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Diffstat (limited to 'pkg/sentry/vfs/vfs.go')
-rw-r--r--pkg/sentry/vfs/vfs.go156
1 files changed, 109 insertions, 47 deletions
diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go
index 9629afee9..9acca8bc7 100644
--- a/pkg/sentry/vfs/vfs.go
+++ b/pkg/sentry/vfs/vfs.go
@@ -38,6 +38,7 @@ import (
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/fspath"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
"gvisor.dev/gvisor/pkg/sync"
"gvisor.dev/gvisor/pkg/syserror"
)
@@ -46,11 +47,13 @@ import (
//
// There is no analogue to the VirtualFilesystem type in Linux, as the
// equivalent state in Linux is global.
+//
+// +stateify savable
type VirtualFilesystem struct {
// mountMu serializes mount mutations.
//
// mountMu is analogous to Linux's namespace_sem.
- mountMu sync.Mutex
+ mountMu sync.Mutex `state:"nosave"`
// mounts maps (mount parent, mount point) pairs to mounts. (Since mounts
// are uniquely namespaced, including mount parent in the key correctly
@@ -79,6 +82,10 @@ type VirtualFilesystem struct {
// mountpoints is analogous to Linux's mountpoint_hashtable.
mountpoints map[*Dentry]map[*Mount]struct{}
+ // lastMountID is the last allocated mount ID. lastMountID is accessed
+ // using atomic memory operations.
+ lastMountID uint64
+
// anonMount is a Mount, not included in mounts or mountpoints,
// representing an anonFilesystem. anonMount is used to back
// VirtualDentries returned by VirtualFilesystem.NewAnonVirtualDentry().
@@ -89,56 +96,59 @@ type VirtualFilesystem struct {
// devices contains all registered Devices. devices is protected by
// devicesMu.
- devicesMu sync.RWMutex
+ devicesMu sync.RWMutex `state:"nosave"`
devices map[devTuple]*registeredDevice
// anonBlockDevMinor contains all allocated anonymous block device minor
// numbers. anonBlockDevMinorNext is a lower bound for the smallest
// unallocated anonymous block device number. anonBlockDevMinorNext and
// anonBlockDevMinor are protected by anonBlockDevMinorMu.
- anonBlockDevMinorMu sync.Mutex
+ anonBlockDevMinorMu sync.Mutex `state:"nosave"`
anonBlockDevMinorNext uint32
anonBlockDevMinor map[uint32]struct{}
// fsTypes contains all registered FilesystemTypes. fsTypes is protected by
// fsTypesMu.
- fsTypesMu sync.RWMutex
+ fsTypesMu sync.RWMutex `state:"nosave"`
fsTypes map[string]*registeredFilesystemType
// filesystems contains all Filesystems. filesystems is protected by
// filesystemsMu.
- filesystemsMu sync.Mutex
+ filesystemsMu sync.Mutex `state:"nosave"`
filesystems map[*Filesystem]struct{}
}
-// New returns a new VirtualFilesystem with no mounts or FilesystemTypes.
-func New() *VirtualFilesystem {
- vfs := &VirtualFilesystem{
- mountpoints: make(map[*Dentry]map[*Mount]struct{}),
- devices: make(map[devTuple]*registeredDevice),
- anonBlockDevMinorNext: 1,
- anonBlockDevMinor: make(map[uint32]struct{}),
- fsTypes: make(map[string]*registeredFilesystemType),
- filesystems: make(map[*Filesystem]struct{}),
- }
+// Init initializes a new VirtualFilesystem with no mounts or FilesystemTypes.
+func (vfs *VirtualFilesystem) Init() error {
+ vfs.mountpoints = make(map[*Dentry]map[*Mount]struct{})
+ vfs.devices = make(map[devTuple]*registeredDevice)
+ vfs.anonBlockDevMinorNext = 1
+ vfs.anonBlockDevMinor = make(map[uint32]struct{})
+ vfs.fsTypes = make(map[string]*registeredFilesystemType)
+ vfs.filesystems = make(map[*Filesystem]struct{})
vfs.mounts.Init()
// Construct vfs.anonMount.
anonfsDevMinor, err := vfs.GetAnonBlockDevMinor()
if err != nil {
- panic(fmt.Sprintf("VirtualFilesystem.GetAnonBlockDevMinor() failed during VirtualFilesystem construction: %v", err))
+ // This shouldn't be possible since anonBlockDevMinorNext was
+ // initialized to 1 above (no device numbers have been allocated yet).
+ panic(fmt.Sprintf("VirtualFilesystem.Init: device number allocation for anonfs failed: %v", err))
}
anonfs := anonFilesystem{
devMinor: anonfsDevMinor,
}
- anonfs.vfsfs.Init(vfs, &anonfs)
- vfs.anonMount = &Mount{
- vfs: vfs,
- fs: &anonfs.vfsfs,
- refs: 1,
+ anonfs.vfsfs.Init(vfs, &anonFilesystemType{}, &anonfs)
+ defer anonfs.vfsfs.DecRef()
+ anonMount, err := vfs.NewDisconnectedMount(&anonfs.vfsfs, nil, &MountOptions{})
+ if err != nil {
+ // We should not be passing any MountOptions that would cause
+ // construction of this mount to fail.
+ panic(fmt.Sprintf("VirtualFilesystem.Init: anonfs mount failed: %v", err))
}
+ vfs.anonMount = anonMount
- return vfs
+ return nil
}
// PathOperation specifies the path operated on by a VFS method.
@@ -169,6 +179,23 @@ type PathOperation struct {
FollowFinalSymlink bool
}
+// AccessAt checks whether a user with creds has access to the file at
+// the given path.
+func (vfs *VirtualFilesystem) AccessAt(ctx context.Context, creds *auth.Credentials, ats AccessTypes, pop *PathOperation) error {
+ rp := vfs.getResolvingPath(creds, pop)
+ for {
+ err := rp.mount.fs.impl.AccessAt(ctx, rp, creds, ats)
+ if err == nil {
+ vfs.putResolvingPath(rp)
+ return nil
+ }
+ if !rp.handleError(err) {
+ vfs.putResolvingPath(rp)
+ return err
+ }
+ }
+}
+
// GetDentryAt returns a VirtualDentry representing the given path, at which a
// file must exist. A reference is taken on the returned VirtualDentry.
func (vfs *VirtualFilesystem) GetDentryAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetDentryOptions) (VirtualDentry, error) {
@@ -208,7 +235,7 @@ func (vfs *VirtualFilesystem) getParentDirAndName(ctx context.Context, creds *au
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.GetParentDentryAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.GetParentDentryAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -249,7 +276,7 @@ func (vfs *VirtualFilesystem) LinkAt(ctx context.Context, creds *auth.Credential
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.LinkAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.LinkAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -285,7 +312,7 @@ func (vfs *VirtualFilesystem) MkdirAt(ctx context.Context, creds *auth.Credentia
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.MkdirAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.MkdirAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -312,13 +339,13 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
rp := vfs.getResolvingPath(creds, pop)
for {
err := rp.mount.fs.impl.MknodAt(ctx, rp, *opts)
- if err != nil {
+ if err == nil {
vfs.putResolvingPath(rp)
return nil
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.MknodAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.MknodAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -333,14 +360,11 @@ func (vfs *VirtualFilesystem) MknodAt(ctx context.Context, creds *auth.Credentia
func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *OpenOptions) (*FileDescription, error) {
// Remove:
//
- // - O_LARGEFILE, which we always report in FileDescription status flags
- // since only 64-bit architectures are supported at this time.
- //
// - O_CLOEXEC, which affects file descriptors and therefore must be
// handled outside of VFS.
//
// - Unknown flags.
- opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_NOCTTY | linux.O_TRUNC | linux.O_APPEND | linux.O_NONBLOCK | linux.O_DSYNC | linux.O_ASYNC | linux.O_DIRECT | linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_NOATIME | linux.O_SYNC | linux.O_PATH | linux.O_TMPFILE
+ opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_NOCTTY | linux.O_TRUNC | linux.O_APPEND | linux.O_NONBLOCK | linux.O_DSYNC | linux.O_ASYNC | linux.O_DIRECT | linux.O_LARGEFILE | linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_NOATIME | linux.O_SYNC | linux.O_PATH | linux.O_TMPFILE
// Linux's __O_SYNC (which we call linux.O_SYNC) implies O_DSYNC.
if opts.Flags&linux.O_SYNC != 0 {
opts.Flags |= linux.O_DSYNC
@@ -380,24 +404,25 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential
if err == nil {
vfs.putResolvingPath(rp)
- // TODO(gvisor.dev/issue/1193): Move inside fsimpl to avoid another call
- // to FileDescription.Stat().
if opts.FileExec {
+ if fd.Mount().Flags.NoExec {
+ fd.DecRef()
+ return nil, syserror.EACCES
+ }
+
// Only a regular file can be executed.
stat, err := fd.Stat(ctx, StatOptions{Mask: linux.STATX_TYPE})
if err != nil {
+ fd.DecRef()
return nil, err
}
- if stat.Mask&linux.STATX_TYPE != 0 {
- // This shouldn't happen, but if type can't be retrieved, file can't
- // be executed.
- return nil, syserror.EACCES
- }
- if linux.FileMode(stat.Mode).FileType() != linux.ModeRegular {
+ if stat.Mask&linux.STATX_TYPE == 0 || stat.Mode&linux.S_IFMT != linux.S_IFREG {
+ fd.DecRef()
return nil, syserror.EACCES
}
}
+ fd.Dentry().InotifyWithParent(linux.IN_OPEN, 0, PathEvent)
return fd, nil
}
if !rp.handleError(err) {
@@ -472,7 +497,7 @@ func (vfs *VirtualFilesystem) RenameAt(ctx context.Context, creds *auth.Credenti
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.RenameAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.RenameAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -505,7 +530,7 @@ func (vfs *VirtualFilesystem) RmdirAt(ctx context.Context, creds *auth.Credentia
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.RmdirAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.RmdirAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -586,7 +611,7 @@ func (vfs *VirtualFilesystem) SymlinkAt(ctx context.Context, creds *auth.Credent
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.SymlinkAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.SymlinkAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -618,7 +643,7 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
}
if checkInvariants {
if rp.canHandleError(err) && rp.Done() {
- panic(fmt.Sprintf("%T.UnlinkAt() consumed all path components and returned %T", rp.mount.fs.impl, err))
+ panic(fmt.Sprintf("%T.UnlinkAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
}
}
if !rp.handleError(err) {
@@ -628,12 +653,39 @@ func (vfs *VirtualFilesystem) UnlinkAt(ctx context.Context, creds *auth.Credenti
}
}
+// BoundEndpointAt gets the bound endpoint at the given path, if one exists.
+func (vfs *VirtualFilesystem) BoundEndpointAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *BoundEndpointOptions) (transport.BoundEndpoint, error) {
+ if !pop.Path.Begin.Ok() {
+ if pop.Path.Absolute {
+ return nil, syserror.ECONNREFUSED
+ }
+ return nil, syserror.ENOENT
+ }
+ rp := vfs.getResolvingPath(creds, pop)
+ for {
+ bep, err := rp.mount.fs.impl.BoundEndpointAt(ctx, rp, *opts)
+ if err == nil {
+ vfs.putResolvingPath(rp)
+ return bep, nil
+ }
+ if checkInvariants {
+ if rp.canHandleError(err) && rp.Done() {
+ panic(fmt.Sprintf("%T.BoundEndpointAt() consumed all path components and returned %v", rp.mount.fs.impl, err))
+ }
+ }
+ if !rp.handleError(err) {
+ vfs.putResolvingPath(rp)
+ return nil, err
+ }
+ }
+}
+
// ListxattrAt returns all extended attribute names for the file at the given
// path.
-func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation) ([]string, error) {
+func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, size uint64) ([]string, error) {
rp := vfs.getResolvingPath(creds, pop)
for {
- names, err := rp.mount.fs.impl.ListxattrAt(ctx, rp)
+ names, err := rp.mount.fs.impl.ListxattrAt(ctx, rp, size)
if err == nil {
vfs.putResolvingPath(rp)
return names, nil
@@ -655,10 +707,10 @@ func (vfs *VirtualFilesystem) ListxattrAt(ctx context.Context, creds *auth.Crede
// GetxattrAt returns the value associated with the given extended attribute
// for the file at the given path.
-func (vfs *VirtualFilesystem) GetxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, name string) (string, error) {
+func (vfs *VirtualFilesystem) GetxattrAt(ctx context.Context, creds *auth.Credentials, pop *PathOperation, opts *GetxattrOptions) (string, error) {
rp := vfs.getResolvingPath(creds, pop)
for {
- val, err := rp.mount.fs.impl.GetxattrAt(ctx, rp, name)
+ val, err := rp.mount.fs.impl.GetxattrAt(ctx, rp, *opts)
if err == nil {
vfs.putResolvingPath(rp)
return val, nil
@@ -743,11 +795,21 @@ func (vfs *VirtualFilesystem) SyncAllFilesystems(ctx context.Context) error {
// VirtualDentry methods require that a reference is held on the VirtualDentry.
//
// VirtualDentry is analogous to Linux's struct path.
+//
+// +stateify savable
type VirtualDentry struct {
mount *Mount
dentry *Dentry
}
+// MakeVirtualDentry creates a VirtualDentry.
+func MakeVirtualDentry(mount *Mount, dentry *Dentry) VirtualDentry {
+ return VirtualDentry{
+ mount: mount,
+ dentry: dentry,
+ }
+}
+
// Ok returns true if vd is not empty. It does not require that a reference is
// held.
func (vd VirtualDentry) Ok() bool {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 03:11:02 +0000