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>

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

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);

net/sched/cls_api.c

@@ -1577,20 +1577,10 @@ 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);

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;

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

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;
 

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) {

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);
 

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:

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) {

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) {

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:

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:

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:

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:

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) {

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) {

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) {