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Message-Id: <20170516172802.1317-7-jiri@resnulli.us>
Date: Tue, 16 May 2017 19:27:58 +0200
From: Jiri Pirko <jiri@...nulli.us>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, jhs@...atatu.com, xiyou.wangcong@...il.com,
dsa@...ulusnetworks.com, edumazet@...gle.com,
stephen@...workplumber.org, daniel@...earbox.net,
alexander.h.duyck@...el.com, simon.horman@...ronome.com,
mlxsw@...lanox.com
Subject: [patch net-next v3 06/10] net: sched: introduce helpers to work with filter chains
From: Jiri Pirko <jiri@...lanox.com>
Introduce struct tcf_chain object and set of helpers around it. Wraps up
insertion, deletion and search in the filter chain.
Signed-off-by: Jiri Pirko <jiri@...lanox.com>
---
include/net/sch_generic.h | 7 ++-
net/sched/cls_api.c | 148 +++++++++++++++++++++++++++++++++-------------
2 files changed, 113 insertions(+), 42 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 98cf2f2..52bceed 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -248,10 +248,15 @@ struct qdisc_skb_cb {
unsigned char data[QDISC_CB_PRIV_LEN];
};
-struct tcf_block {
+struct tcf_chain {
+ struct tcf_proto __rcu *filter_chain;
struct tcf_proto __rcu **p_filter_chain;
};
+struct tcf_block {
+ struct tcf_chain *chain;
+};
+
static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
{
struct qdisc_skb_cb *qcb;
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 72624fa..6f2ea68 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -106,13 +106,12 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
struct nlmsghdr *n,
- struct tcf_proto __rcu **chain, int event)
+ struct tcf_chain *chain, int event)
{
- struct tcf_proto __rcu **it_chain;
struct tcf_proto *tp;
- for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL;
- it_chain = &tp->next)
+ for (tp = rtnl_dereference(chain->filter_chain);
+ tp; tp = rtnl_dereference(tp->next))
tfilter_notify(net, oskb, n, tp, 0, event, false);
}
@@ -187,26 +186,49 @@ static void tcf_proto_destroy(struct tcf_proto *tp)
kfree_rcu(tp, rcu);
}
-static void tcf_chain_destroy(struct tcf_proto __rcu **fl)
+static struct tcf_chain *tcf_chain_create(void)
+{
+ return kzalloc(sizeof(struct tcf_chain), GFP_KERNEL);
+}
+
+static void tcf_chain_destroy(struct tcf_chain *chain)
{
struct tcf_proto *tp;
- while ((tp = rtnl_dereference(*fl)) != NULL) {
- RCU_INIT_POINTER(*fl, tp->next);
+ while ((tp = rtnl_dereference(chain->filter_chain)) != NULL) {
+ RCU_INIT_POINTER(chain->filter_chain, tp->next);
tcf_proto_destroy(tp);
}
+ kfree(chain);
+}
+
+static void
+tcf_chain_filter_chain_ptr_set(struct tcf_chain *chain,
+ struct tcf_proto __rcu **p_filter_chain)
+{
+ chain->p_filter_chain = p_filter_chain;
}
int tcf_block_get(struct tcf_block **p_block,
struct tcf_proto __rcu **p_filter_chain)
{
struct tcf_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
+ int err;
if (!block)
return -ENOMEM;
- block->p_filter_chain = p_filter_chain;
+ block->chain = tcf_chain_create();
+ if (!block->chain) {
+ err = -ENOMEM;
+ goto err_chain_create;
+ }
+ tcf_chain_filter_chain_ptr_set(block->chain, p_filter_chain);
*p_block = block;
return 0;
+
+err_chain_create:
+ kfree(block);
+ return err;
}
EXPORT_SYMBOL(tcf_block_get);
@@ -214,7 +236,7 @@ void tcf_block_put(struct tcf_block *block)
{
if (!block)
return;
- tcf_chain_destroy(block->p_filter_chain);
+ tcf_chain_destroy(block->chain);
kfree(block);
}
EXPORT_SYMBOL(tcf_block_put);
@@ -261,6 +283,65 @@ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
}
EXPORT_SYMBOL(tcf_classify);
+struct tcf_chain_info {
+ struct tcf_proto __rcu **pprev;
+ struct tcf_proto __rcu *next;
+};
+
+static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
+{
+ return rtnl_dereference(*chain_info->pprev);
+}
+
+static void tcf_chain_tp_insert(struct tcf_chain *chain,
+ struct tcf_chain_info *chain_info,
+ struct tcf_proto *tp)
+{
+ if (chain->p_filter_chain &&
+ *chain_info->pprev == chain->filter_chain)
+ *chain->p_filter_chain = tp;
+ RCU_INIT_POINTER(tp->next, rtnl_dereference(*chain_info->pprev));
+ rcu_assign_pointer(*chain_info->pprev, tp);
+}
+
+static void tcf_chain_tp_remove(struct tcf_chain *chain,
+ struct tcf_chain_info *chain_info,
+ struct tcf_proto *tp)
+{
+ struct tcf_proto *next = rtnl_dereference(chain_info->next);
+
+ if (chain->p_filter_chain && tp == chain->filter_chain)
+ *chain->p_filter_chain = next;
+ RCU_INIT_POINTER(*chain_info->pprev, next);
+}
+
+static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
+ struct tcf_chain_info *chain_info,
+ u32 protocol, u32 prio,
+ bool prio_allocate)
+{
+ struct tcf_proto **pprev;
+ struct tcf_proto *tp;
+
+ /* Check the chain for existence of proto-tcf with this priority */
+ for (pprev = &chain->filter_chain;
+ (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
+ if (tp->prio >= prio) {
+ if (tp->prio == prio) {
+ if (prio_allocate ||
+ (tp->protocol != protocol && protocol))
+ return ERR_PTR(-EINVAL);
+ } else {
+ tp = NULL;
+ }
+ break;
+ }
+ }
+ chain_info->pprev = pprev;
+ chain_info->next = tp ? tp->next : NULL;
+ return tp;
+}
+
/* Add/change/delete/get a filter node */
static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
@@ -275,10 +356,9 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
u32 parent;
struct net_device *dev;
struct Qdisc *q;
- struct tcf_proto __rcu **back;
- struct tcf_proto __rcu **chain;
+ struct tcf_chain_info chain_info;
+ struct tcf_chain *chain;
struct tcf_block *block;
- struct tcf_proto *next;
struct tcf_proto *tp;
const struct Qdisc_class_ops *cops;
unsigned long cl;
@@ -363,7 +443,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
err = -EINVAL;
goto errout;
}
- chain = block->p_filter_chain;
+ chain = block->chain;
if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
@@ -372,22 +452,11 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
goto errout;
}
- /* Check the chain for existence of proto-tcf with this priority */
- for (back = chain;
- (tp = rtnl_dereference(*back)) != NULL;
- back = &tp->next) {
- if (tp->prio >= prio) {
- if (tp->prio == prio) {
- if (prio_allocate ||
- (tp->protocol != protocol && protocol)) {
- err = -EINVAL;
- goto errout;
- }
- } else {
- tp = NULL;
- }
- break;
- }
+ tp = tcf_chain_tp_find(chain, &chain_info, protocol,
+ prio, prio_allocate);
+ if (IS_ERR(tp)) {
+ err = PTR_ERR(tp);
+ goto errout;
}
if (tp == NULL) {
@@ -405,7 +474,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
}
if (prio_allocate)
- prio = tcf_auto_prio(rtnl_dereference(*back));
+ prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
protocol, prio, parent, q, block);
@@ -423,8 +492,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
if (fh == 0) {
if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
- next = rtnl_dereference(tp->next);
- RCU_INIT_POINTER(*back, next);
+ tcf_chain_tp_remove(chain, &chain_info, tp);
tfilter_notify(net, skb, n, tp, fh,
RTM_DELTFILTER, false);
tcf_proto_destroy(tp);
@@ -453,11 +521,10 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
err = tp->ops->delete(tp, fh, &last);
if (err)
goto errout;
- next = rtnl_dereference(tp->next);
tfilter_notify(net, skb, n, tp, t->tcm_handle,
RTM_DELTFILTER, false);
if (last) {
- RCU_INIT_POINTER(*back, next);
+ tcf_chain_tp_remove(chain, &chain_info, tp);
tcf_proto_destroy(tp);
}
goto errout;
@@ -474,10 +541,8 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
if (err == 0) {
- if (tp_created) {
- RCU_INIT_POINTER(tp->next, rtnl_dereference(*back));
- rcu_assign_pointer(*back, tp);
- }
+ if (tp_created)
+ tcf_chain_tp_insert(chain, &chain_info, tp);
tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);
} else {
if (tp_created)
@@ -578,7 +643,8 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
struct net_device *dev;
struct Qdisc *q;
struct tcf_block *block;
- struct tcf_proto *tp, __rcu **chain;
+ struct tcf_proto *tp;
+ struct tcf_chain *chain;
struct tcmsg *tcm = nlmsg_data(cb->nlh);
unsigned long cl = 0;
const struct Qdisc_class_ops *cops;
@@ -609,11 +675,11 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
block = cops->tcf_block(q, cl);
if (!block)
goto errout;
- chain = block->p_filter_chain;
+ chain = block->chain;
s_t = cb->args[0];
- for (tp = rtnl_dereference(*chain), t = 0;
+ for (tp = rtnl_dereference(chain->filter_chain), t = 0;
tp; tp = rtnl_dereference(tp->next), t++) {
if (t < s_t)
continue;
--
2.9.3
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