xref: /dragonfly/usr.bin/netstat/main.c (revision 7bc7e232)
1 /*
2  * Copyright (c) 1983, 1988, 1993
3  *	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  * @(#) Copyright (c) 1983, 1988, 1993 Regents of the University of California.  All rights reserved.
34  * @(#)main.c	8.4 (Berkeley) 3/1/94
35  * $FreeBSD: src/usr.bin/netstat/main.c,v 1.34.2.12 2001/09/17 15:17:46 ru Exp $
36  * $DragonFly: src/usr.bin/netstat/main.c,v 1.13 2007/08/16 20:03:58 dillon Exp $
37  */
38 
39 #include <sys/param.h>
40 #include <sys/file.h>
41 #include <sys/protosw.h>
42 #include <sys/socket.h>
43 
44 #include <netinet/in.h>
45 
46 #include <netgraph/socket/ng_socket.h>
47 
48 #include <ctype.h>
49 #include <err.h>
50 #include <errno.h>
51 #include <kvm.h>
52 #include <limits.h>
53 #include <netdb.h>
54 #include <nlist.h>
55 #include <paths.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 #include "netstat.h"
61 
62 static struct nlist nl[] = {
63 #define	N_IFNET		0
64 	{ "_ifnet" },
65 #define	N_IMP		1
66 	{ "_imp_softc" },
67 #define	N_RTSTAT	2
68 	{ "_rtstat" },
69 #define	N_UNIXSW	3
70 	{ "_localsw" },
71 #define N_IDP		4
72 	{ "_nspcb"},
73 #define N_IDPSTAT	5
74 	{ "_idpstat"},
75 #define N_SPPSTAT	6
76 	{ "_spp_istat"},
77 #define N_NSERR		7
78 	{ "_ns_errstat"},
79 #define	N_CLNPSTAT	8
80 	{ "_clnp_stat"},
81 #define	IN_NOTUSED	9
82 	{ "_tp_inpcb" },
83 #define	ISO_TP		10
84 	{ "_tp_refinfo" },
85 #define	N_TPSTAT	11
86 	{ "_tp_stat" },
87 #define	N_ESISSTAT	12
88 	{ "_esis_stat"},
89 #define N_NIMP		13
90 	{ "_nimp"},
91 #define N_RTREE		14
92 	{ "_rt_tables"},
93 #define N_CLTP		15
94 	{ "_cltb"},
95 #define N_CLTPSTAT	16
96 	{ "_cltpstat"},
97 #define	N_NFILE		17
98 	{ "_nfile" },
99 #define	N_FILE		18
100 	{ "_file" },
101 #define N_MRTSTAT	19
102 	{ "_mrtstat" },
103 #define N_MFCTABLE	20
104 	{ "_mfctable" },
105 #define N_VIFTABLE	21
106 	{ "_viftable" },
107 #define N_IPX		22
108 	{ "_ipxpcb"},
109 #define N_IPXSTAT	23
110 	{ "_ipxstat"},
111 #define N_SPXSTAT	24
112 	{ "_spx_istat"},
113 #define N_DDPSTAT	25
114 	{ "_ddpstat"},
115 #define N_DDPCB		26
116 	{ "_ddpcb"},
117 #define N_NGSOCKS	27
118 	{ "_ngsocklist"},
119 #define N_IP6STAT	28
120 	{ "_ip6stat" },
121 #define N_ICMP6STAT	29
122 	{ "_icmp6stat" },
123 #define N_IPSECSTAT	30
124 	{ "_ipsecstat" },
125 #define N_IPSEC6STAT	31
126 	{ "_ipsec6stat" },
127 #define N_PIM6STAT	32
128 	{ "_pim6stat" },
129 #define N_MRT6PROTO	33
130 	{ "_ip6_mrtproto" },
131 #define N_MRT6STAT	34
132 	{ "_mrt6stat" },
133 #define N_MF6CTABLE	35
134 	{ "_mf6ctable" },
135 #define N_MIF6TABLE	36
136 	{ "_mif6table" },
137 #define N_PFKEYSTAT	37
138 	{ "_pfkeystat" },
139 #define N_MBSTAT	38
140 	{ "_mbstat" },
141 #define N_MBTYPES	39
142 	{ "_mbtypes" },
143 #define N_NMBCLUSTERS	40
144 	{ "_nmbclusters" },
145 #define N_NMBUFS	41
146 	{ "_nmbufs" },
147 #define	N_RTTRASH	42
148 	{ "_rttrash" },
149 #define	N_NCPUS		43
150 	{ "_ncpus" },
151 #define	N_CARPSTAT	44
152 	{ "_carpstats" },
153 	{ "" },
154 };
155 
156 struct protox {
157 	u_char	pr_index;		/* index into nlist of cb head */
158 	u_char	pr_sindex;		/* index into nlist of stat block */
159 	u_char	pr_wanted;		/* 1 if wanted, 0 otherwise */
160 	void	(*pr_cblocks)(u_long, char *, int);
161 					/* control blocks printing routine */
162 	void	(*pr_stats)(u_long, char *, int);
163 					/* statistics printing routine */
164 	void	(*pr_istats)(char *);	/* per/if statistics printing routine */
165 	char	*pr_name;		/* well-known name */
166 	int	pr_usesysctl;		/* true if we use sysctl, not kvm */
167 } protox[] = {
168 	{ -1,		-1,		1,	protopr,
169 	  tcp_stats,	NULL,		"tcp",	IPPROTO_TCP },
170 	{ -1,		-1,		1,	protopr,
171 	  udp_stats,	NULL,		"udp",	IPPROTO_UDP },
172 	{ -1,		-1,		1,	protopr,
173 	  NULL,		NULL,		"divert",IPPROTO_DIVERT },
174 	{ -1,		-1,		1,	protopr,
175 	  ip_stats,	NULL,		"ip",	IPPROTO_RAW },
176 	{ -1,		-1,		1,	protopr,
177 	  icmp_stats,	NULL,		"icmp",	IPPROTO_ICMP },
178 	{ -1,		-1,		1,	protopr,
179 	  igmp_stats,	NULL,		"igmp",	IPPROTO_IGMP },
180 #ifdef IPSEC
181 	{ -1,		N_IPSECSTAT,	1,	0,
182 	  ipsec_stats,	NULL,		"ipsec",	0},
183 #endif
184         { -1,           N_CARPSTAT,     1,      0,
185           carp_stats,   NULL,           "carp",         0},
186 	{ -1,		-1,		0,	0,
187 	  0,		NULL,		0 }
188 };
189 
190 #ifdef INET6
191 struct protox ip6protox[] = {
192 	{ -1,		-1,		1,	protopr,
193 	  tcp_stats,	NULL,		"tcp",	IPPROTO_TCP },
194 	{ -1,		-1,		1,	protopr,
195 	  udp_stats,	NULL,		"udp",	IPPROTO_UDP },
196 	{ -1,		N_IP6STAT,	1,	protopr,
197 	  ip6_stats,	ip6_ifstats,	"ip6",	IPPROTO_RAW },
198 	{ -1,		N_ICMP6STAT,	1,	protopr,
199 	  icmp6_stats,	icmp6_ifstats,	"icmp6",IPPROTO_ICMPV6 },
200 #ifdef IPSEC
201 	{ -1,		N_IPSEC6STAT,	1,	0,
202 	  ipsec_stats,	NULL,		"ipsec6",0 },
203 #endif
204 #ifdef notyet
205 	{ -1,		N_PIM6STAT,	1,	0,
206 	  pim6_stats,	NULL,		"pim6",	0 },
207 #endif
208 	{ -1,		-1,		1,	0,
209 	  rip6_stats,	NULL,		"rip6",	0 },
210 	{ -1,		-1,		1,	protopr,
211 	  pim_stats,	NULL,		"pim",	IPPROTO_PIM },
212 	{ -1,		-1,		0,	0,
213 	  0,		NULL,		0,	0 }
214 };
215 #endif /*INET6*/
216 
217 #ifdef IPSEC
218 struct protox pfkeyprotox[] = {
219 	{ -1,		N_PFKEYSTAT,	1,	0,
220 	  pfkey_stats,	NULL,		"pfkey", 0 },
221 	{ -1,		-1,		0,	0,
222 	  0,		NULL,		0,	0 }
223 };
224 #endif
225 
226 struct protox atalkprotox[] = {
227 	{ N_DDPCB,	N_DDPSTAT,	1,	atalkprotopr,
228 	  ddp_stats,	NULL,		"ddp" },
229 	{ -1,		-1,		0,	0,
230 	  0,		NULL,		0 }
231 };
232 
233 struct protox netgraphprotox[] = {
234 	{ N_NGSOCKS,	-1,		1,	netgraphprotopr,
235 	  NULL,		NULL,		"ctrl" },
236 	{ N_NGSOCKS,	-1,		1,	netgraphprotopr,
237 	  NULL,		NULL,		"data" },
238 	{ -1,		NULL,		0,	0,
239 	  0,		NULL,		0 }
240 };
241 
242 struct protox ipxprotox[] = {
243 	{ N_IPX,	N_IPXSTAT,	1,	ipxprotopr,
244 	  ipx_stats,	NULL,		"ipx",	0 },
245 	{ N_IPX,	N_SPXSTAT,	1,	ipxprotopr,
246 	  spx_stats,	NULL,		"spx",	0 },
247 	{ -1,		-1,		0,	0,
248 	  0,		NULL,		0,	0 }
249 };
250 
251 #ifdef NS
252 struct protox nsprotox[] = {
253 	{ N_IDP,	N_IDPSTAT,	1,	nsprotopr,
254 	  idp_stats,	NULL,		"idp" },
255 	{ N_IDP,	N_SPPSTAT,	1,	nsprotopr,
256 	  spp_stats,	NULL,		"spp" },
257 	{ -1,		N_NSERR,	1,	0,
258 	  nserr_stats,	NULL,		"ns_err" },
259 	{ -1,		-1,		0,	0,
260 	  0,		NULL,		0 }
261 };
262 #endif
263 
264 #ifdef ISO
265 struct protox isoprotox[] = {
266 	{ ISO_TP,	N_TPSTAT,	1,	iso_protopr,
267 	  tp_stats,	NULL,		"tp" },
268 	{ N_CLTP,	N_CLTPSTAT,	1,	iso_protopr,
269 	  cltp_stats,	NULL,		"cltp" },
270 	{ -1,		N_CLNPSTAT,	1,	 0,
271 	  clnp_stats,	NULL,		"clnp"},
272 	{ -1,		N_ESISSTAT,	1,	 0,
273 	  esis_stats,	NULL,		"esis"},
274 	{ -1,		-1,		0,	0,
275 	  0,		NULL,		0 }
276 };
277 #endif
278 
279 struct protox *protoprotox[] = {
280 					 protox,
281 #ifdef INET6
282 					 ip6protox,
283 #endif
284 #ifdef IPSEC
285 					 pfkeyprotox,
286 #endif
287 					 ipxprotox, atalkprotox,
288 #ifdef NS
289 					 nsprotox,
290 #endif
291 #ifdef ISO
292 					 isoprotox,
293 #endif
294 					 NULL };
295 
296 static void printproto (struct protox *, char *);
297 static void usage (void);
298 static struct protox *name2protox (char *);
299 static struct protox *knownname (char *);
300 
301 static kvm_t *kvmd;
302 static char *nlistf = NULL, *memf = NULL;
303 
304 int	Aflag;		/* show addresses of protocol control block */
305 int	aflag;		/* show all sockets (including servers) */
306 int	bflag;		/* show i/f total bytes in/out */
307 int	cpuflag = -1;	/* dump route table from specific cpu */
308 int	dflag;		/* show i/f dropped packets */
309 int	gflag;		/* show group (multicast) routing or stats */
310 int	iflag;		/* show interfaces */
311 int	Lflag;		/* show size of listen queues */
312 int	mflag;		/* show memory stats */
313 int	Pflag;		/* show more protocol info (go past 80 columns) */
314 int	numeric_addr;	/* show addresses numerically */
315 int	numeric_port;	/* show ports numerically */
316 static int pflag;	/* show given protocol */
317 int	rflag;		/* show routing tables (or routing stats) */
318 int	sflag;		/* show protocol statistics */
319 int	tflag;		/* show i/f watchdog timers */
320 int	Bflag;		/* show buffer limit instead of buffer use */
321 int	Wflag;		/* wide display */
322 int	zflag;		/* zero stats */
323 
324 int	interval;	/* repeat interval for i/f stats */
325 
326 char	*interface;	/* desired i/f for stats, or NULL for all i/fs */
327 int	unit;		/* unit number for above */
328 
329 int	af;		/* address family */
330 
331 int
332 main(int argc, char **argv)
333 {
334 	struct protox *tp = NULL;  /* for printing cblocks & stats */
335 	int ch;
336 	int n;
337 
338 	af = AF_UNSPEC;
339 
340 	while ((ch = getopt(argc, argv, "Aabc:df:gI:iLlM:mN:nPp:rSsBtuWw:z")) != -1)
341 		switch(ch) {
342 		case 'A':
343 			Aflag = 1;
344 			break;
345 		case 'a':
346 			aflag = 1;
347 			break;
348 		case 'b':
349 			bflag = 1;
350 			break;
351 		case 'c':
352 			kread(0, 0, 0);
353 			kread(nl[N_NCPUS].n_value, (char *)&n, sizeof(n));
354 			cpuflag = strtol(optarg, NULL, 0);
355 			if (cpuflag < 0 || cpuflag >= n)
356 			    errx(1, "cpu %d does not exist", cpuflag);
357 			break;
358 		case 'd':
359 			dflag = 1;
360 			break;
361 		case 'f':
362 #ifdef NS
363 			if (strcmp(optarg, "ns") == 0)
364 				af = AF_NS;
365 			else
366 #endif
367 			if (strcmp(optarg, "ipx") == 0)
368 				af = AF_IPX;
369 			else if (strcmp(optarg, "inet") == 0)
370 				af = AF_INET;
371 #ifdef INET6
372 			else if (strcmp(optarg, "inet6") == 0)
373 				af = AF_INET6;
374 #endif /*INET6*/
375 #ifdef INET6
376 			else if (strcmp(optarg, "pfkey") == 0)
377 				af = PF_KEY;
378 #endif /*INET6*/
379 			else if (strcmp(optarg, "unix") == 0)
380 				af = AF_UNIX;
381 			else if (strcmp(optarg, "atalk") == 0)
382 				af = AF_APPLETALK;
383 			else if (strcmp(optarg, "ng") == 0
384 			    || strcmp(optarg, "netgraph") == 0)
385 				af = AF_NETGRAPH;
386 #ifdef ISO
387 			else if (strcmp(optarg, "iso") == 0)
388 				af = AF_ISO;
389 #endif
390 			else if (strcmp(optarg, "link") == 0)
391 				af = AF_LINK;
392 			else {
393 				errx(1, "%s: unknown address family", optarg);
394 			}
395 			break;
396 		case 'g':
397 			gflag = 1;
398 			break;
399 		case 'I': {
400 			char *cp;
401 
402 			iflag = 1;
403 			for (cp = interface = optarg; isalpha(*cp); cp++)
404 				continue;
405 			unit = atoi(cp);
406 			break;
407 		}
408 		case 'i':
409 			iflag = 1;
410 			break;
411 		case 'L':
412 			Lflag = 1;
413 			break;
414 		case 'M':
415 			memf = optarg;
416 			break;
417 		case 'm':
418 			mflag = 1;
419 			break;
420 		case 'N':
421 			nlistf = optarg;
422 			break;
423 		case 'n':
424 			numeric_addr = numeric_port = 1;
425 			break;
426 		case 'P':
427 			Pflag = 1;
428 			break;
429 		case 'p':
430 			if ((tp = name2protox(optarg)) == NULL) {
431 				errx(1,
432 				     "%s: unknown or uninstrumented protocol",
433 				     optarg);
434 			}
435 			pflag = 1;
436 			break;
437 		case 'r':
438 			rflag = 1;
439 			break;
440 		case 's':
441 			++sflag;
442 			break;
443 		case 'S':
444 			numeric_addr = 1;
445 			break;
446 		case 'B':
447 			Bflag = 1;
448 			break;
449 		case 't':
450 			tflag = 1;
451 			break;
452 		case 'u':
453 			af = AF_UNIX;
454 			break;
455 		case 'W':
456 		case 'l':
457 			Wflag = 1;
458 			break;
459 		case 'w':
460 			interval = atoi(optarg);
461 			iflag = 1;
462 			break;
463 		case 'z':
464 			zflag = 1;
465 			break;
466 		case '?':
467 		default:
468 			usage();
469 		}
470 	argv += optind;
471 	argc -= optind;
472 
473 #define	BACKWARD_COMPATIBILITY
474 #ifdef	BACKWARD_COMPATIBILITY
475 	if (*argv) {
476 		if (isdigit(**argv)) {
477 			interval = atoi(*argv);
478 			if (interval <= 0)
479 				usage();
480 			++argv;
481 			iflag = 1;
482 		}
483 		if (*argv) {
484 			nlistf = *argv;
485 			if (*++argv)
486 				memf = *argv;
487 		}
488 	}
489 #endif
490 
491 	/*
492 	 * Discard setgid privileges if not the running kernel so that bad
493 	 * guys can't print interesting stuff from kernel memory.
494 	 */
495 	if (nlistf != NULL || memf != NULL)
496 		setgid(getgid());
497 
498 	if (mflag) {
499 		if (memf != NULL) {
500 			if (kread(0, 0, 0) == 0)
501 				mbpr(nl[N_MBSTAT].n_value,
502 				    nl[N_MBTYPES].n_value,
503 				    nl[N_NMBCLUSTERS].n_value,
504 				    nl[N_NMBUFS].n_value);
505 		} else
506 			mbpr(0, 0, 0, 0);
507 		exit(0);
508 	}
509 #if 0
510 	/*
511 	 * Keep file descriptors open to avoid overhead
512 	 * of open/close on each call to get* routines.
513 	 */
514 	sethostent(1);
515 	setnetent(1);
516 #else
517 	/*
518 	 * This does not make sense any more with DNS being default over
519 	 * the files.  Doing a setXXXXent(1) causes a tcp connection to be
520 	 * used for the queries, which is slower.
521 	 */
522 #endif
523 	if (iflag && !sflag) {
524 		kread(0, 0, 0);
525 		intpr(interval, nl[N_IFNET].n_value, NULL);
526 		exit(0);
527 	}
528 	if (rflag) {
529 		kread(0, 0, 0);
530 		if (sflag)
531 			rt_stats();
532 		else
533 			routepr(nl[N_RTREE].n_value);
534 		exit(0);
535 	}
536 	if (gflag) {
537 		kread(0, 0, 0);
538 		if (sflag) {
539 			if (af == AF_INET || af == AF_UNSPEC)
540 				mrt_stats(nl[N_MRTSTAT].n_value);
541 #ifdef INET6
542 			if (af == AF_INET6 || af == AF_UNSPEC)
543 				mrt6_stats(nl[N_MRT6STAT].n_value);
544 #endif
545 		} else {
546 			if (af == AF_INET || af == AF_UNSPEC)
547 				mroutepr(nl[N_MFCTABLE].n_value,
548 					 nl[N_VIFTABLE].n_value);
549 #ifdef INET6
550 			if (af == AF_INET6 || af == AF_UNSPEC)
551 				mroute6pr(nl[N_MF6CTABLE].n_value,
552 					  nl[N_MIF6TABLE].n_value);
553 #endif
554 		}
555 		exit(0);
556 	}
557 
558 	kread(0, 0, 0);
559 	if (tp) {
560 		printproto(tp, tp->pr_name);
561 		exit(0);
562 	}
563 	if (af == AF_INET || af == AF_UNSPEC)
564 		for (tp = protox; tp->pr_name; tp++)
565 			printproto(tp, tp->pr_name);
566 #ifdef INET6
567 	if (af == AF_INET6 || af == AF_UNSPEC)
568 		for (tp = ip6protox; tp->pr_name; tp++)
569 			printproto(tp, tp->pr_name);
570 #endif /*INET6*/
571 #ifdef IPSEC
572 	if (af == PF_KEY || af == AF_UNSPEC)
573 		for (tp = pfkeyprotox; tp->pr_name; tp++)
574 			printproto(tp, tp->pr_name);
575 #endif /*IPSEC*/
576 	if (af == AF_IPX || af == AF_UNSPEC) {
577 		kread(0, 0, 0);
578 		for (tp = ipxprotox; tp->pr_name; tp++)
579 			printproto(tp, tp->pr_name);
580 	}
581 	if (af == AF_APPLETALK || af == AF_UNSPEC)
582 		for (tp = atalkprotox; tp->pr_name; tp++)
583 			printproto(tp, tp->pr_name);
584 	if (af == AF_NETGRAPH || af == AF_UNSPEC)
585 		for (tp = netgraphprotox; tp->pr_name; tp++)
586 			printproto(tp, tp->pr_name);
587 #ifdef NS
588 	if (af == AF_NS || af == AF_UNSPEC)
589 		for (tp = nsprotox; tp->pr_name; tp++)
590 			printproto(tp, tp->pr_name);
591 #endif
592 #ifdef ISO
593 	if (af == AF_ISO || af == AF_UNSPEC)
594 		for (tp = isoprotox; tp->pr_name; tp++)
595 			printproto(tp, tp->pr_name);
596 #endif
597 	if ((af == AF_UNIX || af == AF_UNSPEC) && !Lflag && !sflag)
598 		unixpr();
599 	exit(0);
600 }
601 
602 /*
603  * Print out protocol statistics or control blocks (per sflag).
604  * If the interface was not specifically requested, and the symbol
605  * is not in the namelist, ignore this one.
606  */
607 static void
608 printproto(struct protox *tp, char *name)
609 {
610 	void (*pr)(u_long, char *, int);
611 	u_long off;
612 
613 	if (sflag) {
614 		if (iflag) {
615 			if (tp->pr_istats)
616 				intpr(interval, nl[N_IFNET].n_value,
617 				      tp->pr_istats);
618 			else if (pflag)
619 				printf("%s: no per-interface stats routine\n",
620 				    tp->pr_name);
621 			return;
622 		}
623 		else {
624 			pr = tp->pr_stats;
625 			if (!pr) {
626 				if (pflag)
627 					printf("%s: no stats routine\n",
628 					    tp->pr_name);
629 				return;
630 			}
631 			off = tp->pr_usesysctl ? tp->pr_usesysctl
632 				: nl[tp->pr_sindex].n_value;
633 		}
634 	} else {
635 		pr = tp->pr_cblocks;
636 		if (!pr) {
637 			if (pflag)
638 				printf("%s: no PCB routine\n", tp->pr_name);
639 			return;
640 		}
641 		off = tp->pr_usesysctl ? tp->pr_usesysctl
642 			: nl[tp->pr_index].n_value;
643 	}
644 	if (pr != NULL && (off || af != AF_UNSPEC))
645 		(*pr)(off, name, af);
646 }
647 
648 /*
649  * Read kernel memory, return 0 on success.
650  */
651 int
652 kread(u_long addr, char *buf, int size)
653 {
654 	if (kvmd == 0) {
655 		/*
656 		 * XXX.
657 		 */
658 		kvmd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, buf);
659 		if (kvmd != NULL) {
660 			if (kvm_nlist(kvmd, nl) < 0) {
661 				if(nlistf)
662 					errx(1, "%s: kvm_nlist: %s", nlistf,
663 					     kvm_geterr(kvmd));
664 				else
665 					errx(1, "kvm_nlist: %s", kvm_geterr(kvmd));
666 			}
667 
668 			if (nl[0].n_type == 0) {
669 				if(nlistf)
670 					errx(1, "%s: no namelist", nlistf);
671 				else
672 					errx(1, "no namelist");
673 			}
674 		} else {
675 			warnx("kvm not available");
676 			return(-1);
677 		}
678 	}
679 	if (!buf)
680 		return (0);
681 	if (kvm_read(kvmd, addr, buf, size) != size) {
682 		warnx("%s", kvm_geterr(kvmd));
683 		return (-1);
684 	}
685 	return (0);
686 }
687 
688 char *
689 plural(int n)
690 {
691 	return (n != 1 ? "s" : "");
692 }
693 
694 char *
695 plurales(int n)
696 {
697 	return (n != 1 ? "es" : "");
698 }
699 
700 /*
701  * Find the protox for the given "well-known" name.
702  */
703 static struct protox *
704 knownname(char *name)
705 {
706 	struct protox **tpp, *tp;
707 
708 	for (tpp = protoprotox; *tpp; tpp++)
709 		for (tp = *tpp; tp->pr_name; tp++)
710 			if (strcmp(tp->pr_name, name) == 0)
711 				return (tp);
712 	return (NULL);
713 }
714 
715 /*
716  * Find the protox corresponding to name.
717  */
718 static struct protox *
719 name2protox(char *name)
720 {
721 	struct protox *tp;
722 	char **alias;			/* alias from p->aliases */
723 	struct protoent *p;
724 
725 	/*
726 	 * Try to find the name in the list of "well-known" names. If that
727 	 * fails, check if name is an alias for an Internet protocol.
728 	 */
729 	if ((tp = knownname(name)) != NULL)
730 		return (tp);
731 
732 	setprotoent(1);			/* make protocol lookup cheaper */
733 	while ((p = getprotoent()) != NULL) {
734 		/* assert: name not same as p->name */
735 		for (alias = p->p_aliases; *alias; alias++)
736 			if (strcmp(name, *alias) == 0) {
737 				endprotoent();
738 				return (knownname(p->p_name));
739 			}
740 	}
741 	endprotoent();
742 	return (NULL);
743 }
744 
745 static void
746 usage(void)
747 {
748 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n",
749 "usage: netstat [-AaLnSW] [-c cpu] [-f protocol_family | -p protocol]\n"
750 "               [-M core] [-N system]",
751 "       netstat -i | -I interface [-abdnt] [-f address_family]\n"
752 "               [-M core] [-N system]",
753 "       netstat -w wait [-I interface] [-d] [-M core] [-N system]",
754 "       netstat -s [-s] [-z] [-f protocol_family | -p protocol] [-M core]",
755 "       netstat -i | -I interface -s [-f protocol_family | -p protocol]\n"
756 "               [-M core] [-N system]",
757 "       netstat -m [-M core] [-N system]",
758 "       netstat -r [-AanW] [-f address_family] [-M core] [-N system]",
759 "       netstat -rs [-s] [-M core] [-N system]",
760 "       netstat -g [-W] [-f address_family] [-M core] [-N system]",
761 "       netstat -gs [-s] [-f address_family] [-M core] [-N system]");
762 	exit(1);
763 }
764