xref: /netbsd-src/lib/libc/gen/pwcache.c (revision ce63d6c20fc4ec8ddc95c84bb229e3c4ecf82b69)
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[] = "@(#)pwcache.c	5.4 (Berkeley) 6/1/90";
36 #endif /* LIBC_SCCS and not lint */
37 
38 #include <sys/types.h>
39 #include <utmp.h>
40 #include <pwd.h>
41 #include <grp.h>
42 #include <stdio.h>
43 
44 #define	NCACHE	64			/* power of 2 */
45 #define	MASK	NCACHE - 1		/* bits to store with */
46 
47 static	int pwopen = 0;
48 static	int gropen = 0;
49 
50 char *
51 user_from_uid(uid, nouser)
52 	uid_t uid;
53 	int nouser;
54 {
55 	static struct ncache {
56 		uid_t	uid;
57 		char	name[UT_NAMESIZE + 1];
58 	} c_uid[NCACHE];
59 	static char nbuf[15];		/* 32 bits == 10 digits */
60 	register struct passwd *pw;
61 	register struct ncache *cp;
62 
63 	cp = c_uid + (uid & MASK);
64 	if (cp->uid != uid || !*cp->name) {
65 		if (pwopen == 0) {
66 			setpassent(1);
67 			pwopen++;
68 		}
69 		if (!(pw = getpwuid(uid))) {
70 			if (nouser)
71 				return((char *)NULL);
72 			(void)sprintf(nbuf, "%u", uid);
73 			return(nbuf);
74 		}
75 		cp->uid = uid;
76 		(void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
77 		cp->name[UT_NAMESIZE] = '\0';
78 	}
79 	return(cp->name);
80 }
81 
82 char *
83 group_from_gid(gid, nogroup)
84 	gid_t gid;
85 	int nogroup;
86 {
87 	static struct ncache {
88 		gid_t	gid;
89 		char	name[UT_NAMESIZE];
90 	} c_gid[NCACHE];
91 	static char nbuf[15];		/* 32 bits == 10 digits */
92 	register struct group *gr;
93 	register 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++;
100 		}
101 		if (!(gr = getgrgid(gid))) {
102 			if (nogroup)
103 				return((char *)NULL);
104 			(void)sprintf(nbuf, "%u", gid);
105 			return(nbuf);
106 		}
107 		cp->gid = gid;
108 		(void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
109 		cp->name[UT_NAMESIZE] = '\0';
110 	}
111 	return(cp->name);
112 }
113