50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
package sandbox
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import (
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"encoding/gob"
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"fmt"
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"math"
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"os"
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"path"
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"syscall"
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"git.gensokyo.uk/security/fortify/internal/fmsg"
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)
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func init() { gob.Register(new(MountTmpfs)) }
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type MountTmpfs struct {
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Path string
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Size int
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Mode os.FileMode
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}
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func (t *MountTmpfs) apply() error {
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if !path.IsAbs(t.Path) {
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return fmsg.WrapError(syscall.EBADE,
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fmt.Sprintf("path %q is not absolute", t.Path))
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}
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if t.Size < 0 || t.Size > math.MaxUint>>1 {
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return fmsg.WrapError(syscall.EBADE,
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fmt.Sprintf("size %d out of bounds", t.Size))
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}
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target := toSysroot(t.Path)
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if err := os.MkdirAll(target, 0755); err != nil {
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return err
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}
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opt := fmt.Sprintf("mode=%#o", t.Mode)
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if t.Size > 0 {
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opt += fmt.Sprintf(",size=%d", t.Mode)
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}
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return fmsg.WrapErrorSuffix(syscall.Mount("tmpfs", target, "tmpfs",
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syscall.MS_NOSUID|syscall.MS_NODEV, opt),
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fmt.Sprintf("cannot mount tmpfs on %q:", t.Path))
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}
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func (t *MountTmpfs) Is(op FSOp) bool { vt, ok := op.(*MountTmpfs); return ok && *t == *vt }
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func (t *MountTmpfs) String() string { return fmt.Sprintf("tmpfs on %q size %d", t.Path, t.Size) }
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func (f *Filesystem) Tmpfs(dest string, size int, mode os.FileMode) *Filesystem {
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*f = append(*f, &MountTmpfs{dest, size, mode})
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return f
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}
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