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Diffstat (limited to 'pkg/tcpip/link/sharedmem/sharedmem.go')
-rw-r--r--pkg/tcpip/link/sharedmem/sharedmem.go264
1 files changed, 0 insertions, 264 deletions
diff --git a/pkg/tcpip/link/sharedmem/sharedmem.go b/pkg/tcpip/link/sharedmem/sharedmem.go
deleted file mode 100644
index e34b780f8..000000000
--- a/pkg/tcpip/link/sharedmem/sharedmem.go
+++ /dev/null
@@ -1,264 +0,0 @@
-// Copyright 2018 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.
-
-// +build linux
-
-// Package sharedmem provides the implemention of data-link layer endpoints
-// backed by shared memory.
-//
-// Shared memory endpoints can be used in the networking stack by calling New()
-// to create a new endpoint, and then passing it as an argument to
-// Stack.CreateNIC().
-package sharedmem
-
-import (
- "sync"
- "sync/atomic"
- "syscall"
-
- "gvisor.googlesource.com/gvisor/pkg/log"
- "gvisor.googlesource.com/gvisor/pkg/tcpip"
- "gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"
- "gvisor.googlesource.com/gvisor/pkg/tcpip/header"
- "gvisor.googlesource.com/gvisor/pkg/tcpip/link/sharedmem/queue"
- "gvisor.googlesource.com/gvisor/pkg/tcpip/stack"
-)
-
-// QueueConfig holds all the file descriptors needed to describe a tx or rx
-// queue over shared memory. It is used when creating new shared memory
-// endpoints to describe tx and rx queues.
-type QueueConfig struct {
- // DataFD is a file descriptor for the file that contains the data to
- // be transmitted via this queue. Descriptors contain offsets within
- // this file.
- DataFD int
-
- // EventFD is a file descriptor for the event that is signaled when
- // data is becomes available in this queue.
- EventFD int
-
- // TxPipeFD is a file descriptor for the tx pipe associated with the
- // queue.
- TxPipeFD int
-
- // RxPipeFD is a file descriptor for the rx pipe associated with the
- // queue.
- RxPipeFD int
-
- // SharedDataFD is a file descriptor for the file that contains shared
- // state between the two ends of the queue. This data specifies, for
- // example, whether EventFD signaling is enabled or disabled.
- SharedDataFD int
-}
-
-type endpoint struct {
- // mtu (maximum transmission unit) is the maximum size of a packet.
- mtu uint32
-
- // bufferSize is the size of each individual buffer.
- bufferSize uint32
-
- // addr is the local address of this endpoint.
- addr tcpip.LinkAddress
-
- // rx is the receive queue.
- rx rx
-
- // stopRequested is to be accessed atomically only, and determines if
- // the worker goroutines should stop.
- stopRequested uint32
-
- // Wait group used to indicate that all workers have stopped.
- completed sync.WaitGroup
-
- // mu protects the following fields.
- mu sync.Mutex
-
- // tx is the transmit queue.
- tx tx
-
- // workerStarted specifies whether the worker goroutine was started.
- workerStarted bool
-}
-
-// New creates a new shared-memory-based endpoint. Buffers will be broken up
-// into buffers of "bufferSize" bytes.
-func New(mtu, bufferSize uint32, addr tcpip.LinkAddress, tx, rx QueueConfig) (tcpip.LinkEndpointID, error) {
- e := &endpoint{
- mtu: mtu,
- bufferSize: bufferSize,
- addr: addr,
- }
-
- if err := e.tx.init(bufferSize, &tx); err != nil {
- return 0, err
- }
-
- if err := e.rx.init(bufferSize, &rx); err != nil {
- e.tx.cleanup()
- return 0, err
- }
-
- return stack.RegisterLinkEndpoint(e), nil
-}
-
-// Close frees all resources associated with the endpoint.
-func (e *endpoint) Close() {
- // Tell dispatch goroutine to stop, then write to the eventfd so that
- // it wakes up in case it's sleeping.
- atomic.StoreUint32(&e.stopRequested, 1)
- syscall.Write(e.rx.eventFD, []byte{1, 0, 0, 0, 0, 0, 0, 0})
-
- // Cleanup the queues inline if the worker hasn't started yet; we also
- // know it won't start from now on because stopRequested is set to 1.
- e.mu.Lock()
- workerPresent := e.workerStarted
- e.mu.Unlock()
-
- if !workerPresent {
- e.tx.cleanup()
- e.rx.cleanup()
- }
-}
-
-// Wait waits until all workers have stopped after a Close() call.
-func (e *endpoint) Wait() {
- e.completed.Wait()
-}
-
-// Attach implements stack.LinkEndpoint.Attach. It launches the goroutine that
-// reads packets from the rx queue.
-func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
- e.mu.Lock()
- if !e.workerStarted && atomic.LoadUint32(&e.stopRequested) == 0 {
- e.workerStarted = true
- e.completed.Add(1)
- // Link endpoints are not savable. When transportation endpoints
- // are saved, they stop sending outgoing packets and all
- // incoming packets are rejected.
- go e.dispatchLoop(dispatcher) // S/R-SAFE: see above.
- }
- e.mu.Unlock()
-}
-
-// IsAttached implements stack.LinkEndpoint.IsAttached.
-func (e *endpoint) IsAttached() bool {
- e.mu.Lock()
- defer e.mu.Unlock()
- return e.workerStarted
-}
-
-// MTU implements stack.LinkEndpoint.MTU. It returns the value initialized
-// during construction.
-func (e *endpoint) MTU() uint32 {
- return e.mtu - header.EthernetMinimumSize
-}
-
-// Capabilities implements stack.LinkEndpoint.Capabilities.
-func (*endpoint) Capabilities() stack.LinkEndpointCapabilities {
- return 0
-}
-
-// MaxHeaderLength implements stack.LinkEndpoint.MaxHeaderLength. It returns the
-// ethernet frame header size.
-func (*endpoint) MaxHeaderLength() uint16 {
- return header.EthernetMinimumSize
-}
-
-// LinkAddress implements stack.LinkEndpoint.LinkAddress. It returns the local
-// link address.
-func (e *endpoint) LinkAddress() tcpip.LinkAddress {
- return e.addr
-}
-
-// WritePacket writes outbound packets to the file descriptor. If it is not
-// currently writable, the packet is dropped.
-func (e *endpoint) WritePacket(r *stack.Route, _ *stack.GSO, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
- // Add the ethernet header here.
- eth := header.Ethernet(hdr.Prepend(header.EthernetMinimumSize))
- ethHdr := &header.EthernetFields{
- DstAddr: r.RemoteLinkAddress,
- Type: protocol,
- }
- if r.LocalLinkAddress != "" {
- ethHdr.SrcAddr = r.LocalLinkAddress
- } else {
- ethHdr.SrcAddr = e.addr
- }
- eth.Encode(ethHdr)
-
- v := payload.ToView()
- // Transmit the packet.
- e.mu.Lock()
- ok := e.tx.transmit(hdr.View(), v)
- e.mu.Unlock()
-
- if !ok {
- return tcpip.ErrWouldBlock
- }
-
- return nil
-}
-
-// dispatchLoop reads packets from the rx queue in a loop and dispatches them
-// to the network stack.
-func (e *endpoint) dispatchLoop(d stack.NetworkDispatcher) {
- // Post initial set of buffers.
- limit := e.rx.q.PostedBuffersLimit()
- if l := uint64(len(e.rx.data)) / uint64(e.bufferSize); limit > l {
- limit = l
- }
- for i := uint64(0); i < limit; i++ {
- b := queue.RxBuffer{
- Offset: i * uint64(e.bufferSize),
- Size: e.bufferSize,
- ID: i,
- }
- if !e.rx.q.PostBuffers([]queue.RxBuffer{b}) {
- log.Warningf("Unable to post %v-th buffer", i)
- }
- }
-
- // Read in a loop until a stop is requested.
- var rxb []queue.RxBuffer
- for atomic.LoadUint32(&e.stopRequested) == 0 {
- var n uint32
- rxb, n = e.rx.postAndReceive(rxb, &e.stopRequested)
-
- // Copy data from the shared area to its own buffer, then
- // prepare to repost the buffer.
- b := make([]byte, n)
- offset := uint32(0)
- for i := range rxb {
- copy(b[offset:], e.rx.data[rxb[i].Offset:][:rxb[i].Size])
- offset += rxb[i].Size
-
- rxb[i].Size = e.bufferSize
- }
-
- if n < header.EthernetMinimumSize {
- continue
- }
-
- // Send packet up the stack.
- eth := header.Ethernet(b)
- d.DeliverNetworkPacket(e, eth.SourceAddress(), eth.DestinationAddress(), eth.Type(), buffer.View(b[header.EthernetMinimumSize:]).ToVectorisedView())
- }
-
- // Clean state.
- e.tx.cleanup()
- e.rx.cleanup()
-
- e.completed.Done()
-}