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authorkevin.xu <cming.xu@gmail.com>2020-04-27 21:51:31 +0800
committerGitHub <noreply@github.com>2020-04-27 21:51:31 +0800
commite896ca54db67524afc20b644d43c72185e72dc0e (patch)
tree2a16f3a62a5cafd098f1f028c621f1b655589d69 /pkg/sentry/socket/rpcinet/notifier/notifier.go
parent1f19624fa127d7d59cabe29593cc80b7fe6c81f8 (diff)
parent3c67754663f424f2ebbc0ff2a4c80e30618d5355 (diff)
Merge pull request #1 from google/master
catch up
Diffstat (limited to 'pkg/sentry/socket/rpcinet/notifier/notifier.go')
-rw-r--r--pkg/sentry/socket/rpcinet/notifier/notifier.go231
1 files changed, 0 insertions, 231 deletions
diff --git a/pkg/sentry/socket/rpcinet/notifier/notifier.go b/pkg/sentry/socket/rpcinet/notifier/notifier.go
deleted file mode 100644
index 7efe4301f..000000000
--- a/pkg/sentry/socket/rpcinet/notifier/notifier.go
+++ /dev/null
@@ -1,231 +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.
-
-// Package notifier implements an FD notifier implementation over RPC.
-package notifier
-
-import (
- "fmt"
- "sync"
- "syscall"
-
- "golang.org/x/sys/unix"
- "gvisor.dev/gvisor/pkg/sentry/socket/rpcinet/conn"
- pb "gvisor.dev/gvisor/pkg/sentry/socket/rpcinet/syscall_rpc_go_proto"
- "gvisor.dev/gvisor/pkg/waiter"
-)
-
-type fdInfo struct {
- queue *waiter.Queue
- waiting bool
-}
-
-// Notifier holds all the state necessary to issue notifications when IO events
-// occur in the observed FDs.
-type Notifier struct {
- // rpcConn is the connection that is used for sending RPCs.
- rpcConn *conn.RPCConnection
-
- // epFD is the epoll file descriptor used to register for io
- // notifications.
- epFD uint32
-
- // mu protects fdMap.
- mu sync.Mutex
-
- // fdMap maps file descriptors to their notification queues and waiting
- // status.
- fdMap map[uint32]*fdInfo
-}
-
-// NewRPCNotifier creates a new notifier object.
-func NewRPCNotifier(cn *conn.RPCConnection) (*Notifier, error) {
- id, c := cn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_EpollCreate1{&pb.EpollCreate1Request{}}}, false /* ignoreResult */)
- <-c
-
- res := cn.Request(id).Result.(*pb.SyscallResponse_EpollCreate1).EpollCreate1.Result
- if e, ok := res.(*pb.EpollCreate1Response_ErrorNumber); ok {
- return nil, syscall.Errno(e.ErrorNumber)
- }
-
- w := &Notifier{
- rpcConn: cn,
- epFD: res.(*pb.EpollCreate1Response_Fd).Fd,
- fdMap: make(map[uint32]*fdInfo),
- }
-
- go w.waitAndNotify() // S/R-FIXME(b/77962828)
-
- return w, nil
-}
-
-// waitFD waits on mask for fd. The fdMap mutex must be hold.
-func (n *Notifier) waitFD(fd uint32, fi *fdInfo, mask waiter.EventMask) error {
- if !fi.waiting && mask == 0 {
- return nil
- }
-
- e := pb.EpollEvent{
- Events: mask.ToLinux() | unix.EPOLLET,
- Fd: fd,
- }
-
- switch {
- case !fi.waiting && mask != 0:
- id, c := n.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_EpollCtl{&pb.EpollCtlRequest{Epfd: n.epFD, Op: syscall.EPOLL_CTL_ADD, Fd: fd, Event: &e}}}, false /* ignoreResult */)
- <-c
-
- e := n.rpcConn.Request(id).Result.(*pb.SyscallResponse_EpollCtl).EpollCtl.ErrorNumber
- if e != 0 {
- return syscall.Errno(e)
- }
-
- fi.waiting = true
- case fi.waiting && mask == 0:
- id, c := n.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_EpollCtl{&pb.EpollCtlRequest{Epfd: n.epFD, Op: syscall.EPOLL_CTL_DEL, Fd: fd}}}, false /* ignoreResult */)
- <-c
- n.rpcConn.Request(id)
-
- fi.waiting = false
- case fi.waiting && mask != 0:
- id, c := n.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_EpollCtl{&pb.EpollCtlRequest{Epfd: n.epFD, Op: syscall.EPOLL_CTL_MOD, Fd: fd, Event: &e}}}, false /* ignoreResult */)
- <-c
-
- e := n.rpcConn.Request(id).Result.(*pb.SyscallResponse_EpollCtl).EpollCtl.ErrorNumber
- if e != 0 {
- return syscall.Errno(e)
- }
- }
-
- return nil
-}
-
-// addFD adds an FD to the list of FDs observed by n.
-func (n *Notifier) addFD(fd uint32, queue *waiter.Queue) {
- n.mu.Lock()
- defer n.mu.Unlock()
-
- // Panic if we're already notifying on this FD.
- if _, ok := n.fdMap[fd]; ok {
- panic(fmt.Sprintf("File descriptor %d added twice", fd))
- }
-
- // We have nothing to wait for at the moment. Just add it to the map.
- n.fdMap[fd] = &fdInfo{queue: queue}
-}
-
-// updateFD updates the set of events the FD needs to be notified on.
-func (n *Notifier) updateFD(fd uint32) error {
- n.mu.Lock()
- defer n.mu.Unlock()
-
- if fi, ok := n.fdMap[fd]; ok {
- return n.waitFD(fd, fi, fi.queue.Events())
- }
-
- return nil
-}
-
-// RemoveFD removes an FD from the list of FDs observed by n.
-func (n *Notifier) removeFD(fd uint32) {
- n.mu.Lock()
- defer n.mu.Unlock()
-
- // Remove from map, then from epoll object.
- n.waitFD(fd, n.fdMap[fd], 0)
- delete(n.fdMap, fd)
-}
-
-// hasFD returns true if the FD is in the list of observed FDs.
-func (n *Notifier) hasFD(fd uint32) bool {
- n.mu.Lock()
- defer n.mu.Unlock()
-
- _, ok := n.fdMap[fd]
- return ok
-}
-
-// waitAndNotify loops waiting for io event notifications from the epoll
-// object. Once notifications arrive, they are dispatched to the
-// registered queue.
-func (n *Notifier) waitAndNotify() error {
- for {
- id, c := n.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_EpollWait{&pb.EpollWaitRequest{Fd: n.epFD, NumEvents: 100, Msec: -1}}}, false /* ignoreResult */)
- <-c
-
- res := n.rpcConn.Request(id).Result.(*pb.SyscallResponse_EpollWait).EpollWait.Result
- if e, ok := res.(*pb.EpollWaitResponse_ErrorNumber); ok {
- err := syscall.Errno(e.ErrorNumber)
- // NOTE(magi): I don't think epoll_wait can return EAGAIN but I'm being
- // conseratively careful here since exiting the notification thread
- // would be really bad.
- if err == syscall.EINTR || err == syscall.EAGAIN {
- continue
- }
- return err
- }
-
- n.mu.Lock()
- for _, e := range res.(*pb.EpollWaitResponse_Events).Events.Events {
- if fi, ok := n.fdMap[e.Fd]; ok {
- fi.queue.Notify(waiter.EventMaskFromLinux(e.Events))
- }
- }
- n.mu.Unlock()
- }
-}
-
-// AddFD adds an FD to the list of observed FDs.
-func (n *Notifier) AddFD(fd uint32, queue *waiter.Queue) error {
- n.addFD(fd, queue)
- return nil
-}
-
-// UpdateFD updates the set of events the FD needs to be notified on.
-func (n *Notifier) UpdateFD(fd uint32) error {
- return n.updateFD(fd)
-}
-
-// RemoveFD removes an FD from the list of observed FDs.
-func (n *Notifier) RemoveFD(fd uint32) {
- n.removeFD(fd)
-}
-
-// HasFD returns true if the FD is in the list of observed FDs.
-//
-// This should only be used by tests to assert that FDs are correctly
-// registered.
-func (n *Notifier) HasFD(fd uint32) bool {
- return n.hasFD(fd)
-}
-
-// NonBlockingPoll polls the given fd in non-blocking fashion. It is used just
-// to query the FD's current state; this method will block on the RPC response
-// although the syscall is non-blocking.
-func (n *Notifier) NonBlockingPoll(fd uint32, mask waiter.EventMask) waiter.EventMask {
- for {
- id, c := n.rpcConn.NewRequest(pb.SyscallRequest{Args: &pb.SyscallRequest_Poll{&pb.PollRequest{Fd: fd, Events: mask.ToLinux()}}}, false /* ignoreResult */)
- <-c
-
- res := n.rpcConn.Request(id).Result.(*pb.SyscallResponse_Poll).Poll.Result
- if e, ok := res.(*pb.PollResponse_ErrorNumber); ok {
- if syscall.Errno(e.ErrorNumber) == syscall.EINTR {
- continue
- }
- return mask
- }
-
- return waiter.EventMaskFromLinux(res.(*pb.PollResponse_Events).Events)
- }
-}