1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
// 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.
// Package testutil defines types and functions used to test Network Layer
// functionality such as IP fragmentation.
package testutil
import (
"fmt"
"math/rand"
"reflect"
"strings"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/stack"
)
// MockLinkEndpoint is an endpoint used for testing, it stores packets written
// to it and can mock errors.
type MockLinkEndpoint struct {
// WrittenPackets is where packets written to the endpoint are stored.
WrittenPackets []*stack.PacketBuffer
mtu uint32
err *tcpip.Error
allowPackets int
}
// NewMockLinkEndpoint creates a new MockLinkEndpoint.
//
// err is the error that will be returned once allowPackets packets are written
// to the endpoint.
func NewMockLinkEndpoint(mtu uint32, err *tcpip.Error, allowPackets int) *MockLinkEndpoint {
return &MockLinkEndpoint{
mtu: mtu,
err: err,
allowPackets: allowPackets,
}
}
// MTU implements LinkEndpoint.MTU.
func (ep *MockLinkEndpoint) MTU() uint32 { return ep.mtu }
// Capabilities implements LinkEndpoint.Capabilities.
func (*MockLinkEndpoint) Capabilities() stack.LinkEndpointCapabilities { return 0 }
// MaxHeaderLength implements LinkEndpoint.MaxHeaderLength.
func (*MockLinkEndpoint) MaxHeaderLength() uint16 { return 0 }
// LinkAddress implements LinkEndpoint.LinkAddress.
func (*MockLinkEndpoint) LinkAddress() tcpip.LinkAddress { return "" }
// WritePacket implements LinkEndpoint.WritePacket.
func (ep *MockLinkEndpoint) WritePacket(_ stack.RouteInfo, _ *stack.GSO, _ tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) *tcpip.Error {
if ep.allowPackets == 0 {
return ep.err
}
ep.allowPackets--
ep.WrittenPackets = append(ep.WrittenPackets, pkt)
return nil
}
// WritePackets implements LinkEndpoint.WritePackets.
func (ep *MockLinkEndpoint) WritePackets(r stack.RouteInfo, gso *stack.GSO, pkts stack.PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, *tcpip.Error) {
var n int
for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() {
if err := ep.WritePacket(r, gso, protocol, pkt); err != nil {
return n, err
}
n++
}
return n, nil
}
// Attach implements LinkEndpoint.Attach.
func (*MockLinkEndpoint) Attach(stack.NetworkDispatcher) {}
// IsAttached implements LinkEndpoint.IsAttached.
func (*MockLinkEndpoint) IsAttached() bool { return false }
// Wait implements LinkEndpoint.Wait.
func (*MockLinkEndpoint) Wait() {}
// ARPHardwareType implements LinkEndpoint.ARPHardwareType.
func (*MockLinkEndpoint) ARPHardwareType() header.ARPHardwareType { return header.ARPHardwareNone }
// AddHeader implements LinkEndpoint.AddHeader.
func (*MockLinkEndpoint) AddHeader(_, _ tcpip.LinkAddress, _ tcpip.NetworkProtocolNumber, _ *stack.PacketBuffer) {
}
// MakeRandPkt generates a randomized packet. transportHeaderLength indicates
// how many random bytes will be copied in the Transport Header.
// extraHeaderReserveLength indicates how much extra space will be reserved for
// the other headers. The payload is made from Views of the sizes listed in
// viewSizes.
func MakeRandPkt(transportHeaderLength int, extraHeaderReserveLength int, viewSizes []int, proto tcpip.NetworkProtocolNumber) *stack.PacketBuffer {
var views buffer.VectorisedView
for _, s := range viewSizes {
newView := buffer.NewView(s)
if _, err := rand.Read(newView); err != nil {
panic(fmt.Sprintf("rand.Read: %s", err))
}
views.AppendView(newView)
}
pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
ReserveHeaderBytes: transportHeaderLength + extraHeaderReserveLength,
Data: views,
})
pkt.NetworkProtocolNumber = proto
if _, err := rand.Read(pkt.TransportHeader().Push(transportHeaderLength)); err != nil {
panic(fmt.Sprintf("rand.Read: %s", err))
}
return pkt
}
func checkFieldCounts(ref, multi reflect.Value) error {
refTypeName := ref.Type().Name()
multiTypeName := multi.Type().Name()
refNumField := ref.NumField()
multiNumField := multi.NumField()
if refNumField != multiNumField {
return fmt.Errorf("type %s has an incorrect number of fields: got = %d, want = %d (same as type %s)", multiTypeName, multiNumField, refNumField, refTypeName)
}
return nil
}
func validateField(ref reflect.Value, refName string, m tcpip.MultiCounterStat, multiName string) error {
s, ok := ref.Addr().Interface().(**tcpip.StatCounter)
if !ok {
return fmt.Errorf("expected ref type's to be *StatCounter, but its type is %s", ref.Type().Elem().Name())
}
// The field names are expected to match (case insensitive).
if !strings.EqualFold(refName, multiName) {
return fmt.Errorf("wrong field name: got = %s, want = %s", multiName, refName)
}
base := (*s).Value()
m.Increment()
if (*s).Value() != base+1 {
return fmt.Errorf("updates to the '%s MultiCounterStat' counters are not reflected in the '%s CounterStat'", multiName, refName)
}
return nil
}
// ValidateMultiCounterStats verifies that every counter stored in multi is
// correctly tracking its counterpart in the given counters.
func ValidateMultiCounterStats(multi reflect.Value, counters []reflect.Value) error {
for _, c := range counters {
if err := checkFieldCounts(c, multi); err != nil {
return err
}
}
for i := 0; i < multi.NumField(); i++ {
multiName := multi.Type().Field(i).Name
multiUnsafe := unsafeExposeUnexportedFields(multi.Field(i))
if m, ok := multiUnsafe.Addr().Interface().(*tcpip.MultiCounterStat); ok {
for _, c := range counters {
if err := validateField(unsafeExposeUnexportedFields(c.Field(i)), c.Type().Field(i).Name, *m, multiName); err != nil {
return err
}
}
} else {
var countersNextField []reflect.Value
for _, c := range counters {
countersNextField = append(countersNextField, c.Field(i))
}
if err := ValidateMultiCounterStats(multi.Field(i), countersNextField); err != nil {
return err
}
}
}
return nil
}
|
