openlan/pkg/access/access_linux.go

package access

import (
	"github.com/luscis/openlan/pkg/config"
	"github.com/luscis/openlan/pkg/models"
	"github.com/luscis/openlan/pkg/network"
	"github.com/vishvananda/netlink"
)

type Access struct {
	MixAccess
	// private
	brName string
	ipMtu  int
	addr   string
	bypass *netlink.Route
	routes []*models.Route
	link   netlink.Link
	uuid   string
}

func NewAccess(config *config.Access) *Access {
	ipMtu := config.Interface.IPMtu
	if ipMtu == 0 {
		ipMtu = 1500
	}
	p := Access{
		ipMtu:     ipMtu,
		brName:    config.Interface.Bridge,
		MixAccess: NewMixAccess(config),
	}
	return &p
}

func (p *Access) Initialize() {
	w := p.worker

	w.listener.AddAddr = p.AddAddr
	w.listener.DelAddr = p.DelAddr
	w.listener.OnTap = p.OnTap

	p.MixAccess.Initialize()
}

func (p *Access) DelAddr(addr string) error {
	if p.link == nil || addr == "" {
		return nil
	}
	ipAddr, err := netlink.ParseAddr(addr)
	if err != nil {
		p.out.Error("Access.DelAddr.ParseCIDR %s: %s", addr, err)
		return err
	}
	if err := netlink.AddrDel(p.link, ipAddr); err != nil {
		p.out.Warn("Access.DelAddr.UnsetLinkIp: %s", err)
	}
	p.out.Info("Access.DelAddr: %s", addr)
	p.addr = ""
	return nil
}

func (p *Access) AddAddr(addr, gateway string) error {
	if addr == "" || p.link == nil {
		return nil
	}
	ipAddr, err := netlink.ParseAddr(addr)
	if err != nil {
		p.out.Error("Access.AddAddr.ParseCIDR %s: %s", addr, err)
		return err
	}
	if err := netlink.AddrAdd(p.link, ipAddr); err != nil {
		p.out.Warn("Access.AddAddr.SetLinkIp: %s", err)
		return err
	}

	p.addr = addr
	p.out.Info("Access.AddAddr: %s", addr)

	p.AddRoute()

	return nil
}

func (p *Access) UpBr(name string) *netlink.Bridge {
	if name == "" {
		return nil
	}
	la := netlink.LinkAttrs{TxQLen: -1, Name: name}
	br := &netlink.Bridge{LinkAttrs: la}
	if link, err := netlink.LinkByName(name); link == nil {
		p.out.Warn("Access.UpBr: %s %s", name, err)
		err := netlink.LinkAdd(br)
		if err != nil {
			p.out.Warn("Access.UpBr.newBr: %s %s", name, err)
		}
	}
	link, err := netlink.LinkByName(name)
	if link == nil {
		p.out.Error("Access.UpBr: %s %s", name, err)
		return nil
	}
	if err := netlink.LinkSetUp(link); err != nil {
		p.out.Error("Access.UpBr.LinkUp: %s", err)
	}
	return br
}

func (p *Access) OnTap(w *TapWorker) error {
	p.out.Info("Access.OnTap")
	tap := w.device
	name := tap.Name()
	if tap.Type() == network.ProviderVir { // virtual device
		p.out.Error("Access.OnTap: not support %s", tap.Type())
		return nil
	}
	// kernel device
	link, err := netlink.LinkByName(name)
	if err != nil {
		p.out.Error("Access.OnTap: Get %s: %s", name, err)
		return err
	}
	if err := netlink.LinkSetMTU(link, p.ipMtu); err != nil {
		p.out.Error("Access.OnTap.SetMTU: %s", err)
	}
	if br := p.UpBr(p.brName); br != nil {
		if err := netlink.LinkSetMaster(link, br); err != nil {
			p.out.Error("Access.OnTap.AddSlave: Switch dev %s: %s", name, err)
		}
		link, err = netlink.LinkByName(p.brName)
		if err != nil {
			p.out.Error("Access.OnTap: Get %s: %s", p.brName, err)
		}
		if p.config.Interface.Cost > 0 {
			port := network.NewBrPort(name)
			if err := port.Cost(p.config.Interface.Cost); err != nil {
				p.out.Error("Access.OnTap: Cost %s: %s", p.brName, err)
			}
		}
	}
	p.link = link
	return nil
}

func (p *Access) AddRoute() error {
	to := p.config.Forward
	route := p.Network()
	if to == nil || route == nil {
		return nil
	}

	via := route.Gateway
	if via == "" {
		return nil
	}

	for _, prefix := range to {
		out, err := network.RouteAdd(p.IfName(), prefix, via)
		if err != nil {
			p.out.Warn("Access.AddRoute: %s: %s", prefix, out)
			continue
		}
		p.out.Info("Access.AddRoute: %s via %s", prefix, via)
	}
	return nil
}