xfrm: configure policy hash table thresholds by netlink
Enable to specify local and remote prefix length thresholds for the
policy hash table via a netlink XFRM_MSG_NEWSPDINFO message.
prefix length thresholds are specified by XFRMA_SPD_IPV4_HTHRESH and
XFRMA_SPD_IPV6_HTHRESH optional attributes (struct xfrmu_spdhthresh).
example:
struct xfrmu_spdhthresh thresh4 = {
.lbits = 0;
.rbits = 24;
};
struct xfrmu_spdhthresh thresh6 = {
.lbits = 0;
.rbits = 56;
};
struct nlmsghdr *hdr;
struct nl_msg *msg;
msg = nlmsg_alloc();
hdr = nlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, XFRMA_SPD_IPV4_HTHRESH, sizeof(__u32), NLM_F_REQUEST);
nla_put(msg, XFRMA_SPD_IPV4_HTHRESH, sizeof(thresh4), &thresh4);
nla_put(msg, XFRMA_SPD_IPV6_HTHRESH, sizeof(thresh6), &thresh6);
nla_send_auto(sk, msg);
The numbers are the policy selector minimum prefix lengths to put a
policy in the hash table.
- lbits is the local threshold (source address for out policies,
destination address for in and fwd policies).
- rbits is the remote threshold (destination address for out
policies, source address for in and fwd policies).
The default values are:
XFRMA_SPD_IPV4_HTHRESH: 32 32
XFRMA_SPD_IPV6_HTHRESH: 128 128
Dynamic re-building of the SPD is performed when the thresholds values
are changed.
The current thresholds can be read via a XFRM_MSG_GETSPDINFO request:
the kernel replies to XFRM_MSG_GETSPDINFO requests by an
XFRM_MSG_NEWSPDINFO message, with both attributes
XFRMA_SPD_IPV4_HTHRESH and XFRMA_SPD_IPV6_HTHRESH.
Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index e6ff7b4..55bcb86 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -566,6 +566,86 @@
mutex_unlock(&hash_resize_mutex);
}
+static void xfrm_hash_rebuild(struct work_struct *work)
+{
+ struct net *net = container_of(work, struct net,
+ xfrm.policy_hthresh.work);
+ unsigned int hmask;
+ struct xfrm_policy *pol;
+ struct xfrm_policy *policy;
+ struct hlist_head *chain;
+ struct hlist_head *odst;
+ struct hlist_node *newpos;
+ int i;
+ int dir;
+ unsigned seq;
+ u8 lbits4, rbits4, lbits6, rbits6;
+
+ mutex_lock(&hash_resize_mutex);
+
+ /* read selector prefixlen thresholds */
+ do {
+ seq = read_seqbegin(&net->xfrm.policy_hthresh.lock);
+
+ lbits4 = net->xfrm.policy_hthresh.lbits4;
+ rbits4 = net->xfrm.policy_hthresh.rbits4;
+ lbits6 = net->xfrm.policy_hthresh.lbits6;
+ rbits6 = net->xfrm.policy_hthresh.rbits6;
+ } while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
+
+ write_lock_bh(&net->xfrm.xfrm_policy_lock);
+
+ /* reset the bydst and inexact table in all directions */
+ for (dir = 0; dir < XFRM_POLICY_MAX * 2; dir++) {
+ INIT_HLIST_HEAD(&net->xfrm.policy_inexact[dir]);
+ hmask = net->xfrm.policy_bydst[dir].hmask;
+ odst = net->xfrm.policy_bydst[dir].table;
+ for (i = hmask; i >= 0; i--)
+ INIT_HLIST_HEAD(odst + i);
+ if ((dir & XFRM_POLICY_MASK) == XFRM_POLICY_OUT) {
+ /* dir out => dst = remote, src = local */
+ net->xfrm.policy_bydst[dir].dbits4 = rbits4;
+ net->xfrm.policy_bydst[dir].sbits4 = lbits4;
+ net->xfrm.policy_bydst[dir].dbits6 = rbits6;
+ net->xfrm.policy_bydst[dir].sbits6 = lbits6;
+ } else {
+ /* dir in/fwd => dst = local, src = remote */
+ net->xfrm.policy_bydst[dir].dbits4 = lbits4;
+ net->xfrm.policy_bydst[dir].sbits4 = rbits4;
+ net->xfrm.policy_bydst[dir].dbits6 = lbits6;
+ net->xfrm.policy_bydst[dir].sbits6 = rbits6;
+ }
+ }
+
+ /* re-insert all policies by order of creation */
+ list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) {
+ newpos = NULL;
+ chain = policy_hash_bysel(net, &policy->selector,
+ policy->family,
+ xfrm_policy_id2dir(policy->index));
+ hlist_for_each_entry(pol, chain, bydst) {
+ if (policy->priority >= pol->priority)
+ newpos = &pol->bydst;
+ else
+ break;
+ }
+ if (newpos)
+ hlist_add_behind(&policy->bydst, newpos);
+ else
+ hlist_add_head(&policy->bydst, chain);
+ }
+
+ write_unlock_bh(&net->xfrm.xfrm_policy_lock);
+
+ mutex_unlock(&hash_resize_mutex);
+}
+
+void xfrm_policy_hash_rebuild(struct net *net)
+{
+ schedule_work(&net->xfrm.policy_hthresh.work);
+}
+EXPORT_SYMBOL(xfrm_policy_hash_rebuild);
+
/* Generate new index... KAME seems to generate them ordered by cost
* of an absolute inpredictability of ordering of rules. This will not pass. */
static u32 xfrm_gen_index(struct net *net, int dir, u32 index)
@@ -2872,9 +2952,16 @@
htab->dbits6 = 128;
htab->sbits6 = 128;
}
+ net->xfrm.policy_hthresh.lbits4 = 32;
+ net->xfrm.policy_hthresh.rbits4 = 32;
+ net->xfrm.policy_hthresh.lbits6 = 128;
+ net->xfrm.policy_hthresh.rbits6 = 128;
+
+ seqlock_init(&net->xfrm.policy_hthresh.lock);
INIT_LIST_HEAD(&net->xfrm.policy_all);
INIT_WORK(&net->xfrm.policy_hash_work, xfrm_hash_resize);
+ INIT_WORK(&net->xfrm.policy_hthresh.work, xfrm_hash_rebuild);
if (net_eq(net, &init_net))
register_netdevice_notifier(&xfrm_dev_notifier);
return 0;