xref: /linux/samples/bpf/xdp_tx_iptunnel_user.c (revision 2697b79a469b68e3ad3640f55284359c1396278d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2016 Facebook
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 <string.h>
12 #include <net/if.h>
13 #include <arpa/inet.h>
14 #include <netinet/ether.h>
15 #include <unistd.h>
16 #include <time.h>
17 #include <bpf/libbpf.h>
18 #include <bpf/bpf.h>
19 #include "bpf_util.h"
20 #include "xdp_tx_iptunnel_common.h"
21 
22 #define STATS_INTERVAL_S 2U
23 
24 static int ifindex = -1;
25 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
26 static int rxcnt_map_fd;
27 static __u32 prog_id;
28 
29 static void int_exit(int sig)
30 {
31 	__u32 curr_prog_id = 0;
32 
33 	if (ifindex > -1) {
34 		if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
35 			printf("bpf_xdp_query_id failed\n");
36 			exit(1);
37 		}
38 		if (prog_id == curr_prog_id)
39 			bpf_xdp_detach(ifindex, xdp_flags, NULL);
40 		else if (!curr_prog_id)
41 			printf("couldn't find a prog id on a given iface\n");
42 		else
43 			printf("program on interface changed, not removing\n");
44 	}
45 	exit(0);
46 }
47 
48 /* simple per-protocol drop counter
49  */
50 static void poll_stats(unsigned int kill_after_s)
51 {
52 	const unsigned int nr_protos = 256;
53 	unsigned int nr_cpus = bpf_num_possible_cpus();
54 	time_t started_at = time(NULL);
55 	__u64 values[nr_cpus], prev[nr_protos][nr_cpus];
56 	__u32 proto;
57 	int i;
58 
59 	memset(prev, 0, sizeof(prev));
60 
61 	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
62 		sleep(STATS_INTERVAL_S);
63 
64 		for (proto = 0; proto < nr_protos; proto++) {
65 			__u64 sum = 0;
66 
67 			assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
68 						   values) == 0);
69 			for (i = 0; i < nr_cpus; i++)
70 				sum += (values[i] - prev[proto][i]);
71 
72 			if (sum)
73 				printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
74 				       proto, sum, sum / STATS_INTERVAL_S);
75 			memcpy(prev[proto], values, sizeof(values));
76 		}
77 	}
78 }
79 
80 static void usage(const char *cmd)
81 {
82 	printf("Start a XDP prog which encapsulates incoming packets\n"
83 	       "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
84 	       "is used to select packets to encapsulate\n\n");
85 	printf("Usage: %s [...]\n", cmd);
86 	printf("    -i <ifname|ifindex> Interface\n");
87 	printf("    -a <vip-service-address> IPv4 or IPv6\n");
88 	printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
89 	printf("    -s <source-ip> Used in the IPTunnel header\n");
90 	printf("    -d <dest-ip> Used in the IPTunnel header\n");
91 	printf("    -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
92 	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
93 	printf("    -P <IP-Protocol> Default is TCP\n");
94 	printf("    -S use skb-mode\n");
95 	printf("    -N enforce native mode\n");
96 	printf("    -F Force loading the XDP prog\n");
97 	printf("    -h Display this help\n");
98 }
99 
100 static int parse_ipstr(const char *ipstr, unsigned int *addr)
101 {
102 	if (inet_pton(AF_INET6, ipstr, addr) == 1) {
103 		return AF_INET6;
104 	} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
105 		addr[1] = addr[2] = addr[3] = 0;
106 		return AF_INET;
107 	}
108 
109 	fprintf(stderr, "%s is an invalid IP\n", ipstr);
110 	return AF_UNSPEC;
111 }
112 
113 static int parse_ports(const char *port_str, int *min_port, int *max_port)
114 {
115 	char *end;
116 	long tmp_min_port;
117 	long tmp_max_port;
118 
119 	tmp_min_port = strtol(optarg, &end, 10);
120 	if (tmp_min_port < 1 || tmp_min_port > 65535) {
121 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
122 		return 1;
123 	}
124 
125 	if (*end == '-') {
126 		end++;
127 		tmp_max_port = strtol(end, NULL, 10);
128 		if (tmp_max_port < 1 || tmp_max_port > 65535) {
129 			fprintf(stderr, "Invalid port(s):%s\n", optarg);
130 			return 1;
131 		}
132 	} else {
133 		tmp_max_port = tmp_min_port;
134 	}
135 
136 	if (tmp_min_port > tmp_max_port) {
137 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
138 		return 1;
139 	}
140 
141 	if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
142 		fprintf(stderr, "Port range (%s) is larger than %u\n",
143 			port_str, MAX_IPTNL_ENTRIES);
144 		return 1;
145 	}
146 	*min_port = tmp_min_port;
147 	*max_port = tmp_max_port;
148 
149 	return 0;
150 }
151 
152 int main(int argc, char **argv)
153 {
154 	int min_port = 0, max_port = 0, vip2tnl_map_fd;
155 	const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
156 	unsigned char opt_flags[256] = {};
157 	struct bpf_prog_info info = {};
158 	__u32 info_len = sizeof(info);
159 	unsigned int kill_after_s = 0;
160 	struct iptnl_info tnl = {};
161 	struct bpf_program *prog;
162 	struct bpf_object *obj;
163 	struct vip vip = {};
164 	char filename[256];
165 	int opt, prog_fd;
166 	int i, err;
167 
168 	tnl.family = AF_UNSPEC;
169 	vip.protocol = IPPROTO_TCP;
170 
171 	for (i = 0; i < strlen(optstr); i++)
172 		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
173 			opt_flags[(unsigned char)optstr[i]] = 1;
174 
175 	while ((opt = getopt(argc, argv, optstr)) != -1) {
176 		unsigned short family;
177 		unsigned int *v6;
178 
179 		switch (opt) {
180 		case 'i':
181 			ifindex = if_nametoindex(optarg);
182 			if (!ifindex)
183 				ifindex = atoi(optarg);
184 			break;
185 		case 'a':
186 			vip.family = parse_ipstr(optarg, vip.daddr.v6);
187 			if (vip.family == AF_UNSPEC)
188 				return 1;
189 			break;
190 		case 'p':
191 			if (parse_ports(optarg, &min_port, &max_port))
192 				return 1;
193 			break;
194 		case 'P':
195 			vip.protocol = atoi(optarg);
196 			break;
197 		case 's':
198 		case 'd':
199 			if (opt == 's')
200 				v6 = tnl.saddr.v6;
201 			else
202 				v6 = tnl.daddr.v6;
203 
204 			family = parse_ipstr(optarg, v6);
205 			if (family == AF_UNSPEC)
206 				return 1;
207 			if (tnl.family == AF_UNSPEC) {
208 				tnl.family = family;
209 			} else if (tnl.family != family) {
210 				fprintf(stderr,
211 					"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
212 				return 1;
213 			}
214 			break;
215 		case 'm':
216 			if (!ether_aton_r(optarg,
217 					  (struct ether_addr *)tnl.dmac)) {
218 				fprintf(stderr, "Invalid mac address:%s\n",
219 					optarg);
220 				return 1;
221 			}
222 			break;
223 		case 'T':
224 			kill_after_s = atoi(optarg);
225 			break;
226 		case 'S':
227 			xdp_flags |= XDP_FLAGS_SKB_MODE;
228 			break;
229 		case 'N':
230 			/* default, set below */
231 			break;
232 		case 'F':
233 			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
234 			break;
235 		default:
236 			usage(argv[0]);
237 			return 1;
238 		}
239 		opt_flags[opt] = 0;
240 	}
241 
242 	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
243 		xdp_flags |= XDP_FLAGS_DRV_MODE;
244 
245 	for (i = 0; i < strlen(optstr); i++) {
246 		if (opt_flags[(unsigned int)optstr[i]]) {
247 			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
248 			usage(argv[0]);
249 			return 1;
250 		}
251 	}
252 
253 	if (!ifindex) {
254 		fprintf(stderr, "Invalid ifname\n");
255 		return 1;
256 	}
257 
258 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
259 
260 	obj = bpf_object__open_file(filename, NULL);
261 	if (libbpf_get_error(obj))
262 		return 1;
263 
264 	prog = bpf_object__next_program(obj, NULL);
265 	bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
266 
267 	err = bpf_object__load(obj);
268 	if (err) {
269 		printf("bpf_object__load(): %s\n", strerror(errno));
270 		return 1;
271 	}
272 	prog_fd = bpf_program__fd(prog);
273 
274 	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
275 	vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
276 	if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
277 		printf("bpf_object__find_map_fd_by_name failed\n");
278 		return 1;
279 	}
280 
281 	signal(SIGINT, int_exit);
282 	signal(SIGTERM, int_exit);
283 
284 	while (min_port <= max_port) {
285 		vip.dport = htons(min_port++);
286 		if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
287 					BPF_NOEXIST)) {
288 			perror("bpf_map_update_elem(&vip2tnl)");
289 			return 1;
290 		}
291 	}
292 
293 	if (bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL) < 0) {
294 		printf("link set xdp fd failed\n");
295 		return 1;
296 	}
297 
298 	err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
299 	if (err) {
300 		printf("can't get prog info - %s\n", strerror(errno));
301 		return err;
302 	}
303 	prog_id = info.id;
304 
305 	poll_stats(kill_after_s);
306 
307 	bpf_xdp_detach(ifindex, xdp_flags, NULL);
308 
309 	return 0;
310 }
311