[PATCH net 3/5] net: sched: cls_u32: Undo tcf_bind_filter if u32_replace_hw_knode

[Victor Nogueira <victor@mojatatu.com>]

When u32_replace_hw_knode fails, we need to undo the tcf_bind_filter
operation done at u32_set_parms.

Fixes: d34e3e181395 ("net: cls_u32: Add support for skip-sw flag to tc u32 classifier.")

Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
---
 net/sched/cls_u32.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index d15d50de7980..e193db39bee2 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -712,11 +712,13 @@ static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
 	[TCA_U32_FLAGS]		= { .type = NLA_U32 },
 };
 
+#define U32_SET_FLAGS_BOUND 0x1
+
 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 			 unsigned long base,
 			 struct tc_u_knode *n, struct nlattr **tb,
 			 struct nlattr *est, u32 flags, u32 fl_flags,
-			 struct netlink_ext_ack *extack)
+			 u8 *set_flags, struct netlink_ext_ack *extack)
 {
 	int err, ifindex = -1;
 
@@ -763,6 +765,7 @@ static int u32_set_parms(struct net *net, struct tcf_proto *tp,
 	if (tb[TCA_U32_CLASSID]) {
 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
 		tcf_bind_filter(tp, &n->res, base);
+		*set_flags |= U32_SET_FLAGS_BOUND;
 	}
 
 	if (ifindex >= 0)
@@ -853,6 +856,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 		      struct netlink_ext_ack *extack)
 {
 	struct tc_u_common *tp_c = tp->data;
+	u8 set_flags = 0;
 	struct tc_u_hnode *ht;
 	struct tc_u_knode *n;
 	struct tc_u32_sel *s;
@@ -905,7 +909,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 
 		err = u32_set_parms(net, tp, base, new, tb,
 				    tca[TCA_RATE], flags, new->flags,
-				    extack);
+				    &set_flags, extack);
 
 		if (err) {
 			__u32_destroy_key(new);
@@ -914,6 +918,9 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 
 		err = u32_replace_hw_knode(tp, new, flags, extack);
 		if (err) {
+			if (set_flags & U32_SET_FLAGS_BOUND)
+				tcf_unbind_filter(tp, &new->res);
+
 			__u32_destroy_key(new);
 			return err;
 		}
@@ -1075,14 +1082,14 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 #endif
 
 	err = u32_set_parms(net, tp, base, n, tb, tca[TCA_RATE],
-			    flags, n->flags, extack);
+			    flags, n->flags, &set_flags, extack);
 	if (err == 0) {
 		struct tc_u_knode __rcu **ins;
 		struct tc_u_knode *pins;
 
 		err = u32_replace_hw_knode(tp, n, flags, extack);
 		if (err)
-			goto errhw;
+			goto errunbind;
 
 		if (!tc_in_hw(n->flags))
 			n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
@@ -1100,7 +1107,10 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 		return 0;
 	}
 
-errhw:
+errunbind:
+	if (set_flags & U32_SET_FLAGS_BOUND)
+		tcf_unbind_filter(tp, &n->res);
+
 #ifdef CONFIG_CLS_U32_MARK
 	free_percpu(n->pcpu_success);
 #endif
-- 
2.25.1