[PATCH 1/4] xfrm: Move the test on replay window size into the replay check functions

[PATCH 1/4] xfrm: Move the test on replay window size into the replay check functions

[Steffen Klassert]

As it is, the replay check is just performed if the replay window of the
legacy implementation is nonzero. So we move the test on a nonzero replay
window inside the replay check functions to be sure we are testing for the
right implementation.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_input.c  |    2 +-
 net/xfrm/xfrm_replay.c |   17 +++++++++++++++--
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 872065c..e063638 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -173,7 +173,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 			goto drop_unlock;
 		}
 
-		if (x->props.replay_window && x->repl->check(x, skb, seq)) {
+		if (x->repl->check(x, skb, seq)) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATESEQERROR);
 			goto drop_unlock;
 		}
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 2f5be5b..f218385 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -118,6 +118,9 @@ static int xfrm_replay_check(struct xfrm_state *x,
 	u32 diff;
 	u32 seq = ntohl(net_seq);
 
+	if (!x->props.replay_window)
+		return 0;
+
 	if (unlikely(seq == 0))
 		goto err;
 
@@ -193,9 +196,14 @@ static int xfrm_replay_check_bmp(struct xfrm_state *x,
 {
 	unsigned int bitnr, nr;
 	struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
+	u32 pos;
 	u32 seq = ntohl(net_seq);
 	u32 diff =  replay_esn->seq - seq;
-	u32 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
+
+	if (!replay_esn->replay_window)
+		return 0;
+
+	pos = (replay_esn->seq - 1) % replay_esn->replay_window;
 
 	if (unlikely(seq == 0))
 		goto err;
@@ -373,12 +381,17 @@ static int xfrm_replay_check_esn(struct xfrm_state *x,
 	unsigned int bitnr, nr;
 	u32 diff;
 	struct xfrm_replay_state_esn *replay_esn = x->replay_esn;
+	u32 pos;
 	u32 seq = ntohl(net_seq);
-	u32 pos = (replay_esn->seq - 1) % replay_esn->replay_window;
 	u32 wsize = replay_esn->replay_window;
 	u32 top = replay_esn->seq;
 	u32 bottom = top - wsize + 1;
 
+	if (!wsize)
+		return 0;
+
+	pos = (replay_esn->seq - 1) % replay_esn->replay_window;
+
 	if (unlikely(seq == 0 && replay_esn->seq_hi == 0 &&
 		     (replay_esn->seq < replay_esn->replay_window - 1)))
 		goto err;
-- 
1.7.0.4

[PATCH 2/4] xfrm: Assign esn pointers when cloning a state

[Steffen Klassert]

When we clone a xfrm state we have to assign the replay_esn
and the preplay_esn pointers to the state if we use the
new replay detection method. To this end, we add a
xfrm_replay_clone() function that allocates memory for
the replay detection and takes over the necessary values
from the original state.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 include/net/xfrm.h    |   22 ++++++++++++++++++++++
 net/xfrm/xfrm_state.c |    6 ++++++
 2 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index cffa5dc..6ae4bc5 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1601,6 +1601,28 @@ static inline int xfrm_replay_state_esn_len(struct xfrm_replay_state_esn *replay
 }
 
 #ifdef CONFIG_XFRM_MIGRATE
+static inline int xfrm_replay_clone(struct xfrm_state *x,
+				     struct xfrm_state *orig)
+{
+	x->replay_esn = kzalloc(xfrm_replay_state_esn_len(orig->replay_esn),
+				GFP_KERNEL);
+	if (!x->replay_esn)
+		return -ENOMEM;
+
+	x->replay_esn->bmp_len = orig->replay_esn->bmp_len;
+	x->replay_esn->replay_window = orig->replay_esn->replay_window;
+
+	x->preplay_esn = kmemdup(x->replay_esn,
+				 xfrm_replay_state_esn_len(x->replay_esn),
+				 GFP_KERNEL);
+	if (!x->preplay_esn) {
+		kfree(x->replay_esn);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
 {
 	return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index f83a3d1..dd78536 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1181,6 +1181,12 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig, int *errp)
 			goto error;
 	}
 
+	if (orig->replay_esn) {
+		err = xfrm_replay_clone(x, orig);
+		if (err)
+			goto error;
+	}
+
 	memcpy(&x->mark, &orig->mark, sizeof(x->mark));
 
 	err = xfrm_init_state(x);
-- 
1.7.0.4

[PATCH 3/4] xfrm: Check for esn buffer len in xfrm_new_ae

[Steffen Klassert]

In xfrm_new_ae() we may overwrite the allocated esn replay state
buffer with a wrong size. So check that the new size matches the
original allocated size and return an error if this is not the case.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_user.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index fc152d2..ccc4c0c 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -360,6 +360,23 @@ static int attach_aead(struct xfrm_algo_aead **algpp, u8 *props,
 	return 0;
 }
 
+static inline int xfrm_replay_verify_len(struct xfrm_replay_state_esn *replay_esn,
+					 struct nlattr *rp)
+{
+	struct xfrm_replay_state_esn *up;
+
+	if (!replay_esn || !rp)
+		return 0;
+
+	up = nla_data(rp);
+
+	if (xfrm_replay_state_esn_len(replay_esn) !=
+			xfrm_replay_state_esn_len(up))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int xfrm_alloc_replay_state_esn(struct xfrm_replay_state_esn **replay_esn,
 				       struct xfrm_replay_state_esn **preplay_esn,
 				       struct nlattr *rta)
@@ -1766,6 +1783,10 @@ static int xfrm_new_ae(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (x->km.state != XFRM_STATE_VALID)
 		goto out;
 
+	err = xfrm_replay_verify_len(x->replay_esn, rp);
+	if (err)
+		goto out;
+
 	spin_lock_bh(&x->lock);
 	xfrm_update_ae_params(x, attrs);
 	spin_unlock_bh(&x->lock);
-- 
1.7.0.4

[PATCH 4/4] xfrm: Restrict extended sequence numbers to esp

[Steffen Klassert]

The IPsec extended sequence numbers are fully implemented just for
esp. So restrict the usage to esp until other protocols have
support too.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_user.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index ccc4c0c..3d15d3e 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -127,6 +127,9 @@ static inline int verify_replay(struct xfrm_usersa_info *p,
 	if (!rt)
 		return 0;
 
+	if (p->id.proto != IPPROTO_ESP)
+		return -EINVAL;
+
 	if (p->replay_window != 0)
 		return -EINVAL;
 
-- 
1.7.0.4

Re: [PATCH 1/4] xfrm: Move the test on replay window size into the replay check functions

[Herbert Xu]

On Tue, Mar 29, 2011 at 07:45:52AM +0200, Steffen Klassert wrote:
> As it is, the replay check is just performed if the replay window of the
> legacy implementation is nonzero. So we move the test on a nonzero replay
> window inside the replay check functions to be sure we are testing for the
> right implementation.
> 
> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

for all 4 patches.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH 1/4] xfrm: Move the test on replay window size into the replay check functions

[David Miller]

From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 29 Mar 2011 14:20:06 +0800

> On Tue, Mar 29, 2011 at 07:45:52AM +0200, Steffen Klassert wrote:
>> As it is, the replay check is just performed if the replay window of the
>> legacy implementation is nonzero. So we move the test on a nonzero replay
>> window inside the replay check functions to be sure we are testing for the
>> right implementation.
>> 
>> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
> 
> Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
> 
> for all 4 patches.

All applied, thanks Steffen.