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authorgVisor bot <gvisor-bot@google.com>2020-05-04 18:04:29 +0000
committergVisor bot <gvisor-bot@google.com>2020-05-04 18:04:29 +0000
commit23c3b58f2d7ade5f9aa1e8c545223941ded690e4 (patch)
treef1a0dfdd7f921920e7e80ced792fd1b7a532752f /pkg/sentry/fsimpl/devpts/slave.go
parent95cb42d3ad61bc1827f6be769ea66981414d5527 (diff)
parentcbc5bef2a66ece1f9e63b213d4dfa616db488df8 (diff)
Merge release-20200422.0-16-gcbc5bef (automated)
Diffstat (limited to 'pkg/sentry/fsimpl/devpts/slave.go')
-rwxr-xr-xpkg/sentry/fsimpl/devpts/slave.go186
1 files changed, 186 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/devpts/slave.go b/pkg/sentry/fsimpl/devpts/slave.go
new file mode 100755
index 000000000..0a98dc896
--- /dev/null
+++ b/pkg/sentry/fsimpl/devpts/slave.go
@@ -0,0 +1,186 @@
+// 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 devpts
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// LINT.IfChange
+
+// slaveInode is the inode for the slave end of the Terminal.
+type slaveInode struct {
+ kernfs.InodeAttrs
+ kernfs.InodeNoopRefCount
+ kernfs.InodeNotDirectory
+ kernfs.InodeNotSymlink
+
+ // Keep a reference to this inode's dentry.
+ dentry kernfs.Dentry
+
+ // root is the devpts root inode.
+ root *rootInode
+
+ // t is the connected Terminal.
+ t *Terminal
+}
+
+var _ kernfs.Inode = (*slaveInode)(nil)
+
+// Open implements kernfs.Inode.Open.
+func (si *slaveInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
+ si.IncRef()
+ fd := &slaveFileDescription{
+ inode: si,
+ }
+ if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{}); err != nil {
+ si.DecRef()
+ return nil, err
+ }
+ return &fd.vfsfd, nil
+
+}
+
+// Valid implements kernfs.Inode.Valid.
+func (si *slaveInode) Valid(context.Context) bool {
+ // Return valid if the slave still exists.
+ si.root.mu.Lock()
+ defer si.root.mu.Unlock()
+ _, ok := si.root.slaves[si.t.n]
+ return ok
+}
+
+// Stat implements kernfs.Inode.Stat.
+func (si *slaveInode) Stat(vfsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
+ statx, err := si.InodeAttrs.Stat(vfsfs, opts)
+ if err != nil {
+ return linux.Statx{}, err
+ }
+ statx.Blksize = 1024
+ statx.RdevMajor = linux.UNIX98_PTY_SLAVE_MAJOR
+ statx.RdevMinor = si.t.n
+ return statx, nil
+}
+
+// SetStat implements kernfs.Inode.SetStat
+func (si *slaveInode) SetStat(ctx context.Context, vfsfs *vfs.Filesystem, creds *auth.Credentials, opts vfs.SetStatOptions) error {
+ if opts.Stat.Mask&linux.STATX_SIZE != 0 {
+ return syserror.EINVAL
+ }
+ return si.InodeAttrs.SetStat(ctx, vfsfs, creds, opts)
+}
+
+type slaveFileDescription struct {
+ vfsfd vfs.FileDescription
+ vfs.FileDescriptionDefaultImpl
+
+ inode *slaveInode
+}
+
+var _ vfs.FileDescriptionImpl = (*slaveFileDescription)(nil)
+
+// Release implements fs.FileOperations.Release.
+func (sfd *slaveFileDescription) Release() {
+ sfd.inode.DecRef()
+}
+
+// EventRegister implements waiter.Waitable.EventRegister.
+func (sfd *slaveFileDescription) EventRegister(e *waiter.Entry, mask waiter.EventMask) {
+ sfd.inode.t.ld.slaveWaiter.EventRegister(e, mask)
+}
+
+// EventUnregister implements waiter.Waitable.EventUnregister.
+func (sfd *slaveFileDescription) EventUnregister(e *waiter.Entry) {
+ sfd.inode.t.ld.slaveWaiter.EventUnregister(e)
+}
+
+// Readiness implements waiter.Waitable.Readiness.
+func (sfd *slaveFileDescription) Readiness(mask waiter.EventMask) waiter.EventMask {
+ return sfd.inode.t.ld.slaveReadiness()
+}
+
+// Read implements vfs.FileDescriptionImpl.Read.
+func (sfd *slaveFileDescription) Read(ctx context.Context, dst usermem.IOSequence, _ vfs.ReadOptions) (int64, error) {
+ return sfd.inode.t.ld.inputQueueRead(ctx, dst)
+}
+
+// Write implements vfs.FileDescriptionImpl.Write.
+func (sfd *slaveFileDescription) Write(ctx context.Context, src usermem.IOSequence, _ vfs.WriteOptions) (int64, error) {
+ return sfd.inode.t.ld.outputQueueWrite(ctx, src)
+}
+
+// Ioctl implements vfs.FileDescripionImpl.Ioctl.
+func (sfd *slaveFileDescription) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) {
+ switch cmd := args[1].Uint(); cmd {
+ case linux.FIONREAD: // linux.FIONREAD == linux.TIOCINQ
+ // Get the number of bytes in the input queue read buffer.
+ return 0, sfd.inode.t.ld.inputQueueReadSize(ctx, io, args)
+ case linux.TCGETS:
+ return sfd.inode.t.ld.getTermios(ctx, io, args)
+ case linux.TCSETS:
+ return sfd.inode.t.ld.setTermios(ctx, io, args)
+ case linux.TCSETSW:
+ // TODO(b/29356795): This should drain the output queue first.
+ return sfd.inode.t.ld.setTermios(ctx, io, args)
+ case linux.TIOCGPTN:
+ _, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), uint32(sfd.inode.t.n), usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ return 0, err
+ case linux.TIOCGWINSZ:
+ return 0, sfd.inode.t.ld.windowSize(ctx, io, args)
+ case linux.TIOCSWINSZ:
+ return 0, sfd.inode.t.ld.setWindowSize(ctx, io, args)
+ case linux.TIOCSCTTY:
+ // Make the given terminal the controlling terminal of the
+ // calling process.
+ return 0, sfd.inode.t.setControllingTTY(ctx, io, args, false /* isMaster */)
+ case linux.TIOCNOTTY:
+ // Release this process's controlling terminal.
+ return 0, sfd.inode.t.releaseControllingTTY(ctx, io, args, false /* isMaster */)
+ case linux.TIOCGPGRP:
+ // Get the foreground process group.
+ return sfd.inode.t.foregroundProcessGroup(ctx, io, args, false /* isMaster */)
+ case linux.TIOCSPGRP:
+ // Set the foreground process group.
+ return sfd.inode.t.setForegroundProcessGroup(ctx, io, args, false /* isMaster */)
+ default:
+ maybeEmitUnimplementedEvent(ctx, cmd)
+ return 0, syserror.ENOTTY
+ }
+}
+
+// SetStat implements vfs.FileDescriptionImpl.SetStat.
+func (sfd *slaveFileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
+ creds := auth.CredentialsFromContext(ctx)
+ fs := sfd.vfsfd.VirtualDentry().Mount().Filesystem()
+ return sfd.inode.SetStat(ctx, fs, creds, opts)
+}
+
+// Stat implements vfs.FileDescriptionImpl.Stat.
+func (sfd *slaveFileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
+ fs := sfd.vfsfd.VirtualDentry().Mount().Filesystem()
+ return sfd.inode.Stat(fs, opts)
+}
+
+// LINT.ThenChange(../../fs/tty/slave.go)