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
 25static int ifindex = -1;
 26static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 27static int rxcnt_map_fd;
 28static __u32 prog_id;
 29
 30static 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 */
 51static 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
 81static 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
101static 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
114static 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
153int 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}