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Xray-core/app/observatory/burst/healthping.go
Kuzmin Vladimir d7c5a0fc5f
Fix int overflow on x32 processors causing panic ()
During the roll, "duration" is converted to int, causing overflow on x32 processors. The value may be very small or negative, causing a panic in rand.Intn.
2024-09-14 23:47:16 -04:00

255 lines
6.3 KiB
Go

package burst
import (
"context"
"fmt"
"strings"
"sync"
"time"
"github.com/xtls/xray-core/common/dice"
"github.com/xtls/xray-core/common/errors"
)
// HealthPingSettings holds settings for health Checker
type HealthPingSettings struct {
Destination string `json:"destination"`
Connectivity string `json:"connectivity"`
Interval time.Duration `json:"interval"`
SamplingCount int `json:"sampling"`
Timeout time.Duration `json:"timeout"`
}
// HealthPing is the health checker for balancers
type HealthPing struct {
ctx context.Context
access sync.Mutex
ticker *time.Ticker
tickerClose chan struct{}
Settings *HealthPingSettings
Results map[string]*HealthPingRTTS
}
// NewHealthPing creates a new HealthPing with settings
func NewHealthPing(ctx context.Context, config *HealthPingConfig) *HealthPing {
settings := &HealthPingSettings{}
if config != nil {
settings = &HealthPingSettings{
Connectivity: strings.TrimSpace(config.Connectivity),
Destination: strings.TrimSpace(config.Destination),
Interval: time.Duration(config.Interval),
SamplingCount: int(config.SamplingCount),
Timeout: time.Duration(config.Timeout),
}
}
if settings.Destination == "" {
// Destination URL, need 204 for success return default to chromium
// https://github.com/chromium/chromium/blob/main/components/safety_check/url_constants.cc#L10
// https://chromium.googlesource.com/chromium/src/+/refs/heads/main/components/safety_check/url_constants.cc#10
settings.Destination = "https://connectivitycheck.gstatic.com/generate_204"
}
if settings.Interval == 0 {
settings.Interval = time.Duration(1) * time.Minute
} else if settings.Interval < 10 {
errors.LogWarning(ctx, "health check interval is too small, 10s is applied")
settings.Interval = time.Duration(10) * time.Second
}
if settings.SamplingCount <= 0 {
settings.SamplingCount = 10
}
if settings.Timeout <= 0 {
// results are saved after all health pings finish,
// a larger timeout could possibly makes checks run longer
settings.Timeout = time.Duration(5) * time.Second
}
return &HealthPing{
ctx: ctx,
Settings: settings,
Results: nil,
}
}
// StartScheduler implements the HealthChecker
func (h *HealthPing) StartScheduler(selector func() ([]string, error)) {
if h.ticker != nil {
return
}
interval := h.Settings.Interval * time.Duration(h.Settings.SamplingCount)
ticker := time.NewTicker(interval)
tickerClose := make(chan struct{})
h.ticker = ticker
h.tickerClose = tickerClose
go func() {
tags, err := selector()
if err != nil {
errors.LogWarning(h.ctx, "error select outbounds for initial health check: ", err)
return
}
h.Check(tags)
}()
go func() {
for {
go func() {
tags, err := selector()
if err != nil {
errors.LogWarning(h.ctx, "error select outbounds for scheduled health check: ", err)
return
}
h.doCheck(tags, interval, h.Settings.SamplingCount)
h.Cleanup(tags)
}()
select {
case <-ticker.C:
continue
case <-tickerClose:
return
}
}
}()
}
// StopScheduler implements the HealthChecker
func (h *HealthPing) StopScheduler() {
if h.ticker == nil {
return
}
h.ticker.Stop()
h.ticker = nil
close(h.tickerClose)
h.tickerClose = nil
}
// Check implements the HealthChecker
func (h *HealthPing) Check(tags []string) error {
if len(tags) == 0 {
return nil
}
errors.LogInfo(h.ctx, "perform one-time health check for tags ", tags)
h.doCheck(tags, 0, 1)
return nil
}
type rtt struct {
handler string
value time.Duration
}
// doCheck performs the 'rounds' amount checks in given 'duration'. You should make
// sure all tags are valid for current balancer
func (h *HealthPing) doCheck(tags []string, duration time.Duration, rounds int) {
count := len(tags) * rounds
if count == 0 {
return
}
ch := make(chan *rtt, count)
for _, tag := range tags {
handler := tag
client := newPingClient(
h.ctx,
h.Settings.Destination,
h.Settings.Timeout,
handler,
)
for i := 0; i < rounds; i++ {
delay := time.Duration(0)
if duration > 0 {
delay = time.Duration(dice.RollInt63n(int64(duration)))
}
time.AfterFunc(delay, func() {
errors.LogDebug(h.ctx, "checking ", handler)
delay, err := client.MeasureDelay()
if err == nil {
ch <- &rtt{
handler: handler,
value: delay,
}
return
}
if !h.checkConnectivity() {
errors.LogWarning(h.ctx, "network is down")
ch <- &rtt{
handler: handler,
value: 0,
}
return
}
errors.LogWarning(h.ctx, fmt.Sprintf(
"error ping %s with %s: %s",
h.Settings.Destination,
handler,
err,
))
ch <- &rtt{
handler: handler,
value: rttFailed,
}
})
}
}
for i := 0; i < count; i++ {
rtt := <-ch
if rtt.value > 0 {
// should not put results when network is down
h.PutResult(rtt.handler, rtt.value)
}
}
}
// PutResult put a ping rtt to results
func (h *HealthPing) PutResult(tag string, rtt time.Duration) {
h.access.Lock()
defer h.access.Unlock()
if h.Results == nil {
h.Results = make(map[string]*HealthPingRTTS)
}
r, ok := h.Results[tag]
if !ok {
// validity is 2 times to sampling period, since the check are
// distributed in the time line randomly, in extreme cases,
// Previous checks are distributed on the left, and later ones
// on the right
validity := h.Settings.Interval * time.Duration(h.Settings.SamplingCount) * 2
r = NewHealthPingResult(h.Settings.SamplingCount, validity)
h.Results[tag] = r
}
r.Put(rtt)
}
// Cleanup removes results of removed handlers,
// tags should be all valid tags of the Balancer now
func (h *HealthPing) Cleanup(tags []string) {
h.access.Lock()
defer h.access.Unlock()
for tag := range h.Results {
found := false
for _, v := range tags {
if tag == v {
found = true
break
}
}
if !found {
delete(h.Results, tag)
}
}
}
// checkConnectivity checks the network connectivity, it returns
// true if network is good or "connectivity check url" not set
func (h *HealthPing) checkConnectivity() bool {
if h.Settings.Connectivity == "" {
return true
}
tester := newDirectPingClient(
h.Settings.Connectivity,
h.Settings.Timeout,
)
if _, err := tester.MeasureDelay(); err != nil {
return false
}
return true
}