1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_USER_NAMESPACE_H 3 #define _LINUX_USER_NAMESPACE_H 4 5 #include <linux/kref.h> 6 #include <linux/nsproxy.h> 7 #include <linux/ns_common.h> 8 #include <linux/sched.h> 9 #include <linux/workqueue.h> 10 #include <linux/rwsem.h> 11 #include <linux/sysctl.h> 12 #include <linux/err.h> 13 14 #define UID_GID_MAP_MAX_BASE_EXTENTS 5 15 #define UID_GID_MAP_MAX_EXTENTS 340 16 17 struct uid_gid_extent { 18 u32 first; 19 u32 lower_first; 20 u32 count; 21 }; 22 23 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 24 u32 nr_extents; 25 union { 26 struct uid_gid_extent extent[UID_GID_MAP_MAX_BASE_EXTENTS]; 27 struct { 28 struct uid_gid_extent *forward; 29 struct uid_gid_extent *reverse; 30 }; 31 }; 32 }; 33 34 #define USERNS_SETGROUPS_ALLOWED 1UL 35 36 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED 37 38 struct ucounts; 39 40 enum ucount_type { 41 UCOUNT_USER_NAMESPACES, 42 UCOUNT_PID_NAMESPACES, 43 UCOUNT_UTS_NAMESPACES, 44 UCOUNT_IPC_NAMESPACES, 45 UCOUNT_NET_NAMESPACES, 46 UCOUNT_MNT_NAMESPACES, 47 UCOUNT_CGROUP_NAMESPACES, 48 UCOUNT_TIME_NAMESPACES, 49 #ifdef CONFIG_INOTIFY_USER 50 UCOUNT_INOTIFY_INSTANCES, 51 UCOUNT_INOTIFY_WATCHES, 52 #endif 53 UCOUNT_COUNTS, 54 }; 55 56 struct user_namespace { 57 struct uid_gid_map uid_map; 58 struct uid_gid_map gid_map; 59 struct uid_gid_map projid_map; 60 atomic_t count; 61 struct user_namespace *parent; 62 int level; 63 kuid_t owner; 64 kgid_t group; 65 struct ns_common ns; 66 unsigned long flags; 67 68 #ifdef CONFIG_KEYS 69 /* List of joinable keyrings in this namespace. Modification access of 70 * these pointers is controlled by keyring_sem. Once 71 * user_keyring_register is set, it won't be changed, so it can be 72 * accessed directly with READ_ONCE(). 73 */ 74 struct list_head keyring_name_list; 75 struct key *user_keyring_register; 76 struct rw_semaphore keyring_sem; 77 #endif 78 79 /* Register of per-UID persistent keyrings for this namespace */ 80 #ifdef CONFIG_PERSISTENT_KEYRINGS 81 struct key *persistent_keyring_register; 82 #endif 83 struct work_struct work; 84 #ifdef CONFIG_SYSCTL 85 struct ctl_table_set set; 86 struct ctl_table_header *sysctls; 87 #endif 88 struct ucounts *ucounts; 89 int ucount_max[UCOUNT_COUNTS]; 90 } __randomize_layout; 91 92 struct ucounts { 93 struct hlist_node node; 94 struct user_namespace *ns; 95 kuid_t uid; 96 int count; 97 atomic_t ucount[UCOUNT_COUNTS]; 98 }; 99 100 extern struct user_namespace init_user_ns; 101 102 bool setup_userns_sysctls(struct user_namespace *ns); 103 void retire_userns_sysctls(struct user_namespace *ns); 104 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 105 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 106 107 #ifdef CONFIG_USER_NS 108 109 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 110 { 111 if (ns) 112 atomic_inc(&ns->count); 113 return ns; 114 } 115 116 extern int create_user_ns(struct cred *new); 117 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 118 extern void __put_user_ns(struct user_namespace *ns); 119 120 static inline void put_user_ns(struct user_namespace *ns) 121 { 122 if (ns && atomic_dec_and_test(&ns->count)) 123 __put_user_ns(ns); 124 } 125 126 struct seq_operations; 127 extern const struct seq_operations proc_uid_seq_operations; 128 extern const struct seq_operations proc_gid_seq_operations; 129 extern const struct seq_operations proc_projid_seq_operations; 130 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 131 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 132 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 133 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 134 extern int proc_setgroups_show(struct seq_file *m, void *v); 135 extern bool userns_may_setgroups(const struct user_namespace *ns); 136 extern bool in_userns(const struct user_namespace *ancestor, 137 const struct user_namespace *child); 138 extern bool current_in_userns(const struct user_namespace *target_ns); 139 struct ns_common *ns_get_owner(struct ns_common *ns); 140 #else 141 142 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 143 { 144 return &init_user_ns; 145 } 146 147 static inline int create_user_ns(struct cred *new) 148 { 149 return -EINVAL; 150 } 151 152 static inline int unshare_userns(unsigned long unshare_flags, 153 struct cred **new_cred) 154 { 155 if (unshare_flags & CLONE_NEWUSER) 156 return -EINVAL; 157 return 0; 158 } 159 160 static inline void put_user_ns(struct user_namespace *ns) 161 { 162 } 163 164 static inline bool userns_may_setgroups(const struct user_namespace *ns) 165 { 166 return true; 167 } 168 169 static inline bool in_userns(const struct user_namespace *ancestor, 170 const struct user_namespace *child) 171 { 172 return true; 173 } 174 175 static inline bool current_in_userns(const struct user_namespace *target_ns) 176 { 177 return true; 178 } 179 180 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 181 { 182 return ERR_PTR(-EPERM); 183 } 184 #endif 185 186 #endif /* _LINUX_USER_H */ 187