[v4,net-next,2/8] net: Add skb_clear_tstamp() to keep the mono delivery_time

Commit Message

Martin KaFai Lau Feb. 11, 2022, 7:12 a.m. UTC

Right now, skb->tstamp is reset to 0 whenever the skb is forwarded.

If skb->tstamp has the mono delivery_time, clearing it can hurt
the performance when it finally transmits out to fq@phy-dev.

The earlier patch added a skb->mono_delivery_time bit to
flag the skb->tstamp carrying the mono delivery_time.

This patch adds skb_clear_tstamp() helper which keeps
the mono delivery_time and clear everything else.

The delivery_time clearing is postponed until the stack knows the
skb will be delivered locally.  It will be done in a later patch.

Signed-off-by: Martin KaFai Lau <[e-mail]>
---
 drivers/net/loopback.c           |  2 +-
 include/linux/skbuff.h           | 10 +++++++++-
 net/bridge/br_forward.c          |  2 +-
 net/core/filter.c                |  6 +++---
 net/core/skbuff.c                |  2 +-
 net/ipv4/ip_forward.c            |  2 +-
 net/ipv6/ip6_output.c            |  2 +-
 net/netfilter/ipvs/ip_vs_xmit.c  |  6 +++---
 net/netfilter/nf_dup_netdev.c    |  2 +-
 net/netfilter/nf_flow_table_ip.c |  4 ++--
 net/netfilter/nft_fwd_netdev.c   |  2 +-
 net/openvswitch/vport.c          |  2 +-
 net/xfrm/xfrm_interface.c        |  2 +-
 13 files changed, 26 insertions(+), 18 deletions(-)

Patch

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index ed0edf5884ef..70a38fa09299 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -74,7 +74,7 @@  static netdev_tx_t loopback_xmit(struct sk_buff *skb,
 	skb_tx_timestamp(skb);
 
 	/* do not fool net_timestamp_check() with various clock bases */
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 
 	skb_orphan(skb);
 
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 32c793de3801..07e618f8b41a 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3938,6 +3938,14 @@  static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
 	skb->mono_delivery_time = 0;
 }
 
+static inline void skb_clear_tstamp(struct sk_buff *skb)
+{
+	if (skb->mono_delivery_time)
+		return;
+
+	skb->tstamp = 0;
+}
+
 static inline u8 skb_metadata_len(const struct sk_buff *skb)
 {
 	return skb_shinfo(skb)->meta_len;
@@ -4794,7 +4802,7 @@  static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
 #ifdef CONFIG_NET_REDIRECT
 	skb->from_ingress = from_ingress;
 	if (skb->from_ingress)
-		skb->tstamp = 0;
+		skb_clear_tstamp(skb);
 #endif
 }
 
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index ec646656dbf1..02bb620d3b8d 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -62,7 +62,7 @@  EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
 
 int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
 		       net, sk, skb, NULL, skb->dev,
 		       br_dev_queue_push_xmit);
diff --git a/net/core/filter.c b/net/core/filter.c
index f497ca7a16d2..a2d712be4985 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2107,7 +2107,7 @@  static inline int __bpf_tx_skb(struct net_device *dev, struct sk_buff *skb)
 	}
 
 	skb->dev = dev;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 
 	dev_xmit_recursion_inc();
 	ret = dev_queue_xmit(skb);
@@ -2176,7 +2176,7 @@  static int bpf_out_neigh_v6(struct net *net, struct sk_buff *skb,
 	}
 
 	skb->dev = dev;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 
 	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
 		skb = skb_expand_head(skb, hh_len);
@@ -2274,7 +2274,7 @@  static int bpf_out_neigh_v4(struct net *net, struct sk_buff *skb,
 	}
 
 	skb->dev = dev;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 
 	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
 		skb = skb_expand_head(skb, hh_len);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 0118f0afaa4f..3e3da8fdf8f5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5350,7 +5350,7 @@  void skb_scrub_packet(struct sk_buff *skb, bool xnet)
 
 	ipvs_reset(skb);
 	skb->mark = 0;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 }
 EXPORT_SYMBOL_GPL(skb_scrub_packet);
 
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 00ec819f949b..92ba3350274b 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -79,7 +79,7 @@  static int ip_forward_finish(struct net *net, struct sock *sk, struct sk_buff *s
 	if (unlikely(opt->optlen))
 		ip_forward_options(skb);
 
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	return dst_output(net, sk, skb);
 }
 
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 55665f3f7a77..9fc1b08cf622 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -440,7 +440,7 @@  static inline int ip6_forward_finish(struct net *net, struct sock *sk,
 	}
 #endif
 
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	return dst_output(net, sk, skb);
 }
 
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index d2e5a8f644b8..029171379884 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -610,7 +610,7 @@  static inline int ip_vs_tunnel_xmit_prepare(struct sk_buff *skb,
 		nf_reset_ct(skb);
 		skb_forward_csum(skb);
 		if (skb->dev)
-			skb->tstamp = 0;
+			skb_clear_tstamp(skb);
 	}
 	return ret;
 }
@@ -652,7 +652,7 @@  static inline int ip_vs_nat_send_or_cont(int pf, struct sk_buff *skb,
 	if (!local) {
 		skb_forward_csum(skb);
 		if (skb->dev)
-			skb->tstamp = 0;
+			skb_clear_tstamp(skb);
 		NF_HOOK(pf, NF_INET_LOCAL_OUT, cp->ipvs->net, NULL, skb,
 			NULL, skb_dst(skb)->dev, dst_output);
 	} else
@@ -674,7 +674,7 @@  static inline int ip_vs_send_or_cont(int pf, struct sk_buff *skb,
 		ip_vs_drop_early_demux_sk(skb);
 		skb_forward_csum(skb);
 		if (skb->dev)
-			skb->tstamp = 0;
+			skb_clear_tstamp(skb);
 		NF_HOOK(pf, NF_INET_LOCAL_OUT, cp->ipvs->net, NULL, skb,
 			NULL, skb_dst(skb)->dev, dst_output);
 	} else
diff --git a/net/netfilter/nf_dup_netdev.c b/net/netfilter/nf_dup_netdev.c
index a579e59ee5c5..7873bd1389c3 100644
--- a/net/netfilter/nf_dup_netdev.c
+++ b/net/netfilter/nf_dup_netdev.c
@@ -19,7 +19,7 @@  static void nf_do_netdev_egress(struct sk_buff *skb, struct net_device *dev)
 		skb_push(skb, skb->mac_len);
 
 	skb->dev = dev;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	dev_queue_xmit(skb);
 }
 
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 889cf88d3dba..f1d387129f02 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -376,7 +376,7 @@  nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	nf_flow_nat_ip(flow, skb, thoff, dir, iph);
 
 	ip_decrease_ttl(iph);
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 
 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
@@ -611,7 +611,7 @@  nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	nf_flow_nat_ipv6(flow, skb, dir, ip6h);
 
 	ip6h->hop_limit--;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 
 	if (flow_table->flags & NF_FLOWTABLE_COUNTER)
 		nf_ct_acct_update(flow->ct, tuplehash->tuple.dir, skb->len);
diff --git a/net/netfilter/nft_fwd_netdev.c b/net/netfilter/nft_fwd_netdev.c
index fa9301ca6033..4b2b0946c0b6 100644
--- a/net/netfilter/nft_fwd_netdev.c
+++ b/net/netfilter/nft_fwd_netdev.c
@@ -140,7 +140,7 @@  static void nft_fwd_neigh_eval(const struct nft_expr *expr,
 		return;
 
 	skb->dev = dev;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	neigh_xmit(neigh_table, dev, addr, skb);
 out:
 	regs->verdict.code = verdict;
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index cf2ce5812489..82a74f998966 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -507,7 +507,7 @@  void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
 	}
 
 	skb->dev = vport->dev;
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	vport->ops->send(skb);
 	return;
 
diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index 57448fc519fc..4991e99ced9a 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -190,7 +190,7 @@  static void xfrmi_dev_uninit(struct net_device *dev)
 
 static void xfrmi_scrub_packet(struct sk_buff *skb, bool xnet)
 {
-	skb->tstamp = 0;
+	skb_clear_tstamp(skb);
 	skb->pkt_type = PACKET_HOST;
 	skb->skb_iif = 0;
 	skb->ignore_df = 0;