epsocket: support /proc/net/snmp

Netstack has its own stats, we use this to fill /proc/net/snmp.

Note that some metrics are not recorded in Netstack, which will be shown
as 0 in the proc file.

Signed-off-by: Jianfeng Tan <henry.tjf@antfin.com>
Change-Id: Ie0089184507d16f49bc0057b4b0482094417ebe1

2 files changed, 6 insertions, 12 deletions

diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go
index 2b4c5c2f9..65c346046 100644
--- a/pkg/tcpip/transport/tcp/accept.go
+++ b/pkg/tcpip/transport/tcp/accept.go
@@ -297,10 +297,8 @@ func (l *listenContext) createEndpointAndPerformHandshake(s *segment, opts *head
 		return nil, err
 	}
 	ep.mu.Lock()
-	if ep.state != StateEstablished {
-		ep.stack.Stats().TCP.CurrentEstablished.Increment()
-		ep.state = StateEstablished
-	}
+	ep.stack.Stats().TCP.CurrentEstablished.Increment()
+	ep.state = StateEstablished
 	ep.mu.Unlock()
 
 	// Update the receive window scaling. We can't do it before the
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 4467dda82..b724d02bb 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -928,10 +928,8 @@ func (e *endpoint) protocolMainLoop(handshake bool) *tcpip.Error {
 			e.lastErrorMu.Unlock()
 
 			e.mu.Lock()
-			if e.state == StateEstablished || e.state == StateCloseWait {
-				e.stack.Stats().TCP.EstablishedResets.Increment()
-				e.stack.Stats().TCP.CurrentEstablished.Decrement()
-			}
+			e.stack.Stats().TCP.EstablishedResets.Increment()
+			e.stack.Stats().TCP.CurrentEstablished.Decrement()
 			e.state = StateError
 			e.HardError = err
 
@@ -1126,10 +1124,8 @@ func (e *endpoint) protocolMainLoop(handshake bool) *tcpip.Error {
 	// Mark endpoint as closed.
 	e.mu.Lock()
 	if e.state != StateError {
-		if e.state == StateEstablished || e.state == StateCloseWait {
-			e.stack.Stats().TCP.EstablishedResets.Increment()
-			e.stack.Stats().TCP.CurrentEstablished.Decrement()
-		}
+		e.stack.Stats().TCP.EstablishedResets.Increment()
+		e.stack.Stats().TCP.CurrentEstablished.Decrement()
 		e.state = StateClose
 	}
 	// Lock released below.