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 "libbpf.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 		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("    -h Display this help\n");
83 }
84 
85 static int parse_ipstr(const char *ipstr, unsigned int *addr)
86 {
87 	if (inet_pton(AF_INET6, ipstr, addr) == 1) {
88 		return AF_INET6;
89 	} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
90 		addr[1] = addr[2] = addr[3] = 0;
91 		return AF_INET;
92 	}
93 
94 	fprintf(stderr, "%s is an invalid IP\n", ipstr);
95 	return AF_UNSPEC;
96 }
97 
98 static int parse_ports(const char *port_str, int *min_port, int *max_port)
99 {
100 	char *end;
101 	long tmp_min_port;
102 	long tmp_max_port;
103 
104 	tmp_min_port = strtol(optarg, &end, 10);
105 	if (tmp_min_port < 1 || tmp_min_port > 65535) {
106 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
107 		return 1;
108 	}
109 
110 	if (*end == '-') {
111 		end++;
112 		tmp_max_port = strtol(end, NULL, 10);
113 		if (tmp_max_port < 1 || tmp_max_port > 65535) {
114 			fprintf(stderr, "Invalid port(s):%s\n", optarg);
115 			return 1;
116 		}
117 	} else {
118 		tmp_max_port = tmp_min_port;
119 	}
120 
121 	if (tmp_min_port > tmp_max_port) {
122 		fprintf(stderr, "Invalid port(s):%s\n", optarg);
123 		return 1;
124 	}
125 
126 	if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
127 		fprintf(stderr, "Port range (%s) is larger than %u\n",
128 			port_str, MAX_IPTNL_ENTRIES);
129 		return 1;
130 	}
131 	*min_port = tmp_min_port;
132 	*max_port = tmp_max_port;
133 
134 	return 0;
135 }
136 
137 int main(int argc, char **argv)
138 {
139 	unsigned char opt_flags[256] = {};
140 	unsigned int kill_after_s = 0;
141 	const char *optstr = "i:a:p:s:d:m:T:P:Sh";
142 	int min_port = 0, max_port = 0;
143 	struct iptnl_info tnl = {};
144 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
145 	struct vip vip = {};
146 	char filename[256];
147 	int opt;
148 	int i;
149 
150 	tnl.family = AF_UNSPEC;
151 	vip.protocol = IPPROTO_TCP;
152 
153 	for (i = 0; i < strlen(optstr); i++)
154 		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
155 			opt_flags[(unsigned char)optstr[i]] = 1;
156 
157 	while ((opt = getopt(argc, argv, optstr)) != -1) {
158 		unsigned short family;
159 		unsigned int *v6;
160 
161 		switch (opt) {
162 		case 'i':
163 			ifindex = atoi(optarg);
164 			break;
165 		case 'a':
166 			vip.family = parse_ipstr(optarg, vip.daddr.v6);
167 			if (vip.family == AF_UNSPEC)
168 				return 1;
169 			break;
170 		case 'p':
171 			if (parse_ports(optarg, &min_port, &max_port))
172 				return 1;
173 			break;
174 		case 'P':
175 			vip.protocol = atoi(optarg);
176 			break;
177 		case 's':
178 		case 'd':
179 			if (opt == 's')
180 				v6 = tnl.saddr.v6;
181 			else
182 				v6 = tnl.daddr.v6;
183 
184 			family = parse_ipstr(optarg, v6);
185 			if (family == AF_UNSPEC)
186 				return 1;
187 			if (tnl.family == AF_UNSPEC) {
188 				tnl.family = family;
189 			} else if (tnl.family != family) {
190 				fprintf(stderr,
191 					"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
192 				return 1;
193 			}
194 			break;
195 		case 'm':
196 			if (!ether_aton_r(optarg,
197 					  (struct ether_addr *)tnl.dmac)) {
198 				fprintf(stderr, "Invalid mac address:%s\n",
199 					optarg);
200 				return 1;
201 			}
202 			break;
203 		case 'T':
204 			kill_after_s = atoi(optarg);
205 			break;
206 		case 'S':
207 			xdp_flags |= XDP_FLAGS_SKB_MODE;
208 			break;
209 		default:
210 			usage(argv[0]);
211 			return 1;
212 		}
213 		opt_flags[opt] = 0;
214 	}
215 
216 	for (i = 0; i < strlen(optstr); i++) {
217 		if (opt_flags[(unsigned int)optstr[i]]) {
218 			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
219 			usage(argv[0]);
220 			return 1;
221 		}
222 	}
223 
224 	if (setrlimit(RLIMIT_MEMLOCK, &r)) {
225 		perror("setrlimit(RLIMIT_MEMLOCK, RLIM_INFINITY)");
226 		return 1;
227 	}
228 
229 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
230 
231 	if (load_bpf_file(filename)) {
232 		printf("%s", bpf_log_buf);
233 		return 1;
234 	}
235 
236 	if (!prog_fd[0]) {
237 		printf("load_bpf_file: %s\n", strerror(errno));
238 		return 1;
239 	}
240 
241 	signal(SIGINT, int_exit);
242 
243 	while (min_port <= max_port) {
244 		vip.dport = htons(min_port++);
245 		if (bpf_map_update_elem(map_fd[1], &vip, &tnl, BPF_NOEXIST)) {
246 			perror("bpf_map_update_elem(&vip2tnl)");
247 			return 1;
248 		}
249 	}
250 
251 	if (set_link_xdp_fd(ifindex, prog_fd[0], xdp_flags) < 0) {
252 		printf("link set xdp fd failed\n");
253 		return 1;
254 	}
255 
256 	poll_stats(kill_after_s);
257 
258 	set_link_xdp_fd(ifindex, -1, xdp_flags);
259 
260 	return 0;
261 }
262