xref: /freebsd/lib/libc/net/rcmd.c (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
1 /*
2  * Copyright (c) 1983, 1993, 1994
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 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)rcmd.c	8.3 (Berkeley) 3/26/94";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "namespace.h"
41 #include <sys/param.h>
42 #include <sys/socket.h>
43 #include <sys/stat.h>
44 
45 #include <netinet/in.h>
46 #include <arpa/inet.h>
47 
48 #include <signal.h>
49 #include <fcntl.h>
50 #include <netdb.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 #include <pwd.h>
54 #include <errno.h>
55 #include <stdio.h>
56 #include <ctype.h>
57 #include <string.h>
58 #ifdef YP
59 #include <rpc/rpc.h>
60 #include <rpcsvc/yp_prot.h>
61 #include <rpcsvc/ypclnt.h>
62 #endif
63 #include <arpa/nameser.h>
64 #include "un-namespace.h"
65 
66 /* wrapper for KAME-special getnameinfo() */
67 #ifndef NI_WITHSCOPEID
68 #define NI_WITHSCOPEID	0
69 #endif
70 
71 extern int innetgr( const char *, const char *, const char *, const char * );
72 
73 #define max(a, b)	((a > b) ? a : b)
74 
75 int __ivaliduser(FILE *, u_int32_t, const char *, const char *);
76 int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int);
77 int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *,
78     const char *);
79 static int __icheckhost(const struct sockaddr *, socklen_t, const char *);
80 
81 char paddr[NI_MAXHOST];
82 
83 int
84 rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
85 	char **ahost;
86 	u_short rport;
87 	const char *locuser, *remuser, *cmd;
88 	int *fd2p;
89 {
90 	return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
91 }
92 
93 int
94 rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af)
95 	char **ahost;
96 	u_short rport;
97 	const char *locuser, *remuser, *cmd;
98 	int *fd2p;
99 	int af;
100 {
101 	struct addrinfo hints, *res, *ai;
102 	struct sockaddr_storage from;
103 	fd_set reads;
104 	sigset_t oldmask, newmask;
105 	pid_t pid;
106 	int s, aport, lport, timo, error;
107 	char c, *p;
108 	int refused, nres;
109 	char num[8];
110 	static char canonnamebuf[MAXDNAME];	/* is it proper here? */
111 
112 	/* call rcmdsh() with specified remote shell if appropriate. */
113 	if (!issetugid() && (p = getenv("RSH"))) {
114 		struct servent *sp = getservbyname("shell", "tcp");
115 
116 		if (sp && sp->s_port == rport)
117 			return (rcmdsh(ahost, rport, locuser, remuser,
118 			    cmd, p));
119 	}
120 
121 	/* use rsh(1) if non-root and remote port is shell. */
122 	if (geteuid()) {
123 		struct servent *sp = getservbyname("shell", "tcp");
124 
125 		if (sp && sp->s_port == rport)
126 			return (rcmdsh(ahost, rport, locuser, remuser,
127 			    cmd, NULL));
128 	}
129 
130 	pid = getpid();
131 
132 	memset(&hints, 0, sizeof(hints));
133 	hints.ai_flags = AI_CANONNAME;
134 	hints.ai_family = af;
135 	hints.ai_socktype = SOCK_STREAM;
136 	hints.ai_protocol = 0;
137 	(void)snprintf(num, sizeof(num), "%d", ntohs(rport));
138 	error = getaddrinfo(*ahost, num, &hints, &res);
139 	if (error) {
140 		fprintf(stderr, "rcmd: getaddrinfo: %s\n",
141 			gai_strerror(error));
142 		if (error == EAI_SYSTEM)
143 			fprintf(stderr, "rcmd: getaddrinfo: %s\n",
144 				strerror(errno));
145 		return (-1);
146 	}
147 
148 	if (res->ai_canonname
149 	 && strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) {
150 		strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf));
151 		*ahost = canonnamebuf;
152 	}
153 	nres = 0;
154 	for (ai = res; ai; ai = ai->ai_next)
155 		nres++;
156 	ai = res;
157 	refused = 0;
158 	sigemptyset(&newmask);
159 	sigaddset(&newmask, SIGURG);
160 	_sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask);
161 	for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
162 		s = rresvport_af(&lport, ai->ai_family);
163 		if (s < 0) {
164 			if (errno != EAGAIN && ai->ai_next) {
165 				ai = ai->ai_next;
166 				continue;
167 			}
168 			if (errno == EAGAIN)
169 				(void)fprintf(stderr,
170 				    "rcmd: socket: All ports in use\n");
171 			else
172 				(void)fprintf(stderr, "rcmd: socket: %s\n",
173 				    strerror(errno));
174 			freeaddrinfo(res);
175 			_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
176 			    NULL);
177 			return (-1);
178 		}
179 		_fcntl(s, F_SETOWN, pid);
180 		if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
181 			break;
182 		(void)_close(s);
183 		if (errno == EADDRINUSE) {
184 			lport--;
185 			continue;
186 		}
187 		if (errno == ECONNREFUSED)
188 			refused = 1;
189 		if (ai->ai_next == NULL && (!refused || timo > 16)) {
190 			(void)fprintf(stderr, "%s: %s\n",
191 				      *ahost, strerror(errno));
192 			freeaddrinfo(res);
193 			_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
194 			    NULL);
195 			return (-1);
196 		}
197 		if (nres > 1) {
198 			int oerrno = errno;
199 
200 			getnameinfo(ai->ai_addr, ai->ai_addrlen,
201 				    paddr, sizeof(paddr),
202 				    NULL, 0,
203 				    NI_NUMERICHOST|NI_WITHSCOPEID);
204 			(void)fprintf(stderr, "connect to address %s: ",
205 				      paddr);
206 			errno = oerrno;
207 			perror(0);
208 		}
209 		if ((ai = ai->ai_next) == NULL) {
210 			/* refused && timo <= 16 */
211 			struct timespec time_to_sleep, time_remaining;
212 
213 			time_to_sleep.tv_sec = timo;
214 			time_to_sleep.tv_nsec = 0;
215 			(void)_nanosleep(&time_to_sleep, &time_remaining);
216 			timo *= 2;
217 			ai = res;
218 			refused = 0;
219 		}
220 		if (nres > 1) {
221 			getnameinfo(ai->ai_addr, ai->ai_addrlen,
222 				    paddr, sizeof(paddr),
223 				    NULL, 0,
224 				    NI_NUMERICHOST|NI_WITHSCOPEID);
225 			fprintf(stderr, "Trying %s...\n", paddr);
226 		}
227 	}
228 	lport--;
229 	if (fd2p == 0) {
230 		_write(s, "", 1);
231 		lport = 0;
232 	} else {
233 		char num[8];
234 		int s2 = rresvport_af(&lport, ai->ai_family), s3;
235 		int len = ai->ai_addrlen;
236 		int nfds;
237 
238 		if (s2 < 0)
239 			goto bad;
240 		_listen(s2, 1);
241 		(void)snprintf(num, sizeof(num), "%d", lport);
242 		if (_write(s, num, strlen(num)+1) != strlen(num)+1) {
243 			(void)fprintf(stderr,
244 			    "rcmd: write (setting up stderr): %s\n",
245 			    strerror(errno));
246 			(void)_close(s2);
247 			goto bad;
248 		}
249 		nfds = max(s, s2)+1;
250 		if(nfds > FD_SETSIZE) {
251 			fprintf(stderr, "rcmd: too many files\n");
252 			(void)_close(s2);
253 			goto bad;
254 		}
255 again:
256 		FD_ZERO(&reads);
257 		FD_SET(s, &reads);
258 		FD_SET(s2, &reads);
259 		errno = 0;
260 		if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){
261 			if (errno != 0)
262 				(void)fprintf(stderr,
263 				    "rcmd: select (setting up stderr): %s\n",
264 				    strerror(errno));
265 			else
266 				(void)fprintf(stderr,
267 				"select: protocol failure in circuit setup\n");
268 			(void)_close(s2);
269 			goto bad;
270 		}
271 		s3 = _accept(s2, (struct sockaddr *)&from, &len);
272 		switch (from.ss_family) {
273 		case AF_INET:
274 			aport = ntohs(((struct sockaddr_in *)&from)->sin_port);
275 			break;
276 #ifdef INET6
277 		case AF_INET6:
278 			aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
279 			break;
280 #endif
281 		default:
282 			aport = 0;	/* error */
283 			break;
284 		}
285 		/*
286 		 * XXX careful for ftp bounce attacks. If discovered, shut them
287 		 * down and check for the real auxiliary channel to connect.
288 		 */
289 		if (aport == 20) {
290 			_close(s3);
291 			goto again;
292 		}
293 		(void)_close(s2);
294 		if (s3 < 0) {
295 			(void)fprintf(stderr,
296 			    "rcmd: accept: %s\n", strerror(errno));
297 			lport = 0;
298 			goto bad;
299 		}
300 		*fd2p = s3;
301 		if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) {
302 			(void)fprintf(stderr,
303 			    "socket: protocol failure in circuit setup.\n");
304 			goto bad2;
305 		}
306 	}
307 	(void)_write(s, locuser, strlen(locuser)+1);
308 	(void)_write(s, remuser, strlen(remuser)+1);
309 	(void)_write(s, cmd, strlen(cmd)+1);
310 	if (_read(s, &c, 1) != 1) {
311 		(void)fprintf(stderr,
312 		    "rcmd: %s: %s\n", *ahost, strerror(errno));
313 		goto bad2;
314 	}
315 	if (c != 0) {
316 		while (_read(s, &c, 1) == 1) {
317 			(void)_write(STDERR_FILENO, &c, 1);
318 			if (c == '\n')
319 				break;
320 		}
321 		goto bad2;
322 	}
323 	_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
324 	freeaddrinfo(res);
325 	return (s);
326 bad2:
327 	if (lport)
328 		(void)_close(*fd2p);
329 bad:
330 	(void)_close(s);
331 	_sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
332 	freeaddrinfo(res);
333 	return (-1);
334 }
335 
336 int
337 rresvport(port)
338 	int *port;
339 {
340 	return rresvport_af(port, AF_INET);
341 }
342 
343 int
344 rresvport_af(alport, family)
345 	int *alport, family;
346 {
347 	int s;
348 	struct sockaddr_storage ss;
349 	u_short *sport;
350 
351 	memset(&ss, 0, sizeof(ss));
352 	ss.ss_family = family;
353 	switch (family) {
354 	case AF_INET:
355 		((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in);
356 		sport = &((struct sockaddr_in *)&ss)->sin_port;
357 		((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY;
358 		break;
359 #ifdef INET6
360 	case AF_INET6:
361 		((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6);
362 		sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
363 		((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any;
364 		break;
365 #endif
366 	default:
367 		errno = EAFNOSUPPORT;
368 		return -1;
369 	}
370 
371 	s = _socket(ss.ss_family, SOCK_STREAM, 0);
372 	if (s < 0)
373 		return (-1);
374 #if 0 /* compat_exact_traditional_rresvport_semantics */
375 	sin.sin_port = htons((u_short)*alport);
376 	if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
377 		return (s);
378 	if (errno != EADDRINUSE) {
379 		(void)_close(s);
380 		return (-1);
381 	}
382 #endif
383 	*sport = 0;
384 	if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) {
385 		(void)_close(s);
386 		return (-1);
387 	}
388 	*alport = (int)ntohs(*sport);
389 	return (s);
390 }
391 
392 int	__check_rhosts_file = 1;
393 char	*__rcmd_errstr;
394 
395 int
396 ruserok(rhost, superuser, ruser, luser)
397 	const char *rhost, *ruser, *luser;
398 	int superuser;
399 {
400 	struct addrinfo hints, *res, *r;
401 	int error;
402 
403 	memset(&hints, 0, sizeof(hints));
404 	hints.ai_family = PF_UNSPEC;
405 	hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
406 	error = getaddrinfo(rhost, "0", &hints, &res);
407 	if (error)
408 		return (-1);
409 
410 	for (r = res; r; r = r->ai_next) {
411 		if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
412 		    luser) == 0) {
413 			freeaddrinfo(res);
414 			return (0);
415 		}
416 	}
417 	freeaddrinfo(res);
418 	return (-1);
419 }
420 
421 /*
422  * New .rhosts strategy: We are passed an ip address. We spin through
423  * hosts.equiv and .rhosts looking for a match. When the .rhosts only
424  * has ip addresses, we don't have to trust a nameserver.  When it
425  * contains hostnames, we spin through the list of addresses the nameserver
426  * gives us and look for a match.
427  *
428  * Returns 0 if ok, -1 if not ok.
429  */
430 int
431 iruserok(raddr, superuser, ruser, luser)
432 	unsigned long raddr;
433 	int superuser;
434 	const char *ruser, *luser;
435 {
436 	struct sockaddr_in sin;
437 
438 	memset(&sin, 0, sizeof(sin));
439 	sin.sin_family = AF_INET;
440 	sin.sin_len = sizeof(struct sockaddr_in);
441 	memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
442 	return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser,
443 		ruser, luser);
444 }
445 
446 /*
447  * AF independent extension of iruserok.
448  *
449  * Returns 0 if ok, -1 if not ok.
450  */
451 int
452 iruserok_sa(ra, rlen, superuser, ruser, luser)
453 	const void *ra;
454 	int rlen;
455 	int superuser;
456 	const char *ruser, *luser;
457 {
458 	char *cp;
459 	struct stat sbuf;
460 	struct passwd *pwd;
461 	FILE *hostf;
462 	uid_t uid;
463 	int first;
464 	char pbuf[MAXPATHLEN];
465 	const struct sockaddr *raddr;
466 	struct sockaddr_storage ss;
467 
468 	/* avoid alignment issue */
469 	if (rlen > sizeof(ss))
470 		return(-1);
471 	memcpy(&ss, ra, rlen);
472 	raddr = (struct sockaddr *)&ss;
473 
474 	first = 1;
475 	hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
476 again:
477 	if (hostf) {
478 		if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) {
479 			(void)fclose(hostf);
480 			return (0);
481 		}
482 		(void)fclose(hostf);
483 	}
484 	if (first == 1 && (__check_rhosts_file || superuser)) {
485 		first = 0;
486 		if ((pwd = getpwnam(luser)) == NULL)
487 			return (-1);
488 		(void)strcpy(pbuf, pwd->pw_dir);
489 		(void)strcat(pbuf, "/.rhosts");
490 
491 		/*
492 		 * Change effective uid while opening .rhosts.  If root and
493 		 * reading an NFS mounted file system, can't read files that
494 		 * are protected read/write owner only.
495 		 */
496 		uid = geteuid();
497 		(void)seteuid(pwd->pw_uid);
498 		hostf = fopen(pbuf, "r");
499 		(void)seteuid(uid);
500 
501 		if (hostf == NULL)
502 			return (-1);
503 		/*
504 		 * If not a regular file, or is owned by someone other than
505 		 * user or root or if writeable by anyone but the owner, quit.
506 		 */
507 		cp = NULL;
508 		if (lstat(pbuf, &sbuf) < 0)
509 			cp = ".rhosts lstat failed";
510 		else if (!S_ISREG(sbuf.st_mode))
511 			cp = ".rhosts not regular file";
512 		else if (_fstat(fileno(hostf), &sbuf) < 0)
513 			cp = ".rhosts fstat failed";
514 		else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
515 			cp = "bad .rhosts owner";
516 		else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
517 			cp = ".rhosts writeable by other than owner";
518 		/* If there were any problems, quit. */
519 		if (cp) {
520 			__rcmd_errstr = cp;
521 			(void)fclose(hostf);
522 			return (-1);
523 		}
524 		goto again;
525 	}
526 	return (-1);
527 }
528 
529 /*
530  * XXX
531  * Don't make static, used by lpd(8).
532  *
533  * Returns 0 if ok, -1 if not ok.
534  */
535 int
536 __ivaliduser(hostf, raddr, luser, ruser)
537 	FILE *hostf;
538 	u_int32_t raddr;
539 	const char *luser, *ruser;
540 {
541 	struct sockaddr_in sin;
542 
543 	memset(&sin, 0, sizeof(sin));
544 	sin.sin_family = AF_INET;
545 	sin.sin_len = sizeof(struct sockaddr_in);
546 	memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
547 	return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len,
548 		luser, ruser);
549 }
550 
551 /*
552  * Returns 0 if ok, -1 if not ok.
553  *
554  * XXX obsolete API.
555  */
556 int
557 __ivaliduser_af(hostf, raddr, luser, ruser, af, len)
558 	FILE *hostf;
559 	const void *raddr;
560 	const char *luser, *ruser;
561 	int af, len;
562 {
563 	struct sockaddr *sa = NULL;
564 	struct sockaddr_in *sin = NULL;
565 #ifdef INET6
566 	struct sockaddr_in6 *sin6 = NULL;
567 #endif
568 	struct sockaddr_storage ss;
569 
570 	memset(&ss, 0, sizeof(ss));
571 	switch (af) {
572 	case AF_INET:
573 		if (len != sizeof(sin->sin_addr))
574 			return -1;
575 		sin = (struct sockaddr_in *)&ss;
576 		sin->sin_family = AF_INET;
577 		sin->sin_len = sizeof(struct sockaddr_in);
578 		memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr));
579 		break;
580 #ifdef INET6
581 	case AF_INET6:
582 		if (len != sizeof(sin6->sin6_addr))
583 			return -1;
584 		/* you will lose scope info */
585 		sin6 = (struct sockaddr_in6 *)&ss;
586 		sin6->sin6_family = AF_INET6;
587 		sin6->sin6_len = sizeof(struct sockaddr_in6);
588 		memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr));
589 		break;
590 #endif
591 	default:
592 		return -1;
593 	}
594 
595 	sa = (struct sockaddr *)&ss;
596 	return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser);
597 }
598 
599 int
600 __ivaliduser_sa(hostf, raddr, salen, luser, ruser)
601 	FILE *hostf;
602 	const struct sockaddr *raddr;
603 	socklen_t salen;
604 	const char *luser, *ruser;
605 {
606 	char *user, *p;
607 	int ch;
608 	char buf[MAXHOSTNAMELEN + 128];		/* host + login */
609 	char hname[MAXHOSTNAMELEN];
610 	/* Presumed guilty until proven innocent. */
611 	int userok = 0, hostok = 0;
612 #ifdef YP
613 	char *ypdomain;
614 
615 	if (yp_get_default_domain(&ypdomain))
616 		ypdomain = NULL;
617 #else
618 #define	ypdomain NULL
619 #endif
620 	/* We need to get the damn hostname back for netgroup matching. */
621 	if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0,
622 			NI_NAMEREQD) != 0)
623 		hname[0] = '\0';
624 
625 	while (fgets(buf, sizeof(buf), hostf)) {
626 		p = buf;
627 		/* Skip lines that are too long. */
628 		if (strchr(p, '\n') == NULL) {
629 			while ((ch = getc(hostf)) != '\n' && ch != EOF);
630 			continue;
631 		}
632 		if (*p == '\n' || *p == '#') {
633 			/* comment... */
634 			continue;
635 		}
636 		while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
637 			*p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p;
638 			p++;
639 		}
640 		if (*p == ' ' || *p == '\t') {
641 			*p++ = '\0';
642 			while (*p == ' ' || *p == '\t')
643 				p++;
644 			user = p;
645 			while (*p != '\n' && *p != ' ' &&
646 			    *p != '\t' && *p != '\0')
647 				p++;
648 		} else
649 			user = p;
650 		*p = '\0';
651 		/*
652 		 * Do +/- and +@/-@ checking. This looks really nasty,
653 		 * but it matches SunOS's behavior so far as I can tell.
654 		 */
655 		switch(buf[0]) {
656 		case '+':
657 			if (!buf[1]) {     /* '+' matches all hosts */
658 				hostok = 1;
659 				break;
660 			}
661 			if (buf[1] == '@')  /* match a host by netgroup */
662 				hostok = hname[0] != '\0' &&
663 				    innetgr(&buf[2], hname, NULL, ypdomain);
664 			else		/* match a host by addr */
665 				hostok = __icheckhost(raddr, salen,
666 						      (char *)&buf[1]);
667 			break;
668 		case '-':     /* reject '-' hosts and all their users */
669 			if (buf[1] == '@') {
670 				if (hname[0] == '\0' ||
671 				    innetgr(&buf[2], hname, NULL, ypdomain))
672 					return(-1);
673 			} else {
674 				if (__icheckhost(raddr, salen,
675 						 (char *)&buf[1]))
676 					return(-1);
677 			}
678 			break;
679 		default:  /* if no '+' or '-', do a simple match */
680 			hostok = __icheckhost(raddr, salen, buf);
681 			break;
682 		}
683 		switch(*user) {
684 		case '+':
685 			if (!*(user+1)) {      /* '+' matches all users */
686 				userok = 1;
687 				break;
688 			}
689 			if (*(user+1) == '@')  /* match a user by netgroup */
690 				userok = innetgr(user+2, NULL, ruser, ypdomain);
691 			else	   /* match a user by direct specification */
692 				userok = !(strcmp(ruser, user+1));
693 			break;
694 		case '-': 		/* if we matched a hostname, */
695 			if (hostok) {   /* check for user field rejections */
696 				if (!*(user+1))
697 					return(-1);
698 				if (*(user+1) == '@') {
699 					if (innetgr(user+2, NULL,
700 							ruser, ypdomain))
701 						return(-1);
702 				} else {
703 					if (!strcmp(ruser, user+1))
704 						return(-1);
705 				}
706 			}
707 			break;
708 		default:	/* no rejections: try to match the user */
709 			if (hostok)
710 				userok = !(strcmp(ruser,*user ? user : luser));
711 			break;
712 		}
713 		if (hostok && userok)
714 			return(0);
715 	}
716 	return (-1);
717 }
718 
719 /*
720  * Returns "true" if match, 0 if no match.
721  *
722  * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion
723  * if af == AF_INET6.
724  */
725 static int
726 __icheckhost(raddr, salen, lhost)
727 	const struct sockaddr *raddr;
728 	socklen_t salen;
729         const char *lhost;
730 {
731 	struct sockaddr_in sin;
732 	struct sockaddr_in6 *sin6;
733 	struct addrinfo hints, *res, *r;
734 	int error;
735 	char h1[NI_MAXHOST], h2[NI_MAXHOST];
736 
737 	if (raddr->sa_family == AF_INET6) {
738 		sin6 = (struct sockaddr_in6 *)raddr;
739 		if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
740 			memset(&sin, 0, sizeof(sin));
741 			sin.sin_family = AF_INET;
742 			sin.sin_len = sizeof(struct sockaddr_in);
743 			memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
744 			       sizeof(sin.sin_addr));
745 			raddr = (struct sockaddr *)&sin;
746 			salen = sin.sin_len;
747 		}
748 	}
749 
750 	h1[0] = '\0';
751 	if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0,
752 			NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
753 		return (0);
754 
755 	/* Resolve laddr into sockaddr */
756 	memset(&hints, 0, sizeof(hints));
757 	hints.ai_family = raddr->sa_family;
758 	hints.ai_socktype = SOCK_DGRAM;	/*XXX dummy*/
759 	res = NULL;
760 	error = getaddrinfo(lhost, "0", &hints, &res);
761 	if (error)
762 		return (0);
763 
764 	for (r = res; r ; r = r->ai_next) {
765 		h2[0] = '\0';
766 		if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
767 				NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
768 			continue;
769 		if (strcmp(h1, h2) == 0) {
770 			freeaddrinfo(res);
771 			return (1);
772 		}
773 	}
774 
775 	/* No match. */
776 	freeaddrinfo(res);
777 	return (0);
778 }
779