diff options
author | Jamie Liu <jamieliu@google.com> | 2020-05-07 14:00:36 -0700 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-05-07 14:01:53 -0700 |
commit | 9115f26851b6f00ae01e9c130e3b5b342495c9e5 (patch) | |
tree | 1bf2b1e7a6f461d82d34f68a6c607b8c2253bf63 /pkg/sentry/fsimpl/sockfs | |
parent | 1f4087e7cd6c3cc696e6b26446abd6c5214cfd67 (diff) |
Allocate device numbers for VFS2 filesystems.
Updates #1197, #1198, #1672
PiperOrigin-RevId: 310432006
Diffstat (limited to 'pkg/sentry/fsimpl/sockfs')
-rw-r--r-- | pkg/sentry/fsimpl/sockfs/BUILD | 1 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/sockfs/sockfs.go | 46 |
2 files changed, 39 insertions, 8 deletions
diff --git a/pkg/sentry/fsimpl/sockfs/BUILD b/pkg/sentry/fsimpl/sockfs/BUILD index 52084ddb5..9453277b8 100644 --- a/pkg/sentry/fsimpl/sockfs/BUILD +++ b/pkg/sentry/fsimpl/sockfs/BUILD @@ -9,6 +9,7 @@ go_library( deps = [ "//pkg/abi/linux", "//pkg/context", + "//pkg/fspath", "//pkg/sentry/fsimpl/kernfs", "//pkg/sentry/kernel/auth", "//pkg/sentry/vfs", diff --git a/pkg/sentry/fsimpl/sockfs/sockfs.go b/pkg/sentry/fsimpl/sockfs/sockfs.go index 239a9f4b4..ee0828a15 100644 --- a/pkg/sentry/fsimpl/sockfs/sockfs.go +++ b/pkg/sentry/fsimpl/sockfs/sockfs.go @@ -16,8 +16,11 @@ package sockfs import ( + "fmt" + "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/fspath" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" @@ -41,19 +44,42 @@ func (filesystemType) Name() string { return "sockfs" } +type filesystem struct { + kernfs.Filesystem + + devMinor uint32 +} + // NewFilesystem sets up and returns a new sockfs filesystem. // // Note that there should only ever be one instance of sockfs.Filesystem, // backing a global socket mount. -func NewFilesystem(vfsObj *vfs.VirtualFilesystem) *vfs.Filesystem { - fs := &kernfs.Filesystem{} - fs.VFSFilesystem().Init(vfsObj, filesystemType{}, fs) - return fs.VFSFilesystem() +func NewFilesystem(vfsObj *vfs.VirtualFilesystem) (*vfs.Filesystem, error) { + devMinor, err := vfsObj.GetAnonBlockDevMinor() + if err != nil { + return nil, err + } + fs := &filesystem{ + devMinor: devMinor, + } + fs.Filesystem.VFSFilesystem().Init(vfsObj, filesystemType{}, fs) + return fs.Filesystem.VFSFilesystem(), nil +} + +// Release implements vfs.FilesystemImpl.Release. +func (fs *filesystem) Release() { + fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor) + fs.Filesystem.Release() +} + +// PrependPath implements vfs.FilesystemImpl.PrependPath. +func (fs *filesystem) PrependPath(ctx context.Context, vfsroot, vd vfs.VirtualDentry, b *fspath.Builder) error { + inode := vd.Dentry().Impl().(*kernfs.Dentry).Inode().(*inode) + b.PrependComponent(fmt.Sprintf("socket:[%d]", inode.InodeAttrs.Ino())) + return vfs.PrependPathSyntheticError{} } // inode implements kernfs.Inode. -// -// TODO(gvisor.dev/issue/1193): Device numbers. type inode struct { kernfs.InodeNotDirectory kernfs.InodeNotSymlink @@ -67,11 +93,15 @@ func (i *inode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentr } // NewDentry constructs and returns a sockfs dentry. -func NewDentry(creds *auth.Credentials, ino uint64) *vfs.Dentry { +// +// Preconditions: mnt.Filesystem() must have been returned by NewFilesystem(). +func NewDentry(creds *auth.Credentials, mnt *vfs.Mount) *vfs.Dentry { + fs := mnt.Filesystem().Impl().(*filesystem) + // File mode matches net/socket.c:sock_alloc. filemode := linux.FileMode(linux.S_IFSOCK | 0600) i := &inode{} - i.Init(creds, ino, filemode) + i.InodeAttrs.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, fs.Filesystem.NextIno(), filemode) d := &kernfs.Dentry{} d.Init(i) |