forked from moby/libnetwork
/
ov_network.go
633 lines (520 loc) · 12.9 KB
/
ov_network.go
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package overlay
import (
"encoding/json"
"fmt"
"net"
"os"
"sync"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/docker/libnetwork/datastore"
"github.com/docker/libnetwork/driverapi"
"github.com/docker/libnetwork/netutils"
"github.com/docker/libnetwork/osl"
"github.com/docker/libnetwork/resolvconf"
"github.com/docker/libnetwork/types"
"github.com/vishvananda/netlink"
"github.com/vishvananda/netlink/nl"
)
var (
hostMode bool
hostModeOnce sync.Once
)
type networkTable map[string]*network
type subnet struct {
once *sync.Once
vxlanName string
brName string
vni uint32
initErr error
subnetIP *net.IPNet
gwIP *net.IPNet
}
type subnetJSON struct {
SubnetIP string
GwIP string
Vni uint32
}
type network struct {
id string
dbIndex uint64
dbExists bool
sbox osl.Sandbox
endpoints endpointTable
driver *driver
joinCnt int
once *sync.Once
initEpoch int
initErr error
subnets []*subnet
sync.Mutex
}
func (d *driver) CreateNetwork(id string, option map[string]interface{}, ipV4Data, ipV6Data []driverapi.IPAMData) error {
if id == "" {
return fmt.Errorf("invalid network id")
}
// Since we perform lazy configuration make sure we try
// configuring the driver when we enter CreateNetwork
if err := d.configure(); err != nil {
return err
}
n := &network{
id: id,
driver: d,
endpoints: endpointTable{},
once: &sync.Once{},
subnets: []*subnet{},
}
for _, ipd := range ipV4Data {
s := &subnet{
subnetIP: ipd.Pool,
gwIP: ipd.Gateway,
once: &sync.Once{},
}
n.subnets = append(n.subnets, s)
}
if err := n.writeToStore(); err != nil {
return fmt.Errorf("failed to update data store for network %v: %v", n.id, err)
}
d.addNetwork(n)
return nil
}
func (d *driver) DeleteNetwork(nid string) error {
if nid == "" {
return fmt.Errorf("invalid network id")
}
n := d.network(nid)
if n == nil {
return fmt.Errorf("could not find network with id %s", nid)
}
d.deleteNetwork(nid)
return n.releaseVxlanID()
}
func (n *network) incEndpointCount() {
n.Lock()
defer n.Unlock()
n.joinCnt++
}
func (n *network) joinSandbox() error {
// If there is a race between two go routines here only one will win
// the other will wait.
n.once.Do(func() {
// save the error status of initSandbox in n.initErr so that
// all the racing go routines are able to know the status.
n.initErr = n.initSandbox()
})
return n.initErr
}
func (n *network) joinSubnetSandbox(s *subnet) error {
s.once.Do(func() {
s.initErr = n.initSubnetSandbox(s)
})
return s.initErr
}
func (n *network) leaveSandbox() {
n.Lock()
n.joinCnt--
if n.joinCnt != 0 {
n.Unlock()
return
}
// We are about to destroy sandbox since the container is leaving the network
// Reinitialize the once variable so that we will be able to trigger one time
// sandbox initialization(again) when another container joins subsequently.
n.once = &sync.Once{}
for _, s := range n.subnets {
s.once = &sync.Once{}
}
n.Unlock()
n.destroySandbox()
}
func (n *network) destroySandbox() {
sbox := n.sandbox()
if sbox != nil {
for _, iface := range sbox.Info().Interfaces() {
iface.Remove()
}
for _, s := range n.subnets {
if hostMode {
if err := removeFilters(n.id[:12], s.brName); err != nil {
logrus.Warnf("Could not remove overlay filters: %v", err)
}
}
if s.vxlanName != "" {
err := deleteInterface(s.vxlanName)
if err != nil {
logrus.Warnf("could not cleanup sandbox properly: %v", err)
}
}
}
if hostMode {
if err := removeNetworkChain(n.id[:12]); err != nil {
logrus.Warnf("could not remove network chain: %v", err)
}
}
sbox.Destroy()
n.setSandbox(nil)
}
}
func setHostMode() {
if os.Getenv("_OVERLAY_HOST_MODE") != "" {
hostMode = true
return
}
err := createVxlan("testvxlan", 1)
if err != nil {
logrus.Errorf("Failed to create testvxlan interface: %v", err)
return
}
defer deleteInterface("testvxlan")
path := "/proc/self/ns/net"
f, err := os.OpenFile(path, os.O_RDONLY, 0)
if err != nil {
logrus.Errorf("Failed to open path %s for network namespace for setting host mode: %v", path, err)
return
}
defer f.Close()
nsFD := f.Fd()
iface, err := netlink.LinkByName("testvxlan")
if err != nil {
logrus.Errorf("Failed to get link testvxlan: %v", err)
return
}
// If we are not able to move the vxlan interface to a namespace
// then fallback to host mode
if err := netlink.LinkSetNsFd(iface, int(nsFD)); err != nil {
hostMode = true
}
}
func (n *network) generateVxlanName(s *subnet) string {
return "vx-" + fmt.Sprintf("%06x", n.vxlanID(s)) + "-" + n.id[:5]
}
func (n *network) generateBridgeName(s *subnet) string {
return "ov-" + fmt.Sprintf("%06x", n.vxlanID(s)) + "-" + n.id[:5]
}
func isOverlap(nw *net.IPNet) bool {
var nameservers []string
if rc, err := resolvconf.Get(); err == nil {
nameservers = resolvconf.GetNameserversAsCIDR(rc.Content)
}
if err := netutils.CheckNameserverOverlaps(nameservers, nw); err != nil {
return true
}
if err := netutils.CheckRouteOverlaps(nw); err != nil {
return true
}
return false
}
func (n *network) initSubnetSandbox(s *subnet) error {
brName := n.generateBridgeName(s)
vxlanName := n.generateVxlanName(s)
if hostMode {
// Try to delete stale bridge interface if it exists
deleteInterface(brName)
// Try to delete the vxlan interface by vni if already present
deleteVxlanByVNI(n.vxlanID(s))
if isOverlap(s.subnetIP) {
return fmt.Errorf("overlay subnet %s has conflicts in the host while running in host mode", s.subnetIP.String())
}
}
// create a bridge and vxlan device for this subnet and move it to the sandbox
sbox := n.sandbox()
if err := sbox.AddInterface(brName, "br",
sbox.InterfaceOptions().Address(s.gwIP),
sbox.InterfaceOptions().Bridge(true)); err != nil {
return fmt.Errorf("bridge creation in sandbox failed for subnet %q: %v", s.subnetIP.String(), err)
}
err := createVxlan(vxlanName, n.vxlanID(s))
if err != nil {
return err
}
if err := sbox.AddInterface(vxlanName, "vxlan",
sbox.InterfaceOptions().Master(brName)); err != nil {
return fmt.Errorf("vxlan interface creation failed for subnet %q: %v", s.subnetIP.String(), err)
}
if hostMode {
if err := addFilters(n.id[:12], brName); err != nil {
return err
}
}
n.Lock()
s.vxlanName = vxlanName
s.brName = brName
n.Unlock()
return nil
}
func (n *network) initSandbox() error {
n.Lock()
n.initEpoch++
n.Unlock()
hostModeOnce.Do(setHostMode)
if hostMode {
if err := addNetworkChain(n.id[:12]); err != nil {
return err
}
}
sbox, err := osl.NewSandbox(
osl.GenerateKey(fmt.Sprintf("%d-", n.initEpoch)+n.id), !hostMode)
if err != nil {
return fmt.Errorf("could not create network sandbox: %v", err)
}
n.setSandbox(sbox)
n.driver.peerDbUpdateSandbox(n.id)
var nlSock *nl.NetlinkSocket
sbox.InvokeFunc(func() {
nlSock, err = nl.Subscribe(syscall.NETLINK_ROUTE, syscall.RTNLGRP_NEIGH)
if err != nil {
err = fmt.Errorf("failed to subscribe to neighbor group netlink messages")
}
})
go n.watchMiss(nlSock)
return nil
}
func (n *network) watchMiss(nlSock *nl.NetlinkSocket) {
for {
msgs, err := nlSock.Receive()
if err != nil {
logrus.Errorf("Failed to receive from netlink: %v ", err)
continue
}
for _, msg := range msgs {
if msg.Header.Type != syscall.RTM_GETNEIGH && msg.Header.Type != syscall.RTM_NEWNEIGH {
continue
}
neigh, err := netlink.NeighDeserialize(msg.Data)
if err != nil {
logrus.Errorf("Failed to deserialize netlink ndmsg: %v", err)
continue
}
if neigh.IP.To16() != nil {
continue
}
if neigh.State&(netlink.NUD_STALE|netlink.NUD_INCOMPLETE) == 0 {
continue
}
mac, IPmask, vtep, err := n.driver.resolvePeer(n.id, neigh.IP)
if err != nil {
logrus.Errorf("could not resolve peer %q: %v", neigh.IP, err)
continue
}
if err := n.driver.peerAdd(n.id, "dummy", neigh.IP, IPmask, mac, vtep, true); err != nil {
logrus.Errorf("could not add neighbor entry for missed peer %q: %v", neigh.IP, err)
}
}
}
}
func (d *driver) addNetwork(n *network) {
d.Lock()
d.networks[n.id] = n
d.Unlock()
}
func (d *driver) deleteNetwork(nid string) {
d.Lock()
delete(d.networks, nid)
d.Unlock()
}
func (d *driver) network(nid string) *network {
d.Lock()
networks := d.networks
d.Unlock()
n, ok := networks[nid]
if !ok {
n = d.getNetworkFromStore(nid)
if n != nil {
n.driver = d
n.endpoints = endpointTable{}
n.once = &sync.Once{}
networks[nid] = n
}
}
return n
}
func (d *driver) getNetworkFromStore(nid string) *network {
if d.store == nil {
return nil
}
n := &network{id: nid}
if err := d.store.GetObject(datastore.Key(n.Key()...), n); err != nil {
return nil
}
return n
}
func (n *network) sandbox() osl.Sandbox {
n.Lock()
defer n.Unlock()
return n.sbox
}
func (n *network) setSandbox(sbox osl.Sandbox) {
n.Lock()
n.sbox = sbox
n.Unlock()
}
func (n *network) vxlanID(s *subnet) uint32 {
n.Lock()
defer n.Unlock()
return s.vni
}
func (n *network) setVxlanID(s *subnet, vni uint32) {
n.Lock()
s.vni = vni
n.Unlock()
}
func (n *network) Key() []string {
return []string{"overlay", "network", n.id}
}
func (n *network) KeyPrefix() []string {
return []string{"overlay", "network"}
}
func (n *network) Value() []byte {
netJSON := []*subnetJSON{}
for _, s := range n.subnets {
sj := &subnetJSON{
SubnetIP: s.subnetIP.String(),
GwIP: s.gwIP.String(),
Vni: s.vni,
}
netJSON = append(netJSON, sj)
}
b, err := json.Marshal(netJSON)
if err != nil {
return []byte{}
}
return b
}
func (n *network) Index() uint64 {
return n.dbIndex
}
func (n *network) SetIndex(index uint64) {
n.dbIndex = index
n.dbExists = true
}
func (n *network) Exists() bool {
return n.dbExists
}
func (n *network) Skip() bool {
return false
}
func (n *network) SetValue(value []byte) error {
var newNet bool
netJSON := []*subnetJSON{}
err := json.Unmarshal(value, &netJSON)
if err != nil {
return err
}
if len(n.subnets) == 0 {
newNet = true
}
for _, sj := range netJSON {
subnetIPstr := sj.SubnetIP
gwIPstr := sj.GwIP
vni := sj.Vni
subnetIP, _ := types.ParseCIDR(subnetIPstr)
gwIP, _ := types.ParseCIDR(gwIPstr)
if newNet {
s := &subnet{
subnetIP: subnetIP,
gwIP: gwIP,
vni: vni,
once: &sync.Once{},
}
n.subnets = append(n.subnets, s)
} else {
sNet := n.getMatchingSubnet(subnetIP)
if sNet != nil {
sNet.vni = vni
}
}
}
return nil
}
func (n *network) DataScope() string {
return datastore.GlobalScope
}
func (n *network) writeToStore() error {
return n.driver.store.PutObjectAtomic(n)
}
func (n *network) releaseVxlanID() error {
if n.driver.store == nil {
return fmt.Errorf("no datastore configured. cannot release vxlan id")
}
if len(n.subnets) == 0 {
return nil
}
if err := n.driver.store.DeleteObjectAtomic(n); err != nil {
if err == datastore.ErrKeyModified || err == datastore.ErrKeyNotFound {
// In both the above cases we can safely assume that the key has been removed by some other
// instance and so simply get out of here
return nil
}
return fmt.Errorf("failed to delete network to vxlan id map: %v", err)
}
for _, s := range n.subnets {
n.driver.vxlanIdm.Release(uint64(n.vxlanID(s)))
n.setVxlanID(s, 0)
}
return nil
}
func (n *network) obtainVxlanID(s *subnet) error {
//return if the subnet already has a vxlan id assigned
if s.vni != 0 {
return nil
}
if n.driver.store == nil {
return fmt.Errorf("no datastore configured. cannot obtain vxlan id")
}
for {
if err := n.driver.store.GetObject(datastore.Key(n.Key()...), n); err != nil {
return fmt.Errorf("getting network %q from datastore failed %v", n.id, err)
}
if s.vni == 0 {
vxlanID, err := n.driver.vxlanIdm.GetID()
if err != nil {
return fmt.Errorf("failed to allocate vxlan id: %v", err)
}
n.setVxlanID(s, uint32(vxlanID))
if err := n.writeToStore(); err != nil {
n.driver.vxlanIdm.Release(uint64(n.vxlanID(s)))
n.setVxlanID(s, 0)
if err == datastore.ErrKeyModified {
continue
}
return fmt.Errorf("network %q failed to update data store: %v", n.id, err)
}
return nil
}
return nil
}
}
// getSubnetforIP returns the subnet to which the given IP belongs
func (n *network) getSubnetforIP(ip *net.IPNet) *subnet {
for _, s := range n.subnets {
// first check if the mask lengths are the same
i, _ := s.subnetIP.Mask.Size()
j, _ := ip.Mask.Size()
if i != j {
continue
}
if s.subnetIP.Contains(ip.IP) {
return s
}
}
return nil
}
// getMatchingSubnet return the network's subnet that matches the input
func (n *network) getMatchingSubnet(ip *net.IPNet) *subnet {
if ip == nil {
return nil
}
for _, s := range n.subnets {
// first check if the mask lengths are the same
i, _ := s.subnetIP.Mask.Size()
j, _ := ip.Mask.Size()
if i != j {
continue
}
if s.subnetIP.IP.Equal(ip.IP) {
return s
}
}
return nil
}