1
2
3
4#include <linux/bpf.h>
5#include <linux/if_link.h>
6#include <assert.h>
7#include <errno.h>
8#include <signal.h>
9#include <stdio.h>
10#include <stdlib.h>
11#include <stdbool.h>
12#include <string.h>
13#include <net/if.h>
14#include <unistd.h>
15#include <libgen.h>
16#include <sys/resource.h>
17#include <sys/ioctl.h>
18#include <sys/types.h>
19#include <sys/socket.h>
20#include <netinet/in.h>
21
22#include "bpf_util.h"
23#include <bpf/bpf.h>
24#include <bpf/libbpf.h>
25
26static int ifindex_in;
27static int ifindex_out;
28static bool ifindex_out_xdp_dummy_attached = true;
29static bool xdp_devmap_attached;
30static __u32 prog_id;
31static __u32 dummy_prog_id;
32
33static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
34static int rxcnt_map_fd;
35
36static void int_exit(int sig)
37{
38 __u32 curr_prog_id = 0;
39
40 if (bpf_get_link_xdp_id(ifindex_in, &curr_prog_id, xdp_flags)) {
41 printf("bpf_get_link_xdp_id failed\n");
42 exit(1);
43 }
44 if (prog_id == curr_prog_id)
45 bpf_set_link_xdp_fd(ifindex_in, -1, xdp_flags);
46 else if (!curr_prog_id)
47 printf("couldn't find a prog id on iface IN\n");
48 else
49 printf("program on iface IN changed, not removing\n");
50
51 if (ifindex_out_xdp_dummy_attached) {
52 curr_prog_id = 0;
53 if (bpf_get_link_xdp_id(ifindex_out, &curr_prog_id,
54 xdp_flags)) {
55 printf("bpf_get_link_xdp_id failed\n");
56 exit(1);
57 }
58 if (dummy_prog_id == curr_prog_id)
59 bpf_set_link_xdp_fd(ifindex_out, -1, xdp_flags);
60 else if (!curr_prog_id)
61 printf("couldn't find a prog id on iface OUT\n");
62 else
63 printf("program on iface OUT changed, not removing\n");
64 }
65 exit(0);
66}
67
68static void poll_stats(int interval, int ifindex)
69{
70 unsigned int nr_cpus = bpf_num_possible_cpus();
71 __u64 values[nr_cpus], prev[nr_cpus];
72
73 memset(prev, 0, sizeof(prev));
74
75 while (1) {
76 __u64 sum = 0;
77 __u32 key = 0;
78 int i;
79
80 sleep(interval);
81 assert(bpf_map_lookup_elem(rxcnt_map_fd, &key, values) == 0);
82 for (i = 0; i < nr_cpus; i++)
83 sum += (values[i] - prev[i]);
84 if (sum)
85 printf("ifindex %i: %10llu pkt/s\n",
86 ifindex, sum / interval);
87 memcpy(prev, values, sizeof(values));
88 }
89}
90
91static int get_mac_addr(unsigned int ifindex_out, void *mac_addr)
92{
93 char ifname[IF_NAMESIZE];
94 struct ifreq ifr;
95 int fd, ret = -1;
96
97 fd = socket(AF_INET, SOCK_DGRAM, 0);
98 if (fd < 0)
99 return ret;
100
101 if (!if_indextoname(ifindex_out, ifname))
102 goto err_out;
103
104 strcpy(ifr.ifr_name, ifname);
105
106 if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0)
107 goto err_out;
108
109 memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
110 ret = 0;
111
112err_out:
113 close(fd);
114 return ret;
115}
116
117static void usage(const char *prog)
118{
119 fprintf(stderr,
120 "usage: %s [OPTS] <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n\n"
121 "OPTS:\n"
122 " -S use skb-mode\n"
123 " -N enforce native mode\n"
124 " -F force loading prog\n"
125 " -X load xdp program on egress\n",
126 prog);
127}
128
129int main(int argc, char **argv)
130{
131 struct bpf_prog_load_attr prog_load_attr = {
132 .prog_type = BPF_PROG_TYPE_UNSPEC,
133 };
134 struct bpf_program *prog, *dummy_prog, *devmap_prog;
135 int prog_fd, dummy_prog_fd, devmap_prog_fd = 0;
136 int tx_port_map_fd, tx_mac_map_fd;
137 struct bpf_devmap_val devmap_val;
138 struct bpf_prog_info info = {};
139 __u32 info_len = sizeof(info);
140 const char *optstr = "FSNX";
141 struct bpf_object *obj;
142 int ret, opt, key = 0;
143 char filename[256];
144
145 while ((opt = getopt(argc, argv, optstr)) != -1) {
146 switch (opt) {
147 case 'S':
148 xdp_flags |= XDP_FLAGS_SKB_MODE;
149 break;
150 case 'N':
151
152 break;
153 case 'F':
154 xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
155 break;
156 case 'X':
157 xdp_devmap_attached = true;
158 break;
159 default:
160 usage(basename(argv[0]));
161 return 1;
162 }
163 }
164
165 if (!(xdp_flags & XDP_FLAGS_SKB_MODE)) {
166 xdp_flags |= XDP_FLAGS_DRV_MODE;
167 } else if (xdp_devmap_attached) {
168 printf("Load xdp program on egress with SKB mode not supported yet\n");
169 return 1;
170 }
171
172 if (optind == argc) {
173 printf("usage: %s <IFNAME|IFINDEX>_IN <IFNAME|IFINDEX>_OUT\n", argv[0]);
174 return 1;
175 }
176
177 ifindex_in = if_nametoindex(argv[optind]);
178 if (!ifindex_in)
179 ifindex_in = strtoul(argv[optind], NULL, 0);
180
181 ifindex_out = if_nametoindex(argv[optind + 1]);
182 if (!ifindex_out)
183 ifindex_out = strtoul(argv[optind + 1], NULL, 0);
184
185 printf("input: %d output: %d\n", ifindex_in, ifindex_out);
186
187 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
188 prog_load_attr.file = filename;
189
190 if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
191 return 1;
192
193 if (xdp_flags & XDP_FLAGS_SKB_MODE) {
194 prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_general");
195 tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port_general");
196 } else {
197 prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_native");
198 tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port_native");
199 }
200 dummy_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_dummy_prog");
201 if (!prog || dummy_prog < 0 || tx_port_map_fd < 0) {
202 printf("finding prog/dummy_prog/tx_port_map in obj file failed\n");
203 goto out;
204 }
205 prog_fd = bpf_program__fd(prog);
206 dummy_prog_fd = bpf_program__fd(dummy_prog);
207 if (prog_fd < 0 || dummy_prog_fd < 0 || tx_port_map_fd < 0) {
208 printf("bpf_prog_load_xattr: %s\n", strerror(errno));
209 return 1;
210 }
211
212 tx_mac_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_mac");
213 rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
214 if (tx_mac_map_fd < 0 || rxcnt_map_fd < 0) {
215 printf("bpf_object__find_map_fd_by_name failed\n");
216 return 1;
217 }
218
219 if (bpf_set_link_xdp_fd(ifindex_in, prog_fd, xdp_flags) < 0) {
220 printf("ERROR: link set xdp fd failed on %d\n", ifindex_in);
221 return 1;
222 }
223
224 ret = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
225 if (ret) {
226 printf("can't get prog info - %s\n", strerror(errno));
227 return ret;
228 }
229 prog_id = info.id;
230
231
232 if (bpf_set_link_xdp_fd(ifindex_out, dummy_prog_fd,
233 (xdp_flags | XDP_FLAGS_UPDATE_IF_NOEXIST)) < 0) {
234 printf("WARN: link set xdp fd failed on %d\n", ifindex_out);
235 ifindex_out_xdp_dummy_attached = false;
236 }
237
238 memset(&info, 0, sizeof(info));
239 ret = bpf_obj_get_info_by_fd(dummy_prog_fd, &info, &info_len);
240 if (ret) {
241 printf("can't get prog info - %s\n", strerror(errno));
242 return ret;
243 }
244 dummy_prog_id = info.id;
245
246
247 if (xdp_devmap_attached) {
248 unsigned char mac_addr[6];
249
250 devmap_prog = bpf_object__find_program_by_name(obj, "xdp_redirect_map_egress");
251 if (!devmap_prog) {
252 printf("finding devmap_prog in obj file failed\n");
253 goto out;
254 }
255 devmap_prog_fd = bpf_program__fd(devmap_prog);
256 if (devmap_prog_fd < 0) {
257 printf("finding devmap_prog fd failed\n");
258 goto out;
259 }
260
261 if (get_mac_addr(ifindex_out, mac_addr) < 0) {
262 printf("get interface %d mac failed\n", ifindex_out);
263 goto out;
264 }
265
266 ret = bpf_map_update_elem(tx_mac_map_fd, &key, mac_addr, 0);
267 if (ret) {
268 perror("bpf_update_elem tx_mac_map_fd");
269 goto out;
270 }
271 }
272
273 signal(SIGINT, int_exit);
274 signal(SIGTERM, int_exit);
275
276 devmap_val.ifindex = ifindex_out;
277 devmap_val.bpf_prog.fd = devmap_prog_fd;
278 ret = bpf_map_update_elem(tx_port_map_fd, &key, &devmap_val, 0);
279 if (ret) {
280 perror("bpf_update_elem");
281 goto out;
282 }
283
284 poll_stats(2, ifindex_out);
285
286out:
287 return 0;
288}
289
