Add support for Stack level options.

Linux controls socket send/receive buffers using a few sysctl variables
  - net.core.rmem_default
  - net.core.rmem_max
  - net.core.wmem_max
  - net.core.wmem_default
  - net.ipv4.tcp_rmem
  - net.ipv4.tcp_wmem

The first 4 control the default socket buffer sizes for all sockets
raw/packet/tcp/udp and also the maximum permitted socket buffer that can be
specified in setsockopt(SOL_SOCKET, SO_(RCV|SND)BUF,...).

The last two control the TCP auto-tuning limits and override the default
specified in rmem_default/wmem_default as well as the max limits.

Netstack today only implements tcp_rmem/tcp_wmem and incorrectly uses it
to limit the maximum size in setsockopt() as well as uses it for raw/udp
sockets.

This changelist introduces the other 4 and updates the udp/raw sockets to use
the newly introduced variables. The values for min/max match the current
tcp_rmem/wmem values and the default value buffers for UDP/RAW sockets is
updated to match the linux value of 212KiB up from the really low current value
of 32 KiB.

Updates #3043
Fixes #3043

PiperOrigin-RevId: 318089805

1 files changed, 3 insertions, 3 deletions

diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index 9e262c272..06fde2a79 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -144,11 +144,11 @@ func New(t *testing.T, mtu uint32) *Context {
 	})
 
 	// Allow minimum send/receive buffer sizes to be 1 during tests.
-	if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, tcpip.StackSendBufferSizeOption{Min: 1, Default: tcp.DefaultSendBufferSize, Max: 10 * tcp.DefaultSendBufferSize}); err != nil {
+	if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SendBufferSizeOption{Min: 1, Default: tcp.DefaultSendBufferSize, Max: 10 * tcp.DefaultSendBufferSize}); err != nil {
 		t.Fatalf("SetTransportProtocolOption failed: %s", err)
 	}
 
-	if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, tcpip.StackReceiveBufferSizeOption{Min: 1, Default: tcp.DefaultReceiveBufferSize, Max: 10 * tcp.DefaultReceiveBufferSize}); err != nil {
+	if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.ReceiveBufferSizeOption{Min: 1, Default: tcp.DefaultReceiveBufferSize, Max: 10 * tcp.DefaultReceiveBufferSize}); err != nil {
 		t.Fatalf("SetTransportProtocolOption failed: %s", err)
 	}
 
@@ -1091,7 +1091,7 @@ func (c *Context) PassiveConnectWithOptions(maxPayload, wndScale int, synOptions
 // SACKEnabled returns true if the TCP Protocol option SACKEnabled is set to true
 // for the Stack in the context.
 func (c *Context) SACKEnabled() bool {
-	var v tcpip.StackSACKEnabled
+	var v tcp.SACKEnabled
 	if err := c.Stack().TransportProtocolOption(tcp.ProtocolNumber, &v); err != nil {
 		// Stack doesn't support SACK. So just return.
 		return false