From 5c1469de7545a35a16ff2b902e217044a7d2f8a5 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 13 Jun 2010 03:28:03 +0000 Subject: user_ns: Introduce user_nsmap_uid and user_ns_map_gid. Define what happens when a we view a uid from one user_namespace in another user_namepece. - If the user namespaces are the same no mapping is necessary. - For most cases of difference use overflowuid and overflowgid, the uid and gid currently used for 16bit apis when we have a 32bit uid that does fit in 16bits. Effectively the situation is the same, we want to return a uid or gid that is not assigned to any user. - For the case when we happen to be mapping the uid or gid of the creator of the target user namespace use uid 0 and gid as confusing that user with root is not a problem. Signed-off-by: Eric W. Biederman Acked-by: Serge E. Hallyn Signed-off-by: David S. Miller --- include/linux/user_namespace.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/user_namespace.h') diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index cc4f45361dbb..8178156711f9 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -36,6 +36,9 @@ static inline void put_user_ns(struct user_namespace *ns) kref_put(&ns->kref, free_user_ns); } +uid_t user_ns_map_uid(struct user_namespace *to, const struct cred *cred, uid_t uid); +gid_t user_ns_map_gid(struct user_namespace *to, const struct cred *cred, gid_t gid); + #else static inline struct user_namespace *get_user_ns(struct user_namespace *ns) @@ -52,6 +55,17 @@ static inline void put_user_ns(struct user_namespace *ns) { } +static inline uid_t user_ns_map_uid(struct user_namespace *to, + const struct cred *cred, uid_t uid) +{ + return uid; +} +static inline gid_t user_ns_map_gid(struct user_namespace *to, + const struct cred *cred, gid_t gid) +{ + return gid; +} + #endif #endif /* _LINUX_USER_H */ -- cgit v1.2.3-59-g8ed1b