netlink/addr_linux.go
Vishvananda Ishaya 349cca1850 Formatting cleanup
2014-09-15 17:06:08 -07:00

149 lines
3.4 KiB
Go

package netlink
import (
"fmt"
"net"
"strings"
"syscall"
"unsafe"
)
type IfAddrmsg struct {
syscall.IfAddrmsg
}
func newIfAddrmsg(family int) *IfAddrmsg {
return &IfAddrmsg{
IfAddrmsg: syscall.IfAddrmsg{
Family: uint8(family),
},
}
}
// struct ifaddrmsg {
// __u8 ifa_family;
// __u8 ifa_prefixlen; /* The prefix length */
// __u8 ifa_flags; /* Flags */
// __u8 ifa_scope; /* Address scope */
// __u32 ifa_index; /* Link index */
// };
// type IfAddrmsg struct {
// Family uint8
// Prefixlen uint8
// Flags uint8
// Scope uint8
// Index uint32
// }
// SizeofIfAddrmsg = 0x8
func DeserializeIfAddrmsg(b []byte) *IfAddrmsg {
return (*IfAddrmsg)(unsafe.Pointer(&b[0:syscall.SizeofIfAddrmsg][0]))
}
func (msg *IfAddrmsg) Serialize() []byte {
return (*(*[syscall.SizeofIfAddrmsg]byte)(unsafe.Pointer(msg)))[:]
}
func (msg *IfAddrmsg) Len() int {
return syscall.SizeofIfAddrmsg
}
// AddrAdd will add an IP address to a link device.
// Equivalent to: `ip addr del $addr dev $link`
func AddrAdd(link *Link, addr *Addr) error {
req := newNetlinkRequest(syscall.RTM_NEWADDR, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
return addrHandle(link, addr, req)
}
// AddrDel will delete an IP address from a link device.
// Equivalent to: `ip addr del $addr dev $link`
func AddrDel(link *Link, addr *Addr) error {
req := newNetlinkRequest(syscall.RTM_DELADDR, syscall.NLM_F_ACK)
return addrHandle(link, addr, req)
}
func addrHandle(link *Link, addr *Addr, req *NetlinkRequest) error {
if addr.Label != "" && !strings.HasPrefix(addr.Label, link.Name) {
return fmt.Errorf("label must begin with interface name")
}
ensureIndex(link)
family := GetIPFamily(addr.IP)
msg := newIfAddrmsg(family)
msg.Index = uint32(link.Index)
prefixlen, _ := addr.Mask.Size()
msg.Prefixlen = uint8(prefixlen)
req.AddData(msg)
var addrData []byte
if family == FAMILY_V4 {
addrData = addr.IP.To4()
} else {
addrData = addr.IP.To16()
}
localData := newRtAttr(syscall.IFA_LOCAL, addrData)
req.AddData(localData)
addressData := newRtAttr(syscall.IFA_ADDRESS, addrData)
req.AddData(addressData)
if addr.Label != "" {
labelData := newRtAttr(syscall.IFA_LABEL, zeroTerminated(addr.Label))
req.AddData(labelData)
}
_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
return err
}
// AddrList gets a list of IP addresses in the system.
// Equivalent to: `ip addr show`.
// The list can be filtered by link and ip family.
func AddrList(link *Link, family int) ([]Addr, error) {
req := newNetlinkRequest(syscall.RTM_GETADDR, syscall.NLM_F_DUMP)
msg := newIfInfomsg(family)
req.AddData(msg)
msgs, err := req.Execute(syscall.NETLINK_ROUTE, syscall.RTM_NEWADDR)
if err != nil {
return nil, err
}
ensureIndex(link)
res := make([]Addr, 0)
for _, m := range msgs {
msg := DeserializeIfAddrmsg(m)
if link != nil && msg.Index != uint32(link.Index) {
// Ignore messages from other interfaces
continue
}
attrs, err := parseRouteAttr(m[msg.Len():])
if err != nil {
return nil, err
}
var addr Addr
for _, attr := range attrs {
switch attr.Attr.Type {
case syscall.IFA_ADDRESS:
addr.IPNet = &net.IPNet{
IP: attr.Value,
Mask: net.CIDRMask(int(msg.Prefixlen), 8*len(attr.Value)),
}
case syscall.IFA_LABEL:
addr.Label = string(attr.Value[:len(attr.Value)-1])
}
}
res = append(res, addr)
}
return res, nil
}