1/*	$NetBSD: memory.c,v 1.3 2022/04/03 01:10:58 christos Exp $	*/
2
3/* memory.c
4
5   Memory-resident database... */
6
7/*
8 * Copyright (C) 2004-2022 Internet Systems Consortium, Inc. ("ISC")
9 * Copyright (c) 1995-2003 by Internet Software Consortium
10 *
11 * This Source Code Form is subject to the terms of the Mozilla Public
12 * License, v. 2.0. If a copy of the MPL was not distributed with this
13 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
16 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
18 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
21 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 *
23 *   Internet Systems Consortium, Inc.
24 *   PO Box 360
25 *   Newmarket, NH 03857 USA
26 *   <info@isc.org>
27 *   https://www.isc.org/
28 *
29 */
30
31#include <sys/cdefs.h>
32__RCSID("$NetBSD: memory.c,v 1.3 2022/04/03 01:10:58 christos Exp $");
33
34#include "dhcpd.h"
35
36struct group *root_group;
37group_hash_t *group_name_hash;
38int (*group_write_hook) (struct group_object *);
39
40isc_result_t delete_group (struct group_object *group, int writep)
41{
42	struct group_object *d;
43
44	/* The group should exist and be hashed - if not, it's invalid. */
45	if (group_name_hash) {
46		d = (struct group_object *)0;
47		group_hash_lookup (&d, group_name_hash, group -> name,
48				   strlen (group -> name), MDL);
49	} else
50		return DHCP_R_INVALIDARG;
51	if (!d)
52		return DHCP_R_INVALIDARG;
53
54	/* Also not okay to delete a group that's not the one in
55	   the hash table. */
56	if (d != group)
57		return DHCP_R_INVALIDARG;
58
59	/* If it's dynamic, and we're deleting it, we can just blow away the
60	   hash table entry. */
61	if ((group -> flags & GROUP_OBJECT_DYNAMIC) &&
62	    !(group -> flags & GROUP_OBJECT_STATIC)) {
63		group_hash_delete (group_name_hash,
64				   group -> name, strlen (group -> name), MDL);
65	} else {
66		group -> flags |= GROUP_OBJECT_DELETED;
67		if (group -> group)
68			group_dereference (&group -> group, MDL);
69	}
70
71	/* Store the group declaration in the lease file. */
72	if (writep && group_write_hook) {
73		if (!(*group_write_hook) (group))
74			return ISC_R_IOERROR;
75	}
76	return ISC_R_SUCCESS;
77}
78
79isc_result_t supersede_group (struct group_object *group, int writep)
80{
81	struct group_object *t;
82
83	/* Register the group in the group name hash table,
84	   so we can look it up later. */
85	if (group_name_hash) {
86		t = (struct group_object *)0;
87		group_hash_lookup (&t, group_name_hash,
88			group -> name,
89			     strlen (group -> name), MDL);
90		if (t && t != group) {
91			/* If this isn't a dynamic entry, then we need to flag
92			   the replacement as not dynamic either - otherwise,
93			   if the dynamic entry is deleted later, the static
94			   entry will come back next time the server is stopped
95			   and restarted. */
96			if (!(t -> flags & GROUP_OBJECT_DYNAMIC))
97				group -> flags |= GROUP_OBJECT_STATIC;
98
99			/* Delete the old object if it hasn't already been
100			   deleted.  If it has already been deleted, get rid of
101			   the hash table entry.  This is a legitimate
102			   situation - a deleted static object needs to be kept
103			   around so we remember it's deleted. */
104			if (!(t -> flags & GROUP_OBJECT_DELETED))
105				delete_group (t, 0);
106			else {
107				group_hash_delete (group_name_hash,
108						   group -> name,
109						   strlen (group -> name),
110						   MDL);
111				group_object_dereference (&t, MDL);
112			}
113		}
114	} else {
115		group_new_hash(&group_name_hash, GROUP_HASH_SIZE, MDL);
116		t = (struct group_object *)0;
117	}
118
119	/* Add the group to the group name hash if it's not
120	   already there, and also thread it into the list of
121	   dynamic groups if appropriate. */
122	if (!t) {
123		group_hash_add (group_name_hash, group -> name,
124				strlen (group -> name), group, MDL);
125	}
126
127	/* Store the group declaration in the lease file. */
128	if (writep && group_write_hook) {
129		if (!(*group_write_hook) (group))
130			return ISC_R_IOERROR;
131	}
132	return ISC_R_SUCCESS;
133}
134
135int clone_group (struct group **gp, struct group *group,
136		 const char *file, int line)
137{
138	struct group *g = (struct group *)0;
139
140	/* Normally gp should contain the null pointer, but for convenience
141	   it's permissible to clone a group into itself. */
142	if (*gp && *gp != group)
143		return 0;
144	if (!group_allocate (&g, file, line))
145		return 0;
146	if (group == *gp)
147		*gp = (struct group *)0;
148	group_reference (gp, g, file, line);
149	g -> authoritative = group -> authoritative;
150	group_reference (&g -> next, group, file, line);
151	group_dereference (&g, file, line);
152	return 1;
153}
154