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
24static int ifindex = -1;
25static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
26static int rxcnt_map_fd;
27static __u32 prog_id;
28
29static 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 */
50static 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
80static 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
100static 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
113static 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
152int 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