1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2001-2002 Chris D. Faulhaber
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#include <sys/cdefs.h>
30#if 0
31__FBSDID("$FreeBSD: head/lib/libc/posix1e/acl_delete_entry.c 326193 2017-11-25 17:12:48Z pfg $");
32#else
33__RCSID("$NetBSD: acl_delete_entry.c,v 1.1 2020/05/16 18:31:47 christos Exp $");
34#endif
35
36#include "namespace.h"
37#include <sys/types.h>
38#include <sys/acl.h>
39#include <errno.h>
40#include <string.h>
41#include <stdio.h>
42
43#include "acl_support.h"
44
45static int
46_entry_matches(const acl_entry_t a, const acl_entry_t b)
47{
48	/*
49	 * There is a semantical difference here between NFSv4 and POSIX
50	 * draft ACLs.  In POSIX, there may be only one entry for the particular
51	 * user or group.  In NFSv4 ACL, there may be any number of them.  We're
52	 * trying to be more specific here in that case.
53	 */
54	switch (_entry_brand(a)) {
55	case ACL_BRAND_NFS4:
56		if (a->ae_tag != b->ae_tag || a->ae_entry_type != b->ae_entry_type)
57			return (0);
58
59		/* If ae_ids matter, compare them as well. */
60		if (a->ae_tag == ACL_USER || a->ae_tag == ACL_GROUP) {
61			if (a->ae_id != b->ae_id)
62				return (0);
63		}
64
65		return (1);
66
67	default:
68		if ((a->ae_tag == b->ae_tag) && (a->ae_id == b->ae_id))
69			return (1);
70	}
71
72	return (0);
73}
74
75/*
76 * acl_delete_entry() (23.4.9): remove the ACL entry indicated by entry_d
77 * from acl.
78 */
79int
80acl_delete_entry(acl_t acl, acl_entry_t entry_d)
81{
82	struct acl_entry entry_int;
83	size_t i, j;
84	int found = 0;
85
86	if (acl == NULL || entry_d == NULL) {
87		errno = EINVAL;
88		return (-1);
89	}
90
91	if (_entry_brand(entry_d) != _acl_brand(acl)) {
92		errno = EINVAL;
93		return (-1);
94	}
95
96	if ((acl->ats_acl.acl_cnt < 1) ||
97	    (acl->ats_acl.acl_cnt > ACL_MAX_ENTRIES)) {
98		errno = EINVAL;
99		return (-1);
100	}
101
102	/* Use a local copy to prevent deletion of more than this entry */
103	entry_int = *entry_d;
104
105	for (i = 0; i < acl->ats_acl.acl_cnt;) {
106		if (_entry_matches(&(acl->ats_acl.acl_entry[i]), &entry_int)) {
107			/* ...shift the remaining entries... */
108			for (j = i; j < acl->ats_acl.acl_cnt - 1; ++j)
109				acl->ats_acl.acl_entry[j] =
110				    acl->ats_acl.acl_entry[j+1];
111			/* ...drop the count and zero the unused entry... */
112			acl->ats_acl.acl_cnt--;
113			bzero(&acl->ats_acl.acl_entry[j],
114			    sizeof(struct acl_entry));
115			acl->ats_cur_entry = 0;
116
117			/* Continue with the loop to remove all matching entries. */
118			found = 1;
119		} else
120			i++;
121	}
122
123	if (found)
124		return (0);
125
126	errno = EINVAL;
127	return (-1);
128}
129
130int
131acl_delete_entry_np(acl_t acl, int offset)
132{
133	struct acl *acl_int;
134	size_t i;
135
136	if (acl == NULL) {
137		errno = EINVAL;
138		return (-1);
139	}
140
141	acl_int = &acl->ats_acl;
142
143	if (offset < 0 || (size_t)offset >= acl_int->acl_cnt) {
144		errno = EINVAL;
145		return (-1);
146	}
147
148	if ((acl->ats_acl.acl_cnt < 1) ||
149	    (acl->ats_acl.acl_cnt > ACL_MAX_ENTRIES)) {
150		errno = EINVAL;
151		return (-1);
152	}
153
154	/* ...shift the remaining entries... */
155	for (i = offset; i < acl->ats_acl.acl_cnt - 1; ++i)
156		acl->ats_acl.acl_entry[i] =
157		    acl->ats_acl.acl_entry[i+1];
158	/* ...drop the count and zero the unused entry... */
159	acl->ats_acl.acl_cnt--;
160	bzero(&acl->ats_acl.acl_entry[i],
161	    sizeof(struct acl_entry));
162	acl->ats_cur_entry = 0;
163
164	return (0);
165}
166