1 /* $OpenBSD: pwcache.c,v 1.9 2005/08/08 08:05:34 espie Exp $ */ 2 /* 3 * Copyright (c) 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 33 #include <grp.h> 34 #include <pwd.h> 35 #include <stdio.h> 36 #include <string.h> 37 38 #define NCACHE 64 /* power of 2 */ 39 #define MASK (NCACHE - 1) /* bits to store with */ 40 41 char * 42 user_from_uid(uid_t uid, int nouser) 43 { 44 static struct ncache { 45 uid_t uid; 46 char name[_PW_NAME_LEN + 1]; 47 } c_uid[NCACHE]; 48 static int pwopen; 49 static char nbuf[15]; /* 32 bits == 10 digits */ 50 struct passwd *pw; 51 struct ncache *cp; 52 53 cp = c_uid + (uid & MASK); 54 if (cp->uid != uid || !*cp->name) { 55 if (pwopen == 0) { 56 setpassent(1); 57 pwopen = 1; 58 } 59 if ((pw = getpwuid(uid)) == NULL) { 60 if (nouser) 61 return (NULL); 62 (void)snprintf(nbuf, sizeof(nbuf), "%u", uid); 63 return (nbuf); 64 } 65 cp->uid = uid; 66 strlcpy(cp->name, pw->pw_name, sizeof(cp->name)); 67 } 68 return (cp->name); 69 } 70 71 char * 72 group_from_gid(gid_t gid, int nogroup) 73 { 74 static struct ncache { 75 gid_t gid; 76 char name[_PW_NAME_LEN + 1]; 77 } c_gid[NCACHE]; 78 static int gropen; 79 static char nbuf[15]; /* 32 bits == 10 digits */ 80 struct group *gr; 81 struct ncache *cp; 82 83 cp = c_gid + (gid & MASK); 84 if (cp->gid != gid || !*cp->name) { 85 if (gropen == 0) { 86 setgroupent(1); 87 gropen = 1; 88 } 89 if ((gr = getgrgid(gid)) == NULL) { 90 if (nogroup) 91 return (NULL); 92 (void)snprintf(nbuf, sizeof(nbuf), "%u", gid); 93 return (nbuf); 94 } 95 cp->gid = gid; 96 strlcpy(cp->name, gr->gr_name, sizeof(cp->name)); 97 } 98 return (cp->name); 99 } 100