1 /* $NetBSD: pwcache.c,v 1.7 1997/07/13 19:17:13 christos 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 1.7 1997/07/13 19:17:13 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include <sys/types.h> 46 #include <sys/param.h> 47 48 #include <grp.h> 49 #include <pwd.h> 50 #include <stdio.h> 51 #include <string.h> 52 #include <utmp.h> 53 54 #define NCACHE 64 /* power of 2 */ 55 #define MASK (NCACHE - 1) /* bits to store with */ 56 57 char * 58 user_from_uid(uid, nouser) 59 uid_t uid; 60 int nouser; 61 { 62 static struct ncache { 63 uid_t uid; 64 char name[MAXLOGNAME + 1]; 65 } c_uid[NCACHE]; 66 static int pwopen; 67 static char nbuf[15]; /* 32 bits == 10 digits */ 68 register struct passwd *pw; 69 register struct ncache *cp; 70 71 cp = c_uid + (uid & MASK); 72 if (cp->uid != uid || !*cp->name) { 73 if (pwopen == 0) { 74 setpassent(1); 75 pwopen = 1; 76 } 77 if ((pw = getpwuid(uid)) == NULL) { 78 if (nouser) 79 return (NULL); 80 (void)snprintf(nbuf, sizeof(nbuf), "%u", uid); 81 return (nbuf); 82 } 83 cp->uid = uid; 84 (void)strncpy(cp->name, pw->pw_name, MAXLOGNAME); 85 cp->name[MAXLOGNAME] = '\0'; 86 } 87 return (cp->name); 88 } 89 90 char * 91 group_from_gid(gid, nogroup) 92 gid_t gid; 93 int nogroup; 94 { 95 static struct ncache { 96 gid_t gid; 97 char name[MAXLOGNAME + 1]; 98 } c_gid[NCACHE]; 99 static int gropen; 100 static char nbuf[15]; /* 32 bits == 10 digits */ 101 struct group *gr; 102 struct ncache *cp; 103 104 cp = c_gid + (gid & MASK); 105 if (cp->gid != gid || !*cp->name) { 106 if (gropen == 0) { 107 setgroupent(1); 108 gropen = 1; 109 } 110 if ((gr = getgrgid(gid)) == NULL) { 111 if (nogroup) 112 return (NULL); 113 (void)snprintf(nbuf, sizeof(nbuf), "%u", gid); 114 return (nbuf); 115 } 116 cp->gid = gid; 117 (void)strncpy(cp->name, gr->gr_name, MAXLOGNAME); 118 cp->name[MAXLOGNAME] = '\0'; 119 } 120 return (cp->name); 121 } 122