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6e5714ea DM |
1 | #include <linux/kernel.h> |
2 | #include <linux/init.h> | |
3 | #include <linux/cryptohash.h> | |
4 | #include <linux/module.h> | |
5 | #include <linux/cache.h> | |
6 | #include <linux/random.h> | |
7 | #include <linux/hrtimer.h> | |
8 | #include <linux/ktime.h> | |
9 | #include <linux/string.h> | |
10 | ||
11 | #include <net/secure_seq.h> | |
12 | ||
13 | static u32 net_secret[MD5_MESSAGE_BYTES / 4] ____cacheline_aligned; | |
14 | ||
aebda156 | 15 | void net_secret_init(void) |
6e5714ea DM |
16 | { |
17 | get_random_bytes(net_secret, sizeof(net_secret)); | |
6e5714ea | 18 | } |
6e5714ea | 19 | |
68109090 | 20 | #ifdef CONFIG_INET |
6e5714ea DM |
21 | static u32 seq_scale(u32 seq) |
22 | { | |
23 | /* | |
24 | * As close as possible to RFC 793, which | |
25 | * suggests using a 250 kHz clock. | |
26 | * Further reading shows this assumes 2 Mb/s networks. | |
27 | * For 10 Mb/s Ethernet, a 1 MHz clock is appropriate. | |
28 | * For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but | |
29 | * we also need to limit the resolution so that the u32 seq | |
30 | * overlaps less than one time per MSL (2 minutes). | |
31 | * Choosing a clock of 64 ns period is OK. (period of 274 s) | |
32 | */ | |
33 | return seq + (ktime_to_ns(ktime_get_real()) >> 6); | |
34 | } | |
68109090 | 35 | #endif |
6e5714ea | 36 | |
dfd56b8b | 37 | #if IS_ENABLED(CONFIG_IPV6) |
cf533ea5 | 38 | __u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr, |
6e5714ea DM |
39 | __be16 sport, __be16 dport) |
40 | { | |
41 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
42 | u32 hash[MD5_DIGEST_WORDS]; | |
43 | u32 i; | |
44 | ||
45 | memcpy(hash, saddr, 16); | |
46 | for (i = 0; i < 4; i++) | |
747465ef | 47 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
48 | secret[4] = net_secret[4] + |
49 | (((__force u16)sport << 16) + (__force u16)dport); | |
50 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
51 | secret[i] = net_secret[i]; | |
52 | ||
53 | md5_transform(hash, secret); | |
54 | ||
55 | return seq_scale(hash[0]); | |
56 | } | |
57 | EXPORT_SYMBOL(secure_tcpv6_sequence_number); | |
58 | ||
59 | u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, | |
60 | __be16 dport) | |
61 | { | |
62 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
63 | u32 hash[MD5_DIGEST_WORDS]; | |
64 | u32 i; | |
65 | ||
66 | memcpy(hash, saddr, 16); | |
67 | for (i = 0; i < 4; i++) | |
68 | secret[i] = net_secret[i] + (__force u32) daddr[i]; | |
69 | secret[4] = net_secret[4] + (__force u32)dport; | |
70 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
71 | secret[i] = net_secret[i]; | |
72 | ||
73 | md5_transform(hash, secret); | |
74 | ||
75 | return hash[0]; | |
76 | } | |
58a317f1 | 77 | EXPORT_SYMBOL(secure_ipv6_port_ephemeral); |
6e5714ea DM |
78 | #endif |
79 | ||
80 | #ifdef CONFIG_INET | |
81 | __u32 secure_ip_id(__be32 daddr) | |
82 | { | |
83 | u32 hash[MD5_DIGEST_WORDS]; | |
84 | ||
85 | hash[0] = (__force __u32) daddr; | |
86 | hash[1] = net_secret[13]; | |
87 | hash[2] = net_secret[14]; | |
88 | hash[3] = net_secret[15]; | |
89 | ||
90 | md5_transform(hash, net_secret); | |
91 | ||
92 | return hash[0]; | |
93 | } | |
94 | ||
95 | __u32 secure_ipv6_id(const __be32 daddr[4]) | |
96 | { | |
97 | __u32 hash[4]; | |
98 | ||
99 | memcpy(hash, daddr, 16); | |
100 | md5_transform(hash, net_secret); | |
101 | ||
102 | return hash[0]; | |
103 | } | |
104 | ||
105 | __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, | |
106 | __be16 sport, __be16 dport) | |
107 | { | |
108 | u32 hash[MD5_DIGEST_WORDS]; | |
109 | ||
110 | hash[0] = (__force u32)saddr; | |
111 | hash[1] = (__force u32)daddr; | |
112 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
113 | hash[3] = net_secret[15]; | |
114 | ||
115 | md5_transform(hash, net_secret); | |
116 | ||
117 | return seq_scale(hash[0]); | |
118 | } | |
119 | ||
120 | u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) | |
121 | { | |
122 | u32 hash[MD5_DIGEST_WORDS]; | |
123 | ||
124 | hash[0] = (__force u32)saddr; | |
125 | hash[1] = (__force u32)daddr; | |
126 | hash[2] = (__force u32)dport ^ net_secret[14]; | |
127 | hash[3] = net_secret[15]; | |
128 | ||
129 | md5_transform(hash, net_secret); | |
130 | ||
131 | return hash[0]; | |
132 | } | |
133 | EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); | |
134 | #endif | |
135 | ||
a3bf7ae9 | 136 | #if IS_ENABLED(CONFIG_IP_DCCP) |
6e5714ea DM |
137 | u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, |
138 | __be16 sport, __be16 dport) | |
139 | { | |
140 | u32 hash[MD5_DIGEST_WORDS]; | |
141 | u64 seq; | |
142 | ||
143 | hash[0] = (__force u32)saddr; | |
144 | hash[1] = (__force u32)daddr; | |
145 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
146 | hash[3] = net_secret[15]; | |
147 | ||
148 | md5_transform(hash, net_secret); | |
149 | ||
150 | seq = hash[0] | (((u64)hash[1]) << 32); | |
151 | seq += ktime_to_ns(ktime_get_real()); | |
152 | seq &= (1ull << 48) - 1; | |
153 | ||
154 | return seq; | |
155 | } | |
156 | EXPORT_SYMBOL(secure_dccp_sequence_number); | |
157 | ||
dfd56b8b | 158 | #if IS_ENABLED(CONFIG_IPV6) |
6e5714ea DM |
159 | u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, |
160 | __be16 sport, __be16 dport) | |
161 | { | |
162 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
163 | u32 hash[MD5_DIGEST_WORDS]; | |
164 | u64 seq; | |
165 | u32 i; | |
166 | ||
167 | memcpy(hash, saddr, 16); | |
168 | for (i = 0; i < 4; i++) | |
169 | secret[i] = net_secret[i] + daddr[i]; | |
170 | secret[4] = net_secret[4] + | |
171 | (((__force u16)sport << 16) + (__force u16)dport); | |
172 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
173 | secret[i] = net_secret[i]; | |
174 | ||
175 | md5_transform(hash, secret); | |
176 | ||
177 | seq = hash[0] | (((u64)hash[1]) << 32); | |
178 | seq += ktime_to_ns(ktime_get_real()); | |
179 | seq &= (1ull << 48) - 1; | |
180 | ||
181 | return seq; | |
182 | } | |
183 | EXPORT_SYMBOL(secure_dccpv6_sequence_number); | |
184 | #endif | |
185 | #endif |