include/linux/utsname.h

   1 #ifndef _LINUX_UTSNAME_H
   2 #define _LINUX_UTSNAME_H
   3
   4
   5 #include <linux/sched.h>
   6 #include <linux/kref.h>
   7 #include <linux/nsproxy.h>
   8 #include <linux/err.h>
   9 #include <uapi/linux/utsname.h>
  10
  11 enum uts_proc {
  12         UTS_PROC_OSTYPE,
  13         UTS_PROC_OSRELEASE,
  14         UTS_PROC_VERSION,
  15         UTS_PROC_HOSTNAME,
  16         UTS_PROC_DOMAINNAME,
  17 };
  18
  19 struct user_namespace;
  20 extern struct user_namespace init_user_ns;
  21
  22 struct uts_namespace {
  23         struct kref kref;
  24         struct new_utsname name;
  25         struct user_namespace *user_ns;
  26         unsigned int proc_inum;
  27 };
  28 extern struct uts_namespace init_uts_ns;
  29
  30 #ifdef CONFIG_UTS_NS
  31 static inline void get_uts_ns(struct uts_namespace *ns)
  32 {
  33         kref_get(&ns->kref);
  34 }
  35
  36 extern struct uts_namespace *copy_utsname(unsigned long flags,
  37         struct user_namespace *user_ns, struct uts_namespace *old_ns);
  38 extern void free_uts_ns(struct kref *kref);
  39
  40 static inline void put_uts_ns(struct uts_namespace *ns)
  41 {
  42         kref_put(&ns->kref, free_uts_ns);
  43 }
  44 #else
  45 static inline void get_uts_ns(struct uts_namespace *ns)
  46 {
  47 }
  48
  49 static inline void put_uts_ns(struct uts_namespace *ns)
  50 {
  51 }
  52
  53 static inline struct uts_namespace *copy_utsname(unsigned long flags,
  54         struct user_namespace *user_ns, struct uts_namespace *old_ns)
  55 {
  56         if (flags & CLONE_NEWUTS)
  57                 return ERR_PTR(-EINVAL);
  58
  59         return old_ns;
  60 }
  61 #endif
  62
  63 #ifdef CONFIG_PROC_SYSCTL
  64 extern void uts_proc_notify(enum uts_proc proc);
  65 #else
  66 static inline void uts_proc_notify(enum uts_proc proc)
  67 {
  68 }
  69 #endif
  70
  71 static inline struct new_utsname *utsname(void)
  72 {
  73         return &current->nsproxy->uts_ns->name;
  74 }
  75
  76 static inline struct new_utsname *init_utsname(void)
  77 {
  78         return &init_uts_ns.name;
  79 }
  80
  81 extern struct rw_semaphore uts_sem;
  82
  83 #endif /* _LINUX_UTSNAME_H */