
close(allow_prog[i]);
close(cg1);
close(cg2);
close(cg3);
close(cg4);
close(cg5);
cleanup_cgroup_environment();
if (!rc)
printf("### multi:PASS\n");
else
printf("### multi:FAIL\n");
return rc;
}
int main(int argc, char **argv)
{
int rc = 0;
rc = test_foo_bar();
if (rc)
return rc;
return test_multiprog();
}
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