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