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
194
195
196
197
|
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <linux/perf_event.h>
#include <linux/bpf.h>
#include <net/if.h>
#include <errno.h>
#include <assert.h>
#include <sys/sysinfo.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
#include <sys/resource.h>
#include <libgen.h>
#include <linux/if_link.h>
#include "perf-sys.h"
static int if_idx;
static char *if_name;
static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static __u32 prog_id;
static struct perf_buffer *pb = NULL;
static int do_attach(int idx, int fd, const char *name)
{
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
int err;
err = bpf_xdp_attach(idx, fd, xdp_flags, NULL);
if (err < 0) {
printf("ERROR: failed to attach program to %s\n", name);
return err;
}
err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
if (err) {
printf("can't get prog info - %s\n", strerror(errno));
return err;
}
prog_id = info.id;
return err;
}
static int do_detach(int idx, const char *name)
{
__u32 curr_prog_id = 0;
int err = 0;
err = bpf_xdp_query_id(idx, xdp_flags, &curr_prog_id);
if (err) {
printf("bpf_xdp_query_id failed\n");
return err;
}
if (prog_id == curr_prog_id) {
err = bpf_xdp_detach(idx, xdp_flags, NULL);
if (err < 0)
printf("ERROR: failed to detach prog from %s\n", name);
} else if (!curr_prog_id) {
printf("couldn't find a prog id on a %s\n", name);
} else {
printf("program on interface changed, not removing\n");
}
return err;
}
#define SAMPLE_SIZE 64
static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
{
struct {
__u16 cookie;
__u16 pkt_len;
__u8 pkt_data[SAMPLE_SIZE];
} __packed *e = data;
int i;
if (e->cookie != 0xdead) {
printf("BUG cookie %x sized %d\n", e->cookie, size);
return;
}
printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
for (i = 0; i < 14 && i < e->pkt_len; i++)
printf("%02x ", e->pkt_data[i]);
printf("\n");
}
static void sig_handler(int signo)
{
do_detach(if_idx, if_name);
perf_buffer__free(pb);
exit(0);
}
static void usage(const char *prog)
{
fprintf(stderr,
"%s: %s [OPTS] <ifname|ifindex>\n\n"
"OPTS:\n"
" -F force loading prog\n"
" -S use skb-mode\n",
__func__, prog);
}
int main(int argc, char **argv)
{
const char *optstr = "FS";
int prog_fd, map_fd, opt;
struct bpf_program *prog;
struct bpf_object *obj;
struct bpf_map *map;
char filename[256];
int ret, err;
while ((opt = getopt(argc, argv, optstr)) != -1) {
switch (opt) {
case 'F':
xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
break;
case 'S':
xdp_flags |= XDP_FLAGS_SKB_MODE;
break;
default:
usage(basename(argv[0]));
return 1;
}
}
if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
xdp_flags |= XDP_FLAGS_DRV_MODE;
if (optind == argc) {
usage(basename(argv[0]));
return 1;
}
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj))
return 1;
prog = bpf_object__next_program(obj, NULL);
bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
err = bpf_object__load(obj);
if (err)
return 1;
prog_fd = bpf_program__fd(prog);
map = bpf_object__next_map(obj, NULL);
if (!map) {
printf("finding a map in obj file failed\n");
return 1;
}
map_fd = bpf_map__fd(map);
if_idx = if_nametoindex(argv[optind]);
if (!if_idx)
if_idx = strtoul(argv[optind], NULL, 0);
if (!if_idx) {
fprintf(stderr, "Invalid ifname\n");
return 1;
}
if_name = argv[optind];
err = do_attach(if_idx, prog_fd, if_name);
if (err)
return err;
if (signal(SIGINT, sig_handler) ||
signal(SIGHUP, sig_handler) ||
signal(SIGTERM, sig_handler)) {
perror("signal");
return 1;
}
pb = perf_buffer__new(map_fd, 8, print_bpf_output, NULL, NULL, NULL);
err = libbpf_get_error(pb);
if (err) {
perror("perf_buffer setup failed");
return 1;
}
while ((ret = perf_buffer__poll(pb, 1000)) >= 0) {
}
kill(0, SIGINT);
return ret;
}
|
