clash/component/iface/iface.go

116 lines
2.1 KiB
Go

package iface
import (
"errors"
"net"
"time"
"github.com/Dreamacro/clash/common/singledo"
)
type Interface struct {
Index int
Name string
Addrs []*net.IPNet
HardwareAddr net.HardwareAddr
}
var (
ErrIfaceNotFound = errors.New("interface not found")
ErrAddrNotFound = errors.New("addr not found")
)
var interfaces = singledo.NewSingle(time.Second * 20)
func ResolveInterface(name string) (*Interface, error) {
value, err, _ := interfaces.Do(func() (any, error) {
ifaces, err := net.Interfaces()
if err != nil {
return nil, err
}
r := map[string]*Interface{}
for _, iface := range ifaces {
addrs, err := iface.Addrs()
if err != nil {
continue
}
ipNets := make([]*net.IPNet, 0, len(addrs))
for _, addr := range addrs {
ipNet := addr.(*net.IPNet)
if v4 := ipNet.IP.To4(); v4 != nil {
ipNet.IP = v4
}
ipNets = append(ipNets, ipNet)
}
r[iface.Name] = &Interface{
Index: iface.Index,
Name: iface.Name,
Addrs: ipNets,
HardwareAddr: iface.HardwareAddr,
}
}
return r, nil
})
if err != nil {
return nil, err
}
ifaces := value.(map[string]*Interface)
iface, ok := ifaces[name]
if !ok {
return nil, ErrIfaceNotFound
}
return iface, nil
}
func FlushCache() {
interfaces.Reset()
}
func (iface *Interface) PickIPv4Addr(destination net.IP) (*net.IPNet, error) {
return iface.pickIPAddr(destination, func(addr *net.IPNet) bool {
return addr.IP.To4() != nil
})
}
func (iface *Interface) PickIPv6Addr(destination net.IP) (*net.IPNet, error) {
return iface.pickIPAddr(destination, func(addr *net.IPNet) bool {
return addr.IP.To4() == nil
})
}
func (iface *Interface) pickIPAddr(destination net.IP, accept func(addr *net.IPNet) bool) (*net.IPNet, error) {
var fallback *net.IPNet
for _, addr := range iface.Addrs {
if !accept(addr) {
continue
}
if fallback == nil && !addr.IP.IsLinkLocalUnicast() {
fallback = addr
if destination == nil {
break
}
}
if destination != nil && addr.Contains(destination) {
return addr, nil
}
}
if fallback == nil {
return nil, ErrAddrNotFound
}
return fallback, nil
}