| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* Refer to samples/bpf/tcp_bpf.readme for the instructions on |
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| 3 | * how to run this sample program. |
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| 4 | */ |
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| 5 | #include <linux/bpf.h> |
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| 6 | |
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| 7 | #include <bpf/bpf_helpers.h> |
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| 8 | #include <bpf/bpf_endian.h> |
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| 9 | |
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| 10 | #define INTERVAL 1000000000ULL |
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| 11 | |
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| 12 | int _version SEC("version" ) = 1; |
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| 13 | char _license[] SEC("license" ) = "GPL" ; |
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| 14 | |
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| 15 | struct { |
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| 16 | __u32 type; |
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| 17 | __u32 map_flags; |
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| 18 | int *key; |
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| 19 | __u64 *value; |
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| 20 | } bpf_next_dump SEC(".maps" ) = { |
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| 21 | .type = BPF_MAP_TYPE_SK_STORAGE, |
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| 22 | .map_flags = BPF_F_NO_PREALLOC, |
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| 23 | }; |
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| 24 | |
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| 25 | SEC("sockops" ) |
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| 26 | int _sockops(struct bpf_sock_ops *ctx) |
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| 27 | { |
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| 28 | struct bpf_tcp_sock *tcp_sk; |
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| 29 | struct bpf_sock *sk; |
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| 30 | __u64 *next_dump; |
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| 31 | __u64 now; |
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| 32 | |
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| 33 | switch (ctx->op) { |
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| 34 | case BPF_SOCK_OPS_TCP_CONNECT_CB: |
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| 35 | bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG); |
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| 36 | return 1; |
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| 37 | case BPF_SOCK_OPS_RTT_CB: |
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| 38 | break; |
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| 39 | default: |
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| 40 | return 1; |
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| 41 | } |
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| 42 | |
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| 43 | sk = ctx->sk; |
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| 44 | if (!sk) |
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| 45 | return 1; |
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| 46 | |
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| 47 | next_dump = bpf_sk_storage_get(&bpf_next_dump, sk, 0, |
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| 48 | BPF_SK_STORAGE_GET_F_CREATE); |
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| 49 | if (!next_dump) |
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| 50 | return 1; |
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| 51 | |
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| 52 | now = bpf_ktime_get_ns(); |
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| 53 | if (now < *next_dump) |
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| 54 | return 1; |
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| 55 | |
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| 56 | tcp_sk = bpf_tcp_sock(sk); |
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| 57 | if (!tcp_sk) |
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| 58 | return 1; |
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| 59 | |
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| 60 | *next_dump = now + INTERVAL; |
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| 61 | |
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| 62 | bpf_printk("dsack_dups=%u delivered=%u\n" , |
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| 63 | tcp_sk->dsack_dups, tcp_sk->delivered); |
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| 64 | bpf_printk("delivered_ce=%u icsk_retransmits=%u\n" , |
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| 65 | tcp_sk->delivered_ce, tcp_sk->icsk_retransmits); |
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| 66 | |
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| 67 | return 1; |
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| 68 | } |
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| 69 | |
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