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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 | 18 | static u32 net_secret[NET_SECRET_SIZE] ____cacheline_aligned; |
502b4528 | 19 | static u32 ts_secret[2]; |
9a3bab6b | 20 | |
34d92d53 | 21 | static __always_inline void net_secret_init(void) |
6e5714ea | 22 | { |
502b4528 | 23 | net_get_random_once(ts_secret, sizeof(ts_secret)); |
e34c9a69 | 24 | net_get_random_once(net_secret, sizeof(net_secret)); |
6e5714ea | 25 | } |
cb03db9d | 26 | #endif |
6e5714ea | 27 | |
68109090 | 28 | #ifdef CONFIG_INET |
6e5714ea DM |
29 | static u32 seq_scale(u32 seq) |
30 | { | |
31 | /* | |
32 | * As close as possible to RFC 793, which | |
33 | * suggests using a 250 kHz clock. | |
34 | * Further reading shows this assumes 2 Mb/s networks. | |
35 | * For 10 Mb/s Ethernet, a 1 MHz clock is appropriate. | |
36 | * For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but | |
37 | * we also need to limit the resolution so that the u32 seq | |
38 | * overlaps less than one time per MSL (2 minutes). | |
39 | * Choosing a clock of 64 ns period is OK. (period of 274 s) | |
40 | */ | |
d2de875c | 41 | return seq + (ktime_get_real_ns() >> 6); |
6e5714ea | 42 | } |
68109090 | 43 | #endif |
6e5714ea | 44 | |
dfd56b8b | 45 | #if IS_ENABLED(CONFIG_IPV6) |
502b4528 FW |
46 | static u32 secure_tcpv6_ts_off(const __be32 *saddr, const __be32 *daddr) |
47 | { | |
48 | u32 hash[4 + 4 + 1]; | |
49 | ||
50 | if (sysctl_tcp_timestamps != 1) | |
51 | return 0; | |
52 | ||
53 | memcpy(hash, saddr, 16); | |
54 | memcpy(hash + 4, daddr, 16); | |
55 | ||
56 | hash[8] = ts_secret[0]; | |
57 | ||
58 | return jhash2(hash, ARRAY_SIZE(hash), ts_secret[1]); | |
59 | } | |
60 | ||
95a22cae FW |
61 | u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr, |
62 | __be16 sport, __be16 dport, u32 *tsoff) | |
6e5714ea DM |
63 | { |
64 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
65 | u32 hash[MD5_DIGEST_WORDS]; | |
66 | u32 i; | |
67 | ||
9a3bab6b | 68 | net_secret_init(); |
6e5714ea DM |
69 | memcpy(hash, saddr, 16); |
70 | for (i = 0; i < 4; i++) | |
747465ef | 71 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
72 | secret[4] = net_secret[4] + |
73 | (((__force u16)sport << 16) + (__force u16)dport); | |
74 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
75 | secret[i] = net_secret[i]; | |
76 | ||
77 | md5_transform(hash, secret); | |
78 | ||
502b4528 | 79 | *tsoff = secure_tcpv6_ts_off(saddr, daddr); |
6e5714ea DM |
80 | return seq_scale(hash[0]); |
81 | } | |
82 | EXPORT_SYMBOL(secure_tcpv6_sequence_number); | |
83 | ||
84 | u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, | |
85 | __be16 dport) | |
86 | { | |
87 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
88 | u32 hash[MD5_DIGEST_WORDS]; | |
89 | u32 i; | |
90 | ||
9a3bab6b | 91 | net_secret_init(); |
6e5714ea DM |
92 | memcpy(hash, saddr, 16); |
93 | for (i = 0; i < 4; i++) | |
94 | secret[i] = net_secret[i] + (__force u32) daddr[i]; | |
95 | secret[4] = net_secret[4] + (__force u32)dport; | |
96 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
97 | secret[i] = net_secret[i]; | |
98 | ||
99 | md5_transform(hash, secret); | |
100 | ||
101 | return hash[0]; | |
102 | } | |
58a317f1 | 103 | EXPORT_SYMBOL(secure_ipv6_port_ephemeral); |
6e5714ea DM |
104 | #endif |
105 | ||
106 | #ifdef CONFIG_INET | |
502b4528 FW |
107 | static u32 secure_tcp_ts_off(__be32 saddr, __be32 daddr) |
108 | { | |
109 | if (sysctl_tcp_timestamps != 1) | |
110 | return 0; | |
111 | ||
112 | return jhash_3words((__force u32)saddr, (__force u32)daddr, | |
113 | ts_secret[0], ts_secret[1]); | |
114 | } | |
6e5714ea | 115 | |
95a22cae FW |
116 | u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, |
117 | __be16 sport, __be16 dport, u32 *tsoff) | |
6e5714ea DM |
118 | { |
119 | u32 hash[MD5_DIGEST_WORDS]; | |
120 | ||
9a3bab6b | 121 | net_secret_init(); |
6e5714ea DM |
122 | hash[0] = (__force u32)saddr; |
123 | hash[1] = (__force u32)daddr; | |
124 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
125 | hash[3] = net_secret[15]; | |
126 | ||
127 | md5_transform(hash, net_secret); | |
128 | ||
502b4528 | 129 | *tsoff = secure_tcp_ts_off(saddr, daddr); |
6e5714ea DM |
130 | return seq_scale(hash[0]); |
131 | } | |
132 | ||
133 | u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) | |
134 | { | |
135 | u32 hash[MD5_DIGEST_WORDS]; | |
136 | ||
9a3bab6b | 137 | net_secret_init(); |
6e5714ea DM |
138 | hash[0] = (__force u32)saddr; |
139 | hash[1] = (__force u32)daddr; | |
140 | hash[2] = (__force u32)dport ^ net_secret[14]; | |
141 | hash[3] = net_secret[15]; | |
142 | ||
143 | md5_transform(hash, net_secret); | |
144 | ||
145 | return hash[0]; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); | |
148 | #endif | |
149 | ||
a3bf7ae9 | 150 | #if IS_ENABLED(CONFIG_IP_DCCP) |
6e5714ea DM |
151 | u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, |
152 | __be16 sport, __be16 dport) | |
153 | { | |
154 | u32 hash[MD5_DIGEST_WORDS]; | |
155 | u64 seq; | |
156 | ||
9a3bab6b | 157 | net_secret_init(); |
6e5714ea DM |
158 | hash[0] = (__force u32)saddr; |
159 | hash[1] = (__force u32)daddr; | |
160 | hash[2] = ((__force u16)sport << 16) + (__force u16)dport; | |
161 | hash[3] = net_secret[15]; | |
162 | ||
163 | md5_transform(hash, net_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_dccp_sequence_number); | |
172 | ||
dfd56b8b | 173 | #if IS_ENABLED(CONFIG_IPV6) |
6e5714ea DM |
174 | u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, |
175 | __be16 sport, __be16 dport) | |
176 | { | |
177 | u32 secret[MD5_MESSAGE_BYTES / 4]; | |
178 | u32 hash[MD5_DIGEST_WORDS]; | |
179 | u64 seq; | |
180 | u32 i; | |
181 | ||
9a3bab6b | 182 | net_secret_init(); |
6e5714ea DM |
183 | memcpy(hash, saddr, 16); |
184 | for (i = 0; i < 4; i++) | |
68319052 | 185 | secret[i] = net_secret[i] + (__force u32)daddr[i]; |
6e5714ea DM |
186 | secret[4] = net_secret[4] + |
187 | (((__force u16)sport << 16) + (__force u16)dport); | |
188 | for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++) | |
189 | secret[i] = net_secret[i]; | |
190 | ||
191 | md5_transform(hash, secret); | |
192 | ||
193 | seq = hash[0] | (((u64)hash[1]) << 32); | |
d2de875c | 194 | seq += ktime_get_real_ns(); |
6e5714ea DM |
195 | seq &= (1ull << 48) - 1; |
196 | ||
197 | return seq; | |
198 | } | |
199 | EXPORT_SYMBOL(secure_dccpv6_sequence_number); | |
200 | #endif | |
201 | #endif |