glider/rule/rule.go

package rule

import (
	"net"
	"strings"
	"sync"

	"github.com/nadoo/glider/common/log"
	"github.com/nadoo/glider/proxy"
)

// Proxy struct.
type Proxy struct {
	main      *FwdrGroup
	all       []*FwdrGroup
	domainMap sync.Map
	ipMap     sync.Map
	cidrMap   sync.Map
}

// NewProxy returns a new rule proxy.
func NewProxy(mainForwarders []string, mainStrategy *StrategyConfig, rules []*Config) *Proxy {
	rd := &Proxy{main: NewFwdrGroup("main", mainForwarders, mainStrategy)}

	for _, r := range rules {
		group := NewFwdrGroup(r.Name, r.Forward, &r.StrategyConfig)
		rd.all = append(rd.all, group)

		for _, domain := range r.Domain {
			rd.domainMap.Store(strings.ToLower(domain), group)
		}

		for _, ip := range r.IP {
			rd.ipMap.Store(ip, group)
		}

		for _, s := range r.CIDR {
			if _, cidr, err := net.ParseCIDR(s); err == nil {
				rd.cidrMap.Store(cidr, group)
			}
		}
	}

	if len(mainForwarders) > 0 {
		direct := NewFwdrGroup("backup", nil, mainStrategy)
		for _, f := range rd.main.fwdrs {
			// Note: the addr maybe ip address, but no matter here.
			rd.domainMap.Store(strings.ToLower(strings.Split(f.addr, ":")[0]), direct)
		}
	}

	return rd
}

// Dial dials to targer addr and return a conn.
func (p *Proxy) Dial(network, addr string) (net.Conn, proxy.Dialer, error) {
	return p.chooseProxy(addr).Dial(network, addr)
}

// DialUDP connects to the given address via the proxy.
func (p *Proxy) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
	return p.chooseProxy(addr).DialUDP(network, addr)
}

// chooseProxy returns a proxy according to rule.
func (p *Proxy) chooseProxy(dstAddr string) *FwdrGroup {
	host, _, err := net.SplitHostPort(dstAddr)
	if err != nil {
		// TODO: check here
		// logf("[rule] SplitHostPort ERROR: %s", err)
		return p.main
	}

	// find ip
	if ip := net.ParseIP(host); ip != nil {
		// check ip
		if proxy, ok := p.ipMap.Load(ip.String()); ok {
			return proxy.(*FwdrGroup)
		}

		var ret *FwdrGroup
		// check cidr
		p.cidrMap.Range(func(key, value interface{}) bool {
			cidr := key.(*net.IPNet)
			if cidr.Contains(ip) {
				ret = value.(*FwdrGroup)
				return false
			}

			return true
		})

		if ret != nil {
			return ret
		}

	}

	host = strings.ToLower(host)
	for i := len(host); i != -1; {
		i = strings.LastIndexByte(host[:i], '.')
		if proxy, ok := p.domainMap.Load(host[i+1:]); ok {
			return proxy.(*FwdrGroup)
		}
	}

	return p.main
}

// NextDialer returns next dialer according to rule.
func (p *Proxy) NextDialer(dstAddr string) proxy.Dialer {
	return p.chooseProxy(dstAddr).NextDialer(dstAddr)
}

// Record records result while using the dialer from proxy.
func (p *Proxy) Record(dialer proxy.Dialer, success bool) {
	OnRecord(dialer, success)
}

// AddDomainIP used to update ipMap rules according to domainMap rule.
func (p *Proxy) AddDomainIP(domain, ip string) error {
	if ip != "" {
		domain = strings.ToLower(domain)
		for i := len(domain); i != -1; {
			i = strings.LastIndexByte(domain[:i], '.')
			if dialer, ok := p.domainMap.Load(domain[i+1:]); ok {
				p.ipMap.Store(ip, dialer)
				log.F("[rule] add ip=%s, based on rule: domain=%s & domain/ip: %s/%s\n", ip, domain[i+1:], domain, ip)
			}
		}
	}
	return nil
}

// Check .
func (p *Proxy) Check() {
	p.main.Check()

	for _, fwdr := range p.all {
		fwdr.Check()
	}
}