xref: /netbsd-src/lib/libc/gen/pwcache.c (revision d9158b13b5dfe46201430699a3f7a235ecf28df3)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * 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 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 /*static char sccsid[] = "from: @(#)pwcache.c	5.4 (Berkeley) 6/1/90";*/
36 static char rcsid[] = "$Id: pwcache.c,v 1.3 1994/01/19 21:15:46 jtc Exp $";
37 #endif /* LIBC_SCCS and not lint */
38 
39 #include <sys/types.h>
40 #include <utmp.h>
41 #include <pwd.h>
42 #include <grp.h>
43 #include <stdio.h>
44 
45 #define	NCACHE	64			/* power of 2 */
46 #define	MASK	NCACHE - 1		/* bits to store with */
47 
48 static	int pwopen = 0;
49 static	int gropen = 0;
50 
51 char *
52 user_from_uid(uid, nouser)
53 	uid_t uid;
54 	int nouser;
55 {
56 	static struct ncache {
57 		uid_t	uid;
58 		char	name[UT_NAMESIZE + 1];
59 	} c_uid[NCACHE];
60 	static char nbuf[15];		/* 32 bits == 10 digits */
61 	register struct passwd *pw;
62 	register struct ncache *cp;
63 
64 	cp = c_uid + (uid & MASK);
65 	if (cp->uid != uid || !*cp->name) {
66 		if (pwopen == 0) {
67 			setpassent(1);
68 			pwopen++;
69 		}
70 		if (!(pw = getpwuid(uid))) {
71 			if (nouser)
72 				return((char *)NULL);
73 			(void)sprintf(nbuf, "%u", uid);
74 			return(nbuf);
75 		}
76 		cp->uid = uid;
77 		(void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
78 		cp->name[UT_NAMESIZE] = '\0';
79 	}
80 	return(cp->name);
81 }
82 
83 char *
84 group_from_gid(gid, nogroup)
85 	gid_t gid;
86 	int nogroup;
87 {
88 	static struct ncache {
89 		gid_t	gid;
90 		char	name[UT_NAMESIZE + 1];
91 	} c_gid[NCACHE];
92 	static char nbuf[15];		/* 32 bits == 10 digits */
93 	register struct group *gr;
94 	register struct ncache *cp;
95 
96 	cp = c_gid + (gid & MASK);
97 	if (cp->gid != gid || !*cp->name) {
98 		if (gropen == 0) {
99 			setgroupent(1);
100 			gropen++;
101 		}
102 		if (!(gr = getgrgid(gid))) {
103 			if (nogroup)
104 				return((char *)NULL);
105 			(void)sprintf(nbuf, "%u", gid);
106 			return(nbuf);
107 		}
108 		cp->gid = gid;
109 		(void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
110 		cp->name[UT_NAMESIZE] = '\0';
111 	}
112 	return(cp->name);
113 }
114