1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cryptohash.h>
#include <linux/module.h>
#include <linux/cache.h>
#include <linux/random.h>
#include <linux/hrtimer.h>
#include <linux/ktime.h>
#include <linux/string.h>
#include <net/secure_seq.h>
static u32 net_secret[MD5_MESSAGE_BYTES / 4] ____cacheline_aligned;
static int __init net_secret_init(void)
{
get_random_bytes(net_secret, sizeof(net_secret));
return 0;
}
late_initcall(net_secret_init);
static u32 seq_scale(u32 seq)
{
/*
* As close as possible to RFC 793, which
* suggests using a 250 kHz clock.
* Further reading shows this assumes 2 Mb/s networks.
* For 10 Mb/s Ethernet, a 1 MHz clock is appropriate.
* For 10 Gb/s Ethernet, a 1 GHz clock should be ok, but
* we also need to limit the resolution so that the u32 seq
* overlaps less than one time per MSL (2 minutes).
* Choosing a clock of 64 ns period is OK. (period of 274 s)
*/
return seq + (ktime_to_ns(ktime_get_real()) >> 6);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
__u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr,
__be16 sport, __be16 dport)
{
u32 secret[MD5_MESSAGE_BYTES / 4];
u32 hash[MD5_DIGEST_WORDS];
u32 i;
memcpy(hash, saddr, 16);
for (i = 0; i < 4; i++)
secret[i] = net_secret[i] + daddr[i];
secret[4] = net_secret[4] +
(((__force u16)sport << 16) + (__force u16)dport);
for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
secret[i] = net_secret[i];
md5_transform(hash, secret);
return seq_scale(hash[0]);
}
EXPORT_SYMBOL(secure_tcpv6_sequence_number);
u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
__be16 dport)
{
u32 secret[MD5_MESSAGE_BYTES / 4];
u32 hash[MD5_DIGEST_WORDS];
u32 i;
memcpy(hash, saddr, 16);
for (i = 0; i < 4; i++)
secret[i] = net_secret[i] + (__force u32) daddr[i];
secret[4] = net_secret[4] + (__force u32)dport;
for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
secret[i] = net_secret[i];
md5_transform(hash, secret);
return hash[0];
}
#endif
#ifdef CONFIG_INET
__u32 secure_ip_id(__be32 daddr)
{
u32 hash[MD5_DIGEST_WORDS];
hash[0] = (__force __u32) daddr;
hash[1] = net_secret[13];
hash[2] = net_secret[14];
hash[3] = net_secret[15];
md5_transform(hash, net_secret);
return hash[0];
}
__u32 secure_ipv6_id(const __be32 daddr[4])
{
__u32 hash[4];
memcpy(hash, daddr, 16);
md5_transform(hash, net_secret);
return hash[0];
}
__u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
__be16 sport, __be16 dport)
{
u32 hash[MD5_DIGEST_WORDS];
hash[0] = (__force u32)saddr;
hash[1] = (__force u32)daddr;
hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
hash[3] = net_secret[15];
md5_transform(hash, net_secret);
return seq_scale(hash[0]);
}
u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
{
u32 hash[MD5_DIGEST_WORDS];
hash[0] = (__force u32)saddr;
hash[1] = (__force u32)daddr;
hash[2] = (__force u32)dport ^ net_secret[14];
hash[3] = net_secret[15];
md5_transform(hash, net_secret);
return hash[0];
}
EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
#endif
#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr,
__be16 sport, __be16 dport)
{
u32 hash[MD5_DIGEST_WORDS];
u64 seq;
hash[0] = (__force u32)saddr;
hash[1] = (__force u32)daddr;
hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
hash[3] = net_secret[15];
md5_transform(hash, net_secret);
seq = hash[0] | (((u64)hash[1]) << 32);
seq += ktime_to_ns(ktime_get_real());
seq &= (1ull << 48) - 1;
return seq;
}
EXPORT_SYMBOL(secure_dccp_sequence_number);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
__be16 sport, __be16 dport)
{
u32 secret[MD5_MESSAGE_BYTES / 4];
u32 hash[MD5_DIGEST_WORDS];
u64 seq;
u32 i;
memcpy(hash, saddr, 16);
for (i = 0; i < 4; i++)
secret[i] = net_secret[i] + daddr[i];
secret[4] = net_secret[4] +
(((__force u16)sport << 16) + (__force u16)dport);
for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
secret[i] = net_secret[i];
md5_transform(hash, secret);
seq = hash[0] | (((u64)hash[1]) << 32);
seq += ktime_to_ns(ktime_get_real());
seq &= (1ull << 48) - 1;
return seq;
}
EXPORT_SYMBOL(secure_dccpv6_sequence_number);
#endif
#endif
|
