The C and C++ Include Header Files

/usr/include/linux/securebits.h


$ cat -n /usr/include/linux/securebits.h

     1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
     2	#ifndef _LINUX_SECUREBITS_H
     3	#define _LINUX_SECUREBITS_H
     4	
     5	/* Each securesetting is implemented using two bits. One bit specifies
     6	   whether the setting is on or off. The other bit specify whether the
     7	   setting is locked or not. A setting which is locked cannot be
     8	   changed from user-level. */
     9	#define issecure_mask(X)	(1 << (X))
    10	
    11	#define SECUREBITS_DEFAULT 0x00000000
    12	
    13	/* When set UID 0 has no special privileges. When unset, we support
    14	   inheritance of root-permissions and suid-root executable under
    15	   compatibility mode. We raise the effective and inheritable bitmasks
    16	   *of the executable file* if the effective uid of the new process is
    17	   0. If the real uid is 0, we raise the effective (legacy) bit of the
    18	   executable file. */
    19	#define SECURE_NOROOT			0
    20	#define SECURE_NOROOT_LOCKED		1  /* make bit-0 immutable */
    21	
    22	#define SECBIT_NOROOT		(issecure_mask(SECURE_NOROOT))
    23	#define SECBIT_NOROOT_LOCKED	(issecure_mask(SECURE_NOROOT_LOCKED))
    24	
    25	/* When set, setuid to/from uid 0 does not trigger capability-"fixup".
    26	   When unset, to provide compatiblility with old programs relying on
    27	   set*uid to gain/lose privilege, transitions to/from uid 0 cause
    28	   capabilities to be gained/lost. */
    29	#define SECURE_NO_SETUID_FIXUP		2
    30	#define SECURE_NO_SETUID_FIXUP_LOCKED	3  /* make bit-2 immutable */
    31	
    32	#define SECBIT_NO_SETUID_FIXUP	(issecure_mask(SECURE_NO_SETUID_FIXUP))
    33	#define SECBIT_NO_SETUID_FIXUP_LOCKED \
    34				(issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED))
    35	
    36	/* When set, a process can retain its capabilities even after
    37	   transitioning to a non-root user (the set-uid fixup suppressed by
    38	   bit 2). Bit-4 is cleared when a process calls exec(); setting both
    39	   bit 4 and 5 will create a barrier through exec that no exec()'d
    40	   child can use this feature again. */
    41	#define SECURE_KEEP_CAPS		4
    42	#define SECURE_KEEP_CAPS_LOCKED		5  /* make bit-4 immutable */
    43	
    44	#define SECBIT_KEEP_CAPS	(issecure_mask(SECURE_KEEP_CAPS))
    45	#define SECBIT_KEEP_CAPS_LOCKED (issecure_mask(SECURE_KEEP_CAPS_LOCKED))
    46	
    47	/* When set, a process cannot add new capabilities to its ambient set. */
    48	#define SECURE_NO_CAP_AMBIENT_RAISE		6
    49	#define SECURE_NO_CAP_AMBIENT_RAISE_LOCKED	7  /* make bit-6 immutable */
    50	
    51	#define SECBIT_NO_CAP_AMBIENT_RAISE (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
    52	#define SECBIT_NO_CAP_AMBIENT_RAISE_LOCKED \
    53				(issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE_LOCKED))
    54	
    55	#define SECURE_ALL_BITS		(issecure_mask(SECURE_NOROOT) | \
    56					 issecure_mask(SECURE_NO_SETUID_FIXUP) | \
    57					 issecure_mask(SECURE_KEEP_CAPS) | \
    58					 issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
    59	#define SECURE_ALL_LOCKS	(SECURE_ALL_BITS << 1)
    60	
    61	#endif /* _LINUX_SECUREBITS_H */