1 /* $NetBSD: chpass.c,v 1.30 2005/06/02 01:41:38 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1988, 1993, 1994 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993, 1994\n\ 35 The Regents of the University of California. All rights reserved.\n"); 36 #endif /* not lint */ 37 38 #ifndef lint 39 #if 0 40 static char sccsid[] = "@(#)chpass.c 8.4 (Berkeley) 4/2/94"; 41 #else 42 __RCSID("$NetBSD: chpass.c,v 1.30 2005/06/02 01:41:38 lukem Exp $"); 43 #endif 44 #endif /* not lint */ 45 46 #include <sys/param.h> 47 #include <sys/stat.h> 48 #include <sys/time.h> 49 #include <sys/resource.h> 50 51 #include <ctype.h> 52 #include <err.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <pwd.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 #include <util.h> 61 62 #include "chpass.h" 63 #include "pathnames.h" 64 65 static char tempname[] = "/etc/pw.XXXXXX"; 66 uid_t uid; 67 int use_yp; 68 69 void (*Pw_error)(const char *, int, int); 70 71 #ifdef YP 72 extern int _yp_check(char **); /* buried deep inside libc */ 73 #endif 74 75 void baduser(void); 76 void cleanup(void); 77 void usage(void); 78 79 int 80 main(int argc, char **argv) 81 { 82 enum { NEWSH, LOADENTRY, EDITENTRY } op; 83 struct passwd *pw, lpw, old_pw; 84 int ch, dfd, pfd, tfd; 85 #ifdef YP 86 int yflag = 0; 87 #endif 88 char *arg, *username = NULL; 89 90 #ifdef __GNUC__ 91 pw = NULL; /* XXX gcc -Wuninitialized */ 92 arg = NULL; 93 #endif 94 #ifdef YP 95 use_yp = _yp_check(NULL); 96 #endif 97 98 op = EDITENTRY; 99 while ((ch = getopt(argc, argv, "a:s:ly")) != -1) 100 switch (ch) { 101 case 'a': 102 op = LOADENTRY; 103 arg = optarg; 104 break; 105 case 's': 106 op = NEWSH; 107 arg = optarg; 108 break; 109 case 'l': 110 use_yp = 0; 111 break; 112 case 'y': 113 #ifdef YP 114 if (!use_yp) 115 errx(1, "YP not in use."); 116 yflag = 1; 117 #else 118 errx(1, "YP support not compiled in."); 119 #endif 120 break; 121 default: 122 usage(); 123 } 124 argc -= optind; 125 argv += optind; 126 127 uid = getuid(); 128 switch (argc) { 129 case 0: 130 /* nothing */ 131 break; 132 133 case 1: 134 username = argv[0]; 135 break; 136 137 default: 138 usage(); 139 } 140 141 #ifdef YP 142 /* 143 * We need to determine if we _really_ want to use YP. 144 * If we defaulted to YP (i.e. were not given the -y flag), 145 * and the master is not running rpc.yppasswdd, we check 146 * to see if the user exists in the local passwd database. 147 * If so, we use it, otherwise we error out. 148 */ 149 if (use_yp && yflag == 0) { 150 if (check_yppasswdd()) { 151 /* 152 * We weren't able to contact rpc.yppasswdd. 153 * Check to see if we're in the local 154 * password database. If we are, use it. 155 */ 156 if (username != NULL) 157 pw = getpwnam(username); 158 else 159 pw = getpwuid(uid); 160 if (pw != NULL) 161 use_yp = 0; 162 else { 163 warnx("master YP server not running yppasswd" 164 " daemon."); 165 errx(1, "Can't change password."); 166 } 167 } 168 } 169 #endif 170 171 #ifdef YP 172 if (use_yp) 173 Pw_error = yppw_error; 174 else 175 #endif 176 Pw_error = pw_error; 177 178 #ifdef YP 179 if (op == LOADENTRY && use_yp) 180 errx(1, "cannot load entry using YP.\n" 181 "\tUse the -l flag to load local."); 182 #endif 183 184 if (op == EDITENTRY || op == NEWSH) { 185 if (username != NULL) { 186 pw = getpwnam(username); 187 if (pw == NULL) 188 errx(1, "unknown user: %s", username); 189 if (uid && uid != pw->pw_uid) 190 baduser(); 191 } else { 192 pw = getpwuid(uid); 193 if (pw == NULL) 194 errx(1, "unknown user: uid %u", uid); 195 } 196 197 /* Make a copy for later verification */ 198 old_pw = *pw; 199 old_pw.pw_gecos = strdup(old_pw.pw_gecos); 200 if (!old_pw.pw_gecos) { 201 err(1, "strdup"); 202 /*NOTREACHED*/ 203 } 204 } 205 206 if (op == NEWSH) { 207 /* protect p_shell -- it thinks NULL is /bin/sh */ 208 if (!arg[0]) 209 usage(); 210 if (p_shell(arg, pw, NULL)) 211 (*Pw_error)(NULL, 0, 1); 212 } 213 214 if (op == LOADENTRY) { 215 if (uid) 216 baduser(); 217 pw = &lpw; 218 if (!pw_scan(arg, pw, NULL)) 219 exit(1); 220 } 221 222 /* Edit the user passwd information if requested. */ 223 if (op == EDITENTRY) { 224 dfd = mkstemp(tempname); 225 if (dfd < 0 || fcntl(dfd, F_SETFD, 1) < 0) 226 (*Pw_error)(tempname, 1, 1); 227 if (atexit(cleanup)) { 228 cleanup(); 229 errx(1, "couldn't register cleanup"); 230 } 231 display(tempname, dfd, pw); 232 edit(tempname, pw); 233 } 234 235 #ifdef YP 236 if (use_yp) { 237 if (pw_yp(pw, uid)) 238 yppw_error((char *)NULL, 0, 1); 239 else 240 exit(0); 241 /* Will not exit from this if. */ 242 } 243 #endif /* YP */ 244 245 246 /* 247 * Get the passwd lock file and open the passwd file for 248 * reading. 249 */ 250 pw_init(); 251 tfd = pw_lock(0); 252 if (tfd < 0) { 253 if (errno != EEXIST) 254 err(1, "%s", _PATH_MASTERPASSWD_LOCK); 255 warnx("The passwd file is busy, waiting..."); 256 tfd = pw_lock(10); 257 if (tfd < 0) { 258 if (errno != EEXIST) 259 err(1, "%s", _PATH_MASTERPASSWD_LOCK); 260 errx(1, "The passwd file is still busy, " 261 "try again later."); 262 } 263 } 264 if (fcntl(tfd, F_SETFD, 1) < 0) 265 pw_error(_PATH_MASTERPASSWD_LOCK, 1, 1); 266 267 pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0); 268 if (pfd < 0 || fcntl(pfd, F_SETFD, 1) < 0) 269 pw_error(_PATH_MASTERPASSWD, 1, 1); 270 271 /* Copy the passwd file to the lock file, updating pw. */ 272 pw_copy(pfd, tfd, pw, (op == LOADENTRY) ? NULL : &old_pw); 273 274 /* Now finish the passwd file update. */ 275 if (pw_mkdb(username, 0) < 0) 276 pw_error(NULL, 0, 1); 277 278 exit(0); 279 } 280 281 void 282 baduser(void) 283 { 284 285 errx(1, "%s", strerror(EACCES)); 286 } 287 288 void 289 usage(void) 290 { 291 292 (void)fprintf(stderr, 293 "usage: %s [-a list] [-s shell] [-l] [user]\n" 294 " %s [-a list] [-s shell] [-y] [user]\n", 295 getprogname(), getprogname()); 296 exit(1); 297 } 298 299 void 300 cleanup(void) 301 { 302 303 (void)unlink(tempname); 304 } 305