diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-08-08 23:44:00 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-08-15 18:31:37 -0700 |
| commit | ef81bb40bf15f350fe865f31fa42f1082772a576 (patch) | |
| tree | f89c3e9616127d234207a84e108bf147cc393215 /include/net | |
| parent | eb473dd5ad8785d35142966cdcd6896d8dff5a22 (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.h | 12 | ||||
| -rw-r--r-- | include/net/transp_v6.h | 2 |
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); |