diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-07-21 21:25:58 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-07-21 21:25:58 -0700 |
| commit | 87c48fa3b4630905f98268dde838ee43626a060c (patch) | |
| tree | 1374b52ed0514682f836cfa0a6a683eb549c9613 /drivers/char/random.c | |
| parent | 21efcfa0ff27776902a8a15e810147be4d937d69 (diff) | |
ipv6: make fragment identifications less predictable
IPv6 fragment identification generation is way beyond what we use for
IPv4 : It uses a single generator. Its not scalable and allows DOS
attacks.
Now inetpeer is IPv6 aware, we can use it to provide a more secure and
scalable frag ident generator (per destination, instead of system wide)
This patch :
1) defines a new secure_ipv6_id() helper
2) extends inet_getid() to provide 32bit results
3) extends ipv6_select_ident() with a new dest parameter
Reported-by: Fernando Gont <fernando@gont.com.ar>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/char/random.c')
| -rw-r--r-- | drivers/char/random.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c index d4ddeba5668..729281961f2 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1523,6 +1523,21 @@ __u32 secure_ip_id(__be32 daddr) return half_md4_transform(hash, keyptr->secret); } +__u32 secure_ipv6_id(const __be32 daddr[4]) +{ + const struct keydata *keyptr; + __u32 hash[4]; + + keyptr = get_keyptr(); + + hash[0] = (__force __u32)daddr[0]; + hash[1] = (__force __u32)daddr[1]; + hash[2] = (__force __u32)daddr[2]; + hash[3] = (__force __u32)daddr[3]; + + return half_md4_transform(hash, keyptr->secret); +} + #ifdef CONFIG_INET __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, |