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/workqueue.h> 9 #include <linux/rwsem.h> 10 #include <linux/sysctl.h> 11 #include <linux/err.h> 12 13 #define UID_GID_MAP_MAX_EXTENTS 5 14 15 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 16 u32 nr_extents; 17 struct uid_gid_extent { 18 u32 first; 19 u32 lower_first; 20 u32 count; 21 } extent[UID_GID_MAP_MAX_EXTENTS]; 22 }; 23 24 #define USERNS_SETGROUPS_ALLOWED 1UL 25 26 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED 27 28 struct ucounts; 29 30 enum ucount_type { 31 UCOUNT_USER_NAMESPACES, 32 UCOUNT_PID_NAMESPACES, 33 UCOUNT_UTS_NAMESPACES, 34 UCOUNT_IPC_NAMESPACES, 35 UCOUNT_NET_NAMESPACES, 36 UCOUNT_MNT_NAMESPACES, 37 UCOUNT_CGROUP_NAMESPACES, 38 #ifdef CONFIG_INOTIFY_USER 39 UCOUNT_INOTIFY_INSTANCES, 40 UCOUNT_INOTIFY_WATCHES, 41 #endif 42 UCOUNT_COUNTS, 43 }; 44 45 struct user_namespace { 46 struct uid_gid_map uid_map; 47 struct uid_gid_map gid_map; 48 struct uid_gid_map projid_map; 49 atomic_t count; 50 struct user_namespace *parent; 51 int level; 52 kuid_t owner; 53 kgid_t group; 54 struct ns_common ns; 55 unsigned long flags; 56 57 /* Register of per-UID persistent keyrings for this namespace */ 58 #ifdef CONFIG_PERSISTENT_KEYRINGS 59 struct key *persistent_keyring_register; 60 struct rw_semaphore persistent_keyring_register_sem; 61 #endif 62 struct work_struct work; 63 #ifdef CONFIG_SYSCTL 64 struct ctl_table_set set; 65 struct ctl_table_header *sysctls; 66 #endif 67 struct ucounts *ucounts; 68 int ucount_max[UCOUNT_COUNTS]; 69 } __randomize_layout; 70 71 struct ucounts { 72 struct hlist_node node; 73 struct user_namespace *ns; 74 kuid_t uid; 75 int count; 76 atomic_t ucount[UCOUNT_COUNTS]; 77 }; 78 79 extern struct user_namespace init_user_ns; 80 81 bool setup_userns_sysctls(struct user_namespace *ns); 82 void retire_userns_sysctls(struct user_namespace *ns); 83 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 84 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 85 86 #ifdef CONFIG_USER_NS 87 88 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 89 { 90 if (ns) 91 atomic_inc(&ns->count); 92 return ns; 93 } 94 95 extern int create_user_ns(struct cred *new); 96 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 97 extern void __put_user_ns(struct user_namespace *ns); 98 99 static inline void put_user_ns(struct user_namespace *ns) 100 { 101 if (ns && atomic_dec_and_test(&ns->count)) 102 __put_user_ns(ns); 103 } 104 105 struct seq_operations; 106 extern const struct seq_operations proc_uid_seq_operations; 107 extern const struct seq_operations proc_gid_seq_operations; 108 extern const struct seq_operations proc_projid_seq_operations; 109 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 110 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 111 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 112 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 113 extern int proc_setgroups_show(struct seq_file *m, void *v); 114 extern bool userns_may_setgroups(const struct user_namespace *ns); 115 extern bool current_in_userns(const struct user_namespace *target_ns); 116 117 struct ns_common *ns_get_owner(struct ns_common *ns); 118 #else 119 120 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 121 { 122 return &init_user_ns; 123 } 124 125 static inline int create_user_ns(struct cred *new) 126 { 127 return -EINVAL; 128 } 129 130 static inline int unshare_userns(unsigned long unshare_flags, 131 struct cred **new_cred) 132 { 133 if (unshare_flags & CLONE_NEWUSER) 134 return -EINVAL; 135 return 0; 136 } 137 138 static inline void put_user_ns(struct user_namespace *ns) 139 { 140 } 141 142 static inline bool userns_may_setgroups(const struct user_namespace *ns) 143 { 144 return true; 145 } 146 147 static inline bool current_in_userns(const struct user_namespace *target_ns) 148 { 149 return true; 150 } 151 152 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 153 { 154 return ERR_PTR(-EPERM); 155 } 156 #endif 157 158 #endif /* _LINUX_USER_H */ 159