feat: configurable traffic threshold and Feishu bot alerts

backend/internal/trafficmgr/trafficmgr.go

@@ -10,14 +10,12 @@ import (
 	"strings"
 	"time"
 
+	"vpn-platform/backend/internal/alertnotify"
 	"vpn-platform/backend/internal/model"
 	"vpn-platform/backend/internal/sessionmgr"
 	"vpn-platform/backend/internal/store"
 )
 
-// 异常流量阈值：15s 内超过此字节数视为突发（约 50Mbps × 15s ≈ 93MB）
-const rateAlertThreshold = 90 * 1024 * 1024
-
 // CheckQuota 检查指定隧道的流量配额，返回超额动作（"" 表示未超额或无限额）
 func CheckQuota(tunnelID uint, deltaRx, deltaTx int64) string {
 	if store.DB == nil {
@@ -65,7 +63,7 @@ func ResetIfNeeded(policy *model.TrafficPolicy) {
 		policy.UsedBytes = 0
 		policy.LastResetAt = now
 		store.DB.Model(policy).Updates(map[string]interface{}{
-			"used_bytes":   0,
+			"used_bytes":    0,
 			"last_reset_at": now,
 		})
 	}
@@ -74,14 +72,20 @@ func ResetIfNeeded(policy *model.TrafficPolicy) {
 // CheckRateAbnormal 检查流量速率是否异常（突发流量告警）
 func CheckRateAbnormal(tunnelID uint, deltaRx, deltaTx int64, interval time.Duration) bool {
 	total := deltaRx + deltaTx
-	if total <= 0 {
+	if total <= 0 || interval <= 0 {
 		return false
 	}
 	ratePerSec := float64(total) / interval.Seconds()
-	// 超过阈值（约 50Mbps）
-	if total > rateAlertThreshold {
-		sessionmgr.LogConnection(tunnelID, "*", "rate_alert", "",
-			fmt.Sprintf("突发流量 %.1f MB（%.0f Mbps），15s 内增量异常", float64(total)/(1024*1024), ratePerSec*8/(1024*1024)))
+	settings, err := alertnotify.Get()
+	threshold := alertnotify.DefaultThreshold
+	if err == nil {
+		threshold = settings.RateThresholdMbps
+	}
+	// Mbps 按十进制 1,000,000 bits/s 计算，使用真实采样间隔。
+	if ratePerSec*8 > float64(threshold)*1_000_000 {
+		detail := fmt.Sprintf("突发流量 %.1f MiB（%.0f Mbps），采样间隔 %.0f 秒", float64(total)/(1024*1024), ratePerSec*8/1_000_000, interval.Seconds())
+		sessionmgr.LogConnection(tunnelID, "*", "rate_alert", "", detail)
+		alertnotify.Notify(tunnelID, "rate_alert", detail)
 		return true
 	}
 	return false
@@ -91,19 +95,22 @@ func CheckRateAbnormal(tunnelID uint, deltaRx, deltaTx int64, interval time.Dura
 func HandleExceed(tunnelID uint, action string, tunnelName string) {
 	switch action {
 	case "warn":
-		sessionmgr.LogConnection(tunnelID, "*", "quota_exceed", "",
-			fmt.Sprintf("隧道「%s」流量配额已用尽（仅告警）", tunnelName))
+		detail := fmt.Sprintf("隧道「%s」流量配额已用尽（仅告警）", tunnelName)
+		sessionmgr.LogConnection(tunnelID, "*", "quota_exceed", "", detail)
+		alertnotify.Notify(tunnelID, "quota_exceed", detail)
 	case "block":
-		sessionmgr.LogConnection(tunnelID, "*", "quota_exceed", "",
-			fmt.Sprintf("隧道「%s」流量配额已用尽，自动停止", tunnelName))
+		detail := fmt.Sprintf("隧道「%s」流量配额已用尽，自动停止", tunnelName)
+		sessionmgr.LogConnection(tunnelID, "*", "quota_exceed", "", detail)
+		alertnotify.Notify(tunnelID, "quota_exceed", detail)
 		// 由调用方执行 Stop（避免循环依赖，只返回信号）
 	case "throttle":
 		// 降速到 1Mbps
 		var policy model.TrafficPolicy
 		if store.DB.Where("tunnel_id = ?", tunnelID).First(&policy).Error == nil {
 			ApplyRateLimit(tunnelID, 1)
-			sessionmgr.LogConnection(tunnelID, "*", "quota_exceed", "",
-				fmt.Sprintf("隧道「%s」流量配额已用尽，限速至 1 Mbps", tunnelName))
+			detail := fmt.Sprintf("隧道「%s」流量配额已用尽，限速至 1 Mbps", tunnelName)
+			sessionmgr.LogConnection(tunnelID, "*", "quota_exceed", "", detail)
+			alertnotify.Notify(tunnelID, "quota_exceed", detail)
 		}
 	}
 }