Cleanup route handling (#542)

* mikrotik: allow to set DNS, wip: handle routes in wg-controller

* replace old route handling for local controller

* cleanup route handling for local backend

* implement route handling for mikrotik controller

internal/adapters/wgcontroller/local.go

@@ -9,6 +9,7 @@ import (
 	"log/slog"
 	"os"
 	"os/exec"
+	"slices"
 	"strings"
 	"time"
 
@@ -84,8 +85,8 @@ func NewLocalController(cfg *config.Config) (*LocalController, error) {
 		wg: wg,
 		nl: nl,
 
-		shellCmd:              "bash", // we only support bash at the moment
-		resolvConfIfacePrefix: "tun.", // WireGuard interfaces have a tun. prefix in resolvconf
+		shellCmd:              "bash",                            // we only support bash at the moment
+		resolvConfIfacePrefix: cfg.Backend.LocalResolvconfPrefix, // WireGuard interfaces have a tun. prefix in resolvconf
 	}
 
 	return repo, nil
@@ -546,7 +547,11 @@ func (c LocalController) deletePeer(deviceId domain.InterfaceIdentifier, id doma
 
 // region wg-quick-related
 
-func (c LocalController) ExecuteInterfaceHook(id domain.InterfaceIdentifier, hookCmd string) error {
+func (c LocalController) ExecuteInterfaceHook(
+	_ context.Context,
+	id domain.InterfaceIdentifier,
+	hookCmd string,
+) error {
 	if hookCmd == "" {
 		return nil
 	}
@@ -560,7 +565,7 @@ func (c LocalController) ExecuteInterfaceHook(id domain.InterfaceIdentifier, hoo
 	return nil
 }
 
-func (c LocalController) SetDNS(id domain.InterfaceIdentifier, dnsStr, dnsSearchStr string) error {
+func (c LocalController) SetDNS(_ context.Context, id domain.InterfaceIdentifier, dnsStr, dnsSearchStr string) error {
 	if dnsStr == "" && dnsSearchStr == "" {
 		return nil
 	}
@@ -589,7 +594,7 @@ func (c LocalController) SetDNS(id domain.InterfaceIdentifier, dnsStr, dnsSearch
 	return nil
 }
 
-func (c LocalController) UnsetDNS(id domain.InterfaceIdentifier) error {
+func (c LocalController) UnsetDNS(_ context.Context, id domain.InterfaceIdentifier, _, _ string) error {
 	dnsCommand := "resolvconf -d %resPref%i -f"
 
 	err := c.exec(dnsCommand, id)
@@ -611,7 +616,7 @@ func (c LocalController) exec(command string, interfaceId domain.InterfaceIdenti
 	if len(stdin) > 0 {
 		b := &bytes.Buffer{}
 		for _, ln := range stdin {
-			if _, err := fmt.Fprint(b, ln); err != nil {
+			if _, err := fmt.Fprint(b, ln+"\n"); err != nil {
 				return err
 			}
 		}
@@ -619,6 +624,8 @@ func (c LocalController) exec(command string, interfaceId domain.InterfaceIdenti
 	}
 	out, err := cmd.CombinedOutput() // execute and wait for output
 	if err != nil {
+		slog.Warn("failed to executed shell command",
+			"command", commandWithInterfaceName, "stdin", stdin, "output", string(out), "error", err)
 		return fmt.Errorf("failed to exexute shell command %s: %w", commandWithInterfaceName, err)
 	}
 	slog.Debug("executed shell command",
@@ -631,49 +638,116 @@ func (c LocalController) exec(command string, interfaceId domain.InterfaceIdenti
 
 // region routing-related
 
-func (c LocalController) SyncRouteRules(_ context.Context, rules []domain.RouteRule) error {
-	// update fwmark rules
-	if err := c.setFwMarkRules(rules); err != nil {
-		return err
+// SetRoutes sets the routes for the given interface. If no routes are provided, the function is a no-op.
+func (c LocalController) SetRoutes(_ context.Context, info domain.RoutingTableInfo) error {
+	interfaceId := info.Interface.Identifier
+	slog.Debug("setting linux routes", "interface", interfaceId, "table", info.Table, "fwMark", info.FwMark,
+		"cidrs", info.AllowedIps)
+
+	link, err := c.nl.LinkByName(string(interfaceId))
+	if err != nil {
+		return fmt.Errorf("failed to find physical link for %s: %w", interfaceId, err)
 	}
 
-	// update main rule
-	if err := c.setMainRule(rules); err != nil {
-		return err
+	cidrsV4, cidrsV6 := domain.CidrsPerFamily(info.AllowedIps)
+	realTable, realFwMark, err := c.getOrCreateRoutingTableAndFwMark(link, info.Table, info.FwMark)
+	if err != nil {
+		return fmt.Errorf("failed to get or create routing table and fwmark for %s: %w", interfaceId, err)
+	}
+	wgDev, err := c.wg.Device(string(interfaceId))
+	if err != nil {
+		return fmt.Errorf("failed to get wg device for %s: %w", interfaceId, err)
+	}
+	currentFwMark := wgDev.FirewallMark
+	if int(realFwMark) != currentFwMark {
+		slog.Debug("updating fwmark for interface", "interface", interfaceId, "oldFwMark", currentFwMark,
+			"newFwMark", realFwMark, "oldTable", info.Table, "newTable", realTable)
+		if err := c.updateFwMarkOnInterface(interfaceId, int(realFwMark)); err != nil {
+			return fmt.Errorf("failed to update fwmark for interface %s to %d: %w", interfaceId, realFwMark, err)
+		}
 	}
 
-	// cleanup old main rules
-	if err := c.cleanupMainRule(rules); err != nil {
-		return err
+	if err := c.setRoutesForFamily(interfaceId, link, netlink.FAMILY_V4, realTable, realFwMark, cidrsV4); err != nil {
+		return fmt.Errorf("failed to set v4 routes: %w", err)
+	}
+	if err := c.setRoutesForFamily(interfaceId, link, netlink.FAMILY_V6, realTable, realFwMark, cidrsV6); err != nil {
+		return fmt.Errorf("failed to set v6 routes: %w", err)
 	}
 
 	return nil
 }
 
-func (c LocalController) setFwMarkRules(rules []domain.RouteRule) error {
-	for _, rule := range rules {
-		existingRules, err := c.nl.RuleList(int(rule.IpFamily))
+func (c LocalController) setRoutesForFamily(
+	interfaceId domain.InterfaceIdentifier,
+	link netlink.Link,
+	family int,
+	table int,
+	fwMark uint32,
+	cidrs []domain.Cidr,
+) error {
+	// first create or update the routes
+	for _, cidr := range cidrs {
+		err := c.nl.RouteReplace(&netlink.Route{
+			LinkIndex: link.Attrs().Index,
+			Dst:       cidr.IpNet(),
+			Table:     table,
+			Scope:     unix.RT_SCOPE_LINK,
+			Type:      unix.RTN_UNICAST,
+		})
 		if err != nil {
-			return fmt.Errorf("failed to get existing rules for family %s: %w", rule.IpFamily, err)
+			return fmt.Errorf("failed to add/update route %s on table %d for interface %s: %w",
+				cidr.String(), table, interfaceId, err)
 		}
+	}
 
-		ruleExists := false
-		for _, existingRule := range existingRules {
-			if rule.FwMark == existingRule.Mark && rule.Table == existingRule.Table {
-				ruleExists = true
-				break
+	// next remove old routes
+	rawRoutes, err := c.nl.RouteListFiltered(family, &netlink.Route{
+		LinkIndex: link.Attrs().Index,
+		Table:     unix.RT_TABLE_UNSPEC, // all tables
+		Scope:     unix.RT_SCOPE_LINK,
+		Type:      unix.RTN_UNICAST,
+	}, netlink.RT_FILTER_TABLE|netlink.RT_FILTER_TYPE|netlink.RT_FILTER_OIF)
+	if err != nil {
+		return fmt.Errorf("failed to fetch raw routes for interface %s and family-id %d: %w",
+			interfaceId, family, err)
+	}
+	for _, rawRoute := range rawRoutes {
+		if rawRoute.Dst == nil { // handle default route
+			var netlinkAddr domain.Cidr
+			if family == netlink.FAMILY_V4 {
+				netlinkAddr, _ = domain.CidrFromString("0.0.0.0/0")
+			} else {
+				netlinkAddr, _ = domain.CidrFromString("::/0")
 			}
+			rawRoute.Dst = netlinkAddr.IpNet()
 		}
 
-		if ruleExists {
-			continue // rule already exists, no need to recreate it
+		route := domain.CidrFromIpNet(*rawRoute.Dst)
+		if slices.Contains(cidrs, route) {
+			continue
 		}
 
-		// create a missing rule
+		if err := c.nl.RouteDel(&rawRoute); err != nil {
+			return fmt.Errorf("failed to remove deprecated route %s from interface %s: %w", route, interfaceId, err)
+		}
+	}
+
+	// next, update route rules for normal routes
+	if table == 0 {
+		return nil // no need to update route rules as we are using the default table
+	}
+	existingRules, err := c.nl.RuleList(family)
+	if err != nil {
+		return fmt.Errorf("failed to get existing rules for family-id %d: %w", family, err)
+	}
+	ruleExists := slices.ContainsFunc(existingRules, func(rule netlink.Rule) bool {
+		return rule.Mark == fwMark && rule.Table == table
+	})
+	if !ruleExists {
 		if err := c.nl.RuleAdd(&netlink.Rule{
-			Family:            int(rule.IpFamily),
-			Table:             rule.Table,
-			Mark:              rule.FwMark,
+			Family:            family,
+			Table:             table,
+			Mark:              fwMark,
 			Invert:            true,
 			SuppressIfgroup:   -1,
 			SuppressPrefixlen: -1,
@@ -682,15 +756,102 @@ func (c LocalController) setFwMarkRules(rules []domain.RouteRule) error {
 			Goto:              -1,
 			Flow:              -1,
 		}); err != nil {
-			return fmt.Errorf("failed to setup %s rule for fwmark %d and table %d: %w",
-				rule.IpFamily, rule.FwMark, rule.Table, err)
+			return fmt.Errorf("failed to setup rule for fwmark %d and table %d for family-id %d: %w",
+				fwMark, table, family, err)
 		}
 	}
+	mainRuleExists := slices.ContainsFunc(existingRules, func(rule netlink.Rule) bool {
+		return rule.SuppressPrefixlen == 0 && rule.Table == unix.RT_TABLE_MAIN
+	})
+	if !mainRuleExists && domain.ContainsDefaultRoute(cidrs) {
+		err = c.nl.RuleAdd(&netlink.Rule{
+			Family:            family,
+			Table:             unix.RT_TABLE_MAIN,
+			SuppressIfgroup:   -1,
+			SuppressPrefixlen: 0,
+			Priority:          c.getMainRulePriority(existingRules),
+			Mark:              0,
+			Mask:              nil,
+			Goto:              -1,
+			Flow:              -1,
+		})
+	}
+
+	// finally, clean up extra main rules - only one rule is allowed
+	existingRules, err = c.nl.RuleList(family)
+	if err != nil {
+		return fmt.Errorf("failed to get existing main rules for family-id %d: %w", family, err)
+	}
+	mainRuleCount := 0
+	for _, rule := range existingRules {
+		if rule.SuppressPrefixlen == 0 && rule.Table == unix.RT_TABLE_MAIN {
+			mainRuleCount++
+		}
+		if mainRuleCount > 1 {
+			if err := c.nl.RuleDel(&rule); err != nil {
+				return fmt.Errorf("failed to remove extra main rule for family-id %d: %w", family, err)
+			}
+		}
+	}
+
 	return nil
 }
 
+func (c LocalController) getOrCreateRoutingTableAndFwMark(
+	link netlink.Link,
+	tableIn int,
+	fwMarkIn uint32,
+) (
+	table int,
+	fwmark uint32,
+	err error,
+) {
+	table = tableIn
+	fwmark = fwMarkIn
+
+	if fwmark == 0 {
+		// generate a new (temporary) firewall mark based on the interface index
+		fwmark = uint32(c.cfg.Advanced.RouteTableOffset + link.Attrs().Index)
+	}
+	if table == 0 {
+		table = int(fwmark) // generate a new routing table base on interface index
+	}
+	return
+}
+
+func (c LocalController) updateFwMarkOnInterface(interfaceId domain.InterfaceIdentifier, fwMark int) error {
+	// apply the new fwmark to the wireguard interface
+	err := c.wg.ConfigureDevice(string(interfaceId), wgtypes.Config{
+		FirewallMark: &fwMark,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to update fwmark of interface %s to: %d: %w", interfaceId, fwMark, err)
+	}
+
+	return nil
+}
+
+func (c LocalController) getMainRulePriority(existingRules []netlink.Rule) int {
+	prio := c.cfg.Advanced.RulePrioOffset
+	for {
+		isFresh := true
+		for _, existingRule := range existingRules {
+			if existingRule.Priority == prio {
+				isFresh = false
+				break
+			}
+		}
+		if isFresh {
+			break
+		} else {
+			prio++
+		}
+	}
+	return prio
+}
+
 func (c LocalController) getRulePriority(existingRules []netlink.Rule) int {
-	prio := 32700 // linux main rule has a priority of 32766
+	prio := 32700 // linux main rule has a prio of 32766
 	for {
 		isFresh := true
 		for _, existingRule := range existingRules {
@@ -708,126 +869,145 @@ func (c LocalController) getRulePriority(existingRules []netlink.Rule) int {
 	return prio
 }
 
-func (c LocalController) setMainRule(rules []domain.RouteRule) error {
-	var family domain.IpFamily
-	shouldHaveMainRule := false
-	for _, rule := range rules {
-		family = rule.IpFamily
-		if rule.HasDefault == true {
-			shouldHaveMainRule = true
-			break
-		}
-	}
-	if !shouldHaveMainRule {
-		return nil
-	}
+// RemoveRoutes removes the routes for the given interface. If no routes are provided, the function is a no-op.
+func (c LocalController) RemoveRoutes(_ context.Context, info domain.RoutingTableInfo) error {
+	interfaceId := info.Interface.Identifier
+	slog.Debug("removing linux routes", "interface", interfaceId, "table", info.Table, "fwMark", info.FwMark,
+		"cidrs", info.AllowedIps)
 
-	existingRules, err := c.nl.RuleList(int(family))
+	wgDev, err := c.wg.Device(string(interfaceId))
 	if err != nil {
-		return fmt.Errorf("failed to get existing rules for family %s: %w", family, err)
+		slog.Debug("wg device already removed, route cleanup might be incomplete", "interface", interfaceId)
+		wgDev = nil
 	}
-
-	ruleExists := false
-	for _, existingRule := range existingRules {
-		if existingRule.Table == unix.RT_TABLE_MAIN && existingRule.SuppressPrefixlen == 0 {
-			ruleExists = true
-			break
-		}
-	}
-
-	if ruleExists {
-		return nil // rule already exists, skip re-creation
-	}
-
-	if err := c.nl.RuleAdd(&netlink.Rule{
-		Family:            int(family),
-		Table:             unix.RT_TABLE_MAIN,
-		SuppressIfgroup:   -1,
-		SuppressPrefixlen: 0,
-		Priority:          c.getMainRulePriority(existingRules),
-		Mark:              0,
-		Mask:              nil,
-		Goto:              -1,
-		Flow:              -1,
-	}); err != nil {
-		return fmt.Errorf("failed to setup rule for main table: %w", err)
-	}
-
-	return nil
-}
-
-func (c LocalController) getMainRulePriority(existingRules []netlink.Rule) int {
-	priority := c.cfg.Advanced.RulePrioOffset
-	for {
-		isFresh := true
-		for _, existingRule := range existingRules {
-			if existingRule.Priority == priority {
-				isFresh = false
-				break
-			}
-		}
-		if isFresh {
-			break
-		} else {
-			priority++
-		}
-	}
-	return priority
-}
-
-func (c LocalController) cleanupMainRule(rules []domain.RouteRule) error {
-	var family domain.IpFamily
-	for _, rule := range rules {
-		family = rule.IpFamily
-		break
-	}
-
-	existingRules, err := c.nl.RuleList(int(family))
+	link, err := c.nl.LinkByName(string(interfaceId))
 	if err != nil {
-		return fmt.Errorf("failed to get existing rules for family %s: %w", family, err)
+		slog.Debug("physical link already removed, route cleanup might be incomplete", "interface", interfaceId)
+		link = nil
 	}
 
-	shouldHaveMainRule := false
-	for _, rule := range rules {
-		if rule.HasDefault == true {
-			shouldHaveMainRule = true
-			break
+	fwMark := info.FwMark
+	if wgDev != nil && info.FwMark == 0 {
+		fwMark = uint32(wgDev.FirewallMark)
+	}
+	table := info.Table
+	if wgDev != nil && info.Table == 0 {
+		table = wgDev.FirewallMark // use the fwMark as table, this is the default behavior
+	}
+	linkIndex := -1
+	if link != nil {
+		linkIndex = link.Attrs().Index
+	}
+
+	cidrsV4, cidrsV6 := domain.CidrsPerFamily(info.AllowedIps)
+	realTable, realFwMark, err := c.getOrCreateRoutingTableAndFwMark(link, table, fwMark)
+	if err != nil {
+		return fmt.Errorf("failed to get or create routing table and fwmark for %s: %w", interfaceId, err)
+	}
+
+	if linkIndex > 0 {
+		err = c.removeRoutesForFamily(interfaceId, link, netlink.FAMILY_V4, realTable, realFwMark, cidrsV4)
+		if err != nil {
+			return fmt.Errorf("failed to remove v4 routes: %w", err)
+		}
+		err = c.removeRoutesForFamily(interfaceId, link, netlink.FAMILY_V6, realTable, realFwMark, cidrsV6)
+		if err != nil {
+			return fmt.Errorf("failed to remove v6 routes: %w", err)
 		}
 	}
 
-	mainRules := 0
-	for _, existingRule := range existingRules {
-		if existingRule.Table == unix.RT_TABLE_MAIN && existingRule.SuppressPrefixlen == 0 {
-			mainRules++
+	if table > 0 {
+		err = c.removeRouteRulesForTable(netlink.FAMILY_V4, realTable)
+		if err != nil {
+			return fmt.Errorf("failed to remove v4 route rules for %s: %w", interfaceId, err)
 		}
-	}
-
-	removalCount := 0
-	if mainRules > 1 {
-		removalCount = mainRules - 1 // we only want one single rule
-	}
-	if !shouldHaveMainRule {
-		removalCount = mainRules
-	}
-
-	for _, existingRule := range existingRules {
-		if existingRule.Table == unix.RT_TABLE_MAIN && existingRule.SuppressPrefixlen == 0 {
-			if removalCount > 0 {
-				existingRule.Family = int(family) // set family, somehow the RuleList method does not populate the family field
-				if err := c.nl.RuleDel(&existingRule); err != nil {
-					return fmt.Errorf("failed to delete main rule: %w", err)
-				}
-				removalCount--
-			}
+		err = c.removeRouteRulesForTable(netlink.FAMILY_V6, realTable)
+		if err != nil {
+			return fmt.Errorf("failed to remove v6 route rules for %s: %w", interfaceId, err)
 		}
 	}
 
 	return nil
 }
 
-func (c LocalController) DeleteRouteRules(_ context.Context, rules []domain.RouteRule) error {
-	// TODO implement me
-	panic("implement me")
+func (c LocalController) removeRoutesForFamily(
+	interfaceId domain.InterfaceIdentifier,
+	link netlink.Link,
+	family int,
+	table int,
+	fwMark uint32,
+	cidrs []domain.Cidr,
+) error {
+	// first remove all rules
+	existingRules, err := c.nl.RuleList(family)
+	if err != nil {
+		return fmt.Errorf("failed to get existing rules for family %d: %w", family, err)
+	}
+	for _, existingRule := range existingRules {
+		if fwMark == existingRule.Mark && table == existingRule.Table {
+			existingRule.Family = family // set family, somehow the RuleList method does not populate the family field
+			if err := c.nl.RuleDel(&existingRule); err != nil {
+				return fmt.Errorf("failed to delete old fwmark rule: %w", err)
+			}
+		}
+	}
+
+	// next remove all routes
+	rawRoutes, err := c.nl.RouteListFiltered(family, &netlink.Route{
+		LinkIndex: link.Attrs().Index,
+		Table:     unix.RT_TABLE_UNSPEC, // all tables
+		Scope:     unix.RT_SCOPE_LINK,
+		Type:      unix.RTN_UNICAST,
+	}, netlink.RT_FILTER_TABLE|netlink.RT_FILTER_TYPE|netlink.RT_FILTER_OIF)
+	if err != nil {
+		return fmt.Errorf("failed to fetch raw routes for interface %s and family-id %d: %w",
+			interfaceId, family, err)
+	}
+	for _, rawRoute := range rawRoutes {
+		if rawRoute.Dst == nil { // handle default route
+			var netlinkAddr domain.Cidr
+			if family == netlink.FAMILY_V4 {
+				netlinkAddr, _ = domain.CidrFromString("0.0.0.0/0")
+			} else {
+				netlinkAddr, _ = domain.CidrFromString("::/0")
+			}
+			rawRoute.Dst = netlinkAddr.IpNet()
+		}
+
+		if rawRoute.Table != table {
+			continue // ignore routes from other tables
+		}
+
+		route := domain.CidrFromIpNet(*rawRoute.Dst)
+		if !slices.Contains(cidrs, route) {
+			continue // only remove routes that were previously added
+		}
+
+		if err := c.nl.RouteDel(&rawRoute); err != nil {
+			return fmt.Errorf("failed to remove old route %s from interface %s: %w", route, interfaceId, err)
+		}
+	}
+
+	return nil
+}
+
+func (c LocalController) removeRouteRulesForTable(
+	family int,
+	table int,
+) error {
+	existingRules, err := c.nl.RuleList(family)
+	if err != nil {
+		return fmt.Errorf("failed to get existing route rules for family-id %d: %w", family, err)
+	}
+	for _, existingRule := range existingRules {
+		if existingRule.Table == table {
+			err := c.nl.RuleDel(&existingRule)
+			if err != nil {
+				return fmt.Errorf("failed to delete old rule for table %d and family-id %d: %w", table, family, err)
+			}
+		}
+	}
+	return nil
 }
 
 // endregion routing-related

internal/adapters/wgcontroller/mikrotik.go

@@ -15,6 +15,9 @@ import (
 	"github.com/h44z/wg-portal/internal/lowlevel"
 )
 
+const MikrotikRouteDistance = 5
+const MikrotikDefaultRoutingTable = "main"
+
 type MikrotikController struct {
 	coreCfg *config.Config
 	cfg     *config.BackendMikrotik
@@ -22,8 +25,9 @@ type MikrotikController struct {
 	client *lowlevel.MikrotikApiClient
 
 	// Add mutexes to prevent race conditions
-	interfaceMutexes sync.Map // map[domain.InterfaceIdentifier]*sync.Mutex
-	peerMutexes      sync.Map // map[domain.PeerIdentifier]*sync.Mutex
+	interfaceMutexes sync.Map   // map[domain.InterfaceIdentifier]*sync.Mutex
+	peerMutexes      sync.Map   // map[domain.PeerIdentifier]*sync.Mutex
+	coreMutex        sync.Mutex // for updating the core configuration such as routing table or DNS settings
 }
 
 func NewMikrotikController(coreCfg *config.Config, cfg *config.BackendMikrotik) (*MikrotikController, error) {
@@ -40,6 +44,7 @@ func NewMikrotikController(coreCfg *config.Config, cfg *config.BackendMikrotik)
 
 		interfaceMutexes: sync.Map{},
 		peerMutexes:      sync.Map{},
+		coreMutex:        sync.Mutex{},
 	}, nil
 }
 
@@ -763,33 +768,404 @@ func (c *MikrotikController) DeletePeer(
 
 // region wg-quick-related
 
-func (c *MikrotikController) ExecuteInterfaceHook(id domain.InterfaceIdentifier, hookCmd string) error {
+func (c *MikrotikController) ExecuteInterfaceHook(
+	_ context.Context,
+	_ domain.InterfaceIdentifier,
+	_ string,
+) error {
 	// TODO implement me
-	panic("implement me")
+	slog.Error("interface hooks are not yet supported for Mikrotik backends, please open an issue on GitHub")
+	return nil
 }
 
-func (c *MikrotikController) SetDNS(id domain.InterfaceIdentifier, dnsStr, dnsSearchStr string) error {
-	// TODO implement me
-	panic("implement me")
+func (c *MikrotikController) SetDNS(
+	ctx context.Context,
+	_ domain.InterfaceIdentifier,
+	dnsStr, _ string,
+) error {
+	// Lock the interface to prevent concurrent modifications
+	c.coreMutex.Lock()
+	defer c.coreMutex.Unlock()
+
+	// check if the server is already configured
+	wgReply := c.client.Get(ctx, "/ip/dns", &lowlevel.MikrotikRequestOptions{
+		PropList: []string{"servers"},
+	})
+	if wgReply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("unable to find WireGuard dns settings: %v", wgReply.Error)
+	}
+
+	var existingServers []string
+	existingServers = append(existingServers, strings.Split(wgReply.Data.GetString("servers"), ",")...)
+
+	newServers := strings.Split(dnsStr, ",")
+
+	mergedServers := slices.Clone(existingServers)
+	for _, s := range newServers {
+		if s == "" {
+			continue
+		}
+		if !slices.Contains(mergedServers, s) {
+			mergedServers = append(mergedServers, s)
+		}
+	}
+	mergedServersStr := strings.Join(mergedServers, ",")
+
+	reply := c.client.ExecList(ctx, "/ip/dns/set", lowlevel.GenericJsonObject{
+		"servers": mergedServersStr,
+	})
+	if reply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("failed to set DNS servers: %s: %v", mergedServersStr, reply.Error)
+	}
+
+	return nil
 }
 
-func (c *MikrotikController) UnsetDNS(id domain.InterfaceIdentifier) error {
-	// TODO implement me
-	panic("implement me")
+func (c *MikrotikController) UnsetDNS(
+	ctx context.Context,
+	_ domain.InterfaceIdentifier,
+	dnsStr, _ string,
+) error {
+	// Lock the interface to prevent concurrent modifications
+	c.coreMutex.Lock()
+	defer c.coreMutex.Unlock()
+
+	// retrieve current DNS settings
+	wgReply := c.client.Get(ctx, "/ip/dns", &lowlevel.MikrotikRequestOptions{
+		PropList: []string{"servers"},
+	})
+	if wgReply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("unable to find WireGuard dns settings: %v", wgReply.Error)
+	}
+
+	var existingServers []string
+	existingServers = append(existingServers, strings.Split(wgReply.Data.GetString("servers"), ",")...)
+
+	oldServers := strings.Split(dnsStr, ",")
+
+	mergedServers := make([]string, 0, len(existingServers))
+	for _, s := range existingServers {
+		if s == "" {
+			continue
+		}
+		if !slices.Contains(oldServers, s) {
+			mergedServers = append(mergedServers, s) // only keep the servers that are not in the old list
+		}
+	}
+	mergedServersStr := strings.Join(mergedServers, ",")
+
+	reply := c.client.ExecList(ctx, "/ip/dns/set", lowlevel.GenericJsonObject{
+		"servers": mergedServersStr,
+	})
+	if reply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("failed to set DNS servers: %s: %v", mergedServersStr, reply.Error)
+	}
+
+	return nil
 }
 
 // endregion wg-quick-related
 
 // region routing-related
 
-func (c *MikrotikController) SyncRouteRules(_ context.Context, rules []domain.RouteRule) error {
-	// TODO implement me
-	panic("implement me")
+// SetRoutes sets the routes for the given interface. If no routes are provided, the function is a no-op.
+func (c *MikrotikController) SetRoutes(ctx context.Context, info domain.RoutingTableInfo) error {
+	interfaceId := info.Interface.Identifier
+	slog.Debug("setting mikrotik routes", "interface", interfaceId, "table", info.TableStr, "cidrs", info.AllowedIps)
+
+	// Mikrotik needs some time to apply the changes.
+	// If we don't wait, the routes might get created multiple times as the dynamic routes are not yet available.
+	time.Sleep(2 * time.Second)
+
+	tableName, err := c.getOrCreateRoutingTables(ctx, info.Interface.Identifier, info.TableStr)
+	if err != nil {
+		return fmt.Errorf("failed to get or create routing table for %s: %v", interfaceId, err)
+	}
+
+	cidrsV4, cidrsV6 := domain.CidrsPerFamily(info.AllowedIps)
+
+	err = c.setRoutesForFamily(ctx, interfaceId, false, tableName, cidrsV4)
+	if err != nil {
+		return fmt.Errorf("failed to set IPv4 routes for %s: %v", interfaceId, err)
+	}
+
+	err = c.setRoutesForFamily(ctx, interfaceId, true, tableName, cidrsV6)
+	if err != nil {
+		return fmt.Errorf("failed to set IPv6 routes for %s: %v", interfaceId, err)
+	}
+
+	return nil
 }
 
-func (c *MikrotikController) DeleteRouteRules(_ context.Context, rules []domain.RouteRule) error {
-	// TODO implement me
-	panic("implement me")
+func (c *MikrotikController) resolveRouteTableName(name string) string {
+	name = strings.TrimSpace(name)
+
+	var mikrotikTableName string
+	switch strings.ToLower(name) {
+	case "", "0":
+		mikrotikTableName = MikrotikDefaultRoutingTable
+	case MikrotikDefaultRoutingTable:
+		return fmt.Sprintf("wgportal-%s",
+			MikrotikDefaultRoutingTable) // if the Mikrotik Main table should be used, the table-name should be left empty or set to "0".
+	default:
+		mikrotikTableName = name
+	}
+
+	return mikrotikTableName
+}
+
+func (c *MikrotikController) getOrCreateRoutingTables(
+	ctx context.Context,
+	interfaceId domain.InterfaceIdentifier,
+	table string,
+) (string, error) {
+	// retrieve current routing tables
+	wgReply := c.client.Query(ctx, "/routing/table", &lowlevel.MikrotikRequestOptions{
+		PropList: []string{
+			".id", "dynamic", "fib", "name",
+		},
+	})
+	if wgReply.Status != lowlevel.MikrotikApiStatusOk {
+		return "", fmt.Errorf("unable to query routing tables: %v", wgReply.Error)
+	}
+
+	wantedTableName := c.resolveRouteTableName(table)
+
+	// check if the table already exists
+	for _, table := range wgReply.Data {
+		if table.GetString("name") == wantedTableName {
+			return wantedTableName, nil // already exists, nothing to do
+		}
+	}
+
+	// create the table if it does not exist
+	createReply := c.client.Create(ctx, "/routing/table", lowlevel.GenericJsonObject{
+		"name":    wantedTableName,
+		"comment": fmt.Sprintf("Routing Table for %s", interfaceId),
+		"fib":     strconv.FormatBool(true),
+	})
+	if createReply.Status != lowlevel.MikrotikApiStatusOk {
+		return "", fmt.Errorf("failed to create routing table %s: %v", wantedTableName, createReply.Error)
+	}
+
+	return wantedTableName, nil
+}
+
+func (c *MikrotikController) setRoutesForFamily(
+	ctx context.Context,
+	interfaceId domain.InterfaceIdentifier,
+	ipV6 bool,
+	table string,
+	cidrs []domain.Cidr,
+) error {
+	apiPath := "/ip/route"
+	if ipV6 {
+		apiPath = "/ipv6/route"
+	}
+
+	// retrieve current routes
+	wgReply := c.client.Query(ctx, apiPath, &lowlevel.MikrotikRequestOptions{
+		PropList: []string{
+			".id", "disabled", "inactive", "distance", "dst-address", "dynamic", "gateway", "immediate-gw",
+			"routing-table", "scope", "target-scope", "client-dns", "comment", "disabled", "responder",
+		},
+		Filters: map[string]string{
+			"gateway": string(interfaceId),
+		},
+	})
+	if wgReply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("unable to find WireGuard IP route settings (v6=%t): %v", ipV6, wgReply.Error)
+	}
+
+	// first create or update the routes
+	for _, cidr := range cidrs {
+		// check if the route already exists
+		exists := false
+		for _, route := range wgReply.Data {
+			existingRoute, err := domain.CidrFromString(route.GetString("dst-address"))
+			if err != nil {
+				slog.Warn("failed to parse route destination address",
+					"cidr", route.GetString("dst-address"), "error", err)
+				continue
+			}
+			if existingRoute.EqualPrefix(cidr) && route.GetString("routing-table") == table {
+				exists = true
+				break
+			}
+		}
+		if exists {
+			continue // route already exists, nothing to do
+		}
+
+		// create the route
+		reply := c.client.Create(ctx, apiPath, lowlevel.GenericJsonObject{
+			"gateway":       string(interfaceId),
+			"dst-address":   cidr.String(),
+			"distance":      strconv.Itoa(MikrotikRouteDistance),
+			"disabled":      strconv.FormatBool(false),
+			"routing-table": table,
+		})
+		if reply.Status != lowlevel.MikrotikApiStatusOk {
+			return fmt.Errorf("failed to create new route %s via %s: %v", cidr.String(), interfaceId, reply.Error)
+		}
+	}
+
+	// finally, remove the routes that are not in the new list
+	for _, route := range wgReply.Data {
+		if route.GetBool("dynamic") {
+			continue // dynamic routes are not managed by the controller, nothing to do
+		}
+
+		existingRoute, err := domain.CidrFromString(route.GetString("dst-address"))
+		if err != nil {
+			slog.Warn("failed to parse route destination address",
+				"cidr", route.GetString("dst-address"), "error", err)
+			continue
+		}
+
+		valid := false
+		for _, cidr := range cidrs {
+			if existingRoute.EqualPrefix(cidr) {
+				valid = true
+				break
+			}
+		}
+		if valid {
+			continue // route is still valid, nothing to do
+		}
+
+		// remove the route
+		reply := c.client.Delete(ctx, apiPath+"/"+route.GetString(".id"))
+		if reply.Status != lowlevel.MikrotikApiStatusOk {
+			return fmt.Errorf("failed to remove outdated route %s: %v", existingRoute.String(), reply.Error)
+		}
+	}
+
+	return nil
+}
+
+// RemoveRoutes removes the routes for the given interface. If no routes are provided, the function is a no-op.
+func (c *MikrotikController) RemoveRoutes(ctx context.Context, info domain.RoutingTableInfo) error {
+	interfaceId := info.Interface.Identifier
+	slog.Debug("removing mikrotik routes", "interface", interfaceId, "table", info.TableStr, "cidrs", info.AllowedIps)
+
+	tableName := c.resolveRouteTableName(info.TableStr)
+
+	cidrsV4, cidrsV6 := domain.CidrsPerFamily(info.AllowedIps)
+
+	err := c.removeRoutesForFamily(ctx, interfaceId, false, tableName, cidrsV4)
+	if err != nil {
+		return fmt.Errorf("failed to remove IPv4 routes for %s: %v", interfaceId, err)
+	}
+
+	err = c.removeRoutesForFamily(ctx, interfaceId, true, tableName, cidrsV6)
+	if err != nil {
+		return fmt.Errorf("failed to remove IPv6 routes for %s: %v", interfaceId, err)
+	}
+
+	err = c.removeRoutingTable(ctx, tableName)
+	if err != nil {
+		return fmt.Errorf("failed to remove routing table for %s: %v", interfaceId, err)
+	}
+
+	return nil
+}
+
+func (c *MikrotikController) removeRoutesForFamily(
+	ctx context.Context,
+	interfaceId domain.InterfaceIdentifier,
+	ipV6 bool,
+	table string,
+	cidrs []domain.Cidr,
+) error {
+	apiPath := "/ip/route"
+	if ipV6 {
+		apiPath = "/ipv6/route"
+	}
+
+	// retrieve current routes
+	wgReply := c.client.Query(ctx, apiPath, &lowlevel.MikrotikRequestOptions{
+		PropList: []string{
+			".id", "disabled", "inactive", "distance", "dst-address", "dynamic", "gateway", "immediate-gw",
+			"routing-table", "scope", "target-scope", "client-dns", "comment", "disabled", "responder",
+		},
+		Filters: map[string]string{
+			"gateway": string(interfaceId),
+		},
+	})
+	if wgReply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("unable to find WireGuard IP route settings (v6=%t): %v", ipV6, wgReply.Error)
+	}
+
+	// remove the routes from the list
+	for _, route := range wgReply.Data {
+		if route.GetBool("dynamic") {
+			continue // dynamic routes are not managed by the controller, nothing to do
+		}
+
+		existingRoute, err := domain.CidrFromString(route.GetString("dst-address"))
+		if err != nil {
+			slog.Warn("failed to parse route destination address",
+				"cidr", route.GetString("dst-address"), "error", err)
+			continue
+		}
+
+		remove := false
+		for _, cidr := range cidrs {
+			if existingRoute.EqualPrefix(cidr) && route.GetString("routing-table") == table {
+				remove = true
+				break
+			}
+		}
+		if !remove {
+			continue // route is still valid, nothing to do
+		}
+
+		// remove the route
+		reply := c.client.Delete(ctx, apiPath+"/"+route.GetString(".id"))
+		if reply.Status != lowlevel.MikrotikApiStatusOk {
+			return fmt.Errorf("failed to remove old route %s: %v", existingRoute.String(), reply.Error)
+		}
+	}
+
+	return nil
+}
+
+func (c *MikrotikController) removeRoutingTable(
+	ctx context.Context,
+	table string,
+) error {
+	if table == MikrotikDefaultRoutingTable {
+		return nil // we cannot remove the default table
+	}
+
+	// retrieve current routing tables
+	wgReply := c.client.Query(ctx, "/routing/table", &lowlevel.MikrotikRequestOptions{
+		PropList: []string{
+			".id", "dynamic", "fib", "name",
+		},
+	})
+	if wgReply.Status != lowlevel.MikrotikApiStatusOk {
+		return fmt.Errorf("unable to query routing tables: %v", wgReply.Error)
+	}
+
+	for _, existingTable := range wgReply.Data {
+		if existingTable.GetBool("dynamic") {
+			continue // dynamic tables are not managed by the controller, nothing to do
+		}
+		if existingTable.GetString("name") != table {
+			continue // not the table we want to remove
+		}
+
+		// remove the table
+		reply := c.client.Delete(ctx, "/routing/table/"+existingTable.GetString(".id"))
+		if reply.Status != lowlevel.MikrotikApiStatusOk {
+			return fmt.Errorf("failed to remove routing table %s: %v", table, reply.Error)
+		}
+		return nil
+	}
+
+	return nil
 }
 
 // endregion routing-related