1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <stdbool.h>
5 #include <errno.h>
6 #include <netdb.h>
7
8 #include <sys/bitcount.h>
9 #include <sys/param.h>
10 #include <sys/linker.h>
11 #include <sys/module.h>
12 #include <sys/socket.h>
13 #include <sys/sysctl.h>
14 #include <sys/time.h>
15 #include <sys/types.h>
16
17 #include <netinet/in.h>
18 #include <arpa/inet.h>
19
20 #include <net/ethernet.h>
21 #include <net/if.h>
22 #include <net/if_dl.h>
23 #include <net/if_types.h>
24 #include <netlink/netlink.h>
25 #include <netlink/netlink_route.h>
26 #include <netlink/netlink_snl.h>
27 #include <netlink/netlink_snl_route.h>
28 #include <netlink/netlink_snl_route_compat.h>
29 #include <netlink/netlink_snl_route_parsers.h>
30
31 #include <libxo/xo.h>
32 #include "arp.h"
33
34 #define RTF_ANNOUNCE RTF_PROTO2
35
36 static void
nl_init_socket(struct snl_state * ss)37 nl_init_socket(struct snl_state *ss)
38 {
39 if (snl_init(ss, NETLINK_ROUTE))
40 return;
41
42 if (modfind("netlink") == -1 && errno == ENOENT) {
43 /* Try to load */
44 if (kldload("netlink") == -1)
45 xo_err(1, "netlink is not loaded and load attempt failed");
46 if (snl_init(ss, NETLINK_ROUTE))
47 return;
48 }
49
50 xo_err(1, "unable to open netlink socket");
51 }
52
53 static bool
get_link_info(struct snl_state * ss,uint32_t ifindex,struct snl_parsed_link_simple * link)54 get_link_info(struct snl_state *ss, uint32_t ifindex,
55 struct snl_parsed_link_simple *link)
56 {
57 struct snl_writer nw;
58
59 snl_init_writer(ss, &nw);
60
61 struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETLINK);
62 struct ifinfomsg *ifmsg = snl_reserve_msg_object(&nw, struct ifinfomsg);
63 if (ifmsg != NULL)
64 ifmsg->ifi_index = ifindex;
65 if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
66 return (false);
67
68 hdr = snl_read_reply(ss, hdr->nlmsg_seq);
69
70 if (hdr == NULL || hdr->nlmsg_type != RTM_NEWLINK)
71 return (false);
72
73 if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser_simple, link))
74 return (false);
75
76 return (true);
77 }
78
79
80
81 static bool
has_l2(struct snl_state * ss,uint32_t ifindex)82 has_l2(struct snl_state *ss, uint32_t ifindex)
83 {
84 struct snl_parsed_link_simple link = {};
85
86 if (!get_link_info(ss, ifindex, &link))
87 return (false);
88
89 return (valid_type(link.ifi_type) != 0);
90 }
91
92 static uint32_t
get_myfib(void)93 get_myfib(void)
94 {
95 uint32_t fibnum = 0;
96 size_t len = sizeof(fibnum);
97
98 sysctlbyname("net.my_fibnum", (void *)&fibnum, &len, NULL, 0);
99
100 return (fibnum);
101 }
102
103 static int
guess_ifindex(struct snl_state * ss,uint32_t fibnum,struct in_addr addr)104 guess_ifindex(struct snl_state *ss, uint32_t fibnum, struct in_addr addr)
105 {
106 struct snl_writer nw;
107
108 snl_init_writer(ss, &nw);
109
110 struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETROUTE);
111 struct rtmsg *rtm = snl_reserve_msg_object(&nw, struct rtmsg);
112 rtm->rtm_family = AF_INET;
113
114 struct sockaddr_in dst = { .sin_family = AF_INET, .sin_addr = addr };
115 snl_add_msg_attr_ip(&nw, RTA_DST, (struct sockaddr *)&dst);
116 snl_add_msg_attr_u32(&nw, RTA_TABLE, fibnum);
117
118 if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
119 return (0);
120
121 hdr = snl_read_reply(ss, hdr->nlmsg_seq);
122
123 if (hdr->nlmsg_type != NL_RTM_NEWROUTE) {
124 /* No route found, unable to guess ifindex */
125 return (0);
126 }
127
128 struct snl_parsed_route r = {};
129 if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_route_parser, &r))
130 return (0);
131
132 if (r.rta_multipath.num_nhops > 0 || (r.rta_rtflags & RTF_GATEWAY))
133 return (0);
134
135 /* Check if the interface is of supported type */
136 if (has_l2(ss, r.rta_oif))
137 return (r.rta_oif);
138
139 /* Check the case when we matched the loopback route for P2P */
140 snl_init_writer(ss, &nw);
141 hdr = snl_create_msg_request(&nw, RTM_GETNEXTHOP);
142 snl_reserve_msg_object(&nw, struct nhmsg);
143
144 int off = snl_add_msg_attr_nested(&nw, NHA_FREEBSD);
145 snl_add_msg_attr_u32(&nw, NHAF_KID, r.rta_knh_id);
146 snl_add_msg_attr_u8(&nw, NHAF_FAMILY, AF_INET);
147 snl_add_msg_attr_u32(&nw, NHAF_TABLE, fibnum);
148 snl_end_attr_nested(&nw, off);
149
150 if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
151 return (0);
152
153 hdr = snl_read_reply(ss, hdr->nlmsg_seq);
154
155 if (hdr->nlmsg_type != NL_RTM_NEWNEXTHOP) {
156 /* No nexthop found, unable to guess ifindex */
157 return (0);
158 }
159
160 struct snl_parsed_nhop nh = {};
161 if (!snl_parse_nlmsg(ss, hdr, &snl_nhmsg_parser, &nh))
162 return (0);
163
164 return (nh.nhaf_aif);
165 }
166
167 static uint32_t
fix_ifindex(struct snl_state * ss,uint32_t ifindex,struct in_addr addr)168 fix_ifindex(struct snl_state *ss, uint32_t ifindex, struct in_addr addr)
169 {
170 if (ifindex == 0)
171 ifindex = guess_ifindex(ss, get_myfib(), addr);
172 return (ifindex);
173 }
174
175 static void
print_entry(struct snl_parsed_neigh * neigh,struct snl_parsed_link_simple * link)176 print_entry(struct snl_parsed_neigh *neigh, struct snl_parsed_link_simple *link)
177 {
178 const char *host;
179 struct hostent *hp;
180 struct sockaddr_in *addr = (struct sockaddr_in *)neigh->nda_dst;
181
182 xo_open_instance("arp-cache");
183
184 if (!opts.nflag)
185 hp = gethostbyaddr((caddr_t)&(addr->sin_addr),
186 sizeof(addr->sin_addr), AF_INET);
187 else
188 hp = 0;
189 if (hp)
190 host = hp->h_name;
191 else {
192 host = "?";
193 if (h_errno == TRY_AGAIN)
194 opts.nflag = true;
195 }
196 xo_emit("{:hostname/%s} ({:ip-address/%s}) at ", host,
197 inet_ntoa(addr->sin_addr));
198 if (neigh->nda_lladdr != NULL) {
199 struct sockaddr_dl sdl = {
200 .sdl_family = AF_LINK,
201 .sdl_type = link->ifi_type,
202 .sdl_len = sizeof(struct sockaddr_dl),
203 .sdl_alen = NLA_DATA_LEN(neigh->nda_lladdr),
204 };
205 memcpy(sdl.sdl_data, NLA_DATA(neigh->nda_lladdr), sdl.sdl_alen);
206
207 if ((sdl.sdl_type == IFT_ETHER ||
208 sdl.sdl_type == IFT_L2VLAN ||
209 sdl.sdl_type == IFT_BRIDGE) &&
210 sdl.sdl_alen == ETHER_ADDR_LEN)
211 xo_emit("{:mac-address/%s}",
212 ether_ntoa((struct ether_addr *)LLADDR(&sdl)));
213 else {
214
215 xo_emit("{:mac-address/%s}", link_ntoa(&sdl));
216 }
217 } else
218 xo_emit("{d:/(incomplete)}{en:incomplete/true}");
219 xo_emit(" on {:interface/%s}", link->ifla_ifname);
220
221 if (neigh->ndaf_next_ts == 0)
222 xo_emit("{d:/ permanent}{en:permanent/true}");
223 else {
224 time_t expire_time;
225 struct timeval now;
226
227 gettimeofday(&now, 0);
228 if ((expire_time = neigh->ndaf_next_ts - now.tv_sec) > 0)
229 xo_emit(" expires in {:expires/%d} seconds",
230 (int)expire_time);
231 else
232 xo_emit("{d:/ expired}{en:expired/true}");
233 }
234
235 if (neigh->ndm_flags & NTF_PROXY)
236 xo_emit("{d:/ published}{en:published/true}");
237
238 switch(link->ifi_type) {
239 case IFT_ETHER:
240 xo_emit(" [{:type/ethernet}]");
241 break;
242 case IFT_FDDI:
243 xo_emit(" [{:type/fddi}]");
244 break;
245 case IFT_ATM:
246 xo_emit(" [{:type/atm}]");
247 break;
248 case IFT_L2VLAN:
249 xo_emit(" [{:type/vlan}]");
250 break;
251 case IFT_IEEE1394:
252 xo_emit(" [{:type/firewire}]");
253 break;
254 case IFT_BRIDGE:
255 xo_emit(" [{:type/bridge}]");
256 break;
257 case IFT_INFINIBAND:
258 xo_emit(" [{:type/infiniband}]");
259 break;
260 default:
261 break;
262 }
263
264 xo_emit("\n");
265
266 xo_close_instance("arp-cache");
267 }
268
269 int
print_entries_nl(uint32_t ifindex,struct in_addr addr)270 print_entries_nl(uint32_t ifindex, struct in_addr addr)
271 {
272 struct snl_state ss_req = {}, ss_cmd = {};
273 struct snl_parsed_link_simple link = {};
274 struct snl_writer nw;
275
276 nl_init_socket(&ss_req);
277 snl_init_writer(&ss_req, &nw);
278
279 struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETNEIGH);
280 struct ndmsg *ndmsg = snl_reserve_msg_object(&nw, struct ndmsg);
281 if (ndmsg != NULL) {
282 ndmsg->ndm_family = AF_INET;
283 /* let kernel filter results by interface if provided */
284 ndmsg->ndm_ifindex = ifindex;
285 }
286
287 if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(&ss_req, hdr)) {
288 snl_free(&ss_req);
289 return (0);
290 }
291
292 uint32_t nlmsg_seq = hdr->nlmsg_seq;
293 struct snl_errmsg_data e = {};
294 int count = 0;
295 nl_init_socket(&ss_cmd);
296
297 while ((hdr = snl_read_reply_multi(&ss_req, nlmsg_seq, &e)) != NULL) {
298 struct snl_parsed_neigh neigh = {};
299 struct sockaddr_in *neighaddr;
300
301 if (!snl_parse_nlmsg(&ss_req, hdr, &snl_rtm_neigh_parser, &neigh))
302 continue;
303
304 if (neigh.nda_ifindex != link.ifi_index) {
305 snl_clear_lb(&ss_cmd);
306 memset(&link, 0, sizeof(link));
307 if (!get_link_info(&ss_cmd, neigh.nda_ifindex, &link))
308 continue;
309 }
310
311 /* filter results based on host if provided */
312 neighaddr = (struct sockaddr_in *)neigh.nda_dst;
313 if (addr.s_addr &&
314 (addr.s_addr != neighaddr->sin_addr.s_addr))
315 continue;
316
317 print_entry(&neigh, &link);
318 count++;
319 snl_clear_lb(&ss_req);
320 }
321
322 snl_free(&ss_req);
323 snl_free(&ss_cmd);
324
325 return (count);
326 }
327
328 int
delete_nl(uint32_t ifindex,char * host)329 delete_nl(uint32_t ifindex, char *host)
330 {
331 struct snl_state ss = {};
332 struct snl_writer nw;
333 struct sockaddr_in *dst;
334
335 dst = getaddr(host);
336 if (dst == NULL)
337 return (1);
338
339 nl_init_socket(&ss);
340
341 ifindex = fix_ifindex(&ss, ifindex, dst->sin_addr);
342 if (ifindex == 0) {
343 xo_warnx("delete: cannot locate %s", host);
344 snl_free(&ss);
345 return (0);
346 }
347
348 snl_init_writer(&ss, &nw);
349 struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_DELNEIGH);
350 struct ndmsg *ndmsg = snl_reserve_msg_object(&nw, struct ndmsg);
351 if (ndmsg != NULL) {
352 ndmsg->ndm_family = AF_INET;
353 ndmsg->ndm_ifindex = ifindex;
354 }
355 snl_add_msg_attr_ip(&nw, NDA_DST, (struct sockaddr *)dst);
356
357 if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(&ss, hdr)) {
358 snl_free(&ss);
359 return (1);
360 }
361
362 struct snl_errmsg_data e = {};
363 snl_read_reply_code(&ss, hdr->nlmsg_seq, &e);
364 if (e.error != 0) {
365 if (e.error_str != NULL)
366 xo_warnx("delete %s: %s (%s)", host, strerror(e.error), e.error_str);
367 else
368 xo_warnx("delete %s: %s", host, strerror(e.error));
369 } else
370 printf("%s (%s) deleted\n", host, inet_ntoa(dst->sin_addr));
371
372 snl_free(&ss);
373
374 return (e.error != 0);
375 }
376
377 int
set_nl(uint32_t ifindex,struct sockaddr_in * dst,struct sockaddr_dl * sdl,char * host)378 set_nl(uint32_t ifindex, struct sockaddr_in *dst, struct sockaddr_dl *sdl, char *host)
379 {
380 struct snl_state ss = {};
381 struct snl_writer nw;
382
383 nl_init_socket(&ss);
384
385 ifindex = fix_ifindex(&ss, ifindex, dst->sin_addr);
386 if (ifindex == 0) {
387 xo_warnx("set: cannot locate %s", host);
388 snl_free(&ss);
389 return (0);
390 }
391
392 snl_init_writer(&ss, &nw);
393 struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_NEWNEIGH);
394 hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_REPLACE;
395 struct ndmsg *ndmsg = snl_reserve_msg_object(&nw, struct ndmsg);
396 if (ndmsg != NULL) {
397 uint8_t nl_flags = 0;
398
399 ndmsg->ndm_family = AF_INET;
400 ndmsg->ndm_ifindex = ifindex;
401 ndmsg->ndm_state = (opts.expire_time == 0) ? \
402 NUD_PERMANENT : NUD_NONE;
403
404 if (opts.flags & RTF_ANNOUNCE)
405 nl_flags |= NTF_PROXY;
406 if (opts.expire_time == 0)
407 nl_flags |= NTF_STICKY;
408 ndmsg->ndm_flags = nl_flags;
409 }
410 snl_add_msg_attr_ip(&nw, NDA_DST, (struct sockaddr *)dst);
411 snl_add_msg_attr(&nw, NDA_LLADDR, sdl->sdl_alen, LLADDR(sdl));
412
413 if (opts.expire_time != 0) {
414 struct timeval now;
415
416 gettimeofday(&now, 0);
417 int off = snl_add_msg_attr_nested(&nw, NDA_FREEBSD);
418 snl_add_msg_attr_u32(&nw, NDAF_NEXT_STATE_TS, now.tv_sec + opts.expire_time);
419 snl_end_attr_nested(&nw, off);
420 }
421
422 if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(&ss, hdr)) {
423 snl_free(&ss);
424 return (1);
425 }
426
427 struct snl_errmsg_data e = {};
428 snl_read_reply_code(&ss, hdr->nlmsg_seq, &e);
429 if (e.error != 0) {
430 if (e.error_str != NULL)
431 xo_warnx("set: %s: %s (%s)", host, strerror(e.error), e.error_str);
432 else
433 xo_warnx("set %s: %s", host, strerror(e.error));
434 }
435 snl_free(&ss);
436
437 return (e.error != 0);
438 }
439
440