chore(pmtud): remove calls to syscall in favor of unix and windows

- syscall is deprecated and is not kept up-to-date
- each OS is inherently different hence the syscall being deprecated

internal/pmtud/tcp/tcp_windows.go

@@ -1,37 +1,58 @@
 package tcp
 
 import (
-	"syscall"
+	"net/netip"
 	"time"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
 )
 
-type fileDescriptor syscall.Handle
+type fileDescriptor windows.Handle
 
-func sendTo(fd fileDescriptor, p []byte, flags int, to syscall.Sockaddr) (err error) {
-	return syscall.Sendto(syscall.Handle(fd), p, flags, to)
+func socket(domain int, typ int, proto int) (fd windows.Handle, err error) {
+	return windows.Socket(domain, typ, proto)
+}
+
+func closeSocket(fd windows.Handle) error {
+	return windows.Close(fd)
+}
+
+func sendTo(fd fileDescriptor, p []byte, flags int, to windows.Sockaddr) (err error) {
+	return windows.Sendto(windows.Handle(fd), p, flags, to)
 }
 
 func setSocketTimeout(fd fileDescriptor, timeout time.Duration) (err error) {
 	timeval := int(timeout.Milliseconds())
-	return syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, windows.SO_RCVTIMEO, timeval)
+	return windows.SetsockoptInt(windows.Handle(fd), windows.SOL_SOCKET, windows.SO_RCVTIMEO, timeval)
 }
 
-func recvFrom(fd fileDescriptor, p []byte, flags int) (n int, from syscall.Sockaddr, err error) {
-	return syscall.Recvfrom(syscall.Handle(fd), p, flags)
+func recvFrom(fd fileDescriptor, p []byte, flags int) (n int, from windows.Sockaddr, err error) {
+	return windows.Recvfrom(windows.Handle(fd), p, flags)
 }
 
-func setMTUDiscovery(fd syscall.Handle) error {
+func setMTUDiscovery(fd windows.Handle) error {
 	panic("not implemented")
 }
 
-func setNonBlock(fd syscall.Handle) error {
+func setNonBlock(fd windows.Handle) error {
 	// Windows: Use ioctlsocket with FIONBIO
 	var arg uint32 = 1 // 1 to enable non-blocking mode
 	var bytesReturned uint32
 	const FIONBIO = 0x8004667e
-	return syscall.WSAIoctl(fd, FIONBIO, (*byte)(unsafe.Pointer(&arg)),
+	return windows.WSAIoctl(fd, FIONBIO, (*byte)(unsafe.Pointer(&arg)),
 		uint32(unsafe.Sizeof(arg)), nil, 0, &bytesReturned, nil, 0)
 }
+
+func makeSockAddr(addr netip.AddrPort) windows.Sockaddr {
+	if addr.Addr().Is4() {
+		return &windows.SockaddrInet4{
+			Port: int(addr.Port()),
+			Addr: addr.Addr().As4(),
+		}
+	}
+	return &windows.SockaddrInet6{
+		Port: int(addr.Port()),
+		Addr: addr.Addr().As16(),
+	}
+}