101 lines
2.3 KiB
C
101 lines
2.3 KiB
C
|
/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
|
||
|
|
*
|
||
|
|
* 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.
|
||
|
|
*/
|
||
|
|
#include <linux/skbuff.h>
|
||
|
|
#include <linux/netdevice.h>
|
||
|
|
#include <linux/version.h>
|
||
|
|
#include <uapi/linux/bpf.h>
|
||
|
|
#include "bpf_helpers.h"
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") my_map = {
|
||
|
|
.type = BPF_MAP_TYPE_HASH,
|
||
|
|
.key_size = sizeof(long),
|
||
|
|
.value_size = sizeof(long),
|
||
|
|
.max_entries = 1024,
|
||
|
|
};
|
||
|
|
|
||
|
|
/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
|
||
|
|
* example will no longer be meaningful
|
||
|
|
*/
|
||
|
|
SEC("kprobe/kfree_skb")
|
||
|
|
int bpf_prog2(struct pt_regs *ctx)
|
||
|
|
{
|
||
|
|
long loc = 0;
|
||
|
|
long init_val = 1;
|
||
|
|
long *value;
|
||
|
|
|
||
|
|
/* read ip of kfree_skb caller.
|
||
|
|
* non-portable version of __builtin_return_address(0)
|
||
|
|
*/
|
||
|
|
BPF_KPROBE_READ_RET_IP(loc, ctx);
|
||
|
|
|
||
|
|
value = bpf_map_lookup_elem(&my_map, &loc);
|
||
|
|
if (value)
|
||
|
|
*value += 1;
|
||
|
|
else
|
||
|
|
bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
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);
|
||
|
|
}
|
||
|
|
|
||
|
|
struct hist_key {
|
||
|
|
char comm[16];
|
||
|
|
u64 pid_tgid;
|
||
|
|
u64 uid_gid;
|
||
|
|
u64 index;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct bpf_map_def SEC("maps") my_hist_map = {
|
||
|
|
.type = BPF_MAP_TYPE_PERCPU_HASH,
|
||
|
|
.key_size = sizeof(struct hist_key),
|
||
|
|
.value_size = sizeof(long),
|
||
|
|
.max_entries = 1024,
|
||
|
|
};
|
||
|
|
|
||
|
|
SEC("kprobe/sys_write")
|
||
|
|
int bpf_prog3(struct pt_regs *ctx)
|
||
|
|
{
|
||
|
|
long write_size = PT_REGS_PARM3(ctx);
|
||
|
|
long init_val = 1;
|
||
|
|
long *value;
|
||
|
|
struct hist_key key;
|
||
|
|
|
||
|
|
key.index = log2l(write_size);
|
||
|
|
key.pid_tgid = bpf_get_current_pid_tgid();
|
||
|
|
key.uid_gid = bpf_get_current_uid_gid();
|
||
|
|
bpf_get_current_comm(&key.comm, sizeof(key.comm));
|
||
|
|
|
||
|
|
value = bpf_map_lookup_elem(&my_hist_map, &key);
|
||
|
|
if (value)
|
||
|
|
__sync_fetch_and_add(value, 1);
|
||
|
|
else
|
||
|
|
bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
char _license[] SEC("license") = "GPL";
|
||
|
|
u32 _version SEC("version") = LINUX_VERSION_CODE;
|