docker.io/libnetwork/ipam/utils.go

82 lines
1.9 KiB
Go

package ipam
import (
"fmt"
"net"
"github.com/docker/libnetwork/ipamapi"
"github.com/docker/libnetwork/types"
)
type ipVersion int
const (
v4 = 4
v6 = 6
)
func getAddressRange(pool string, masterNw *net.IPNet) (*AddressRange, error) {
ip, nw, err := net.ParseCIDR(pool)
if err != nil {
return nil, ipamapi.ErrInvalidSubPool
}
lIP, e := types.GetHostPartIP(nw.IP, masterNw.Mask)
if e != nil {
return nil, fmt.Errorf("failed to compute range's lowest ip address: %v", e)
}
bIP, e := types.GetBroadcastIP(nw.IP, nw.Mask)
if e != nil {
return nil, fmt.Errorf("failed to compute range's broadcast ip address: %v", e)
}
hIP, e := types.GetHostPartIP(bIP, masterNw.Mask)
if e != nil {
return nil, fmt.Errorf("failed to compute range's highest ip address: %v", e)
}
nw.IP = ip
return &AddressRange{nw, ipToUint64(types.GetMinimalIP(lIP)), ipToUint64(types.GetMinimalIP(hIP))}, nil
}
// It generates the ip address in the passed subnet specified by
// the passed host address ordinal
func generateAddress(ordinal uint64, network *net.IPNet) net.IP {
var address [16]byte
// Get network portion of IP
if getAddressVersion(network.IP) == v4 {
copy(address[:], network.IP.To4())
} else {
copy(address[:], network.IP)
}
end := len(network.Mask)
addIntToIP(address[:end], ordinal)
return net.IP(address[:end])
}
func getAddressVersion(ip net.IP) ipVersion {
if ip.To4() == nil {
return v6
}
return v4
}
// Adds the ordinal IP to the current array
// 192.168.0.0 + 53 => 192.168.0.53
func addIntToIP(array []byte, ordinal uint64) {
for i := len(array) - 1; i >= 0; i-- {
array[i] |= (byte)(ordinal & 0xff)
ordinal >>= 8
}
}
// Convert an ordinal to the respective IP address
func ipToUint64(ip []byte) (value uint64) {
cip := types.GetMinimalIP(ip)
for i := 0; i < len(cip); i++ {
j := len(cip) - 1 - i
value += uint64(cip[i]) << uint(j*8)
}
return value
}