diff options
Diffstat (limited to 'runsc/fsgofer')
| -rw-r--r-- | runsc/fsgofer/filter/config.go | 1 | ||||
| -rw-r--r-- | runsc/fsgofer/fsgofer.go | 60 |
2 files changed, 48 insertions, 13 deletions
diff --git a/runsc/fsgofer/filter/config.go b/runsc/fsgofer/filter/config.go index 1dce36965..88814b83c 100644 --- a/runsc/fsgofer/filter/config.go +++ b/runsc/fsgofer/filter/config.go @@ -128,6 +128,7 @@ var allowedSyscalls = seccomp.SyscallRules{ syscall.SYS_MADVISE: {}, unix.SYS_MEMFD_CREATE: {}, /// Used by flipcall.PacketWindowAllocator.Init(). syscall.SYS_MKDIRAT: {}, + syscall.SYS_MKNODAT: {}, // Used by the Go runtime as a temporarily workaround for a Linux // 5.2-5.4 bug. // diff --git a/runsc/fsgofer/fsgofer.go b/runsc/fsgofer/fsgofer.go index 74977c313..b7521bda7 100644 --- a/runsc/fsgofer/fsgofer.go +++ b/runsc/fsgofer/fsgofer.go @@ -139,7 +139,7 @@ func (a *attachPoint) Attach() (p9.File, error) { return nil, fmt.Errorf("unable to open %q: %v", a.prefix, err) } - stat, err := stat(f.FD()) + stat, err := fstat(f.FD()) if err != nil { return nil, fmt.Errorf("unable to stat %q: %v", a.prefix, err) } @@ -352,7 +352,7 @@ func newFDMaybe(file *fd.FD) *fd.FD { return dup } -func stat(fd int) (syscall.Stat_t, error) { +func fstat(fd int) (syscall.Stat_t, error) { var stat syscall.Stat_t if err := syscall.Fstat(fd, &stat); err != nil { return syscall.Stat_t{}, err @@ -360,6 +360,14 @@ func stat(fd int) (syscall.Stat_t, error) { return stat, nil } +func stat(path string) (syscall.Stat_t, error) { + var stat syscall.Stat_t + if err := syscall.Stat(path, &stat); err != nil { + return syscall.Stat_t{}, err + } + return stat, nil +} + func fchown(fd int, uid p9.UID, gid p9.GID) error { return syscall.Fchownat(fd, "", int(uid), int(gid), linux.AT_EMPTY_PATH|unix.AT_SYMLINK_NOFOLLOW) } @@ -388,7 +396,7 @@ func (l *localFile) Open(flags p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) { } } - stat, err := stat(newFile.FD()) + stat, err := fstat(newFile.FD()) if err != nil { if newFile != l.file { newFile.Close() @@ -449,7 +457,7 @@ func (l *localFile) Create(name string, mode p9.OpenFlags, perm p9.FileMode, uid if err := fchown(child.FD(), uid, gid); err != nil { return nil, nil, p9.QID{}, 0, extractErrno(err) } - stat, err := stat(child.FD()) + stat, err := fstat(child.FD()) if err != nil { return nil, nil, p9.QID{}, 0, extractErrno(err) } @@ -497,7 +505,7 @@ func (l *localFile) Mkdir(name string, perm p9.FileMode, uid p9.UID, gid p9.GID) if err := fchown(f.FD(), uid, gid); err != nil { return p9.QID{}, extractErrno(err) } - stat, err := stat(f.FD()) + stat, err := fstat(f.FD()) if err != nil { return p9.QID{}, extractErrno(err) } @@ -517,7 +525,7 @@ func (l *localFile) Walk(names []string) ([]p9.QID, p9.File, error) { return nil, nil, extractErrno(err) } - stat, err := stat(newFile.FD()) + stat, err := fstat(newFile.FD()) if err != nil { newFile.Close() return nil, nil, extractErrno(err) @@ -542,7 +550,7 @@ func (l *localFile) Walk(names []string) ([]p9.QID, p9.File, error) { if err != nil { return nil, nil, extractErrno(err) } - stat, err := stat(f.FD()) + stat, err := fstat(f.FD()) if err != nil { f.Close() return nil, nil, extractErrno(err) @@ -592,7 +600,7 @@ func (l *localFile) FSync() error { // GetAttr implements p9.File. func (l *localFile) GetAttr(_ p9.AttrMask) (p9.QID, p9.AttrMask, p9.Attr, error) { - stat, err := stat(l.file.FD()) + stat, err := fstat(l.file.FD()) if err != nil { return p9.QID{}, p9.AttrMask{}, p9.Attr{}, extractErrno(err) } @@ -880,7 +888,7 @@ func (l *localFile) Symlink(target, newName string, uid p9.UID, gid p9.GID) (p9. if err := fchown(f.FD(), uid, gid); err != nil { return p9.QID{}, extractErrno(err) } - stat, err := stat(f.FD()) + stat, err := fstat(f.FD()) if err != nil { return p9.QID{}, extractErrno(err) } @@ -907,13 +915,39 @@ func (l *localFile) Link(target p9.File, newName string) error { } // Mknod implements p9.File. -// -// Not implemented. -func (*localFile) Mknod(_ string, _ p9.FileMode, _ uint32, _ uint32, _ p9.UID, _ p9.GID) (p9.QID, error) { +func (l *localFile) Mknod(name string, mode p9.FileMode, _ uint32, _ uint32, uid p9.UID, gid p9.GID) (p9.QID, error) { + conf := l.attachPoint.conf + if conf.ROMount { + if conf.PanicOnWrite { + panic("attempt to write to RO mount") + } + return p9.QID{}, syscall.EROFS + } + + hostPath := path.Join(l.hostPath, name) + + // Return EEXIST if the file already exists. + if _, err := stat(hostPath); err == nil { + return p9.QID{}, syscall.EEXIST + } + // From mknod(2) man page: // "EPERM: [...] if the filesystem containing pathname does not support // the type of node requested." - return p9.QID{}, syscall.EPERM + if mode.FileType() != p9.ModeRegular { + return p9.QID{}, syscall.EPERM + } + + // Allow Mknod to create regular files. + if err := syscall.Mknod(hostPath, uint32(mode), 0); err != nil { + return p9.QID{}, err + } + + stat, err := stat(hostPath) + if err != nil { + return p9.QID{}, extractErrno(err) + } + return l.attachPoint.makeQID(stat), nil } // UnlinkAt implements p9.File. |