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 /* OPENBSD ORIGINAL: lib/libc/gen/pwcache.c */
32 
33 #include "includes.h"
34 
35 #include <sys/types.h>
36 
37 #include <grp.h>
38 #include <pwd.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 
43 #define	NCACHE	64			/* power of 2 */
44 #define	MASK	(NCACHE - 1)		/* bits to store with */
45 
46 #ifndef HAVE_USER_FROM_UID
47 char *
user_from_uid(uid_t uid,int nouser)48 user_from_uid(uid_t uid, int nouser)
49 {
50 	static struct ncache {
51 		uid_t	uid;
52 		char	*name;
53 	} c_uid[NCACHE];
54 	static int pwopen;
55 	static char nbuf[15];		/* 32 bits == 10 digits */
56 	struct passwd *pw;
57 	struct ncache *cp;
58 
59 	cp = c_uid + (uid & MASK);
60 	if (cp->uid != uid || cp->name == NULL) {
61 		if (pwopen == 0) {
62 #ifdef HAVE_SETPASSENT
63 			setpassent(1);
64 #endif
65 			pwopen = 1;
66 		}
67 		if ((pw = getpwuid(uid)) == NULL) {
68 			if (nouser)
69 				return (NULL);
70 			(void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
71 		}
72 		cp->uid = uid;
73 		if (cp->name != NULL)
74 			free(cp->name);
75 		cp->name = strdup(pw ? pw->pw_name : nbuf);
76 	}
77 	return (cp->name);
78 }
79 #endif
80 
81 #ifndef HAVE_GROUP_FROM_GID
82 char *
group_from_gid(gid_t gid,int nogroup)83 group_from_gid(gid_t gid, int nogroup)
84 {
85 	static struct ncache {
86 		gid_t	gid;
87 		char	*name;
88 	} c_gid[NCACHE];
89 	static int gropen;
90 	static char nbuf[15];		/* 32 bits == 10 digits */
91 	struct group *gr;
92 	struct ncache *cp;
93 
94 	cp = c_gid + (gid & MASK);
95 	if (cp->gid != gid || cp->name == NULL) {
96 		if (gropen == 0) {
97 #ifdef HAVE_SETGROUPENT
98 			setgroupent(1);
99 #endif
100 			gropen = 1;
101 		}
102 		if ((gr = getgrgid(gid)) == NULL) {
103 			if (nogroup)
104 				return (NULL);
105 			(void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
106 		}
107 		cp->gid = gid;
108 		if (cp->name != NULL)
109 			free(cp->name);
110 		cp->name = strdup(gr ? gr->gr_name : nbuf);
111 	}
112 	return (cp->name);
113 }
114 #endif
115