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