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Diffstat (limited to 'pkg/tcpip/socketops.go')
| -rw-r--r-- | pkg/tcpip/socketops.go | 520 |
1 files changed, 520 insertions, 0 deletions
diff --git a/pkg/tcpip/socketops.go b/pkg/tcpip/socketops.go new file mode 100644 index 000000000..f3ad40fdf --- /dev/null +++ b/pkg/tcpip/socketops.go @@ -0,0 +1,520 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package tcpip + +import ( + "sync/atomic" + + "gvisor.dev/gvisor/pkg/sync" +) + +// SocketOptionsHandler holds methods that help define endpoint specific +// behavior for socket level socket options. These must be implemented by +// endpoints to get notified when socket level options are set. +type SocketOptionsHandler interface { + // OnReuseAddressSet is invoked when SO_REUSEADDR is set for an endpoint. + OnReuseAddressSet(v bool) + + // OnReusePortSet is invoked when SO_REUSEPORT is set for an endpoint. + OnReusePortSet(v bool) + + // OnKeepAliveSet is invoked when SO_KEEPALIVE is set for an endpoint. + OnKeepAliveSet(v bool) + + // OnDelayOptionSet is invoked when TCP_NODELAY is set for an endpoint. + // Note that v will be the inverse of TCP_NODELAY option. + OnDelayOptionSet(v bool) + + // OnCorkOptionSet is invoked when TCP_CORK is set for an endpoint. + OnCorkOptionSet(v bool) + + // LastError is invoked when SO_ERROR is read for an endpoint. + LastError() *Error + + // UpdateLastError updates the endpoint specific last error field. + UpdateLastError(err *Error) + + // HasNIC is invoked to check if the NIC is valid for SO_BINDTODEVICE. + HasNIC(v int32) bool +} + +// DefaultSocketOptionsHandler is an embeddable type that implements no-op +// implementations for SocketOptionsHandler methods. +type DefaultSocketOptionsHandler struct{} + +var _ SocketOptionsHandler = (*DefaultSocketOptionsHandler)(nil) + +// OnReuseAddressSet implements SocketOptionsHandler.OnReuseAddressSet. +func (*DefaultSocketOptionsHandler) OnReuseAddressSet(bool) {} + +// OnReusePortSet implements SocketOptionsHandler.OnReusePortSet. +func (*DefaultSocketOptionsHandler) OnReusePortSet(bool) {} + +// OnKeepAliveSet implements SocketOptionsHandler.OnKeepAliveSet. +func (*DefaultSocketOptionsHandler) OnKeepAliveSet(bool) {} + +// OnDelayOptionSet implements SocketOptionsHandler.OnDelayOptionSet. +func (*DefaultSocketOptionsHandler) OnDelayOptionSet(bool) {} + +// OnCorkOptionSet implements SocketOptionsHandler.OnCorkOptionSet. +func (*DefaultSocketOptionsHandler) OnCorkOptionSet(bool) {} + +// LastError implements SocketOptionsHandler.LastError. +func (*DefaultSocketOptionsHandler) LastError() *Error { + return nil +} + +// UpdateLastError implements SocketOptionsHandler.UpdateLastError. +func (*DefaultSocketOptionsHandler) UpdateLastError(*Error) {} + +// HasNIC implements SocketOptionsHandler.HasNIC. +func (*DefaultSocketOptionsHandler) HasNIC(int32) bool { + return false +} + +// SocketOptions contains all the variables which store values for SOL_SOCKET, +// SOL_IP, SOL_IPV6 and SOL_TCP level options. +// +// +stateify savable +type SocketOptions struct { + handler SocketOptionsHandler + + // These fields are accessed and modified using atomic operations. + + // broadcastEnabled determines whether datagram sockets are allowed to + // send packets to a broadcast address. + broadcastEnabled uint32 + + // passCredEnabled determines whether SCM_CREDENTIALS socket control + // messages are enabled. + passCredEnabled uint32 + + // noChecksumEnabled determines whether UDP checksum is disabled while + // transmitting for this socket. + noChecksumEnabled uint32 + + // reuseAddressEnabled determines whether Bind() should allow reuse of + // local address. + reuseAddressEnabled uint32 + + // reusePortEnabled determines whether to permit multiple sockets to be + // bound to an identical socket address. + reusePortEnabled uint32 + + // keepAliveEnabled determines whether TCP keepalive is enabled for this + // socket. + keepAliveEnabled uint32 + + // multicastLoopEnabled determines whether multicast packets sent over a + // non-loopback interface will be looped back. + multicastLoopEnabled uint32 + + // receiveTOSEnabled is used to specify if the TOS ancillary message is + // passed with incoming packets. + receiveTOSEnabled uint32 + + // receiveTClassEnabled is used to specify if the IPV6_TCLASS ancillary + // message is passed with incoming packets. + receiveTClassEnabled uint32 + + // receivePacketInfoEnabled is used to specify if more inforamtion is + // provided with incoming packets such as interface index and address. + receivePacketInfoEnabled uint32 + + // hdrIncludeEnabled is used to indicate for a raw endpoint that all packets + // being written have an IP header and the endpoint should not attach an IP + // header. + hdrIncludedEnabled uint32 + + // v6OnlyEnabled is used to determine whether an IPv6 socket is to be + // restricted to sending and receiving IPv6 packets only. + v6OnlyEnabled uint32 + + // quickAckEnabled is used to represent the value of TCP_QUICKACK option. + // It currently does not have any effect on the TCP endpoint. + quickAckEnabled uint32 + + // delayOptionEnabled is used to specify if data should be sent out immediately + // by the transport protocol. For TCP, it determines if the Nagle algorithm + // is on or off. + delayOptionEnabled uint32 + + // corkOptionEnabled is used to specify if data should be held until segments + // are full by the TCP transport protocol. + corkOptionEnabled uint32 + + // receiveOriginalDstAddress is used to specify if the original destination of + // the incoming packet should be returned as an ancillary message. + receiveOriginalDstAddress uint32 + + // recvErrEnabled determines whether extended reliable error message passing + // is enabled. + recvErrEnabled uint32 + + // errQueue is the per-socket error queue. It is protected by errQueueMu. + errQueueMu sync.Mutex `state:"nosave"` + errQueue sockErrorList + + // bindToDevice determines the device to which the socket is bound. + bindToDevice int32 + + // mu protects the access to the below fields. + mu sync.Mutex `state:"nosave"` + + // linger determines the amount of time the socket should linger before + // close. We currently implement this option for TCP socket only. + linger LingerOption +} + +// InitHandler initializes the handler. This must be called before using the +// socket options utility. +func (so *SocketOptions) InitHandler(handler SocketOptionsHandler) { + so.handler = handler +} + +func storeAtomicBool(addr *uint32, v bool) { + var val uint32 + if v { + val = 1 + } + atomic.StoreUint32(addr, val) +} + +// SetLastError sets the last error for a socket. +func (so *SocketOptions) SetLastError(err *Error) { + so.handler.UpdateLastError(err) +} + +// GetBroadcast gets value for SO_BROADCAST option. +func (so *SocketOptions) GetBroadcast() bool { + return atomic.LoadUint32(&so.broadcastEnabled) != 0 +} + +// SetBroadcast sets value for SO_BROADCAST option. +func (so *SocketOptions) SetBroadcast(v bool) { + storeAtomicBool(&so.broadcastEnabled, v) +} + +// GetPassCred gets value for SO_PASSCRED option. +func (so *SocketOptions) GetPassCred() bool { + return atomic.LoadUint32(&so.passCredEnabled) != 0 +} + +// SetPassCred sets value for SO_PASSCRED option. +func (so *SocketOptions) SetPassCred(v bool) { + storeAtomicBool(&so.passCredEnabled, v) +} + +// GetNoChecksum gets value for SO_NO_CHECK option. +func (so *SocketOptions) GetNoChecksum() bool { + return atomic.LoadUint32(&so.noChecksumEnabled) != 0 +} + +// SetNoChecksum sets value for SO_NO_CHECK option. +func (so *SocketOptions) SetNoChecksum(v bool) { + storeAtomicBool(&so.noChecksumEnabled, v) +} + +// GetReuseAddress gets value for SO_REUSEADDR option. +func (so *SocketOptions) GetReuseAddress() bool { + return atomic.LoadUint32(&so.reuseAddressEnabled) != 0 +} + +// SetReuseAddress sets value for SO_REUSEADDR option. +func (so *SocketOptions) SetReuseAddress(v bool) { + storeAtomicBool(&so.reuseAddressEnabled, v) + so.handler.OnReuseAddressSet(v) +} + +// GetReusePort gets value for SO_REUSEPORT option. +func (so *SocketOptions) GetReusePort() bool { + return atomic.LoadUint32(&so.reusePortEnabled) != 0 +} + +// SetReusePort sets value for SO_REUSEPORT option. +func (so *SocketOptions) SetReusePort(v bool) { + storeAtomicBool(&so.reusePortEnabled, v) + so.handler.OnReusePortSet(v) +} + +// GetKeepAlive gets value for SO_KEEPALIVE option. +func (so *SocketOptions) GetKeepAlive() bool { + return atomic.LoadUint32(&so.keepAliveEnabled) != 0 +} + +// SetKeepAlive sets value for SO_KEEPALIVE option. +func (so *SocketOptions) SetKeepAlive(v bool) { + storeAtomicBool(&so.keepAliveEnabled, v) + so.handler.OnKeepAliveSet(v) +} + +// GetMulticastLoop gets value for IP_MULTICAST_LOOP option. +func (so *SocketOptions) GetMulticastLoop() bool { + return atomic.LoadUint32(&so.multicastLoopEnabled) != 0 +} + +// SetMulticastLoop sets value for IP_MULTICAST_LOOP option. +func (so *SocketOptions) SetMulticastLoop(v bool) { + storeAtomicBool(&so.multicastLoopEnabled, v) +} + +// GetReceiveTOS gets value for IP_RECVTOS option. +func (so *SocketOptions) GetReceiveTOS() bool { + return atomic.LoadUint32(&so.receiveTOSEnabled) != 0 +} + +// SetReceiveTOS sets value for IP_RECVTOS option. +func (so *SocketOptions) SetReceiveTOS(v bool) { + storeAtomicBool(&so.receiveTOSEnabled, v) +} + +// GetReceiveTClass gets value for IPV6_RECVTCLASS option. +func (so *SocketOptions) GetReceiveTClass() bool { + return atomic.LoadUint32(&so.receiveTClassEnabled) != 0 +} + +// SetReceiveTClass sets value for IPV6_RECVTCLASS option. +func (so *SocketOptions) SetReceiveTClass(v bool) { + storeAtomicBool(&so.receiveTClassEnabled, v) +} + +// GetReceivePacketInfo gets value for IP_PKTINFO option. +func (so *SocketOptions) GetReceivePacketInfo() bool { + return atomic.LoadUint32(&so.receivePacketInfoEnabled) != 0 +} + +// SetReceivePacketInfo sets value for IP_PKTINFO option. +func (so *SocketOptions) SetReceivePacketInfo(v bool) { + storeAtomicBool(&so.receivePacketInfoEnabled, v) +} + +// GetHeaderIncluded gets value for IP_HDRINCL option. +func (so *SocketOptions) GetHeaderIncluded() bool { + return atomic.LoadUint32(&so.hdrIncludedEnabled) != 0 +} + +// SetHeaderIncluded sets value for IP_HDRINCL option. +func (so *SocketOptions) SetHeaderIncluded(v bool) { + storeAtomicBool(&so.hdrIncludedEnabled, v) +} + +// GetV6Only gets value for IPV6_V6ONLY option. +func (so *SocketOptions) GetV6Only() bool { + return atomic.LoadUint32(&so.v6OnlyEnabled) != 0 +} + +// SetV6Only sets value for IPV6_V6ONLY option. +// +// Preconditions: the backing TCP or UDP endpoint must be in initial state. +func (so *SocketOptions) SetV6Only(v bool) { + storeAtomicBool(&so.v6OnlyEnabled, v) +} + +// GetQuickAck gets value for TCP_QUICKACK option. +func (so *SocketOptions) GetQuickAck() bool { + return atomic.LoadUint32(&so.quickAckEnabled) != 0 +} + +// SetQuickAck sets value for TCP_QUICKACK option. +func (so *SocketOptions) SetQuickAck(v bool) { + storeAtomicBool(&so.quickAckEnabled, v) +} + +// GetDelayOption gets inverted value for TCP_NODELAY option. +func (so *SocketOptions) GetDelayOption() bool { + return atomic.LoadUint32(&so.delayOptionEnabled) != 0 +} + +// SetDelayOption sets inverted value for TCP_NODELAY option. +func (so *SocketOptions) SetDelayOption(v bool) { + storeAtomicBool(&so.delayOptionEnabled, v) + so.handler.OnDelayOptionSet(v) +} + +// GetCorkOption gets value for TCP_CORK option. +func (so *SocketOptions) GetCorkOption() bool { + return atomic.LoadUint32(&so.corkOptionEnabled) != 0 +} + +// SetCorkOption sets value for TCP_CORK option. +func (so *SocketOptions) SetCorkOption(v bool) { + storeAtomicBool(&so.corkOptionEnabled, v) + so.handler.OnCorkOptionSet(v) +} + +// GetReceiveOriginalDstAddress gets value for IP(V6)_RECVORIGDSTADDR option. +func (so *SocketOptions) GetReceiveOriginalDstAddress() bool { + return atomic.LoadUint32(&so.receiveOriginalDstAddress) != 0 +} + +// SetReceiveOriginalDstAddress sets value for IP(V6)_RECVORIGDSTADDR option. +func (so *SocketOptions) SetReceiveOriginalDstAddress(v bool) { + storeAtomicBool(&so.receiveOriginalDstAddress, v) +} + +// GetRecvError gets value for IP*_RECVERR option. +func (so *SocketOptions) GetRecvError() bool { + return atomic.LoadUint32(&so.recvErrEnabled) != 0 +} + +// SetRecvError sets value for IP*_RECVERR option. +func (so *SocketOptions) SetRecvError(v bool) { + storeAtomicBool(&so.recvErrEnabled, v) + if !v { + so.pruneErrQueue() + } +} + +// GetLastError gets value for SO_ERROR option. +func (so *SocketOptions) GetLastError() *Error { + return so.handler.LastError() +} + +// GetOutOfBandInline gets value for SO_OOBINLINE option. +func (*SocketOptions) GetOutOfBandInline() bool { + return true +} + +// SetOutOfBandInline sets value for SO_OOBINLINE option. We currently do not +// support disabling this option. +func (*SocketOptions) SetOutOfBandInline(bool) {} + +// GetLinger gets value for SO_LINGER option. +func (so *SocketOptions) GetLinger() LingerOption { + so.mu.Lock() + linger := so.linger + so.mu.Unlock() + return linger +} + +// SetLinger sets value for SO_LINGER option. +func (so *SocketOptions) SetLinger(linger LingerOption) { + so.mu.Lock() + so.linger = linger + so.mu.Unlock() +} + +// SockErrOrigin represents the constants for error origin. +type SockErrOrigin uint8 + +const ( + // SockExtErrorOriginNone represents an unknown error origin. + SockExtErrorOriginNone SockErrOrigin = iota + + // SockExtErrorOriginLocal indicates a local error. + SockExtErrorOriginLocal + + // SockExtErrorOriginICMP indicates an IPv4 ICMP error. + SockExtErrorOriginICMP + + // SockExtErrorOriginICMP6 indicates an IPv6 ICMP error. + SockExtErrorOriginICMP6 +) + +// IsICMPErr indicates if the error originated from an ICMP error. +func (origin SockErrOrigin) IsICMPErr() bool { + return origin == SockExtErrorOriginICMP || origin == SockExtErrorOriginICMP6 +} + +// SockError represents a queue entry in the per-socket error queue. +// +// +stateify savable +type SockError struct { + sockErrorEntry + + // Err is the error caused by the errant packet. + Err *Error + // ErrOrigin indicates the error origin. + ErrOrigin SockErrOrigin + // ErrType is the type in the ICMP header. + ErrType uint8 + // ErrCode is the code in the ICMP header. + ErrCode uint8 + // ErrInfo is additional info about the error. + ErrInfo uint32 + + // Payload is the errant packet's payload. + Payload []byte + // Dst is the original destination address of the errant packet. + Dst FullAddress + // Offender is the original sender address of the errant packet. + Offender FullAddress + // NetProto is the network protocol being used to transmit the packet. + NetProto NetworkProtocolNumber +} + +// pruneErrQueue resets the queue. +func (so *SocketOptions) pruneErrQueue() { + so.errQueueMu.Lock() + so.errQueue.Reset() + so.errQueueMu.Unlock() +} + +// DequeueErr dequeues a socket extended error from the error queue and returns +// it. Returns nil if queue is empty. +func (so *SocketOptions) DequeueErr() *SockError { + so.errQueueMu.Lock() + defer so.errQueueMu.Unlock() + + err := so.errQueue.Front() + if err != nil { + so.errQueue.Remove(err) + } + return err +} + +// PeekErr returns the error in the front of the error queue. Returns nil if +// the error queue is empty. +func (so *SocketOptions) PeekErr() *SockError { + so.errQueueMu.Lock() + defer so.errQueueMu.Unlock() + return so.errQueue.Front() +} + +// QueueErr inserts the error at the back of the error queue. +// +// Preconditions: so.GetRecvError() == true. +func (so *SocketOptions) QueueErr(err *SockError) { + so.errQueueMu.Lock() + defer so.errQueueMu.Unlock() + so.errQueue.PushBack(err) +} + +// QueueLocalErr queues a local error onto the local queue. +func (so *SocketOptions) QueueLocalErr(err *Error, net NetworkProtocolNumber, info uint32, dst FullAddress, payload []byte) { + so.QueueErr(&SockError{ + Err: err, + ErrOrigin: SockExtErrorOriginLocal, + ErrInfo: info, + Payload: payload, + Dst: dst, + NetProto: net, + }) +} + +// GetBindToDevice gets value for SO_BINDTODEVICE option. +func (so *SocketOptions) GetBindToDevice() int32 { + return atomic.LoadInt32(&so.bindToDevice) +} + +// SetBindToDevice sets value for SO_BINDTODEVICE option. +func (so *SocketOptions) SetBindToDevice(bindToDevice int32) *Error { + if !so.handler.HasNIC(bindToDevice) { + return ErrUnknownDevice + } + + atomic.StoreInt32(&so.bindToDevice, bindToDevice) + return nil +} |