/usr/share/gocode/src/github.com/docker/libnetwork/osl/namespace_linux.go is in golang-github-docker-libnetwork-dev 0.8.0-dev.2+git20170202.599.45b4086-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 | package osl
import (
"fmt"
"io/ioutil"
"net"
"os"
"os/exec"
"path/filepath"
"runtime"
"strconv"
"strings"
"sync"
"syscall"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/reexec"
"github.com/docker/libnetwork/ns"
"github.com/docker/libnetwork/types"
"github.com/vishvananda/netlink"
"github.com/vishvananda/netns"
)
const defaultPrefix = "/var/run/docker"
var (
once sync.Once
garbagePathMap = make(map[string]bool)
gpmLock sync.Mutex
gpmWg sync.WaitGroup
gpmCleanupPeriod = 60 * time.Second
gpmChan = make(chan chan struct{})
prefix = defaultPrefix
)
// The networkNamespace type is the linux implementation of the Sandbox
// interface. It represents a linux network namespace, and moves an interface
// into it when called on method AddInterface or sets the gateway etc.
type networkNamespace struct {
path string
iFaces []*nwIface
gw net.IP
gwv6 net.IP
staticRoutes []*types.StaticRoute
neighbors []*neigh
nextIfIndex int
isDefault bool
nlHandle *netlink.Handle
sync.Mutex
}
// SetBasePath sets the base url prefix for the ns path
func SetBasePath(path string) {
prefix = path
}
func init() {
reexec.Register("netns-create", reexecCreateNamespace)
}
func basePath() string {
return filepath.Join(prefix, "netns")
}
func createBasePath() {
err := os.MkdirAll(basePath(), 0755)
if err != nil {
panic("Could not create net namespace path directory")
}
// Start the garbage collection go routine
go removeUnusedPaths()
}
func removeUnusedPaths() {
gpmLock.Lock()
period := gpmCleanupPeriod
gpmLock.Unlock()
ticker := time.NewTicker(period)
for {
var (
gc chan struct{}
gcOk bool
)
select {
case <-ticker.C:
case gc, gcOk = <-gpmChan:
}
gpmLock.Lock()
pathList := make([]string, 0, len(garbagePathMap))
for path := range garbagePathMap {
pathList = append(pathList, path)
}
garbagePathMap = make(map[string]bool)
gpmWg.Add(1)
gpmLock.Unlock()
for _, path := range pathList {
os.Remove(path)
}
gpmWg.Done()
if gcOk {
close(gc)
}
}
}
func addToGarbagePaths(path string) {
gpmLock.Lock()
garbagePathMap[path] = true
gpmLock.Unlock()
}
func removeFromGarbagePaths(path string) {
gpmLock.Lock()
delete(garbagePathMap, path)
gpmLock.Unlock()
}
// GC triggers garbage collection of namespace path right away
// and waits for it.
func GC() {
gpmLock.Lock()
if len(garbagePathMap) == 0 {
// No need for GC if map is empty
gpmLock.Unlock()
return
}
gpmLock.Unlock()
// if content exists in the garbage paths
// we can trigger GC to run, providing a
// channel to be notified on completion
waitGC := make(chan struct{})
gpmChan <- waitGC
// wait for GC completion
<-waitGC
}
// GenerateKey generates a sandbox key based on the passed
// container id.
func GenerateKey(containerID string) string {
maxLen := 12
// Read sandbox key from host for overlay
if strings.HasPrefix(containerID, "-") {
var (
index int
indexStr string
tmpkey string
)
dir, err := ioutil.ReadDir(basePath())
if err != nil {
return ""
}
for _, v := range dir {
id := v.Name()
if strings.HasSuffix(id, containerID[:maxLen-1]) {
indexStr = strings.TrimSuffix(id, containerID[:maxLen-1])
tmpindex, err := strconv.Atoi(indexStr)
if err != nil {
return ""
}
if tmpindex > index {
index = tmpindex
tmpkey = id
}
}
}
containerID = tmpkey
if containerID == "" {
return ""
}
}
if len(containerID) < maxLen {
maxLen = len(containerID)
}
return basePath() + "/" + containerID[:maxLen]
}
// NewSandbox provides a new sandbox instance created in an os specific way
// provided a key which uniquely identifies the sandbox
func NewSandbox(key string, osCreate, isRestore bool) (Sandbox, error) {
if !isRestore {
err := createNetworkNamespace(key, osCreate)
if err != nil {
return nil, err
}
} else {
once.Do(createBasePath)
}
n := &networkNamespace{path: key, isDefault: !osCreate}
sboxNs, err := netns.GetFromPath(n.path)
if err != nil {
return nil, fmt.Errorf("failed get network namespace %q: %v", n.path, err)
}
defer sboxNs.Close()
n.nlHandle, err = netlink.NewHandleAt(sboxNs, syscall.NETLINK_ROUTE)
if err != nil {
return nil, fmt.Errorf("failed to create a netlink handle: %v", err)
}
err = n.nlHandle.SetSocketTimeout(ns.NetlinkSocketsTimeout)
if err != nil {
logrus.Warnf("Failed to set the timeout on the sandbox netlink handle sockets: %v", err)
}
if err = n.loopbackUp(); err != nil {
n.nlHandle.Delete()
return nil, err
}
return n, nil
}
func (n *networkNamespace) InterfaceOptions() IfaceOptionSetter {
return n
}
func (n *networkNamespace) NeighborOptions() NeighborOptionSetter {
return n
}
func mountNetworkNamespace(basePath string, lnPath string) error {
return syscall.Mount(basePath, lnPath, "bind", syscall.MS_BIND, "")
}
// GetSandboxForExternalKey returns sandbox object for the supplied path
func GetSandboxForExternalKey(basePath string, key string) (Sandbox, error) {
if err := createNamespaceFile(key); err != nil {
return nil, err
}
if err := mountNetworkNamespace(basePath, key); err != nil {
return nil, err
}
n := &networkNamespace{path: key}
sboxNs, err := netns.GetFromPath(n.path)
if err != nil {
return nil, fmt.Errorf("failed get network namespace %q: %v", n.path, err)
}
defer sboxNs.Close()
n.nlHandle, err = netlink.NewHandleAt(sboxNs, syscall.NETLINK_ROUTE)
if err != nil {
return nil, fmt.Errorf("failed to create a netlink handle: %v", err)
}
err = n.nlHandle.SetSocketTimeout(ns.NetlinkSocketsTimeout)
if err != nil {
logrus.Warnf("Failed to set the timeout on the sandbox netlink handle sockets: %v", err)
}
if err = n.loopbackUp(); err != nil {
n.nlHandle.Delete()
return nil, err
}
return n, nil
}
func reexecCreateNamespace() {
if len(os.Args) < 2 {
logrus.Fatal("no namespace path provided")
}
if err := mountNetworkNamespace("/proc/self/ns/net", os.Args[1]); err != nil {
logrus.Fatal(err)
}
}
func createNetworkNamespace(path string, osCreate bool) error {
if err := createNamespaceFile(path); err != nil {
return err
}
cmd := &exec.Cmd{
Path: reexec.Self(),
Args: append([]string{"netns-create"}, path),
Stdout: os.Stdout,
Stderr: os.Stderr,
}
if osCreate {
cmd.SysProcAttr = &syscall.SysProcAttr{}
cmd.SysProcAttr.Cloneflags = syscall.CLONE_NEWNET
}
if err := cmd.Run(); err != nil {
return fmt.Errorf("namespace creation reexec command failed: %v", err)
}
return nil
}
func unmountNamespaceFile(path string) {
if _, err := os.Stat(path); err == nil {
syscall.Unmount(path, syscall.MNT_DETACH)
}
}
func createNamespaceFile(path string) (err error) {
var f *os.File
once.Do(createBasePath)
// Remove it from garbage collection list if present
removeFromGarbagePaths(path)
// If the path is there unmount it first
unmountNamespaceFile(path)
// wait for garbage collection to complete if it is in progress
// before trying to create the file.
gpmWg.Wait()
if f, err = os.Create(path); err == nil {
f.Close()
}
return err
}
func (n *networkNamespace) loopbackUp() error {
iface, err := n.nlHandle.LinkByName("lo")
if err != nil {
return err
}
return n.nlHandle.LinkSetUp(iface)
}
func (n *networkNamespace) InvokeFunc(f func()) error {
return nsInvoke(n.nsPath(), func(nsFD int) error { return nil }, func(callerFD int) error {
f()
return nil
})
}
// InitOSContext initializes OS context while configuring network resources
func InitOSContext() func() {
runtime.LockOSThread()
if err := ns.SetNamespace(); err != nil {
logrus.Error(err)
}
return runtime.UnlockOSThread
}
func nsInvoke(path string, prefunc func(nsFD int) error, postfunc func(callerFD int) error) error {
defer InitOSContext()()
newNs, err := netns.GetFromPath(path)
if err != nil {
return fmt.Errorf("failed get network namespace %q: %v", path, err)
}
defer newNs.Close()
// Invoked before the namespace switch happens but after the namespace file
// handle is obtained.
if err := prefunc(int(newNs)); err != nil {
return fmt.Errorf("failed in prefunc: %v", err)
}
if err = netns.Set(newNs); err != nil {
return err
}
defer ns.SetNamespace()
// Invoked after the namespace switch.
return postfunc(ns.ParseHandlerInt())
}
func (n *networkNamespace) nsPath() string {
n.Lock()
defer n.Unlock()
return n.path
}
func (n *networkNamespace) Info() Info {
return n
}
func (n *networkNamespace) Key() string {
return n.path
}
func (n *networkNamespace) Destroy() error {
if n.nlHandle != nil {
n.nlHandle.Delete()
}
// Assuming no running process is executing in this network namespace,
// unmounting is sufficient to destroy it.
if err := syscall.Unmount(n.path, syscall.MNT_DETACH); err != nil {
return err
}
// Stash it into the garbage collection list
addToGarbagePaths(n.path)
return nil
}
// Restore restore the network namespace
func (n *networkNamespace) Restore(ifsopt map[string][]IfaceOption, routes []*types.StaticRoute, gw net.IP, gw6 net.IP) error {
// restore interfaces
for name, opts := range ifsopt {
if !strings.Contains(name, "+") {
return fmt.Errorf("wrong iface name in restore osl sandbox interface: %s", name)
}
seps := strings.Split(name, "+")
srcName := seps[0]
dstPrefix := seps[1]
i := &nwIface{srcName: srcName, dstName: dstPrefix, ns: n}
i.processInterfaceOptions(opts...)
if i.master != "" {
i.dstMaster = n.findDst(i.master, true)
if i.dstMaster == "" {
return fmt.Errorf("could not find an appropriate master %q for %q",
i.master, i.srcName)
}
}
if n.isDefault {
i.dstName = i.srcName
} else {
links, err := n.nlHandle.LinkList()
if err != nil {
return fmt.Errorf("failed to retrieve list of links in network namespace %q during restore", n.path)
}
// due to the docker network connect/disconnect, so the dstName should
// restore from the namespace
for _, link := range links {
addrs, err := n.nlHandle.AddrList(link, netlink.FAMILY_V4)
if err != nil {
return err
}
ifaceName := link.Attrs().Name
if strings.HasPrefix(ifaceName, "vxlan") {
if i.dstName == "vxlan" {
i.dstName = ifaceName
break
}
}
// find the interface name by ip
if i.address != nil {
for _, addr := range addrs {
if addr.IPNet.String() == i.address.String() {
i.dstName = ifaceName
break
}
continue
}
if i.dstName == ifaceName {
break
}
}
// This is to find the interface name of the pair in overlay sandbox
if strings.HasPrefix(ifaceName, "veth") {
if i.master != "" && i.dstName == "veth" {
i.dstName = ifaceName
}
}
}
var index int
indexStr := strings.TrimPrefix(i.dstName, dstPrefix)
if indexStr != "" {
index, err = strconv.Atoi(indexStr)
if err != nil {
return err
}
}
index++
n.Lock()
if index > n.nextIfIndex {
n.nextIfIndex = index
}
n.iFaces = append(n.iFaces, i)
n.Unlock()
}
}
// restore routes
for _, r := range routes {
n.Lock()
n.staticRoutes = append(n.staticRoutes, r)
n.Unlock()
}
// restore gateway
if len(gw) > 0 {
n.Lock()
n.gw = gw
n.Unlock()
}
if len(gw6) > 0 {
n.Lock()
n.gwv6 = gw6
n.Unlock()
}
return nil
}
|