build-sys: move more files from core/ to share/ that are generic enough

[elogind.git] / src / shared / securebits.h

diff --git a/src/shared/securebits.h b/src/shared/securebits.h
new file mode 100644 (file)
index 0000000..98fbe0d
--- /dev/null
+++ b/src/shared/securebits.h
@@ -0,0 +1,45 @@
+#ifndef _LINUX_SECUREBITS_H
+#define _LINUX_SECUREBITS_H 1
+
+/* This is minimal version of Linux' linux/securebits.h header file,
+ * which is licensed GPL2 */
+
+#define SECUREBITS_DEFAULT 0x00000000
+
+/* When set UID 0 has no special privileges. When unset, we support
+   inheritance of root-permissions and suid-root executable under
+   compatibility mode. We raise the effective and inheritable bitmasks
+   *of the executable file* if the effective uid of the new process is
+   0. If the real uid is 0, we raise the effective (legacy) bit of the
+   executable file. */
+#define SECURE_NOROOT                  0
+#define SECURE_NOROOT_LOCKED           1  /* make bit-0 immutable */
+
+/* When set, setuid to/from uid 0 does not trigger capability-"fixup".
+   When unset, to provide compatibility with old programs relying on
+   set*uid to gain/lose privilege, transitions to/from uid 0 cause
+   capabilities to be gained/lost. */
+#define SECURE_NO_SETUID_FIXUP         2
+#define SECURE_NO_SETUID_FIXUP_LOCKED  3  /* make bit-2 immutable */
+
+/* When set, a process can retain its capabilities even after
+   transitioning to a non-root user (the set-uid fixup suppressed by
+   bit 2). Bit-4 is cleared when a process calls exec(); setting both
+   bit 4 and 5 will create a barrier through exec that no exec()'d
+   child can use this feature again. */
+#define SECURE_KEEP_CAPS               4
+#define SECURE_KEEP_CAPS_LOCKED                5  /* make bit-4 immutable */
+
+/* Each securesetting is implemented using two bits. One bit specifies
+   whether the setting is on or off. The other bit specify whether the
+   setting is locked or not. A setting which is locked cannot be
+   changed from user-level. */
+#define issecure_mask(X)       (1 << (X))
+#define issecure(X)            (issecure_mask(X) & current_cred_xxx(securebits))
+
+#define SECURE_ALL_BITS                (issecure_mask(SECURE_NOROOT) | \
+                                 issecure_mask(SECURE_NO_SETUID_FIXUP) | \
+                                 issecure_mask(SECURE_KEEP_CAPS))
+#define SECURE_ALL_LOCKS       (SECURE_ALL_BITS << 1)
+
+#endif /* !_LINUX_SECUREBITS_H */