LXR linux/tools/testing/selftests/bpf/socket_cookie

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (c) 2018 Facebook
   3
   4#include <linux/bpf.h>
   5#include <sys/socket.h>
   6
   7#include "bpf_helpers.h"
   8#include "bpf_endian.h"
   9
  10struct bpf_map_def SEC("maps") socket_cookies = {
  11        .type = BPF_MAP_TYPE_HASH,
  12        .key_size = sizeof(__u64),
  13        .value_size = sizeof(__u32),
  14        .max_entries = 1 << 8,
  15};
  16
  17SEC("cgroup/connect6")
  18int set_cookie(struct bpf_sock_addr *ctx)
  19{
  20        __u32 cookie_value = 0xFF;
  21        __u64 cookie_key;
  22
  23        if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
  24                return 1;
  25
  26        cookie_key = bpf_get_socket_cookie(ctx);
  27        if (bpf_map_update_elem(&socket_cookies, &cookie_key, &cookie_value, 0))
  28                return 0;
  29
  30        return 1;
  31}
  32
  33SEC("sockops")
  34int update_cookie(struct bpf_sock_ops *ctx)
  35{
  36        __u32 new_cookie_value;
  37        __u32 *cookie_value;
  38        __u64 cookie_key;
  39
  40        if (ctx->family != AF_INET6)
  41                return 1;
  42
  43        if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
  44                return 1;
  45
  46        cookie_key = bpf_get_socket_cookie(ctx);
  47
  48        cookie_value = bpf_map_lookup_elem(&socket_cookies, &cookie_key);
  49        if (!cookie_value)
  50                return 1;
  51
  52        new_cookie_value = (ctx->local_port << 8) | *cookie_value;
  53        bpf_map_update_elem(&socket_cookies, &cookie_key, &new_cookie_value, 0);
  54
  55        return 1;
  56}
  57
  58int _version SEC("version") = 1;
  59
  60char _license[] SEC("license") = "GPL";
  61