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