xref: /freebsd/usr.sbin/rpc.yppasswdd/yppasswdd_server.c (revision 77b7cdf1999ee965ad494fddd184b18f532ac91a)
1 /*
2  * Copyright (c) 1995, 1996
3  *	Bill Paul <wpaul@ctr.columbia.edu>.  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 Bill Paul.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/fcntl.h>
38 #include <sys/socket.h>
39 #include <sys/stat.h>
40 #include <sys/wait.h>
41 
42 #include <arpa/inet.h>
43 #include <netinet/in.h>
44 
45 #include <ctype.h>
46 #include <db.h>
47 #include <dirent.h>
48 #include <errno.h>
49 #include <limits.h>
50 #include <pwd.h>
51 #include <signal.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include <libgen.h>
58 #include <libutil.h>
59 
60 #include <rpc/rpc.h>
61 #include <rpcsvc/yp.h>
62 struct dom_binding;
63 #include <rpcsvc/ypclnt.h>
64 #include "yppasswdd_extern.h"
65 #include "yppasswd.h"
66 #include "yppasswd_private.h"
67 #include "ypxfr_extern.h"
68 #include "yp_extern.h"
69 
70 static struct passwd yp_password;
71 
72 static void
73 copy_yp_pass(char *p, int x, int m)
74 {
75 	char *t, *s = p;
76 	static char *buf;
77 
78 	yp_password.pw_fields = 0;
79 
80 	buf = realloc(buf, m + 10);
81 	bzero(buf, m + 10);
82 
83 	/* Turn all colons into NULLs */
84 	while (strchr(s, ':')) {
85 		s = (strchr(s, ':') + 1);
86 		*(s - 1)= '\0';
87 	}
88 
89 	t = buf;
90 #define EXPAND(e)       e = t; while ((*t++ = *p++));
91         EXPAND(yp_password.pw_name);
92 	yp_password.pw_fields |= _PWF_NAME;
93         EXPAND(yp_password.pw_passwd);
94 	yp_password.pw_fields |= _PWF_PASSWD;
95 	yp_password.pw_uid = atoi(p);
96         p += (strlen(p) + 1);
97 	yp_password.pw_fields |= _PWF_UID;
98 	yp_password.pw_gid = atoi(p);
99         p += (strlen(p) + 1);
100 	yp_password.pw_fields |= _PWF_GID;
101 	if (x) {
102 		EXPAND(yp_password.pw_class);
103 		yp_password.pw_fields |= _PWF_CLASS;
104 		yp_password.pw_change = atol(p);
105 		p += (strlen(p) + 1);
106 		yp_password.pw_fields |= _PWF_CHANGE;
107 		yp_password.pw_expire = atol(p);
108 		p += (strlen(p) + 1);
109 		yp_password.pw_fields |= _PWF_EXPIRE;
110 	}
111         EXPAND(yp_password.pw_gecos);
112 	yp_password.pw_fields |= _PWF_GECOS;
113         EXPAND(yp_password.pw_dir);
114 	yp_password.pw_fields |= _PWF_DIR;
115         EXPAND(yp_password.pw_shell);
116 	yp_password.pw_fields |= _PWF_SHELL;
117 
118 	return;
119 }
120 
121 static int
122 validchars(char *arg)
123 {
124 	size_t i;
125 
126 	for (i = 0; i < strlen(arg); i++) {
127 		if (iscntrl(arg[i])) {
128 			yp_error("string contains a control character");
129 			return(1);
130 		}
131 		if (arg[i] == ':') {
132 			yp_error("string contains a colon");
133 			return(1);
134 		}
135 		/* Be evil: truncate strings with \n in them silently. */
136 		if (arg[i] == '\n') {
137 			arg[i] = '\0';
138 			return(0);
139 		}
140 	}
141 	return(0);
142 }
143 
144 static int
145 validate_master(struct passwd *opw __unused, struct x_master_passwd *npw)
146 {
147 
148 	if (npw->pw_name[0] == '+' || npw->pw_name[0] == '-') {
149 		yp_error("client tried to modify an NIS entry");
150 		return(1);
151 	}
152 
153 	if (validchars(npw->pw_shell)) {
154 		yp_error("specified shell contains invalid characters");
155 		return(1);
156 	}
157 
158 	if (validchars(npw->pw_gecos)) {
159 		yp_error("specified gecos field contains invalid characters");
160 		return(1);
161 	}
162 
163 	if (validchars(npw->pw_passwd)) {
164 		yp_error("specified password contains invalid characters");
165 		return(1);
166 	}
167 	return(0);
168 }
169 
170 static int
171 validate(struct passwd *opw, struct x_passwd *npw)
172 {
173 
174 	if (npw->pw_name[0] == '+' || npw->pw_name[0] == '-') {
175 		yp_error("client tried to modify an NIS entry");
176 		return(1);
177 	}
178 
179 	if ((uid_t)npw->pw_uid != opw->pw_uid) {
180 		yp_error("UID mismatch: client says user %s has UID %d",
181 			 npw->pw_name, npw->pw_uid);
182 		yp_error("database says user %s has UID %d", opw->pw_name,
183 			 opw->pw_uid);
184 		return(1);
185 	}
186 
187 	if ((gid_t)npw->pw_gid != opw->pw_gid) {
188 		yp_error("GID mismatch: client says user %s has GID %d",
189 			 npw->pw_name, npw->pw_gid);
190 		yp_error("database says user %s has GID %d", opw->pw_name,
191 			 opw->pw_gid);
192 		return(1);
193 	}
194 
195 	/*
196 	 * Don't allow the user to shoot himself in the foot,
197 	 * even on purpose.
198 	 */
199 	if (!ok_shell(npw->pw_shell)) {
200 		yp_error("%s is not a valid shell", npw->pw_shell);
201 		return(1);
202 	}
203 
204 	if (validchars(npw->pw_shell)) {
205 		yp_error("specified shell contains invalid characters");
206 		return(1);
207 	}
208 
209 	if (validchars(npw->pw_gecos)) {
210 		yp_error("specified gecos field contains invalid characters");
211 		return(1);
212 	}
213 
214 	if (validchars(npw->pw_passwd)) {
215 		yp_error("specified password contains invalid characters");
216 		return(1);
217 	}
218 	return(0);
219 }
220 
221 /*
222  * Kludge alert:
223  * In order to have one rpc.yppasswdd support multiple domains,
224  * we have to cheat: we search each directory under /var/yp
225  * and try to match the user in each master.passwd.byname
226  * map that we find. If the user matches (username, uid and gid
227  * all agree), then we use that domain. If we match the user in
228  * more than one database, we must abort.
229  */
230 static char *
231 find_domain(struct x_passwd *pw)
232 {
233 	struct stat statbuf;
234 	struct dirent *dirp;
235 	DIR *dird;
236 	char yp_mapdir[MAXPATHLEN + 2];
237 	static char domain[YPMAXDOMAIN];
238 	char *tmp = NULL;
239 	DBT key, data;
240 	int hit = 0;
241 
242 	yp_error("performing multidomain lookup");
243 
244 	if ((dird = opendir(yp_dir)) == NULL) {
245 		yp_error("opendir(%s) failed: %s", yp_dir, strerror(errno));
246 		return(NULL);
247 	}
248 
249 	while ((dirp = readdir(dird)) != NULL) {
250 		snprintf(yp_mapdir, sizeof yp_mapdir, "%s/%s",
251 							yp_dir, dirp->d_name);
252 		if (stat(yp_mapdir, &statbuf) < 0) {
253 			yp_error("stat(%s) failed: %s", yp_mapdir,
254 							strerror(errno));
255 			closedir(dird);
256 			return(NULL);
257 		}
258 		if (S_ISDIR(statbuf.st_mode)) {
259 			tmp = (char *)dirp->d_name;
260 			key.data = pw->pw_name;
261 			key.size = strlen(pw->pw_name);
262 
263 			if (yp_get_record(tmp,"master.passwd.byname",
264 			  		&key, &data, 0) != YP_TRUE) {
265 				continue;
266 			}
267 			*((char *)data.data + data.size) = '\0';
268 			copy_yp_pass(data.data, 1, data.size);
269 			if (yp_password.pw_uid == (uid_t)pw->pw_uid &&
270 			    yp_password.pw_gid == (gid_t)pw->pw_gid) {
271 				hit++;
272 				snprintf(domain, YPMAXDOMAIN, "%s", tmp);
273 			}
274 		}
275 	}
276 
277 	closedir(dird);
278 	if (hit > 1) {
279 		yp_error("found same user in two different domains");
280 		return(NULL);
281 	} else
282 		return((char *)&domain);
283 }
284 
285 static const char *maps[] = {
286 	"master.passwd.byname",
287 	"master.passwd.byuid",
288 	"passwd.byname",
289 	"passwd.byuid"
290 };
291 
292 static const char *formats[] = {
293 	"%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s",
294 	"%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s",
295 	"%s:%s:%d:%d:%s:%s:%s",
296 	"%s:%s:%d:%d:%s:%s:%s"
297 };
298 
299 static int
300 update_inplace(struct passwd *pw, char *domain)
301 {
302 	DB *dbp = NULL;
303 	DBT key = { NULL, 0 };
304 	DBT data = { NULL, 0 };
305 	char pwbuf[YPMAXRECORD];
306 	char keybuf[20];
307 	int i;
308 	char *ptr = NULL;
309 	static char yp_last[] = "YP_LAST_MODIFIED";
310 	char yplastbuf[YPMAXRECORD];
311 
312 	snprintf(yplastbuf, sizeof yplastbuf, "%llu",
313 	    (unsigned long long)time(NULL));
314 
315 	for (i = 0; i < 4; i++) {
316 
317 		if (i % 2) {
318 			snprintf(keybuf, sizeof keybuf,
319 			    "%llu", (unsigned long long)pw->pw_uid);
320 			key.data = &keybuf;
321 			key.size = strlen(keybuf);
322 		} else {
323 			key.data = pw->pw_name;
324 			key.size = strlen(pw->pw_name);
325 		}
326 
327 		/*
328 		 * XXX The passwd.byname and passwd.byuid maps come in
329 		 * two flavors: secure and insecure. The secure version
330 		 * has a '*' in the password field whereas the insecure one
331 		 * has a real crypted password. The maps will be insecure
332 		 * if they were built with 'unsecure = TRUE' enabled in
333 		 * /var/yp/Makefile, but we'd have no way of knowing if
334 		 * this has been done unless we were to try parsing the
335 		 * Makefile, which is a disgusting thought. Instead, we
336 		 * read the records from the maps, skip to the first ':'
337 		 * in them, and then look at the character immediately
338 		 * following it. If it's an '*' then the map is 'secure'
339 		 * and we must not insert a real password into the pw_passwd
340 		 * field. If it's not an '*', then we put the real crypted
341 		 * password in.
342 		 */
343 		if (yp_get_record(domain,maps[i],&key,&data,1) != YP_TRUE) {
344 			yp_error("couldn't read %s/%s: %s", domain,
345 						maps[i], strerror(errno));
346 			return(1);
347 		}
348 
349 		if ((ptr = strchr(data.data, ':')) == NULL) {
350 			yp_error("no colon in passwd record?!");
351 			return(1);
352 		}
353 
354 		/*
355 		 * XXX Supposing we have more than one user with the same
356 		 * UID? (Or more than one user with the same name?) We could
357 		 * end up modifying the wrong record if were not careful.
358 		 */
359 		if (i % 2) {
360 			if (strncmp(data.data, pw->pw_name,
361 							strlen(pw->pw_name))) {
362 				yp_error("warning: found entry for UID %d \
363 in map %s@%s with wrong name (%.*s)", pw->pw_uid, maps[i], domain,
364 				    (int)(ptr - (char *)data.data),
365 				    (char *)data.data);
366 				yp_error("there may be more than one user \
367 with the same UID - continuing");
368 				continue;
369 			}
370 		} else {
371 			/*
372 			 * We're really being ultra-paranoid here.
373 			 * This is generally a 'can't happen' condition.
374 			 */
375 			snprintf(pwbuf, sizeof pwbuf, ":%d:%d:", pw->pw_uid,
376 								  pw->pw_gid);
377 			if (!strstr(data.data, pwbuf)) {
378 				yp_error("warning: found entry for user %s \
379 in map %s@%s with wrong UID", pw->pw_name, maps[i], domain);
380 				yp_error("there may be more than one user \
381 with the same name - continuing");
382 				continue;
383 			}
384 		}
385 
386 		if (i < 2) {
387 			snprintf(pwbuf, sizeof pwbuf, formats[i],
388 			   pw->pw_name, pw->pw_passwd, pw->pw_uid,
389 			   pw->pw_gid, pw->pw_class, pw->pw_change,
390 			   pw->pw_expire, pw->pw_gecos, pw->pw_dir,
391 			   pw->pw_shell);
392 		} else {
393 			snprintf(pwbuf, sizeof pwbuf, formats[i],
394 			   pw->pw_name, *(ptr+1) == '*' ? "*" : pw->pw_passwd,
395 			   pw->pw_uid, pw->pw_gid, pw->pw_gecos, pw->pw_dir,
396 			   pw->pw_shell);
397 		}
398 
399 #define FLAGS O_RDWR|O_CREAT
400 
401 		if ((dbp = yp_open_db_rw(domain, maps[i], FLAGS)) == NULL) {
402 			yp_error("couldn't open %s/%s r/w: %s",domain,
403 						maps[i],strerror(errno));
404 			return(1);
405 		}
406 
407 		data.data = pwbuf;
408 		data.size = strlen(pwbuf);
409 
410 		if (yp_put_record(dbp, &key, &data, 1) != YP_TRUE) {
411 			yp_error("failed to update record in %s/%s", domain,
412 								maps[i]);
413 			(void)(dbp->close)(dbp);
414 			return(1);
415 		}
416 
417 		key.data = yp_last;
418 		key.size = strlen(yp_last);
419 		data.data = (char *)&yplastbuf;
420 		data.size = strlen(yplastbuf);
421 
422 		if (yp_put_record(dbp, &key, &data, 1) != YP_TRUE) {
423 			yp_error("failed to update timestamp in %s/%s", domain,
424 								maps[i]);
425 			(void)(dbp->close)(dbp);
426 			return(1);
427 		}
428 
429 		(void)(dbp->close)(dbp);
430 	}
431 
432 	return(0);
433 }
434 
435 int *
436 yppasswdproc_update_1_svc(yppasswd *argp, struct svc_req *rqstp)
437 {
438 	static int  result;
439 	struct sockaddr_in *rqhost;
440 	DBT key, data;
441 	int rval = 0;
442 	int pfd, tfd;
443 	int pid;
444 	int passwd_changed = 0;
445 	int shell_changed = 0;
446 	int gecos_changed = 0;
447 	char *oldshell = NULL;
448 	char *oldgecos = NULL;
449 	char *passfile_hold;
450 	char passfile_buf[MAXPATHLEN + 2];
451 	char *domain = yppasswd_domain;
452 	static struct sockaddr_in clntaddr;
453 	static struct timeval t_saved, t_test;
454 
455 	/*
456 	 * Normal user updates always use the 'default' master.passwd file.
457 	 */
458 
459 	passfile = passfile_default;
460 	result = 1;
461 
462 	rqhost = svc_getcaller(rqstp->rq_xprt);
463 
464 	gettimeofday(&t_test, NULL);
465 	if (!bcmp(rqhost, &clntaddr, sizeof *rqhost) &&
466 		t_test.tv_sec > t_saved.tv_sec &&
467 		t_test.tv_sec - t_saved.tv_sec < 300) {
468 
469 		bzero(&clntaddr, sizeof clntaddr);
470 		bzero(&t_saved, sizeof t_saved);
471 		return(NULL);
472 	}
473 
474 	bcopy(rqhost, &clntaddr, sizeof clntaddr);
475 	gettimeofday(&t_saved, NULL);
476 
477 	if (yp_access(resvport ? "master.passwd.byname" : NULL, rqstp)) {
478 		yp_error("rejected update request from unauthorized host");
479 		svcerr_auth(rqstp->rq_xprt, AUTH_BADCRED);
480 		return(&result);
481 	}
482 
483 	/*
484 	 * Step one: find the user. (It's kinda pointless to
485 	 * proceed if the user doesn't exist.) We look for the
486 	 * user in the master.passwd.byname database, _NOT_ by
487 	 * using getpwent() and friends! We can't use getpwent()
488 	 * since the NIS master server is not guaranteed to be
489 	 * configured as an NIS client.
490 	 */
491 
492 	if (multidomain) {
493 		if ((domain = find_domain(&argp->newpw)) == NULL) {
494 			yp_error("multidomain lookup failed - aborting update");
495 			return(&result);
496 		} else
497 			yp_error("updating user %s in domain %s",
498 					argp->newpw.pw_name, domain);
499 	}
500 
501 	key.data = argp->newpw.pw_name;
502 	key.size = strlen(argp->newpw.pw_name);
503 
504 	if ((rval = yp_get_record(domain,"master.passwd.byname",
505 		  	&key, &data, 0)) != YP_TRUE) {
506 		if (rval == YP_NOKEY) {
507 			yp_error("user %s not found in passwd database",
508 			 	argp->newpw.pw_name);
509 		} else {
510 			yp_error("database access error: %s",
511 			 	yperr_string(rval));
512 		}
513 		return(&result);
514 	}
515 
516 	/* Nul terminate, please. */
517 	*((char *)data.data + data.size) = '\0';
518 
519 	copy_yp_pass(data.data, 1, data.size);
520 
521 	/* Step 2: check that the supplied oldpass is valid. */
522 
523 	if (strcmp(crypt(argp->oldpass, yp_password.pw_passwd),
524 					yp_password.pw_passwd)) {
525 		yp_error("rejected change attempt -- bad password");
526 		yp_error("client address: %s username: %s",
527 			  inet_ntoa(rqhost->sin_addr),
528 			  argp->newpw.pw_name);
529 		return(&result);
530 	}
531 
532 	/* Step 3: validate the arguments passed to us by the client. */
533 
534 	if (validate(&yp_password, &argp->newpw)) {
535 		yp_error("rejecting change attempt: bad arguments");
536 		yp_error("client address: %s username: %s",
537 			 inet_ntoa(rqhost->sin_addr),
538 			 argp->newpw.pw_name);
539 		svcerr_decode(rqstp->rq_xprt);
540 		return(&result);
541 	}
542 
543 	/* Step 4: update the user's passwd structure. */
544 
545 	if (!no_chsh && strcmp(argp->newpw.pw_shell, yp_password.pw_shell)) {
546 		oldshell = yp_password.pw_shell;
547 		yp_password.pw_shell = argp->newpw.pw_shell;
548 		shell_changed++;
549 	}
550 
551 
552 	if (!no_chfn && strcmp(argp->newpw.pw_gecos, yp_password.pw_gecos)) {
553 		oldgecos = yp_password.pw_gecos;
554 		yp_password.pw_gecos = argp->newpw.pw_gecos;
555 		gecos_changed++;
556 	}
557 
558 	if (strcmp(argp->newpw.pw_passwd, yp_password.pw_passwd)) {
559 		yp_password.pw_passwd = argp->newpw.pw_passwd;
560 		yp_password.pw_change = 0;
561 		passwd_changed++;
562 	}
563 
564 	/*
565 	 * If the caller specified a domain other than our 'default'
566 	 * domain, change the path to master.passwd accordingly.
567 	 */
568 
569 	if (strcmp(domain, yppasswd_domain)) {
570 		snprintf(passfile_buf, sizeof(passfile_buf),
571 			"%s/%s/master.passwd", yp_dir, domain);
572 		passfile = (char *)&passfile_buf;
573 	}
574 
575 	/* Step 5: make a new password file with the updated info. */
576 
577 	if (pw_init(dirname(passfile), passfile)) {
578 		yp_error("pw_init() failed");
579 		return &result;
580 	}
581 	if ((pfd = pw_lock()) == -1) {
582 		pw_fini();
583 		yp_error("pw_lock() failed");
584 		return &result;
585 	}
586 	if ((tfd = pw_tmp(-1)) == -1) {
587 		pw_fini();
588 		yp_error("pw_tmp() failed");
589 		return &result;
590 	}
591 	if (pw_copy(pfd, tfd, &yp_password, NULL) == -1) {
592 		pw_fini();
593 		yp_error("pw_copy() failed");
594 		return &result;
595 	}
596 	if (pw_mkdb(yp_password.pw_name) == -1) {
597 		pw_fini();
598 		yp_error("pw_mkdb() failed");
599 		return &result;
600 	}
601 	pw_fini();
602 
603 	if (inplace) {
604 		if ((rval = update_inplace(&yp_password, domain))) {
605 			yp_error("inplace update failed -- rebuilding maps");
606 		}
607 	}
608 
609 	switch ((pid = fork())) {
610 	case 0:
611 		if (inplace && !rval) {
612     			execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile,
613 				yppasswd_domain, "pushpw", (char *)NULL);
614 		} else {
615     			execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile,
616 				yppasswd_domain, (char *)NULL);
617 		}
618     		yp_error("couldn't exec map update process: %s",
619 					strerror(errno));
620 		unlink(passfile);
621 		rename(passfile_hold, passfile);
622     		exit(1);
623 		break;
624 	case -1:
625 		yp_error("fork() failed: %s", strerror(errno));
626 		unlink(passfile);
627 		rename(passfile_hold, passfile);
628 		return(&result);
629 		break;
630 	default:
631 		unlink(passfile_hold);
632 		break;
633 	}
634 
635 	if (verbose) {
636 		yp_error("update completed for user %s (uid %d):",
637 						argp->newpw.pw_name,
638 						argp->newpw.pw_uid);
639 
640 		if (passwd_changed)
641 			yp_error("password changed");
642 
643 		if (gecos_changed)
644 			yp_error("gecos changed ('%s' -> '%s')",
645 					oldgecos, argp->newpw.pw_gecos);
646 
647 		if (shell_changed)
648 			yp_error("shell changed ('%s' -> '%s')",
649 					oldshell, argp->newpw.pw_shell);
650 	}
651 
652 	result = 0;
653 	return (&result);
654 }
655 
656 /*
657  * Note that this function performs a little less sanity checking
658  * than the last one. Since only the superuser is allowed to use it,
659  * it is assumed that the caller knows what he's doing.
660  */
661 int *
662 yppasswdproc_update_master_1_svc(master_yppasswd *argp,
663     struct svc_req *rqstp)
664 {
665 	static int result;
666 	int pfd, tfd;
667 	int pid;
668 	uid_t uid;
669 	int rval = 0;
670 	DBT key, data;
671 	char *passfile_hold;
672 	char passfile_buf[MAXPATHLEN + 2];
673 	struct sockaddr_in *rqhost;
674 	SVCXPRT	*transp;
675 
676 	result = 1;
677 	transp = rqstp->rq_xprt;
678 
679 	/*
680 	 * NO AF_INET CONNETCIONS ALLOWED!
681 	 */
682 	rqhost = svc_getcaller(transp);
683 	if (rqhost->sin_family != AF_UNIX) {
684 		yp_error("Alert! %s/%d attempted to use superuser-only \
685 procedure!\n", inet_ntoa(rqhost->sin_addr), rqhost->sin_port);
686 		svcerr_auth(transp, AUTH_BADCRED);
687 		return(&result);
688 	}
689 
690 	if (rqstp->rq_cred.oa_flavor != AUTH_SYS) {
691 		yp_error("caller didn't send proper credentials");
692 		svcerr_auth(transp, AUTH_BADCRED);
693 		return(&result);
694 	}
695 
696 	if (__rpc_get_local_uid(transp, &uid) < 0) {
697 		yp_error("caller didn't send proper credentials");
698 		svcerr_auth(transp, AUTH_BADCRED);
699 		return(&result);
700 	}
701 
702 	if (uid) {
703 		yp_error("caller euid is %d, expecting 0 -- rejecting request",
704 		    uid);
705 		svcerr_auth(rqstp->rq_xprt, AUTH_BADCRED);
706 		return(&result);
707 	}
708 
709 	passfile = passfile_default;
710 
711 	key.data = argp->newpw.pw_name;
712 	key.size = strlen(argp->newpw.pw_name);
713 
714 	/*
715 	 * The superuser may add entries to the passwd maps if
716 	 * rpc.yppasswdd is started with the -a flag. Paranoia
717 	 * prevents me from allowing additions by default.
718 	 */
719 	if ((rval = yp_get_record(argp->domain, "master.passwd.byname",
720 			  &key, &data, 0)) != YP_TRUE) {
721 		if (rval == YP_NOKEY) {
722 			yp_error("user %s not found in passwd database",
723 				 argp->newpw.pw_name);
724 			if (allow_additions)
725 				yp_error("notice: adding user %s to \
726 master.passwd database for domain %s", argp->newpw.pw_name, argp->domain);
727 			else
728 				yp_error("restart rpc.yppasswdd with the -a flag to \
729 allow additions to be made to the password database");
730 		} else {
731 			yp_error("database access error: %s",
732 				 yperr_string(rval));
733 		}
734 		if (!allow_additions)
735 			return(&result);
736 	} else {
737 
738 		/* Nul terminate, please. */
739 		*((char *)data.data + data.size) = '\0';
740 
741 		copy_yp_pass(data.data, 1, data.size);
742 	}
743 
744 	/*
745 	 * Perform a small bit of sanity checking.
746 	 */
747 	if (validate_master(rval == YP_TRUE ? &yp_password:NULL,&argp->newpw)){
748 		yp_error("rejecting update attempt for %s: bad arguments",
749 			 argp->newpw.pw_name);
750 		return(&result);
751 	}
752 
753 	/*
754 	 * If the caller specified a domain other than our 'default'
755 	 * domain, change the path to master.passwd accordingly.
756 	 */
757 
758 	if (strcmp(argp->domain, yppasswd_domain)) {
759 		snprintf(passfile_buf, sizeof(passfile_buf),
760 			"%s/%s/master.passwd", yp_dir, argp->domain);
761 		passfile = (char *)&passfile_buf;
762 	}
763 
764 	if (pw_init(dirname(passfile), passfile)) {
765 		yp_error("pw_init() failed");
766 		return &result;
767 	}
768 	if ((pfd = pw_lock()) == -1) {
769 		pw_fini();
770 		yp_error("pw_lock() failed");
771 		return &result;
772 	}
773 	if ((tfd = pw_tmp(-1)) == -1) {
774 		pw_fini();
775 		yp_error("pw_tmp() failed");
776 		return &result;
777 	}
778 	if (pw_copy(pfd, tfd, (struct passwd *)&argp->newpw, NULL) == -1) {
779 		pw_fini();
780 		yp_error("pw_copy() failed");
781 		return &result;
782 	}
783 	if (pw_mkdb(argp->newpw.pw_name) == -1) {
784 		pw_fini();
785 		yp_error("pw_mkdb() failed");
786 		return &result;
787 	}
788 	pw_fini();
789 
790 	if (inplace) {
791 		if ((rval = update_inplace((struct passwd *)&argp->newpw,
792 							argp->domain))) {
793 			yp_error("inplace update failed -- rebuilding maps");
794 		}
795 	}
796 
797 	switch ((pid = fork())) {
798 	case 0:
799 		if (inplace && !rval) {
800     			execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile,
801 				argp->domain, "pushpw", (char *)NULL);
802     		} else {
803 			execlp(MAP_UPDATE_PATH, MAP_UPDATE, passfile,
804 				argp->domain, (char *)NULL);
805 		}
806     		yp_error("couldn't exec map update process: %s",
807 					strerror(errno));
808 		unlink(passfile);
809 		rename(passfile_hold, passfile);
810     		exit(1);
811 		break;
812 	case -1:
813 		yp_error("fork() failed: %s", strerror(errno));
814 		unlink(passfile);
815 		rename(passfile_hold, passfile);
816 		return(&result);
817 		break;
818 	default:
819 		unlink(passfile_hold);
820 		break;
821 	}
822 
823 	yp_error("performed update of user %s (uid %d) domain %s",
824 						argp->newpw.pw_name,
825 						argp->newpw.pw_uid,
826 						argp->domain);
827 
828 	result = 0;
829 	return(&result);
830 }
831