interfaces.go

// @@
// @ Author       : Eacher
// @ Date         : 2023-06-21 08:16:59
// @ LastEditTime : 2023-09-20 11:48:59
// @ LastEditors  : Eacher
// @ --------------------------------------------------------------------------------<
// @ Description  : 
// @ --------------------------------------------------------------------------------<
// @ FilePath     : /20yyq/networkmanager/interfaces.go
// @@
package networkmanager

import (
	"net"
	"sync"
	"time"
	"syscall"

	"github.com/20yyq/packet"
	"github.com/20yyq/netlink"
)

const (
	SOCK_CLOEXEC	= syscall.SOCK_CLOEXEC
	SOL_SOCKET		= syscall.SOL_SOCKET
	SOCK_RAW		= syscall.SOCK_RAW
	SO_RCVTIMEO		= syscall.SO_RCVTIMEO
	NLMSG_HDRLEN	= syscall.NLMSG_HDRLEN
	NETLINK_ROUTE	= syscall.NETLINK_ROUTE

	AF_NETLINK		= syscall.AF_NETLINK
	AF_UNSPEC		= syscall.AF_UNSPEC
	AF_INET			= syscall.AF_INET
	AF_INET6		= syscall.AF_INET6

	IFA_LOCAL		= syscall.IFA_LOCAL
	IFA_BROADCAST	= syscall.IFA_BROADCAST
	IFA_ANYCAST		= syscall.IFA_ANYCAST
	IFA_LABEL		= syscall.IFA_LABEL
	IFA_CACHEINFO	= syscall.IFA_CACHEINFO
	IFA_ADDRESS		= syscall.IFA_ADDRESS
	IFF_UP			= syscall.IFF_UP

	NLM_F_CREATE	= syscall.NLM_F_CREATE
	NLM_F_REQUEST	= syscall.NLM_F_REQUEST
	NLM_F_EXCL		= syscall.NLM_F_EXCL
	NLM_F_ACK		= syscall.NLM_F_ACK
	NLM_F_DUMP		= syscall.NLM_F_DUMP
	NLM_F_REPLACE	= syscall.NLM_F_REPLACE

	RTM_NEWADDR		= syscall.RTM_NEWADDR
	RTM_GETADDR		= syscall.RTM_GETADDR
	RTM_DELADDR		= syscall.RTM_DELADDR
	RTM_NEWLINK		= syscall.RTM_NEWLINK
	RTM_GETROUTE	= syscall.RTM_GETROUTE
	RTM_NEWROUTE	= syscall.RTM_NEWROUTE
	RTM_DELROUTE	= syscall.RTM_DELROUTE

	RTA_DST			= syscall.RTA_DST
	RTA_SRC			= syscall.RTA_SRC
	RTA_PREFSRC		= syscall.RTA_PREFSRC
	RTA_IIF			= syscall.RTA_IIF
	RTA_OIF			= syscall.RTA_OIF
	RTA_GATEWAY		= syscall.RTA_GATEWAY
	RTA_PRIORITY	= syscall.RTA_PRIORITY
	RTA_METRICS		= syscall.RTA_METRICS
	RTA_FLOW		= syscall.RTA_FLOW
	RTA_TABLE		= syscall.RTA_TABLE
	RTA_CACHEINFO	= syscall.RTA_CACHEINFO

	RT_TABLE_MAIN	= syscall.RT_TABLE_MAIN
	RT_SCOPE_UNIVERSE = syscall.RT_SCOPE_UNIVERSE
	RTPROT_BOOT		= syscall.RTPROT_BOOT
	RTN_UNICAST		= syscall.RTN_UNICAST

	RTNLGRP_ND_USEROPT	= syscall.RTNLGRP_ND_USEROPT

	SizeofRtAttr	= syscall.SizeofRtAttr
)

type Interface struct {
	iface	*net.Interface
	conn 	*netlink.NetlinkRoute
	
	mutex 	sync.Mutex
}

func InterfaceByName(ifname string) (*Interface, error) {
	iface := &Interface{}
	var err error
	if iface.iface, err = net.InterfaceByName(ifname); err != nil {
		return nil, err
	}
	iface.conn = &netlink.NetlinkRoute{
		DevName: iface.iface.Name,
		Sal: &syscall.SockaddrNetlink{Family: AF_NETLINK, Groups: syscall.RTNLGRP_LINK},
	}
	return iface, iface.conn.Init() 
}

func (ifi *Interface) Up() error {
	if ifi.iface.Flags&0x01 != 0 {
		return nil
	}
	sm := netlink.SendNLMessage{
		NlMsghdr: &packet.NlMsghdr{Type: RTM_NEWLINK, Flags: NLM_F_REQUEST|NLM_F_ACK, Seq: randReq()},
	}
	sm.Attrs = append(sm.Attrs, packet.IfInfomsg{Family: AF_UNSPEC, Flags: IFF_UP, Change: IFF_UP, Index: int32(ifi.iface.Index)})
	rm := netlink.ReceiveNLMessage{Data: make([]byte, 1024)}
	err := ifi.conn.Exchange(&sm, &rm)
	if err == nil {
		if err = DeserializeNlMsgerr(rm.MsgList[0]); err == nil {
			ifi.iface.Flags |= 0x01
		}
	}
	return err
}

func (ifi *Interface) Down() error {
	if ifi.iface.Flags&0x01 != 1 {
		return nil
	}
	sm := netlink.SendNLMessage{
		NlMsghdr: &packet.NlMsghdr{Type: RTM_NEWLINK, Flags: NLM_F_REQUEST|NLM_F_ACK, Seq: randReq()},
	}
	sm.Attrs = append(sm.Attrs, packet.IfInfomsg{Family: AF_UNSPEC, Change: IFF_UP, Index: int32(ifi.iface.Index)})
	rm := netlink.ReceiveNLMessage{Data: make([]byte, 1024)}
	err := ifi.conn.Exchange(&sm, &rm)
	if err == nil {
		if err = DeserializeNlMsgerr(rm.MsgList[0]); err == nil {
			ifi.iface.Flags &= 0xFFFFFFFE
		}
	}
	return err
}

func (ifi *Interface) Close() {
	ifi.mutex.Lock()
	defer ifi.mutex.Unlock()
	ifi.conn.Close()
}

func randReq() uint32 {
	return uint32(time.Now().UnixNano() & 0xFFFFFFFF)
}