/
main.go
172 lines (146 loc) · 3.94 KB
/
main.go
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// Package main reads lines from files and writes them to a Windows
// event log.
package main
import (
"bufio"
"flag"
"fmt"
"math"
"os"
"os/signal"
"sync"
"sync/atomic"
"time"
"github.com/andrewkroh/sys/windows/svc/eventlog"
"github.com/juju/ratelimit"
)
// EventCreate.exe has valid event IDs in the range of 1-1000 where each
// event message requires a single parameter.
const eventCreateMsgFile = "%SystemRoot%\\System32\\EventCreate.exe"
var (
file = flag.String("f", "", "file to read")
log = flag.String("l", "EventSystem", "event source name")
id = flag.Uint("id", 512, "event id")
max = flag.Uint("max", 0, "maximum events to write")
rate = flag.Float64("rate", 0, "rate limit in events per second")
interval = flag.Duration("interval", 0, "interval at which to send events")
install = flag.Bool("install", false, "install new event source")
provider = flag.String("provider", "Application", "provider name to install")
source = flag.String("source", "", "source name to install, must be specified to install new event source")
)
type eventgen struct {
file *os.File // Input file to read from.
log *eventlog.Log // Windows event log.
tb *ratelimit.Bucket // Token bucker for rate limiting.
count uint32 // Total number of events written.
max uint32 // Max lines to read.
done chan struct{} // Channel used to signal to stop.
}
func (eg *eventgen) installSignalHandler() {
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
go func() {
once := sync.Once{}
for _ = range c {
once.Do(func() { close(eg.done) })
}
}()
}
func (eg *eventgen) reportEvents(wg *sync.WaitGroup) {
defer wg.Done()
scanner := bufio.NewScanner(eg.file)
for scanner.Scan() {
if eg.tb != nil {
for !eg.tb.WaitMaxDuration(1, time.Second) {
select {
case <-eg.done:
return
default:
}
}
}
eg.log.Report(eventlog.Info, uint32(*id), []string{scanner.Text()})
numRead := atomic.AddUint32(&eg.count, 1)
if eg.max != 0 && numRead >= eg.max {
return
}
select {
case <-eg.done:
return
default:
}
}
}
func registerSource(provider, sourceName string) error {
if provider == "" {
return fmt.Errorf("provider cannot be empty")
}
if sourceName == "" {
return fmt.Errorf("source cannot be empty")
}
alreadyInstalled, err := eventlog.InstallAsEventCreate(provider, sourceName,
eventlog.Error|eventlog.Warning|eventlog.Info|eventlog.Success|
eventlog.AuditSuccess|eventlog.AuditFailure)
if err != nil {
return err
}
if alreadyInstalled {
fmt.Printf("%s/%s already exists\n", provider, sourceName)
return nil
}
fmt.Printf("%s/%s installed\n", provider, sourceName)
return nil
}
func main() {
flag.Parse()
if *install {
err := registerSource(*provider, *source)
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
return
}
if *file == "" {
fmt.Fprintln(os.Stderr, "-f is required")
flag.Usage()
os.Exit(1)
}
// Open a handle to the event log.
log, err := eventlog.Open(*log)
if err != nil {
fmt.Fprintln(os.Stderr, "opening eventlog:", err)
os.Exit(1)
}
// Open the file on disk.
file, err := os.Open(*file)
if err != nil {
fmt.Fprintln(os.Stderr, "opening file:", err)
os.Exit(1)
}
defer file.Close()
eg := &eventgen{
file: file,
max: uint32(*max),
done: make(chan struct{}),
log: log,
}
eg.installSignalHandler()
// Rate limit writing using a token bucket.
if *rate != 0 {
eg.tb = ratelimit.NewBucketWithRate(*rate, int64(math.Ceil(*rate)))
eg.tb.TakeAvailable(eg.tb.Available())
} else if *interval != 0 {
eg.tb = ratelimit.NewBucket(*interval, 1)
eg.tb.TakeAvailable(eg.tb.Available())
}
start := time.Now()
// Start a new worker to read lines from the file.
wg := &sync.WaitGroup{}
wg.Add(1)
go eg.reportEvents(wg)
wg.Wait()
elapsed := time.Since(start)
fmt.Println("elapsed time:", elapsed)
fmt.Println("event count:", atomic.LoadUint32(&eg.count))
}