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-rw-r--r--Documentation/networking/ethtool-netlink.rst3
-rw-r--r--Documentation/networking/index.rst1
-rw-r--r--Documentation/networking/sysfs-tagging.rst48
3 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index d53bcb31645a..b5a79881551f 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -206,6 +206,7 @@ Userspace to kernel:
``ETHTOOL_MSG_TSINFO_GET`` get timestamping info
``ETHTOOL_MSG_CABLE_TEST_ACT`` action start cable test
``ETHTOOL_MSG_CABLE_TEST_TDR_ACT`` action start raw TDR cable test
+ ``ETHTOOL_MSG_TUNNEL_INFO_GET`` get tunnel offload info
===================================== ================================
Kernel to userspace:
@@ -239,6 +240,7 @@ Kernel to userspace:
``ETHTOOL_MSG_TSINFO_GET_REPLY`` timestamping info
``ETHTOOL_MSG_CABLE_TEST_NTF`` Cable test results
``ETHTOOL_MSG_CABLE_TEST_TDR_NTF`` Cable test TDR results
+ ``ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY`` tunnel offload info
===================================== =================================
``GET`` requests are sent by userspace applications to retrieve device
@@ -1363,4 +1365,5 @@ are netlink only.
``ETHTOOL_SFECPARAM`` n/a
n/a ''ETHTOOL_MSG_CABLE_TEST_ACT''
n/a ''ETHTOOL_MSG_CABLE_TEST_TDR_ACT''
+ n/a ``ETHTOOL_MSG_TUNNEL_INFO_GET``
=================================== =====================================
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index c29496fff81c..611e4b130c1e 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -95,6 +95,7 @@ Contents:
seg6-sysctl
strparser
switchdev
+ sysfs-tagging
tc-actions-env-rules
tcp-thin
team
diff --git a/Documentation/networking/sysfs-tagging.rst b/Documentation/networking/sysfs-tagging.rst
new file mode 100644
index 000000000000..83647e10c207
--- /dev/null
+++ b/Documentation/networking/sysfs-tagging.rst
@@ -0,0 +1,48 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============
+Sysfs tagging
+=============
+
+(Taken almost verbatim from Eric Biederman's netns tagging patch
+commit msg)
+
+The problem. Network devices show up in sysfs and with the network
+namespace active multiple devices with the same name can show up in
+the same directory, ouch!
+
+To avoid that problem and allow existing applications in network
+namespaces to see the same interface that is currently presented in
+sysfs, sysfs now has tagging directory support.
+
+By using the network namespace pointers as tags to separate out
+the sysfs directory entries we ensure that we don't have conflicts
+in the directories and applications only see a limited set of
+the network devices.
+
+Each sysfs directory entry may be tagged with a namespace via the
+``void *ns member`` of its ``kernfs_node``. If a directory entry is tagged,
+then ``kernfs_node->flags`` will have a flag between KOBJ_NS_TYPE_NONE
+and KOBJ_NS_TYPES, and ns will point to the namespace to which it
+belongs.
+
+Each sysfs superblock's kernfs_super_info contains an array
+``void *ns[KOBJ_NS_TYPES]``. When a task in a tagging namespace
+kobj_nstype first mounts sysfs, a new superblock is created. It
+will be differentiated from other sysfs mounts by having its
+``s_fs_info->ns[kobj_nstype]`` set to the new namespace. Note that
+through bind mounting and mounts propagation, a task can easily view
+the contents of other namespaces' sysfs mounts. Therefore, when a
+namespace exits, it will call kobj_ns_exit() to invalidate any
+kernfs_node->ns pointers pointing to it.
+
+Users of this interface:
+
+- define a type in the ``kobj_ns_type`` enumeration.
+- call kobj_ns_type_register() with its ``kobj_ns_type_operations`` which has
+
+ - current_ns() which returns current's namespace
+ - netlink_ns() which returns a socket's namespace
+ - initial_ns() which returns the initial namesapce
+
+- call kobj_ns_exit() when an individual tag is no longer valid