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
|
package rtnl
import (
"net"
"github.com/jsimonetti/rtnetlink/v2/internal/unix"
"github.com/jsimonetti/rtnetlink/v2"
)
// AddrAdd associates an IP-address with an interface.
//
// iface, _ := net.InterfaceByName("lo")
// conn.AddrAdd(iface, rtnl.MustParseAddr("127.0.0.1/8"))
func (c *Conn) AddrAdd(ifc *net.Interface, addr *net.IPNet) error {
af, err := addrFamily(addr.IP)
if err != nil {
return err
}
scope := addrScope(addr.IP)
prefixlen, _ := addr.Mask.Size()
tx := &rtnetlink.AddressMessage{
Family: uint8(af),
PrefixLength: uint8(prefixlen),
Scope: uint8(scope),
Index: uint32(ifc.Index),
Attributes: &rtnetlink.AddressAttributes{
Address: addr.IP,
Local: addr.IP,
},
}
if ip4 := addr.IP.To4(); ip4 != nil {
tx.Attributes.Broadcast = broadcastAddr(addr)
tx.Attributes.Address = ip4
tx.Attributes.Local = ip4
}
return c.Conn.Address.New(tx)
}
// AddrDel revokes an IP-address from an interface.
//
// iface, _ := net.InterfaceByName("lo")
// conn.AddrDel(iface, rtnl.MustParseAddr("127.0.0.1/8"))
func (c *Conn) AddrDel(ifc *net.Interface, addr *net.IPNet) error {
af, err := addrFamily(addr.IP)
if err != nil {
return err
}
prefixlen, _ := addr.Mask.Size()
rx, err := c.Addrs(ifc, af)
if err != nil {
return err
}
for _, v := range rx {
plen, _ := v.Mask.Size()
if plen == prefixlen && v.IP.Equal(addr.IP) {
tx := &rtnetlink.AddressMessage{
Family: uint8(af),
PrefixLength: uint8(prefixlen),
Index: uint32(ifc.Index),
Attributes: &rtnetlink.AddressAttributes{
Address: addr.IP,
},
}
if ip4 := addr.IP.To4(); ip4 != nil {
tx.Attributes.Broadcast = broadcastAddr(addr)
tx.Attributes.Address = ip4
}
return c.Conn.Address.Delete(tx)
}
}
return &net.AddrError{Err: "address not found", Addr: addr.IP.String()}
}
// Addrs returns IP addresses matching the interface and address family.
// To retrieve all addresses configured for the system, run:
//
// conn.Addrs(nil, 0)
func (c *Conn) Addrs(ifc *net.Interface, family int) (out []*net.IPNet, err error) {
rx, err := c.Conn.Address.List()
if err != nil {
return nil, err
}
match := func(v *rtnetlink.AddressMessage, ifc *net.Interface, family int) bool {
if ifc != nil && v.Index != uint32(ifc.Index) {
return false
}
if family != 0 && v.Family != uint8(family) {
return false
}
return true
}
for _, m := range rx {
if match(&m, ifc, family) {
bitlen := 8 * len(m.Attributes.Address)
a := &net.IPNet{
IP: m.Attributes.Address,
Mask: net.CIDRMask(int(m.PrefixLength), bitlen),
}
out = append(out, a)
}
}
return
}
// ParseAddr parses a CIDR string into a host address and network mask.
// This is a convenience wrapper around net.ParseCIDR(), which surprisingly
// returns the network address and mask instead of the host address and mask.
func ParseAddr(s string) (*net.IPNet, error) {
addr, cidr, err := net.ParseCIDR(s)
if err != nil {
return nil, err
}
// Overwrite cidr's network address with the host address
// parsed from the string representation.
cidr.IP = addr
if isSubnetAddr(cidr) {
return nil, &net.AddrError{
Err: "attempted to parse a subnet address into a host address",
Addr: cidr.IP.String(),
}
}
return cidr, nil
}
// MustParseAddr wraps ParseAddr, but panics on error.
// Use to conveniently parse a known-valid or hardcoded
// address into a function argument.
//
// iface, _ := net.InterfaceByName("enp2s0")
// conn.AddrDel(iface, rtnl.MustParseAddr("10.1.1.1/24"))
func MustParseAddr(s string) *net.IPNet {
n, err := ParseAddr(s)
if err != nil {
panic(err)
}
return n
}
func addrFamily(ip net.IP) (int, error) {
if ip.To4() != nil {
return unix.AF_INET, nil
}
if len(ip) == net.IPv6len {
return unix.AF_INET6, nil
}
return 0, &net.AddrError{Err: "invalid IP address", Addr: ip.String()}
}
func addrScope(ip net.IP) int {
if ip.IsGlobalUnicast() {
return unix.RT_SCOPE_UNIVERSE
}
if ip.IsLoopback() {
return unix.RT_SCOPE_HOST
}
return unix.RT_SCOPE_LINK
}
func broadcastAddr(ipnet *net.IPNet) net.IP {
ip := ipnet.IP.To4()
if ip == nil {
return nil
}
mask := net.IP(ipnet.Mask).To4()
n := len(ip)
if n != len(mask) {
return nil
}
out := make(net.IP, n)
for i := 0; i < n; i++ {
out[i] = ip[i] | ^mask[i]
}
return out
}
// isSubnetAddr returns true if ipnet is a network (subnet) address.
// It applies ipnet's subnet mask onto itself and compares the result to the
// value of ipnet's IP field.
func isSubnetAddr(ipnet *net.IPNet) bool {
// Addresses with /32 and /128 are always hosts.
if ones, bits := ipnet.Mask.Size(); ones == bits {
return false
}
if ipnet.IP.Mask(ipnet.Mask).Equal(ipnet.IP) {
return true
}
return false
}
|
