From: Eric Dumazet <dada1@cosmosbay•com>
To: David Miller <davem@davemloft•net>
Cc: netdev@vger•kernel.org, kaber@trash•net, stable@kernel•org
Subject: [NET] random : secure_tcp_sequence_number should not assume CONFIG_KTIME_SCALAR
Date: Tue, 13 Nov 2007 14:41:19 +0100 [thread overview]
Message-ID: <4739A97F.60206@cosmosbay.com> (raw)
In-Reply-To: <20071113.035019.268404275.davem@davemloft.net>
[-- Attachment #1: Type: text/plain, Size: 694 bytes --]
I discovered one other incorrect use of .tv64 (coming from me, I must
confess)
I guess this patch is needed for 2.6.24 and stable (2.6.22 & 2.6.23)
Thank you
[NET] random : secure_tcp_sequence_number should not assume
CONFIG_KTIME_SCALAR
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>
[-- Attachment #2: random.patch --]
[-- Type: text/plain, Size: 1146 bytes --]
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 1756b1f..5fee056 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1494,7 +1494,7 @@ __u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr,
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 saddr, __be32 daddr,
* 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 saddr, __be32 daddr,
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",
next prev parent reply other threads:[~2007-11-13 13:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-13 11:30 [NET] netfilter : xt_time should not assume CONFIG_KTIME_SCALAR Eric Dumazet
2007-11-13 11:50 ` David Miller
2007-11-13 12:07 ` Patrick McHardy
2007-11-13 12:48 ` Eric Dumazet
2007-11-13 15:38 ` Patrick McHardy
2007-11-13 13:41 ` Eric Dumazet [this message]
2007-11-14 5:13 ` [NET] random : secure_tcp_sequence_number " David Miller
2007-11-14 19:49 ` [stable] " Greg KH
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