1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2017 Cavium, Inc.
3  */
4 #include <linux/bpf.h>
5 #include <linux/netlink.h>
6 #include <linux/rtnetlink.h>
7 #include <assert.h>
8 #include <errno.h>
9 #include <signal.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <sys/socket.h>
14 #include <unistd.h>
15 #include <bpf/bpf.h>
16 #include <arpa/inet.h>
17 #include <fcntl.h>
18 #include <poll.h>
19 #include <net/if.h>
20 #include <netdb.h>
21 #include <sys/ioctl.h>
22 #include <sys/syscall.h>
23 #include "bpf_util.h"
24 #include <bpf/libbpf.h>
25 #include <sys/resource.h>
26 #include <libgen.h>
27 
28 int sock, sock_arp, flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
29 static int total_ifindex;
30 static int *ifindex_list;
31 static __u32 *prog_id_list;
32 char buf[8192];
33 static int lpm_map_fd;
34 static int rxcnt_map_fd;
35 static int arp_table_map_fd;
36 static int exact_match_map_fd;
37 static int tx_port_map_fd;
38 
39 static int get_route_table(int rtm_family);
40 static void int_exit(int sig)
41 {
42 	__u32 prog_id = 0;
43 	int i = 0;
44 
45 	for (i = 0; i < total_ifindex; i++) {
46 		if (bpf_get_link_xdp_id(ifindex_list[i], &prog_id, flags)) {
47 			printf("bpf_get_link_xdp_id on iface %d failed\n",
48 			       ifindex_list[i]);
49 			exit(1);
50 		}
51 		if (prog_id_list[i] == prog_id)
52 			bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
53 		else if (!prog_id)
54 			printf("couldn't find a prog id on iface %d\n",
55 			       ifindex_list[i]);
56 		else
57 			printf("program on iface %d changed, not removing\n",
58 			       ifindex_list[i]);
59 		prog_id = 0;
60 	}
61 	exit(0);
62 }
63 
64 static void close_and_exit(int sig)
65 {
66 	close(sock);
67 	close(sock_arp);
68 
69 	int_exit(0);
70 }
71 
72 /* Get the mac address of the interface given interface name */
73 static __be64 getmac(char *iface)
74 {
75 	struct ifreq ifr;
76 	__be64 mac = 0;
77 	int fd, i;
78 
79 	fd = socket(AF_INET, SOCK_DGRAM, 0);
80 	ifr.ifr_addr.sa_family = AF_INET;
81 	strncpy(ifr.ifr_name, iface, IFNAMSIZ - 1);
82 	if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
83 		printf("ioctl failed leaving....\n");
84 		return -1;
85 	}
86 	for (i = 0; i < 6 ; i++)
87 		*((__u8 *)&mac + i) = (__u8)ifr.ifr_hwaddr.sa_data[i];
88 	close(fd);
89 	return mac;
90 }
91 
92 static int recv_msg(struct sockaddr_nl sock_addr, int sock)
93 {
94 	struct nlmsghdr *nh;
95 	int len, nll = 0;
96 	char *buf_ptr;
97 
98 	buf_ptr = buf;
99 	while (1) {
100 		len = recv(sock, buf_ptr, sizeof(buf) - nll, 0);
101 		if (len < 0)
102 			return len;
103 
104 		nh = (struct nlmsghdr *)buf_ptr;
105 
106 		if (nh->nlmsg_type == NLMSG_DONE)
107 			break;
108 		buf_ptr += len;
109 		nll += len;
110 		if ((sock_addr.nl_groups & RTMGRP_NEIGH) == RTMGRP_NEIGH)
111 			break;
112 
113 		if ((sock_addr.nl_groups & RTMGRP_IPV4_ROUTE) == RTMGRP_IPV4_ROUTE)
114 			break;
115 	}
116 	return nll;
117 }
118 
119 /* Function to parse the route entry returned by netlink
120  * Updates the route entry related map entries
121  */
122 static void read_route(struct nlmsghdr *nh, int nll)
123 {
124 	char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
125 	struct bpf_lpm_trie_key *prefix_key;
126 	struct rtattr *rt_attr;
127 	struct rtmsg *rt_msg;
128 	int rtm_family;
129 	int rtl;
130 	int i;
131 	struct route_table {
132 		int  dst_len, iface, metric;
133 		char *iface_name;
134 		__be32 dst, gw;
135 		__be64 mac;
136 	} route;
137 	struct arp_table {
138 		__be64 mac;
139 		__be32 dst;
140 	};
141 
142 	struct direct_map {
143 		struct arp_table arp;
144 		int ifindex;
145 		__be64 mac;
146 	} direct_entry;
147 
148 	if (nh->nlmsg_type == RTM_DELROUTE)
149 		printf("DELETING Route entry\n");
150 	else if (nh->nlmsg_type == RTM_GETROUTE)
151 		printf("READING Route entry\n");
152 	else if (nh->nlmsg_type == RTM_NEWROUTE)
153 		printf("NEW Route entry\n");
154 	else
155 		printf("%d\n", nh->nlmsg_type);
156 
157 	memset(&route, 0, sizeof(route));
158 	printf("Destination     Gateway         Genmask         Metric Iface\n");
159 	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
160 		rt_msg = (struct rtmsg *)NLMSG_DATA(nh);
161 		rtm_family = rt_msg->rtm_family;
162 		if (rtm_family == AF_INET)
163 			if (rt_msg->rtm_table != RT_TABLE_MAIN)
164 				continue;
165 		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
166 		rtl = RTM_PAYLOAD(nh);
167 
168 		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
169 			switch (rt_attr->rta_type) {
170 			case NDA_DST:
171 				sprintf(dsts, "%u",
172 					(*((__be32 *)RTA_DATA(rt_attr))));
173 				break;
174 			case RTA_GATEWAY:
175 				sprintf(gws, "%u",
176 					*((__be32 *)RTA_DATA(rt_attr)));
177 				break;
178 			case RTA_OIF:
179 				sprintf(ifs, "%u",
180 					*((int *)RTA_DATA(rt_attr)));
181 				break;
182 			case RTA_METRICS:
183 				sprintf(metrics, "%u",
184 					*((int *)RTA_DATA(rt_attr)));
185 			default:
186 				break;
187 			}
188 		}
189 		sprintf(dsts_len, "%d", rt_msg->rtm_dst_len);
190 		route.dst = atoi(dsts);
191 		route.dst_len = atoi(dsts_len);
192 		route.gw = atoi(gws);
193 		route.iface = atoi(ifs);
194 		route.metric = atoi(metrics);
195 		route.iface_name = alloca(sizeof(char *) * IFNAMSIZ);
196 		route.iface_name = if_indextoname(route.iface, route.iface_name);
197 		route.mac = getmac(route.iface_name);
198 		if (route.mac == -1)
199 			int_exit(0);
200 		assert(bpf_map_update_elem(tx_port_map_fd,
201 					   &route.iface, &route.iface, 0) == 0);
202 		if (rtm_family == AF_INET) {
203 			struct trie_value {
204 				__u8 prefix[4];
205 				__be64 value;
206 				int ifindex;
207 				int metric;
208 				__be32 gw;
209 			} *prefix_value;
210 			struct in_addr dst_addr, gw_addr, mask_addr;
211 
212 			prefix_key = alloca(sizeof(*prefix_key) + 3);
213 			prefix_value = alloca(sizeof(*prefix_value));
214 
215 			prefix_key->prefixlen = 32;
216 			prefix_key->prefixlen = route.dst_len;
217 			direct_entry.mac = route.mac & 0xffffffffffff;
218 			direct_entry.ifindex = route.iface;
219 			direct_entry.arp.mac = 0;
220 			direct_entry.arp.dst = 0;
221 			if (route.dst_len == 32) {
222 				if (nh->nlmsg_type == RTM_DELROUTE) {
223 					assert(bpf_map_delete_elem(exact_match_map_fd,
224 								   &route.dst) == 0);
225 				} else {
226 					if (bpf_map_lookup_elem(arp_table_map_fd,
227 								&route.dst,
228 								&direct_entry.arp.mac) == 0)
229 						direct_entry.arp.dst = route.dst;
230 					assert(bpf_map_update_elem(exact_match_map_fd,
231 								   &route.dst,
232 								   &direct_entry, 0) == 0);
233 				}
234 			}
235 			for (i = 0; i < 4; i++)
236 				prefix_key->data[i] = (route.dst >> i * 8) & 0xff;
237 
238 			dst_addr.s_addr = route.dst;
239 			printf("%-16s", inet_ntoa(dst_addr));
240 
241 			gw_addr.s_addr = route.gw;
242 			printf("%-16s", inet_ntoa(gw_addr));
243 
244 			mask_addr.s_addr = htonl(~(0xffffffffU >> route.dst_len));
245 			printf("%-16s%-7d%s\n", inet_ntoa(mask_addr),
246 			       route.metric,
247 			       route.iface_name);
248 
249 			if (bpf_map_lookup_elem(lpm_map_fd, prefix_key,
250 						prefix_value) < 0) {
251 				for (i = 0; i < 4; i++)
252 					prefix_value->prefix[i] = prefix_key->data[i];
253 				prefix_value->value = route.mac & 0xffffffffffff;
254 				prefix_value->ifindex = route.iface;
255 				prefix_value->gw = route.gw;
256 				prefix_value->metric = route.metric;
257 
258 				assert(bpf_map_update_elem(lpm_map_fd,
259 							   prefix_key,
260 							   prefix_value, 0
261 							   ) == 0);
262 			} else {
263 				if (nh->nlmsg_type == RTM_DELROUTE) {
264 					printf("deleting entry\n");
265 					printf("prefix key=%d.%d.%d.%d/%d",
266 					       prefix_key->data[0],
267 					       prefix_key->data[1],
268 					       prefix_key->data[2],
269 					       prefix_key->data[3],
270 					       prefix_key->prefixlen);
271 					assert(bpf_map_delete_elem(lpm_map_fd,
272 								   prefix_key
273 								   ) == 0);
274 					/* Rereading the route table to check if
275 					 * there is an entry with the same
276 					 * prefix but a different metric as the
277 					 * deleted enty.
278 					 */
279 					get_route_table(AF_INET);
280 				} else if (prefix_key->data[0] ==
281 					   prefix_value->prefix[0] &&
282 					   prefix_key->data[1] ==
283 					   prefix_value->prefix[1] &&
284 					   prefix_key->data[2] ==
285 					   prefix_value->prefix[2] &&
286 					   prefix_key->data[3] ==
287 					   prefix_value->prefix[3] &&
288 					   route.metric >= prefix_value->metric) {
289 					continue;
290 				} else {
291 					for (i = 0; i < 4; i++)
292 						prefix_value->prefix[i] =
293 							prefix_key->data[i];
294 					prefix_value->value =
295 						route.mac & 0xffffffffffff;
296 					prefix_value->ifindex = route.iface;
297 					prefix_value->gw = route.gw;
298 					prefix_value->metric = route.metric;
299 					assert(bpf_map_update_elem(lpm_map_fd,
300 								   prefix_key,
301 								   prefix_value,
302 								   0) == 0);
303 				}
304 			}
305 		}
306 		memset(&route, 0, sizeof(route));
307 		memset(dsts, 0, sizeof(dsts));
308 		memset(dsts_len, 0, sizeof(dsts_len));
309 		memset(gws, 0, sizeof(gws));
310 		memset(ifs, 0, sizeof(ifs));
311 		memset(&route, 0, sizeof(route));
312 	}
313 }
314 
315 /* Function to read the existing route table  when the process is launched*/
316 static int get_route_table(int rtm_family)
317 {
318 	struct sockaddr_nl sa;
319 	struct nlmsghdr *nh;
320 	int sock, seq = 0;
321 	struct msghdr msg;
322 	struct iovec iov;
323 	int ret = 0;
324 	int nll;
325 
326 	struct {
327 		struct nlmsghdr nl;
328 		struct rtmsg rt;
329 		char buf[8192];
330 	} req;
331 
332 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
333 	if (sock < 0) {
334 		printf("open netlink socket: %s\n", strerror(errno));
335 		return -1;
336 	}
337 	memset(&sa, 0, sizeof(sa));
338 	sa.nl_family = AF_NETLINK;
339 	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
340 		printf("bind to netlink: %s\n", strerror(errno));
341 		ret = -1;
342 		goto cleanup;
343 	}
344 	memset(&req, 0, sizeof(req));
345 	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
346 	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
347 	req.nl.nlmsg_type = RTM_GETROUTE;
348 
349 	req.rt.rtm_family = rtm_family;
350 	req.rt.rtm_table = RT_TABLE_MAIN;
351 	req.nl.nlmsg_pid = 0;
352 	req.nl.nlmsg_seq = ++seq;
353 	memset(&msg, 0, sizeof(msg));
354 	iov.iov_base = (void *)&req.nl;
355 	iov.iov_len = req.nl.nlmsg_len;
356 	msg.msg_iov = &iov;
357 	msg.msg_iovlen = 1;
358 	ret = sendmsg(sock, &msg, 0);
359 	if (ret < 0) {
360 		printf("send to netlink: %s\n", strerror(errno));
361 		ret = -1;
362 		goto cleanup;
363 	}
364 	memset(buf, 0, sizeof(buf));
365 	nll = recv_msg(sa, sock);
366 	if (nll < 0) {
367 		printf("recv from netlink: %s\n", strerror(nll));
368 		ret = -1;
369 		goto cleanup;
370 	}
371 	nh = (struct nlmsghdr *)buf;
372 	read_route(nh, nll);
373 cleanup:
374 	close(sock);
375 	return ret;
376 }
377 
378 /* Function to parse the arp entry returned by netlink
379  * Updates the arp entry related map entries
380  */
381 static void read_arp(struct nlmsghdr *nh, int nll)
382 {
383 	struct rtattr *rt_attr;
384 	char dsts[24], mac[24];
385 	struct ndmsg *rt_msg;
386 	int rtl, ndm_family;
387 
388 	struct arp_table {
389 		__be64 mac;
390 		__be32 dst;
391 	} arp_entry;
392 	struct direct_map {
393 		struct arp_table arp;
394 		int ifindex;
395 		__be64 mac;
396 	} direct_entry;
397 
398 	if (nh->nlmsg_type == RTM_GETNEIGH)
399 		printf("READING arp entry\n");
400 	printf("Address         HwAddress\n");
401 	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
402 		struct in_addr dst_addr;
403 		char mac_str[18];
404 		int len = 0, i;
405 
406 		rt_msg = (struct ndmsg *)NLMSG_DATA(nh);
407 		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
408 		ndm_family = rt_msg->ndm_family;
409 		rtl = RTM_PAYLOAD(nh);
410 		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
411 			switch (rt_attr->rta_type) {
412 			case NDA_DST:
413 				sprintf(dsts, "%u",
414 					*((__be32 *)RTA_DATA(rt_attr)));
415 				break;
416 			case NDA_LLADDR:
417 				sprintf(mac, "%lld",
418 					*((__be64 *)RTA_DATA(rt_attr)));
419 				break;
420 			default:
421 				break;
422 			}
423 		}
424 		arp_entry.dst = atoi(dsts);
425 		arp_entry.mac = atol(mac);
426 
427 		dst_addr.s_addr = arp_entry.dst;
428 		for (i = 0; i < 6; i++)
429 			len += snprintf(mac_str + len, 18 - len, "%02llx%s",
430 					((arp_entry.mac >> i * 8) & 0xff),
431 					i < 5 ? ":" : "");
432 		printf("%-16s%s\n", inet_ntoa(dst_addr), mac_str);
433 
434 		if (ndm_family == AF_INET) {
435 			if (bpf_map_lookup_elem(exact_match_map_fd,
436 						&arp_entry.dst,
437 						&direct_entry) == 0) {
438 				if (nh->nlmsg_type == RTM_DELNEIGH) {
439 					direct_entry.arp.dst = 0;
440 					direct_entry.arp.mac = 0;
441 				} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
442 					direct_entry.arp.dst = arp_entry.dst;
443 					direct_entry.arp.mac = arp_entry.mac;
444 				}
445 				assert(bpf_map_update_elem(exact_match_map_fd,
446 							   &arp_entry.dst,
447 							   &direct_entry, 0
448 							   ) == 0);
449 				memset(&direct_entry, 0, sizeof(direct_entry));
450 			}
451 			if (nh->nlmsg_type == RTM_DELNEIGH) {
452 				assert(bpf_map_delete_elem(arp_table_map_fd,
453 							   &arp_entry.dst) == 0);
454 			} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
455 				assert(bpf_map_update_elem(arp_table_map_fd,
456 							   &arp_entry.dst,
457 							   &arp_entry.mac, 0
458 							   ) == 0);
459 			}
460 		}
461 		memset(&arp_entry, 0, sizeof(arp_entry));
462 		memset(dsts, 0, sizeof(dsts));
463 	}
464 }
465 
466 /* Function to read the existing arp table  when the process is launched*/
467 static int get_arp_table(int rtm_family)
468 {
469 	struct sockaddr_nl sa;
470 	struct nlmsghdr *nh;
471 	int sock, seq = 0;
472 	struct msghdr msg;
473 	struct iovec iov;
474 	int ret = 0;
475 	int nll;
476 	struct {
477 		struct nlmsghdr nl;
478 		struct ndmsg rt;
479 		char buf[8192];
480 	} req;
481 
482 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
483 	if (sock < 0) {
484 		printf("open netlink socket: %s\n", strerror(errno));
485 		return -1;
486 	}
487 	memset(&sa, 0, sizeof(sa));
488 	sa.nl_family = AF_NETLINK;
489 	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
490 		printf("bind to netlink: %s\n", strerror(errno));
491 		ret = -1;
492 		goto cleanup;
493 	}
494 	memset(&req, 0, sizeof(req));
495 	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
496 	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
497 	req.nl.nlmsg_type = RTM_GETNEIGH;
498 	req.rt.ndm_state = NUD_REACHABLE;
499 	req.rt.ndm_family = rtm_family;
500 	req.nl.nlmsg_pid = 0;
501 	req.nl.nlmsg_seq = ++seq;
502 	memset(&msg, 0, sizeof(msg));
503 	iov.iov_base = (void *)&req.nl;
504 	iov.iov_len = req.nl.nlmsg_len;
505 	msg.msg_iov = &iov;
506 	msg.msg_iovlen = 1;
507 	ret = sendmsg(sock, &msg, 0);
508 	if (ret < 0) {
509 		printf("send to netlink: %s\n", strerror(errno));
510 		ret = -1;
511 		goto cleanup;
512 	}
513 	memset(buf, 0, sizeof(buf));
514 	nll = recv_msg(sa, sock);
515 	if (nll < 0) {
516 		printf("recv from netlink: %s\n", strerror(nll));
517 		ret = -1;
518 		goto cleanup;
519 	}
520 	nh = (struct nlmsghdr *)buf;
521 	read_arp(nh, nll);
522 cleanup:
523 	close(sock);
524 	return ret;
525 }
526 
527 /* Function to keep track and update changes in route and arp table
528  * Give regular statistics of packets forwarded
529  */
530 static int monitor_route(void)
531 {
532 	unsigned int nr_cpus = bpf_num_possible_cpus();
533 	const unsigned int nr_keys = 256;
534 	struct pollfd fds_route, fds_arp;
535 	__u64 prev[nr_keys][nr_cpus];
536 	struct sockaddr_nl la, lr;
537 	__u64 values[nr_cpus];
538 	struct nlmsghdr *nh;
539 	int nll, ret = 0;
540 	int interval = 5;
541 	__u32 key;
542 	int i;
543 
544 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
545 	if (sock < 0) {
546 		printf("open netlink socket: %s\n", strerror(errno));
547 		return -1;
548 	}
549 
550 	fcntl(sock, F_SETFL, O_NONBLOCK);
551 	memset(&lr, 0, sizeof(lr));
552 	lr.nl_family = AF_NETLINK;
553 	lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY;
554 	if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) {
555 		printf("bind to netlink: %s\n", strerror(errno));
556 		ret = -1;
557 		goto cleanup;
558 	}
559 	fds_route.fd = sock;
560 	fds_route.events = POLL_IN;
561 
562 	sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
563 	if (sock_arp < 0) {
564 		printf("open netlink socket: %s\n", strerror(errno));
565 		return -1;
566 	}
567 
568 	fcntl(sock_arp, F_SETFL, O_NONBLOCK);
569 	memset(&la, 0, sizeof(la));
570 	la.nl_family = AF_NETLINK;
571 	la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY;
572 	if (bind(sock_arp, (struct sockaddr *)&la, sizeof(la)) < 0) {
573 		printf("bind to netlink: %s\n", strerror(errno));
574 		ret = -1;
575 		goto cleanup;
576 	}
577 	fds_arp.fd = sock_arp;
578 	fds_arp.events = POLL_IN;
579 
580 	memset(prev, 0, sizeof(prev));
581 	do {
582 		signal(SIGINT, close_and_exit);
583 		signal(SIGTERM, close_and_exit);
584 
585 		sleep(interval);
586 		for (key = 0; key < nr_keys; key++) {
587 			__u64 sum = 0;
588 
589 			assert(bpf_map_lookup_elem(rxcnt_map_fd,
590 						   &key, values) == 0);
591 			for (i = 0; i < nr_cpus; i++)
592 				sum += (values[i] - prev[key][i]);
593 			if (sum)
594 				printf("proto %u: %10llu pkt/s\n",
595 				       key, sum / interval);
596 			memcpy(prev[key], values, sizeof(values));
597 		}
598 
599 		memset(buf, 0, sizeof(buf));
600 		if (poll(&fds_route, 1, 3) == POLL_IN) {
601 			nll = recv_msg(lr, sock);
602 			if (nll < 0) {
603 				printf("recv from netlink: %s\n", strerror(nll));
604 				ret = -1;
605 				goto cleanup;
606 			}
607 
608 			nh = (struct nlmsghdr *)buf;
609 			printf("Routing table updated.\n");
610 			read_route(nh, nll);
611 		}
612 		memset(buf, 0, sizeof(buf));
613 		if (poll(&fds_arp, 1, 3) == POLL_IN) {
614 			nll = recv_msg(la, sock_arp);
615 			if (nll < 0) {
616 				printf("recv from netlink: %s\n", strerror(nll));
617 				ret = -1;
618 				goto cleanup;
619 			}
620 
621 			nh = (struct nlmsghdr *)buf;
622 			read_arp(nh, nll);
623 		}
624 
625 	} while (1);
626 cleanup:
627 	close(sock);
628 	return ret;
629 }
630 
631 static void usage(const char *prog)
632 {
633 	fprintf(stderr,
634 		"%s: %s [OPTS] interface name list\n\n"
635 		"OPTS:\n"
636 		"    -S    use skb-mode\n"
637 		"    -F    force loading prog\n",
638 		__func__, prog);
639 }
640 
641 int main(int ac, char **argv)
642 {
643 	struct bpf_prog_load_attr prog_load_attr = {
644 		.prog_type	= BPF_PROG_TYPE_XDP,
645 	};
646 	struct bpf_prog_info info = {};
647 	__u32 info_len = sizeof(info);
648 	const char *optstr = "SF";
649 	struct bpf_object *obj;
650 	char filename[256];
651 	char **ifname_list;
652 	int prog_fd, opt;
653 	int err, i = 1;
654 
655 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
656 	prog_load_attr.file = filename;
657 
658 	total_ifindex = ac - 1;
659 	ifname_list = (argv + 1);
660 
661 	while ((opt = getopt(ac, argv, optstr)) != -1) {
662 		switch (opt) {
663 		case 'S':
664 			flags |= XDP_FLAGS_SKB_MODE;
665 			total_ifindex--;
666 			ifname_list++;
667 			break;
668 		case 'F':
669 			flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
670 			total_ifindex--;
671 			ifname_list++;
672 			break;
673 		default:
674 			usage(basename(argv[0]));
675 			return 1;
676 		}
677 	}
678 
679 	if (!(flags & XDP_FLAGS_SKB_MODE))
680 		flags |= XDP_FLAGS_DRV_MODE;
681 
682 	if (optind == ac) {
683 		usage(basename(argv[0]));
684 		return 1;
685 	}
686 
687 	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
688 		return 1;
689 
690 	printf("\n******************loading bpf file*********************\n");
691 	if (!prog_fd) {
692 		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
693 		return 1;
694 	}
695 
696 	lpm_map_fd = bpf_object__find_map_fd_by_name(obj, "lpm_map");
697 	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
698 	arp_table_map_fd = bpf_object__find_map_fd_by_name(obj, "arp_table");
699 	exact_match_map_fd = bpf_object__find_map_fd_by_name(obj,
700 							     "exact_match");
701 	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
702 	if (lpm_map_fd < 0 || rxcnt_map_fd < 0 || arp_table_map_fd < 0 ||
703 	    exact_match_map_fd < 0 || tx_port_map_fd < 0) {
704 		printf("bpf_object__find_map_fd_by_name failed\n");
705 		return 1;
706 	}
707 
708 	ifindex_list = (int *)calloc(total_ifindex, sizeof(int *));
709 	for (i = 0; i < total_ifindex; i++) {
710 		ifindex_list[i] = if_nametoindex(ifname_list[i]);
711 		if (!ifindex_list[i]) {
712 			printf("Couldn't translate interface name: %s",
713 			       strerror(errno));
714 			return 1;
715 		}
716 	}
717 	prog_id_list = (__u32 *)calloc(total_ifindex, sizeof(__u32 *));
718 	for (i = 0; i < total_ifindex; i++) {
719 		if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd, flags) < 0) {
720 			printf("link set xdp fd failed\n");
721 			int recovery_index = i;
722 
723 			for (i = 0; i < recovery_index; i++)
724 				bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
725 
726 			return 1;
727 		}
728 		err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
729 		if (err) {
730 			printf("can't get prog info - %s\n", strerror(errno));
731 			return err;
732 		}
733 		prog_id_list[i] = info.id;
734 		memset(&info, 0, sizeof(info));
735 		printf("Attached to %d\n", ifindex_list[i]);
736 	}
737 	signal(SIGINT, int_exit);
738 	signal(SIGTERM, int_exit);
739 
740 	printf("\n*******************ROUTE TABLE*************************\n");
741 	get_route_table(AF_INET);
742 	printf("\n*******************ARP TABLE***************************\n");
743 	get_arp_table(AF_INET);
744 	if (monitor_route() < 0) {
745 		printf("Error in receiving route update");
746 		return 1;
747 	}
748 
749 	return 0;
750 }
751