1 /* Copyright (c) 2016 Facebook
2  *
3  * This program is free software; you can redistribute it and/or
4  * modify it under the terms of version 2 of the GNU General Public
5  * License as published by the Free Software Foundation.
6  */
7 #include <linux/bpf.h>
8 #include <linux/if_link.h>
9 #include <assert.h>
10 #include <errno.h>
11 #include <signal.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <sys/resource.h>
16 #include <arpa/inet.h>
17 #include <netinet/ether.h>
18 #include <unistd.h>
19 #include <time.h>
20 #include "bpf_load.h"
21 #include <bpf/bpf.h>
22 #include "bpf_util.h"
23 #include "xdp_tx_iptunnel_common.h"
24 
25 #define STATS_INTERVAL_S 2U
26 
27 static int ifindex = -1;
28 static __u32 xdp_flags = 0;
29 
30 static void int_exit(int sig)
31 {
32 	if (ifindex > -1)
33 		bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
34 	exit(0);
35 }
36 
37 /* simple per-protocol drop counter
38  */
39 static void poll_stats(unsigned int kill_after_s)
40 {
41 	const unsigned int nr_protos = 256;
42 	unsigned int nr_cpus = bpf_num_possible_cpus();
43 	time_t started_at = time(NULL);
44 	__u64 values[nr_cpus], prev[nr_protos][nr_cpus];
45 	__u32 proto;
46 	int i;
47 
48 	memset(prev, 0, sizeof(prev));
49 
50 	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
51 		sleep(STATS_INTERVAL_S);
52 
53 		for (proto = 0; proto < nr_protos; proto++) {
54 			__u64 sum = 0;
55 
56 			assert(bpf_map_lookup_elem(map_fd[0], &proto, values) == 0);
57 			for (i = 0; i < nr_cpus; i++)
58 				sum += (values[i] - prev[proto][i]);
59 
60 			if (sum)
61 				printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
62 				       proto, sum, sum / STATS_INTERVAL_S);
63 			memcpy(prev[proto], values, sizeof(values));
64 		}
65 	}
66 }
67 
68 static void usage(const char *cmd)
69 {
70 	printf("Start a XDP prog which encapsulates incoming packets\n"
71 	       "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
72 	       "is used to select packets to encapsulate\n\n");
73 	printf("Usage: %s [...]\n", cmd);
74 	printf("    -i <ifindex> Interface Index\n");
75 	printf("    -a <vip-service-address> IPv4 or IPv6\n");
76 	printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
77 	printf("    -s <source-ip> Used in the IPTunnel header\n");
78 	printf("    -d <dest-ip> Used in the IPTunnel header\n");
79 	printf("    -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
80 	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
81 	printf("    -P <IP-Protocol> Default is TCP\n");
82 	printf("    -S use skb-mode\n");
83 	printf("    -N enforce native mode\n");
84 	printf("    -h Display this help\n");
85 }
86 
87 static int parse_ipstr(const char *ipstr, unsigned int *addr)
88 {
89 	if (inet_pton(AF_INET6, ipstr, addr) == 1) {
90 		return AF_INET6;
91 	} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
92 		addr[1] = addr[2] = addr[3] = 0;
93 		return AF_INET;
94 	}
95 
96 	fprintf(stderr, "%s is an invalid IP\n", ipstr);
97 	return AF_UNSPEC;
98 }
99 
100 static int parse_ports(const char *port_str, int *min_port, int *max_port)
101 {
102 	char *end;
103 	long tmp_min_port;
104 	long tmp_max_port;
105 
106 	tmp_min_port = strtol(optarg, &end, 10);
107 	if (tmp_min_port < 1 || tmp_min_port > 65535) {
108 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
109 		return 1;
110 	}
111 
112 	if (*end == '-') {
113 		end++;
114 		tmp_max_port = strtol(end, NULL, 10);
115 		if (tmp_max_port < 1 || tmp_max_port > 65535) {
116 			fprintf(stderr, "Invalid port(s):%s\n", optarg);
117 			return 1;
118 		}
119 	} else {
120 		tmp_max_port = tmp_min_port;
121 	}
122 
123 	if (tmp_min_port > tmp_max_port) {
124 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
125 		return 1;
126 	}
127 
128 	if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
129 		fprintf(stderr, "Port range (%s) is larger than %u\n",
130 			port_str, MAX_IPTNL_ENTRIES);
131 		return 1;
132 	}
133 	*min_port = tmp_min_port;
134 	*max_port = tmp_max_port;
135 
136 	return 0;
137 }
138 
139 int main(int argc, char **argv)
140 {
141 	unsigned char opt_flags[256] = {};
142 	unsigned int kill_after_s = 0;
143 	const char *optstr = "i:a:p:s:d:m:T:P:SNh";
144 	int min_port = 0, max_port = 0;
145 	struct iptnl_info tnl = {};
146 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
147 	struct vip vip = {};
148 	char filename[256];
149 	int opt;
150 	int i;
151 
152 	tnl.family = AF_UNSPEC;
153 	vip.protocol = IPPROTO_TCP;
154 
155 	for (i = 0; i < strlen(optstr); i++)
156 		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
157 			opt_flags[(unsigned char)optstr[i]] = 1;
158 
159 	while ((opt = getopt(argc, argv, optstr)) != -1) {
160 		unsigned short family;
161 		unsigned int *v6;
162 
163 		switch (opt) {
164 		case 'i':
165 			ifindex = atoi(optarg);
166 			break;
167 		case 'a':
168 			vip.family = parse_ipstr(optarg, vip.daddr.v6);
169 			if (vip.family == AF_UNSPEC)
170 				return 1;
171 			break;
172 		case 'p':
173 			if (parse_ports(optarg, &min_port, &max_port))
174 				return 1;
175 			break;
176 		case 'P':
177 			vip.protocol = atoi(optarg);
178 			break;
179 		case 's':
180 		case 'd':
181 			if (opt == 's')
182 				v6 = tnl.saddr.v6;
183 			else
184 				v6 = tnl.daddr.v6;
185 
186 			family = parse_ipstr(optarg, v6);
187 			if (family == AF_UNSPEC)
188 				return 1;
189 			if (tnl.family == AF_UNSPEC) {
190 				tnl.family = family;
191 			} else if (tnl.family != family) {
192 				fprintf(stderr,
193 					"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
194 				return 1;
195 			}
196 			break;
197 		case 'm':
198 			if (!ether_aton_r(optarg,
199 					  (struct ether_addr *)tnl.dmac)) {
200 				fprintf(stderr, "Invalid mac address:%s\n",
201 					optarg);
202 				return 1;
203 			}
204 			break;
205 		case 'T':
206 			kill_after_s = atoi(optarg);
207 			break;
208 		case 'S':
209 			xdp_flags |= XDP_FLAGS_SKB_MODE;
210 			break;
211 		case 'N':
212 			xdp_flags |= XDP_FLAGS_DRV_MODE;
213 			break;
214 		default:
215 			usage(argv[0]);
216 			return 1;
217 		}
218 		opt_flags[opt] = 0;
219 	}
220 
221 	for (i = 0; i < strlen(optstr); i++) {
222 		if (opt_flags[(unsigned int)optstr[i]]) {
223 			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
224 			usage(argv[0]);
225 			return 1;
226 		}
227 	}
228 
229 	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
230 		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
231 		return 1;
232 	}
233 
234 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
235 
236 	if (load_bpf_file(filename)) {
237 		printf("%s", bpf_log_buf);
238 		return 1;
239 	}
240 
241 	if (!prog_fd[0]) {
242 		printf("load_bpf_file: %s\n", strerror(errno));
243 		return 1;
244 	}
245 
246 	signal(SIGINT, int_exit);
247 	signal(SIGTERM, int_exit);
248 
249 	while (min_port <= max_port) {
250 		vip.dport = htons(min_port++);
251 		if (bpf_map_update_elem(map_fd[1], &vip, &tnl, BPF_NOEXIST)) {
252 			perror("bpf_map_update_elem(&vip2tnl)");
253 			return 1;
254 		}
255 	}
256 
257 	if (bpf_set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
258 		printf("link set xdp fd failed\n");
259 		return 1;
260 	}
261 
262 	poll_stats(kill_after_s);
263 
264 	bpf_set_link_xdp_fd(ifindex, -1, xdp_flags);
265 
266 	return 0;
267 }
268