[PATCH net-next v4 03/11] net-timestamp: reorganize in skb_tstamp_tx_output()

[Jason Xing <kerneljasonxing@gmail.com>]

From: Jason Xing <kernelxing@tencent.com>

It's a prep for bpf print function later. This patch only puts the
original generating logic into one function, so that we integrate
bpf print easily. No functional changes here.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
---
 include/linux/skbuff.h |  4 ++--
 net/core/dev.c         |  3 +--
 net/core/skbuff.c      | 41 +++++++++++++++++++++++++++++++++++------
 3 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 58009fa66102..53c6913560e4 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -39,6 +39,7 @@
 #include <net/net_debug.h>
 #include <net/dropreason-core.h>
 #include <net/netmem.h>
+#include <uapi/linux/errqueue.h>
 
 /**
  * DOC: skb checksums
@@ -4535,8 +4536,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb,
 static inline void skb_tx_timestamp(struct sk_buff *skb)
 {
 	skb_clone_tx_timestamp(skb);
-	if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
-		skb_tstamp_tx(skb, NULL);
+	__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SND);
 }
 
 /**
diff --git a/net/core/dev.c b/net/core/dev.c
index 45a8c3dd4a64..5d584950564b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4350,8 +4350,7 @@ int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
 	skb_reset_mac_header(skb);
 	skb_assert_len(skb);
 
-	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
-		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
+	__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
 
 	/* Disable soft irqs for various locks below. Also
 	 * stops preemption for RCU.
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6841e61a6bd0..74b840ffaf94 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5539,10 +5539,10 @@ void skb_complete_tx_timestamp(struct sk_buff *skb,
 }
 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
 
-void __skb_tstamp_tx(struct sk_buff *orig_skb,
-		     const struct sk_buff *ack_skb,
-		     struct skb_shared_hwtstamps *hwtstamps,
-		     struct sock *sk, int tstype)
+static void skb_tstamp_tx_output(struct sk_buff *orig_skb,
+				 const struct sk_buff *ack_skb,
+				 struct skb_shared_hwtstamps *hwtstamps,
+				 struct sock *sk, int tstype)
 {
 	struct sk_buff *skb;
 	bool tsonly, opt_stats = false;
@@ -5594,13 +5594,42 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb,
 
 	__skb_complete_tx_timestamp(skb, sk, tstype, opt_stats);
 }
+
+static bool skb_tstamp_is_set(const struct sk_buff *skb, int tstype)
+{
+	switch (tstype) {
+	case SCM_TSTAMP_SCHED:
+		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
+			return true;
+		return false;
+	case SCM_TSTAMP_SND:
+		if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP))
+			return true;
+		return false;
+	case SCM_TSTAMP_ACK:
+		if (TCP_SKB_CB(skb)->txstamp_ack)
+			return true;
+		return false;
+	}
+
+	return false;
+}
+
+void __skb_tstamp_tx(struct sk_buff *orig_skb,
+		     const struct sk_buff *ack_skb,
+		     struct skb_shared_hwtstamps *hwtstamps,
+		     struct sock *sk, int tstype)
+{
+	if (unlikely(skb_tstamp_is_set(orig_skb, tstype)))
+		skb_tstamp_tx_output(orig_skb, ack_skb, hwtstamps, sk, tstype);
+}
 EXPORT_SYMBOL_GPL(__skb_tstamp_tx);
 
 void skb_tstamp_tx(struct sk_buff *orig_skb,
 		   struct skb_shared_hwtstamps *hwtstamps)
 {
-	return __skb_tstamp_tx(orig_skb, NULL, hwtstamps, orig_skb->sk,
-			       SCM_TSTAMP_SND);
+	return skb_tstamp_tx_output(orig_skb, NULL, hwtstamps, orig_skb->sk,
+				    SCM_TSTAMP_SND);
 }
 EXPORT_SYMBOL_GPL(skb_tstamp_tx);
 
-- 
2.37.3