From af699626ee268244423b3c6d43e4daaca40a3ed0 Mon Sep 17 00:00:00 2001 From: Paul Blakey Date: Sun, 16 Feb 2020 12:01:24 +0200 Subject: [PATCH] net: sched: Support specifying a starting chain via tc skb ext Set the starting chain from the tc skb ext chain value. Once we read the tc skb ext, delete it, so cloned/redirect packets won't inherit it. In order to lookup a chain by the chain index on the ingress block at ingress classification, provide a lookup function. Co-developed-by: Vlad Buslov Signed-off-by: Vlad Buslov Signed-off-by: Paul Blakey Reviewed-by: Jiri Pirko Signed-off-by: Saeed Mahameed --- net/sched/cls_api.c | 39 +++++++++++++++++++++++++++++++++++---- 1 file changed, 35 insertions(+), 4 deletions(-) diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index a634c85f1e0e..e604ebec1282 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -454,6 +454,20 @@ static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block, return NULL; } +#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) +static struct tcf_chain *tcf_chain_lookup_rcu(const struct tcf_block *block, + u32 chain_index) +{ + struct tcf_chain *chain; + + list_for_each_entry_rcu(chain, &block->chain_list, list) { + if (chain->index == chain_index) + return chain; + } + return NULL; +} +#endif + static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, u32 seq, u16 flags, int event, bool unicast); @@ -1562,13 +1576,13 @@ static int tcf_block_setup(struct tcf_block *block, */ static inline int __tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, + const struct tcf_proto *orig_tp, struct tcf_result *res, bool compat_mode, u32 *last_executed_chain) { #ifdef CONFIG_NET_CLS_ACT const int max_reclassify_loop = 4; - const struct tcf_proto *orig_tp = tp; const struct tcf_proto *first_tp; int limit = 0; @@ -1619,7 +1633,7 @@ int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp, { u32 last_executed_chain = 0; - return __tcf_classify(skb, tp, res, compat_mode, + return __tcf_classify(skb, tp, tp, res, compat_mode, &last_executed_chain); } EXPORT_SYMBOL(tcf_classify); @@ -1632,14 +1646,31 @@ int tcf_classify_ingress(struct sk_buff *skb, #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT) u32 last_executed_chain = 0; - return __tcf_classify(skb, tp, res, compat_mode, + return __tcf_classify(skb, tp, tp, res, compat_mode, &last_executed_chain); #else u32 last_executed_chain = tp ? tp->chain->index : 0; + const struct tcf_proto *orig_tp = tp; struct tc_skb_ext *ext; int ret; - ret = __tcf_classify(skb, tp, res, compat_mode, &last_executed_chain); + ext = skb_ext_find(skb, TC_SKB_EXT); + + if (ext && ext->chain) { + struct tcf_chain *fchain; + + fchain = tcf_chain_lookup_rcu(ingress_block, ext->chain); + if (!fchain) + return TC_ACT_SHOT; + + /* Consume, so cloned/redirect skbs won't inherit ext */ + skb_ext_del(skb, TC_SKB_EXT); + + tp = rcu_dereference_bh(fchain->filter_chain); + } + + ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, + &last_executed_chain); /* If we missed on some chain */ if (ret == TC_ACT_UNSPEC && last_executed_chain) { -- 2.11.0