forked from krolaw/dhcp4
/
bound_linux.go
46 lines (39 loc) · 1.03 KB
/
bound_linux.go
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// +build linux
package conn
import (
"net"
"os"
"syscall"
)
func NewUDP4BoundListener(interfaceName, laddr string) (pc net.PacketConn, e error) {
addr, err := net.ResolveUDPAddr("udp4", laddr)
if err != nil {
return nil, err
}
s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
if err != nil {
return nil, err
}
defer func() { // clean up if something goes wrong
if e != nil {
syscall.Close(s)
}
}()
if err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
return nil, err
}
if err := syscall.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_BROADCAST, 1); err != nil {
return nil, err
}
if err := syscall.SetsockoptString(s, syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, interfaceName); err != nil {
return nil, err
}
lsa := syscall.SockaddrInet4{Port: addr.Port}
copy(lsa.Addr[:], addr.IP.To4())
if err := syscall.Bind(s, &lsa); err != nil {
return nil, err
}
f := os.NewFile(uintptr(s), "")
defer f.Close()
return net.FilePacketConn(f)
}