ipneigh.c revision 232642c28c5320e6cf1e32f667f866c5f7372bfe 
1/*
2 * ipneigh.c		"ip neigh".
3 *
4 *		This program is free software; you can redistribute it and/or
5 *		modify it under the terms of the GNU General Public License
6 *		as published by the Free Software Foundation; either version
7 *		2 of the License, or (at your option) any later version.
8 *
9 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 *
11 */
12
13#include <stdio.h>
14#include <stdlib.h>
15#include <unistd.h>
16#include <syslog.h>
17#include <fcntl.h>
18#include <string.h>
19#include <sys/time.h>
20#include <sys/socket.h>
21#include <netinet/in.h>
22#include <netinet/ip.h>
23
24#include "rt_names.h"
25#include "utils.h"
26#include "ip_common.h"
27
28#define NUD_VALID	(NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY)
29#define MAX_ROUNDS	10
30
31static struct
32{
33	int family;
34        int index;
35	int state;
36	int unused_only;
37	inet_prefix pfx;
38	int flushed;
39	char *flushb;
40	int flushp;
41	int flushe;
42} filter;
43
44static void usage(void) __attribute__((noreturn));
45
46static void usage(void)
47{
48	fprintf(stderr, "Usage: ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ]\n"
49		        "          [ nud { permanent | noarp | stale | reachable } ]\n"
50		        "          | proxy ADDR } [ dev DEV ]\n");
51	fprintf(stderr, "       ip neigh {show|flush} [ to PREFIX ] [ dev DEV ] [ nud STATE ]\n");
52	exit(-1);
53}
54
55int nud_state_a2n(unsigned *state, char *arg)
56{
57	if (matches(arg, "permanent") == 0)
58		*state = NUD_PERMANENT;
59	else if (matches(arg, "reachable") == 0)
60		*state = NUD_REACHABLE;
61	else if (strcmp(arg, "noarp") == 0)
62		*state = NUD_NOARP;
63	else if (strcmp(arg, "none") == 0)
64		*state = NUD_NONE;
65	else if (strcmp(arg, "stale") == 0)
66		*state = NUD_STALE;
67	else if (strcmp(arg, "incomplete") == 0)
68		*state = NUD_INCOMPLETE;
69	else if (strcmp(arg, "delay") == 0)
70		*state = NUD_DELAY;
71	else if (strcmp(arg, "probe") == 0)
72		*state = NUD_PROBE;
73	else if (matches(arg, "failed") == 0)
74		*state = NUD_FAILED;
75	else {
76		if (get_unsigned(state, arg, 0))
77			return -1;
78		if (*state>=0x100 || (*state&((*state)-1)))
79			return -1;
80	}
81	return 0;
82}
83
84static int flush_update(void)
85{
86	if (rtnl_send_check(&rth, filter.flushb, filter.flushp) < 0) {
87		perror("Failed to send flush request");
88		return -1;
89	}
90	filter.flushp = 0;
91	return 0;
92}
93
94
95static int ipneigh_modify(int cmd, int flags, int argc, char **argv)
96{
97	struct {
98		struct nlmsghdr 	n;
99		struct ndmsg 		ndm;
100		char   			buf[256];
101	} req;
102	char  *d = NULL;
103	int dst_ok = 0;
104	int lladdr_ok = 0;
105	char * lla = NULL;
106	inet_prefix dst;
107
108	memset(&req, 0, sizeof(req));
109
110	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
111	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
112	req.n.nlmsg_type = cmd;
113	req.ndm.ndm_family = preferred_family;
114	req.ndm.ndm_state = NUD_PERMANENT;
115
116	while (argc > 0) {
117		if (matches(*argv, "lladdr") == 0) {
118			NEXT_ARG();
119			if (lladdr_ok)
120				duparg("lladdr", *argv);
121			lla = *argv;
122			lladdr_ok = 1;
123		} else if (strcmp(*argv, "nud") == 0) {
124			unsigned state;
125			NEXT_ARG();
126			if (nud_state_a2n(&state, *argv))
127				invarg("nud state is bad", *argv);
128			req.ndm.ndm_state = state;
129		} else if (matches(*argv, "proxy") == 0) {
130			NEXT_ARG();
131			if (matches(*argv, "help") == 0)
132				usage();
133			if (dst_ok)
134				duparg("address", *argv);
135			get_addr(&dst, *argv, preferred_family);
136			dst_ok = 1;
137			req.ndm.ndm_flags |= NTF_PROXY;
138		} else if (strcmp(*argv, "dev") == 0) {
139			NEXT_ARG();
140			d = *argv;
141		} else {
142			if (strcmp(*argv, "to") == 0) {
143				NEXT_ARG();
144			}
145			if (matches(*argv, "help") == 0) {
146				NEXT_ARG();
147			}
148			if (dst_ok)
149				duparg2("to", *argv);
150			get_addr(&dst, *argv, preferred_family);
151			dst_ok = 1;
152		}
153		argc--; argv++;
154	}
155	if (d == NULL || !dst_ok || dst.family == AF_UNSPEC) {
156		fprintf(stderr, "Device and destination are required arguments.\n");
157		exit(-1);
158	}
159	req.ndm.ndm_family = dst.family;
160	addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen);
161
162	if (lla && strcmp(lla, "null")) {
163		char llabuf[20];
164		int l;
165
166		l = ll_addr_a2n(llabuf, sizeof(llabuf), lla);
167		addattr_l(&req.n, sizeof(req), NDA_LLADDR, llabuf, l);
168	}
169
170	ll_init_map(&rth);
171
172	if ((req.ndm.ndm_ifindex = ll_name_to_index(d)) == 0) {
173		fprintf(stderr, "Cannot find device \"%s\"\n", d);
174		return -1;
175	}
176
177	if (rtnl_talk(&rth, &req.n, 0, 0, NULL, NULL, NULL) < 0)
178		exit(2);
179
180	return 0;
181}
182
183
184int print_neigh(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
185{
186	FILE *fp = (FILE*)arg;
187	struct ndmsg *r = NLMSG_DATA(n);
188	int len = n->nlmsg_len;
189	struct rtattr * tb[NDA_MAX+1];
190	char abuf[256];
191
192	if (n->nlmsg_type != RTM_NEWNEIGH && n->nlmsg_type != RTM_DELNEIGH) {
193		fprintf(stderr, "Not RTM_NEWNEIGH: %08x %08x %08x\n",
194			n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
195
196		return 0;
197	}
198	len -= NLMSG_LENGTH(sizeof(*r));
199	if (len < 0) {
200		fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
201		return -1;
202	}
203
204	if (filter.flushb && n->nlmsg_type != RTM_NEWNEIGH)
205		return 0;
206
207	if (filter.family && filter.family != r->ndm_family)
208		return 0;
209	if (filter.index && filter.index != r->ndm_ifindex)
210		return 0;
211	if (!(filter.state&r->ndm_state) &&
212	    (r->ndm_state || !(filter.state&0x100)) &&
213             (r->ndm_family != AF_DECnet))
214		return 0;
215
216	parse_rtattr(tb, NDA_MAX, NDA_RTA(r), n->nlmsg_len - NLMSG_LENGTH(sizeof(*r)));
217
218	if (tb[NDA_DST]) {
219		if (filter.pfx.family) {
220			inet_prefix dst;
221			memset(&dst, 0, sizeof(dst));
222			dst.family = r->ndm_family;
223			memcpy(&dst.data, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));
224			if (inet_addr_match(&dst, &filter.pfx, filter.pfx.bitlen))
225				return 0;
226		}
227	}
228	if (filter.unused_only && tb[NDA_CACHEINFO]) {
229		struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
230		if (ci->ndm_refcnt)
231			return 0;
232	}
233
234	if (filter.flushb) {
235		struct nlmsghdr *fn;
236		if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
237			if (flush_update())
238				return -1;
239		}
240		fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
241		memcpy(fn, n, n->nlmsg_len);
242		fn->nlmsg_type = RTM_DELNEIGH;
243		fn->nlmsg_flags = NLM_F_REQUEST;
244		fn->nlmsg_seq = ++rth.seq;
245		filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
246		filter.flushed++;
247		if (show_stats < 2)
248			return 0;
249	}
250
251	if (tb[NDA_DST]) {
252		fprintf(fp, "%s ",
253			format_host(r->ndm_family,
254				    RTA_PAYLOAD(tb[NDA_DST]),
255				    RTA_DATA(tb[NDA_DST]),
256				    abuf, sizeof(abuf)));
257	}
258	if (!filter.index && r->ndm_ifindex)
259		fprintf(fp, "dev %s ", ll_index_to_name(r->ndm_ifindex));
260	if (tb[NDA_LLADDR]) {
261		SPRINT_BUF(b1);
262		fprintf(fp, "lladdr %s", ll_addr_n2a(RTA_DATA(tb[NDA_LLADDR]),
263					      RTA_PAYLOAD(tb[NDA_LLADDR]),
264					      ll_index_to_type(r->ndm_ifindex),
265					      b1, sizeof(b1)));
266	}
267	if (r->ndm_flags & NTF_ROUTER) {
268		fprintf(fp, " router");
269	}
270	if (tb[NDA_CACHEINFO] && show_stats) {
271		struct nda_cacheinfo *ci = RTA_DATA(tb[NDA_CACHEINFO]);
272		int hz = get_user_hz();
273
274		if (ci->ndm_refcnt)
275			printf(" ref %d", ci->ndm_refcnt);
276		fprintf(fp, " used %d/%d/%d", ci->ndm_used/hz,
277		       ci->ndm_confirmed/hz, ci->ndm_updated/hz);
278	}
279
280#ifdef NDA_PROBES
281	if (tb[NDA_PROBES] && show_stats) {
282		__u32 p = *(__u32 *) RTA_DATA(tb[NDA_PROBES]);
283		fprintf(fp, " probes %u", p);
284	}
285#endif
286
287	if (r->ndm_state) {
288		int nud = r->ndm_state;
289		fprintf(fp, " ");
290
291#define PRINT_FLAG(f) if (nud & NUD_##f) { \
292	nud &= ~NUD_##f; fprintf(fp, #f "%s", nud ? "," : ""); }
293		PRINT_FLAG(INCOMPLETE);
294		PRINT_FLAG(REACHABLE);
295		PRINT_FLAG(STALE);
296		PRINT_FLAG(DELAY);
297		PRINT_FLAG(PROBE);
298		PRINT_FLAG(FAILED);
299		PRINT_FLAG(NOARP);
300		PRINT_FLAG(PERMANENT);
301#undef PRINT_FLAG
302	}
303	fprintf(fp, "\n");
304
305	fflush(fp);
306	return 0;
307}
308
309void ipneigh_reset_filter()
310{
311	memset(&filter, 0, sizeof(filter));
312	filter.state = ~0;
313}
314
315int do_show_or_flush(int argc, char **argv, int flush)
316{
317	char *filter_dev = NULL;
318	int state_given = 0;
319
320	ipneigh_reset_filter();
321
322	if (!filter.family)
323		filter.family = preferred_family;
324
325	if (flush) {
326		if (argc <= 0) {
327			fprintf(stderr, "Flush requires arguments.\n");
328			return -1;
329		}
330		filter.state = ~(NUD_PERMANENT|NUD_NOARP);
331	} else
332		filter.state = 0xFF & ~NUD_NOARP;
333
334	while (argc > 0) {
335		if (strcmp(*argv, "dev") == 0) {
336			NEXT_ARG();
337			if (filter_dev)
338				duparg("dev", *argv);
339			filter_dev = *argv;
340		} else if (strcmp(*argv, "unused") == 0) {
341			filter.unused_only = 1;
342		} else if (strcmp(*argv, "nud") == 0) {
343			unsigned state;
344			NEXT_ARG();
345			if (!state_given) {
346				state_given = 1;
347				filter.state = 0;
348			}
349			if (nud_state_a2n(&state, *argv)) {
350				if (strcmp(*argv, "all") != 0)
351					invarg("nud state is bad", *argv);
352				state = ~0;
353				if (flush)
354					state &= ~NUD_NOARP;
355			}
356			if (state == 0)
357				state = 0x100;
358			filter.state |= state;
359		} else {
360			if (strcmp(*argv, "to") == 0) {
361				NEXT_ARG();
362			}
363			if (matches(*argv, "help") == 0)
364				usage();
365			get_prefix(&filter.pfx, *argv, filter.family);
366			if (filter.family == AF_UNSPEC)
367				filter.family = filter.pfx.family;
368		}
369		argc--; argv++;
370	}
371
372	ll_init_map(&rth);
373
374	if (filter_dev) {
375		if ((filter.index = ll_name_to_index(filter_dev)) == 0) {
376			fprintf(stderr, "Cannot find device \"%s\"\n", filter_dev);
377			return -1;
378		}
379	}
380
381	if (flush) {
382		int round = 0;
383		char flushb[4096-512];
384
385		filter.flushb = flushb;
386		filter.flushp = 0;
387		filter.flushe = sizeof(flushb);
388		filter.state &= ~NUD_FAILED;
389
390		while (round < MAX_ROUNDS) {
391			if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
392				perror("Cannot send dump request");
393				exit(1);
394			}
395			filter.flushed = 0;
396			if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
397				fprintf(stderr, "Flush terminated\n");
398				exit(1);
399			}
400			if (filter.flushed == 0) {
401				if (show_stats) {
402					if (round == 0)
403						printf("Nothing to flush.\n");
404					else
405						printf("*** Flush is complete after %d round%s ***\n", round, round>1?"s":"");
406				}
407				fflush(stdout);
408				return 0;
409			}
410			round++;
411			if (flush_update() < 0)
412				exit(1);
413			if (show_stats) {
414				printf("\n*** Round %d, deleting %d entries ***\n", round, filter.flushed);
415				fflush(stdout);
416			}
417		}
418		printf("*** Flush not complete bailing out after %d rounds\n",
419			MAX_ROUNDS);
420		return 1;
421	}
422
423	if (rtnl_wilddump_request(&rth, filter.family, RTM_GETNEIGH) < 0) {
424		perror("Cannot send dump request");
425		exit(1);
426	}
427
428	if (rtnl_dump_filter(&rth, print_neigh, stdout, NULL, NULL) < 0) {
429		fprintf(stderr, "Dump terminated\n");
430		exit(1);
431	}
432
433	return 0;
434}
435
436int do_ipneigh(int argc, char **argv)
437{
438	if (argc > 0) {
439		if (matches(*argv, "add") == 0)
440			return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_EXCL, argc-1, argv+1);
441		if (matches(*argv, "change") == 0 ||
442		    strcmp(*argv, "chg") == 0)
443			return ipneigh_modify(RTM_NEWNEIGH, NLM_F_REPLACE, argc-1, argv+1);
444		if (matches(*argv, "replace") == 0)
445			return ipneigh_modify(RTM_NEWNEIGH, NLM_F_CREATE|NLM_F_REPLACE, argc-1, argv+1);
446		if (matches(*argv, "delete") == 0)
447			return ipneigh_modify(RTM_DELNEIGH, 0, argc-1, argv+1);
448		if (matches(*argv, "get") == 0) {
449			fprintf(stderr, "Sorry, \"neigh get\" is not implemented :-(\n");
450			return -1;
451		}
452		if (matches(*argv, "show") == 0 ||
453		    matches(*argv, "lst") == 0 ||
454		    matches(*argv, "list") == 0)
455			return do_show_or_flush(argc-1, argv+1, 0);
456		if (matches(*argv, "flush") == 0)
457			return do_show_or_flush(argc-1, argv+1, 1);
458		if (matches(*argv, "help") == 0)
459			usage();
460	} else
461		return do_show_or_flush(0, NULL, 0);
462
463	fprintf(stderr, "Command \"%s\" is unknown, try \"ip neigh help\".\n", *argv);
464	exit(-1);
465}
466