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_extent { 16 u32 first; 17 u32 lower_first; 18 u32 count; 19 }; 20 21 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 22 u32 nr_extents; 23 union { 24 struct uid_gid_extent extent[UID_GID_MAP_MAX_EXTENTS]; 25 struct { 26 struct uid_gid_extent *forward; 27 struct uid_gid_extent *reverse; 28 }; 29 }; 30 }; 31 32 #define USERNS_SETGROUPS_ALLOWED 1UL 33 34 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED 35 36 struct ucounts; 37 38 enum ucount_type { 39 UCOUNT_USER_NAMESPACES, 40 UCOUNT_PID_NAMESPACES, 41 UCOUNT_UTS_NAMESPACES, 42 UCOUNT_IPC_NAMESPACES, 43 UCOUNT_NET_NAMESPACES, 44 UCOUNT_MNT_NAMESPACES, 45 UCOUNT_CGROUP_NAMESPACES, 46 #ifdef CONFIG_INOTIFY_USER 47 UCOUNT_INOTIFY_INSTANCES, 48 UCOUNT_INOTIFY_WATCHES, 49 #endif 50 UCOUNT_COUNTS, 51 }; 52 53 struct user_namespace { 54 struct uid_gid_map uid_map; 55 struct uid_gid_map gid_map; 56 struct uid_gid_map projid_map; 57 atomic_t count; 58 struct user_namespace *parent; 59 int level; 60 kuid_t owner; 61 kgid_t group; 62 struct ns_common ns; 63 unsigned long flags; 64 65 /* Register of per-UID persistent keyrings for this namespace */ 66 #ifdef CONFIG_PERSISTENT_KEYRINGS 67 struct key *persistent_keyring_register; 68 struct rw_semaphore persistent_keyring_register_sem; 69 #endif 70 struct work_struct work; 71 #ifdef CONFIG_SYSCTL 72 struct ctl_table_set set; 73 struct ctl_table_header *sysctls; 74 #endif 75 struct ucounts *ucounts; 76 int ucount_max[UCOUNT_COUNTS]; 77 } __randomize_layout; 78 79 struct ucounts { 80 struct hlist_node node; 81 struct user_namespace *ns; 82 kuid_t uid; 83 int count; 84 atomic_t ucount[UCOUNT_COUNTS]; 85 }; 86 87 extern struct user_namespace init_user_ns; 88 89 bool setup_userns_sysctls(struct user_namespace *ns); 90 void retire_userns_sysctls(struct user_namespace *ns); 91 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 92 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 93 94 #ifdef CONFIG_USER_NS 95 96 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 97 { 98 if (ns) 99 atomic_inc(&ns->count); 100 return ns; 101 } 102 103 extern int create_user_ns(struct cred *new); 104 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 105 extern void __put_user_ns(struct user_namespace *ns); 106 107 static inline void put_user_ns(struct user_namespace *ns) 108 { 109 if (ns && atomic_dec_and_test(&ns->count)) 110 __put_user_ns(ns); 111 } 112 113 struct seq_operations; 114 extern const struct seq_operations proc_uid_seq_operations; 115 extern const struct seq_operations proc_gid_seq_operations; 116 extern const struct seq_operations proc_projid_seq_operations; 117 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 118 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 119 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 120 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 121 extern int proc_setgroups_show(struct seq_file *m, void *v); 122 extern bool userns_may_setgroups(const struct user_namespace *ns); 123 extern bool in_userns(const struct user_namespace *ancestor, 124 const struct user_namespace *child); 125 extern bool current_in_userns(const struct user_namespace *target_ns); 126 struct ns_common *ns_get_owner(struct ns_common *ns); 127 #else 128 129 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 130 { 131 return &init_user_ns; 132 } 133 134 static inline int create_user_ns(struct cred *new) 135 { 136 return -EINVAL; 137 } 138 139 static inline int unshare_userns(unsigned long unshare_flags, 140 struct cred **new_cred) 141 { 142 if (unshare_flags & CLONE_NEWUSER) 143 return -EINVAL; 144 return 0; 145 } 146 147 static inline void put_user_ns(struct user_namespace *ns) 148 { 149 } 150 151 static inline bool userns_may_setgroups(const struct user_namespace *ns) 152 { 153 return true; 154 } 155 156 static inline bool in_userns(const struct user_namespace *ancestor, 157 const struct user_namespace *child) 158 { 159 return true; 160 } 161 162 static inline bool current_in_userns(const struct user_namespace *target_ns) 163 { 164 return true; 165 } 166 167 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 168 { 169 return ERR_PTR(-EPERM); 170 } 171 #endif 172 173 #endif /* _LINUX_USER_H */ 174