xref: /freebsd/usr.bin/netstat/if.c (revision 52ec752989b2e6d4e9a59a8ff25d8ff596d85e62)
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 #include <arpa/inet.h>
59 
60 #include <signal.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65 
66 #include "netstat.h"
67 
68 #define	YES	1
69 #define	NO	0
70 
71 static void sidewaysintpr (u_int, u_long);
72 static void catchalarm (int);
73 
74 #ifdef INET6
75 static char ntop_buf[INET6_ADDRSTRLEN];		/* for inet_ntop() */
76 static int bdg_done;
77 #endif
78 
79 /* print bridge statistics */
80 void
81 bdg_stats(u_long dummy __unused, const char *name, int af1 __unused)
82 {
83     int i;
84     size_t slen ;
85     struct bdg_stats s ;
86     int mib[4] ;
87 
88     slen = sizeof(s);
89 
90     mib[0] = CTL_NET ;
91     mib[1] = PF_LINK ;
92     mib[2] = IFT_ETHER ;
93     mib[3] = PF_BDG ;
94     if (sysctl(mib,4, &s,&slen,NULL,0)==-1)
95 	return ; /* no bridging */
96 #ifdef INET6
97     if (bdg_done != 0)
98 	return;
99     else
100 	bdg_done = 1;
101 #endif
102     printf("-- Bridging statistics (%s) --\n", name) ;
103     printf(
104 "Name          In      Out  Forward     Drop    Bcast    Mcast    Local  Unknown\n");
105     for (i = 0 ; i < 16 ; i++) {
106 	if (s.s[i].name[0])
107 	printf("%-6s %9ld%9ld%9ld%9ld%9ld%9ld%9ld%9ld\n",
108 	  s.s[i].name,
109 	  s.s[i].p_in[(int)BDG_IN],
110 	  s.s[i].p_in[(int)BDG_OUT],
111 	  s.s[i].p_in[(int)BDG_FORWARD],
112 	  s.s[i].p_in[(int)BDG_DROP],
113 	  s.s[i].p_in[(int)BDG_BCAST],
114 	  s.s[i].p_in[(int)BDG_MCAST],
115 	  s.s[i].p_in[(int)BDG_LOCAL],
116 	  s.s[i].p_in[(int)BDG_UNKNOWN] );
117     }
118 }
119 
120 
121 
122 
123 /*
124  * Display a formatted value, or a '-' in the same space.
125  */
126 static void
127 show_stat(const char *fmt, int width, u_long value, short showvalue)
128 {
129 	char newfmt[32];
130 
131 	/* Construct the format string */
132 	if (showvalue) {
133 		sprintf(newfmt, "%%%d%s", width, fmt);
134 		printf(newfmt, value);
135 	} else {
136 		sprintf(newfmt, "%%%ds", width);
137 		printf(newfmt, "-");
138 	}
139 }
140 
141 
142 
143 /*
144  * Print a description of the network interfaces.
145  */
146 void
147 intpr(int _interval, u_long ifnetaddr, void (*pfunc)(char *))
148 {
149 	struct ifnet ifnet;
150 	struct ifnethead ifnethead;
151 	union {
152 		struct ifaddr ifa;
153 		struct in_ifaddr in;
154 #ifdef INET6
155 		struct in6_ifaddr in6;
156 #endif
157 		struct ipx_ifaddr ipx;
158 	} ifaddr;
159 	u_long ifaddraddr;
160 	u_long ifaddrfound;
161 	u_long ifnetfound;
162 	u_long opackets;
163 	u_long ipackets;
164 	u_long obytes;
165 	u_long ibytes;
166 	u_long oerrors;
167 	u_long ierrors;
168 	u_long collisions;
169 	short timer;
170 	int drops;
171 	struct sockaddr *sa = NULL;
172 	char name[IFNAMSIZ];
173 	short network_layer;
174 	short link_layer;
175 
176 	if (ifnetaddr == 0) {
177 		printf("ifnet: symbol not defined\n");
178 		return;
179 	}
180 	if (_interval) {
181 		sidewaysintpr((unsigned)_interval, ifnetaddr);
182 		return;
183 	}
184 	if (kread(ifnetaddr, (char *)&ifnethead, sizeof ifnethead))
185 		return;
186 	ifnetaddr = (u_long)TAILQ_FIRST(&ifnethead);
187 	if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
188 		return;
189 
190 	if (!pfunc) {
191 		if (Wflag)
192 			printf("%-7.7s", "Name");
193 		else
194 			printf("%-5.5s", "Name");
195 		printf(" %5.5s %-13.13s %-17.17s %8.8s %5.5s",
196 		    "Mtu", "Network", "Address", "Ipkts", "Ierrs");
197 		if (bflag)
198 			printf(" %10.10s","Ibytes");
199 		printf(" %8.8s %5.5s", "Opkts", "Oerrs");
200 		if (bflag)
201 			printf(" %10.10s","Obytes");
202 		printf(" %5s", "Coll");
203 		if (tflag)
204 			printf(" %s", "Time");
205 		if (dflag)
206 			printf(" %s", "Drop");
207 		putchar('\n');
208 	}
209 	ifaddraddr = 0;
210 	while (ifnetaddr || ifaddraddr) {
211 		struct sockaddr_in *sin;
212 #ifdef INET6
213 		struct sockaddr_in6 *sin6;
214 #endif
215 		char *cp;
216 		int n, m;
217 
218 		network_layer = 0;
219 		link_layer = 0;
220 
221 		if (ifaddraddr == 0) {
222 			ifnetfound = ifnetaddr;
223 			if (kread(ifnetaddr, (char *)&ifnet, sizeof ifnet))
224 				return;
225 			strlcpy(name, ifnet.if_xname, sizeof(name));
226 			ifnetaddr = (u_long)TAILQ_NEXT(&ifnet, if_link);
227 			if (interface != 0 && (strcmp(name, interface) != 0))
228 				continue;
229 			cp = index(name, '\0');
230 
231 			if (pfunc) {
232 				(*pfunc)(name);
233 				continue;
234 			}
235 
236 			if ((ifnet.if_flags&IFF_UP) == 0)
237 				*cp++ = '*';
238 			*cp = '\0';
239 			ifaddraddr = (u_long)TAILQ_FIRST(&ifnet.if_addrhead);
240 		}
241 		ifaddrfound = ifaddraddr;
242 
243 		/*
244 		 * Get the interface stats.  These may get
245 		 * overriden below on a per-interface basis.
246 		 */
247 		opackets = ifnet.if_opackets;
248 		ipackets = ifnet.if_ipackets;
249 		obytes = ifnet.if_obytes;
250 		ibytes = ifnet.if_ibytes;
251 		oerrors = ifnet.if_oerrors;
252 		ierrors = ifnet.if_ierrors;
253 		collisions = ifnet.if_collisions;
254 		timer = ifnet.if_timer;
255 		drops = ifnet.if_snd.ifq_drops;
256 
257 		if (ifaddraddr == 0) {
258 			if (Wflag)
259 				printf("%-7.7s", name);
260 			else
261 				printf("%-5.5s", name);
262 			printf(" %5lu ", ifnet.if_mtu);
263 			printf("%-13.13s ", "none");
264 			printf("%-17.17s ", "none");
265 		} else {
266 			if (kread(ifaddraddr, (char *)&ifaddr, sizeof ifaddr)) {
267 				ifaddraddr = 0;
268 				continue;
269 			}
270 #define CP(x) ((char *)(x))
271 			cp = (CP(ifaddr.ifa.ifa_addr) - CP(ifaddraddr)) +
272 				CP(&ifaddr);
273 			sa = (struct sockaddr *)cp;
274 			if (af != AF_UNSPEC && sa->sa_family != af) {
275 				ifaddraddr =
276 				    (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
277 				continue;
278 			}
279 			if (Wflag)
280 				printf("%-7.7s", name);
281 			else
282 				printf("%-5.5s", name);
283 			printf(" %5lu ", ifnet.if_mtu);
284 			switch (sa->sa_family) {
285 			case AF_UNSPEC:
286 				printf("%-13.13s ", "none");
287 				printf("%-15.15s ", "none");
288 				break;
289 			case AF_INET:
290 				sin = (struct sockaddr_in *)sa;
291 #ifdef notdef
292 				/* can't use inet_makeaddr because kernel
293 				 * keeps nets unshifted.
294 				 */
295 				in = inet_makeaddr(ifaddr.in.ia_subnet,
296 					INADDR_ANY);
297 				printf("%-13.13s ", netname(in.s_addr,
298 				    ifaddr.in.ia_subnetmask));
299 #else
300 				printf("%-13.13s ",
301 				    netname(htonl(ifaddr.in.ia_subnet),
302 				    ifaddr.in.ia_subnetmask));
303 #endif
304 				printf("%-17.17s ",
305 				    routename(sin->sin_addr.s_addr));
306 
307 				network_layer = 1;
308 				break;
309 #ifdef INET6
310 			case AF_INET6:
311 				sin6 = (struct sockaddr_in6 *)sa;
312 				printf("%-13.13s ",
313 				       netname6(&ifaddr.in6.ia_addr,
314 						&ifaddr.in6.ia_prefixmask.sin6_addr));
315 				printf("%-17.17s ",
316 				    inet_ntop(AF_INET6,
317 					&sin6->sin6_addr,
318 					ntop_buf, sizeof(ntop_buf)));
319 
320 				network_layer = 1;
321 				break;
322 #endif /*INET6*/
323 			case AF_IPX:
324 				{
325 				struct sockaddr_ipx *sipx =
326 					(struct sockaddr_ipx *)sa;
327 				u_long net;
328 				char netnum[10];
329 
330 				*(union ipx_net *) &net = sipx->sipx_addr.x_net;
331 				sprintf(netnum, "%lx", (u_long)ntohl(net));
332 				printf("ipx:%-8s  ", netnum);
333 /*				printf("ipx:%-8s ", netname(net, 0L)); */
334 				printf("%-17s ",
335 				    ipx_phost((struct sockaddr *)sipx));
336 				}
337 
338 				network_layer = 1;
339 				break;
340 
341 			case AF_APPLETALK:
342 				printf("atalk:%-12.12s ",atalk_print(sa,0x10) );
343 				printf("%-11.11s  ",atalk_print(sa,0x0b) );
344 				break;
345 			case AF_LINK:
346 				{
347 				struct sockaddr_dl *sdl =
348 					(struct sockaddr_dl *)sa;
349 				char linknum[10];
350 				cp = (char *)LLADDR(sdl);
351 				n = sdl->sdl_alen;
352 				sprintf(linknum, "<Link#%d>", sdl->sdl_index);
353 				m = printf("%-13.13s ", linknum);
354 				}
355 				goto hexprint;
356 			default:
357 				m = printf("(%d)", sa->sa_family);
358 				for (cp = sa->sa_len + (char *)sa;
359 					--cp > sa->sa_data && (*cp == 0);) {}
360 				n = cp - sa->sa_data + 1;
361 				cp = sa->sa_data;
362 			hexprint:
363 				while (--n >= 0)
364 					m += printf("%02x%c", *cp++ & 0xff,
365 						    n > 0 ? ':' : ' ');
366 				m = 32 - m;
367 				while (m-- > 0)
368 					putchar(' ');
369 
370 				link_layer = 1;
371 				break;
372 			}
373 
374 			/*
375 			 * Fixup the statistics for interfaces that
376 			 * update stats for their network addresses
377 			 */
378 			if (network_layer) {
379 				opackets = ifaddr.in.ia_ifa.if_opackets;
380 				ipackets = ifaddr.in.ia_ifa.if_ipackets;
381 				obytes = ifaddr.in.ia_ifa.if_obytes;
382 				ibytes = ifaddr.in.ia_ifa.if_ibytes;
383 			}
384 
385 			ifaddraddr = (u_long)TAILQ_NEXT(&ifaddr.ifa, ifa_link);
386 		}
387 
388 		show_stat("lu", 8, ipackets, link_layer|network_layer);
389 		printf(" ");
390 		show_stat("lu", 5, ierrors, link_layer);
391 		printf(" ");
392 		if (bflag) {
393 			show_stat("lu", 10, ibytes, link_layer|network_layer);
394 			printf(" ");
395 		}
396 		show_stat("lu", 8, opackets, link_layer|network_layer);
397 		printf(" ");
398 		show_stat("lu", 5, oerrors, link_layer);
399 		printf(" ");
400 		if (bflag) {
401 			show_stat("lu", 10, obytes, link_layer|network_layer);
402 			printf(" ");
403 		}
404 		show_stat("lu", 5, collisions, link_layer);
405 		if (tflag) {
406 			printf(" ");
407 			show_stat("d", 3, timer, link_layer);
408 		}
409 		if (dflag) {
410 			printf(" ");
411 			show_stat("d", 3, drops, link_layer);
412 		}
413 		putchar('\n');
414 		if (aflag && ifaddrfound) {
415 			/*
416 			 * Print family's multicast addresses
417 			 */
418 			struct ifmultiaddr *multiaddr;
419 			struct ifmultiaddr ifma;
420 			union {
421 				struct sockaddr sa;
422 				struct sockaddr_in in;
423 #ifdef INET6
424 				struct sockaddr_in6 in6;
425 #endif /* INET6 */
426 				struct sockaddr_dl dl;
427 			} msa;
428 			const char *fmt;
429 
430 			TAILQ_FOREACH(multiaddr, &ifnet.if_multiaddrs, ifma_link) {
431 				if (kread((u_long)multiaddr, (char *)&ifma,
432 					  sizeof ifma))
433 					break;
434 				multiaddr = &ifma;
435 				if (kread((u_long)ifma.ifma_addr, (char *)&msa,
436 					  sizeof msa))
437 					break;
438 				if (msa.sa.sa_family != sa->sa_family)
439 					continue;
440 
441 				fmt = 0;
442 				switch (msa.sa.sa_family) {
443 				case AF_INET:
444 					fmt = routename(msa.in.sin_addr.s_addr);
445 					break;
446 #ifdef INET6
447 				case AF_INET6:
448 					printf("%23s %-19.19s(refs: %d)\n", "",
449 					       inet_ntop(AF_INET6,
450 							 &msa.in6.sin6_addr,
451 							 ntop_buf,
452 							 sizeof(ntop_buf)),
453 					       ifma.ifma_refcount);
454 					break;
455 #endif /* INET6 */
456 				case AF_LINK:
457 					switch (msa.dl.sdl_type) {
458 					case IFT_ETHER:
459 					case IFT_FDDI:
460 						fmt = ether_ntoa(
461 							(struct ether_addr *)
462 							LLADDR(&msa.dl));
463 						break;
464 					}
465 					break;
466 				}
467 				if (fmt)
468 					printf("%23s %s\n", "", fmt);
469 			}
470 		}
471 	}
472 }
473 
474 struct	iftot {
475 	SLIST_ENTRY(iftot) chain;
476 	char	ift_name[IFNAMSIZ];	/* interface name */
477 	u_long	ift_ip;			/* input packets */
478 	u_long	ift_ie;			/* input errors */
479 	u_long	ift_op;			/* output packets */
480 	u_long	ift_oe;			/* output errors */
481 	u_long	ift_co;			/* collisions */
482 	u_int	ift_dr;			/* drops */
483 	u_long	ift_ib;			/* input bytes */
484 	u_long	ift_ob;			/* output bytes */
485 };
486 
487 u_char	signalled;			/* set if alarm goes off "early" */
488 
489 /*
490  * Print a running summary of interface statistics.
491  * Repeat display every interval seconds, showing statistics
492  * collected over that interval.  Assumes that interval is non-zero.
493  * First line printed at top of screen is always cumulative.
494  * XXX - should be rewritten to use ifmib(4).
495  */
496 static void
497 sidewaysintpr(unsigned interval1, u_long off)
498 {
499 	struct ifnet ifnet;
500 	u_long firstifnet;
501 	struct ifnethead ifnethead;
502 	struct iftot *iftot, *ip, *ipn, *total, *sum, *interesting;
503 	int line;
504 	int oldmask, first;
505 	u_long interesting_off;
506 
507 	if (kread(off, (char *)&ifnethead, sizeof ifnethead))
508 		return;
509 	firstifnet = (u_long)TAILQ_FIRST(&ifnethead);
510 
511 	if ((iftot = malloc(sizeof(struct iftot))) == NULL) {
512 		printf("malloc failed\n");
513 		exit(1);
514 	}
515 	memset(iftot, 0, sizeof(struct iftot));
516 
517 	interesting = NULL;
518 	interesting_off = 0;
519 	for (off = firstifnet, ip = iftot; off;) {
520 		char name[IFNAMSIZ];
521 
522 		if (kread(off, (char *)&ifnet, sizeof ifnet))
523 			break;
524 		strlcpy(name, ifnet.if_xname, sizeof(name));
525 		if (interface && strcmp(name, interface) == 0) {
526 			interesting = ip;
527 			interesting_off = off;
528 		}
529 		snprintf(ip->ift_name, sizeof(ip->ift_name), "(%s)", name);;
530 		if ((ipn = malloc(sizeof(struct iftot))) == NULL) {
531 			printf("malloc failed\n");
532 			exit(1);
533 		}
534 		memset(ipn, 0, sizeof(struct iftot));
535 		SLIST_NEXT(ip, chain) = ipn;
536 		ip = ipn;
537 		off = (u_long)TAILQ_NEXT(&ifnet, if_link);
538 	}
539 	if ((total = malloc(sizeof(struct iftot))) == NULL) {
540 		printf("malloc failed\n");
541 		exit(1);
542 	}
543 	memset(total, 0, sizeof(struct iftot));
544 	if ((sum = malloc(sizeof(struct iftot))) == NULL) {
545 		printf("malloc failed\n");
546 		exit(1);
547 	}
548 	memset(sum, 0, sizeof(struct iftot));
549 
550 	(void)signal(SIGALRM, catchalarm);
551 	signalled = NO;
552 	(void)alarm(interval1);
553 	first = 1;
554 banner:
555 	printf("%17s %14s %16s", "input",
556 	    interesting ? interesting->ift_name : "(Total)", "output");
557 	putchar('\n');
558 	printf("%10s %5s %10s %10s %5s %10s %5s",
559 	    "packets", "errs", "bytes", "packets", "errs", "bytes", "colls");
560 	if (dflag)
561 		printf(" %5.5s", "drops");
562 	putchar('\n');
563 	fflush(stdout);
564 	line = 0;
565 loop:
566 	if (interesting != NULL) {
567 		ip = interesting;
568 		if (kread(interesting_off, (char *)&ifnet, sizeof ifnet)) {
569 			printf("???\n");
570 			exit(1);
571 		};
572 		if (!first) {
573 			printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
574 				ifnet.if_ipackets - ip->ift_ip,
575 				ifnet.if_ierrors - ip->ift_ie,
576 				ifnet.if_ibytes - ip->ift_ib,
577 				ifnet.if_opackets - ip->ift_op,
578 				ifnet.if_oerrors - ip->ift_oe,
579 				ifnet.if_obytes - ip->ift_ob,
580 				ifnet.if_collisions - ip->ift_co);
581 			if (dflag)
582 				printf(" %5u", ifnet.if_snd.ifq_drops - ip->ift_dr);
583 		}
584 		ip->ift_ip = ifnet.if_ipackets;
585 		ip->ift_ie = ifnet.if_ierrors;
586 		ip->ift_ib = ifnet.if_ibytes;
587 		ip->ift_op = ifnet.if_opackets;
588 		ip->ift_oe = ifnet.if_oerrors;
589 		ip->ift_ob = ifnet.if_obytes;
590 		ip->ift_co = ifnet.if_collisions;
591 		ip->ift_dr = ifnet.if_snd.ifq_drops;
592 	} else {
593 		sum->ift_ip = 0;
594 		sum->ift_ie = 0;
595 		sum->ift_ib = 0;
596 		sum->ift_op = 0;
597 		sum->ift_oe = 0;
598 		sum->ift_ob = 0;
599 		sum->ift_co = 0;
600 		sum->ift_dr = 0;
601 		for (off = firstifnet, ip = iftot;
602 		     off && SLIST_NEXT(ip, chain) != NULL;
603 		     ip = SLIST_NEXT(ip, chain)) {
604 			if (kread(off, (char *)&ifnet, sizeof ifnet)) {
605 				off = 0;
606 				continue;
607 			}
608 			sum->ift_ip += ifnet.if_ipackets;
609 			sum->ift_ie += ifnet.if_ierrors;
610 			sum->ift_ib += ifnet.if_ibytes;
611 			sum->ift_op += ifnet.if_opackets;
612 			sum->ift_oe += ifnet.if_oerrors;
613 			sum->ift_ob += ifnet.if_obytes;
614 			sum->ift_co += ifnet.if_collisions;
615 			sum->ift_dr += ifnet.if_snd.ifq_drops;
616 			off = (u_long)TAILQ_NEXT(&ifnet, if_link);
617 		}
618 		if (!first) {
619 			printf("%10lu %5lu %10lu %10lu %5lu %10lu %5lu",
620 				sum->ift_ip - total->ift_ip,
621 				sum->ift_ie - total->ift_ie,
622 				sum->ift_ib - total->ift_ib,
623 				sum->ift_op - total->ift_op,
624 				sum->ift_oe - total->ift_oe,
625 				sum->ift_ob - total->ift_ob,
626 				sum->ift_co - total->ift_co);
627 			if (dflag)
628 				printf(" %5u", sum->ift_dr - total->ift_dr);
629 		}
630 		*total = *sum;
631 	}
632 	if (!first)
633 		putchar('\n');
634 	fflush(stdout);
635 	oldmask = sigblock(sigmask(SIGALRM));
636 	if (! signalled) {
637 		sigpause(0);
638 	}
639 	sigsetmask(oldmask);
640 	signalled = NO;
641 	(void)alarm(interval1);
642 	line++;
643 	first = 0;
644 	if (line == 21)
645 		goto banner;
646 	else
647 		goto loop;
648 	/*NOTREACHED*/
649 }
650 
651 /*
652  * Called if an interval expires before sidewaysintpr has completed a loop.
653  * Sets a flag to not wait for the alarm.
654  */
655 static void
656 catchalarm(int signo __unused)
657 {
658 	signalled = YES;
659 }
660