100 lines
2.1 KiB
C
100 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2018 Facebook
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#include "vmlinux.h"
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_endian.h>
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#include <bpf/bpf_tracing.h>
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#define AF_INET6 10
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struct socket_cookie {
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__u64 cookie_key;
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__u32 cookie_value;
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};
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struct {
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__uint(type, BPF_MAP_TYPE_SK_STORAGE);
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__uint(map_flags, BPF_F_NO_PREALLOC);
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__type(key, int);
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__type(value, struct socket_cookie);
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} socket_cookies SEC(".maps");
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/*
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* These three programs get executed in a row on connect() syscalls. The
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* userspace side of the test creates a client socket, issues a connect() on it
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* and then checks that the local storage associated with this socket has:
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* cookie_value == local_port << 8 | 0xFF
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* The different parts of this cookie_value are appended by those hooks if they
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* all agree on the output of bpf_get_socket_cookie().
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*/
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SEC("cgroup/connect6")
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int set_cookie(struct bpf_sock_addr *ctx)
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{
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struct socket_cookie *p;
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if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
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return 1;
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p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0,
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BPF_SK_STORAGE_GET_F_CREATE);
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if (!p)
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return 1;
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p->cookie_value = 0xF;
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p->cookie_key = bpf_get_socket_cookie(ctx);
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return 1;
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}
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SEC("sockops")
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int update_cookie_sockops(struct bpf_sock_ops *ctx)
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{
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struct bpf_sock *sk = ctx->sk;
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struct socket_cookie *p;
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if (ctx->family != AF_INET6)
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return 1;
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if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
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return 1;
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if (!sk)
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return 1;
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p = bpf_sk_storage_get(&socket_cookies, sk, 0, 0);
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if (!p)
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return 1;
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if (p->cookie_key != bpf_get_socket_cookie(ctx))
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return 1;
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p->cookie_value |= (ctx->local_port << 8);
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return 1;
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}
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SEC("fexit/inet_stream_connect")
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int BPF_PROG(update_cookie_tracing, struct socket *sock,
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struct sockaddr *uaddr, int addr_len, int flags)
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{
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struct socket_cookie *p;
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if (uaddr->sa_family != AF_INET6)
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return 0;
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p = bpf_sk_storage_get(&socket_cookies, sock->sk, 0, 0);
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if (!p)
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return 0;
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if (p->cookie_key != bpf_get_socket_cookie(sock->sk))
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return 0;
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p->cookie_value |= 0xF0;
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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