forked from casdoor/casdoor
135 lines
3.4 KiB
Go
135 lines
3.4 KiB
Go
// Copyright 2024 The casbin Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package rule
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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/casdoor/casdoor/object"
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"github.com/casdoor/casdoor/util"
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"golang.org/x/time/rate"
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)
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type IpRateRule struct {
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ruleName string
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}
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type IpRateLimiter struct {
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ips map[string]*rate.Limiter
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mu *sync.RWMutex
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r rate.Limit
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b int
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}
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var blackList = map[string]map[string]time.Time{}
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var ipRateLimiters = map[string]*IpRateLimiter{}
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// NewIpRateLimiter .
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func NewIpRateLimiter(r rate.Limit, b int) *IpRateLimiter {
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i := &IpRateLimiter{
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ips: make(map[string]*rate.Limiter),
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mu: &sync.RWMutex{},
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r: r,
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b: b,
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}
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return i
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}
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// AddIP creates a new rate limiter and adds it to the ips map,
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// using the IP address as the key
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func (i *IpRateLimiter) AddIP(ip string) *rate.Limiter {
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i.mu.Lock()
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defer i.mu.Unlock()
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limiter := rate.NewLimiter(i.r, i.b)
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i.ips[ip] = limiter
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return limiter
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}
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// GetLimiter returns the rate limiter for the provided IP address if it exists.
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// Otherwise, calls AddIP to add IP address to the map
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func (i *IpRateLimiter) GetLimiter(ip string) *rate.Limiter {
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i.mu.Lock()
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limiter, exists := i.ips[ip]
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if !exists {
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i.mu.Unlock()
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return i.AddIP(ip)
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}
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i.mu.Unlock()
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return limiter
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}
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func (r *IpRateRule) checkRule(expressions []*object.Expression, req *http.Request) (*RuleResult, error) {
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expression := expressions[0] // IpRate rule should have only one expression
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clientIp := util.GetClientIp(req)
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// If the client IP is in the blacklist, check the block time
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createAt, ok := blackList[r.ruleName][clientIp]
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if ok {
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blockTime := util.ParseInt(expression.Value)
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if time.Now().Sub(createAt) < time.Duration(blockTime)*time.Second {
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return &RuleResult{
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Action: "Block",
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Reason: "Rate limit exceeded",
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}, nil
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} else {
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delete(blackList[r.ruleName], clientIp)
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}
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}
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// If the client IP is not in the blacklist, check the rate limit
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ipRateLimiter := ipRateLimiters[r.ruleName]
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parseInt := util.ParseInt(expression.Operator)
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if ipRateLimiter == nil {
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ipRateLimiter = NewIpRateLimiter(rate.Limit(parseInt), parseInt)
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ipRateLimiters[r.ruleName] = ipRateLimiter
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}
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// If the rate limit has changed, update the rate limiter
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limiter := ipRateLimiter.GetLimiter(clientIp)
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if ipRateLimiter.r != rate.Limit(parseInt) {
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ipRateLimiter.r = rate.Limit(parseInt)
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ipRateLimiter.b = parseInt
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limiter.SetLimit(ipRateLimiter.r)
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limiter.SetBurst(ipRateLimiter.b)
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err := limiter.Wait(req.Context())
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if err != nil {
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return nil, err
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}
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} else {
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// If the rate limit is exceeded, add the client IP to the blacklist
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allow := limiter.Allow()
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if !allow {
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blackList[r.ruleName] = map[string]time.Time{}
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blackList[r.ruleName][clientIp] = time.Now()
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return &RuleResult{
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Action: "Block",
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Reason: "Rate limit exceeded",
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}, nil
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}
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}
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return nil, nil
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}
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