1 files changed, 200 insertions, 0 deletions

diff --git a/include/linux/uidgid.h b/include/linux/uidgid.h
new file mode 100644
index 000000000000..8e522cbcef29
--- /dev/null
+++ b/include/linux/uidgid.h
@@ -0,0 +1,200 @@
+#ifndef _LINUX_UIDGID_H
+#define _LINUX_UIDGID_H
+
+/*
+ * A set of types for the internal kernel types representing uids and gids.
+ *
+ * The types defined in this header allow distinguishing which uids and gids in
+ * the kernel are values used by userspace and which uid and gid values are
+ * the internal kernel values.  With the addition of user namespaces the values
+ * can be different.  Using the type system makes it possible for the compiler
+ * to detect when we overlook these differences.
+ *
+ */
+#include <linux/types.h>
+#include <linux/highuid.h>
+
+struct user_namespace;
+extern struct user_namespace init_user_ns;
+
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+
+typedef struct {
+        uid_t val;
+} kuid_t;
+
+
+typedef struct {
+        gid_t val;
+} kgid_t;
+
+#define KUIDT_INIT(value) (kuid_t){ value }
+#define KGIDT_INIT(value) (kgid_t){ value }
+
+static inline uid_t __kuid_val(kuid_t uid)
+{
+        return uid.val;
+}
+
+static inline gid_t __kgid_val(kgid_t gid)
+{
+        return gid.val;
+}
+
+#else
+
+typedef uid_t kuid_t;
+typedef gid_t kgid_t;
+
+static inline uid_t __kuid_val(kuid_t uid)
+{
+        return uid;
+}
+
+static inline gid_t __kgid_val(kgid_t gid)
+{
+        return gid;
+}
+
+#define KUIDT_INIT(value) ((kuid_t) value )
+#define KGIDT_INIT(value) ((kgid_t) value )
+
+#endif
+
+#define GLOBAL_ROOT_UID KUIDT_INIT(0)
+#define GLOBAL_ROOT_GID KGIDT_INIT(0)
+
+#define INVALID_UID KUIDT_INIT(-1)
+#define INVALID_GID KGIDT_INIT(-1)
+
+static inline bool uid_eq(kuid_t left, kuid_t right)
+{
+        return __kuid_val(left) == __kuid_val(right);
+}
+
+static inline bool gid_eq(kgid_t left, kgid_t right)
+{
+        return __kgid_val(left) == __kgid_val(right);
+}
+
+static inline bool uid_gt(kuid_t left, kuid_t right)
+{
+        return __kuid_val(left) > __kuid_val(right);
+}
+
+static inline bool gid_gt(kgid_t left, kgid_t right)
+{
+        return __kgid_val(left) > __kgid_val(right);
+}
+
+static inline bool uid_gte(kuid_t left, kuid_t right)
+{
+        return __kuid_val(left) >= __kuid_val(right);
+}
+
+static inline bool gid_gte(kgid_t left, kgid_t right)
+{
+        return __kgid_val(left) >= __kgid_val(right);
+}
+
+static inline bool uid_lt(kuid_t left, kuid_t right)
+{
+        return __kuid_val(left) < __kuid_val(right);
+}
+
+static inline bool gid_lt(kgid_t left, kgid_t right)
+{
+        return __kgid_val(left) < __kgid_val(right);
+}
+
+static inline bool uid_lte(kuid_t left, kuid_t right)
+{
+        return __kuid_val(left) <= __kuid_val(right);
+}
+
+static inline bool gid_lte(kgid_t left, kgid_t right)
+{
+        return __kgid_val(left) <= __kgid_val(right);
+}
+
+static inline bool uid_valid(kuid_t uid)
+{
+        return !uid_eq(uid, INVALID_UID);
+}
+
+static inline bool gid_valid(kgid_t gid)
+{
+        return !gid_eq(gid, INVALID_GID);
+}
+
+#ifdef CONFIG_USER_NS
+
+extern kuid_t make_kuid(struct user_namespace *from, uid_t uid);
+extern kgid_t make_kgid(struct user_namespace *from, gid_t gid);
+
+extern uid_t from_kuid(struct user_namespace *to, kuid_t uid);
+extern gid_t from_kgid(struct user_namespace *to, kgid_t gid);
+extern uid_t from_kuid_munged(struct user_namespace *to, kuid_t uid);
+extern gid_t from_kgid_munged(struct user_namespace *to, kgid_t gid);
+
+static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
+{
+        return from_kuid(ns, uid) != (uid_t) -1;
+}
+
+static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
+{
+        return from_kgid(ns, gid) != (gid_t) -1;
+}
+
+#else
+
+static inline kuid_t make_kuid(struct user_namespace *from, uid_t uid)
+{
+        return KUIDT_INIT(uid);
+}
+
+static inline kgid_t make_kgid(struct user_namespace *from, gid_t gid)
+{
+        return KGIDT_INIT(gid);
+}
+
+static inline uid_t from_kuid(struct user_namespace *to, kuid_t kuid)
+{
+        return __kuid_val(kuid);
+}
+
+static inline gid_t from_kgid(struct user_namespace *to, kgid_t kgid)
+{
+        return __kgid_val(kgid);
+}
+
+static inline uid_t from_kuid_munged(struct user_namespace *to, kuid_t kuid)
+{
+        uid_t uid = from_kuid(to, kuid);
+        if (uid == (uid_t)-1)
+                uid = overflowuid;
+        return uid;
+}
+
+static inline gid_t from_kgid_munged(struct user_namespace *to, kgid_t kgid)
+{
+        gid_t gid = from_kgid(to, kgid);
+        if (gid == (gid_t)-1)
+                gid = overflowgid;
+        return gid;
+}
+
+static inline bool kuid_has_mapping(struct user_namespace *ns, kuid_t uid)
+{
+        return true;
+}
+
+static inline bool kgid_has_mapping(struct user_namespace *ns, kgid_t gid)
+{
+        return true;
+}
+
+#endif /* CONFIG_USER_NS */
+
+#endif /* _LINUX_UIDGID_H */