summaryrefslogtreecommitdiffhomepage
path: root/pkg/tcpip/transport/tcp
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/tcpip/transport/tcp')
-rw-r--r--pkg/tcpip/transport/tcp/endpoint.go10
-rw-r--r--pkg/tcpip/transport/tcp/snd.go13
2 files changed, 17 insertions, 6 deletions
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 7d18e3612..5656890f6 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -1596,6 +1596,16 @@ func (e *endpoint) maybeEnableSACKPermitted(synOpts *header.TCPSynOptions) {
}
}
+// maxOptionSize return the maximum size of TCP options.
+func (e *endpoint) maxOptionSize() (size int) {
+ var maxSackBlocks [header.TCPMaxSACKBlocks]header.SACKBlock
+ options := e.makeOptions(maxSackBlocks[:])
+ size = len(options)
+ putOptions(options)
+
+ return size
+}
+
// completeState makes a full copy of the endpoint and returns it. This is used
// before invoking the probe. The state returned may not be fully consistent if
// there are intervening syscalls when the state is being copied.
diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go
index e38932df7..18365a673 100644
--- a/pkg/tcpip/transport/tcp/snd.go
+++ b/pkg/tcpip/transport/tcp/snd.go
@@ -172,6 +172,11 @@ type fastRecovery struct {
}
func newSender(ep *endpoint, iss, irs seqnum.Value, sndWnd seqnum.Size, mss uint16, sndWndScale int) *sender {
+ // The sender MUST reduce the TCP data length to account for any IP or
+ // TCP options that it is including in the packets that it sends.
+ // See: https://tools.ietf.org/html/rfc6691#section-2
+ maxPayloadSize := int(mss) - ep.maxOptionSize()
+
s := &sender{
ep: ep,
sndCwnd: InitialCwnd,
@@ -183,7 +188,7 @@ func newSender(ep *endpoint, iss, irs seqnum.Value, sndWnd seqnum.Size, mss uint
rto: 1 * time.Second,
rttMeasureSeqNum: iss + 1,
lastSendTime: time.Now(),
- maxPayloadSize: int(mss),
+ maxPayloadSize: maxPayloadSize,
maxSentAck: irs + 1,
fr: fastRecovery{
// See: https://tools.ietf.org/html/rfc6582#section-3.2 Step 1.
@@ -226,11 +231,7 @@ func (s *sender) initCongestionControl(congestionControlName CongestionControlOp
func (s *sender) updateMaxPayloadSize(mtu, count int) {
m := mtu - header.TCPMinimumSize
- // Calculate the maximum option size.
- var maxSackBlocks [header.TCPMaxSACKBlocks]header.SACKBlock
- options := s.ep.makeOptions(maxSackBlocks[:])
- m -= len(options)
- putOptions(options)
+ m -= s.ep.maxOptionSize()
// We don't adjust up for now.
if m >= s.maxPayloadSize {