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