Mephimeow
78 lines
1.3 KiB
Go
78 lines
1.3 KiB
Go
package auth
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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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)
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type visitor struct {
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count int
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lastSeen time.Time
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}
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type RateLimiter struct {
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mu sync.Mutex
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visitors map[string]*visitor
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rate int
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window time.Duration
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}
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func NewRateLimiter(rate int, window time.Duration) *RateLimiter {
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rl := &RateLimiter{
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visitors: make(map[string]*visitor),
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rate: rate,
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window: window,
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}
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go rl.cleanup()
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return rl
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}
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func (rl *RateLimiter) cleanup() {
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ticker := time.NewTicker(10 * time.Minute)
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defer ticker.Stop()
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for range ticker.C {
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rl.mu.Lock()
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now := time.Now()
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for ip, v := range rl.visitors {
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if now.Sub(v.lastSeen) > rl.window*2 {
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delete(rl.visitors, ip)
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}
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}
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rl.mu.Unlock()
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}
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}
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func (rl *RateLimiter) Middleware() gin.HandlerFunc {
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return func(c *gin.Context) {
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ip := c.ClientIP()
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rl.mu.Lock()
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v, exists := rl.visitors[ip]
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now := time.Now()
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if !exists || now.Sub(v.lastSeen) > rl.window {
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rl.visitors[ip] = &visitor{count: 1, lastSeen: now}
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rl.mu.Unlock()
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c.Next()
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return
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}
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v.count++
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v.lastSeen = now
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if v.count > rl.rate {
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rl.mu.Unlock()
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c.JSON(http.StatusTooManyRequests, ErrorResponse{Error: "too many requests, try again later"})
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c.Abort()
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return
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}
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rl.mu.Unlock()
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c.Next()
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}
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}
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