4 files changed, 248 insertions, 0 deletions
diff --git a/pkg/sentry/inet/context.go b/pkg/sentry/inet/context.go
new file mode 100644
index 000000000..8550c4793
--- /dev/null
+++ b/pkg/sentry/inet/context.go
@@ -0,0 +1,35 @@
+// 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 inet
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
+)
+
+// contextID is the inet package's type for context.Context.Value keys.
+type contextID int
+
+const (
+	// CtxStack is a Context.Value key for a network stack.
+	CtxStack contextID = iota
+)
+
+// StackFromContext returns the network stack associated with ctx.
+func StackFromContext(ctx context.Context) Stack {
+	if v := ctx.Value(CtxStack); v != nil {
+		return v.(Stack)
+	}
+	return nil
+}
diff --git a/pkg/sentry/inet/inet.go b/pkg/sentry/inet/inet.go
new file mode 100644
index 000000000..7c104fd47
--- /dev/null
+++ b/pkg/sentry/inet/inet.go
@@ -0,0 +1,104 @@
+// 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 inet defines semantics for IP stacks.
+package inet
+
+// Stack represents a TCP/IP stack.
+type Stack interface {
+	// Interfaces returns all network interfaces as a mapping from interface
+	// indexes to interface properties. Interface indices are strictly positive
+	// integers.
+	Interfaces() map[int32]Interface
+
+	// InterfaceAddrs returns all network interface addresses as a mapping from
+	// interface indexes to a slice of associated interface address properties.
+	InterfaceAddrs() map[int32][]InterfaceAddr
+
+	// SupportsIPv6 returns true if the stack supports IPv6 connectivity.
+	SupportsIPv6() bool
+
+	// TCPReceiveBufferSize returns TCP receive buffer size settings.
+	TCPReceiveBufferSize() (TCPBufferSize, error)
+
+	// SetTCPReceiveBufferSize attempts to change TCP receive buffer size
+	// settings.
+	SetTCPReceiveBufferSize(size TCPBufferSize) error
+
+	// TCPSendBufferSize returns TCP send buffer size settings.
+	TCPSendBufferSize() (TCPBufferSize, error)
+
+	// SetTCPSendBufferSize attempts to change TCP send buffer size settings.
+	SetTCPSendBufferSize(size TCPBufferSize) error
+
+	// TCPSACKEnabled returns true if RFC 2018 TCP Selective Acknowledgements
+	// are enabled.
+	TCPSACKEnabled() (bool, error)
+
+	// SetTCPSACKEnabled attempts to change TCP selective acknowledgement
+	// settings.
+	SetTCPSACKEnabled(enabled bool) error
+}
+
+// Interface contains information about a network interface.
+type Interface struct {
+	// Keep these fields sorted in the order they appear in rtnetlink(7).
+
+	// DeviceType is the device type, a Linux ARPHRD_* constant.
+	DeviceType uint16
+
+	// Flags is the device flags; see netdevice(7), under "Ioctls",
+	// "SIOCGIFFLAGS, SIOCSIFFLAGS".
+	Flags uint32
+
+	// Name is the device name.
+	Name string
+
+	// Addr is the hardware device address.
+	Addr []byte
+
+	// MTU is the maximum transmission unit.
+	MTU uint32
+}
+
+// InterfaceAddr contains information about a network interface address.
+type InterfaceAddr struct {
+	// Keep these fields sorted in the order they appear in rtnetlink(7).
+
+	// Family is the address family, a Linux AF_* constant.
+	Family uint8
+
+	// PrefixLen is the address prefix length.
+	PrefixLen uint8
+
+	// Flags is the address flags.
+	Flags uint8
+
+	// Addr is the actual address.
+	Addr []byte
+}
+
+// TCPBufferSize contains settings controlling TCP buffer sizing.
+//
+// +stateify savable
+type TCPBufferSize struct {
+	// Min is the minimum size.
+	Min int
+
+	// Default is the default size.
+	Default int
+
+	// Max is the maximum size.
+	Max int
+}
diff --git a/pkg/sentry/inet/inet_state_autogen.go b/pkg/sentry/inet/inet_state_autogen.go
new file mode 100755
index 000000000..9f8460ec0
--- /dev/null
+++ b/pkg/sentry/inet/inet_state_autogen.go
@@ -0,0 +1,26 @@
+// automatically generated by stateify.
+
+package inet
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/state"
+)
+
+func (x *TCPBufferSize) beforeSave() {}
+func (x *TCPBufferSize) save(m state.Map) {
+	x.beforeSave()
+	m.Save("Min", &x.Min)
+	m.Save("Default", &x.Default)
+	m.Save("Max", &x.Max)
+}
+
+func (x *TCPBufferSize) afterLoad() {}
+func (x *TCPBufferSize) load(m state.Map) {
+	m.Load("Min", &x.Min)
+	m.Load("Default", &x.Default)
+	m.Load("Max", &x.Max)
+}
+
+func init() {
+	state.Register("inet.TCPBufferSize", (*TCPBufferSize)(nil), state.Fns{Save: (*TCPBufferSize).save, Load: (*TCPBufferSize).load})
+}
diff --git a/pkg/sentry/inet/test_stack.go b/pkg/sentry/inet/test_stack.go
new file mode 100644
index 000000000..624371eb6
--- /dev/null
+++ b/pkg/sentry/inet/test_stack.go
@@ -0,0 +1,83 @@
+// 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 inet
+
+// TestStack is a dummy implementation of Stack for tests.
+type TestStack struct {
+	InterfacesMap     map[int32]Interface
+	InterfaceAddrsMap map[int32][]InterfaceAddr
+	SupportsIPv6Flag  bool
+	TCPRecvBufSize    TCPBufferSize
+	TCPSendBufSize    TCPBufferSize
+	TCPSACKFlag       bool
+}
+
+// NewTestStack returns a TestStack with no network interfaces. The value of
+// all other options is unspecified; tests that rely on specific values must
+// set them explicitly.
+func NewTestStack() *TestStack {
+	return &TestStack{
+		InterfacesMap:     make(map[int32]Interface),
+		InterfaceAddrsMap: make(map[int32][]InterfaceAddr),
+	}
+}
+
+// Interfaces implements Stack.Interfaces.
+func (s *TestStack) Interfaces() map[int32]Interface {
+	return s.InterfacesMap
+}
+
+// InterfaceAddrs implements Stack.InterfaceAddrs.
+func (s *TestStack) InterfaceAddrs() map[int32][]InterfaceAddr {
+	return s.InterfaceAddrsMap
+}
+
+// SupportsIPv6 implements Stack.SupportsIPv6.
+func (s *TestStack) SupportsIPv6() bool {
+	return s.SupportsIPv6Flag
+}
+
+// TCPReceiveBufferSize implements Stack.TCPReceiveBufferSize.
+func (s *TestStack) TCPReceiveBufferSize() (TCPBufferSize, error) {
+	return s.TCPRecvBufSize, nil
+}
+
+// SetTCPReceiveBufferSize implements Stack.SetTCPReceiveBufferSize.
+func (s *TestStack) SetTCPReceiveBufferSize(size TCPBufferSize) error {
+	s.TCPRecvBufSize = size
+	return nil
+}
+
+// TCPSendBufferSize implements Stack.TCPSendBufferSize.
+func (s *TestStack) TCPSendBufferSize() (TCPBufferSize, error) {
+	return s.TCPSendBufSize, nil
+}
+
+// SetTCPSendBufferSize implements Stack.SetTCPSendBufferSize.
+func (s *TestStack) SetTCPSendBufferSize(size TCPBufferSize) error {
+	s.TCPSendBufSize = size
+	return nil
+}
+
+// TCPSACKEnabled implements Stack.TCPSACKEnabled.
+func (s *TestStack) TCPSACKEnabled() (bool, error) {
+	return s.TCPSACKFlag, nil
+}
+
+// SetTCPSACKEnabled implements Stack.SetTCPSACKEnabled.
+func (s *TestStack) SetTCPSACKEnabled(enabled bool) error {
+	s.TCPSACKFlag = enabled
+	return nil
+}