1 // Copyright 2011 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // +build darwin freebsd netbsd openbsd
7 // Routing sockets and messages
13 // Round the length of a raw sockaddr up to align it properly.
14 func rsaAlignOf(salen int) int {
16 // NOTE: It seems like 64-bit Darwin kernel still requires 32-bit
17 // aligned access to BSD subsystem.
24 return (salen + salign - 1) & ^(salign - 1)
27 // RouteRIB returns routing information base, as known as RIB,
28 // which consists of network facility information, states and
30 func RouteRIB(facility, param int) ([]byte, error) {
31 mib := []_C_int{CTL_NET, AF_ROUTE, 0, 0, _C_int(facility), _C_int(param)}
34 if err := sysctl(mib, nil, &n, nil, 0); err != nil {
40 tab := make([]byte, n)
41 if err := sysctl(mib, &tab[0], &n, nil, 0); err != nil {
47 // RoutingMessage represents a routing message.
48 type RoutingMessage interface {
52 const anyMessageLen = int(unsafe.Sizeof(anyMessage{}))
54 type anyMessage struct {
60 // RouteMessage represents a routing message containing routing
62 type RouteMessage struct {
67 const rtaRtMask = RTA_DST | RTA_GATEWAY | RTA_NETMASK | RTA_GENMASK
69 func (m *RouteMessage) sockaddr() []Sockaddr {
75 for i := uint(0); i < RTAX_MAX; i++ {
76 if m.Header.Addrs&rtaRtMask&(1<<i) == 0 {
79 rsa := (*RawSockaddr)(unsafe.Pointer(&b[0]))
81 case RTAX_DST, RTAX_GATEWAY:
82 sa, err := anyToSockaddr((*RawSockaddrAny)(unsafe.Pointer(rsa)))
90 case RTAX_NETMASK, RTAX_GENMASK:
93 rsa4 := (*RawSockaddrInet4)(unsafe.Pointer(&b[0]))
94 sa := new(SockaddrInet4)
95 for j := 0; rsa4.Len > 0 && j < int(rsa4.Len)-int(unsafe.Offsetof(rsa4.Addr)); j++ {
96 sa.Addr[j] = rsa4.Addr[j]
100 rsa6 := (*RawSockaddrInet6)(unsafe.Pointer(&b[0]))
101 sa := new(SockaddrInet6)
102 for j := 0; rsa6.Len > 0 && j < int(rsa6.Len)-int(unsafe.Offsetof(rsa6.Addr)); j++ {
103 sa.Addr[j] = rsa6.Addr[j]
108 b = b[rsaAlignOf(int(rsa.Len)):]
113 // InterfaceMessage represents a routing message containing
114 // network interface entries.
115 type InterfaceMessage struct {
120 func (m *InterfaceMessage) sockaddr() (sas []Sockaddr) {
121 if m.Header.Addrs&RTA_IFP == 0 {
124 sa, err := anyToSockaddr((*RawSockaddrAny)(unsafe.Pointer(&m.Data[0])))
128 return append(sas, sa)
131 // InterfaceAddrMessage represents a routing message containing
132 // network interface address entries.
133 type InterfaceAddrMessage struct {
138 const rtaIfaMask = RTA_IFA | RTA_NETMASK | RTA_BRD
140 func (m *InterfaceAddrMessage) sockaddr() (sas []Sockaddr) {
141 if m.Header.Addrs&rtaIfaMask == 0 {
145 for i := uint(0); i < RTAX_MAX; i++ {
146 if m.Header.Addrs&rtaIfaMask&(1<<i) == 0 {
149 rsa := (*RawSockaddr)(unsafe.Pointer(&b[0]))
152 sa, err := anyToSockaddr((*RawSockaddrAny)(unsafe.Pointer(rsa)))
156 sas = append(sas, sa)
158 if rsa.Family == AF_UNSPEC {
159 rsa.Family = AF_INET // an old fasion, AF_UNSPEC means AF_INET
161 sa, err := anyToSockaddr((*RawSockaddrAny)(unsafe.Pointer(rsa)))
165 sas = append(sas, sa)
169 b = b[rsaAlignOf(int(rsa.Len)):]
174 // ParseRoutingMessage parses b as routing messages and returns the
175 // slice containing the RoutingMessage interfaces.
176 func ParseRoutingMessage(b []byte) (msgs []RoutingMessage, err error) {
177 for len(b) >= anyMessageLen {
178 any := (*anyMessage)(unsafe.Pointer(&b[0]))
179 if any.Version != RTM_VERSION {
182 msgs = append(msgs, any.toRoutingMessage(b))
188 // ParseRoutingMessage parses msg's payload as raw sockaddrs and
189 // returns the slice containing the Sockaddr interfaces.
190 func ParseRoutingSockaddr(msg RoutingMessage) (sas []Sockaddr, err error) {
191 return append(sas, msg.sockaddr()...), nil