96 lines
2.0 KiB
Go
96 lines
2.0 KiB
Go
package proxy
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import (
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"context"
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"fmt"
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"net"
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"github.com/things-go/go-socks5"
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)
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// SOCKSProxy is a SOCKS5 proxy server with domain filtering.
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type SOCKSProxy struct {
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server *socks5.Server
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listener net.Listener
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filter FilterFunc
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debug bool
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port int
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}
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// NewSOCKSProxy creates a new SOCKS5 proxy with the given filter.
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func NewSOCKSProxy(filter FilterFunc, debug bool) *SOCKSProxy {
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return &SOCKSProxy{
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filter: filter,
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debug: debug,
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}
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}
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// fenceRuleSet implements socks5.RuleSet for domain filtering.
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type fenceRuleSet struct {
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filter FilterFunc
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debug bool
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}
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func (r *fenceRuleSet) Allow(ctx context.Context, req *socks5.Request) (context.Context, bool) {
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host := req.DestAddr.FQDN
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if host == "" {
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host = req.DestAddr.IP.String()
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}
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port := req.DestAddr.Port
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allowed := r.filter(host, port)
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if r.debug {
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if allowed {
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fmt.Printf("[fence:socks] Allowed: %s:%d\n", host, port)
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} else {
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fmt.Printf("[fence:socks] Blocked: %s:%d\n", host, port)
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}
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}
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return ctx, allowed
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}
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// Start starts the SOCKS5 proxy on a random available port.
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func (p *SOCKSProxy) Start() (int, error) {
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// Create listener first to get a random port
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listener, err := net.Listen("tcp", "127.0.0.1:0")
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if err != nil {
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return 0, fmt.Errorf("failed to listen: %w", err)
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}
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p.listener = listener
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p.port = listener.Addr().(*net.TCPAddr).Port
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server := socks5.NewServer(
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socks5.WithRule(&fenceRuleSet{
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filter: p.filter,
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debug: p.debug,
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}),
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)
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p.server = server
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go func() {
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if err := p.server.Serve(p.listener); err != nil {
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if p.debug {
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fmt.Printf("[fence:socks] Server error: %v\n", err)
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}
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}
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}()
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if p.debug {
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fmt.Printf("[fence:socks] SOCKS5 proxy listening on localhost:%d\n", p.port)
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}
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return p.port, nil
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}
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// Stop stops the SOCKS5 proxy.
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func (p *SOCKSProxy) Stop() error {
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if p.listener != nil {
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return p.listener.Close()
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}
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return nil
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}
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// Port returns the port the proxy is listening on.
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func (p *SOCKSProxy) Port() int {
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return p.port
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}
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