2.11BSD#431 - /usr/src/lib/libc/gen/getpwent.c

   1: /*
   2:  * Copyright (c) 1988 The Regents of the University of California.
   3:  * All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms are permitted
   6:  * provided that the above copyright notice and this paragraph are
   7:  * duplicated in all such forms and that any documentation,
   8:  * advertising materials, and other materials related to such
   9:  * distribution and use acknowledge that the software was developed
  10:  * by the University of California, Berkeley.  The name of the
  11:  * University may not be used to endorse or promote products derived
  12:  * from this software without specific prior written permission.
  13:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16:  */
  17: 
  18: #if defined(LIBC_SCCS) && !defined(lint)
  19: static char sccsid[] = "@(#)getpwent.c	5.9.1 (2.11BSD) 1996/1/12";
  20: #endif /* LIBC_SCCS and not lint */
  21: 
  22: #include <sys/types.h>
  23: #include <string.h>
  24: #include <stdlib.h>
  25: #include <sys/file.h>
  26: #include <stdio.h>
  27: #include <pwd.h>
  28: #include <ndbm.h>
  29: 
  30: static DBM *_pw_db;
  31: static FILE *_pw_fp;
  32: static struct passwd _pw_passwd;
  33: static int _pw_rewind = 1, _pw_stayopen;
  34: static char _pw_flag, *_pw_file = _PATH_PASSWD;
  35: 
  36: #define MAXLINELENGTH   256
  37: static char line[MAXLINELENGTH];
  38: 
  39: struct passwd *
  40: getpwent()
  41: {
  42:     datum key;
  43:     register int rval;
  44: 
  45:     if (!_pw_db && !_pw_fp && !start_pw())
  46:         return((struct passwd *)NULL);
  47:     do {
  48:         if (_pw_db) {
  49:             key.dptr = NULL;
  50:             rval = fetch_pw(key);
  51:         } else /* _pw_fp */
  52:             rval = scanpw();
  53:     } while (rval && _pw_flag != _PW_KEYBYNAME);
  54:     if (rval)
  55:         getpw();
  56:     return(rval ? &_pw_passwd : (struct passwd *)NULL);
  57: }
  58: 
  59: struct passwd *
  60: getpwnam(nam)
  61:     char *nam;
  62: {
  63:     register int rval;
  64: 
  65:     if (!start_pw())
  66:         return((struct passwd *)NULL);
  67:     if (_pw_db) {
  68:         datum key;
  69: 
  70:         key.dptr = nam;
  71:         key.dsize = strlen(nam);
  72:         rval = fetch_pw(key);
  73:     } else /* _pw_fp */
  74:         for (rval = 0; scanpw();)
  75:             if (!strcmp(nam, _pw_passwd.pw_name)) {
  76:                 rval = 1;
  77:                 break;
  78:             }
  79:     if (!_pw_stayopen)
  80:         endpwent();
  81:     if (rval)
  82:         getpw();
  83:     return(rval ? &_pw_passwd : (struct passwd *)NULL);
  84: }
  85: 
  86: struct passwd *
  87: getpwuid(uid)
  88:     int uid;
  89: {
  90:     register int rval;
  91: 
  92:     if (!start_pw())
  93:         return((struct passwd *)NULL);
  94:     if (_pw_db) {
  95:         datum key;
  96: 
  97:         key.dptr = (char *)&uid;
  98:         key.dsize = sizeof(uid);
  99:         rval = fetch_pw(key);
 100:     } else /* _pw_fp */
 101:         for (rval = 0; scanpw();)
 102:             if (_pw_passwd.pw_uid == uid) {
 103:                 rval = 1;
 104:                 break;
 105:             }
 106:     if (!_pw_stayopen)
 107:         endpwent();
 108:     if (rval)
 109:         getpw();
 110:     return(rval ? &_pw_passwd : (struct passwd *)NULL);
 111: }
 112: 
 113: static
 114: start_pw()
 115: {
 116:     register char *p;
 117: 
 118:     if (_pw_db) {
 119:         _pw_rewind = 1;
 120:         return(1);
 121:     }
 122:     if (_pw_fp) {
 123:         rewind(_pw_fp);
 124:         return(1);
 125:     }
 126:     if (_pw_db = dbm_open(_pw_file, O_RDONLY, 0)) {
 127:         _pw_rewind = 1;
 128:         return(1);
 129:     }
 130:     /*
 131: 	 * special case; if it's the official password file, look in
 132: 	 * the master password file, otherwise, look in the file itself.
 133: 	 */
 134:     p = strcmp(_pw_file, _PATH_PASSWD) ? _pw_file : _PATH_MASTERPASSWD;
 135:     if (_pw_fp = fopen(p, "r"))
 136:         return(1);
 137:     return(0);
 138: }
 139: 
 140: setpwent()
 141: {
 142:     return(setpassent(0));
 143: }
 144: 
 145: setpassent(stayopen)
 146:     int stayopen;
 147: {
 148:     if (!start_pw())
 149:         return(0);
 150:     _pw_stayopen = stayopen;
 151:     return(1);
 152: }
 153: 
 154: void
 155: endpwent()
 156: {
 157:     if (_pw_db) {
 158:         dbm_close(_pw_db);
 159:         _pw_db = (DBM *)NULL;
 160:     } else if (_pw_fp) {
 161:         (void)fclose(_pw_fp);
 162:         _pw_fp = (FILE *)NULL;
 163:     }
 164: }
 165: 
 166: void
 167: setpwfile(file)
 168:     char *file;
 169: {
 170:     _pw_file = file;
 171: }
 172: 
 173: static
 174: scanpw()
 175: {
 176:     register char *cp;
 177:     char    *bp = line;
 178:     register int ch;
 179: 
 180:     for (;;) {
 181:         if (!(fgets(line, sizeof(line), _pw_fp)))
 182:             return(0);
 183:         /* skip lines that are too big */
 184:         if (!(cp = index(line, '\n'))) {
 185:             while ((ch = fgetc(_pw_fp)) != '\n' && ch != EOF)
 186:                 ;
 187:             continue;
 188:         }
 189:         *cp = '\0';
 190:         _pw_passwd.pw_name = strsep(&bp, ":");
 191:         _pw_passwd.pw_passwd = strsep(&bp, ":");
 192:         if (!(cp = strsep(&bp, ":")))
 193:             continue;
 194:         _pw_passwd.pw_uid = atoi(cp);
 195:         if (!(cp = strsep(&bp, ":")))
 196:             continue;
 197:         _pw_passwd.pw_gid = atoi(cp);
 198:         _pw_passwd.pw_class = strsep(&bp, ":");
 199:         if (!(cp = strsep(&bp, ":")))
 200:             continue;
 201:         _pw_passwd.pw_change = atol(cp);
 202:         if (!(cp = strsep(&bp, ":")))
 203:             continue;
 204:         _pw_passwd.pw_expire = atol(cp);
 205:         _pw_passwd.pw_gecos = strsep(&bp, ":");
 206:         _pw_passwd.pw_dir = strsep(&bp, ":");
 207:         _pw_passwd.pw_shell = strsep(&bp, ":");
 208:         if (!_pw_passwd.pw_shell)
 209:             continue;
 210:         return(1);
 211:     }
 212:     /* NOTREACHED */
 213: }
 214: 
 215: static
 216: fetch_pw(key)
 217:     datum key;
 218: {
 219:     register char *p, *t;
 220: 
 221:     /*
 222: 	 * the .dir file is LOCK_EX locked by programs that are
 223: 	 * renaming the various password files.
 224: 	 */
 225:     if (flock(dbm_dirfno(_pw_db), LOCK_SH))
 226:         return(0);
 227:     if (!key.dptr)
 228:         if (_pw_rewind) {
 229:             _pw_rewind = 0;
 230:             key = dbm_firstkey(_pw_db);
 231:         } else
 232:             key = dbm_nextkey(_pw_db);
 233:     if (key.dptr)
 234:         key = dbm_fetch(_pw_db, key);
 235:     (void)flock(dbm_dirfno(_pw_db), LOCK_UN);
 236:     if (!(p = key.dptr))
 237:         return(0);
 238:     t = line;
 239: #define EXPAND(e)   e = t; while (*t++ = *p++);
 240:     EXPAND(_pw_passwd.pw_name);
 241:     EXPAND(_pw_passwd.pw_passwd);
 242:     bcopy(p, (char *)&_pw_passwd.pw_uid, sizeof(int));
 243:     p += sizeof(int);
 244:     bcopy(p, (char *)&_pw_passwd.pw_gid, sizeof(int));
 245:     p += sizeof(int);
 246:     bcopy(p, (char *)&_pw_passwd.pw_change, sizeof(time_t));
 247:     p += sizeof(time_t);
 248:     EXPAND(_pw_passwd.pw_class);
 249:     EXPAND(_pw_passwd.pw_gecos);
 250:     EXPAND(_pw_passwd.pw_dir);
 251:     EXPAND(_pw_passwd.pw_shell);
 252:     bcopy(p, (char *)&_pw_passwd.pw_expire, sizeof(time_t));
 253:     p += sizeof(time_t);
 254:     _pw_flag = *p;
 255:     return(1);
 256: }
 257: 
 258: static
 259: getpw()
 260: {
 261:     static char pwbuf[50];
 262:     off_t lseek();
 263:     long pos;
 264:     int fd, n;
 265:     register char *p;
 266: 
 267:     if (geteuid())
 268:         return;
 269:     /*
 270: 	 * special case; if it's the official password file, look in
 271: 	 * the master password file, otherwise, look in the file itself.
 272: 	 */
 273:     p = strcmp(_pw_file, _PATH_PASSWD) ? _pw_file : _PATH_MASTERPASSWD;
 274:     if ((fd = open(p, O_RDONLY, 0)) < 0)
 275:         return;
 276:     pos = atol(_pw_passwd.pw_passwd);
 277:     if (lseek(fd, pos, L_SET) != pos)
 278:         goto bad;
 279:     if ((n = read(fd, pwbuf, sizeof(pwbuf) - 1)) < 0)
 280:         goto bad;
 281:     pwbuf[n] = '\0';
 282:     for (p = pwbuf; *p; ++p)
 283:         if (*p == ':') {
 284:             *p = '\0';
 285:             _pw_passwd.pw_passwd = pwbuf;
 286:             break;
 287:         }
 288: bad:    (void)close(fd);
 289: }

Defined functions

Defined variables

Defined macros