diff options
Diffstat (limited to 'pkg/tcpip/stack/stack.go')
| -rw-r--r-- | pkg/tcpip/stack/stack.go | 72 |
1 files changed, 59 insertions, 13 deletions
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index ebb6c5e3b..41398a1b6 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -20,7 +20,9 @@ package stack import ( + "bytes" "encoding/binary" + mathrand "math/rand" "sync/atomic" "time" @@ -31,7 +33,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip" "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/seqnum" "gvisor.dev/gvisor/pkg/waiter" @@ -51,7 +52,7 @@ const ( type transportProtocolState struct { proto TransportProtocol - defaultHandler func(r *Route, id TransportEndpointID, pkt tcpip.PacketBuffer) bool + defaultHandler func(r *Route, id TransportEndpointID, pkt PacketBuffer) bool } // TCPProbeFunc is the expected function type for a TCP probe function to be @@ -428,7 +429,7 @@ type Stack struct { // tables are the iptables packet filtering and manipulation rules. The are // protected by tablesMu.` - tables iptables.IPTables + tables IPTables // resumableEndpoints is a list of endpoints that need to be resumed if the // stack is being restored. @@ -462,6 +463,14 @@ type Stack struct { // opaqueIIDOpts hold the options for generating opaque interface identifiers // (IIDs) as outlined by RFC 7217. opaqueIIDOpts OpaqueInterfaceIdentifierOptions + + // forwarder holds the packets that wait for their link-address resolutions + // to complete, and forwards them when each resolution is done. + forwarder *forwardQueue + + // randomGenerator is an injectable pseudo random generator that can be + // used when a random number is required. + randomGenerator *mathrand.Rand } // UniqueID is an abstract generator of unique identifiers. @@ -522,9 +531,16 @@ type Options struct { // this is non-nil. RawFactory RawFactory - // OpaqueIIDOpts hold the options for generating opaque interface identifiers - // (IIDs) as outlined by RFC 7217. + // OpaqueIIDOpts hold the options for generating opaque interface + // identifiers (IIDs) as outlined by RFC 7217. OpaqueIIDOpts OpaqueInterfaceIdentifierOptions + + // RandSource is an optional source to use to generate random + // numbers. If omitted it defaults to a Source seeded by the data + // returned by rand.Read(). + // + // RandSource must be thread-safe. + RandSource mathrand.Source } // TransportEndpointInfo holds useful information about a transport endpoint @@ -551,11 +567,13 @@ type TransportEndpointInfo struct { RegisterNICID tcpip.NICID } -// AddrNetProto unwraps the specified address if it is a V4-mapped V6 address -// and returns the network protocol number to be used to communicate with the -// specified address. It returns an error if the passed address is incompatible -// with the receiver. -func (e *TransportEndpointInfo) AddrNetProto(addr tcpip.FullAddress, v6only bool) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) { +// AddrNetProtoLocked unwraps the specified address if it is a V4-mapped V6 +// address and returns the network protocol number to be used to communicate +// with the specified address. It returns an error if the passed address is +// incompatible with the receiver. +// +// Preconditon: the parent endpoint mu must be held while calling this method. +func (e *TransportEndpointInfo) AddrNetProtoLocked(addr tcpip.FullAddress, v6only bool) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) { netProto := e.NetProto switch len(addr.Addr) { case header.IPv4AddressSize: @@ -618,6 +636,13 @@ func New(opts Options) *Stack { opts.UniqueID = new(uniqueIDGenerator) } + randSrc := opts.RandSource + if randSrc == nil { + // Source provided by mathrand.NewSource is not thread-safe so + // we wrap it in a simple thread-safe version. + randSrc = &lockedRandomSource{src: mathrand.NewSource(generateRandInt64())} + } + // Make sure opts.NDPConfigs contains valid values only. opts.NDPConfigs.validate() @@ -639,6 +664,8 @@ func New(opts Options) *Stack { uniqueIDGenerator: opts.UniqueID, ndpDisp: opts.NDPDisp, opaqueIIDOpts: opts.OpaqueIIDOpts, + forwarder: newForwardQueue(), + randomGenerator: mathrand.New(randSrc), } // Add specified network protocols. @@ -731,7 +758,7 @@ func (s *Stack) TransportProtocolOption(transport tcpip.TransportProtocolNumber, // // It must be called only during initialization of the stack. Changing it as the // stack is operating is not supported. -func (s *Stack) SetTransportProtocolHandler(p tcpip.TransportProtocolNumber, h func(*Route, TransportEndpointID, tcpip.PacketBuffer) bool) { +func (s *Stack) SetTransportProtocolHandler(p tcpip.TransportProtocolNumber, h func(*Route, TransportEndpointID, PacketBuffer) bool) { state := s.transportProtocols[p] if state != nil { state.defaultHandler = h @@ -1694,7 +1721,7 @@ func (s *Stack) IsInGroup(nicID tcpip.NICID, multicastAddr tcpip.Address) (bool, } // IPTables returns the stack's iptables. -func (s *Stack) IPTables() iptables.IPTables { +func (s *Stack) IPTables() IPTables { s.tablesMu.RLock() t := s.tables s.tablesMu.RUnlock() @@ -1702,7 +1729,7 @@ func (s *Stack) IPTables() iptables.IPTables { } // SetIPTables sets the stack's iptables. -func (s *Stack) SetIPTables(ipt iptables.IPTables) { +func (s *Stack) SetIPTables(ipt IPTables) { s.tablesMu.Lock() s.tables = ipt s.tablesMu.Unlock() @@ -1812,6 +1839,12 @@ func (s *Stack) Seed() uint32 { return s.seed } +// Rand returns a reference to a pseudo random generator that can be used +// to generate random numbers as required. +func (s *Stack) Rand() *mathrand.Rand { + return s.randomGenerator +} + func generateRandUint32() uint32 { b := make([]byte, 4) if _, err := rand.Read(b); err != nil { @@ -1819,3 +1852,16 @@ func generateRandUint32() uint32 { } return binary.LittleEndian.Uint32(b) } + +func generateRandInt64() int64 { + b := make([]byte, 8) + if _, err := rand.Read(b); err != nil { + panic(err) + } + buf := bytes.NewReader(b) + var v int64 + if err := binary.Read(buf, binary.LittleEndian, &v); err != nil { + panic(err) + } + return v +} |