xref: /freebsd/usr.bin/netstat/if.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
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))
218 		return;
219 	ifnetaddr = (u_long)TAILQ_FIRST(&ifnethead);
220 	if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
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))
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 				ifaddraddr = 0;
303 				continue;
304 			}
305 #define CP(x) ((char *)(x))
306 			cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
307 				CP(&ifaddr);
308 			sa = (struct sockaddr *)cp;
309 			if (af != AF_UNSPEC && sa->sa_family != af) {
310 				ifaddraddr =
311 				    (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
312 				continue;
313 			}
314 			if (Wflag)
315 				printf("%-7.7s", name);
316 			else
317 				printf("%-5.5s", name);
318 			printf(" %5lu ", ifnet.if_mtu);
319 			switch (sa->sa_family) {
320 			case AF_UNSPEC:
321 				printf("%-13.13s ", "none");
322 				printf("%-15.15s ", "none");
323 				break;
324 			case AF_INET:
325 				sockin = (struct sockaddr_in *)sa;
326 #ifdef notdef
327 				/* can't use inet_makeaddr because kernel
328 				 * keeps nets unshifted.
329 				 */
330 				in = inet_makeaddr(ifaddr.in.ia_subnet,
331 					INADDR_ANY);
332 				printf("%-13.13s ", netname(in.s_addr,
333 				    ifaddr.in.ia_subnetmask));
334 #else
335 				printf("%-13.13s ",
336 				    netname(htonl(ifaddr.in.ia_subnet),
337 				    ifaddr.in.ia_subnetmask));
338 #endif
339 				printf("%-17.17s ",
340 				    routename(sockin->sin_addr.s_addr));
341 
342 				network_layer = 1;
343 				break;
344 #ifdef INET6
345 			case AF_INET6:
346 				sockin6 = (struct sockaddr_in6 *)sa;
347 				printf("%-13.13s ",
348 				       netname6(&ifaddr.in6.ia_addr,
349 						&ifaddr.in6.ia_prefixmask.sin6_addr));
350 				printf("%-17.17s ",
351 				    inet_ntop(AF_INET6,
352 					&sockin6->sin6_addr,
353 					ntop_buf, sizeof(ntop_buf)));
354 
355 				network_layer = 1;
356 				break;
357 #endif /*INET6*/
358 			case AF_IPX:
359 				{
360 				struct sockaddr_ipx *sipx =
361 					(struct sockaddr_ipx *)sa;
362 				u_long net;
363 				char netnum[10];
364 
365 				*(union ipx_net *) &net = sipx->sipx_addr.x_net;
366 				sprintf(netnum, "%lx", (u_long)ntohl(net));
367 				printf("ipx:%-8s  ", netnum);
368 /*				printf("ipx:%-8s ", netname(net, 0L)); */
369 				printf("%-17s ",
370 				    ipx_phost((struct sockaddr *)sipx));
371 				}
372 
373 				network_layer = 1;
374 				break;
375 
376 			case AF_APPLETALK:
377 				printf("atalk:%-12.12s ",atalk_print(sa,0x10) );
378 				printf("%-11.11s  ",atalk_print(sa,0x0b) );
379 				break;
380 			case AF_LINK:
381 				{
382 				struct sockaddr_dl *sdl =
383 					(struct sockaddr_dl *)sa;
384 				char linknum[10];
385 				cp = (char *)LLADDR(sdl);
386 				n = sdl->sdl_alen;
387 				sprintf(linknum, "<Link#%d>", sdl->sdl_index);
388 				m = printf("%-13.13s ", linknum);
389 				}
390 				goto hexprint;
391 			default:
392 				m = printf("(%d)", sa->sa_family);
393 				for (cp = sa->sa_len + (char *)sa;
394 					--cp > sa->sa_data && (*cp == 0);) {}
395 				n = cp - sa->sa_data + 1;
396 				cp = sa->sa_data;
397 			hexprint:
398 				while (--n >= 0)
399 					m += printf("%02x%c", *cp++ & 0xff,
400 						    n > 0 ? ':' : ' ');
401 				m = 32 - m;
402 				while (m-- > 0)
403 					putchar(' ');
404 
405 				link_layer = 1;
406 				break;
407 			}
408 
409 			/*
410 			 * Fixup the statistics for interfaces that
411 			 * update stats for their network addresses
412 			 */
413 			if (network_layer) {
414 				opackets = ifaddr.in.ia_ifa.if_opackets;
415 				ipackets = ifaddr.in.ia_ifa.if_ipackets;
416 				obytes = ifaddr.in.ia_ifa.if_obytes;
417 				ibytes = ifaddr.in.ia_ifa.if_ibytes;
418 			}
419 
420 			ifaddraddr = (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
421 		}
422 
423 		show_stat("lu", 8, ipackets, link_layer|network_layer);
424 		show_stat("lu", 5, ierrors, link_layer);
425 		if (bflag)
426 			show_stat("lu", 10, ibytes, link_layer|network_layer);
427 
428 		show_stat("lu", 8, opackets, link_layer|network_layer);
429 		show_stat("lu", 5, oerrors, link_layer);
430 		if (bflag)
431 			show_stat("lu", 10, obytes, link_layer|network_layer);
432 
433 		show_stat("NRSlu", 5, collisions, link_layer);
434 		if (tflag)
435 			show_stat("LSd", 4, timer, link_layer);
436 		if (dflag)
437 			show_stat("LSd", 4, drops, link_layer);
438 		putchar('\n');
439 
440 		if (aflag && ifaddrfound) {
441 			/*
442 			 * Print family's multicast addresses
443 			 */
444 			struct ifmultiaddr *multiaddr;
445 			struct ifmultiaddr ifma;
446 			union {
447 				struct sockaddr sa;
448 				struct sockaddr_in in;
449 #ifdef INET6
450 				struct sockaddr_in6 in6;
451 #endif /* INET6 */
452 				struct sockaddr_dl dl;
453 			} msa;
454 			const char *fmt;
455 
456 			TAILQ_FOREACH(multiaddr, &ifnet.if_multiaddrs, ifma_link) {
457 				if (kread((u_long)multiaddr, (char *)&ifma,
458 					  sizeof ifma))
459 					break;
460 				multiaddr = &ifma;
461 				if (kread((u_long)ifma.ifma_addr, (char *)&msa,
462 					  sizeof msa))
463 					break;
464 				if (msa.sa.sa_family != sa->sa_family)
465 					continue;
466 
467 				fmt = 0;
468 				switch (msa.sa.sa_family) {
469 				case AF_INET:
470 					fmt = routename(msa.in.sin_addr.s_addr);
471 					break;
472 #ifdef INET6
473 				case AF_INET6:
474 					printf("%*s %-19.19s(refs: %d)\n",
475 					       Wflag ? 27 : 25, "",
476 					       inet_ntop(AF_INET6,
477 							 &msa.in6.sin6_addr,
478 							 ntop_buf,
479 							 sizeof(ntop_buf)),
480 					       ifma.ifma_refcount);
481 					break;
482 #endif /* INET6 */
483 				case AF_LINK:
484 					switch (msa.dl.sdl_type) {
485 					case IFT_ETHER:
486 					case IFT_FDDI:
487 						fmt = ether_ntoa(
488 							(struct ether_addr *)
489 							LLADDR(&msa.dl));
490 						break;
491 					}
492 					break;
493 				}
494 				if (fmt) {
495 					printf("%*s %-17.17s",
496 					    Wflag ? 27 : 25, "", fmt);
497 					if (msa.sa.sa_family == AF_LINK) {
498 						printf(" %8lu", imcasts);
499 						printf("%*s",
500 						    bflag ? 17 : 6, "");
501 						printf(" %8lu", omcasts);
502 					}
503 					putchar('\n');
504 				}
505 			}
506 		}
507 	}
508 }
509 
510 struct	iftot {
511 	SLIST_ENTRY(iftot) chain;
512 	char	ift_name[IFNAMSIZ];	/* interface name */
513 	u_long	ift_ip;			/* input packets */
514 	u_long	ift_ie;			/* input errors */
515 	u_long	ift_op;			/* output packets */
516 	u_long	ift_oe;			/* output errors */
517 	u_long	ift_co;			/* collisions */
518 	u_int	ift_dr;			/* drops */
519 	u_long	ift_ib;			/* input bytes */
520 	u_long	ift_ob;			/* output bytes */
521 };
522 
523 u_char	signalled;			/* set if alarm goes off "early" */
524 
525 /*
526  * Print a running summary of interface statistics.
527  * Repeat display every interval1 seconds, showing statistics
528  * collected over that interval.  Assumes that interval1 is non-zero.
529  * First line printed at top of screen is always cumulative.
530  * XXX - should be rewritten to use ifmib(4).
531  */
532 static void
533 sidewaysintpr(int interval1, u_long off)
534 {
535 	struct ifnet ifnet;
536 	u_long firstifnet;
537 	struct ifnethead ifnethead;
538 	struct itimerval interval_it;
539 	struct iftot *iftot, *ip, *ipn, *total, *sum, *interesting;
540 	int line;
541 	int oldmask, first;
542 	u_long interesting_off;
543 
544 	if (kread(off, (char *)&ifnethead, sizeof ifnethead))
545 		return;
546 	firstifnet = (u_long)TAILQ_FIRST(&ifnethead);
547 
548 	if ((iftot = malloc(sizeof(struct iftot))) == NULL) {
549 		printf("malloc failed\n");
550 		exit(1);
551 	}
552 	memset(iftot, 0, sizeof(struct iftot));
553 
554 	interesting = NULL;
555 	interesting_off = 0;
556 	for (off = firstifnet, ip = iftot; off;) {
557 		char name[IFNAMSIZ];
558 
559 		if (kread(off, (char *)&ifnet, sizeof ifnet))
560 			break;
561 		strlcpy(name, ifnet.if_xname, sizeof(name));
562 		if (interface && strcmp(name, interface) == 0) {
563 			interesting = ip;
564 			interesting_off = off;
565 		}
566 		snprintf(ip->ift_name, sizeof(ip->ift_name), "(%s)", name);;
567 		if ((ipn = malloc(sizeof(struct iftot))) == NULL) {
568 			printf("malloc failed\n");
569 			exit(1);
570 		}
571 		memset(ipn, 0, sizeof(struct iftot));
572 		SLIST_NEXT(ip, chain) = ipn;
573 		ip = ipn;
574 		off = (u_long)TAILQ_NEXT(&ifnet, if_link);
575 	}
576 	if (interface && interesting == NULL)
577 		errx(1, "%s: unknown interface", interface);
578 	if ((total = malloc(sizeof(struct iftot))) == NULL) {
579 		printf("malloc failed\n");
580 		exit(1);
581 	}
582 	memset(total, 0, sizeof(struct iftot));
583 	if ((sum = malloc(sizeof(struct iftot))) == NULL) {
584 		printf("malloc failed\n");
585 		exit(1);
586 	}
587 	memset(sum, 0, sizeof(struct iftot));
588 
589 	(void)signal(SIGALRM, catchalarm);
590 	signalled = NO;
591 	interval_it.it_interval.tv_sec = interval1;
592 	interval_it.it_interval.tv_usec = 0;
593 	interval_it.it_value = interval_it.it_interval;
594 	setitimer(ITIMER_REAL, &interval_it, NULL);
595 	first = 1;
596 banner:
597 	printf("%17s %14s %16s", "input",
598 	    interesting ? interesting->ift_name : "(Total)", "output");
599 	putchar('\n');
600 	printf("%10s %5s %10s %10s %5s %10s %5s",
601 	    "packets", "errs", "bytes", "packets", "errs", "bytes", "colls");
602 	if (dflag)
603 		printf(" %5.5s", "drops");
604 	putchar('\n');
605 	fflush(stdout);
606 	line = 0;
607 loop:
608 	if (interesting != NULL) {
609 		ip = interesting;
610 		if (kread(interesting_off, (char *)&ifnet, sizeof ifnet)) {
611 			printf("???\n");
612 			exit(1);
613 		};
614 		if (!first) {
615 			show_stat("lu", 10, ifnet.if_ipackets - ip->ift_ip, 1);
616 			show_stat("lu", 5, ifnet.if_ierrors - ip->ift_ie, 1);
617 			show_stat("lu", 10, ifnet.if_ibytes - ip->ift_ib, 1);
618 			show_stat("lu", 10, ifnet.if_opackets - ip->ift_op, 1);
619 			show_stat("lu", 5, ifnet.if_oerrors - ip->ift_oe, 1);
620 			show_stat("lu", 10, ifnet.if_obytes - ip->ift_ob, 1);
621 			show_stat("NRSlu", 5,
622 			    ifnet.if_collisions - ip->ift_co, 1);
623 			if (dflag)
624 				show_stat("LSu", 5,
625 				    ifnet.if_snd.ifq_drops - ip->ift_dr, 1);
626 		}
627 		ip->ift_ip = ifnet.if_ipackets;
628 		ip->ift_ie = ifnet.if_ierrors;
629 		ip->ift_ib = ifnet.if_ibytes;
630 		ip->ift_op = ifnet.if_opackets;
631 		ip->ift_oe = ifnet.if_oerrors;
632 		ip->ift_ob = ifnet.if_obytes;
633 		ip->ift_co = ifnet.if_collisions;
634 		ip->ift_dr = ifnet.if_snd.ifq_drops;
635 	} else {
636 		sum->ift_ip = 0;
637 		sum->ift_ie = 0;
638 		sum->ift_ib = 0;
639 		sum->ift_op = 0;
640 		sum->ift_oe = 0;
641 		sum->ift_ob = 0;
642 		sum->ift_co = 0;
643 		sum->ift_dr = 0;
644 		for (off = firstifnet, ip = iftot;
645 		     off && SLIST_NEXT(ip, chain) != NULL;
646 		     ip = SLIST_NEXT(ip, chain)) {
647 			if (kread(off, (char *)&ifnet, sizeof ifnet)) {
648 				off = 0;
649 				continue;
650 			}
651 			sum->ift_ip += ifnet.if_ipackets;
652 			sum->ift_ie += ifnet.if_ierrors;
653 			sum->ift_ib += ifnet.if_ibytes;
654 			sum->ift_op += ifnet.if_opackets;
655 			sum->ift_oe += ifnet.if_oerrors;
656 			sum->ift_ob += ifnet.if_obytes;
657 			sum->ift_co += ifnet.if_collisions;
658 			sum->ift_dr += ifnet.if_snd.ifq_drops;
659 			off = (u_long)TAILQ_NEXT(&ifnet, if_link);
660 		}
661 		if (!first) {
662 			show_stat("lu", 10, sum->ift_ip - total->ift_ip, 1);
663 			show_stat("lu", 5, sum->ift_ie - total->ift_ie, 1);
664 			show_stat("lu", 10, sum->ift_ib - total->ift_ib, 1);
665 			show_stat("lu", 10, sum->ift_op - total->ift_op, 1);
666 			show_stat("lu", 5, sum->ift_oe - total->ift_oe, 1);
667 			show_stat("lu", 10, sum->ift_ob - total->ift_ob, 1);
668 			show_stat("NRSlu", 5, sum->ift_co - total->ift_co, 1);
669 			if (dflag)
670 				show_stat("LSu", 5,
671 				    sum->ift_dr - total->ift_dr, 1);
672 		}
673 		*total = *sum;
674 	}
675 	if (!first)
676 		putchar('\n');
677 	fflush(stdout);
678 	oldmask = sigblock(sigmask(SIGALRM));
679 	while (!signalled)
680 		sigpause(0);
681 	signalled = NO;
682 	sigsetmask(oldmask);
683 	line++;
684 	first = 0;
685 	if (line == 21)
686 		goto banner;
687 	else
688 		goto loop;
689 	/*NOTREACHED*/
690 }
691 
692 /*
693  * Set a flag to indicate that a signal from the periodic itimer has been
694  * caught.
695  */
696 static void
697 catchalarm(int signo __unused)
698 {
699 	signalled = YES;
700 }
701