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