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WIP for ip allocator

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
This commit is contained in:
Michael Crosby 2014-01-22 15:52:39 -08:00
parent 700db10c85
commit 9e2e8a923c
2 changed files with 230 additions and 121 deletions

View file

@ -1,7 +1,6 @@
package docker
import (
"encoding/binary"
"errors"
"fmt"
"github.com/dotcloud/docker/pkg/iptables"
@ -25,61 +24,6 @@ const (
siocBRADDBR = 0x89a0
)
// Calculates the first and last IP addresses in an IPNet
func networkRange(network *net.IPNet) (net.IP, net.IP) {
netIP := network.IP.To4()
firstIP := netIP.Mask(network.Mask)
lastIP := net.IPv4(0, 0, 0, 0).To4()
for i := 0; i < len(lastIP); i++ {
lastIP[i] = netIP[i] | ^network.Mask[i]
}
return firstIP, lastIP
}
// Detects overlap between one IPNet and another
func networkOverlaps(netX *net.IPNet, netY *net.IPNet) bool {
firstIP, _ := networkRange(netX)
if netY.Contains(firstIP) {
return true
}
firstIP, _ = networkRange(netY)
if netX.Contains(firstIP) {
return true
}
return false
}
// Converts a 4 bytes IP into a 32 bit integer
func ipToInt(ip net.IP) int32 {
return int32(binary.BigEndian.Uint32(ip.To4()))
}
// Converts 32 bit integer into a 4 bytes IP address
func intToIP(n int32) net.IP {
b := make([]byte, 4)
binary.BigEndian.PutUint32(b, uint32(n))
return net.IP(b)
}
// Given a netmask, calculates the number of available hosts
func networkSize(mask net.IPMask) int32 {
m := net.IPv4Mask(0, 0, 0, 0)
for i := 0; i < net.IPv4len; i++ {
m[i] = ^mask[i]
}
return int32(binary.BigEndian.Uint32(m)) + 1
}
func checkRouteOverlaps(networks []netlink.Route, dockerNetwork *net.IPNet) error {
for _, network := range networks {
if network.IPNet != nil && networkOverlaps(dockerNetwork, network.IPNet) {
return fmt.Errorf("Network %s is already routed: '%s'", dockerNetwork, network)
}
}
return nil
}
func checkNameserverOverlaps(nameservers []string, dockerNetwork *net.IPNet) error {
if len(nameservers) > 0 {
for _, ns := range nameservers {
@ -142,10 +86,7 @@ func CreateBridgeIface(config *DaemonConfig) error {
if err != nil {
return err
}
routes, err := netlink.NetworkGetRoutes()
if err != nil {
return err
}
// TODO: @crosbymichael register route
if err := checkRouteOverlaps(routes, dockerNetwork); err == nil {
if err := checkNameserverOverlaps(nameservers, dockerNetwork); err == nil {
ifaceAddr = addr
@ -441,67 +382,6 @@ type allocatedIP struct {
}
func (alloc *IPAllocator) run() {
firstIP, _ := networkRange(alloc.network)
ipNum := ipToInt(firstIP)
ownIP := ipToInt(alloc.network.IP)
size := networkSize(alloc.network.Mask)
pos := int32(1)
max := size - 2 // -1 for the broadcast address, -1 for the gateway address
for {
var (
newNum int32
inUse bool
)
// Find first unused IP, give up after one whole round
for attempt := int32(0); attempt < max; attempt++ {
newNum = ipNum + pos
pos = pos%max + 1
// The network's IP is never okay to use
if newNum == ownIP {
continue
}
if _, inUse = alloc.inUse[newNum]; !inUse {
// We found an unused IP
break
}
}
ip := allocatedIP{ip: intToIP(newNum)}
if inUse {
ip.err = errors.New("No unallocated IP available")
}
select {
case quit := <-alloc.quit:
if quit {
return
}
case alloc.queueAlloc <- ip:
alloc.inUse[newNum] = struct{}{}
case released := <-alloc.queueReleased:
r := ipToInt(released)
delete(alloc.inUse, r)
if inUse {
// If we couldn't allocate a new IP, the released one
// will be the only free one now, so instantly use it
// next time
pos = r - ipNum
} else {
// Use same IP as last time
if pos == 1 {
pos = max
} else {
pos--
}
}
}
}
}
func (alloc *IPAllocator) Acquire() (net.IP, error) {

View file

@ -0,0 +1,229 @@
package ipallocator
import (
"encoding/binary"
"errors"
"github.com/dotcloud/docker/pkg/netlink"
"net"
"sync"
)
type networkSet map[iPNet]iPSet
type iPSet map[string]struct{}
type iPNet struct {
IP string
Mask string
}
var (
ErrNetworkAlreadyAllocated = errors.New("requested network overlaps with existing network")
ErrNetworkAlreadyRegisterd = errors.New("requested network is already registered")
lock = sync.Mutex{}
allocatedIPs = networkSet{}
availableIPS = networkSet{}
)
func RegisterNetwork(network *net.IPNet) error {
lock.Lock()
defer lock.Unlock()
routes, err := netlink.NetworkGetRoutes()
if err != nil {
return err
}
if err := checkRouteOverlaps(routes, network); err != nil {
return err
}
if err := checkExistingNetworkOverlaps(network); err != nil {
return err
}
allocatedIPs[newIPNet(network)] = iPSet{}
return nil
}
func RequestIP(ip *net.IPAddr) (*net.IPAddr, error) {
lock.Lock()
defer lock.Unlock()
if ip == nil {
next, err := getNextIp()
if err != nil {
return nil, err
}
return next, nil
}
if err := validateIP(ip); err != nil {
return nil, err
}
return ip, nil
}
func ReleaseIP(ip *net.IPAddr) error {
lock.Lock()
defer lock.Unlock()
}
func getNextIp(network iPNet) (net.IPAddr, error) {
if available, exists := availableIPS[network]; exists {
}
var (
netNetwork = newNetIPNet(network)
firstIP, _ = networkRange(netNetwork)
ipNum = ipToInt(firstIP)
ownIP = ipToInt(netNetwork.IP)
size = networkSize(netNetwork.Mask)
pos = int32(1)
max = size - 2 // -1 for the broadcast address, -1 for the gateway address
)
for {
var (
newNum int32
inUse bool
)
// Find first unused IP, give up after one whole round
for attempt := int32(0); attempt < max; attempt++ {
newNum = ipNum + pos
pos = pos%max + 1
// The network's IP is never okay to use
if newNum == ownIP {
continue
}
if _, inUse = alloc.inUse[newNum]; !inUse {
// We found an unused IP
break
}
}
ip := allocatedIP{ip: intToIP(newNum)}
if inUse {
ip.err = errors.New("No unallocated IP available")
}
select {
case quit := <-alloc.quit:
if quit {
return
}
case alloc.queueAlloc <- ip:
alloc.inUse[newNum] = struct{}{}
case released := <-alloc.queueReleased:
r := ipToInt(released)
delete(alloc.inUse, r)
if inUse {
// If we couldn't allocate a new IP, the released one
// will be the only free one now, so instantly use it
// next time
pos = r - ipNum
} else {
// Use same IP as last time
if pos == 1 {
pos = max
} else {
pos--
}
}
}
}
}
func validateIP(ip *net.IPAddr) error {
}
func checkRouteOverlaps(networks []netlink.Route, toCheck *net.IPNet) error {
for _, network := range networks {
if network.IPNet != nil && networkOverlaps(toCheck, network.IPNet) {
return ErrNetworkAlreadyAllocated
}
}
return nil
}
// Detects overlap between one IPNet and another
func networkOverlaps(netX *net.IPNet, netY *net.IPNet) bool {
if firstIP, _ := networkRange(netX); netY.Contains(firstIP) {
return true
}
if firstIP, _ := networkRange(netY); netX.Contains(firstIP) {
return true
}
return false
}
func checkExistingNetworkOverlaps(network *net.IPNet) error {
for existing := range allocatedIPs {
if newIPNet(network) == existing {
return ErrNetworkAlreadyRegisterd
}
if networkOverlaps(network, existing) {
return ErrNetworkAlreadyAllocated
}
}
return nil
}
// Calculates the first and last IP addresses in an IPNet
func networkRange(network *net.IPNet) (net.IP, net.IP) {
var (
netIP = network.IP.To4()
firstIP = netIP.Mask(network.Mask)
lastIP = net.IPv4(0, 0, 0, 0).To4()
)
for i := 0; i < len(lastIP); i++ {
lastIP[i] = netIP[i] | ^network.Mask[i]
}
return firstIP, lastIP
}
func newIPNet(network *net.IPNet) iPNet {
return iPNet{
IP: string(network.IP),
Mask: string(network.Mask),
}
}
func newNetIPNet(network iPNet) *net.IPNet {
return &net.IPNet{
IP: []byte(network.IP),
Mask: []byte(network.Mask),
}
}
// Converts a 4 bytes IP into a 32 bit integer
func ipToInt(ip net.IP) int32 {
return int32(binary.BigEndian.Uint32(ip.To4()))
}
// Converts 32 bit integer into a 4 bytes IP address
func intToIP(n int32) net.IP {
b := make([]byte, 4)
binary.BigEndian.PutUint32(b, uint32(n))
return net.IP(b)
}
// Given a netmask, calculates the number of available hosts
func networkSize(mask net.IPMask) int32 {
m := net.IPv4Mask(0, 0, 0, 0)
for i := 0; i < net.IPv4len; i++ {
m[i] = ^mask[i]
}
return int32(binary.BigEndian.Uint32(m)) + 1
}