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authorEric Dumazet <eric.dumazet@gmail.com>2011-08-08 23:44:00 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-15 18:31:37 -0700
commitef81bb40bf15f350fe865f31fa42f1082772a576 (patch)
treef89c3e9616127d234207a84e108bf147cc393215 /include/net
parenteb473dd5ad8785d35142966cdcd6896d8dff5a22 (diff)
ipv6: make fragment identifications less predictable
[ Backport of upstream commit 87c48fa3b4630905f98268dde838ee43626a060c ] Fernando Gont reported current IPv6 fragment identification generation was not secure, because using a very predictable system-wide generator, allowing various attacks. IPv4 uses inetpeer cache to address this problem and to get good performance. We'll use this mechanism when IPv6 inetpeer is stable enough in linux-3.1 For the time being, we use jhash on destination address to provide less predictable identifications. Also remove a spinlock and use cmpxchg() to get better SMP performance. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/net')
-rw-r--r--include/net/ipv6.h12
-rw-r--r--include/net/transp_v6.h2
2 files changed, 3 insertions, 11 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index c033ed00df7..3b5ac1fbff3 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -463,17 +463,7 @@ static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_add
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
diff --git a/include/net/transp_v6.h b/include/net/transp_v6.h
index 5271a741c3a..45ce307e954 100644
--- a/include/net/transp_v6.h
+++ b/include/net/transp_v6.h
@@ -14,6 +14,8 @@ extern struct proto tcpv6_prot;
struct flowi6;
+extern void initialize_hashidentrnd(void);
+
/* extension headers */
extern int ipv6_exthdrs_init(void);
extern void ipv6_exthdrs_exit(void);