diff options
Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/util/net/interface.go')
| -rw-r--r-- | vendor/k8s.io/apimachinery/pkg/util/net/interface.go | 73 |
1 files changed, 57 insertions, 16 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/util/net/interface.go b/vendor/k8s.io/apimachinery/pkg/util/net/interface.go index daf5d2496..836494d57 100644 --- a/vendor/k8s.io/apimachinery/pkg/util/net/interface.go +++ b/vendor/k8s.io/apimachinery/pkg/util/net/interface.go @@ -36,6 +36,18 @@ const ( familyIPv6 AddressFamily = 6 ) +type AddressFamilyPreference []AddressFamily + +var ( + preferIPv4 = AddressFamilyPreference{familyIPv4, familyIPv6} + preferIPv6 = AddressFamilyPreference{familyIPv6, familyIPv4} +) + +const ( + // LoopbackInterfaceName is the default name of the loopback interface + LoopbackInterfaceName = "lo" +) + const ( ipv4RouteFile = "/proc/net/route" ipv6RouteFile = "/proc/net/ipv6_route" @@ -53,7 +65,7 @@ type RouteFile struct { parse func(input io.Reader) ([]Route, error) } -// noRoutesError can be returned by ChooseBindAddress() in case of no routes +// noRoutesError can be returned in case of no routes type noRoutesError struct { message string } @@ -254,7 +266,7 @@ func getIPFromInterface(intfName string, forFamily AddressFamily, nw networkInte return nil, nil } -// memberOF tells if the IP is of the desired family. Used for checking interface addresses. +// memberOf tells if the IP is of the desired family. Used for checking interface addresses. func memberOf(ip net.IP, family AddressFamily) bool { if ip.To4() != nil { return family == familyIPv4 @@ -265,8 +277,8 @@ func memberOf(ip net.IP, family AddressFamily) bool { // chooseIPFromHostInterfaces looks at all system interfaces, trying to find one that is up that // has a global unicast address (non-loopback, non-link local, non-point2point), and returns the IP. -// Searches for IPv4 addresses, and then IPv6 addresses. -func chooseIPFromHostInterfaces(nw networkInterfacer) (net.IP, error) { +// addressFamilies determines whether it prefers IPv4 or IPv6 +func chooseIPFromHostInterfaces(nw networkInterfacer, addressFamilies AddressFamilyPreference) (net.IP, error) { intfs, err := nw.Interfaces() if err != nil { return nil, err @@ -274,7 +286,7 @@ func chooseIPFromHostInterfaces(nw networkInterfacer) (net.IP, error) { if len(intfs) == 0 { return nil, fmt.Errorf("no interfaces found on host.") } - for _, family := range []AddressFamily{familyIPv4, familyIPv6} { + for _, family := range addressFamilies { klog.V(4).Infof("Looking for system interface with a global IPv%d address", uint(family)) for _, intf := range intfs { if !isInterfaceUp(&intf) { @@ -321,15 +333,19 @@ func chooseIPFromHostInterfaces(nw networkInterfacer) (net.IP, error) { // IP of the interface with a gateway on it (with priority given to IPv4). For a node // with no internet connection, it returns error. func ChooseHostInterface() (net.IP, error) { + return chooseHostInterface(preferIPv4) +} + +func chooseHostInterface(addressFamilies AddressFamilyPreference) (net.IP, error) { var nw networkInterfacer = networkInterface{} if _, err := os.Stat(ipv4RouteFile); os.IsNotExist(err) { - return chooseIPFromHostInterfaces(nw) + return chooseIPFromHostInterfaces(nw, addressFamilies) } routes, err := getAllDefaultRoutes() if err != nil { return nil, err } - return chooseHostInterfaceFromRoute(routes, nw) + return chooseHostInterfaceFromRoute(routes, nw, addressFamilies) } // networkInterfacer defines an interface for several net library functions. Production @@ -377,10 +393,10 @@ func getAllDefaultRoutes() ([]Route, error) { } // chooseHostInterfaceFromRoute cycles through each default route provided, looking for a -// global IP address from the interface for the route. Will first look all each IPv4 route for -// an IPv4 IP, and then will look at each IPv6 route for an IPv6 IP. -func chooseHostInterfaceFromRoute(routes []Route, nw networkInterfacer) (net.IP, error) { - for _, family := range []AddressFamily{familyIPv4, familyIPv6} { +// global IP address from the interface for the route. addressFamilies determines whether it +// prefers IPv4 or IPv6 +func chooseHostInterfaceFromRoute(routes []Route, nw networkInterfacer, addressFamilies AddressFamilyPreference) (net.IP, error) { + for _, family := range addressFamilies { klog.V(4).Infof("Looking for default routes with IPv%d addresses", uint(family)) for _, route := range routes { if route.Family != family { @@ -401,12 +417,19 @@ func chooseHostInterfaceFromRoute(routes []Route, nw networkInterfacer) (net.IP, return nil, fmt.Errorf("unable to select an IP from default routes.") } -// If bind-address is usable, return it directly -// If bind-address is not usable (unset, 0.0.0.0, or loopback), we will use the host's default -// interface. -func ChooseBindAddress(bindAddress net.IP) (net.IP, error) { +// ResolveBindAddress returns the IP address of a daemon, based on the given bindAddress: +// If bindAddress is unset, it returns the host's default IP, as with ChooseHostInterface(). +// If bindAddress is unspecified or loopback, it returns the default IP of the same +// address family as bindAddress. +// Otherwise, it just returns bindAddress. +func ResolveBindAddress(bindAddress net.IP) (net.IP, error) { + addressFamilies := preferIPv4 + if bindAddress != nil && memberOf(bindAddress, familyIPv6) { + addressFamilies = preferIPv6 + } + if bindAddress == nil || bindAddress.IsUnspecified() || bindAddress.IsLoopback() { - hostIP, err := ChooseHostInterface() + hostIP, err := chooseHostInterface(addressFamilies) if err != nil { return nil, err } @@ -414,3 +437,21 @@ func ChooseBindAddress(bindAddress net.IP) (net.IP, error) { } return bindAddress, nil } + +// ChooseBindAddressForInterface choose a global IP for a specific interface, with priority given to IPv4. +// This is required in case of network setups where default routes are present, but network +// interfaces use only link-local addresses (e.g. as described in RFC5549). +// e.g when using BGP to announce a host IP over link-local ip addresses and this ip address is attached to the lo interface. +func ChooseBindAddressForInterface(intfName string) (net.IP, error) { + var nw networkInterfacer = networkInterface{} + for _, family := range preferIPv4 { + ip, err := getIPFromInterface(intfName, family, nw) + if err != nil { + return nil, err + } + if ip != nil { + return ip, nil + } + } + return nil, fmt.Errorf("unable to select an IP from %s network interface", intfName) +} |