xref: /freebsd/usr.bin/netstat/main.c (revision cb166ce422ac2bc81f42c2a2e2cd68625c11478d)
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 	{ "" },
147 };
148 
149 struct protox {
150 	u_char	pr_index;		/* index into nlist of cb head */
151 	u_char	pr_sindex;		/* index into nlist of stat block */
152 	u_char	pr_wanted;		/* 1 if wanted, 0 otherwise */
153 	void	(*pr_cblocks)();	/* control blocks printing routine */
154 	void	(*pr_stats)();		/* statistics printing routine */
155 	void	(*pr_istats)();		/* per/if statistics printing routine */
156 	char	*pr_name;		/* well-known name */
157 	int	pr_usesysctl;		/* true if we use sysctl, not kvm */
158 } protox[] = {
159 	{ -1,		-1,		1,	protopr,
160 	  tcp_stats,	NULL,		"tcp",	IPPROTO_TCP },
161 	{ -1,		-1,		1,	protopr,
162 	  udp_stats,	NULL,		"udp",	IPPROTO_UDP },
163 	{ -1,		-1,		1,	protopr,
164 	  NULL,		NULL,		"divert",IPPROTO_DIVERT },
165 	{ -1,		-1,		1,	protopr,
166 	  ip_stats,	NULL,		"ip",	IPPROTO_RAW },
167 	{ -1,		-1,		1,	protopr,
168 	  icmp_stats,	NULL,		"icmp",	IPPROTO_ICMP },
169 	{ -1,		-1,		1,	protopr,
170 	  igmp_stats,	NULL,		"igmp",	IPPROTO_IGMP },
171 #ifdef IPSEC
172 	{ -1,		N_IPSECSTAT,	1,	0,
173 	  ipsec_stats,	NULL,		"ipsec",	0},
174 #endif
175 	{ -1,		-1,		1,	protopr,
176 	  bdg_stats,	NULL,		"bdg",	1 /* bridging... */ },
177 	{ -1,		-1,		0,	0,
178 	  0,		NULL,		0 }
179 };
180 
181 #ifdef INET6
182 struct protox ip6protox[] = {
183 	{ -1,		-1,		1,	protopr,
184 	  tcp_stats,	NULL,		"tcp",	IPPROTO_TCP },
185 	{ -1,		-1,		1,	protopr,
186 	  udp_stats,	NULL,		"udp",	IPPROTO_UDP },
187 	{ -1,		N_IP6STAT,	1,	0,
188 	  ip6_stats,	ip6_ifstats,	"ip6",	0 },
189 	{ -1,		N_ICMP6STAT,	1,	0,
190 	  icmp6_stats,	icmp6_ifstats,	"icmp6",0 },
191 #ifdef IPSEC
192 	{ -1,		N_IPSEC6STAT,	1,	0,
193 	  ipsec_stats,	NULL,		"ipsec6",0 },
194 #endif
195 #ifdef notyet
196 	{ -1,		N_PIM6STAT,	1,	0,
197 	  pim6_stats,	NULL,		"pim6",	0 },
198 #endif
199 	{ -1,		-1,		1,	protopr,
200 	  bdg_stats,	NULL,		"bdg",	1 /* bridging... */ },
201 	{ -1,		-1,		0,	0,
202 	  0,		NULL,		0,	0 }
203 };
204 #endif /*INET6*/
205 
206 struct protox atalkprotox[] = {
207 	{ N_DDPCB,	N_DDPSTAT,	1,	atalkprotopr,
208 	  ddp_stats,	NULL,		"ddp" },
209 	{ -1,		-1,		0,	0,
210 	  0,		NULL,		0 }
211 };
212 
213 struct protox netgraphprotox[] = {
214 	{ N_NGSOCKS,	-1,		1,	netgraphprotopr,
215 	  NULL,		NULL,		"ctrl" },
216 	{ N_NGSOCKS,	-1,		1,	netgraphprotopr,
217 	  NULL,		NULL,		"data" },
218 	{ -1,		NULL,		0,	0,
219 	  0,		NULL,		0 }
220 };
221 
222 struct protox ipxprotox[] = {
223 	{ N_IPX,	N_IPXSTAT,	1,	ipxprotopr,
224 	  ipx_stats,	NULL,		"ipx",	0 },
225 	{ N_IPX,	N_SPXSTAT,	1,	ipxprotopr,
226 	  spx_stats,	NULL,		"spx",	0 },
227 	{ -1,		-1,		0,	0,
228 	  0,		NULL,		0,	0 }
229 };
230 
231 #ifdef NS
232 struct protox nsprotox[] = {
233 	{ N_IDP,	N_IDPSTAT,	1,	nsprotopr,
234 	  idp_stats,	NULL,		"idp" },
235 	{ N_IDP,	N_SPPSTAT,	1,	nsprotopr,
236 	  spp_stats,	NULL,		"spp" },
237 	{ -1,		N_NSERR,	1,	0,
238 	  nserr_stats,	NULL,		"ns_err" },
239 	{ -1,		-1,		0,	0,
240 	  0,		NULL,		0 }
241 };
242 #endif
243 
244 #ifdef ISO
245 struct protox isoprotox[] = {
246 	{ ISO_TP,	N_TPSTAT,	1,	iso_protopr,
247 	  tp_stats,	NULL,		"tp" },
248 	{ N_CLTP,	N_CLTPSTAT,	1,	iso_protopr,
249 	  cltp_stats,	NULL,		"cltp" },
250 	{ -1,		N_CLNPSTAT,	1,	 0,
251 	  clnp_stats,	NULL,		"clnp"},
252 	{ -1,		N_ESISSTAT,	1,	 0,
253 	  esis_stats,	NULL,		"esis"},
254 	{ -1,		-1,		0,	0,
255 	  0,		NULL,		0 }
256 };
257 #endif
258 
259 struct protox *protoprotox[] = {
260 					 protox,
261 #ifdef INET6
262 					 ip6protox,
263 #endif
264 					 ipxprotox, atalkprotox,
265 #ifdef NS
266 					 nsprotox,
267 #endif
268 #ifdef ISO
269 					 isoprotox,
270 #endif
271 					 NULL };
272 
273 static void printproto __P((struct protox *, char *));
274 static void usage __P((void));
275 static struct protox *name2protox __P((char *));
276 static struct protox *knownname __P((char *));
277 
278 static kvm_t *kvmd;
279 char *nlistf = NULL, *memf = NULL;
280 
281 int
282 main(argc, argv)
283 	int argc;
284 	char *argv[];
285 {
286 	register struct protox *tp = NULL;  /* for printing cblocks & stats */
287 	int ch;
288 
289 	af = AF_UNSPEC;
290 
291 	while ((ch = getopt(argc, argv, "Aabdf:ghI:lLiM:mN:np:rstuw:")) != -1)
292 		switch(ch) {
293 		case 'A':
294 			Aflag = 1;
295 			break;
296 		case 'a':
297 			aflag = 1;
298 			break;
299 		case 'b':
300 			bflag = 1;
301 			break;
302 		case 'd':
303 			dflag = 1;
304 			break;
305 		case 'f':
306 #ifdef NS
307 			if (strcmp(optarg, "ns") == 0)
308 				af = AF_NS;
309 			else
310 #endif
311 			if (strcmp(optarg, "ipx") == 0)
312 				af = AF_IPX;
313 			else if (strcmp(optarg, "inet") == 0)
314 				af = AF_INET;
315 #ifdef INET6
316 			else if (strcmp(optarg, "inet6") == 0)
317 				af = AF_INET6;
318 #endif /*INET6*/
319 			else if (strcmp(optarg, "unix") == 0)
320 				af = AF_UNIX;
321 			else if (strcmp(optarg, "atalk") == 0)
322 				af = AF_APPLETALK;
323 			else if (strcmp(optarg, "ng") == 0
324 			    || strcmp(optarg, "netgraph") == 0)
325 				af = AF_NETGRAPH;
326 #ifdef ISO
327 			else if (strcmp(optarg, "iso") == 0)
328 				af = AF_ISO;
329 #endif
330 			else {
331 				errx(1, "%s: unknown address family", optarg);
332 			}
333 			break;
334 		case 'g':
335 			gflag = 1;
336 			break;
337 		case 'I': {
338 			char *cp;
339 
340 			iflag = 1;
341 			for (cp = interface = optarg; isalpha(*cp); cp++)
342 				continue;
343 			unit = atoi(cp);
344 			break;
345 		}
346 		case 'i':
347 			iflag = 1;
348 			break;
349 		case 'l':
350 			lflag = 1;
351 			break;
352 		case 'L':
353 			Lflag = 1;
354 			break;
355 		case 'M':
356 			memf = optarg;
357 			break;
358 		case 'm':
359 			mflag = 1;
360 			break;
361 		case 'N':
362 			nlistf = optarg;
363 			break;
364 		case 'n':
365 			nflag = 1;
366 			break;
367 		case 'p':
368 			if ((tp = name2protox(optarg)) == NULL) {
369 				errx(1,
370 				     "%s: unknown or uninstrumented protocol",
371 				     optarg);
372 			}
373 			pflag = 1;
374 			break;
375 		case 'r':
376 			rflag = 1;
377 			break;
378 		case 's':
379 			++sflag;
380 			break;
381 		case 't':
382 			tflag = 1;
383 			break;
384 		case 'u':
385 			af = AF_UNIX;
386 			break;
387 		case 'w':
388 			interval = atoi(optarg);
389 			iflag = 1;
390 			break;
391 		case '?':
392 		default:
393 			usage();
394 		}
395 	argv += optind;
396 	argc -= optind;
397 
398 #define	BACKWARD_COMPATIBILITY
399 #ifdef	BACKWARD_COMPATIBILITY
400 	if (*argv) {
401 		if (isdigit(**argv)) {
402 			interval = atoi(*argv);
403 			if (interval <= 0)
404 				usage();
405 			++argv;
406 			iflag = 1;
407 		}
408 		if (*argv) {
409 			nlistf = *argv;
410 			if (*++argv)
411 				memf = *argv;
412 		}
413 	}
414 #endif
415 
416 	/*
417 	 * Discard setgid privileges if not the running kernel so that bad
418 	 * guys can't print interesting stuff from kernel memory.
419 	 */
420 	if (nlistf != NULL || memf != NULL)
421 		setgid(getgid());
422 
423 	if (mflag) {
424 		mbpr();
425 		exit(0);
426 	}
427 	if (pflag) {
428 		if (iflag && tp->pr_istats) {
429 			kread(0, 0, 0);
430 			intpr(interval, nl[N_IFNET].n_value, tp->pr_istats);
431 			exit(0);
432 		}
433 		if (!tp->pr_stats) {
434 			printf("%s: no stats routine\n", tp->pr_name);
435 			exit(0);
436 		}
437 		if (tp->pr_usesysctl) {
438 			(*tp->pr_stats)(tp->pr_usesysctl, tp->pr_name);
439 		} else {
440 			kread(0, 0, 0);
441 			(*tp->pr_stats)(nl[tp->pr_sindex].n_value,
442 					tp->pr_name);
443 		}
444 		exit(0);
445 	}
446 #if 0
447 	/*
448 	 * Keep file descriptors open to avoid overhead
449 	 * of open/close on each call to get* routines.
450 	 */
451 	sethostent(1);
452 	setnetent(1);
453 #else
454 	/*
455 	 * This does not make sense any more with DNS being default over
456 	 * the files.  Doing a setXXXXent(1) causes a tcp connection to be
457 	 * used for the queries, which is slower.
458 	 */
459 #endif
460 	if (iflag) {
461 		if (sflag && af != AF_UNSPEC)
462 			goto protostat;
463 
464 		kread(0, 0, 0);
465 		intpr(interval, nl[N_IFNET].n_value, NULL);
466 		exit(0);
467 	}
468 	if (rflag) {
469 		kread(0, 0, 0);
470 		if (sflag)
471 			rt_stats(nl[N_RTSTAT].n_value);
472 		else
473 			routepr(nl[N_RTREE].n_value);
474 		exit(0);
475 	}
476 	if (gflag) {
477 		kread(0, 0, 0);
478 		if (sflag) {
479 			if (af == AF_INET || af == AF_UNSPEC)
480 				mrt_stats(nl[N_MRTSTAT].n_value);
481 #ifdef INET6
482 			if (af == AF_INET6 || af == AF_UNSPEC)
483 				mrt6_stats(nl[N_MRT6STAT].n_value);
484 #endif
485 		} else {
486 			if (af == AF_INET || af == AF_UNSPEC)
487 				mroutepr(nl[N_MFCTABLE].n_value,
488 					 nl[N_VIFTABLE].n_value);
489 #ifdef INET6
490 			if (af == AF_INET6 || af == AF_UNSPEC)
491 				mroute6pr(nl[N_MF6CTABLE].n_value,
492 					  nl[N_MIF6TABLE].n_value);
493 #endif
494 		}
495 		exit(0);
496 	}
497 
498   protostat:
499 	kread(0, 0, 0);
500 	if (af == AF_INET || af == AF_UNSPEC)
501 		for (tp = protox; tp->pr_name; tp++)
502 			printproto(tp, tp->pr_name);
503 #ifdef INET6
504 	if (af == AF_INET6 || af == AF_UNSPEC)
505 		for (tp = ip6protox; tp->pr_name; tp++)
506 			printproto(tp, tp->pr_name);
507 #endif /*INET6*/
508 	if (af == AF_IPX || af == AF_UNSPEC) {
509 		kread(0, 0, 0);
510 		for (tp = ipxprotox; tp->pr_name; tp++)
511 			printproto(tp, tp->pr_name);
512 	}
513 	if (af == AF_APPLETALK || af == AF_UNSPEC)
514 		for (tp = atalkprotox; tp->pr_name; tp++)
515 			printproto(tp, tp->pr_name);
516 	if (af == AF_NETGRAPH || af == AF_UNSPEC)
517 		for (tp = netgraphprotox; tp->pr_name; tp++)
518 			printproto(tp, tp->pr_name);
519 #ifdef NS
520 	if (af == AF_NS || af == AF_UNSPEC)
521 		for (tp = nsprotox; tp->pr_name; tp++)
522 			printproto(tp, tp->pr_name);
523 #endif
524 #ifdef ISO
525 	if (af == AF_ISO || af == AF_UNSPEC)
526 		for (tp = isoprotox; tp->pr_name; tp++)
527 			printproto(tp, tp->pr_name);
528 #endif
529 	if ((af == AF_UNIX || af == AF_UNSPEC) && !Lflag && !sflag)
530 		unixpr();
531 	exit(0);
532 }
533 
534 /*
535  * Print out protocol statistics or control blocks (per sflag).
536  * If the interface was not specifically requested, and the symbol
537  * is not in the namelist, ignore this one.
538  */
539 static void
540 printproto(tp, name)
541 	register struct protox *tp;
542 	char *name;
543 {
544 	void (*pr)();
545 	u_long off;
546 
547 	if (sflag) {
548 		if (iflag) {
549 			if (tp->pr_istats)
550 				intpr(interval, nl[N_IFNET].n_value,
551 				      tp->pr_istats);
552 			return;
553 		}
554 		else {
555 			pr = tp->pr_stats;
556 			off = tp->pr_usesysctl ? tp->pr_usesysctl
557 				: nl[tp->pr_sindex].n_value;
558 		}
559 	} else {
560 		pr = tp->pr_cblocks;
561 		off = tp->pr_usesysctl ? tp->pr_usesysctl
562 			: nl[tp->pr_index].n_value;
563 	}
564 	if (pr != NULL && (off || af != AF_UNSPEC))
565 		(*pr)(off, name, af);
566 }
567 
568 /*
569  * Read kernel memory, return 0 on success.
570  */
571 int
572 kread(addr, buf, size)
573 	u_long addr;
574 	char *buf;
575 	int size;
576 {
577 	if (kvmd == 0) {
578 		/*
579 		 * XXX.
580 		 */
581 		kvmd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, buf);
582 		if (kvmd != NULL) {
583 			if (kvm_nlist(kvmd, nl) < 0) {
584 				if(nlistf)
585 					errx(1, "%s: kvm_nlist: %s", nlistf,
586 					     kvm_geterr(kvmd));
587 				else
588 					errx(1, "kvm_nlist: %s", kvm_geterr(kvmd));
589 			}
590 
591 			if (nl[0].n_type == 0) {
592 				if(nlistf)
593 					errx(1, "%s: no namelist", nlistf);
594 				else
595 					errx(1, "no namelist");
596 			}
597 		} else {
598 			warnx("kvm not available");
599 			return(-1);
600 		}
601 	}
602 	if (!buf)
603 		return (0);
604 	if (kvm_read(kvmd, addr, buf, size) != size) {
605 		warnx("%s", kvm_geterr(kvmd));
606 		return (-1);
607 	}
608 	return (0);
609 }
610 
611 char *
612 plural(n)
613 	int n;
614 {
615 	return (n != 1 ? "s" : "");
616 }
617 
618 char *
619 plurales(n)
620 	int n;
621 {
622 	return (n != 1 ? "es" : "");
623 }
624 
625 /*
626  * Find the protox for the given "well-known" name.
627  */
628 static struct protox *
629 knownname(name)
630 	char *name;
631 {
632 	struct protox **tpp, *tp;
633 
634 	for (tpp = protoprotox; *tpp; tpp++)
635 		for (tp = *tpp; tp->pr_name; tp++)
636 			if (strcmp(tp->pr_name, name) == 0)
637 				return (tp);
638 	return (NULL);
639 }
640 
641 /*
642  * Find the protox corresponding to name.
643  */
644 static struct protox *
645 name2protox(name)
646 	char *name;
647 {
648 	struct protox *tp;
649 	char **alias;			/* alias from p->aliases */
650 	struct protoent *p;
651 
652 	/*
653 	 * Try to find the name in the list of "well-known" names. If that
654 	 * fails, check if name is an alias for an Internet protocol.
655 	 */
656 	if ((tp = knownname(name)) != NULL)
657 		return (tp);
658 
659 	setprotoent(1);			/* make protocol lookup cheaper */
660 	while ((p = getprotoent()) != NULL) {
661 		/* assert: name not same as p->name */
662 		for (alias = p->p_aliases; *alias; alias++)
663 			if (strcmp(name, *alias) == 0) {
664 				endprotoent();
665 				return (knownname(p->p_name));
666 			}
667 	}
668 	endprotoent();
669 	return (NULL);
670 }
671 
672 static void
673 usage()
674 {
675 	(void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
676 "usage: netstat [-Aan] [-f address_family] [-M core] [-N system]",
677 "       netstat [-abdghimnrs] [-f address_family] [-M core] [-N system]",
678 "       netstat [-bdn] [-I interface] [-M core] [-N system] [-w wait]",
679 "       netstat [-M core] [-N system] [-p protocol]");
680 	exit(1);
681 }
682 
683 void
684 trimdomain(cp)
685 	char *cp;
686 {
687 	static char domain[MAXHOSTNAMELEN + 1];
688 	static int first = 1;
689 	char *s;
690 
691 	if (first) {
692 		first = 0;
693 		if (gethostname(domain, MAXHOSTNAMELEN) == 0 &&
694 		    (s = strchr(domain, '.')))
695 			(void) strcpy(domain, s + 1);
696 		else
697 			domain[0] = 0;
698 	}
699 
700 	if (domain[0]) {
701 		while ((cp = strchr(cp, '.'))) {
702 			if (!strcasecmp(cp + 1, domain)) {
703 				*cp = 0;	/* hit it */
704 				break;
705 			} else {
706 				cp++;
707 			}
708 		}
709 	}
710 }
711 
712