1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <sys/resource.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_util.h"
#define MAX_INDEX 64
#define MAX_STARS 38
/* my_map, my_hist_map */
static int map_fd[2];
static void stars(char *str, long val, long max, int width)
{
int i;
for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
str[i] = '*';
if (val > max)
str[i - 1] = '+';
str[i] = '\0';
}
struct task {
char comm[16];
__u64 pid_tgid;
__u64 uid_gid;
};
struct hist_key {
struct task t;
__u32 index;
};
#define SIZE sizeof(struct task)
static void print_hist_for_pid(int fd, void *task)
{
unsigned int nr_cpus = bpf_num_possible_cpus();
struct hist_key key = {}, next_key;
long values[nr_cpus];
char starstr[MAX_STARS];
long value;
long data[MAX_INDEX] = {};
int max_ind = -1;
long max_value = 0;
int i, ind;
while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
if (memcmp(&next_key, task, SIZE)) {
key = next_key;
continue;
}
bpf_map_lookup_elem(fd, &next_key, values);
value = 0;
for (i = 0; i < nr_cpus; i++)
value += values[i];
ind = next_key.index;
data[ind] = value;
if (value && ind > max_ind)
max_ind = ind;
if (value > max_value)
max_value = value;
key = next_key;
}
printf(" syscall write() stats\n");
printf(" byte_size : count distribution\n");
for (i = 1; i <= max_ind + 1; i++) {
stars(starstr, data[i - 1], max_value, MAX_STARS);
printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
(1l << i) >> 1, (1l << i) - 1, data[i - 1],
MAX_STARS, starstr);
}
}
static void print_hist(int fd)
{
struct hist_key key = {}, next_key;
static struct task tasks[1024];
int task_cnt = 0;
int i;
while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
int found = 0;
for (i = 0; i < task_cnt; i++)
if (memcmp(&tasks[i], &next_key, SIZE) == 0)
found = 1;
if (!found)
memcpy(&tasks[task_cnt++], &next_key, SIZE);
key = next_key;
}
for (i = 0; i < task_cnt; i++) {
printf("\npid %d cmd %s uid %d\n",
(__u32) tasks[i].pid_tgid,
tasks[i].comm,
(__u32) tasks[i].uid_gid);
print_hist_for_pid(fd, &tasks[i]);
}
}
static void int_exit(int sig)
{
print_hist(map_fd[1]);
exit(0);
}
int main(int ac, char **argv)
{
struct rlimit r = {1024*1024, RLIM_INFINITY};
long key, next_key, value;
struct bpf_link *links[2];
struct bpf_program *prog;
struct bpf_object *obj;
char filename[256];
int i, j = 0;
FILE *f;
if (setrlimit(RLIMIT_MEMLOCK, &r)) {
perror("setrlimit(RLIMIT_MEMLOCK)");
return 1;
}
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
return 0;
}
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
map_fd[0] = bpf_object__find_map_fd_by_name(obj, "my_map");
map_fd[1] = bpf_object__find_map_fd_by_name(obj, "my_hist_map");
if (map_fd[0] < 0 || map_fd[1] < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
signal(SIGINT, int_exit);
signal(SIGTERM, int_exit);
/* start 'ping' in the background to have some kfree_skb events */
f = popen("ping -4 -c5 localhost", "r");
(void) f;
/* start 'dd' in the background to have plenty of 'write' syscalls */
f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r");
(void) f;
bpf_object__for_each_program(prog, obj) {
links[j] = bpf_program__attach(prog);
if (libbpf_get_error(links[j])) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
links[j] = NULL;
goto cleanup;
}
j++;
}
for (i = 0; i < 5; i++) {
key = 0;
while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) {
bpf_map_lookup_elem(map_fd[0], &next_key, &value);
printf("location 0x%lx count %ld\n", next_key, value);
key = next_key;
}
if (key)
printf("\n");
sleep(1);
}
print_hist(map_fd[1]);
cleanup:
for (j--; j >= 0; j--)
bpf_link__destroy(links[j]);
bpf_object__close(obj);
return 0;
}
|
