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 uid_gid_map projid_map; 24 struct kref kref; 25 struct user_namespace *parent; 26 kuid_t owner; 27 kgid_t group; 28 }; 29 30 extern struct user_namespace init_user_ns; 31 32 #ifdef CONFIG_USER_NS 33 34 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 35 { 36 if (ns) 37 kref_get(&ns->kref); 38 return ns; 39 } 40 41 extern int create_user_ns(struct cred *new); 42 extern void free_user_ns(struct kref *kref); 43 44 static inline void put_user_ns(struct user_namespace *ns) 45 { 46 if (ns) 47 kref_put(&ns->kref, free_user_ns); 48 } 49 50 struct seq_operations; 51 extern struct seq_operations proc_uid_seq_operations; 52 extern struct seq_operations proc_gid_seq_operations; 53 extern struct seq_operations proc_projid_seq_operations; 54 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 55 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 56 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 57 #else 58 59 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 60 { 61 return &init_user_ns; 62 } 63 64 static inline int create_user_ns(struct cred *new) 65 { 66 return -EINVAL; 67 } 68 69 static inline void put_user_ns(struct user_namespace *ns) 70 { 71 } 72 73 #endif 74 75 #endif /* _LINUX_USER_H */ 76