libnetwork/drivers/bridge/interface.go

80 lines
2.1 KiB
Go

package bridge
import (
"fmt"
"net"
"github.com/vishvananda/netlink"
)
const (
// DefaultBridgeName is the default name for the bridge interface managed
// by the driver when unspecified by the caller.
DefaultBridgeName = "docker0"
)
// Interface models the bridge network device.
type bridgeInterface struct {
Link netlink.Link
bridgeIPv4 *net.IPNet
bridgeIPv6 *net.IPNet
gatewayIPv4 net.IP
gatewayIPv6 net.IP
}
// newInterface creates a new bridge interface structure. It attempts to find
// an already existing device identified by the configuration BridgeName field,
// or the default bridge name when unspecified, but doesn't attempt to create
// one when missing
func newInterface(config *networkConfiguration) *bridgeInterface {
i := &bridgeInterface{}
// Initialize the bridge name to the default if unspecified.
if config.BridgeName == "" {
config.BridgeName = DefaultBridgeName
}
// Attempt to find an existing bridge named with the specified name.
i.Link, _ = netlink.LinkByName(config.BridgeName)
return i
}
// exists indicates if the existing bridge interface exists on the system.
func (i *bridgeInterface) exists() bool {
return i.Link != nil
}
// addresses returns a single IPv4 address and all IPv6 addresses for the
// bridge interface.
func (i *bridgeInterface) addresses() (netlink.Addr, []netlink.Addr, error) {
v4addr, err := netlink.AddrList(i.Link, netlink.FAMILY_V4)
if err != nil {
return netlink.Addr{}, nil, err
}
v6addr, err := netlink.AddrList(i.Link, netlink.FAMILY_V6)
if err != nil {
return netlink.Addr{}, nil, err
}
if len(v4addr) == 0 {
return netlink.Addr{}, v6addr, nil
}
return v4addr[0], v6addr, nil
}
func (i *bridgeInterface) programIPv6Address() error {
_, nlAddressList, err := i.addresses()
if err != nil {
return &IPv6AddrAddError{IP: i.bridgeIPv6, Err: fmt.Errorf("failed to retrieve address list: %v", err)}
}
nlAddr := netlink.Addr{IPNet: i.bridgeIPv6}
if findIPv6Address(nlAddr, nlAddressList) {
return nil
}
if err := netlink.AddrAdd(i.Link, &nlAddr); err != nil {
return &IPv6AddrAddError{IP: i.bridgeIPv6, Err: err}
}
return nil
}