From 30b0cf90c6dd82e7ebb3fcb5ba8447f1baeb80be Mon Sep 17 00:00:00 2001 From: Paul Blakey Date: Thu, 12 Mar 2020 12:23:07 +0200 Subject: [PATCH] net/sched: act_ct: Support restoring conntrack info on skbs Provide an API to restore the ct state pointer. This may be used by drivers to restore the ct state if they miss in tc chain after they already did the hardware connection tracking action (ct_metadata action). For example, consider the following rule on chain 0 that is in_hw, however chain 1 is not_in_hw: $ tc filter add dev ... chain 0 ... \ flower ... action ct pipe action goto chain 1 Packets of a flow offloaded (via nf flow table offload) by the driver hit this rule in hardware, will be marked with the ct metadata action (mark, label, zone) that does the equivalent of the software ct action, and when the packet jumps to hardware chain 1, there would be a miss. CT was already processed in hardware. Therefore, the driver's miss handling should restore the ct state on the skb, using the provided API, and continue the packet processing in chain 1. Signed-off-by: Paul Blakey Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller --- include/net/flow_offload.h | 1 + include/net/tc_act/tc_ct.h | 7 +++++++ net/sched/act_ct.c | 16 ++++++++++++++++ 3 files changed, 24 insertions(+) diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h index ba43349..a039c90 100644 --- a/include/net/flow_offload.h +++ b/include/net/flow_offload.h @@ -227,6 +227,7 @@ struct flow_action_entry { u16 zone; } ct; struct { + unsigned long cookie; u32 mark; u32 labels[4]; } ct_metadata; diff --git a/include/net/tc_act/tc_ct.h b/include/net/tc_act/tc_ct.h index cf3492e..735da59 100644 --- a/include/net/tc_act/tc_ct.h +++ b/include/net/tc_act/tc_ct.h @@ -55,6 +55,13 @@ static inline uint16_t tcf_ct_zone(const struct tc_action *a) { return 0; } static inline int tcf_ct_action(const struct tc_action *a) { return 0; } #endif /* CONFIG_NF_CONNTRACK */ +#if IS_ENABLED(CONFIG_NET_ACT_CT) +void tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie); +#else +static inline void +tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie) { } +#endif + static inline bool is_tcf_ct(const struct tc_action *a) { #if defined(CONFIG_NET_CLS_ACT) && IS_ENABLED(CONFIG_NF_CONNTRACK) diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c index 9c522bc..31eef8a 100644 --- a/net/sched/act_ct.c +++ b/net/sched/act_ct.c @@ -170,6 +170,7 @@ static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct, { struct nf_conn_labels *ct_labels; struct flow_action_entry *entry; + enum ip_conntrack_info ctinfo; u32 *act_ct_labels; entry = tcf_ct_flow_table_flow_action_get_next(action); @@ -177,6 +178,10 @@ static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct, #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) entry->ct_metadata.mark = ct->mark; #endif + ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED : + IP_CT_ESTABLISHED_REPLY; + /* aligns with the CT reference on the SKB nf_ct_set */ + entry->ct_metadata.cookie = (unsigned long)ct | ctinfo; act_ct_labels = entry->ct_metadata.labels; ct_labels = nf_ct_labels_find(ct); @@ -1530,6 +1535,17 @@ static void __exit ct_cleanup_module(void) destroy_workqueue(act_ct_wq); } +void tcf_ct_flow_table_restore_skb(struct sk_buff *skb, unsigned long cookie) +{ + enum ip_conntrack_info ctinfo = cookie & NFCT_INFOMASK; + struct nf_conn *ct; + + ct = (struct nf_conn *)(cookie & NFCT_PTRMASK); + nf_conntrack_get(&ct->ct_general); + nf_ct_set(skb, ct, ctinfo); +} +EXPORT_SYMBOL_GPL(tcf_ct_flow_table_restore_skb); + module_init(ct_init_module); module_exit(ct_cleanup_module); MODULE_AUTHOR("Paul Blakey "); -- 2.7.4