1 /* $NetBSD: pwcache.c,v 1.4 1995/02/27 04:35:47 cgd 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 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)pwcache.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 static char rcsid[] = "$NetBSD: pwcache.c,v 1.4 1995/02/27 04:35:47 cgd Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/types.h> 45 46 #include <grp.h> 47 #include <pwd.h> 48 #include <stdio.h> 49 #include <utmp.h> 50 51 #define NCACHE 64 /* power of 2 */ 52 #define MASK NCACHE - 1 /* bits to store with */ 53 54 char * 55 user_from_uid(uid, nouser) 56 uid_t uid; 57 int nouser; 58 { 59 static struct ncache { 60 uid_t uid; 61 char name[UT_NAMESIZE + 1]; 62 } c_uid[NCACHE]; 63 static int pwopen; 64 static char nbuf[15]; /* 32 bits == 10 digits */ 65 register struct passwd *pw; 66 register struct ncache *cp; 67 68 cp = c_uid + (uid & MASK); 69 if (cp->uid != uid || !*cp->name) { 70 if (pwopen == 0) { 71 setpassent(1); 72 pwopen = 1; 73 } 74 if ((pw = getpwuid(uid)) == NULL) { 75 if (nouser) 76 return (NULL); 77 (void)snprintf(nbuf, sizeof(nbuf), "%u", uid); 78 return (nbuf); 79 } 80 cp->uid = uid; 81 (void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE); 82 cp->name[UT_NAMESIZE] = '\0'; 83 } 84 return (cp->name); 85 } 86 87 char * 88 group_from_gid(gid, nogroup) 89 gid_t gid; 90 int nogroup; 91 { 92 static struct ncache { 93 gid_t gid; 94 char name[UT_NAMESIZE + 1]; 95 } c_gid[NCACHE]; 96 static int gropen; 97 static char nbuf[15]; /* 32 bits == 10 digits */ 98 struct group *gr; 99 struct ncache *cp; 100 101 cp = c_gid + (gid & MASK); 102 if (cp->gid != gid || !*cp->name) { 103 if (gropen == 0) { 104 setgroupent(1); 105 gropen = 1; 106 } 107 if ((gr = getgrgid(gid)) == NULL) { 108 if (nogroup) 109 return (NULL); 110 (void)snprintf(nbuf, sizeof(nbuf), "%u", gid); 111 return (nbuf); 112 } 113 cp->gid = gid; 114 (void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE); 115 cp->name[UT_NAMESIZE] = '\0'; 116 } 117 return (cp->name); 118 } 119