xref: /freebsd/lib/libc/posix1e/acl_id_to_name.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1999-2001, 2008 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 /*
29  * Support functionality for the POSIX.1e ACL interface
30  * These calls are intended only to be called within the library.
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/types.h>
37 #include "namespace.h"
38 #include <sys/acl.h>
39 #include "un-namespace.h"
40 #include <errno.h>
41 #include <grp.h>
42 #include <pwd.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <assert.h>
47 
48 #include "acl_support.h"
49 
50 /*
51  * Given a uid/gid, return a username/groupname for the text form of an ACL.
52  * Note that we truncate user and group names, rather than error out, as
53  * this is consistent with other tools manipulating user and group names.
54  * XXX NOT THREAD SAFE, RELIES ON GETPWUID, GETGRGID
55  * XXX USES *PW* AND *GR* WHICH ARE STATEFUL AND THEREFORE THIS ROUTINE
56  * MAY HAVE SIDE-EFFECTS
57  */
58 int
59 _posix1e_acl_id_to_name(acl_tag_t tag, uid_t id, ssize_t buf_len, char *buf,
60     int flags)
61 {
62 	struct group	*g;
63 	struct passwd	*p;
64 	int	i;
65 
66 	switch(tag) {
67 	case ACL_USER:
68 		if (flags & ACL_TEXT_NUMERIC_IDS)
69 			p = NULL;
70 		else
71 			p = getpwuid(id);
72 		if (!p)
73 			i = snprintf(buf, buf_len, "%d", id);
74 		else
75 			i = snprintf(buf, buf_len, "%s", p->pw_name);
76 
77 		if (i < 0) {
78 			errno = ENOMEM;
79 			return (-1);
80 		}
81 		return (0);
82 
83 	case ACL_GROUP:
84 		if (flags & ACL_TEXT_NUMERIC_IDS)
85 			g = NULL;
86 		else
87 			g = getgrgid(id);
88 		if (g == NULL)
89 			i = snprintf(buf, buf_len, "%d", id);
90 		else
91 			i = snprintf(buf, buf_len, "%s", g->gr_name);
92 
93 		if (i < 0) {
94 			errno = ENOMEM;
95 			return (-1);
96 		}
97 		return (0);
98 
99 	default:
100 		return (EINVAL);
101 	}
102 }
103