net: sched: Move drop_reason to struct tc_skb_cb

Move drop_reason from struct tcf_result to skb cb - more specifically to
struct tc_skb_cb. With that, we'll be able to also set the drop reason for
the remaining qdiscs (aside from clsact) that do not have access to
tcf_result when time comes to set the skb drop reason.

Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 16 deletions

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 3a7770eff52d..db500aa9f841 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -1119,7 +1119,7 @@ repeat:
 			}
 		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
 			if (unlikely(!rcu_access_pointer(a->goto_chain))) {
-				tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+				tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 				return TC_ACT_SHOT;
 			}
 			tcf_action_goto_chain_exec(a, res);
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index dc1c19a25882..199406e4bcdd 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1657,7 +1657,6 @@ static inline int __tcf_classify(struct sk_buff *skb,
 				 int act_index,
 				 u32 *last_executed_chain)
 {
-	u32 orig_reason = res->drop_reason;
 #ifdef CONFIG_NET_CLS_ACT
 	const int max_reclassify_loop = 16;
 	const struct tcf_proto *first_tp;
@@ -1682,13 +1681,13 @@ reclassify:
 			 */
 			if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
 				     !tp->ops->get_exts)) {
-				tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+				tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 				return TC_ACT_SHOT;
 			}
 
 			exts = tp->ops->get_exts(tp, n->handle);
 			if (unlikely(!exts || n->exts != exts)) {
-				tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+				tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 				return TC_ACT_SHOT;
 			}
 
@@ -1712,18 +1711,12 @@ reclassify:
 			goto reset;
 		}
 #endif
-		if (err >= 0) {
-			/* Policy drop or drop reason is over-written by
-			 * classifiers with a bogus value(0) */
-			if (err == TC_ACT_SHOT &&
-			    res->drop_reason == SKB_NOT_DROPPED_YET)
-				tcf_set_drop_reason(res, orig_reason);
+		if (err >= 0)
 			return err;
-		}
 	}
 
 	if (unlikely(n)) {
-		tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+		tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 		return TC_ACT_SHOT;
 	}
 
@@ -1735,7 +1728,7 @@ reset:
 				       tp->chain->block->index,
 				       tp->prio & 0xffff,
 				       ntohs(tp->protocol));
-		tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+		tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 		return TC_ACT_SHOT;
 	}
 
@@ -1773,7 +1766,7 @@ int tcf_classify(struct sk_buff *skb,
 				n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
 								&act_index);
 				if (!n) {
-					tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+					tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 					return TC_ACT_SHOT;
 				}
 
@@ -1784,7 +1777,7 @@ int tcf_classify(struct sk_buff *skb,
 
 			fchain = tcf_chain_lookup_rcu(block, chain);
 			if (!fchain) {
-				tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+				tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 				return TC_ACT_SHOT;
 			}
 
@@ -1806,7 +1799,7 @@ int tcf_classify(struct sk_buff *skb,
 
 			ext = tc_skb_ext_alloc(skb);
 			if (WARN_ON_ONCE(!ext)) {
-				tcf_set_drop_reason(res, SKB_DROP_REASON_TC_ERROR);
+				tcf_set_drop_reason(skb, SKB_DROP_REASON_TC_ERROR);
 				return TC_ACT_SHOT;
 			}