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Diffstat (limited to 'pkg/sentry/socket/netstack/netstack.go')
-rw-r--r--pkg/sentry/socket/netstack/netstack.go536
1 files changed, 407 insertions, 129 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index debf9bce0..d5879c10f 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -29,26 +29,26 @@ import (
"io"
"math"
"reflect"
- "sync"
+ "sync/atomic"
"syscall"
"time"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/binary"
+ "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/metric"
+ "gvisor.dev/gvisor/pkg/safemem"
"gvisor.dev/gvisor/pkg/sentry/arch"
- "gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
"gvisor.dev/gvisor/pkg/sentry/inet"
"gvisor.dev/gvisor/pkg/sentry/kernel"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
- "gvisor.dev/gvisor/pkg/sentry/safemem"
"gvisor.dev/gvisor/pkg/sentry/socket"
"gvisor.dev/gvisor/pkg/sentry/socket/netfilter"
"gvisor.dev/gvisor/pkg/sentry/unimpl"
- "gvisor.dev/gvisor/pkg/sentry/usermem"
+ "gvisor.dev/gvisor/pkg/sync"
"gvisor.dev/gvisor/pkg/syserr"
"gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/tcpip"
@@ -57,12 +57,19 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+ "gvisor.dev/gvisor/pkg/usermem"
"gvisor.dev/gvisor/pkg/waiter"
)
func mustCreateMetric(name, description string) *tcpip.StatCounter {
var cm tcpip.StatCounter
- metric.MustRegisterCustomUint64Metric(name, false /* sync */, description, cm.Value)
+ metric.MustRegisterCustomUint64Metric(name, true /* cumulative */, false /* sync */, description, cm.Value)
+ return &cm
+}
+
+func mustCreateGauge(name, description string) *tcpip.StatCounter {
+ var cm tcpip.StatCounter
+ metric.MustRegisterCustomUint64Metric(name, false /* cumulative */, false /* sync */, description, cm.Value)
return &cm
}
@@ -138,17 +145,23 @@ var Metrics = tcpip.Stats{
},
},
IP: tcpip.IPStats{
- PacketsReceived: mustCreateMetric("/netstack/ip/packets_received", "Total number of IP packets received from the link layer in nic.DeliverNetworkPacket."),
- InvalidAddressesReceived: mustCreateMetric("/netstack/ip/invalid_addresses_received", "Total number of IP packets received with an unknown or invalid destination address."),
- PacketsDelivered: mustCreateMetric("/netstack/ip/packets_delivered", "Total number of incoming IP packets that are successfully delivered to the transport layer via HandlePacket."),
- PacketsSent: mustCreateMetric("/netstack/ip/packets_sent", "Total number of IP packets sent via WritePacket."),
- OutgoingPacketErrors: mustCreateMetric("/netstack/ip/outgoing_packet_errors", "Total number of IP packets which failed to write to a link-layer endpoint."),
- MalformedPacketsReceived: mustCreateMetric("/netstack/ip/malformed_packets_received", "Total number of IP packets which failed IP header validation checks."),
- MalformedFragmentsReceived: mustCreateMetric("/netstack/ip/malformed_fragments_received", "Total number of IP fragments which failed IP fragment validation checks."),
+ PacketsReceived: mustCreateMetric("/netstack/ip/packets_received", "Total number of IP packets received from the link layer in nic.DeliverNetworkPacket."),
+ InvalidDestinationAddressesReceived: mustCreateMetric("/netstack/ip/invalid_addresses_received", "Total number of IP packets received with an unknown or invalid destination address."),
+ InvalidSourceAddressesReceived: mustCreateMetric("/netstack/ip/invalid_source_addresses_received", "Total number of IP packets received with an unknown or invalid source address."),
+ PacketsDelivered: mustCreateMetric("/netstack/ip/packets_delivered", "Total number of incoming IP packets that are successfully delivered to the transport layer via HandlePacket."),
+ PacketsSent: mustCreateMetric("/netstack/ip/packets_sent", "Total number of IP packets sent via WritePacket."),
+ OutgoingPacketErrors: mustCreateMetric("/netstack/ip/outgoing_packet_errors", "Total number of IP packets which failed to write to a link-layer endpoint."),
+ MalformedPacketsReceived: mustCreateMetric("/netstack/ip/malformed_packets_received", "Total number of IP packets which failed IP header validation checks."),
+ MalformedFragmentsReceived: mustCreateMetric("/netstack/ip/malformed_fragments_received", "Total number of IP fragments which failed IP fragment validation checks."),
},
TCP: tcpip.TCPStats{
ActiveConnectionOpenings: mustCreateMetric("/netstack/tcp/active_connection_openings", "Number of connections opened successfully via Connect."),
PassiveConnectionOpenings: mustCreateMetric("/netstack/tcp/passive_connection_openings", "Number of connections opened successfully via Listen."),
+ CurrentEstablished: mustCreateGauge("/netstack/tcp/current_established", "Number of connections in ESTABLISHED state now."),
+ CurrentConnected: mustCreateGauge("/netstack/tcp/current_open", "Number of connections that are in connected state."),
+ EstablishedResets: mustCreateMetric("/netstack/tcp/established_resets", "Number of times TCP connections have made a direct transition to the CLOSED state from either the ESTABLISHED state or the CLOSE-WAIT state"),
+ EstablishedClosed: mustCreateMetric("/netstack/tcp/established_closed", "Number of times established TCP connections made a transition to CLOSED state."),
+ EstablishedTimedout: mustCreateMetric("/netstack/tcp/established_timedout", "Number of times an established connection was reset because of keep-alive time out."),
ListenOverflowSynDrop: mustCreateMetric("/netstack/tcp/listen_overflow_syn_drop", "Number of times the listen queue overflowed and a SYN was dropped."),
ListenOverflowAckDrop: mustCreateMetric("/netstack/tcp/listen_overflow_ack_drop", "Number of times the listen queue overflowed and the final ACK in the handshake was dropped."),
ListenOverflowSynCookieSent: mustCreateMetric("/netstack/tcp/listen_overflow_syn_cookie_sent", "Number of times a SYN cookie was sent."),
@@ -218,17 +231,25 @@ type commonEndpoint interface {
// transport.Endpoint.SetSockOpt.
SetSockOpt(interface{}) *tcpip.Error
+ // SetSockOptBool implements tcpip.Endpoint.SetSockOptBool and
+ // transport.Endpoint.SetSockOptBool.
+ SetSockOptBool(opt tcpip.SockOptBool, v bool) *tcpip.Error
+
// SetSockOptInt implements tcpip.Endpoint.SetSockOptInt and
// transport.Endpoint.SetSockOptInt.
- SetSockOptInt(opt tcpip.SockOpt, v int) *tcpip.Error
+ SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error
// GetSockOpt implements tcpip.Endpoint.GetSockOpt and
// transport.Endpoint.GetSockOpt.
GetSockOpt(interface{}) *tcpip.Error
+ // GetSockOptBool implements tcpip.Endpoint.GetSockOptBool and
+ // transport.Endpoint.GetSockOpt.
+ GetSockOptBool(opt tcpip.SockOptBool) (bool, *tcpip.Error)
+
// GetSockOptInt implements tcpip.Endpoint.GetSockOptInt and
// transport.Endpoint.GetSockOpt.
- GetSockOptInt(opt tcpip.SockOpt) (int, *tcpip.Error)
+ GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error)
}
// SocketOperations encapsulates all the state needed to represent a network stack
@@ -250,6 +271,12 @@ type SocketOperations struct {
skType linux.SockType
protocol int
+ // readViewHasData is 1 iff readView has data to be read, 0 otherwise.
+ // Must be accessed using atomic operations. It must only be written
+ // with readMu held but can be read without holding readMu. The latter
+ // is required to avoid deadlocks in epoll Readiness checks.
+ readViewHasData uint32
+
// readMu protects access to the below fields.
readMu sync.Mutex `state:"nosave"`
// readView contains the remaining payload from the last packet.
@@ -279,7 +306,7 @@ type SocketOperations struct {
// New creates a new endpoint socket.
func New(t *kernel.Task, family int, skType linux.SockType, protocol int, queue *waiter.Queue, endpoint tcpip.Endpoint) (*fs.File, *syserr.Error) {
if skType == linux.SOCK_STREAM {
- if err := endpoint.SetSockOpt(tcpip.DelayOption(1)); err != nil {
+ if err := endpoint.SetSockOptBool(tcpip.DelayOption, true); err != nil {
return nil, syserr.TranslateNetstackError(err)
}
}
@@ -312,22 +339,15 @@ func bytesToIPAddress(addr []byte) tcpip.Address {
// converts it to the FullAddress format. It supports AF_UNIX, AF_INET,
// AF_INET6, and AF_PACKET addresses.
//
-// strict indicates whether addresses with the AF_UNSPEC family are accepted of not.
-//
// AddressAndFamily returns an address and its family.
-func AddressAndFamily(sfamily int, addr []byte, strict bool) (tcpip.FullAddress, uint16, *syserr.Error) {
+func AddressAndFamily(addr []byte) (tcpip.FullAddress, uint16, *syserr.Error) {
// Make sure we have at least 2 bytes for the address family.
if len(addr) < 2 {
return tcpip.FullAddress{}, 0, syserr.ErrInvalidArgument
}
- family := usermem.ByteOrder.Uint16(addr)
- if family != uint16(sfamily) && (!strict && family != linux.AF_UNSPEC) {
- return tcpip.FullAddress{}, family, syserr.ErrAddressFamilyNotSupported
- }
-
// Get the rest of the fields based on the address family.
- switch family {
+ switch family := usermem.ByteOrder.Uint16(addr); family {
case linux.AF_UNIX:
path := addr[2:]
if len(path) > linux.UnixPathMax {
@@ -403,21 +423,24 @@ func (s *SocketOperations) isPacketBased() bool {
// fetchReadView updates the readView field of the socket if it's currently
// empty. It assumes that the socket is locked.
+//
+// Precondition: s.readMu must be held.
func (s *SocketOperations) fetchReadView() *syserr.Error {
if len(s.readView) > 0 {
return nil
}
-
s.readView = nil
s.sender = tcpip.FullAddress{}
v, cms, err := s.Endpoint.Read(&s.sender)
if err != nil {
+ atomic.StoreUint32(&s.readViewHasData, 0)
return syserr.TranslateNetstackError(err)
}
s.readView = v
s.readCM = cms
+ atomic.StoreUint32(&s.readViewHasData, 1)
return nil
}
@@ -518,7 +541,7 @@ func (s *SocketOperations) Write(ctx context.Context, _ *fs.File, src usermem.IO
}
if resCh != nil {
- t := ctx.(*kernel.Task)
+ t := kernel.TaskFromContext(ctx)
if err := t.Block(resCh); err != nil {
return 0, syserr.FromError(err).ToError()
}
@@ -591,7 +614,7 @@ func (s *SocketOperations) ReadFrom(ctx context.Context, _ *fs.File, r io.Reader
}
if resCh != nil {
- t := ctx.(*kernel.Task)
+ t := kernel.TaskFromContext(ctx)
if err := t.Block(resCh); err != nil {
return 0, syserr.FromError(err).ToError()
}
@@ -616,20 +639,48 @@ func (s *SocketOperations) Readiness(mask waiter.EventMask) waiter.EventMask {
// Check our cached value iff the caller asked for readability and the
// endpoint itself is currently not readable.
if (mask & ^r & waiter.EventIn) != 0 {
- s.readMu.Lock()
- if len(s.readView) > 0 {
+ if atomic.LoadUint32(&s.readViewHasData) == 1 {
r |= waiter.EventIn
}
- s.readMu.Unlock()
}
return r
}
+func (s *SocketOperations) checkFamily(family uint16, exact bool) *syserr.Error {
+ if family == uint16(s.family) {
+ return nil
+ }
+ if !exact && family == linux.AF_INET && s.family == linux.AF_INET6 {
+ v, err := s.Endpoint.GetSockOptBool(tcpip.V6OnlyOption)
+ if err != nil {
+ return syserr.TranslateNetstackError(err)
+ }
+ if !v {
+ return nil
+ }
+ }
+ return syserr.ErrInvalidArgument
+}
+
+// mapFamily maps the AF_INET ANY address to the IPv4-mapped IPv6 ANY if the
+// receiver's family is AF_INET6.
+//
+// This is a hack to work around the fact that both IPv4 and IPv6 ANY are
+// represented by the empty string.
+//
+// TODO(gvisor.dev/issue/1556): remove this function.
+func (s *SocketOperations) mapFamily(addr tcpip.FullAddress, family uint16) tcpip.FullAddress {
+ if len(addr.Addr) == 0 && s.family == linux.AF_INET6 && family == linux.AF_INET {
+ addr.Addr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x00"
+ }
+ return addr
+}
+
// Connect implements the linux syscall connect(2) for sockets backed by
// tpcip.Endpoint.
func (s *SocketOperations) Connect(t *kernel.Task, sockaddr []byte, blocking bool) *syserr.Error {
- addr, family, err := AddressAndFamily(s.family, sockaddr, false /* strict */)
+ addr, family, err := AddressAndFamily(sockaddr)
if err != nil {
return err
}
@@ -641,6 +692,12 @@ func (s *SocketOperations) Connect(t *kernel.Task, sockaddr []byte, blocking boo
}
return syserr.TranslateNetstackError(err)
}
+
+ if err := s.checkFamily(family, false /* exact */); err != nil {
+ return err
+ }
+ addr = s.mapFamily(addr, family)
+
// Always return right away in the non-blocking case.
if !blocking {
return syserr.TranslateNetstackError(s.Endpoint.Connect(addr))
@@ -669,9 +726,43 @@ func (s *SocketOperations) Connect(t *kernel.Task, sockaddr []byte, blocking boo
// Bind implements the linux syscall bind(2) for sockets backed by
// tcpip.Endpoint.
func (s *SocketOperations) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error {
- addr, _, err := AddressAndFamily(s.family, sockaddr, true /* strict */)
- if err != nil {
- return err
+ if len(sockaddr) < 2 {
+ return syserr.ErrInvalidArgument
+ }
+
+ family := usermem.ByteOrder.Uint16(sockaddr)
+ var addr tcpip.FullAddress
+
+ // Bind for AF_PACKET requires only family, protocol and ifindex.
+ // In function AddressAndFamily, we check the address length which is
+ // not needed for AF_PACKET bind.
+ if family == linux.AF_PACKET {
+ var a linux.SockAddrLink
+ if len(sockaddr) < sockAddrLinkSize {
+ return syserr.ErrInvalidArgument
+ }
+ binary.Unmarshal(sockaddr[:sockAddrLinkSize], usermem.ByteOrder, &a)
+
+ if a.Protocol != uint16(s.protocol) {
+ return syserr.ErrInvalidArgument
+ }
+
+ addr = tcpip.FullAddress{
+ NIC: tcpip.NICID(a.InterfaceIndex),
+ Addr: tcpip.Address(a.HardwareAddr[:header.EthernetAddressSize]),
+ }
+ } else {
+ var err *syserr.Error
+ addr, family, err = AddressAndFamily(sockaddr)
+ if err != nil {
+ return err
+ }
+
+ if err = s.checkFamily(family, true /* exact */); err != nil {
+ return err
+ }
+
+ addr = s.mapFamily(addr, family)
}
// Issue the bind request to the endpoint.
@@ -822,7 +913,11 @@ func (s *SocketOperations) GetSockOpt(t *kernel.Task, level, name int, outPtr us
return nil, syserr.ErrInvalidArgument
}
- info, err := netfilter.GetInfo(t, s.Endpoint, outPtr)
+ stack := inet.StackFromContext(t)
+ if stack == nil {
+ return nil, syserr.ErrNoDevice
+ }
+ info, err := netfilter.GetInfo(t, stack.(*Stack).Stack, outPtr)
if err != nil {
return nil, err
}
@@ -833,7 +928,11 @@ func (s *SocketOperations) GetSockOpt(t *kernel.Task, level, name int, outPtr us
return nil, syserr.ErrInvalidArgument
}
- entries, err := netfilter.GetEntries(t, s.Endpoint, outPtr, outLen)
+ stack := inet.StackFromContext(t)
+ if stack == nil {
+ return nil, syserr.ErrNoDevice
+ }
+ entries, err := netfilter.GetEntries(t, stack.(*Stack).Stack, outPtr, outLen)
if err != nil {
return nil, err
}
@@ -847,7 +946,7 @@ func (s *SocketOperations) GetSockOpt(t *kernel.Task, level, name int, outPtr us
// GetSockOpt can be used to implement the linux syscall getsockopt(2) for
// sockets backed by a commonEndpoint.
-func GetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, skType linux.SockType, level, name, outLen int) (interface{}, *syserr.Error) {
+func GetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, family int, skType linux.SockType, level, name, outLen int) (interface{}, *syserr.Error) {
switch level {
case linux.SOL_SOCKET:
return getSockOptSocket(t, s, ep, family, skType, name, outLen)
@@ -872,8 +971,15 @@ func GetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int,
return nil, syserr.ErrProtocolNotAvailable
}
+func boolToInt32(v bool) int32 {
+ if v {
+ return 1
+ }
+ return 0
+}
+
// getSockOptSocket implements GetSockOpt when level is SOL_SOCKET.
-func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family int, skType linux.SockType, name, outLen int) (interface{}, *syserr.Error) {
+func getSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, family int, skType linux.SockType, name, outLen int) (interface{}, *syserr.Error) {
// TODO(b/124056281): Stop rejecting short optLen values in getsockopt.
switch name {
case linux.SO_ERROR:
@@ -905,12 +1011,11 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.PasscredOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.PasscredOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.SO_SNDBUF:
if outLen < sizeOfInt32 {
@@ -949,61 +1054,67 @@ func getSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, family
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.ReuseAddressOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.ReuseAddressOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.SO_REUSEPORT:
if outLen < sizeOfInt32 {
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.ReusePortOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.ReusePortOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.SO_BINDTODEVICE:
var v tcpip.BindToDeviceOption
if err := ep.GetSockOpt(&v); err != nil {
return nil, syserr.TranslateNetstackError(err)
}
- if len(v) == 0 {
+ if v == 0 {
return []byte{}, nil
}
if outLen < linux.IFNAMSIZ {
return nil, syserr.ErrInvalidArgument
}
- return append([]byte(v), 0), nil
+ s := t.NetworkContext()
+ if s == nil {
+ return nil, syserr.ErrNoDevice
+ }
+ nic, ok := s.Interfaces()[int32(v)]
+ if !ok {
+ // The NICID no longer indicates a valid interface, probably because that
+ // interface was removed.
+ return nil, syserr.ErrUnknownDevice
+ }
+ return append([]byte(nic.Name), 0), nil
case linux.SO_BROADCAST:
if outLen < sizeOfInt32 {
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.BroadcastOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.BroadcastOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.SO_KEEPALIVE:
if outLen < sizeOfInt32 {
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.KeepaliveEnabledOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.KeepaliveEnabledOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.SO_LINGER:
if outLen < linux.SizeOfLinger {
@@ -1053,47 +1164,41 @@ func getSockOptTCP(t *kernel.Task, ep commonEndpoint, name, outLen int) (interfa
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.DelayOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.DelayOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- if v == 0 {
- return int32(1), nil
- }
- return int32(0), nil
+ return boolToInt32(!v), nil
case linux.TCP_CORK:
if outLen < sizeOfInt32 {
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.CorkOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.CorkOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.TCP_QUICKACK:
if outLen < sizeOfInt32 {
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.QuickAckOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.QuickAckOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.TCP_MAXSEG:
if outLen < sizeOfInt32 {
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.MaxSegOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptInt(tcpip.MaxSegOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
@@ -1123,6 +1228,18 @@ func getSockOptTCP(t *kernel.Task, ep commonEndpoint, name, outLen int) (interfa
return int32(time.Duration(v) / time.Second), nil
+ case linux.TCP_USER_TIMEOUT:
+ if outLen < sizeOfInt32 {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ var v tcpip.TCPUserTimeoutOption
+ if err := ep.GetSockOpt(&v); err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+
+ return int32(time.Duration(v) / time.Millisecond), nil
+
case linux.TCP_INFO:
var v tcpip.TCPInfoOption
if err := ep.GetSockOpt(&v); err != nil {
@@ -1171,6 +1288,30 @@ func getSockOptTCP(t *kernel.Task, ep commonEndpoint, name, outLen int) (interfa
copy(b, v)
return b, nil
+ case linux.TCP_LINGER2:
+ if outLen < sizeOfInt32 {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ var v tcpip.TCPLingerTimeoutOption
+ if err := ep.GetSockOpt(&v); err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+
+ return int32(time.Duration(v) / time.Second), nil
+
+ case linux.TCP_DEFER_ACCEPT:
+ if outLen < sizeOfInt32 {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ var v tcpip.TCPDeferAcceptOption
+ if err := ep.GetSockOpt(&v); err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+
+ return int32(time.Duration(v) / time.Second), nil
+
default:
emitUnimplementedEventTCP(t, name)
}
@@ -1185,12 +1326,11 @@ func getSockOptIPv6(t *kernel.Task, ep commonEndpoint, name, outLen int) (interf
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.V6OnlyOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.V6OnlyOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- return int32(v), nil
+ return boolToInt32(v), nil
case linux.IPV6_PATHMTU:
t.Kernel().EmitUnimplementedEvent(t)
@@ -1200,8 +1340,8 @@ func getSockOptIPv6(t *kernel.Task, ep commonEndpoint, name, outLen int) (interf
if outLen == 0 {
return make([]byte, 0), nil
}
- var v tcpip.IPv6TrafficClassOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptInt(tcpip.IPv6TrafficClassOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
@@ -1214,6 +1354,17 @@ func getSockOptIPv6(t *kernel.Task, ep commonEndpoint, name, outLen int) (interf
}
return ib, nil
+ case linux.IPV6_RECVTCLASS:
+ if outLen < sizeOfInt32 {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ v, err := ep.GetSockOptBool(tcpip.ReceiveTClassOption)
+ if err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+ return boolToInt32(v), nil
+
default:
emitUnimplementedEventIPv6(t, name)
}
@@ -1228,8 +1379,8 @@ func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int, family in
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.TTLOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptInt(tcpip.TTLOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
@@ -1245,8 +1396,8 @@ func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int, family in
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.MulticastTTLOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptInt(tcpip.MulticastTTLOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
@@ -1271,23 +1422,19 @@ func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int, family in
return nil, syserr.ErrInvalidArgument
}
- var v tcpip.MulticastLoopOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptBool(tcpip.MulticastLoopOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
-
- if v {
- return int32(1), nil
- }
- return int32(0), nil
+ return boolToInt32(v), nil
case linux.IP_TOS:
// Length handling for parity with Linux.
if outLen == 0 {
return []byte(nil), nil
}
- var v tcpip.IPv4TOSOption
- if err := ep.GetSockOpt(&v); err != nil {
+ v, err := ep.GetSockOptInt(tcpip.IPv4TOSOption)
+ if err != nil {
return nil, syserr.TranslateNetstackError(err)
}
if outLen < sizeOfInt32 {
@@ -1295,6 +1442,28 @@ func getSockOptIP(t *kernel.Task, ep commonEndpoint, name, outLen int, family in
}
return int32(v), nil
+ case linux.IP_RECVTOS:
+ if outLen < sizeOfInt32 {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ v, err := ep.GetSockOptBool(tcpip.ReceiveTOSOption)
+ if err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+ return boolToInt32(v), nil
+
+ case linux.IP_PKTINFO:
+ if outLen < sizeOfInt32 {
+ return nil, syserr.ErrInvalidArgument
+ }
+
+ v, err := ep.GetSockOptBool(tcpip.ReceiveIPPacketInfoOption)
+ if err != nil {
+ return nil, syserr.TranslateNetstackError(err)
+ }
+ return boolToInt32(v), nil
+
default:
emitUnimplementedEventIP(t, name)
}
@@ -1328,12 +1497,32 @@ func (s *SocketOperations) SetSockOpt(t *kernel.Task, level int, name int, optVa
return nil
}
+ if s.skType == linux.SOCK_RAW && level == linux.IPPROTO_IP {
+ switch name {
+ case linux.IPT_SO_SET_REPLACE:
+ if len(optVal) < linux.SizeOfIPTReplace {
+ return syserr.ErrInvalidArgument
+ }
+
+ stack := inet.StackFromContext(t)
+ if stack == nil {
+ return syserr.ErrNoDevice
+ }
+ // Stack must be a netstack stack.
+ return netfilter.SetEntries(stack.(*Stack).Stack, optVal)
+
+ case linux.IPT_SO_SET_ADD_COUNTERS:
+ // TODO(gvisor.dev/issue/170): Counter support.
+ return nil
+ }
+ }
+
return SetSockOpt(t, s, s.Endpoint, level, name, optVal)
}
// SetSockOpt can be used to implement the linux syscall setsockopt(2) for
// sockets backed by a commonEndpoint.
-func SetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, level int, name int, optVal []byte) *syserr.Error {
+func SetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, level int, name int, optVal []byte) *syserr.Error {
switch level {
case linux.SOL_SOCKET:
return setSockOptSocket(t, s, ep, name, optVal)
@@ -1360,7 +1549,7 @@ func SetSockOpt(t *kernel.Task, s socket.Socket, ep commonEndpoint, level int, n
}
// setSockOptSocket implements SetSockOpt when level is SOL_SOCKET.
-func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
+func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
switch name {
case linux.SO_SNDBUF:
if len(optVal) < sizeOfInt32 {
@@ -1384,7 +1573,7 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.ReuseAddressOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.ReuseAddressOption, v != 0))
case linux.SO_REUSEPORT:
if len(optVal) < sizeOfInt32 {
@@ -1392,14 +1581,27 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.ReusePortOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.ReusePortOption, v != 0))
case linux.SO_BINDTODEVICE:
n := bytes.IndexByte(optVal, 0)
if n == -1 {
n = len(optVal)
}
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(optVal[:n])))
+ name := string(optVal[:n])
+ if name == "" {
+ return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(0)))
+ }
+ s := t.NetworkContext()
+ if s == nil {
+ return syserr.ErrNoDevice
+ }
+ for nicID, nic := range s.Interfaces() {
+ if nic.Name == name {
+ return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BindToDeviceOption(nicID)))
+ }
+ }
+ return syserr.ErrUnknownDevice
case linux.SO_BROADCAST:
if len(optVal) < sizeOfInt32 {
@@ -1407,7 +1609,7 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.BroadcastOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.BroadcastOption, v != 0))
case linux.SO_PASSCRED:
if len(optVal) < sizeOfInt32 {
@@ -1415,7 +1617,7 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.PasscredOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.PasscredOption, v != 0))
case linux.SO_KEEPALIVE:
if len(optVal) < sizeOfInt32 {
@@ -1423,7 +1625,7 @@ func setSockOptSocket(t *kernel.Task, s socket.Socket, ep commonEndpoint, name i
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.KeepaliveEnabledOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.KeepaliveEnabledOption, v != 0))
case linux.SO_SNDTIMEO:
if len(optVal) < linux.SizeOfTimeval {
@@ -1495,11 +1697,7 @@ func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *
}
v := usermem.ByteOrder.Uint32(optVal)
- var o tcpip.DelayOption
- if v == 0 {
- o = 1
- }
- return syserr.TranslateNetstackError(ep.SetSockOpt(o))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.DelayOption, v == 0))
case linux.TCP_CORK:
if len(optVal) < sizeOfInt32 {
@@ -1507,7 +1705,7 @@ func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.CorkOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.CorkOption, v != 0))
case linux.TCP_QUICKACK:
if len(optVal) < sizeOfInt32 {
@@ -1515,7 +1713,7 @@ func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.QuickAckOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.QuickAckOption, v != 0))
case linux.TCP_MAXSEG:
if len(optVal) < sizeOfInt32 {
@@ -1523,7 +1721,7 @@ func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.MaxSegOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.MaxSegOption, int(v)))
case linux.TCP_KEEPIDLE:
if len(optVal) < sizeOfInt32 {
@@ -1547,6 +1745,17 @@ func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *
}
return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.KeepaliveIntervalOption(time.Second * time.Duration(v))))
+ case linux.TCP_USER_TIMEOUT:
+ if len(optVal) < sizeOfInt32 {
+ return syserr.ErrInvalidArgument
+ }
+
+ v := int32(usermem.ByteOrder.Uint32(optVal))
+ if v < 0 {
+ return syserr.ErrInvalidArgument
+ }
+ return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.TCPUserTimeoutOption(time.Millisecond * time.Duration(v))))
+
case linux.TCP_CONGESTION:
v := tcpip.CongestionControlOption(optVal)
if err := ep.SetSockOpt(v); err != nil {
@@ -1554,6 +1763,24 @@ func setSockOptTCP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *
}
return nil
+ case linux.TCP_LINGER2:
+ if len(optVal) < sizeOfInt32 {
+ return syserr.ErrInvalidArgument
+ }
+
+ v := usermem.ByteOrder.Uint32(optVal)
+ return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.TCPLingerTimeoutOption(time.Second * time.Duration(v))))
+
+ case linux.TCP_DEFER_ACCEPT:
+ if len(optVal) < sizeOfInt32 {
+ return syserr.ErrInvalidArgument
+ }
+ v := int32(usermem.ByteOrder.Uint32(optVal))
+ if v < 0 {
+ v = 0
+ }
+ return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.TCPDeferAcceptOption(time.Second * time.Duration(v))))
+
case linux.TCP_REPAIR_OPTIONS:
t.Kernel().EmitUnimplementedEvent(t)
@@ -1574,13 +1801,14 @@ func setSockOptIPv6(t *kernel.Task, ep commonEndpoint, name int, optVal []byte)
}
v := usermem.ByteOrder.Uint32(optVal)
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.V6OnlyOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.V6OnlyOption, v != 0))
case linux.IPV6_ADD_MEMBERSHIP,
linux.IPV6_DROP_MEMBERSHIP,
linux.IPV6_IPSEC_POLICY,
linux.IPV6_JOIN_ANYCAST,
linux.IPV6_LEAVE_ANYCAST,
+ // TODO(b/148887420): Add support for IPV6_PKTINFO.
linux.IPV6_PKTINFO,
linux.IPV6_ROUTER_ALERT,
linux.IPV6_XFRM_POLICY,
@@ -1604,7 +1832,15 @@ func setSockOptIPv6(t *kernel.Task, ep commonEndpoint, name int, optVal []byte)
if v == -1 {
v = 0
}
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.IPv6TrafficClassOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.IPv6TrafficClassOption, int(v)))
+
+ case linux.IPV6_RECVTCLASS:
+ v, err := parseIntOrChar(optVal)
+ if err != nil {
+ return err
+ }
+
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.ReceiveTClassOption, v != 0))
default:
emitUnimplementedEventIPv6(t, name)
@@ -1681,7 +1917,7 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
if v < 0 || v > 255 {
return syserr.ErrInvalidArgument
}
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.MulticastTTLOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.MulticastTTLOption, int(v)))
case linux.IP_ADD_MEMBERSHIP:
req, err := copyInMulticastRequest(optVal, false /* allowAddr */)
@@ -1728,9 +1964,7 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
return err
}
- return syserr.TranslateNetstackError(ep.SetSockOpt(
- tcpip.MulticastLoopOption(v != 0),
- ))
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.MulticastLoopOption, v != 0))
case linux.MCAST_JOIN_GROUP:
// FIXME(b/124219304): Implement MCAST_JOIN_GROUP.
@@ -1749,7 +1983,7 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
} else if v < 1 || v > 255 {
return syserr.ErrInvalidArgument
}
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.TTLOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.TTLOption, int(v)))
case linux.IP_TOS:
if len(optVal) == 0 {
@@ -1759,7 +1993,24 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
if err != nil {
return err
}
- return syserr.TranslateNetstackError(ep.SetSockOpt(tcpip.IPv4TOSOption(v)))
+ return syserr.TranslateNetstackError(ep.SetSockOptInt(tcpip.IPv4TOSOption, int(v)))
+
+ case linux.IP_RECVTOS:
+ v, err := parseIntOrChar(optVal)
+ if err != nil {
+ return err
+ }
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.ReceiveTOSOption, v != 0))
+
+ case linux.IP_PKTINFO:
+ if len(optVal) == 0 {
+ return nil
+ }
+ v, err := parseIntOrChar(optVal)
+ if err != nil {
+ return err
+ }
+ return syserr.TranslateNetstackError(ep.SetSockOptBool(tcpip.ReceiveIPPacketInfoOption, v != 0))
case linux.IP_ADD_SOURCE_MEMBERSHIP,
linux.IP_BIND_ADDRESS_NO_PORT,
@@ -1776,12 +2027,10 @@ func setSockOptIP(t *kernel.Task, ep commonEndpoint, name int, optVal []byte) *s
linux.IP_NODEFRAG,
linux.IP_OPTIONS,
linux.IP_PASSSEC,
- linux.IP_PKTINFO,
linux.IP_RECVERR,
linux.IP_RECVFRAGSIZE,
linux.IP_RECVOPTS,
linux.IP_RECVORIGDSTADDR,
- linux.IP_RECVTOS,
linux.IP_RECVTTL,
linux.IP_RETOPTS,
linux.IP_TRANSPARENT,
@@ -1874,7 +2123,6 @@ func emitUnimplementedEventIPv6(t *kernel.Task, name int) {
linux.IPV6_RECVPATHMTU,
linux.IPV6_RECVPKTINFO,
linux.IPV6_RECVRTHDR,
- linux.IPV6_RECVTCLASS,
linux.IPV6_RTHDR,
linux.IPV6_RTHDRDSTOPTS,
linux.IPV6_TCLASS,
@@ -1979,8 +2227,8 @@ func ConvertAddress(family int, addr tcpip.FullAddress) (linux.SockAddr, uint32)
case linux.AF_INET6:
var out linux.SockAddrInet6
- if len(addr.Addr) == 4 {
- // Copy address is v4-mapped format.
+ if len(addr.Addr) == header.IPv4AddressSize {
+ // Copy address in v4-mapped format.
copy(out.Addr[12:], addr.Addr)
out.Addr[10] = 0xff
out.Addr[11] = 0xff
@@ -2042,11 +2290,16 @@ func (s *SocketOperations) coalescingRead(ctx context.Context, dst usermem.IOSeq
var copied int
// Copy as many views as possible into the user-provided buffer.
- for dst.NumBytes() != 0 {
+ for {
+ // Always do at least one fetchReadView, even if the number of bytes to
+ // read is 0.
err = s.fetchReadView()
if err != nil {
break
}
+ if dst.NumBytes() == 0 {
+ break
+ }
var n int
var e error
@@ -2064,6 +2317,10 @@ func (s *SocketOperations) coalescingRead(ctx context.Context, dst usermem.IOSeq
}
copied += n
s.readView.TrimFront(n)
+ if len(s.readView) == 0 {
+ atomic.StoreUint32(&s.readViewHasData, 0)
+ }
+
dst = dst.DropFirst(n)
if e != nil {
err = syserr.FromError(e)
@@ -2110,9 +2367,9 @@ func (s *SocketOperations) nonBlockingRead(ctx context.Context, dst usermem.IOSe
// caller-supplied buffer.
s.readMu.Lock()
n, err := s.coalescingRead(ctx, dst, trunc)
- s.readMu.Unlock()
cmsg := s.controlMessages()
s.fillCmsgInq(&cmsg)
+ s.readMu.Unlock()
return n, 0, nil, 0, cmsg, err
}
@@ -2186,6 +2443,10 @@ func (s *SocketOperations) nonBlockingRead(ctx context.Context, dst usermem.IOSe
s.readView.TrimFront(int(n))
}
+ if len(s.readView) == 0 {
+ atomic.StoreUint32(&s.readViewHasData, 0)
+ }
+
var flags int
if msgLen > int(n) {
flags |= linux.MSG_TRUNC
@@ -2201,7 +2462,18 @@ func (s *SocketOperations) nonBlockingRead(ctx context.Context, dst usermem.IOSe
}
func (s *SocketOperations) controlMessages() socket.ControlMessages {
- return socket.ControlMessages{IP: tcpip.ControlMessages{HasTimestamp: s.readCM.HasTimestamp && s.sockOptTimestamp, Timestamp: s.readCM.Timestamp}}
+ return socket.ControlMessages{
+ IP: tcpip.ControlMessages{
+ HasTimestamp: s.readCM.HasTimestamp && s.sockOptTimestamp,
+ Timestamp: s.readCM.Timestamp,
+ HasTOS: s.readCM.HasTOS,
+ TOS: s.readCM.TOS,
+ HasTClass: s.readCM.HasTClass,
+ TClass: s.readCM.TClass,
+ HasIPPacketInfo: s.readCM.HasIPPacketInfo,
+ PacketInfo: s.readCM.PacketInfo,
+ },
+ }
}
// updateTimestamp sets the timestamp for SIOCGSTAMP. It should be called after
@@ -2294,10 +2566,14 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to []
var addr *tcpip.FullAddress
if len(to) > 0 {
- addrBuf, _, err := AddressAndFamily(s.family, to, true /* strict */)
+ addrBuf, family, err := AddressAndFamily(to)
if err != nil {
return 0, err
}
+ if err := s.checkFamily(family, false /* exact */); err != nil {
+ return 0, err
+ }
+ addrBuf = s.mapFamily(addrBuf, family)
addr = &addrBuf
}
@@ -2382,7 +2658,9 @@ func (s *SocketOperations) Ioctl(ctx context.Context, _ *fs.File, io usermem.IO,
}
// Add bytes removed from the endpoint but not yet sent to the caller.
+ s.readMu.Lock()
v += len(s.readView)
+ s.readMu.Unlock()
if v > math.MaxInt32 {
v = math.MaxInt32