LXR linux/tools/testing/selftests/bpf/progs/udp

   1// SPDX-License-Identifier: GPL-2.0-only
   2
   3#include <sys/socket.h>
   4#include <linux/bpf.h>
   5#include <bpf/bpf_helpers.h>
   6
   7int invocations = 0, in_use = 0;
   8
   9struct {
  10        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  11        __uint(map_flags, BPF_F_NO_PREALLOC);
  12        __type(key, int);
  13        __type(value, int);
  14} sk_map SEC(".maps");
  15
  16SEC("cgroup/sock_create")
  17int sock(struct bpf_sock *ctx)
  18{
  19        int *sk_storage;
  20        __u32 key;
  21
  22        if (ctx->type != SOCK_DGRAM)
  23                return 1;
  24
  25        sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0,
  26                                        BPF_SK_STORAGE_GET_F_CREATE);
  27        if (!sk_storage)
  28                return 0;
  29        *sk_storage = 0xdeadbeef;
  30
  31        __sync_fetch_and_add(&invocations, 1);
  32
  33        if (in_use > 0) {
  34                /* BPF_CGROUP_INET_SOCK_RELEASE is _not_ called
  35                 * when we return an error from the BPF
  36                 * program!
  37                 */
  38                return 0;
  39        }
  40
  41        __sync_fetch_and_add(&in_use, 1);
  42        return 1;
  43}
  44
  45SEC("cgroup/sock_release")
  46int sock_release(struct bpf_sock *ctx)
  47{
  48        int *sk_storage;
  49        __u32 key;
  50
  51        if (ctx->type != SOCK_DGRAM)
  52                return 1;
  53
  54        sk_storage = bpf_sk_storage_get(&sk_map, ctx, 0, 0);
  55        if (!sk_storage || *sk_storage != 0xdeadbeef)
  56                return 0;
  57
  58        __sync_fetch_and_add(&invocations, 1);
  59        __sync_fetch_and_add(&in_use, -1);
  60        return 1;
  61}
  62