Commit 9b474ece authored by Sargun Dhillon's avatar Sargun Dhillon Committed by David S. Miller

samples, bpf: Add automated test for cgroup filter attachments

This patch adds the sample program test_cgrp2_attach2. This program is
similar to test_cgrp2_attach, but it performs automated testing of the
cgroupv2 BPF attached filters. It runs the following checks:
* Simple filter attachment
* Application of filters to child cgroups
* Overriding filters on child cgroups
	* Checking that this still works when the parent filter is removed

The filters that are used here are simply allow all / deny all filters, so
it isn't checking the actual functionality of the filters, but rather
the behaviour  around detachment / attachment. If net_cls is enabled,
this test will fail.
Signed-off-by: default avatarSargun Dhillon <sargun@sargun.me>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1a922fee
......@@ -23,6 +23,7 @@ hostprogs-y += map_perf_test
hostprogs-y += test_overhead
hostprogs-y += test_cgrp2_array_pin
hostprogs-y += test_cgrp2_attach
hostprogs-y += test_cgrp2_attach2
hostprogs-y += test_cgrp2_sock
hostprogs-y += test_cgrp2_sock2
hostprogs-y += xdp1
......@@ -54,6 +55,7 @@ map_perf_test-objs := bpf_load.o libbpf.o map_perf_test_user.o
test_overhead-objs := bpf_load.o libbpf.o test_overhead_user.o
test_cgrp2_array_pin-objs := libbpf.o test_cgrp2_array_pin.o
test_cgrp2_attach-objs := libbpf.o test_cgrp2_attach.o
test_cgrp2_attach2-objs := libbpf.o test_cgrp2_attach2.o cgroup_helpers.o
test_cgrp2_sock-objs := libbpf.o test_cgrp2_sock.o
test_cgrp2_sock2-objs := bpf_load.o libbpf.o test_cgrp2_sock2.o
xdp1-objs := bpf_load.o libbpf.o xdp1_user.o
......
/* 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.
*
* - 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 <unistd.h>
#include <linux/bpf.h>
#include "libbpf.h"
#include "cgroup_helpers.h"
#define FOO "/foo"
#define BAR "/foo/bar/"
#define PING_CMD "ping -c1 -w1 127.0.0.1"
static int prog_load(int verdict)
{
int ret;
struct bpf_insn prog[] = {
BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
BPF_EXIT_INSN(),
};
ret = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SKB,
prog, sizeof(prog), "GPL", 0);
if (ret < 0) {
log_err("Loading program");
printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
return 0;
}
return ret;
}
int main(int argc, char **argv)
{
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)) {
log_err("Attaching prog to /foo");
goto err;
}
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;
assert(system(PING_CMD) != 0);
if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS)) {
log_err("Attaching prog to /foo/bar");
goto err;
}
assert(system(PING_CMD) == 0);
if (bpf_prog_detach(bar, BPF_CGROUP_INET_EGRESS)) {
log_err("Detaching program from /foo/bar");
goto err;
}
assert(system(PING_CMD) != 0);
if (bpf_prog_attach(allow_prog, bar, BPF_CGROUP_INET_EGRESS)) {
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;
}
assert(system(PING_CMD) == 0);
goto out;
err:
rc = 1;
out:
close(foo);
close(bar);
cleanup_cgroup_environment();
return rc;
}
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