1 // SPDX-License-Identifier: GPL-2.0
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <string.h>
5 #include <linux/perf_event.h>
6 #include <linux/bpf.h>
7 #include <net/if.h>
8 #include <errno.h>
9 #include <assert.h>
10 #include <sys/sysinfo.h>
11 #include <sys/ioctl.h>
12 #include <signal.h>
13 #include <libbpf.h>
14 #include <bpf/bpf.h>
15
16 #include "perf-sys.h"
17 #include "trace_helpers.h"
18
19 #define MAX_CPUS 128
20 static int pmu_fds[MAX_CPUS], if_idx;
21 static struct perf_event_mmap_page *headers[MAX_CPUS];
22 static char *if_name;
23
do_attach(int idx,int fd,const char * name)24 static int do_attach(int idx, int fd, const char *name)
25 {
26 int err;
27
28 err = bpf_set_link_xdp_fd(idx, fd, 0);
29 if (err < 0)
30 printf("ERROR: failed to attach program to %s\n", name);
31
32 return err;
33 }
34
do_detach(int idx,const char * name)35 static int do_detach(int idx, const char *name)
36 {
37 int err;
38
39 err = bpf_set_link_xdp_fd(idx, -1, 0);
40 if (err < 0)
41 printf("ERROR: failed to detach program from %s\n", name);
42
43 return err;
44 }
45
46 #define SAMPLE_SIZE 64
47
print_bpf_output(void * data,int size)48 static int print_bpf_output(void *data, int size)
49 {
50 struct {
51 __u16 cookie;
52 __u16 pkt_len;
53 __u8 pkt_data[SAMPLE_SIZE];
54 } __packed *e = data;
55 int i;
56
57 if (e->cookie != 0xdead) {
58 printf("BUG cookie %x sized %d\n",
59 e->cookie, size);
60 return LIBBPF_PERF_EVENT_ERROR;
61 }
62
63 printf("Pkt len: %-5d bytes. Ethernet hdr: ", e->pkt_len);
64 for (i = 0; i < 14 && i < e->pkt_len; i++)
65 printf("%02x ", e->pkt_data[i]);
66 printf("\n");
67
68 return LIBBPF_PERF_EVENT_CONT;
69 }
70
test_bpf_perf_event(int map_fd,int num)71 static void test_bpf_perf_event(int map_fd, int num)
72 {
73 struct perf_event_attr attr = {
74 .sample_type = PERF_SAMPLE_RAW,
75 .type = PERF_TYPE_SOFTWARE,
76 .config = PERF_COUNT_SW_BPF_OUTPUT,
77 .wakeup_events = 1, /* get an fd notification for every event */
78 };
79 int i;
80
81 for (i = 0; i < num; i++) {
82 int key = i;
83
84 pmu_fds[i] = sys_perf_event_open(&attr, -1/*pid*/, i/*cpu*/,
85 -1/*group_fd*/, 0);
86
87 assert(pmu_fds[i] >= 0);
88 assert(bpf_map_update_elem(map_fd, &key,
89 &pmu_fds[i], BPF_ANY) == 0);
90 ioctl(pmu_fds[i], PERF_EVENT_IOC_ENABLE, 0);
91 }
92 }
93
sig_handler(int signo)94 static void sig_handler(int signo)
95 {
96 do_detach(if_idx, if_name);
97 exit(0);
98 }
99
main(int argc,char ** argv)100 int main(int argc, char **argv)
101 {
102 struct bpf_prog_load_attr prog_load_attr = {
103 .prog_type = BPF_PROG_TYPE_XDP,
104 };
105 struct bpf_object *obj;
106 struct bpf_map *map;
107 int prog_fd, map_fd;
108 char filename[256];
109 int ret, err, i;
110 int numcpus;
111
112 if (argc < 2) {
113 printf("Usage: %s <ifname>\n", argv[0]);
114 return 1;
115 }
116
117 numcpus = get_nprocs();
118 if (numcpus > MAX_CPUS)
119 numcpus = MAX_CPUS;
120
121 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
122 prog_load_attr.file = filename;
123
124 if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
125 return 1;
126
127 if (!prog_fd) {
128 printf("load_bpf_file: %s\n", strerror(errno));
129 return 1;
130 }
131
132 map = bpf_map__next(NULL, obj);
133 if (!map) {
134 printf("finding a map in obj file failed\n");
135 return 1;
136 }
137 map_fd = bpf_map__fd(map);
138
139 if_idx = if_nametoindex(argv[1]);
140 if (!if_idx)
141 if_idx = strtoul(argv[1], NULL, 0);
142
143 if (!if_idx) {
144 fprintf(stderr, "Invalid ifname\n");
145 return 1;
146 }
147 if_name = argv[1];
148 err = do_attach(if_idx, prog_fd, argv[1]);
149 if (err)
150 return err;
151
152 if (signal(SIGINT, sig_handler) ||
153 signal(SIGHUP, sig_handler) ||
154 signal(SIGTERM, sig_handler)) {
155 perror("signal");
156 return 1;
157 }
158
159 test_bpf_perf_event(map_fd, numcpus);
160
161 for (i = 0; i < numcpus; i++)
162 if (perf_event_mmap_header(pmu_fds[i], &headers[i]) < 0)
163 return 1;
164
165 ret = perf_event_poller_multi(pmu_fds, headers, numcpus,
166 print_bpf_output);
167 kill(0, SIGINT);
168 return ret;
169 }
170
