初始提交：OCI 面板后端（含 GenAI 网关一期）

internal/api/ratelimit.go

@@ -0,0 +1,82 @@
+package api
+
+import (
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"golang.org/x/time/rate"
+
+	"oci-portal/internal/service"
+)
+
+// ipEvictInterval 是陈旧限速条目的回收周期。
+const ipEvictInterval = 10 * time.Minute
+
+// ipRateLimiter 维护每 IP 令牌桶;速率与突发取安全设置快照,
+// 设置变更后既有桶就地调参;陈旧条目由后台 ticker 惰性回收。
+type ipRateLimiter struct {
+	mu       sync.RWMutex
+	limiters map[string]*ipEntry
+}
+
+type ipEntry struct {
+	limiter  *rate.Limiter
+	lastSeen time.Time
+}
+
+func newIPRateLimiter() *ipRateLimiter {
+	l := &ipRateLimiter{limiters: make(map[string]*ipEntry)}
+	go l.evictLoop()
+	return l
+}
+
+// get 返回 ip 对应的令牌桶,参数与当前配置不一致时就地调整。
+func (l *ipRateLimiter) get(ip string, rps, burst int) *rate.Limiter {
+	l.mu.RLock()
+	entry, ok := l.limiters[ip]
+	l.mu.RUnlock()
+	if !ok {
+		l.mu.Lock()
+		if entry, ok = l.limiters[ip]; !ok {
+			entry = &ipEntry{limiter: rate.NewLimiter(rate.Limit(rps), burst)}
+			l.limiters[ip] = entry
+		}
+		l.mu.Unlock()
+	}
+	entry.lastSeen = time.Now()
+	if entry.limiter.Limit() != rate.Limit(rps) || entry.limiter.Burst() != burst {
+		entry.limiter.SetLimit(rate.Limit(rps))
+		entry.limiter.SetBurst(burst)
+	}
+	return entry.limiter
+}
+
+func (l *ipRateLimiter) evictLoop() {
+	ticker := time.NewTicker(ipEvictInterval)
+	defer ticker.Stop()
+	for range ticker.C {
+		l.mu.Lock()
+		cutoff := time.Now().Add(-ipEvictInterval)
+		for ip, e := range l.limiters {
+			if e.lastSeen.Before(cutoff) {
+				delete(l.limiters, ip)
+			}
+		}
+		l.mu.Unlock()
+	}
+}
+
+// IPRateMiddleware 返回全局 IP 限速中间件;超限返回 429,参数随安全设置热更新。
+func IPRateMiddleware(settings *service.SettingService) gin.HandlerFunc {
+	lm := newIPRateLimiter()
+	return func(c *gin.Context) {
+		sec := settings.SecurityCached()
+		if !lm.get(requestIP(c), sec.IPRateRPS, sec.IPRateBurst).Allow() {
+			c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{"error": "rate limit exceeded"})
+			return
+		}
+		c.Next()
+	}
+}