1 /* $NetBSD: chpass.c,v 1.28 2003/08/07 11:13:18 agc 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 1.28 2003/08/07 11:13:18 agc 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) __P((const char *, int, int)); 70 71 #ifdef YP 72 extern int _yp_check __P((char **)); /* buried deep inside libc */ 73 #endif 74 75 void baduser __P((void)); 76 void cleanup __P((void)); 77 int main __P((int, char **)); 78 void usage __P((void)); 79 80 int 81 main(argc, argv) 82 int argc; 83 char **argv; 84 { 85 enum { NEWSH, LOADENTRY, EDITENTRY } op; 86 struct passwd *pw, lpw, old_pw; 87 int ch, dfd, pfd, tfd; 88 #ifdef YP 89 int yflag; 90 #endif 91 char *arg, *username = NULL; 92 93 #ifdef __GNUC__ 94 pw = NULL; /* XXX gcc -Wuninitialized */ 95 arg = NULL; 96 #endif 97 #ifdef YP 98 use_yp = _yp_check(NULL); 99 #endif 100 101 op = EDITENTRY; 102 while ((ch = getopt(argc, argv, "a:s:ly")) != -1) 103 switch (ch) { 104 case 'a': 105 op = LOADENTRY; 106 arg = optarg; 107 break; 108 case 's': 109 op = NEWSH; 110 arg = optarg; 111 break; 112 case 'l': 113 use_yp = 0; 114 break; 115 case 'y': 116 #ifdef YP 117 if (!use_yp) 118 errx(1, "YP not in use."); 119 yflag = 1; 120 #else 121 errx(1, "YP support not compiled in."); 122 #endif 123 break; 124 default: 125 usage(); 126 } 127 argc -= optind; 128 argv += optind; 129 130 uid = getuid(); 131 switch (argc) { 132 case 0: 133 /* nothing */ 134 break; 135 136 case 1: 137 username = argv[0]; 138 break; 139 140 default: 141 usage(); 142 } 143 144 #ifdef YP 145 /* 146 * We need to determine if we _really_ want to use YP. 147 * If we defaulted to YP (i.e. were not given the -y flag), 148 * and the master is not running rpc.yppasswdd, we check 149 * to see if the user exists in the local passwd database. 150 * If so, we use it, otherwise we error out. 151 */ 152 if (use_yp && yflag == 0) { 153 if (check_yppasswdd()) { 154 /* 155 * We weren't able to contact rpc.yppasswdd. 156 * Check to see if we're in the local 157 * password database. If we are, use it. 158 */ 159 if (username != NULL) 160 pw = getpwnam(username); 161 else 162 pw = getpwuid(uid); 163 if (pw != NULL) 164 use_yp = 0; 165 else { 166 warnx("master YP server not running yppasswd" 167 " daemon."); 168 errx(1, "Can't change password."); 169 } 170 } 171 } 172 #endif 173 174 #ifdef YP 175 if (use_yp) 176 Pw_error = yppw_error; 177 else 178 #endif 179 Pw_error = pw_error; 180 181 #ifdef YP 182 if (op == LOADENTRY && use_yp) 183 errx(1, "cannot load entry using YP.\n" 184 "\tUse the -l flag to load local."); 185 #endif 186 187 if (op == EDITENTRY || op == NEWSH) { 188 if (username != NULL) { 189 pw = getpwnam(username); 190 if (pw == NULL) 191 errx(1, "unknown user: %s", username); 192 if (uid && uid != pw->pw_uid) 193 baduser(); 194 } else { 195 pw = getpwuid(uid); 196 if (pw == NULL) 197 errx(1, "unknown user: uid %u", uid); 198 } 199 200 /* Make a copy for later verification */ 201 old_pw = *pw; 202 old_pw.pw_gecos = strdup(old_pw.pw_gecos); 203 if (!old_pw.pw_gecos) { 204 err(1, "strdup"); 205 /*NOTREACHED*/ 206 } 207 } 208 209 if (op == NEWSH) { 210 /* protect p_shell -- it thinks NULL is /bin/sh */ 211 if (!arg[0]) 212 usage(); 213 if (p_shell(arg, pw, NULL)) 214 (*Pw_error)(NULL, 0, 1); 215 } 216 217 if (op == LOADENTRY) { 218 if (uid) 219 baduser(); 220 pw = &lpw; 221 if (!pw_scan(arg, pw, NULL)) 222 exit(1); 223 } 224 225 /* Edit the user passwd information if requested. */ 226 if (op == EDITENTRY) { 227 dfd = mkstemp(tempname); 228 if (dfd < 0 || fcntl(dfd, F_SETFD, 1) < 0) 229 (*Pw_error)(tempname, 1, 1); 230 if (atexit(cleanup)) { 231 cleanup(); 232 errx(1, "couldn't register cleanup"); 233 } 234 display(tempname, dfd, pw); 235 edit(tempname, pw); 236 } 237 238 #ifdef YP 239 if (use_yp) { 240 if (pw_yp(pw, uid)) 241 yppw_error((char *)NULL, 0, 1); 242 else 243 exit(0); 244 /* Will not exit from this if. */ 245 } 246 #endif /* YP */ 247 248 249 /* 250 * Get the passwd lock file and open the passwd file for 251 * reading. 252 */ 253 pw_init(); 254 tfd = pw_lock(0); 255 if (tfd < 0) { 256 if (errno != EEXIST) 257 err(1, "%s", _PATH_MASTERPASSWD_LOCK); 258 warnx("The passwd file is busy, waiting..."); 259 tfd = pw_lock(10); 260 if (tfd < 0) { 261 if (errno != EEXIST) 262 err(1, "%s", _PATH_MASTERPASSWD_LOCK); 263 errx(1, "The passwd file is still busy, " 264 "try again later."); 265 } 266 } 267 if (fcntl(tfd, F_SETFD, 1) < 0) 268 pw_error(_PATH_MASTERPASSWD_LOCK, 1, 1); 269 270 pfd = open(_PATH_MASTERPASSWD, O_RDONLY, 0); 271 if (pfd < 0 || fcntl(pfd, F_SETFD, 1) < 0) 272 pw_error(_PATH_MASTERPASSWD, 1, 1); 273 274 /* Copy the passwd file to the lock file, updating pw. */ 275 pw_copy(pfd, tfd, pw, (op == LOADENTRY) ? NULL : &old_pw); 276 277 /* Now finish the passwd file update. */ 278 if (pw_mkdb(username, 0) < 0) 279 pw_error(NULL, 0, 1); 280 281 exit(0); 282 } 283 284 void 285 baduser() 286 { 287 288 errx(1, "%s", strerror(EACCES)); 289 } 290 291 void 292 usage() 293 { 294 295 (void)fprintf(stderr, 296 "usage: %s [-a list] [-s shell] [-l] [user]\n" 297 " %s [-a list] [-s shell] [-y] [user]\n", 298 getprogname(), getprogname()); 299 exit(1); 300 } 301 302 void 303 cleanup() 304 { 305 306 (void)unlink(tempname); 307 } 308