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 /* Register of per-UID persistent keyrings for this namespace */ 32 #ifdef CONFIG_PERSISTENT_KEYRINGS 33 struct key *persistent_keyring_register; 34 struct rw_semaphore persistent_keyring_register_sem; 35 #endif 36 }; 37 38 extern struct user_namespace init_user_ns; 39 40 #ifdef CONFIG_USER_NS 41 42 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 43 { 44 if (ns) 45 atomic_inc(&ns->count); 46 return ns; 47 } 48 49 extern int create_user_ns(struct cred *new); 50 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 51 extern void free_user_ns(struct user_namespace *ns); 52 53 static inline void put_user_ns(struct user_namespace *ns) 54 { 55 if (ns && atomic_dec_and_test(&ns->count)) 56 free_user_ns(ns); 57 } 58 59 struct seq_operations; 60 extern struct seq_operations proc_uid_seq_operations; 61 extern struct seq_operations proc_gid_seq_operations; 62 extern struct seq_operations proc_projid_seq_operations; 63 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 64 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 65 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 66 #else 67 68 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 69 { 70 return &init_user_ns; 71 } 72 73 static inline int create_user_ns(struct cred *new) 74 { 75 return -EINVAL; 76 } 77 78 static inline int unshare_userns(unsigned long unshare_flags, 79 struct cred **new_cred) 80 { 81 if (unshare_flags & CLONE_NEWUSER) 82 return -EINVAL; 83 return 0; 84 } 85 86 static inline void put_user_ns(struct user_namespace *ns) 87 { 88 } 89 90 #endif 91 92 #endif /* _LINUX_USER_H */ 93