c8ed668593
Once we enable -Wall for BPF sources, compiler will complain about lots of unused variables, variables that are set but never read, etc. Fix all these issues first before enabling -Wall in Makefile. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
59 lines
1.1 KiB
C
59 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
#include <sys/socket.h>
|
|
#include <linux/bpf.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
|
|
int invocations = 0, in_use = 0;
|
|
|
|
struct {
|
|
__uint(type, BPF_MAP_TYPE_SK_STORAGE);
|
|
__uint(map_flags, BPF_F_NO_PREALLOC);
|
|
__type(key, int);
|
|
__type(value, int);
|
|
} sk_map SEC(".maps");
|
|
|
|
SEC("cgroup/sock_create")
|
|
int sock(struct bpf_sock *ctx)
|
|
{
|
|
int *sk_storage;
|
|
|
|
if (ctx->type != SOCK_DGRAM)
|
|
return 1;
|
|
|
|
sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0,
|
|
BPF_SK_STORAGE_GET_F_CREATE);
|
|
if (!sk_storage)
|
|
return 0;
|
|
*sk_storage = 0xdeadbeef;
|
|
|
|
__sync_fetch_and_add(&invocations, 1);
|
|
|
|
if (in_use > 0) {
|
|
/* BPF_CGROUP_INET_SOCK_RELEASE is _not_ called
|
|
* when we return an error from the BPF
|
|
* program!
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
__sync_fetch_and_add(&in_use, 1);
|
|
return 1;
|
|
}
|
|
|
|
SEC("cgroup/sock_release")
|
|
int sock_release(struct bpf_sock *ctx)
|
|
{
|
|
int *sk_storage;
|
|
|
|
if (ctx->type != SOCK_DGRAM)
|
|
return 1;
|
|
|
|
sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0, 0);
|
|
if (!sk_storage || *sk_storage != 0xdeadbeef)
|
|
return 0;
|
|
|
|
__sync_fetch_and_add(&invocations, 1);
|
|
__sync_fetch_and_add(&in_use, -1);
|
|
return 1;
|
|
}
|