diff options
Diffstat (limited to 'pkg/tcpip')
| -rw-r--r-- | pkg/tcpip/header/udp.go | 5 | ||||
| -rw-r--r-- | pkg/tcpip/tcpip.go | 48 | ||||
| -rw-r--r-- | pkg/tcpip/transport/icmp/endpoint.go | 4 | ||||
| -rw-r--r-- | pkg/tcpip/transport/raw/endpoint.go | 7 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 68 | ||||
| -rw-r--r-- | pkg/tcpip/transport/udp/endpoint.go | 14 |
6 files changed, 81 insertions, 65 deletions
diff --git a/pkg/tcpip/header/udp.go b/pkg/tcpip/header/udp.go index c1f454805..74412c894 100644 --- a/pkg/tcpip/header/udp.go +++ b/pkg/tcpip/header/udp.go @@ -27,6 +27,11 @@ const ( udpChecksum = 6 ) +const ( + // UDPMaximumPacketSize is the largest possible UDP packet. + UDPMaximumPacketSize = 0xffff +) + // UDPFields contains the fields of a UDP packet. It is used to describe the // fields of a packet that needs to be encoded. type UDPFields struct { diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index ebf8a2d04..2534069ab 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -261,31 +261,34 @@ type FullAddress struct { Port uint16 } -// Payload provides an interface around data that is being sent to an endpoint. -// This allows the endpoint to request the amount of data it needs based on -// internal buffers without exposing them. 'p.Get(p.Size())' reads all the data. -type Payload interface { - // Get returns a slice containing exactly 'min(size, p.Size())' bytes. - Get(size int) ([]byte, *Error) - - // Size returns the payload size. - Size() int +// Payloader is an interface that provides data. +// +// This interface allows the endpoint to request the amount of data it needs +// based on internal buffers without exposing them. +type Payloader interface { + // FullPayload returns all available bytes. + FullPayload() ([]byte, *Error) + + // Payload returns a slice containing at most size bytes. + Payload(size int) ([]byte, *Error) } -// SlicePayload implements Payload on top of slices for convenience. +// SlicePayload implements Payloader for slices. +// +// This is typically used for tests. type SlicePayload []byte -// Get implements Payload. -func (s SlicePayload) Get(size int) ([]byte, *Error) { - if size > s.Size() { - size = s.Size() - } - return s[:size], nil +// FullPayload implements Payloader.FullPayload. +func (s SlicePayload) FullPayload() ([]byte, *Error) { + return s, nil } -// Size implements Payload. -func (s SlicePayload) Size() int { - return len(s) +// Payload implements Payloader.Payload. +func (s SlicePayload) Payload(size int) ([]byte, *Error) { + if size > len(s) { + size = len(s) + } + return s[:size], nil } // A ControlMessages contains socket control messages for IP sockets. @@ -338,7 +341,7 @@ type Endpoint interface { // ErrNoLinkAddress and a notification channel is returned for the caller to // block. Channel is closed once address resolution is complete (success or // not). The channel is only non-nil in this case. - Write(Payload, WriteOptions) (int64, <-chan struct{}, *Error) + Write(Payloader, WriteOptions) (int64, <-chan struct{}, *Error) // Peek reads data without consuming it from the endpoint. // @@ -432,6 +435,11 @@ type WriteOptions struct { // EndOfRecord has the same semantics as Linux's MSG_EOR. EndOfRecord bool + + // Atomic means that all data fetched from Payloader must be written to the + // endpoint. If Atomic is false, then data fetched from the Payloader may be + // discarded if available endpoint buffer space is unsufficient. + Atomic bool } // SockOpt represents socket options which values have the int type. diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go index e1f622af6..3db060384 100644 --- a/pkg/tcpip/transport/icmp/endpoint.go +++ b/pkg/tcpip/transport/icmp/endpoint.go @@ -204,7 +204,7 @@ func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err *tcpi // Write writes data to the endpoint's peer. This method does not block // if the data cannot be written. -func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.) if opts.More { return 0, nil, tcpip.ErrInvalidOptionValue @@ -289,7 +289,7 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha } } - v, err := p.Get(p.Size()) + v, err := p.FullPayload() if err != nil { return 0, nil, err } diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go index 13e17e2a6..cf1c5c433 100644 --- a/pkg/tcpip/transport/raw/endpoint.go +++ b/pkg/tcpip/transport/raw/endpoint.go @@ -207,7 +207,7 @@ func (ep *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMes } // Write implements tcpip.Endpoint.Write. -func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (ep *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // MSG_MORE is unimplemented. This also means that MSG_EOR is a no-op. if opts.More { return 0, nil, tcpip.ErrInvalidOptionValue @@ -220,9 +220,8 @@ func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64 return 0, nil, tcpip.ErrInvalidEndpointState } - payloadBytes, err := payload.Get(payload.Size()) + payloadBytes, err := p.FullPayload() if err != nil { - ep.mu.RUnlock() return 0, nil, err } @@ -230,7 +229,7 @@ func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64 // destination address, route using that address. if !ep.associated { ip := header.IPv4(payloadBytes) - if !ip.IsValid(payload.Size()) { + if !ip.IsValid(len(payloadBytes)) { ep.mu.RUnlock() return 0, nil, tcpip.ErrInvalidOptionValue } diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index ac927569a..dd931f88c 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -806,7 +806,7 @@ func (e *endpoint) isEndpointWritableLocked() (int, *tcpip.Error) { } // Write writes data to the endpoint's peer. -func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // Linux completely ignores any address passed to sendto(2) for TCP sockets // (without the MSG_FASTOPEN flag). Corking is unimplemented, so opts.More // and opts.EndOfRecord are also ignored. @@ -821,47 +821,52 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha return 0, nil, err } - e.sndBufMu.Unlock() - e.mu.RUnlock() - - // Nothing to do if the buffer is empty. - if p.Size() == 0 { - return 0, nil, nil + // We can release locks while copying data. + // + // This is not possible if atomic is set, because we can't allow the + // available buffer space to be consumed by some other caller while we + // are copying data in. + if !opts.Atomic { + e.sndBufMu.Unlock() + e.mu.RUnlock() } - // Copy in memory without holding sndBufMu so that worker goroutine can - // make progress independent of this operation. - v, perr := p.Get(avail) - if perr != nil { + // Fetch data. + v, perr := p.Payload(avail) + if perr != nil || len(v) == 0 { + if opts.Atomic { // See above. + e.sndBufMu.Unlock() + e.mu.RUnlock() + } + // Note that perr may be nil if len(v) == 0. return 0, nil, perr } - e.mu.RLock() - e.sndBufMu.Lock() + if !opts.Atomic { // See above. + e.mu.RLock() + e.sndBufMu.Lock() - // Because we released the lock before copying, check state again - // to make sure the endpoint is still in a valid state for a - // write. - avail, err = e.isEndpointWritableLocked() - if err != nil { - e.sndBufMu.Unlock() - e.mu.RUnlock() - return 0, nil, err - } + // Because we released the lock before copying, check state again + // to make sure the endpoint is still in a valid state for a write. + avail, err = e.isEndpointWritableLocked() + if err != nil { + e.sndBufMu.Unlock() + e.mu.RUnlock() + return 0, nil, err + } - // Discard any excess data copied in due to avail being reduced due to a - // simultaneous write call to the socket. - if avail < len(v) { - v = v[:avail] + // Discard any excess data copied in due to avail being reduced due + // to a simultaneous write call to the socket. + if avail < len(v) { + v = v[:avail] + } } // Add data to the send queue. - l := len(v) s := newSegmentFromView(&e.route, e.id, v) - e.sndBufUsed += l - e.sndBufInQueue += seqnum.Size(l) + e.sndBufUsed += len(v) + e.sndBufInQueue += seqnum.Size(len(v)) e.sndQueue.PushBack(s) - e.sndBufMu.Unlock() // Release the endpoint lock to prevent deadlocks due to lock // order inversion when acquiring workMu. @@ -875,7 +880,8 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha // Let the protocol goroutine do the work. e.sndWaker.Assert() } - return int64(l), nil, nil + + return int64(len(v)), nil, nil } // Peek reads data without consuming it from the endpoint. diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index dccb9a7eb..6ac7c067a 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -15,7 +15,6 @@ package udp import ( - "math" "sync" "gvisor.dev/gvisor/pkg/tcpip" @@ -277,17 +276,12 @@ func (e *endpoint) connectRoute(nicid tcpip.NICID, addr tcpip.FullAddress, netPr // Write writes data to the endpoint's peer. This method does not block // if the data cannot be written. -func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.) if opts.More { return 0, nil, tcpip.ErrInvalidOptionValue } - if p.Size() > math.MaxUint16 { - // Payload can't possibly fit in a packet. - return 0, nil, tcpip.ErrMessageTooLong - } - to := opts.To e.mu.RLock() @@ -370,10 +364,14 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha } } - v, err := p.Get(p.Size()) + v, err := p.FullPayload() if err != nil { return 0, nil, err } + if len(v) > header.UDPMaximumPacketSize { + // Payload can't possibly fit in a packet. + return 0, nil, tcpip.ErrMessageTooLong + } ttl := route.DefaultTTL() if header.IsV4MulticastAddress(route.RemoteAddress) || header.IsV6MulticastAddress(route.RemoteAddress) { |