From 8865fdd4e1538a775c5ac2157fb8eb45bee9dc18 Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:49 -0500
Subject: [PATCH 1/7] net: sched: cls: fix code style issues

This patch changes some code style issues pointed out by checkpatch
inside the TC cls subsystem.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/sch_generic.h | 3 ++-
 net/sched/cls_matchall.c  | 2 +-
 net/sched/cls_u32.c       | 8 ++++----
 3 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index cfc19d0ba2add..c90f5fe6bed90 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -240,7 +240,8 @@ struct tcf_proto_ops {
 					struct tcf_proto*, unsigned long,
 					u32 handle, struct nlattr **,
 					void **, bool);
-	int			(*delete)(struct tcf_proto*, void *, bool*);
+	int			(*delete)(struct tcf_proto *tp, void *arg,
+					  bool *last);
 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
 	void			(*bind_class)(void *, u32, unsigned long);
 
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index d0e57c86636f4..aeae89eeed0d0 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -203,7 +203,7 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 		goto err_set_parms;
 
 	if (!tc_skip_hw(new->flags)) {
-		err = mall_replace_hw_filter(tp, new, (unsigned long) new);
+		err = mall_replace_hw_filter(tp, new, (unsigned long)new);
 		if (err)
 			goto err_replace_hw_filter;
 	}
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 020d328d0afd7..84129b3c14e53 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -783,7 +783,7 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 		if (handle) {
 			ht_down = u32_lookup_ht(ht->tp_c, handle);
 
-			if (ht_down == NULL)
+			if (!ht_down)
 				return -EINVAL;
 			ht_down->refcnt++;
 		}
@@ -907,7 +907,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 	size_t size;
 #endif
 
-	if (opt == NULL)
+	if (!opt)
 		return handle ? -EINVAL : 0;
 
 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, NULL);
@@ -1011,7 +1011,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 			htid = ht->handle;
 		} else {
 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
-			if (ht == NULL)
+			if (!ht)
 				return -EINVAL;
 		}
 	} else {
@@ -1023,7 +1023,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 		return -EINVAL;
 
 	if (handle) {
-		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
+		if (TC_U32_HTID(handle) && TC_U32_HTID(handle ^ htid))
 			return -EINVAL;
 		handle = htid | TC_U32_NODE(handle);
 		err = idr_alloc_ext(&ht->handle_idr, NULL, NULL,

From c35a4acc298528ac7ac8d21284af7cad981aa79d Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:50 -0500
Subject: [PATCH 2/7] net: sched: cls_api: handle generic cls errors

This patch adds extack support for generic cls handling. The extack
will be set deeper to each called function which is not part of netdev
core api.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/sched/cls_api.c | 52 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 41 insertions(+), 11 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 86d6e9d2cf004..3e3841adbd5c5 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -122,7 +122,8 @@ static inline u32 tcf_auto_prio(struct tcf_proto *tp)
 }
 
 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
-					  u32 prio, struct tcf_chain *chain)
+					  u32 prio, struct tcf_chain *chain,
+					  struct netlink_ext_ack *extack)
 {
 	struct tcf_proto *tp;
 	int err;
@@ -148,6 +149,7 @@ static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
 			module_put(tp->ops->owner);
 			err = -EAGAIN;
 		} else {
+			NL_SET_ERR_MSG(extack, "TC classifier not found");
 			err = -ENOENT;
 		}
 		goto errout;
@@ -935,7 +937,8 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 			      struct nlmsghdr *n, struct tcf_proto *tp,
 			      struct tcf_block *block, struct Qdisc *q,
-			      u32 parent, void *fh, bool unicast, bool *last)
+			      u32 parent, void *fh, bool unicast, bool *last,
+			      struct netlink_ext_ack *extack)
 {
 	struct sk_buff *skb;
 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -947,6 +950,7 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 
 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
 			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER) <= 0) {
+		NL_SET_ERR_MSG(extack, "Failed to build del event notification");
 		kfree_skb(skb);
 		return -EINVAL;
 	}
@@ -960,8 +964,11 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 	if (unicast)
 		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
 
-	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
-			      n->nlmsg_flags & NLM_F_ECHO);
+	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
+			     n->nlmsg_flags & NLM_F_ECHO);
+	if (err < 0)
+		NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
+	return err;
 }
 
 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
@@ -1021,8 +1028,10 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	if (prio == 0) {
 		switch (n->nlmsg_type) {
 		case RTM_DELTFILTER:
-			if (protocol || t->tcm_handle || tca[TCA_KIND])
+			if (protocol || t->tcm_handle || tca[TCA_KIND]) {
+				NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
 				return -ENOENT;
+			}
 			break;
 		case RTM_NEWTFILTER:
 			/* If no priority is provided by the user,
@@ -1035,6 +1044,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 			}
 			/* fall-through */
 		default:
+			NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
 			return -ENOENT;
 		}
 	}
@@ -1063,23 +1073,31 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 			parent = q->handle;
 		} else {
 			q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
-			if (!q)
+			if (!q) {
+				NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
 				return -EINVAL;
+			}
 		}
 
 		/* Is it classful? */
 		cops = q->ops->cl_ops;
-		if (!cops)
+		if (!cops) {
+			NL_SET_ERR_MSG(extack, "Qdisc not classful");
 			return -EINVAL;
+		}
 
-		if (!cops->tcf_block)
+		if (!cops->tcf_block) {
+			NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
 			return -EOPNOTSUPP;
+		}
 
 		/* Do we search for filter, attached to class? */
 		if (TC_H_MIN(parent)) {
 			cl = cops->find(q, parent);
-			if (cl == 0)
+			if (cl == 0) {
+				NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
 				return -ENOENT;
+			}
 		}
 
 		/* And the last stroke */
@@ -1097,12 +1115,14 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
 	if (chain_index > TC_ACT_EXT_VAL_MASK) {
+		NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
 		err = -EINVAL;
 		goto errout;
 	}
 	chain = tcf_chain_get(block, chain_index,
 			      n->nlmsg_type == RTM_NEWTFILTER);
 	if (!chain) {
+		NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
 		err = n->nlmsg_type == RTM_NEWTFILTER ? -ENOMEM : -EINVAL;
 		goto errout;
 	}
@@ -1118,6 +1138,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
 			       prio, prio_allocate);
 	if (IS_ERR(tp)) {
+		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
 		err = PTR_ERR(tp);
 		goto errout;
 	}
@@ -1126,12 +1147,14 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		/* Proto-tcf does not exist, create new one */
 
 		if (tca[TCA_KIND] == NULL || !protocol) {
+			NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
 			err = -EINVAL;
 			goto errout;
 		}
 
 		if (n->nlmsg_type != RTM_NEWTFILTER ||
 		    !(n->nlmsg_flags & NLM_F_CREATE)) {
+			NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
 			err = -ENOENT;
 			goto errout;
 		}
@@ -1140,13 +1163,14 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 			prio = tcf_auto_prio(tcf_chain_tp_prev(&chain_info));
 
 		tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
-				      protocol, prio, chain);
+				      protocol, prio, chain, extack);
 		if (IS_ERR(tp)) {
 			err = PTR_ERR(tp);
 			goto errout;
 		}
 		tp_created = 1;
 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
+		NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
 		err = -EINVAL;
 		goto errout;
 	}
@@ -1165,6 +1189,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 		if (n->nlmsg_type != RTM_NEWTFILTER ||
 		    !(n->nlmsg_flags & NLM_F_CREATE)) {
+			NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
 			err = -ENOENT;
 			goto errout;
 		}
@@ -1176,13 +1201,15 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 			if (n->nlmsg_flags & NLM_F_EXCL) {
 				if (tp_created)
 					tcf_proto_destroy(tp);
+				NL_SET_ERR_MSG(extack, "Filter already exists");
 				err = -EEXIST;
 				goto errout;
 			}
 			break;
 		case RTM_DELTFILTER:
 			err = tfilter_del_notify(net, skb, n, tp, block,
-						 q, parent, fh, false, &last);
+						 q, parent, fh, false, &last,
+						 extack);
 			if (err)
 				goto errout;
 			if (last) {
@@ -1193,8 +1220,11 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 		case RTM_GETTFILTER:
 			err = tfilter_notify(net, skb, n, tp, block, q, parent,
 					     fh, RTM_NEWTFILTER, true);
+			if (err < 0)
+				NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
 			goto errout;
 		default:
+			NL_SET_ERR_MSG(extack, "Invalid netlink message type");
 			err = -EINVAL;
 			goto errout;
 		}

From 7306db38a67cf6b8e1ca354b1d0c0117b7b880d5 Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:51 -0500
Subject: [PATCH 3/7] net: sched: cls: add extack support for change callback

This patch adds extack support for classifier change callback api. This
prepares to handle extack support inside each specific classifier
implementation.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/sch_generic.h | 3 ++-
 net/sched/cls_api.c       | 3 ++-
 net/sched/cls_basic.c     | 3 ++-
 net/sched/cls_bpf.c       | 2 +-
 net/sched/cls_cgroup.c    | 3 ++-
 net/sched/cls_flow.c      | 2 +-
 net/sched/cls_flower.c    | 2 +-
 net/sched/cls_fw.c        | 2 +-
 net/sched/cls_matchall.c  | 2 +-
 net/sched/cls_route.c     | 3 ++-
 net/sched/cls_rsvp.h      | 2 +-
 net/sched/cls_tcindex.c   | 3 ++-
 net/sched/cls_u32.c       | 3 ++-
 13 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index c90f5fe6bed90..ee398bcd46e7b 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -239,7 +239,8 @@ struct tcf_proto_ops {
 	int			(*change)(struct net *net, struct sk_buff *,
 					struct tcf_proto*, unsigned long,
 					u32 handle, struct nlattr **,
-					void **, bool);
+					void **, bool,
+					struct netlink_ext_ack *);
 	int			(*delete)(struct tcf_proto *tp, void *arg,
 					  bool *last);
 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 3e3841adbd5c5..06797c2e81025 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1231,7 +1231,8 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 	}
 
 	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);
+			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
+			      extack);
 	if (err == 0) {
 		if (tp_created)
 			tcf_chain_tp_insert(chain, &chain_info, tp);
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index 5f169ded347e8..2cc38cd719383 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -175,7 +175,8 @@ static int basic_set_parms(struct net *net, struct tcf_proto *tp,
 
 static int basic_change(struct net *net, struct sk_buff *in_skb,
 			struct tcf_proto *tp, unsigned long base, u32 handle,
-			struct nlattr **tca, void **arg, bool ovr)
+			struct nlattr **tca, void **arg, bool ovr,
+			struct netlink_ext_ack *extack)
 {
 	int err;
 	struct basic_head *head = rtnl_dereference(tp->root);
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index cf72aefcf98da..e51eb503a23a2 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -452,7 +452,7 @@ static int cls_bpf_set_parms(struct net *net, 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,
-			  void **arg, bool ovr)
+			  void **arg, bool ovr, struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 	struct cls_bpf_prog *oldprog = *arg;
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 309d5899265f8..b74af0b558208 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -91,7 +91,8 @@ static void cls_cgroup_destroy_rcu(struct rcu_head *root)
 static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 			     struct tcf_proto *tp, unsigned long base,
 			     u32 handle, struct nlattr **tca,
-			     void **arg, bool ovr)
+			     void **arg, bool ovr,
+			     struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[TCA_CGROUP_MAX + 1];
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 28cd6fb52c16b..faa0b6793a171 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -401,7 +401,7 @@ static void flow_destroy_filter(struct rcu_head *head)
 static int flow_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
-		       void **arg, bool ovr)
+		       void **arg, bool ovr, struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *fold, *fnew;
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index f61df19b10264..7d92bbeeba545 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -853,7 +853,7 @@ static int fl_set_parms(struct net *net, struct tcf_proto *tp,
 static int fl_change(struct net *net, struct sk_buff *in_skb,
 		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle, struct nlattr **tca,
-		     void **arg, bool ovr)
+		     void **arg, bool ovr, struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *fold = *arg;
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 20f0de1a960a7..72784491ce20a 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -257,7 +257,7 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 static int fw_change(struct net *net, struct sk_buff *in_skb,
 		     struct tcf_proto *tp, unsigned long base,
 		     u32 handle, struct nlattr **tca, void **arg,
-		     bool ovr)
+		     bool ovr, struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = *arg;
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index aeae89eeed0d0..689bd199aa142 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -160,7 +160,7 @@ static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 static int mall_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle, struct nlattr **tca,
-		       void **arg, bool ovr)
+		       void **arg, bool ovr, struct netlink_ext_ack *extack)
 {
 	struct cls_mall_head *head = rtnl_dereference(tp->root);
 	struct nlattr *tb[TCA_MATCHALL_MAX + 1];
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index a1f2b1b7c0145..f436d4d894a92 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -471,7 +471,8 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 
 static int route4_change(struct net *net, struct sk_buff *in_skb,
 			 struct tcf_proto *tp, unsigned long base, u32 handle,
-			 struct nlattr **tca, void **arg, bool ovr)
+			 struct nlattr **tca, void **arg, bool ovr,
+			 struct netlink_ext_ack *extack)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	struct route4_filter __rcu **fp;
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index cf325625c99da..d1f67529c01d6 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -486,7 +486,7 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 		       struct tcf_proto *tp, unsigned long base,
 		       u32 handle,
 		       struct nlattr **tca,
-		       void **arg, bool ovr)
+		       void **arg, bool ovr, struct netlink_ext_ack *extack)
 {
 	struct rsvp_head *data = rtnl_dereference(tp->root);
 	struct rsvp_filter *f, *nfp;
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 67467ae24c976..0ec84cf2d6b77 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -520,7 +520,8 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 static int
 tcindex_change(struct net *net, struct sk_buff *in_skb,
 	       struct tcf_proto *tp, unsigned long base, u32 handle,
-	       struct nlattr **tca, void **arg, bool ovr)
+	       struct nlattr **tca, void **arg, bool ovr,
+	       struct netlink_ext_ack *extack)
 {
 	struct nlattr *opt = tca[TCA_OPTIONS];
 	struct nlattr *tb[TCA_TCINDEX_MAX + 1];
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 84129b3c14e53..d9cadebc7eaa7 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -893,7 +893,8 @@ static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
 
 static int u32_change(struct net *net, struct sk_buff *in_skb,
 		      struct tcf_proto *tp, unsigned long base, u32 handle,
-		      struct nlattr **tca, void **arg, bool ovr)
+		      struct nlattr **tca, void **arg, bool ovr,
+		      struct netlink_ext_ack *extack)
 {
 	struct tc_u_common *tp_c = tp->data;
 	struct tc_u_hnode *ht;

From 50a561900e66a03f5127edac57487079bc0b8201 Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:52 -0500
Subject: [PATCH 4/7] net: sched: cls: add extack support for tcf_exts_validate

The tcf_exts_validate function calls the act api change callback. For
preparing extack support for act api, this patch adds the extack as
parameter for this function which is common used in cls implementations.

Furthermore the tcf_exts_validate will call action init callback which
prepares the TC action subsystem for extack support.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/pkt_cls.h    |  3 ++-
 net/sched/cls_api.c      |  7 +++++--
 net/sched/cls_basic.c    |  8 +++++---
 net/sched/cls_bpf.c      |  8 +++++---
 net/sched/cls_cgroup.c   |  3 ++-
 net/sched/cls_flow.c     |  3 ++-
 net/sched/cls_flower.c   |  8 +++++---
 net/sched/cls_fw.c       | 10 ++++++----
 net/sched/cls_matchall.c |  8 +++++---
 net/sched/cls_route.c    |  6 +++---
 net/sched/cls_rsvp.h     |  2 +-
 net/sched/cls_tcindex.c  |  6 +++---
 net/sched/cls_u32.c      | 10 ++++++----
 13 files changed, 50 insertions(+), 32 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 789d818c4a618..6dd009e10e5dc 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -376,7 +376,8 @@ 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, bool ovr);
+		      struct tcf_exts *exts, bool ovr,
+		      struct netlink_ext_ack *extack);
 void tcf_exts_destroy(struct tcf_exts *exts);
 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src);
 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 06797c2e81025..f365970dc68c4 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1423,7 +1423,8 @@ void tcf_exts_destroy(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, bool ovr)
+		      struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
+		      struct netlink_ext_ack *extack)
 {
 #ifdef CONFIG_NET_CLS_ACT
 	{
@@ -1456,8 +1457,10 @@ int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
 	}
 #else
 	if ((exts->action && tb[exts->action]) ||
-	    (exts->police && tb[exts->police]))
+	    (exts->police && tb[exts->police])) {
+		NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
 		return -EOPNOTSUPP;
+	}
 #endif
 
 	return 0;
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index 2cc38cd719383..b7bcf67641bf2 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -152,11 +152,12 @@ 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, bool ovr)
+			   struct nlattr *est, bool ovr,
+			   struct netlink_ext_ack *extack)
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
 	if (err < 0)
 		return err;
 
@@ -222,7 +223,8 @@ static int basic_change(struct net *net, struct sk_buff *in_skb,
 		fnew->handle = idr_index;
 	}
 
-	err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr);
+	err = basic_set_parms(net, tp, fnew, base, tb, tca[TCA_RATE], ovr,
+			      extack);
 	if (err < 0) {
 		if (!fold)
 			idr_remove_ext(&head->handle_idr, fnew->handle);
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index e51eb503a23a2..c86072779b0a5 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -403,7 +403,8 @@ static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 
 static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 			     struct cls_bpf_prog *prog, unsigned long base,
-			     struct nlattr **tb, struct nlattr *est, bool ovr)
+			     struct nlattr **tb, struct nlattr *est, bool ovr,
+			     struct netlink_ext_ack *extack)
 {
 	bool is_bpf, is_ebpf, have_exts = false;
 	u32 gen_flags = 0;
@@ -414,7 +415,7 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
 		return -EINVAL;
 
-	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr);
+	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, ovr, extack);
 	if (ret < 0)
 		return ret;
 
@@ -500,7 +501,8 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 		prog->handle = handle;
 	}
 
-	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
+	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr,
+				extack);
 	if (ret < 0)
 		goto errout_idr;
 
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index b74af0b558208..aaafcf6965f70 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -122,7 +122,8 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 	if (err < 0)
 		goto errout;
 
-	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &new->exts, ovr,
+				extack);
 	if (err < 0)
 		goto errout;
 
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index faa0b6793a171..07816133cbb9e 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -454,7 +454,8 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
 	if (err < 0)
 		goto err2;
 
-	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, ovr,
+				extack);
 	if (err < 0)
 		goto err2;
 
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 7d92bbeeba545..8235ed9143c4e 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -827,11 +827,12 @@ static int fl_check_assign_mask(struct cls_fl_head *head,
 static int fl_set_parms(struct net *net, struct tcf_proto *tp,
 			struct cls_fl_filter *f, struct fl_flow_mask *mask,
 			unsigned long base, struct nlattr **tb,
-			struct nlattr *est, bool ovr)
+			struct nlattr *est, bool ovr,
+			struct netlink_ext_ack *extack)
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
 	if (err < 0)
 		return err;
 
@@ -916,7 +917,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		}
 	}
 
-	err = fl_set_parms(net, tp, fnew, &mask, base, tb, tca[TCA_RATE], ovr);
+	err = fl_set_parms(net, tp, fnew, &mask, base, tb, tca[TCA_RATE], ovr,
+			   extack);
 	if (err)
 		goto errout_idr;
 
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 72784491ce20a..72a924a38753d 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -218,13 +218,15 @@ static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
 
 static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 			struct fw_filter *f, struct nlattr **tb,
-			struct nlattr **tca, unsigned long base, bool ovr)
+			struct nlattr **tca, unsigned long base, bool ovr,
+			struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	u32 mask;
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &f->exts, ovr,
+				extack);
 	if (err < 0)
 		return err;
 
@@ -296,7 +298,7 @@ static int fw_change(struct net *net, struct sk_buff *in_skb,
 			return err;
 		}
 
-		err = fw_set_parms(net, tp, fnew, tb, tca, base, ovr);
+		err = fw_set_parms(net, tp, fnew, tb, tca, base, ovr, extack);
 		if (err < 0) {
 			tcf_exts_destroy(&fnew->exts);
 			kfree(fnew);
@@ -345,7 +347,7 @@ static int fw_change(struct net *net, struct sk_buff *in_skb,
 	f->id = handle;
 	f->tp = tp;
 
-	err = fw_set_parms(net, tp, f, tb, tca, base, ovr);
+	err = fw_set_parms(net, tp, f, tb, tca, base, ovr, extack);
 	if (err < 0)
 		goto errout;
 
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index 689bd199aa142..9a0901ee6b741 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -142,11 +142,12 @@ static const struct nla_policy mall_policy[TCA_MATCHALL_MAX + 1] = {
 static int mall_set_parms(struct net *net, struct tcf_proto *tp,
 			  struct cls_mall_head *head,
 			  unsigned long base, struct nlattr **tb,
-			  struct nlattr *est, bool ovr)
+			  struct nlattr *est, bool ovr,
+			  struct netlink_ext_ack *extack)
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, est, &head->exts, ovr, extack);
 	if (err < 0)
 		return err;
 
@@ -198,7 +199,8 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 	new->handle = handle;
 	new->flags = flags;
 
-	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr);
+	err = mall_set_parms(net, tp, new, base, tb, tca[TCA_RATE], ovr,
+			     extack);
 	if (err)
 		goto err_set_parms;
 
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index f436d4d894a92..92d683851cb08 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -389,7 +389,7 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 			    unsigned long base, struct route4_filter *f,
 			    u32 handle, struct route4_head *head,
 			    struct nlattr **tb, struct nlattr *est, int new,
-			    bool ovr)
+			    bool ovr, struct netlink_ext_ack *extack)
 {
 	u32 id = 0, to = 0, nhandle = 0x8000;
 	struct route4_filter *fp;
@@ -397,7 +397,7 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 	struct route4_bucket *b;
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
 	if (err < 0)
 		return err;
 
@@ -516,7 +516,7 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
 	}
 
 	err = route4_set_parms(net, tp, base, f, handle, head, tb,
-			       tca[TCA_RATE], new, ovr);
+			       tca[TCA_RATE], new, ovr, extack);
 	if (err < 0)
 		goto errout;
 
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index d1f67529c01d6..c27d23694002f 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -511,7 +511,7 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb,
 	err = tcf_exts_init(&e, TCA_RSVP_ACT, TCA_RSVP_POLICE);
 	if (err < 0)
 		return err;
-	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr, extack);
 	if (err < 0)
 		goto errout2;
 
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 0ec84cf2d6b77..9d6621caa92fb 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -322,7 +322,7 @@ static int
 tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 		  u32 handle, struct tcindex_data *p,
 		  struct tcindex_filter_result *r, struct nlattr **tb,
-		  struct nlattr *est, bool ovr)
+		  struct nlattr *est, bool ovr, struct netlink_ext_ack *extack)
 {
 	struct tcindex_filter_result new_filter_result, *old_r = r;
 	struct tcindex_filter_result cr;
@@ -334,7 +334,7 @@ tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	err = tcf_exts_init(&e, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 	if (err < 0)
 		return err;
-	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
+	err = tcf_exts_validate(net, tp, tb, est, &e, ovr, extack);
 	if (err < 0)
 		goto errout;
 
@@ -541,7 +541,7 @@ tcindex_change(struct net *net, struct sk_buff *in_skb,
 		return err;
 
 	return tcindex_set_parms(net, tp, base, handle, p, r, tb,
-				 tca[TCA_RATE], ovr);
+				 tca[TCA_RATE], ovr, extack);
 }
 
 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index d9cadebc7eaa7..933058bbd0a9e 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -765,11 +765,12 @@ static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 			 unsigned long base, struct tc_u_hnode *ht,
 			 struct tc_u_knode *n, struct nlattr **tb,
-			 struct nlattr *est, bool ovr)
+			 struct nlattr *est, bool ovr,
+			 struct netlink_ext_ack *extack)
 {
 	int err;
 
-	err = tcf_exts_validate(net, tp, tb, est, &n->exts, ovr);
+	err = tcf_exts_validate(net, tp, tb, est, &n->exts, ovr, extack);
 	if (err < 0)
 		return err;
 
@@ -937,7 +938,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 
 		err = u32_set_parms(net, tp, base,
 				    rtnl_dereference(n->ht_up), new, tb,
-				    tca[TCA_RATE], ovr);
+				    tca[TCA_RATE], ovr, extack);
 
 		if (err) {
 			u32_destroy_key(tp, new, false);
@@ -1084,7 +1085,8 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 	}
 #endif
 
-	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
+	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr,
+			    extack);
 	if (err == 0) {
 		struct tc_u_knode __rcu **ins;
 		struct tc_u_knode *pins;

From 571acf2106963d6c1c0ce1ed13e711bd296b2d25 Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:53 -0500
Subject: [PATCH 5/7] net: sched: cls: add extack support for delete callback

This patch adds extack support for classifier delete callback api. This
prepares to handle extack support inside each specific classifier
implementation.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/sch_generic.h | 3 ++-
 net/sched/cls_api.c       | 2 +-
 net/sched/cls_basic.c     | 3 ++-
 net/sched/cls_bpf.c       | 3 ++-
 net/sched/cls_cgroup.c    | 3 ++-
 net/sched/cls_flow.c      | 3 ++-
 net/sched/cls_flower.c    | 3 ++-
 net/sched/cls_fw.c        | 3 ++-
 net/sched/cls_matchall.c  | 3 ++-
 net/sched/cls_route.c     | 3 ++-
 net/sched/cls_rsvp.h      | 3 ++-
 net/sched/cls_tcindex.c   | 5 +++--
 net/sched/cls_u32.c       | 3 ++-
 13 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index ee398bcd46e7b..cd1be1f25c36a 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -242,7 +242,8 @@ struct tcf_proto_ops {
 					void **, bool,
 					struct netlink_ext_ack *);
 	int			(*delete)(struct tcf_proto *tp, void *arg,
-					  bool *last);
+					  bool *last,
+					  struct netlink_ext_ack *);
 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
 	void			(*bind_class)(void *, u32, unsigned long);
 
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index f365970dc68c4..f5d293416f46a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -955,7 +955,7 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
 		return -EINVAL;
 	}
 
-	err = tp->ops->delete(tp, fh, last);
+	err = tp->ops->delete(tp, fh, last, extack);
 	if (err) {
 		kfree_skb(skb);
 		return err;
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index b7bcf67641bf2..6088be65d1676 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -130,7 +130,8 @@ static void basic_destroy(struct tcf_proto *tp)
 	kfree_rcu(head, rcu);
 }
 
-static int basic_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int basic_delete(struct tcf_proto *tp, void *arg, bool *last,
+			struct netlink_ext_ack *extack)
 {
 	struct basic_head *head = rtnl_dereference(tp->root);
 	struct basic_filter *f = arg;
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index c86072779b0a5..fc024fc3ec2fa 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -295,7 +295,8 @@ static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)
 		__cls_bpf_delete_prog(prog);
 }
 
-static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last,
+			  struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
 
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index aaafcf6965f70..1b54fbfca414f 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -156,7 +156,8 @@ static void cls_cgroup_destroy(struct tcf_proto *tp)
 	}
 }
 
-static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last,
+			     struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
index 07816133cbb9e..64c24b4880581 100644
--- a/net/sched/cls_flow.c
+++ b/net/sched/cls_flow.c
@@ -575,7 +575,8 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static int flow_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int flow_delete(struct tcf_proto *tp, void *arg, bool *last,
+		       struct netlink_ext_ack *extack)
 {
 	struct flow_head *head = rtnl_dereference(tp->root);
 	struct flow_filter *f = arg;
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 8235ed9143c4e..50145b873ff14 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -985,7 +985,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static int fl_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int fl_delete(struct tcf_proto *tp, void *arg, bool *last,
+		     struct netlink_ext_ack *extack)
 {
 	struct cls_fl_head *head = rtnl_dereference(tp->root);
 	struct cls_fl_filter *f = arg;
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 72a924a38753d..bd21ed83eb07a 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -172,7 +172,8 @@ static void fw_destroy(struct tcf_proto *tp)
 	kfree_rcu(head, rcu);
 }
 
-static int fw_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int fw_delete(struct tcf_proto *tp, void *arg, bool *last,
+		     struct netlink_ext_ack *extack)
 {
 	struct fw_head *head = rtnl_dereference(tp->root);
 	struct fw_filter *f = arg;
diff --git a/net/sched/cls_matchall.c b/net/sched/cls_matchall.c
index 9a0901ee6b741..f67d3d7fcf40b 100644
--- a/net/sched/cls_matchall.c
+++ b/net/sched/cls_matchall.c
@@ -225,7 +225,8 @@ static int mall_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static int mall_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int mall_delete(struct tcf_proto *tp, void *arg, bool *last,
+		       struct netlink_ext_ack *extack)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index 92d683851cb08..55467c30d5245 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -316,7 +316,8 @@ static void route4_destroy(struct tcf_proto *tp)
 	kfree_rcu(head, rcu);
 }
 
-static int route4_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int route4_delete(struct tcf_proto *tp, void *arg, bool *last,
+			 struct netlink_ext_ack *extack)
 {
 	struct route4_head *head = rtnl_dereference(tp->root);
 	struct route4_filter *f = arg;
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h
index c27d23694002f..5cc0df690cff6 100644
--- a/net/sched/cls_rsvp.h
+++ b/net/sched/cls_rsvp.h
@@ -350,7 +350,8 @@ static void rsvp_destroy(struct tcf_proto *tp)
 	kfree_rcu(data, rcu);
 }
 
-static int rsvp_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int rsvp_delete(struct tcf_proto *tp, void *arg, bool *last,
+		       struct netlink_ext_ack *extack)
 {
 	struct rsvp_head *head = rtnl_dereference(tp->root);
 	struct rsvp_filter *nfp, *f = arg;
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 9d6621caa92fb..01a163e0b6aa2 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -193,7 +193,8 @@ static void tcindex_destroy_fexts(struct rcu_head *head)
 	tcf_queue_work(&f->work);
 }
 
-static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
+			  struct netlink_ext_ack *extack)
 {
 	struct tcindex_data *p = rtnl_dereference(tp->root);
 	struct tcindex_filter_result *r = arg;
@@ -246,7 +247,7 @@ static int tcindex_destroy_element(struct tcf_proto *tp,
 {
 	bool last;
 
-	return tcindex_delete(tp, arg, &last);
+	return tcindex_delete(tp, arg, &last, NULL);
 }
 
 static void __tcindex_destroy(struct rcu_head *head)
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 933058bbd0a9e..7f772da8e6272 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -672,7 +672,8 @@ static void u32_destroy(struct tcf_proto *tp)
 	tp->data = NULL;
 }
 
-static int u32_delete(struct tcf_proto *tp, void *arg, bool *last)
+static int u32_delete(struct tcf_proto *tp, void *arg, bool *last,
+		      struct netlink_ext_ack *extack)
 {
 	struct tc_u_hnode *ht = arg;
 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);

From 1057c55f6b6cdc4fa3e8e29cfb9061c211e58395 Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:54 -0500
Subject: [PATCH 6/7] net: sched: cls: add extack support for tcf_change_indev

This patch adds extack handling for the tcf_change_indev function which
is common used by TC classifier implementations.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/net/pkt_cls.h  | 7 +++++--
 net/sched/cls_flower.c | 7 ++++---
 net/sched/cls_fw.c     | 2 +-
 net/sched/cls_u32.c    | 2 +-
 4 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 6dd009e10e5dc..2e4b8e436d25d 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -557,13 +557,16 @@ static inline int tcf_valid_offset(const struct sk_buff *skb,
 #include <net/net_namespace.h>
 
 static inline int
-tcf_change_indev(struct net *net, struct nlattr *indev_tlv)
+tcf_change_indev(struct net *net, struct nlattr *indev_tlv,
+		 struct netlink_ext_ack *extack)
 {
 	char indev[IFNAMSIZ];
 	struct net_device *dev;
 
-	if (nla_strlcpy(indev, indev_tlv, IFNAMSIZ) >= IFNAMSIZ)
+	if (nla_strlcpy(indev, indev_tlv, IFNAMSIZ) >= IFNAMSIZ) {
+		NL_SET_ERR_MSG(extack, "Interface name too long");
 		return -EINVAL;
+	}
 	dev = __dev_get_by_name(net, indev);
 	if (!dev)
 		return -ENODEV;
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 50145b873ff14..c6ac4a612c4ac 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -526,13 +526,14 @@ static void fl_set_key_ip(struct nlattr **tb,
 }
 
 static int fl_set_key(struct net *net, struct nlattr **tb,
-		      struct fl_flow_key *key, struct fl_flow_key *mask)
+		      struct fl_flow_key *key, struct fl_flow_key *mask,
+		      struct netlink_ext_ack *extack)
 {
 	__be16 ethertype;
 	int ret = 0;
 #ifdef CONFIG_NET_CLS_IND
 	if (tb[TCA_FLOWER_INDEV]) {
-		int err = tcf_change_indev(net, tb[TCA_FLOWER_INDEV]);
+		int err = tcf_change_indev(net, tb[TCA_FLOWER_INDEV], extack);
 		if (err < 0)
 			return err;
 		key->indev_ifindex = err;
@@ -841,7 +842,7 @@ static int fl_set_parms(struct net *net, struct tcf_proto *tp,
 		tcf_bind_filter(tp, &f->res, base);
 	}
 
-	err = fl_set_key(net, tb, &f->key, &mask->key);
+	err = fl_set_key(net, tb, &f->key, &mask->key, extack);
 	if (err)
 		return err;
 
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index bd21ed83eb07a..94d159a8869ac 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -239,7 +239,7 @@ static int fw_set_parms(struct net *net, struct tcf_proto *tp,
 #ifdef CONFIG_NET_CLS_IND
 	if (tb[TCA_FW_INDEV]) {
 		int ret;
-		ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
+		ret = tcf_change_indev(net, tb[TCA_FW_INDEV], extack);
 		if (ret < 0)
 			return ret;
 		f->ifindex = ret;
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 7f772da8e6272..e8963ed358997 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -804,7 +804,7 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 #ifdef CONFIG_NET_CLS_IND
 	if (tb[TCA_U32_INDEV]) {
 		int ret;
-		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
+		ret = tcf_change_indev(net, tb[TCA_U32_INDEV], extack);
 		if (ret < 0)
 			return -EINVAL;
 		n->ifindex = ret;

From 4b981dbc22727fbb9162ec76a2d0a1c4ecb0831c Mon Sep 17 00:00:00 2001
From: Alexander Aring <aring@mojatatu.com>
Date: Thu, 18 Jan 2018 11:20:55 -0500
Subject: [PATCH 7/7] net: sched: cls_u32: add extack support

This patch adds extack support for the u32 classifier as example for
delete and init callback.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/sched/cls_u32.c | 58 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 14 deletions(-)

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index e8963ed358997..57113e9361558 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -689,13 +689,16 @@ static int u32_delete(struct tcf_proto *tp, void *arg, bool *last,
 		goto out;
 	}
 
-	if (root_ht == ht)
+	if (root_ht == ht) {
+		NL_SET_ERR_MSG_MOD(extack, "Not allowed to delete root node");
 		return -EINVAL;
+	}
 
 	if (ht->refcnt == 1) {
 		ht->refcnt--;
 		u32_destroy_hnode(tp, ht);
 	} else {
+		NL_SET_ERR_MSG_MOD(extack, "Can not delete in-use filter");
 		return -EBUSY;
 	}
 
@@ -779,14 +782,18 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
 		struct tc_u_hnode *ht_down = NULL, *ht_old;
 
-		if (TC_U32_KEY(handle))
+		if (TC_U32_KEY(handle)) {
+			NL_SET_ERR_MSG_MOD(extack, "u32 Link handle must be a hash table");
 			return -EINVAL;
+		}
 
 		if (handle) {
 			ht_down = u32_lookup_ht(ht->tp_c, handle);
 
-			if (!ht_down)
+			if (!ht_down) {
+				NL_SET_ERR_MSG_MOD(extack, "Link hash table not found");
 				return -EINVAL;
+			}
 			ht_down->refcnt++;
 		}
 
@@ -910,28 +917,40 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 	size_t size;
 #endif
 
-	if (!opt)
-		return handle ? -EINVAL : 0;
+	if (!opt) {
+		if (handle) {
+			NL_SET_ERR_MSG_MOD(extack, "Filter handle requires options");
+			return -EINVAL;
+		} else {
+			return 0;
+		}
+	}
 
-	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, NULL);
+	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, extack);
 	if (err < 0)
 		return err;
 
 	if (tb[TCA_U32_FLAGS]) {
 		flags = nla_get_u32(tb[TCA_U32_FLAGS]);
-		if (!tc_flags_valid(flags))
+		if (!tc_flags_valid(flags)) {
+			NL_SET_ERR_MSG_MOD(extack, "Invalid filter flags");
 			return -EINVAL;
+		}
 	}
 
 	n = *arg;
 	if (n) {
 		struct tc_u_knode *new;
 
-		if (TC_U32_KEY(n->handle) == 0)
+		if (TC_U32_KEY(n->handle) == 0) {
+			NL_SET_ERR_MSG_MOD(extack, "Key node id cannot be zero");
 			return -EINVAL;
+		}
 
-		if (n->flags != flags)
+		if (n->flags != flags) {
+			NL_SET_ERR_MSG_MOD(extack, "Key node flags do not match passed flags");
 			return -EINVAL;
+		}
 
 		new = u32_init_knode(tp, n);
 		if (!new)
@@ -965,10 +984,14 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 	if (tb[TCA_U32_DIVISOR]) {
 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
 
-		if (--divisor > 0x100)
+		if (--divisor > 0x100) {
+			NL_SET_ERR_MSG_MOD(extack, "Exceeded maximum 256 hash buckets");
 			return -EINVAL;
-		if (TC_U32_KEY(handle))
+		}
+		if (TC_U32_KEY(handle)) {
+			NL_SET_ERR_MSG_MOD(extack, "Divisor can only be used on a hash table");
 			return -EINVAL;
+		}
 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
 		if (ht == NULL)
 			return -ENOBUFS;
@@ -1014,20 +1037,26 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 			htid = ht->handle;
 		} else {
 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
-			if (!ht)
+			if (!ht) {
+				NL_SET_ERR_MSG_MOD(extack, "Specified hash table not found");
 				return -EINVAL;
+			}
 		}
 	} else {
 		ht = rtnl_dereference(tp->root);
 		htid = ht->handle;
 	}
 
-	if (ht->divisor < TC_U32_HASH(htid))
+	if (ht->divisor < TC_U32_HASH(htid)) {
+		NL_SET_ERR_MSG_MOD(extack, "Specified hash table buckets exceed configured value");
 		return -EINVAL;
+	}
 
 	if (handle) {
-		if (TC_U32_HTID(handle) && TC_U32_HTID(handle ^ htid))
+		if (TC_U32_HTID(handle) && TC_U32_HTID(handle ^ htid)) {
+			NL_SET_ERR_MSG_MOD(extack, "Handle specified hash table address mismatch");
 			return -EINVAL;
+		}
 		handle = htid | TC_U32_NODE(handle);
 		err = idr_alloc_ext(&ht->handle_idr, NULL, NULL,
 				    handle, handle + 1,
@@ -1038,6 +1067,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 		handle = gen_new_kid(ht, htid);
 
 	if (tb[TCA_U32_SEL] == NULL) {
+		NL_SET_ERR_MSG_MOD(extack, "Selector not specified");
 		err = -EINVAL;
 		goto erridr;
 	}