| Message ID | 1473148036-32630-4-git-send-email-avagin@openvz.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Andrei Vagin (avagin@openvz.org): > From: Andrey Vagin <avagin@openvz.org> > > Pid and user namepaces are hierarchical. There is no way to discover > parent-child relationships. > > In a future we will use this interface to dump and restore nested > namespaces. > > Signed-off-by: Andrei Vagin <avagin@openvz.org> Acked-by: Serge Hallyn <serge@hallyn.com> > --- > fs/nsfs.c | 4 ++++ > include/linux/proc_ns.h | 1 + > include/uapi/linux/nsfs.h | 2 ++ > kernel/pid_namespace.c | 19 +++++++++++++++++++ > kernel/user_namespace.c | 1 + > 5 files changed, 27 insertions(+) > > diff --git a/fs/nsfs.c b/fs/nsfs.c > index be7d193..11a4b15 100644 > --- a/fs/nsfs.c > +++ b/fs/nsfs.c > @@ -170,6 +170,10 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl, > switch (ioctl) { > case NS_GET_USERNS: > return open_related_ns(ns, ns_get_owner); > + case NS_GET_PARENT: > + if (!ns->ops->get_parent) > + return -EINVAL; > + return open_related_ns(ns, ns->ops->get_parent); > default: > return -ENOTTY; > } > diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h > index ca85a43..12cb8bd 100644 > --- a/include/linux/proc_ns.h > +++ b/include/linux/proc_ns.h > @@ -19,6 +19,7 @@ struct proc_ns_operations { > void (*put)(struct ns_common *ns); > int (*install)(struct nsproxy *nsproxy, struct ns_common *ns); > struct user_namespace *(*owner)(struct ns_common *ns); > + struct ns_common *(*get_parent)(struct ns_common *ns); > }; > > extern const struct proc_ns_operations netns_operations; > diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h > index 5cacd5c..3af6172 100644 > --- a/include/uapi/linux/nsfs.h > +++ b/include/uapi/linux/nsfs.h > @@ -7,5 +7,7 @@ > > /* Returns a file descriptor that refers to an owning user namespace */ > #define NS_GET_USERNS _IO(NSIO, 0x1) > +/* Returns a file descriptor that refers to a parent namespace */ > +#define NS_GET_PARENT _IO(NSIO, 0x2) > > #endif /* __LINUX_NSFS_H */ > diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c > index c18f0f4f..aad470b 100644 > --- a/kernel/pid_namespace.c > +++ b/kernel/pid_namespace.c > @@ -405,6 +405,24 @@ static int pidns_install(struct nsproxy *nsproxy, struct ns_common *ns) > return 0; > } > > +static struct ns_common *pidns_get_parent(struct ns_common *ns) > +{ > + struct pid_namespace *active = task_active_pid_ns(current); > + struct pid_namespace *pid_ns, *p; > + > + /* See if the parent is in the current namespace */ > + pid_ns = p = to_pid_ns(ns)->parent; > + for (;;) { > + if (!p) > + return ERR_PTR(-EPERM); > + if (p == active) > + break; > + p = p->parent; > + } > + > + return &get_pid_ns(pid_ns)->ns; > +} > + > static struct user_namespace *pidns_owner(struct ns_common *ns) > { > return to_pid_ns(ns)->user_ns; > @@ -417,6 +435,7 @@ const struct proc_ns_operations pidns_operations = { > .put = pidns_put, > .install = pidns_install, > .owner = pidns_owner, > + .get_parent = pidns_get_parent, > }; > > static __init int pid_namespaces_init(void) > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c > index 42a64d5..33b523c 100644 > --- a/kernel/user_namespace.c > +++ b/kernel/user_namespace.c > @@ -1080,6 +1080,7 @@ const struct proc_ns_operations userns_operations = { > .put = userns_put, > .install = userns_install, > .owner = userns_owner, > + .get_parent = ns_get_owner, > }; > > static __init int user_namespaces_init(void) > -- > 2.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/nsfs.c b/fs/nsfs.c index be7d193..11a4b15 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -170,6 +170,10 @@ static long ns_ioctl(struct file *filp, unsigned int ioctl, switch (ioctl) { case NS_GET_USERNS: return open_related_ns(ns, ns_get_owner); + case NS_GET_PARENT: + if (!ns->ops->get_parent) + return -EINVAL; + return open_related_ns(ns, ns->ops->get_parent); default: return -ENOTTY; } diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index ca85a43..12cb8bd 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -19,6 +19,7 @@ struct proc_ns_operations { void (*put)(struct ns_common *ns); int (*install)(struct nsproxy *nsproxy, struct ns_common *ns); struct user_namespace *(*owner)(struct ns_common *ns); + struct ns_common *(*get_parent)(struct ns_common *ns); }; extern const struct proc_ns_operations netns_operations; diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h index 5cacd5c..3af6172 100644 --- a/include/uapi/linux/nsfs.h +++ b/include/uapi/linux/nsfs.h @@ -7,5 +7,7 @@ /* Returns a file descriptor that refers to an owning user namespace */ #define NS_GET_USERNS _IO(NSIO, 0x1) +/* Returns a file descriptor that refers to a parent namespace */ +#define NS_GET_PARENT _IO(NSIO, 0x2) #endif /* __LINUX_NSFS_H */ diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index c18f0f4f..aad470b 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -405,6 +405,24 @@ static int pidns_install(struct nsproxy *nsproxy, struct ns_common *ns) return 0; } +static struct ns_common *pidns_get_parent(struct ns_common *ns) +{ + struct pid_namespace *active = task_active_pid_ns(current); + struct pid_namespace *pid_ns, *p; + + /* See if the parent is in the current namespace */ + pid_ns = p = to_pid_ns(ns)->parent; + for (;;) { + if (!p) + return ERR_PTR(-EPERM); + if (p == active) + break; + p = p->parent; + } + + return &get_pid_ns(pid_ns)->ns; +} + static struct user_namespace *pidns_owner(struct ns_common *ns) { return to_pid_ns(ns)->user_ns; @@ -417,6 +435,7 @@ const struct proc_ns_operations pidns_operations = { .put = pidns_put, .install = pidns_install, .owner = pidns_owner, + .get_parent = pidns_get_parent, }; static __init int pid_namespaces_init(void) diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 42a64d5..33b523c 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -1080,6 +1080,7 @@ const struct proc_ns_operations userns_operations = { .put = userns_put, .install = userns_install, .owner = userns_owner, + .get_parent = ns_get_owner, }; static __init int user_namespaces_init(void)