net-sysfs: add netdev_change_owner()

Add a function to change the owner of a network device when it is moved
between network namespaces.

Currently, when moving network devices between network namespaces the
ownership of the corresponding sysfs entries is not changed. This leads
to problems when tools try to operate on the corresponding sysfs files.
This leads to a bug whereby a network device that is created in a
network namespaces owned by a user namespace will have its corresponding
sysfs entry owned by the root user of the corresponding user namespace.
If such a network device has to be moved back to the host network
namespace the permissions will still be set to the user namespaces. This
means unprivileged users can e.g. trigger uevents for such incorrectly
owned devices. They can also modify the settings of the device itself.
Both of these things are unwanted.

For example, workloads will create network devices in the host network
namespace. Other tools will then proceed to move such devices between
network namespaces owner by other user namespaces. While the ownership
of the device itself is updated in
net/core/net-sysfs.c:dev_change_net_namespace() the corresponding sysfs
entry for the device is not:

drwxr-xr-x 5 nobody nobody 0 Jan 25 18:08 .
drwxr-xr-x 9 nobody nobody 0 Jan 25 18:08 ..
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_assign_type
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 addr_len
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 address
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 broadcast
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_changes
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_down_count
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 carrier_up_count
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_id
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dev_port
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 dormant
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 duplex
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 flags
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 gro_flush_timeout
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifalias
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 ifindex
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 iflink
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 link_mode
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 mtu
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 name_assign_type
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 netdev_group
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 operstate
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_id
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_port_name
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 phys_switch_id
drwxr-xr-x 2 nobody nobody 0 Jan 25 18:09 power
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 proto_down
drwxr-xr-x 4 nobody nobody 0 Jan 25 18:09 queues
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 speed
drwxr-xr-x 2 nobody nobody 0 Jan 25 18:09 statistics
lrwxrwxrwx 1 nobody nobody 0 Jan 25 18:08 subsystem -> ../../../../class/net
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:09 tx_queue_len
-r--r--r-- 1 nobody nobody 4096 Jan 25 18:09 type
-rw-r--r-- 1 nobody nobody 4096 Jan 25 18:08 uevent

However, if a device is created directly in the network namespace then
the device's sysfs permissions will be correctly updated:

drwxr-xr-x 5 root root 0 Jan 25 18:12 .
drwxr-xr-x 9 nobody nobody 0 Jan 25 18:08 ..
-r--r--r-- 1 root root 4096 Jan 25 18:12 addr_assign_type
-r--r--r-- 1 root root 4096 Jan 25 18:12 addr_len
-r--r--r-- 1 root root 4096 Jan 25 18:12 address
-r--r--r-- 1 root root 4096 Jan 25 18:12 broadcast
-rw-r--r-- 1 root root 4096 Jan 25 18:12 carrier
-r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_changes
-r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_down_count
-r--r--r-- 1 root root 4096 Jan 25 18:12 carrier_up_count
-r--r--r-- 1 root root 4096 Jan 25 18:12 dev_id
-r--r--r-- 1 root root 4096 Jan 25 18:12 dev_port
-r--r--r-- 1 root root 4096 Jan 25 18:12 dormant
-r--r--r-- 1 root root 4096 Jan 25 18:12 duplex
-rw-r--r-- 1 root root 4096 Jan 25 18:12 flags
-rw-r--r-- 1 root root 4096 Jan 25 18:12 gro_flush_timeout
-rw-r--r-- 1 root root 4096 Jan 25 18:12 ifalias
-r--r--r-- 1 root root 4096 Jan 25 18:12 ifindex
-r--r--r-- 1 root root 4096 Jan 25 18:12 iflink
-r--r--r-- 1 root root 4096 Jan 25 18:12 link_mode
-rw-r--r-- 1 root root 4096 Jan 25 18:12 mtu
-r--r--r-- 1 root root 4096 Jan 25 18:12 name_assign_type
-rw-r--r-- 1 root root 4096 Jan 25 18:12 netdev_group
-r--r--r-- 1 root root 4096 Jan 25 18:12 operstate
-r--r--r-- 1 root root 4096 Jan 25 18:12 phys_port_id
-r--r--r-- 1 root root 4096 Jan 25 18:12 phys_port_name
-r--r--r-- 1 root root 4096 Jan 25 18:12 phys_switch_id
drwxr-xr-x 2 root root 0 Jan 25 18:12 power
-rw-r--r-- 1 root root 4096 Jan 25 18:12 proto_down
drwxr-xr-x 4 root root 0 Jan 25 18:12 queues
-r--r--r-- 1 root root 4096 Jan 25 18:12 speed
drwxr-xr-x 2 root root 0 Jan 25 18:12 statistics
lrwxrwxrwx 1 nobody nobody 0 Jan 25 18:12 subsystem -> ../../../../class/net
-rw-r--r-- 1 root root 4096 Jan 25 18:12 tx_queue_len
-r--r--r-- 1 root root 4096 Jan 25 18:12 type
-rw-r--r-- 1 root root 4096 Jan 25 18:12 uevent

Now, when creating a network device in a network namespace owned by a
user namespace and moving it to the host the permissions will be set to
the id that the user namespace root user has been mapped to on the host
leading to all sorts of permission issues:

458752
drwxr-xr-x 5 458752 458752 0 Jan 25 18:12 .
drwxr-xr-x 9 root root 0 Jan 25 18:08 ..
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 addr_assign_type
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 addr_len
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 address
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 broadcast
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_changes
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_down_count
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 carrier_up_count
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dev_id
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dev_port
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 dormant
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 duplex
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 flags
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 gro_flush_timeout
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 ifalias
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 ifindex
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 iflink
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 link_mode
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 mtu
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 name_assign_type
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 netdev_group
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 operstate
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_port_id
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_port_name
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 phys_switch_id
drwxr-xr-x 2 458752 458752 0 Jan 25 18:12 power
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 proto_down
drwxr-xr-x 4 458752 458752 0 Jan 25 18:12 queues
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 speed
drwxr-xr-x 2 458752 458752 0 Jan 25 18:12 statistics
lrwxrwxrwx 1 root root 0 Jan 25 18:12 subsystem -> ../../../../class/net
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 tx_queue_len
-r--r--r-- 1 458752 458752 4096 Jan 25 18:12 type
-rw-r--r-- 1 458752 458752 4096 Jan 25 18:12 uevent

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: netdev_kobject_init: annotate with __init

netdev_kobject_init() is only being called from __init context,
that is, net_dev_init(), so annotate it with __init as well, thus
the kernel can take this as a hint that the function is used only
during the initialization phase and free up used memory resources
after its invocation.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: Add CONFIG_XPS

This patch adds XPS_CONFIG option to enable and disable XPS. This is
done in the same manner as RPS_CONFIG. This is also fixes build
failure in XPS code when SMP is not enabled.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xps: Transmit Packet Steering

This patch implements transmit packet steering (XPS) for multiqueue
devices. XPS selects a transmit queue during packet transmission based
on configuration. This is done by mapping the CPU transmitting the
packet to a queue. This is the transmit side analogue to RPS-- where
RPS is selecting a CPU based on receive queue, XPS selects a queue
based on the CPU (previously there was an XPS patch from Eric
Dumazet, but that might more appropriately be called transmit completion
steering).

Each transmit queue can be associated with a number of CPUs which will
use the queue to send packets. This is configured as a CPU mask on a
per queue basis in:

/sys/class/net/eth<n>/queues/tx-<n>/xps_cpus

The mappings are stored per device in an inverted data structure that
maps CPUs to queues. In the netdevice structure this is an array of
num_possible_cpu structures where each structure holds and array of
queue_indexes for queues which that CPU can use.

The benefits of XPS are improved locality in the per queue data
structures. Also, transmit completions are more likely to be done
nearer to the sending thread, so this should promote locality back
to the socket on free (e.g. UDP). The benefits of XPS are dependent on
cache hierarchy, application load, and other factors. XPS would
nominally be configured so that a queue would only be shared by CPUs
which are sharing a cache, the degenerative configuration woud be that
each CPU has it's own queue.

Below are some benchmark results which show the potential benfit of
this patch. The netperf test has 500 instances of netperf TCP_RR test
with 1 byte req. and resp.

bnx2x on 16 core AMD
XPS (16 queues, 1 TX queue per CPU) 1234K at 100% CPU
No XPS (16 queues) 996K at 100% CPU

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow changing number of RX queues after device allocation

For RPS, we create a kobject for each RX queue based on the number of
queues passed to alloc_netdev_mq(). However, drivers generally do not
determine the numbers of hardware queues to use until much later, so
this usually represents the maximum number the driver may use and not
the actual number in use.

For TX queues, drivers can update the actual number using
netif_set_real_num_tx_queues(). Add a corresponding function for RX
queues, netif_set_real_num_rx_queues().

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Expose all network devices in a namespaces in sysfs

This reverts commit aaf8cdc34ddba08122f02217d9d684e2f9f5d575.

Drivers like the ipw2100 call device_create_group when they
are initialized and device_remove_group when they are shutdown.
Moving them between namespaces deletes their sysfs groups early.

In particular the following call chain results.
netdev_unregister_kobject -> device_del -> kobject_del -> sysfs_remove_dir
With sysfs_remove_dir recursively deleting all of it's subdirectories,
and nothing adding them back.

Ouch!

Therefore we need to call something that ultimate calls sysfs_mv_dir
as that sysfs function can move sysfs directories between namespaces
without deleting their subdirectories or their contents. Allowing
us to avoid placing extra boiler plate into every driver that does
something interesting with sysfs.

Currently the function that provides that capability is device_rename.
That is the code works without nasty side effects as originally written.

So remove the misguided fix for moving devices between namespaces. The
bug in the kobject layer that inspired it has now been recognized and
fixed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

netns: Fix device renaming for sysfs

When a netdev is moved across namespaces with the
'dev_change_net_namespace' function, the 'device_rename' function is
used to fixup kobject and refresh the sysfs tree. The device_rename
function will call kobject_rename and this one will check if there is
an object with the same name and this is the case because we are
renaming the object with the same name.

The use of 'device_rename' seems for me wrong because we usually don't
rename it but just move it across namespaces. As we just want to do a
mini "netdev_[un]register", IMO the functions
'netdev_[un]register_kobject' should be used instead, like an usual
network device [un]registering.

This patch replace device_rename by netdev_unregister_kobject,
followed by netdev_register_kobject.

The netdev_register_kobject will call device_initialize and will raise
a warning indicating the device was already initialized. In order to
fix that, I split the device initialization into a separate function
and use it together with 'netdev_register_kobject' into
register_netdevice. So we can safely call 'netdev_register_kobject' in
'dev_change_net_namespace'.

This fix will allow to properly use the sysfs per namespace which is
coming from -mm tree.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

[NET]: Remove in-code externs for some functions from net/core/dev.c

Inconsistent prototype and real type for functions may have worse
consequences, than those for variables, so move them into a header.

Since they are used privately in net/core, make this file reside in
the same place.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>