48 lines
1.1 KiB
Go
48 lines
1.1 KiB
Go
|
// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
|
||
|
|
|
||
|
|
package dhcpd
|
||
|
|
|
||
|
|
import (
|
||
|
|
"net"
|
||
|
|
"os"
|
||
|
|
"syscall"
|
||
|
|
|
||
|
|
"golang.org/x/net/ipv4"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Create a socket for receiving broadcast packets
|
||
|
|
func newBroadcastPacketConn(bindAddr net.IP, port int, ifname string) (*ipv4.PacketConn, error) {
|
||
|
|
s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
|
||
|
|
if 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.SetsockoptInt(s, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
if err := syscall.SetsockoptString(s, syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, ifname); err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
addr := syscall.SockaddrInet4{Port: port}
|
||
|
|
copy(addr.Addr[:], bindAddr.To4())
|
||
|
|
err = syscall.Bind(s, &addr)
|
||
|
|
if err != nil {
|
||
|
|
syscall.Close(s)
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
f := os.NewFile(uintptr(s), "")
|
||
|
|
c, err := net.FilePacketConn(f)
|
||
|
|
f.Close()
|
||
|
|
if err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
|
||
|
|
p := ipv4.NewPacketConn(c)
|
||
|
|
return p, nil
|
||
|
|
}
|