xref: /freebsd/sbin/route/route_netlink.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <err.h>
5 #include <errno.h>
6 
7 #include <sys/bitcount.h>
8 #include <sys/param.h>
9 #include <sys/linker.h>
10 #include <sys/module.h>
11 #include <sys/socket.h>
12 #include <sys/sysctl.h>
13 #include <sys/time.h>
14 #include <sys/types.h>
15 
16 #include <netinet/in.h>
17 #include <arpa/inet.h>
18 
19 #include <net/ethernet.h>
20 #include <net/if.h>
21 #include <net/if_dl.h>
22 #include <net/if_types.h>
23 #include <netlink/netlink.h>
24 #include <netlink/netlink_route.h>
25 #include <netlink/netlink_snl.h>
26 #include <netlink/netlink_snl_route.h>
27 #include <netlink/netlink_snl_route_compat.h>
28 #include <netlink/netlink_snl_route_parsers.h>
29 
30 const char *routename(struct sockaddr *);
31 const char *netname(struct sockaddr *);
32 void printb(int, const char *);
33 extern const char routeflags[];
34 extern int verbose, debugonly;
35 
36 int rtmsg_nl(int cmd, int rtm_flags, int fib, int rtm_addrs, struct sockaddr_storage *so,
37     struct rt_metrics *rt_metrics);
38 int flushroutes_fib_nl(int fib, int af);
39 void monitor_nl(int fib);
40 
41 struct nl_helper;
42 struct snl_msg_info;
43 static void print_getmsg(struct nl_helper *h, struct nlmsghdr *hdr,
44     struct sockaddr *dst);
45 static void print_nlmsg(struct nl_helper *h, struct nlmsghdr *hdr,
46     struct snl_msg_info *cinfo);
47 
48 #define s6_addr32 __u6_addr.__u6_addr32
49 #define	bitcount32(x)	__bitcount32((uint32_t)(x))
50 static int
51 inet6_get_plen(const struct in6_addr *addr)
52 {
53 
54 	return (bitcount32(addr->s6_addr32[0]) + bitcount32(addr->s6_addr32[1]) +
55 	    bitcount32(addr->s6_addr32[2]) + bitcount32(addr->s6_addr32[3]));
56 }
57 
58 static void
59 ip6_writemask(struct in6_addr *addr6, uint8_t mask)
60 {
61 	uint32_t *cp;
62 
63 	for (cp = (uint32_t *)addr6; mask >= 32; mask -= 32)
64 		*cp++ = 0xFFFFFFFF;
65 	if (mask > 0)
66 		*cp = htonl(mask ? ~((1 << (32 - mask)) - 1) : 0);
67 }
68 
69 static struct sockaddr *
70 get_netmask(struct snl_state *ss, int family, int plen)
71 {
72 	if (family == AF_INET) {
73 		if (plen == 32)
74 			return (NULL);
75 
76 		struct sockaddr_in *sin = snl_allocz(ss, sizeof(*sin));
77 
78 		sin->sin_len = sizeof(*sin);
79 		sin->sin_family = family;
80 		sin->sin_addr.s_addr = htonl(plen ? ~((1 << (32 - plen)) - 1) : 0);
81 
82 		return (struct sockaddr *)sin;
83 	} else if (family == AF_INET6) {
84 		if (plen == 128)
85 			return (NULL);
86 
87 		struct sockaddr_in6 *sin6 = snl_allocz(ss, sizeof(*sin6));
88 
89 		sin6->sin6_len = sizeof(*sin6);
90 		sin6->sin6_family = family;
91 		ip6_writemask(&sin6->sin6_addr, plen);
92 
93 		return (struct sockaddr *)sin6;
94 	}
95 	return (NULL);
96 }
97 
98 static void
99 nl_init_socket(struct snl_state *ss)
100 {
101 	if (snl_init(ss, NETLINK_ROUTE))
102 		return;
103 
104 	if (modfind("netlink") == -1 && errno == ENOENT) {
105 		/* Try to load */
106 		if (kldload("netlink") == -1)
107 			err(1, "netlink is not loaded and load attempt failed");
108 		if (snl_init(ss, NETLINK_ROUTE))
109 			return;
110 	}
111 
112 	err(1, "unable to open netlink socket");
113 }
114 
115 struct nl_helper {
116 	struct snl_state ss_cmd;
117 };
118 
119 static void
120 nl_helper_init(struct nl_helper *h)
121 {
122 	nl_init_socket(&h->ss_cmd);
123 }
124 
125 static void
126 nl_helper_free(struct nl_helper *h)
127 {
128 	snl_free(&h->ss_cmd);
129 }
130 
131 static struct sockaddr *
132 get_addr(struct sockaddr_storage *so, int rtm_addrs, int addr_type)
133 {
134 	struct sockaddr *sa = NULL;
135 
136 	if (rtm_addrs & (1 << addr_type))
137 		sa = (struct sockaddr *)&so[addr_type];
138 	return (sa);
139 }
140 
141 static int
142 rtmsg_nl_int(struct nl_helper *h, int cmd, int rtm_flags, int fib, int rtm_addrs,
143     struct sockaddr_storage *so, struct rt_metrics *rt_metrics)
144 {
145 	struct snl_state *ss = &h->ss_cmd;
146 	struct snl_writer nw;
147 	int nl_type = 0, nl_flags = 0;
148 
149 	snl_init_writer(ss, &nw);
150 
151 	switch (cmd) {
152 	case RTSOCK_RTM_ADD:
153 		nl_type = RTM_NEWROUTE;
154 		nl_flags = NLM_F_CREATE | NLM_F_APPEND; /* Do append by default */
155 		break;
156 	case RTSOCK_RTM_CHANGE:
157 		nl_type = RTM_NEWROUTE;
158 		nl_flags = NLM_F_REPLACE;
159 		break;
160 	case RTSOCK_RTM_DELETE:
161 		nl_type = RTM_DELROUTE;
162 		break;
163 	case RTSOCK_RTM_GET:
164 		nl_type = RTM_GETROUTE;
165 		break;
166 	default:
167 		exit(1);
168 	}
169 
170 	struct sockaddr *dst = get_addr(so, rtm_addrs, RTAX_DST);
171 	struct sockaddr *mask = get_addr(so, rtm_addrs, RTAX_NETMASK);
172 	struct sockaddr *gw = get_addr(so, rtm_addrs, RTAX_GATEWAY);
173 
174 	if (dst == NULL)
175 		return (EINVAL);
176 
177 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, nl_type);
178 	hdr->nlmsg_flags |= nl_flags;
179 
180 	int plen = 0;
181 	int rtm_type = RTN_UNICAST;
182 
183 	switch (dst->sa_family) {
184 	case AF_INET:
185 	    {
186 		struct sockaddr_in *mask4 = (struct sockaddr_in *)mask;
187 
188 		if ((rtm_flags & RTF_HOST) == 0 && mask4 != NULL)
189 			plen = bitcount32(mask4->sin_addr.s_addr);
190 		else
191 			plen = 32;
192 		break;
193 	    }
194 	case AF_INET6:
195 	    {
196 		struct sockaddr_in6 *mask6 = (struct sockaddr_in6 *)mask;
197 
198 		if ((rtm_flags & RTF_HOST) == 0 && mask6 != NULL)
199 			plen = inet6_get_plen(&mask6->sin6_addr);
200 		else
201 			plen = 128;
202 		break;
203 	    }
204 	default:
205 		return (ENOTSUP);
206 	}
207 
208 	if (rtm_flags & RTF_REJECT)
209 		rtm_type = RTN_PROHIBIT;
210 	else if (rtm_flags & RTF_BLACKHOLE)
211 		rtm_type = RTN_BLACKHOLE;
212 
213 	struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
214 	rtm->rtm_family = dst->sa_family;
215 	rtm->rtm_protocol = RTPROT_STATIC;
216 	rtm->rtm_type = rtm_type;
217 	rtm->rtm_dst_len = plen;
218 
219 	/* Request exact prefix match if mask is set */
220 	if ((cmd == RTSOCK_RTM_GET) && (mask != NULL))
221 		rtm->rtm_flags = RTM_F_PREFIX;
222 
223 	snl_add_msg_attr_ip(&nw, RTA_DST, dst);
224 	snl_add_msg_attr_u32(&nw, RTA_TABLE, fib);
225 
226 	uint32_t rta_oif = 0;
227 
228 	if (gw != NULL) {
229 		if (rtm_flags & RTF_GATEWAY) {
230 			if (gw->sa_family == dst->sa_family)
231 				snl_add_msg_attr_ip(&nw, RTA_GATEWAY, gw);
232 			else
233 				snl_add_msg_attr_ipvia(&nw, RTA_VIA, gw);
234 			if (gw->sa_family == AF_INET6) {
235 				struct sockaddr_in6 *gw6 = (struct sockaddr_in6 *)gw;
236 
237 				if (IN6_IS_ADDR_LINKLOCAL(&gw6->sin6_addr))
238 					rta_oif = gw6->sin6_scope_id;
239 			}
240 		} else {
241 			/* Should be AF_LINK */
242 			struct sockaddr_dl *sdl = (struct sockaddr_dl *)gw;
243 			if (sdl->sdl_index != 0)
244 				rta_oif = sdl->sdl_index;
245 		}
246 	}
247 
248 	if (dst->sa_family == AF_INET6 && rta_oif == 0) {
249 		struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
250 
251 		if (IN6_IS_ADDR_LINKLOCAL(&dst6->sin6_addr))
252 			rta_oif = dst6->sin6_scope_id;
253 	}
254 
255 	if (rta_oif != 0)
256 		snl_add_msg_attr_u32(&nw, RTA_OIF, rta_oif);
257 	if (rtm_flags != 0)
258 		snl_add_msg_attr_u32(&nw, NL_RTA_RTFLAGS, rtm_flags);
259 
260 	if (rt_metrics->rmx_mtu > 0) {
261 		int off = snl_add_msg_attr_nested(&nw, RTA_METRICS);
262 		snl_add_msg_attr_u32(&nw, RTAX_MTU, rt_metrics->rmx_mtu);
263 		snl_end_attr_nested(&nw, off);
264 	}
265 
266 	if (rt_metrics->rmx_weight > 0)
267 		snl_add_msg_attr_u32(&nw, NL_RTA_WEIGHT, rt_metrics->rmx_weight);
268 
269 	if ((hdr = snl_finalize_msg(&nw)) && snl_send_message(ss, hdr)) {
270 		struct snl_errmsg_data e = {};
271 
272 		hdr = snl_read_reply(ss, hdr->nlmsg_seq);
273 		if (nl_type == NL_RTM_GETROUTE) {
274 			if (hdr->nlmsg_type == NL_RTM_NEWROUTE) {
275 				print_getmsg(h, hdr, dst);
276 				return (0);
277 			}
278 		}
279 
280 		if (snl_parse_errmsg(ss, hdr, &e)) {
281 			switch (e.error) {
282 			case (ESRCH):
283 				warnx("route has not been found");
284 				break;
285 			default:
286 				if (e.error == 0)
287 					break;
288 				warnc(e.error, "message indicates error");
289 			}
290 
291 			return (e.error);
292 		}
293 	}
294 
295 	return (EINVAL);
296 }
297 
298 int
299 rtmsg_nl(int cmd, int rtm_flags, int fib, int rtm_addrs,
300     struct sockaddr_storage *so, struct rt_metrics *rt_metrics)
301 {
302 	struct nl_helper h = {};
303 
304 	nl_helper_init(&h);
305 	int error = rtmsg_nl_int(&h, cmd, rtm_flags, fib, rtm_addrs, so, rt_metrics);
306 	nl_helper_free(&h);
307 
308 	return (error);
309 }
310 
311 static void
312 get_ifdata(struct nl_helper *h, uint32_t ifindex, struct snl_parsed_link_simple *link)
313 {
314 	struct snl_state *ss = &h->ss_cmd;
315 	struct snl_writer nw;
316 
317 	snl_init_writer(ss, &nw);
318 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, NL_RTM_GETLINK);
319 	struct ifinfomsg *ifmsg = snl_reserve_msg_object(&nw, struct ifinfomsg);
320 	if (ifmsg != NULL)
321 		ifmsg->ifi_index = ifindex;
322 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
323 		return;
324 
325 	hdr = snl_read_reply(ss, hdr->nlmsg_seq);
326 
327 	if (hdr != NULL && hdr->nlmsg_type == RTM_NEWLINK) {
328 		snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser_simple, link);
329 	}
330 
331 	if (link->ifla_ifname == NULL) {
332 		char ifname[16];
333 
334 		snprintf(ifname, sizeof(ifname), "if#%u", ifindex);
335 		int len = strlen(ifname);
336 		char *buf = snl_allocz(ss, len + 1);
337 		strlcpy(buf, ifname, len + 1);
338 		link->ifla_ifname = buf;
339 	}
340 }
341 
342 static void
343 print_getmsg(struct nl_helper *h, struct nlmsghdr *hdr, struct sockaddr *dst)
344 {
345 	struct snl_state *ss = &h->ss_cmd;
346 	struct timespec ts;
347 	struct snl_parsed_route r = { .rtax_weight = RT_DEFAULT_WEIGHT };
348 
349 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_route_parser, &r))
350 		return;
351 
352 	struct snl_parsed_link_simple link = {};
353 	get_ifdata(h, r.rta_oif, &link);
354 
355 	if (r.rtax_mtu == 0)
356 		r.rtax_mtu = link.ifla_mtu;
357 	r.rta_rtflags |= (RTF_UP | RTF_DONE);
358 
359 	(void)printf("   route to: %s\n", routename(dst));
360 
361 	if (r.rta_dst)
362 		(void)printf("destination: %s\n", routename(r.rta_dst));
363 	struct sockaddr *mask = get_netmask(ss, r.rtm_family, r.rtm_dst_len);
364 	if (mask)
365 		(void)printf("       mask: %s\n", routename(mask));
366 	if (r.rta_gw && (r.rta_rtflags & RTF_GATEWAY))
367 		(void)printf("    gateway: %s\n", routename(r.rta_gw));
368 	(void)printf("        fib: %u\n", (unsigned int)r.rta_table);
369 	if (link.ifla_ifname)
370 		(void)printf("  interface: %s\n", link.ifla_ifname);
371 	(void)printf("      flags: ");
372 	printb(r.rta_rtflags, routeflags);
373 
374 	struct rt_metrics rmx = {
375 		.rmx_mtu = r.rtax_mtu,
376 		.rmx_weight = r.rtax_weight,
377 		.rmx_expire = r.rta_expire,
378 	};
379 
380 	printf("\n%9s %9s %9s %9s %9s %10s %9s\n", "recvpipe",
381 	    "sendpipe", "ssthresh", "rtt,msec", "mtu   ", "weight", "expire");
382 	printf("%8lu  ", rmx.rmx_recvpipe);
383 	printf("%8lu  ", rmx.rmx_sendpipe);
384 	printf("%8lu  ", rmx.rmx_ssthresh);
385 	printf("%8lu  ", 0UL);
386 	printf("%8lu  ", rmx.rmx_mtu);
387 	printf("%8lu  ", rmx.rmx_weight);
388 	if (rmx.rmx_expire > 0)
389 		clock_gettime(CLOCK_REALTIME_FAST, &ts);
390 	else
391 		ts.tv_sec = 0;
392 	printf("%8ld \n", (long)(rmx.rmx_expire - ts.tv_sec));
393 }
394 
395 static void
396 print_prefix(struct nl_helper *h, char *buf, int bufsize, struct sockaddr *sa, int plen)
397 {
398 	int sz = 0;
399 
400 	if (sa == NULL) {
401 		snprintf(buf, bufsize, "<NULL>");
402 		return;
403 	}
404 
405 	switch (sa->sa_family) {
406 	case AF_INET:
407 		{
408 			struct sockaddr_in *sin = (struct sockaddr_in *)sa;
409 			char abuf[INET_ADDRSTRLEN];
410 
411 			inet_ntop(AF_INET, &sin->sin_addr, abuf, sizeof(abuf));
412 			sz = snprintf(buf, bufsize, "%s", abuf);
413 			break;
414 		}
415 	case AF_INET6:
416 		{
417 			struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
418 			char abuf[INET6_ADDRSTRLEN];
419 			char *ifname = NULL;
420 
421 			inet_ntop(AF_INET6, &sin6->sin6_addr, abuf, sizeof(abuf));
422 			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
423 				struct snl_parsed_link_simple link = {};
424 
425 				if (sin6->sin6_scope_id != 0) {
426 					get_ifdata(h, sin6->sin6_scope_id, &link);
427 					ifname = link.ifla_ifname;
428 				}
429 			}
430 			if (ifname == NULL)
431 				sz = snprintf(buf, bufsize, "%s", abuf);
432 			else
433 				sz = snprintf(buf, bufsize, "%s%%%s", abuf, ifname);
434 			break;
435 		}
436 	default:
437 		snprintf(buf, bufsize, "unknown_af#%d", sa->sa_family);
438 		plen = -1;
439 	}
440 
441 	if (plen >= 0)
442 		snprintf(buf + sz, bufsize - sz, "/%d", plen);
443 }
444 
445 static int
446 print_line_prefix(struct nlmsghdr *hdr, struct snl_msg_info *cinfo,
447     const char *cmd, const char *name)
448 {
449 	struct timespec tp;
450 	struct tm tm;
451 	char buf[32];
452 
453 	clock_gettime(CLOCK_REALTIME, &tp);
454 	localtime_r(&tp.tv_sec, &tm);
455 
456 	strftime(buf, sizeof(buf), "%T", &tm);
457 	int len = printf("%s.%03ld PID %4u %s %s ", buf, tp.tv_nsec / 1000000,
458 	    cinfo->process_id, cmd, name);
459 
460 	return (len);
461 }
462 
463 static const char *
464 get_action_name(struct nlmsghdr *hdr, int new_cmd)
465 {
466 	if (hdr->nlmsg_type == new_cmd) {
467 		//return ((hdr->nlmsg_flags & NLM_F_REPLACE) ? "replace" : "add");
468 		return ("add/repl");
469 	} else
470 		return ("delete");
471 }
472 
473 static void
474 print_nlmsg_route_nhop(struct nl_helper *h, struct snl_parsed_route *r,
475     struct rta_mpath_nh *nh, bool first)
476 {
477 	// gw 10.0.0.1 ifp vtnet0 mtu 1500 table inet.0
478 	if (nh->gw != NULL) {
479 		char gwbuf[128];
480 		print_prefix(h, gwbuf, sizeof(gwbuf), nh->gw, -1);
481 		printf("gw %s ", gwbuf);
482 	}
483 
484 	if (nh->ifindex != 0) {
485 		struct snl_parsed_link_simple link = {};
486 
487 		get_ifdata(h, nh->ifindex, &link);
488 		if (nh->rtax_mtu == 0)
489 			nh->rtax_mtu = link.ifla_mtu;
490 		printf("iface %s ", link.ifla_ifname);
491 		if (nh->rtax_mtu != 0)
492 			printf("mtu %d ", nh->rtax_mtu);
493 	}
494 
495 	if (first) {
496 		switch (r->rtm_family) {
497 			case AF_INET:
498 				printf("table inet.%d", r->rta_table);
499 				break;
500 			case AF_INET6:
501 				printf("table inet6.%d", r->rta_table);
502 				break;
503 		}
504 	}
505 
506 	printf("\n");
507 }
508 
509 static void
510 print_nlmsg_route(struct nl_helper *h, struct nlmsghdr *hdr,
511     struct snl_msg_info *cinfo)
512 {
513 	struct snl_parsed_route r = { .rtax_weight = RT_DEFAULT_WEIGHT };
514 	struct snl_state *ss = &h->ss_cmd;
515 
516 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_route_parser, &r))
517 		return;
518 
519 	// 20:19:41.333 add route 10.0.0.0/24 gw 10.0.0.1 ifp vtnet0 mtu 1500 table inet.0
520 
521 	const char *cmd = get_action_name(hdr, RTM_NEWROUTE);
522 	int len = print_line_prefix(hdr, cinfo, cmd, "route");
523 
524 	char buf[128];
525 	print_prefix(h, buf, sizeof(buf), r.rta_dst, r.rtm_dst_len);
526 	len += strlen(buf) + 1;
527 	printf("%s ", buf);
528 
529 	switch (r.rtm_type) {
530 	case RTN_BLACKHOLE:
531 		printf("blackhole\n");
532 		return;
533 	case RTN_UNREACHABLE:
534 		printf("unreach(reject)\n");
535 		return;
536 	case RTN_PROHIBIT:
537 		printf("prohibit(reject)\n");
538 		return;
539 	}
540 
541 	if (r.rta_multipath.num_nhops != 0) {
542 		bool first = true;
543 
544 		memset(buf, ' ', sizeof(buf));
545 		buf[len] = '\0';
546 
547 		for (uint32_t i = 0; i < r.rta_multipath.num_nhops; i++) {
548 			struct rta_mpath_nh *nh = r.rta_multipath.nhops[i];
549 
550 			if (!first)
551 				printf("%s", buf);
552 			print_nlmsg_route_nhop(h, &r, nh, first);
553 			first = false;
554 		}
555 	} else {
556 		struct rta_mpath_nh nh = {
557 			.gw = r.rta_gw,
558 			.ifindex = r.rta_oif,
559 			.rtax_mtu = r.rtax_mtu,
560 		};
561 
562 		print_nlmsg_route_nhop(h, &r, &nh, true);
563 	}
564 }
565 
566 static const char *operstate[] = {
567 	"UNKNOWN",	/* 0, IF_OPER_UNKNOWN */
568 	"NOTPRESENT",	/* 1, IF_OPER_NOTPRESENT */
569 	"DOWN",		/* 2, IF_OPER_DOWN */
570 	"LLDOWN",	/* 3, IF_OPER_LOWERLAYERDOWN */
571 	"TESTING",	/* 4, IF_OPER_TESTING */
572 	"DORMANT",	/* 5, IF_OPER_DORMANT */
573 	"UP",		/* 6, IF_OPER_UP */
574 };
575 
576 static void
577 print_nlmsg_link(struct nl_helper *h, struct nlmsghdr *hdr,
578     struct snl_msg_info *cinfo)
579 {
580 	struct snl_parsed_link l = {};
581 	struct snl_state *ss = &h->ss_cmd;
582 
583 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser, &l))
584 		return;
585 
586 	// 20:19:41.333 add iface#3 vtnet0 admin UP oper UP mtu 1500 table inet.0
587 	const char *cmd = get_action_name(hdr, RTM_NEWLINK);
588 	print_line_prefix(hdr, cinfo, cmd, "iface");
589 
590 	printf("iface#%u %s ", l.ifi_index, l.ifla_ifname);
591 	printf("admin %s ", (l.ifi_flags & IFF_UP) ? "UP" : "DOWN");
592 	if (l.ifla_operstate < NL_ARRAY_LEN(operstate))
593 		printf("oper %s ", operstate[l.ifla_operstate]);
594 	if (l.ifla_mtu > 0)
595 		printf("mtu %u ", l.ifla_mtu);
596 
597 	printf("\n");
598 }
599 
600 static void
601 print_nlmsg_addr(struct nl_helper *h, struct nlmsghdr *hdr,
602     struct snl_msg_info *cinfo)
603 {
604 	struct snl_parsed_addr attrs = {};
605 	struct snl_state *ss = &h->ss_cmd;
606 
607 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_addr_parser, &attrs))
608 		return;
609 
610 	// add addr 192.168.1.1/24 iface vtnet0
611 	const char *cmd = get_action_name(hdr, RTM_NEWADDR);
612 	print_line_prefix(hdr, cinfo, cmd, "addr");
613 
614 	char buf[128];
615 	struct sockaddr *addr = attrs.ifa_local ? attrs.ifa_local : attrs.ifa_address;
616 	print_prefix(h, buf, sizeof(buf), addr, attrs.ifa_prefixlen);
617 	printf("%s ", buf);
618 
619 	struct snl_parsed_link_simple link = {};
620 	get_ifdata(h, attrs.ifa_index, &link);
621 
622 	if (link.ifi_flags & IFF_POINTOPOINT) {
623 		char buf[64];
624 		print_prefix(h, buf, sizeof(buf), attrs.ifa_address, -1);
625 		printf("-> %s ", buf);
626 	}
627 
628 	printf("iface %s ", link.ifla_ifname);
629 
630 	printf("\n");
631 }
632 
633 static const char *nudstate[] = {
634 	"INCOMPLETE",		/* 0x01(0) */
635 	"REACHABLE",		/* 0x02(1) */
636 	"STALE",		/* 0x04(2) */
637 	"DELAY",		/* 0x08(3) */
638 	"PROBE",		/* 0x10(4) */
639 	"FAILED",		/* 0x20(5) */
640 };
641 
642 #define	NUD_INCOMPLETE		0x01	/* No lladdr, address resolution in progress */
643 #define	NUD_REACHABLE		0x02	/* reachable & recently resolved */
644 #define	NUD_STALE		0x04	/* has lladdr but it's stale */
645 #define	NUD_DELAY		0x08	/* has lladdr, is stale, probes delayed */
646 #define	NUD_PROBE		0x10	/* has lladdr, is stale, probes sent */
647 #define	NUD_FAILED		0x20	/* unused */
648 
649 
650 static void
651 print_nlmsg_neigh(struct nl_helper *h, struct nlmsghdr *hdr,
652     struct snl_msg_info *cinfo)
653 {
654 	struct snl_parsed_neigh attrs = {};
655 	struct snl_state *ss = &h->ss_cmd;
656 
657 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_neigh_parser, &attrs))
658 		return;
659 
660 	// add addr 192.168.1.1 state %s lladdr %s iface vtnet0
661 	const char *cmd = get_action_name(hdr, RTM_NEWNEIGH);
662 	print_line_prefix(hdr, cinfo, cmd, "neigh");
663 
664 	char buf[128];
665 	print_prefix(h, buf, sizeof(buf), attrs.nda_dst, -1);
666 	printf("%s ", buf);
667 
668 	struct snl_parsed_link_simple link = {};
669 	get_ifdata(h, attrs.nda_ifindex, &link);
670 
671 	for (unsigned int i = 0; i < NL_ARRAY_LEN(nudstate); i++) {
672 		if ((1 << i) & attrs.ndm_state) {
673 			printf("state %s ", nudstate[i]);
674 			break;
675 		}
676 	}
677 
678 	if (attrs.nda_lladdr != NULL) {
679 		int if_type = link.ifi_type;
680 
681 		if ((if_type == IFT_ETHER || if_type == IFT_L2VLAN || if_type == IFT_BRIDGE) &&
682 		    NLA_DATA_LEN(attrs.nda_lladdr) == ETHER_ADDR_LEN) {
683 			struct ether_addr *ll;
684 
685 			ll = (struct ether_addr *)NLA_DATA(attrs.nda_lladdr);
686 			printf("lladdr %s ", ether_ntoa(ll));
687 		} else {
688 			struct sockaddr_dl sdl = {
689 				.sdl_len = sizeof(sdl),
690 				.sdl_family = AF_LINK,
691 				.sdl_index = attrs.nda_ifindex,
692 				.sdl_type = if_type,
693 				.sdl_alen = NLA_DATA_LEN(attrs.nda_lladdr),
694 			};
695 			if (sdl.sdl_alen < sizeof(sdl.sdl_data)) {
696 				void *ll = NLA_DATA(attrs.nda_lladdr);
697 
698 				memcpy(sdl.sdl_data, ll, sdl.sdl_alen);
699 				printf("lladdr %s ", link_ntoa(&sdl));
700 			}
701 		}
702 	}
703 
704 	if (link.ifla_ifname != NULL)
705 		printf("iface %s ", link.ifla_ifname);
706 	printf("\n");
707 }
708 
709 static void
710 print_nlmsg_generic(struct nl_helper *h, struct nlmsghdr *hdr, struct snl_msg_info *cinfo)
711 {
712 	const char *cmd = get_action_name(hdr, 0);
713 	print_line_prefix(hdr, cinfo, cmd, "unknown message");
714 	printf(" type %u\n", hdr->nlmsg_type);
715 }
716 
717 static void
718 print_nlmsg(struct nl_helper *h, struct nlmsghdr *hdr, struct snl_msg_info *cinfo)
719 {
720 	switch (hdr->nlmsg_type) {
721 	case RTM_NEWLINK:
722 	case RTM_DELLINK:
723 		print_nlmsg_link(h, hdr, cinfo);
724 		break;
725 	case RTM_NEWADDR:
726 	case RTM_DELADDR:
727 		print_nlmsg_addr(h, hdr, cinfo);
728 		break;
729 	case RTM_NEWROUTE:
730 	case RTM_DELROUTE:
731 		print_nlmsg_route(h, hdr, cinfo);
732 		break;
733 	case RTM_NEWNEIGH:
734 	case RTM_DELNEIGH:
735 		print_nlmsg_neigh(h, hdr, cinfo);
736 		break;
737 	default:
738 		print_nlmsg_generic(h, hdr, cinfo);
739 	}
740 
741 	snl_clear_lb(&h->ss_cmd);
742 }
743 
744 void
745 monitor_nl(int fib)
746 {
747 	struct snl_state ss_event = {};
748 	struct nl_helper h;
749 
750 	nl_init_socket(&ss_event);
751 	nl_helper_init(&h);
752 
753 	int groups[] = {
754 		RTNLGRP_LINK,
755 		RTNLGRP_NEIGH,
756 		RTNLGRP_NEXTHOP,
757 #ifdef INET
758 		RTNLGRP_IPV4_IFADDR,
759 		RTNLGRP_IPV4_ROUTE,
760 #endif
761 #ifdef INET6
762 		RTNLGRP_IPV6_IFADDR,
763 		RTNLGRP_IPV6_ROUTE,
764 #endif
765 	};
766 
767 	int optval = 1;
768 	socklen_t optlen = sizeof(optval);
769 	setsockopt(ss_event.fd, SOL_NETLINK, NETLINK_MSG_INFO, &optval, optlen);
770 
771 	for (unsigned int i = 0; i < NL_ARRAY_LEN(groups); i++) {
772 		int error;
773 		int optval = groups[i];
774 		socklen_t optlen = sizeof(optval);
775 		error = setsockopt(ss_event.fd, SOL_NETLINK,
776 		    NETLINK_ADD_MEMBERSHIP, &optval, optlen);
777 		if (error != 0)
778 			warn("Unable to subscribe to group %d", optval);
779 	}
780 
781 	struct snl_msg_info attrs = {};
782 	struct nlmsghdr *hdr;
783 	while ((hdr = snl_read_message_dbg(&ss_event, &attrs)) != NULL)
784 	{
785 		print_nlmsg(&h, hdr, &attrs);
786 		snl_clear_lb(&h.ss_cmd);
787 		snl_clear_lb(&ss_event);
788 	}
789 
790 	snl_free(&ss_event);
791 	nl_helper_free(&h);
792 	exit(0);
793 }
794 
795 static void
796 print_flushed_route(struct snl_parsed_route *r, struct sockaddr *gw)
797 {
798 	struct sockaddr *sa = r->rta_dst;
799 
800 	printf("%-20.20s ", r->rta_rtflags & RTF_HOST ?
801 	    routename(sa) : netname(sa));
802 	sa = gw;
803 	printf("%-20.20s ", routename(sa));
804 	printf("-fib %-3d ", r->rta_table);
805 	printf("done\n");
806 }
807 
808 static int
809 flushroute_one(struct nl_helper *h, struct snl_parsed_route *r)
810 {
811 	struct snl_state *ss = &h->ss_cmd;
812 	struct snl_errmsg_data e = {};
813 	struct snl_writer nw;
814 
815 	snl_init_writer(ss, &nw);
816 
817 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, NL_RTM_DELROUTE);
818 	struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
819 	rtm->rtm_family = r->rtm_family;
820 	rtm->rtm_dst_len = r->rtm_dst_len;
821 
822 	snl_add_msg_attr_u32(&nw, RTA_TABLE, r->rta_table);
823 	snl_add_msg_attr_ip(&nw, RTA_DST, r->rta_dst);
824 
825 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
826 		return (ENOMEM);
827 
828 	if (!snl_read_reply_code(ss, hdr->nlmsg_seq, &e)) {
829 		return (e.error);
830 		if (e.error == EPERM)
831 			errc(1, e.error, "RTM_DELROUTE failed:");
832 		else
833 			warnc(e.error, "RTM_DELROUTE failed:");
834 		return (true);
835 	};
836 
837 	if (verbose) {
838 		struct snl_msg_info attrs = {};
839 		print_nlmsg(h, hdr, &attrs);
840 	}
841 	else {
842 		if (r->rta_multipath.num_nhops != 0) {
843 			for (uint32_t i = 0; i < r->rta_multipath.num_nhops; i++) {
844 				struct rta_mpath_nh *nh = r->rta_multipath.nhops[i];
845 
846 				print_flushed_route(r, nh->gw);
847 			}
848 
849 		} else
850 			print_flushed_route(r, r->rta_gw);
851 	}
852 
853 	return (0);
854 }
855 
856 int
857 flushroutes_fib_nl(int fib, int af)
858 {
859 	struct snl_state ss = {};
860 	struct snl_writer nw;
861 	struct nl_helper h = {};
862 
863 	nl_init_socket(&ss);
864 	snl_init_writer(&ss, &nw);
865 
866 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, NL_RTM_GETROUTE);
867 	hdr->nlmsg_flags |= NLM_F_DUMP;
868 	struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
869 	rtm->rtm_family = af;
870 	snl_add_msg_attr_u32(&nw, RTA_TABLE, fib);
871 
872 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(&ss, hdr)) {
873 		snl_free(&ss);
874 		return (EINVAL);
875 	}
876 
877 	struct snl_errmsg_data e = {};
878 	uint32_t nlm_seq = hdr->nlmsg_seq;
879 
880 	nl_helper_init(&h);
881 
882 	while ((hdr = snl_read_reply_multi(&ss, nlm_seq, &e)) != NULL) {
883 		struct snl_parsed_route r = { .rtax_weight = RT_DEFAULT_WEIGHT };
884 		int error;
885 
886 		if (!snl_parse_nlmsg(&ss, hdr, &snl_rtm_route_parser, &r))
887 			continue;
888 		if (verbose) {
889 			struct snl_msg_info attrs = {};
890 			print_nlmsg(&h, hdr, &attrs);
891 		}
892 		if (r.rta_table != (uint32_t)fib || r.rtm_family != af)
893 			continue;
894 		if ((r.rta_rtflags & RTF_GATEWAY) == 0)
895 			continue;
896 		if (debugonly)
897 			continue;
898 
899 		if ((error = flushroute_one(&h, &r)) != 0) {
900 			if (error == EPERM)
901 				errc(1, error, "RTM_DELROUTE failed:");
902 			else
903 				warnc(error, "RTM_DELROUTE failed:");
904 		}
905 		snl_clear_lb(&h.ss_cmd);
906 	}
907 
908 	snl_free(&ss);
909 	nl_helper_free(&h);
910 
911 	return (e.error);
912 }
913 
914