History

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).

Willem de Bruijn committed 9 years ago

Commit e7246e11 parent d6264076 files · +23 −22Browse files

Unified · Split

6 files
  1. drivers/net/ifb.c +1 −1
  2. include/linux/skbuff.h +4 −1
  3. include/net/sch_generic.h +11 −0
  4. include/uapi/linux/pkt_cls.h +0 −6
  5. net/core/dev.c +3 −7
  6. net/sched/act_api.c +4 −7
drivers/net/ifb.c+1−1
@@ -81,7 +81,7 @@ static void ifb_ri_tasklet(unsigned long _txp) · 80 unmodified lines
81 u32 from = G_TC_FROM(skb->tc_verd);81 u32 from = G_TC_FROM(skb->tc_verd);
82 82
83 skb->tc_verd = 0;83 skb->tc_verd = 0;
84 skb->tc_verd = SET_TC_NCLS(skb->tc_verd);84 skb->tc_skip_classify = 1;
85 85
86 u64_stats_update_begin(&txp->tsync);86 u64_stats_update_begin(&txp->tsync);
87 txp->tx_packets++;87 txp->tx_packets++;
include/linux/skbuff.h+4−1
@@ -589,6 +589,7 @@ static inline bool skb_mstamp_after(const struct skb_mstamp *t1, · 588 unmodified lines
589 * @pkt_type: Packet class589 * @pkt_type: Packet class
590 * @fclone: skbuff clone status590 * @fclone: skbuff clone status
591 * @ipvs_property: skbuff is owned by ipvs591 * @ipvs_property: skbuff is owned by ipvs
592 * @tc_skip_classify: do not classify packet. set by IFB device
592 * @peeked: this packet has been seen already, so stats have been593 * @peeked: this packet has been seen already, so stats have been
593 * done for it, don't do them again594 * done for it, don't do them again
594 * @nf_trace: netfilter packet trace flag595 * @nf_trace: netfilter packet trace flag
@@ -749,7 +750,9 @@ struct sk_buff { · 154 unmodified lines
749#ifdef CONFIG_NET_SWITCHDEV750#ifdef CONFIG_NET_SWITCHDEV
750 __u8 offload_fwd_mark:1;751 __u8 offload_fwd_mark:1;
751#endif752#endif
752 /* 2, 4 or 5 bit hole */753#ifdef CONFIG_NET_CLS_ACT
754 __u8 tc_skip_classify:1;
755#endif
753 756
754#ifdef CONFIG_NET_SCHED757#ifdef CONFIG_NET_SCHED
755 __u16 tc_index; /* traffic control index */758 __u16 tc_index; /* traffic control index */
include/net/sch_generic.h+11−0
@@ -418,6 +418,17 @@ static inline bool skb_at_tc_ingress(const struct sk_buff *skb) · 417 unmodified lines
418#endif418#endif
419}419}
420 420
421static inline bool skb_skip_tc_classify(struct sk_buff *skb)
422{
423#ifdef CONFIG_NET_CLS_ACT
424 if (skb->tc_skip_classify) {
425 skb->tc_skip_classify = 0;
426 return true;
427 }
428#endif
429 return false;
430}
431
421/* Reset all TX qdiscs greater then index of a device. */432/* Reset all TX qdiscs greater then index of a device. */
422static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)433static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
423{434{
include/uapi/linux/pkt_cls.h+0−6
@@ -22,8 +22,6 @@ bit 6,7: Where this packet was last seen · 21 unmodified lines
221: on the Ingress221: on the Ingress
232: on the Egress232: on the Egress
24 24
25bit 8: when set --> Request not to classify on ingress.
26
27 *25 *
28 * */26 * */
29 27
@@ -36,10 +34,6 @@ bit 8: when set --> Request not to classify on ingress. · 6 unmodified lines
36#define AT_INGRESS 0x134#define AT_INGRESS 0x1
37#define AT_EGRESS 0x235#define AT_EGRESS 0x2
38 36
39#define TC_NCLS _TC_MAKEMASK1(8)
40#define SET_TC_NCLS(v) ( TC_NCLS | (v & ~TC_NCLS))
41#define CLR_TC_NCLS(v) ( v & ~TC_NCLS)
42
43#define S_TC_AT _TC_MAKE32(12)37#define S_TC_AT _TC_MAKE32(12)
44#define M_TC_AT _TC_MAKEMASK(2,S_TC_AT)38#define M_TC_AT _TC_MAKEMASK(2,S_TC_AT)
45#define G_TC_AT(x) _TC_GETVALUE(x,S_TC_AT,M_TC_AT)39#define G_TC_AT(x) _TC_GETVALUE(x,S_TC_AT,M_TC_AT)
net/core/dev.c+3−7
@@ -4093,12 +4093,8 @@ another_round: · 4092 unmodified lines
4093 goto out;4093 goto out;
4094 }4094 }
4095 4095
4096#ifdef CONFIG_NET_CLS_ACT4096 if (skb_skip_tc_classify(skb))
4097 if (skb->tc_verd & TC_NCLS) {4097 goto skip_classify;
4098 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
4099 goto ncls;
4100 }
4101#endif
4102 4098
4103 if (pfmemalloc)4099 if (pfmemalloc)
4104 goto skip_taps;4100 goto skip_taps;
@@ -4128,8 +4124,8 @@ skip_taps: · 23 unmodified lines
4128#endif4124#endif
4129#ifdef CONFIG_NET_CLS_ACT4125#ifdef CONFIG_NET_CLS_ACT
4130 skb->tc_verd = 0;4126 skb->tc_verd = 0;
4131ncls:
4132#endif4127#endif
4128skip_classify:
4133 if (pfmemalloc && !skb_pfmemalloc_protocol(skb))4129 if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
4134 goto drop;4130 goto drop;
4135 4131
net/sched/act_api.c+4−7
@@ -426,11 +426,9 @@ int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions, · 425 unmodified lines
426{426{
427 int ret = -1, i;427 int ret = -1, i;
428 428
429 if (skb->tc_verd & TC_NCLS) {429 if (skb_skip_tc_classify(skb))
430 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);430 return TC_ACT_OK;
431 ret = TC_ACT_OK;431
432 goto exec_done;
433 }
434 for (i = 0; i < nr_actions; i++) {432 for (i = 0; i < nr_actions; i++) {
435 const struct tc_action *a = actions[i];433 const struct tc_action *a = actions[i];
436 434
@@ -439,9 +437,8 @@ repeat: · 2 unmodified lines
439 if (ret == TC_ACT_REPEAT)437 if (ret == TC_ACT_REPEAT)
440 goto repeat; /* we need a ttl - JHS */438 goto repeat; /* we need a ttl - JHS */
441 if (ret != TC_ACT_PIPE)439 if (ret != TC_ACT_PIPE)
442 goto exec_done;440 break;
443 }441 }
444exec_done:
445 return ret;442 return ret;
446}443}
447EXPORT_SYMBOL(tcf_action_exec);444EXPORT_SYMBOL(tcf_action_exec);