1 /* Copyright (C) 2017 Cavium, Inc.
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.
8 #include <linux/netlink.h>
9 #include <linux/rtnetlink.h>
16 #include <sys/socket.h>
20 #include <arpa/inet.h>
25 #include <sys/ioctl.h>
26 #include <sys/syscall.h>
29 int sock, sock_arp, flags = 0;
30 static int total_ifindex;
34 static int get_route_table(int rtm_family);
35 static void int_exit(int sig)
39 for (i = 0; i < total_ifindex; i++)
40 bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
44 static void close_and_exit(int sig)
51 for (i = 0; i < total_ifindex; i++)
52 bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
56 /* Get the mac address of the interface given interface name */
57 static __be64 getmac(char *iface)
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");
70 for (i = 0; i < 6 ; i++)
71 *((__u8 *)&mac + i) = (__u8)ifr.ifr_hwaddr.sa_data[i];
76 static int recv_msg(struct sockaddr_nl sock_addr, int sock)
84 len = recv(sock, buf_ptr, sizeof(buf) - nll, 0);
88 nh = (struct nlmsghdr *)buf_ptr;
90 if (nh->nlmsg_type == NLMSG_DONE)
94 if ((sock_addr.nl_groups & RTMGRP_NEIGH) == RTMGRP_NEIGH)
97 if ((sock_addr.nl_groups & RTMGRP_IPV4_ROUTE) == RTMGRP_IPV4_ROUTE)
103 /* Function to parse the route entry returned by netlink
104 * Updates the route entry related map entries
106 static void read_route(struct nlmsghdr *nh, int nll)
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;
116 int dst_len, iface, metric;
127 struct arp_table arp;
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");
139 printf("%d\n", nh->nlmsg_type);
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)
149 rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
150 rtl = RTM_PAYLOAD(nh);
152 for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
153 switch (rt_attr->rta_type) {
156 (*((__be32 *)RTA_DATA(rt_attr))));
160 *((__be32 *)RTA_DATA(rt_attr)));
164 *((int *)RTA_DATA(rt_attr)));
167 sprintf(metrics, "%u",
168 *((int *)RTA_DATA(rt_attr)));
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) {
185 for (i = 0; i < total_ifindex; i++)
186 bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
189 assert(bpf_map_update_elem(map_fd[4], &route.iface, &route.iface, 0) == 0);
190 if (rtm_family == AF_INET) {
199 prefix_key = alloca(sizeof(*prefix_key) + 3);
200 prefix_value = alloca(sizeof(*prefix_value));
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);
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);
217 for (i = 0; i < 4; i++)
218 prefix_key->data[i] = (route.dst >> i * 8) & 0xff;
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,
228 if (bpf_map_lookup_elem(map_fd[0], prefix_key,
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;
237 assert(bpf_map_update_elem(map_fd[0],
242 if (nh->nlmsg_type == RTM_DELROUTE) {
243 printf("deleting entry\n");
244 printf("prefix key=%d.%d.%d.%d/%d",
249 prefix_key->prefixlen);
250 assert(bpf_map_delete_elem(map_fd[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
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) {
270 for (i = 0; i < 4; i++)
271 prefix_value->prefix[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(
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));
295 /* Function to read the existing route table when the process is launched*/
296 static int get_route_table(int rtm_family)
298 struct sockaddr_nl sa;
312 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
314 printf("open netlink socket: %s\n", strerror(errno));
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));
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;
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;
338 ret = sendmsg(sock, &msg, 0);
340 printf("send to netlink: %s\n", strerror(errno));
344 memset(buf, 0, sizeof(buf));
345 nll = recv_msg(sa, sock);
347 printf("recv from netlink: %s\n", strerror(nll));
351 nh = (struct nlmsghdr *)buf;
358 /* Function to parse the arp entry returned by netlink
359 * Updates the arp entry related map entries
361 static void read_arp(struct nlmsghdr *nh, int nll)
363 struct rtattr *rt_attr;
364 char dsts[24], mac[24];
365 struct ndmsg *rt_msg;
373 struct arp_table arp;
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) {
390 *((__be32 *)RTA_DATA(rt_attr)));
394 *((__be64 *)RTA_DATA(rt_attr)));
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;
413 assert(bpf_map_update_elem(map_fd[3],
417 memset(&direct_entry, 0, sizeof(direct_entry));
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],
428 memset(&arp_entry, 0, sizeof(arp_entry));
429 memset(dsts, 0, sizeof(dsts));
433 /* Function to read the existing arp table when the process is launched*/
434 static int get_arp_table(int rtm_family)
436 struct sockaddr_nl sa;
449 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
451 printf("open netlink socket: %s\n", strerror(errno));
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));
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;
474 ret = sendmsg(sock, &msg, 0);
476 printf("send to netlink: %s\n", strerror(errno));
480 memset(buf, 0, sizeof(buf));
481 nll = recv_msg(sa, sock);
483 printf("recv from netlink: %s\n", strerror(nll));
487 nh = (struct nlmsghdr *)buf;
494 /* Function to keep track and update changes in route and arp table
495 * Give regular statistics of packets forwarded
497 static int monitor_route(void)
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];
511 sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
513 printf("open netlink socket: %s\n", strerror(errno));
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));
527 fds_route.events = POLL_IN;
529 sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
531 printf("open netlink socket: %s\n", strerror(errno));
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));
544 fds_arp.fd = sock_arp;
545 fds_arp.events = POLL_IN;
547 memset(prev, 0, sizeof(prev));
549 signal(SIGINT, close_and_exit);
550 signal(SIGTERM, close_and_exit);
553 for (key = 0; key < nr_keys; key++) {
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]);
560 printf("proto %u: %10llu pkt/s\n",
561 key, sum / interval);
562 memcpy(prev[key], values, sizeof(values));
565 memset(buf, 0, sizeof(buf));
566 if (poll(&fds_route, 1, 3) == POLL_IN) {
567 nll = recv_msg(lr, sock);
569 printf("recv from netlink: %s\n", strerror(nll));
574 nh = (struct nlmsghdr *)buf;
575 printf("Routing table updated.\n");
578 memset(buf, 0, sizeof(buf));
579 if (poll(&fds_arp, 1, 3) == POLL_IN) {
580 nll = recv_msg(la, sock_arp);
582 printf("recv from netlink: %s\n", strerror(nll));
587 nh = (struct nlmsghdr *)buf;
597 int main(int ac, char **argv)
603 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
605 printf("usage: %s [-S] Interface name list\n", argv[0]);
608 if (!strcmp(argv[1], "-S")) {
609 flags = XDP_FLAGS_SKB_MODE;
610 total_ifindex = ac - 2;
611 ifname_list = (argv + 2);
614 total_ifindex = ac - 1;
615 ifname_list = (argv + 1);
617 if (load_bpf_file(filename)) {
618 printf("%s", bpf_log_buf);
621 printf("\n**************loading bpf file*********************\n\n\n");
623 printf("load_bpf_file: %s\n", strerror(errno));
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",
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;
640 for (i = 0; i < recovery_index; i++)
641 bpf_set_link_xdp_fd(ifindex_list[i], -1, flags);
645 printf("Attached to %d\n", ifindex_list[i]);
647 signal(SIGINT, int_exit);
648 signal(SIGTERM, int_exit);
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");