Make net_ns_get_ownership() reusable by networking code outside of core. This is useful, for example, to allow bridge related sysfs files to be owned by container root.
Add a function comment since this is a potentially dangerous function to use given the way that kobject_get_ownership() works by initializing uid and gid before calling .get_ownership(). Signed-off-by: Tyler Hicks <[email protected]> --- include/net/net_namespace.h | 7 +++++++ net/core/net-sysfs.c | 15 --------------- net/core/net_namespace.c | 25 +++++++++++++++++++++++++ 3 files changed, 32 insertions(+), 15 deletions(-) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index a71264d75d7f..a257710527ce 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -170,6 +170,8 @@ extern struct net init_net; struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, struct net *old_net); +void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); + void net_ns_barrier(void); #else /* CONFIG_NET_NS */ #include <linux/sched.h> @@ -182,6 +184,11 @@ static inline struct net *copy_net_ns(unsigned long flags, return old_net; } +static inline void net_ns_get_ownership(const struct net *net, + kuid_t *uid, kgid_t *gid) +{ +} + static inline void net_ns_barrier(void) {} #endif /* CONFIG_NET_NS */ diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 41d84c40fe51..a3ad8108d296 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -656,21 +656,6 @@ static const struct attribute_group wireless_group = { #define net_class_groups NULL #endif /* CONFIG_SYSFS */ -static void net_ns_get_ownership(const struct net *net, - kuid_t *uid, kgid_t *gid) -{ - if (net) { - kuid_t ns_root_uid = make_kuid(net->user_ns, 0); - kgid_t ns_root_gid = make_kgid(net->user_ns, 0); - - if (uid_valid(ns_root_uid)) - *uid = ns_root_uid; - - if (gid_valid(ns_root_gid)) - *gid = ns_root_gid; - } -} - #ifdef CONFIG_SYSFS #define to_rx_queue_attr(_attr) \ container_of(_attr, struct rx_queue_attribute, attr) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index a11e03f920d3..5257875fa84d 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -448,6 +448,31 @@ struct net *copy_net_ns(unsigned long flags, return net; } +/** + * net_ns_get_ownership - get sysfs ownership data for @net + * @net: network namespace in question (can be NULL) + * @uid: kernel user ID for sysfs objects (must be GLOBAL_ROOT_UID) + * @gid: kernel group ID for sysfs objects (must be GLOBAL_ROOT_GID) + * + * Returns the uid/gid pair of root in the user namespace associated with the + * given network namespace. The caller must initialize @uid and @gid to + * GLOBAL_ROOT_UID/GLOBAL_ROOT_GID before calling this function. + */ +void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid) +{ + if (net) { + kuid_t ns_root_uid = make_kuid(net->user_ns, 0); + kgid_t ns_root_gid = make_kgid(net->user_ns, 0); + + if (uid_valid(ns_root_uid)) + *uid = ns_root_uid; + + if (gid_valid(ns_root_gid)) + *gid = ns_root_gid; + } +} +EXPORT_SYMBOL_GPL(net_ns_get_ownership); + static void unhash_nsid(struct net *net, struct net *last) { struct net *tmp; -- 2.7.4
