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

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (c) 2018 Facebook
   3
   4#include "vmlinux.h"
   5
   6#include <bpf/bpf_helpers.h>
   7#include <bpf/bpf_endian.h>
   8#include <bpf/bpf_tracing.h>
   9
  10#define AF_INET6 10
  11
  12struct socket_cookie {
  13        __u64 cookie_key;
  14        __u32 cookie_value;
  15};
  16
  17struct {
  18        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  19        __uint(map_flags, BPF_F_NO_PREALLOC);
  20        __type(key, int);
  21        __type(value, struct socket_cookie);
  22} socket_cookies SEC(".maps");
  23
  24/*
  25 * These three programs get executed in a row on connect() syscalls. The
  26 * userspace side of the test creates a client socket, issues a connect() on it
  27 * and then checks that the local storage associated with this socket has:
  28 * cookie_value == local_port << 8 | 0xFF
  29 * The different parts of this cookie_value are appended by those hooks if they
  30 * all agree on the output of bpf_get_socket_cookie().
  31 */
  32SEC("cgroup/connect6")
  33int set_cookie(struct bpf_sock_addr *ctx)
  34{
  35        struct socket_cookie *p;
  36
  37        if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
  38                return 1;
  39
  40        p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0,
  41                               BPF_SK_STORAGE_GET_F_CREATE);
  42        if (!p)
  43                return 1;
  44
  45        p->cookie_value = 0xF;
  46        p->cookie_key = bpf_get_socket_cookie(ctx);
  47
  48        return 1;
  49}
  50
  51SEC("sockops")
  52int update_cookie_sockops(struct bpf_sock_ops *ctx)
  53{
  54        struct bpf_sock *sk = ctx->sk;
  55        struct socket_cookie *p;
  56
  57        if (ctx->family != AF_INET6)
  58                return 1;
  59
  60        if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
  61                return 1;
  62
  63        if (!sk)
  64                return 1;
  65
  66        p = bpf_sk_storage_get(&socket_cookies, sk, 0, 0);
  67        if (!p)
  68                return 1;
  69
  70        if (p->cookie_key != bpf_get_socket_cookie(ctx))
  71                return 1;
  72
  73        p->cookie_value |= (ctx->local_port << 8);
  74
  75        return 1;
  76}
  77
  78SEC("fexit/inet_stream_connect")
  79int BPF_PROG(update_cookie_tracing, struct socket *sock,
  80             struct sockaddr *uaddr, int addr_len, int flags)
  81{
  82        struct socket_cookie *p;
  83
  84        if (uaddr->sa_family != AF_INET6)
  85                return 0;
  86
  87        p = bpf_sk_storage_get(&socket_cookies, sock->sk, 0, 0);
  88        if (!p)
  89                return 0;
  90
  91        if (p->cookie_key != bpf_get_socket_cookie(sock->sk))
  92                return 0;
  93
  94        p->cookie_value |= 0xF0;
  95
  96        return 0;
  97}
  98
  99char _license[] SEC("license") = "GPL";
 100