admin/gluetun
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Maintenance: improve error codes in IP routing

Browse Source
This commit is contained in:
Quentin McGaw
2021-05-10 17:33:31 +00:00
parent 5a0418bba6
commit 810ff62c26
5 changed files with 103 additions and 53 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
cmd/gluetun/main.go
View File

@@ -2,6 +2,7 @@ package main
import (
"context"
"errors"
"fmt"
"net"
"net/http"
@@ -45,6 +46,10 @@ var (
buildDate = "an unknown date"
)
var (
errSetupRouting = errors.New("cannot setup routing")
)
func main() {
buildInfo := models.BuildInformation{
Version: version,
@@ -204,12 +209,12 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
firewallConf.SetNetworkInformation(defaultInterface, defaultGateway, localNetworks, defaultIP)
if err := routingConf.Setup(); err != nil {
return err
return fmt.Errorf("%w: %s", errSetupRouting, err)
}
defer func() {
routingConf.SetVerbose(false)
if err := routingConf.TearDown(); err != nil {
logger.Error(err)
logger.Error("cannot teardown routing: " + err.Error())
}
}()

37
internal/routing/enable.go
View File

@@ -1,28 +1,33 @@
package routing
import (
"errors"
"fmt"
"net"
)
var (
ErrSetup = fmt.Errorf("cannot setup routing")
ErrTeardown = fmt.Errorf("cannot teardown routing")
)
const (
table = 200
priority = 100
)
var (
ErrDefaultIP = errors.New("cannot get default IP address")
ErrDefaultRoute = errors.New("cannot get default route")
ErrIPRuleAdd = errors.New("cannot add IP rule")
ErrIPRuleDelete = errors.New("cannot delete IP rule")
ErrRouteAdd = errors.New("cannot add route")
ErrSubnetsOutboundSet = errors.New("cannot set outbound subnets routes")
)
func (r *routing) Setup() (err error) {
defaultIP, err := r.DefaultIP()
if err != nil {
return fmt.Errorf("%s: %w", ErrSetup, err)
return fmt.Errorf("%w: %s", ErrDefaultIP, err)
}
defaultInterfaceName, defaultGateway, err := r.DefaultRoute()
if err != nil {
return fmt.Errorf("%s: %w", ErrSetup, err)
return fmt.Errorf("%w: %s", ErrDefaultRoute, err)
}
defer func() {
@@ -30,22 +35,22 @@ func (r *routing) Setup() (err error) {
return
}
if err := r.TearDown(); err != nil {
r.logger.Error(err)
r.logger.Error("cannot reverse routing changes: " + err.Error())
}
}()
if err := r.addIPRule(defaultIP, table, priority); err != nil {
return fmt.Errorf("%s: %w", ErrSetup, err)
return fmt.Errorf("%w: %s", ErrIPRuleAdd, err)
}
defaultDestination := net.IPNet{IP: net.IPv4(0, 0, 0, 0), Mask: net.IPv4Mask(0, 0, 0, 0)}
if err := r.addRouteVia(defaultDestination, defaultGateway, defaultInterfaceName, table); err != nil {
return fmt.Errorf("%s: %w", ErrSetup, err)
return fmt.Errorf("%w: %s", ErrRouteAdd, err)
}
r.stateMutex.RLock()
outboundSubnets := r.outboundSubnets
r.stateMutex.RUnlock()
if err := r.setOutboundRoutes(outboundSubnets, defaultInterfaceName, defaultGateway); err != nil {
return fmt.Errorf("%s: %w", ErrSetup, err)
return fmt.Errorf("%w: %s", ErrSubnetsOutboundSet, err)
}
return nil
@@ -54,23 +59,23 @@ func (r *routing) Setup() (err error) {
func (r *routing) TearDown() error {
defaultIP, err := r.DefaultIP()
if err != nil {
return fmt.Errorf("%s: %w", ErrTeardown, err)
return fmt.Errorf("%w: %s", ErrDefaultIP, err)
}
defaultInterfaceName, defaultGateway, err := r.DefaultRoute()
if err != nil {
return fmt.Errorf("%s: %w", ErrTeardown, err)
return fmt.Errorf("%w: %s", ErrDefaultRoute, err)
}
defaultNet := net.IPNet{IP: net.IPv4(0, 0, 0, 0), Mask: net.IPv4Mask(0, 0, 0, 0)}
if err := r.deleteRouteVia(defaultNet, defaultGateway, defaultInterfaceName, table); err != nil {
return fmt.Errorf("%s: %w", ErrTeardown, err)
return fmt.Errorf("%w: %s", ErrRouteDelete, err)
}
if err := r.deleteIPRule(defaultIP, table, priority); err != nil {
return fmt.Errorf("%s: %w", ErrTeardown, err)
return fmt.Errorf("%w: %s", ErrIPRuleDelete, err)
}
if err := r.setOutboundRoutes(nil, defaultInterfaceName, defaultGateway); err != nil {
return fmt.Errorf("%s: %w", ErrSetup, err)
return fmt.Errorf("%w: %s", ErrSubnetsOutboundSet, err)
}
return nil

31
internal/routing/mutate.go
View File

@@ -2,12 +2,20 @@ package routing
import (
"bytes"
"errors"
"fmt"
"net"
"github.com/vishvananda/netlink"
)
var (
ErrRouteReplace = errors.New("cannot replace route")
ErrRouteDelete = errors.New("cannot delete route")
ErrRuleAdd = errors.New("cannot add routing rule")
ErrRuleDel = errors.New("cannot delete routing rule")
)
func (r *routing) addRouteVia(destination net.IPNet, gateway net.IP, iface string, table int) error {
destinationStr := destination.String()
if r.verbose {
@@ -19,7 +27,7 @@ func (r *routing) addRouteVia(destination net.IPNet, gateway net.IP, iface strin
link, err := netlink.LinkByName(iface)
if err != nil {
return fmt.Errorf("cannot add route for %s: %w", destinationStr, err)
return fmt.Errorf("%w: interface %s: %s", ErrLinkByName, iface, err)
}
route := netlink.Route{
Dst: &destination,
@@ -28,7 +36,8 @@ func (r *routing) addRouteVia(destination net.IPNet, gateway net.IP, iface strin
Table: table,
}
if err := netlink.RouteReplace(&route); err != nil {
return fmt.Errorf("cannot add route for %s: %w", destinationStr, err)
return fmt.Errorf("%w: for subnet %s at interface %s: %s",
ErrRouteReplace, destinationStr, iface, err)
}
return nil
}
@@ -44,7 +53,7 @@ func (r *routing) deleteRouteVia(destination net.IPNet, gateway net.IP, iface st
link, err := netlink.LinkByName(iface)
if err != nil {
return fmt.Errorf("cannot delete route for %s: %w", destinationStr, err)
return fmt.Errorf("%w: for interface %s: %s", ErrLinkByName, iface, err)
}
route := netlink.Route{
Dst: &destination,
@@ -53,7 +62,8 @@ func (r *routing) deleteRouteVia(destination net.IPNet, gateway net.IP, iface st
Table: table,
}
if err := netlink.RouteDel(&route); err != nil {
return fmt.Errorf("cannot delete route for %s: %w", destinationStr, err)
return fmt.Errorf("%w: for subnet %s at interface %s: %s",
ErrRouteDelete, destinationStr, iface, err)
}
return nil
}
@@ -71,7 +81,7 @@ func (r *routing) addIPRule(src net.IP, table, priority int) error {
rules, err := netlink.RuleList(netlink.FAMILY_ALL)
if err != nil {
return fmt.Errorf("cannot add ip rule: %w", err)
return fmt.Errorf("%w: %s", ErrRulesList, err)
}
for _, existingRule := range rules {
if existingRule.Src != nil &&
@@ -83,7 +93,10 @@ func (r *routing) addIPRule(src net.IP, table, priority int) error {
}
}
return netlink.RuleAdd(rule)
if err := netlink.RuleAdd(rule); err != nil {
return fmt.Errorf("%w: for rule %q: %s", ErrRuleAdd, rule, err)
}
return nil
}
func (r *routing) deleteIPRule(src net.IP, table, priority int) error {
@@ -99,7 +112,7 @@ func (r *routing) deleteIPRule(src net.IP, table, priority int) error {
rules, err := netlink.RuleList(netlink.FAMILY_ALL)
if err != nil {
return fmt.Errorf("cannot add ip rule: %w", err)
return fmt.Errorf("%w: %s", ErrRulesList, err)
}
for _, existingRule := range rules {
if existingRule.Src != nil &&
@@ -107,7 +120,9 @@ func (r *routing) deleteIPRule(src net.IP, table, priority int) error {
bytes.Equal(existingRule.Src.Mask, rule.Src.Mask) &&
existingRule.Priority == rule.Priority &&
existingRule.Table == rule.Table {
return netlink.RuleDel(rule)
if err := netlink.RuleDel(rule); err != nil {
return fmt.Errorf("%w: for rule %q: %s", ErrRuleDel, rule, err)
}
}
}
return nil

11
internal/routing/outboundsubnets.go
View File

@@ -1,14 +1,19 @@
package routing
import (
"errors"
"fmt"
"net"
)
var (
ErrAddOutboundSubnet = errors.New("cannot add outbound subnet to routes")
)
func (r *routing) SetOutboundRoutes(outboundSubnets []net.IPNet) error {
defaultInterface, defaultGateway, err := r.DefaultRoute()
if err != nil {
return fmt.Errorf("cannot set oubtound subnets in routing: %w", err)
return err
}
return r.setOutboundRoutes(outboundSubnets, defaultInterface, defaultGateway)
}
@@ -27,7 +32,7 @@ func (r *routing) setOutboundRoutes(outboundSubnets []net.IPNet,
r.removeOutboundSubnets(subnetsToRemove, defaultInterfaceName, defaultGateway)
if err := r.addOutboundSubnets(subnetsToAdd, defaultInterfaceName, defaultGateway); err != nil {
return fmt.Errorf("cannot set outbound subnets in routing: %w", err)
return err
}
return nil
@@ -50,7 +55,7 @@ func (r *routing) addOutboundSubnets(subnets []net.IPNet,
for _, subnet := range subnets {
const table = 0
if err := r.addRouteVia(subnet, defaultGateway, defaultInterfaceName, table); err != nil {
return fmt.Errorf("cannot add outbound subnet %s to routing: %w", subnet, err)
return fmt.Errorf("%w: %s: %s", ErrAddOutboundSubnet, subnet, err)
}
r.outboundSubnets = append(r.outboundSubnets, subnet)
}

68
internal/routing/reader.go
View File

@@ -2,6 +2,7 @@ package routing
import (
"bytes"
"errors"
"fmt"
"net"
@@ -15,10 +16,28 @@ type LocalNetwork struct {
IP net.IP
}
var (
ErrInterfaceIPNotFound = errors.New("IP address not found for interface")
ErrInterfaceListAddr = errors.New("cannot list interface addresses")
ErrInterfaceNotFound = errors.New("network interface not found")
ErrLinkByIndex = errors.New("cannot obtain link by index")
ErrLinkByName = errors.New("cannot obtain link by name")
ErrLinkDefaultNotFound = errors.New("default link not found")
ErrLinkList = errors.New("cannot list links")
ErrLinkLocalNotFound = errors.New("local link not found")
ErrRouteDefaultNotFound = errors.New("default route not found")
ErrRoutesList = errors.New("cannot list routes")
ErrRulesList = errors.New("cannot list rules")
ErrSubnetDefaultNotFound = errors.New("default subnet not found")
ErrSubnetLocalNotFound = errors.New("local subnet not found")
ErrVPNDestinationIPNotFound = errors.New("VPN destination IP address not found")
ErrVPNLocalGatewayIPNotFound = errors.New("VPN local gateway IP address not found")
)
func (r *routing) DefaultRoute() (defaultInterface string, defaultGateway net.IP, err error) {
routes, err := netlink.RouteList(nil, netlink.FAMILY_ALL)
if err != nil {
return "", nil, fmt.Errorf("cannot list routes: %w", err)
return "", nil, fmt.Errorf("%w: %s", ErrRoutesList, err)
}
for _, route := range routes {
if route.Dst == nil {
@@ -26,7 +45,7 @@ func (r *routing) DefaultRoute() (defaultInterface string, defaultGateway net.IP
linkIndex := route.LinkIndex
link, err := netlink.LinkByIndex(linkIndex)
if err != nil {
return "", nil, fmt.Errorf("cannot obtain link with index %d for default route: %w", linkIndex, err)
return "", nil, fmt.Errorf("%w: for default route at index %d: %s", ErrLinkByIndex, linkIndex, err)
}
attributes := link.Attrs()
defaultInterface = attributes.Name
@@ -36,13 +55,13 @@ func (r *routing) DefaultRoute() (defaultInterface string, defaultGateway net.IP
return defaultInterface, defaultGateway, nil
}
}
return "", nil, fmt.Errorf("cannot find default route in %d routes", len(routes))
return "", nil, fmt.Errorf("%w: in %d route(s)", ErrRouteDefaultNotFound, len(routes))
}
func (r *routing) DefaultIP() (ip net.IP, err error) {
routes, err := netlink.RouteList(nil, netlink.FAMILY_ALL)
if err != nil {
return nil, fmt.Errorf("cannot get default IP address: %w", err)
return nil, fmt.Errorf("%w: %s", ErrRoutesList, err)
}
defaultLinkName := ""
@@ -51,13 +70,13 @@ func (r *routing) DefaultIP() (ip net.IP, err error) {
linkIndex := route.LinkIndex
link, err := netlink.LinkByIndex(linkIndex)
if err != nil {
return nil, fmt.Errorf("cannot get default IP address: %w", err)
return nil, fmt.Errorf("%w: for default route at index %d: %s", ErrLinkByIndex, linkIndex, err)
}
defaultLinkName = link.Attrs().Name
}
}
if len(defaultLinkName) == 0 {
return nil, fmt.Errorf("cannot find default link name in %d routes", len(routes))
return nil, fmt.Errorf("%w: in %d route(s)", ErrLinkDefaultNotFound, len(routes))
}
return r.assignedIP(defaultLinkName)
@@ -66,7 +85,7 @@ func (r *routing) DefaultIP() (ip net.IP, err error) {
func (r *routing) LocalSubnet() (defaultSubnet net.IPNet, err error) {
routes, err := netlink.RouteList(nil, netlink.FAMILY_ALL)
if err != nil {
return defaultSubnet, fmt.Errorf("cannot find local subnet: %w", err)
return defaultSubnet, fmt.Errorf("%w: %s", ErrRoutesList, err)
}
defaultLinkIndex := -1
@@ -77,7 +96,7 @@ func (r *routing) LocalSubnet() (defaultSubnet net.IPNet, err error) {
}
}
if defaultLinkIndex == -1 {
return defaultSubnet, fmt.Errorf("cannot find local subnet: cannot find default link")
return defaultSubnet, fmt.Errorf("%w: in %d route(s)", ErrLinkDefaultNotFound, len(routes))
}
for _, route := range routes {
@@ -91,13 +110,13 @@ func (r *routing) LocalSubnet() (defaultSubnet net.IPNet, err error) {
return defaultSubnet, nil
}
return defaultSubnet, fmt.Errorf("cannot find default subnet in %d routes", len(routes))
return defaultSubnet, fmt.Errorf("%w: in %d routes", ErrSubnetDefaultNotFound, len(routes))
}
func (r *routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
links, err := netlink.LinkList()
if err != nil {
return localNetworks, fmt.Errorf("cannot find local subnet: %w", err)
return localNetworks, fmt.Errorf("%w: %s", ErrLinkList, err)
}
localLinks := make(map[int]struct{})
@@ -114,12 +133,12 @@ func (r *routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
}
if len(localLinks) == 0 {
return localNetworks, fmt.Errorf("cannot find any local interfaces")
return localNetworks, fmt.Errorf("%w: in %d links", ErrLinkLocalNotFound, len(links))
}
routes, err := netlink.RouteList(nil, netlink.FAMILY_V4)
if err != nil {
return localNetworks, fmt.Errorf("cannot list local routes: %w", err)
return localNetworks, fmt.Errorf("%w: %s", ErrRoutesList, err)
}
for _, route := range routes {
@@ -138,14 +157,14 @@ func (r *routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
link, err := netlink.LinkByIndex(route.LinkIndex)
if err != nil {
return localNetworks, fmt.Errorf("cannot get link by index: %w", err)
return localNetworks, fmt.Errorf("%w: at index %d: %s", ErrLinkByIndex, route.LinkIndex, err)
}
localNet.InterfaceName = link.Attrs().Name
ip, err := r.assignedIP(localNet.InterfaceName)
if err != nil {
return localNetworks, fmt.Errorf("cannot get IP assigned to link: %w", err)
return localNetworks, err
}
localNet.IP = ip
@@ -154,7 +173,7 @@ func (r *routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
}
if len(localNetworks) == 0 {
return localNetworks, fmt.Errorf("cannot find any local networks across %d routes", len(routes))
return localNetworks, fmt.Errorf("%w: in %d routes", ErrSubnetLocalNotFound, len(routes))
}
return localNetworks, nil
@@ -163,11 +182,11 @@ func (r *routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
func (r *routing) assignedIP(interfaceName string) (ip net.IP, err error) {
iface, err := net.InterfaceByName(interfaceName)
if err != nil {
return nil, err
return nil, fmt.Errorf("%w: %s: %s", ErrInterfaceNotFound, interfaceName, err)
}
addresses, err := iface.Addrs()
if err != nil {
return nil, err
return nil, fmt.Errorf("%w: %s: %s", ErrInterfaceListAddr, interfaceName, err)
}
for _, address := range addresses {
switch value := address.(type) {
@@ -177,13 +196,14 @@ func (r *routing) assignedIP(interfaceName string) (ip net.IP, err error) {
return value.IP, nil
}
}
return nil, fmt.Errorf("IP address not found in addresses of interface %s", interfaceName)
return nil, fmt.Errorf("%w: interface %s in %d addresses",
ErrInterfaceIPNotFound, interfaceName, len(addresses))
}
func (r *routing) VPNDestinationIP() (ip net.IP, err error) {
routes, err := netlink.RouteList(nil, netlink.FAMILY_ALL)
if err != nil {
return nil, fmt.Errorf("cannot find VPN destination IP: %w", err)
return nil, fmt.Errorf("%w: %s", ErrRoutesList, err)
}
defaultLinkIndex := -1
@@ -194,7 +214,7 @@ func (r *routing) VPNDestinationIP() (ip net.IP, err error) {
}
}
if defaultLinkIndex == -1 {
return nil, fmt.Errorf("cannot find VPN destination IP: cannot find default link")
return nil, fmt.Errorf("%w: in %d route(s)", ErrLinkDefaultNotFound, len(routes))
}
for _, route := range routes {
@@ -205,18 +225,18 @@ func (r *routing) VPNDestinationIP() (ip net.IP, err error) {
return route.Dst.IP, nil
}
}
return nil, fmt.Errorf("cannot find VPN destination IP address from ip routes")
return nil, fmt.Errorf("%w: in %d routes", ErrVPNDestinationIPNotFound, len(routes))
}
func (r *routing) VPNLocalGatewayIP() (ip net.IP, err error) {
routes, err := netlink.RouteList(nil, netlink.FAMILY_ALL)
if err != nil {
return nil, fmt.Errorf("cannot find VPN local gateway IP: %w", err)
return nil, fmt.Errorf("%w: %s", ErrRoutesList, err)
}
for _, route := range routes {
link, err := netlink.LinkByIndex(route.LinkIndex)
if err != nil {
return nil, fmt.Errorf("cannot find VPN local gateway IP: %w", err)
return nil, fmt.Errorf("%w: %s", ErrLinkByIndex, err)
}
interfaceName := link.Attrs().Name
if interfaceName == string(constants.TUN) &&
@@ -225,7 +245,7 @@ func (r *routing) VPNLocalGatewayIP() (ip net.IP, err error) {
return route.Gw, nil
}
}
return nil, fmt.Errorf("cannot find VPN local gateway IP address from ip routes")
return nil, fmt.Errorf("%w: in %d routes", ErrVPNLocalGatewayIPNotFound, len(routes))
}
func IPIsPrivate(ip net.IP) bool {