net/sched: store the last executed chain also for clsact egress

currently, only 'ingress' and 'clsact ingress' qdiscs store the tc 'chain
id' in the skb extension. However, userspace programs (like ovs) are able
to setup egress rules, and datapath gets confused in case it doesn't find
the 'chain id' for a packet that's "recirculated" by tc.
Change tcf_classify() to have the same semantic as tcf_classify_ingress()
so that a single function can be called in ingress / egress, using the tc
ingress / egress block respectively.

Suggested-by: Alaa Hleilel <alaa@nvidia.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index ec78239..dc28fcb 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -76,12 +76,10 @@ static inline struct Qdisc *tcf_block_q(struct tcf_block *block)
 	return block->q;
 }
 
-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_block *ingress_block,
-			 const struct tcf_proto *tp, struct tcf_result *res,
-			 bool compat_mode);
+int tcf_classify(struct sk_buff *skb,
+		 const struct tcf_block *block,
+		 const struct tcf_proto *tp, struct tcf_result *res,
+		 bool compat_mode);
 
 #else
 static inline bool tcf_block_shared(struct tcf_block *block)
@@ -138,20 +136,14 @@ void tc_setup_cb_block_unregister(struct tcf_block *block, flow_setup_cb_t *cb,
 {
 }
 
-static inline int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+static inline int tcf_classify(struct sk_buff *skb,
+			       const struct tcf_block *block,
+			       const struct tcf_proto *tp,
 			       struct tcf_result *res, bool compat_mode)
 {
 	return TC_ACT_UNSPEC;
 }
 
-static inline int tcf_classify_ingress(struct sk_buff *skb,
-				       const struct tcf_block *ingress_block,
-				       const struct tcf_proto *tp,
-				       struct tcf_result *res, bool compat_mode)
-{
-	return TC_ACT_UNSPEC;
-}
-
 #endif
 
 static inline unsigned long
diff --git a/net/core/dev.c b/net/core/dev.c
index dcc87fc..b51e41d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4012,7 +4012,7 @@ sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
 	qdisc_skb_cb(skb)->post_ct = false;
 	mini_qdisc_bstats_cpu_update(miniq, skb);
 
-	switch (tcf_classify(skb, miniq->filter_list, &cl_res, false)) {
+	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
 	case TC_ACT_OK:
 	case TC_ACT_RECLASSIFY:
 		skb->tc_index = TC_H_MIN(cl_res.classid);
@@ -5164,8 +5164,7 @@ 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_ingress(skb, miniq->block, miniq->filter_list,
-				     &cl_res, false)) {
+	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
 	case TC_ACT_OK:
 	case TC_ACT_RECLASSIFY:
 		skb->tc_index = TC_H_MIN(cl_res.classid);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 1167cd0..7be5b9d 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1577,21 +1577,11 @@ static inline int __tcf_classify(struct sk_buff *skb,
 #endif
 }
 
-int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+int tcf_classify(struct sk_buff *skb,
+		 const struct tcf_block *block,
+		 const struct tcf_proto *tp,
 		 struct tcf_result *res, bool compat_mode)
 {
-	u32 last_executed_chain = 0;
-
-	return __tcf_classify(skb, tp, tp, res, compat_mode,
-			      &last_executed_chain);
-}
-EXPORT_SYMBOL(tcf_classify);
-
-int tcf_classify_ingress(struct sk_buff *skb,
-			 const struct tcf_block *ingress_block,
-			 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;
 
@@ -1603,20 +1593,22 @@ int tcf_classify_ingress(struct sk_buff *skb,
 	struct tc_skb_ext *ext;
 	int ret;
 
-	ext = skb_ext_find(skb, TC_SKB_EXT);
+	if (block) {
+		ext = skb_ext_find(skb, TC_SKB_EXT);
 
-	if (ext && ext->chain) {
-		struct tcf_chain *fchain;
+		if (ext && ext->chain) {
+			struct tcf_chain *fchain;
 
-		fchain = tcf_chain_lookup_rcu(ingress_block, ext->chain);
-		if (!fchain)
-			return TC_ACT_SHOT;
+			fchain = tcf_chain_lookup_rcu(block, ext->chain);
+			if (!fchain)
+				return TC_ACT_SHOT;
 
-		/* Consume, so cloned/redirect skbs won't inherit ext */
-		skb_ext_del(skb, TC_SKB_EXT);
+			/* Consume, so cloned/redirect skbs won't inherit ext */
+			skb_ext_del(skb, TC_SKB_EXT);
 
-		tp = rcu_dereference_bh(fchain->filter_chain);
-		last_executed_chain = fchain->index;
+			tp = rcu_dereference_bh(fchain->filter_chain);
+			last_executed_chain = fchain->index;
+		}
 	}
 
 	ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
@@ -1635,7 +1627,7 @@ int tcf_classify_ingress(struct sk_buff *skb,
 	return ret;
 #endif
 }
-EXPORT_SYMBOL(tcf_classify_ingress);
+EXPORT_SYMBOL(tcf_classify);
 
 struct tcf_chain_info {
 	struct tcf_proto __rcu **pprev;
@@ -3825,7 +3817,7 @@ struct sk_buff *tcf_qevent_handle(struct tcf_qevent *qe, struct Qdisc *sch, stru
 
 	fl = rcu_dereference_bh(qe->filter_chain);
 
-	switch (tcf_classify(skb, fl, &cl_res, false)) {
+	switch (tcf_classify(skb, NULL, fl, &cl_res, false)) {
 	case TC_ACT_SHOT:
 		qdisc_qstats_drop(sch);
 		__qdisc_drop(skb, to_free);
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index d0c9a57..7d85181 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -394,7 +394,7 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		list_for_each_entry(flow, &p->flows, list) {
 			fl = rcu_dereference_bh(flow->filter_list);
 			if (fl) {
-				result = tcf_classify(skb, fl, &res, true);
+				result = tcf_classify(skb, NULL, fl, &res, true);
 				if (result < 0)
 					continue;
 				flow = (struct atm_flow_data *)res.class;
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 9515428..ecc5c4d 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1665,7 +1665,7 @@ static u32 cake_classify(struct Qdisc *sch, struct cake_tin_data **t,
 		goto hash;
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	result = tcf_classify(skb, filter, &res, false);
+	result = tcf_classify(skb, NULL, filter, &res, false);
 
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index b79a7e2..2dabaff 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -228,7 +228,7 @@ cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 		/*
 		 * Step 2+n. Apply classifier.
 		 */
-		result = tcf_classify(skb, fl, &res, true);
+		result = tcf_classify(skb, NULL, fl, &res, true);
 		if (!fl || result < 0)
 			goto fallback;
 
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index fc1e470..642cd17 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -317,7 +317,7 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch,
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 	fl = rcu_dereference_bh(q->filter_list);
-	result = tcf_classify(skb, fl, &res, false);
+	result = tcf_classify(skb, NULL, fl, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index d320bcf..4c100d1 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -242,7 +242,7 @@ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	else {
 		struct tcf_result res;
 		struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
-		int result = tcf_classify(skb, fl, &res, false);
+		int result = tcf_classify(skb, NULL, fl, &res, false);
 
 		pr_debug("result %d class 0x%04x\n", result, res.classid);
 
diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c
index c1e84d1..925924f 100644
--- a/net/sched/sch_ets.c
+++ b/net/sched/sch_ets.c
@@ -390,7 +390,7 @@ static struct ets_class *ets_classify(struct sk_buff *skb, struct Qdisc *sch,
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 	if (TC_H_MAJ(skb->priority) != sch->handle) {
 		fl = rcu_dereference_bh(q->filter_list);
-		err = tcf_classify(skb, fl, &res, false);
+		err = tcf_classify(skb, NULL, fl, &res, false);
 #ifdef CONFIG_NET_CLS_ACT
 		switch (err) {
 		case TC_ACT_STOLEN:
diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c
index bbd5f87..c4afdd0 100644
--- a/net/sched/sch_fq_codel.c
+++ b/net/sched/sch_fq_codel.c
@@ -91,7 +91,7 @@ static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
 		return fq_codel_hash(q, skb) + 1;
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	result = tcf_classify(skb, filter, &res, false);
+	result = tcf_classify(skb, NULL, filter, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c
index cac6849..830f355 100644
--- a/net/sched/sch_fq_pie.c
+++ b/net/sched/sch_fq_pie.c
@@ -94,7 +94,7 @@ static unsigned int fq_pie_classify(struct sk_buff *skb, struct Qdisc *sch,
 		return fq_pie_hash(q, skb) + 1;
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	result = tcf_classify(skb, filter, &res, false);
+	result = tcf_classify(skb, NULL, filter, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index bf0034c..b7ac30c 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1130,7 +1130,7 @@ hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 	head = &q->root;
 	tcf = rcu_dereference_bh(q->root.filter_list);
-	while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
+	while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
 		case TC_ACT_QUEUED:
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 5f7ac27..81ea833 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -238,7 +238,7 @@ static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
 	}
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
+	while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
 		case TC_ACT_QUEUED:
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 5c27b42..e282e73 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -36,7 +36,7 @@ multiq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 	int err;
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	err = tcf_classify(skb, fl, &res, false);
+	err = tcf_classify(skb, NULL, fl, &res, false);
 #ifdef CONFIG_NET_CLS_ACT
 	switch (err) {
 	case TC_ACT_STOLEN:
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 3eabb87..03fdf31 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -39,7 +39,7 @@ prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 	if (TC_H_MAJ(skb->priority) != sch->handle) {
 		fl = rcu_dereference_bh(q->filter_list);
-		err = tcf_classify(skb, fl, &res, false);
+		err = tcf_classify(skb, NULL, fl, &res, false);
 #ifdef CONFIG_NET_CLS_ACT
 		switch (err) {
 		case TC_ACT_STOLEN:
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index b692a0d..58a9d42 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -690,7 +690,7 @@ static struct qfq_class *qfq_classify(struct sk_buff *skb, struct Qdisc *sch,
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 	fl = rcu_dereference_bh(q->filter_list);
-	result = tcf_classify(skb, fl, &res, false);
+	result = tcf_classify(skb, NULL, fl, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index dde829d..3d061a1 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -257,7 +257,7 @@ static bool sfb_classify(struct sk_buff *skb, struct tcf_proto *fl,
 	struct tcf_result res;
 	int result;
 
-	result = tcf_classify(skb, fl, &res, false);
+	result = tcf_classify(skb, NULL, fl, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 066754a..f8e569f 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -178,7 +178,7 @@ static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch,
 		return sfq_hash(q, skb) + 1;
 
 	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
-	result = tcf_classify(skb, fl, &res, false);
+	result = tcf_classify(skb, NULL, fl, &res, false);
 	if (result >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
 		switch (result) {