dhcp: Can't build/run on macOS due to client.go code

go build
# github.com/insomniacslk/dhcp/dhcpv4
../../insomniacslk/dhcp/dhcpv4/client.go:125:25: undefined: unix.AF_PACKET
../../insomniacslk/dhcp/dhcpv4/client.go:125:68: undefined: unix.ETH_P_IP
../../insomniacslk/dhcp/dhcpv4/client.go:133:12: undefined: unix.SockaddrLinklayer

There are no constants in package golang.org/x/sys/unix for darwin_amd64

grep AF_PACKET *
grep: linux: Is a directory
syscall_linux.go:// SockaddrLinklayer implements the Sockaddr interface for AF_PACKET type sockets.
syscall_linux.go:	sa.raw.Family = AF_PACKET
syscall_linux.go:	case AF_PACKET:
zerrors_linux_386.go:	AF_PACKET                            = 0x11
zerrors_linux_amd64.go:	AF_PACKET                            = 0x11
zerrors_linux_arm.go:	AF_PACKET                            = 0x11
zerrors_linux_arm64.go:	AF_PACKET                            = 0x11
zerrors_linux_mips.go:	AF_PACKET                            = 0x11
zerrors_linux_mips64.go:	AF_PACKET                            = 0x11
zerrors_linux_mips64le.go:	AF_PACKET                            = 0x11
zerrors_linux_mipsle.go:	AF_PACKET                            = 0x11
zerrors_linux_ppc64.go:	AF_PACKET                            = 0x11
zerrors_linux_ppc64le.go:	AF_PACKET                            = 0x11
zerrors_linux_riscv64.go:	AF_PACKET                            = 0x11
zerrors_linux_s390x.go:	AF_PACKET                            = 0x11
zerrors_linux_sparc64.go:	AF_PACKET                        = 0x11
zerrors_solaris_amd64.go:	AF_PACKET                     = 0x20

This is a commit probably breaks compilation:
https://github.com/insomniacslk/dhcp/commit/4eedccfd12105dbcde88298e87bbbcf41aa7c1df

In BSD system AF_PACKET should be replaced by AF_LINK

BTW, why not to move client for separate package? I just removed file client.go from repo in order to compile server code.