143 lines
3.1 KiB
Go
143 lines
3.1 KiB
Go
package chain
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import (
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"bytes"
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"context"
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"fmt"
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"net"
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"github.com/go-gost/gost/pkg/connector"
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"github.com/go-gost/gost/pkg/hosts"
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"github.com/go-gost/gost/pkg/logger"
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"github.com/go-gost/gost/pkg/resolver"
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)
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type Router struct {
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Retries int
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Chain *Chain
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Hosts hosts.HostMapper
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Resolver resolver.Resolver
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Logger logger.Logger
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}
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func (r *Router) Dial(ctx context.Context, network, address string) (conn net.Conn, err error) {
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conn, err = r.dial(ctx, network, address)
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if err != nil {
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return
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}
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if network == "udp" || network == "udp4" || network == "udp6" {
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if _, ok := conn.(net.PacketConn); !ok {
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return &packetConn{conn}, nil
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}
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}
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return
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}
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func (r *Router) dial(ctx context.Context, network, address string) (conn net.Conn, err error) {
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count := r.Retries + 1
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if count <= 0 {
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count = 1
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}
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r.Logger.Debugf("dial %s/%s", address, network)
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for i := 0; i < count; i++ {
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route := r.Chain.GetRouteFor(network, address)
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if r.Logger.IsLevelEnabled(logger.DebugLevel) {
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buf := bytes.Buffer{}
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for _, node := range route.Path() {
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fmt.Fprintf(&buf, "%s@%s > ", node.Name(), node.Addr())
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}
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fmt.Fprintf(&buf, "%s", address)
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r.Logger.Debugf("route(retry=%d) %s", i, buf.String())
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}
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address, err = r.resolve(ctx, address)
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if err != nil {
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r.Logger.Error(err)
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break
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}
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conn, err = route.Dial(ctx, network, address)
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if err == nil {
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break
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}
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r.Logger.Errorf("route(retry=%d) %s", i, err)
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}
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return
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}
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func (r *Router) resolve(ctx context.Context, addr string) (string, error) {
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if addr == "" {
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return addr, nil
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}
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host, port, err := net.SplitHostPort(addr)
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if err != nil || host == "" {
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return "", err
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}
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if r.Hosts != nil {
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if ip := r.Hosts.Lookup(host); ip != nil {
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r.Logger.Debugf("hit hosts: %s -> %s", host, ip)
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return net.JoinHostPort(ip.String(), port), nil
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}
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}
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if r.Resolver != nil {
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ips, err := r.Resolver.Resolve(ctx, host)
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if err != nil {
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r.Logger.Error(err)
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}
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if len(ips) == 0 {
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return "", fmt.Errorf("resolver: domain %s does not exists", host)
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}
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return net.JoinHostPort(ips[0].String(), port), nil
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}
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return addr, nil
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}
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func (r *Router) Bind(ctx context.Context, network, address string, opts ...connector.BindOption) (ln net.Listener, err error) {
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count := r.Retries + 1
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if count <= 0 {
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count = 1
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}
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r.Logger.Debugf("bind on %s/%s", address, network)
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for i := 0; i < count; i++ {
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route := r.Chain.GetRouteFor(network, address)
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if r.Logger.IsLevelEnabled(logger.DebugLevel) {
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buf := bytes.Buffer{}
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for _, node := range route.Path() {
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fmt.Fprintf(&buf, "%s@%s > ", node.Name(), node.Addr())
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}
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fmt.Fprintf(&buf, "%s", address)
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r.Logger.Debugf("route(retry=%d) %s", i, buf.String())
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}
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ln, err = route.Bind(ctx, network, address, opts...)
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if err == nil {
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break
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}
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r.Logger.Errorf("route(retry=%d) %s", i, err)
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}
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return
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}
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type packetConn struct {
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net.Conn
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}
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func (c *packetConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
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n, err = c.Read(b)
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addr = c.Conn.RemoteAddr()
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return
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}
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func (c *packetConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
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return c.Write(b)
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}
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