samples/bpf: extend test_cgrp2_attach2 test to use cgroup storage

The test_cgrp2_attach test covers bpf cgroup attachment code well,
so let's re-use it for testing allocation/releasing of cgroup storage.

The extension is pretty straightforward: the bpf program will use
the cgroup storage to save the number of transmitted bytes.

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>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Roman Gushchin 2018-08-02 14:27:30 -07:00 committed by Daniel Borkmann
parent 68cfa3ac6b
commit 28ba068760

View file

@ -8,7 +8,8 @@
* 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 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
*
@ -21,12 +22,15 @@
#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"
@ -205,6 +209,8 @@ static int map_fd = -1;
static int prog_load_cnt(int verdict, int val)
{
int cgroup_storage_fd;
if (map_fd < 0)
map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
if (map_fd < 0) {
@ -212,6 +218,13 @@ static int prog_load_cnt(int verdict, int val)
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;
}
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 */
@ -222,6 +235,11 @@ static int prog_load_cnt(int verdict, int val)
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_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
BPF_EXIT_INSN(),
};
@ -237,6 +255,7 @@ static int prog_load_cnt(int verdict, int val)
printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
return 0;
}
close(cgroup_storage_fd);
return ret;
}