linux/tools/testing/selftests/bpf/progs/cgroup_getset_retval_getsockopt.c
YiFei Zhu b8bff6f890 selftests/bpf: Test bpf_{get,set}_retval behavior with cgroup/sockopt
The tests checks how different ways of interacting with the helpers
(getting retval, setting EUNATCH, EISCONN, and legacy reject
returning 0 without setting retval), produce different results in
both the setsockopt syscall and the retval returned by the helper.
A few more tests verify the interaction between the retval of the
helper and the retval in getsockopt context.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/43ec60d679ae3f4f6fd2460559c28b63cb93cd12.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-19 12:51:30 -08:00

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C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2021 Google LLC.
*/
#include <errno.h>
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
__u32 invocations = 0;
__u32 assertion_error = 0;
__u32 retval_value = 0;
__u32 ctx_retval_value = 0;
SEC("cgroup/getsockopt")
int get_retval(struct bpf_sockopt *ctx)
{
retval_value = bpf_get_retval();
ctx_retval_value = ctx->retval;
__sync_fetch_and_add(&invocations, 1);
return 1;
}
SEC("cgroup/getsockopt")
int set_eisconn(struct bpf_sockopt *ctx)
{
__sync_fetch_and_add(&invocations, 1);
if (bpf_set_retval(-EISCONN))
assertion_error = 1;
return 1;
}
SEC("cgroup/getsockopt")
int clear_retval(struct bpf_sockopt *ctx)
{
__sync_fetch_and_add(&invocations, 1);
ctx->retval = 0;
return 1;
}