xref: /freebsd/usr.bin/netstat/if.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
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 #ifndef lint
35 /*
36 static char sccsid[] = "@(#)if.c	8.3 (Berkeley) 4/28/95";
37 */
38 static const char rcsid[] =
39   "$FreeBSD$";
40 #endif /* not lint */
41 
42 #include <sys/types.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/sysctl.h>
46 #include <sys/time.h>
47 
48 #include <net/if.h>
49 #include <net/if_var.h>
50 #include <net/if_dl.h>
51 #include <net/if_types.h>
52 #include <net/bridge.h>
53 #include <net/ethernet.h>
54 #include <netinet/in.h>
55 #include <netinet/in_var.h>
56 #include <netipx/ipx.h>
57 #include <netipx/ipx_if.h>
58 #ifdef NS
59 #include <netns/ns.h>
60 #include <netns/ns_if.h>
61 #endif
62 #ifdef ISO
63 #include <netiso/iso.h>
64 #include <netiso/iso_var.h>
65 #endif
66 #include <arpa/inet.h>
67 
68 #include <signal.h>
69 #include <stdio.h>
70 #include <stdlib.h>
71 #include <string.h>
72 #include <unistd.h>
73 
74 #include "netstat.h"
75 
76 #define	YES	1
77 #define	NO	0
78 
79 static void sidewaysintpr (u_int, u_long);
80 static void catchalarm (int);
81 
82 #ifdef INET6
83 static char ntop_buf[INET6_ADDRSTRLEN];		/* for inet_ntop() */
84 static int bdg_done;
85 #endif
86 
87 /* print bridge statistics */
88 void
89 bdg_stats(u_long dummy __unused, const char *name, int af1 __unused)
90 {
91     int i;
92     size_t slen ;
93     struct bdg_stats s ;
94     int mib[4] ;
95 
96     slen = sizeof(s);
97 
98     mib[0] = CTL_NET ;
99     mib[1] = PF_LINK ;
100     mib[2] = IFT_ETHER ;
101     mib[3] = PF_BDG ;
102     if (sysctl(mib,4, &s,&slen,NULL,0)==-1)
103 	return ; /* no bridging */
104 #ifdef INET6
105     if (bdg_done != 0)
106 	return;
107     else
108 	bdg_done = 1;
109 #endif
110     printf("-- Bridging statistics (%s) --\n", name) ;
111     printf(
112 "Name          In      Out  Forward     Drop    Bcast    Mcast    Local  Unknown\n");
113     for (i = 0 ; i < 16 ; i++) {
114 	if (s.s[i].name[0])
115 	printf("%-6s %9ld%9ld%9ld%9ld%9ld%9ld%9ld%9ld\n",
116 	  s.s[i].name,
117 	  s.s[i].p_in[(int)BDG_IN],
118 	  s.s[i].p_in[(int)BDG_OUT],
119 	  s.s[i].p_in[(int)BDG_FORWARD],
120 	  s.s[i].p_in[(int)BDG_DROP],
121 	  s.s[i].p_in[(int)BDG_BCAST],
122 	  s.s[i].p_in[(int)BDG_MCAST],
123 	  s.s[i].p_in[(int)BDG_LOCAL],
124 	  s.s[i].p_in[(int)BDG_UNKNOWN] );
125     }
126 }
127 
128 
129 
130 
131 /*
132  * Display a formatted value, or a '-' in the same space.
133  */
134 static void
135 show_stat(const char *fmt, int width, u_long value, short showvalue)
136 {
137 	char newfmt[32];
138 
139 	/* Construct the format string */
140 	if (showvalue) {
141 		sprintf(newfmt, "%%%d%s", width, fmt);
142 		printf(newfmt, value);
143 	} else {
144 		sprintf(newfmt, "%%%ds", width);
145 		printf(newfmt, "-");
146 	}
147 }
148 
149 
150 
151 /*
152  * Print a description of the network interfaces.
153  */
154 void
155 intpr(int _interval, u_long ifnetaddr, void (*pfunc)(char *))
156 {
157 	struct ifnet ifnet;
158 	struct ifnethead ifnethead;
159 	union {
160 		struct ifaddr ifa;
161 		struct in_ifaddr in;
162 #ifdef INET6
163 		struct in6_ifaddr in6;
164 #endif
165 		struct ipx_ifaddr ipx;
166 #ifdef NS
167 		struct ns_ifaddr ns;
168 #endif
169 #ifdef ISO
170 		struct iso_ifaddr iso;
171 #endif
172 	} ifaddr;
173 	u_long ifaddraddr;
174 	u_long ifaddrfound;
175 	u_long ifnetfound;
176 	u_long opackets;
177 	u_long ipackets;
178 	u_long obytes;
179 	u_long ibytes;
180 	u_long oerrors;
181 	u_long ierrors;
182 	u_long collisions;
183 	short timer;
184 	int drops;
185 	struct sockaddr *sa = NULL;
186 	char name[32], tname[16];
187 	short network_layer;
188 	short link_layer;
189 
190 	if (ifnetaddr == 0) {
191 		printf("ifnet: symbol not defined\n");
192 		return;
193 	}
194 	if (_interval) {
195 		sidewaysintpr((unsigned)_interval, ifnetaddr);
196 		return;
197 	}
198 	if (kread(ifnetaddr, (char *)&ifnethead, sizeof ifnethead))
199 		return;
200 	ifnetaddr = (u_long)TAILQ_FIRST(&ifnethead);
201 	if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
202 		return;
203 
204 	if (!pfunc) {
205 		printf("%-5.5s %5.5s %-13.13s %-17.17s %8.8s %5.5s",
206 		       "Name", "Mtu", "Network", "Address", "Ipkts", "Ierrs");
207 		if (bflag)
208 			printf(" %10.10s","Ibytes");
209 		printf(" %8.8s %5.5s", "Opkts", "Oerrs");
210 		if (bflag)
211 			printf(" %10.10s","Obytes");
212 		printf(" %5s", "Coll");
213 		if (tflag)
214 			printf(" %s", "Time");
215 		if (dflag)
216 			printf(" %s", "Drop");
217 		putchar('\n');
218 	}
219 	ifaddraddr = 0;
220 	while (ifnetaddr || ifaddraddr) {
221 		struct sockaddr_in *sin;
222 #ifdef INET6
223 		struct sockaddr_in6 *sin6;
224 #endif
225 		char *cp;
226 		int n, m;
227 
228 		network_layer = 0;
229 		link_layer = 0;
230 
231 		if (ifaddraddr == 0) {
232 			ifnetfound = ifnetaddr;
233 			if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet) ||
234 			    kread((u_long)ifnet.if_name, tname, 16))
235 				return;
236 			tname[sizeof(tname) - 1] = '\0';
237 			ifnetaddr = (u_long)TAILQ_NEXT(&ifnet, if_link);
238 			snprintf(name, sizeof(name), "%s%d", tname,
239 			    ifnet.if_unit);
240 			if (interface != 0 && (strcmp(name, interface) != 0))
241 				continue;
242 			cp = index(name, '\0');
243 
244 			if (pfunc) {
245 				(*pfunc)(name);
246 				continue;
247 			}
248 
249 			if ((ifnet.if_flags&IFF_UP) == 0)
250 				*cp++ = '*';
251 			*cp = '\0';
252 			ifaddraddr = (u_long)TAILQ_FIRST(&ifnet.if_addrhead);
253 		}
254 		ifaddrfound = ifaddraddr;
255 
256 		/*
257 		 * Get the interface stats.  These may get
258 		 * overriden below on a per-interface basis.
259 		 */
260 		opackets = ifnet.if_opackets;
261 		ipackets = ifnet.if_ipackets;
262 		obytes = ifnet.if_obytes;
263 		ibytes = ifnet.if_ibytes;
264 		oerrors = ifnet.if_oerrors;
265 		ierrors = ifnet.if_ierrors;
266 		collisions = ifnet.if_collisions;
267 		timer = ifnet.if_timer;
268 		drops = ifnet.if_snd.ifq_drops;
269 
270 		if (ifaddraddr == 0) {
271 			printf("%-5.5s %5lu ", name, ifnet.if_mtu);
272 			printf("%-13.13s ", "none");
273 			printf("%-17.17s ", "none");
274 		} else {
275 			if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
276 				ifaddraddr = 0;
277 				continue;
278 			}
279 #define CP(x) ((char *)(x))
280 			cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
281 				CP(&ifaddr);
282 			sa = (struct sockaddr *)cp;
283 			if (af != AF_UNSPEC && sa->sa_family != af) {
284 				ifaddraddr =
285 				    (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
286 				continue;
287 			}
288 			printf("%-5.5s %5lu ", name, ifnet.if_mtu);
289 			switch (sa->sa_family) {
290 			case AF_UNSPEC:
291 				printf("%-13.13s ", "none");
292 				printf("%-15.15s ", "none");
293 				break;
294 			case AF_INET:
295 				sin = (struct sockaddr_in *)sa;
296 #ifdef notdef
297 				/* can't use inet_makeaddr because kernel
298 				 * keeps nets unshifted.
299 				 */
300 				in = inet_makeaddr(ifaddr.in.ia_subnet,
301 					INADDR_ANY);
302 				printf("%-13.13s ", netname(in.s_addr,
303 				    ifaddr.in.ia_subnetmask));
304 #else
305 				printf("%-13.13s ",
306 				    netname(htonl(ifaddr.in.ia_subnet),
307 				    ifaddr.in.ia_subnetmask));
308 #endif
309 				printf("%-17.17s ",
310 				    routename(sin->sin_addr.s_addr));
311 
312 				network_layer = 1;
313 				break;
314 #ifdef INET6
315 			case AF_INET6:
316 				sin6 = (struct sockaddr_in6 *)sa;
317 				printf("%-13.13s ",
318 				       netname6(&ifaddr.in6.ia_addr,
319 						&ifaddr.in6.ia_prefixmask.sin6_addr));
320 				printf("%-17.17s ",
321 				    inet_ntop(AF_INET6,
322 					&sin6->sin6_addr,
323 					ntop_buf, sizeof(ntop_buf)));
324 
325 				network_layer = 1;
326 				break;
327 #endif /*INET6*/
328 			case AF_IPX:
329 				{
330 				struct sockaddr_ipx *sipx =
331 					(struct sockaddr_ipx *)sa;
332 				u_long net;
333 				char netnum[10];
334 
335 				*(union ipx_net *) &net = sipx->sipx_addr.x_net;
336 				sprintf(netnum, "%lx", (u_long)ntohl(net));
337 				printf("ipx:%-8s  ", netnum);
338 /*				printf("ipx:%-8s ", netname(net, 0L)); */
339 				printf("%-17s ",
340 				    ipx_phost((struct sockaddr *)sipx));
341 				}
342 
343 				network_layer = 1;
344 				break;
345 
346 			case AF_APPLETALK:
347 				printf("atalk:%-12.12s ",atalk_print(sa,0x10) );
348 				printf("%-11.11s  ",atalk_print(sa,0x0b) );
349 				break;
350 #ifdef NS
351 			case AF_NS:
352 				{
353 				struct sockaddr_ns *sns =
354 					(struct sockaddr_ns *)sa;
355 				u_long net;
356 				char netnum[10];
357 
358 				*(union ns_net *) &net = sns->sns_addr.x_net;
359 				sprintf(netnum, "%lxH", ntohl(net));
360 				upHex(netnum);
361 				printf("ns:%-10s ", netnum);
362 				printf("%-17s ",
363 				    ns_phost((struct sockaddr *)sns));
364 				}
365 				break;
366 #endif
367 			case AF_LINK:
368 				{
369 				struct sockaddr_dl *sdl =
370 					(struct sockaddr_dl *)sa;
371 				char linknum[10];
372 				cp = (char *)LLADDR(sdl);
373 				n = sdl->sdl_alen;
374 				sprintf(linknum, "<Link#%d>", sdl->sdl_index);
375 				m = printf("%-13.13s ", linknum);
376 				}
377 				goto hexprint;
378 			default:
379 				m = printf("(%d)", sa->sa_family);
380 				for (cp = sa->sa_len + (char *)sa;
381 					--cp > sa->sa_data && (*cp == 0);) {}
382 				n = cp - sa->sa_data + 1;
383 				cp = sa->sa_data;
384 			hexprint:
385 				while (--n >= 0)
386 					m += printf("%02x%c", *cp++ & 0xff,
387 						    n > 0 ? ':' : ' ');
388 				m = 32 - m;
389 				while (m-- > 0)
390 					putchar(' ');
391 
392 				link_layer = 1;
393 				break;
394 			}
395 
396 			/*
397 			 * Fixup the statistics for interfaces that
398 			 * update stats for their network addresses
399 			 */
400 			if (network_layer) {
401 				opackets = ifaddr.in.ia_ifa.if_opackets;
402 				ipackets = ifaddr.in.ia_ifa.if_ipackets;
403 				obytes = ifaddr.in.ia_ifa.if_obytes;
404 				ibytes = ifaddr.in.ia_ifa.if_ibytes;
405 			}
406 
407 			ifaddraddr = (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
408 		}
409 
410 		show_stat("lu", 8, ipackets, link_layer|network_layer);
411 		printf(" ");
412 		show_stat("lu", 5, ierrors, link_layer);
413 		printf(" ");
414 		if (bflag) {
415 			show_stat("lu", 10, ibytes, link_layer|network_layer);
416 			printf(" ");
417 		}
418 		show_stat("lu", 8, opackets, link_layer|network_layer);
419 		printf(" ");
420 		show_stat("lu", 5, oerrors, link_layer);
421 		printf(" ");
422 		if (bflag) {
423 			show_stat("lu", 10, obytes, link_layer|network_layer);
424 			printf(" ");
425 		}
426 		show_stat("lu", 5, collisions, link_layer);
427 		if (tflag) {
428 			printf(" ");
429 			show_stat("d", 3, timer, link_layer);
430 		}
431 		if (dflag) {
432 			printf(" ");
433 			show_stat("d", 3, drops, link_layer);
434 		}
435 		putchar('\n');
436 		if (aflag && ifaddrfound) {
437 			/*
438 			 * Print family's multicast addresses
439 			 */
440 			struct ifmultiaddr *multiaddr;
441 			struct ifmultiaddr ifma;
442 			union {
443 				struct sockaddr sa;
444 				struct sockaddr_in in;
445 #ifdef INET6
446 				struct sockaddr_in6 in6;
447 #endif /* INET6 */
448 				struct sockaddr_dl dl;
449 			} msa;
450 			const char *fmt;
451 
452 			TAILQ_FOREACH(multiaddr, &ifnet.if_multiaddrs, ifma_link) {
453 				if (kread((u_long)multiaddr, (char *)&ifma,
454 					  sizeof ifma))
455 					break;
456 				multiaddr = &ifma;
457 				if (kread((u_long)ifma.ifma_addr, (char *)&msa,
458 					  sizeof msa))
459 					break;
460 				if (msa.sa.sa_family != sa->sa_family)
461 					continue;
462 
463 				fmt = 0;
464 				switch (msa.sa.sa_family) {
465 				case AF_INET:
466 					fmt = routename(msa.in.sin_addr.s_addr);
467 					break;
468 #ifdef INET6
469 				case AF_INET6:
470 					printf("%23s %-19.19s(refs: %d)\n", "",
471 					       inet_ntop(AF_INET6,
472 							 &msa.in6.sin6_addr,
473 							 ntop_buf,
474 							 sizeof(ntop_buf)),
475 					       ifma.ifma_refcount);
476 					break;
477 #endif /* INET6 */
478 				case AF_LINK:
479 					switch (msa.dl.sdl_type) {
480 					case IFT_ETHER:
481 					case IFT_FDDI:
482 						fmt = ether_ntoa(
483 							(struct ether_addr *)
484 							LLADDR(&msa.dl));
485 						break;
486 					}
487 					break;
488 				}
489 				if (fmt)
490 					printf("%23s %s\n", "", fmt);
491 			}
492 		}
493 	}
494 }
495 
496 struct	iftot {
497 	SLIST_ENTRY(iftot) chain;
498 	char	ift_name[16];		/* interface name */
499 	u_long	ift_ip;			/* input packets */
500 	u_long	ift_ie;			/* input errors */
501 	u_long	ift_op;			/* output packets */
502 	u_long	ift_oe;			/* output errors */
503 	u_long	ift_co;			/* collisions */
504 	u_int	ift_dr;			/* drops */
505 	u_long	ift_ib;			/* input bytes */
506 	u_long	ift_ob;			/* output bytes */
507 };
508 
509 u_char	signalled;			/* set if alarm goes off "early" */
510 
511 /*
512  * Print a running summary of interface statistics.
513  * Repeat display every interval seconds, showing statistics
514  * collected over that interval.  Assumes that interval is non-zero.
515  * First line printed at top of screen is always cumulative.
516  * XXX - should be rewritten to use ifmib(4).
517  */
518 static void
519 sidewaysintpr(unsigned interval1, u_long off)
520 {
521 	struct ifnet ifnet;
522 	u_long firstifnet;
523 	struct ifnethead ifnethead;
524 	struct iftot *iftot, *ip, *ipn, *total, *sum, *interesting;
525 	int line;
526 	int oldmask, first;
527 	u_long interesting_off;
528 
529 	if (kread(off, (char *)&ifnethead, sizeof ifnethead))
530 		return;
531 	firstifnet = (u_long)TAILQ_FIRST(&ifnethead);
532 
533 	if ((iftot = malloc(sizeof(struct iftot))) == NULL) {
534 		printf("malloc failed\n");
535 		exit(1);
536 	}
537 	memset(iftot, 0, sizeof(struct iftot));
538 
539 	interesting = NULL;
540 	interesting_off = 0;
541 	for (off = firstifnet, ip = iftot; off;) {
542 		char name[16], tname[16];
543 
544 		if (kread(off, (char *)&ifnet, sizeof ifnet))
545 			break;
546 		if (kread((u_long)ifnet.if_name, tname, sizeof(tname)))
547 			break;
548 		tname[sizeof(tname) - 1] = '\0';
549 		snprintf(name, sizeof(name), "%s%d", tname, ifnet.if_unit);
550 		if (interface && strcmp(name, interface) == 0) {
551 			interesting = ip;
552 			interesting_off = off;
553 		}
554 		snprintf(ip->ift_name, sizeof(ip->ift_name), "(%s)", name);;
555 		if ((ipn = malloc(sizeof(struct iftot))) == NULL) {
556 			printf("malloc failed\n");
557 			exit(1);
558 		}
559 		memset(ipn, 0, sizeof(struct iftot));
560 		SLIST_NEXT(ip, chain) = ipn;
561 		ip = ipn;
562 		off = (u_long)TAILQ_NEXT(&ifnet, if_link);
563 	}
564 	if ((total = malloc(sizeof(struct iftot))) == NULL) {
565 		printf("malloc failed\n");
566 		exit(1);
567 	}
568 	memset(total, 0, sizeof(struct iftot));
569 	if ((sum = malloc(sizeof(struct iftot))) == NULL) {
570 		printf("malloc failed\n");
571 		exit(1);
572 	}
573 	memset(sum, 0, sizeof(struct iftot));
574 
575 	(void)signal(SIGALRM, catchalarm);
576 	signalled = NO;
577 	(void)alarm(interval1);
578 	first = 1;
579 banner:
580 	printf("%17s %14s %16s", "input",
581 	    interesting ? interesting->ift_name : "(Total)", "output");
582 	putchar('\n');
583 	printf("%10s %5s %10s %10s %5s %10s %5s",
584 	    "packets", "errs", "bytes", "packets", "errs", "bytes", "colls");
585 	if (dflag)
586 		printf(" %5.5s", "drops");
587 	putchar('\n');
588 	fflush(stdout);
589 	line = 0;
590 loop:
591 	if (interesting != NULL) {
592 		ip = interesting;
593 		if (kread(interesting_off, (char *)&ifnet, sizeof ifnet)) {
594 			printf("???\n");
595 			exit(1);
596 		};
597 		if (!first) {
598 			printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
599 				ifnet.if_ipackets - ip->ift_ip,
600 				ifnet.if_ierrors - ip->ift_ie,
601 				ifnet.if_ibytes - ip->ift_ib,
602 				ifnet.if_opackets - ip->ift_op,
603 				ifnet.if_oerrors - ip->ift_oe,
604 				ifnet.if_obytes - ip->ift_ob,
605 				ifnet.if_collisions - ip->ift_co);
606 			if (dflag)
607 				printf(" %5u", ifnet.if_snd.ifq_drops - ip->ift_dr);
608 		}
609 		ip->ift_ip = ifnet.if_ipackets;
610 		ip->ift_ie = ifnet.if_ierrors;
611 		ip->ift_ib = ifnet.if_ibytes;
612 		ip->ift_op = ifnet.if_opackets;
613 		ip->ift_oe = ifnet.if_oerrors;
614 		ip->ift_ob = ifnet.if_obytes;
615 		ip->ift_co = ifnet.if_collisions;
616 		ip->ift_dr = ifnet.if_snd.ifq_drops;
617 	} else {
618 		sum->ift_ip = 0;
619 		sum->ift_ie = 0;
620 		sum->ift_ib = 0;
621 		sum->ift_op = 0;
622 		sum->ift_oe = 0;
623 		sum->ift_ob = 0;
624 		sum->ift_co = 0;
625 		sum->ift_dr = 0;
626 		for (off = firstifnet, ip = iftot;
627 		     off && SLIST_NEXT(ip, chain) != NULL;
628 		     ip = SLIST_NEXT(ip, chain)) {
629 			if (kread(off, (char *)&ifnet, sizeof ifnet)) {
630 				off = 0;
631 				continue;
632 			}
633 			sum->ift_ip += ifnet.if_ipackets;
634 			sum->ift_ie += ifnet.if_ierrors;
635 			sum->ift_ib += ifnet.if_ibytes;
636 			sum->ift_op += ifnet.if_opackets;
637 			sum->ift_oe += ifnet.if_oerrors;
638 			sum->ift_ob += ifnet.if_obytes;
639 			sum->ift_co += ifnet.if_collisions;
640 			sum->ift_dr += ifnet.if_snd.ifq_drops;
641 			off = (u_long)TAILQ_NEXT(&ifnet, if_link);
642 		}
643 		if (!first) {
644 			printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
645 				sum->ift_ip - total->ift_ip,
646 				sum->ift_ie - total->ift_ie,
647 				sum->ift_ib - total->ift_ib,
648 				sum->ift_op - total->ift_op,
649 				sum->ift_oe - total->ift_oe,
650 				sum->ift_ob - total->ift_ob,
651 				sum->ift_co - total->ift_co);
652 			if (dflag)
653 				printf(" %5u", sum->ift_dr - total->ift_dr);
654 		}
655 		*total = *sum;
656 	}
657 	if (!first)
658 		putchar('\n');
659 	fflush(stdout);
660 	oldmask = sigblock(sigmask(SIGALRM));
661 	if (! signalled) {
662 		sigpause(0);
663 	}
664 	sigsetmask(oldmask);
665 	signalled = NO;
666 	(void)alarm(interval1);
667 	line++;
668 	first = 0;
669 	if (line == 21)
670 		goto banner;
671 	else
672 		goto loop;
673 	/*NOTREACHED*/
674 }
675 
676 /*
677  * Called if an interval expires before sidewaysintpr has completed a loop.
678  * Sets a flag to not wait for the alarm.
679  */
680 static void
681 catchalarm(int signo __unused)
682 {
683 	signalled = YES;
684 }
685