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net-sched: cls_flow: add perturbation support
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Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Patrick McHardy authored and David S. Miller committed Jul 15, 2008
1 parent 0c4c8ca commit 72d9794
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Showing 2 changed files with 44 additions and 9 deletions.
1 change: 1 addition & 0 deletions include/linux/pkt_cls.h
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Original file line number Diff line number Diff line change
Expand Up @@ -374,6 +374,7 @@ enum
TCA_FLOW_ACT,
TCA_FLOW_POLICE,
TCA_FLOW_EMATCHES,
TCA_FLOW_PERTURB,
__TCA_FLOW_MAX
};

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52 changes: 43 additions & 9 deletions net/sched/cls_flow.c
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,8 @@ struct flow_filter {
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;
Expand All @@ -47,11 +49,9 @@ struct flow_filter {
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,
Expand Down Expand Up @@ -348,7 +348,7 @@ static int flow_classify(struct sk_buff *skb, struct tcf_proto *tp,
}

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;
Expand All @@ -369,6 +369,15 @@ static int flow_classify(struct sk_buff *skb, struct tcf_proto *tp,
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 },
Expand All @@ -381,6 +390,7 @@ static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
[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,
Expand All @@ -394,6 +404,7 @@ static int flow_change(struct tcf_proto *tp, unsigned long base,
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;
Expand Down Expand Up @@ -442,6 +453,14 @@ static int flow_change(struct tcf_proto *tp, unsigned long base,
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)
Expand All @@ -455,6 +474,12 @@ static int flow_change(struct tcf_proto *tp, unsigned long base,
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)
Expand All @@ -467,6 +492,11 @@ static int flow_change(struct tcf_proto *tp, unsigned long base,

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);
Expand Down Expand Up @@ -495,6 +525,11 @@ static int flow_change(struct tcf_proto *tp, unsigned long base,
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);

Expand All @@ -512,6 +547,7 @@ static int flow_change(struct tcf_proto *tp, unsigned long base,

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);
Expand All @@ -532,11 +568,6 @@ static int flow_init(struct tcf_proto *tp)
{
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;
Expand Down Expand Up @@ -605,6 +636,9 @@ static int flow_dump(struct tcf_proto *tp, unsigned long fh,
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
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