mirror of
https://github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin.git
synced 2026-07-21 11:38:59 +02:00
552b30a9ef
* Handle X forwarded for in the plugin * Update docker-compose.cloudflare.yml Change to version v1.0.9 * 🍱 fix + isolate cache * 🍱 missing files * 🍱 lint Co-authored-by: MathieuHa <mathieu@hanotaux.fr> Co-authored-by: Max Lerebourg <maxlerebourg@gmail.com>
384 lines
11 KiB
Go
384 lines
11 KiB
Go
package crowdsec_bouncer_traefik_plugin
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import (
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"bytes"
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"context"
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"encoding/json"
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"fmt"
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"io"
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"io/ioutil"
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"log"
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"math/rand"
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"net"
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"net/http"
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"net/url"
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"text/template"
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"time"
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ttl_map "github.com/leprosus/golang-ttl-map"
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ip "github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/ip"
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)
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const (
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streamMode = "stream"
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liveMode = "live"
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noneMode = "none"
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crowdsecLapiHeader = "X-Api-Key"
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crowdsecLapiRoute = "v1/decisions"
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crowdsecLapiStreamRoute = "v1/decisions/stream"
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cacheBannedValue = "t"
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cacheNoBannedValue = "f"
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)
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// Config the plugin configuration.
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type Config struct {
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Enabled bool `json:"enabled,omitempty"`
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CrowdsecMode string `json:"crowdsecMode,omitempty"`
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CrowdsecLapiScheme string `json:"crowdsecLapiScheme,omitempty"`
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CrowdsecLapiHost string `json:"crowdsecLapiHost,omitempty"`
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CrowdsecLapiKey string `json:"crowdsecLapiKey,omitempty"`
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UpdateIntervalSeconds int64 `json:"updateIntervalSeconds,omitempty"`
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DefaultDecisionSeconds int64 `json:"defaultDecisionSeconds,omitempty"`
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ForwardedHeadersTrustedIPs []string `json:"forwardedheaderstrustedips,omitempty"`
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}
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// CreateConfig creates the default plugin configuration.
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func CreateConfig() *Config {
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return &Config{
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Enabled: false,
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CrowdsecMode: liveMode,
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CrowdsecLapiScheme: "http",
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CrowdsecLapiHost: "crowdsec:8080",
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CrowdsecLapiKey: "",
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UpdateIntervalSeconds: 60,
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DefaultDecisionSeconds: 60,
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ForwardedHeadersTrustedIPs: []string{},
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}
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}
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// Bouncer a Bouncer plugin.
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type Bouncer struct {
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next http.Handler
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name string
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template *template.Template
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enabled bool
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crowdsecStreamHealthy bool
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crowdsecScheme string
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crowdsecHost string
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crowdsecKey string
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crowdsecMode string
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updateInterval int64
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defaultDecisionTimeout int64
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poolStrategy *ip.PoolStrategy
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client *http.Client
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cache *ttl_map.Heap
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}
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// New creates the crowdsec bouncer plugin.
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func New(ctx context.Context, next http.Handler, config *Config, name string) (http.Handler, error) {
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err := validateParams(config)
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if err != nil {
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return nil, err
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}
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checker, _ := ip.NewChecker(config.ForwardedHeadersTrustedIPs)
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bouncer := &Bouncer{
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next: next,
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name: name,
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template: template.New("CrowdsecBouncer").Delims("[[", "]]"),
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enabled: config.Enabled,
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crowdsecStreamHealthy: false,
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crowdsecMode: config.CrowdsecMode,
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crowdsecScheme: config.CrowdsecLapiScheme,
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crowdsecHost: config.CrowdsecLapiHost,
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crowdsecKey: config.CrowdsecLapiKey,
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updateInterval: config.UpdateIntervalSeconds,
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defaultDecisionTimeout: config.DefaultDecisionSeconds,
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poolStrategy: &ip.PoolStrategy{
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Checker: checker,
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},
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client: &http.Client{
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Transport: &http.Transport{
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MaxIdleConns: 10,
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IdleConnTimeout: 30 * time.Second,
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},
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Timeout: 5 * time.Second,
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},
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cache: ttl_map.New(),
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}
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if config.CrowdsecMode == streamMode {
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go func() {
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rand.Seed(time.Now().UnixNano())
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timeout := rand.Int63n(30)
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logger(fmt.Sprintf("Wait: %v", timeout))
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time.Sleep(time.Duration(timeout) * time.Second)
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go handleStreamCache(bouncer)
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ticker := time.NewTicker(time.Duration(config.UpdateIntervalSeconds) * time.Second)
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for range ticker.C {
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go handleStreamCache(bouncer)
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}
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}()
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}
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return bouncer, nil
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}
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// ServeHTTP principal function of plugin.
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func (bouncer *Bouncer) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
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if !bouncer.enabled {
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bouncer.next.ServeHTTP(rw, req)
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return
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}
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remoteHost, err := getRemoteIP(bouncer, req)
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if err != nil {
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bouncer.next.ServeHTTP(rw, req)
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return
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}
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if bouncer.crowdsecMode != noneMode {
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isBanned, err := getDecision(bouncer.cache, remoteHost)
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if err == nil {
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if isBanned {
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rw.WriteHeader(http.StatusForbidden)
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} else {
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bouncer.next.ServeHTTP(rw, req)
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}
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return
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}
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}
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// Right here if we cannot join the stream we forbid the request to go on.
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if bouncer.crowdsecMode == streamMode {
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if bouncer.crowdsecStreamHealthy {
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bouncer.next.ServeHTTP(rw, req)
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} else {
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rw.WriteHeader(http.StatusForbidden)
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}
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} else {
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handleNoStreamCache(bouncer, rw, req, remoteHost)
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}
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}
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// CUSTOM CODE.
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// TODO place in another file.
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// Decision Body returned from Crowdsec LAPI.
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type Decision struct {
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ID int `json:"id"`
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Origin string `json:"origin"`
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Type string `json:"type"`
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Scope string `json:"scope"`
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Value string `json:"value"`
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Duration string `json:"duration"`
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Scenario string `json:"scenario"`
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Simulated bool `json:"simulated"`
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}
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// Stream Body returned from Crowdsec Stream LAPI.
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type Stream struct {
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Deleted []Decision `json:"deleted"`
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New []Decision `json:"new"`
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}
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func logger(str string) {
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log.Printf("Crowdsec Bouncer Traefik Plugin - %s", str)
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}
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func contains(source []string, target string) bool {
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for _, item := range source {
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if item == target {
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return true
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}
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}
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return false
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}
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// It returns the first IP that is not in the pool, or the empty string otherwise.
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func getRemoteIP(bouncer *Bouncer, req *http.Request) (string, error) {
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remoteIP := bouncer.poolStrategy.GetIP(req)
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if len(remoteIP) != 0 {
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return remoteIP, nil
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}
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remoteIP, _, err := net.SplitHostPort(req.RemoteAddr)
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if err != nil {
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logger(fmt.Sprintf("failed to extract ip from remote address: %v", err))
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return "", err
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}
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return remoteIP, nil
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}
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// Get Decision check in the cache if the IP has the banned / not banned value.
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// Otherwise return with an error to add the IP in cache if we are on.
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func getDecision(cache *ttl_map.Heap, clientIP string) (bool, error) {
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banned, isCached := cache.Get(clientIP)
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bannedString, isValid := banned.(string)
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if isCached && isValid && len(bannedString) > 0 {
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return bannedString == cacheBannedValue, nil
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}
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return false, fmt.Errorf("no cache data")
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}
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func setDecision(cache *ttl_map.Heap, clientIP string, isBanned bool, duration int64) {
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if isBanned {
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logger(fmt.Sprintf("%v banned", clientIP))
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cache.Set(clientIP, cacheBannedValue, duration)
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} else {
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cache.Set(clientIP, cacheNoBannedValue, duration)
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}
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}
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func deleteDecision(cache *ttl_map.Heap, clientIP string) {
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cache.Del(clientIP)
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}
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// We are now in none or live mode.
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func handleNoStreamCache(bouncer *Bouncer, rw http.ResponseWriter, req *http.Request, remoteHost string) {
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routeURL := url.URL{
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Scheme: bouncer.crowdsecScheme,
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Host: bouncer.crowdsecHost,
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Path: crowdsecLapiRoute,
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RawQuery: fmt.Sprintf("ip=%v&banned=true", remoteHost),
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}
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body := crowdsecQuery(bouncer, routeURL.String())
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if bytes.Equal(body, []byte("null")) {
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if bouncer.crowdsecMode == liveMode {
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setDecision(bouncer.cache, remoteHost, false, bouncer.defaultDecisionTimeout)
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}
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bouncer.next.ServeHTTP(rw, req)
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return
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}
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var decisions []Decision
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err := json.Unmarshal(body, &decisions)
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if err != nil {
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logger(fmt.Sprintf("failed to parse body: %s", err))
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rw.WriteHeader(http.StatusForbidden)
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return
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}
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if len(decisions) == 0 {
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if bouncer.crowdsecMode == liveMode {
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setDecision(bouncer.cache, remoteHost, false, bouncer.defaultDecisionTimeout)
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}
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bouncer.next.ServeHTTP(rw, req)
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return
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}
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rw.WriteHeader(http.StatusForbidden)
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duration, err := time.ParseDuration(decisions[0].Duration)
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if err != nil {
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logger(fmt.Sprintf("failed to parse duration: %s", err))
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return
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}
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if bouncer.crowdsecMode == liveMode {
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setDecision(bouncer.cache, remoteHost, true, int64(duration.Seconds()))
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}
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}
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func handleStreamCache(bouncer *Bouncer) {
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// TODO clean properly on exit.
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streamRouteURL := url.URL{
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Scheme: bouncer.crowdsecScheme,
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Host: bouncer.crowdsecHost,
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Path: crowdsecLapiStreamRoute,
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RawQuery: fmt.Sprintf("startup=%t", !bouncer.crowdsecStreamHealthy),
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}
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body := crowdsecQuery(bouncer, streamRouteURL.String())
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var stream Stream
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err := json.Unmarshal(body, &stream)
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if err != nil {
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logger(fmt.Sprintf("error while parsing body: %s", err))
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bouncer.crowdsecStreamHealthy = false
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return
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}
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for _, decision := range stream.New {
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duration, err := time.ParseDuration(decision.Duration)
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if err == nil {
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setDecision(bouncer.cache, decision.Value, true, int64(duration.Seconds()))
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}
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}
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for _, decision := range stream.Deleted {
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deleteDecision(bouncer.cache, decision.Value)
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}
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bouncer.crowdsecStreamHealthy = true
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}
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func crowdsecQuery(bouncer *Bouncer, stringURL string) []byte {
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var req *http.Request
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req, _ = http.NewRequest(http.MethodGet, stringURL, nil)
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req.Header.Add(crowdsecLapiHeader, bouncer.crowdsecKey)
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res, err := bouncer.client.Do(req)
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if err != nil {
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logger(fmt.Sprintf("error while fetching %v: %s", stringURL, err))
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bouncer.crowdsecStreamHealthy = false
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return nil
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}
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if res.StatusCode != http.StatusOK {
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logger(fmt.Sprintf("error while fetching %v, status code: %d", stringURL, res.StatusCode))
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bouncer.crowdsecStreamHealthy = false
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return nil
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}
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defer func(body io.ReadCloser) {
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err = body.Close()
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if err != nil {
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logger(fmt.Sprintf("failed to close body reader: %s", err))
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}
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}(res.Body)
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body, err := ioutil.ReadAll(res.Body)
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if err != nil {
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logger(fmt.Sprintf("error while reading body: %s", err))
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bouncer.crowdsecStreamHealthy = false
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return nil
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}
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return body
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}
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func validateParams(config *Config) error {
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requiredStrings := map[string]string{
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"CrowdsecLapiScheme": config.CrowdsecLapiScheme,
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"CrowdsecLapiHost": config.CrowdsecLapiHost,
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"CrowdsecLapiKey": config.CrowdsecLapiKey,
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"CrowdsecMode": config.CrowdsecMode,
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}
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requiredInt := map[string]int64{
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"UpdateIntervalSeconds": config.UpdateIntervalSeconds,
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"DefaultDecisionSeconds": config.DefaultDecisionSeconds,
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}
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for key, val := range requiredInt {
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if val < 1 {
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return fmt.Errorf("%v: cannot be less than 1", key)
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}
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}
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for key, val := range requiredStrings {
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if len(val) == 0 {
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return fmt.Errorf("%v: cannot be empty", key)
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}
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}
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if !contains([]string{noneMode, liveMode, streamMode}, config.CrowdsecMode) {
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return fmt.Errorf("CrowdsecMode: must be one of 'none', 'live' or 'stream'")
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}
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if !contains([]string{"http", "https"}, config.CrowdsecLapiScheme) {
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return fmt.Errorf("CrowdsecLapiScheme: must be one of 'http' or 'https'")
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}
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testURL := url.URL{
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Scheme: config.CrowdsecLapiScheme,
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Host: config.CrowdsecLapiHost,
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}
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_, err := http.NewRequest(http.MethodGet, testURL.String(), nil)
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if err != nil {
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return fmt.Errorf("CrowdsecLapiScheme://CrowdsecLapiHost: '%v://%v' must be an URL", config.CrowdsecLapiScheme, config.CrowdsecLapiHost)
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}
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if len(config.ForwardedHeadersTrustedIPs) > 0 {
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_, err = ip.NewChecker(config.ForwardedHeadersTrustedIPs)
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if err != nil {
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return fmt.Errorf("ForwardedHeadersTrustedIPs must be a list of IP/CIDR :%v", err)
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}
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} else {
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logger("No IP provided for ForwardedHeadersTrustedIPs")
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}
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return nil
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}
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