nss-mymachines: map userns users of containers to real user names

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

diff --git a/src/shared/macro.h b/src/shared/macro.h
index 6a5742824479165f846e2df2f32c69d935998d9d..58530a398089a1ff16b199111bde046659a3bf40 100644 (file)
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -26,6 +26,7 @@
 #include <sys/types.h>
 #include <sys/uio.h>
 #include <inttypes.h>
+#include <stdbool.h>
 
 #define _printf_(a,b) __attribute__ ((format (printf, a, b)))
 #define _alloc_(...) __attribute__ ((alloc_size(__VA_ARGS__)))
@@ -67,6 +68,10 @@
         _Pragma("GCC diagnostic push");                                 \
         _Pragma("GCC diagnostic ignored \"-Wshadow\"")
 
+#define DISABLE_WARNING_INCOMPATIBLE_POINTER_TYPES                      \
+        _Pragma("GCC diagnostic push");                                 \
+        _Pragma("GCC diagnostic ignored \"-Wincompatible-pointer-types\"")
+
 #define REENABLE_WARNING                                                \
         _Pragma("GCC diagnostic pop")
 
@@ -238,16 +243,26 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
 #else
 #define assert_cc(expr)                                                 \
         DISABLE_WARNING_DECLARATION_AFTER_STATEMENT;                    \
-        struct CONCATENATE(_assert_struct_, __LINE__) {                 \
+        struct CONCATENATE(_assert_struct_, __COUNTER__) {              \
                 char x[(expr) ? 0 : -1];                                \
         };                                                              \
         REENABLE_WARNING
 #endif
 
+#define assert_log(expr) ((_likely_(expr))      \
+        ? (true)                                \
+        : (log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__), false))
+
 #define assert_return(expr, r)                                          \
         do {                                                            \
-                if (_unlikely_(!(expr))) {                              \
-                        log_assert_failed_return(#expr, __FILE__, __LINE__, __PRETTY_FUNCTION__); \
+                if (!assert_log(expr))                                  \
+                        return (r);                                     \
+        } while (false)
+
+#define assert_return_errno(expr, r, err)                               \
+        do {                                                            \
+                if (!assert_log(expr)) {                                \
+                        errno = err;                                    \
                         return (r);                                     \
                 }                                                       \
         } while (false)
@@ -275,6 +290,14 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
 #define PTR_TO_SIZE(p) ((size_t) ((uintptr_t) (p)))
 #define SIZE_TO_PTR(u) ((void *) ((uintptr_t) (u)))
 
+/* The following macros add 1 when converting things, since UID 0 is a
+ * valid UID, while the pointer NULL is special */
+#define PTR_TO_UID(p) ((uid_t) (((uintptr_t) (p))-1))
+#define UID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
+
+#define PTR_TO_GID(p) ((gid_t) (((uintptr_t) (p))-1))
+#define GID_TO_PTR(u) ((void*) (((uintptr_t) (u))+1))
+
 #define memzero(x,l) (memset((x), 0, (l)))
 #define zero(x) (memzero(&(x), sizeof(x)))
 
@@ -371,7 +394,8 @@ do {                                                                    \
 
 /* Returns the number of chars needed to format variables of the
  * specified type as a decimal string. Adds in extra space for a
- * negative '-' prefix. */
+ * negative '-' prefix (hence works correctly on signed
+ * types). Includes space for the trailing NUL. */
 #define DECIMAL_STR_MAX(type)                                           \
         (2+(sizeof(type) <= 1 ? 3 :                                     \
             sizeof(type) <= 2 ? 5 :                                     \
@@ -438,4 +462,26 @@ do {                                                                    \
 #define GID_INVALID ((gid_t) -1)
 #define MODE_INVALID ((mode_t) -1)
 
+static inline bool UID_IS_INVALID(uid_t uid) {
+        /* We consider both the old 16bit -1 user and the newer 32bit
+         * -1 user invalid, since they are or used to be incompatible
+         * with syscalls such as setresuid() or chown(). */
+
+        return uid == (uid_t) ((uint32_t) -1) || uid == (uid_t) ((uint16_t) -1);
+}
+
+static inline bool GID_IS_INVALID(gid_t gid) {
+        return gid == (gid_t) ((uint32_t) -1) || gid == (gid_t) ((uint16_t) -1);
+}
+
+#define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
+        static inline void func##p(type *p) {                   \
+                if (*p)                                         \
+                        func(*p);                               \
+        }                                                       \
+        struct __useless_struct_to_allow_trailing_semicolon__
+
+#define CMSG_FOREACH(cmsg, mh)                                          \
+        for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
+
 #include "log.h"