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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) |
25429d7b | 15 | #include <net/tcp.h> |
9a3bab6b | 16 | #define NET_SECRET_SIZE (MD5_MESSAGE_BYTES / 4) |
6e5714ea | 17 | |
9a3bab6b ED |
18 | static u32 net_secret[NET_SECRET_SIZE] ____cacheline_aligned; |
19 | ||
34d92d53 | 20 | static __always_inline void net_secret_init(void) |
6e5714ea | 21 | { |
e34c9a69 | 22 | net_get_random_once(net_secret, sizeof(net_secret)); |
6e5714ea | 23 | } |
cb03db9d | 24 | #endif |
6e5714ea | 25 | |
68109090 | 26 | #ifdef CONFIG_INET |
6e5714ea DM |
27 | static u32 seq_scale(u32 seq) |
28 | { | |
29 | /* | |
30 | * As close as possible to RFC 793, which | |
31 | * suggests using a 250 kHz clock. | |
32 | * Further reading shows this assumes 2 Mb/s networks. | |
33 | * For 10 Mb/s Ethernet, a 1 MHz clock is appropriate. | |
34 | * For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but | |
35 | * we also need to limit the resolution so that the u32 seq | |
36 | * overlaps less than one time per MSL (2 minutes). | |
37 | * Choosing a clock of 64 ns period is OK. (period of 274 s) | |
38 | */ | |
d2de875c | 39 | return seq + (ktime_get_real_ns() >> 6); |
6e5714ea | 40 | } |
68109090 | 41 | #endif |
6e5714ea | 42 | |
dfd56b8b | 43 | #if IS_ENABLED(CONFIG_IPV6) |
95a22cae FW |
44 | u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr, |
45 | __be16 sport, __be16 dport, u32 *tsoff) | |
6e5714ea DM |
46 | { |
47 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
48 | u32 hash[MD5_DIGEST_WORDS]; | |
49 | u32 i; | |
50 | ||
9a3bab6b | 51 | net_secret_init(); |
6e5714ea DM |
52 | memcpy(hash, saddr, 16); |
53 | for (i = 0; i < 4; i++) | |
747465ef | 54 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
55 | secret[4] = net_secret[4] + |
56 | (((__force u16)sport << 16) + (__force u16)dport); | |
57 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
58 | secret[i] = net_secret[i]; | |
59 | ||
60 | md5_transform(hash, secret); | |
61 | ||
25429d7b | 62 | *tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0; |
6e5714ea DM |
63 | return seq_scale(hash[0]); |
64 | } | |
65 | EXPORT_SYMBOL(secure_tcpv6_sequence_number); | |
66 | ||
67 | u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, | |
68 | __be16 dport) | |
69 | { | |
70 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
71 | u32 hash[MD5_DIGEST_WORDS]; | |
72 | u32 i; | |
73 | ||
9a3bab6b | 74 | net_secret_init(); |
6e5714ea DM |
75 | memcpy(hash, saddr, 16); |
76 | for (i = 0; i < 4; i++) | |
77 | secret[i] = net_secret[i] + (__force u32) daddr[i]; | |
78 | secret[4] = net_secret[4] + (__force u32)dport; | |
79 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
80 | secret[i] = net_secret[i]; | |
81 | ||
82 | md5_transform(hash, secret); | |
83 | ||
84 | return hash[0]; | |
85 | } | |
58a317f1 | 86 | EXPORT_SYMBOL(secure_ipv6_port_ephemeral); |
6e5714ea DM |
87 | #endif |
88 | ||
89 | #ifdef CONFIG_INET | |
6e5714ea | 90 | |
95a22cae FW |
91 | u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, |
92 | __be16 sport, __be16 dport, u32 *tsoff) | |
6e5714ea DM |
93 | { |
94 | u32 hash[MD5_DIGEST_WORDS]; | |
95 | ||
9a3bab6b | 96 | net_secret_init(); |
6e5714ea DM |
97 | hash[0] = (__force u32)saddr; |
98 | hash[1] = (__force u32)daddr; | |
99 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
100 | hash[3] = net_secret[15]; | |
101 | ||
102 | md5_transform(hash, net_secret); | |
103 | ||
25429d7b | 104 | *tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0; |
6e5714ea DM |
105 | return seq_scale(hash[0]); |
106 | } | |
107 | ||
108 | u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) | |
109 | { | |
110 | u32 hash[MD5_DIGEST_WORDS]; | |
111 | ||
9a3bab6b | 112 | net_secret_init(); |
6e5714ea DM |
113 | hash[0] = (__force u32)saddr; |
114 | hash[1] = (__force u32)daddr; | |
115 | hash[2] = (__force u32)dport ^ net_secret[14]; | |
116 | hash[3] = net_secret[15]; | |
117 | ||
118 | md5_transform(hash, net_secret); | |
119 | ||
120 | return hash[0]; | |
121 | } | |
122 | EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); | |
123 | #endif | |
124 | ||
a3bf7ae9 | 125 | #if IS_ENABLED(CONFIG_IP_DCCP) |
6e5714ea DM |
126 | u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, |
127 | __be16 sport, __be16 dport) | |
128 | { | |
129 | u32 hash[MD5_DIGEST_WORDS]; | |
130 | u64 seq; | |
131 | ||
9a3bab6b | 132 | net_secret_init(); |
6e5714ea DM |
133 | hash[0] = (__force u32)saddr; |
134 | hash[1] = (__force u32)daddr; | |
135 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
136 | hash[3] = net_secret[15]; | |
137 | ||
138 | md5_transform(hash, net_secret); | |
139 | ||
140 | seq = hash[0] | (((u64)hash[1]) << 32); | |
d2de875c | 141 | seq += ktime_get_real_ns(); |
6e5714ea DM |
142 | seq &= (1ull << 48) - 1; |
143 | ||
144 | return seq; | |
145 | } | |
146 | EXPORT_SYMBOL(secure_dccp_sequence_number); | |
147 | ||
dfd56b8b | 148 | #if IS_ENABLED(CONFIG_IPV6) |
6e5714ea DM |
149 | u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, |
150 | __be16 sport, __be16 dport) | |
151 | { | |
152 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
153 | u32 hash[MD5_DIGEST_WORDS]; | |
154 | u64 seq; | |
155 | u32 i; | |
156 | ||
9a3bab6b | 157 | net_secret_init(); |
6e5714ea DM |
158 | memcpy(hash, saddr, 16); |
159 | for (i = 0; i < 4; i++) | |
68319052 | 160 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
161 | secret[4] = net_secret[4] + |
162 | (((__force u16)sport << 16) + (__force u16)dport); | |
163 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
164 | secret[i] = net_secret[i]; | |
165 | ||
166 | md5_transform(hash, secret); | |
167 | ||
168 | seq = hash[0] | (((u64)hash[1]) << 32); | |
d2de875c | 169 | seq += ktime_get_real_ns(); |
6e5714ea DM |
170 | seq &= (1ull << 48) - 1; |
171 | ||
172 | return seq; | |
173 | } | |
174 | EXPORT_SYMBOL(secure_dccpv6_sequence_number); | |
175 | #endif | |
176 | #endif |