[patch 02/60] NET: random : secure_tcp_sequence_number should not assume CONFIG_KTIME_SCALAR

Greg KH
2007-12-13T06:56:23Z

[-- Attachment #1: net-random-secure_tcp_sequence_number-should-not-assume-config_ktime_scalar.patch --]
[-- Type: text/plain, Size: 1969 bytes --]

2.6.23-stable review patch. If anyone has any objections, please let us
know.

------------------
From: Eric Dumazet <dada1@cosmosbay.com>

[NET] random : secure_tcp_sequence_number should not assume CONFIG_KTIME_SCALAR

[ Upstream commit: 6dd10a62353a50b30b30e0c18653650975b29c71 ]

All 32 bits machines but i386 dont have CONFIG_KTIME_SCALAR. On these
machines, ktime.tv64 is more than 4 times the (correct) result given
by ktime_to_ns()

Again on these machines, using ktime_get_real().tv64 >> 6 give a
32bits rollover every 64 seconds, which is not wanted (less than the
120 s MSL)

Using ktime_to_ns() is the portable way to get nsecs from a ktime, and
have correct code.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/char/random.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1494,7 +1494,7 @@ __u32 secure_tcpv6_sequence_number(__be3
seq = twothirdsMD4Transform((const __u32 *)daddr, hash) & HASH_MASK;
seq += keyptr->count;

- seq += ktime_get_real().tv64;
+ seq += ktime_to_ns(ktime_get_real());

return seq;
}
@@ -1556,7 +1556,7 @@ __u32 secure_tcp_sequence_number(__be32
* overlaps less than one time per MSL (2 minutes).
* Choosing a clock of 64 ns period is OK. (period of 274 s)
*/
- seq += ktime_get_real().tv64 >> 6;
+ seq += ktime_to_ns(ktime_get_real()) >> 6;
#if 0
printk("init_seq(%lx, %lx, %d, %d) = %d\n",
saddr, daddr, sport, dport, seq);
@@ -1616,7 +1616,7 @@ u64 secure_dccp_sequence_number(__be32 s
seq = half_md4_transform(hash, keyptr->secret);
seq |= ((u64)keyptr->count) << (32 - HASH_BITS);

- seq += ktime_get_real().tv64;
+ seq += ktime_to_ns(ktime_get_real());
seq &= (1ull << 48) - 1;
#if 0
printk("dccp init_seq(%lx, %lx, %d, %d) = %d\n",

--