1 | /* |
2 | * Copyright (c) 2009-2024 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 | |
29 | /*- |
30 | * Copyright (C) 2003 WIDE Project. |
31 | * All rights reserved. |
32 | * |
33 | * Redistribution and use in source and binary forms, with or without |
34 | * modification, are permitted provided that the following conditions |
35 | * are met: |
36 | * 1. Redistributions of source code must retain the above copyright |
37 | * notice, this list of conditions and the following disclaimer. |
38 | * 2. Redistributions in binary form must reproduce the above copyright |
39 | * notice, this list of conditions and the following disclaimer in the |
40 | * documentation and/or other materials provided with the distribution. |
41 | * 3. Neither the name of the project nor the names of its contributors |
42 | * may be used to endorse or promote products derived from this software |
43 | * without specific prior written permission. |
44 | * |
45 | * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND |
46 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
47 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
48 | * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE |
49 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
50 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
51 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
52 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
53 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
54 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
55 | * SUCH DAMAGE. |
56 | */ |
57 | |
58 | /*- |
59 | * Copyright 1998 Niels Provos <provos@citi.umich.edu> |
60 | * All rights reserved. |
61 | * |
62 | * Theo de Raadt <deraadt@openbsd.org> came up with the idea of using |
63 | * such a mathematical system to generate more random (yet non-repeating) |
64 | * ids to solve the resolver/named problem. But Niels designed the |
65 | * actual system based on the constraints. |
66 | * |
67 | * Redistribution and use in source and binary forms, with or without |
68 | * modification, are permitted provided that the following conditions |
69 | * are met: |
70 | * 1. Redistributions of source code must retain the above copyright |
71 | * notice, this list of conditions and the following disclaimer. |
72 | * 2. Redistributions in binary form must reproduce the above copyright |
73 | * notice, this list of conditions and the following disclaimer in the |
74 | * documentation and/or other materials provided with the distribution. |
75 | * 3. All advertising materials mentioning features or use of this software |
76 | * must display the following acknowledgement: |
77 | * This product includes software developed by Niels Provos. |
78 | * 4. The name of the author may not be used to endorse or promote products |
79 | * derived from this software without specific prior written permission. |
80 | * |
81 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
82 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
83 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
84 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
85 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
86 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
87 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
88 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
89 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
90 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
91 | */ |
92 | |
93 | #include <sys/cdefs.h> |
94 | |
95 | #include <sys/mcache.h> |
96 | #include <sys/types.h> |
97 | #include <sys/param.h> |
98 | #include <sys/kernel.h> |
99 | #include <libkern/libkern.h> |
100 | #include <dev/random/randomdev.h> |
101 | |
102 | #include <netinet/ip6.h> |
103 | #include <netinet6/ip6_var.h> |
104 | |
105 | uint32_t |
106 | ip6_randomid(uint64_t salt) |
107 | { |
108 | uint32_t new_id; |
109 | /* |
110 | * Mostly the salt value is heap or stack pointer value. |
111 | * To avoid any chance of leaking address apply macro that |
112 | * adds per-boot random number to it. |
113 | */ |
114 | uint64_t salt_tmp = VM_KERNEL_ADDRPERM(salt); |
115 | VERIFY(salt_tmp != 0); |
116 | |
117 | /* |
118 | * When the passed salt values are addresses, it is possible some bits |
119 | * to not change at all, for example some higher order bits may not change |
120 | * and some lower order bits may be all 0s given particular alignment and object |
121 | * sizes. |
122 | * Therefore we compute a XOR'd 16bit value by considering all the bits |
123 | * of the salt to increase the likelihood of it being different. |
124 | */ |
125 | uint32_t new_id_salt = (uint32_t)(((salt_tmp >> 48) ^ (salt_tmp >> 32) ^ |
126 | (salt_tmp >> 16) ^ salt_tmp) & 0xFF); |
127 | |
128 | /* Avoid returning IP ID value of 0 */ |
129 | do { |
130 | read_random(buffer: &new_id, numBytes: sizeof(new_id)); |
131 | } while (new_id == new_id_salt); |
132 | |
133 | return new_id ^ new_id_salt; |
134 | } |
135 | |
136 | uint32_t |
137 | ip6_randomflowlabel(void) |
138 | { |
139 | return RandomULong() & IPV6_FLOWLABEL_MASK; |
140 | } |
141 | |