diff options
Diffstat (limited to 'pkg/tcpip')
| -rw-r--r-- | pkg/tcpip/tcpip.go | 17 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 64 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/protocol.go | 21 |
3 files changed, 100 insertions, 2 deletions
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 1ca4088c9..6270146fa 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -622,6 +622,19 @@ const ( // // A zero value indicates the default. TTLOption + + // TCPSynCountOption is used by SetSockOpt/GetSockOpt to specify the number of + // SYN retransmits that TCP should send before aborting the attempt to + // connect. It cannot exceed 255. + // + // NOTE: This option is currently only stubbed out and is no-op. + TCPSynCountOption + + // TCPWindowClampOption is used by SetSockOpt/GetSockOpt to bound the size + // of the advertised window to this value. + // + // NOTE: This option is currently only stubed out and is a no-op + TCPWindowClampOption ) // ErrorOption is used in GetSockOpt to specify that the last error reported by @@ -690,6 +703,10 @@ type TCPMinRTOOption time.Duration // switches to using SYN cookies. type TCPSynRcvdCountThresholdOption uint64 +// TCPSynRetriesOption is used by SetSockOpt/GetSockOpt to specify stack-wide +// default for number of times SYN is retransmitted before aborting a connect. +type TCPSynRetriesOption uint8 + // MulticastInterfaceOption is used by SetSockOpt/GetSockOpt to specify a // default interface for multicast. type MulticastInterfaceOption struct { diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index 07d3e64c8..71735029e 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -470,6 +470,17 @@ type endpoint struct { // for this endpoint using the TCP_MAXSEG setsockopt. userMSS uint16 + // maxSynRetries is the maximum number of SYN retransmits that TCP should + // send before aborting the attempt to connect. It cannot exceed 255. + // + // NOTE: This is currently a no-op and does not change the SYN + // retransmissions. + maxSynRetries uint8 + + // windowClamp is used to bound the size of the advertised window to + // this value. + windowClamp uint32 + // The following fields are used to manage the send buffer. When // segments are ready to be sent, they are added to sndQueue and the // protocol goroutine is signaled via sndWaker. @@ -795,8 +806,10 @@ func newEndpoint(s *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQue interval: 75 * time.Second, count: 9, }, - uniqueID: s.UniqueID(), - txHash: s.Rand().Uint32(), + uniqueID: s.UniqueID(), + txHash: s.Rand().Uint32(), + windowClamp: DefaultReceiveBufferSize, + maxSynRetries: DefaultSynRetries, } var ss SendBufferSizeOption @@ -829,6 +842,11 @@ func newEndpoint(s *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQue e.tcpLingerTimeout = time.Duration(tcpLT) } + var synRetries tcpip.TCPSynRetriesOption + if err := s.TransportProtocolOption(ProtocolNumber, &synRetries); err == nil { + e.maxSynRetries = uint8(synRetries) + } + if p := s.GetTCPProbe(); p != nil { e.probe = p } @@ -1603,6 +1621,36 @@ func (e *endpoint) SetSockOptInt(opt tcpip.SockOptInt, v int) *tcpip.Error { e.ttl = uint8(v) e.UnlockUser() + case tcpip.TCPSynCountOption: + if v < 1 || v > 255 { + return tcpip.ErrInvalidOptionValue + } + e.LockUser() + e.maxSynRetries = uint8(v) + e.UnlockUser() + + case tcpip.TCPWindowClampOption: + if v == 0 { + e.LockUser() + switch e.EndpointState() { + case StateClose, StateInitial: + e.windowClamp = 0 + e.UnlockUser() + return nil + default: + e.UnlockUser() + return tcpip.ErrInvalidOptionValue + } + } + var rs ReceiveBufferSizeOption + if err := e.stack.TransportProtocolOption(ProtocolNumber, &rs); err == nil { + if v < rs.Min/2 { + v = rs.Min / 2 + } + } + e.LockUser() + e.windowClamp = uint32(v) + e.UnlockUser() } return nil } @@ -1826,6 +1874,18 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) { e.UnlockUser() return v, nil + case tcpip.TCPSynCountOption: + e.LockUser() + v := int(e.maxSynRetries) + e.UnlockUser() + return v, nil + + case tcpip.TCPWindowClampOption: + e.LockUser() + v := int(e.windowClamp) + e.UnlockUser() + return v, nil + default: return -1, tcpip.ErrUnknownProtocolOption } diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go index cfd9a4e8e..1e64283b5 100644 --- a/pkg/tcpip/transport/tcp/protocol.go +++ b/pkg/tcpip/transport/tcp/protocol.go @@ -64,6 +64,10 @@ const ( // DefaultTCPTimeWaitTimeout is the amount of time that sockets linger // in TIME_WAIT state before being marked closed. DefaultTCPTimeWaitTimeout = 60 * time.Second + + // DefaultSynRetries is the default value for the number of SYN retransmits + // before a connect is aborted. + DefaultSynRetries = 6 ) // SACKEnabled option can be used to enable SACK support in the TCP @@ -164,6 +168,7 @@ type protocol struct { tcpTimeWaitTimeout time.Duration minRTO time.Duration synRcvdCount synRcvdCounter + synRetries uint8 dispatcher *dispatcher } @@ -346,6 +351,15 @@ func (p *protocol) SetOption(option interface{}) *tcpip.Error { p.mu.Unlock() return nil + case tcpip.TCPSynRetriesOption: + if v < 1 || v > 255 { + return tcpip.ErrInvalidOptionValue + } + p.mu.Lock() + p.synRetries = uint8(v) + p.mu.Unlock() + return nil + default: return tcpip.ErrUnknownProtocolOption } @@ -420,6 +434,12 @@ func (p *protocol) Option(option interface{}) *tcpip.Error { p.mu.RUnlock() return nil + case *tcpip.TCPSynRetriesOption: + p.mu.RLock() + *v = tcpip.TCPSynRetriesOption(p.synRetries) + p.mu.RUnlock() + return nil + default: return tcpip.ErrUnknownProtocolOption } @@ -452,6 +472,7 @@ func NewProtocol() stack.TransportProtocol { tcpTimeWaitTimeout: DefaultTCPTimeWaitTimeout, synRcvdCount: synRcvdCounter{threshold: SynRcvdCountThreshold}, dispatcher: newDispatcher(runtime.GOMAXPROCS(0)), + synRetries: DefaultSynRetries, minRTO: MinRTO, } } |