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 UID_GID_MAP_MAX_EXTENTS 5 10 11 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 12 u32 nr_extents; 13 struct uid_gid_extent { 14 u32 first; 15 u32 lower_first; 16 u32 count; 17 } extent[UID_GID_MAP_MAX_EXTENTS]; 18 }; 19 20 struct user_namespace { 21 struct uid_gid_map uid_map; 22 struct uid_gid_map gid_map; 23 struct kref kref; 24 struct user_namespace *parent; 25 kuid_t owner; 26 kgid_t group; 27 }; 28 29 extern struct user_namespace init_user_ns; 30 31 #ifdef CONFIG_USER_NS 32 33 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 34 { 35 if (ns) 36 kref_get(&ns->kref); 37 return ns; 38 } 39 40 extern int create_user_ns(struct cred *new); 41 extern void free_user_ns(struct kref *kref); 42 43 static inline void put_user_ns(struct user_namespace *ns) 44 { 45 if (ns) 46 kref_put(&ns->kref, free_user_ns); 47 } 48 49 struct seq_operations; 50 extern struct seq_operations proc_uid_seq_operations; 51 extern struct seq_operations proc_gid_seq_operations; 52 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 53 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 54 #else 55 56 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 57 { 58 return &init_user_ns; 59 } 60 61 static inline int create_user_ns(struct cred *new) 62 { 63 return -EINVAL; 64 } 65 66 static inline void put_user_ns(struct user_namespace *ns) 67 { 68 } 69 70 #endif 71 72 #endif /* _LINUX_USER_H */ 73