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moby--moby/libnetwork/ns/init_linux.go
Alessandro Boch 117131c41b Gracefully handle missing xfrm modules
If xfrm modules cannot be loaded:
- Create netlink.Handle only for ROUTE socket
- Reject local join on overlay secure network

Signed-off-by: Alessandro Boch <aboch@docker.com>
2016-06-20 17:25:32 -07:00

86 lines
2.1 KiB
Go

package ns
import (
"fmt"
"os"
"os/exec"
"strings"
"sync"
"syscall"
log "github.com/Sirupsen/logrus"
"github.com/vishvananda/netlink"
"github.com/vishvananda/netns"
)
var (
initNs netns.NsHandle
initNl *netlink.Handle
initOnce sync.Once
)
// Init initializes a new network namespace
func Init() {
var err error
initNs, err = netns.Get()
if err != nil {
log.Errorf("could not get initial namespace: %v", err)
}
initNl, err = netlink.NewHandle(getSupportedNlFamilies()...)
if err != nil {
log.Errorf("could not create netlink handle on initial namespace: %v", err)
}
}
// SetNamespace sets the initial namespace handler
func SetNamespace() error {
initOnce.Do(Init)
if err := netns.Set(initNs); err != nil {
linkInfo, linkErr := getLink()
if linkErr != nil {
linkInfo = linkErr.Error()
}
return fmt.Errorf("failed to set to initial namespace, %v, initns fd %d: %v", linkInfo, initNs, err)
}
return nil
}
// ParseHandlerInt transforms the namespace handler into an integer
func ParseHandlerInt() int {
return int(getHandler())
}
// GetHandler returns the namespace handler
func getHandler() netns.NsHandle {
initOnce.Do(Init)
return initNs
}
func getLink() (string, error) {
return os.Readlink(fmt.Sprintf("/proc/%d/task/%d/ns/net", os.Getpid(), syscall.Gettid()))
}
// NlHandle returns the netlink handler
func NlHandle() *netlink.Handle {
initOnce.Do(Init)
return initNl
}
func getSupportedNlFamilies() []int {
fams := []int{syscall.NETLINK_ROUTE}
if err := loadXfrmModules(); err != nil {
log.Warnf("Could not load necessary modules for IPSEC rules: %v", err)
return fams
}
return append(fams, syscall.NETLINK_XFRM)
}
func loadXfrmModules() error {
if out, err := exec.Command("modprobe", "-va", "xfrm_user").CombinedOutput(); err != nil {
return fmt.Errorf("Running modprobe xfrm_user failed with message: `%s`, error: %v", strings.TrimSpace(string(out)), err)
}
if out, err := exec.Command("modprobe", "-va", "xfrm_algo").CombinedOutput(); err != nil {
return fmt.Errorf("Running modprobe xfrm_algo failed with message: `%s`, error: %v", strings.TrimSpace(string(out)), err)
}
return nil
}