From: Mike Yuan <me@yhndnzj.com>
Date: Tue, 24 Dec 2024 15:59:48 +0000 (+0100)
Subject: capability-util: make CAPABILITY_QUINTET_NULL const, introduce capability_quintet_is_... 
X-Git-Tag: v258-rc1~1762^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6f3854fd6338ae5d9169684cae93fb7de7204232;p=thirdparty%2Fsystemd.git

capability-util: make CAPABILITY_QUINTET_NULL const, introduce capability_quintet_is_fully_set() helper

Follow-up for 1184626a269e38dcdfcd1042975a31d4eb30cd5e

See 9bb64f1b8d2252d558f209a04b171d65b5ef131b for rationale
of the first change.
---

diff --git a/src/basic/capability-util.c b/src/basic/capability-util.c
index 627af121386..ccdb31fe4cd 100644
--- a/src/basic/capability-util.c
+++ b/src/basic/capability-util.c
@@ -661,11 +661,7 @@ int pidref_get_capability(const PidRef *pidref, CapabilityQuintet *ret) {
                 }
         }
 
-        if (q.effective == CAP_MASK_UNSET ||
-            q.inheritable == CAP_MASK_UNSET ||
-            q.permitted == CAP_MASK_UNSET ||
-            q.effective == CAP_MASK_UNSET ||
-            q.ambient == CAP_MASK_UNSET)
+        if (!capability_quintet_is_fully_set(&q))
                 return -EBADMSG;
 
         r = pidref_verify(pidref);
diff --git a/src/basic/capability-util.h b/src/basic/capability-util.h
index 9caae1ac064..89c6cbec414 100644
--- a/src/basic/capability-util.h
+++ b/src/basic/capability-util.h
@@ -10,8 +10,10 @@
 #include "missing_capability.h"
 #include "pidref.h"
 
-/* Special marker used when storing a capabilities mask as "unset" */
+/* Special marker used when storing a capabilities mask as "unset". This would need to be updated as soon as
+ * Linux learns more than 63 caps. */
 #define CAP_MASK_UNSET UINT64_MAX
+assert_cc(CAP_LAST_CAP < 64);
 
 /* All possible capabilities bits on */
 #define CAP_MASK_ALL UINT64_C(0x7fffffffffffffff)
@@ -20,6 +22,10 @@
  * be able to use UINT64_MAX as indicator for "not set". The latter makes capability 63 unavailable. */
 #define CAP_LIMIT 62
 
+static inline bool capability_is_set(uint64_t v) {
+        return v != CAP_MASK_UNSET;
+}
+
 unsigned cap_last_cap(void);
 int have_effective_cap(int value);
 int capability_gain_cap_setpcap(cap_t *return_caps);
@@ -56,8 +62,7 @@ static inline bool cap_test_all(uint64_t caps) {
 #define CAP_TO_MASK_CORRECTED(x) (1U << ((x) & 31U))
 
 typedef struct CapabilityQuintet {
-        /* Stores all five types of capabilities in one go. Note that we use UINT64_MAX for unset here. This hence
-         * needs to be updated as soon as Linux learns more than 63 caps. */
+        /* Stores all five types of capabilities in one go. */
         uint64_t effective;
         uint64_t bounding;
         uint64_t inheritable;
@@ -65,13 +70,7 @@ typedef struct CapabilityQuintet {
         uint64_t ambient;
 } CapabilityQuintet;
 
-assert_cc(CAP_LAST_CAP < 64);
-
-#define CAPABILITY_QUINTET_NULL (CapabilityQuintet) { CAP_MASK_UNSET, CAP_MASK_UNSET, CAP_MASK_UNSET, CAP_MASK_UNSET, CAP_MASK_UNSET }
-
-static inline bool capability_is_set(uint64_t v) {
-        return v != CAP_MASK_UNSET;
-}
+#define CAPABILITY_QUINTET_NULL (const CapabilityQuintet) { CAP_MASK_UNSET, CAP_MASK_UNSET, CAP_MASK_UNSET, CAP_MASK_UNSET, CAP_MASK_UNSET }
 
 static inline bool capability_quintet_is_set(const CapabilityQuintet *q) {
         return capability_is_set(q->effective) ||
@@ -81,6 +80,14 @@ static inline bool capability_quintet_is_set(const CapabilityQuintet *q) {
                 capability_is_set(q->ambient);
 }
 
+static inline bool capability_quintet_is_fully_set(const CapabilityQuintet *q) {
+        return capability_is_set(q->effective) &&
+                capability_is_set(q->bounding) &&
+                capability_is_set(q->inheritable) &&
+                capability_is_set(q->permitted) &&
+                capability_is_set(q->ambient);
+}
+
 /* Mangles the specified caps quintet taking the current bounding set into account:
  * drops all caps from all five sets if our bounding set doesn't allow them.
  * Returns true if the quintet was modified. */