feat: udpping

This commit is contained in:
2026-03-27 01:29:21 +08:00
parent 0bd66b6ac8
commit 5b231141a7
4 changed files with 849 additions and 0 deletions

389
cmd/udpping/main.go Normal file
View File

@@ -0,0 +1,389 @@
package main
import (
"encoding/json"
"errors"
"flag"
"fmt"
"io"
"math"
"os"
"sort"
"strings"
"time"
)
const (
defaultPeerID = "pinger"
defaultServer = "127.0.0.1:9001"
defaultCount = 100
defaultInterval = 100 * time.Millisecond
defaultSize = 64
defaultTimeout = 3 * time.Second
minExpiryPoll = 10 * time.Millisecond
maxExpiryPoll = 100 * time.Millisecond
)
type config struct {
id string
server string
to string
echo bool
count int
interval time.Duration
size int
timeout time.Duration
bindIP string
latencyLog string
}
type pingPayload struct {
Seq uint64 `json:"seq"`
TSUnixNano int64 `json:"ts_ns"`
Pad string `json:"pad"`
}
type pendingPing struct {
deadline time.Time
}
type replyDisposition int
const (
replyMatched replyDisposition = iota
replyDuplicate
replyUnexpected
)
type replyResult struct {
disposition replyDisposition
rtt time.Duration
}
type pingTracker struct {
timeout time.Duration
sent int
duplicates int
pending map[uint64]pendingPing
seen map[uint64]struct{}
samples []time.Duration
}
type rttSummary struct {
Sent int
Received int
Duplicates int
LossPct float64
Min time.Duration
Avg time.Duration
Max time.Duration
P50 time.Duration
P95 time.Duration
P99 time.Duration
StdDev time.Duration
HasSamples bool
}
func main() {
if err := runMain(os.Args[1:], os.Stdout, os.Stderr, time.Now); err != nil {
if errors.Is(err, flag.ErrHelp) {
return
}
_, _ = fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
}
func runMain(args []string, stdout, stderr io.Writer, now func() time.Time) error {
cfg, err := parseConfig(args, stderr)
if err != nil {
return err
}
return runPlatform(cfg, stdout, stderr, now)
}
func parseConfig(args []string, stderr io.Writer) (config, error) {
cfg := config{}
flags := flag.NewFlagSet("udpping", flag.ContinueOnError)
flags.SetOutput(stderr)
flags.StringVar(&cfg.id, "id", defaultPeerID, "local peer identity")
flags.StringVar(&cfg.server, "server", defaultServer, "UDP server address")
flags.StringVar(&cfg.to, "to", "", "target peer identity in ping mode")
flags.BoolVar(&cfg.echo, "echo", false, "echo back every received text message")
flags.IntVar(&cfg.count, "count", defaultCount, "number of pings to send; 0 means run until interrupted")
flags.DurationVar(&cfg.interval, "interval", defaultInterval, "delay between ping sends")
flags.IntVar(&cfg.size, "size", defaultSize, "application payload size in bytes")
flags.DurationVar(&cfg.timeout, "timeout", defaultTimeout, "per-ping timeout")
flags.StringVar(&cfg.bindIP, "bind-ip", "", "optional local source IP used when dialing the server")
flags.StringVar(&cfg.latencyLog, "latency-log", "", "optional JSONL file path for latency timestamp logs")
if err := flags.Parse(args); err != nil {
return config{}, err
}
if flags.NArg() > 0 {
return config{}, fmt.Errorf("unexpected positional arguments: %s", strings.Join(flags.Args(), " "))
}
cfg.id = strings.TrimSpace(cfg.id)
cfg.server = strings.TrimSpace(cfg.server)
cfg.to = strings.TrimSpace(cfg.to)
cfg.bindIP = strings.TrimSpace(cfg.bindIP)
cfg.latencyLog = strings.TrimSpace(cfg.latencyLog)
if err := cfg.validate(); err != nil {
return config{}, err
}
return cfg, nil
}
func (c config) validate() error {
if c.id == "" {
return fmt.Errorf("flag -id is required")
}
if c.server == "" {
return fmt.Errorf("flag -server is required")
}
if !c.echo && c.to == "" {
return fmt.Errorf("flag -to is required unless -echo is set")
}
if c.count < 0 {
return fmt.Errorf("flag -count must be greater than or equal to zero")
}
if c.interval <= 0 {
return fmt.Errorf("flag -interval must be greater than zero")
}
if c.size <= 0 {
return fmt.Errorf("flag -size must be greater than zero")
}
if c.timeout <= 0 {
return fmt.Errorf("flag -timeout must be greater than zero")
}
return nil
}
func buildPingPayload(seq uint64, tsUnixNano int64, size int) ([]byte, error) {
payload := pingPayload{
Seq: seq,
TSUnixNano: tsUnixNano,
Pad: "",
}
body, err := json.Marshal(payload)
if err != nil {
return nil, fmt.Errorf("encode ping payload: %w", err)
}
if len(body) > size {
return nil, fmt.Errorf("requested payload size %d is too small; minimum is %d", size, len(body))
}
payload.Pad = strings.Repeat("A", size-len(body))
body, err = json.Marshal(payload)
if err != nil {
return nil, fmt.Errorf("encode padded ping payload: %w", err)
}
if len(body) != size {
return nil, fmt.Errorf("encode padded ping payload: got %d bytes, want %d", len(body), size)
}
return body, nil
}
func parsePingPayload(body []byte) (pingPayload, error) {
var payload pingPayload
if err := json.Unmarshal(body, &payload); err != nil {
return pingPayload{}, fmt.Errorf("decode ping payload: %w", err)
}
if payload.Seq == 0 {
return pingPayload{}, fmt.Errorf("decode ping payload: seq must be greater than zero")
}
if payload.TSUnixNano <= 0 {
return pingPayload{}, fmt.Errorf("decode ping payload: ts_ns must be greater than zero")
}
return payload, nil
}
func newPingTracker(timeout time.Duration) *pingTracker {
return &pingTracker{
timeout: timeout,
pending: make(map[uint64]pendingPing),
seen: make(map[uint64]struct{}),
}
}
func (t *pingTracker) markSent(seq uint64, sentAt time.Time) {
t.sent++
t.pending[seq] = pendingPing{deadline: sentAt.Add(t.timeout)}
t.seen[seq] = struct{}{}
}
func (t *pingTracker) observeReply(payload pingPayload, receivedAt time.Time) replyResult {
if _, ok := t.seen[payload.Seq]; !ok {
return replyResult{disposition: replyUnexpected}
}
if _, ok := t.pending[payload.Seq]; !ok {
t.duplicates++
return replyResult{disposition: replyDuplicate}
}
delete(t.pending, payload.Seq)
rtt := receivedAt.Sub(time.Unix(0, payload.TSUnixNano))
if rtt < 0 {
rtt = 0
}
t.samples = append(t.samples, rtt)
return replyResult{
disposition: replyMatched,
rtt: rtt,
}
}
func (t *pingTracker) expire(now time.Time) []uint64 {
expired := make([]uint64, 0)
for seq, pending := range t.pending {
if !pending.deadline.After(now) {
expired = append(expired, seq)
delete(t.pending, seq)
}
}
sort.Slice(expired, func(i, j int) bool {
return expired[i] < expired[j]
})
return expired
}
func (t *pingTracker) pendingCount() int {
return len(t.pending)
}
func (t *pingTracker) summary() rttSummary {
return calculateRTTSummary(t.samples, t.sent, t.duplicates)
}
func calculateRTTSummary(samples []time.Duration, sent, duplicates int) rttSummary {
summary := rttSummary{
Sent: sent,
Received: len(samples),
Duplicates: duplicates,
}
if sent > 0 {
summary.LossPct = float64(sent-len(samples)) * 100 / float64(sent)
}
if len(samples) == 0 {
return summary
}
sorted := append([]time.Duration(nil), samples...)
sort.Slice(sorted, func(i, j int) bool {
return sorted[i] < sorted[j]
})
var sum float64
for _, sample := range sorted {
sum += float64(sample)
}
avg := sum / float64(len(sorted))
var variance float64
for _, sample := range sorted {
delta := float64(sample) - avg
variance += delta * delta
}
variance /= float64(len(sorted))
summary.Min = sorted[0]
summary.Avg = time.Duration(math.Round(avg))
summary.Max = sorted[len(sorted)-1]
summary.P50 = percentileDuration(sorted, 0.50)
summary.P95 = percentileDuration(sorted, 0.95)
summary.P99 = percentileDuration(sorted, 0.99)
summary.StdDev = time.Duration(math.Round(math.Sqrt(variance)))
summary.HasSamples = true
return summary
}
func percentileDuration(sorted []time.Duration, percentile float64) time.Duration {
if len(sorted) == 0 {
return 0
}
if percentile <= 0 {
return sorted[0]
}
if percentile >= 1 {
return sorted[len(sorted)-1]
}
index := int(math.Ceil(percentile*float64(len(sorted)))) - 1
if index < 0 {
index = 0
}
if index >= len(sorted) {
index = len(sorted) - 1
}
return sorted[index]
}
func formatRTT(duration time.Duration) string {
return fmt.Sprintf("%.2fms", float64(duration)/float64(time.Millisecond))
}
func writePingHeader(w io.Writer, cfg config) error {
_, err := fmt.Fprintf(w, "UDP PING %s via %s (payload=%d bytes, UDP)\n", cfg.to, cfg.server, cfg.size)
return err
}
func writeMatchedReply(w io.Writer, seq uint64, rtt time.Duration) error {
_, err := fmt.Fprintf(w, "seq=%d rtt=%s\n", seq, formatRTT(rtt))
return err
}
func writeTimeout(w io.Writer, seq uint64) error {
_, err := fmt.Fprintf(w, "seq=%d timeout\n", seq)
return err
}
func writeSummary(w io.Writer, target string, summary rttSummary) error {
if _, err := fmt.Fprintf(w, "--- %s udp ping statistics ---\n", target); err != nil {
return err
}
if _, err := fmt.Fprintf(
w,
"%d packets transmitted, %d received, %d duplicates, %.2f%% packet loss\n",
summary.Sent,
summary.Received,
summary.Duplicates,
summary.LossPct,
); err != nil {
return err
}
if !summary.HasSamples {
_, err := fmt.Fprintln(w, "rtt min/avg/max/p50/p95/p99 = n/a/n/a/n/a/n/a/n/a/n/a, stddev=n/a")
return err
}
_, err := fmt.Fprintf(
w,
"rtt min/avg/max/p50/p95/p99 = %s/%s/%s/%s/%s/%s, stddev=%s\n",
formatRTT(summary.Min),
formatRTT(summary.Avg),
formatRTT(summary.Max),
formatRTT(summary.P50),
formatRTT(summary.P95),
formatRTT(summary.P99),
formatRTT(summary.StdDev),
)
return err
}
func expiryPollInterval(timeout time.Duration) time.Duration {
interval := timeout / 4
if interval < minExpiryPoll {
return minExpiryPoll
}
if interval > maxExpiryPoll {
return maxExpiryPoll
}
return interval
}