80 lines
1.6 KiB
Go
80 lines
1.6 KiB
Go
package middleware
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import (
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"net/http"
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"sync"
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"time"
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"github.com/gin-gonic/gin"
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"golang.org/x/time/rate"
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)
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// IPRateLimiter holds rate limiters for each IP address
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type IPRateLimiter struct {
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ips map[string]*rate.Limiter
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mu sync.Mutex
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r rate.Limit
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b int
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lastSeen map[string]time.Time
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}
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// NewIPRateLimiter creates a new IPRateLimiter
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func NewIPRateLimiter(r rate.Limit, b int) *IPRateLimiter {
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l := &IPRateLimiter{
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ips: make(map[string]*rate.Limiter),
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lastSeen: make(map[string]time.Time),
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r: r,
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b: b,
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}
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// Background cleanup of old IPs
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go func() {
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for {
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time.Sleep(time.Minute * 10)
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l.mu.Lock()
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for ip, t := range l.lastSeen {
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if time.Since(t) > time.Minute*30 {
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delete(l.ips, ip)
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delete(l.lastSeen, ip)
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}
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}
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l.mu.Unlock()
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}
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}()
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return l
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}
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// GetLimiter returns the rate limiter for the provided IP address
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func (i *IPRateLimiter) GetLimiter(ip string) *rate.Limiter {
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i.mu.Lock()
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defer i.mu.Unlock()
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limiter, exists := i.ips[ip]
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if !exists {
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limiter = rate.NewLimiter(i.r, i.b)
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i.ips[ip] = limiter
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}
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i.lastSeen[ip] = time.Now()
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return limiter
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}
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// RateLimit returns a gin middleware that limits requests by IP
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// rps: Requests per second
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// burst: Max burst size
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func RateLimit(rps float64, burst int) gin.HandlerFunc {
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limiter := NewIPRateLimiter(rate.Limit(rps), burst)
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return func(c *gin.Context) {
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ip := c.ClientIP()
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if !limiter.GetLimiter(ip).Allow() {
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c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{
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"error": "Too many requests. Please try again later.",
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})
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return
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}
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c.Next()
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}
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}
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