Until now, we assumed that in case of error when adding FDB entries, the
write operation will fail, but this is not the case. Instead, we need to
check that the number of entries reported in the response is equal to
the number of entries specified in the request.

Fixes: 56ade8fe ("mlxsw: spectrum: Add initial support for Spectrum ASIC")
Reported-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NShalom Toledo <shalomt@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Daniel Axtens says:

====================
GSO_BY_FRAGS correctness improvements

As requested [1], I went through and had a look at users of gso_size to
see if there were things that need to be fixed to consider
GSO_BY_FRAGS, and I have tried to improve our helper functions to deal
with this case.

I found a few. This fixes bugs relating to the use of
skb_gso_*_seglen() where GSO_BY_FRAGS is not considered.

Patch 1 renames skb_gso_validate_mtu to skb_gso_validate_network_len.
This is follow-up to my earlier patch 2b16f048 ("net: create
skb_gso_validate_mac_len()"), and just makes everything a bit clearer.

Patches 2 and 3 replace the final users of skb_gso_network_seglen() -
which doesn't consider GSO_BY_FRAGS - with
skb_gso_validate_network_len(), which does. This allows me to make the
skb_gso_*_seglen functions private in patch 4 - now future users won't
accidentally do the wrong comparison.

Two things remain. One is qdisc_pkt_len_init, which is discussed at
[2] - it's caught up in the GSO_DODGY mess. I don't have any expertise
in GSO_DODGY, and it looks like a good clean fix will involve
unpicking the whole validation mess, so I have left it for now.

Secondly, there are 3 eBPF opcodes that change the gso_size of an SKB
and don't consider GSO_BY_FRAGS. This is going through the bpf tree.

Regards,
Daniel

[1] https://patchwork.ozlabs.org/comment/1852414/
[2] https://www.spinics.net/lists/netdev/msg482397.html

PS: This is all in the core networking stack. For a driver to be
affected by this it would need to support NETIF_F_GSO_SCTP /
NETIF_F_GSO_SOFTWARE and then either use gso_size or not be a purely
virtual device. (Many drivers look at gso_size, but do not support
SCTP segmentation, so the core network will segment an SCTP gso before
it hits them.) Based on that, the only driver that may be affected is
sunvnet, but I have no way of testing it, so I haven't looked at it.

v2: split out bpf stuff
    fix review comments from Dave Miller
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

They're very hard to use properly as they do not consider the
GSO_BY_FRAGS case. Code should use skb_gso_validate_network_len
and skb_gso_validate_mac_len as they do consider this case.

Make the seglen functions static, which stops people using them
outside of skbuff.c
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace skb_gso_network_seglen() with
skb_gso_validate_network_len(), as it considers the GSO_BY_FRAGS
case.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tbf_enqueue() checks the size of a packet before enqueuing it.
However, the GSO size check does not consider the GSO_BY_FRAGS
case, and so will drop GSO SCTP packets, causing a massive drop
in throughput.

Use skb_gso_validate_mac_len() instead, as it does consider that
case.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If you take a GSO skb, and split it into packets, will the network
length (L3 headers + L4 headers + payload) of those packets be small
enough to fit within a given MTU?

skb_gso_validate_mtu gives you the answer to that question. However,
we recently added to add a way to validate the MAC length of a split GSO
skb (L2+L3+L4+payload), and the names get confusing, so rename
skb_gso_validate_mtu to skb_gso_validate_network_len
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simon Wunderlich says:

====================
Here are some batman-adv bugfixes:

 - fix skb checksum issues, by Matthias Schiffer (2 patches)

 - fix exception handling when dumping data objects through netlink,
   by Sven Eckelmann (4 patches)

 - fix handling of interface indices, by Sven Eckelmann
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter/IPVS fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Put back reference on CLUSTERIP configuration structure from the
   error path, patch from Florian Westphal.

2) Put reference on CLUSTERIP configuration instead of freeing it,
   another cpu may still be walking over it, also from Florian.

3) Refetch pointer to IPv6 header from nf_nat_ipv6_manip_pkt() given
   packet manipulation may reallocation the skbuff header, from Florian.

4) Missing match size sanity checks in ebt_among, from Florian.

5) Convert BUG_ON to WARN_ON in ebtables, from Florian.

6) Sanity check userspace offsets from ebtables kernel, from Florian.

7) Missing checksum replace call in flowtable IPv4 DNAT, from Felix
   Fietkau.

8) Bump the right stats on checksum error from bridge netfilter,
   from Taehee Yoo.

9) Unset interface flag in IPv6 fib lookups otherwise we get
   misleading routing lookup results, from Florian.

10) Missing sk_to_full_sk() in ip6_route_me_harder() from Eric Dumazet.

11) Don't allow devices to be part of multiple flowtables at the same
    time, this may break setups.

12) Missing netlink attribute validation in flowtable deletion.

13) Wrong array index in nf_unregister_net_hook() call from error path
    in flowtable addition path.

14) Fix FTP IPVS helper when NAT mangling is in place, patch from
    Julian Anastasov.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2018-03-02' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Three more patches:
 * fix for a regression in 4-addr mode with fast-RX
 * fix for a Kconfig problem with the new regdb
 * fix for the long-standing TCP performance issue in
   wifi using the new sk_pacing_shift_update()
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 0933a578 ("rds: tcp: use sock_create_lite() to create the
accept socket") has a reference counting issue in TCP socket creation
when accepting a new connection.  The code uses sock_create_lite() to
create a kernel socket.  But it does not do __module_get() on the
socket owner.  When the connection is shutdown and sock_release() is
called to free the socket, the owner's reference count is decremented
and becomes incorrect.  Note that this bug only shows up when the socket
owner is configured as a kernel module.

v2: Update comments

Fixes: 0933a578 ("rds: tcp: use sock_create_lite() to create the accept socket")
Signed-off-by: NKa-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2018-02-28

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Add schedule points and reduce the number of loop iterations
   the test_bpf kernel module is performing in order to not hog
   the CPU for too long, from Eric.

2) Fix an out of bounds access in tail calls in the ppc64 BPF
   JIT compiler, from Daniel.

3) Fix a crash on arm64 on unaligned BPF xadd operations that
   could be triggered via interpreter and JIT, from Daniel.

Please not that once you merge net into net-next at some point, there
is a minor merge conflict in test_verifier.c since test cases had
been added at the end in both trees. Resolution is trivial: keep all
the test cases from both trees.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If ethtool_ops->get_fecparam returns an error, pass that error on to the
 user, rather than ignoring it.

Fixes: 1a5f3da2 ("net: ethtool: add support for forward error correction modes")
Signed-off-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When ip_error() is called the device is the l3mdev master instead of the
original device. So the forwarding check should be on the original one.

Changes from v2:
- Handle the original device disappearing (per David Ahern)
- Minimize the change in code order

Changes from v1:
- Only need to reset the device on which __in_dev_get_rcu() is done (per
  David Ahern).
Signed-off-by: NStephen Suryaputra <ssuryaextr@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Setting an interface into a VRF fails with 'RTNETLINK answers: File
exists' if one of its VLAN interfaces is already in the same VRF.
As the VRF is an upper device of the VLAN interface, it is also showing
up as an upper device of the interface itself. The solution is to
restrict this check to devices other than master. As only one master
device can be linked to a device, the check in this case is that the
upper device (VRF) being linked to is not the same as the master device
instead of it not being any one of the upper devices.

The following example shows an interface ens12 (with a VLAN interface
ens12.10) being set into VRF green, which behaves as expected:

  # ip link add link ens12 ens12.10 type vlan id 10
  # ip link set dev ens12 master vrfgreen
  # ip link show dev ens12
    3: ens12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel
       master vrfgreen state UP mode DEFAULT group default qlen 1000
       link/ether 52:54:00:4c:a0:45 brd ff:ff:ff:ff:ff:ff

But if the VLAN interface has previously been set into the same VRF,
then setting the interface into the VRF fails:

  # ip link set dev ens12 nomaster
  # ip link set dev ens12.10 master vrfgreen
  # ip link show dev ens12.10
    39: ens12.10@ens12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500
    qdisc noqueue master vrfgreen state UP mode DEFAULT group default
    qlen 1000 link/ether 52:54:00:4c:a0:45 brd ff:ff:ff:ff:ff:ff
  # ip link set dev ens12 master vrfgreen
    RTNETLINK answers: File exists

The workaround is to move the VLAN interface back into the default VRF
beforehand, but it has to be shut first so as to avoid the risk of
traffic leaking from the VRF. This fix avoids needing this workaround.
Signed-off-by: NMike Manning <mmanning@att.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The newly introudced ip_min_valid_pmtu variable is only used when
CONFIG_SYSCTL is set:

net/ipv4/route.c:135:12: error: 'ip_min_valid_pmtu' defined but not used [-Werror=unused-variable]

This moves it to the other variables like it, to avoid the harmless
warning.

Fixes: c7272c2f ("net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The IPS_NAT_MASK check in 4.12 replaced previous check for nfct_nat()
which was needed to fix a crash in 2.6.36-rc, see
commit 7bcbf81a ("ipvs: avoid oops for passive FTP").
But as IPVS does not set the IPS_SRC_NAT and IPS_DST_NAT bits,
checking for IPS_NAT_MASK prevents PASV response to be properly
mangled and blocks the transfer. Remove the check as it is not
needed after 3.12 commit 41d73ec0 ("netfilter: nf_conntrack:
make sequence number adjustments usuable without NAT") which
changes nfct_nat() with nfct_seqadj() and especially after 3.13
commit b25adce1 ("ipvs: correct usage/allocation of seqadj
ext in ipvs").

Thanks to Li Shuang and Florian Westphal for reporting the problem!
Reported-by: NLi Shuang <shuali@redhat.com>
Fixes: be7be6e1 ("netfilter: ipvs: fix incorrect conflict resolution")
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Jiri Pirko says:

====================
mlxsw: couple of fixes

Couple of unrelated fixes for mlxsw.

---
v1->v2:
-patch 2:
 - rebase on top of current -net tree
 - removed forgotten empty line
-patch 3:
 - new patch
-patch 4:
 - new patch
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

One of the basic construct in the device is a port-VLAN pair, which can
be bound to a FID or a RIF in order to direct packets to the bridge or
the router, respectively.

Since not all the netdevs are configured with a VLAN (e.g., sw1p1 vs.
sw1p1.10), VID 1 is used to represent these and thus this VID can be
used by both upper devices of mlxsw ports and by the driver itself.

However, this VID is not reference counted and therefore might be freed
prematurely, which can result in various WARNINGs. For example:

$ ip link add name br0 type bridge vlan_filtering 1
$ teamd -t team0 -d -c '{"runner": {"name": "lacp"}}'
$ ip link set dev team0 master br0
$ ip link set dev enp1s0np1 master team0
$ ip address add 192.0.2.1/24 dev enp1s0np1

The enslavement to team0 will fail because team0 already has an upper
and thus vlan_vids_del_by_dev() will be executed as part of team's error
path which will delete VID 1 from enp1s0np1 (added by br0 as PVID). The
WARNING will be generated when the driver will realize it can't find VID
1 on the port and bind it to a RIF.

Fix this by adding a reference count to the VLAN entries on the port, in
a similar fashion to the reference counting used by the corresponding
'vlan_vid_info' structure in the 8021q driver.

Fixes: c57529e1 ("mlxsw: spectrum: Replace vPorts with Port-VLAN")
Reported-by: NTal Bar <talb@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Tested-by: NTal Bar <talb@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When multicast snooping is enabled, the Linux bridge resorts to flooding
unregistered multicast packets to all ports only in case it did not
detect a querier in the network.

The above condition is not reflected to underlying drivers, which is
especially problematic in IPv6 environments, as multicast snooping is
enabled by default and since neighbour solicitation packets might be
treated as unregistered multicast packets in case there is no
corresponding MDB entry.

Until the Linux bridge reflects its querier state to underlying drivers,
simply treat unregistered multicast packets as broadcast and allow them
to reach their destination.

Fixes: 9df552ef ("mlxsw: spectrum: Improve IPv6 unregistered multicast flooding")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current code uses global variables, adjusts them and passes pointer down
to devlink. With every other mlxsw_core instance, the previously passed
pointer values are rewritten. Fix this by de-globalize the variables and
also memcpy size_params during devlink resource registration.
Also, introduce a convenient size_param_init helper.

Fixes: ef3116e5 ("mlxsw: spectrum: Register KVD resources with devlink")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IP_TTL, IP_ECN and IP_DSCP are using the same offset within the
scratchpad as L4 ports. Fix this by shifting all up.

Fixes: 5f57e090 ("mlxsw: acl: Add ip ttl acl element")
Fixes: i80d0fe47 ("mlxsw: acl: Add ip tos acl element")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ursula Braun says:

====================
net/smc: fixes 2018-02-28

here are 3 smc bug fixes for the net-tree. Karsten's first patch is
the reworked version of last week's
   "[PATCH net-next 2/5] net/smc: fix structure size"
patch, now solved without using __packed, and now targetted for net
instead of net-next.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

when sock_create_kern(..., a) returns an error, 'a' might not be a valid
pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and
and a->sk->sk_rcvbuf; not doing that caused the following crash:

general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ #18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410
RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746
RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020
RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0
FS:  0000000001afb880(0000) GS:ffff8801db200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  __sock_create+0x4d4/0x850 net/socket.c:1285
  sock_create net/socket.c:1325 [inline]
  SYSC_socketpair net/socket.c:1409 [inline]
  SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366
  do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x26/0x9b
RIP: 0033:0x4404b9
RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b
RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031
R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000
Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48
b8
00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02
00
0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00
RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8

Fixes: cd6851f3 smc: remote memory buffers (RMBs)
Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The CONFIRM LINK reply message must contain the link_id sent
by the server. And set the link_id explicitly when
initializing the link.
Signed-off-by: NKarsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The sizeof(struct smc_cdc_msg) evaluates to 48 bytes instead of the
required 44 bytes. We need to use the constant value of
SMC_WR_TX_SIZE to set and check the control message length.
Signed-off-by: NKarsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We try to disable NAPI to prevent a single XDP TX queue being used by
multiple cpus. But we don't check if device is up (NAPI is enabled),
this could result stall because of infinite wait in
napi_disable(). Fixing this by checking device state through
netif_running() before.

Fixes: 4941d472 ("virtio-net: do not reset during XDP set")
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The link to the pdf containing the algorithm description is now a
dead link; it seems http://www.ifp.illinois.edu/~srikant/ has been
moved to https://sites.google.com/a/illinois.edu/srikant/ and none of
the original papers can be found there...

I have replaced it with the only working copy I was able to find.

n.b. there is also a copy available at:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.296.6350&rep=rep1&type=pdf

However, this seems to only be a *cached* version, so I am unsure
exactly how reliable that link can be expected to remain over time
and have decided against using that one.
Signed-off-by: NJoey Pabalinas <joeypabalinas@gmail.com>

 1 file changed, 1 insertion(+), 1 deletion(-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For tests that are using the maximal number of BPF instruction, each
run takes 20 usec. Looping 10,000 times on them totals 200 ms, which
is bad when the loop is not preemptible.

test_bpf: #264 BPF_MAXINSNS: Call heavy transformations jited:1 19248
18548 PASS
test_bpf: #269 BPF_MAXINSNS: ld_abs+get_processor_id jited:1 20896 PASS

Lets divide by ten the number of iterations, so that max latency is
20ms. We could use need_resched() to break the loop earlier if we
believe 20 ms is too much.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

When the connection is reset, there is no point in
keeping the packets on the write queue until the connection
is closed.

RFC 793 (page 70) and RFC 793-bis (page 64) both suggest
purging the write queue upon RST:
https://tools.ietf.org/html/draft-ietf-tcpm-rfc793bis-07

Moreover, this is essential for a correct MSG_ZEROCOPY
implementation, because userspace cannot call close(fd)
before receiving zerocopy signals even when the connection
is reset.

Fixes: f214f915 ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: NSoheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Yuchung Cheng says:

====================
tcp: revert a F-RTO extension due to broken middle-boxes

This patch series reverts a (non-standard) TCP F-RTO extension that aimed
to detect more spurious timeouts. Unfortunately it could result in poor
performance due to broken middle-boxes that modify TCP packets. E.g.
https://www.spinics.net/lists/netdev/msg484154.html
We believe the best and simplest solution is to just revert the change.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 89fe18e4.

While the patch could detect more spurious timeouts, it could cause
poor TCP performance on broken middle-boxes that modifies TCP packets
(e.g. receive window, SACK options). Since the performance gain is
much smaller compared to the potential loss. The best solution is
to fully revert the change.

Fixes: 89fe18e4 ("tcp: extend F-RTO to catch more spurious timeouts")
Reported-by: NTeodor Milkov <tm@del.bg>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit cc663f4d. While fixing
some broken middle-boxes that modifies receive window fields, it does not
address middle-boxes that strip off SACK options. The best solution is
to fully revert this patch and the root F-RTO enhancement.

Fixes: cc663f4d ("tcp: restrict F-RTO to work-around broken middle-boxes")
Reported-by: NTeodor Milkov <tm@del.bg>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Julian Wiedmann says:

====================
s390/qeth: fixes 2018-02-27

please apply some more qeth patches for -net and stable.

One patch fixes a performance bug in the TSO path. Then there's several
more fixes for IP management on L3 devices - including a revert, so that
the subsequent fix cleanly applies to earlier kernels.
The final patch takes care of a race in the control IO code that causes
qeth to miss the cmd response, and subsequently trigger device recovery.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If multiple IPA commands are build & sent out concurrently,
fill_ipacmd_header() may assign a seqno value to a command that's
different from what send_control_data() later assigns to this command's
reply.
This is due to other commands passing through send_control_data(),
and incrementing card->seqno.ipa along the way.

So one IPA command has no reply that's waiting for its seqno, while some
other IPA command has multiple reply objects waiting for it.
Only one of those waiting replies wins, and the other(s) times out and
triggers a recovery via send_ipa_cmd().

Fix this by making sure that the same seqno value is assigned to
a command and its reply object.
Do so immediately before submitting the command & while holding the
irq_pending "lock", to produce nicely ascending seqnos.

As a side effect, *all* IPA commands now use a reply object that's
waiting for its actual seqno. Previously, early IPA commands that were
submitted while the card was still DOWN used the "catch-all" IDX seqno.
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current code ("qeth_l3_ip_from_hash()") matches a queried address object
against objects in the IP table by IP address, Mask/Prefix Length and
MAC address ("qeth_l3_ipaddrs_is_equal()"). But what callers actually
require is either
a) "is this IP address registered" (ie. match by IP address only),
before adding a new address.
b) or "is this address object registered" (ie. match all relevant
   attributes), before deleting an address.

Right now
1. the ADD path is too strict in its lookup, and eg. doesn't detect
conflicts between an existing NORMAL address and a new VIPA address
(because the NORMAL address will have mask != 0, while VIPA has
a mask == 0),
2. the DELETE path is not strict enough, and eg. allows del_rxip() to
delete a VIPA address as long as the IP address matches.

Fix all this by adding helpers (_addr_match_ip() and _addr_match_all())
that do the appropriate checking.

Note that the ADD path for NORMAL addresses is special, as qeth keeps
track of how many times such an address is in use (and there is no
immediate way of returning errors to the caller). So when a requested
NORMAL address _fully_ matches an existing one, it's not considered a
conflict and we merely increment the refcount.

Fixes: 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit cb816192.

The issue this attempted to fix never actually occurs.
l3_add_rxip() checks (via l3_ip_from_hash()) if the requested address
was previously added to the card. If so, it returns -EEXIST and doesn't
call l3_add_ip().
As a result, the "address exists" path in l3_add_ip() is never taken
for rxip addresses, and this patch had no effect.

Fixes: cb816192 ("s390/qeth: fix using of ref counter for rxip addresses")
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Registering an IPv4 address with the HW takes quite a while, so we
temporarily drop the ip_htable lock. Any concurrent add/remove of the
same IP adjusts the IP's use count, and (on remove) is then blocked by
addr->in_progress.
After the register call has completed, we check the use count for
concurrently attempted add/remove calls - and possibly straight-away
deregister the IP again. This happens via l3_delete_ip(), which
1) looks up the queried IP in the htable (getting a reference to the
   *same* queried object),
2) deregisters the IP from the HW, and
3) frees the IP object.

The caller in l3_add_ip() then does a second free on the same object.

For this case, skip all the extra checks and lookups in l3_delete_ip()
and just deregister & free the IP object ourselves.

Fixes: 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the HW is not reachable, then none of the IPs in qeth's internal
table has been registered with the HW yet. So when deleting such an IP,
there's no need to stage it for deregistration - just drop it from
the table.

This fixes the "add-delete-add" scenario on an offline card, where the
the second "add" merely increments the IP's use count. But as the IP is
still set to DISP_ADDR_DELETE from the previous "delete" step,
l3_recover_ip() won't register it with the HW when the card goes online.

Fixes: 5f78e29c ("qeth: optimize IP handling in rx_mode callback")
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth_get_elements_for_range() doesn't know how to handle a 0-length
range (ie. start == end), and returns 1 when it should return 0.
Such ranges occur on TSO skbs, where the L2/L3/L4 headers (and thus all
of the skb's linear data) are skipped when mapping the skb into regular
buffer elements.

This overestimation may cause several performance-related issues:
1. sub-optimal IO buffer selection, where the next buffer gets selected
   even though the skb would actually still fit into the current buffer.
2. forced linearization, if the element count for a non-linear skb
   exceeds QETH_MAX_BUFFER_ELEMENTS.

Rather than modifying qeth_get_elements_for_range() and adding overhead
to every caller, fix up those callers that are in risk of passing a
0-length range.

Fixes: 2863c613 ("qeth: refactor calculation of SBALE count")
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't include in the Rx bytecount of the packet sent up the stack:
the FCB (frame control block), and the padding bytes inserted by
the controller into the frame payload, nor the FCS. All these are
being pulled out of the skb by gfar_process_frame().
This issue is old, likely from the driver's beginnings, however
it was amplified by recent:
commit d903ec77 ("gianfar: simplify FCS handling and fix memory leak")
which basically added the FCS to the Rx bytecount, and so brought
this to my attention.
Signed-off-by: NClaudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>