diff options
Diffstat (limited to 'vfs/mountinfo.go')
| -rw-r--r-- | vfs/mountinfo.go | 260 |
1 files changed, 0 insertions, 260 deletions
diff --git a/vfs/mountinfo.go b/vfs/mountinfo.go deleted file mode 100644 index bcb3063f..00000000 --- a/vfs/mountinfo.go +++ /dev/null @@ -1,260 +0,0 @@ -// Package vfs provides bindings and iterators over proc_pid_mountinfo(5). -package vfs - -import ( - "bufio" - "errors" - "fmt" - "io" - "iter" - "slices" - "strconv" - "strings" - "syscall" -) - -const ( - MS_NOSYMFOLLOW = 0x100 -) - -var ( - ErrMountInfoFields = errors.New("unexpected field count") - ErrMountInfoEmpty = errors.New("unexpected empty field") - ErrMountInfoDevno = errors.New("bad maj:min field") - ErrMountInfoSep = errors.New("bad optional fields separator") -) - -type ( - // A MountInfoDecoder reads and decodes proc_pid_mountinfo(5) entries from an input stream. - MountInfoDecoder struct { - s *bufio.Scanner - m *MountInfo - - current *MountInfo - parseErr error - complete bool - } - - // MountInfo represents the contents of a proc_pid_mountinfo(5) document. - MountInfo struct { - Next *MountInfo - MountInfoEntry - } - - // MountInfoEntry represents a proc_pid_mountinfo(5) entry. - MountInfoEntry struct { - // mount ID: a unique ID for the mount (may be reused after umount(2)). - ID int `json:"id"` - // parent ID: the ID of the parent mount (or of self for the root of this mount namespace's mount tree). - Parent int `json:"parent"` - // major:minor: the value of st_dev for files on this filesystem (see stat(2)). - Devno DevT `json:"devno"` - // root: the pathname of the directory in the filesystem which forms the root of this mount. - Root string `json:"root"` - // mount point: the pathname of the mount point relative to the process's root directory. - Target string `json:"target"` - // mount options: per-mount options (see mount(2)). - VfsOptstr string `json:"vfs_optstr"` - // optional fields: zero or more fields of the form "tag[:value]"; see below. - // separator: the end of the optional fields is marked by a single hyphen. - OptFields []string `json:"opt_fields"` - // filesystem type: the filesystem type in the form "type[.subtype]". - FsType string `json:"fstype"` - // mount source: filesystem-specific information or "none". - Source string `json:"source"` - // super options: per-superblock options (see mount(2)). - FsOptstr string `json:"fs_optstr"` - } - - DevT [2]int -) - -// Flags interprets VfsOptstr and returns the resulting flags and unmatched options. -func (e *MountInfoEntry) Flags() (flags uintptr, unmatched []string) { - for _, s := range strings.Split(e.VfsOptstr, ",") { - switch s { - case "rw": - case "ro": - flags |= syscall.MS_RDONLY - case "nosuid": - flags |= syscall.MS_NOSUID - case "nodev": - flags |= syscall.MS_NODEV - case "noexec": - flags |= syscall.MS_NOEXEC - case "nosymfollow": - flags |= MS_NOSYMFOLLOW - case "noatime": - flags |= syscall.MS_NOATIME - case "nodiratime": - flags |= syscall.MS_NODIRATIME - case "relatime": - flags |= syscall.MS_RELATIME - default: - unmatched = append(unmatched, s) - } - } - return -} - -// NewMountInfoDecoder returns a new decoder that reads from r. -// -// The decoder introduces its own buffering and may read data from r beyond the mountinfo entries requested. -func NewMountInfoDecoder(r io.Reader) *MountInfoDecoder { - return &MountInfoDecoder{s: bufio.NewScanner(r)} -} - -func (d *MountInfoDecoder) Decode(v **MountInfo) (err error) { - for d.scan() { - } - err = d.Err() - if err == nil { - *v = d.m - } - return -} - -// Entries returns an iterator over mountinfo entries. -func (d *MountInfoDecoder) Entries() iter.Seq[*MountInfoEntry] { - return func(yield func(*MountInfoEntry) bool) { - for cur := d.m; cur != nil; cur = cur.Next { - if !yield(&cur.MountInfoEntry) { - return - } - } - for d.scan() { - if !yield(&d.current.MountInfoEntry) { - return - } - } - } -} - -func (d *MountInfoDecoder) Err() error { - if err := d.s.Err(); err != nil { - return err - } - return d.parseErr -} - -func (d *MountInfoDecoder) scan() bool { - if d.complete { - return false - } - if !d.s.Scan() { - d.complete = true - return false - } - - m := new(MountInfo) - if err := parseMountInfoLine(d.s.Text(), &m.MountInfoEntry); err != nil { - d.parseErr = err - d.complete = true - return false - } - - if d.current == nil { - d.m = m - d.current = d.m - } else { - d.current.Next = m - d.current = d.current.Next - } - return true -} - -func parseMountInfoLine(s string, ent *MountInfoEntry) error { - // prevent proceeding with misaligned fields due to optional fields - f := strings.Split(s, " ") - if len(f) < 10 { - return ErrMountInfoFields - } - - // 36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue - // (1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11) - - // (1) id - if id, err := strconv.Atoi(f[0]); err != nil { // 0 - return err - } else { - ent.ID = id - } - - // (2) parent - if parent, err := strconv.Atoi(f[1]); err != nil { // 1 - return err - } else { - ent.Parent = parent - } - - // (3) maj:min - if n, err := fmt.Sscanf(f[2], "%d:%d", &ent.Devno[0], &ent.Devno[1]); err != nil { - return err - } else if n != 2 { - // unreachable - return ErrMountInfoDevno - } - - // (4) mountroot - ent.Root = Unmangle(f[3]) - if ent.Root == "" { - return ErrMountInfoEmpty - } - - // (5) target - ent.Target = Unmangle(f[4]) - if ent.Target == "" { - return ErrMountInfoEmpty - } - - // (6) vfs options (fs-independent) - ent.VfsOptstr = Unmangle(f[5]) - if ent.VfsOptstr == "" { - return ErrMountInfoEmpty - } - - // (7) optional fields, terminated by " - " - i := len(f) - 4 - ent.OptFields = f[6:i] - - // (8) optional fields end marker - if f[i] != "-" { - return ErrMountInfoSep - } - i++ - - // (9) FS type - ent.FsType = Unmangle(f[i]) - if ent.FsType == "" { - return ErrMountInfoEmpty - } - i++ - - // (10) source -- maybe empty string - ent.Source = Unmangle(f[i]) - i++ - - // (11) fs options (fs specific) - ent.FsOptstr = Unmangle(f[i]) - - return nil -} - -func (e *MountInfoEntry) EqualWithIgnore(want *MountInfoEntry, ignore string) bool { - return (e.ID == want.ID || want.ID == -1) && - (e.Parent == want.Parent || want.Parent == -1) && - (e.Devno == want.Devno || (want.Devno[0] == -1 && want.Devno[1] == -1)) && - (e.Root == want.Root || want.Root == ignore) && - (e.Target == want.Target || want.Target == ignore) && - (e.VfsOptstr == want.VfsOptstr || want.VfsOptstr == ignore) && - (slices.Equal(e.OptFields, want.OptFields) || (len(want.OptFields) == 1 && want.OptFields[0] == ignore)) && - (e.FsType == want.FsType || want.FsType == ignore) && - (e.Source == want.Source || want.Source == ignore) && - (e.FsOptstr == want.FsOptstr || want.FsOptstr == ignore) -} - -func (e *MountInfoEntry) String() string { - return fmt.Sprintf("%d %d %d:%d %s %s %s %s %s %s %s", - e.ID, e.Parent, e.Devno[0], e.Devno[1], e.Root, e.Target, e.VfsOptstr, - strings.Join(append(e.OptFields, "-"), " "), e.FsType, e.Source, e.FsOptstr) -} |
