1
2
3
4static const char *__doc__ =
5"XDP redirect tool, using BPF_MAP_TYPE_DEVMAP\n"
6"Usage: xdp_redirect_map <IFINDEX|IFNAME>_IN <IFINDEX|IFNAME>_OUT\n";
7
8#include <linux/bpf.h>
9#include <linux/if_link.h>
10#include <assert.h>
11#include <errno.h>
12#include <signal.h>
13#include <stdio.h>
14#include <stdlib.h>
15#include <stdbool.h>
16#include <string.h>
17#include <net/if.h>
18#include <unistd.h>
19#include <libgen.h>
20#include <getopt.h>
21#include <bpf/bpf.h>
22#include <bpf/libbpf.h>
23#include "bpf_util.h"
24#include "xdp_sample_user.h"
25#include "xdp_redirect_map.skel.h"
26
27static int mask = SAMPLE_RX_CNT | SAMPLE_REDIRECT_ERR_MAP_CNT |
28 SAMPLE_EXCEPTION_CNT | SAMPLE_DEVMAP_XMIT_CNT_MULTI;
29
30DEFINE_SAMPLE_INIT(xdp_redirect_map);
31
32static const struct option long_options[] = {
33 { "help", no_argument, NULL, 'h' },
34 { "skb-mode", no_argument, NULL, 'S' },
35 { "force", no_argument, NULL, 'F' },
36 { "load-egress", no_argument, NULL, 'X' },
37 { "stats", no_argument, NULL, 's' },
38 { "interval", required_argument, NULL, 'i' },
39 { "verbose", no_argument, NULL, 'v' },
40 {}
41};
42
43int main(int argc, char **argv)
44{
45 struct bpf_devmap_val devmap_val = {};
46 bool xdp_devmap_attached = false;
47 struct xdp_redirect_map *skel;
48 char str[2 * IF_NAMESIZE + 1];
49 char ifname_out[IF_NAMESIZE];
50 struct bpf_map *tx_port_map;
51 char ifname_in[IF_NAMESIZE];
52 int ifindex_in, ifindex_out;
53 unsigned long interval = 2;
54 int ret = EXIT_FAIL_OPTION;
55 struct bpf_program *prog;
56 bool generic = false;
57 bool force = false;
58 bool tried = false;
59 bool error = true;
60 int opt, key = 0;
61
62 while ((opt = getopt_long(argc, argv, "hSFXi:vs",
63 long_options, NULL)) != -1) {
64 switch (opt) {
65 case 'S':
66 generic = true;
67
68 mask &= ~(SAMPLE_DEVMAP_XMIT_CNT |
69 SAMPLE_DEVMAP_XMIT_CNT_MULTI);
70 break;
71 case 'F':
72 force = true;
73 break;
74 case 'X':
75 xdp_devmap_attached = true;
76 break;
77 case 'i':
78 interval = strtoul(optarg, NULL, 0);
79 break;
80 case 'v':
81 sample_switch_mode();
82 break;
83 case 's':
84 mask |= SAMPLE_REDIRECT_MAP_CNT;
85 break;
86 case 'h':
87 error = false;
88 default:
89 sample_usage(argv, long_options, __doc__, mask, error);
90 return ret;
91 }
92 }
93
94 if (argc <= optind + 1) {
95 sample_usage(argv, long_options, __doc__, mask, true);
96 goto end;
97 }
98
99 ifindex_in = if_nametoindex(argv[optind]);
100 if (!ifindex_in)
101 ifindex_in = strtoul(argv[optind], NULL, 0);
102
103 ifindex_out = if_nametoindex(argv[optind + 1]);
104 if (!ifindex_out)
105 ifindex_out = strtoul(argv[optind + 1], NULL, 0);
106
107 if (!ifindex_in || !ifindex_out) {
108 fprintf(stderr, "Bad interface index or name\n");
109 sample_usage(argv, long_options, __doc__, mask, true);
110 goto end;
111 }
112
113 skel = xdp_redirect_map__open();
114 if (!skel) {
115 fprintf(stderr, "Failed to xdp_redirect_map__open: %s\n",
116 strerror(errno));
117 ret = EXIT_FAIL_BPF;
118 goto end;
119 }
120
121 ret = sample_init_pre_load(skel);
122 if (ret < 0) {
123 fprintf(stderr, "Failed to sample_init_pre_load: %s\n", strerror(-ret));
124 ret = EXIT_FAIL_BPF;
125 goto end_destroy;
126 }
127
128
129 if (xdp_devmap_attached) {
130 ret = get_mac_addr(ifindex_out, skel->rodata->tx_mac_addr);
131 if (ret < 0) {
132 fprintf(stderr, "Failed to get interface %d mac address: %s\n",
133 ifindex_out, strerror(-ret));
134 ret = EXIT_FAIL;
135 goto end_destroy;
136 }
137 }
138
139 skel->rodata->from_match[0] = ifindex_in;
140 skel->rodata->to_match[0] = ifindex_out;
141
142 ret = xdp_redirect_map__load(skel);
143 if (ret < 0) {
144 fprintf(stderr, "Failed to xdp_redirect_map__load: %s\n",
145 strerror(errno));
146 ret = EXIT_FAIL_BPF;
147 goto end_destroy;
148 }
149
150 ret = sample_init(skel, mask);
151 if (ret < 0) {
152 fprintf(stderr, "Failed to initialize sample: %s\n", strerror(-ret));
153 ret = EXIT_FAIL;
154 goto end_destroy;
155 }
156
157 prog = skel->progs.xdp_redirect_map_native;
158 tx_port_map = skel->maps.tx_port_native;
159restart:
160 if (sample_install_xdp(prog, ifindex_in, generic, force) < 0) {
161
162
163
164 fprintf(stderr,
165 "Trying fallback to sizeof(int) as value_size for devmap in generic mode\n");
166 if (generic && !tried) {
167 prog = skel->progs.xdp_redirect_map_general;
168 tx_port_map = skel->maps.tx_port_general;
169 tried = true;
170 goto restart;
171 }
172 ret = EXIT_FAIL_XDP;
173 goto end_destroy;
174 }
175
176
177 sample_install_xdp(skel->progs.xdp_redirect_dummy_prog, ifindex_out, generic, force);
178
179 devmap_val.ifindex = ifindex_out;
180 if (xdp_devmap_attached)
181 devmap_val.bpf_prog.fd = bpf_program__fd(skel->progs.xdp_redirect_map_egress);
182 ret = bpf_map_update_elem(bpf_map__fd(tx_port_map), &key, &devmap_val, 0);
183 if (ret < 0) {
184 fprintf(stderr, "Failed to update devmap value: %s\n",
185 strerror(errno));
186 ret = EXIT_FAIL_BPF;
187 goto end_destroy;
188 }
189
190 ret = EXIT_FAIL;
191 if (!if_indextoname(ifindex_in, ifname_in)) {
192 fprintf(stderr, "Failed to if_indextoname for %d: %s\n", ifindex_in,
193 strerror(errno));
194 goto end_destroy;
195 }
196
197 if (!if_indextoname(ifindex_out, ifname_out)) {
198 fprintf(stderr, "Failed to if_indextoname for %d: %s\n", ifindex_out,
199 strerror(errno));
200 goto end_destroy;
201 }
202
203 safe_strncpy(str, get_driver_name(ifindex_in), sizeof(str));
204 printf("Redirecting from %s (ifindex %d; driver %s) to %s (ifindex %d; driver %s)\n",
205 ifname_in, ifindex_in, str, ifname_out, ifindex_out, get_driver_name(ifindex_out));
206 snprintf(str, sizeof(str), "%s->%s", ifname_in, ifname_out);
207
208 ret = sample_run(interval, NULL, NULL);
209 if (ret < 0) {
210 fprintf(stderr, "Failed during sample run: %s\n", strerror(-ret));
211 ret = EXIT_FAIL;
212 goto end_destroy;
213 }
214 ret = EXIT_OK;
215end_destroy:
216 xdp_redirect_map__destroy(skel);
217end:
218 sample_exit(ret);
219}
220
