summaryrefslogtreecommitdiffhomepage
path: root/pkg
diff options
context:
space:
mode:
Diffstat (limited to 'pkg')
-rw-r--r--pkg/tcpip/ports/ports.go148
-rwxr-xr-xpkg/tcpip/ports/ports_state_autogen.go20
-rw-r--r--pkg/tcpip/transport/tcp/endpoint.go25
-rwxr-xr-xpkg/tcpip/transport/tcp/tcp_state_autogen.go2
-rw-r--r--pkg/tcpip/transport/udp/endpoint.go19
-rwxr-xr-xpkg/tcpip/transport/udp/udp_state_autogen.go2
6 files changed, 174 insertions, 42 deletions
diff --git a/pkg/tcpip/ports/ports.go b/pkg/tcpip/ports/ports.go
index 30cea8996..6c5e19e8f 100644
--- a/pkg/tcpip/ports/ports.go
+++ b/pkg/tcpip/ports/ports.go
@@ -41,6 +41,30 @@ type portDescriptor struct {
port uint16
}
+// Flags represents the type of port reservation.
+//
+// +stateify savable
+type Flags struct {
+ // MostRecent represents UDP SO_REUSEADDR.
+ MostRecent bool
+
+ // LoadBalanced indicates SO_REUSEPORT.
+ //
+ // LoadBalanced takes precidence over MostRecent.
+ LoadBalanced bool
+}
+
+func (f Flags) bits() reuseFlag {
+ var rf reuseFlag
+ if f.MostRecent {
+ rf |= mostRecentFlag
+ }
+ if f.LoadBalanced {
+ rf |= loadBalancedFlag
+ }
+ return rf
+}
+
// PortManager manages allocating, reserving and releasing ports.
type PortManager struct {
mu sync.RWMutex
@@ -54,9 +78,59 @@ type PortManager struct {
hint uint32
}
+type reuseFlag int
+
+const (
+ mostRecentFlag reuseFlag = 1 << iota
+ loadBalancedFlag
+ nextFlag
+
+ flagMask = nextFlag - 1
+)
+
type portNode struct {
- reuse bool
- refs int
+ // refs stores the count for each possible flag combination.
+ refs [nextFlag]int
+}
+
+func (p portNode) totalRefs() int {
+ var total int
+ for _, r := range p.refs {
+ total += r
+ }
+ return total
+}
+
+// flagRefs returns the number of references with all specified flags.
+func (p portNode) flagRefs(flags reuseFlag) int {
+ var total int
+ for i, r := range p.refs {
+ if reuseFlag(i)&flags == flags {
+ total += r
+ }
+ }
+ return total
+}
+
+// allRefsHave returns if all references have all specified flags.
+func (p portNode) allRefsHave(flags reuseFlag) bool {
+ for i, r := range p.refs {
+ if reuseFlag(i)&flags == flags && r > 0 {
+ return false
+ }
+ }
+ return true
+}
+
+// intersectionRefs returns the set of flags shared by all references.
+func (p portNode) intersectionRefs() reuseFlag {
+ intersection := flagMask
+ for i, r := range p.refs {
+ if r > 0 {
+ intersection &= reuseFlag(i)
+ }
+ }
+ return intersection
}
// deviceNode is never empty. When it has no elements, it is removed from the
@@ -66,30 +140,44 @@ type deviceNode map[tcpip.NICID]portNode
// isAvailable checks whether binding is possible by device. If not binding to a
// device, check against all portNodes. If binding to a specific device, check
// against the unspecified device and the provided device.
-func (d deviceNode) isAvailable(reuse bool, bindToDevice tcpip.NICID) bool {
+//
+// If either of the port reuse flags is enabled on any of the nodes, all nodes
+// sharing a port must share at least one reuse flag. This matches Linux's
+// behavior.
+func (d deviceNode) isAvailable(flags Flags, bindToDevice tcpip.NICID) bool {
+ flagBits := flags.bits()
if bindToDevice == 0 {
// Trying to binding all devices.
- if !reuse {
+ if flagBits == 0 {
// Can't bind because the (addr,port) is already bound.
return false
}
+ intersection := flagMask
for _, p := range d {
- if !p.reuse {
- // Can't bind because the (addr,port) was previously bound without reuse.
+ i := p.intersectionRefs()
+ intersection &= i
+ if intersection&flagBits == 0 {
+ // Can't bind because the (addr,port) was
+ // previously bound without reuse.
return false
}
}
return true
}
+ intersection := flagMask
+
if p, ok := d[0]; ok {
- if !reuse || !p.reuse {
+ intersection = p.intersectionRefs()
+ if intersection&flagBits == 0 {
return false
}
}
if p, ok := d[bindToDevice]; ok {
- if !reuse || !p.reuse {
+ i := p.intersectionRefs()
+ intersection &= i
+ if intersection&flagBits == 0 {
return false
}
}
@@ -103,12 +191,12 @@ type bindAddresses map[tcpip.Address]deviceNode
// isAvailable checks whether an IP address is available to bind to. If the
// address is the "any" address, check all other addresses. Otherwise, just
// check against the "any" address and the provided address.
-func (b bindAddresses) isAvailable(addr tcpip.Address, reuse bool, bindToDevice tcpip.NICID) bool {
+func (b bindAddresses) isAvailable(addr tcpip.Address, flags Flags, bindToDevice tcpip.NICID) bool {
if addr == anyIPAddress {
// If binding to the "any" address then check that there are no conflicts
// with all addresses.
for _, d := range b {
- if !d.isAvailable(reuse, bindToDevice) {
+ if !d.isAvailable(flags, bindToDevice) {
return false
}
}
@@ -117,14 +205,14 @@ func (b bindAddresses) isAvailable(addr tcpip.Address, reuse bool, bindToDevice
// Check that there is no conflict with the "any" address.
if d, ok := b[anyIPAddress]; ok {
- if !d.isAvailable(reuse, bindToDevice) {
+ if !d.isAvailable(flags, bindToDevice) {
return false
}
}
// Check that this is no conflict with the provided address.
if d, ok := b[addr]; ok {
- if !d.isAvailable(reuse, bindToDevice) {
+ if !d.isAvailable(flags, bindToDevice) {
return false
}
}
@@ -190,17 +278,17 @@ func (s *PortManager) pickEphemeralPort(offset, count uint32, testPort func(p ui
}
// IsPortAvailable tests if the given port is available on all given protocols.
-func (s *PortManager) IsPortAvailable(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool {
+func (s *PortManager) IsPortAvailable(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) bool {
s.mu.Lock()
defer s.mu.Unlock()
- return s.isPortAvailableLocked(networks, transport, addr, port, reuse, bindToDevice)
+ return s.isPortAvailableLocked(networks, transport, addr, port, flags, bindToDevice)
}
-func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool {
+func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) bool {
for _, network := range networks {
desc := portDescriptor{network, transport, port}
if addrs, ok := s.allocatedPorts[desc]; ok {
- if !addrs.isAvailable(addr, reuse, bindToDevice) {
+ if !addrs.isAvailable(addr, flags, bindToDevice) {
return false
}
}
@@ -212,14 +300,14 @@ func (s *PortManager) isPortAvailableLocked(networks []tcpip.NetworkProtocolNumb
// reserved by another endpoint. If port is zero, ReservePort will search for
// an unreserved ephemeral port and reserve it, returning its value in the
// "port" return value.
-func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) (reservedPort uint16, err *tcpip.Error) {
+func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) (reservedPort uint16, err *tcpip.Error) {
s.mu.Lock()
defer s.mu.Unlock()
// If a port is specified, just try to reserve it for all network
// protocols.
if port != 0 {
- if !s.reserveSpecificPort(networks, transport, addr, port, reuse, bindToDevice) {
+ if !s.reserveSpecificPort(networks, transport, addr, port, flags, bindToDevice) {
return 0, tcpip.ErrPortInUse
}
return port, nil
@@ -227,15 +315,16 @@ func (s *PortManager) ReservePort(networks []tcpip.NetworkProtocolNumber, transp
// A port wasn't specified, so try to find one.
return s.PickEphemeralPort(func(p uint16) (bool, *tcpip.Error) {
- return s.reserveSpecificPort(networks, transport, addr, p, reuse, bindToDevice), nil
+ return s.reserveSpecificPort(networks, transport, addr, p, flags, bindToDevice), nil
})
}
// reserveSpecificPort tries to reserve the given port on all given protocols.
-func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, reuse bool, bindToDevice tcpip.NICID) bool {
- if !s.isPortAvailableLocked(networks, transport, addr, port, reuse, bindToDevice) {
+func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) bool {
+ if !s.isPortAvailableLocked(networks, transport, addr, port, flags, bindToDevice) {
return false
}
+ flagBits := flags.bits()
// Reserve port on all network protocols.
for _, network := range networks {
@@ -250,12 +339,9 @@ func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber
d = make(deviceNode)
m[addr] = d
}
- if n, ok := d[bindToDevice]; ok {
- n.refs++
- d[bindToDevice] = n
- } else {
- d[bindToDevice] = portNode{reuse: reuse, refs: 1}
- }
+ n := d[bindToDevice]
+ n.refs[flagBits]++
+ d[bindToDevice] = n
}
return true
@@ -263,10 +349,12 @@ func (s *PortManager) reserveSpecificPort(networks []tcpip.NetworkProtocolNumber
// ReleasePort releases the reservation on a port/IP combination so that it can
// be reserved by other endpoints.
-func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, bindToDevice tcpip.NICID) {
+func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transport tcpip.TransportProtocolNumber, addr tcpip.Address, port uint16, flags Flags, bindToDevice tcpip.NICID) {
s.mu.Lock()
defer s.mu.Unlock()
+ flagBits := flags.bits()
+
for _, network := range networks {
desc := portDescriptor{network, transport, port}
if m, ok := s.allocatedPorts[desc]; ok {
@@ -278,9 +366,9 @@ func (s *PortManager) ReleasePort(networks []tcpip.NetworkProtocolNumber, transp
if !ok {
continue
}
- n.refs--
+ n.refs[flagBits]--
d[bindToDevice] = n
- if n.refs == 0 {
+ if n.refs == [nextFlag]int{} {
delete(d, bindToDevice)
}
if len(d) == 0 {
diff --git a/pkg/tcpip/ports/ports_state_autogen.go b/pkg/tcpip/ports/ports_state_autogen.go
index 664cc3e71..badae1397 100755
--- a/pkg/tcpip/ports/ports_state_autogen.go
+++ b/pkg/tcpip/ports/ports_state_autogen.go
@@ -2,3 +2,23 @@
package ports
+import (
+ "gvisor.dev/gvisor/pkg/state"
+)
+
+func (x *Flags) beforeSave() {}
+func (x *Flags) save(m state.Map) {
+ x.beforeSave()
+ m.Save("MostRecent", &x.MostRecent)
+ m.Save("LoadBalanced", &x.LoadBalanced)
+}
+
+func (x *Flags) afterLoad() {}
+func (x *Flags) load(m state.Map) {
+ m.Load("MostRecent", &x.MostRecent)
+ m.Load("LoadBalanced", &x.LoadBalanced)
+}
+
+func init() {
+ state.Register("ports.Flags", (*Flags)(nil), state.Fns{Save: (*Flags).save, Load: (*Flags).load})
+}
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 9d4a87e30..4861ab513 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -30,6 +30,7 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/hash/jenkins"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/iptables"
+ "gvisor.dev/gvisor/pkg/tcpip/ports"
"gvisor.dev/gvisor/pkg/tcpip/seqnum"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tmutex"
@@ -343,6 +344,7 @@ type endpoint struct {
// Values used to reserve a port or register a transport endpoint
// (which ever happens first).
boundBindToDevice tcpip.NICID
+ boundPortFlags ports.Flags
// effectiveNetProtos contains the network protocols actually in use. In
// most cases it will only contain "netProto", but in cases like IPv6
@@ -737,9 +739,10 @@ func (e *endpoint) Close() {
e.isRegistered = false
}
- e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundBindToDevice)
+ e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundPortFlags, e.boundBindToDevice)
e.isPortReserved = false
e.boundBindToDevice = 0
+ e.boundPortFlags = ports.Flags{}
}
// Mark endpoint as closed.
@@ -800,10 +803,11 @@ func (e *endpoint) cleanupLocked() {
}
if e.isPortReserved {
- e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundBindToDevice)
+ e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundPortFlags, e.boundBindToDevice)
e.isPortReserved = false
}
e.boundBindToDevice = 0
+ e.boundPortFlags = ports.Flags{}
e.route.Release()
e.stack.CompleteTransportEndpointCleanup(e)
@@ -1775,7 +1779,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) *tc
}
// reusePort is false below because connect cannot reuse a port even if
// reusePort was set.
- if !e.stack.IsPortAvailable(netProtos, ProtocolNumber, e.ID.LocalAddress, p, false /* reusePort */, e.bindToDevice) {
+ if !e.stack.IsPortAvailable(netProtos, ProtocolNumber, e.ID.LocalAddress, p, ports.Flags{LoadBalanced: false}, e.bindToDevice) {
return false, nil
}
@@ -1802,7 +1806,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) *tc
// before Connect: in such a case we don't want to hold on to
// reservations anymore.
if e.isPortReserved {
- e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, origID.LocalAddress, origID.LocalPort, e.boundBindToDevice)
+ e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, origID.LocalAddress, origID.LocalPort, e.boundPortFlags, e.boundBindToDevice)
e.isPortReserved = false
}
@@ -2034,28 +2038,33 @@ func (e *endpoint) Bind(addr tcpip.FullAddress) (err *tcpip.Error) {
}
}
- port, err := e.stack.ReservePort(netProtos, ProtocolNumber, addr.Addr, addr.Port, e.reusePort, e.bindToDevice)
+ flags := ports.Flags{
+ LoadBalanced: e.reusePort,
+ }
+ port, err := e.stack.ReservePort(netProtos, ProtocolNumber, addr.Addr, addr.Port, flags, e.bindToDevice)
if err != nil {
return err
}
e.boundBindToDevice = e.bindToDevice
+ e.boundPortFlags = flags
e.isPortReserved = true
e.effectiveNetProtos = netProtos
e.ID.LocalPort = port
// Any failures beyond this point must remove the port registration.
- defer func(bindToDevice tcpip.NICID) {
+ defer func(portFlags ports.Flags, bindToDevice tcpip.NICID) {
if err != nil {
- e.stack.ReleasePort(netProtos, ProtocolNumber, addr.Addr, port, bindToDevice)
+ e.stack.ReleasePort(netProtos, ProtocolNumber, addr.Addr, port, portFlags, bindToDevice)
e.isPortReserved = false
e.effectiveNetProtos = nil
e.ID.LocalPort = 0
e.ID.LocalAddress = ""
e.boundNICID = 0
e.boundBindToDevice = 0
+ e.boundPortFlags = ports.Flags{}
}
- }(e.boundBindToDevice)
+ }(e.boundPortFlags, e.boundBindToDevice)
// If an address is specified, we must ensure that it's one of our
// local addresses.
diff --git a/pkg/tcpip/transport/tcp/tcp_state_autogen.go b/pkg/tcpip/transport/tcp/tcp_state_autogen.go
index 9d16e3526..cc3f5c931 100755
--- a/pkg/tcpip/transport/tcp/tcp_state_autogen.go
+++ b/pkg/tcpip/transport/tcp/tcp_state_autogen.go
@@ -112,6 +112,7 @@ func (x *endpoint) save(m state.Map) {
m.Save("isConnectNotified", &x.isConnectNotified)
m.Save("broadcast", &x.broadcast)
m.Save("boundBindToDevice", &x.boundBindToDevice)
+ m.Save("boundPortFlags", &x.boundPortFlags)
m.Save("workerRunning", &x.workerRunning)
m.Save("workerCleanup", &x.workerCleanup)
m.Save("sendTSOk", &x.sendTSOk)
@@ -165,6 +166,7 @@ func (x *endpoint) load(m state.Map) {
m.Load("isConnectNotified", &x.isConnectNotified)
m.Load("broadcast", &x.broadcast)
m.Load("boundBindToDevice", &x.boundBindToDevice)
+ m.Load("boundPortFlags", &x.boundPortFlags)
m.Load("workerRunning", &x.workerRunning)
m.Load("workerCleanup", &x.workerCleanup)
m.Load("sendTSOk", &x.sendTSOk)
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 4b161e404..1ac4705af 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -21,6 +21,7 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/iptables"
+ "gvisor.dev/gvisor/pkg/tcpip/ports"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/waiter"
)
@@ -107,6 +108,7 @@ type endpoint struct {
// Values used to reserve a port or register a transport endpoint.
// (which ever happens first).
boundBindToDevice tcpip.NICID
+ boundPortFlags ports.Flags
// sendTOS represents IPv4 TOS or IPv6 TrafficClass,
// applied while sending packets. Defaults to 0 as on Linux.
@@ -180,8 +182,9 @@ func (e *endpoint) Close() {
switch e.state {
case StateBound, StateConnected:
e.stack.UnregisterTransportEndpoint(e.RegisterNICID, e.effectiveNetProtos, ProtocolNumber, e.ID, e, e.boundBindToDevice)
- e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundBindToDevice)
+ e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundPortFlags, e.boundBindToDevice)
e.boundBindToDevice = 0
+ e.boundPortFlags = ports.Flags{}
}
for _, mem := range e.multicastMemberships {
@@ -895,7 +898,8 @@ func (e *endpoint) Disconnect() *tcpip.Error {
} else {
if e.ID.LocalPort != 0 {
// Release the ephemeral port.
- e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundBindToDevice)
+ e.stack.ReleasePort(e.effectiveNetProtos, ProtocolNumber, e.ID.LocalAddress, e.ID.LocalPort, e.boundPortFlags, e.boundBindToDevice)
+ e.boundPortFlags = ports.Flags{}
}
e.state = StateInitial
}
@@ -1042,16 +1046,23 @@ func (*endpoint) Accept() (tcpip.Endpoint, *waiter.Queue, *tcpip.Error) {
func (e *endpoint) registerWithStack(nicID tcpip.NICID, netProtos []tcpip.NetworkProtocolNumber, id stack.TransportEndpointID) (stack.TransportEndpointID, tcpip.NICID, *tcpip.Error) {
if e.ID.LocalPort == 0 {
- port, err := e.stack.ReservePort(netProtos, ProtocolNumber, id.LocalAddress, id.LocalPort, e.reusePort, e.bindToDevice)
+ flags := ports.Flags{
+ LoadBalanced: e.reusePort,
+ // FIXME(b/129164367): Support SO_REUSEADDR.
+ MostRecent: false,
+ }
+ port, err := e.stack.ReservePort(netProtos, ProtocolNumber, id.LocalAddress, id.LocalPort, flags, e.bindToDevice)
if err != nil {
return id, e.bindToDevice, err
}
+ e.boundPortFlags = flags
id.LocalPort = port
}
err := e.stack.RegisterTransportEndpoint(nicID, netProtos, ProtocolNumber, id, e, e.reusePort, e.bindToDevice)
if err != nil {
- e.stack.ReleasePort(netProtos, ProtocolNumber, id.LocalAddress, id.LocalPort, e.bindToDevice)
+ e.stack.ReleasePort(netProtos, ProtocolNumber, id.LocalAddress, id.LocalPort, e.boundPortFlags, e.bindToDevice)
+ e.boundPortFlags = ports.Flags{}
}
return id, e.bindToDevice, err
}
diff --git a/pkg/tcpip/transport/udp/udp_state_autogen.go b/pkg/tcpip/transport/udp/udp_state_autogen.go
index 48a3bfc79..5c4b43214 100755
--- a/pkg/tcpip/transport/udp/udp_state_autogen.go
+++ b/pkg/tcpip/transport/udp/udp_state_autogen.go
@@ -49,6 +49,7 @@ func (x *endpoint) save(m state.Map) {
m.Save("bindToDevice", &x.bindToDevice)
m.Save("broadcast", &x.broadcast)
m.Save("boundBindToDevice", &x.boundBindToDevice)
+ m.Save("boundPortFlags", &x.boundPortFlags)
m.Save("sendTOS", &x.sendTOS)
m.Save("shutdownFlags", &x.shutdownFlags)
m.Save("multicastMemberships", &x.multicastMemberships)
@@ -76,6 +77,7 @@ func (x *endpoint) load(m state.Map) {
m.Load("bindToDevice", &x.bindToDevice)
m.Load("broadcast", &x.broadcast)
m.Load("boundBindToDevice", &x.boundBindToDevice)
+ m.Load("boundPortFlags", &x.boundPortFlags)
m.Load("sendTOS", &x.sendTOS)
m.Load("shutdownFlags", &x.shutdownFlags)
m.Load("multicastMemberships", &x.multicastMemberships)