Commit b6a3c606 authored by Victor Nogueira's avatar Victor Nogueira Committed by David S. Miller
Browse files

net: sched: Make tc-related drop reason more flexible for remaining qdiscs 

Incrementing on Daniel's patch[1], make tc-related drop reason more
flexible for remaining qdiscs - that is, all qdiscs aside from clsact.
In essence, the drop reason will be set by cls_api and act_api in case
any error occurred in the data path. With that, we can give the user more
detailed information so that they can distinguish between a policy drop
or an error drop.

[1] https://lore.kernel.org/all/20231009092655.22025-1-daniel@iogearbox.net



Signed-off-by: default avatarVictor Nogueira <victor@mojatatu.com>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fb278072

include/net/pkt_cls.h

+0 −16
Original line number Diff line number Diff line
@@ -154,22 +154,6 @@ __cls_set_class(unsigned long *clp, unsigned long cl) 
	return xchg(clp, cl);

}



struct tc_skb_cb;



static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb);



static inline enum skb_drop_reason

tcf_get_drop_reason(const struct sk_buff *skb)

{

	return tc_skb_cb(skb)->drop_reason;

}



static inline void tcf_set_drop_reason(const struct sk_buff *skb,

				       enum skb_drop_reason reason)

{

	tc_skb_cb(skb)->drop_reason = reason;

}



static inline void

__tcf_bind_filter(struct Qdisc *q, struct tcf_result *r, unsigned long base)

{

include/net/pkt_sched.h

+0 −19
Original line number Diff line number Diff line
@@ -275,25 +275,6 @@ static inline void skb_txtime_consumed(struct sk_buff *skb) 
	skb->tstamp = ktime_set(0, 0);

}



struct tc_skb_cb {

	struct qdisc_skb_cb qdisc_cb;

	u32 drop_reason;



	u16 zone; /* Only valid if post_ct = true */

	u16 mru;

	u8 post_ct:1;

	u8 post_ct_snat:1;

	u8 post_ct_dnat:1;

};



static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)

{

	struct tc_skb_cb *cb = (struct tc_skb_cb *)skb->cb;



	BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));

	return cb;

}



static inline bool tc_qdisc_stats_dump(struct Qdisc *sch,

				       unsigned long cl,

				       struct qdisc_walker *arg)

include/net/sch_generic.h

+31 −0
Original line number Diff line number Diff line
@@ -1036,6 +1036,37 @@ static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 
	return skb;

}



struct tc_skb_cb {

	struct qdisc_skb_cb qdisc_cb;

	u32 drop_reason;



	u16 zone; /* Only valid if post_ct = true */

	u16 mru;

	u8 post_ct:1;

	u8 post_ct_snat:1;

	u8 post_ct_dnat:1;

};



static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)

{

	struct tc_skb_cb *cb = (struct tc_skb_cb *)skb->cb;



	BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));

	return cb;

}



static inline enum skb_drop_reason

tcf_get_drop_reason(const struct sk_buff *skb)

{

	return tc_skb_cb(skb)->drop_reason;

}



static inline void tcf_set_drop_reason(const struct sk_buff *skb,

				       enum skb_drop_reason reason)

{

	tc_skb_cb(skb)->drop_reason = reason;

}



/* Instead of calling kfree_skb() while root qdisc lock is held,

 * queue the skb for future freeing at end of __dev_xmit_skb()

 */

net/core/dev.c

+5 −2
Original line number Diff line number Diff line
@@ -3753,6 +3753,8 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 


	qdisc_calculate_pkt_len(skb, q);



	tcf_set_drop_reason(skb, SKB_DROP_REASON_QDISC_DROP);



	if (q->flags & TCQ_F_NOLOCK) {

		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&

		    qdisc_run_begin(q)) {
@@ -3782,7 +3784,7 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 
no_lock_out:

		if (unlikely(to_free))

			kfree_skb_list_reason(to_free,

					      SKB_DROP_REASON_QDISC_DROP);

					      tcf_get_drop_reason(to_free));

		return rc;

	}
@@ -3837,7 +3839,8 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, 
	}

	spin_unlock(root_lock);

	if (unlikely(to_free))

		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);

		kfree_skb_list_reason(to_free,

				      tcf_get_drop_reason(to_free));

	if (unlikely(contended))

		spin_unlock(&q->busylock);

	return rc;