From e7246e122aaa99ebbb8ad7da80f35a20577bd8af Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Sat, 7 Jan 2017 17:06:35 -0500 Subject: [PATCH] net-tc: extract skip classify bit from tc_verd Packets sent by the IFB device skip subsequent tc classification. A single bit governs this state. Move it out of tc_verd in anticipation of removing that __u16 completely. The new bitfield tc_skip_classify temporarily uses one bit of a hole, until tc_verd is removed completely in a follow-up patch. Remove the bit hole comment. It could be 2, 3, 4 or 5 bits long. With that many options, little value in documenting it. Introduce a helper function to deduplicate the logic in the two sites that check this bit. The field tc_skip_classify is set only in IFB on skbs cloned in act_mirred, so original packet sources do not have to clear the bit when reusing packets (notably, pktgen and octeon). Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- drivers/net/ifb.c | 2 +- include/linux/skbuff.h | 5 ++++- include/net/sch_generic.h | 11 +++++++++++ include/uapi/linux/pkt_cls.h | 6 ------ net/core/dev.c | 10 +++------- net/sched/act_api.c | 11 ++++------- 6 files changed, 23 insertions(+), 22 deletions(-) diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c index 082534e187fc..442c4c4a9606 100644 --- a/drivers/net/ifb.c +++ b/drivers/net/ifb.c @@ -81,7 +81,7 @@ static void ifb_ri_tasklet(unsigned long _txp) u32 from = G_TC_FROM(skb->tc_verd); skb->tc_verd = 0; - skb->tc_verd = SET_TC_NCLS(skb->tc_verd); + skb->tc_skip_classify = 1; u64_stats_update_begin(&txp->tsync); txp->tx_packets++; diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index b53c0cfd417e..570f60ec6cb4 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -589,6 +589,7 @@ static inline bool skb_mstamp_after(const struct skb_mstamp *t1, * @pkt_type: Packet class * @fclone: skbuff clone status * @ipvs_property: skbuff is owned by ipvs + * @tc_skip_classify: do not classify packet. set by IFB device * @peeked: this packet has been seen already, so stats have been * done for it, don't do them again * @nf_trace: netfilter packet trace flag @@ -749,7 +750,9 @@ struct sk_buff { #ifdef CONFIG_NET_SWITCHDEV __u8 offload_fwd_mark:1; #endif - /* 2, 4 or 5 bit hole */ +#ifdef CONFIG_NET_CLS_ACT + __u8 tc_skip_classify:1; +#endif #ifdef CONFIG_NET_SCHED __u16 tc_index; /* traffic control index */ diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 498f81b229a4..857356f2d74b 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -418,6 +418,17 @@ static inline bool skb_at_tc_ingress(const struct sk_buff *skb) #endif } +static inline bool skb_skip_tc_classify(struct sk_buff *skb) +{ +#ifdef CONFIG_NET_CLS_ACT + if (skb->tc_skip_classify) { + skb->tc_skip_classify = 0; + return true; + } +#endif + return false; +} + /* Reset all TX qdiscs greater then index of a device. */ static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) { diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index bba23dbb3ab6..1eed5d7509bc 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -22,8 +22,6 @@ bit 6,7: Where this packet was last seen 1: on the Ingress 2: on the Egress -bit 8: when set --> Request not to classify on ingress. - * * */ @@ -36,10 +34,6 @@ bit 8: when set --> Request not to classify on ingress. #define AT_INGRESS 0x1 #define AT_EGRESS 0x2 -#define TC_NCLS _TC_MAKEMASK1(8) -#define SET_TC_NCLS(v) ( TC_NCLS | (v & ~TC_NCLS)) -#define CLR_TC_NCLS(v) ( v & ~TC_NCLS) - #define S_TC_AT _TC_MAKE32(12) #define M_TC_AT _TC_MAKEMASK(2,S_TC_AT) #define G_TC_AT(x) _TC_GETVALUE(x,S_TC_AT,M_TC_AT) diff --git a/net/core/dev.c b/net/core/dev.c index 56818f7eab2b..e39e35d2e082 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4093,12 +4093,8 @@ another_round: goto out; } -#ifdef CONFIG_NET_CLS_ACT - if (skb->tc_verd & TC_NCLS) { - skb->tc_verd = CLR_TC_NCLS(skb->tc_verd); - goto ncls; - } -#endif + if (skb_skip_tc_classify(skb)) + goto skip_classify; if (pfmemalloc) goto skip_taps; @@ -4128,8 +4124,8 @@ skip_taps: #endif #ifdef CONFIG_NET_CLS_ACT skb->tc_verd = 0; -ncls: #endif +skip_classify: if (pfmemalloc && !skb_pfmemalloc_protocol(skb)) goto drop; diff --git a/net/sched/act_api.c b/net/sched/act_api.c index 2095c83ce773..f04715a57300 100644 --- a/net/sched/act_api.c +++ b/net/sched/act_api.c @@ -426,11 +426,9 @@ int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions, { int ret = -1, i; - if (skb->tc_verd & TC_NCLS) { - skb->tc_verd = CLR_TC_NCLS(skb->tc_verd); - ret = TC_ACT_OK; - goto exec_done; - } + if (skb_skip_tc_classify(skb)) + return TC_ACT_OK; + for (i = 0; i < nr_actions; i++) { const struct tc_action *a = actions[i]; @@ -439,9 +437,8 @@ repeat: if (ret == TC_ACT_REPEAT) goto repeat; /* we need a ttl - JHS */ if (ret != TC_ACT_PIPE) - goto exec_done; + break; } -exec_done: return ret; } EXPORT_SYMBOL(tcf_action_exec); -- 2.20.1