xref: /freebsd/usr.bin/systat/netstat.c (revision 6ff6d951ade3f3379932df7f878ef3ea272cfc59) 
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. 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 #include <sys/cdefs.h>
35 
36 __FBSDID("$FreeBSD$");
37 
38 #ifdef lint
39 static const char sccsid[] = "@(#)netstat.c	8.1 (Berkeley) 6/6/93";
40 #endif
41 
42 /*
43  * netstat
44  */
45 #include <sys/param.h>
46 #include <sys/queue.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/protosw.h>
50 
51 #include <netinet/in.h>
52 #include <arpa/inet.h>
53 #include <net/route.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/ip.h>
56 #ifdef INET6
57 #include <netinet/ip6.h>
58 #endif
59 #include <netinet/in_pcb.h>
60 #include <netinet/ip_icmp.h>
61 #include <netinet/icmp_var.h>
62 #include <netinet/ip_var.h>
63 #include <netinet/tcp.h>
64 #include <netinet/tcpip.h>
65 #include <netinet/tcp_seq.h>
66 #include <netinet/tcp_var.h>
67 #define TCPSTATES
68 #include <netinet/tcp_fsm.h>
69 #include <netinet/tcp_timer.h>
70 #include <netinet/tcp_var.h>
71 #include <netinet/tcp_debug.h>
72 #include <netinet/udp.h>
73 #include <netinet/udp_var.h>
74 
75 #include <netdb.h>
76 #include <nlist.h>
77 #include <paths.h>
78 #include <stdlib.h>
79 #include <string.h>
80 
81 #include "systat.h"
82 #include "extern.h"
83 
84 static struct netinfo *enter(struct inpcb *, int, const char *);
85 static void enter_kvm(struct inpcb *, struct socket *, int, const char *);
86 static void enter_sysctl(struct inpcb *, struct xsocket *, int, const char *);
87 static void fetchnetstat_kvm(void);
88 static void fetchnetstat_sysctl(void);
89 static char *inetname(struct sockaddr *);
90 static void inetprint(struct sockaddr *, const char *);
91 
92 #define	streq(a,b)	(strcmp(a,b)==0)
93 #define	YMAX(w)		((w)->_maxy-1)
94 
95 WINDOW *
96 opennetstat(void)
97 {
98 	sethostent(1);
99 	setnetent(1);
100 	return (subwin(stdscr, LINES-3-1, 0, MAINWIN_ROW, 0));
101 }
102 
103 struct netinfo {
104 	TAILQ_ENTRY(netinfo) chain;
105 	short	ni_line;		/* line on screen */
106 	short	ni_seen;		/* 0 when not present in list */
107 	short	ni_flags;
108 #define	NIF_LACHG	0x1		/* local address changed */
109 #define	NIF_FACHG	0x2		/* foreign address changed */
110 	short	ni_state;		/* tcp state */
111 	const char	*ni_proto;		/* protocol */
112 	struct sockaddr_storage ni_lsa;	/* local address */
113 	struct sockaddr_storage	ni_fsa;	/* foreign address */
114 	u_int	ni_rcvcc;		/* rcv buffer character count */
115 	u_int	ni_sndcc;		/* snd buffer character count */
116 };
117 
118 TAILQ_HEAD(netinfohead, netinfo) netcb = TAILQ_HEAD_INITIALIZER(netcb);
119 
120 static	int aflag = 0;
121 static	int nflag = 0;
122 static	int lastrow = 1;
123 
124 void
125 closenetstat(WINDOW *w)
126 {
127 	struct netinfo *p;
128 
129 	endhostent();
130 	endnetent();
131 	TAILQ_FOREACH(p, &netcb, chain) {
132 		if (p->ni_line != -1)
133 			lastrow--;
134 		p->ni_line = -1;
135 	}
136         if (w != NULL) {
137 		wclear(w);
138 		wrefresh(w);
139 		delwin(w);
140 	}
141 }
142 
143 static const char *miblist[] = {
144 	"net.inet.tcp.pcblist",
145 	"net.inet.udp.pcblist"
146 };
147 
148 static char tcb[] = "tcb", udb[] = "udb";
149 
150 struct nlist namelist[] = {
151 #define	X_TCB	0
152 	{ .n_name = tcb },
153 #define	X_UDB	1
154 	{ .n_name = udb },
155 	{ .n_name = NULL },
156 };
157 
158 int
159 initnetstat(void)
160 {
161 	protos = TCP|UDP;
162 	return(1);
163 }
164 
165 void
166 fetchnetstat(void)
167 {
168 	if (use_kvm)
169 		fetchnetstat_kvm();
170 	else
171 		fetchnetstat_sysctl();
172 }
173 
174 static void
175 fetchnetstat_kvm(void)
176 {
177 	struct inpcb *next;
178 	struct netinfo *p;
179 	struct inpcbhead head;
180 	struct inpcb inpcb;
181 	struct socket sockb;
182 	struct tcpcb tcpcb;
183 	void *off;
184 	int istcp;
185 
186 	if (namelist[X_TCB].n_value == 0)
187 		return;
188 	TAILQ_FOREACH(p, &netcb, chain)
189 		p->ni_seen = 0;
190 	if (protos&TCP) {
191 		off = NPTR(X_TCB);
192 		istcp = 1;
193 	}
194 	else if (protos&UDP) {
195 		off = NPTR(X_UDB);
196 		istcp = 0;
197 	}
198 	else {
199 		error("No protocols to display");
200 		return;
201 	}
202 again:
203 	KREAD(off, &head, sizeof (struct inpcbhead));
204 	LIST_FOREACH(next, &head, inp_list) {
205 		KREAD(next, &inpcb, sizeof (inpcb));
206 		next = &inpcb;
207 		if (!aflag) {
208 			if (inpcb.inp_vflag & INP_IPV4) {
209 				if (inet_lnaof(inpcb.inp_laddr) == INADDR_ANY)
210 					continue;
211 			}
212 #ifdef INET6
213 			else if (inpcb.inp_vflag & INP_IPV6) {
214 				if (memcmp(&inpcb.in6p_laddr,
215 				    &in6addr_any, sizeof(in6addr_any)) == 0)
216 					continue;
217 			}
218 #endif
219 		}
220 		if (nhosts && !checkhost(&inpcb))
221 			continue;
222 		if (nports && !checkport(&inpcb))
223 			continue;
224 		if (istcp) {
225 			if (inpcb.inp_vflag & INP_TIMEWAIT) {
226 				bzero(&sockb, sizeof(sockb));
227 				enter_kvm(&inpcb, &sockb, TCPS_TIME_WAIT,
228 					 "tcp");
229 			} else {
230 				KREAD(inpcb.inp_socket, &sockb,
231 					sizeof (sockb));
232 				KREAD(inpcb.inp_ppcb, &tcpcb, sizeof (tcpcb));
233 				enter_kvm(&inpcb, &sockb, tcpcb.t_state,
234 					"tcp");
235 			}
236 		} else
237 			enter_kvm(&inpcb, &sockb, 0, "udp");
238 	}
239 	if (istcp && (protos&UDP)) {
240 		istcp = 0;
241 		off = NPTR(X_UDB);
242 		goto again;
243 	}
244 }
245 
246 static void
247 fetchnetstat_sysctl(void)
248 {
249 	struct netinfo *p;
250 	int idx;
251 	struct xinpgen *inpg;
252 	char *cur, *end;
253 	struct inpcb *inpcb;
254 	struct xinpcb *xip = NULL;
255 	struct xtcpcb *xtp = NULL;
256 	int plen;
257 	size_t lsz;
258 
259 	TAILQ_FOREACH(p, &netcb, chain)
260 		p->ni_seen = 0;
261 	if (protos&TCP) {
262 		idx = 0;
263 	} else if (protos&UDP) {
264 		idx = 1;
265 	} else {
266 		error("No protocols to display");
267 		return;
268 	}
269 
270 	for (;idx < 2; idx++) {
271 		if (idx == 1 && !(protos&UDP))
272 			break;
273 		inpg = (struct xinpgen *)sysctl_dynread(miblist[idx], &lsz);
274 		if (inpg == NULL) {
275 			error("sysctl(%s...) failed", miblist[idx]);
276 			continue;
277 		}
278 		/*
279 		 * We currently do no require a consistent pcb list.
280 		 * Try to be robust in case of struct size changes
281 		 */
282 		cur = ((char *)inpg) + inpg->xig_len;
283 		/* There is also a trailing struct xinpgen */
284 		end = ((char *)inpg) + lsz - inpg->xig_len;
285 		if (end <= cur) {
286 			free(inpg);
287 			continue;
288 		}
289 		if (idx == 0) { /* TCP */
290 			xtp = (struct xtcpcb *)cur;
291 			plen = xtp->xt_len;
292 		} else {
293 			xip = (struct xinpcb *)cur;
294 			plen = xip->xi_len;
295 		}
296 		while (cur + plen <= end) {
297 			if (idx == 0) { /* TCP */
298 				xtp = (struct xtcpcb *)cur;
299 				inpcb = &xtp->xt_inp;
300 			} else {
301 				xip = (struct xinpcb *)cur;
302 				inpcb = &xip->xi_inp;
303 			}
304 			cur += plen;
305 
306 			if (!aflag) {
307 				if (inpcb->inp_vflag & INP_IPV4) {
308 					if (inet_lnaof(inpcb->inp_laddr) ==
309 					    INADDR_ANY)
310 						continue;
311 				}
312 #ifdef INET6
313 				else if (inpcb->inp_vflag & INP_IPV6) {
314 					if (memcmp(&inpcb->in6p_laddr,
315 					    &in6addr_any, sizeof(in6addr_any))
316 					    == 0)
317 						continue;
318 				}
319 #endif
320 			}
321 			if (nhosts && !checkhost(inpcb))
322 				continue;
323 			if (nports && !checkport(inpcb))
324 				continue;
325 			if (idx == 0)	/* TCP */
326 				enter_sysctl(inpcb, &xtp->xt_socket,
327 				    xtp->xt_tp.t_state, "tcp");
328 			else		/* UDP */
329 				enter_sysctl(inpcb, &xip->xi_socket, 0, "udp");
330 		}
331 		free(inpg);
332 	}
333 }
334 
335 static void
336 enter_kvm(struct inpcb *inp, struct socket *so, int state, const char *proto)
337 {
338 	struct netinfo *p;
339 
340 	if ((p = enter(inp, state, proto)) != NULL) {
341 		p->ni_rcvcc = so->so_rcv.sb_cc;
342 		p->ni_sndcc = so->so_snd.sb_cc;
343 	}
344 }
345 
346 static void
347 enter_sysctl(struct inpcb *inp, struct xsocket *so, int state, const char *proto)
348 {
349 	struct netinfo *p;
350 
351 	if ((p = enter(inp, state, proto)) != NULL) {
352 		p->ni_rcvcc = so->so_rcv.sb_cc;
353 		p->ni_sndcc = so->so_snd.sb_cc;
354 	}
355 }
356 
357 
358 static struct netinfo *
359 enter(struct inpcb *inp, int state, const char *proto)
360 {
361 	struct netinfo *p;
362 	struct sockaddr_storage lsa, fsa;
363 	struct sockaddr_in *sa4;
364 #ifdef INET6
365 	struct sockaddr_in6 *sa6;
366 #endif
367 
368 	memset(&lsa, 0, sizeof(lsa));
369 	memset(&fsa, 0, sizeof(fsa));
370 	if (inp->inp_vflag & INP_IPV4) {
371 		sa4 = (struct sockaddr_in *)&lsa;
372 		sa4->sin_addr = inp->inp_laddr;
373 		sa4->sin_port = inp->inp_lport;
374 		sa4->sin_family = AF_INET;
375 		sa4->sin_len = sizeof(struct sockaddr_in);
376 
377 		sa4 = (struct sockaddr_in *)&fsa;
378 		sa4->sin_addr = inp->inp_faddr;
379 		sa4->sin_port = inp->inp_fport;
380 		sa4->sin_family = AF_INET;
381 		sa4->sin_len = sizeof(struct sockaddr_in);
382 	}
383 #ifdef INET6
384 	else if (inp->inp_vflag & INP_IPV6) {
385 		sa6 = (struct sockaddr_in6 *)&lsa;
386 		memcpy(&sa6->sin6_addr, &inp->in6p_laddr,
387 		    sizeof(struct in6_addr));
388 		sa6->sin6_port = inp->inp_lport;
389 		sa6->sin6_family = AF_INET6;
390 		sa6->sin6_len = sizeof(struct sockaddr_in6);
391 
392 		sa6 = (struct sockaddr_in6 *)&fsa;
393 		memcpy(&sa6->sin6_addr, &inp->in6p_faddr,
394 		    sizeof(struct in6_addr));
395 		sa6->sin6_port = inp->inp_fport;
396 		sa6->sin6_family = AF_INET6;
397 		sa6->sin6_len = sizeof(struct sockaddr_in6);
398 	}
399 #endif
400 	else
401 		return NULL;
402 
403 	/*
404 	 * Only take exact matches, any sockets with
405 	 * previously unbound addresses will be deleted
406 	 * below in the display routine because they
407 	 * will appear as ``not seen'' in the kernel
408 	 * data structures.
409 	 */
410 	TAILQ_FOREACH(p, &netcb, chain) {
411 		if (!streq(proto, p->ni_proto))
412 			continue;
413 		if (p->ni_lsa.ss_family != lsa.ss_family ||
414 		    memcmp(&p->ni_lsa, &lsa, lsa.ss_len) != 0)
415 			continue;
416 		if (p->ni_fsa.ss_family == fsa.ss_family &&
417 		    memcmp(&p->ni_fsa, &fsa, fsa.ss_len) == 0)
418 			break;
419 	}
420 	if (p == NULL) {
421 		if ((p = malloc(sizeof(*p))) == NULL) {
422 			error("Out of memory");
423 			return NULL;
424 		}
425 		TAILQ_INSERT_HEAD(&netcb, p, chain);
426 		p->ni_line = -1;
427 		memcpy(&p->ni_lsa, &lsa, lsa.ss_len);
428 		memcpy(&p->ni_fsa, &fsa, fsa.ss_len);
429 		p->ni_proto = strdup(proto);
430 		p->ni_flags = NIF_LACHG|NIF_FACHG;
431 	}
432 	p->ni_state = state;
433 	p->ni_seen = 1;
434 	return p;
435 }
436 
437 /* column locations */
438 #define	LADDR	0
439 #define	FADDR	LADDR+23
440 #define	PROTO	FADDR+23
441 #define	RCVCC	PROTO+6
442 #define	SNDCC	RCVCC+7
443 #define	STATE	SNDCC+7
444 
445 
446 void
447 labelnetstat(void)
448 {
449 	if (use_kvm && namelist[X_TCB].n_type == 0)
450 		return;
451 	wmove(wnd, 0, 0); wclrtobot(wnd);
452 	mvwaddstr(wnd, 0, LADDR, "Local Address");
453 	mvwaddstr(wnd, 0, FADDR, "Foreign Address");
454 	mvwaddstr(wnd, 0, PROTO, "Proto");
455 	mvwaddstr(wnd, 0, RCVCC, "Recv-Q");
456 	mvwaddstr(wnd, 0, SNDCC, "Send-Q");
457 	mvwaddstr(wnd, 0, STATE, "(state)");
458 }
459 
460 void
461 shownetstat(void)
462 {
463 	struct netinfo *p, *q;
464 	char proto[6];
465 	const char *family = "";
466 
467 	/*
468 	 * First, delete any connections that have gone
469 	 * away and adjust the position of connections
470 	 * below to reflect the deleted line.
471 	 */
472 	p = TAILQ_FIRST(&netcb);
473 	while (p != NULL) {
474 		if (p->ni_line == -1 || p->ni_seen) {
475 			p = TAILQ_NEXT(p, chain);
476 			continue;
477 		}
478 		wmove(wnd, p->ni_line, 0); wdeleteln(wnd);
479 		TAILQ_FOREACH(q, &netcb, chain)
480 			if (q != p && q->ni_line > p->ni_line) {
481 				q->ni_line--;
482 				/* this shouldn't be necessary */
483 				q->ni_flags |= NIF_LACHG|NIF_FACHG;
484 			}
485 		lastrow--;
486 		q = TAILQ_NEXT(p, chain);
487 		TAILQ_REMOVE(&netcb, p, chain);
488 		free(p);
489 		p = q;
490 	}
491 	/*
492 	 * Update existing connections and add new ones.
493 	 */
494 	TAILQ_FOREACH(p, &netcb, chain) {
495 		if (p->ni_line == -1) {
496 			/*
497 			 * Add a new entry if possible.
498 			 */
499 			if (lastrow > YMAX(wnd))
500 				continue;
501 			p->ni_line = lastrow++;
502 			p->ni_flags |= NIF_LACHG|NIF_FACHG;
503 		}
504 		if (p->ni_flags & NIF_LACHG) {
505 			wmove(wnd, p->ni_line, LADDR);
506 			inetprint((struct sockaddr *)&p->ni_lsa, p->ni_proto);
507 			p->ni_flags &= ~NIF_LACHG;
508 		}
509 		if (p->ni_flags & NIF_FACHG) {
510 			wmove(wnd, p->ni_line, FADDR);
511 			inetprint((struct sockaddr *)&p->ni_fsa, p->ni_proto);
512 			p->ni_flags &= ~NIF_FACHG;
513 		}
514 #ifdef INET6
515 		family = (p->ni_lsa.ss_family == AF_INET) ? "4" : "6";
516 #endif
517 		snprintf(proto, sizeof(proto), "%s%s", p->ni_proto, family);
518 		mvwaddstr(wnd, p->ni_line, PROTO, proto);
519 		mvwprintw(wnd, p->ni_line, RCVCC, "%6u", p->ni_rcvcc);
520 		mvwprintw(wnd, p->ni_line, SNDCC, "%6u", p->ni_sndcc);
521 		if (streq(p->ni_proto, "tcp")) {
522 			if (p->ni_state < 0 || p->ni_state >= TCP_NSTATES)
523 				mvwprintw(wnd, p->ni_line, STATE, "%d",
524 				    p->ni_state);
525 			else
526 				mvwaddstr(wnd, p->ni_line, STATE,
527 				    tcpstates[p->ni_state]);
528 		}
529 		wclrtoeol(wnd);
530 	}
531 	if (lastrow < YMAX(wnd)) {
532 		wmove(wnd, lastrow, 0); wclrtobot(wnd);
533 		wmove(wnd, YMAX(wnd), 0); wdeleteln(wnd);	/* XXX */
534 	}
535 }
536 
537 /*
538  * Pretty print an Internet address (net address + port).
539  * If the nflag was specified, use numbers instead of names.
540  */
541 static void
542 inetprint(struct sockaddr *sa, const char *proto)
543 {
544 	struct servent *sp = 0;
545 	char line[80], *cp;
546 	int port;
547 
548 	switch (sa->sa_family) {
549 	case AF_INET:
550 		port = ((struct sockaddr_in *)sa)->sin_port;
551 		break;
552 #ifdef INET6
553 	case AF_INET6:
554 		port = ((struct sockaddr_in6 *)sa)->sin6_port;
555 		break;
556 #endif
557 	default:
558 		port = 0;
559 		break;
560 	}
561 	snprintf(line, sizeof(line), "%.*s.", 16, inetname(sa));
562 	cp = index(line, '\0');
563 	if (!nflag && port)
564 		sp = getservbyport(port, proto);
565 	if (sp || port == 0)
566 		snprintf(cp, sizeof(line) - (cp - line), "%.8s",
567 		    sp ? sp->s_name : "*");
568 	else
569 		snprintf(cp, sizeof(line) - (cp - line), "%d",
570 		    ntohs((u_short)port));
571 	/* pad to full column to clear any garbage */
572 	cp = index(line, '\0');
573 	while (cp - line < 22)
574 		*cp++ = ' ';
575 	line[22] = '\0';
576 	waddstr(wnd, line);
577 }
578 
579 /*
580  * Construct an Internet address representation.
581  * If the nflag has been supplied, give
582  * numeric value, otherwise try for symbolic name.
583  */
584 static char *
585 inetname(struct sockaddr *sa)
586 {
587 	char *cp = 0;
588 	static char line[NI_MAXHOST];
589 	struct hostent *hp;
590 	struct netent *np;
591 	struct in_addr in;
592 
593 #ifdef INET6
594 	if (sa->sa_family == AF_INET6) {
595 		if (memcmp(&((struct sockaddr_in6 *)sa)->sin6_addr,
596 		    &in6addr_any, sizeof(in6addr_any)) == 0)
597 			strcpy(line, "*");
598 		else
599 			getnameinfo(sa, sa->sa_len, line, sizeof(line), NULL, 0,
600 			    nflag ? NI_NUMERICHOST : 0);
601 		return (line);
602 	}
603 #endif
604 
605 	in = ((struct sockaddr_in *)sa)->sin_addr;
606 	if (!nflag && in.s_addr != INADDR_ANY) {
607 		int net = inet_netof(in);
608 		int lna = inet_lnaof(in);
609 
610 		if (lna == INADDR_ANY) {
611 			np = getnetbyaddr(net, AF_INET);
612 			if (np)
613 				cp = np->n_name;
614 		}
615 		if (cp == 0) {
616 			hp = gethostbyaddr((char *)&in, sizeof (in), AF_INET);
617 			if (hp)
618 				cp = hp->h_name;
619 		}
620 	}
621 	if (in.s_addr == INADDR_ANY)
622 		strcpy(line, "*");
623 	else if (cp)
624 		snprintf(line, sizeof(line), "%s", cp);
625 	else {
626 		in.s_addr = ntohl(in.s_addr);
627 #define C(x)	((x) & 0xff)
628 		snprintf(line, sizeof(line), "%u.%u.%u.%u", C(in.s_addr >> 24),
629 			C(in.s_addr >> 16), C(in.s_addr >> 8), C(in.s_addr));
630 	}
631 	return (line);
632 }
633 
634 int
635 cmdnetstat(const char *cmd, const char *args)
636 {
637 	if (prefix(cmd, "all")) {
638 		aflag = !aflag;
639 		goto fixup;
640 	}
641 	if  (prefix(cmd, "numbers") || prefix(cmd, "names")) {
642 		struct netinfo *p;
643 		int new;
644 
645 		new = prefix(cmd, "numbers");
646 		if (new == nflag)
647 			return (1);
648 		TAILQ_FOREACH(p, &netcb, chain) {
649 			if (p->ni_line == -1)
650 				continue;
651 			p->ni_flags |= NIF_LACHG|NIF_FACHG;
652 		}
653 		nflag = new;
654 		goto redisplay;
655 	}
656 	if (!netcmd(cmd, args))
657 		return (0);
658 fixup:
659 	fetchnetstat();
660 redisplay:
661 	shownetstat();
662 	refresh();
663 	return (1);
664 }
665