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