mirror of
https://github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin.git
synced 2026-07-21 11:38:59 +02:00
420 lines
12 KiB
Go
420 lines
12 KiB
Go
// Package crowdsec_bouncer_traefik_plugin implements a middleware that communicates with crowdsec.
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// It can cache results to filesystem or redis, or even ask crowdsec for every requests.
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package crowdsec_bouncer_traefik_plugin //nolint:revive,stylecheck
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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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"net/http"
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"net/url"
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"text/template"
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"time"
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cache "github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/pkg/cache"
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ip "github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/pkg/ip"
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logger "github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/pkg/logger"
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simpleredis "github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/pkg/simpleredis"
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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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cacheTimeoutKey = "updated"
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)
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//nolint:gochecknoglobals
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var (
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crowdsecStreamHealthy = false
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ticker chan bool
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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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LogLevel string `json:"logLevel,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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ForwardedHeadersCustomName string `json:"forwardedheaderscustomheader,omitempty"`
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ForwardedHeadersTrustedIPs []string `json:"forwardedHeadersTrustedIps,omitempty"`
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ClientTrustedIPs []string `json:"clientTrustedIps,omitempty"`
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RedisCacheEnabled bool `json:"redisCacheEnabled,omitempty"`
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RedisCacheHost string `json:"redisCacheHost,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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LogLevel: "INFO",
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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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ClientTrustedIPs: []string{},
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ForwardedHeadersTrustedIPs: []string{},
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ForwardedHeadersCustomName: "X-Forwarded-For",
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RedisCacheEnabled: false,
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RedisCacheHost: "redis:6379",
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}
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}
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// Bouncer a Bouncer struct.
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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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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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customHeader string
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clientPoolStrategy *ip.PoolStrategy
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serverPoolStrategy *ip.PoolStrategy
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client *http.Client
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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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logger.Init(config.LogLevel)
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err := validateParams(config)
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if err != nil {
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logger.Info(err.Error())
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return nil, err
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}
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serverChecker, _ := ip.NewChecker(config.ForwardedHeadersTrustedIPs)
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clientChecker, _ := ip.NewChecker(config.ClientTrustedIPs)
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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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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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customHeader: config.ForwardedHeadersCustomName,
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defaultDecisionTimeout: config.DefaultDecisionSeconds,
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serverPoolStrategy: &ip.PoolStrategy{
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Checker: serverChecker,
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},
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clientPoolStrategy: &ip.PoolStrategy{
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Checker: clientChecker,
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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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}
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if config.RedisCacheEnabled {
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cache.InitRedisClient(config.RedisCacheHost)
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}
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if config.CrowdsecMode == streamMode && ticker == nil {
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ticker = startTicker(config, func() {
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handleStreamCache(bouncer)
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})
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go handleStreamCache(bouncer)
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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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//
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//nolint:nestif
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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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// Here we check for the trusted IPs in the customHeader
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remoteIP, err := ip.GetRemoteIP(req, bouncer.serverPoolStrategy, bouncer.customHeader)
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if err != nil {
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logger.Error(fmt.Sprintf("ServeHTTP ip:%s %w", remoteIP, err))
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rw.WriteHeader(http.StatusForbidden)
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return
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}
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trusted, err := bouncer.clientPoolStrategy.Checker.Contains(remoteIP)
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if err != nil {
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logger.Info(err.Error())
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return
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}
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// if our IP is in the trusted list we bypass the next checks
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logger.Debug(fmt.Sprintf("ServeHTTP ip:%s isTrusted:%v", remoteIP, trusted))
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if trusted {
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bouncer.next.ServeHTTP(rw, req)
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return
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}
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// TODO This should be simplified
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healthy := crowdsecStreamHealthy
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if bouncer.crowdsecMode != noneMode {
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isBanned, err := cache.GetDecision(remoteIP)
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if err != nil {
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logger.Debug(err.Error())
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if err.Error() == simpleredis.RedisUnreachable {
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healthy = false
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}
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} else {
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logger.Debug(fmt.Sprintf("ServeHTTP ip:%s cache:hit isBanned:%v", remoteIP, isBanned))
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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 healthy {
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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, remoteIP)
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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 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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func startTicker(config *Config, work func()) chan bool {
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ticker := time.NewTicker(time.Duration(config.UpdateIntervalSeconds) * time.Second)
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stop := make(chan bool, 1)
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go func() {
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defer logger.Debug("ticker:stopped")
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for {
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select {
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case <-ticker.C:
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go work()
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case <-stop:
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return
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}
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}
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}()
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return stop
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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, remoteIP 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", remoteIP),
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}
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body, err := crowdsecQuery(bouncer, routeURL.String())
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if err != nil {
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logger.Error(err.Error())
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rw.WriteHeader(http.StatusForbidden)
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return
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}
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if bytes.Equal(body, []byte("null")) {
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if bouncer.crowdsecMode == liveMode {
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cache.SetDecision(remoteIP, 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.Error(fmt.Sprintf("handleNoStreamCache:parseBody: %w", 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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cache.SetDecision(remoteIP, 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.Error(fmt.Sprintf("handleNoStreamCache:parseDuration %w", err))
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return
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}
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if bouncer.crowdsecMode == liveMode {
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cache.SetDecision(remoteIP, 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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// Instead of blocking the goroutine interval for all the secondary node,
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// if the master service is shut down, other goroutine can take the lead
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// because updated routine information is in the cache
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_, err := cache.GetDecision(cacheTimeoutKey)
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if err == nil {
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logger.Debug("handleStreamCache:alreadyUpdated")
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return
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}
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cache.SetDecision(cacheTimeoutKey, false, bouncer.updateInterval-1)
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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", !crowdsecStreamHealthy),
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}
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body, err := crowdsecQuery(bouncer, streamRouteURL.String())
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if err != nil {
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logger.Error(err.Error())
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crowdsecStreamHealthy = false
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return
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}
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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.Error(fmt.Sprintf("handleStreamCache:parsingBody %w", err))
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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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cache.SetDecision(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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cache.DeleteDecision(decision.Value)
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}
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crowdsecStreamHealthy = true
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}
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func crowdsecQuery(bouncer *Bouncer, stringURL string) ([]byte, error) {
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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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return nil, fmt.Errorf("crowdsecQuery url:%s %w", stringURL, err)
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}
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if res.StatusCode != http.StatusOK {
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return nil, fmt.Errorf("crowdsecQuery url:%s, statusCode:%d", stringURL, res.StatusCode)
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}
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defer func() {
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if err = res.Body.Close(); err != nil {
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logger.Error(fmt.Sprintf("crowdsecQuery:closeBody %w", err))
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}
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}()
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body, err := io.ReadAll(res.Body)
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if err != nil {
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return nil, fmt.Errorf("crowdsecQuery:readBody %w", err)
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}
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return body, nil
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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 :%w", err)
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}
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} else {
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logger.Debug("No IP provided for ForwardedHeadersTrustedIPs")
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}
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if len(config.ClientTrustedIPs) > 0 {
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_, err = ip.NewChecker(config.ClientTrustedIPs)
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if err != nil {
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return fmt.Errorf("TrustedIPs must be a list of IP/CIDR :%w", err)
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}
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} else {
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logger.Debug("No IP provided for TrustedIPs")
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}
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return nil
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}
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