Commit 9410c940 authored by Paul Blakey's avatar Paul Blakey Committed by Saeed Mahameed
Browse files

net: sched: Introduce ingress classification function 



TC multi chain configuration can cause offloaded tc chains to miss in
hardware after jumping to some chain. In such cases the software should
continue from the chain that missed in hardware, as the hardware may
have manipulated the packet and updated some counters.

Currently a single tcf classification function serves both ingress and
egress. However, multi chain miss processing (get tc skb extension on
hw miss, set tc skb extension on tc miss) should happen only on
ingress.

Refactor the code to use ingress classification function, and move setting
the tc skb extension from general classification to it, as a prestep
for supporting the hw miss scenario.

Co-developed-by: default avatarVlad Buslov <vladbu@mellanox.com>
Signed-off-by: default avatarVlad Buslov <vladbu@mellanox.com>
Signed-off-by: default avatarPaul Blakey <paulb@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
parent 2bb07f4e

include/net/pkt_cls.h

+10 −0
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ static inline struct Qdisc *tcf_block_q(struct tcf_block *block) 


int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,

		 struct tcf_result *res, bool compat_mode);

int tcf_classify_ingress(struct sk_buff *skb, const struct tcf_proto *tp,

			 struct tcf_result *res, bool compat_mode);



#else

static inline bool tcf_block_shared(struct tcf_block *block)
@@ -133,6 +135,14 @@ static inline int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 
{

	return TC_ACT_UNSPEC;

}



static inline int tcf_classify_ingress(struct sk_buff *skb,

				       const struct tcf_proto *tp,

				       struct tcf_result *res, bool compat_mode)

{

	return TC_ACT_UNSPEC;

}



#endif



static inline unsigned long

net/core/dev.c

+2 −1
Original line number Diff line number Diff line
@@ -4860,7 +4860,8 @@ sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret, 
	skb->tc_at_ingress = 1;

	mini_qdisc_bstats_cpu_update(miniq, skb);



	switch (tcf_classify(skb, miniq->filter_list, &cl_res, false)) {

	switch (tcf_classify_ingress(skb, miniq->filter_list, &cl_res,

				     false)) {

	case TC_ACT_OK:

	case TC_ACT_RECLASSIFY:

		skb->tc_index = TC_H_MIN(cl_res.classid);

net/sched/cls_api.c

+44 −14
Original line number Diff line number Diff line
@@ -1559,8 +1559,11 @@ static int tcf_block_setup(struct tcf_block *block, 
 * to this qdisc, (optionally) tests for protocol and asks

 * specific classifiers.

 */

int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,

		 struct tcf_result *res, bool compat_mode)

static inline int __tcf_classify(struct sk_buff *skb,

				 const struct tcf_proto *tp,

				 struct tcf_result *res,

				 bool compat_mode,

				 u32 *last_executed_chain)

{

#ifdef CONFIG_NET_CLS_ACT

	const int max_reclassify_loop = 4;
@@ -1582,21 +1585,11 @@ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 
#ifdef CONFIG_NET_CLS_ACT

		if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {

			first_tp = orig_tp;

			*last_executed_chain = first_tp->chain->index;

			goto reset;

		} else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {

			first_tp = res->goto_tp;



#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)

			{

				struct tc_skb_ext *ext;



				ext = skb_ext_add(skb, TC_SKB_EXT);

				if (WARN_ON_ONCE(!ext))

					return TC_ACT_SHOT;



				ext->chain = err & TC_ACT_EXT_VAL_MASK;

			}

#endif

			*last_executed_chain = err & TC_ACT_EXT_VAL_MASK;

			goto reset;

		}

#endif
@@ -1619,8 +1612,45 @@ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, 
	goto reclassify;

#endif

}



int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,

		 struct tcf_result *res, bool compat_mode)

{

	u32 last_executed_chain = 0;



	return __tcf_classify(skb, tp, res, compat_mode,

			      &last_executed_chain);

}

EXPORT_SYMBOL(tcf_classify);



int tcf_classify_ingress(struct sk_buff *skb, const struct tcf_proto *tp,

			 struct tcf_result *res, bool compat_mode)

{

#if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)

	u32 last_executed_chain = 0;



	return __tcf_classify(skb, tp, res, compat_mode,

			      &last_executed_chain);

#else

	u32 last_executed_chain = tp ? tp->chain->index : 0;

	struct tc_skb_ext *ext;

	int ret;



	ret = __tcf_classify(skb, tp, res, compat_mode, &last_executed_chain);



	/* If we missed on some chain */

	if (ret == TC_ACT_UNSPEC && last_executed_chain) {

		ext = skb_ext_add(skb, TC_SKB_EXT);

		if (WARN_ON_ONCE(!ext))

			return TC_ACT_SHOT;

		ext->chain = last_executed_chain;

	}



	return ret;

#endif

}

EXPORT_SYMBOL(tcf_classify_ingress);



struct tcf_chain_info {

	struct tcf_proto __rcu **pprev;

	struct tcf_proto __rcu *next;