include/linux/utsname.h

   1 #ifndef _LINUX_UTSNAME_H
   2 #define _LINUX_UTSNAME_H
   3
   4 #define __OLD_UTS_LEN 8
   5
   6 struct oldold_utsname {
   7         char sysname[9];
   8         char nodename[9];
   9         char release[9];
  10         char version[9];
  11         char machine[9];
  12 };
  13
  14 #define __NEW_UTS_LEN 64
  15
  16 struct old_utsname {
  17         char sysname[65];
  18         char nodename[65];
  19         char release[65];
  20         char version[65];
  21         char machine[65];
  22 };
  23
  24 struct new_utsname {
  25         char sysname[__NEW_UTS_LEN + 1];
  26         char nodename[__NEW_UTS_LEN + 1];
  27         char release[__NEW_UTS_LEN + 1];
  28         char version[__NEW_UTS_LEN + 1];
  29         char machine[__NEW_UTS_LEN + 1];
  30         char domainname[__NEW_UTS_LEN + 1];
  31 };
  32
  33 #ifdef __KERNEL__
  34
  35 #include <linux/sched.h>
  36 #include <linux/kref.h>
  37 #include <linux/nsproxy.h>
  38 #include <linux/err.h>
  39
  40 struct user_namespace;
  41 extern struct user_namespace init_user_ns;
  42
  43 struct uts_namespace {
  44         struct kref kref;
  45         struct new_utsname name;
  46         struct user_namespace *user_ns;
  47 };
  48 extern struct uts_namespace init_uts_ns;
  49
  50 #ifdef CONFIG_UTS_NS
  51 static inline void get_uts_ns(struct uts_namespace *ns)
  52 {
  53         kref_get(&ns->kref);
  54 }
  55
  56 extern struct uts_namespace *copy_utsname(unsigned long flags,
  57                                           struct task_struct *tsk);
  58 extern void free_uts_ns(struct kref *kref);
  59
  60 static inline void put_uts_ns(struct uts_namespace *ns)
  61 {
  62         kref_put(&ns->kref, free_uts_ns);
  63 }
  64 #else
  65 static inline void get_uts_ns(struct uts_namespace *ns)
  66 {
  67 }
  68
  69 static inline void put_uts_ns(struct uts_namespace *ns)
  70 {
  71 }
  72
  73 static inline struct uts_namespace *copy_utsname(unsigned long flags,
  74                                                  struct task_struct *tsk)
  75 {
  76         if (flags & CLONE_NEWUTS)
  77                 return ERR_PTR(-EINVAL);
  78
  79         return tsk->nsproxy->uts_ns;
  80 }
  81 #endif
  82
  83 static inline struct new_utsname *utsname(void)
  84 {
  85         return &current->nsproxy->uts_ns->name;
  86 }
  87
  88 static inline struct new_utsname *init_utsname(void)
  89 {
  90         return &init_uts_ns.name;
  91 }
  92
  93 extern struct rw_semaphore uts_sem;
  94
  95 #endif /* __KERNEL__ */
  96
  97 #endif /* _LINUX_UTSNAME_H */