diff options
author | Tyler Hicks <tyhicks@canonical.com> | 2018-07-21 00:56:53 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2018-07-21 09:44:36 +0300 |
commit | fbdeaed408cf2728c62640c10848ddb1b67e63d3 (patch) | |
tree | 4c06f4a43d4516e7f1f83db877f4f4c49b01077f | |
parent | b0e37c0d8a6abed0cd1b611314a7ebf50b0a8ed4 (diff) | |
download | linux-fbdeaed408cf2728c62640c10848ddb1b67e63d3.tar.xz |
net: create reusable function for getting ownership info of sysfs inodes
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 <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | include/net/net_namespace.h | 10 | ||||
-rw-r--r-- | net/core/net-sysfs.c | 18 | ||||
-rw-r--r-- | net/core/net_namespace.c | 28 |
3 files changed, 38 insertions, 18 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index a71264d75d7f..9b5fdc50519a 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -10,6 +10,7 @@ #include <linux/workqueue.h> #include <linux/list.h> #include <linux/sysctl.h> +#include <linux/uidgid.h> #include <net/flow.h> #include <net/netns/core.h> @@ -170,6 +171,8 @@ 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 +185,13 @@ 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) +{ + *uid = GLOBAL_ROOT_UID; + *gid = GLOBAL_ROOT_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 ada065fc685e..0a95bcf64cdc 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -656,24 +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; - } else { - *uid = GLOBAL_ROOT_UID; - *gid = GLOBAL_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..738871af5efa 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -17,6 +17,7 @@ #include <linux/user_namespace.h> #include <linux/net_namespace.h> #include <linux/sched/task.h> +#include <linux/uidgid.h> #include <net/sock.h> #include <net/netlink.h> @@ -448,6 +449,33 @@ dec_ucounts: 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 + * @gid: kernel group ID for sysfs objects + * + * Returns the uid/gid pair of root in the user namespace associated with the + * given network namespace. + */ +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; + } else { + *uid = GLOBAL_ROOT_UID; + *gid = GLOBAL_ROOT_GID; + } +} +EXPORT_SYMBOL_GPL(net_ns_get_ownership); + static void unhash_nsid(struct net *net, struct net *last) { struct net *tmp; |