1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)pwcache.c 8.1 (Berkeley) 6/4/93 34 * $FreeBSD: src/lib/libc/gen/pwcache.c,v 1.10 2002/03/22 02:35:47 imp Exp $ 35 * $DragonFly: src/lib/libc/gen/pwcache.c,v 1.5 2005/11/13 00:07:42 swildner Exp $ 36 */ 37 38 #include <sys/types.h> 39 40 #include <grp.h> 41 #include <pwd.h> 42 #include <stdio.h> 43 #include <string.h> 44 #include <utmp.h> 45 46 #define NCACHE 64 /* power of 2 */ 47 #define MASK (NCACHE - 1) /* bits to store with */ 48 49 const char * 50 user_from_uid(uid_t uid, int nouser) 51 { 52 static struct ncache { 53 uid_t uid; 54 int found; 55 char name[UT_NAMESIZE + 1]; 56 } c_uid[NCACHE]; 57 static int pwopen; 58 struct passwd *pw; 59 struct ncache *cp; 60 61 cp = c_uid + (uid & MASK); 62 if (cp->uid != uid || !*cp->name) { 63 if (pwopen == 0) { 64 setpassent(1); 65 pwopen = 1; 66 } 67 pw = getpwuid(uid); 68 cp->uid = uid; 69 if (pw != NULL) { 70 cp->found = 1; 71 strncpy(cp->name, pw->pw_name, UT_NAMESIZE); 72 cp->name[UT_NAMESIZE] = '\0'; 73 } else { 74 cp->found = 0; 75 snprintf(cp->name, UT_NAMESIZE, "%u", uid); 76 if (nouser) 77 return (NULL); 78 } 79 } 80 return ((nouser && !cp->found) ? NULL : cp->name); 81 } 82 83 const char * 84 group_from_gid(gid_t gid, int nogroup) 85 { 86 static struct ncache { 87 gid_t gid; 88 int found; 89 char name[UT_NAMESIZE + 1]; 90 } c_gid[NCACHE]; 91 static int gropen; 92 struct group *gr; 93 struct ncache *cp; 94 95 cp = c_gid + (gid & MASK); 96 if (cp->gid != gid || !*cp->name) { 97 if (gropen == 0) { 98 setgroupent(1); 99 gropen = 1; 100 } 101 gr = getgrgid(gid); 102 cp->gid = gid; 103 if (gr != NULL) { 104 cp->found = 1; 105 strncpy(cp->name, gr->gr_name, UT_NAMESIZE); 106 cp->name[UT_NAMESIZE] = '\0'; 107 } else { 108 cp->found = 0; 109 snprintf(cp->name, UT_NAMESIZE, "%u", gid); 110 if (nogroup) 111 return (NULL); 112 } 113 } 114 return ((nogroup && !cp->found) ? NULL : cp->name); 115 } 116