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authorPetr Vaněk <pv@excello.cz>2020-05-30 14:39:12 +0200
committerSteffen Klassert <steffen.klassert@secunet.com>2020-06-24 07:51:01 +0200
commit428d2459cceb77357b81c242ca22462a6a904817 (patch)
treeaefb323f38c25bfdb809b4666699bb5b32c7f0f8 /net/xfrm
parent8af7b4525acf5012b2f111a8b168b8647f2c8d60 (diff)
downloadlinux-428d2459cceb77357b81c242ca22462a6a904817.tar.bz2
xfrm: introduce oseq-may-wrap flag
RFC 4303 in section 3.3.3 suggests to disable anti-replay for manually distributed ICVs in which case the sender does not need to monitor or reset the counter. However, the sender still increments the counter and when it reaches the maximum value, the counter rolls over back to zero. This patch introduces new extra_flag XFRM_SA_XFLAG_OSEQ_MAY_WRAP which allows sequence number to cycle in outbound packets if set. This flag is used only in legacy and bmp code, because esn should not be negotiated if anti-replay is disabled (see note in 3.3.3 section). Signed-off-by: Petr Vaněk <pv@excello.cz> Acked-by: Christophe Gouault <christophe.gouault@6wind.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Diffstat (limited to 'net/xfrm')
-rw-r--r--net/xfrm/xfrm_replay.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 98943f8d01aa..c6a4338a0d08 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -89,7 +89,8 @@ static int xfrm_replay_overflow(struct xfrm_state *x, struct sk_buff *skb)
if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
XFRM_SKB_CB(skb)->seq.output.low = ++x->replay.oseq;
XFRM_SKB_CB(skb)->seq.output.hi = 0;
- if (unlikely(x->replay.oseq == 0)) {
+ if (unlikely(x->replay.oseq == 0) &&
+ !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
x->replay.oseq--;
xfrm_audit_state_replay_overflow(x, skb);
err = -EOVERFLOW;
@@ -168,7 +169,8 @@ static int xfrm_replay_overflow_bmp(struct xfrm_state *x, struct sk_buff *skb)
if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
XFRM_SKB_CB(skb)->seq.output.low = ++replay_esn->oseq;
XFRM_SKB_CB(skb)->seq.output.hi = 0;
- if (unlikely(replay_esn->oseq == 0)) {
+ if (unlikely(replay_esn->oseq == 0) &&
+ !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
replay_esn->oseq--;
xfrm_audit_state_replay_overflow(x, skb);
err = -EOVERFLOW;
@@ -572,7 +574,8 @@ static int xfrm_replay_overflow_offload(struct xfrm_state *x, struct sk_buff *sk
XFRM_SKB_CB(skb)->seq.output.hi = 0;
xo->seq.hi = 0;
- if (unlikely(oseq < x->replay.oseq)) {
+ if (unlikely(oseq < x->replay.oseq) &&
+ !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
xfrm_audit_state_replay_overflow(x, skb);
err = -EOVERFLOW;
@@ -611,7 +614,8 @@ static int xfrm_replay_overflow_offload_bmp(struct xfrm_state *x, struct sk_buff
XFRM_SKB_CB(skb)->seq.output.hi = 0;
xo->seq.hi = 0;
- if (unlikely(oseq < replay_esn->oseq)) {
+ if (unlikely(oseq < replay_esn->oseq) &&
+ !(x->props.extra_flags & XFRM_SA_XFLAG_OSEQ_MAY_WRAP)) {
xfrm_audit_state_replay_overflow(x, skb);
err = -EOVERFLOW;