1 /* $NetBSD: pwcache.c,v 1.8 1997/07/21 14:07:25 jtc Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)pwcache.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: pwcache.c,v 1.8 1997/07/21 14:07:25 jtc Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/types.h> 47 #include <sys/param.h> 48 49 #include <grp.h> 50 #include <pwd.h> 51 #include <stdio.h> 52 #include <string.h> 53 #include <utmp.h> 54 55 #ifdef __weak_alias 56 __weak_alias(user_from_uid,_user_from_uid); 57 __weak_alias(group_from_gid,_group_from_gid); 58 #endif 59 60 #define NCACHE 64 /* power of 2 */ 61 #define MASK (NCACHE - 1) /* bits to store with */ 62 63 char * 64 user_from_uid(uid, nouser) 65 uid_t uid; 66 int nouser; 67 { 68 static struct ncache { 69 uid_t uid; 70 char name[MAXLOGNAME + 1]; 71 } c_uid[NCACHE]; 72 static int pwopen; 73 static char nbuf[15]; /* 32 bits == 10 digits */ 74 register struct passwd *pw; 75 register struct ncache *cp; 76 77 cp = c_uid + (uid & MASK); 78 if (cp->uid != uid || !*cp->name) { 79 if (pwopen == 0) { 80 setpassent(1); 81 pwopen = 1; 82 } 83 if ((pw = getpwuid(uid)) == NULL) { 84 if (nouser) 85 return (NULL); 86 (void)snprintf(nbuf, sizeof(nbuf), "%u", uid); 87 return (nbuf); 88 } 89 cp->uid = uid; 90 (void)strncpy(cp->name, pw->pw_name, MAXLOGNAME); 91 cp->name[MAXLOGNAME] = '\0'; 92 } 93 return (cp->name); 94 } 95 96 char * 97 group_from_gid(gid, nogroup) 98 gid_t gid; 99 int nogroup; 100 { 101 static struct ncache { 102 gid_t gid; 103 char name[MAXLOGNAME + 1]; 104 } c_gid[NCACHE]; 105 static int gropen; 106 static char nbuf[15]; /* 32 bits == 10 digits */ 107 struct group *gr; 108 struct ncache *cp; 109 110 cp = c_gid + (gid & MASK); 111 if (cp->gid != gid || !*cp->name) { 112 if (gropen == 0) { 113 setgroupent(1); 114 gropen = 1; 115 } 116 if ((gr = getgrgid(gid)) == NULL) { 117 if (nogroup) 118 return (NULL); 119 (void)snprintf(nbuf, sizeof(nbuf), "%u", gid); 120 return (nbuf); 121 } 122 cp->gid = gid; 123 (void)strncpy(cp->name, gr->gr_name, MAXLOGNAME); 124 cp->name[MAXLOGNAME] = '\0'; 125 } 126 return (cp->name); 127 } 128