5 files changed, 74 insertions, 3 deletions
diff --git a/pkg/tcpip/stack/BUILD b/pkg/tcpip/stack/BUILD
index 705cf01ee..8febd54c8 100644
--- a/pkg/tcpip/stack/BUILD
+++ b/pkg/tcpip/stack/BUILD
@@ -18,6 +18,7 @@ go_template_instance(
 go_library(
     name = "stack",
     srcs = [
+        "dhcpv6configurationfromndpra_string.go",
         "icmp_rate_limit.go",
         "linkaddrcache.go",
         "linkaddrentry_list.go",
diff --git a/pkg/tcpip/stack/dhcpv6configurationfromndpra_string.go b/pkg/tcpip/stack/dhcpv6configurationfromndpra_string.go
new file mode 100644
index 000000000..8b4213eec
--- /dev/null
+++ b/pkg/tcpip/stack/dhcpv6configurationfromndpra_string.go
@@ -0,0 +1,39 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Code generated by "stringer -type=DHCPv6ConfigurationFromNDPRA"; DO NOT EDIT.
+
+package stack
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[DHCPv6NoConfiguration-0]
+	_ = x[DHCPv6ManagedAddress-1]
+	_ = x[DHCPv6OtherConfigurations-2]
+}
+
+const _DHCPv6ConfigurationFromNDPRA_name = "DHCPv6NoConfigurationDHCPv6ManagedAddressDHCPv6OtherConfigurations"
+
+var _DHCPv6ConfigurationFromNDPRA_index = [...]uint8{0, 21, 41, 66}
+
+func (i DHCPv6ConfigurationFromNDPRA) String() string {
+	if i < 0 || i >= DHCPv6ConfigurationFromNDPRA(len(_DHCPv6ConfigurationFromNDPRA_index)-1) {
+		return "DHCPv6ConfigurationFromNDPRA(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _DHCPv6ConfigurationFromNDPRA_name[_DHCPv6ConfigurationFromNDPRA_index[i]:_DHCPv6ConfigurationFromNDPRA_index[i+1]]
+}
diff --git a/pkg/tcpip/transport/tcp/BUILD b/pkg/tcpip/transport/tcp/BUILD
index 272e8f570..a32f9eacf 100644
--- a/pkg/tcpip/transport/tcp/BUILD
+++ b/pkg/tcpip/transport/tcp/BUILD
@@ -32,6 +32,7 @@ go_library(
     srcs = [
         "accept.go",
         "connect.go",
+        "connect_unsafe.go",
         "cubic.go",
         "cubic_state.go",
         "dispatcher.go",
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index ae4f3f3a9..c0f73ef16 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -624,17 +624,17 @@ func parseSynSegmentOptions(s *segment) header.TCPSynOptions {
 
 var optionPool = sync.Pool{
 	New: func() interface{} {
-		return make([]byte, maxOptionSize)
+		return &[maxOptionSize]byte{}
 	},
 }
 
 func getOptions() []byte {
-	return optionPool.Get().([]byte)
+	return (*optionPool.Get().(*[maxOptionSize]byte))[:]
 }
 
 func putOptions(options []byte) {
 	// Reslice to full capacity.
-	optionPool.Put(options[0:cap(options)])
+	optionPool.Put(optionsToArray(options))
 }
 
 func makeSynOptions(opts header.TCPSynOptions) []byte {
diff --git a/pkg/tcpip/transport/tcp/connect_unsafe.go b/pkg/tcpip/transport/tcp/connect_unsafe.go
new file mode 100644
index 000000000..cfc304616
--- /dev/null
+++ b/pkg/tcpip/transport/tcp/connect_unsafe.go
@@ -0,0 +1,30 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tcp
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// optionsToArray converts a slice of capacity >-= maxOptionSize to an array.
+//
+// optionsToArray panics if the capacity of options is smaller than
+// maxOptionSize.
+func optionsToArray(options []byte) *[maxOptionSize]byte {
+	// Reslice to full capacity.
+	options = options[0:maxOptionSize]
+	return (*[maxOptionSize]byte)(unsafe.Pointer((*reflect.SliceHeader)(unsafe.Pointer(&options)).Data))
+}