1 /*
2 * Copyright (c) 2020 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 #include <kern/zalloc.h>
29 #include <net/if.h>
30 #include <net/if_var.h>
31 #include <netinet/in.h>
32 #include <netinet6/in6_var.h>
33 #include <netinet6/in6_ifattach.h>
34 #include <netinet/ip6.h>
35 #include <netinet6/ip6_var.h>
36 #include <netinet6/nd6.h>
37 #include <netinet6/scope6_var.h>
38 #include <sys/mcache.h>
39
40 #define NDRTI_ZONE_NAME "nd6_route_info" /* zone name */
41
42 static struct nd_route_info *nd6_rti_lookup(struct nd_route_info *);
43
44 static ZONE_DEFINE(ndrti_zone, "nd6_route_info",
45 sizeof(struct nd_route_info), ZC_ZFREE_CLEARMEM);
46
47 static boolean_t nd6_rti_list_busy = FALSE; /* protected by nd6_mutex */
48
49
50 void
nd6_rti_list_wait(const char * func)51 nd6_rti_list_wait(const char *func)
52 {
53 LCK_MTX_ASSERT(nd6_mutex, LCK_MTX_ASSERT_OWNED);
54 while (nd6_rti_list_busy) {
55 nd6log2(debug, "%s: someone else is operating "
56 "on rti list. Entering sleep.\n", func);
57 (void) msleep(&nd6_rti_list_busy, nd6_mutex, (PZERO - 1),
58 func, NULL);
59 LCK_MTX_ASSERT(nd6_mutex, LCK_MTX_ASSERT_OWNED);
60 }
61 nd6_rti_list_busy = TRUE;
62 }
63
64 void
nd6_rti_list_signal_done(void)65 nd6_rti_list_signal_done(void)
66 {
67 LCK_MTX_ASSERT(nd6_mutex, LCK_MTX_ASSERT_OWNED);
68 nd6_rti_list_busy = FALSE;
69 wakeup(&nd6_rti_list_busy);
70 }
71
72 struct nd_route_info *
ndrti_alloc(void)73 ndrti_alloc(void)
74 {
75 return zalloc_flags(ndrti_zone, Z_WAITOK | Z_ZERO);
76 }
77
78 void
ndrti_free(struct nd_route_info * rti)79 ndrti_free(struct nd_route_info *rti)
80 {
81 if (!TAILQ_EMPTY(&rti->nd_rti_router_list)) {
82 panic("%s: rti freed with non-empty router list", __func__);
83 }
84 zfree(ndrti_zone, rti);
85 }
86
87 static struct nd_route_info *
nd6_rti_lookup(struct nd_route_info * rti)88 nd6_rti_lookup(struct nd_route_info *rti)
89 {
90 struct nd_route_info *tmp_rti = NULL;
91
92 LCK_MTX_ASSERT(nd6_mutex, LCK_MTX_ASSERT_OWNED);
93
94 TAILQ_FOREACH(tmp_rti, &nd_rti_list, nd_rti_entry) {
95 if (IN6_ARE_ADDR_EQUAL(&tmp_rti->nd_rti_prefix, &rti->nd_rti_prefix) &&
96 tmp_rti->nd_rti_prefixlen == rti->nd_rti_prefixlen) {
97 break;
98 }
99 }
100 return tmp_rti;
101 }
102
103 void
nd6_rtilist_update(struct nd_route_info * new_rti,struct nd_defrouter * dr)104 nd6_rtilist_update(struct nd_route_info *new_rti, struct nd_defrouter *dr)
105 {
106 struct nd_route_info *rti = NULL;
107
108 lck_mtx_lock(nd6_mutex);
109 VERIFY(new_rti != NULL && dr != NULL);
110 nd6_rti_list_wait(__func__);
111
112 if ((rti = nd6_rti_lookup(new_rti)) != NULL) {
113 (void)defrtrlist_update(dr, &rti->nd_rti_router_list);
114 /*
115 * The above may have removed an entry from default router list.
116 * If it did and the list is now empty, remove the rti as well.
117 */
118 if (TAILQ_EMPTY(&rti->nd_rti_router_list)) {
119 TAILQ_REMOVE(&nd_rti_list, rti, nd_rti_entry);
120 ndrti_free(rti);
121 }
122 } else if (dr->rtlifetime != 0) {
123 rti = ndrti_alloc();
124 TAILQ_INIT(&rti->nd_rti_router_list);
125 rti->nd_rti_prefix = new_rti->nd_rti_prefix;
126 rti->nd_rti_prefixlen = new_rti->nd_rti_prefixlen;
127 (void)defrtrlist_update(dr, &rti->nd_rti_router_list);
128 TAILQ_INSERT_HEAD(&nd_rti_list, rti, nd_rti_entry);
129 }
130 /* If rti doesn't exist and lifetime is 0, simply ignore */
131 nd6_rti_list_signal_done();
132 lck_mtx_unlock(nd6_mutex);
133 }
134
135 void
nd6_rti_purge(struct nd_route_info * new_rti)136 nd6_rti_purge(struct nd_route_info *new_rti)
137 {
138 VERIFY(new_rti != NULL);
139 LCK_MTX_ASSERT(nd6_mutex, LCK_MTX_ASSERT_OWNED);
140
141 struct nd_route_info *rti = NULL;
142 nd6_rti_list_wait(__func__);
143
144 if ((rti = nd6_rti_lookup(new_rti)) != NULL) {
145 struct nd_defrouter *dr = NULL;
146 struct nd_defrouter *ndr = NULL;
147
148 TAILQ_FOREACH_SAFE(dr, &rti->nd_rti_router_list, dr_entry, ndr) {
149 TAILQ_REMOVE(&rti->nd_rti_router_list, dr, dr_entry);
150 defrtrlist_del(dr, &rti->nd_rti_router_list);
151 NDDR_REMREF(dr);
152 }
153 TAILQ_REMOVE(&nd_rti_list, rti, nd_rti_entry);
154 ndrti_free(rti);
155 }
156 nd6_rti_list_signal_done();
157 }
158