securebits.h 2.2 KB

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  1. #ifndef _UAPI_LINUX_SECUREBITS_H
  2. #define _UAPI_LINUX_SECUREBITS_H
  3. /* Each securesetting is implemented using two bits. One bit specifies
  4. whether the setting is on or off. The other bit specify whether the
  5. setting is locked or not. A setting which is locked cannot be
  6. changed from user-level. */
  7. #define issecure_mask(X) (1 << (X))
  8. #define SECUREBITS_DEFAULT 0x00000000
  9. /* When set UID 0 has no special privileges. When unset, we support
  10. inheritance of root-permissions and suid-root executable under
  11. compatibility mode. We raise the effective and inheritable bitmasks
  12. *of the executable file* if the effective uid of the new process is
  13. 0. If the real uid is 0, we raise the effective (legacy) bit of the
  14. executable file. */
  15. #define SECURE_NOROOT 0
  16. #define SECURE_NOROOT_LOCKED 1 /* make bit-0 immutable */
  17. #define SECBIT_NOROOT (issecure_mask(SECURE_NOROOT))
  18. #define SECBIT_NOROOT_LOCKED (issecure_mask(SECURE_NOROOT_LOCKED))
  19. /* When set, setuid to/from uid 0 does not trigger capability-"fixup".
  20. When unset, to provide compatiblility with old programs relying on
  21. set*uid to gain/lose privilege, transitions to/from uid 0 cause
  22. capabilities to be gained/lost. */
  23. #define SECURE_NO_SETUID_FIXUP 2
  24. #define SECURE_NO_SETUID_FIXUP_LOCKED 3 /* make bit-2 immutable */
  25. #define SECBIT_NO_SETUID_FIXUP (issecure_mask(SECURE_NO_SETUID_FIXUP))
  26. #define SECBIT_NO_SETUID_FIXUP_LOCKED \
  27. (issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED))
  28. /* When set, a process can retain its capabilities even after
  29. transitioning to a non-root user (the set-uid fixup suppressed by
  30. bit 2). Bit-4 is cleared when a process calls exec(); setting both
  31. bit 4 and 5 will create a barrier through exec that no exec()'d
  32. child can use this feature again. */
  33. #define SECURE_KEEP_CAPS 4
  34. #define SECURE_KEEP_CAPS_LOCKED 5 /* make bit-4 immutable */
  35. #define SECBIT_KEEP_CAPS (issecure_mask(SECURE_KEEP_CAPS))
  36. #define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED))
  37. #define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) | \
  38. issecure_mask(SECURE_NO_SETUID_FIXUP) | \
  39. issecure_mask(SECURE_KEEP_CAPS))
  40. #define SECURE_ALL_LOCKS (SECURE_ALL_BITS << 1)
  41. #endif /* _UAPI_LINUX_SECUREBITS_H */