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1/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
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#include <linux/skbuff.h>
8#include <linux/netdevice.h>
9#include <linux/version.h>
10#include <uapi/linux/bpf.h>
11#include "bpf_helpers.h"
12
13struct bpf_map_def SEC("maps") my_map = {
14 .type = BPF_MAP_TYPE_HASH,
15 .key_size = sizeof(long),
16 .value_size = sizeof(long),
17 .max_entries = 1024,
18};
19
20/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
21 * example will no longer be meaningful
22 */
23SEC("kprobe/kfree_skb")
24int bpf_prog2(struct pt_regs *ctx)
25{
26 long loc = 0;
27 long init_val = 1;
28 long *value;
29
30 /* read ip of kfree_skb caller.
31 * non-portable version of __builtin_return_address(0)
32 */
33 BPF_KPROBE_READ_RET_IP(loc, ctx);
34
35 value = bpf_map_lookup_elem(&my_map, &loc);
36 if (value)
37 *value += 1;
38 else
39 bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY);
40 return 0;
41}
42
43static unsigned int log2(unsigned int v)
44{
45 unsigned int r;
46 unsigned int shift;
47
48 r = (v > 0xFFFF) << 4; v >>= r;
49 shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
50 shift = (v > 0xF) << 2; v >>= shift; r |= shift;
51 shift = (v > 0x3) << 1; v >>= shift; r |= shift;
52 r |= (v >> 1);
53 return r;
54}
55
56static unsigned int log2l(unsigned long v)
57{
58 unsigned int hi = v >> 32;
59 if (hi)
60 return log2(hi) + 32;
61 else
62 return log2(v);
63}
64
65struct hist_key {
66 char comm[16];
67 u64 pid_tgid;
68 u64 uid_gid;
69 u32 index;
70};
71
72struct bpf_map_def SEC("maps") my_hist_map = {
73 .type = BPF_MAP_TYPE_PERCPU_HASH,
74 .key_size = sizeof(struct hist_key),
75 .value_size = sizeof(long),
76 .max_entries = 1024,
77};
78
79SEC("kprobe/sys_write")
80int bpf_prog3(struct pt_regs *ctx)
81{
82 long write_size = PT_REGS_PARM3(ctx);
83 long init_val = 1;
84 long *value;
85 struct hist_key key = {};
86
87 key.index = log2l(write_size);
88 key.pid_tgid = bpf_get_current_pid_tgid();
89 key.uid_gid = bpf_get_current_uid_gid();
90 bpf_get_current_comm(&key.comm, sizeof(key.comm));
91
92 value = bpf_map_lookup_elem(&my_hist_map, &key);
93 if (value)
94 __sync_fetch_and_add(value, 1);
95 else
96 bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY);
97 return 0;
98}
99char _license[] SEC("license") = "GPL";
100u32 _version SEC("version") = LINUX_VERSION_CODE;
1/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
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#include <linux/skbuff.h>
8#include <linux/netdevice.h>
9#include <linux/version.h>
10#include <uapi/linux/bpf.h>
11#include "bpf_helpers.h"
12
13struct bpf_map_def SEC("maps") my_map = {
14 .type = BPF_MAP_TYPE_HASH,
15 .key_size = sizeof(long),
16 .value_size = sizeof(long),
17 .max_entries = 1024,
18};
19
20/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
21 * example will no longer be meaningful
22 */
23SEC("kprobe/kfree_skb")
24int bpf_prog2(struct pt_regs *ctx)
25{
26 long loc = 0;
27 long init_val = 1;
28 long *value;
29
30 /* read ip of kfree_skb caller.
31 * non-portable version of __builtin_return_address(0)
32 */
33 BPF_KPROBE_READ_RET_IP(loc, ctx);
34
35 value = bpf_map_lookup_elem(&my_map, &loc);
36 if (value)
37 *value += 1;
38 else
39 bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY);
40 return 0;
41}
42
43static unsigned int log2(unsigned int v)
44{
45 unsigned int r;
46 unsigned int shift;
47
48 r = (v > 0xFFFF) << 4; v >>= r;
49 shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
50 shift = (v > 0xF) << 2; v >>= shift; r |= shift;
51 shift = (v > 0x3) << 1; v >>= shift; r |= shift;
52 r |= (v >> 1);
53 return r;
54}
55
56static unsigned int log2l(unsigned long v)
57{
58 unsigned int hi = v >> 32;
59 if (hi)
60 return log2(hi) + 32;
61 else
62 return log2(v);
63}
64
65struct hist_key {
66 char comm[16];
67 u64 pid_tgid;
68 u64 uid_gid;
69 u64 index;
70};
71
72struct bpf_map_def SEC("maps") my_hist_map = {
73 .type = BPF_MAP_TYPE_PERCPU_HASH,
74 .key_size = sizeof(struct hist_key),
75 .value_size = sizeof(long),
76 .max_entries = 1024,
77};
78
79SEC("kprobe/sys_write")
80int bpf_prog3(struct pt_regs *ctx)
81{
82 long write_size = PT_REGS_PARM3(ctx);
83 long init_val = 1;
84 long *value;
85 struct hist_key key;
86
87 key.index = log2l(write_size);
88 key.pid_tgid = bpf_get_current_pid_tgid();
89 key.uid_gid = bpf_get_current_uid_gid();
90 bpf_get_current_comm(&key.comm, sizeof(key.comm));
91
92 value = bpf_map_lookup_elem(&my_hist_map, &key);
93 if (value)
94 __sync_fetch_and_add(value, 1);
95 else
96 bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY);
97 return 0;
98}
99char _license[] SEC("license") = "GPL";
100u32 _version SEC("version") = LINUX_VERSION_CODE;