linux-stable.git/net/openvswitch/datapath.c, branch v6.0.7

openvswitch: switch from WARN to pr_warn

2022-11-03T15:00:33+00:00

[ Upstream commit fd954cc1919e35cb92f78671cab6e42d661945a3 ]

As noted by Paolo Abeni, pr_warn doesn't generate any splat and can still
preserve the warning to the user that feature downgrade occurred.  We
likely cannot introduce other kinds of checks / enforcement here because
syzbot can generate different genl versions to the datapath.

Reported-by: syzbot+31cde0bef4bbf8ba2d86@syzkaller.appspotmail.com
Fixes: 44da5ae5fbea ("openvswitch: Drop user features if old user space attempted to create datapath")
Cc: Thomas Graf 
Signed-off-by: Aaron Conole 
Acked-by: Ilya Maximets 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

openvswitch: Fix overreporting of drops in dropwatch

2022-10-21T10:39:06+00:00

[ Upstream commit c21ab2afa2c64896a7f0e3cbc6845ec63dcfad2e ]

Currently queue_userspace_packet will call kfree_skb for all frames,
whether or not an error occurred. This can result in a single dropped
frame being reported as multiple drops in dropwatch. This functions
caller may also call kfree_skb in case of an error. This patch will
consume the skbs instead and allow caller's to use kfree_skb.

Signed-off-by: Mike Pattrick 
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109957
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

openvswitch: Fix double reporting of drops in dropwatch

2022-10-21T10:39:06+00:00

[ Upstream commit 1100248a5c5ccd57059eb8d02ec077e839a23826 ]

Frames sent to userspace can be reported as dropped in
ovs_dp_process_packet, however, if they are dropped in the netlink code
then netlink_attachskb will report the same frame as dropped.

This patch checks for error codes which indicate that the frame has
already been freed.

Signed-off-by: Mike Pattrick 
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2109946
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

openvswitch: fix memory leak at failed datapath creation

2022-08-27T02:26:30+00:00

ovs_dp_cmd_new()->ovs_dp_change()->ovs_dp_set_upcall_portids()
allocates array via kmalloc.
If for some reason new_vport() fails during ovs_dp_cmd_new()
dp->upcall_portids must be freed.
Add missing kfree.

Kmemleak example:
unreferenced object 0xffff88800c382500 (size 64):
  comm "dump_state", pid 323, jiffies 4294955418 (age 104.347s)
  hex dump (first 32 bytes):
    5e c2 79 e4 1f 7a 38 c7 09 21 38 0c 80 88 ff ff  ^.y..z8..!8.....
    03 00 00 00 0a 00 00 00 14 00 00 00 28 00 00 00  ............(...
  backtrace:
    [<0000000071bebc9f>] ovs_dp_set_upcall_portids+0x38/0xa0
    [<000000000187d8bd>] ovs_dp_change+0x63/0xe0
    [<000000002397e446>] ovs_dp_cmd_new+0x1f0/0x380
    [<00000000aa06f36e>] genl_family_rcv_msg_doit+0xea/0x150
    [<000000008f583bc4>] genl_rcv_msg+0xdc/0x1e0
    [<00000000fa10e377>] netlink_rcv_skb+0x50/0x100
    [<000000004959cece>] genl_rcv+0x24/0x40
    [<000000004699ac7f>] netlink_unicast+0x23e/0x360
    [<00000000c153573e>] netlink_sendmsg+0x24e/0x4b0
    [<000000006f4aa380>] sock_sendmsg+0x62/0x70
    [<00000000d0068654>] ____sys_sendmsg+0x230/0x270
    [<0000000012dacf7d>] ___sys_sendmsg+0x88/0xd0
    [<0000000011776020>] __sys_sendmsg+0x59/0xa0
    [<000000002e8f2dc1>] do_syscall_64+0x3b/0x90
    [<000000003243e7cb>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: b83d23a2a38b ("openvswitch: Introduce per-cpu upcall dispatch")
Acked-by: Aaron Conole 
Signed-off-by: Andrey Zhadchenko 
Link: https://lore.kernel.org/r/20220825020326.664073-1-andrey.zhadchenko@virtuozzo.com
Signed-off-by: Jakub Kicinski

net/sched: Enable tc skb ext allocation on chain miss only when needed

2022-02-05T10:12:53+00:00

Currently tc skb extension is used to send miss info from
tc to ovs datapath module, and driver to tc. For the tc to ovs
miss it is currently always allocated even if it will not
be used by ovs datapath (as it depends on a requested feature).

Export the static key which is used by openvswitch module to
guard this code path as well, so it will be skipped if ovs
datapath doesn't need it. Enable this code path once
ovs datapath needs it.

Signed-off-by: Paul Blakey 
Reviewed-by: Jamal Hadi Salim 
Signed-off-by: David S. Miller

openvswitch: fix sparse warning incorrect type

2021-07-27T10:48:43+00:00

fix incorrect type in argument 1 (different address spaces)

../net/openvswitch/datapath.c:169:17: warning: incorrect type in argument 1 (different address spaces)
../net/openvswitch/datapath.c:169:17:    expected void const *
../net/openvswitch/datapath.c:169:17:    got struct dp_nlsk_pids [noderef] __rcu *upcall_portids

Found at: https://patchwork.kernel.org/project/netdevbpf/patch/20210630095350.817785-1-mark.d.gray@redhat.com/#24285159

Signed-off-by: Mark Gray 
Signed-off-by: David S. Miller

openvswitch: fix alignment issues

2021-07-27T10:48:42+00:00

Signed-off-by: Mark Gray 
Signed-off-by: David S. Miller

openvswitch: Introduce per-cpu upcall dispatch

2021-07-16T18:06:33+00:00

The Open vSwitch kernel module uses the upcall mechanism to send
packets from kernel space to user space when it misses in the kernel
space flow table. The upcall sends packets via a Netlink socket.
Currently, a Netlink socket is created for every vport. In this way,
there is a 1:1 mapping between a vport and a Netlink socket.
When a packet is received by a vport, if it needs to be sent to
user space, it is sent via the corresponding Netlink socket.

This mechanism, with various iterations of the corresponding user
space code, has seen some limitations and issues:

* On systems with a large number of vports, there is a correspondingly
large number of Netlink sockets which can limit scaling.
(https://bugzilla.redhat.com/show_bug.cgi?id=1526306)
* Packet reordering on upcalls.
(https://bugzilla.redhat.com/show_bug.cgi?id=1844576)
* A thundering herd issue.
(https://bugzilla.redhat.com/show_bug.cgi?id=1834444)

This patch introduces an alternative, feature-negotiated, upcall
mode using a per-cpu dispatch rather than a per-vport dispatch.

In this mode, the Netlink socket to be used for the upcall is
selected based on the CPU of the thread that is executing the upcall.
In this way, it resolves the issues above as:

a) The number of Netlink sockets scales with the number of CPUs
rather than the number of vports.
b) Ordering per-flow is maintained as packets are distributed to
CPUs based on mechanisms such as RSS and flows are distributed
to a single user space thread.
c) Packets from a flow can only wake up one user space thread.

The corresponding user space code can be found at:
https://mail.openvswitch.org/pipermail/ovs-dev/2021-July/385139.html

Bugzilla: https://bugzilla.redhat.com/1844576
Signed-off-by: Mark Gray 
Acked-by: Flavio Leitner 
Acked-by: Pravin B Shelar 
Signed-off-by: David S. Miller

openvswitch: add trace points

2021-06-22T17:47:32+00:00

This makes openvswitch module use the event tracing framework
to log the upcall interface and action execution pipeline.  When
using openvswitch as the packet forwarding engine, some types of
debugging are made possible simply by using the ovs-vswitchd's
ofproto/trace command.  However, such a command has some
limitations:

  1. When trying to trace packets that go through the CT action,
     the state of the packet can't be determined, and probably
     would be potentially wrong.

  2. Deducing problem packets can sometimes be difficult as well
     even if many of the flows are known

  3. It's possible to use the openvswitch module even without
     the ovs-vswitchd (although, not common use).

Introduce the event tracing points here to make it possible for
working through these problems in kernel space.  The style is
copied from the mac80211 driver-trace / trace code for
consistency - this creates some checkpatch splats, but the
official 'guide' for adding tracepoints, as well as the existing
examples all add the same splats so it seems acceptable.

Signed-off-by: Aaron Conole 
Signed-off-by: David S. Miller

net: openvswitch: silence suspicious RCU usage warning

2020-11-04T00:57:42+00:00

Silence suspicious RCU usage warning in ovs_flow_tbl_masks_cache_resize()
by replacing rcu_dereference() with rcu_dereference_ovsl().

In addition, when creating a new datapath, make sure it's configured under
the ovs_lock.

Fixes: 9bf24f594c6a ("net: openvswitch: make masks cache size configurable")
Reported-by: syzbot+9a8f8bfcc56e8578016c@syzkaller.appspotmail.com
Signed-off-by: Eelco Chaudron 
Link: https://lore.kernel.org/r/160439190002.56943.1418882726496275961.stgit@ebuild
Signed-off-by: Jakub Kicinski