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 <sys/resource.h>
14 #include <arpa/inet.h>
15 #include <netinet/ether.h>
16 #include <unistd.h>
17 #include <time.h>
18 #include <bpf/libbpf.h>
19 #include <bpf/bpf.h>
20 #include "bpf_util.h"
21 #include "xdp_tx_iptunnel_common.h"
22 
23 #define STATS_INTERVAL_S 2U
24 
25 static int ifindex = -1;
26 static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
27 static int rxcnt_map_fd;
28 static __u32 prog_id;
29 
30 static void int_exit(int sig)
31 {
32 	__u32 curr_prog_id = 0;
33 
34 	if (ifindex > -1) {
35 		if (bpf_get_link_xdp_id(ifindex, &curr_prog_id, xdp_flags)) {
36 			printf("bpf_get_link_xdp_id failed\n");
37 			exit(1);
38 		}
39 		if (prog_id == curr_prog_id)
40 			bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
41 		else if (!curr_prog_id)
42 			printf("couldn't find a prog id on a given iface\n");
43 		else
44 			printf("program on interface changed, not removing\n");
45 	}
46 	exit(0);
47 }
48 
49 /* simple per-protocol drop counter
50  */
51 static void poll_stats(unsigned int kill_after_s)
52 {
53 	const unsigned int nr_protos = 256;
54 	unsigned int nr_cpus = bpf_num_possible_cpus();
55 	time_t started_at = time(NULL);
56 	__u64 values[nr_cpus], prev[nr_protos][nr_cpus];
57 	__u32 proto;
58 	int i;
59 
60 	memset(prev, 0, sizeof(prev));
61 
62 	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
63 		sleep(STATS_INTERVAL_S);
64 
65 		for (proto = 0; proto < nr_protos; proto++) {
66 			__u64 sum = 0;
67 
68 			assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
69 						   values) == 0);
70 			for (i = 0; i < nr_cpus; i++)
71 				sum += (values[i] - prev[proto][i]);
72 
73 			if (sum)
74 				printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
75 				       proto, sum, sum / STATS_INTERVAL_S);
76 			memcpy(prev[proto], values, sizeof(values));
77 		}
78 	}
79 }
80 
81 static void usage(const char *cmd)
82 {
83 	printf("Start a XDP prog which encapsulates incoming packets\n"
84 	       "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
85 	       "is used to select packets to encapsulate\n\n");
86 	printf("Usage: %s [...]\n", cmd);
87 	printf("    -i <ifname|ifindex> Interface\n");
88 	printf("    -a <vip-service-address> IPv4 or IPv6\n");
89 	printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
90 	printf("    -s <source-ip> Used in the IPTunnel header\n");
91 	printf("    -d <dest-ip> Used in the IPTunnel header\n");
92 	printf("    -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
93 	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
94 	printf("    -P <IP-Protocol> Default is TCP\n");
95 	printf("    -S use skb-mode\n");
96 	printf("    -N enforce native mode\n");
97 	printf("    -F Force loading the XDP prog\n");
98 	printf("    -h Display this help\n");
99 }
100 
101 static int parse_ipstr(const char *ipstr, unsigned int *addr)
102 {
103 	if (inet_pton(AF_INET6, ipstr, addr) == 1) {
104 		return AF_INET6;
105 	} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
106 		addr[1] = addr[2] = addr[3] = 0;
107 		return AF_INET;
108 	}
109 
110 	fprintf(stderr, "%s is an invalid IP\n", ipstr);
111 	return AF_UNSPEC;
112 }
113 
114 static int parse_ports(const char *port_str, int *min_port, int *max_port)
115 {
116 	char *end;
117 	long tmp_min_port;
118 	long tmp_max_port;
119 
120 	tmp_min_port = strtol(optarg, &end, 10);
121 	if (tmp_min_port < 1 || tmp_min_port > 65535) {
122 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
123 		return 1;
124 	}
125 
126 	if (*end == '-') {
127 		end++;
128 		tmp_max_port = strtol(end, NULL, 10);
129 		if (tmp_max_port < 1 || tmp_max_port > 65535) {
130 			fprintf(stderr, "Invalid port(s):%s\n", optarg);
131 			return 1;
132 		}
133 	} else {
134 		tmp_max_port = tmp_min_port;
135 	}
136 
137 	if (tmp_min_port > tmp_max_port) {
138 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
139 		return 1;
140 	}
141 
142 	if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
143 		fprintf(stderr, "Port range (%s) is larger than %u\n",
144 			port_str, MAX_IPTNL_ENTRIES);
145 		return 1;
146 	}
147 	*min_port = tmp_min_port;
148 	*max_port = tmp_max_port;
149 
150 	return 0;
151 }
152 
153 int main(int argc, char **argv)
154 {
155 	struct bpf_prog_load_attr prog_load_attr = {
156 		.prog_type	= BPF_PROG_TYPE_XDP,
157 	};
158 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
159 	int min_port = 0, max_port = 0, vip2tnl_map_fd;
160 	const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
161 	unsigned char opt_flags[256] = {};
162 	struct bpf_prog_info info = {};
163 	__u32 info_len = sizeof(info);
164 	unsigned int kill_after_s = 0;
165 	struct iptnl_info tnl = {};
166 	struct bpf_object *obj;
167 	struct vip vip = {};
168 	char filename[256];
169 	int opt, prog_fd;
170 	int i, err;
171 
172 	tnl.family = AF_UNSPEC;
173 	vip.protocol = IPPROTO_TCP;
174 
175 	for (i = 0; i < strlen(optstr); i++)
176 		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
177 			opt_flags[(unsigned char)optstr[i]] = 1;
178 
179 	while ((opt = getopt(argc, argv, optstr)) != -1) {
180 		unsigned short family;
181 		unsigned int *v6;
182 
183 		switch (opt) {
184 		case 'i':
185 			ifindex = if_nametoindex(optarg);
186 			if (!ifindex)
187 				ifindex = atoi(optarg);
188 			break;
189 		case 'a':
190 			vip.family = parse_ipstr(optarg, vip.daddr.v6);
191 			if (vip.family == AF_UNSPEC)
192 				return 1;
193 			break;
194 		case 'p':
195 			if (parse_ports(optarg, &min_port, &max_port))
196 				return 1;
197 			break;
198 		case 'P':
199 			vip.protocol = atoi(optarg);
200 			break;
201 		case 's':
202 		case 'd':
203 			if (opt == 's')
204 				v6 = tnl.saddr.v6;
205 			else
206 				v6 = tnl.daddr.v6;
207 
208 			family = parse_ipstr(optarg, v6);
209 			if (family == AF_UNSPEC)
210 				return 1;
211 			if (tnl.family == AF_UNSPEC) {
212 				tnl.family = family;
213 			} else if (tnl.family != family) {
214 				fprintf(stderr,
215 					"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
216 				return 1;
217 			}
218 			break;
219 		case 'm':
220 			if (!ether_aton_r(optarg,
221 					  (struct ether_addr *)tnl.dmac)) {
222 				fprintf(stderr, "Invalid mac address:%s\n",
223 					optarg);
224 				return 1;
225 			}
226 			break;
227 		case 'T':
228 			kill_after_s = atoi(optarg);
229 			break;
230 		case 'S':
231 			xdp_flags |= XDP_FLAGS_SKB_MODE;
232 			break;
233 		case 'N':
234 			/* default, set below */
235 			break;
236 		case 'F':
237 			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
238 			break;
239 		default:
240 			usage(argv[0]);
241 			return 1;
242 		}
243 		opt_flags[opt] = 0;
244 	}
245 
246 	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
247 		xdp_flags |= XDP_FLAGS_DRV_MODE;
248 
249 	for (i = 0; i < strlen(optstr); i++) {
250 		if (opt_flags[(unsigned int)optstr[i]]) {
251 			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
252 			usage(argv[0]);
253 			return 1;
254 		}
255 	}
256 
257 	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
258 		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
259 		return 1;
260 	}
261 
262 	if (!ifindex) {
263 		fprintf(stderr, "Invalid ifname\n");
264 		return 1;
265 	}
266 
267 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
268 	prog_load_attr.file = filename;
269 
270 	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
271 		return 1;
272 
273 	if (!prog_fd) {
274 		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
275 		return 1;
276 	}
277 
278 	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
279 	vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
280 	if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
281 		printf("bpf_object__find_map_fd_by_name failed\n");
282 		return 1;
283 	}
284 
285 	signal(SIGINT, int_exit);
286 	signal(SIGTERM, int_exit);
287 
288 	while (min_port <= max_port) {
289 		vip.dport = htons(min_port++);
290 		if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
291 					BPF_NOEXIST)) {
292 			perror("bpf_map_update_elem(&vip2tnl)");
293 			return 1;
294 		}
295 	}
296 
297 	if (bpf_set_link_xdp_fd(ifindex, prog_fd, xdp_flags) < 0) {
298 		printf("link set xdp fd failed\n");
299 		return 1;
300 	}
301 
302 	err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
303 	if (err) {
304 		printf("can't get prog info - %s\n", strerror(errno));
305 		return err;
306 	}
307 	prog_id = info.id;
308 
309 	poll_stats(kill_after_s);
310 
311 	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
312 
313 	return 0;
314 }
315