From: Antony Antony antony.antony@secunet.com
[ Upstream commit 4e484b3e969b52effd95c17f7a86f39208b2ccf4 ]
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@intel.com accept XFRM_MSG_MAPPING only when XFRMA_ENCAP is present
Co-developed-by: Thomas Egerer thomas.egerer@secunet.com Signed-off-by: Thomas Egerer thomas.egerer@secunet.com Signed-off-by: Antony Antony antony.antony@secunet.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 2308210793a01..2589e4c0501bd 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 eda0426ec4c2b..4e29d78518902 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 2bf2693901631..a0f62fa02e06e 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 a2f4001221d16..78d51399a0f4b 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 3a3cb09eec122..d75ac53ee7b42 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; }