diff options
Diffstat (limited to 'include/linux/mnt_idmapping.h')
| -rw-r--r-- | include/linux/mnt_idmapping.h | 226 |
1 files changed, 28 insertions, 198 deletions
diff --git a/include/linux/mnt_idmapping.h b/include/linux/mnt_idmapping.h index 0ccca33a7a6d..057c89867aa2 100644 --- a/include/linux/mnt_idmapping.h +++ b/include/linux/mnt_idmapping.h @@ -113,167 +113,23 @@ static inline bool vfsgid_eq_kgid(vfsgid_t vfsgid, kgid_t kgid) #define AS_KUIDT(val) (kuid_t){ __vfsuid_val(val) } #define AS_KGIDT(val) (kgid_t){ __vfsgid_val(val) } -#ifdef CONFIG_MULTIUSER -/** - * vfsgid_in_group_p() - check whether a vfsuid matches the caller's groups - * @vfsgid: the mnt gid to match - * - * This function can be used to determine whether @vfsuid matches any of the - * caller's groups. - * - * Return: 1 if vfsuid matches caller's groups, 0 if not. - */ -static inline int vfsgid_in_group_p(vfsgid_t vfsgid) -{ - return in_group_p(AS_KGIDT(vfsgid)); -} -#else -static inline int vfsgid_in_group_p(vfsgid_t vfsgid) -{ - return 1; -} -#endif +int vfsgid_in_group_p(vfsgid_t vfsgid); -/** - * initial_idmapping - check whether this is the initial mapping - * @ns: idmapping to check - * - * Check whether this is the initial mapping, mapping 0 to 0, 1 to 1, - * [...], 1000 to 1000 [...]. - * - * Return: true if this is the initial mapping, false if not. - */ -static inline bool initial_idmapping(const struct user_namespace *ns) -{ - return ns == &init_user_ns; -} +vfsuid_t make_vfsuid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, kuid_t kuid); -/** - * no_idmapping - check whether we can skip remapping a kuid/gid - * @mnt_userns: the mount's idmapping - * @fs_userns: the filesystem's idmapping - * - * This function can be used to check whether a remapping between two - * idmappings is required. - * An idmapped mount is a mount that has an idmapping attached to it that - * is different from the filsystem's idmapping and the initial idmapping. - * If the initial mapping is used or the idmapping of the mount and the - * filesystem are identical no remapping is required. - * - * Return: true if remapping can be skipped, false if not. - */ -static inline bool no_idmapping(const struct user_namespace *mnt_userns, - const struct user_namespace *fs_userns) -{ - return initial_idmapping(mnt_userns) || mnt_userns == fs_userns; -} +vfsgid_t make_vfsgid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, kgid_t kgid); -/** - * make_vfsuid - map a filesystem kuid into a mnt_userns - * @mnt_userns: the mount's idmapping - * @fs_userns: the filesystem's idmapping - * @kuid : kuid to be mapped - * - * Take a @kuid and remap it from @fs_userns into @mnt_userns. Use this - * function when preparing a @kuid to be reported to userspace. - * - * If no_idmapping() determines that this is not an idmapped mount we can - * simply return @kuid unchanged. - * If initial_idmapping() tells us that the filesystem is not mounted with an - * idmapping we know the value of @kuid won't change when calling - * from_kuid() so we can simply retrieve the value via __kuid_val() - * directly. - * - * Return: @kuid mapped according to @mnt_userns. - * If @kuid has no mapping in either @mnt_userns or @fs_userns INVALID_UID is - * returned. - */ +kuid_t from_vfsuid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, vfsuid_t vfsuid); -static inline vfsuid_t make_vfsuid(struct user_namespace *mnt_userns, - struct user_namespace *fs_userns, - kuid_t kuid) -{ - uid_t uid; - - if (no_idmapping(mnt_userns, fs_userns)) - return VFSUIDT_INIT(kuid); - if (initial_idmapping(fs_userns)) - uid = __kuid_val(kuid); - else - uid = from_kuid(fs_userns, kuid); - if (uid == (uid_t)-1) - return INVALID_VFSUID; - return VFSUIDT_INIT(make_kuid(mnt_userns, uid)); -} - -/** - * make_vfsgid - map a filesystem kgid into a mnt_userns - * @mnt_userns: the mount's idmapping - * @fs_userns: the filesystem's idmapping - * @kgid : kgid to be mapped - * - * Take a @kgid and remap it from @fs_userns into @mnt_userns. Use this - * function when preparing a @kgid to be reported to userspace. - * - * If no_idmapping() determines that this is not an idmapped mount we can - * simply return @kgid unchanged. - * If initial_idmapping() tells us that the filesystem is not mounted with an - * idmapping we know the value of @kgid won't change when calling - * from_kgid() so we can simply retrieve the value via __kgid_val() - * directly. - * - * Return: @kgid mapped according to @mnt_userns. - * If @kgid has no mapping in either @mnt_userns or @fs_userns INVALID_GID is - * returned. - */ - -static inline vfsgid_t make_vfsgid(struct user_namespace *mnt_userns, - struct user_namespace *fs_userns, - kgid_t kgid) -{ - gid_t gid; - - if (no_idmapping(mnt_userns, fs_userns)) - return VFSGIDT_INIT(kgid); - if (initial_idmapping(fs_userns)) - gid = __kgid_val(kgid); - else - gid = from_kgid(fs_userns, kgid); - if (gid == (gid_t)-1) - return INVALID_VFSGID; - return VFSGIDT_INIT(make_kgid(mnt_userns, gid)); -} - -/** - * from_vfsuid - map a vfsuid into the filesystem idmapping - * @mnt_userns: the mount's idmapping - * @fs_userns: the filesystem's idmapping - * @vfsuid : vfsuid to be mapped - * - * Map @vfsuid into the filesystem idmapping. This function has to be used in - * order to e.g. write @vfsuid to inode->i_uid. - * - * Return: @vfsuid mapped into the filesystem idmapping - */ -static inline kuid_t from_vfsuid(struct user_namespace *mnt_userns, - struct user_namespace *fs_userns, - vfsuid_t vfsuid) -{ - uid_t uid; - - if (no_idmapping(mnt_userns, fs_userns)) - return AS_KUIDT(vfsuid); - uid = from_kuid(mnt_userns, AS_KUIDT(vfsuid)); - if (uid == (uid_t)-1) - return INVALID_UID; - if (initial_idmapping(fs_userns)) - return KUIDT_INIT(uid); - return make_kuid(fs_userns, uid); -} +kgid_t from_vfsgid(struct mnt_idmap *idmap, + struct user_namespace *fs_userns, vfsgid_t vfsgid); /** * vfsuid_has_fsmapping - check whether a vfsuid maps into the filesystem - * @mnt_userns: the mount's idmapping + * @idmap: the mount's idmapping * @fs_userns: the filesystem's idmapping * @vfsuid: vfsuid to be mapped * @@ -283,11 +139,11 @@ static inline kuid_t from_vfsuid(struct user_namespace *mnt_userns, * * Return: true if @vfsuid has a mapping in the filesystem, false if not. */ -static inline bool vfsuid_has_fsmapping(struct user_namespace *mnt_userns, +static inline bool vfsuid_has_fsmapping(struct mnt_idmap *idmap, struct user_namespace *fs_userns, vfsuid_t vfsuid) { - return uid_valid(from_vfsuid(mnt_userns, fs_userns, vfsuid)); + return uid_valid(from_vfsuid(idmap, fs_userns, vfsuid)); } static inline bool vfsuid_has_mapping(struct user_namespace *userns, @@ -310,35 +166,8 @@ static inline kuid_t vfsuid_into_kuid(vfsuid_t vfsuid) } /** - * from_vfsgid - map a vfsgid into the filesystem idmapping - * @mnt_userns: the mount's idmapping - * @fs_userns: the filesystem's idmapping - * @vfsgid : vfsgid to be mapped - * - * Map @vfsgid into the filesystem idmapping. This function has to be used in - * order to e.g. write @vfsgid to inode->i_gid. - * - * Return: @vfsgid mapped into the filesystem idmapping - */ -static inline kgid_t from_vfsgid(struct user_namespace *mnt_userns, - struct user_namespace *fs_userns, - vfsgid_t vfsgid) -{ - gid_t gid; - - if (no_idmapping(mnt_userns, fs_userns)) - return AS_KGIDT(vfsgid); - gid = from_kgid(mnt_userns, AS_KGIDT(vfsgid)); - if (gid == (gid_t)-1) - return INVALID_GID; - if (initial_idmapping(fs_userns)) - return KGIDT_INIT(gid); - return make_kgid(fs_userns, gid); -} - -/** * vfsgid_has_fsmapping - check whether a vfsgid maps into the filesystem - * @mnt_userns: the mount's idmapping + * @idmap: the mount's idmapping * @fs_userns: the filesystem's idmapping * @vfsgid: vfsgid to be mapped * @@ -348,11 +177,11 @@ static inline kgid_t from_vfsgid(struct user_namespace *mnt_userns, * * Return: true if @vfsgid has a mapping in the filesystem, false if not. */ -static inline bool vfsgid_has_fsmapping(struct user_namespace *mnt_userns, +static inline bool vfsgid_has_fsmapping(struct mnt_idmap *idmap, struct user_namespace *fs_userns, vfsgid_t vfsgid) { - return gid_valid(from_vfsgid(mnt_userns, fs_userns, vfsgid)); + return gid_valid(from_vfsgid(idmap, fs_userns, vfsgid)); } static inline bool vfsgid_has_mapping(struct user_namespace *userns, @@ -375,8 +204,8 @@ static inline kgid_t vfsgid_into_kgid(vfsgid_t vfsgid) } /** - * mapped_fsuid - return caller's fsuid mapped up into a mnt_userns - * @mnt_userns: the mount's idmapping + * mapped_fsuid - return caller's fsuid mapped according to an idmapping + * @idmap: the mount's idmapping * @fs_userns: the filesystem's idmapping * * Use this helper to initialize a new vfs or filesystem object based on @@ -385,18 +214,17 @@ static inline kgid_t vfsgid_into_kgid(vfsgid_t vfsgid) * O_CREAT. Other examples include the allocation of quotas for a specific * user. * - * Return: the caller's current fsuid mapped up according to @mnt_userns. + * Return: the caller's current fsuid mapped up according to @idmap. */ -static inline kuid_t mapped_fsuid(struct user_namespace *mnt_userns, +static inline kuid_t mapped_fsuid(struct mnt_idmap *idmap, struct user_namespace *fs_userns) { - return from_vfsuid(mnt_userns, fs_userns, - VFSUIDT_INIT(current_fsuid())); + return from_vfsuid(idmap, fs_userns, VFSUIDT_INIT(current_fsuid())); } /** - * mapped_fsgid - return caller's fsgid mapped up into a mnt_userns - * @mnt_userns: the mount's idmapping + * mapped_fsgid - return caller's fsgid mapped according to an idmapping + * @idmap: the mount's idmapping * @fs_userns: the filesystem's idmapping * * Use this helper to initialize a new vfs or filesystem object based on @@ -405,13 +233,15 @@ static inline kuid_t mapped_fsuid(struct user_namespace *mnt_userns, * O_CREAT. Other examples include the allocation of quotas for a specific * user. * - * Return: the caller's current fsgid mapped up according to @mnt_userns. + * Return: the caller's current fsgid mapped up according to @idmap. */ -static inline kgid_t mapped_fsgid(struct user_namespace *mnt_userns, +static inline kgid_t mapped_fsgid(struct mnt_idmap *idmap, struct user_namespace *fs_userns) { - return from_vfsgid(mnt_userns, fs_userns, - VFSGIDT_INIT(current_fsgid())); + return from_vfsgid(idmap, fs_userns, VFSGIDT_INIT(current_fsgid())); } +bool check_fsmapping(const struct mnt_idmap *idmap, + const struct super_block *sb); + #endif /* _LINUX_MNT_IDMAPPING_H */ |