From: Guillaume Nault <gnault@redhat.com>
Date: Mon, 23 Mar 2020 21:48:49 +0100
Subject: cls_flower: Add extack support for mpls options
Patch-mainline: v5.7-rc1
Git-commit: 442f730e48a77eb3d60ec9a97da1a0e9e802711b
References: bsc#1176447

Pass extack down to fl_set_key_mpls() and set message on error.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/cls_flower.c |   23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -766,7 +766,8 @@ static int fl_set_key_port_range(struct
 
 static int fl_set_key_mpls(struct nlattr **tb,
 			   struct flow_dissector_key_mpls *key_val,
-			   struct flow_dissector_key_mpls *key_mask)
+			   struct flow_dissector_key_mpls *key_mask,
+			   struct netlink_ext_ack *extack)
 {
 	if (tb[TCA_FLOWER_KEY_MPLS_TTL]) {
 		key_val->mpls_ttl = nla_get_u8(tb[TCA_FLOWER_KEY_MPLS_TTL]);
@@ -775,24 +776,36 @@ static int fl_set_key_mpls(struct nlattr
 	if (tb[TCA_FLOWER_KEY_MPLS_BOS]) {
 		u8 bos = nla_get_u8(tb[TCA_FLOWER_KEY_MPLS_BOS]);
 
-		if (bos & ~MPLS_BOS_MASK)
+		if (bos & ~MPLS_BOS_MASK) {
+			NL_SET_ERR_MSG_ATTR(extack,
+					    tb[TCA_FLOWER_KEY_MPLS_BOS],
+					    "Bottom Of Stack (BOS) must be 0 or 1");
 			return -EINVAL;
+		}
 		key_val->mpls_bos = bos;
 		key_mask->mpls_bos = MPLS_BOS_MASK;
 	}
 	if (tb[TCA_FLOWER_KEY_MPLS_TC]) {
 		u8 tc = nla_get_u8(tb[TCA_FLOWER_KEY_MPLS_TC]);
 
-		if (tc & ~MPLS_TC_MASK)
+		if (tc & ~MPLS_TC_MASK) {
+			NL_SET_ERR_MSG_ATTR(extack,
+					    tb[TCA_FLOWER_KEY_MPLS_TC],
+					    "Traffic Class (TC) must be between 0 and 7");
 			return -EINVAL;
+		}
 		key_val->mpls_tc = tc;
 		key_mask->mpls_tc = MPLS_TC_MASK;
 	}
 	if (tb[TCA_FLOWER_KEY_MPLS_LABEL]) {
 		u32 label = nla_get_u32(tb[TCA_FLOWER_KEY_MPLS_LABEL]);
 
-		if (label & ~MPLS_LABEL_MASK)
+		if (label & ~MPLS_LABEL_MASK) {
+			NL_SET_ERR_MSG_ATTR(extack,
+					    tb[TCA_FLOWER_KEY_MPLS_LABEL],
+					    "Label must be between 0 and 1048575");
 			return -EINVAL;
+		}
 		key_val->mpls_label = label;
 		key_mask->mpls_label = MPLS_LABEL_MASK;
 	}
@@ -1364,7 +1377,7 @@ static int fl_set_key(struct net *net, s
 			       sizeof(key->icmp.code));
 	} else if (key->basic.n_proto == htons(ETH_P_MPLS_UC) ||
 		   key->basic.n_proto == htons(ETH_P_MPLS_MC)) {
-		ret = fl_set_key_mpls(tb, &key->mpls, &mask->mpls);
+		ret = fl_set_key_mpls(tb, &key->mpls, &mask->mpls, extack);
 		if (ret)
 			return ret;
 	} else if (key->basic.n_proto == htons(ETH_P_ARP) ||