1 /* $NetBSD: pwcache.c,v 1.6 1996/12/20 20:16:07 sommerfe 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 1.6 1996/12/20 20:16:07 sommerfe Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/types.h> 45 #include <sys/param.h> 46 47 #include <grp.h> 48 #include <pwd.h> 49 #include <stdio.h> 50 #include <string.h> 51 #include <utmp.h> 52 53 #define NCACHE 64 /* power of 2 */ 54 #define MASK NCACHE - 1 /* bits to store with */ 55 56 char * 57 user_from_uid(uid, nouser) 58 uid_t uid; 59 int nouser; 60 { 61 static struct ncache { 62 uid_t uid; 63 char name[MAXLOGNAME + 1]; 64 } c_uid[NCACHE]; 65 static int pwopen; 66 static char nbuf[15]; /* 32 bits == 10 digits */ 67 register struct passwd *pw; 68 register struct ncache *cp; 69 70 cp = c_uid + (uid & MASK); 71 if (cp->uid != uid || !*cp->name) { 72 if (pwopen == 0) { 73 setpassent(1); 74 pwopen = 1; 75 } 76 if ((pw = getpwuid(uid)) == NULL) { 77 if (nouser) 78 return (NULL); 79 (void)snprintf(nbuf, sizeof(nbuf), "%u", uid); 80 return (nbuf); 81 } 82 cp->uid = uid; 83 (void)strncpy(cp->name, pw->pw_name, MAXLOGNAME); 84 cp->name[MAXLOGNAME] = '\0'; 85 } 86 return (cp->name); 87 } 88 89 char * 90 group_from_gid(gid, nogroup) 91 gid_t gid; 92 int nogroup; 93 { 94 static struct ncache { 95 gid_t gid; 96 char name[MAXLOGNAME + 1]; 97 } c_gid[NCACHE]; 98 static int gropen; 99 static char nbuf[15]; /* 32 bits == 10 digits */ 100 struct group *gr; 101 struct ncache *cp; 102 103 cp = c_gid + (gid & MASK); 104 if (cp->gid != gid || !*cp->name) { 105 if (gropen == 0) { 106 setgroupent(1); 107 gropen = 1; 108 } 109 if ((gr = getgrgid(gid)) == NULL) { 110 if (nogroup) 111 return (NULL); 112 (void)snprintf(nbuf, sizeof(nbuf), "%u", gid); 113 return (nbuf); 114 } 115 cp->gid = gid; 116 (void)strncpy(cp->name, gr->gr_name, MAXLOGNAME); 117 cp->name[MAXLOGNAME] = '\0'; 118 } 119 return (cp->name); 120 } 121