sshpiper/plugin/failtoban/main.go

103 lines
2.8 KiB
Go

//go:build full || e2e
package main
import (
"fmt"
"net"
"os"
"os/signal"
"syscall"
"time"
gocache "github.com/patrickmn/go-cache"
log "github.com/sirupsen/logrus"
"github.com/tg123/sshpiper/libplugin"
"github.com/urfave/cli/v2"
)
func main() {
libplugin.CreateAndRunPluginTemplate(&libplugin.PluginTemplate{
Name: "failtoban",
Usage: "failtoban plugin, block ip after too many auth failures",
Flags: []cli.Flag{
&cli.IntFlag{
Name: "max-failures",
Usage: "max failures",
EnvVars: []string{"SSHPIPERD_FAILTOBAN_MAX_FAILURES"},
Value: 5,
},
&cli.DurationFlag{
Name: "ban-duration",
Usage: "ban duration",
EnvVars: []string{"SSHPIPERD_FAILTOBAN_BAN_DURATION"},
Value: 60 * time.Minute,
},
&cli.BoolFlag{
Name: "log-only",
Usage: "log only mode, no ban, useful for working with other tools like fail2ban",
EnvVars: []string{"SSHPIPERD_FAILTOBAN_LOG_ONLY"},
Value: false,
},
},
CreateConfig: func(c *cli.Context) (*libplugin.SshPiperPluginConfig, error) {
maxFailures := c.Int("max-failures")
banDuration := c.Duration("ban-duration")
logOnly := c.Bool("log-only")
cache := gocache.New(banDuration, banDuration/2*3)
// register signal handler
go func() {
sigChan := make(chan os.Signal, 1)
signal.Notify(sigChan, syscall.SIGHUP)
for {
<-sigChan
cache.Flush()
log.Info("failtoban: cache reset due to SIGHUP")
}
}()
return &libplugin.SshPiperPluginConfig{
NoClientAuthCallback: func(conn libplugin.ConnMetadata) (*libplugin.Upstream, error) {
// in case someone put the failtoban plugin before other plugins
return &libplugin.Upstream{
Auth: libplugin.CreateNextPluginAuth(map[string]string{}),
}, nil
},
NewConnectionCallback: func(conn libplugin.ConnMetadata) error {
if logOnly {
return nil
}
ip, _, _ := net.SplitHostPort(conn.RemoteAddr())
failed, found := cache.Get(ip)
if !found {
// init
return cache.Add(ip, 0, banDuration)
}
if failed.(int) >= maxFailures {
return fmt.Errorf("failtoban: ip %v too auth many failures", ip)
}
return nil
},
UpstreamAuthFailureCallback: func(conn libplugin.ConnMetadata, method string, err error, allowmethods []string) {
ip, _, _ := net.SplitHostPort(conn.RemoteAddr())
failed, _ := cache.IncrementInt(ip, 1)
log.Warnf("failtoban: %v auth failed. current status: fail %v times, max allowed %v", ip, failed, maxFailures)
},
PipeCreateErrorCallback: func(remoteAddr string, err error) {
ip, _, _ := net.SplitHostPort(remoteAddr)
failed, _ := cache.IncrementInt(ip, 1)
log.Warnf("failtoban: %v pipe create failed, reason %v. current status: fail %v times, max allowed %v", ip, err, failed, maxFailures)
},
}, nil
},
})
}