xref: /freebsd/usr.bin/netstat/if.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2013 Gleb Smirnoff <glebius@FreeBSD.org>
3  * Copyright (c) 1983, 1988, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 4. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #if 0
32 #ifndef lint
33 static char sccsid[] = "@(#)if.c	8.3 (Berkeley) 4/28/95";
34 #endif /* not lint */
35 #endif
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/protosw.h>
42 #include <sys/socket.h>
43 #include <sys/socketvar.h>
44 #include <sys/time.h>
45 
46 #include <net/if.h>
47 #include <net/if_dl.h>
48 #include <net/if_types.h>
49 #include <net/ethernet.h>
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 #include <arpa/inet.h>
53 #ifdef PF
54 #include <net/pfvar.h>
55 #include <net/if_pfsync.h>
56 #endif
57 
58 #include <err.h>
59 #include <errno.h>
60 #include <ifaddrs.h>
61 #include <libutil.h>
62 #ifdef INET6
63 #include <netdb.h>
64 #endif
65 #include <signal.h>
66 #include <stdbool.h>
67 #include <stdint.h>
68 #include <stdio.h>
69 #include <stdlib.h>
70 #include <string.h>
71 #include <sysexits.h>
72 #include <unistd.h>
73 #include <libxo/xo.h>
74 
75 #include "netstat.h"
76 
77 static void sidewaysintpr(void);
78 
79 #ifdef PF
80 static const char* pfsyncacts[] = {
81 	/* PFSYNC_ACT_CLR */		"clear all request",
82 	/* PFSYNC_ACT_INS */		"state insert",
83 	/* PFSYNC_ACT_INS_ACK */	"state inserted ack",
84 	/* PFSYNC_ACT_UPD */		"state update",
85 	/* PFSYNC_ACT_UPD_C */		"compressed state update",
86 	/* PFSYNC_ACT_UPD_REQ */	"uncompressed state request",
87 	/* PFSYNC_ACT_DEL */		"state delete",
88 	/* PFSYNC_ACT_DEL_C */		"compressed state delete",
89 	/* PFSYNC_ACT_INS_F */		"fragment insert",
90 	/* PFSYNC_ACT_DEL_F */		"fragment delete",
91 	/* PFSYNC_ACT_BUS */		"bulk update mark",
92 	/* PFSYNC_ACT_TDB */		"TDB replay counter update",
93 	/* PFSYNC_ACT_EOF */		"end of frame mark",
94 };
95 
96 static const char* pfsyncacts_name[] = {
97 	/* PFSYNC_ACT_CLR */		"clear-all-request",
98 	/* PFSYNC_ACT_INS */		"state-insert",
99 	/* PFSYNC_ACT_INS_ACK */	"state-inserted-ack",
100 	/* PFSYNC_ACT_UPD */		"state-update",
101 	/* PFSYNC_ACT_UPD_C */		"compressed-state-update",
102 	/* PFSYNC_ACT_UPD_REQ */	"uncompressed-state-request",
103 	/* PFSYNC_ACT_DEL */		"state-delete",
104 	/* PFSYNC_ACT_DEL_C */		"compressed-state-delete",
105 	/* PFSYNC_ACT_INS_F */		"fragment-insert",
106 	/* PFSYNC_ACT_DEL_F */		"fragment-delete",
107 	/* PFSYNC_ACT_BUS */		"bulk-update-mark",
108 	/* PFSYNC_ACT_TDB */		"TDB-replay-counter-update",
109 	/* PFSYNC_ACT_EOF */		"end-of-frame-mark",
110 };
111 
112 static void
113 pfsync_acts_stats(const char *list, const char *desc, uint64_t *a)
114 {
115 	int i;
116 
117 	xo_open_list(list);
118 	for (i = 0; i < PFSYNC_ACT_MAX; i++, a++) {
119 		if (*a || sflag <= 1) {
120 			xo_open_instance(list);
121 			xo_emit("\t\t{e:name}{:count/%ju} {N:/%s%s %s}\n",
122 			    pfsyncacts_name[i], (uintmax_t)(*a),
123 			    pfsyncacts[i], plural(*a), desc);
124 			xo_close_instance(list);
125 		}
126 	}
127 	xo_close_list(list);
128 }
129 
130 /*
131  * Dump pfsync statistics structure.
132  */
133 void
134 pfsync_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
135 {
136 	struct pfsyncstats pfsyncstat;
137 
138 	if (fetch_stats("net.pfsync.stats", off, &pfsyncstat,
139 	    sizeof(pfsyncstat), kread) != 0)
140 		return;
141 
142 	xo_emit("{T:/%s}:\n", name);
143 	xo_open_container(name);
144 
145 #define	p(f, m) if (pfsyncstat.f || sflag <= 1) \
146 	xo_emit(m, (uintmax_t)pfsyncstat.f, plural(pfsyncstat.f))
147 
148 	p(pfsyncs_ipackets, "\t{:received-inet-packets/%ju} "
149 	    "{N:/packet%s received (IPv4)}\n");
150 	p(pfsyncs_ipackets6, "\t{:received-inet6-packets/%ju} "
151 	    "{N:/packet%s received (IPv6)}\n");
152 	pfsync_acts_stats("input-histogram", "received",
153 	    &pfsyncstat.pfsyncs_iacts[0]);
154 	p(pfsyncs_badif, "\t\t/{:dropped-bad-interface/%ju} "
155 	    "{N:/packet%s discarded for bad interface}\n");
156 	p(pfsyncs_badttl, "\t\t{:dropped-bad-ttl/%ju} "
157 	    "{N:/packet%s discarded for bad ttl}\n");
158 	p(pfsyncs_hdrops, "\t\t{:dropped-short-header/%ju} "
159 	    "{N:/packet%s shorter than header}\n");
160 	p(pfsyncs_badver, "\t\t{:dropped-bad-version/%ju} "
161 	    "{N:/packet%s discarded for bad version}\n");
162 	p(pfsyncs_badauth, "\t\t{:dropped-bad-auth/%ju} "
163 	    "{N:/packet%s discarded for bad HMAC}\n");
164 	p(pfsyncs_badact,"\t\t{:dropped-bad-action/%ju} "
165 	    "{N:/packet%s discarded for bad action}\n");
166 	p(pfsyncs_badlen, "\t\t{:dropped-short/%ju} "
167 	    "{N:/packet%s discarded for short packet}\n");
168 	p(pfsyncs_badval, "\t\t{:dropped-bad-values/%ju} "
169 	    "{N:/state%s discarded for bad values}\n");
170 	p(pfsyncs_stale, "\t\t{:dropped-stale-state/%ju} "
171 	    "{N:/stale state%s}\n");
172 	p(pfsyncs_badstate, "\t\t{:dropped-failed-lookup/%ju} "
173 	    "{N:/failed state lookup\\/insert%s}\n");
174 	p(pfsyncs_opackets, "\t{:sent-inet-packets/%ju} "
175 	    "{N:/packet%s sent (IPv4})\n");
176 	p(pfsyncs_opackets6, "\t{:send-inet6-packets/%ju} "
177 	    "{N:/packet%s sent (IPv6})\n");
178 	pfsync_acts_stats("output-histogram", "sent",
179 	    &pfsyncstat.pfsyncs_oacts[0]);
180 	p(pfsyncs_onomem, "\t\t{:discarded-no-memory/%ju} "
181 	    "{N:/failure%s due to mbuf memory error}\n");
182 	p(pfsyncs_oerrors, "\t\t{:send-errors/%ju} "
183 	    "{N:/send error%s}\n");
184 #undef p
185 	xo_close_container(name);
186 }
187 #endif /* PF */
188 
189 /*
190  * Display a formatted value, or a '-' in the same space.
191  */
192 static void
193 show_stat(const char *fmt, int width, const char *name,
194     u_long value, short showvalue, int div1000)
195 {
196 	const char *lsep, *rsep;
197 	char newfmt[64];
198 
199 	lsep = "";
200 	if (strncmp(fmt, "LS", 2) == 0) {
201 		lsep = " ";
202 		fmt += 2;
203 	}
204 	rsep = " ";
205 	if (strncmp(fmt, "NRS", 3) == 0) {
206 		rsep = "";
207 		fmt += 3;
208 	}
209 	if (showvalue == 0) {
210 		/* Print just dash. */
211 		xo_emit("{P:/%s}{D:/%*s}{P:/%s}", lsep, width, "-", rsep);
212 		return;
213 	}
214 
215 	/*
216 	 * XXX: workaround {P:} modifier can't be empty and doesn't seem to
217 	 * take args... so we need to conditionally include it in the format.
218 	 */
219 #define maybe_pad(pad)	do {						    \
220 	if (strlen(pad)) {						    \
221 		snprintf(newfmt, sizeof(newfmt), "{P:%s}", pad);	    \
222 		xo_emit(newfmt);					    \
223 	}								    \
224 } while (0)
225 
226 	if (hflag) {
227 		char buf[5];
228 
229 		/* Format in human readable form. */
230 		humanize_number(buf, sizeof(buf), (int64_t)value, "",
231 		    HN_AUTOSCALE, HN_NOSPACE | HN_DECIMAL | \
232 		    ((div1000) ? HN_DIVISOR_1000 : 0));
233 		maybe_pad(lsep);
234 		snprintf(newfmt, sizeof(newfmt), "{:%s/%%%ds}", name, width);
235 		xo_emit(newfmt, buf);
236 		maybe_pad(rsep);
237 	} else {
238 		/* Construct the format string. */
239 		maybe_pad(lsep);
240 		snprintf(newfmt, sizeof(newfmt), "{:%s/%%%d%s}",
241 		    name, width, fmt);
242 		xo_emit(newfmt, value);
243 		maybe_pad(rsep);
244 	}
245 }
246 
247 /*
248  * Find next multiaddr for a given interface name.
249  */
250 static struct ifmaddrs *
251 next_ifma(struct ifmaddrs *ifma, const char *name, const sa_family_t family)
252 {
253 
254 	for(; ifma != NULL; ifma = ifma->ifma_next) {
255 		struct sockaddr_dl *sdl;
256 
257 		sdl = (struct sockaddr_dl *)ifma->ifma_name;
258 		if (ifma->ifma_addr->sa_family == family &&
259 		    strcmp(sdl->sdl_data, name) == 0)
260 			break;
261 	}
262 
263 	return (ifma);
264 }
265 
266 /*
267  * Print a description of the network interfaces.
268  */
269 void
270 intpr(void (*pfunc)(char *), int af)
271 {
272 	struct ifaddrs *ifap, *ifa;
273 	struct ifmaddrs *ifmap, *ifma;
274 	u_int ifn_len_max = 5, ifn_len;
275 	u_int has_ipv6 = 0, net_len = 13, addr_len = 17;
276 
277 	if (interval)
278 		return sidewaysintpr();
279 
280 	if (getifaddrs(&ifap) != 0)
281 		err(EX_OSERR, "getifaddrs");
282 	if (aflag && getifmaddrs(&ifmap) != 0)
283 		err(EX_OSERR, "getifmaddrs");
284 
285 	if (Wflag) {
286 		for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
287 			if (interface != NULL &&
288 			    strcmp(ifa->ifa_name, interface) != 0)
289 				continue;
290 			if (af != AF_UNSPEC && ifa->ifa_addr->sa_family != af)
291 				continue;
292 			ifn_len = strlen(ifa->ifa_name);
293 			if ((ifa->ifa_flags & IFF_UP) == 0)
294 				++ifn_len;
295 			ifn_len_max = MAX(ifn_len_max, ifn_len);
296 			if (ifa->ifa_addr->sa_family == AF_INET6)
297 				has_ipv6 = 1;
298 		}
299 		if (has_ipv6) {
300 			net_len = 24;
301 			addr_len = 39;
302 		} else
303 			net_len = 18;
304 	}
305 
306 	xo_open_list("interface");
307 	if (!pfunc) {
308 		xo_emit("{T:/%-*.*s}", ifn_len_max, ifn_len_max, "Name");
309 		xo_emit(" {T:/%5.5s} {T:/%-*.*s} {T:/%-*.*s} {T:/%8.8s} "
310 		    "{T:/%5.5s} {T:/%5.5s}",
311 		    "Mtu", net_len, net_len, "Network", addr_len, addr_len,
312 		    "Address", "Ipkts", "Ierrs", "Idrop");
313 		if (bflag)
314 			xo_emit(" {T:/%10.10s}","Ibytes");
315 		xo_emit(" {T:/%8.8s} {T:/%5.5s}", "Opkts", "Oerrs");
316 		if (bflag)
317 			xo_emit(" {T:/%10.10s}","Obytes");
318 		xo_emit(" {T:/%5s}", "Coll");
319 		if (dflag)
320 			xo_emit(" {T:/%5.5s}", "Drop");
321 		xo_emit("\n");
322 	}
323 
324 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
325 		bool network = false, link = false;
326 		char *name, *xname, buf[IFNAMSIZ+1];
327 		const char *nn, *rn;
328 
329 		if (interface != NULL && strcmp(ifa->ifa_name, interface) != 0)
330 			continue;
331 
332 		name = ifa->ifa_name;
333 
334 		if (pfunc) {
335 
336 			(*pfunc)(name);
337 
338 			/*
339 			 * Skip all ifaddrs belonging to same interface.
340 			 */
341 			while(ifa->ifa_next != NULL &&
342 			    (strcmp(ifa->ifa_next->ifa_name, name) == 0)) {
343 				ifa = ifa->ifa_next;
344 			}
345 			continue;
346 		}
347 
348 		if (af != AF_UNSPEC && ifa->ifa_addr->sa_family != af)
349 			continue;
350 
351 		xo_open_instance("interface");
352 
353 		if ((ifa->ifa_flags & IFF_UP) == 0) {
354 			xname = stpcpy(buf, name);
355 			*xname++ = '*';
356 			*xname = '\0';
357 			xname = buf;
358 		} else
359 			xname = name;
360 
361 		xo_emit("{d:/%-*.*s}{etk:name}{eq:flags/0x%x}",
362 		    ifn_len_max, ifn_len_max, xname, name, ifa->ifa_flags);
363 
364 #define IFA_MTU(ifa)	(((struct if_data *)(ifa)->ifa_data)->ifi_mtu)
365 		show_stat("lu", 6, "mtu", IFA_MTU(ifa), IFA_MTU(ifa), 0);
366 #undef IFA_MTU
367 
368 		switch (ifa->ifa_addr->sa_family) {
369 		case AF_UNSPEC:
370 			xo_emit("{:network/%-*.*s} ", net_len, net_len,
371 			    "none");
372 			xo_emit("{:address/%-*.*s} ", addr_len, addr_len,
373 			    "none");
374 			break;
375 		case AF_INET:
376 #ifdef INET6
377 		case AF_INET6:
378 #endif /* INET6 */
379 			nn = netname(ifa->ifa_addr, ifa->ifa_netmask);
380 			rn = routename(ifa->ifa_addr, numeric_addr);
381 			if (Wflag) {
382 				xo_emit("{t:network/%-*s} ", net_len, nn);
383 				xo_emit("{t:address/%-*s} ", addr_len, rn);
384 			} else {
385 				xo_emit("{d:network/%-*.*s}{et:network} ",
386 				    net_len, net_len, nn, nn);
387 				xo_emit("{d:address/%-*.*s}{et:address} ",
388 				    addr_len, addr_len, rn, rn);
389 			}
390 
391 			network = true;
392 			break;
393 		case AF_LINK:
394 		    {
395 			struct sockaddr_dl *sdl;
396 			char linknum[10];
397 
398 			sdl = (struct sockaddr_dl *)ifa->ifa_addr;
399 			sprintf(linknum, "<Link#%d>", sdl->sdl_index);
400 			xo_emit("{t:network/%-*.*s} ", net_len, net_len,
401 			    linknum);
402 			if (sdl->sdl_nlen == 0 &&
403 			    sdl->sdl_alen == 0 &&
404 			    sdl->sdl_slen == 0)
405 				xo_emit("{P:/%*s} ", addr_len, "");
406 			else
407 				xo_emit("{t:address/%-*.*s} ", addr_len,
408 				    addr_len, routename(ifa->ifa_addr, 1));
409 			link = true;
410 			break;
411 		    }
412 		}
413 
414 #define	IFA_STAT(s)	(((struct if_data *)ifa->ifa_data)->ifi_ ## s)
415 		show_stat("lu", 8, "received-packets", IFA_STAT(ipackets),
416 		    link|network, 1);
417 		show_stat("lu", 5, "received-errors", IFA_STAT(ierrors),
418 		    link, 1);
419 		show_stat("lu", 5, "dropped-packets", IFA_STAT(iqdrops),
420 		    link, 1);
421 		if (bflag)
422 			show_stat("lu", 10, "received-bytes", IFA_STAT(ibytes),
423 			    link|network, 0);
424 		show_stat("lu", 8, "sent-packets", IFA_STAT(opackets),
425 		    link|network, 1);
426 		show_stat("lu", 5, "send-errors", IFA_STAT(oerrors), link, 1);
427 		if (bflag)
428 			show_stat("lu", 10, "sent-bytes", IFA_STAT(obytes),
429 			    link|network, 0);
430 		show_stat("NRSlu", 5, "collisions", IFA_STAT(collisions),
431 		    link, 1);
432 		if (dflag)
433 			show_stat("LSlu", 5, "dropped-packets",
434 			    IFA_STAT(oqdrops), link, 1);
435 		xo_emit("\n");
436 
437 		if (!aflag) {
438 			xo_close_instance("interface");
439 			continue;
440 		}
441 
442 		/*
443 		 * Print family's multicast addresses.
444 		 */
445 		xo_open_list("multicast-address");
446 		for (ifma = next_ifma(ifmap, ifa->ifa_name,
447 		    ifa->ifa_addr->sa_family);
448 		    ifma != NULL;
449 		    ifma = next_ifma(ifma, ifa->ifa_name,
450 		    ifa->ifa_addr->sa_family)) {
451 			const char *fmt = NULL;
452 
453 			xo_open_instance("multicast-address");
454 			switch (ifma->ifma_addr->sa_family) {
455 			case AF_LINK:
456 			    {
457 				struct sockaddr_dl *sdl;
458 
459 				sdl = (struct sockaddr_dl *)ifma->ifma_addr;
460 				if (sdl->sdl_type != IFT_ETHER &&
461 				    sdl->sdl_type != IFT_FDDI)
462 					break;
463 			    }
464 				/* FALLTHROUGH */
465 			case AF_INET:
466 #ifdef INET6
467 			case AF_INET6:
468 #endif /* INET6 */
469 				fmt = routename(ifma->ifma_addr, numeric_addr);
470 				break;
471 			}
472 			if (fmt) {
473 				if (Wflag)
474 					xo_emit("{P:/%27s }"
475 					    "{t:address/%-17s/}", "", fmt);
476 				else
477 					xo_emit("{P:/%25s }"
478 					    "{t:address/%-17.17s/}", "", fmt);
479 				if (ifma->ifma_addr->sa_family == AF_LINK) {
480 					xo_emit(" {:received-packets/%8lu}",
481 					    IFA_STAT(imcasts));
482 					xo_emit("{P:/%*s}", bflag? 17 : 6, "");
483 					xo_emit(" {:sent-packets/%8lu}",
484 					    IFA_STAT(omcasts));
485  				}
486 				xo_emit("\n");
487 			}
488 			xo_close_instance("multicast-address");
489 			ifma = ifma->ifma_next;
490 		}
491 		xo_close_list("multicast-address");
492 		xo_close_instance("interface");
493 	}
494 	xo_close_list("interface");
495 
496 	freeifaddrs(ifap);
497 	if (aflag)
498 		freeifmaddrs(ifmap);
499 }
500 
501 struct iftot {
502 	u_long	ift_ip;			/* input packets */
503 	u_long	ift_ie;			/* input errors */
504 	u_long	ift_id;			/* input drops */
505 	u_long	ift_op;			/* output packets */
506 	u_long	ift_oe;			/* output errors */
507 	u_long	ift_od;			/* output drops */
508 	u_long	ift_co;			/* collisions */
509 	u_long	ift_ib;			/* input bytes */
510 	u_long	ift_ob;			/* output bytes */
511 };
512 
513 /*
514  * Obtain stats for interface(s).
515  */
516 static void
517 fill_iftot(struct iftot *st)
518 {
519 	struct ifaddrs *ifap, *ifa;
520 	bool found = false;
521 
522 	if (getifaddrs(&ifap) != 0)
523 		xo_err(EX_OSERR, "getifaddrs");
524 
525 	bzero(st, sizeof(*st));
526 
527 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
528 		if (ifa->ifa_addr->sa_family != AF_LINK)
529 			continue;
530 		if (interface) {
531 			if (strcmp(ifa->ifa_name, interface) == 0)
532 				found = true;
533 			else
534 				continue;
535 		}
536 
537 		st->ift_ip += IFA_STAT(ipackets);
538 		st->ift_ie += IFA_STAT(ierrors);
539 		st->ift_id += IFA_STAT(iqdrops);
540 		st->ift_ib += IFA_STAT(ibytes);
541 		st->ift_op += IFA_STAT(opackets);
542 		st->ift_oe += IFA_STAT(oerrors);
543 		st->ift_od += IFA_STAT(oqdrops);
544 		st->ift_ob += IFA_STAT(obytes);
545  		st->ift_co += IFA_STAT(collisions);
546 	}
547 
548 	if (interface && found == false)
549 		xo_err(EX_DATAERR, "interface %s not found", interface);
550 
551 	freeifaddrs(ifap);
552 }
553 
554 /*
555  * Set a flag to indicate that a signal from the periodic itimer has been
556  * caught.
557  */
558 static sig_atomic_t signalled;
559 static void
560 catchalarm(int signo __unused)
561 {
562 	signalled = true;
563 }
564 
565 /*
566  * Print a running summary of interface statistics.
567  * Repeat display every interval seconds, showing statistics
568  * collected over that interval.  Assumes that interval is non-zero.
569  * First line printed at top of screen is always cumulative.
570  */
571 static void
572 sidewaysintpr(void)
573 {
574 	struct iftot ift[2], *new, *old;
575 	struct itimerval interval_it;
576 	int oldmask, line;
577 
578 	new = &ift[0];
579 	old = &ift[1];
580 	fill_iftot(old);
581 
582 	(void)signal(SIGALRM, catchalarm);
583 	signalled = false;
584 	interval_it.it_interval.tv_sec = interval;
585 	interval_it.it_interval.tv_usec = 0;
586 	interval_it.it_value = interval_it.it_interval;
587 	setitimer(ITIMER_REAL, &interval_it, NULL);
588 	xo_open_list("interface-statistics");
589 
590 banner:
591 	xo_emit("{T:/%17s} {T:/%14s} {T:/%16s}\n", "input",
592 	    interface != NULL ? interface : "(Total)", "output");
593 	xo_emit("{T:/%10s} {T:/%5s} {T:/%5s} {T:/%10s} {T:/%10s} {T:/%5s} "
594 	    "{T:/%10s} {T:/%5s}",
595 	    "packets", "errs", "idrops", "bytes", "packets", "errs", "bytes",
596 	    "colls");
597 	if (dflag)
598 		xo_emit(" {T:/%5.5s}", "drops");
599 	xo_emit("\n");
600 	xo_flush();
601 	line = 0;
602 
603 loop:
604 	if ((noutputs != 0) && (--noutputs == 0)) {
605 		xo_close_list("interface-statistics");
606 		return;
607 	}
608 	oldmask = sigblock(sigmask(SIGALRM));
609 	while (!signalled)
610 		sigpause(0);
611 	signalled = false;
612 	sigsetmask(oldmask);
613 	line++;
614 
615 	fill_iftot(new);
616 
617 	xo_open_instance("stats");
618 	show_stat("lu", 10, "received-packets",
619 	    new->ift_ip - old->ift_ip, 1, 1);
620 	show_stat("lu", 5, "received-errors",
621 	    new->ift_ie - old->ift_ie, 1, 1);
622 	show_stat("lu", 5, "dropped-packets",
623 	    new->ift_id - old->ift_id, 1, 1);
624 	show_stat("lu", 10, "received-bytes",
625 	    new->ift_ib - old->ift_ib, 1, 0);
626 	show_stat("lu", 10, "sent-packets",
627 	    new->ift_op - old->ift_op, 1, 1);
628 	show_stat("lu", 5, "send-errors",
629 	    new->ift_oe - old->ift_oe, 1, 1);
630 	show_stat("lu", 10, "sent-bytes",
631 	    new->ift_ob - old->ift_ob, 1, 0);
632 	show_stat("NRSlu", 5, "collisions",
633 	    new->ift_co - old->ift_co, 1, 1);
634 	if (dflag)
635 		show_stat("LSlu", 5, "dropped-packets",
636 		    new->ift_od - old->ift_od, 1, 1);
637 	xo_close_instance("stats");
638 	xo_emit("\n");
639 	xo_flush();
640 
641 	if (new == &ift[0]) {
642 		new = &ift[1];
643 		old = &ift[0];
644 	} else {
645 		new = &ift[0];
646 		old = &ift[1];
647 	}
648 
649 	if (line == 21)
650 		goto banner;
651 	else
652 		goto loop;
653 
654 	/* NOTREACHED */
655 }
656