Use ipset (fixe #2, #4, #5)

Author: olarriga

README.md

@@ -4,7 +4,7 @@
   <img width="330" height="330" src="/etc/banisher.png">
 </p>
 
-The Banisher watches in real time your systemd journal and bans, via iptables, hosts who match on yours rules.  
+The Banisher watches in real time your systemd journal and bans, via ipset and iptables, hosts who match on yours rules.  
 
 Currently hosts (IP) are banished for 1 hour (configurable in config.yml).
 
@@ -28,7 +28,7 @@ __WARNING The Banisher works only with logs handled by systemd journal and is cu
 
 1. Download the lastest debian package from the [releases section](https://github.com/olarriga/banisher/releases).
 2. Modify the /etc/banisher.yml file to define the configuration according to your needs
-3. Restart The Banisher (`systemctl restart banisher.service`).
+3. Restart The Banisher (`systemctl restart banisher`).
 
 ### Config
 
@@ -122,7 +122,7 @@ For example if you want those two rules, your config file will be:
   IPpos: 0
 ```  
 
-## And what can i do if something goes wrong !!!
+## And what can i do if something goes wrong ?
 
 An iptables rules will be automaticaly removed after defaultBanishmentDuration (defined in your config file).
 
@@ -137,7 +137,7 @@ If you made a mistake, just:
 
 ### Prerequisite
 
-- [Task](https://taskfile.dev/) is used for compilation with a Docker image to handle glibc version issue to keep The Banisher compatible with debian buster (debian 10).
+- [Task](https://taskfile.dev/) is used for compilation with a Docker image to handle glibc version issue to keep The Banisher compatible with debian buster and bullseye (debian 10 and 11).
 - To compile without the Docker image, the libsystemd0 library is needed (for debian like: `sudo apt install libsystemd-dev`).
 - The Banisher is dynamically linked with the glibc.
 

banisher.go

@@ -4,15 +4,16 @@ import (
 	"log"
 	"net"
 	"strconv"
-	"strings"
 	"sync"
 	"time"
 
-	"github.com/dgraph-io/badger"
-
 	"github.com/coreos/go-iptables/iptables"
+	badger "github.com/dgraph-io/badger/v3"
+	"github.com/nadoo/ipset"
 )
 
+const ipsetName = "banisher"
+
 // Banisher is THE banisher
 type Banisher struct {
 	sync.Mutex
@@ -23,11 +24,17 @@ type Banisher struct {
 func NewBanisher(databaseFile string) (b *Banisher, err error) {
 	b = new(Banisher)
 
-	// badger
-	options := badger.DefaultOptions(databaseFile)
-	options.SyncWrites = true
+	// badger options
+	var options badger.Options
+	if databaseFile == ":memory:" {
+		options = badger.DefaultOptions("").WithInMemory(true)
+	} else {
+		options = badger.DefaultOptions(databaseFile)
+		options.SyncWrites = true
+	}
 	options.Logger = nil
 
+	// open badger database
 	b.db, err = badger.Open(options)
 	if err != nil {
 		return nil, err
@@ -38,6 +45,12 @@ func NewBanisher(databaseFile string) (b *Banisher, err error) {
 	if err != nil {
 		return nil, err
 	}
+
+	// ipset binding
+	if err = ipset.Init(); err != nil {
+		return nil, err
+	}
+
 	return
 }
 
@@ -80,9 +93,9 @@ func (b *Banisher) Add(ip, ruleName string) {
 		return
 	}
 
-	// iptables
-	if err = b.IPT.AppendUnique("filter", "INPUT", "-s", ip, "-j", "DROP"); err != nil {
-		log.Println("failed to ad iptable rule:", err)
+	// ipset
+	if err = b.filterIP(ip); err != nil {
+		log.Println("failed to add an entry to ipset:", err)
 		return
 	}
 
@@ -93,9 +106,9 @@ func (b *Banisher) Add(ip, ruleName string) {
 
 	if err != nil {
 		log.Printf("failed to add %s in db: %s", ip, err)
-		// remove from iptables
-		if err = b.IPT.Delete("filter", "INPUT", "-s", ip, "-j", "DROP"); err != nil {
-			log.Printf("failed to remove %s from iptables: %s", ip, err)
+		// remove from ipset
+		if err = b.unFilterIP(ip); err != nil {
+			log.Printf("failed to remove %s from ipset: %s", ip, err)
 		}
 		return
 	}
@@ -105,11 +118,9 @@ func (b *Banisher) Add(ip, ruleName string) {
 // Remove unban an IP
 func (b *Banisher) Remove(ip string) {
 	var err error
-	if err = b.IPT.Delete("filter", "INPUT", "-s", ip, "-j", "DROP"); err != nil {
-		if !strings.Contains(err.Error(), "matching rule exist") {
-			log.Printf("failed to delete iptables rules for %s : %s", ip, err)
-			return
-		}
+	if err = b.unFilterIP(ip); err != nil {
+		log.Printf("failed to remove %s from ipset: %s", ip, err)
+		return
 	}
 	err = b.db.Update(func(txn *badger.Txn) error {
 		return txn.Delete([]byte(ip))
@@ -122,21 +133,46 @@ func (b *Banisher) Remove(ip string) {
 }
 
 // Restore restore iptables rules from DB
-func (b Banisher) Restore() error {
-	err := b.db.View(func(txn *badger.Txn) error {
-		opts := badger.DefaultIteratorOptions
-		opts.PrefetchSize = 20
-		it := txn.NewIterator(opts)
-		defer it.Close()
-		for it.Rewind(); it.Valid(); it.Next() {
-			ip := it.Item().Key()
-			if err := b.IPT.AppendUnique("filter", "INPUT", "-s", string(ip), "-j", "DROP"); err != nil {
-				return err
-			}
+func (b *Banisher) Restore() error {
+
+	// create an empty ipset for The Banisher
+	ipset.Destroy(ipsetName)
+	if err := ipset.Create(ipsetName); err != nil {
+		return err
+	}
+	if err := ipset.Flush(ipsetName); err != nil {
+		return err
+	}
+
+	// create the iptable rule if it does not exist
+	exists, err := b.IPT.Exists("filter", "INPUT", "-m", "set", "--match-set", ipsetName, "src", "-j", "DROP")
+	if err != nil {
+		return err
+	}
+	if !exists {
+		if err := b.IPT.Insert("filter", "INPUT", 1, "-m", "set", "--match-set", ipsetName, "src", "-j", "DROP"); err != nil {
+			return err
 		}
+	}
+
+	if !b.db.Opts().InMemory {
+		err := b.db.View(func(txn *badger.Txn) error {
+			opts := badger.DefaultIteratorOptions
+			opts.PrefetchSize = 20
+			it := txn.NewIterator(opts)
+			defer it.Close()
+			for it.Rewind(); it.Valid(); it.Next() {
+				ip := it.Item().Key()
+				if err := b.filterIP(string(ip)); err != nil {
+					return err
+				}
+			}
+			return nil
+		})
+		return err
+	} else {
 		return nil
-	})
-	return err
+	}
 }
 
 // GC remove expired banishment
@@ -172,3 +208,27 @@ func (b *Banisher) GC() {
 		time.Sleep(time.Duration(5) * time.Minute)
 	}
 }
+
+func (b *Banisher) Clear() error {
+
+	// remove iptable rule
+	if err := b.IPT.Delete("filter", "INPUT", "-m", "set", "--match-set", ipsetName, "src", "-j", "DROP"); err != nil {
+		return err
+	}
+
+	// clear and remove ipset
+	if err := ipset.Flush(ipsetName); err != nil {
+		return err
+	}
+	ipset.Destroy(ipsetName)
+
+	return nil
+}
+
+func (b *Banisher) filterIP(ip string) error {
+	return ipset.Add(ipsetName, ip)
+}
+
+func (b *Banisher) unFilterIP(ip string) error {
+	return ipset.Del(ipsetName, ip)
+}

debian/banisher.service

@@ -4,7 +4,7 @@ After=network.target auditd.service
 
 [Service]
 ExecStartPre=/usr/bin/install -m 755 -o root -g root -d /var/lib/banisher
-ExecStart=/usr/sbin/banisher -conf=/etc/banisher.yml -db=/var/lib/banisher/db.bdg -systemd
+ExecStart=/usr/sbin/banisher -conf=/etc/banisher.yml -db=:memory: -systemd
 KillMode=process
 Restart=on-failure
 StandardOutput=syslog

debian/control

@@ -3,7 +3,9 @@ Version: #version#
 Section: net
 Priority: optional
 Architecture: amd64
-Depends: libc6 (>= 2.28)
+Depends: libc6 (>= 2.28), iptables
+Suggests: ipset
 Essential: no
 Maintainer: Olivier LARRIGAUDIERE
 Description: Watches your systemd journal and bans, with no delay, abusers.
+Homepage: https://github.com/olarriga/banisher

go.mod

@@ -5,17 +5,28 @@ go 1.19
 require (
 	github.com/coreos/go-iptables v0.6.0
 	github.com/coreos/go-systemd v0.0.0-20191104093116-d3cd4ed1dbcf
-	github.com/dgraph-io/badger v1.6.2
+	github.com/dgraph-io/badger/v3 v3.2103.5
+	github.com/marcsauter/single v0.0.0-20201009143647-9f8d81240be2
+	github.com/nadoo/ipset v0.5.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
-	github.com/AndreasBriese/bbloom v0.0.0-20190825152654-46b345b51c96 // indirect
 	github.com/cespare/xxhash v1.1.0 // indirect
-	github.com/dgraph-io/ristretto v0.0.2 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/dgraph-io/ristretto v0.1.1 // indirect
 	github.com/dustin/go-humanize v1.0.0 // indirect
-	github.com/golang/protobuf v1.3.1 // indirect
-	github.com/pkg/errors v0.8.1 // indirect
-	golang.org/x/net v0.0.0-20190620200207-3b0461eec859 // indirect
-	golang.org/x/sys v0.0.0-20190626221950-04f50cda93cb // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/glog v1.0.0 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/golang/snappy v0.0.4 // indirect
+	github.com/google/flatbuffers v22.11.23+incompatible // indirect
+	github.com/klauspost/compress v1.15.13 // indirect
+	github.com/kr/pretty v0.2.0 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	go.opencensus.io v0.24.0 // indirect
+	golang.org/x/net v0.4.0 // indirect
+	golang.org/x/sys v0.3.0 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 )