net_sched: add network namespace support for tc actions

Currently tc actions are stored in a per-module hashtable,
therefore are visible to all network namespaces. This is
probably the last part of the tc subsystem which is not
aware of netns now. This patch makes them per-netns,
several tc action API's need to be adjusted for this.

The tc action API code is ugly due to historical reasons,
we need to refactor that code in the future.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 58 insertions, 55 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index acafaf7434fc..96066665e376 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -36,10 +36,9 @@ static void free_tcf(struct rcu_head *head)
 	kfree(p);
 }
 
-static void tcf_hash_destroy(struct tc_action *a)
+static void tcf_hash_destroy(struct tcf_hashinfo *hinfo, struct tc_action *a)
 {
 	struct tcf_common *p = a->priv;
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
 
 	spin_lock_bh(&hinfo->lock);
 	hlist_del(&p->tcfc_head);
@@ -68,7 +67,7 @@ int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
 		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
 			if (a->ops->cleanup)
 				a->ops->cleanup(a, bind);
-			tcf_hash_destroy(a);
+			tcf_hash_destroy(a->hinfo, a);
 			ret = ACT_P_DELETED;
 		}
 	}
@@ -77,10 +76,9 @@ int __tcf_hash_release(struct tc_action *a, bool bind, bool strict)
 }
 EXPORT_SYMBOL(__tcf_hash_release);
 
-static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
-			   struct tc_action *a)
+static int tcf_dump_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
+			   struct netlink_callback *cb, struct tc_action *a)
 {
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
 	struct hlist_head *head;
 	struct tcf_common *p;
 	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
@@ -126,9 +124,9 @@ nla_put_failure:
 	goto done;
 }
 
-static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
+static int tcf_del_walker(struct tcf_hashinfo *hinfo, struct sk_buff *skb,
+			  struct tc_action *a)
 {
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
 	struct hlist_head *head;
 	struct hlist_node *n;
 	struct tcf_common *p;
@@ -163,18 +161,24 @@ nla_put_failure:
 	return ret;
 }
 
-static int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
-			      int type, struct tc_action *a)
+int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
+		       struct netlink_callback *cb, int type,
+		       struct tc_action *a)
 {
+	struct tcf_hashinfo *hinfo = tn->hinfo;
+
+	a->hinfo = hinfo;
+
 	if (type == RTM_DELACTION) {
-		return tcf_del_walker(skb, a);
+		return tcf_del_walker(hinfo, skb, a);
 	} else if (type == RTM_GETACTION) {
-		return tcf_dump_walker(skb, cb, a);
+		return tcf_dump_walker(hinfo, skb, cb, a);
 	} else {
 		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
 		return -EINVAL;
 	}
 }
+EXPORT_SYMBOL(tcf_generic_walker);
 
 static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 {
@@ -191,8 +195,9 @@ static struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
 	return p;
 }
 
-u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
+u32 tcf_hash_new_index(struct tc_action_net *tn)
 {
+	struct tcf_hashinfo *hinfo = tn->hinfo;
 	u32 val = hinfo->index;
 
 	do {
@@ -205,28 +210,31 @@ u32 tcf_hash_new_index(struct tcf_hashinfo *hinfo)
 }
 EXPORT_SYMBOL(tcf_hash_new_index);
 
-int tcf_hash_search(struct tc_action *a, u32 index)
+int tcf_hash_search(struct tc_action_net *tn, struct tc_action *a, u32 index)
 {
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
+	struct tcf_hashinfo *hinfo = tn->hinfo;
 	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
 
 	if (p) {
 		a->priv = p;
+		a->hinfo = hinfo;
 		return 1;
 	}
 	return 0;
 }
 EXPORT_SYMBOL(tcf_hash_search);
 
-int tcf_hash_check(u32 index, struct tc_action *a, int bind)
+int tcf_hash_check(struct tc_action_net *tn, u32 index, struct tc_action *a,
+		   int bind)
 {
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
+	struct tcf_hashinfo *hinfo = tn->hinfo;
 	struct tcf_common *p = NULL;
 	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
 		if (bind)
 			p->tcfc_bindcnt++;
 		p->tcfc_refcnt++;
 		a->priv = p;
+		a->hinfo = hinfo;
 		return 1;
 	}
 	return 0;
@@ -243,11 +251,11 @@ void tcf_hash_cleanup(struct tc_action *a, struct nlattr *est)
 }
 EXPORT_SYMBOL(tcf_hash_cleanup);
 
-int tcf_hash_create(u32 index, struct nlattr *est, struct tc_action *a,
-		    int size, int bind, bool cpustats)
+int tcf_hash_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
+		    struct tc_action *a, int size, int bind, bool cpustats)
 {
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
 	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
+	struct tcf_hashinfo *hinfo = tn->hinfo;
 	int err = -ENOMEM;
 
 	if (unlikely(!p))
@@ -272,7 +280,7 @@ err2:
 	}
 	spin_lock_init(&p->tcfc_lock);
 	INIT_HLIST_NODE(&p->tcfc_head);
-	p->tcfc_index = index ? index : tcf_hash_new_index(hinfo);
+	p->tcfc_index = index ? index : tcf_hash_new_index(tn);
 	p->tcfc_tm.install = jiffies;
 	p->tcfc_tm.lastuse = jiffies;
 	if (est) {
@@ -286,14 +294,15 @@ err2:
 	}
 
 	a->priv = (void *) p;
+	a->hinfo = hinfo;
 	return 0;
 }
 EXPORT_SYMBOL(tcf_hash_create);
 
-void tcf_hash_insert(struct tc_action *a)
+void tcf_hash_insert(struct tc_action_net *tn, struct tc_action *a)
 {
 	struct tcf_common *p = a->priv;
-	struct tcf_hashinfo *hinfo = a->ops->hinfo;
+	struct tcf_hashinfo *hinfo = tn->hinfo;
 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
 
 	spin_lock_bh(&hinfo->lock);
@@ -302,11 +311,12 @@ void tcf_hash_insert(struct tc_action *a)
 }
 EXPORT_SYMBOL(tcf_hash_insert);
 
-static void tcf_hashinfo_destroy(const struct tc_action_ops *ops)
+void tcf_hashinfo_destroy(const struct tc_action_ops *ops,
+			  struct tcf_hashinfo *hinfo)
 {
-	struct tcf_hashinfo *hinfo = ops->hinfo;
 	struct tc_action a = {
 		.ops = ops,
+		.hinfo = hinfo,
 	};
 	int i;
 
@@ -327,60 +337,52 @@ static void tcf_hashinfo_destroy(const struct tc_action_ops *ops)
 	}
 	kfree(hinfo->htab);
 }
+EXPORT_SYMBOL(tcf_hashinfo_destroy);
 
 static LIST_HEAD(act_base);
 static DEFINE_RWLOCK(act_mod_lock);
 
-int tcf_register_action(struct tc_action_ops *act, unsigned int mask)
+int tcf_register_action(struct tc_action_ops *act,
+			struct pernet_operations *ops)
 {
 	struct tc_action_ops *a;
-	int err;
+	int ret;
 
-	/* Must supply act, dump and init */
-	if (!act->act || !act->dump || !act->init)
+	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
 		return -EINVAL;
 
-	/* Supply defaults */
-	if (!act->lookup)
-		act->lookup = tcf_hash_search;
-	if (!act->walk)
-		act->walk = tcf_generic_walker;
-
-	act->hinfo = kmalloc(sizeof(struct tcf_hashinfo), GFP_KERNEL);
-	if (!act->hinfo)
-		return -ENOMEM;
-	err = tcf_hashinfo_init(act->hinfo, mask);
-	if (err) {
-		kfree(act->hinfo);
-		return err;
-	}
-
 	write_lock(&act_mod_lock);
 	list_for_each_entry(a, &act_base, head) {
 		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
 			write_unlock(&act_mod_lock);
-			tcf_hashinfo_destroy(act);
-			kfree(act->hinfo);
 			return -EEXIST;
 		}
 	}
 	list_add_tail(&act->head, &act_base);
 	write_unlock(&act_mod_lock);
+
+	ret = register_pernet_subsys(ops);
+	if (ret) {
+		tcf_unregister_action(act, ops);
+		return ret;
+	}
+
 	return 0;
 }
 EXPORT_SYMBOL(tcf_register_action);
 
-int tcf_unregister_action(struct tc_action_ops *act)
+int tcf_unregister_action(struct tc_action_ops *act,
+			  struct pernet_operations *ops)
 {
 	struct tc_action_ops *a;
 	int err = -ENOENT;
 
+	unregister_pernet_subsys(ops);
+
 	write_lock(&act_mod_lock);
 	list_for_each_entry(a, &act_base, head) {
 		if (a == act) {
 			list_del(&act->head);
-			tcf_hashinfo_destroy(act);
-			kfree(act->hinfo);
 			err = 0;
 			break;
 		}
@@ -747,8 +749,8 @@ static struct tc_action *create_a(int i)
 	return act;
 }
 
-static struct tc_action *
-tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
+static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
+					  struct nlmsghdr *n, u32 portid)
 {
 	struct nlattr *tb[TCA_ACT_MAX + 1];
 	struct tc_action *a;
@@ -775,7 +777,7 @@ tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
 	if (a->ops == NULL) /* could happen in batch of actions */
 		goto err_free;
 	err = -ENOENT;
-	if (a->ops->lookup(a, index) == 0)
+	if (a->ops->lookup(net, a, index) == 0)
 		goto err_mod;
 
 	module_put(a->ops->owner);
@@ -845,7 +847,7 @@ static int tca_action_flush(struct net *net, struct nlattr *nla,
 	if (nest == NULL)
 		goto out_module_put;
 
-	err = a.ops->walk(skb, &dcb, RTM_DELACTION, &a);
+	err = a.ops->walk(net, skb, &dcb, RTM_DELACTION, &a);
 	if (err < 0)
 		goto out_module_put;
 	if (err == 0)
@@ -923,7 +925,7 @@ tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
 	}
 
 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
-		act = tcf_action_get_1(tb[i], n, portid);
+		act = tcf_action_get_1(net, tb[i], n, portid);
 		if (IS_ERR(act)) {
 			ret = PTR_ERR(act);
 			goto err;
@@ -1070,6 +1072,7 @@ find_dump_kind(const struct nlmsghdr *n)
 static int
 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
 {
+	struct net *net = sock_net(skb->sk);
 	struct nlmsghdr *nlh;
 	unsigned char *b = skb_tail_pointer(skb);
 	struct nlattr *nest;
@@ -1104,7 +1107,7 @@ tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
 	if (nest == NULL)
 		goto out_module_put;
 
-	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
+	ret = a_o->walk(net, skb, cb, RTM_GETACTION, &a);
 	if (ret < 0)
 		goto out_module_put;