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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-10-19 21:48:56 +0200
committerDavid S. Miller <davem@davemloft.net>2013-10-19 19:45:35 -0400
commitb23a002fc6f0c19846ee0382f019429af54a27e9 (patch)
tree9cb494a707c4145a8a42f0cf6eb6853e487f06a5 /net/ipv6/syncookies.c
parentnet: introduce new macro net_get_random_once (diff)
downloadlinux-dev-b23a002fc6f0c19846ee0382f019429af54a27e9.tar.xz
linux-dev-b23a002fc6f0c19846ee0382f019429af54a27e9.zip
inet: split syncookie keys for ipv4 and ipv6 and initialize with net_get_random_once
This patch splits the secret key for syncookies for ipv4 and ipv6 and initializes them with net_get_random_once. This change was the reason I did this series. I think the initialization of the syncookie_secret is way to early. Cc: Florian Westphal <fw@strlen.de> Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
-rw-r--r--net/ipv6/syncookies.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index d04d3f1dd9b7..535a3ad262f1 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -24,6 +24,8 @@
#define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
+static u32 syncookie6_secret[2][16-4+SHA_DIGEST_WORDS];
+
/* RFC 2460, Section 8.3:
* [ipv6 tcp] MSS must be computed as the maximum packet size minus 60 [..]
*
@@ -61,14 +63,18 @@ static DEFINE_PER_CPU(__u32 [16 + 5 + SHA_WORKSPACE_WORDS],
static u32 cookie_hash(const struct in6_addr *saddr, const struct in6_addr *daddr,
__be16 sport, __be16 dport, u32 count, int c)
{
- __u32 *tmp = __get_cpu_var(ipv6_cookie_scratch);
+ __u32 *tmp;
+
+ net_get_random_once(syncookie6_secret, sizeof(syncookie6_secret));
+
+ tmp = __get_cpu_var(ipv6_cookie_scratch);
/*
* we have 320 bits of information to hash, copy in the remaining
- * 192 bits required for sha_transform, from the syncookie_secret
+ * 192 bits required for sha_transform, from the syncookie6_secret
* and overwrite the digest with the secret
*/
- memcpy(tmp + 10, syncookie_secret[c], 44);
+ memcpy(tmp + 10, syncookie6_secret[c], 44);
memcpy(tmp, saddr, 16);
memcpy(tmp + 4, daddr, 16);
tmp[8] = ((__force u32)sport << 16) + (__force u32)dport;