xref: /freebsd/usr.bin/systat/netstat.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5) 
1 /*-
2  * Copyright (c) 1980, 1992, 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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 
32 __FBSDID("$FreeBSD$");
33 
34 #ifdef lint
35 static const char sccsid[] = "@(#)netstat.c	8.1 (Berkeley) 6/6/93";
36 #endif
37 
38 /*
39  * netstat
40  */
41 #include <sys/param.h>
42 #include <sys/queue.h>
43 #include <sys/socket.h>
44 #define	_WANT_SOCKET
45 #include <sys/socketvar.h>
46 #include <sys/protosw.h>
47 
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
50 #include <net/route.h>
51 #include <netinet/in_systm.h>
52 #include <netinet/ip.h>
53 #ifdef INET6
54 #include <netinet/ip6.h>
55 #endif
56 #define	_WANT_INPCB
57 #include <netinet/in_pcb.h>
58 #include <netinet/ip_icmp.h>
59 #include <netinet/icmp_var.h>
60 #include <netinet/ip_var.h>
61 #include <netinet/tcp.h>
62 #include <netinet/tcpip.h>
63 #include <netinet/tcp_seq.h>
64 #define TCPSTATES
65 #include <netinet/tcp_fsm.h>
66 #include <netinet/tcp_timer.h>
67 #define	_WANT_TCPCB
68 #include <netinet/tcp_var.h>
69 #include <netinet/tcp_debug.h>
70 #include <netinet/udp.h>
71 #include <netinet/udp_var.h>
72 
73 #include <netdb.h>
74 #include <nlist.h>
75 #include <paths.h>
76 #include <stdlib.h>
77 #include <string.h>
78 
79 #include "systat.h"
80 #include "extern.h"
81 
82 static struct netinfo *enter(struct in_conninfo *, uint8_t, int, const char *);
83 static void enter_kvm(struct inpcb *, struct socket *, int, const char *);
84 static void enter_sysctl(struct xinpcb *, struct xsocket *, int, const char *);
85 static void fetchnetstat_kvm(void);
86 static void fetchnetstat_sysctl(void);
87 static char *inetname(struct sockaddr *);
88 static void inetprint(struct sockaddr *, const char *);
89 
90 #define	streq(a,b)	(strcmp(a,b)==0)
91 #define	YMAX(w)		(getmaxy(w)-2)
92 
93 WINDOW *
94 opennetstat(void)
95 {
96 	sethostent(1);
97 	setnetent(1);
98 	return (subwin(stdscr, LINES-3-1, 0, MAINWIN_ROW, 0));
99 }
100 
101 struct netinfo {
102 	TAILQ_ENTRY(netinfo) chain;
103 	short	ni_line;		/* line on screen */
104 	short	ni_seen;		/* 0 when not present in list */
105 	short	ni_flags;
106 #define	NIF_LACHG	0x1		/* local address changed */
107 #define	NIF_FACHG	0x2		/* foreign address changed */
108 	short	ni_state;		/* tcp state */
109 	const char	*ni_proto;		/* protocol */
110 	struct sockaddr_storage ni_lsa;	/* local address */
111 	struct sockaddr_storage	ni_fsa;	/* foreign address */
112 	u_int	ni_rcvcc;		/* rcv buffer character count */
113 	u_int	ni_sndcc;		/* snd buffer character count */
114 };
115 
116 TAILQ_HEAD(netinfohead, netinfo) netcb = TAILQ_HEAD_INITIALIZER(netcb);
117 
118 static	int aflag = 0;
119 static	int nflag = 0;
120 static	int lastrow = 1;
121 
122 void
123 closenetstat(WINDOW *w)
124 {
125 	struct netinfo *p;
126 
127 	endhostent();
128 	endnetent();
129 	TAILQ_FOREACH(p, &netcb, chain) {
130 		if (p->ni_line != -1)
131 			lastrow--;
132 		p->ni_line = -1;
133 	}
134 	if (w != NULL) {
135 		wclear(w);
136 		wrefresh(w);
137 		delwin(w);
138 	}
139 }
140 
141 static const char *miblist[] = {
142 	"net.inet.tcp.pcblist",
143 	"net.inet.udp.pcblist"
144 };
145 
146 static char tcb[] = "tcb", udb[] = "udb";
147 
148 struct nlist namelist[] = {
149 #define	X_TCB	0
150 	{ .n_name = tcb },
151 #define	X_UDB	1
152 	{ .n_name = udb },
153 	{ .n_name = NULL },
154 };
155 
156 int
157 initnetstat(void)
158 {
159 	protos = TCP|UDP;
160 	return(1);
161 }
162 
163 void
164 fetchnetstat(void)
165 {
166 	if (use_kvm)
167 		fetchnetstat_kvm();
168 	else
169 		fetchnetstat_sysctl();
170 }
171 
172 static void
173 fetchnetstat_kvm(void)
174 {
175 	struct inpcb *next;
176 	struct netinfo *p;
177 	struct inpcbhead head;
178 	struct inpcb inpcb;
179 	struct socket sockb;
180 	struct tcpcb tcpcb;
181 	void *off;
182 	int istcp;
183 
184 	if (namelist[X_TCB].n_value == 0)
185 		return;
186 	TAILQ_FOREACH(p, &netcb, chain)
187 		p->ni_seen = 0;
188 	if (protos&TCP) {
189 		off = NPTR(X_TCB);
190 		istcp = 1;
191 	}
192 	else if (protos&UDP) {
193 		off = NPTR(X_UDB);
194 		istcp = 0;
195 	}
196 	else {
197 		error("No protocols to display");
198 		return;
199 	}
200 again:
201 	KREAD(off, &head, sizeof (struct inpcbhead));
202 	LIST_FOREACH(next, &head, inp_list) {
203 		KREAD(next, &inpcb, sizeof (inpcb));
204 		next = &inpcb;
205 		if (!aflag) {
206 			if (inpcb.inp_vflag & INP_IPV4) {
207 				if (inet_lnaof(inpcb.inp_laddr) == INADDR_ANY)
208 					continue;
209 			}
210 #ifdef INET6
211 			else if (inpcb.inp_vflag & INP_IPV6) {
212 				if (memcmp(&inpcb.in6p_laddr,
213 				    &in6addr_any, sizeof(in6addr_any)) == 0)
214 					continue;
215 			}
216 #endif
217 		}
218 		if (nhosts && !checkhost(&inpcb.inp_inc))
219 			continue;
220 		if (nports && !checkport(&inpcb.inp_inc))
221 			continue;
222 		if (istcp) {
223 			if (inpcb.inp_flags & INP_TIMEWAIT) {
224 				bzero(&sockb, sizeof(sockb));
225 				enter_kvm(&inpcb, &sockb, TCPS_TIME_WAIT,
226 					 "tcp");
227 			} else {
228 				KREAD(inpcb.inp_socket, &sockb,
229 					sizeof (sockb));
230 				KREAD(inpcb.inp_ppcb, &tcpcb, sizeof (tcpcb));
231 				enter_kvm(&inpcb, &sockb, tcpcb.t_state,
232 					"tcp");
233 			}
234 		} else
235 			enter_kvm(&inpcb, &sockb, 0, "udp");
236 	}
237 	if (istcp && (protos&UDP)) {
238 		istcp = 0;
239 		off = NPTR(X_UDB);
240 		goto again;
241 	}
242 }
243 
244 static void
245 fetchnetstat_sysctl(void)
246 {
247 	struct netinfo *p;
248 	int idx;
249 	struct xinpgen *inpg;
250 	char *cur, *end;
251 	struct xinpcb *xip = NULL;
252 	struct xtcpcb *xtp = NULL;
253 	int plen;
254 	size_t lsz;
255 
256 	TAILQ_FOREACH(p, &netcb, chain)
257 		p->ni_seen = 0;
258 	if (protos&TCP) {
259 		idx = 0;
260 	} else if (protos&UDP) {
261 		idx = 1;
262 	} else {
263 		error("No protocols to display");
264 		return;
265 	}
266 
267 	for (;idx < 2; idx++) {
268 		if (idx == 1 && !(protos&UDP))
269 			break;
270 		inpg = (struct xinpgen *)sysctl_dynread(miblist[idx], &lsz);
271 		if (inpg == NULL) {
272 			error("sysctl(%s...) failed", miblist[idx]);
273 			continue;
274 		}
275 		/*
276 		 * We currently do no require a consistent pcb list.
277 		 * Try to be robust in case of struct size changes
278 		 */
279 		cur = ((char *)inpg) + inpg->xig_len;
280 		/* There is also a trailing struct xinpgen */
281 		end = ((char *)inpg) + lsz - inpg->xig_len;
282 		if (end <= cur) {
283 			free(inpg);
284 			continue;
285 		}
286 		if (idx == 0) { /* TCP */
287 			xtp = (struct xtcpcb *)cur;
288 			plen = xtp->xt_len;
289 		} else {
290 			xip = (struct xinpcb *)cur;
291 			plen = xip->xi_len;
292 		}
293 		while (cur + plen <= end) {
294 			if (idx == 0) { /* TCP */
295 				xtp = (struct xtcpcb *)cur;
296 				xip = &xtp->xt_inp;
297 			} else {
298 				xip = (struct xinpcb *)cur;
299 			}
300 			cur += plen;
301 
302 			if (!aflag) {
303 				if (xip->inp_vflag & INP_IPV4) {
304 					if (inet_lnaof(xip->inp_laddr) ==
305 					    INADDR_ANY)
306 						continue;
307 				}
308 #ifdef INET6
309 				else if (xip->inp_vflag & INP_IPV6) {
310 					if (memcmp(&xip->in6p_laddr,
311 					    &in6addr_any, sizeof(in6addr_any))
312 					    == 0)
313 						continue;
314 				}
315 #endif
316 			}
317 			if (nhosts && !checkhost(&xip->inp_inc))
318 				continue;
319 			if (nports && !checkport(&xip->inp_inc))
320 				continue;
321 			if (idx == 0)
322 				enter_sysctl(xip, &xip->xi_socket,
323 				    xtp->t_state, "tcp");
324 			else
325 				enter_sysctl(xip, &xip->xi_socket, 0, "udp");
326 		}
327 		free(inpg);
328 	}
329 }
330 
331 static void
332 enter_kvm(struct inpcb *inp, struct socket *so, int state, const char *proto)
333 {
334 	struct netinfo *p;
335 
336 	if ((p = enter(&inp->inp_inc, inp->inp_vflag, state, proto)) != NULL) {
337 		p->ni_rcvcc = so->so_rcv.sb_ccc;
338 		p->ni_sndcc = so->so_snd.sb_ccc;
339 	}
340 }
341 
342 static void
343 enter_sysctl(struct xinpcb *xip, struct xsocket *so, int state,
344     const char *proto)
345 {
346 	struct netinfo *p;
347 
348 	if ((p = enter(&xip->inp_inc, xip->inp_vflag, state, proto)) != NULL) {
349 		p->ni_rcvcc = so->so_rcv.sb_cc;
350 		p->ni_sndcc = so->so_snd.sb_cc;
351 	}
352 }
353 
354 static struct netinfo *
355 enter(struct in_conninfo *inc, uint8_t vflag, int state, const char *proto)
356 {
357 	struct netinfo *p;
358 	struct sockaddr_storage lsa, fsa;
359 	struct sockaddr_in *sa4;
360 #ifdef INET6
361 	struct sockaddr_in6 *sa6;
362 #endif
363 
364 	memset(&lsa, 0, sizeof(lsa));
365 	memset(&fsa, 0, sizeof(fsa));
366 	if (vflag & INP_IPV4) {
367 		sa4 = (struct sockaddr_in *)&lsa;
368 		sa4->sin_addr = inc->inc_laddr;
369 		sa4->sin_port = inc->inc_lport;
370 		sa4->sin_family = AF_INET;
371 		sa4->sin_len = sizeof(struct sockaddr_in);
372 
373 		sa4 = (struct sockaddr_in *)&fsa;
374 		sa4->sin_addr = inc->inc_faddr;
375 		sa4->sin_port = inc->inc_fport;
376 		sa4->sin_family = AF_INET;
377 		sa4->sin_len = sizeof(struct sockaddr_in);
378 	}
379 #ifdef INET6
380 	else if (vflag & INP_IPV6) {
381 		sa6 = (struct sockaddr_in6 *)&lsa;
382 		memcpy(&sa6->sin6_addr, &inc->inc6_laddr,
383 		    sizeof(struct in6_addr));
384 		sa6->sin6_port = inc->inc_lport;
385 		sa6->sin6_family = AF_INET6;
386 		sa6->sin6_len = sizeof(struct sockaddr_in6);
387 
388 		sa6 = (struct sockaddr_in6 *)&fsa;
389 		memcpy(&sa6->sin6_addr, &inc->inc6_faddr,
390 		    sizeof(struct in6_addr));
391 		sa6->sin6_port = inc->inc_fport;
392 		sa6->sin6_family = AF_INET6;
393 		sa6->sin6_len = sizeof(struct sockaddr_in6);
394 	}
395 #endif
396 	else
397 		return NULL;
398 
399 	/*
400 	 * Only take exact matches, any sockets with
401 	 * previously unbound addresses will be deleted
402 	 * below in the display routine because they
403 	 * will appear as ``not seen'' in the kernel
404 	 * data structures.
405 	 */
406 	TAILQ_FOREACH(p, &netcb, chain) {
407 		if (!streq(proto, p->ni_proto))
408 			continue;
409 		if (p->ni_lsa.ss_family != lsa.ss_family ||
410 		    memcmp(&p->ni_lsa, &lsa, lsa.ss_len) != 0)
411 			continue;
412 		if (p->ni_fsa.ss_family == fsa.ss_family &&
413 		    memcmp(&p->ni_fsa, &fsa, fsa.ss_len) == 0)
414 			break;
415 	}
416 	if (p == NULL) {
417 		if ((p = malloc(sizeof(*p))) == NULL) {
418 			error("Out of memory");
419 			return NULL;
420 		}
421 		TAILQ_INSERT_HEAD(&netcb, p, chain);
422 		p->ni_line = -1;
423 		memcpy(&p->ni_lsa, &lsa, lsa.ss_len);
424 		memcpy(&p->ni_fsa, &fsa, fsa.ss_len);
425 		p->ni_proto = strdup(proto);
426 		p->ni_flags = NIF_LACHG|NIF_FACHG;
427 	}
428 	p->ni_state = state;
429 	p->ni_seen = 1;
430 	return p;
431 }
432 
433 /* column locations */
434 #define	LADDR	0
435 #define	FADDR	LADDR+23
436 #define	PROTO	FADDR+23
437 #define	RCVCC	PROTO+6
438 #define	SNDCC	RCVCC+7
439 #define	STATE	SNDCC+7
440 
441 void
442 labelnetstat(void)
443 {
444 	if (use_kvm && namelist[X_TCB].n_type == 0)
445 		return;
446 	wmove(wnd, 0, 0); wclrtobot(wnd);
447 	mvwaddstr(wnd, 0, LADDR, "Local Address");
448 	mvwaddstr(wnd, 0, FADDR, "Foreign Address");
449 	mvwaddstr(wnd, 0, PROTO, "Proto");
450 	mvwaddstr(wnd, 0, RCVCC, "Recv-Q");
451 	mvwaddstr(wnd, 0, SNDCC, "Send-Q");
452 	mvwaddstr(wnd, 0, STATE, "(state)");
453 }
454 
455 void
456 shownetstat(void)
457 {
458 	struct netinfo *p, *q;
459 	char proto[6];
460 	const char *family = "";
461 
462 	/*
463 	 * First, delete any connections that have gone
464 	 * away and adjust the position of connections
465 	 * below to reflect the deleted line.
466 	 */
467 	p = TAILQ_FIRST(&netcb);
468 	while (p != NULL) {
469 		if (p->ni_line == -1 || p->ni_seen) {
470 			p = TAILQ_NEXT(p, chain);
471 			continue;
472 		}
473 		wmove(wnd, p->ni_line, 0); wdeleteln(wnd);
474 		TAILQ_FOREACH(q, &netcb, chain)
475 			if (q != p && q->ni_line > p->ni_line) {
476 				q->ni_line--;
477 				/* this shouldn't be necessary */
478 				q->ni_flags |= NIF_LACHG|NIF_FACHG;
479 			}
480 		lastrow--;
481 		q = TAILQ_NEXT(p, chain);
482 		TAILQ_REMOVE(&netcb, p, chain);
483 		free(p);
484 		p = q;
485 	}
486 	/*
487 	 * Update existing connections and add new ones.
488 	 */
489 	TAILQ_FOREACH(p, &netcb, chain) {
490 		if (p->ni_line == -1) {
491 			/*
492 			 * Add a new entry if possible.
493 			 */
494 			if (lastrow > YMAX(wnd))
495 				continue;
496 			p->ni_line = lastrow++;
497 			p->ni_flags |= NIF_LACHG|NIF_FACHG;
498 		}
499 		if (p->ni_flags & NIF_LACHG) {
500 			wmove(wnd, p->ni_line, LADDR);
501 			inetprint((struct sockaddr *)&p->ni_lsa, p->ni_proto);
502 			p->ni_flags &= ~NIF_LACHG;
503 		}
504 		if (p->ni_flags & NIF_FACHG) {
505 			wmove(wnd, p->ni_line, FADDR);
506 			inetprint((struct sockaddr *)&p->ni_fsa, p->ni_proto);
507 			p->ni_flags &= ~NIF_FACHG;
508 		}
509 #ifdef INET6
510 		family = (p->ni_lsa.ss_family == AF_INET) ? "4" : "6";
511 #endif
512 		snprintf(proto, sizeof(proto), "%s%s", p->ni_proto, family);
513 		mvwaddstr(wnd, p->ni_line, PROTO, proto);
514 		mvwprintw(wnd, p->ni_line, RCVCC, "%6u", p->ni_rcvcc);
515 		mvwprintw(wnd, p->ni_line, SNDCC, "%6u", p->ni_sndcc);
516 		if (streq(p->ni_proto, "tcp")) {
517 			if (p->ni_state < 0 || p->ni_state >= TCP_NSTATES)
518 				mvwprintw(wnd, p->ni_line, STATE, "%d",
519 				    p->ni_state);
520 			else
521 				mvwaddstr(wnd, p->ni_line, STATE,
522 				    tcpstates[p->ni_state]);
523 		}
524 		wclrtoeol(wnd);
525 	}
526 	if (lastrow < YMAX(wnd)) {
527 		wmove(wnd, lastrow, 0); wclrtobot(wnd);
528 		wmove(wnd, YMAX(wnd), 0); wdeleteln(wnd);	/* XXX */
529 	}
530 }
531 
532 /*
533  * Pretty print an Internet address (net address + port).
534  * If the nflag was specified, use numbers instead of names.
535  */
536 static void
537 inetprint(struct sockaddr *sa, const char *proto)
538 {
539 	struct servent *sp = 0;
540 	char line[80], *cp;
541 	int port;
542 
543 	switch (sa->sa_family) {
544 	case AF_INET:
545 		port = ((struct sockaddr_in *)sa)->sin_port;
546 		break;
547 #ifdef INET6
548 	case AF_INET6:
549 		port = ((struct sockaddr_in6 *)sa)->sin6_port;
550 		break;
551 #endif
552 	default:
553 		port = 0;
554 		break;
555 	}
556 	snprintf(line, sizeof(line), "%.*s.", 16, inetname(sa));
557 	cp = strchr(line, '\0');
558 	if (!nflag && port)
559 		sp = getservbyport(port, proto);
560 	if (sp || port == 0)
561 		snprintf(cp, sizeof(line) - (cp - line), "%.8s",
562 		    sp ? sp->s_name : "*");
563 	else
564 		snprintf(cp, sizeof(line) - (cp - line), "%d",
565 		    ntohs((u_short)port));
566 	/* pad to full column to clear any garbage */
567 	cp = strchr(line, '\0');
568 	while (cp - line < 22)
569 		*cp++ = ' ';
570 	line[22] = '\0';
571 	waddstr(wnd, line);
572 }
573 
574 /*
575  * Construct an Internet address representation.
576  * If the nflag has been supplied, give
577  * numeric value, otherwise try for symbolic name.
578  */
579 static char *
580 inetname(struct sockaddr *sa)
581 {
582 	char *cp = 0;
583 	static char line[NI_MAXHOST];
584 	struct hostent *hp;
585 	struct netent *np;
586 	struct in_addr in;
587 
588 #ifdef INET6
589 	if (sa->sa_family == AF_INET6) {
590 		if (memcmp(&((struct sockaddr_in6 *)sa)->sin6_addr,
591 		    &in6addr_any, sizeof(in6addr_any)) == 0)
592 			strcpy(line, "*");
593 		else
594 			getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
595 			    nflag ? NI_NUMERICHOST : 0);
596 		return (line);
597 	}
598 #endif
599 
600 	in = ((struct sockaddr_in *)sa)->sin_addr;
601 	if (!nflag && in.s_addr != INADDR_ANY) {
602 		int net = inet_netof(in);
603 		int lna = inet_lnaof(in);
604 
605 		if (lna == INADDR_ANY) {
606 			np = getnetbyaddr(net, AF_INET);
607 			if (np)
608 				cp = np->n_name;
609 		}
610 		if (cp == NULL) {
611 			hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET);
612 			if (hp)
613 				cp = hp->h_name;
614 		}
615 	}
616 	if (in.s_addr == INADDR_ANY)
617 		strcpy(line, "*");
618 	else if (cp)
619 		snprintf(line, sizeof(line), "%s", cp);
620 	else {
621 		in.s_addr = ntohl(in.s_addr);
622 #define C(x)	((x) & 0xff)
623 		snprintf(line, sizeof(line), "%u.%u.%u.%u", C(in.s_addr >> 24),
624 			C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr));
625 	}
626 	return (line);
627 }
628 
629 int
630 cmdnetstat(const char *cmd, const char *args)
631 {
632 	if (prefix(cmd, "all")) {
633 		aflag = !aflag;
634 		goto fixup;
635 	}
636 	if  (prefix(cmd, "numbers") || prefix(cmd, "names")) {
637 		struct netinfo *p;
638 		int new;
639 
640 		new = prefix(cmd, "numbers");
641 		if (new == nflag)
642 			return (1);
643 		TAILQ_FOREACH(p, &netcb, chain) {
644 			if (p->ni_line == -1)
645 				continue;
646 			p->ni_flags |= NIF_LACHG|NIF_FACHG;
647 		}
648 		nflag = new;
649 		goto redisplay;
650 	}
651 	if (!netcmd(cmd, args))
652 		return (0);
653 fixup:
654 	fetchnetstat();
655 redisplay:
656 	shownetstat();
657 	refresh();
658 	return (1);
659 }
660