Merge release-20200522.0-66-g162848e1 (automated)

2 files changed, 23 insertions, 4 deletions

diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 6bf2e1a64..e5bd0247c 100644
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -124,7 +124,7 @@ func (s *Statx) UnmarshalBytes(src []byte) {
 // Packed implements marshal.Marshallable.Packed.
 //go:nosplit
 func (s *Statx) Packed() bool {
-    return s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed()
+    return s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed()
 }
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
@@ -138,7 +138,7 @@ func (s *Statx) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (s *Statx) UnmarshalUnsafe(src []byte) {
-    if s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+    if s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
         safecopy.CopyOut(unsafe.Pointer(s), src)
     } else {
         s.UnmarshalBytes(src)
@@ -148,7 +148,7 @@ func (s *Statx) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (s *Statx) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
-    if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+    if !s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() {
         // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
@@ -204,7 +204,7 @@ func (s *Statx) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (s *Statx) WriteTo(w io.Writer) (int64, error) {
-    if !s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() {
+    if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
         // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, s.SizeBytes())
         s.MarshalBytes(buf)
diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go
index 06dc9b7d7..3a19c4468 100644
--- a/pkg/tcpip/transport/tcp/snd.go
+++ b/pkg/tcpip/transport/tcp/snd.go
@@ -816,6 +816,25 @@ func (s *sender) maybeSendSegment(seg *segment, limit int, end seqnum.Value) (se
 			panic("Netstack queues FIN segments without data.")
 		}
 
+		segEnd = seg.sequenceNumber.Add(seqnum.Size(seg.data.Size()))
+		// If the entire segment cannot be accomodated in the receiver
+		// advertized window, skip splitting and sending of the segment.
+		// ref: net/ipv4/tcp_output.c::tcp_snd_wnd_test()
+		//
+		// Linux checks this for all segment transmits not triggered
+		// by a probe timer. On this condition, it defers the segment
+		// split and transmit to a short probe timer.
+		// ref: include/net/tcp.h::tcp_check_probe_timer()
+		// ref: net/ipv4/tcp_output.c::tcp_write_wakeup()
+		//
+		// Instead of defining a new transmit timer, we attempt to split the
+		// segment right here if there are no pending segments.
+		// If there are pending segments, segment transmits are deferred
+		// to the retransmit timer handler.
+		if s.sndUna != s.sndNxt && !segEnd.LessThan(end) {
+			return false
+		}
+
 		if !seg.sequenceNumber.LessThan(end) {
 			return false
 		}