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01: #ifndef _LINUX_SECUREBITS_H
02: #define _LINUX_SECUREBITS_H 1
03: 
04: /* Each securesetting is implemented using two bits. One bit specifies
05:    whether the setting is on or off. The other bit specify whether the
06:    setting is locked or not. A setting which is locked cannot be
07:    changed from user-level. */
08: #define issecure_mask(X)        (1 << (X))
09: 
10: #define SECUREBITS_DEFAULT 0x00000000
11: 
12: /* When set UID 0 has no special privileges. When unset, we support
13:    inheritance of root-permissions and suid-root executable under
14:    compatibility mode. We raise the effective and inheritable bitmasks
15:    *of the executable file* if the effective uid of the new process is
16:    0. If the real uid is 0, we raise the effective (legacy) bit of the
17:    executable file. */
18: #define SECURE_NOROOT                   0
19: #define SECURE_NOROOT_LOCKED            1  /* make bit-0 immutable */
20: 
21: #define SECBIT_NOROOT           (issecure_mask(SECURE_NOROOT))
22: #define SECBIT_NOROOT_LOCKED    (issecure_mask(SECURE_NOROOT_LOCKED))
23: 
24: /* When set, setuid to/from uid 0 does not trigger capability-"fixup".
25:    When unset, to provide compatiblility with old programs relying on
26:    set*uid to gain/lose privilege, transitions to/from uid 0 cause
27:    capabilities to be gained/lost. */
28: #define SECURE_NO_SETUID_FIXUP          2
29: #define SECURE_NO_SETUID_FIXUP_LOCKED   3  /* make bit-2 immutable */
30: 
31: #define SECBIT_NO_SETUID_FIXUP  (issecure_mask(SECURE_NO_SETUID_FIXUP))
32: #define SECBIT_NO_SETUID_FIXUP_LOCKED \
33:                         (issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED))
34: 
35: /* When set, a process can retain its capabilities even after
36:    transitioning to a non-root user (the set-uid fixup suppressed by
37:    bit 2). Bit-4 is cleared when a process calls exec(); setting both
38:    bit 4 and 5 will create a barrier through exec that no exec()'d
39:    child can use this feature again. */
40: #define SECURE_KEEP_CAPS                4
41: #define SECURE_KEEP_CAPS_LOCKED         5  /* make bit-4 immutable */
42: 
43: #define SECBIT_KEEP_CAPS        (issecure_mask(SECURE_KEEP_CAPS))
44: #define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED))
45: 
46: #define SECURE_ALL_BITS         (issecure_mask(SECURE_NOROOT) | \
47:                                  issecure_mask(SECURE_NO_SETUID_FIXUP) | \
48:                                  issecure_mask(SECURE_KEEP_CAPS))
49: #define SECURE_ALL_LOCKS        (SECURE_ALL_BITS << 1)
50: 
51: #endif /* !_LINUX_SECUREBITS_H */
52: 

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