🐛 fix(oceanbase): 修复 Oracle 租户 SSH 预探测超时

- 拆分 OceanBase Oracle 预探测的拨号超时与握手读取超时
- SSH 跳板机场景下使用完整连接超时，避免内网目标被误判不可达
- 保留 MySQL handshake 短读取超时，避免 TNS 端口测试连接变慢
- 补充 SSH 预探测超时与短读取行为回归测试

internal/db/oceanbase_impl.go

@@ -59,10 +59,11 @@ import (
 )
 
 const (
-	oceanbaseDriverName     = "oceanbase"
-	defaultOceanBasePort    = 2881
-	oceanBaseProtocolMySQL  = "mysql"
-	oceanBaseProtocolOracle = "oracle"
+	oceanbaseDriverName             = "oceanbase"
+	defaultOceanBasePort            = 2881
+	oceanBaseProtocolMySQL          = "mysql"
+	oceanBaseProtocolOracle         = "oracle"
+	oceanBaseOracleProbeReadTimeout = 3 * time.Second
 )
 
 // OceanBaseDB 支持 OceanBase MySQL/Oracle 两种租户协议。
@@ -519,18 +520,25 @@ func probeOceanBaseMySQLWireHandshake(host string, port int, timeout time.Durati
 }
 
 func probeOceanBaseMySQLWireHandshakeDetail(config connection.ConnectionConfig, timeout time.Duration) oceanBaseMySQLWireProbeResult {
-	if timeout <= 0 {
-		timeout = 2 * time.Second
+	return probeOceanBaseMySQLWireHandshakeDetailWithTimeouts(config, timeout, timeout)
+}
+
+func probeOceanBaseMySQLWireHandshakeDetailWithTimeouts(config connection.ConnectionConfig, dialTimeout time.Duration, readTimeout time.Duration) oceanBaseMySQLWireProbeResult {
+	if dialTimeout <= 0 {
+		dialTimeout = 2 * time.Second
+	}
+	if readTimeout <= 0 {
+		readTimeout = dialTimeout
 	}
 	addr := normalizeMySQLAddress(config.Host, config.Port)
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	ctx, cancel := context.WithTimeout(context.Background(), dialTimeout)
 	defer cancel()
 	conn, err := oceanBaseProbeDialContext(ctx, config, addr)
 	if err != nil {
 		return oceanBaseMySQLWireProbeResult{err: err}
 	}
 	defer conn.Close()
-	_ = conn.SetDeadline(time.Now().Add(timeout))
+	_ = conn.SetDeadline(time.Now().Add(readTimeout))
 
 	header := make([]byte, 4)
 	if _, err := io.ReadFull(conn, header); err != nil {
@@ -680,11 +688,16 @@ func (o *OceanBaseDB) Connect(config connection.ConnectionConfig) error {
 
 	if protocol == oceanBaseProtocolOracle {
 		// 预探测目标端口的实际协议，决定走哪条 Oracle 连接路径。
-		probeTimeout := getConnectTimeout(runConfig)
-		if probeTimeout > 3*time.Second {
-			probeTimeout = 3 * time.Second
+		// SSH 跳板机到内网目标的 direct-tcpip 拨号可能慢于 3 秒；只收紧握手读取超时，避免误判内网目标不可达。
+		probeDialTimeout := getConnectTimeout(runConfig)
+		if !runConfig.UseSSH && probeDialTimeout > oceanBaseOracleProbeReadTimeout {
+			probeDialTimeout = oceanBaseOracleProbeReadTimeout
 		}
-		probeResult := probeOceanBaseMySQLWireHandshakeDetail(runConfig, probeTimeout)
+		probeReadTimeout := oceanBaseOracleProbeReadTimeout
+		if probeReadTimeout > probeDialTimeout {
+			probeReadTimeout = probeDialTimeout
+		}
+		probeResult := probeOceanBaseMySQLWireHandshakeDetailWithTimeouts(runConfig, probeDialTimeout, probeReadTimeout)
 		switch {
 		case probeResult.probeSucceeded && probeResult.isOBMySQLWire:
 			// 明确识别为 OB MySQL wire 端口：直接走 OBClient capability 路径

internal/db/oceanbase_impl_test.go

@@ -520,6 +520,90 @@ func TestProbeOceanBaseMySQLWireHandshakeUsesSSHConfiguredDialer(t *testing.T) {
 	}
 }
 
+func TestOceanBaseOracleConnectUsesFullSSHTimeoutForProbeDial(t *testing.T) {
+	originalDial := oceanBaseProbeDialContext
+	t.Cleanup(func() { oceanBaseProbeDialContext = originalDial })
+
+	var observedDialTimeout time.Duration
+	oceanBaseProbeDialContext = func(ctx context.Context, config connection.ConnectionConfig, address string) (net.Conn, error) {
+		if deadline, ok := ctx.Deadline(); ok {
+			observedDialTimeout = time.Until(deadline)
+		}
+		return nil, errors.New("remote dial denied")
+	}
+
+	ob := &OceanBaseDB{}
+	err := ob.Connect(connection.ConnectionConfig{
+		Type:              "oceanbase",
+		Host:              "172.22.39.20",
+		Port:              12883,
+		User:              "SBDEV@SERVICE:srv_yhcs",
+		Password:          "secret",
+		Database:          "srv_yhcs",
+		OceanBaseProtocol: oceanBaseProtocolOracle,
+		Timeout:           12,
+		UseSSH:            true,
+		SSH: connection.SSHConfig{
+			Host: "jump.example.com",
+			Port: 22,
+			User: "ops",
+		},
+	})
+	if err == nil {
+		t.Fatal("expected connect error from mocked probe dialer")
+	}
+	if observedDialTimeout < 10*time.Second {
+		t.Fatalf("expected SSH probe dial to use the full configured timeout, got about %s", observedDialTimeout)
+	}
+}
+
+func TestProbeOceanBaseMySQLWireHandshakeSplitsDialAndReadTimeout(t *testing.T) {
+	originalDial := oceanBaseProbeDialContext
+	t.Cleanup(func() { oceanBaseProbeDialContext = originalDial })
+
+	var observedDialTimeout time.Duration
+	var serverConn net.Conn
+	oceanBaseProbeDialContext = func(ctx context.Context, config connection.ConnectionConfig, address string) (net.Conn, error) {
+		if deadline, ok := ctx.Deadline(); ok {
+			observedDialTimeout = time.Until(deadline)
+		}
+		clientConn, remoteConn := net.Pipe()
+		serverConn = remoteConn
+		return clientConn, nil
+	}
+	t.Cleanup(func() {
+		if serverConn != nil {
+			_ = serverConn.Close()
+		}
+	})
+
+	started := time.Now()
+	result := probeOceanBaseMySQLWireHandshakeDetailWithTimeouts(connection.ConnectionConfig{
+		Host:   "172.22.39.20",
+		Port:   12883,
+		UseSSH: true,
+		SSH: connection.SSHConfig{
+			Host: "jump.example.com",
+			Port: 22,
+			User: "ops",
+		},
+	}, 12*time.Second, 50*time.Millisecond)
+	elapsed := time.Since(started)
+
+	if observedDialTimeout < 10*time.Second {
+		t.Fatalf("expected probe dial context to keep the long dial timeout, got about %s", observedDialTimeout)
+	}
+	if elapsed > 500*time.Millisecond {
+		t.Fatalf("expected handshake read to use short timeout, elapsed=%s", elapsed)
+	}
+	if !result.probeSucceeded || !result.tcpReachable {
+		t.Fatalf("expected short read timeout to be treated as reachable non-MySQL-wire probe, got %+v", result)
+	}
+	if result.err == nil {
+		t.Fatalf("expected read timeout error to be recorded for diagnostics")
+	}
+}
+
 // probe 放宽 protocol_version 检查后，普通 MySQL/MariaDB（server_version 不含 OB 关键字）
 // 应仍判定为非 OB MySQL wire（由 regular_mysql_is_not_flagged / mariadb_is_not_flagged 子用例
 // 覆盖）。原 IgnoresNonMySQLProtocol 测试因 probe 不再严格区分 mysql vs 非 mysql 而失效，已删除。