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 unsigned int proc_inum; 29 }; 30 31 extern struct user_namespace init_user_ns; 32 33 #ifdef CONFIG_USER_NS 34 35 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 36 { 37 if (ns) 38 kref_get(&ns->kref); 39 return ns; 40 } 41 42 extern int create_user_ns(struct cred *new); 43 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 44 extern void free_user_ns(struct kref *kref); 45 46 static inline void put_user_ns(struct user_namespace *ns) 47 { 48 if (ns) 49 kref_put(&ns->kref, free_user_ns); 50 } 51 52 struct seq_operations; 53 extern struct seq_operations proc_uid_seq_operations; 54 extern struct seq_operations proc_gid_seq_operations; 55 extern struct seq_operations proc_projid_seq_operations; 56 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 57 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 58 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 59 #else 60 61 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 62 { 63 return &init_user_ns; 64 } 65 66 static inline int create_user_ns(struct cred *new) 67 { 68 return -EINVAL; 69 } 70 71 static inline int unshare_userns(unsigned long unshare_flags, 72 struct cred **new_cred) 73 { 74 if (unshare_flags & CLONE_NEWUSER) 75 return -EINVAL; 76 return 0; 77 } 78 79 static inline void put_user_ns(struct user_namespace *ns) 80 { 81 } 82 83 #endif 84 85 #endif /* _LINUX_USER_H */ 86