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>
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index c033ed0..3b5ac1f 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -463,17 +463,7 @@
return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
}
-static __inline__ void ipv6_select_ident(struct frag_hdr *fhdr)
-{
- static u32 ipv6_fragmentation_id = 1;
- static DEFINE_SPINLOCK(ip6_id_lock);
-
- spin_lock_bh(&ip6_id_lock);
- fhdr->identification = htonl(ipv6_fragmentation_id);
- if (++ipv6_fragmentation_id == 0)
- ipv6_fragmentation_id = 1;
- spin_unlock_bh(&ip6_id_lock);
-}
+extern void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt);
/*
* Prototypes exported by ipv6