xref: /netbsd-src/usr.bin/netstat/inet.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: inet.c,v 1.28 1998/01/07 22:55:07 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "from: @(#)inet.c	8.4 (Berkeley) 4/20/94";
40 #else
41 __RCSID("$NetBSD: inet.c,v 1.28 1998/01/07 22:55:07 lukem Exp $");
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/param.h>
46 #include <sys/queue.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/mbuf.h>
50 #include <sys/protosw.h>
51 
52 #include <net/route.h>
53 #include <netinet/in.h>
54 #include <netinet/in_systm.h>
55 #include <netinet/ip.h>
56 #include <netinet/in_pcb.h>
57 #include <netinet/ip_icmp.h>
58 #include <netinet/icmp_var.h>
59 #include <netinet/igmp_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 #include <netinet/tcp_var.h>
68 #include <netinet/tcp_debug.h>
69 #include <netinet/udp.h>
70 #include <netinet/udp_var.h>
71 
72 #include <arpa/inet.h>
73 #include <netdb.h>
74 #include <stdio.h>
75 #include <string.h>
76 #include <unistd.h>
77 #include "netstat.h"
78 
79 struct	inpcb inpcb;
80 struct	tcpcb tcpcb;
81 struct	socket sockb;
82 
83 char	*inetname __P((struct in_addr *));
84 void	inetprint __P((struct in_addr *, u_int16_t, const char *, int));
85 
86 /*
87  * Print a summary of connections related to an Internet
88  * protocol.  For TCP, also give state of connection.
89  * Listening processes (aflag) are suppressed unless the
90  * -a (all) flag is specified.
91  */
92 void
93 protopr(off, name)
94 	u_long off;
95 	char *name;
96 {
97 	struct inpcbtable table;
98 	struct inpcb *head, *next, *prev;
99 	struct inpcb inpcb;
100 	int istcp;
101 	static int first = 1;
102 
103 	if (off == 0)
104 		return;
105 	istcp = strcmp(name, "tcp") == 0;
106 	kread(off, (char *)&table, sizeof table);
107 	prev = head =
108 	    (struct inpcb *)&((struct inpcbtable *)off)->inpt_queue.cqh_first;
109 	next = table.inpt_queue.cqh_first;
110 
111 	while (next != head) {
112 		kread((u_long)next, (char *)&inpcb, sizeof inpcb);
113 		if (inpcb.inp_queue.cqe_prev != prev) {
114 			printf("???\n");
115 			break;
116 		}
117 		prev = next;
118 		next = inpcb.inp_queue.cqe_next;
119 
120 		if (!aflag &&
121 		    inet_lnaof(inpcb.inp_laddr) == INADDR_ANY)
122 			continue;
123 		kread((u_long)inpcb.inp_socket, (char *)&sockb, sizeof (sockb));
124 		if (istcp) {
125 			kread((u_long)inpcb.inp_ppcb,
126 			    (char *)&tcpcb, sizeof (tcpcb));
127 		}
128 		if (first) {
129 			printf("Active Internet connections");
130 			if (aflag)
131 				printf(" (including servers)");
132 			putchar('\n');
133 			if (Aflag)
134 				printf("%-8.8s ", "PCB");
135 			printf(Aflag ?
136 				"%-5.5s %-6.6s %-6.6s  %-18.18s %-18.18s %s\n" :
137 				"%-5.5s %-6.6s %-6.6s  %-22.22s %-22.22s %s\n",
138 				"Proto", "Recv-Q", "Send-Q",
139 				"Local Address", "Foreign Address", "(state)");
140 			first = 0;
141 		}
142 		if (Aflag)
143 			if (istcp)
144 				printf("%8lx ", (u_long) inpcb.inp_ppcb);
145 			else
146 				printf("%8lx ", (u_long) prev);
147 		printf("%-5.5s %6ld %6ld ", name, sockb.so_rcv.sb_cc,
148 			sockb.so_snd.sb_cc);
149 		if (nflag) {
150 			inetprint(&inpcb.inp_laddr, inpcb.inp_lport, name, 1);
151 			inetprint(&inpcb.inp_faddr, inpcb.inp_fport, name, 1);
152 		} else if (inpcb.inp_flags & INP_ANONPORT) {
153 			inetprint(&inpcb.inp_laddr, inpcb.inp_lport, name, 1);
154 			inetprint(&inpcb.inp_faddr, inpcb.inp_fport, name, 0);
155 		} else {
156 			inetprint(&inpcb.inp_laddr, inpcb.inp_lport, name, 0);
157 			inetprint(&inpcb.inp_faddr, inpcb.inp_fport, name,
158 			    inpcb.inp_lport != inpcb.inp_fport);
159 		}
160 		if (istcp) {
161 			if (tcpcb.t_state < 0 || tcpcb.t_state >= TCP_NSTATES)
162 				printf(" %d", tcpcb.t_state);
163 			else
164 				printf(" %s", tcpstates[tcpcb.t_state]);
165 		}
166 		putchar('\n');
167 	}
168 }
169 
170 /*
171  * Dump TCP statistics structure.
172  */
173 void
174 tcp_stats(off, name)
175 	u_long off;
176 	char *name;
177 {
178 	struct tcpstat tcpstat;
179 
180 	if (off == 0)
181 		return;
182 	printf ("%s:\n", name);
183 	kread(off, (char *)&tcpstat, sizeof (tcpstat));
184 
185 #define	ps(f, m) if (tcpstat.f || sflag <= 1) \
186     printf(m, tcpstat.f)
187 #define	p(f, m) if (tcpstat.f || sflag <= 1) \
188     printf(m, tcpstat.f, plural(tcpstat.f))
189 #define	p2(f1, f2, m) if (tcpstat.f1 || tcpstat.f2 || sflag <= 1) \
190     printf(m, tcpstat.f1, plural(tcpstat.f1), tcpstat.f2, plural(tcpstat.f2))
191 #define	p2s(f1, f2, m) if (tcpstat.f1 || tcpstat.f2 || sflag <= 1) \
192     printf(m, tcpstat.f1, plural(tcpstat.f1), tcpstat.f2)
193 #define	p3(f, m) if (tcpstat.f || sflag <= 1) \
194     printf(m, tcpstat.f, plurales(tcpstat.f))
195 
196 	p(tcps_sndtotal, "\t%lu packet%s sent\n");
197 	p2(tcps_sndpack,tcps_sndbyte,
198 		"\t\t%lu data packet%s (%lu byte%s)\n");
199 	p2(tcps_sndrexmitpack, tcps_sndrexmitbyte,
200 		"\t\t%lu data packet%s (%lu byte%s) retransmitted\n");
201 	p2s(tcps_sndacks, tcps_delack,
202 		"\t\t%lu ack-only packet%s (%lu delayed)\n");
203 	p(tcps_sndurg, "\t\t%lu URG only packet%s\n");
204 	p(tcps_sndprobe, "\t\t%lu window probe packet%s\n");
205 	p(tcps_sndwinup, "\t\t%lu window update packet%s\n");
206 	p(tcps_sndctrl, "\t\t%lu control packet%s\n");
207 	p(tcps_rcvtotal, "\t%lu packet%s received\n");
208 	p2(tcps_rcvackpack, tcps_rcvackbyte, "\t\t%lu ack%s (for %lu byte%s)\n");
209 	p(tcps_rcvdupack, "\t\t%lu duplicate ack%s\n");
210 	p(tcps_rcvacktoomuch, "\t\t%lu ack%s for unsent data\n");
211 	p2(tcps_rcvpack, tcps_rcvbyte,
212 		"\t\t%lu packet%s (%lu byte%s) received in-sequence\n");
213 	p2(tcps_rcvduppack, tcps_rcvdupbyte,
214 		"\t\t%lu completely duplicate packet%s (%lu byte%s)\n");
215 	p(tcps_pawsdrop, "\t\t%lu old duplicate packet%s\n");
216 	p2(tcps_rcvpartduppack, tcps_rcvpartdupbyte,
217 		"\t\t%lu packet%s with some dup. data (%lu byte%s duped)\n");
218 	p2(tcps_rcvoopack, tcps_rcvoobyte,
219 		"\t\t%lu out-of-order packet%s (%lu byte%s)\n");
220 	p2(tcps_rcvpackafterwin, tcps_rcvbyteafterwin,
221 		"\t\t%lu packet%s (%lu byte%s) of data after window\n");
222 	p(tcps_rcvwinprobe, "\t\t%lu window probe%s\n");
223 	p(tcps_rcvwinupd, "\t\t%lu window update packet%s\n");
224 	p(tcps_rcvafterclose, "\t\t%lu packet%s received after close\n");
225 	p(tcps_rcvbadsum, "\t\t%lu discarded for bad checksum%s\n");
226 	p(tcps_rcvbadoff, "\t\t%lu discarded for bad header offset field%s\n");
227 	ps(tcps_rcvshort, "\t\t%lu discarded because packet too short\n");
228 	p(tcps_connattempt, "\t%lu connection request%s\n");
229 	p(tcps_accepts, "\t%lu connection accept%s\n");
230 	p(tcps_connects, "\t%lu connection%s established (including accepts)\n");
231 	p2(tcps_closed, tcps_drops,
232 		"\t%lu connection%s closed (including %lu drop%s)\n");
233 	p(tcps_conndrops, "\t%lu embryonic connection%s dropped\n");
234 	p2(tcps_rttupdated, tcps_segstimed,
235 		"\t%lu segment%s updated rtt (of %lu attempt%s)\n");
236 	p(tcps_rexmttimeo, "\t%lu retransmit timeout%s\n");
237 	p(tcps_timeoutdrop, "\t\t%lu connection%s dropped by rexmit timeout\n");
238 	p2(tcps_persisttimeo, tcps_persistdrops,
239 	   "\t%lu persist timeout%s (resulting in %lu dropped connection%s)\n");
240 	p(tcps_keeptimeo, "\t%lu keepalive timeout%s\n");
241 	p(tcps_keepprobe, "\t\t%lu keepalive probe%s sent\n");
242 	p(tcps_keepdrops, "\t\t%lu connection%s dropped by keepalive\n");
243 	p(tcps_predack, "\t%lu correct ACK header prediction%s\n");
244 	p(tcps_preddat, "\t%lu correct data packet header prediction%s\n");
245 	p3(tcps_pcbhashmiss, "\t%lu PCB hash miss%s\n");
246 	ps(tcps_noport, "\t%lu dropped due to no socket\n");
247 	p(tcps_connsdrained, "\t%lu connection%s drained due to memory shortage\n");
248 
249 	p(tcps_badsyn, "\t%lu bad connection attempt%s\n");
250 	ps(tcps_sc_added, "\t%lu SYN cache entries added\n");
251 	p(tcps_sc_collisions, "\t\t%lu hash collision%s\n");
252 	ps(tcps_sc_completed, "\t\t%lu completed\n");
253 	ps(tcps_sc_aborted, "\t\t%lu aborted (no space to build PCB)\n");
254 	ps(tcps_sc_timed_out, "\t\t%lu timed out\n");
255 	ps(tcps_sc_overflowed, "\t\t%lu dropped due to overflow\n");
256 	ps(tcps_sc_bucketoverflow, "\t\t%lu dropped due to bucket overflow\n");
257 	ps(tcps_sc_reset, "\t\t%lu dropped due to RST\n");
258 	ps(tcps_sc_unreach, "\t\t%lu dropped due to ICMP unreachable\n");
259 	p(tcps_sc_dupesyn, "\t%lu duplicate SYN%s received for entries already in the cache\n");
260 	p(tcps_sc_dropped, "\t%lu SYN%s dropped (no route or no space)\n");
261 
262 #undef p
263 #undef ps
264 #undef p2
265 #undef p2s
266 #undef p3
267 }
268 
269 /*
270  * Dump UDP statistics structure.
271  */
272 void
273 udp_stats(off, name)
274 	u_long off;
275 	char *name;
276 {
277 	struct udpstat udpstat;
278 	u_long delivered;
279 
280 	if (off == 0)
281 		return;
282 	printf("%s:\n", name);
283 	kread(off, (char *)&udpstat, sizeof (udpstat));
284 
285 #define	ps(f, m) if (udpstat.f || sflag <= 1) \
286     printf(m, udpstat.f)
287 #define	p(f, m) if (udpstat.f || sflag <= 1) \
288     printf(m, udpstat.f, plural(udpstat.f))
289 #define	p3(f, m) if (udpstat.f || sflag <= 1) \
290     printf(m, udpstat.f, plurales(udpstat.f))
291 
292 	p(udps_ipackets, "\t%lu datagram%s received\n");
293 	ps(udps_hdrops, "\t%lu with incomplete header\n");
294 	ps(udps_badlen, "\t%lu with bad data length field\n");
295 	ps(udps_badsum, "\t%lu with bad checksum\n");
296 	ps(udps_noport, "\t%lu dropped due to no socket\n");
297 	p(udps_noportbcast, "\t%lu broadcast/multicast datagram%s dropped due to no socket\n");
298 	ps(udps_fullsock, "\t%lu dropped due to full socket buffers\n");
299 	delivered = udpstat.udps_ipackets -
300 		    udpstat.udps_hdrops -
301 		    udpstat.udps_badlen -
302 		    udpstat.udps_badsum -
303 		    udpstat.udps_noport -
304 		    udpstat.udps_noportbcast -
305 		    udpstat.udps_fullsock;
306 	if (delivered || sflag <= 1)
307 		printf("\t%lu delivered\n", delivered);
308 	p3(udps_pcbhashmiss, "\t%lu PCB hash miss%s\n");
309 	p(udps_opackets, "\t%lu datagram%s output\n");
310 
311 #undef ps
312 #undef p
313 #undef p3
314 }
315 
316 /*
317  * Dump IP statistics structure.
318  */
319 void
320 ip_stats(off, name)
321 	u_long off;
322 	char *name;
323 {
324 	struct ipstat ipstat;
325 
326 	if (off == 0)
327 		return;
328 	kread(off, (char *)&ipstat, sizeof (ipstat));
329 	printf("%s:\n", name);
330 
331 #define	ps(f, m) if (ipstat.f || sflag <= 1) \
332     printf(m, ipstat.f)
333 #define	p(f, m) if (ipstat.f || sflag <= 1) \
334     printf(m, ipstat.f, plural(ipstat.f))
335 
336 	p(ips_total, "\t%lu total packet%s received\n");
337 	p(ips_badsum, "\t%lu bad header checksum%s\n");
338 	ps(ips_toosmall, "\t%lu with size smaller than minimum\n");
339 	ps(ips_tooshort, "\t%lu with data size < data length\n");
340 	ps(ips_toolong, "\t%lu with length > max ip packet size\n");
341 	ps(ips_badhlen, "\t%lu with header length < data size\n");
342 	ps(ips_badlen, "\t%lu with data length < header length\n");
343 	ps(ips_badoptions, "\t%lu with bad options\n");
344 	ps(ips_badvers, "\t%lu with incorrect version number\n");
345 	p(ips_fragments, "\t%lu fragment%s received\n");
346 	p(ips_fragdropped, "\t%lu fragment%s dropped (dup or out of space)\n");
347 	p(ips_badfrags, "\t%lu malformed fragment%s dropped\n");
348 	p(ips_fragtimeout, "\t%lu fragment%s dropped after timeout\n");
349 	p(ips_reassembled, "\t%lu packet%s reassembled ok\n");
350 	p(ips_delivered, "\t%lu packet%s for this host\n");
351 	p(ips_noproto, "\t%lu packet%s for unknown/unsupported protocol\n");
352 	p(ips_forward, "\t%lu packet%s forwarded\n");
353 	p(ips_cantforward, "\t%lu packet%s not forwardable\n");
354 	p(ips_redirectsent, "\t%lu redirect%s sent\n");
355 	p(ips_localout, "\t%lu packet%s sent from this host\n");
356 	p(ips_rawout, "\t%lu packet%s sent with fabricated ip header\n");
357 	p(ips_odropped, "\t%lu output packet%s dropped due to no bufs, etc.\n");
358 	p(ips_noroute, "\t%lu output packet%s discarded due to no route\n");
359 	p(ips_fragmented, "\t%lu output datagram%s fragmented\n");
360 	p(ips_ofragments, "\t%lu fragment%s created\n");
361 	p(ips_cantfrag, "\t%lu datagram%s that can't be fragmented\n");
362 #undef ps
363 #undef p
364 }
365 
366 static	char *icmpnames[] = {
367 	"echo reply",
368 	"#1",
369 	"#2",
370 	"destination unreachable",
371 	"source quench",
372 	"routing redirect",
373 	"#6",
374 	"#7",
375 	"echo",
376 	"#9",
377 	"#10",
378 	"time exceeded",
379 	"parameter problem",
380 	"time stamp",
381 	"time stamp reply",
382 	"information request",
383 	"information request reply",
384 	"address mask request",
385 	"address mask reply",
386 };
387 
388 /*
389  * Dump ICMP statistics.
390  */
391 void
392 icmp_stats(off, name)
393 	u_long off;
394 	char *name;
395 {
396 	struct icmpstat icmpstat;
397 	int i, first;
398 
399 	if (off == 0)
400 		return;
401 	kread(off, (char *)&icmpstat, sizeof (icmpstat));
402 	printf("%s:\n", name);
403 
404 #define	p(f, m) if (icmpstat.f || sflag <= 1) \
405     printf(m, icmpstat.f, plural(icmpstat.f))
406 
407 	p(icps_error, "\t%lu call%s to icmp_error\n");
408 	p(icps_oldicmp,
409 	    "\t%lu error%s not generated because old message was icmp\n");
410 	for (first = 1, i = 0; i < ICMP_MAXTYPE + 1; i++)
411 		if (icmpstat.icps_outhist[i] != 0) {
412 			if (first) {
413 				printf("\tOutput histogram:\n");
414 				first = 0;
415 			}
416 			printf("\t\t%s: %lu\n", icmpnames[i],
417 				icmpstat.icps_outhist[i]);
418 		}
419 	p(icps_badcode, "\t%lu message%s with bad code fields\n");
420 	p(icps_tooshort, "\t%lu message%s < minimum length\n");
421 	p(icps_checksum, "\t%lu bad checksum%s\n");
422 	p(icps_badlen, "\t%lu message%s with bad length\n");
423 	for (first = 1, i = 0; i < ICMP_MAXTYPE + 1; i++)
424 		if (icmpstat.icps_inhist[i] != 0) {
425 			if (first) {
426 				printf("\tInput histogram:\n");
427 				first = 0;
428 			}
429 			printf("\t\t%s: %lu\n", icmpnames[i],
430 				icmpstat.icps_inhist[i]);
431 		}
432 	p(icps_reflect, "\t%lu message response%s generated\n");
433 #undef p
434 }
435 
436 /*
437  * Dump IGMP statistics structure.
438  */
439 void
440 igmp_stats(off, name)
441 	u_long off;
442 	char *name;
443 {
444 	struct igmpstat igmpstat;
445 
446 	if (off == 0)
447 		return;
448 	kread(off, (char *)&igmpstat, sizeof (igmpstat));
449 	printf("%s:\n", name);
450 
451 #define	p(f, m) if (igmpstat.f || sflag <= 1) \
452     printf(m, igmpstat.f, plural(igmpstat.f))
453 #define	py(f, m) if (igmpstat.f || sflag <= 1) \
454     printf(m, igmpstat.f, igmpstat.f != 1 ? "ies" : "y")
455 	p(igps_rcv_total, "\t%lu message%s received\n");
456         p(igps_rcv_tooshort, "\t%lu message%s received with too few bytes\n");
457         p(igps_rcv_badsum, "\t%lu message%s received with bad checksum\n");
458         py(igps_rcv_queries, "\t%lu membership quer%s received\n");
459         py(igps_rcv_badqueries, "\t%lu membership quer%s received with invalid field(s)\n");
460         p(igps_rcv_reports, "\t%lu membership report%s received\n");
461         p(igps_rcv_badreports, "\t%lu membership report%s received with invalid field(s)\n");
462         p(igps_rcv_ourreports, "\t%lu membership report%s received for groups to which we belong\n");
463         p(igps_snd_reports, "\t%lu membership report%s sent\n");
464 #undef p
465 #undef py
466 }
467 
468 /*
469  * Pretty print an Internet address (net address + port).
470  * If the nflag was specified, use numbers instead of names.
471  */
472 void
473 inetprint(in, port, proto, numeric)
474 	struct in_addr *in;
475 	u_int16_t port;
476 	const char *proto;
477 	int numeric;
478 {
479 	struct servent *sp = 0;
480 	char line[80], *cp;
481 	int width;
482 
483 	sprintf(line, "%.*s.", (Aflag && !numeric) ? 12 : 16, inetname(in));
484 	cp = strchr(line, '\0');
485 	if (!numeric && port)
486 		sp = getservbyport((int)port, proto);
487 	if (sp || port == 0)
488 		sprintf(cp, "%.8s", sp ? sp->s_name : "*");
489 	else
490 		sprintf(cp, "%u", ntohs(port));
491 	width = Aflag ? 18 : 22;
492 	printf(" %-*.*s", width, width, line);
493 }
494 
495 /*
496  * Construct an Internet address representation.
497  * If the nflag has been supplied, give
498  * numeric value, otherwise try for symbolic name.
499  */
500 char *
501 inetname(inp)
502 	struct in_addr *inp;
503 {
504 	char *cp;
505 	static char line[50];
506 	struct hostent *hp;
507 	struct netent *np;
508 	static char domain[MAXHOSTNAMELEN + 1];
509 	static int first = 1;
510 
511 	if (first && !nflag) {
512 		first = 0;
513 		if (gethostname(domain, MAXHOSTNAMELEN) == 0 &&
514 		    (cp = strchr(domain, '.')))
515 			(void) strcpy(domain, cp + 1);
516 		else
517 			domain[0] = 0;
518 	}
519 	cp = 0;
520 	if (!nflag && inp->s_addr != INADDR_ANY) {
521 		int net = inet_netof(*inp);
522 		int lna = inet_lnaof(*inp);
523 
524 		if (lna == INADDR_ANY) {
525 			np = getnetbyaddr(net, AF_INET);
526 			if (np)
527 				cp = np->n_name;
528 		}
529 		if (cp == 0) {
530 			hp = gethostbyaddr((char *)inp, sizeof (*inp), AF_INET);
531 			if (hp) {
532 				if ((cp = strchr(hp->h_name, '.')) &&
533 				    !strcmp(cp + 1, domain))
534 					*cp = 0;
535 				cp = hp->h_name;
536 			}
537 		}
538 	}
539 	if (inp->s_addr == INADDR_ANY)
540 		strcpy(line, "*");
541 	else if (cp)
542 		strcpy(line, cp);
543 	else {
544 		inp->s_addr = ntohl(inp->s_addr);
545 #define C(x)	((x) & 0xff)
546 		sprintf(line, "%u.%u.%u.%u", C(inp->s_addr >> 24),
547 		    C(inp->s_addr >> 16), C(inp->s_addr >> 8), C(inp->s_addr));
548 	}
549 	return (line);
550 }
551