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Message-ID: <e7382eefea550d10cb5f13030dbe809f0366c9bf.1639758955.git.antony.antony@secunet.com>
Date: Fri, 17 Dec 2021 17:46:18 +0100
From: Antony Antony <antony.antony@...unet.com>
To: Steffen Klassert <steffen.klassert@...unet.com>
CC: Thomas Egerer <thomas.egerer@...unet.com>,
Herbert Xu <herbert@...dor.apana.org.au>,
Antony Antony <antony.antony@...unet.com>,
"David S. Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>, <netdev@...r.kernel.org>
Subject: [PATCH ipsec-next v2] xfrm: rate limit SA mapping change message to
user space
Kernel generates mapping change message, XFRM_MSG_MAPPING,
when a source port change is detected on a input state with UDP
encapsulation set. Kernel generates a message for each IPsec packet
with new source port. For a high speed flow per packet mapping change
message can be excessive, and can overload the user space listener.
Introduce rate limiting for XFRM_MSG_MAPPING message to the user space.
The rate limiting is configurable via netlink, when adding a new SA or
updating it. Use the new attribute XFRMA_MTIMER_THRESH in seconds.
v1->v2 change:
update xfrm_sa_len()
Co-developed-by: Thomas Egerer <thomas.egerer@...unet.com>
Signed-off-by: Thomas Egerer <thomas.egerer@...unet.com>
Signed-off-by: Antony Antony <antony.antony@...unet.com>
---
include/net/xfrm.h | 5 +++++
include/uapi/linux/xfrm.h | 1 +
net/xfrm/xfrm_state.c | 23 ++++++++++++++++++++++-
net/xfrm/xfrm_user.c | 15 ++++++++++++++-
4 files changed, 42 insertions(+), 2 deletions(-)
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 2308210793a0..f3842f6bf40d 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -232,6 +232,11 @@ struct xfrm_state {
u32 replay_maxage;
u32 replay_maxdiff;
+ /* mapping change rate limiting */
+ unsigned long new_mapping; /* jiffies */
+ unsigned long mapping_maxage; /* jiffies for input SA */
+ __be16 new_mapping_sport;
+
/* Replay detection notification timer */
struct timer_list rtimer;
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index eda0426ec4c2..4e29d7851890 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -313,6 +313,7 @@ enum xfrm_attr_type_t {
XFRMA_SET_MARK, /* __u32 */
XFRMA_SET_MARK_MASK, /* __u32 */
XFRMA_IF_ID, /* __u32 */
+ XFRMA_MTIMER_THRESH, /* __u32 in seconds for input SA */
__XFRMA_MAX
#define XFRMA_OUTPUT_MARK XFRMA_SET_MARK /* Compatibility */
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index a2f4001221d1..5d28de6416f6 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1593,6 +1593,9 @@ static struct xfrm_state *xfrm_state_clone(struct xfrm_state *orig,
x->km.seq = orig->km.seq;
x->replay = orig->replay;
x->preplay = orig->preplay;
+ x->mapping_maxage = orig->mapping_maxage;
+ x->new_mapping = 0;
+ x->new_mapping_sport = 0;
return x;
@@ -2242,7 +2245,7 @@ int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol)
}
EXPORT_SYMBOL(km_query);
-int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport)
+static int __km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport)
{
int err = -EINVAL;
struct xfrm_mgr *km;
@@ -2257,6 +2260,24 @@ int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport)
rcu_read_unlock();
return err;
}
+
+int km_new_mapping(struct xfrm_state *x, xfrm_address_t *ipaddr, __be16 sport)
+{
+ int ret = 0;
+
+ if (x->mapping_maxage) {
+ if ((jiffies - x->new_mapping) > x->mapping_maxage ||
+ x->new_mapping_sport != sport) {
+ x->new_mapping_sport = sport;
+ x->new_mapping = jiffies;
+ ret = __km_new_mapping(x, ipaddr, sport);
+ }
+ } else {
+ ret = __km_new_mapping(x, ipaddr, sport);
+ }
+
+ return ret;
+}
EXPORT_SYMBOL(km_new_mapping);
void km_policy_expired(struct xfrm_policy *pol, int dir, int hard, u32 portid)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 7c36cc1f3d79..61c6615ea586 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -521,6 +521,7 @@ static void xfrm_update_ae_params(struct xfrm_state *x, struct nlattr **attrs,
struct nlattr *lt = attrs[XFRMA_LTIME_VAL];
struct nlattr *et = attrs[XFRMA_ETIMER_THRESH];
struct nlattr *rt = attrs[XFRMA_REPLAY_THRESH];
+ struct nlattr *mt = attrs[XFRMA_MTIMER_THRESH];
if (re) {
struct xfrm_replay_state_esn *replay_esn;
@@ -552,6 +553,9 @@ static void xfrm_update_ae_params(struct xfrm_state *x, struct nlattr **attrs,
if (rt)
x->replay_maxdiff = nla_get_u32(rt);
+
+ if (mt)
+ x->mapping_maxage = nla_get_u32(mt);
}
static void xfrm_smark_init(struct nlattr **attrs, struct xfrm_mark *m)
@@ -1024,8 +1028,14 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
if (ret)
goto out;
}
- if (x->security)
+ if (x->security) {
ret = copy_sec_ctx(x->security, skb);
+ if (ret)
+ goto out;
+ }
+ if (x->mapping_maxage)
+ ret = nla_put_u32(skb, XFRMA_MTIMER_THRESH,
+ (x->mapping_maxage / HZ));
out:
return ret;
}
@@ -3069,6 +3079,9 @@ static inline unsigned int xfrm_sa_len(struct xfrm_state *x)
/* Must count x->lastused as it may become non-zero behind our back. */
l += nla_total_size_64bit(sizeof(u64));
+ if (x->mapping_maxage)
+ l += nla_total_size(sizeof(x->mapping_maxage));
+
return l;
}
--
2.30.2
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