94 lines
2.2 KiB
Go
94 lines
2.2 KiB
Go
package connect
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import (
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"context"
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"fmt"
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"net"
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"time"
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"go.uber.org/zap"
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)
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// DirectFactory Direct-UDP 直连工厂（Layer 1）
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type DirectFactory struct {
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stunServers []string
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logger *zap.Logger
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}
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// NewDirectFactory 创建 Direct-UDP 工厂
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func NewDirectFactory(stunServers []string, logger *zap.Logger) *DirectFactory {
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return &DirectFactory{
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stunServers: stunServers,
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logger: logger,
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}
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}
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// Layer 返回传输层类型
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func (f *DirectFactory) Layer() Layer {
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return LayerDirectUDP
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}
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// Name 返回传输方式名称
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func (f *DirectFactory) Name() string {
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return "Direct-UDP"
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}
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// Dial 建立 Direct-UDP 直连
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func (f *DirectFactory) Dial(ctx context.Context, config *DialConfig) (net.Conn, error) {
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f.logger.Info("开始建立 Direct-UDP 直连",
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zap.String("peer_id", config.PeerID))
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servers := f.stunServers
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if len(servers) == 0 {
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servers = config.STUNServers
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}
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if len(servers) == 0 {
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f.logger.Warn("未配置 STUN 服务器列表，仅尝试内部 P2P 打洞")
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}
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var candidates []string
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if len(servers) > 0 {
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// 1. 创建 STUN 客户端收集候选地址
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stun := NewSTUNClient(servers, f.logger)
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candidates = stun.CollectCandidates()
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}
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if len(candidates) == 0 {
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f.logger.Warn("未能收集到任何 STUN 候选地址，回退至 PeerID")
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// As a fallback, maybe PeerID contains IP:PORT
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candidates = append(candidates, config.PeerID)
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}
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f.logger.Info("STUN 候选地址收集完成",
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zap.Strings("candidates", candidates))
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// 2. 实际 P2P 连接尝试
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f.logger.Warn("当前尝试所有候选地址...")
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dialer := &net.Dialer{
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Timeout: 5 * time.Second,
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}
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// 建立 UDP 连接并返回最近可用的
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var lastErr error
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for _, candidate := range candidates {
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if candidate == "" { continue }
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conn, err := dialer.DialContext(ctx, "udp", candidate)
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if err == nil {
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f.logger.Info("Direct-UDP 直连建立成功",
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zap.String("peer_id", config.PeerID),
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zap.String("remote_addr", conn.RemoteAddr().String()))
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return conn, nil
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}
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f.logger.Warn("候选地址连接失败",
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zap.String("candidate", candidate),
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zap.Error(err))
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lastErr = err
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}
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return nil, fmt.Errorf("所有候选地址 UDP 连接均失败，最后错误：%w", lastErr)
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}
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