net/sched: Retire tcindex classifier

The tcindex classifier has served us well for about a quarter of a century
but has not been getting much TLC due to lack of known users. Most recently
it has become easy prey to syzkaller. For this reason, we are retiring it.

Signed-off-by: Jamal Hadi Salim <[email protected]>
Acked-by: Jiri Pirko <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: jhsmt

include/net/tc_wrapper.h

@@ -154,7 +154,6 @@ TC_INDIRECT_FILTER_DECLARE(mall_classify);
 TC_INDIRECT_FILTER_DECLARE(route4_classify);
 TC_INDIRECT_FILTER_DECLARE(rsvp_classify);
 TC_INDIRECT_FILTER_DECLARE(rsvp6_classify);
-TC_INDIRECT_FILTER_DECLARE(tcindex_classify);
 TC_INDIRECT_FILTER_DECLARE(u32_classify);
 
 static inline int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
@@ -207,10 +206,6 @@ static inline int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 	if (tp->classify == rsvp6_classify)
 		return rsvp6_classify(skb, tp, res);
 #endif
-#if IS_BUILTIN(CONFIG_NET_CLS_TCINDEX)
-	if (tp->classify == tcindex_classify)
-		return tcindex_classify(skb, tp, res);
-#endif
 
 skip:
 	return tp->classify(skb, tp, res);

net/sched/Kconfig

@@ -468,17 +468,6 @@ config NET_CLS_BASIC
 	  To compile this code as a module, choose M here: the
 	  module will be called cls_basic.
 
-config NET_CLS_TCINDEX
-	tristate "Traffic-Control Index (TCINDEX)"
-	select NET_CLS
-	help
-	  Say Y here if you want to be able to classify packets based on
-	  traffic control indices. You will want this feature if you want
-	  to implement Differentiated Services together with DSMARK.
-
-	  To compile this code as a module, choose M here: the
-	  module will be called cls_tcindex.
-
 config NET_CLS_ROUTE4
 	tristate "Routing decision (ROUTE)"
 	depends on INET

net/sched/Makefile

@@ -68,7 +68,6 @@ obj-$(CONFIG_NET_CLS_U32)	+= cls_u32.o
 obj-$(CONFIG_NET_CLS_ROUTE4)	+= cls_route.o
 obj-$(CONFIG_NET_CLS_FW)	+= cls_fw.o
 obj-$(CONFIG_NET_CLS_RSVP)	+= cls_rsvp.o
-obj-$(CONFIG_NET_CLS_TCINDEX)	+= cls_tcindex.o
 obj-$(CONFIG_NET_CLS_RSVP6)	+= cls_rsvp6.o
 obj-$(CONFIG_NET_CLS_BASIC)	+= cls_basic.o
 obj-$(CONFIG_NET_CLS_FLOW)	+= cls_flow.o