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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 11struct 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 20struct 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 34extern struct user_namespace init_user_ns; 35 36#ifdef CONFIG_USER_NS 37 38static 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 45extern int create_user_ns(struct cred *new); 46extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 47extern void free_user_ns(struct user_namespace *ns); 48 49static 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 55struct seq_operations; 56extern struct seq_operations proc_uid_seq_operations; 57extern struct seq_operations proc_gid_seq_operations; 58extern struct seq_operations proc_projid_seq_operations; 59extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 60extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 61extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 62#else 63 64static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 65{ 66 return &init_user_ns; 67} 68 69static inline int create_user_ns(struct cred *new) 70{ 71 return -EINVAL; 72} 73 74static 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 82static inline void put_user_ns(struct user_namespace *ns) 83{ 84} 85 86#endif 87 88void update_mnt_policy(struct user_namespace *userns); 89 90#endif /* _LINUX_USER_H */