banlist

README.md

@@ -122,6 +122,13 @@ If you want to change them - check available options in the help message (`!pm h
 * **!pm mailboxes** - Show the list of all mailboxes
 * **!pm delete** <mailbox> - Delete specific mailbox
 
+---
+
+* **!pm banlist** - Enable/disable banlist and show current values
+* **!pm banlist:add** - Ban an IP
+* **!pm banlist:remove** - Unban an IP
+* **!pm banlist:reset** - Reset banlist
+
 </details>
 
 

bot/access.go

@@ -2,6 +2,7 @@ package bot
 
 import (
 	"context"
+	"net"
 	"regexp"
 	"strings"
 
@@ -71,6 +72,29 @@ func (b *Bot) allowSend(actorID id.UserID, targetRoomID id.RoomID) bool {
 	return !cfg.NoSend()
 }
 
+// IsBanned checks if address is banned
+func (b *Bot) IsBanned(addr net.Addr) bool {
+	if !b.getBotSettings().BanlistEnabled() {
+		return false
+	}
+	return b.getBanlist().Has(addr)
+}
+
+// Ban an address
+func (b *Bot) Ban(addr net.Addr) {
+	if !b.getBotSettings().BanlistEnabled() {
+		return
+	}
+
+	b.log.Debug("banning %s", addr.String())
+	banlist := b.getBanlist()
+	banlist.Add(addr)
+	err := b.setBanlist(banlist)
+	if err != nil {
+		b.log.Error("cannot update banlist with %s: %v", addr.String(), err)
+	}
+}
+
 // AllowAuth check if SMTP login (email) and password are valid
 func (b *Bot) AllowAuth(email, password string) bool {
 	var suffix bool

bot/command.go

@@ -22,6 +22,10 @@ const (
 	commandQueueBatch    = botOptionQueueBatch
 	commandQueueRetries  = botOptionQueueRetries
 	commandDelete        = "delete"
+	commandBanlist       = "banlist"
+	commandBanlistAdd    = "banlist:add"
+	commandBanlistRemove = "banlist:remove"
+	commandBanlistReset  = "banlist:reset"
 	commandMailboxes     = "mailboxes"
 )
 
@@ -211,6 +215,27 @@ func (b *Bot) initCommands() commandList {
 			description: "Delete specific mailbox",
 			allowed:     b.allowAdmin,
 		},
+		{allowed: b.allowAdmin}, // delimiter
+		{
+			key:         commandBanlist,
+			description: "Enable/disable banlist and show current values",
+			allowed:     b.allowAdmin,
+		},
+		{
+			key:         commandBanlistAdd,
+			description: "Ban an IP",
+			allowed:     b.allowAdmin,
+		},
+		{
+			key:         commandBanlistRemove,
+			description: "Unban an IP",
+			allowed:     b.allowAdmin,
+		},
+		{
+			key:         commandBanlistReset,
+			description: "Reset banlist",
+			allowed:     b.allowAdmin,
+		},
 	}
 }
 
@@ -245,6 +270,14 @@ func (b *Bot) handleCommand(ctx context.Context, evt *event.Event, commandSlice
 		b.runCatchAll(ctx, commandSlice)
 	case commandDelete:
 		b.runDelete(ctx, commandSlice)
+	case commandBanlist:
+		b.runBanlist(ctx, commandSlice)
+	case commandBanlistAdd:
+		b.runBanlistAdd(ctx, commandSlice)
+	case commandBanlistRemove:
+		b.runBanlistRemove(ctx, commandSlice)
+	case commandBanlistReset:
+		b.runBanlistReset(ctx)
 	case commandMailboxes:
 		b.sendMailboxes(ctx)
 	default:

bot/command_admin.go

@@ -3,6 +3,7 @@ package bot
 import (
 	"context"
 	"fmt"
+	"net"
 	"sort"
 	"strings"
 
@@ -205,3 +206,104 @@ func (b *Bot) runCatchAll(ctx context.Context, commandSlice []string) {
 
 	b.SendNotice(ctx, evt.RoomID, fmt.Sprintf("Catch-all is set to: `%s` (%s).", mailbox, utils.EmailsList(mailbox, "")))
 }
+
+func (b *Bot) runBanlist(ctx context.Context, commandSlice []string) {
+	evt := eventFromContext(ctx)
+	cfg := b.getBotSettings()
+	if len(commandSlice) < 2 {
+		banlist := b.getBanlist()
+		var msg strings.Builder
+		if len(banlist) > 0 {
+			msg.WriteString("Currently: `")
+			msg.WriteString(cfg.Get(botOptionBanlistEnabled))
+			msg.WriteString("` (`")
+			msg.WriteString(strings.Join(banlist.Slice(), " "))
+			msg.WriteString("`)\n\n")
+		}
+		if !cfg.BanlistEnabled() {
+			msg.WriteString("To enable banlist, send `")
+			msg.WriteString(b.prefix)
+			msg.WriteString(" banlist true`\n\n")
+		}
+		msg.WriteString("To ban somebody: `")
+		msg.WriteString(b.prefix)
+		msg.WriteString(" banlist:add IP1 IP2 IP3...`")
+		msg.WriteString("where each ip is IPv4 or IPv6\n")
+
+		b.SendNotice(ctx, evt.RoomID, msg.String())
+		return
+	}
+	value := utils.SanitizeBoolString(commandSlice[1])
+	cfg.Set(botOptionBanlistEnabled, value)
+	err := b.setBotSettings(cfg)
+	if err != nil {
+		b.Error(ctx, evt.RoomID, "cannot set bot config: %v", err)
+	}
+	b.SendNotice(ctx, evt.RoomID, "banlist has been updated")
+}
+
+func (b *Bot) runBanlistAdd(ctx context.Context, commandSlice []string) {
+	evt := eventFromContext(ctx)
+	if len(commandSlice) < 2 {
+		b.runBanlist(ctx, commandSlice)
+		return
+	}
+	banlist := b.getBanlist()
+
+	ips := commandSlice[1:]
+	for _, ip := range ips {
+		addr, err := net.ResolveIPAddr("ip", ip)
+		if err != nil {
+			b.Error(ctx, evt.RoomID, "cannot add %s to banlist: %v", ip, err)
+			return
+		}
+		banlist.Add(addr)
+	}
+
+	err := b.setBanlist(banlist)
+	if err != nil {
+		b.Error(ctx, evt.RoomID, "cannot set banlist: %v", err)
+		return
+	}
+
+	b.SendNotice(ctx, evt.RoomID, "banlist has been updated, kupo")
+}
+
+func (b *Bot) runBanlistRemove(ctx context.Context, commandSlice []string) {
+	evt := eventFromContext(ctx)
+	if len(commandSlice) < 2 {
+		b.runBanlist(ctx, commandSlice)
+		return
+	}
+	banlist := b.getBanlist()
+
+	ips := commandSlice[1:]
+	for _, ip := range ips {
+		addr, err := net.ResolveIPAddr("ip", ip)
+		if err != nil {
+			b.Error(ctx, evt.RoomID, "cannot remove %s from banlist: %v", ip, err)
+			return
+		}
+		banlist.Remove(addr)
+	}
+
+	err := b.setBanlist(banlist)
+	if err != nil {
+		b.Error(ctx, evt.RoomID, "cannot set banlist: %v", err)
+		return
+	}
+
+	b.SendNotice(ctx, evt.RoomID, "banlist has been updated, kupo")
+}
+
+func (b *Bot) runBanlistReset(ctx context.Context) {
+	evt := eventFromContext(ctx)
+
+	err := b.setBanlist(banList{})
+	if err != nil {
+		b.Error(ctx, evt.RoomID, "cannot set banlist: %v", err)
+		return
+	}
+
+	b.SendNotice(ctx, evt.RoomID, "banlist has been reset, kupo")
+}

bot/settings_banlist.go

@@ -0,0 +1,74 @@
+package bot
+
+import (
+	"net"
+	"time"
+
+	"gitlab.com/etke.cc/postmoogle/utils"
+)
+
+// account data key
+const acBanlistKey = "cc.etke.postmoogle.banlist"
+
+type banList map[string]string
+
+// Slice returns slice of banlist items
+func (b banList) Slice() []string {
+	slice := make([]string, 0, len(b))
+	for item := range b {
+		slice = append(slice, item)
+	}
+
+	return slice
+}
+
+func (b banList) getKey(addr net.Addr) string {
+	key := addr.String()
+	host, _, _ := net.SplitHostPort(key) //nolint:errcheck // either way it's ok
+	if host != "" {
+		key = host
+	}
+	return key
+}
+
+// Has addr in banlist
+func (b banList) Has(addr net.Addr) bool {
+	_, ok := b[b.getKey(addr)]
+	return ok
+}
+
+// Add an addr to banlist
+func (b banList) Add(addr net.Addr) {
+	key := b.getKey(addr)
+	if _, ok := b[key]; ok {
+		return
+	}
+
+	b[key] = time.Now().UTC().Format(time.RFC1123Z)
+}
+
+// Remove an addr from banlist
+func (b banList) Remove(addr net.Addr) {
+	key := b.getKey(addr)
+	if _, ok := b[key]; !ok {
+		return
+	}
+
+	delete(b, key)
+}
+
+func (b *Bot) getBanlist() banList {
+	config, err := b.lp.GetAccountData(acBanlistKey)
+	if err != nil {
+		b.log.Error("cannot get banlist: %v", utils.UnwrapError(err))
+	}
+	if config == nil {
+		config = map[string]string{}
+	}
+
+	return config
+}
+
+func (b *Bot) setBanlist(cfg banList) error {
+	return utils.UnwrapError(b.lp.SetAccountData(acBanlistKey, cfg))
+}

bot/settings_bot.go

@@ -17,6 +17,7 @@ const (
 	botOptionDKIMPrivateKey = "dkim.pem"
 	botOptionQueueBatch     = "queue:batch"
 	botOptionQueueRetries   = "queue:retries"
+	botOptionBanlistEnabled = "banlist:enabled"
 )
 
 type botSettings map[string]string
@@ -50,6 +51,11 @@ func (s botSettings) CatchAll() string {
 	return s.Get(botOptionCatchAll)
 }
 
+// BanlistEnabled option
+func (s botSettings) BanlistEnabled() bool {
+	return utils.Bool(s.Get(botOptionBanlistEnabled))
+}
+
 // DKIMSignature (DNS TXT record)
 func (s botSettings) DKIMSignature() string {
 	return s.Get(botOptionDKIMSignature)

smtp/manager.go

@@ -40,6 +40,8 @@ type Manager struct {
 
 type matrixbot interface {
 	AllowAuth(string, string) bool
+	IsBanned(net.Addr) bool
+	Ban(net.Addr)
 	GetMapping(string) (id.RoomID, bool)
 	GetIFOptions(id.RoomID) utils.IncomingFilteringOptions
 	IncomingEmail(context.Context, *utils.Email) error

smtp/server.go

@@ -23,11 +23,17 @@ type mailServer struct {
 // Login used for outgoing mail submissions only (when you use postmoogle as smtp server in your scripts)
 func (m *mailServer) Login(state *smtp.ConnectionState, username, password string) (smtp.Session, error) {
 	m.log.Debug("Login state=%+v username=%+v", state, username)
+	if m.bot.IsBanned(state.RemoteAddr) {
+		return nil, errors.New("please, don't bother me anymore")
+	}
+
 	if !utils.AddressValid(username) {
+		m.bot.Ban(state.RemoteAddr)
 		return nil, errors.New("please, provide an email address")
 	}
 
 	if !m.bot.AllowAuth(username, password) {
+		m.bot.Ban(state.RemoteAddr)
 		return nil, errors.New("email or password is invalid")
 	}
 
@@ -44,6 +50,10 @@ func (m *mailServer) Login(state *smtp.ConnectionState, username, password strin
 // AnonymousLogin used for incoming mail submissions only
 func (m *mailServer) AnonymousLogin(state *smtp.ConnectionState) (smtp.Session, error) {
 	m.log.Debug("AnonymousLogin state=%+v", state)
+	if m.bot.IsBanned(state.RemoteAddr) {
+		return nil, errors.New("please, don't bother me anymore")
+	}
+
 	return &incomingSession{
 		ctx:          sentry.SetHubOnContext(context.Background(), sentry.CurrentHub().Clone()),
 		getRoomID:    m.bot.GetMapping,
@@ -51,6 +61,7 @@ func (m *mailServer) AnonymousLogin(state *smtp.ConnectionState) (smtp.Session,
 		receiveEmail: m.ReceiveEmail,
 		log:          m.log,
 		domains:      m.domains,
+		addr:         state.RemoteAddr,
 	}, nil
 }
 

smtp/session.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"io"
+	"net"
 
 	"github.com/emersion/go-smtp"
 	"github.com/getsentry/sentry-go"
@@ -21,9 +22,11 @@ type incomingSession struct {
 	getRoomID    func(string) (id.RoomID, bool)
 	getFilters   func(id.RoomID) utils.IncomingFilteringOptions
 	receiveEmail func(context.Context, *utils.Email) error
+	ban          func(net.Addr)
 	domains      []string
 
 	ctx  context.Context
+	addr net.Addr
 	to   string
 	from string
 }
@@ -31,6 +34,7 @@ type incomingSession struct {
 func (s *incomingSession) Mail(from string, opts smtp.MailOptions) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("from", from)
 	if !utils.AddressValid(from) {
+		s.ban(s.addr)
 		return errors.New("please, provide email address")
 	}
 	s.from = from
@@ -50,17 +54,20 @@ func (s *incomingSession) Rcpt(to string) error {
 	}
 	if !domainok {
 		s.log.Debug("wrong domain of %s", to)
+		s.ban(s.addr)
 		return smtp.ErrAuthRequired
 	}
 
 	roomID, ok := s.getRoomID(utils.Mailbox(to))
 	if !ok {
 		s.log.Debug("mapping for %s not found", to)
+		s.ban(s.addr)
 		return smtp.ErrAuthRequired
 	}
 
 	validations := s.getFilters(roomID)
 	if !validateEmail(s.from, s.to, s.log, validations) {
+		s.ban(s.addr)
 		return smtp.ErrAuthRequired
 	}