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_EXTENTS 5 15 16 struct uid_gid_map { /* 64 bytes -- 1 cache line */ 17 u32 nr_extents; 18 struct uid_gid_extent { 19 u32 first; 20 u32 lower_first; 21 u32 count; 22 } extent[UID_GID_MAP_MAX_EXTENTS]; 23 }; 24 25 #define USERNS_SETGROUPS_ALLOWED 1UL 26 27 #define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED 28 29 struct ucounts; 30 31 enum ucount_type { 32 UCOUNT_USER_NAMESPACES, 33 UCOUNT_PID_NAMESPACES, 34 UCOUNT_UTS_NAMESPACES, 35 UCOUNT_IPC_NAMESPACES, 36 UCOUNT_NET_NAMESPACES, 37 UCOUNT_MNT_NAMESPACES, 38 UCOUNT_CGROUP_NAMESPACES, 39 #ifdef CONFIG_INOTIFY_USER 40 UCOUNT_INOTIFY_INSTANCES, 41 UCOUNT_INOTIFY_WATCHES, 42 #endif 43 UCOUNT_COUNTS, 44 }; 45 46 struct user_namespace { 47 struct uid_gid_map uid_map; 48 struct uid_gid_map gid_map; 49 struct uid_gid_map projid_map; 50 atomic_t count; 51 struct user_namespace *parent; 52 int level; 53 kuid_t owner; 54 kgid_t group; 55 struct ns_common ns; 56 unsigned long flags; 57 58 /* Register of per-UID persistent keyrings for this namespace */ 59 #ifdef CONFIG_PERSISTENT_KEYRINGS 60 struct key *persistent_keyring_register; 61 struct rw_semaphore persistent_keyring_register_sem; 62 #endif 63 struct work_struct work; 64 #ifdef CONFIG_SYSCTL 65 struct ctl_table_set set; 66 struct ctl_table_header *sysctls; 67 #endif 68 struct ucounts *ucounts; 69 int ucount_max[UCOUNT_COUNTS]; 70 } __randomize_layout; 71 72 struct ucounts { 73 struct hlist_node node; 74 struct user_namespace *ns; 75 kuid_t uid; 76 int count; 77 atomic_t ucount[UCOUNT_COUNTS]; 78 }; 79 80 extern struct user_namespace init_user_ns; 81 82 bool setup_userns_sysctls(struct user_namespace *ns); 83 void retire_userns_sysctls(struct user_namespace *ns); 84 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid, enum ucount_type type); 85 void dec_ucount(struct ucounts *ucounts, enum ucount_type type); 86 87 #ifdef CONFIG_USER_NS 88 89 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 90 { 91 if (ns) 92 atomic_inc(&ns->count); 93 return ns; 94 } 95 96 extern int create_user_ns(struct cred *new); 97 extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); 98 extern void __put_user_ns(struct user_namespace *ns); 99 100 static inline void put_user_ns(struct user_namespace *ns) 101 { 102 if (ns && atomic_dec_and_test(&ns->count)) 103 __put_user_ns(ns); 104 } 105 106 struct seq_operations; 107 extern const struct seq_operations proc_uid_seq_operations; 108 extern const struct seq_operations proc_gid_seq_operations; 109 extern const struct seq_operations proc_projid_seq_operations; 110 extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); 111 extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); 112 extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); 113 extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); 114 extern int proc_setgroups_show(struct seq_file *m, void *v); 115 extern bool userns_may_setgroups(const struct user_namespace *ns); 116 extern bool in_userns(const struct user_namespace *ancestor, 117 const struct user_namespace *child); 118 extern bool current_in_userns(const struct user_namespace *target_ns); 119 struct ns_common *ns_get_owner(struct ns_common *ns); 120 #else 121 122 static inline struct user_namespace *get_user_ns(struct user_namespace *ns) 123 { 124 return &init_user_ns; 125 } 126 127 static inline int create_user_ns(struct cred *new) 128 { 129 return -EINVAL; 130 } 131 132 static inline int unshare_userns(unsigned long unshare_flags, 133 struct cred **new_cred) 134 { 135 if (unshare_flags & CLONE_NEWUSER) 136 return -EINVAL; 137 return 0; 138 } 139 140 static inline void put_user_ns(struct user_namespace *ns) 141 { 142 } 143 144 static inline bool userns_may_setgroups(const struct user_namespace *ns) 145 { 146 return true; 147 } 148 149 static inline bool in_userns(const struct user_namespace *ancestor, 150 const struct user_namespace *child) 151 { 152 return true; 153 } 154 155 static inline bool current_in_userns(const struct user_namespace *target_ns) 156 { 157 return true; 158 } 159 160 static inline struct ns_common *ns_get_owner(struct ns_common *ns) 161 { 162 return ERR_PTR(-EPERM); 163 } 164 #endif 165 166 #endif /* _LINUX_USER_H */ 167