1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright (c) 1997-2001 by Sun Microsystems, Inc. 24 * All rights reserved. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 31 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.5 */ 32 33 #include <sys/types.h> 34 #include <stdio.h> 35 #include <userdefs.h> 36 #include <pwd.h> 37 38 #include <sys/param.h> 39 #ifndef MAXUID 40 #include <limits.h> 41 #ifdef UID_MAX 42 #define MAXUID UID_MAX 43 #else 44 #define MAXUID 60000 45 #endif 46 #endif 47 48 static uid_t getrangeboundid(uid_t start, uid_t stop); 49 static int isreserveduid(uid_t uid); 50 51 /* 52 * Find the highest uid currently in use and return it. If the highest unused 53 * uid is MAXUID, then attempt to find a hole in the range. If there are no 54 * more unused uids, then return -1. 55 */ 56 uid_t 57 findnextuid(void) 58 { 59 uid_t uid = DEFRID + 1; 60 struct passwd *pwd; 61 uchar_t overflow = 0; 62 63 setpwent(); 64 for (pwd = getpwent(); pwd != NULL; pwd = getpwent()) { 65 if (isreserveduid(pwd->pw_uid)) /* Skip reserved IDs */ 66 continue; 67 if (pwd->pw_uid >= uid) { 68 if (pwd->pw_uid == MAXUID) { /* Overflow check */ 69 overflow = 1; 70 break; 71 } 72 uid = pwd->pw_uid + 1; 73 while (isreserveduid(uid) && 74 uid < MAXUID) { /* Skip reserved IDs */ 75 uid++; 76 } 77 } 78 } 79 endpwent(); 80 if (overflow == 1) /* Find a hole */ 81 return (getrangeboundid(DEFRID + 1, MAXUID)); 82 return (uid); 83 } 84 85 /* 86 * Check to see that the uid is a reserved uid 87 * -- nobody, noaccess or nobody4 88 */ 89 static int 90 isreserveduid(uid_t uid) 91 { 92 return (uid == 60001 || uid == 60002 || uid == 65534); 93 } 94 95 96 /* 97 * getrangeboundid() attempts to return the next valid usable id between the 98 * supplied upper and lower limits. If these limits exceed the system 99 * boundaries of DEFRID +1 and MAXUID (lower and upper bound respectively), 100 * then they are ignored and DEFRID + 1 and MAXUID are used. 101 * 102 * Returns a valid uid_t between DEFRID +1 and MAXUID, -1 is returned on fail 103 */ 104 static uid_t 105 getrangeboundid(uid_t start, uid_t stop) 106 { 107 uid_t low = (start <= DEFRID) ? DEFRID + 1 : start; 108 uid_t high = (stop < MAXUID) ? stop : MAXUID; 109 uid_t uid; 110 111 for (uid = low; uid <= high; uid++) { 112 if (isreserveduid(uid)) 113 continue; 114 if (getpwuid(uid) == NULL) 115 break; 116 } 117 return ((uid > high) ? -1 : uid); 118 }