forked from TykTechnologies/tyk
/
session_manager.go
272 lines (231 loc) · 7.85 KB
/
session_manager.go
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package gateway
import (
"net/http"
"time"
"github.com/TykTechnologies/leakybucket"
"github.com/TykTechnologies/leakybucket/memorycache"
"github.com/TykTechnologies/tyk/config"
"github.com/TykTechnologies/tyk/storage"
"github.com/TykTechnologies/tyk/user"
)
type PublicSession struct {
Quota struct {
QuotaMax int64 `json:"quota_max"`
QuotaRemaining int64 `json:"quota_remaining"`
QuotaRenews int64 `json:"quota_renews"`
} `json:"quota"`
RateLimit struct {
Rate float64 `json:"requests"`
Per float64 `json:"per_unit"`
} `json:"rate_limit"`
}
const (
QuotaKeyPrefix = "quota-"
RateLimitKeyPrefix = "rate-limit-"
)
// SessionLimiter is the rate limiter for the API, use ForwardMessage() to
// check if a message should pass through or not
type SessionLimiter struct {
bucketStore leakybucket.Storage
}
func (l *SessionLimiter) doRollingWindowWrite(key, rateLimiterKey, rateLimiterSentinelKey string,
currentSession *user.SessionState,
store storage.Handler,
globalConf *config.Config,
apiLimit *user.APILimit, dryRun bool) bool {
var per, rate float64
if apiLimit != nil { // respect limit on API level
per = apiLimit.Per
rate = apiLimit.Rate
} else {
per = currentSession.Per
rate = currentSession.Rate
}
log.Debug("[RATELIMIT] Inbound raw key is: ", key)
log.Debug("[RATELIMIT] Rate limiter key is: ", rateLimiterKey)
pipeline := globalConf.EnableNonTransactionalRateLimiter
var ratePerPeriodNow int
if dryRun {
ratePerPeriodNow, _ = store.GetRollingWindow(rateLimiterKey, int64(per), pipeline)
} else {
ratePerPeriodNow, _ = store.SetRollingWindow(rateLimiterKey, int64(per), "-1", pipeline)
}
//log.Info("Num Requests: ", ratePerPeriodNow)
// Subtract by 1 because of the delayed add in the window
subtractor := 1
if globalConf.EnableSentinelRateLimiter {
// and another subtraction because of the preemptive limit
subtractor = 2
}
// The test TestRateLimitForAPIAndRateLimitAndQuotaCheck
// will only work with ththese two lines here
//log.Info("break: ", (int(currentSession.Rate) - subtractor))
if ratePerPeriodNow > int(rate)-subtractor {
// Set a sentinel value with expire
if globalConf.EnableSentinelRateLimiter {
if !dryRun {
store.SetRawKey(rateLimiterSentinelKey, "1", int64(per))
}
}
return true
}
return false
}
type sessionFailReason uint
const (
sessionFailNone sessionFailReason = iota
sessionFailRateLimit
sessionFailQuota
)
// ForwardMessage will enforce rate limiting, returning a non-zero
// sessionFailReason if session limits have been exceeded.
// Key values to manage rate are Rate and Per, e.g. Rate of 10 messages
// Per 10 seconds
func (l *SessionLimiter) ForwardMessage(r *http.Request, currentSession *user.SessionState, key string, store storage.Handler, enableRL, enableQ bool, globalConf *config.Config, apiID string, dryRun bool) sessionFailReason {
// check for limit on API level (set to session by ApplyPolicies)
var apiLimit *user.APILimit
var allowanceScope string
if len(currentSession.AccessRights) > 0 {
if rights, ok := currentSession.AccessRights[apiID]; !ok {
log.WithField("apiID", apiID).Debug("[RATE] unexpected apiID")
return sessionFailRateLimit
} else {
apiLimit = rights.Limit
allowanceScope = rights.AllowanceScope
}
}
if apiLimit == nil {
apiLimit = &user.APILimit{
QuotaMax: currentSession.QuotaMax,
QuotaRenewalRate: currentSession.QuotaRenewalRate,
QuotaRenews: currentSession.QuotaRenews,
Rate: currentSession.Rate,
Per: currentSession.Per,
ThrottleInterval: currentSession.ThrottleInterval,
ThrottleRetryLimit: currentSession.ThrottleRetryLimit,
}
}
if enableRL {
rateScope := ""
if allowanceScope != "" {
rateScope = allowanceScope + "-"
}
if globalConf.EnableSentinelRateLimiter {
rateLimiterKey := RateLimitKeyPrefix + rateScope + currentSession.KeyHash()
rateLimiterSentinelKey := RateLimitKeyPrefix + rateScope + currentSession.KeyHash() + ".BLOCKED"
go l.doRollingWindowWrite(key, rateLimiterKey, rateLimiterSentinelKey, currentSession, store, globalConf, apiLimit, dryRun)
// Check sentinel
_, sentinelActive := store.GetRawKey(rateLimiterSentinelKey)
if sentinelActive == nil {
// Sentinel is set, fail
return sessionFailRateLimit
}
} else if globalConf.EnableRedisRollingLimiter {
rateLimiterKey := RateLimitKeyPrefix + rateScope + currentSession.KeyHash()
rateLimiterSentinelKey := RateLimitKeyPrefix + rateScope + currentSession.KeyHash() + ".BLOCKED"
if l.doRollingWindowWrite(key, rateLimiterKey, rateLimiterSentinelKey, currentSession, store, globalConf, apiLimit, dryRun) {
return sessionFailRateLimit
}
} else {
// In-memory limiter
if l.bucketStore == nil {
l.bucketStore = memorycache.New()
}
bucketKey := key + ":" + rateScope + currentSession.LastUpdated
currRate := apiLimit.Rate
per := apiLimit.Per
// DRL will always overflow with more servers on low rates
rate := uint(currRate * float64(DRLManager.RequestTokenValue))
if rate < uint(DRLManager.CurrentTokenValue()) {
rate = uint(DRLManager.CurrentTokenValue())
}
userBucket, err := l.bucketStore.Create(bucketKey, rate, time.Duration(per)*time.Second)
if err != nil {
log.Error("Failed to create bucket!")
return sessionFailRateLimit
}
if dryRun {
// if userBucket is empty and not expired.
if userBucket.Remaining() == 0 && time.Now().Before(userBucket.Reset()) {
return sessionFailRateLimit
}
} else {
_, errF := userBucket.Add(uint(DRLManager.CurrentTokenValue()))
if errF != nil {
return sessionFailRateLimit
}
}
}
}
if enableQ {
if globalConf.LegacyEnableAllowanceCountdown {
currentSession.Allowance--
}
if l.RedisQuotaExceeded(r, currentSession, allowanceScope, apiLimit, store) {
return sessionFailQuota
}
}
return sessionFailNone
}
func (l *SessionLimiter) RedisQuotaExceeded(r *http.Request, currentSession *user.SessionState, scope string, limit *user.APILimit, store storage.Handler) bool {
// Unlimited?
if limit.QuotaMax == -1 || limit.QuotaMax == 0 {
// No quota set
return false
}
quotaScope := ""
if scope != "" {
quotaScope = scope + "-"
}
rawKey := QuotaKeyPrefix + quotaScope + currentSession.KeyHash()
quotaRenewalRate := limit.QuotaRenewalRate
quotaRenews := limit.QuotaRenews
quotaMax := limit.QuotaMax
log.Debug("[QUOTA] Quota limiter key is: ", rawKey)
log.Debug("Renewing with TTL: ", quotaRenewalRate)
// INCR the key (If it equals 1 - set EXPIRE)
qInt := store.IncrememntWithExpire(rawKey, quotaRenewalRate)
// if the returned val is >= quota: block
if qInt-1 >= quotaMax {
renewalDate := time.Unix(quotaRenews, 0)
log.Debug("Renewal Date is: ", renewalDate)
log.Debug("As epoch: ", quotaRenews)
log.Debug("Session: ", currentSession)
log.Debug("Now:", time.Now())
if time.Now().After(renewalDate) {
// The renewal date is in the past, we should update the quota!
// Also, this fixes legacy issues where there is no TTL on quota buckets
log.Debug("Incorrect key expiry setting detected, correcting")
go store.DeleteRawKey(rawKey)
qInt = 1
} else {
// Renewal date is in the future and the quota is exceeded
return true
}
}
// If this is a new Quota period, ensure we let the end user know
if qInt == 1 {
quotaRenews = time.Now().Unix() + quotaRenewalRate
ctxScheduleSessionUpdate(r)
}
// If not, pass and set the values of the session to quotamax - counter
remaining := quotaMax - qInt
if remaining < 0 {
remaining = 0
}
for k, v := range currentSession.AccessRights {
if v.Limit == nil {
continue
}
if v.AllowanceScope == scope {
v.Limit.QuotaRemaining = remaining
v.Limit.QuotaRenews = quotaRenews
}
currentSession.AccessRights[k] = v
}
if scope == "" {
currentSession.QuotaRemaining = remaining
currentSession.QuotaRenews = quotaRenews
}
return false
}