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Message-ID: <af6150a0d0ae51bdbbf34c81ca0d0d74b17fa16f.1640178517.git.antony.antony@secunet.com>
Date: Wed, 22 Dec 2021 14:11:18 +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 v3] xfrm: rate limit SA mapping change message to
user space
Kernel generates mapping change message, XFRM_MSG_MAPPING,
when a source port chage 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()
v2->v3 changes:
use u32 insted unsigned long to reduce size of struct xfrm_state
fix xfrm_ompat size Reported-by: kernel test robot <lkp@...el.com>
accept XFRM_MSG_MAPPING only when XFRMA_ENCAP is present
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_compat.c | 6 ++++--
net/xfrm/xfrm_state.c | 23 ++++++++++++++++++++++-
net/xfrm/xfrm_user.c | 18 +++++++++++++++++-
5 files changed, 49 insertions(+), 4 deletions(-)
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 2308210793a0..2589e4c0501b 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -200,6 +200,11 @@ struct xfrm_state {
struct xfrm_algo_aead *aead;
const char *geniv;
+ /* mapping change rate limiting */
+ __be16 new_mapping_sport;
+ u32 new_mapping; /* seconds */
+ u32 mapping_maxage; /* seconds for input SA */
+
/* Data for encapsulator */
struct xfrm_encap_tmpl *encap;
struct sock __rcu *encap_sk;
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_compat.c b/net/xfrm/xfrm_compat.c
index 2bf269390163..a0f62fa02e06 100644
--- a/net/xfrm/xfrm_compat.c
+++ b/net/xfrm/xfrm_compat.c
@@ -127,6 +127,7 @@ static const struct nla_policy compat_policy[XFRMA_MAX+1] = {
[XFRMA_SET_MARK] = { .type = NLA_U32 },
[XFRMA_SET_MARK_MASK] = { .type = NLA_U32 },
[XFRMA_IF_ID] = { .type = NLA_U32 },
+ [XFRMA_MTIMER_THRESH] = { .type = NLA_U32 },
};
static struct nlmsghdr *xfrm_nlmsg_put_compat(struct sk_buff *skb,
@@ -274,9 +275,10 @@ static int xfrm_xlate64_attr(struct sk_buff *dst, const struct nlattr *src)
case XFRMA_SET_MARK:
case XFRMA_SET_MARK_MASK:
case XFRMA_IF_ID:
+ case XFRMA_MTIMER_THRESH:
return xfrm_nla_cpy(dst, src, nla_len(src));
default:
- BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
+ BUILD_BUG_ON(XFRMA_MAX != XFRMA_MTIMER_THRESH);
pr_warn_once("unsupported nla_type %d\n", src->nla_type);
return -EOPNOTSUPP;
}
@@ -431,7 +433,7 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla,
int err;
if (type > XFRMA_MAX) {
- BUILD_BUG_ON(XFRMA_MAX != XFRMA_IF_ID);
+ BUILD_BUG_ON(XFRMA_MAX != XFRMA_MTIMER_THRESH);
NL_SET_ERR_MSG(extack, "Bad attribute");
return -EOPNOTSUPP;
}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index a2f4001221d1..78d51399a0f4 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 / HZ - x->new_mapping) > x->mapping_maxage ||
+ x->new_mapping_sport != sport) {
+ x->new_mapping_sport = sport;
+ x->new_mapping = jiffies / HZ;
+ 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..130240680655 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -282,6 +282,10 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
err = 0;
+ if (attrs[XFRMA_MTIMER_THRESH])
+ if (!attrs[XFRMA_ENCAP])
+ err = -EINVAL;
+
out:
return err;
}
@@ -521,6 +525,7 @@ 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 +557,9 @@ 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 +1032,13 @@ 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);
out:
return ret;
}
@@ -3069,6 +3082,9 @@ 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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