[kube-proxy/ipvs] Protect Netlink calls with a mutex

pkg/util/ipvs/ipvs_linux.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"net"
 	"strings"
+	"sync"
 	"syscall"
 
 	libipvs "github.com/docker/libnetwork/ipvs"
@@ -34,6 +35,7 @@ import (
 type runner struct {
 	exec       utilexec.Interface
 	ipvsHandle *libipvs.Handle
+	mu         sync.Mutex // Protect Netlink calls
 }
 
 // Protocol is the IPVS service protocol type
@@ -58,6 +60,8 @@ func (runner *runner) AddVirtualServer(vs *VirtualServer) error {
 	if err != nil {
 		return err
 	}
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.NewService(svc)
 }
 
@@ -67,6 +71,8 @@ func (runner *runner) UpdateVirtualServer(vs *VirtualServer) error {
 	if err != nil {
 		return err
 	}
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.UpdateService(svc)
 }
 
@@ -76,6 +82,8 @@ func (runner *runner) DeleteVirtualServer(vs *VirtualServer) error {
 	if err != nil {
 		return err
 	}
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.DelService(svc)
 }
 
@@ -85,7 +93,10 @@ func (runner *runner) GetVirtualServer(vs *VirtualServer) (*VirtualServer, error
 	if err != nil {
 		return nil, err
 	}
+	runner.mu.Lock()
 	ipvsSvc, err := runner.ipvsHandle.GetService(svc)
+	runner.mu.Unlock()
+
 	if err != nil {
 		return nil, err
 	}
@@ -98,7 +109,9 @@ func (runner *runner) GetVirtualServer(vs *VirtualServer) (*VirtualServer, error
 
 // GetVirtualServers is part of ipvs.Interface.
 func (runner *runner) GetVirtualServers() ([]*VirtualServer, error) {
+	runner.mu.Lock()
 	ipvsSvcs, err := runner.ipvsHandle.GetServices()
+	runner.mu.Unlock()
 	if err != nil {
 		return nil, err
 	}
@@ -115,6 +128,8 @@ func (runner *runner) GetVirtualServers() ([]*VirtualServer, error) {
 
 // Flush is part of ipvs.Interface. Currently we delete IPVS services one by one
 func (runner *runner) Flush() error {
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.Flush()
 }
 
@@ -128,6 +143,8 @@ func (runner *runner) AddRealServer(vs *VirtualServer, rs *RealServer) error {
 	if err != nil {
 		return err
 	}
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.NewDestination(svc, dst)
 }
 
@@ -141,6 +158,8 @@ func (runner *runner) DeleteRealServer(vs *VirtualServer, rs *RealServer) error
 	if err != nil {
 		return err
 	}
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.DelDestination(svc, dst)
 }
 
@@ -153,6 +172,8 @@ func (runner *runner) UpdateRealServer(vs *VirtualServer, rs *RealServer) error
 	if err != nil {
 		return err
 	}
+	runner.mu.Lock()
+	defer runner.mu.Unlock()
 	return runner.ipvsHandle.UpdateDestination(svc, dst)
 }
 
@@ -162,7 +183,9 @@ func (runner *runner) GetRealServers(vs *VirtualServer) ([]*RealServer, error) {
 	if err != nil {
 		return nil, err
 	}
+	runner.mu.Lock()
 	dsts, err := runner.ipvsHandle.GetDestinations(svc)
+	runner.mu.Unlock()
 	if err != nil {
 		return nil, err
 	}