Files
routewatch/internal/routewatch/asnfetcher.go

325 lines
8.2 KiB
Go

// Package routewatch contains the ASN WHOIS fetcher for background updates.
package routewatch
import (
"context"
"log/slog"
"sync"
"time"
"git.eeqj.de/sneak/routewatch/internal/database"
"git.eeqj.de/sneak/routewatch/internal/server"
"git.eeqj.de/sneak/routewatch/internal/whois"
)
// ASN fetcher configuration constants.
const (
// baseInterval is the starting interval between fetch attempts.
baseInterval = 15 * time.Second
// minInterval is the minimum interval after successes (rate limit).
minInterval = 1 * time.Second
// maxInterval is the maximum interval after failures (backoff cap).
maxInterval = 5 * time.Minute
// backoffMultiplier is how much to multiply interval on failure.
backoffMultiplier = 2
// whoisStaleThreshold is how old WHOIS data can be before refresh.
whoisStaleThreshold = 30 * 24 * time.Hour // 30 days
// immediateQueueSize is the buffer size for immediate fetch requests.
immediateQueueSize = 100
// statsWindow is how long to keep stats for.
statsWindow = time.Hour
)
// ASNFetcher handles background WHOIS lookups for ASNs.
type ASNFetcher struct {
db database.Store
whoisClient *whois.Client
logger *slog.Logger
immediateQueue chan int
stopCh chan struct{}
wg sync.WaitGroup
// fetchMu ensures only one fetch runs at a time
fetchMu sync.Mutex
// interval tracking with mutex protection
intervalMu sync.Mutex
currentInterval time.Duration
consecutiveFails int
// hourly stats tracking
statsMu sync.Mutex
successTimes []time.Time
errorTimes []time.Time
}
// NewASNFetcher creates a new ASN fetcher.
func NewASNFetcher(db database.Store, logger *slog.Logger) *ASNFetcher {
return &ASNFetcher{
db: db,
whoisClient: whois.NewClient(),
logger: logger.With("component", "asn_fetcher"),
immediateQueue: make(chan int, immediateQueueSize),
stopCh: make(chan struct{}),
currentInterval: baseInterval,
successTimes: make([]time.Time, 0),
errorTimes: make([]time.Time, 0),
}
}
// Start begins the background ASN fetcher goroutine.
func (f *ASNFetcher) Start() {
f.wg.Add(1)
go f.run()
f.logger.Info("ASN fetcher started",
"base_interval", baseInterval,
"min_interval", minInterval,
"max_interval", maxInterval,
)
}
// Stop gracefully shuts down the fetcher.
func (f *ASNFetcher) Stop() {
close(f.stopCh)
f.wg.Wait()
f.logger.Info("ASN fetcher stopped")
}
// QueueImmediate queues an ASN for immediate WHOIS lookup.
// Non-blocking - if queue is full, the request is dropped.
func (f *ASNFetcher) QueueImmediate(asn int) {
select {
case f.immediateQueue <- asn:
f.logger.Debug("Queued immediate WHOIS lookup", "asn", asn)
default:
f.logger.Debug("Immediate queue full, dropping request", "asn", asn)
}
}
// GetStats returns statistics about fetcher activity.
func (f *ASNFetcher) GetStats() server.ASNFetcherStats {
f.statsMu.Lock()
defer f.statsMu.Unlock()
f.intervalMu.Lock()
interval := f.currentInterval
fails := f.consecutiveFails
f.intervalMu.Unlock()
// Prune old entries and count
cutoff := time.Now().Add(-statsWindow)
f.successTimes = pruneOldTimes(f.successTimes, cutoff)
f.errorTimes = pruneOldTimes(f.errorTimes, cutoff)
return server.ASNFetcherStats{
SuccessesLastHour: len(f.successTimes),
ErrorsLastHour: len(f.errorTimes),
CurrentInterval: interval,
ConsecutiveFails: fails,
}
}
// pruneOldTimes removes times older than cutoff and returns the pruned slice.
func pruneOldTimes(times []time.Time, cutoff time.Time) []time.Time {
result := make([]time.Time, 0, len(times))
for _, t := range times {
if t.After(cutoff) {
result = append(result, t)
}
}
return result
}
// getInterval returns the current fetch interval.
func (f *ASNFetcher) getInterval() time.Duration {
f.intervalMu.Lock()
defer f.intervalMu.Unlock()
return f.currentInterval
}
// recordSuccess decreases the interval on successful fetch.
func (f *ASNFetcher) recordSuccess() {
f.intervalMu.Lock()
f.consecutiveFails = 0
// Decrease interval by half, but not below minimum
newInterval := f.currentInterval / backoffMultiplier
if newInterval < minInterval {
newInterval = minInterval
}
if newInterval != f.currentInterval {
f.logger.Debug("Decreased fetch interval",
"old_interval", f.currentInterval,
"new_interval", newInterval,
)
f.currentInterval = newInterval
}
f.intervalMu.Unlock()
// Record success time for stats
f.statsMu.Lock()
f.successTimes = append(f.successTimes, time.Now())
f.statsMu.Unlock()
}
// recordFailure increases the interval on failed fetch using exponential backoff.
func (f *ASNFetcher) recordFailure() {
f.intervalMu.Lock()
f.consecutiveFails++
// Exponential backoff: multiply by 2, capped at max
newInterval := f.currentInterval * backoffMultiplier
if newInterval > maxInterval {
newInterval = maxInterval
}
if newInterval != f.currentInterval {
f.logger.Debug("Increased fetch interval due to failure",
"old_interval", f.currentInterval,
"new_interval", newInterval,
"consecutive_failures", f.consecutiveFails,
)
f.currentInterval = newInterval
}
f.intervalMu.Unlock()
// Record error time for stats
f.statsMu.Lock()
f.errorTimes = append(f.errorTimes, time.Now())
f.statsMu.Unlock()
}
// run is the main background loop.
func (f *ASNFetcher) run() {
defer f.wg.Done()
timer := time.NewTimer(f.getInterval())
defer timer.Stop()
for {
select {
case <-f.stopCh:
return
case asn := <-f.immediateQueue:
// Process immediate request (respects lock)
f.tryFetch(asn)
// Reset timer after immediate fetch
timer.Reset(f.getInterval())
case <-timer.C:
// Background fetch of stale/missing ASN
f.fetchNextStale()
// Reset timer with potentially updated interval
timer.Reset(f.getInterval())
}
}
}
// tryFetch attempts to fetch and update an ASN, respecting the fetch lock.
// Returns true if fetch was successful.
func (f *ASNFetcher) tryFetch(asn int) bool {
// Try to acquire lock, skip if another fetch is running
if !f.fetchMu.TryLock() {
f.logger.Debug("Skipping fetch, another fetch in progress", "asn", asn)
return false
}
defer f.fetchMu.Unlock()
return f.fetchAndUpdate(asn)
}
// fetchNextStale finds and fetches the next ASN needing WHOIS data.
func (f *ASNFetcher) fetchNextStale() {
// Try to acquire lock, skip if another fetch is running
if !f.fetchMu.TryLock() {
f.logger.Debug("Skipping stale fetch, another fetch in progress")
return
}
defer f.fetchMu.Unlock()
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
asn, err := f.db.GetNextStaleASN(ctx, whoisStaleThreshold)
if err != nil {
if err != database.ErrNoStaleASN {
f.logger.Error("Failed to get stale ASN", "error", err)
f.recordFailure()
}
// No stale ASN is not a failure, just nothing to do
return
}
f.fetchAndUpdate(asn)
}
// fetchAndUpdate performs a WHOIS lookup and updates the database.
// Returns true if successful.
func (f *ASNFetcher) fetchAndUpdate(asn int) bool {
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
f.logger.Info("Fetching WHOIS data", "asn", asn)
info, err := f.whoisClient.LookupASN(ctx, asn)
if err != nil {
f.logger.Error("WHOIS lookup failed", "asn", asn, "error", err)
f.recordFailure()
return false
}
// Update database with WHOIS data
err = f.db.UpdateASNWHOIS(ctx, &database.ASNWHOISUpdate{
ASN: asn,
ASName: info.ASName,
OrgName: info.OrgName,
OrgID: info.OrgID,
Address: info.Address,
CountryCode: info.CountryCode,
AbuseEmail: info.AbuseEmail,
AbusePhone: info.AbusePhone,
TechEmail: info.TechEmail,
TechPhone: info.TechPhone,
RIR: info.RIR,
RIRRegDate: info.RegDate,
RIRLastMod: info.LastMod,
WHOISRaw: info.RawResponse,
})
if err != nil {
f.logger.Error("Failed to update ASN WHOIS data", "asn", asn, "error", err)
f.recordFailure()
return false
}
f.recordSuccess()
f.logger.Info("Updated ASN WHOIS data",
"asn", asn,
"org_name", info.OrgName,
"country", info.CountryCode,
"rir", info.RIR,
"next_interval", f.getInterval(),
)
return true
}
// GetStaleThreshold returns the WHOIS stale threshold duration.
func GetStaleThreshold() time.Duration {
return whoisStaleThreshold
}