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
|
package virtualnetwork
import (
"math"
"net"
"net/http"
"os"
"github.com/containers/gvisor-tap-vsock/pkg/tap"
"github.com/containers/gvisor-tap-vsock/pkg/types"
"github.com/pkg/errors"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/link/sniffer"
"gvisor.dev/gvisor/pkg/tcpip/network/arp"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
)
type VirtualNetwork struct {
configuration *types.Configuration
stack *stack.Stack
networkSwitch *tap.Switch
servicesMux http.Handler
ipPool *tap.IPPool
}
func New(configuration *types.Configuration) (*VirtualNetwork, error) {
_, subnet, err := net.ParseCIDR(configuration.Subnet)
if err != nil {
return nil, errors.Wrap(err, "cannot parse subnet cidr")
}
var endpoint stack.LinkEndpoint
ipPool := tap.NewIPPool(subnet)
ipPool.Reserve(net.ParseIP(configuration.GatewayIP), configuration.GatewayMacAddress)
for ip, mac := range configuration.DHCPStaticLeases {
ipPool.Reserve(net.ParseIP(ip), mac)
}
tapEndpoint, err := tap.NewLinkEndpoint(configuration.Debug, configuration.MTU, configuration.GatewayMacAddress, configuration.GatewayIP, configuration.GatewayVirtualIPs)
if err != nil {
return nil, errors.Wrap(err, "cannot create tap endpoint")
}
networkSwitch := tap.NewSwitch(configuration.Debug, configuration.MTU)
tapEndpoint.Connect(networkSwitch)
networkSwitch.Connect(tapEndpoint)
if configuration.CaptureFile != "" {
_ = os.Remove(configuration.CaptureFile)
fd, err := os.Create(configuration.CaptureFile)
if err != nil {
return nil, errors.Wrap(err, "cannot create capture file")
}
endpoint, err = sniffer.NewWithWriter(tapEndpoint, fd, math.MaxUint32)
if err != nil {
return nil, errors.Wrap(err, "cannot create sniffer")
}
} else {
endpoint = tapEndpoint
}
stack, err := createStack(configuration, endpoint)
if err != nil {
return nil, errors.Wrap(err, "cannot create network stack")
}
mux, err := addServices(configuration, stack, ipPool)
if err != nil {
return nil, errors.Wrap(err, "cannot add network services")
}
return &VirtualNetwork{
configuration: configuration,
stack: stack,
networkSwitch: networkSwitch,
servicesMux: mux,
ipPool: ipPool,
}, nil
}
func (n *VirtualNetwork) BytesSent() uint64 {
if n.networkSwitch == nil {
return 0
}
return n.networkSwitch.Sent
}
func (n *VirtualNetwork) BytesReceived() uint64 {
if n.networkSwitch == nil {
return 0
}
return n.networkSwitch.Received
}
func createStack(configuration *types.Configuration, endpoint stack.LinkEndpoint) (*stack.Stack, error) {
s := stack.New(stack.Options{
NetworkProtocols: []stack.NetworkProtocolFactory{
ipv4.NewProtocol,
arp.NewProtocol,
},
TransportProtocols: []stack.TransportProtocolFactory{
tcp.NewProtocol,
udp.NewProtocol,
icmp.NewProtocol4,
},
})
if err := s.CreateNIC(1, endpoint); err != nil {
return nil, errors.New(err.String())
}
if err := s.AddProtocolAddress(1, tcpip.ProtocolAddress{
Protocol: ipv4.ProtocolNumber,
AddressWithPrefix: tcpip.AddrFrom4Slice(net.ParseIP(configuration.GatewayIP).To4()).WithPrefix(),
}, stack.AddressProperties{}); err != nil {
return nil, errors.New(err.String())
}
s.SetSpoofing(1, true)
s.SetPromiscuousMode(1, true)
_, parsedSubnet, err := net.ParseCIDR(configuration.Subnet)
if err != nil {
return nil, errors.Wrap(err, "cannot parse cidr")
}
subnet, err := tcpip.NewSubnet(tcpip.AddrFromSlice(parsedSubnet.IP), tcpip.MaskFromBytes(parsedSubnet.Mask))
if err != nil {
return nil, errors.Wrap(err, "cannot parse subnet")
}
s.SetRouteTable([]tcpip.Route{
{
Destination: subnet,
Gateway: tcpip.Address{},
NIC: 1,
},
})
return s, nil
}
|
