xref: /freebsd/usr.bin/netstat/main.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
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 
34 #ifndef lint
35 char const copyright[] =
36 "@(#) Copyright (c) 1983, 1988, 1993\n\
37 	Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)main.c	8.4 (Berkeley) 3/1/94";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <sys/param.h>
49 #include <sys/file.h>
50 #include <sys/protosw.h>
51 #include <sys/socket.h>
52 
53 #include <netinet/in.h>
54 
55 #include <netgraph/ng_socket.h>
56 
57 #include <ctype.h>
58 #include <err.h>
59 #include <errno.h>
60 #include <kvm.h>
61 #include <limits.h>
62 #include <netdb.h>
63 #include <nlist.h>
64 #include <paths.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 #include "netstat.h"
70 
71 static struct nlist nl[] = {
72 #define	N_IFNET		0
73 	{ "_ifnet" },
74 #define	N_IMP		1
75 	{ "_imp_softc" },
76 #define	N_RTSTAT	2
77 	{ "_rtstat" },
78 #define	N_UNIXSW	3
79 	{ "_localsw" },
80 #define N_IDP		4
81 	{ "_nspcb"},
82 #define N_IDPSTAT	5
83 	{ "_idpstat"},
84 #define N_SPPSTAT	6
85 	{ "_spp_istat"},
86 #define N_NSERR		7
87 	{ "_ns_errstat"},
88 #define	N_CLNPSTAT	8
89 	{ "_clnp_stat"},
90 #define	IN_NOTUSED	9
91 	{ "_tp_inpcb" },
92 #define	ISO_TP		10
93 	{ "_tp_refinfo" },
94 #define	N_TPSTAT	11
95 	{ "_tp_stat" },
96 #define	N_ESISSTAT	12
97 	{ "_esis_stat"},
98 #define N_NIMP		13
99 	{ "_nimp"},
100 #define N_RTREE		14
101 	{ "_rt_tables"},
102 #define N_CLTP		15
103 	{ "_cltb"},
104 #define N_CLTPSTAT	16
105 	{ "_cltpstat"},
106 #define	N_NFILE		17
107 	{ "_nfile" },
108 #define	N_FILE		18
109 	{ "_file" },
110 #define N_MRTSTAT	19
111 	{ "_mrtstat" },
112 #define N_MFCTABLE	20
113 	{ "_mfctable" },
114 #define N_VIFTABLE	21
115 	{ "_viftable" },
116 #define N_IPX		22
117 	{ "_ipxpcb"},
118 #define N_IPXSTAT	23
119 	{ "_ipxstat"},
120 #define N_SPXSTAT	24
121 	{ "_spx_istat"},
122 #define N_DDPSTAT	25
123 	{ "_ddpstat"},
124 #define N_DDPCB		26
125 	{ "_ddpcb"},
126 #define N_NGSOCKS	27
127 	{ "_ngsocklist"},
128 #define N_IP6STAT	28
129 	{ "_ip6stat" },
130 #define N_ICMP6STAT	29
131 	{ "_icmp6stat" },
132 #define N_IPSECSTAT	30
133 	{ "_ipsecstat" },
134 #define N_IPSEC6STAT	31
135 	{ "_ipsec6stat" },
136 #define N_PIM6STAT	32
137 	{ "_pim6stat" },
138 #define N_MRT6PROTO	33
139 	{ "_ip6_mrtproto" },
140 #define N_MRT6STAT	34
141 	{ "_mrt6stat" },
142 #define N_MF6CTABLE	35
143 	{ "_mf6ctable" },
144 #define N_MIF6TABLE	36
145 	{ "_mif6table" },
146 #define N_PFKEYSTAT	37
147 	{ "_pfkeystat" },
148 	{ "" },
149 };
150 
151 struct protox {
152 	u_char	pr_index;		/* index into nlist of cb head */
153 	u_char	pr_sindex;		/* index into nlist of stat block */
154 	u_char	pr_wanted;		/* 1 if wanted, 0 otherwise */
155 	void	(*pr_cblocks)();	/* control blocks printing routine */
156 	void	(*pr_stats)();		/* statistics printing routine */
157 	void	(*pr_istats)();		/* per/if statistics printing routine */
158 	char	*pr_name;		/* well-known name */
159 	int	pr_usesysctl;		/* true if we use sysctl, not kvm */
160 } protox[] = {
161 	{ -1,		-1,		1,	protopr,
162 	  tcp_stats,	NULL,		"tcp",	IPPROTO_TCP },
163 	{ -1,		-1,		1,	protopr,
164 	  udp_stats,	NULL,		"udp",	IPPROTO_UDP },
165 	{ -1,		-1,		1,	protopr,
166 	  NULL,		NULL,		"divert",IPPROTO_DIVERT },
167 	{ -1,		-1,		1,	protopr,
168 	  ip_stats,	NULL,		"ip",	IPPROTO_RAW },
169 	{ -1,		-1,		1,	protopr,
170 	  icmp_stats,	NULL,		"icmp",	IPPROTO_ICMP },
171 	{ -1,		-1,		1,	protopr,
172 	  igmp_stats,	NULL,		"igmp",	IPPROTO_IGMP },
173 #ifdef IPSEC
174 	{ -1,		N_IPSECSTAT,	1,	0,
175 	  ipsec_stats,	NULL,		"ipsec",	0},
176 #endif
177 	{ -1,		-1,		1,	0,
178 	  bdg_stats,	NULL,		"bdg",	1 /* bridging... */ },
179 	{ -1,		-1,		0,	0,
180 	  0,		NULL,		0 }
181 };
182 
183 #ifdef INET6
184 struct protox ip6protox[] = {
185 	{ -1,		-1,		1,	protopr,
186 	  tcp_stats,	NULL,		"tcp",	IPPROTO_TCP },
187 	{ -1,		-1,		1,	protopr,
188 	  udp_stats,	NULL,		"udp",	IPPROTO_UDP },
189 	{ -1,		N_IP6STAT,	1,	0,
190 	  ip6_stats,	ip6_ifstats,	"ip6",	0 },
191 	{ -1,		N_ICMP6STAT,	1,	0,
192 	  icmp6_stats,	icmp6_ifstats,	"icmp6",0 },
193 #ifdef IPSEC
194 	{ -1,		N_IPSEC6STAT,	1,	0,
195 	  ipsec_stats,	NULL,		"ipsec6",0 },
196 #endif
197 #ifdef notyet
198 	{ -1,		N_PIM6STAT,	1,	0,
199 	  pim6_stats,	NULL,		"pim6",	0 },
200 #endif
201 	{ -1,		-1,		1,	0,
202 	  bdg_stats,	NULL,		"bdg",	1 /* bridging... */ },
203 	{ -1,		-1,		0,	0,
204 	  0,		NULL,		0,	0 }
205 };
206 #endif /*INET6*/
207 
208 #ifdef IPSEC
209 struct protox pfkeyprotox[] = {
210 	{ -1,		N_PFKEYSTAT,	1,	0,
211 	  pfkey_stats,	NULL,		"pfkey", 0 },
212 	{ -1,		-1,		0,	0,
213 	  0,		NULL,		0,	0 }
214 };
215 #endif
216 
217 struct protox atalkprotox[] = {
218 	{ N_DDPCB,	N_DDPSTAT,	1,	atalkprotopr,
219 	  ddp_stats,	NULL,		"ddp" },
220 	{ -1,		-1,		0,	0,
221 	  0,		NULL,		0 }
222 };
223 
224 struct protox netgraphprotox[] = {
225 	{ N_NGSOCKS,	-1,		1,	netgraphprotopr,
226 	  NULL,		NULL,		"ctrl" },
227 	{ N_NGSOCKS,	-1,		1,	netgraphprotopr,
228 	  NULL,		NULL,		"data" },
229 	{ -1,		NULL,		0,	0,
230 	  0,		NULL,		0 }
231 };
232 
233 struct protox ipxprotox[] = {
234 	{ N_IPX,	N_IPXSTAT,	1,	ipxprotopr,
235 	  ipx_stats,	NULL,		"ipx",	0 },
236 	{ N_IPX,	N_SPXSTAT,	1,	ipxprotopr,
237 	  spx_stats,	NULL,		"spx",	0 },
238 	{ -1,		-1,		0,	0,
239 	  0,		NULL,		0,	0 }
240 };
241 
242 #ifdef NS
243 struct protox nsprotox[] = {
244 	{ N_IDP,	N_IDPSTAT,	1,	nsprotopr,
245 	  idp_stats,	NULL,		"idp" },
246 	{ N_IDP,	N_SPPSTAT,	1,	nsprotopr,
247 	  spp_stats,	NULL,		"spp" },
248 	{ -1,		N_NSERR,	1,	0,
249 	  nserr_stats,	NULL,		"ns_err" },
250 	{ -1,		-1,		0,	0,
251 	  0,		NULL,		0 }
252 };
253 #endif
254 
255 #ifdef ISO
256 struct protox isoprotox[] = {
257 	{ ISO_TP,	N_TPSTAT,	1,	iso_protopr,
258 	  tp_stats,	NULL,		"tp" },
259 	{ N_CLTP,	N_CLTPSTAT,	1,	iso_protopr,
260 	  cltp_stats,	NULL,		"cltp" },
261 	{ -1,		N_CLNPSTAT,	1,	 0,
262 	  clnp_stats,	NULL,		"clnp"},
263 	{ -1,		N_ESISSTAT,	1,	 0,
264 	  esis_stats,	NULL,		"esis"},
265 	{ -1,		-1,		0,	0,
266 	  0,		NULL,		0 }
267 };
268 #endif
269 
270 struct protox *protoprotox[] = {
271 					 protox,
272 #ifdef INET6
273 					 ip6protox,
274 #endif
275 #ifdef IPSEC
276 					 pfkeyprotox,
277 #endif
278 					 ipxprotox, atalkprotox,
279 #ifdef NS
280 					 nsprotox,
281 #endif
282 #ifdef ISO
283 					 isoprotox,
284 #endif
285 					 NULL };
286 
287 static void printproto __P((struct protox *, char *));
288 static void usage __P((void));
289 static struct protox *name2protox __P((char *));
290 static struct protox *knownname __P((char *));
291 
292 static kvm_t *kvmd;
293 char *nlistf = NULL, *memf = NULL;
294 
295 int
296 main(argc, argv)
297 	int argc;
298 	char *argv[];
299 {
300 	register struct protox *tp = NULL;  /* for printing cblocks & stats */
301 	int ch;
302 
303 	af = AF_UNSPEC;
304 
305 	while ((ch = getopt(argc, argv, "Aabdf:ghI:lLiM:mN:np:rstuw:")) != -1)
306 		switch(ch) {
307 		case 'A':
308 			Aflag = 1;
309 			break;
310 		case 'a':
311 			aflag = 1;
312 			break;
313 		case 'b':
314 			bflag = 1;
315 			break;
316 		case 'd':
317 			dflag = 1;
318 			break;
319 		case 'f':
320 #ifdef NS
321 			if (strcmp(optarg, "ns") == 0)
322 				af = AF_NS;
323 			else
324 #endif
325 			if (strcmp(optarg, "ipx") == 0)
326 				af = AF_IPX;
327 			else if (strcmp(optarg, "inet") == 0)
328 				af = AF_INET;
329 #ifdef INET6
330 			else if (strcmp(optarg, "inet6") == 0)
331 				af = AF_INET6;
332 #endif /*INET6*/
333 #ifdef INET6
334 			else if (strcmp(optarg, "pfkey") == 0)
335 				af = PF_KEY;
336 #endif /*INET6*/
337 			else if (strcmp(optarg, "unix") == 0)
338 				af = AF_UNIX;
339 			else if (strcmp(optarg, "atalk") == 0)
340 				af = AF_APPLETALK;
341 			else if (strcmp(optarg, "ng") == 0
342 			    || strcmp(optarg, "netgraph") == 0)
343 				af = AF_NETGRAPH;
344 #ifdef ISO
345 			else if (strcmp(optarg, "iso") == 0)
346 				af = AF_ISO;
347 #endif
348 			else {
349 				errx(1, "%s: unknown address family", optarg);
350 			}
351 			break;
352 		case 'g':
353 			gflag = 1;
354 			break;
355 		case 'I': {
356 			char *cp;
357 
358 			iflag = 1;
359 			for (cp = interface = optarg; isalpha(*cp); cp++)
360 				continue;
361 			unit = atoi(cp);
362 			break;
363 		}
364 		case 'i':
365 			iflag = 1;
366 			break;
367 		case 'l':
368 			lflag = 1;
369 			break;
370 		case 'L':
371 			Lflag = 1;
372 			break;
373 		case 'M':
374 			memf = optarg;
375 			break;
376 		case 'm':
377 			mflag = 1;
378 			break;
379 		case 'N':
380 			nlistf = optarg;
381 			break;
382 		case 'n':
383 			nflag = 1;
384 			break;
385 		case 'p':
386 			if ((tp = name2protox(optarg)) == NULL) {
387 				errx(1,
388 				     "%s: unknown or uninstrumented protocol",
389 				     optarg);
390 			}
391 			pflag = 1;
392 			break;
393 		case 'r':
394 			rflag = 1;
395 			break;
396 		case 's':
397 			++sflag;
398 			break;
399 		case 't':
400 			tflag = 1;
401 			break;
402 		case 'u':
403 			af = AF_UNIX;
404 			break;
405 		case 'w':
406 			interval = atoi(optarg);
407 			iflag = 1;
408 			break;
409 		case '?':
410 		default:
411 			usage();
412 		}
413 	argv += optind;
414 	argc -= optind;
415 
416 #define	BACKWARD_COMPATIBILITY
417 #ifdef	BACKWARD_COMPATIBILITY
418 	if (*argv) {
419 		if (isdigit(**argv)) {
420 			interval = atoi(*argv);
421 			if (interval <= 0)
422 				usage();
423 			++argv;
424 			iflag = 1;
425 		}
426 		if (*argv) {
427 			nlistf = *argv;
428 			if (*++argv)
429 				memf = *argv;
430 		}
431 	}
432 #endif
433 
434 	/*
435 	 * Discard setgid privileges if not the running kernel so that bad
436 	 * guys can't print interesting stuff from kernel memory.
437 	 */
438 	if (nlistf != NULL || memf != NULL)
439 		setgid(getgid());
440 
441 	if (mflag) {
442 		mbpr();
443 		exit(0);
444 	}
445 	if (pflag) {
446 		if (iflag && tp->pr_istats) {
447 			kread(0, 0, 0);
448 			intpr(interval, nl[N_IFNET].n_value, tp->pr_istats);
449 			exit(0);
450 		}
451 		if (!tp->pr_stats) {
452 			printf("%s: no stats routine\n", tp->pr_name);
453 			exit(0);
454 		}
455 		if (tp->pr_usesysctl) {
456 			(*tp->pr_stats)(tp->pr_usesysctl, tp->pr_name);
457 		} else {
458 			kread(0, 0, 0);
459 			(*tp->pr_stats)(nl[tp->pr_sindex].n_value,
460 					tp->pr_name);
461 		}
462 		exit(0);
463 	}
464 #if 0
465 	/*
466 	 * Keep file descriptors open to avoid overhead
467 	 * of open/close on each call to get* routines.
468 	 */
469 	sethostent(1);
470 	setnetent(1);
471 #else
472 	/*
473 	 * This does not make sense any more with DNS being default over
474 	 * the files.  Doing a setXXXXent(1) causes a tcp connection to be
475 	 * used for the queries, which is slower.
476 	 */
477 #endif
478 	if (iflag) {
479 		if (sflag && af != AF_UNSPEC)
480 			goto protostat;
481 
482 		kread(0, 0, 0);
483 		intpr(interval, nl[N_IFNET].n_value, NULL);
484 		exit(0);
485 	}
486 	if (rflag) {
487 		kread(0, 0, 0);
488 		if (sflag)
489 			rt_stats(nl[N_RTSTAT].n_value);
490 		else
491 			routepr(nl[N_RTREE].n_value);
492 		exit(0);
493 	}
494 	if (gflag) {
495 		kread(0, 0, 0);
496 		if (sflag) {
497 			if (af == AF_INET || af == AF_UNSPEC)
498 				mrt_stats(nl[N_MRTSTAT].n_value);
499 #ifdef INET6
500 			if (af == AF_INET6 || af == AF_UNSPEC)
501 				mrt6_stats(nl[N_MRT6STAT].n_value);
502 #endif
503 		} else {
504 			if (af == AF_INET || af == AF_UNSPEC)
505 				mroutepr(nl[N_MFCTABLE].n_value,
506 					 nl[N_VIFTABLE].n_value);
507 #ifdef INET6
508 			if (af == AF_INET6 || af == AF_UNSPEC)
509 				mroute6pr(nl[N_MF6CTABLE].n_value,
510 					  nl[N_MIF6TABLE].n_value);
511 #endif
512 		}
513 		exit(0);
514 	}
515 
516   protostat:
517 	kread(0, 0, 0);
518 	if (af == AF_INET || af == AF_UNSPEC)
519 		for (tp = protox; tp->pr_name; tp++)
520 			printproto(tp, tp->pr_name);
521 #ifdef INET6
522 	if (af == AF_INET6 || af == AF_UNSPEC)
523 		for (tp = ip6protox; tp->pr_name; tp++)
524 			printproto(tp, tp->pr_name);
525 #endif /*INET6*/
526 #ifdef IPSEC
527 	if (af == PF_KEY || af == AF_UNSPEC)
528 		for (tp = pfkeyprotox; tp->pr_name; tp++)
529 			printproto(tp, tp->pr_name);
530 #endif /*IPSEC*/
531 	if (af == AF_IPX || af == AF_UNSPEC) {
532 		kread(0, 0, 0);
533 		for (tp = ipxprotox; tp->pr_name; tp++)
534 			printproto(tp, tp->pr_name);
535 	}
536 	if (af == AF_APPLETALK || af == AF_UNSPEC)
537 		for (tp = atalkprotox; tp->pr_name; tp++)
538 			printproto(tp, tp->pr_name);
539 	if (af == AF_NETGRAPH || af == AF_UNSPEC)
540 		for (tp = netgraphprotox; tp->pr_name; tp++)
541 			printproto(tp, tp->pr_name);
542 #ifdef NS
543 	if (af == AF_NS || af == AF_UNSPEC)
544 		for (tp = nsprotox; tp->pr_name; tp++)
545 			printproto(tp, tp->pr_name);
546 #endif
547 #ifdef ISO
548 	if (af == AF_ISO || af == AF_UNSPEC)
549 		for (tp = isoprotox; tp->pr_name; tp++)
550 			printproto(tp, tp->pr_name);
551 #endif
552 	if ((af == AF_UNIX || af == AF_UNSPEC) && !Lflag && !sflag)
553 		unixpr();
554 	exit(0);
555 }
556 
557 /*
558  * Print out protocol statistics or control blocks (per sflag).
559  * If the interface was not specifically requested, and the symbol
560  * is not in the namelist, ignore this one.
561  */
562 static void
563 printproto(tp, name)
564 	register struct protox *tp;
565 	char *name;
566 {
567 	void (*pr)();
568 	u_long off;
569 
570 	if (sflag) {
571 		if (iflag) {
572 			if (tp->pr_istats)
573 				intpr(interval, nl[N_IFNET].n_value,
574 				      tp->pr_istats);
575 			return;
576 		}
577 		else {
578 			pr = tp->pr_stats;
579 			off = tp->pr_usesysctl ? tp->pr_usesysctl
580 				: nl[tp->pr_sindex].n_value;
581 		}
582 	} else {
583 		pr = tp->pr_cblocks;
584 		off = tp->pr_usesysctl ? tp->pr_usesysctl
585 			: nl[tp->pr_index].n_value;
586 	}
587 	if (pr != NULL && (off || af != AF_UNSPEC))
588 		(*pr)(off, name, af);
589 }
590 
591 /*
592  * Read kernel memory, return 0 on success.
593  */
594 int
595 kread(addr, buf, size)
596 	u_long addr;
597 	char *buf;
598 	int size;
599 {
600 	if (kvmd == 0) {
601 		/*
602 		 * XXX.
603 		 */
604 		kvmd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, buf);
605 		if (kvmd != NULL) {
606 			if (kvm_nlist(kvmd, nl) < 0) {
607 				if(nlistf)
608 					errx(1, "%s: kvm_nlist: %s", nlistf,
609 					     kvm_geterr(kvmd));
610 				else
611 					errx(1, "kvm_nlist: %s", kvm_geterr(kvmd));
612 			}
613 
614 			if (nl[0].n_type == 0) {
615 				if(nlistf)
616 					errx(1, "%s: no namelist", nlistf);
617 				else
618 					errx(1, "no namelist");
619 			}
620 		} else {
621 			warnx("kvm not available");
622 			return(-1);
623 		}
624 	}
625 	if (!buf)
626 		return (0);
627 	if (kvm_read(kvmd, addr, buf, size) != size) {
628 		warnx("%s", kvm_geterr(kvmd));
629 		return (-1);
630 	}
631 	return (0);
632 }
633 
634 char *
635 plural(n)
636 	int n;
637 {
638 	return (n != 1 ? "s" : "");
639 }
640 
641 char *
642 plurales(n)
643 	int n;
644 {
645 	return (n != 1 ? "es" : "");
646 }
647 
648 /*
649  * Find the protox for the given "well-known" name.
650  */
651 static struct protox *
652 knownname(name)
653 	char *name;
654 {
655 	struct protox **tpp, *tp;
656 
657 	for (tpp = protoprotox; *tpp; tpp++)
658 		for (tp = *tpp; tp->pr_name; tp++)
659 			if (strcmp(tp->pr_name, name) == 0)
660 				return (tp);
661 	return (NULL);
662 }
663 
664 /*
665  * Find the protox corresponding to name.
666  */
667 static struct protox *
668 name2protox(name)
669 	char *name;
670 {
671 	struct protox *tp;
672 	char **alias;			/* alias from p->aliases */
673 	struct protoent *p;
674 
675 	/*
676 	 * Try to find the name in the list of "well-known" names. If that
677 	 * fails, check if name is an alias for an Internet protocol.
678 	 */
679 	if ((tp = knownname(name)) != NULL)
680 		return (tp);
681 
682 	setprotoent(1);			/* make protocol lookup cheaper */
683 	while ((p = getprotoent()) != NULL) {
684 		/* assert: name not same as p->name */
685 		for (alias = p->p_aliases; *alias; alias++)
686 			if (strcmp(name, *alias) == 0) {
687 				endprotoent();
688 				return (knownname(p->p_name));
689 			}
690 	}
691 	endprotoent();
692 	return (NULL);
693 }
694 
695 static void
696 usage()
697 {
698 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
699 "usage: netstat [-AaLln] [-f address_family] [-M core] [-N system]",
700 "       netstat [-abdghilmnrs] [-f address_family] [-M core] [-N system]",
701 "       netstat [-bdn] [-I interface] [-M core] [-N system] [-w wait]",
702 "       netstat [-M core] [-N system] [-p protocol]");
703 	exit(1);
704 }
705 
706 void
707 trimdomain(cp)
708 	char *cp;
709 {
710 	static char domain[MAXHOSTNAMELEN + 1];
711 	static int first = 1;
712 	char *s;
713 
714 	if (first) {
715 		first = 0;
716 		if (gethostname(domain, MAXHOSTNAMELEN) == 0 &&
717 		    (s = strchr(domain, '.')))
718 			(void) strcpy(domain, s + 1);
719 		else
720 			domain[0] = 0;
721 	}
722 
723 	if (domain[0]) {
724 		while ((cp = strchr(cp, '.'))) {
725 			if (!strcasecmp(cp + 1, domain)) {
726 				*cp = 0;	/* hit it */
727 				break;
728 			} else {
729 				cp++;
730 			}
731 		}
732 	}
733 }
734 
735