Commit 2f7ef2f8 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

sched, cls: check if we could overwrite actions when changing a filter 



When actions are attached to a filter, they are a part of the filter
itself, so when changing a filter we should allow to overwrite the actions
inside as well.

In my specific case, when I tried to _append_ a new action to an existing
filter which already has an action, I got EEXIST since kernel refused
to overwrite the existing one in kernel.

This patch checks if we are changing the filter checking NLM_F_CREATE flag
(Sigh, filters don't use NLM_F_REPLACE...) and then passes the boolean down
to actions. This fixes the problem above.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarCong Wang <cwang@twopensource.com>
Signed-off-by: default avatarJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4940b8cd

include/net/pkt_cls.h

+1 −1
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ tcf_exts_exec(struct sk_buff *skb, struct tcf_exts *exts, 


int tcf_exts_validate(struct net *net, struct tcf_proto *tp,

		      struct nlattr **tb, struct nlattr *rate_tlv,

		      struct tcf_exts *exts);

		      struct tcf_exts *exts, bool ovr);

void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts);

void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,

		     struct tcf_exts *src);

include/net/sch_generic.h

+1 −1
Original line number Diff line number Diff line
@@ -199,7 +199,7 @@ struct tcf_proto_ops { 
	int			(*change)(struct net *net, struct sk_buff *,

					struct tcf_proto*, unsigned long,

					u32 handle, struct nlattr **,

					unsigned long *);

					unsigned long *, bool);

	int			(*delete)(struct tcf_proto*, unsigned long);

	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);

net/sched/cls_api.c

+5 −4
Original line number Diff line number Diff line
@@ -317,7 +317,8 @@ replay: 
		}

	}



	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh);

	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) {

			spin_lock_bh(root_lock);
@@ -504,7 +505,7 @@ void tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts) 
EXPORT_SYMBOL(tcf_exts_destroy);



int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,

		  struct nlattr *rate_tlv, struct tcf_exts *exts)

		  struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)

{

#ifdef CONFIG_NET_CLS_ACT

	{
@@ -513,7 +514,7 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 
		INIT_LIST_HEAD(&exts->actions);

		if (exts->police && tb[exts->police]) {

			act = tcf_action_init_1(net, tb[exts->police], rate_tlv,

						"police", TCA_ACT_NOREPLACE,

						"police", ovr,

						TCA_ACT_BIND);

			if (IS_ERR(act))

				return PTR_ERR(act);
@@ -523,7 +524,7 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb, 
		} else if (exts->action && tb[exts->action]) {

			int err;

			err = tcf_action_init(net, tb[exts->action], rate_tlv,

					      NULL, TCA_ACT_NOREPLACE,

					      NULL, ovr,

					      TCA_ACT_BIND, &exts->actions);

			if (err)

				return err;

net/sched/cls_basic.c

+5 −5
Original line number Diff line number Diff line
@@ -130,14 +130,14 @@ static const struct nla_policy basic_policy[TCA_BASIC_MAX + 1] = { 
static int basic_set_parms(struct net *net, struct tcf_proto *tp,

			   struct basic_filter *f, unsigned long base,

			   struct nlattr **tb,

			   struct nlattr *est)

			   struct nlattr *est, bool ovr)

{

	int err;

	struct tcf_exts e;

	struct tcf_ematch_tree t;



	tcf_exts_init(&e, TCA_BASIC_ACT, TCA_BASIC_POLICE);

	err = tcf_exts_validate(net, tp, tb, est, &e);

	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);

	if (err < 0)

		return err;
@@ -161,7 +161,7 @@ errout: 


static int basic_change(struct net *net, struct sk_buff *in_skb,

			struct tcf_proto *tp, unsigned long base, u32 handle,

			struct nlattr **tca, unsigned long *arg)

			struct nlattr **tca, unsigned long *arg, bool ovr)

{

	int err;

	struct basic_head *head = tp->root;
@@ -179,7 +179,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb, 
	if (f != NULL) {

		if (handle && f->handle != handle)

			return -EINVAL;

		return basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE]);

		return basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr);

	}



	err = -ENOBUFS;
@@ -206,7 +206,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb, 
		f->handle = head->hgenerator;

	}



	err = basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE]);

	err = basic_set_parms(net, tp, f, base, tb, tca[TCA_RATE], ovr);

	if (err < 0)

		goto errout;

net/sched/cls_bpf.c

+5 −5
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ static void cls_bpf_put(struct tcf_proto *tp, unsigned long f) 
static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,

				   struct cls_bpf_prog *prog,

				   unsigned long base, struct nlattr **tb,

				   struct nlattr *est)

				   struct nlattr *est, bool ovr)

{

	struct sock_filter *bpf_ops, *bpf_old;

	struct tcf_exts exts;
@@ -170,7 +170,7 @@ static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp, 
		return -EINVAL;



	tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);

	ret = tcf_exts_validate(net, tp, tb, est, &exts);

	ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);

	if (ret < 0)

		return ret;
@@ -242,7 +242,7 @@ static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp, 
static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,

			  struct tcf_proto *tp, unsigned long base,

			  u32 handle, struct nlattr **tca,

			  unsigned long *arg)

			  unsigned long *arg, bool ovr)

{

	struct cls_bpf_head *head = tp->root;

	struct cls_bpf_prog *prog = (struct cls_bpf_prog *) *arg;
@@ -260,7 +260,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 
		if (handle && prog->handle != handle)

			return -EINVAL;

		return cls_bpf_modify_existing(net, tp, prog, base, tb,

					       tca[TCA_RATE]);

					       tca[TCA_RATE], ovr);

	}



	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
@@ -277,7 +277,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb, 
		goto errout;

	}



	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE]);

	ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE], ovr);

	if (ret < 0)

		goto errout;

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