linux.git/net/ipv4, branch v4.20-rc4

tcp: defer SACK compression after DupThresh

2018-11-21T23:49:52+00:00

Jean-Louis reported a TCP regression and bisected to recent SACK
compression.

After a loss episode (receiver not able to keep up and dropping
packets because its backlog is full), linux TCP stack is sending
a single SACK (DUPACK).

Sender waits a full RTO timer before recovering losses.

While RFC 6675 says in section 5, "Algorithm Details",

   (2) If DupAcks < DupThresh but IsLost (HighACK + 1) returns true --
       indicating at least three segments have arrived above the current
       cumulative acknowledgment point, which is taken to indicate loss
       -- go to step (4).
...
   (4) Invoke fast retransmit and enter loss recovery as follows:

there are old TCP stacks not implementing this strategy, and
still counting the dupacks before starting fast retransmit.

While these stacks probably perform poorly when receivers implement
LRO/GRO, we should be a little more gentle to them.

This patch makes sure we do not enable SACK compression unless
3 dupacks have been sent since last rcv_nxt update.

Ideally we should even rearm the timer to send one or two
more DUPACK if no more packets are coming, but that will
be work aiming for linux-4.21.

Many thanks to Jean-Louis for bisecting the issue, providing
packet captures and testing this patch.

Fixes: 5d9f4262b7ea ("tcp: add SACK compression")
Reported-by: Jean-Louis Dupond 
Tested-by: Jean-Louis Dupond 
Signed-off-by: Eric Dumazet 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller

tcp: Fix SOF_TIMESTAMPING_RX_HARDWARE to use the latest timestamp during TCP coalescing

2018-11-20T18:32:11+00:00

During tcp coalescing ensure that the skb hardware timestamp refers to the
highest sequence number data.
Previously only the software timestamp was updated during coalescing.

Signed-off-by: Stephen Mallon 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip_tunnel: don't force DF when MTU is locked

2018-11-18T05:50:55+00:00

The various types of tunnels running over IPv4 can ask to set the DF
bit to do PMTU discovery. However, PMTU discovery is subject to the
threshold set by the net.ipv4.route.min_pmtu sysctl, and is also
disabled on routes with "mtu lock". In those cases, we shouldn't set
the DF bit.

This patch makes setting the DF bit conditional on the route's MTU
locking state.

This issue seems to be older than git history.

Signed-off-by: Sabrina Dubroca 
Reviewed-by: Stefano Brivio 
Signed-off-by: David S. Miller

inet: frags: better deal with smp races

2018-11-09T02:40:30+00:00

Multiple cpus might attempt to insert a new fragment in rhashtable,
if for example RPS is buggy, as reported by 배석진 in
https://patchwork.ozlabs.org/patch/994601/

We use rhashtable_lookup_get_insert_key() instead of
rhashtable_insert_fast() to let cpus losing the race
free their own inet_frag_queue and use the one that
was inserted by another cpu.

Fixes: 648700f76b03 ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Eric Dumazet 
Reported-by: 배석진 
Signed-off-by: David S. Miller

net: bpfilter: fix iptables failure if bpfilter_umh is disabled

2018-11-06T01:12:18+00:00

When iptables command is executed, ip_{set/get}sockopt() try to upload
bpfilter.ko if bpfilter is enabled. if it couldn't find bpfilter.ko,
command is failed.
bpfilter.ko is generated if CONFIG_BPFILTER_UMH is enabled.
ip_{set/get}sockopt() only checks CONFIG_BPFILTER.
So that if CONFIG_BPFILTER is enabled and CONFIG_BPFILTER_UMH is disabled,
iptables command is always failed.

test config:
   CONFIG_BPFILTER=y
   # CONFIG_BPFILTER_UMH is not set

test command:
   %iptables -L
   iptables: No chain/target/match by that name.

Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module")
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller

net: drop skb on failure in ip_check_defrag()

2018-11-01T20:55:30+00:00

Most callers of pskb_trim_rcsum() simply drop the skb when
it fails, however, ip_check_defrag() still continues to pass
the skb up to stack. This is suspicious.

In ip_check_defrag(), after we learn the skb is an IP fragment,
passing the skb to callers makes no sense, because callers expect
fragments are defrag'ed on success. So, dropping the skb when we
can't defrag it is reasonable.

Note, prior to commit 88078d98d1bb, this is not a big problem as
checksum will be fixed up anyway. After it, the checksum is not
correct on failure.

Found this during code review.

Fixes: 88078d98d1bb ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
Cc: Eric Dumazet 
Signed-off-by: Cong Wang 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2018-11-01T16:16:01+00:00

Pull networking fixes from David Miller:

 1) BPF verifier fixes from Daniel Borkmann.

 2) HNS driver fixes from Huazhong Tan.

 3) FDB only works for ethernet devices, reject attempts to install FDB
    rules for others. From Ido Schimmel.

 4) Fix spectre V1 in vhost, from Jason Wang.

 5) Don't pass on-stack object to irq_set_affinity_hint() in mvpp2
    driver, from Marc Zyngier.

 6) Fix mlx5e checksum handling when RXFCS is enabled, from Eric
    Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (49 commits)
  openvswitch: Fix push/pop ethernet validation
  net: stmmac: Fix stmmac_mdio_reset() when building stmmac as modules
  bpf: test make sure to run unpriv test cases in test_verifier
  bpf: add various test cases to test_verifier
  bpf: don't set id on after map lookup with ptr_to_map_val return
  bpf: fix partial copy of map_ptr when dst is scalar
  libbpf: Fix compile error in libbpf_attach_type_by_name
  kselftests/bpf: use ping6 as the default ipv6 ping binary if it exists
  selftests: mlxsw: qos_mc_aware: Add a test for UC awareness
  selftests: mlxsw: qos_mc_aware: Tweak for min shaper
  mlxsw: spectrum: Set minimum shaper on MC TCs
  mlxsw: reg: QEEC: Add minimum shaper fields
  net: hns3: bugfix for rtnl_lock's range in the hclgevf_reset()
  net: hns3: bugfix for rtnl_lock's range in the hclge_reset()
  net: hns3: bugfix for handling mailbox while the command queue reinitialized
  net: hns3: fix incorrect return value/type of some functions
  net: hns3: bugfix for hclge_mdio_write and hclge_mdio_read
  net: hns3: bugfix for is_valid_csq_clean_head()
  net: hns3: remove unnecessary queue reset in the hns3_uninit_all_ring()
  net: hns3: bugfix for the initialization of command queue's spin lock
  ...

mm: remove include/linux/bootmem.h

2018-10-31T15:54:16+00:00

Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include 

@@
@@
- #include 
+ #include 

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
  Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
  Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport 
Signed-off-by: Stephen Rothwell 
Acked-by: Michal Hocko 
Cc: Catalin Marinas 
Cc: Chris Zankel 
Cc: "David S. Miller" 
Cc: Geert Uytterhoeven 
Cc: Greentime Hu 
Cc: Greg Kroah-Hartman 
Cc: Guan Xuetao 
Cc: Ingo Molnar 
Cc: "James E.J. Bottomley" 
Cc: Jonas Bonn 
Cc: Jonathan Corbet 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Martin Schwidefsky 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Burton 
Cc: Richard Kuo 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Serge Semin 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vineet Gupta 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

bpf: tcp_bpf_recvmsg should return EAGAIN when nonblocking and no data

2018-10-30T22:31:22+00:00

We return 0 in the case of a nonblocking socket that has no data
available. However, this is incorrect and may confuse applications.
After this patch we do the correct thing and return the error
EAGAIN.

Quoting return codes from recvmsg manpage,

EAGAIN or EWOULDBLOCK
 The socket is marked nonblocking and the receive operation would
 block, or a receive timeout had been set and the timeout expired
 before data was received.

Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend 
Acked-by: Song Liu 
Signed-off-by: Daniel Borkmann

ipv4/igmp: fix v1/v2 switchback timeout based on rfc3376, 8.12

2018-10-30T03:26:06+00:00

Similiar with ipv6 mcast commit 89225d1ce6af3 ("net: ipv6: mld: fix v1/v2
switchback timeout to rfc3810, 9.12.")

i) RFC3376 8.12. Older Version Querier Present Timeout says:

   The Older Version Querier Interval is the time-out for transitioning
   a host back to IGMPv3 mode once an older version query is heard.
   When an older version query is received, hosts set their Older
   Version Querier Present Timer to Older Version Querier Interval.

   This value MUST be ((the Robustness Variable) times (the Query
   Interval in the last Query received)) plus (one Query Response
   Interval).

Currently we only use a hardcode value IGMP_V1/v2_ROUTER_PRESENT_TIMEOUT.
Fix it by adding two new items mr_qi(Query Interval) and mr_qri(Query Response
Interval) in struct in_device.

Now we can calculate the switchback time via (mr_qrv * mr_qi) + mr_qri.
We need update these values when receive IGMPv3 queries.

Reported-by: Ying Xu 
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller