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\t\tGateway\t\tGenmask\t\tMetric\t\tIface\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 
211 			prefix_key = alloca(sizeof(*prefix_key) + 3);
212 			prefix_value = alloca(sizeof(*prefix_value));
213 
214 			prefix_key->prefixlen = 32;
215 			prefix_key->prefixlen = route.dst_len;
216 			direct_entry.mac = route.mac & 0xffffffffffff;
217 			direct_entry.ifindex = route.iface;
218 			direct_entry.arp.mac = 0;
219 			direct_entry.arp.dst = 0;
220 			if (route.dst_len == 32) {
221 				if (nh->nlmsg_type == RTM_DELROUTE) {
222 					assert(bpf_map_delete_elem(exact_match_map_fd,
223 								   &route.dst) == 0);
224 				} else {
225 					if (bpf_map_lookup_elem(arp_table_map_fd,
226 								&route.dst,
227 								&direct_entry.arp.mac) == 0)
228 						direct_entry.arp.dst = route.dst;
229 					assert(bpf_map_update_elem(exact_match_map_fd,
230 								   &route.dst,
231 								   &direct_entry, 0) == 0);
232 				}
233 			}
234 			for (i = 0; i < 4; i++)
235 				prefix_key->data[i] = (route.dst >> i * 8) & 0xff;
236 
237 			printf("%3d.%d.%d.%d\t\t%3x\t\t%d\t\t%d\t\t%s\n",
238 			       (int)prefix_key->data[0],
239 			       (int)prefix_key->data[1],
240 			       (int)prefix_key->data[2],
241 			       (int)prefix_key->data[3],
242 			       route.gw, route.dst_len,
243 			       route.metric,
244 			       route.iface_name);
245 			if (bpf_map_lookup_elem(lpm_map_fd, prefix_key,
246 						prefix_value) < 0) {
247 				for (i = 0; i < 4; i++)
248 					prefix_value->prefix[i] = prefix_key->data[i];
249 				prefix_value->value = route.mac & 0xffffffffffff;
250 				prefix_value->ifindex = route.iface;
251 				prefix_value->gw = route.gw;
252 				prefix_value->metric = route.metric;
253 
254 				assert(bpf_map_update_elem(lpm_map_fd,
255 							   prefix_key,
256 							   prefix_value, 0
257 							   ) == 0);
258 			} else {
259 				if (nh->nlmsg_type == RTM_DELROUTE) {
260 					printf("deleting entry\n");
261 					printf("prefix key=%d.%d.%d.%d/%d",
262 					       prefix_key->data[0],
263 					       prefix_key->data[1],
264 					       prefix_key->data[2],
265 					       prefix_key->data[3],
266 					       prefix_key->prefixlen);
267 					assert(bpf_map_delete_elem(lpm_map_fd,
268 								   prefix_key
269 								   ) == 0);
270 					/* Rereading the route table to check if
271 					 * there is an entry with the same
272 					 * prefix but a different metric as the
273 					 * deleted enty.
274 					 */
275 					get_route_table(AF_INET);
276 				} else if (prefix_key->data[0] ==
277 					   prefix_value->prefix[0] &&
278 					   prefix_key->data[1] ==
279 					   prefix_value->prefix[1] &&
280 					   prefix_key->data[2] ==
281 					   prefix_value->prefix[2] &&
282 					   prefix_key->data[3] ==
283 					   prefix_value->prefix[3] &&
284 					   route.metric >= prefix_value->metric) {
285 					continue;
286 				} else {
287 					for (i = 0; i < 4; i++)
288 						prefix_value->prefix[i] =
289 							prefix_key->data[i];
290 					prefix_value->value =
291 						route.mac & 0xffffffffffff;
292 					prefix_value->ifindex = route.iface;
293 					prefix_value->gw = route.gw;
294 					prefix_value->metric = route.metric;
295 					assert(bpf_map_update_elem(lpm_map_fd,
296 								   prefix_key,
297 								   prefix_value,
298 								   0) == 0);
299 				}
300 			}
301 		}
302 		memset(&route, 0, sizeof(route));
303 		memset(dsts, 0, sizeof(dsts));
304 		memset(dsts_len, 0, sizeof(dsts_len));
305 		memset(gws, 0, sizeof(gws));
306 		memset(ifs, 0, sizeof(ifs));
307 		memset(&route, 0, sizeof(route));
308 	}
309 }
310 
311 /* Function to read the existing route table  when the process is launched*/
312 static int get_route_table(int rtm_family)
313 {
314 	struct sockaddr_nl sa;
315 	struct nlmsghdr *nh;
316 	int sock, seq = 0;
317 	struct msghdr msg;
318 	struct iovec iov;
319 	int ret = 0;
320 	int nll;
321 
322 	struct {
323 		struct nlmsghdr nl;
324 		struct rtmsg rt;
325 		char buf[8192];
326 	} req;
327 
328 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
329 	if (sock < 0) {
330 		printf("open netlink socket: %s\n", strerror(errno));
331 		return -1;
332 	}
333 	memset(&sa, 0, sizeof(sa));
334 	sa.nl_family = AF_NETLINK;
335 	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
336 		printf("bind to netlink: %s\n", strerror(errno));
337 		ret = -1;
338 		goto cleanup;
339 	}
340 	memset(&req, 0, sizeof(req));
341 	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
342 	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
343 	req.nl.nlmsg_type = RTM_GETROUTE;
344 
345 	req.rt.rtm_family = rtm_family;
346 	req.rt.rtm_table = RT_TABLE_MAIN;
347 	req.nl.nlmsg_pid = 0;
348 	req.nl.nlmsg_seq = ++seq;
349 	memset(&msg, 0, sizeof(msg));
350 	iov.iov_base = (void *)&req.nl;
351 	iov.iov_len = req.nl.nlmsg_len;
352 	msg.msg_iov = &iov;
353 	msg.msg_iovlen = 1;
354 	ret = sendmsg(sock, &msg, 0);
355 	if (ret < 0) {
356 		printf("send to netlink: %s\n", strerror(errno));
357 		ret = -1;
358 		goto cleanup;
359 	}
360 	memset(buf, 0, sizeof(buf));
361 	nll = recv_msg(sa, sock);
362 	if (nll < 0) {
363 		printf("recv from netlink: %s\n", strerror(nll));
364 		ret = -1;
365 		goto cleanup;
366 	}
367 	nh = (struct nlmsghdr *)buf;
368 	read_route(nh, nll);
369 cleanup:
370 	close(sock);
371 	return ret;
372 }
373 
374 /* Function to parse the arp entry returned by netlink
375  * Updates the arp entry related map entries
376  */
377 static void read_arp(struct nlmsghdr *nh, int nll)
378 {
379 	struct rtattr *rt_attr;
380 	char dsts[24], mac[24];
381 	struct ndmsg *rt_msg;
382 	int rtl, ndm_family;
383 
384 	struct arp_table {
385 		__be64 mac;
386 		__be32 dst;
387 	} arp_entry;
388 	struct direct_map {
389 		struct arp_table arp;
390 		int ifindex;
391 		__be64 mac;
392 	} direct_entry;
393 
394 	if (nh->nlmsg_type == RTM_GETNEIGH)
395 		printf("READING arp entry\n");
396 	printf("Address\tHwAddress\n");
397 	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
398 		rt_msg = (struct ndmsg *)NLMSG_DATA(nh);
399 		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
400 		ndm_family = rt_msg->ndm_family;
401 		rtl = RTM_PAYLOAD(nh);
402 		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
403 			switch (rt_attr->rta_type) {
404 			case NDA_DST:
405 				sprintf(dsts, "%u",
406 					*((__be32 *)RTA_DATA(rt_attr)));
407 				break;
408 			case NDA_LLADDR:
409 				sprintf(mac, "%lld",
410 					*((__be64 *)RTA_DATA(rt_attr)));
411 				break;
412 			default:
413 				break;
414 			}
415 		}
416 		arp_entry.dst = atoi(dsts);
417 		arp_entry.mac = atol(mac);
418 		printf("%x\t\t%llx\n", arp_entry.dst, arp_entry.mac);
419 		if (ndm_family == AF_INET) {
420 			if (bpf_map_lookup_elem(exact_match_map_fd,
421 						&arp_entry.dst,
422 						&direct_entry) == 0) {
423 				if (nh->nlmsg_type == RTM_DELNEIGH) {
424 					direct_entry.arp.dst = 0;
425 					direct_entry.arp.mac = 0;
426 				} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
427 					direct_entry.arp.dst = arp_entry.dst;
428 					direct_entry.arp.mac = arp_entry.mac;
429 				}
430 				assert(bpf_map_update_elem(exact_match_map_fd,
431 							   &arp_entry.dst,
432 							   &direct_entry, 0
433 							   ) == 0);
434 				memset(&direct_entry, 0, sizeof(direct_entry));
435 			}
436 			if (nh->nlmsg_type == RTM_DELNEIGH) {
437 				assert(bpf_map_delete_elem(arp_table_map_fd,
438 							   &arp_entry.dst) == 0);
439 			} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
440 				assert(bpf_map_update_elem(arp_table_map_fd,
441 							   &arp_entry.dst,
442 							   &arp_entry.mac, 0
443 							   ) == 0);
444 			}
445 		}
446 		memset(&arp_entry, 0, sizeof(arp_entry));
447 		memset(dsts, 0, sizeof(dsts));
448 	}
449 }
450 
451 /* Function to read the existing arp table  when the process is launched*/
452 static int get_arp_table(int rtm_family)
453 {
454 	struct sockaddr_nl sa;
455 	struct nlmsghdr *nh;
456 	int sock, seq = 0;
457 	struct msghdr msg;
458 	struct iovec iov;
459 	int ret = 0;
460 	int nll;
461 	struct {
462 		struct nlmsghdr nl;
463 		struct ndmsg rt;
464 		char buf[8192];
465 	} req;
466 
467 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
468 	if (sock < 0) {
469 		printf("open netlink socket: %s\n", strerror(errno));
470 		return -1;
471 	}
472 	memset(&sa, 0, sizeof(sa));
473 	sa.nl_family = AF_NETLINK;
474 	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
475 		printf("bind to netlink: %s\n", strerror(errno));
476 		ret = -1;
477 		goto cleanup;
478 	}
479 	memset(&req, 0, sizeof(req));
480 	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
481 	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
482 	req.nl.nlmsg_type = RTM_GETNEIGH;
483 	req.rt.ndm_state = NUD_REACHABLE;
484 	req.rt.ndm_family = rtm_family;
485 	req.nl.nlmsg_pid = 0;
486 	req.nl.nlmsg_seq = ++seq;
487 	memset(&msg, 0, sizeof(msg));
488 	iov.iov_base = (void *)&req.nl;
489 	iov.iov_len = req.nl.nlmsg_len;
490 	msg.msg_iov = &iov;
491 	msg.msg_iovlen = 1;
492 	ret = sendmsg(sock, &msg, 0);
493 	if (ret < 0) {
494 		printf("send to netlink: %s\n", strerror(errno));
495 		ret = -1;
496 		goto cleanup;
497 	}
498 	memset(buf, 0, sizeof(buf));
499 	nll = recv_msg(sa, sock);
500 	if (nll < 0) {
501 		printf("recv from netlink: %s\n", strerror(nll));
502 		ret = -1;
503 		goto cleanup;
504 	}
505 	nh = (struct nlmsghdr *)buf;
506 	read_arp(nh, nll);
507 cleanup:
508 	close(sock);
509 	return ret;
510 }
511 
512 /* Function to keep track and update changes in route and arp table
513  * Give regular statistics of packets forwarded
514  */
515 static int monitor_route(void)
516 {
517 	unsigned int nr_cpus = bpf_num_possible_cpus();
518 	const unsigned int nr_keys = 256;
519 	struct pollfd fds_route, fds_arp;
520 	__u64 prev[nr_keys][nr_cpus];
521 	struct sockaddr_nl la, lr;
522 	__u64 values[nr_cpus];
523 	struct nlmsghdr *nh;
524 	int nll, ret = 0;
525 	int interval = 5;
526 	__u32 key;
527 	int i;
528 
529 	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
530 	if (sock < 0) {
531 		printf("open netlink socket: %s\n", strerror(errno));
532 		return -1;
533 	}
534 
535 	fcntl(sock, F_SETFL, O_NONBLOCK);
536 	memset(&lr, 0, sizeof(lr));
537 	lr.nl_family = AF_NETLINK;
538 	lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY;
539 	if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) {
540 		printf("bind to netlink: %s\n", strerror(errno));
541 		ret = -1;
542 		goto cleanup;
543 	}
544 	fds_route.fd = sock;
545 	fds_route.events = POLL_IN;
546 
547 	sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
548 	if (sock_arp < 0) {
549 		printf("open netlink socket: %s\n", strerror(errno));
550 		return -1;
551 	}
552 
553 	fcntl(sock_arp, F_SETFL, O_NONBLOCK);
554 	memset(&la, 0, sizeof(la));
555 	la.nl_family = AF_NETLINK;
556 	la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY;
557 	if (bind(sock_arp, (struct sockaddr *)&la, sizeof(la)) < 0) {
558 		printf("bind to netlink: %s\n", strerror(errno));
559 		ret = -1;
560 		goto cleanup;
561 	}
562 	fds_arp.fd = sock_arp;
563 	fds_arp.events = POLL_IN;
564 
565 	memset(prev, 0, sizeof(prev));
566 	do {
567 		signal(SIGINT, close_and_exit);
568 		signal(SIGTERM, close_and_exit);
569 
570 		sleep(interval);
571 		for (key = 0; key < nr_keys; key++) {
572 			__u64 sum = 0;
573 
574 			assert(bpf_map_lookup_elem(rxcnt_map_fd,
575 						   &key, values) == 0);
576 			for (i = 0; i < nr_cpus; i++)
577 				sum += (values[i] - prev[key][i]);
578 			if (sum)
579 				printf("proto %u: %10llu pkt/s\n",
580 				       key, sum / interval);
581 			memcpy(prev[key], values, sizeof(values));
582 		}
583 
584 		memset(buf, 0, sizeof(buf));
585 		if (poll(&fds_route, 1, 3) == POLL_IN) {
586 			nll = recv_msg(lr, sock);
587 			if (nll < 0) {
588 				printf("recv from netlink: %s\n", strerror(nll));
589 				ret = -1;
590 				goto cleanup;
591 			}
592 
593 			nh = (struct nlmsghdr *)buf;
594 			printf("Routing table updated.\n");
595 			read_route(nh, nll);
596 		}
597 		memset(buf, 0, sizeof(buf));
598 		if (poll(&fds_arp, 1, 3) == POLL_IN) {
599 			nll = recv_msg(la, sock_arp);
600 			if (nll < 0) {
601 				printf("recv from netlink: %s\n", strerror(nll));
602 				ret = -1;
603 				goto cleanup;
604 			}
605 
606 			nh = (struct nlmsghdr *)buf;
607 			read_arp(nh, nll);
608 		}
609 
610 	} while (1);
611 cleanup:
612 	close(sock);
613 	return ret;
614 }
615 
616 static void usage(const char *prog)
617 {
618 	fprintf(stderr,
619 		"%s: %s [OPTS] interface name list\n\n"
620 		"OPTS:\n"
621 		"    -S    use skb-mode\n"
622 		"    -F    force loading prog\n",
623 		__func__, prog);
624 }
625 
626 int main(int ac, char **argv)
627 {
628 	struct bpf_prog_load_attr prog_load_attr = {
629 		.prog_type	= BPF_PROG_TYPE_XDP,
630 	};
631 	struct bpf_prog_info info = {};
632 	__u32 info_len = sizeof(info);
633 	const char *optstr = "SF";
634 	struct bpf_object *obj;
635 	char filename[256];
636 	char **ifname_list;
637 	int prog_fd, opt;
638 	int err, i = 1;
639 
640 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
641 	prog_load_attr.file = filename;
642 
643 	total_ifindex = ac - 1;
644 	ifname_list = (argv + 1);
645 
646 	while ((opt = getopt(ac, argv, optstr)) != -1) {
647 		switch (opt) {
648 		case 'S':
649 			flags |= XDP_FLAGS_SKB_MODE;
650 			total_ifindex--;
651 			ifname_list++;
652 			break;
653 		case 'F':
654 			flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
655 			total_ifindex--;
656 			ifname_list++;
657 			break;
658 		default:
659 			usage(basename(argv[0]));
660 			return 1;
661 		}
662 	}
663 
664 	if (!(flags & XDP_FLAGS_SKB_MODE))
665 		flags |= XDP_FLAGS_DRV_MODE;
666 
667 	if (optind == ac) {
668 		usage(basename(argv[0]));
669 		return 1;
670 	}
671 
672 	if (bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd))
673 		return 1;
674 
675 	printf("\n**************loading bpf file*********************\n\n\n");
676 	if (!prog_fd) {
677 		printf("bpf_prog_load_xattr: %s\n", strerror(errno));
678 		return 1;
679 	}
680 
681 	lpm_map_fd = bpf_object__find_map_fd_by_name(obj, "lpm_map");
682 	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
683 	arp_table_map_fd = bpf_object__find_map_fd_by_name(obj, "arp_table");
684 	exact_match_map_fd = bpf_object__find_map_fd_by_name(obj,
685 							     "exact_match");
686 	tx_port_map_fd = bpf_object__find_map_fd_by_name(obj, "tx_port");
687 	if (lpm_map_fd < 0 || rxcnt_map_fd < 0 || arp_table_map_fd < 0 ||
688 	    exact_match_map_fd < 0 || tx_port_map_fd < 0) {
689 		printf("bpf_object__find_map_fd_by_name failed\n");
690 		return 1;
691 	}
692 
693 	ifindex_list = (int *)calloc(total_ifindex, sizeof(int *));
694 	for (i = 0; i < total_ifindex; i++) {
695 		ifindex_list[i] = if_nametoindex(ifname_list[i]);
696 		if (!ifindex_list[i]) {
697 			printf("Couldn't translate interface name: %s",
698 			       strerror(errno));
699 			return 1;
700 		}
701 	}
702 	prog_id_list = (__u32 *)calloc(total_ifindex, sizeof(__u32 *));
703 	for (i = 0; i < total_ifindex; i++) {
704 		if (bpf_set_link_xdp_fd(ifindex_list[i], prog_fd, flags) < 0) {
705 			printf("link set xdp fd failed\n");
706 			int recovery_index = i;
707 
708 			for (i = 0; i < recovery_index; i++)
709 				bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
710 
711 			return 1;
712 		}
713 		err = bpf_obj_get_info_by_fd(prog_fd, &info, &info_len);
714 		if (err) {
715 			printf("can't get prog info - %s\n", strerror(errno));
716 			return err;
717 		}
718 		prog_id_list[i] = info.id;
719 		memset(&info, 0, sizeof(info));
720 		printf("Attached to %d\n", ifindex_list[i]);
721 	}
722 	signal(SIGINT, int_exit);
723 	signal(SIGTERM, int_exit);
724 
725 	printf("*******************ROUTE TABLE*************************\n\n\n");
726 	get_route_table(AF_INET);
727 	printf("*******************ARP TABLE***************************\n\n\n");
728 	get_arp_table(AF_INET);
729 	if (monitor_route() < 0) {
730 		printf("Error in receiving route update");
731 		return 1;
732 	}
733 
734 	return 0;
735 }
736