projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| f74599f7 TG |
1 | /* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch> |
| 2 | * | |
| 3 | * This program is free software; you can redistribute it and/or | |
| 4 | * modify it under the terms of version 2 of the GNU General Public | |
| 5 | * License as published by the Free Software Foundation. | |
| 6 | * | |
| 7 | * This program is distributed in the hope that it will be useful, but | |
| 8 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 10 | * General Public License for more details. | |
| 11 | */ | |
| 12 | ||
| 13 | #include <uapi/linux/bpf.h> | |
| 14 | #include <uapi/linux/if_ether.h> | |
| 15 | #include <uapi/linux/ip.h> | |
| 16 | #include <uapi/linux/in.h> | |
| 17 | #include "bpf_helpers.h" | |
| 18 | ||
| 19 | # define printk(fmt, ...) \ | |
| 20 | ({ \ | |
| 21 | char ____fmt[] = fmt; \ | |
| 22 | bpf_trace_printk(____fmt, sizeof(____fmt), \ | |
| 23 | ##__VA_ARGS__); \ | |
| 24 | }) | |
| 25 | ||
| 26 | struct bpf_elf_map { | |
| 27 | __u32 type; | |
| 28 | __u32 size_key; | |
| 29 | __u32 size_value; | |
| 30 | __u32 max_elem; | |
| 31 | __u32 flags; | |
| 32 | __u32 id; | |
| 33 | __u32 pinning; | |
| 34 | }; | |
| 35 | ||
| 36 | struct bpf_elf_map SEC("maps") lwt_len_hist_map = { | |
| 37 | .type = BPF_MAP_TYPE_PERCPU_HASH, | |
| 38 | .size_key = sizeof(__u64), | |
| 39 | .size_value = sizeof(__u64), | |
| 40 | .pinning = 2, | |
| 41 | .max_elem = 1024, | |
| 42 | }; | |
| 43 | ||
| 44 | static unsigned int log2(unsigned int v) | |
| 45 | { | |
| 46 | unsigned int r; | |
| 47 | unsigned int shift; | |
| 48 | ||
| 49 | r = (v > 0xFFFF) << 4; v >>= r; | |
| 50 | shift = (v > 0xFF) << 3; v >>= shift; r |= shift; | |
| 51 | shift = (v > 0xF) << 2; v >>= shift; r |= shift; | |
| 52 | shift = (v > 0x3) << 1; v >>= shift; r |= shift; | |
| 53 | r |= (v >> 1); | |
| 54 | return r; | |
| 55 | } | |
| 56 | ||
| 57 | static unsigned int log2l(unsigned long v) | |
| 58 | { | |
| 59 | unsigned int hi = v >> 32; | |
| 60 | if (hi) | |
| 61 | return log2(hi) + 32; | |
| 62 | else | |
| 63 | return log2(v); | |
| 64 | } | |
| 65 | ||
| 66 | SEC("len_hist") | |
| 67 | int do_len_hist(struct __sk_buff *skb) | |
| 68 | { | |
| 69 | __u64 *value, key, init_val = 1; | |
| 70 | ||
| 71 | key = log2l(skb->len); | |
| 72 | ||
| 73 | value = bpf_map_lookup_elem(&lwt_len_hist_map, &key); | |
| 74 | if (value) | |
| 75 | __sync_fetch_and_add(value, 1); | |
| 76 | else | |
| 77 | bpf_map_update_elem(&lwt_len_hist_map, &key, &init_val, BPF_ANY); | |
| 78 | ||
| 79 | return BPF_OK; | |
| 80 | } | |
| 81 | ||
| 82 | char _license[] SEC("license") = "GPL"; |