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 int level; 27 kuid_t owner; 28 kgid_t group; 29 unsigned int proc_inum; 30 bool may_mount_sysfs; 31 bool may_mount_proc; 32 }; 33 34 extern struct user_namespace init_user_ns; 35 36 #ifdef CONFIG_USER_NS 37 38 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 39 { 40 if (ns) 41 atomic_inc(&ns->count); 42 return ns; 43 } 44 45 extern int create_user_ns(struct cred *new); 46 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 47 extern void free_user_ns(struct user_namespace *ns); 48 49 static inline void put_user_ns(struct user_namespace *ns) 50 { 51 if (ns && atomic_dec_and_test(&ns->count)) 52 free_user_ns(ns); 53 } 54 55 struct seq_operations; 56 extern struct seq_operations proc_uid_seq_operations; 57 extern struct seq_operations proc_gid_seq_operations; 58 extern struct seq_operations proc_projid_seq_operations; 59 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 60 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 61 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 62 #else 63 64 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 65 { 66 return &init_user_ns; 67 } 68 69 static inline int create_user_ns(struct cred *new) 70 { 71 return -EINVAL; 72 } 73 74 static inline int unshare_userns(unsigned long unshare_flags, 75 struct cred **new_cred) 76 { 77 if (unshare_flags & CLONE_NEWUSER) 78 return -EINVAL; 79 return 0; 80 } 81 82 static inline void put_user_ns(struct user_namespace *ns) 83 { 84 } 85 86 #endif 87 88 void update_mnt_policy(struct user_namespace *userns); 89 90 #endif /* _LINUX_USER_H */ 91