1#ifndef _LINUX_USER_NAMESPACE_H 2#define _LINUX_USER_NAMESPACE_H 3 4#include <linux/kref.h> 5#include <linux/nsproxy.h> 6#include <linux/sched.h> 7#include <linux/err.h> 8 9#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 8) 10#define UIDHASH_SZ (1 << UIDHASH_BITS) 11 12struct user_namespace { 13 struct kref kref; 14 struct hlist_head uidhash_table[UIDHASH_SZ]; 15 struct user_struct *creator; 16 struct work_struct destroyer; 17}; 18 19extern struct user_namespace init_user_ns; 20 21#ifdef CONFIG_USER_NS 22 23static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 24{ 25 if (ns) 26 kref_get(&ns->kref); 27 return ns; 28} 29 30extern int create_user_ns(struct cred *new); 31extern void free_user_ns(struct kref *kref); 32 33static inline void put_user_ns(struct user_namespace *ns) 34{ 35 if (ns) 36 kref_put(&ns->kref, free_user_ns); 37} 38 39uid_t user_ns_map_uid(struct user_namespace *to, const struct cred *cred, uid_t uid); 40gid_t user_ns_map_gid(struct user_namespace *to, const struct cred *cred, gid_t gid); 41 42#else 43 44static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 45{ 46 return &init_user_ns; 47} 48 49static inline int create_user_ns(struct cred *new) 50{ 51 return -EINVAL; 52} 53 54static inline void put_user_ns(struct user_namespace *ns) 55{ 56} 57 58static inline uid_t user_ns_map_uid(struct user_namespace *to, 59 const struct cred *cred, uid_t uid) 60{ 61 return uid; 62} 63static inline gid_t user_ns_map_gid(struct user_namespace *to, 64 const struct cred *cred, gid_t gid) 65{ 66 return gid; 67} 68 69#endif 70 71#endif /* _LINUX_USER_H */ 72