net-sched: cls_flow: add perturbation support
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 971b867..8f63a1a 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -36,6 +36,8 @@
struct list_head list;
struct tcf_exts exts;
struct tcf_ematch_tree ematches;
+ struct timer_list perturb_timer;
+ u32 perturb_period;
u32 handle;
u32 nkeys;
@@ -47,11 +49,9 @@
u32 addend;
u32 divisor;
u32 baseclass;
+ u32 hashrnd;
};
-static u32 flow_hashrnd __read_mostly;
-static int flow_hashrnd_initted __read_mostly;
-
static const struct tcf_ext_map flow_ext_map = {
.action = TCA_FLOW_ACT,
.police = TCA_FLOW_POLICE,
@@ -348,7 +348,7 @@
}
if (f->mode == FLOW_MODE_HASH)
- classid = jhash2(keys, f->nkeys, flow_hashrnd);
+ classid = jhash2(keys, f->nkeys, f->hashrnd);
else {
classid = keys[0];
classid = (classid & f->mask) ^ f->xor;
@@ -369,6 +369,15 @@
return -1;
}
+static void flow_perturbation(unsigned long arg)
+{
+ struct flow_filter *f = (struct flow_filter *)arg;
+
+ get_random_bytes(&f->hashrnd, 4);
+ if (f->perturb_period)
+ mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
+}
+
static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
[TCA_FLOW_KEYS] = { .type = NLA_U32 },
[TCA_FLOW_MODE] = { .type = NLA_U32 },
@@ -381,6 +390,7 @@
[TCA_FLOW_ACT] = { .type = NLA_NESTED },
[TCA_FLOW_POLICE] = { .type = NLA_NESTED },
[TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
+ [TCA_FLOW_PERTURB] = { .type = NLA_U32 },
};
static int flow_change(struct tcf_proto *tp, unsigned long base,
@@ -394,6 +404,7 @@
struct tcf_exts e;
struct tcf_ematch_tree t;
unsigned int nkeys = 0;
+ unsigned int perturb_period = 0;
u32 baseclass = 0;
u32 keymask = 0;
u32 mode;
@@ -442,6 +453,14 @@
mode = nla_get_u32(tb[TCA_FLOW_MODE]);
if (mode != FLOW_MODE_HASH && nkeys > 1)
goto err2;
+
+ if (mode == FLOW_MODE_HASH)
+ perturb_period = f->perturb_period;
+ if (tb[TCA_FLOW_PERTURB]) {
+ if (mode != FLOW_MODE_HASH)
+ goto err2;
+ perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
+ }
} else {
err = -EINVAL;
if (!handle)
@@ -455,6 +474,12 @@
if (mode != FLOW_MODE_HASH && nkeys > 1)
goto err2;
+ if (tb[TCA_FLOW_PERTURB]) {
+ if (mode != FLOW_MODE_HASH)
+ goto err2;
+ perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
+ }
+
if (TC_H_MAJ(baseclass) == 0)
baseclass = TC_H_MAKE(tp->q->handle, baseclass);
if (TC_H_MIN(baseclass) == 0)
@@ -467,6 +492,11 @@
f->handle = handle;
f->mask = ~0U;
+
+ get_random_bytes(&f->hashrnd, 4);
+ f->perturb_timer.function = flow_perturbation;
+ f->perturb_timer.data = (unsigned long)f;
+ init_timer_deferrable(&f->perturb_timer);
}
tcf_exts_change(tp, &f->exts, &e);
@@ -495,6 +525,11 @@
if (baseclass)
f->baseclass = baseclass;
+ f->perturb_period = perturb_period;
+ del_timer(&f->perturb_timer);
+ if (perturb_period)
+ mod_timer(&f->perturb_timer, jiffies + perturb_period);
+
if (*arg == 0)
list_add_tail(&f->list, &head->filters);
@@ -512,6 +547,7 @@
static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
{
+ del_timer_sync(&f->perturb_timer);
tcf_exts_destroy(tp, &f->exts);
tcf_em_tree_destroy(tp, &f->ematches);
kfree(f);
@@ -532,11 +568,6 @@
{
struct flow_head *head;
- if (!flow_hashrnd_initted) {
- get_random_bytes(&flow_hashrnd, 4);
- flow_hashrnd_initted = 1;
- }
-
head = kzalloc(sizeof(*head), GFP_KERNEL);
if (head == NULL)
return -ENOBUFS;
@@ -605,6 +636,9 @@
if (f->baseclass)
NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
+ if (f->perturb_period)
+ NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
+
if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
goto nla_put_failure;
#ifdef CONFIG_NET_EMATCH