aboutsummaryrefslogtreecommitdiffhomepage
diff options
context:
space:
mode:
Diffstat
-rw-r--r--sandbox/vfs/mountinfo.go213
-rw-r--r--sandbox/vfs/mountinfo_test.go176
2 files changed, 253 insertions, 136 deletions
diff --git a/sandbox/vfs/mountinfo.go b/sandbox/vfs/mountinfo.go
index df2940a4..b2634128 100644
--- a/sandbox/vfs/mountinfo.go
+++ b/sandbox/vfs/mountinfo.go
@@ -5,6 +5,7 @@ import (
"errors"
"fmt"
"io"
+ "iter"
"strconv"
"strings"
"syscall"
@@ -18,13 +19,23 @@ var (
)
type (
- // MountInfo represents a /proc/pid/mountinfo document.
+ // 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 line in /proc/pid/mountinfo.
+ // 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"`
@@ -77,95 +88,145 @@ func (e *MountInfoEntry) Flags() (flags uintptr, unmatched []string) {
return
}
-// ParseMountInfo parses a mountinfo file according to proc_pid_mountinfo(5).
-func ParseMountInfo(r io.Reader) (*MountInfo, int, error) {
- var m, cur *MountInfo
- s := bufio.NewScanner(r)
+// 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)}
+}
- var n int
- for s.Scan() {
- n++
+func (d *MountInfoDecoder) Decode(v **MountInfo) (err error) {
+ for d.scan() {
+ }
+ err = d.Err()
+ if err == nil {
+ *v = d.m
+ }
+ return
+}
- if cur == nil {
- m = new(MountInfo)
- cur = m
- } else {
- cur.Next = new(MountInfo)
- cur = cur.Next
+// 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
+ }
}
-
- // prevent proceeding with misaligned fields due to optional fields
- f := strings.Split(s.Text(), " ")
- if len(f) < 10 {
- return nil, -1, ErrMountInfoFields
+ for d.scan() {
+ if !yield(&d.current.MountInfoEntry) {
+ return
+ }
}
+ }
+}
- // 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)
+func (d *MountInfoDecoder) Err() error {
+ if err := d.s.Err(); err != nil {
+ return err
+ }
+ return d.parseErr
+}
- // (1) id
- if id, err := strconv.Atoi(f[0]); err != nil { // 0
- return nil, -1, err
- } else {
- cur.ID = id
- }
+func (d *MountInfoDecoder) scan() bool {
+ if d.complete {
+ return false
+ }
+ if !d.s.Scan() {
+ d.complete = true
+ return false
+ }
- // (2) parent
- if parent, err := strconv.Atoi(f[1]); err != nil { // 1
- return nil, -1, err
- } else {
- cur.Parent = parent
- }
+ m := new(MountInfo)
+ if err := parseMountInfoLine(d.s.Text(), &m.MountInfoEntry); err != nil {
+ d.parseErr = err
+ d.complete = true
+ return false
+ }
- // (3) maj:min
- if n, err := fmt.Sscanf(f[2], "%d:%d", &cur.Devno[0], &cur.Devno[1]); err != nil {
- return nil, -1, err
- } else if n != 2 {
- // unreachable
- return nil, -1, ErrMountInfoDevno
- }
+ if d.current == nil {
+ d.m = m
+ d.current = d.m
+ } else {
+ d.current.Next = m
+ d.current = d.current.Next
+ }
+ return true
+}
- // (4) mountroot
- cur.Root = Unmangle(f[3])
- if cur.Root == "" {
- return nil, -1, ErrMountInfoEmpty
- }
+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
+ }
- // (5) target
- cur.Target = Unmangle(f[4])
- if cur.Target == "" {
- return nil, -1, ErrMountInfoEmpty
- }
+ // 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)
- // (6) vfs options (fs-independent)
- cur.VfsOptstr = Unmangle(f[5])
- if cur.VfsOptstr == "" {
- return nil, -1, ErrMountInfoEmpty
- }
+ // (1) id
+ if id, err := strconv.Atoi(f[0]); err != nil { // 0
+ return err
+ } else {
+ ent.ID = id
+ }
- // (7) optional fields, terminated by " - "
- i := len(f) - 4
- cur.OptFields = f[6:i]
+ // (2) parent
+ if parent, err := strconv.Atoi(f[1]); err != nil { // 1
+ return err
+ } else {
+ ent.Parent = parent
+ }
- // (8) optional fields end marker
- if f[i] != "-" {
- return nil, -1, ErrMountInfoSep
- }
- i++
+ // (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
+ }
- // (9) FS type
- cur.FsType = Unmangle(f[i])
- if cur.FsType == "" {
- return nil, -1, ErrMountInfoEmpty
- }
- i++
+ // (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
+ }
- // (10) source -- maybe empty string
- cur.Source = Unmangle(f[i])
- i++
+ // (7) optional fields, terminated by " - "
+ i := len(f) - 4
+ ent.OptFields = f[6:i]
- // (11) fs options (fs specific)
- cur.FsOptstr = Unmangle(f[i])
+ // (8) optional fields end marker
+ if f[i] != "-" {
+ return ErrMountInfoSep
}
- return m, n, s.Err()
+ 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
}
diff --git a/sandbox/vfs/mountinfo_test.go b/sandbox/vfs/mountinfo_test.go
index f97a05e9..e3382d24 100644
--- a/sandbox/vfs/mountinfo_test.go
+++ b/sandbox/vfs/mountinfo_test.go
@@ -2,6 +2,7 @@ package vfs_test
import (
"errors"
+ "iter"
"reflect"
"slices"
"strconv"
@@ -12,57 +13,62 @@ import (
"git.gensokyo.uk/security/fortify/sandbox/vfs"
)
-func TestParseMountInfo(t *testing.T) {
- testCases := []struct {
- name string
- sample string
- wantErr error
- wantError string
- want []*wantMountInfo
- }{
+func TestMountInfo(t *testing.T) {
+ testCases := []mountInfoTest{
{"count", sampleMountinfoShort + `
21 20 0:53/ /mnt/test rw,relatime - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, vfs.ErrMountInfoFields, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ vfs.ErrMountInfoFields, "", nil},
{"sep", sampleMountinfoShort + `
21 20 0:53 / /mnt/test rw,relatime shared:212 _ tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, vfs.ErrMountInfoSep, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ vfs.ErrMountInfoSep, "", nil},
{"id", sampleMountinfoShort + `
id 20 0:53 / /mnt/test rw,relatime shared:212 - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, strconv.ErrSyntax, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ strconv.ErrSyntax, "", nil},
{"parent", sampleMountinfoShort + `
21 parent 0:53 / /mnt/test rw,relatime shared:212 - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, strconv.ErrSyntax, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ strconv.ErrSyntax, "", nil},
{"devno", sampleMountinfoShort + `
21 20 053 / /mnt/test rw,relatime shared:212 - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, nil, "unexpected EOF", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ nil, "unexpected EOF", nil},
{"maj", sampleMountinfoShort + `
21 20 maj:53 / /mnt/test rw,relatime shared:212 - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, nil, "expected integer", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ nil, "expected integer", nil},
{"min", sampleMountinfoShort + `
21 20 0:min / /mnt/test rw,relatime shared:212 - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, nil, "expected integer", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ nil, "expected integer", nil},
{"mountroot", sampleMountinfoShort + `
21 20 0:53 /mnt/test rw,relatime - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, vfs.ErrMountInfoEmpty, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ vfs.ErrMountInfoEmpty, "", nil},
{"target", sampleMountinfoShort + `
21 20 0:53 / rw,relatime - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, vfs.ErrMountInfoEmpty, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ vfs.ErrMountInfoEmpty, "", nil},
{"vfs options", sampleMountinfoShort + `
21 20 0:53 / /mnt/test - tmpfs rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, vfs.ErrMountInfoEmpty, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ vfs.ErrMountInfoEmpty, "", nil},
{"FS type", sampleMountinfoShort + `
21 20 0:53 / /mnt/test rw,relatime - rw
-21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`, vfs.ErrMountInfoEmpty, "", nil},
+21 16 0:17 / /sys/fs/cgroup rw,nosuid,nodev,noexec,relatime - tmpfs tmpfs rw,mode=755`,
+ vfs.ErrMountInfoEmpty, "", nil},
{"base", sampleMountinfoShort, nil, "", []*wantMountInfo{
m(15, 20, 0, 3, "/", "/proc", "rw,relatime", o(), "proc", "/proc", "rw", syscall.MS_RELATIME, nil),
@@ -122,54 +128,104 @@ id 20 0:53 / /mnt/test rw,relatime shared:212 - tmpfs rw
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
- got, n, err := vfs.ParseMountInfo(strings.NewReader(tc.sample))
- if !errors.Is(err, tc.wantErr) {
- if tc.wantError == "" {
- t.Errorf("ParseMountInfo: error = %v, wantErr %v",
- err, tc.wantErr)
- } else if err != nil && err.Error() != tc.wantError {
- t.Errorf("ParseMountInfo: error = %q, wantError %q",
- err, tc.wantError)
- }
- }
+ t.Run("decode", func(t *testing.T) {
+ var got *vfs.MountInfo
+ d := vfs.NewMountInfoDecoder(strings.NewReader(tc.sample))
+ err := d.Decode(&got)
+ tc.check(t, true,
+ func(yield func(*vfs.MountInfoEntry) bool) {
+ for cur := got; cur != nil; cur = cur.Next {
+ if !yield(&cur.MountInfoEntry) {
+ return
+ }
+ }
+ }, func() error { return err })
+ t.Run("reuse", func(t *testing.T) {
+ tc.check(t, false,
+ d.Entries(), d.Err)
+ })
+ })
- wantCount := len(tc.want)
- if tc.wantErr != nil || tc.wantError != "" {
- wantCount = -1
- }
- if n != wantCount {
- t.Errorf("ParseMountInfo: got %d entries, want %d", n, wantCount)
- }
+ t.Run("iter", func(t *testing.T) {
+ d := vfs.NewMountInfoDecoder(strings.NewReader(tc.sample))
+ tc.check(t, false,
+ d.Entries(), d.Err)
- i := 0
- for cur := got; cur != nil; cur = cur.Next {
- if i == len(tc.want) {
- t.Errorf("ParseMountInfo: got more than %d entries", len(tc.want))
- break
- }
+ t.Run("reuse", func(t *testing.T) {
+ tc.check(t, false,
+ d.Entries(), d.Err)
+ })
+ })
- if !reflect.DeepEqual(&cur.MountInfoEntry, &tc.want[i].MountInfoEntry) {
- t.Errorf("ParseMountInfo: entry %d\ngot: %#v\nwant: %#v",
- i, cur.MountInfoEntry, tc.want[i])
- }
+ t.Run("yield", func(t *testing.T) {
+ d := vfs.NewMountInfoDecoder(strings.NewReader(tc.sample))
+ v := false
+ d.Entries()(func(entry *vfs.MountInfoEntry) bool { v = !v; return v })
+ d.Entries()(func(entry *vfs.MountInfoEntry) bool { return false })
- flags, unmatched := cur.Flags()
- if flags != tc.want[i].flags {
- t.Errorf("Flags(%q): %#x, want %#x",
- cur.VfsOptstr, flags, tc.want[i].flags)
- }
- if !slices.Equal(unmatched, tc.want[i].unmatched) {
- t.Errorf("Flags(%q): unmatched = %#q, want %#q",
- cur.VfsOptstr, unmatched, tc.want[i].unmatched)
- }
+ tc.check(t, false,
+ d.Entries(), d.Err)
- i++
- }
+ t.Run("reuse", func(t *testing.T) {
+ tc.check(t, false,
+ d.Entries(), d.Err)
+ })
+ })
+ })
+ }
+}
+
+type mountInfoTest struct {
+ name string
+ sample string
+ wantErr error
+ wantError string
+ want []*wantMountInfo
+}
- if i != len(tc.want) {
- t.Errorf("ParseMountInfo: got %d entries, want %d", i, len(tc.want))
+func (tc *mountInfoTest) check(t *testing.T, checkDecode bool,
+ got iter.Seq[*vfs.MountInfoEntry], gotErr func() error) {
+ i := 0
+ for cur := range got {
+ if i == len(tc.want) {
+ if !checkDecode && (tc.wantErr != nil || tc.wantError != "") {
+ continue
}
- })
+
+ t.Errorf("ParseMountInfo: got more than %d entries", len(tc.want))
+ break
+ }
+
+ if !reflect.DeepEqual(cur, &tc.want[i].MountInfoEntry) {
+ t.Errorf("ParseMountInfo: entry %d\ngot: %#v\nwant: %#v",
+ i, cur, tc.want[i])
+ }
+
+ flags, unmatched := cur.Flags()
+ if flags != tc.want[i].flags {
+ t.Errorf("Flags(%q): %#x, want %#x",
+ cur.VfsOptstr, flags, tc.want[i].flags)
+ }
+ if !slices.Equal(unmatched, tc.want[i].unmatched) {
+ t.Errorf("Flags(%q): unmatched = %#q, want %#q",
+ cur.VfsOptstr, unmatched, tc.want[i].unmatched)
+ }
+
+ i++
+ }
+
+ if i != len(tc.want) {
+ t.Errorf("ParseMountInfo: got %d entries, want %d", i, len(tc.want))
+ }
+
+ if err := gotErr(); !errors.Is(err, tc.wantErr) {
+ if tc.wantError == "" {
+ t.Errorf("ParseMountInfo: error = %v, wantErr %v",
+ err, tc.wantErr)
+ } else if err != nil && err.Error() != tc.wantError {
+ t.Errorf("ParseMountInfo: error = %q, wantError %q",
+ err, tc.wantError)
+ }
}
}
generated by cgit v1.3.1 (git 2.54.0) at 2026-08-30 09:59:31 +0000