xfrm: add state hashtable keyed by seq

When creating new states with seq set in xfrm_usersa_info, we walk
through all the states already installed in that netns to find a
matching ACQUIRE state (__xfrm_find_acq_byseq, called from
xfrm_state_add). This causes severe slowdowns on systems with a large
number of states.

This patch introduces a hashtable using x->km.seq as key, so that the
corresponding state can be found in a reasonable time.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Sabrina Dubroca 2021-04-25 21:47:12 +02:00 committed by Steffen Klassert
parent 335a2a1fce
commit fe9f1d8779
4 changed files with 61 additions and 13 deletions

View File

@ -42,6 +42,7 @@ struct netns_xfrm {
struct hlist_head __rcu *state_bydst;
struct hlist_head __rcu *state_bysrc;
struct hlist_head __rcu *state_byspi;
struct hlist_head __rcu *state_byseq;
unsigned int state_hmask;
unsigned int state_num;
struct work_struct state_hash_work;

View File

@ -154,6 +154,7 @@ struct xfrm_state {
};
struct hlist_node bysrc;
struct hlist_node byspi;
struct hlist_node byseq;
refcount_t refcnt;
spinlock_t lock;

View File

@ -131,6 +131,13 @@ __xfrm_spi_hash(const xfrm_address_t *daddr, __be32 spi, u8 proto,
return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
}
static inline unsigned int
__xfrm_seq_hash(u32 seq, unsigned int hmask)
{
unsigned int h = seq;
return (h ^ (h >> 10) ^ (h >> 20)) & hmask;
}
static inline unsigned int __idx_hash(u32 index, unsigned int hmask)
{
return (index ^ (index >> 8)) & hmask;

View File

@ -78,10 +78,16 @@ xfrm_spi_hash(struct net *net, const xfrm_address_t *daddr,
return __xfrm_spi_hash(daddr, spi, proto, family, net->xfrm.state_hmask);
}
static unsigned int xfrm_seq_hash(struct net *net, u32 seq)
{
return __xfrm_seq_hash(seq, net->xfrm.state_hmask);
}
static void xfrm_hash_transfer(struct hlist_head *list,
struct hlist_head *ndsttable,
struct hlist_head *nsrctable,
struct hlist_head *nspitable,
struct hlist_head *nseqtable,
unsigned int nhashmask)
{
struct hlist_node *tmp;
@ -106,6 +112,11 @@ static void xfrm_hash_transfer(struct hlist_head *list,
nhashmask);
hlist_add_head_rcu(&x->byspi, nspitable + h);
}
if (x->km.seq) {
h = __xfrm_seq_hash(x->km.seq, nhashmask);
hlist_add_head_rcu(&x->byseq, nseqtable + h);
}
}
}
@ -117,7 +128,7 @@ static unsigned long xfrm_hash_new_size(unsigned int state_hmask)
static void xfrm_hash_resize(struct work_struct *work)
{
struct net *net = container_of(work, struct net, xfrm.state_hash_work);
struct hlist_head *ndst, *nsrc, *nspi, *odst, *osrc, *ospi;
struct hlist_head *ndst, *nsrc, *nspi, *nseq, *odst, *osrc, *ospi, *oseq;
unsigned long nsize, osize;
unsigned int nhashmask, ohashmask;
int i;
@ -137,6 +148,13 @@ static void xfrm_hash_resize(struct work_struct *work)
xfrm_hash_free(nsrc, nsize);
return;
}
nseq = xfrm_hash_alloc(nsize);
if (!nseq) {
xfrm_hash_free(ndst, nsize);
xfrm_hash_free(nsrc, nsize);
xfrm_hash_free(nspi, nsize);
return;
}
spin_lock_bh(&net->xfrm.xfrm_state_lock);
write_seqcount_begin(&net->xfrm.xfrm_state_hash_generation);
@ -144,15 +162,17 @@ static void xfrm_hash_resize(struct work_struct *work)
nhashmask = (nsize / sizeof(struct hlist_head)) - 1U;
odst = xfrm_state_deref_prot(net->xfrm.state_bydst, net);
for (i = net->xfrm.state_hmask; i >= 0; i--)
xfrm_hash_transfer(odst + i, ndst, nsrc, nspi, nhashmask);
xfrm_hash_transfer(odst + i, ndst, nsrc, nspi, nseq, nhashmask);
osrc = xfrm_state_deref_prot(net->xfrm.state_bysrc, net);
ospi = xfrm_state_deref_prot(net->xfrm.state_byspi, net);
oseq = xfrm_state_deref_prot(net->xfrm.state_byseq, net);
ohashmask = net->xfrm.state_hmask;
rcu_assign_pointer(net->xfrm.state_bydst, ndst);
rcu_assign_pointer(net->xfrm.state_bysrc, nsrc);
rcu_assign_pointer(net->xfrm.state_byspi, nspi);
rcu_assign_pointer(net->xfrm.state_byseq, nseq);
net->xfrm.state_hmask = nhashmask;
write_seqcount_end(&net->xfrm.xfrm_state_hash_generation);
@ -165,6 +185,7 @@ static void xfrm_hash_resize(struct work_struct *work)
xfrm_hash_free(odst, osize);
xfrm_hash_free(osrc, osize);
xfrm_hash_free(ospi, osize);
xfrm_hash_free(oseq, osize);
}
static DEFINE_SPINLOCK(xfrm_state_afinfo_lock);
@ -621,6 +642,7 @@ struct xfrm_state *xfrm_state_alloc(struct net *net)
INIT_HLIST_NODE(&x->bydst);
INIT_HLIST_NODE(&x->bysrc);
INIT_HLIST_NODE(&x->byspi);
INIT_HLIST_NODE(&x->byseq);
hrtimer_init(&x->mtimer, CLOCK_BOOTTIME, HRTIMER_MODE_ABS_SOFT);
x->mtimer.function = xfrm_timer_handler;
timer_setup(&x->rtimer, xfrm_replay_timer_handler, 0);
@ -664,6 +686,8 @@ int __xfrm_state_delete(struct xfrm_state *x)
list_del(&x->km.all);
hlist_del_rcu(&x->bydst);
hlist_del_rcu(&x->bysrc);
if (x->km.seq)
hlist_del_rcu(&x->byseq);
if (x->id.spi)
hlist_del_rcu(&x->byspi);
net->xfrm.state_num--;
@ -1148,6 +1172,10 @@ found:
h = xfrm_spi_hash(net, &x->id.daddr, x->id.spi, x->id.proto, encap_family);
hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
}
if (x->km.seq) {
h = xfrm_seq_hash(net, x->km.seq);
hlist_add_head_rcu(&x->byseq, net->xfrm.state_byseq + h);
}
x->lft.hard_add_expires_seconds = net->xfrm.sysctl_acq_expires;
hrtimer_start(&x->mtimer,
ktime_set(net->xfrm.sysctl_acq_expires, 0),
@ -1263,6 +1291,12 @@ static void __xfrm_state_insert(struct xfrm_state *x)
hlist_add_head_rcu(&x->byspi, net->xfrm.state_byspi + h);
}
if (x->km.seq) {
h = xfrm_seq_hash(net, x->km.seq);
hlist_add_head_rcu(&x->byseq, net->xfrm.state_byseq + h);
}
hrtimer_start(&x->mtimer, ktime_set(1, 0), HRTIMER_MODE_REL_SOFT);
if (x->replay_maxage)
mod_timer(&x->rtimer, jiffies + x->replay_maxage);
@ -1932,20 +1966,18 @@ xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src, int n,
static struct xfrm_state *__xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq)
{
int i;
unsigned int h = xfrm_seq_hash(net, seq);
struct xfrm_state *x;
for (i = 0; i <= net->xfrm.state_hmask; i++) {
struct xfrm_state *x;
hlist_for_each_entry(x, net->xfrm.state_bydst+i, bydst) {
if (x->km.seq == seq &&
(mark & x->mark.m) == x->mark.v &&
x->km.state == XFRM_STATE_ACQ) {
xfrm_state_hold(x);
return x;
}
hlist_for_each_entry_rcu(x, net->xfrm.state_byseq + h, byseq) {
if (x->km.seq == seq &&
(mark & x->mark.m) == x->mark.v &&
x->km.state == XFRM_STATE_ACQ) {
xfrm_state_hold(x);
return x;
}
}
return NULL;
}
@ -2660,6 +2692,9 @@ int __net_init xfrm_state_init(struct net *net)
net->xfrm.state_byspi = xfrm_hash_alloc(sz);
if (!net->xfrm.state_byspi)
goto out_byspi;
net->xfrm.state_byseq = xfrm_hash_alloc(sz);
if (!net->xfrm.state_byseq)
goto out_byseq;
net->xfrm.state_hmask = ((sz / sizeof(struct hlist_head)) - 1);
net->xfrm.state_num = 0;
@ -2669,6 +2704,8 @@ int __net_init xfrm_state_init(struct net *net)
&net->xfrm.xfrm_state_lock);
return 0;
out_byseq:
xfrm_hash_free(net->xfrm.state_byspi, sz);
out_byspi:
xfrm_hash_free(net->xfrm.state_bysrc, sz);
out_bysrc:
@ -2688,6 +2725,8 @@ void xfrm_state_fini(struct net *net)
WARN_ON(!list_empty(&net->xfrm.state_all));
sz = (net->xfrm.state_hmask + 1) * sizeof(struct hlist_head);
WARN_ON(!hlist_empty(net->xfrm.state_byseq));
xfrm_hash_free(net->xfrm.state_byseq, sz);
WARN_ON(!hlist_empty(net->xfrm.state_byspi));
xfrm_hash_free(net->xfrm.state_byspi, sz);
WARN_ON(!hlist_empty(net->xfrm.state_bysrc));