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/ns_common.h> 7 #include <linux/sched.h> 8 #include <linux/err.h> 9 10 #define UID_GID_MAP_MAX_EXTENTS 5 11 12 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 13 u32 nr_extents; 14 struct uid_gid_extent { 15 u32 first; 16 u32 lower_first; 17 u32 count; 18 } extent[UID_GID_MAP_MAX_EXTENTS]; 19 }; 20 21 #define USERNS_SETGROUPS_ALLOWED 1UL 22 23 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED 24 25 struct user_namespace { 26 struct uid_gid_map uid_map; 27 struct uid_gid_map gid_map; 28 struct uid_gid_map projid_map; 29 atomic_t count; 30 struct user_namespace *parent; 31 int level; 32 kuid_t owner; 33 kgid_t group; 34 struct ns_common ns; 35 unsigned long flags; 36 37 /* Register of per-UID persistent keyrings for this namespace */ 38 #ifdef CONFIG_PERSISTENT_KEYRINGS 39 struct key *persistent_keyring_register; 40 struct rw_semaphore persistent_keyring_register_sem; 41 #endif 42 }; 43 44 extern struct user_namespace init_user_ns; 45 46 #ifdef CONFIG_USER_NS 47 48 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 49 { 50 if (ns) 51 atomic_inc(&ns->count); 52 return ns; 53 } 54 55 extern int create_user_ns(struct cred *new); 56 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 57 extern void free_user_ns(struct user_namespace *ns); 58 59 static inline void put_user_ns(struct user_namespace *ns) 60 { 61 if (ns && atomic_dec_and_test(&ns->count)) 62 free_user_ns(ns); 63 } 64 65 struct seq_operations; 66 extern const struct seq_operations proc_uid_seq_operations; 67 extern const struct seq_operations proc_gid_seq_operations; 68 extern const struct seq_operations proc_projid_seq_operations; 69 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 70 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 71 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 72 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 73 extern int proc_setgroups_show(struct seq_file *m, void *v); 74 extern bool userns_may_setgroups(const struct user_namespace *ns); 75 #else 76 77 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 78 { 79 return &init_user_ns; 80 } 81 82 static inline int create_user_ns(struct cred *new) 83 { 84 return -EINVAL; 85 } 86 87 static inline int unshare_userns(unsigned long unshare_flags, 88 struct cred **new_cred) 89 { 90 if (unshare_flags & CLONE_NEWUSER) 91 return -EINVAL; 92 return 0; 93 } 94 95 static inline void put_user_ns(struct user_namespace *ns) 96 { 97 } 98 99 static inline bool userns_may_setgroups(const struct user_namespace *ns) 100 { 101 return true; 102 } 103 #endif 104 105 #endif /* _LINUX_USER_H */ 106