Michael Stapelberg 38af7fd18d Initial commit
2017-03-04 11:22:48 +01:00

125 lines
3.2 KiB
Go

package iface
import (
"net"
"syscall"
"unsafe"
)
// as per https://manpages.debian.org/jessie/manpages/netdevice.7.en.html
type ifreqAddr struct {
name [16]byte
addr syscall.RawSockaddrInet4
pad [8]byte
}
// as per https://manpages.debian.org/jessie/manpages/netdevice.7.en.html
type ifreqFlags struct {
name [16]byte
flags uint16
pad [22]byte
}
// as per http://lxr.free-electrons.com/source/include/uapi/linux/route.h#L30
type rtentry struct {
pad1 uint64
dst syscall.RawSockaddrInet4
gateway syscall.RawSockaddrInet4
genmask syscall.RawSockaddrInet4
flags uint16
pad [512]byte
}
type Configsocket struct {
fd int
name [16]byte
}
func NewConfigSocket(iface string) (Configsocket, error) {
fd, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
if err != nil {
return Configsocket{}, err
}
cs := Configsocket{
fd: fd,
}
copy(cs.name[:], []byte(iface))
return cs, nil
}
func (cs Configsocket) Close() error {
return syscall.Close(cs.fd)
}
func (cs Configsocket) ifreqAddr(request uintptr, addr net.IP) error {
req := ifreqAddr{
name: cs.name,
addr: syscall.RawSockaddrInet4{
Family: syscall.AF_INET,
},
}
copy(req.addr.Addr[:], addr)
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(cs.fd), request, uintptr(unsafe.Pointer(&req))); errno != 0 {
return errno
}
return nil
}
func (cs Configsocket) SetAddress(addr net.IP) error {
return cs.ifreqAddr(syscall.SIOCSIFADDR, addr)
}
func (cs Configsocket) SetNetmask(addr net.IPMask) error {
return cs.ifreqAddr(syscall.SIOCSIFNETMASK, net.IP(addr))
}
func (cs Configsocket) SetBroadcast(addr net.IP) error {
return cs.ifreqAddr(syscall.SIOCSIFBRDADDR, addr)
}
func (cs Configsocket) Up() error {
req := ifreqFlags{name: cs.name}
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(cs.fd), syscall.SIOCGIFFLAGS, uintptr(unsafe.Pointer(&req))); errno != 0 {
return errno
}
req.flags |= syscall.IFF_UP
req.flags |= syscall.IFF_RUNNING
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(cs.fd), syscall.SIOCSIFFLAGS, uintptr(unsafe.Pointer(&req))); errno != 0 {
return errno
}
return nil
}
func (cs Configsocket) AddRoute(dst, gateway net.IP, genmask net.IPMask) syscall.Errno {
req := rtentry{
dst: syscall.RawSockaddrInet4{Family: syscall.AF_INET},
gateway: syscall.RawSockaddrInet4{Family: syscall.AF_INET},
genmask: syscall.RawSockaddrInet4{Family: syscall.AF_INET},
flags: syscall.RTF_UP | syscall.RTF_GATEWAY,
}
copy(req.dst.Addr[:], dst)
copy(req.gateway.Addr[:], gateway)
copy(req.genmask.Addr[:], genmask)
_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(cs.fd), syscall.SIOCADDRT, uintptr(unsafe.Pointer(&req)))
return errno
}
func (cs Configsocket) DelRoute(dst, gateway net.IP, genmask net.IPMask) syscall.Errno {
req := rtentry{
dst: syscall.RawSockaddrInet4{Family: syscall.AF_INET},
gateway: syscall.RawSockaddrInet4{Family: syscall.AF_INET},
genmask: syscall.RawSockaddrInet4{Family: syscall.AF_INET},
flags: syscall.RTF_UP | syscall.RTF_GATEWAY,
}
copy(req.dst.Addr[:], dst)
copy(req.gateway.Addr[:], gateway)
copy(req.genmask.Addr[:], genmask)
_, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(cs.fd), syscall.SIOCDELRT, uintptr(unsafe.Pointer(&req)))
return errno
}