83 строки
1.9 KiB
C
83 строки
1.9 KiB
C
/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*/
|
|
|
|
#include <uapi/linux/bpf.h>
|
|
#include <uapi/linux/if_ether.h>
|
|
#include <uapi/linux/ip.h>
|
|
#include <uapi/linux/in.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
|
|
# define printk(fmt, ...) \
|
|
({ \
|
|
char ____fmt[] = fmt; \
|
|
bpf_trace_printk(____fmt, sizeof(____fmt), \
|
|
##__VA_ARGS__); \
|
|
})
|
|
|
|
struct bpf_elf_map {
|
|
__u32 type;
|
|
__u32 size_key;
|
|
__u32 size_value;
|
|
__u32 max_elem;
|
|
__u32 flags;
|
|
__u32 id;
|
|
__u32 pinning;
|
|
};
|
|
|
|
struct bpf_elf_map SEC("maps") lwt_len_hist_map = {
|
|
.type = BPF_MAP_TYPE_PERCPU_HASH,
|
|
.size_key = sizeof(__u64),
|
|
.size_value = sizeof(__u64),
|
|
.pinning = 2,
|
|
.max_elem = 1024,
|
|
};
|
|
|
|
static unsigned int log2(unsigned int v)
|
|
{
|
|
unsigned int r;
|
|
unsigned int shift;
|
|
|
|
r = (v > 0xFFFF) << 4; v >>= r;
|
|
shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
|
|
shift = (v > 0xF) << 2; v >>= shift; r |= shift;
|
|
shift = (v > 0x3) << 1; v >>= shift; r |= shift;
|
|
r |= (v >> 1);
|
|
return r;
|
|
}
|
|
|
|
static unsigned int log2l(unsigned long v)
|
|
{
|
|
unsigned int hi = v >> 32;
|
|
if (hi)
|
|
return log2(hi) + 32;
|
|
else
|
|
return log2(v);
|
|
}
|
|
|
|
SEC("len_hist")
|
|
int do_len_hist(struct __sk_buff *skb)
|
|
{
|
|
__u64 *value, key, init_val = 1;
|
|
|
|
key = log2l(skb->len);
|
|
|
|
value = bpf_map_lookup_elem(&lwt_len_hist_map, &key);
|
|
if (value)
|
|
__sync_fetch_and_add(value, 1);
|
|
else
|
|
bpf_map_update_elem(&lwt_len_hist_map, &key, &init_val, BPF_ANY);
|
|
|
|
return BPF_OK;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|