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 atomic_t count; 25 struct user_namespace *parent; 26 kuid_t owner; 27 kgid_t group; 28 unsigned int proc_inum; 29 bool may_mount_sysfs; 30 bool may_mount_proc; 31 }; 32 33 extern struct user_namespace init_user_ns; 34 35 #ifdef CONFIG_USER_NS 36 37 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 38 { 39 if (ns) 40 atomic_inc(&ns->count); 41 return ns; 42 } 43 44 extern int create_user_ns(struct cred *new); 45 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 46 extern void free_user_ns(struct user_namespace *ns); 47 48 static inline void put_user_ns(struct user_namespace *ns) 49 { 50 if (ns && atomic_dec_and_test(&ns->count)) 51 free_user_ns(ns); 52 } 53 54 struct seq_operations; 55 extern struct seq_operations proc_uid_seq_operations; 56 extern struct seq_operations proc_gid_seq_operations; 57 extern struct seq_operations proc_projid_seq_operations; 58 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 59 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 60 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 61 #else 62 63 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 64 { 65 return &init_user_ns; 66 } 67 68 static inline int create_user_ns(struct cred *new) 69 { 70 return -EINVAL; 71 } 72 73 static inline int unshare_userns(unsigned long unshare_flags, 74 struct cred **new_cred) 75 { 76 if (unshare_flags & CLONE_NEWUSER) 77 return -EINVAL; 78 return 0; 79 } 80 81 static inline void put_user_ns(struct user_namespace *ns) 82 { 83 } 84 85 #endif 86 87 void update_mnt_policy(struct user_namespace *userns); 88 89 #endif /* _LINUX_USER_H */ 90