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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> | |
e34c9a69 | 10 | #include <linux/net.h> |
6e5714ea DM |
11 | |
12 | #include <net/secure_seq.h> | |
13 | ||
cb03db9d | 14 | #if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET) |
9a3bab6b | 15 | #define NET_SECRET_SIZE (MD5_MESSAGE_BYTES / 4) |
6e5714ea | 16 | |
9a3bab6b ED |
17 | static u32 net_secret[NET_SECRET_SIZE] ____cacheline_aligned; |
18 | ||
34d92d53 | 19 | static __always_inline void net_secret_init(void) |
6e5714ea | 20 | { |
e34c9a69 | 21 | net_get_random_once(net_secret, sizeof(net_secret)); |
6e5714ea | 22 | } |
cb03db9d | 23 | #endif |
6e5714ea | 24 | |
68109090 | 25 | #ifdef CONFIG_INET |
6e5714ea DM |
26 | static u32 seq_scale(u32 seq) |
27 | { | |
28 | /* | |
29 | * As close as possible to RFC 793, which | |
30 | * suggests using a 250 kHz clock. | |
31 | * Further reading shows this assumes 2 Mb/s networks. | |
32 | * For 10 Mb/s Ethernet, a 1 MHz clock is appropriate. | |
33 | * For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but | |
34 | * we also need to limit the resolution so that the u32 seq | |
35 | * overlaps less than one time per MSL (2 minutes). | |
36 | * Choosing a clock of 64 ns period is OK. (period of 274 s) | |
37 | */ | |
d2de875c | 38 | return seq + (ktime_get_real_ns() >> 6); |
6e5714ea | 39 | } |
68109090 | 40 | #endif |
6e5714ea | 41 | |
dfd56b8b | 42 | #if IS_ENABLED(CONFIG_IPV6) |
cf533ea5 | 43 | __u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr, |
6e5714ea DM |
44 | __be16 sport, __be16 dport) |
45 | { | |
46 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
47 | u32 hash[MD5_DIGEST_WORDS]; | |
48 | u32 i; | |
49 | ||
9a3bab6b | 50 | net_secret_init(); |
6e5714ea DM |
51 | memcpy(hash, saddr, 16); |
52 | for (i = 0; i < 4; i++) | |
747465ef | 53 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
54 | secret[4] = net_secret[4] + |
55 | (((__force u16)sport << 16) + (__force u16)dport); | |
56 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
57 | secret[i] = net_secret[i]; | |
58 | ||
59 | md5_transform(hash, secret); | |
60 | ||
61 | return seq_scale(hash[0]); | |
62 | } | |
63 | EXPORT_SYMBOL(secure_tcpv6_sequence_number); | |
64 | ||
65 | u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, | |
66 | __be16 dport) | |
67 | { | |
68 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
69 | u32 hash[MD5_DIGEST_WORDS]; | |
70 | u32 i; | |
71 | ||
9a3bab6b | 72 | net_secret_init(); |
6e5714ea DM |
73 | memcpy(hash, saddr, 16); |
74 | for (i = 0; i < 4; i++) | |
75 | secret[i] = net_secret[i] + (__force u32) daddr[i]; | |
76 | secret[4] = net_secret[4] + (__force u32)dport; | |
77 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
78 | secret[i] = net_secret[i]; | |
79 | ||
80 | md5_transform(hash, secret); | |
81 | ||
82 | return hash[0]; | |
83 | } | |
58a317f1 | 84 | EXPORT_SYMBOL(secure_ipv6_port_ephemeral); |
6e5714ea DM |
85 | #endif |
86 | ||
87 | #ifdef CONFIG_INET | |
6e5714ea DM |
88 | |
89 | __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, | |
90 | __be16 sport, __be16 dport) | |
91 | { | |
92 | u32 hash[MD5_DIGEST_WORDS]; | |
93 | ||
9a3bab6b | 94 | net_secret_init(); |
6e5714ea DM |
95 | hash[0] = (__force u32)saddr; |
96 | hash[1] = (__force u32)daddr; | |
97 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
98 | hash[3] = net_secret[15]; | |
99 | ||
100 | md5_transform(hash, net_secret); | |
101 | ||
102 | return seq_scale(hash[0]); | |
103 | } | |
104 | ||
105 | u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) | |
106 | { | |
107 | u32 hash[MD5_DIGEST_WORDS]; | |
108 | ||
9a3bab6b | 109 | net_secret_init(); |
6e5714ea DM |
110 | hash[0] = (__force u32)saddr; |
111 | hash[1] = (__force u32)daddr; | |
112 | hash[2] = (__force u32)dport ^ net_secret[14]; | |
113 | hash[3] = net_secret[15]; | |
114 | ||
115 | md5_transform(hash, net_secret); | |
116 | ||
117 | return hash[0]; | |
118 | } | |
119 | EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); | |
120 | #endif | |
121 | ||
a3bf7ae9 | 122 | #if IS_ENABLED(CONFIG_IP_DCCP) |
6e5714ea DM |
123 | u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, |
124 | __be16 sport, __be16 dport) | |
125 | { | |
126 | u32 hash[MD5_DIGEST_WORDS]; | |
127 | u64 seq; | |
128 | ||
9a3bab6b | 129 | net_secret_init(); |
6e5714ea DM |
130 | hash[0] = (__force u32)saddr; |
131 | hash[1] = (__force u32)daddr; | |
132 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
133 | hash[3] = net_secret[15]; | |
134 | ||
135 | md5_transform(hash, net_secret); | |
136 | ||
137 | seq = hash[0] | (((u64)hash[1]) << 32); | |
d2de875c | 138 | seq += ktime_get_real_ns(); |
6e5714ea DM |
139 | seq &= (1ull << 48) - 1; |
140 | ||
141 | return seq; | |
142 | } | |
143 | EXPORT_SYMBOL(secure_dccp_sequence_number); | |
144 | ||
dfd56b8b | 145 | #if IS_ENABLED(CONFIG_IPV6) |
6e5714ea DM |
146 | u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, |
147 | __be16 sport, __be16 dport) | |
148 | { | |
149 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
150 | u32 hash[MD5_DIGEST_WORDS]; | |
151 | u64 seq; | |
152 | u32 i; | |
153 | ||
9a3bab6b | 154 | net_secret_init(); |
6e5714ea DM |
155 | memcpy(hash, saddr, 16); |
156 | for (i = 0; i < 4; i++) | |
68319052 | 157 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
158 | secret[4] = net_secret[4] + |
159 | (((__force u16)sport << 16) + (__force u16)dport); | |
160 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
161 | secret[i] = net_secret[i]; | |
162 | ||
163 | md5_transform(hash, secret); | |
164 | ||
165 | seq = hash[0] | (((u64)hash[1]) << 32); | |
d2de875c | 166 | seq += ktime_get_real_ns(); |
6e5714ea DM |
167 | seq &= (1ull << 48) - 1; |
168 | ||
169 | return seq; | |
170 | } | |
171 | EXPORT_SYMBOL(secure_dccpv6_sequence_number); | |
172 | #endif | |
173 | #endif |