| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 user_namespace { |
| 26 | struct uid_gid_map uid_map; |
| 27 | struct uid_gid_map gid_map; |
| 28 | struct uid_gid_map projid_map; |
| 29 | atomic_t count; |
| 30 | struct user_namespace *parent; |
| 31 | int level; |
| 32 | kuid_t owner; |
| 33 | kgid_t group; |
| 34 | struct ns_common ns; |
| 35 | unsigned long flags; |
| 36 | |
| 37 | /* Register of per-UID persistent keyrings for this namespace */ |
| 38 | #ifdef CONFIG_PERSISTENT_KEYRINGS |
| 39 | struct key *persistent_keyring_register; |
| 40 | struct rw_semaphore persistent_keyring_register_sem; |
| 41 | #endif |
| 42 | }; |
| 43 | |
| 44 | extern struct user_namespace init_user_ns; |
| 45 | |
| 46 | #ifdef CONFIG_USER_NS |
| 47 | |
| 48 | static inline struct user_namespace *get_user_ns(struct user_namespace *ns) |
| 49 | { |
| 50 | if (ns) |
| 51 | atomic_inc(&ns->count); |
| 52 | return ns; |
| 53 | } |
| 54 | |
| 55 | extern int create_user_ns(struct cred *new); |
| 56 | extern int unshare_userns(unsigned long unshare_flags, struct cred **new_cred); |
| 57 | extern void free_user_ns(struct user_namespace *ns); |
| 58 | |
| 59 | static inline void put_user_ns(struct user_namespace *ns) |
| 60 | { |
| 61 | if (ns && atomic_dec_and_test(&ns->count)) |
| 62 | free_user_ns(ns); |
| 63 | } |
| 64 | |
| 65 | struct seq_operations; |
| 66 | extern const struct seq_operations proc_uid_seq_operations; |
| 67 | extern const struct seq_operations proc_gid_seq_operations; |
| 68 | extern const struct seq_operations proc_projid_seq_operations; |
| 69 | extern ssize_t proc_uid_map_write(struct file *, const char __user *, size_t, loff_t *); |
| 70 | extern ssize_t proc_gid_map_write(struct file *, const char __user *, size_t, loff_t *); |
| 71 | extern ssize_t proc_projid_map_write(struct file *, const char __user *, size_t, loff_t *); |
| 72 | extern ssize_t proc_setgroups_write(struct file *, const char __user *, size_t, loff_t *); |
| 73 | extern int proc_setgroups_show(struct seq_file *m, void *v); |
| 74 | extern bool userns_may_setgroups(const struct user_namespace *ns); |
| 75 | #else |
| 76 | |
| 77 | static inline struct user_namespace *get_user_ns(struct user_namespace *ns) |
| 78 | { |
| 79 | return &init_user_ns; |
| 80 | } |
| 81 | |
| 82 | static inline int create_user_ns(struct cred *new) |
| 83 | { |
| 84 | return -EINVAL; |
| 85 | } |
| 86 | |
| 87 | static inline int unshare_userns(unsigned long unshare_flags, |
| 88 | struct cred **new_cred) |
| 89 | { |
| 90 | if (unshare_flags & CLONE_NEWUSER) |
| 91 | return -EINVAL; |
| 92 | return 0; |
| 93 | } |
| 94 | |
| 95 | static inline void put_user_ns(struct user_namespace *ns) |
| 96 | { |
| 97 | } |
| 98 | |
| 99 | static inline bool userns_may_setgroups(const struct user_namespace *ns) |
| 100 | { |
| 101 | return true; |
| 102 | } |
| 103 | #endif |
| 104 | |
| 105 | #endif /* _LINUX_USER_H */ |