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