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
|
// SPDX-License-Identifier: GPL-2.0
#include <error.h>
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
const char *cfg_pin_path = "/sys/fs/bpf/flow_dissector";
const char *cfg_map_name = "jmp_table";
bool cfg_attach = true;
char *cfg_section_name;
char *cfg_path_name;
static void load_and_attach_program(void)
{
struct bpf_program *prog, *main_prog;
struct bpf_map *prog_array;
int i, fd, prog_fd, ret;
struct bpf_object *obj;
int prog_array_fd;
ret = bpf_prog_load(cfg_path_name, BPF_PROG_TYPE_FLOW_DISSECTOR, &obj,
&prog_fd);
if (ret)
error(1, 0, "bpf_prog_load %s", cfg_path_name);
main_prog = bpf_object__find_program_by_title(obj, cfg_section_name);
if (!main_prog)
error(1, 0, "bpf_object__find_program_by_title %s",
cfg_section_name);
prog_fd = bpf_program__fd(main_prog);
if (prog_fd < 0)
error(1, 0, "bpf_program__fd");
prog_array = bpf_object__find_map_by_name(obj, cfg_map_name);
if (!prog_array)
error(1, 0, "bpf_object__find_map_by_name %s", cfg_map_name);
prog_array_fd = bpf_map__fd(prog_array);
if (prog_array_fd < 0)
error(1, 0, "bpf_map__fd %s", cfg_map_name);
i = 0;
bpf_object__for_each_program(prog, obj) {
fd = bpf_program__fd(prog);
if (fd < 0)
error(1, 0, "bpf_program__fd");
if (fd != prog_fd) {
printf("%d: %s\n", i, bpf_program__title(prog, false));
bpf_map_update_elem(prog_array_fd, &i, &fd, BPF_ANY);
++i;
}
}
ret = bpf_prog_attach(prog_fd, 0 /* Ignore */, BPF_FLOW_DISSECTOR, 0);
if (ret)
error(1, 0, "bpf_prog_attach %s", cfg_path_name);
ret = bpf_object__pin(obj, cfg_pin_path);
if (ret)
error(1, 0, "bpf_object__pin %s", cfg_pin_path);
}
static void detach_program(void)
{
char command[64];
int ret;
ret = bpf_prog_detach(0, BPF_FLOW_DISSECTOR);
if (ret)
error(1, 0, "bpf_prog_detach");
/* To unpin, it is necessary and sufficient to just remove this dir */
sprintf(command, "rm -r %s", cfg_pin_path);
ret = system(command);
if (ret)
error(1, errno, command);
}
static void parse_opts(int argc, char **argv)
{
bool attach = false;
bool detach = false;
int c;
while ((c = getopt(argc, argv, "adp:s:")) != -1) {
switch (c) {
case 'a':
if (detach)
error(1, 0, "attach/detach are exclusive");
attach = true;
break;
case 'd':
if (attach)
error(1, 0, "attach/detach are exclusive");
detach = true;
break;
case 'p':
if (cfg_path_name)
error(1, 0, "only one prog name can be given");
cfg_path_name = optarg;
break;
case 's':
if (cfg_section_name)
error(1, 0, "only one section can be given");
cfg_section_name = optarg;
break;
}
}
if (detach)
cfg_attach = false;
if (cfg_attach && !cfg_path_name)
error(1, 0, "must provide a path to the BPF program");
if (cfg_attach && !cfg_section_name)
error(1, 0, "must provide a section name");
}
int main(int argc, char **argv)
{
parse_opts(argc, argv);
if (cfg_attach)
load_and_attach_program();
else
detach_program();
return 0;
}
|
