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 };
  27 extern struct uts_namespace init_uts_ns;
  28
  29 #ifdef CONFIG_UTS_NS
  30 static inline void get_uts_ns(struct uts_namespace *ns)
  31 {
  32         kref_get(&ns->kref);
  33 }
  34
  35 extern struct uts_namespace *copy_utsname(unsigned long flags,
  36                                           struct task_struct *tsk);
  37 extern void free_uts_ns(struct kref *kref);
  38
  39 static inline void put_uts_ns(struct uts_namespace *ns)
  40 {
  41         kref_put(&ns->kref, free_uts_ns);
  42 }
  43 #else
  44 static inline void get_uts_ns(struct uts_namespace *ns)
  45 {
  46 }
  47
  48 static inline void put_uts_ns(struct uts_namespace *ns)
  49 {
  50 }
  51
  52 static inline struct uts_namespace *copy_utsname(unsigned long flags,
  53                                                  struct task_struct *tsk)
  54 {
  55         if (flags & CLONE_NEWUTS)
  56                 return ERR_PTR(-EINVAL);
  57
  58         return tsk->nsproxy->uts_ns;
  59 }
  60 #endif
  61
  62 #ifdef CONFIG_PROC_SYSCTL
  63 extern void uts_proc_notify(enum uts_proc proc);
  64 #else
  65 static inline void uts_proc_notify(enum uts_proc proc)
  66 {
  67 }
  68 #endif
  69
  70 static inline struct new_utsname *utsname(void)
  71 {
  72         return &current->nsproxy->uts_ns->name;
  73 }
  74
  75 static inline struct new_utsname *init_utsname(void)
  76 {
  77         return &init_uts_ns.name;
  78 }
  79
  80 extern struct rw_semaphore uts_sem;
  81
  82 #endif /* _LINUX_UTSNAME_H */