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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 | */ | |
38 | return seq + (ktime_to_ns(ktime_get_real()) >> 6); | |
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 | |
88 | __u32 secure_ip_id(__be32 daddr) | |
89 | { | |
90 | u32 hash[MD5_DIGEST_WORDS]; | |
91 | ||
9a3bab6b | 92 | net_secret_init(); |
6e5714ea DM |
93 | hash[0] = (__force __u32) daddr; |
94 | hash[1] = net_secret[13]; | |
95 | hash[2] = net_secret[14]; | |
96 | hash[3] = net_secret[15]; | |
97 | ||
98 | md5_transform(hash, net_secret); | |
99 | ||
100 | return hash[0]; | |
101 | } | |
102 | ||
103 | __u32 secure_ipv6_id(const __be32 daddr[4]) | |
104 | { | |
105 | __u32 hash[4]; | |
106 | ||
9a3bab6b | 107 | net_secret_init(); |
6e5714ea DM |
108 | memcpy(hash, daddr, 16); |
109 | md5_transform(hash, net_secret); | |
110 | ||
111 | return hash[0]; | |
112 | } | |
113 | ||
114 | __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, | |
115 | __be16 sport, __be16 dport) | |
116 | { | |
117 | u32 hash[MD5_DIGEST_WORDS]; | |
118 | ||
9a3bab6b | 119 | net_secret_init(); |
6e5714ea DM |
120 | hash[0] = (__force u32)saddr; |
121 | hash[1] = (__force u32)daddr; | |
122 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
123 | hash[3] = net_secret[15]; | |
124 | ||
125 | md5_transform(hash, net_secret); | |
126 | ||
127 | return seq_scale(hash[0]); | |
128 | } | |
129 | ||
130 | u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) | |
131 | { | |
132 | u32 hash[MD5_DIGEST_WORDS]; | |
133 | ||
9a3bab6b | 134 | net_secret_init(); |
6e5714ea DM |
135 | hash[0] = (__force u32)saddr; |
136 | hash[1] = (__force u32)daddr; | |
137 | hash[2] = (__force u32)dport ^ net_secret[14]; | |
138 | hash[3] = net_secret[15]; | |
139 | ||
140 | md5_transform(hash, net_secret); | |
141 | ||
142 | return hash[0]; | |
143 | } | |
144 | EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); | |
145 | #endif | |
146 | ||
a3bf7ae9 | 147 | #if IS_ENABLED(CONFIG_IP_DCCP) |
6e5714ea DM |
148 | u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, |
149 | __be16 sport, __be16 dport) | |
150 | { | |
151 | u32 hash[MD5_DIGEST_WORDS]; | |
152 | u64 seq; | |
153 | ||
9a3bab6b | 154 | net_secret_init(); |
6e5714ea DM |
155 | hash[0] = (__force u32)saddr; |
156 | hash[1] = (__force u32)daddr; | |
157 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
158 | hash[3] = net_secret[15]; | |
159 | ||
160 | md5_transform(hash, net_secret); | |
161 | ||
162 | seq = hash[0] | (((u64)hash[1]) << 32); | |
163 | seq += ktime_to_ns(ktime_get_real()); | |
164 | seq &= (1ull << 48) - 1; | |
165 | ||
166 | return seq; | |
167 | } | |
168 | EXPORT_SYMBOL(secure_dccp_sequence_number); | |
169 | ||
dfd56b8b | 170 | #if IS_ENABLED(CONFIG_IPV6) |
6e5714ea DM |
171 | u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, |
172 | __be16 sport, __be16 dport) | |
173 | { | |
174 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
175 | u32 hash[MD5_DIGEST_WORDS]; | |
176 | u64 seq; | |
177 | u32 i; | |
178 | ||
9a3bab6b | 179 | net_secret_init(); |
6e5714ea DM |
180 | memcpy(hash, saddr, 16); |
181 | for (i = 0; i < 4; i++) | |
182 | secret[i] = net_secret[i] + daddr[i]; | |
183 | secret[4] = net_secret[4] + | |
184 | (((__force u16)sport << 16) + (__force u16)dport); | |
185 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
186 | secret[i] = net_secret[i]; | |
187 | ||
188 | md5_transform(hash, secret); | |
189 | ||
190 | seq = hash[0] | (((u64)hash[1]) << 32); | |
191 | seq += ktime_to_ns(ktime_get_real()); | |
192 | seq &= (1ull << 48) - 1; | |
193 | ||
194 | return seq; | |
195 | } | |
196 | EXPORT_SYMBOL(secure_dccpv6_sequence_number); | |
197 | #endif | |
198 | #endif |