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Maintenance: improve error codes in IP routing

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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
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68
internal/routing/reader.go
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@@ -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 {