xref: /freebsd/usr.bin/netstat/if.c (revision db612abe8df3355d1eb23bb3b50fdd97bc21e979)
1 /*-
2  * Copyright (c) 1983, 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if 0
35 #ifndef lint
36 static char sccsid[] = "@(#)if.c	8.3 (Berkeley) 4/28/95";
37 #endif /* not lint */
38 #endif
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/types.h>
44 #include <sys/protosw.h>
45 #include <sys/socket.h>
46 #include <sys/socketvar.h>
47 #include <sys/sysctl.h>
48 #include <sys/time.h>
49 
50 #include <net/if.h>
51 #include <net/if_var.h>
52 #include <net/if_dl.h>
53 #include <net/if_types.h>
54 #include <net/ethernet.h>
55 #include <net/pfvar.h>
56 #include <net/if_pfsync.h>
57 #include <netinet/in.h>
58 #include <netinet/in_var.h>
59 #include <netipx/ipx.h>
60 #include <netipx/ipx_if.h>
61 #include <arpa/inet.h>
62 
63 #include <err.h>
64 #include <errno.h>
65 #include <libutil.h>
66 #include <signal.h>
67 #include <stdint.h>
68 #include <stdio.h>
69 #include <stdlib.h>
70 #include <string.h>
71 #include <unistd.h>
72 
73 #include "netstat.h"
74 
75 #define	YES	1
76 #define	NO	0
77 
78 static void sidewaysintpr(int, u_long);
79 static void catchalarm(int);
80 
81 #ifdef INET6
82 static char ntop_buf[INET6_ADDRSTRLEN];		/* for inet_ntop() */
83 #endif
84 
85 /*
86  * Dump pfsync statistics structure.
87  */
88 void
89 pfsync_stats(u_long off, const char *name, int af1 __unused, int proto __unused)
90 {
91 	struct pfsyncstats pfsyncstat, zerostat;
92 	size_t len = sizeof(struct pfsyncstats);
93 
94 	if (live) {
95 		if (zflag)
96 			memset(&zerostat, 0, len);
97 		if (sysctlbyname("net.inet.pfsync.stats", &pfsyncstat, &len,
98 		    zflag ? &zerostat : NULL, zflag ? len : 0) < 0) {
99 			if (errno != ENOENT)
100 				warn("sysctl: net.inet.pfsync.stats");
101 			return;
102 		}
103 	} else
104 		kread(off, &pfsyncstat, len);
105 
106 	printf("%s:\n", name);
107 
108 #define	p(f, m) if (pfsyncstat.f || sflag <= 1) \
109 	printf(m, (uintmax_t)pfsyncstat.f, plural(pfsyncstat.f))
110 #define	p2(f, m) if (pfsyncstat.f || sflag <= 1) \
111 	printf(m, (uintmax_t)pfsyncstat.f)
112 
113 	p(pfsyncs_ipackets, "\t%ju packet%s received (IPv4)\n");
114 	p(pfsyncs_ipackets6, "\t%ju packet%s received (IPv6)\n");
115 	p(pfsyncs_badif, "\t\t%ju packet%s discarded for bad interface\n");
116 	p(pfsyncs_badttl, "\t\t%ju packet%s discarded for bad ttl\n");
117 	p(pfsyncs_hdrops, "\t\t%ju packet%s shorter than header\n");
118 	p(pfsyncs_badver, "\t\t%ju packet%s discarded for bad version\n");
119 	p(pfsyncs_badauth, "\t\t%ju packet%s discarded for bad HMAC\n");
120 	p(pfsyncs_badact,"\t\t%ju packet%s discarded for bad action\n");
121 	p(pfsyncs_badlen, "\t\t%ju packet%s discarded for short packet\n");
122 	p(pfsyncs_badval, "\t\t%ju state%s discarded for bad values\n");
123 	p(pfsyncs_stale, "\t\t%ju stale state%s\n");
124 	p(pfsyncs_badstate, "\t\t%ju failed state lookup/insert%s\n");
125 	p(pfsyncs_opackets, "\t%ju packet%s sent (IPv4)\n");
126 	p(pfsyncs_opackets6, "\t%ju packet%s sent (IPv6)\n");
127 	p2(pfsyncs_onomem, "\t\t%ju send failed due to mbuf memory error\n");
128 	p2(pfsyncs_oerrors, "\t\t%ju send error\n");
129 #undef p
130 #undef p2
131 }
132 
133 /*
134  * Display a formatted value, or a '-' in the same space.
135  */
136 static void
137 show_stat(const char *fmt, int width, u_long value, short showvalue)
138 {
139 	const char *lsep, *rsep;
140 	char newfmt[32];
141 
142 	lsep = "";
143 	if (strncmp(fmt, "LS", 2) == 0) {
144 		lsep = " ";
145 		fmt += 2;
146 	}
147 	rsep = " ";
148 	if (strncmp(fmt, "NRS", 3) == 0) {
149 		rsep = "";
150 		fmt += 3;
151 	}
152 	if (showvalue == 0) {
153 		/* Print just dash. */
154 		sprintf(newfmt, "%s%%%ds%s", lsep, width, rsep);
155 		printf(newfmt, "-");
156 		return;
157 	}
158 
159 	if (hflag) {
160 		char buf[5];
161 
162 		/* Format in human readable form. */
163 		humanize_number(buf, sizeof(buf), (int64_t)value, "",
164 		    HN_AUTOSCALE, HN_NOSPACE | HN_DECIMAL);
165 		sprintf(newfmt, "%s%%%ds%s", lsep, width, rsep);
166 		printf(newfmt, buf);
167 	} else {
168 		/* Construct the format string. */
169 		sprintf(newfmt, "%s%%%d%s%s", lsep, width, fmt, rsep);
170 		printf(newfmt, value);
171 	}
172 }
173 
174 /*
175  * Print a description of the network interfaces.
176  */
177 void
178 intpr(int interval1, u_long ifnetaddr, void (*pfunc)(char *))
179 {
180 	struct ifnet ifnet;
181 	struct ifnethead ifnethead;
182 	union {
183 		struct ifaddr ifa;
184 		struct in_ifaddr in;
185 #ifdef INET6
186 		struct in6_ifaddr in6;
187 #endif
188 		struct ipx_ifaddr ipx;
189 	} ifaddr;
190 	u_long ifaddraddr;
191 	u_long ifaddrfound;
192 	u_long ifnetfound;
193 	u_long opackets;
194 	u_long ipackets;
195 	u_long obytes;
196 	u_long ibytes;
197 	u_long omcasts;
198 	u_long imcasts;
199 	u_long oerrors;
200 	u_long ierrors;
201 	u_long collisions;
202 	short timer;
203 	int drops;
204 	struct sockaddr *sa = NULL;
205 	char name[IFNAMSIZ];
206 	short network_layer;
207 	short link_layer;
208 
209 	if (ifnetaddr == 0) {
210 		printf("ifnet: symbol not defined\n");
211 		return;
212 	}
213 	if (interval1) {
214 		sidewaysintpr(interval1, ifnetaddr);
215 		return;
216 	}
217 	if (kread(ifnetaddr, (char *)&ifnethead, sizeof ifnethead) != 0)
218 		return;
219 	ifnetaddr = (u_long)TAILQ_FIRST(&ifnethead);
220 	if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet) != 0)
221 		return;
222 
223 	if (!pfunc) {
224 		if (Wflag)
225 			printf("%-7.7s", "Name");
226 		else
227 			printf("%-5.5s", "Name");
228 		printf(" %5.5s %-13.13s %-17.17s %8.8s %5.5s",
229 		    "Mtu", "Network", "Address", "Ipkts", "Ierrs");
230 		if (bflag)
231 			printf(" %10.10s","Ibytes");
232 		printf(" %8.8s %5.5s", "Opkts", "Oerrs");
233 		if (bflag)
234 			printf(" %10.10s","Obytes");
235 		printf(" %5s", "Coll");
236 		if (tflag)
237 			printf(" %s", "Time");
238 		if (dflag)
239 			printf(" %s", "Drop");
240 		putchar('\n');
241 	}
242 	ifaddraddr = 0;
243 	while (ifnetaddr || ifaddraddr) {
244 		struct sockaddr_in *sockin;
245 #ifdef INET6
246 		struct sockaddr_in6 *sockin6;
247 #endif
248 		char *cp;
249 		int n, m;
250 
251 		network_layer = 0;
252 		link_layer = 0;
253 
254 		if (ifaddraddr == 0) {
255 			ifnetfound = ifnetaddr;
256 			if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet) != 0)
257 				return;
258 			strlcpy(name, ifnet.if_xname, sizeof(name));
259 			ifnetaddr = (u_long)TAILQ_NEXT(&ifnet, if_link);
260 			if (interface != 0 && strcmp(name, interface) != 0)
261 				continue;
262 			cp = index(name, '\0');
263 
264 			if (pfunc) {
265 				(*pfunc)(name);
266 				continue;
267 			}
268 
269 			if ((ifnet.if_flags&IFF_UP) == 0)
270 				*cp++ = '*';
271 			*cp = '\0';
272 			ifaddraddr = (u_long)TAILQ_FIRST(&ifnet.if_addrhead);
273 		}
274 		ifaddrfound = ifaddraddr;
275 
276 		/*
277 		 * Get the interface stats.  These may get
278 		 * overriden below on a per-interface basis.
279 		 */
280 		opackets = ifnet.if_opackets;
281 		ipackets = ifnet.if_ipackets;
282 		obytes = ifnet.if_obytes;
283 		ibytes = ifnet.if_ibytes;
284 		omcasts = ifnet.if_omcasts;
285 		imcasts = ifnet.if_imcasts;
286 		oerrors = ifnet.if_oerrors;
287 		ierrors = ifnet.if_ierrors;
288 		collisions = ifnet.if_collisions;
289 		timer = ifnet.if_timer;
290 		drops = ifnet.if_snd.ifq_drops;
291 
292 		if (ifaddraddr == 0) {
293 			if (Wflag)
294 				printf("%-7.7s", name);
295 			else
296 				printf("%-5.5s", name);
297 			printf(" %5lu ", ifnet.if_mtu);
298 			printf("%-13.13s ", "none");
299 			printf("%-17.17s ", "none");
300 		} else {
301 			if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)
302 			    != 0) {
303 				ifaddraddr = 0;
304 				continue;
305 			}
306 #define	CP(x) ((char *)(x))
307 			cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
308 				CP(&ifaddr);
309 			sa = (struct sockaddr *)cp;
310 			if (af != AF_UNSPEC && sa->sa_family != af) {
311 				ifaddraddr =
312 				    (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
313 				continue;
314 			}
315 			if (Wflag)
316 				printf("%-7.7s", name);
317 			else
318 				printf("%-5.5s", name);
319 			printf(" %5lu ", ifnet.if_mtu);
320 			switch (sa->sa_family) {
321 			case AF_UNSPEC:
322 				printf("%-13.13s ", "none");
323 				printf("%-15.15s ", "none");
324 				break;
325 			case AF_INET:
326 				sockin = (struct sockaddr_in *)sa;
327 #ifdef notdef
328 				/* can't use inet_makeaddr because kernel
329 				 * keeps nets unshifted.
330 				 */
331 				in = inet_makeaddr(ifaddr.in.ia_subnet,
332 					INADDR_ANY);
333 				printf("%-13.13s ", netname(in.s_addr,
334 				    ifaddr.in.ia_subnetmask));
335 #else
336 				printf("%-13.13s ",
337 				    netname(htonl(ifaddr.in.ia_subnet),
338 				    ifaddr.in.ia_subnetmask));
339 #endif
340 				printf("%-17.17s ",
341 				    routename(sockin->sin_addr.s_addr));
342 
343 				network_layer = 1;
344 				break;
345 #ifdef INET6
346 			case AF_INET6:
347 				sockin6 = (struct sockaddr_in6 *)sa;
348 				printf("%-13.13s ",
349 				       netname6(&ifaddr.in6.ia_addr,
350 						&ifaddr.in6.ia_prefixmask.sin6_addr));
351 				printf("%-17.17s ",
352 				    inet_ntop(AF_INET6,
353 					&sockin6->sin6_addr,
354 					ntop_buf, sizeof(ntop_buf)));
355 
356 				network_layer = 1;
357 				break;
358 #endif /*INET6*/
359 			case AF_IPX:
360 				{
361 				struct sockaddr_ipx *sipx =
362 					(struct sockaddr_ipx *)sa;
363 				u_long net;
364 				char netnum[10];
365 
366 				*(union ipx_net *) &net = sipx->sipx_addr.x_net;
367 				sprintf(netnum, "%lx", (u_long)ntohl(net));
368 				printf("ipx:%-8s  ", netnum);
369 /*				printf("ipx:%-8s ", netname(net, 0L)); */
370 				printf("%-17s ",
371 				    ipx_phost((struct sockaddr *)sipx));
372 				}
373 
374 				network_layer = 1;
375 				break;
376 
377 			case AF_APPLETALK:
378 				printf("atalk:%-12.12s ",atalk_print(sa,0x10) );
379 				printf("%-11.11s  ",atalk_print(sa,0x0b) );
380 				break;
381 			case AF_LINK:
382 				{
383 				struct sockaddr_dl *sdl =
384 					(struct sockaddr_dl *)sa;
385 				char linknum[10];
386 				cp = (char *)LLADDR(sdl);
387 				n = sdl->sdl_alen;
388 				sprintf(linknum, "<Link#%d>", sdl->sdl_index);
389 				m = printf("%-13.13s ", linknum);
390 				}
391 				goto hexprint;
392 			default:
393 				m = printf("(%d)", sa->sa_family);
394 				for (cp = sa->sa_len + (char *)sa;
395 					--cp > sa->sa_data && (*cp == 0);) {}
396 				n = cp - sa->sa_data + 1;
397 				cp = sa->sa_data;
398 			hexprint:
399 				while (--n >= 0)
400 					m += printf("%02x%c", *cp++ & 0xff,
401 						    n > 0 ? ':' : ' ');
402 				m = 32 - m;
403 				while (m-- > 0)
404 					putchar(' ');
405 
406 				link_layer = 1;
407 				break;
408 			}
409 
410 			/*
411 			 * Fixup the statistics for interfaces that
412 			 * update stats for their network addresses
413 			 */
414 			if (network_layer) {
415 				opackets = ifaddr.in.ia_ifa.if_opackets;
416 				ipackets = ifaddr.in.ia_ifa.if_ipackets;
417 				obytes = ifaddr.in.ia_ifa.if_obytes;
418 				ibytes = ifaddr.in.ia_ifa.if_ibytes;
419 			}
420 
421 			ifaddraddr = (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
422 		}
423 
424 		show_stat("lu", 8, ipackets, link_layer|network_layer);
425 		show_stat("lu", 5, ierrors, link_layer);
426 		if (bflag)
427 			show_stat("lu", 10, ibytes, link_layer|network_layer);
428 
429 		show_stat("lu", 8, opackets, link_layer|network_layer);
430 		show_stat("lu", 5, oerrors, link_layer);
431 		if (bflag)
432 			show_stat("lu", 10, obytes, link_layer|network_layer);
433 
434 		show_stat("NRSlu", 5, collisions, link_layer);
435 		if (tflag)
436 			show_stat("LSd", 4, timer, link_layer);
437 		if (dflag)
438 			show_stat("LSd", 4, drops, link_layer);
439 		putchar('\n');
440 
441 		if (aflag && ifaddrfound) {
442 			/*
443 			 * Print family's multicast addresses
444 			 */
445 			struct ifmultiaddr *multiaddr;
446 			struct ifmultiaddr ifma;
447 			union {
448 				struct sockaddr sa;
449 				struct sockaddr_in in;
450 #ifdef INET6
451 				struct sockaddr_in6 in6;
452 #endif /* INET6 */
453 				struct sockaddr_dl dl;
454 			} msa;
455 			const char *fmt;
456 
457 			TAILQ_FOREACH(multiaddr, &ifnet.if_multiaddrs, ifma_link) {
458 				if (kread((u_long)multiaddr, (char *)&ifma,
459 					  sizeof ifma) != 0)
460 					break;
461 				multiaddr = &ifma;
462 				if (kread((u_long)ifma.ifma_addr, (char *)&msa,
463 					  sizeof msa) != 0)
464 					break;
465 				if (msa.sa.sa_family != sa->sa_family)
466 					continue;
467 
468 				fmt = 0;
469 				switch (msa.sa.sa_family) {
470 				case AF_INET:
471 					fmt = routename(msa.in.sin_addr.s_addr);
472 					break;
473 #ifdef INET6
474 				case AF_INET6:
475 					printf("%*s %-19.19s(refs: %d)\n",
476 					       Wflag ? 27 : 25, "",
477 					       inet_ntop(AF_INET6,
478 							 &msa.in6.sin6_addr,
479 							 ntop_buf,
480 							 sizeof(ntop_buf)),
481 					       ifma.ifma_refcount);
482 					break;
483 #endif /* INET6 */
484 				case AF_LINK:
485 					switch (msa.dl.sdl_type) {
486 					case IFT_ETHER:
487 					case IFT_FDDI:
488 						fmt = ether_ntoa(
489 							(struct ether_addr *)
490 							LLADDR(&msa.dl));
491 						break;
492 					}
493 					break;
494 				}
495 				if (fmt) {
496 					printf("%*s %-17.17s",
497 					    Wflag ? 27 : 25, "", fmt);
498 					if (msa.sa.sa_family == AF_LINK) {
499 						printf(" %8lu", imcasts);
500 						printf("%*s",
501 						    bflag ? 17 : 6, "");
502 						printf(" %8lu", omcasts);
503 					}
504 					putchar('\n');
505 				}
506 			}
507 		}
508 	}
509 }
510 
511 struct	iftot {
512 	SLIST_ENTRY(iftot) chain;
513 	char	ift_name[IFNAMSIZ];	/* interface name */
514 	u_long	ift_ip;			/* input packets */
515 	u_long	ift_ie;			/* input errors */
516 	u_long	ift_op;			/* output packets */
517 	u_long	ift_oe;			/* output errors */
518 	u_long	ift_co;			/* collisions */
519 	u_int	ift_dr;			/* drops */
520 	u_long	ift_ib;			/* input bytes */
521 	u_long	ift_ob;			/* output bytes */
522 };
523 
524 u_char	signalled;			/* set if alarm goes off "early" */
525 
526 /*
527  * Print a running summary of interface statistics.
528  * Repeat display every interval1 seconds, showing statistics
529  * collected over that interval.  Assumes that interval1 is non-zero.
530  * First line printed at top of screen is always cumulative.
531  * XXX - should be rewritten to use ifmib(4).
532  */
533 static void
534 sidewaysintpr(int interval1, u_long off)
535 {
536 	struct ifnet ifnet;
537 	u_long firstifnet;
538 	struct ifnethead ifnethead;
539 	struct itimerval interval_it;
540 	struct iftot *iftot, *ip, *ipn, *total, *sum, *interesting;
541 	int line;
542 	int oldmask, first;
543 	u_long interesting_off;
544 
545 	if (kread(off, (char *)&ifnethead, sizeof ifnethead) != 0)
546 		return;
547 	firstifnet = (u_long)TAILQ_FIRST(&ifnethead);
548 
549 	if ((iftot = malloc(sizeof(struct iftot))) == NULL) {
550 		printf("malloc failed\n");
551 		exit(1);
552 	}
553 	memset(iftot, 0, sizeof(struct iftot));
554 
555 	interesting = NULL;
556 	interesting_off = 0;
557 	for (off = firstifnet, ip = iftot; off;) {
558 		char name[IFNAMSIZ];
559 
560 		if (kread(off, (char *)&ifnet, sizeof ifnet) != 0)
561 			break;
562 		strlcpy(name, ifnet.if_xname, sizeof(name));
563 		if (interface && strcmp(name, interface) == 0) {
564 			interesting = ip;
565 			interesting_off = off;
566 		}
567 		snprintf(ip->ift_name, sizeof(ip->ift_name), "(%s)", name);;
568 		if ((ipn = malloc(sizeof(struct iftot))) == NULL) {
569 			printf("malloc failed\n");
570 			exit(1);
571 		}
572 		memset(ipn, 0, sizeof(struct iftot));
573 		SLIST_NEXT(ip, chain) = ipn;
574 		ip = ipn;
575 		off = (u_long)TAILQ_NEXT(&ifnet, if_link);
576 	}
577 	if (interface && interesting == NULL)
578 		errx(1, "%s: unknown interface", interface);
579 	if ((total = malloc(sizeof(struct iftot))) == NULL) {
580 		printf("malloc failed\n");
581 		exit(1);
582 	}
583 	memset(total, 0, sizeof(struct iftot));
584 	if ((sum = malloc(sizeof(struct iftot))) == NULL) {
585 		printf("malloc failed\n");
586 		exit(1);
587 	}
588 	memset(sum, 0, sizeof(struct iftot));
589 
590 	(void)signal(SIGALRM, catchalarm);
591 	signalled = NO;
592 	interval_it.it_interval.tv_sec = interval1;
593 	interval_it.it_interval.tv_usec = 0;
594 	interval_it.it_value = interval_it.it_interval;
595 	setitimer(ITIMER_REAL, &interval_it, NULL);
596 	first = 1;
597 banner:
598 	printf("%17s %14s %16s", "input",
599 	    interesting ? interesting->ift_name : "(Total)", "output");
600 	putchar('\n');
601 	printf("%10s %5s %10s %10s %5s %10s %5s",
602 	    "packets", "errs", "bytes", "packets", "errs", "bytes", "colls");
603 	if (dflag)
604 		printf(" %5.5s", "drops");
605 	putchar('\n');
606 	fflush(stdout);
607 	line = 0;
608 loop:
609 	if (interesting != NULL) {
610 		ip = interesting;
611 		if (kread(interesting_off, (char *)&ifnet, sizeof ifnet) != 0) {
612 			printf("???\n");
613 			exit(1);
614 		};
615 		if (!first) {
616 			show_stat("lu", 10, ifnet.if_ipackets - ip->ift_ip, 1);
617 			show_stat("lu", 5, ifnet.if_ierrors - ip->ift_ie, 1);
618 			show_stat("lu", 10, ifnet.if_ibytes - ip->ift_ib, 1);
619 			show_stat("lu", 10, ifnet.if_opackets - ip->ift_op, 1);
620 			show_stat("lu", 5, ifnet.if_oerrors - ip->ift_oe, 1);
621 			show_stat("lu", 10, ifnet.if_obytes - ip->ift_ob, 1);
622 			show_stat("NRSlu", 5,
623 			    ifnet.if_collisions - ip->ift_co, 1);
624 			if (dflag)
625 				show_stat("LSu", 5,
626 				    ifnet.if_snd.ifq_drops - ip->ift_dr, 1);
627 		}
628 		ip->ift_ip = ifnet.if_ipackets;
629 		ip->ift_ie = ifnet.if_ierrors;
630 		ip->ift_ib = ifnet.if_ibytes;
631 		ip->ift_op = ifnet.if_opackets;
632 		ip->ift_oe = ifnet.if_oerrors;
633 		ip->ift_ob = ifnet.if_obytes;
634 		ip->ift_co = ifnet.if_collisions;
635 		ip->ift_dr = ifnet.if_snd.ifq_drops;
636 	} else {
637 		sum->ift_ip = 0;
638 		sum->ift_ie = 0;
639 		sum->ift_ib = 0;
640 		sum->ift_op = 0;
641 		sum->ift_oe = 0;
642 		sum->ift_ob = 0;
643 		sum->ift_co = 0;
644 		sum->ift_dr = 0;
645 		for (off = firstifnet, ip = iftot;
646 		     off && SLIST_NEXT(ip, chain) != NULL;
647 		     ip = SLIST_NEXT(ip, chain)) {
648 			if (kread(off, (char *)&ifnet, sizeof ifnet) != 0) {
649 				off = 0;
650 				continue;
651 			}
652 			sum->ift_ip += ifnet.if_ipackets;
653 			sum->ift_ie += ifnet.if_ierrors;
654 			sum->ift_ib += ifnet.if_ibytes;
655 			sum->ift_op += ifnet.if_opackets;
656 			sum->ift_oe += ifnet.if_oerrors;
657 			sum->ift_ob += ifnet.if_obytes;
658 			sum->ift_co += ifnet.if_collisions;
659 			sum->ift_dr += ifnet.if_snd.ifq_drops;
660 			off = (u_long)TAILQ_NEXT(&ifnet, if_link);
661 		}
662 		if (!first) {
663 			show_stat("lu", 10, sum->ift_ip - total->ift_ip, 1);
664 			show_stat("lu", 5, sum->ift_ie - total->ift_ie, 1);
665 			show_stat("lu", 10, sum->ift_ib - total->ift_ib, 1);
666 			show_stat("lu", 10, sum->ift_op - total->ift_op, 1);
667 			show_stat("lu", 5, sum->ift_oe - total->ift_oe, 1);
668 			show_stat("lu", 10, sum->ift_ob - total->ift_ob, 1);
669 			show_stat("NRSlu", 5, sum->ift_co - total->ift_co, 1);
670 			if (dflag)
671 				show_stat("LSu", 5,
672 				    sum->ift_dr - total->ift_dr, 1);
673 		}
674 		*total = *sum;
675 	}
676 	if (!first)
677 		putchar('\n');
678 	fflush(stdout);
679 	oldmask = sigblock(sigmask(SIGALRM));
680 	while (!signalled)
681 		sigpause(0);
682 	signalled = NO;
683 	sigsetmask(oldmask);
684 	line++;
685 	first = 0;
686 	if (line == 21)
687 		goto banner;
688 	else
689 		goto loop;
690 	/*NOTREACHED*/
691 }
692 
693 /*
694  * Set a flag to indicate that a signal from the periodic itimer has been
695  * caught.
696  */
697 static void
698 catchalarm(int signo __unused)
699 {
700 	signalled = YES;
701 }
702