Commit Graph

6225 Commits

Author SHA1 Message Date
Florian Westphal
55d8694fa8 net: tcp: assign tcp cong_ops when tcp sk is created
Split assignment and initialization from one into two functions.

This is required by followup patches that add Datacenter TCP
(DCTCP) congestion control algorithm - we need to be able to
determine if the connection is moderated by DCTCP before the
3WHS has finished.

As we walk the available congestion control list during the
assignment, we are always guaranteed to have Reno present as
it's fixed compiled-in. Therefore, since we're doing the
early assignment, we don't have a real use for the Reno alias
tcp_init_congestion_ops anymore and can thus remove it.

Actual usage of the congestion control operations are being
made after the 3WHS has finished, in some cases however we
can access get_info() via diag if implemented, therefore we
need to zero out the private area for those modules.

Joint work with Daniel Borkmann and Glenn Judd.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29 00:13:10 -04:00
Rick Jones
825bae5d97 arp: Do not perturb drop profiles with ignored ARP packets
We do not wish to disturb dropwatch or perf drop profiles with an ARP
we will ignore.

Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 17:30:35 -04:00
David S. Miller
f5c7e1a47a Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2014-09-25

1) Remove useless hash_resize_mutex in xfrm_hash_resize().
   This mutex is used only there, but xfrm_hash_resize()
   can't be called concurrently at all. From Ying Xue.

2) Extend policy hashing to prefixed policies based on
   prefix lenght thresholds. From Christophe Gouault.

3) Make the policy hash table thresholds configurable
   via netlink. From Christophe Gouault.

4) Remove the maximum authentication length for AH.
   This was needed to limit stack usage. We switched
   already to allocate space, so no need to keep the
   limit. From Herbert Xu.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 17:19:15 -04:00
WANG Cong
2c1a4311b6 neigh: check error pointer instead of NULL for ipv4_neigh_lookup()
Fixes: commit f187bc6efb ("ipv4: No need to set generic neighbour pointer")
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 17:16:04 -04:00
Peter Pan(潘卫平)
155c6e1ad4 tcp: use tcp_flags in tcp_data_queue()
This patch is a cleanup which follows the idea in commit e11ecddf51 (tcp: use
TCP_SKB_CB(skb)->tcp_flags in input path),
and it may reduce register pressure since skb->cb[] access is fast,
bacause skb is probably in a register.

v2: remove variable th
v3: reword the changelog

Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 16:37:57 -04:00
Eric Dumazet
cd7d8498c9 tcp: change tcp_skb_pcount() location
Our goal is to access no more than one cache line access per skb in
a write or receive queue when doing the various walks.

After recent TCP_SKB_CB() reorganizations, it is almost done.

Last part is tcp_skb_pcount() which currently uses
skb_shinfo(skb)->gso_segs, which is a terrible choice, because it needs
3 cache lines in current kernel (skb->head, skb->end, and
shinfo->gso_segs are all in 3 different cache lines, far from skb->cb)

This very simple patch reuses space currently taken by tcp_tw_isn
only in input path, as tcp_skb_pcount is only needed for skb stored in
write queue.

This considerably speeds up tcp_ack(), granted we avoid shinfo->tx_flags
to get SKBTX_ACK_TSTAMP, which seems possible.

This also speeds up all sack processing in general.

This speeds up tcp_sendmsg() because it no longer has to access/dirty
shinfo.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 16:36:48 -04:00
Eric Dumazet
971f10eca1 tcp: better TCP_SKB_CB layout to reduce cache line misses
TCP maintains lists of skb in write queue, and in receive queues
(in order and out of order queues)

Scanning these lists both in input and output path usually requires
access to skb->next, TCP_SKB_CB(skb)->seq, and TCP_SKB_CB(skb)->end_seq

These fields are currently in two different cache lines, meaning we
waste lot of memory bandwidth when these queues are big and flows
have either packet drops or packet reorders.

We can move TCP_SKB_CB(skb)->header at the end of TCP_SKB_CB, because
this header is not used in fast path. This allows TCP to search much faster
in the skb lists.

Even with regular flows, we save one cache line miss in fast path.

Thanks to Christoph Paasch for noticing we need to cleanup
skb->cb[] (IPCB/IP6CB) before entering IP stack in tx path,
and that I forgot IPCB use in tcp_v4_hnd_req() and tcp_v4_save_options().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 16:35:43 -04:00
Eric Dumazet
24a2d43d88 ipv4: rename ip_options_echo to __ip_options_echo()
ip_options_echo() assumes struct ip_options is provided in &IPCB(skb)->opt
Lets break this assumption, but provide a helper to not change all call points.

ip_send_unicast_reply() gets a new struct ip_options pointer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-28 16:35:42 -04:00
Dan Williams
3f33407856 net: make tcp_cleanup_rbuf private
net_dma was the only external user so this can become local to tcp.c
again.

Cc: James Morris <jmorris@namei.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-09-28 07:22:21 -07:00
Dan Williams
d27f9bc104 net_dma: revert 'copied_early'
Now that tcp_dma_try_early_copy() is gone nothing ever sets
copied_early.

Also reverts "53240c208776 tcp: Fix possible double-ack w/ user dma"
since it is no longer necessary.

Cc: Ali Saidi <saidi@engin.umich.edu>
Cc: James Morris <jmorris@namei.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Neal Cardwell <ncardwell@google.com>
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-09-28 07:22:21 -07:00
Dan Williams
7bced39751 net_dma: simple removal
Per commit "77873803363c net_dma: mark broken" net_dma is no longer used
and there is no plan to fix it.

This is the mechanical removal of bits in CONFIG_NET_DMA ifdef guards.
Reverting the remainder of the net_dma induced changes is deferred to
subsequent patches.

Marked for stable due to Roman's report of a memory leak in
dma_pin_iovec_pages():

    https://lkml.org/lkml/2014/9/3/177

Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: David Whipple <whipple@securedatainnovations.ch>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: <stable@vger.kernel.org>
Reported-by: Roman Gushchin <klamm@yandex-team.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2014-09-28 07:05:16 -07:00
Eric Dumazet
f4a775d144 net: introduce __skb_header_release()
While profiling TCP stack, I noticed one useless atomic operation
in tcp_sendmsg(), caused by skb_header_release().

It turns out all current skb_header_release() users have a fresh skb,
that no other user can see, so we can avoid one atomic operation.

Introduce __skb_header_release() to clearly document this.

This gave me a 1.5 % improvement on TCP_RR workload.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 15:40:06 -04:00
Steffen Klassert
d61746b2e7 ip_tunnel: Don't allow to add the same tunnel multiple times.
When we try to add an already existing tunnel, we don't return
an error. Instead we continue and call ip_tunnel_update().
This means that we can change existing tunnels by adding
the same tunnel multiple times. It is even possible to change
the tunnel endpoints of the fallback device.

We fix this by returning an error if we try to add an existing
tunnel.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 00:41:30 -04:00
Tom Herbert
53e5039896 net: Remove gso_send_check as an offload callback
The send_check logic was only interesting in cases of TCP offload and
UDP UFO where the checksum needed to be initialized to the pseudo
header checksum. Now we've moved that logic into the related
gso_segment functions so gso_send_check is no longer needed.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 00:22:47 -04:00
Tom Herbert
f71470b37e udp: move logic out of udp[46]_ufo_send_check
In udp[46]_ufo_send_check the UDP checksum initialized to the pseudo
header checksum. We can move this logic into udp[46]_ufo_fragment.
After this change udp[64]_ufo_send_check is a no-op.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 00:22:46 -04:00
Tom Herbert
d020f8f733 tcp: move logic out of tcp_v[64]_gso_send_check
In tcp_v[46]_gso_send_check the TCP checksum is initialized to the
pseudo header checksum using __tcp_v[46]_send_check. We can move this
logic into new tcp[46]_gso_segment functions to be done when
ip_summed != CHECKSUM_PARTIAL (ip_summed == CHECKSUM_PARTIAL should be
the common case, possibly always true when taking GSO path). After this
change tcp_v[46]_gso_send_check is no-op.

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26 00:22:46 -04:00
Tejun Heo
d06efebf0c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block into for-3.18
This is to receive 0a30288da1 ("blk-mq, percpu_ref: implement a
kludge for SCSI blk-mq stall during probe") which implements
__percpu_ref_kill_expedited() to work around SCSI blk-mq stall.  The
commit reverted and patches to implement proper fix will be added.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
2014-09-24 13:00:21 -04:00
Eric Dumazet
bd1e75abf4 tcp: add coalescing attempt in tcp_ofo_queue()
In order to make TCP more resilient in presence of reorders, we need
to allow coalescing to happen when skbs from out of order queue are
transferred into receive queue. LRO/GRO can be completely canceled
in some pathological cases, like per packet load balancing on aggregated
links.

I had to move tcp_try_coalesce() up in the file above tcp_ofo_queue()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23 12:47:38 -04:00
Eric Dumazet
4cdf507d54 icmp: add a global rate limitation
Current ICMP rate limiting uses inetpeer cache, which is an RBL tree
protected by a lock, meaning that hosts can be stuck hard if all cpus
want to check ICMP limits.

When say a DNS or NTP server process is restarted, inetpeer tree grows
quick and machine comes to its knees.

iptables can not help because the bottleneck happens before ICMP
messages are even cooked and sent.

This patch adds a new global limitation, using a token bucket filter,
controlled by two new sysctl :

icmp_msgs_per_sec - INTEGER
    Limit maximal number of ICMP packets sent per second from this host.
    Only messages whose type matches icmp_ratemask are
    controlled by this limit.
    Default: 1000

icmp_msgs_burst - INTEGER
    icmp_msgs_per_sec controls number of ICMP packets sent per second,
    while icmp_msgs_burst controls the burst size of these packets.
    Default: 50

Note that if we really want to send millions of ICMP messages per
second, we might extend idea and infra added in commit 04ca6973f7
("ip: make IP identifiers less predictable") :
add a token bucket in the ip_idents hash and no longer rely on inetpeer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23 12:47:38 -04:00
David S. Miller
1f6d80358d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	arch/mips/net/bpf_jit.c
	drivers/net/can/flexcan.c

Both the flexcan and MIPS bpf_jit conflicts were cases of simple
overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23 12:09:27 -04:00
Eric Dumazet
a35165ca10 ipv4: do not use this_cpu_ptr() in preemptible context
this_cpu_ptr() in preemptible context is generally bad

Sep 22 05:05:55 br kernel: [   94.608310] BUG: using smp_processor_id()
in
preemptible [00000000] code: ip/2261
Sep 22 05:05:55 br kernel: [   94.608316] caller is
tunnel_dst_set.isra.28+0x20/0x60 [ip_tunnel]
Sep 22 05:05:55 br kernel: [   94.608319] CPU: 3 PID: 2261 Comm: ip Not
tainted
3.17.0-rc5 #82

We can simply use raw_cpu_ptr(), as preemption is safe in these
contexts.

Should fix https://bugzilla.kernel.org/show_bug.cgi?id=84991

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Joe <joe9mail@gmail.com>
Fixes: 9a4aa9af44 ("ipv4: Use percpu Cache route in IP tunnels")
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-22 18:31:18 -04:00
Eric Dumazet
fcdd1cf4dd tcp: avoid possible arithmetic overflows
icsk_rto is a 32bit field, and icsk_backoff can reach 15 by default,
or more if some sysctl (eg tcp_retries2) are changed.

Better use 64bit to perform icsk_rto << icsk_backoff operations

As Joe Perches suggested, add a helper for this.

Yuchung spotted the tcp_v4_err() case.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-22 16:27:10 -04:00
Tom Herbert
4565e9919c gre: Setup and TX path for gre/UDP foo-over-udp encapsulation
Added netlink attrs to configure FOU encapsulation for GRE, netlink
handling of these flags, and properly adjust MTU for encapsulation.
ip_tunnel_encap is called from ip_tunnel_xmit to actually perform FOU
encapsulation.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 17:15:32 -04:00
Tom Herbert
473ab820dd ipip: Setup and TX path for ipip/UDP foo-over-udp encapsulation
Add netlink handling for IP tunnel encapsulation parameters and
and adjustment of MTU for encapsulation.  ip_tunnel_encap is called
from ip_tunnel_xmit to actually perform FOU encapsulation.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 17:15:32 -04:00
Tom Herbert
5632848653 net: Changes to ip_tunnel to support foo-over-udp encapsulation
This patch changes IP tunnel to support (secondary) encapsulation,
Foo-over-UDP. Changes include:

1) Adding tun_hlen as the tunnel header length, encap_hlen as the
   encapsulation header length, and hlen becomes the grand total
   of these.
2) Added common netlink define to support FOU encapsulation.
3) Routines to perform FOU encapsulation.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 17:15:32 -04:00
Tom Herbert
afe93325bc fou: Add GRO support
Implement fou_gro_receive and fou_gro_complete, and populate these
in the correponsing udp_offloads for the socket. Added ipproto to
udp_offloads and pass this from UDP to the fou GRO routine in proto
field of napi_gro_cb structure.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 17:15:31 -04:00
Tom Herbert
23461551c0 fou: Support for foo-over-udp RX path
This patch provides a receive path for foo-over-udp. This allows
direct encapsulation of IP protocols over UDP. The bound destination
port is used to map to an IP protocol, and the XFRM framework
(udp_encap_rcv) is used to receive encapsulated packets. Upon
reception, the encapsulation header is logically removed (pointer
to transport header is advanced) and the packet is reinjected into
the receive path with the IP protocol indicated by the mapping.

Netlink is used to configure FOU ports. The configuration information
includes the port number to bind to and the IP protocol corresponding
to that port.

This should support GRE/UDP
(http://tools.ietf.org/html/draft-yong-tsvwg-gre-in-udp-encap-02),
as will as the other IP tunneling protocols (IPIP, SIT).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 17:15:31 -04:00
Tom Herbert
ce3e02867e net: Export inet_offloads and inet6_offloads
Want to be able to use these in foo-over-udp offloads, etc.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 17:15:31 -04:00
Eric Dumazet
cb93471acc tcp: do not fake tcp headers in tcp_send_rcvq()
Now we no longer rely on having tcp headers for skbs in receive queue,
tcp repair do not need to build fake ones.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 16:04:13 -04:00
Andy Zhou
6a93cc9052 udp-tunnel: Add a few more UDP tunnel APIs
Added a few more UDP tunnel APIs that can be shared by UDP based
tunnel protocol implementation. The main ones are highlighted below.

setup_udp_tunnel_sock() configures UDP listener socket for
receiving UDP encapsulated packets.

udp_tunnel_xmit_skb() and upd_tunnel6_xmit_skb() transmit skb
using UDP encapsulation.

udp_tunnel_sock_release() closes the UDP tunnel listener socket.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 15:57:15 -04:00
Andy Zhou
fd384412e1 udp_tunnel: Seperate ipv6 functions into its own file.
Add ip6_udp_tunnel.c for ipv6 UDP tunnel functions to avoid ifdefs
in udp_tunnel.c

Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19 15:57:15 -04:00
Herbert Xu
689f1c9de2 ipsec: Remove obsolete MAX_AH_AUTH_LEN
While tracking down the MAX_AH_AUTH_LEN crash in an old kernel
I thought that this limit was rather arbitrary and we should
just get rid of it.

In fact it seems that we've already done all the work needed
to remove it apart from actually removing it.  This limit was
there in order to limit stack usage.  Since we've already
switched over to allocating scratch space using kmalloc, there
is no longer any need to limit the authentication length.

This patch kills all references to it, including the BUG_ONs
that led me here.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-09-18 10:54:36 +02:00
Steffen Klassert
f92ee61982 xfrm: Generate blackhole routes only from route lookup functions
Currently we genarate a blackhole route route whenever we have
matching policies but can not resolve the states. Here we assume
that dst_output() is called to kill the balckholed packets.
Unfortunately this assumption is not true in all cases, so
it is possible that these packets leave the system unwanted.

We fix this by generating blackhole routes only from the
route lookup functions, here we can guarantee a call to
dst_output() afterwards.

Fixes: 2774c131b1 ("xfrm: Handle blackhole route creation via afinfo.")
Reported-by: Konstantinos Kolelis <k.kolelis@sirrix.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-09-16 10:08:40 +02:00
Eric Dumazet
b3d6cb92fd tcp: do not copy headers in tcp_collapse()
tcp_collapse() wants to shrink skb so that the overhead is minimal.

Now we store tcp flags into TCP_SKB_CB(skb)->tcp_flags, we no longer
need to keep around full headers.
Whole available space is dedicated to the payload.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15 14:41:08 -04:00
Eric Dumazet
e93a0435f8 tcp: allow segment with FIN in tcp_try_coalesce()
We can allow a segment with FIN to be aggregated,
if we take care to add tcp flags,
and if skb_try_coalesce() takes care of zero sized skbs.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15 14:41:07 -04:00
Eric Dumazet
e11ecddf51 tcp: use TCP_SKB_CB(skb)->tcp_flags in input path
Input path of TCP do not currently uses TCP_SKB_CB(skb)->tcp_flags,
which is only used in output path.

tcp_recvmsg(), looks at tcp_hdr(skb)->syn for every skb found in receive queue,
and its unfortunate because this bit is located in a cache line right before
the payload.

We can simplify TCP by copying tcp flags into TCP_SKB_CB(skb)->tcp_flags.

This patch does so, and avoids the cache line miss in tcp_recvmsg()

Following patches will
- allow a segment with FIN being coalesced in tcp_try_coalesce()
- simplify tcp_collapse() by not copying the headers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15 14:41:07 -04:00
Scott Wood
2d8f7e2c8a udp: Fix inverted NAPI_GRO_CB(skb)->flush test
Commit 2abb7cdc0d ("udp: Add support for doing checksum unnecessary
conversion") caused napi_gro_cb structs with the "flush" field zero to
take the "udp_gro_receive" path rather than the "set flush to 1" path
that they would previously take.  As a result I saw booting from an NFS
root hang shortly after starting userspace, with "server not
responding" messages.

This change to the handling of "flush == 0" packets appears to be
incidental to the goal of adding new code in the case where
skb_gro_checksum_validate_zero_check() returns zero.  Based on that and
the fact that it breaks things, I'm assuming that it is unintentional.

Fixes: 2abb7cdc0d ("udp: Add support for doing checksum unnecessary conversion")
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-12 17:55:41 -04:00
Pablo Neira Ayuso
0bbe80e571 netfilter: masquerading needs to be independent of x_tables in Kconfig
Users are starting to test nf_tables with no x_tables support. Therefore,
masquerading needs to be indenpendent of it from Kconfig.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-12 09:40:18 +02:00
Pablo Neira Ayuso
3e8dc212a0 netfilter: NFT_CHAIN_NAT_IPV* is independent of NFT_NAT
Now that we have masquerading support in nf_tables, the NAT chain can
be use with it, not only for SNAT/DNAT. So make this chain type
independent of it.

While at it, move it inside the scope of 'if NF_NAT_IPV*' to simplify
dependencies.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-12 09:40:17 +02:00
David S. Miller
0aac383353 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
nf-next pull request

The following patchset contains Netfilter/IPVS updates for your
net-next tree. Regarding nf_tables, most updates focus on consolidating
the NAT infrastructure and adding support for masquerading. More
specifically, they are:

1) use __u8 instead of u_int8_t in arptables header, from
   Mike Frysinger.

2) Add support to match by skb->pkttype to the meta expression, from
   Ana Rey.

3) Add support to match by cpu to the meta expression, also from
   Ana Rey.

4) A smatch warning about IPSET_ATTR_MARKMASK validation, patch from
   Vytas Dauksa.

5) Fix netnet and netportnet hash types the range support for IPv4,
   from Sergey Popovich.

6) Fix missing-field-initializer warnings resolved, from Mark Rustad.

7) Dan Carperter reported possible integer overflows in ipset, from
   Jozsef Kadlecsick.

8) Filter out accounting objects in nfacct by type, so you can
   selectively reset quotas, from Alexey Perevalov.

9) Move specific NAT IPv4 functions to the core so x_tables and
   nf_tables can share the same NAT IPv4 engine.

10) Use the new NAT IPv4 functions from nft_chain_nat_ipv4.

11) Move specific NAT IPv6 functions to the core so x_tables and
    nf_tables can share the same NAT IPv4 engine.

12) Use the new NAT IPv6 functions from nft_chain_nat_ipv6.

13) Refactor code to add nft_delrule(), which can be reused in the
    enhancement of the NFT_MSG_DELTABLE to remove a table and its
    content, from Arturo Borrero.

14) Add a helper function to unregister chain hooks, from
    Arturo Borrero.

15) A cleanup to rename to nft_delrule_by_chain for consistency with
    the new nft_*() functions, also from Arturo.

16) Add support to match devgroup to the meta expression, from Ana Rey.

17) Reduce stack usage for IPVS socket option, from Julian Anastasov.

18) Remove unnecessary textsearch state initialization in xt_string,
    from Bojan Prtvar.

19) Add several helper functions to nf_tables, more work to prepare
    the enhancement of NFT_MSG_DELTABLE, again from Arturo Borrero.

20) Enhance NFT_MSG_DELTABLE to delete a table and its content, from
    Arturo Borrero.

21) Support NAT flags in the nat expression to indicate the flavour,
    eg. random fully, from Arturo.

22) Add missing audit code to ebtables when replacing tables, from
    Nicolas Dichtel.

23) Generalize the IPv4 masquerading code to allow its re-use from
    nf_tables, from Arturo.

24) Generalize the IPv6 masquerading code, also from Arturo.

25) Add the new masq expression to support IPv4/IPv6 masquerading
    from nf_tables, also from Arturo.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-10 12:46:32 -07:00
Tom Herbert
9667e9bb3f ipip: Add gro callbacks to ipip offload
Add inet_gro_receive and inet_gro_complete to ipip_offload to
support GRO.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 21:29:33 -07:00
Eric Dumazet
72bb17b37b ipv4: udp4_gro_complete() is static
net/ipv4/udp_offload.c:339:5: warning: symbol 'udp4_gro_complete' was
not declared. Should it be static?

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Fixes: 57c67ff4bd ("udp: additional GRO support")
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 20:10:45 -07:00
Eric Dumazet
8e380f004e ipv4: rcu cleanup in ip_ra_control()
Remove one sparse warning :
net/ipv4/ip_sockglue.c:328:22: warning: incorrect type in assignment (different address spaces)
net/ipv4/ip_sockglue.c:328:22:    expected struct ip_ra_chain [noderef] <asn:4>*next
net/ipv4/ip_sockglue.c:328:22:    got struct ip_ra_chain *[assigned] ra

And replace one rcu_assign_ptr() by RCU_INIT_POINTER() where applicable.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 20:10:44 -07:00
Eric Dumazet
ca777eff51 tcp: remove dst refcount false sharing for prequeue mode
Alexander Duyck reported high false sharing on dst refcount in tcp stack
when prequeue is used. prequeue is the mechanism used when a thread is
blocked in recvmsg()/read() on a TCP socket, using a blocking model
rather than select()/poll()/epoll() non blocking one.

We already try to use RCU in input path as much as possible, but we were
forced to take a refcount on the dst when skb escaped RCU protected
region. When/if the user thread runs on different cpu, dst_release()
will then touch dst refcount again.

Commit 093162553c (tcp: force a dst refcount when prequeue packet)
was an example of a race fix.

It turns out the only remaining usage of skb->dst for a packet stored
in a TCP socket prequeue is IP early demux.

We can add a logic to detect when IP early demux is probably going
to use skb->dst. Because we do an optimistic check rather than duplicate
existing logic, we need to guard inet_sk_rx_dst_set() and
inet6_sk_rx_dst_set() from using a NULL dst.

Many thanks to Alexander for providing a nice bug report, git bisection,
and reproducer.

Tested using Alexander script on a 40Gb NIC, 8 RX queues.
Hosts have 24 cores, 48 hyper threads.

echo 0 >/proc/sys/net/ipv4/tcp_autocorking

for i in `seq 0 47`
do
  for j in `seq 0 2`
  do
     netperf -H $DEST -t TCP_STREAM -l 1000 \
             -c -C -T $i,$i -P 0 -- \
             -m 64 -s 64K -D &
  done
done

Before patch : ~6Mpps and ~95% cpu usage on receiver
After patch : ~9Mpps and ~35% cpu usage on receiver.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 16:54:41 -07:00
Vincent Bernat
49a601589c net/ipv4: bind ip_nonlocal_bind to current netns
net.ipv4.ip_nonlocal_bind sysctl was global to all network
namespaces. This patch allows to set a different value for each
network namespace.

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 11:27:09 -07:00
Arturo Borrero
9ba1f726be netfilter: nf_tables: add new nft_masq expression
The nft_masq expression is intended to perform NAT in the masquerade flavour.

We decided to have the masquerade functionality in a separated expression other
than nft_nat.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-09 16:31:30 +02:00
Arturo Borrero
8dd33cc93e netfilter: nf_nat: generalize IPv4 masquerading support for nf_tables
Let's refactor the code so we can reach the masquerade functionality
from outside the xt context (ie. nftables).

The patch includes the addition of an atomic counter to the masquerade
notifier: the stuff to be done by the notifier is the same for xt and
nftables. Therefore, only one notification handler is needed.

This factorization only involves IPv4; a similar patch follows to
handle IPv6.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-09 16:31:29 +02:00
Willem de Bruijn
a7f26b7e1e inet: remove dead inetpeer sequence code
inetpeer sequence numbers are no longer incremented, so no need to
check and flush the tree. The function that increments the sequence
number was already dead code and removed in in "ipv4: remove unused
function" (068a6e18). Remove the code that checks for a change, too.

Verifying that v4_seq and v6_seq are never incremented and thus that
flush_check compares bp->flush_seq to 0 is trivial.

The second part of the change removes flush_check completely even
though bp->flush_seq is exactly !0 once, at initialization. This
change is correct because the time this branch is true is when
bp->root == peer_avl_empty_rcu, in which the branch and
inetpeer_invalidate_tree are a NOOP.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-08 16:42:42 -07:00
Tom Herbert
1e701f1698 net: Fix GRE RX to use skb_transport_header for GRE header offset
GRE assumes that the GRE header is at skb_network_header +
ip_hrdlen(skb). It is more general to use skb_transport_header
and this allows the possbility of inserting additional header
between IP and GRE (which is what we will done in Generic UDP
Encapsulation for GRE).

Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-08 15:23:05 -07:00
David S. Miller
eb84d6b604 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-09-07 21:41:53 -07:00
Tejun Heo
908c7f1949 percpu_counter: add @gfp to percpu_counter_init()
Percpu allocator now supports allocation mask.  Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.

We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion.  This is the one with
the most users.  Other percpu data structures are a lot easier to
convert.

This patch doesn't make any functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
2014-09-08 09:51:29 +09:00
Neal Cardwell
87d943085b tcp: remove obsolete comment about TCP_SKB_CB(skb)->when in tcp_fragment()
The TCP_SKB_CB(skb)->when field no longer exists as of recent change
7faee5c0d5 ("tcp: remove TCP_SKB_CB(skb)->when"). And in any case,
tcp_fragment() is called on already-transmitted packets from the
__tcp_retransmit_skb() call site, so copying timestamps of any kind
in this spot is quite sensible.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reported-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-06 12:29:10 -07:00
Eric Dumazet
7faee5c0d5 tcp: remove TCP_SKB_CB(skb)->when
After commit 740b0f1841 ("tcp: switch rtt estimations to usec resolution"),
we no longer need to maintain timestamps in two different fields.

TCP_SKB_CB(skb)->when can be removed, as same information sits in skb_mstamp.stamp_jiffies

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:49:33 -07:00
Eric Dumazet
04317dafd1 tcp: introduce TCP_SKB_CB(skb)->tcp_tw_isn
TCP_SKB_CB(skb)->when has different meaning in output and input paths.

In output path, it contains a timestamp.
In input path, it contains an ISN, chosen by tcp_timewait_state_process()

Lets add a different name to ease code comprehension.

Note that 'when' field will disappear in following patch,
as skb_mstamp already contains timestamp, the anonymous
union will promptly disappear as well.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:49:33 -07:00
Alexander Duyck
82eabd9eb2 net: merge cases where sock_efree and sock_edemux are the same function
Since sock_efree and sock_demux are essentially the same code for non-TCP
sockets and the case where CONFIG_INET is not defined we can combine the
code or replace the call to sock_edemux in several spots.  As a result we
can avoid a bit of unnecessary code or code duplication.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:43:45 -07:00
Eric Dumazet
d546c62154 ipv4: harden fnhe_hashfun()
Lets make this hash function a bit secure, as ICMP attacks are still
in the wild.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:40:33 -07:00
Eric Dumazet
caa415270c ipv4: fix a race in update_or_create_fnhe()
nh_exceptions is effectively used under rcu, but lacks proper
barriers. Between kzalloc() and setting of nh->nh_exceptions(),
we need a proper memory barrier.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:15:50 -07:00
Hannes Frederic Sowa
a9fe8e2994 ipv4: implement igmp_qrv sysctl to tune igmp robustness variable
As in IPv6 people might increase the igmp query robustness variable to
make sure unsolicited state change reports aren't lost on the network. Add
and document this new knob to igmp code.

RFCs allow tuning this parameter back to first IGMP RFC, so we also use
this setting for all counters, including source specific multicast.

Also take over sysctl value when upping the interface and don't reuse
the last one seen on the interface.

Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-04 22:26:14 -07:00
Pablo Neira Ayuso
65cd90ac76 netfilter: nft_chain_nat_ipv4: use generic IPv4 NAT code from core
Use the exported IPv4 NAT functions that are provided by the core. This
removes duplicated code so iptables and nft use the same NAT codebase.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-02 17:14:11 +02:00
Pablo Neira Ayuso
30766f4c2d netfilter: nat: move specific NAT IPv4 to core
Move the specific NAT IPv4 core functions that are called from the
hooks from iptable_nat.c to nf_nat_l3proto_ipv4.c. This prepares the
ground to allow iptables and nft to use the same NAT engine code that
comes in a follow up patch.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-02 17:14:10 +02:00
Willem de Bruijn
364a9e9324 sock: deduplicate errqueue dequeue
sk->sk_error_queue is dequeued in four locations. All share the
exact same logic. Deduplicate.

Also collapse the two critical sections for dequeue (at the top of
the recv handler) and signal (at the bottom).

This moves signal generation for the next packet forward, which should
be harmless.

It also changes the behavior if the recv handler exits early with an
error. Previously, a signal for follow-up packets on the errqueue
would then not be scheduled. The new behavior, to always signal, is
arguably a bug fix.

For rxrpc, the change causes the same function to be called repeatedly
for each queued packet (because the recv handler == sk_error_report).
It is likely that all packets will fail for the same reason (e.g.,
memory exhaustion).

This code runs without sk_lock held, so it is not safe to trust that
sk->sk_err is immutable inbetween releasing q->lock and the subsequent
test. Introduce int err just to avoid this potential race.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-01 21:49:08 -07:00
Tom Herbert
884d338c04 gre: Add support for checksum unnecessary conversions
Call skb_checksum_try_convert and skb_gro_checksum_try_convert
after checksum is found present and validated in the GRE header
for normal and GRO paths respectively.

In GRO path, call skb_gro_checksum_try_convert

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-01 21:36:28 -07:00
Tom Herbert
2abb7cdc0d udp: Add support for doing checksum unnecessary conversion
Add support for doing CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE
conversion in UDP tunneling path.

In the normal UDP path, we call skb_checksum_try_convert after locating
the UDP socket. The check is that checksum conversion is enabled for
the socket (new flag in UDP socket) and that checksum field is
non-zero.

In the UDP GRO path, we call skb_gro_checksum_try_convert after
checksum is validated and checksum field is non-zero. Since this is
already in GRO we assume that checksum conversion is always wanted.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-01 21:36:28 -07:00
stephen hemminger
688d1945bc tcp: whitespace fixes
Fix places where there is space before tab, long lines, and
awkward if(){, double spacing etc. Add blank line after declaration/initialization.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-01 18:12:45 -07:00
Tom Herbert
662880f442 net: Allow GRO to use and set levels of checksum unnecessary
Allow GRO path to "consume" checksums provided in CHECKSUM_UNNECESSARY
and to report new checksums verfied for use in fallback to normal
path.

Change GRO checksum path to track csum_level using a csum_cnt field
in NAPI_GRO_CB. On GRO initialization, if ip_summed is
CHECKSUM_UNNECESSARY set NAPI_GRO_CB(skb)->csum_cnt to
skb->csum_level + 1. For each checksum verified, decrement
NAPI_GRO_CB(skb)->csum_cnt while its greater than zero. If a checksum
is verfied and NAPI_GRO_CB(skb)->csum_cnt == 0, we have verified a
deeper checksum than originally indicated in skbuf so increment
csum_level (or initialize to CHECKSUM_UNNECESSARY if ip_summed is
CHECKSUM_NONE or CHECKSUM_COMPLETE).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-29 20:41:11 -07:00
Tom Herbert
77cffe23c1 net: Clarification of CHECKSUM_UNNECESSARY
This patch:
 - Clarifies the specific requirements of devices returning
   CHECKSUM_UNNECESSARY (comments in skbuff.h).
 - Adds csum_level field to skbuff. This is used to express how
   many checksums are covered by CHECKSUM_UNNECESSARY (stores n - 1).
   This replaces the overloading of skb->encapsulation, that field is
   is now only used to indicate inner headers are valid.
 - Change __skb_checksum_validate_needed to "consume" each checksum
   as indicated by csum_level as layers of the the packet are parsed.
 - Remove skb_pop_rcv_encapsulation, no longer needed in the new
   csum_level model.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-29 20:41:11 -07:00
Florian Westphal
253ff51635 tcp: syncookies: mark cookie_secret read_mostly
only written once.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-27 16:30:49 -07:00
Christoph Lameter
903ceff7ca net: Replace get_cpu_var through this_cpu_ptr
Replace uses of get_cpu_var for address calculation through this_cpu_ptr.

Cc: netdev@vger.kernel.org
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:47 -04:00
Tom Herbert
48a5fc7731 gre: When GRE csum is present count as encap layer wrt csum
In GRE demux if the GRE checksum pop rcv encapsulation so that any
encapsulated checksums are treated as tunnel checksums.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-24 18:09:24 -07:00
Tom Herbert
57c67ff4bd udp: additional GRO support
Implement GRO for UDPv6. Add UDP checksum verification in gro_receive
for both UDP4 and UDP6 calling skb_gro_checksum_validate_zero_check.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-24 18:09:24 -07:00
Tom Herbert
149d0774a7 tcp: Call skb_gro_checksum_validate
In tcp[64]_gro_receive call skb_gro_checksum_validate to validate TCP
checksum in the gro context.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-24 18:09:24 -07:00
Tom Herbert
758f75d1ff gre: call skb_gro_checksum_simple_validate
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-24 18:09:23 -07:00
Daniel Borkmann
8fc54f6891 net: use reciprocal_scale() helper
Replace open codings of (((u64) <x> * <y>) >> 32) with reciprocal_scale().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23 12:21:21 -07:00
Yuchung Cheng
989e04c5bc tcp: improve undo on timeout
Upon timeout, undo (via both timestamps/Eifel and DSACKs) was
disabled if any retransmits were still in flight.  The concern was
perhaps that spurious retransmission sent in a previous recovery
episode may trigger DSACKs to falsely undo the current recovery.

However, this inadvertently misses undo opportunities (using either
TCP timestamps or DSACKs) when timeout occurs during a loss episode,
i.e.  recurring timeouts or timeout during fast recovery. In these
cases some retransmissions will be in flight but we should allow
undo. Furthermore, we should only reset undo_marker and undo_retrans
upon timeout if we are starting a new recovery episode. Finally,
when we do reset our undo state, we now do so in a manner similar
to tcp_enter_recovery(), so that we require a DSACK for each of
the outstsanding retransmissions. This will achieve the original
goal by requiring that we receive the same number of DSACKs as
retransmissions.

This patch increases the undo events by 50% on Google servers.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22 21:28:02 -07:00
Himangi Saraogi
c72c95a064 ipconfig: Use time_before
The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.

A simplified version of the Coccinelle semantic patch making this change
is as follows:

@change@
expression E1,E2;
@@
- jiffies - E1 < E2
+ time_before(jiffies, E1+E2)

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22 12:23:11 -07:00
Andreea-Cristina Bernat
e6b688838e net/ipv4/igmp.c: Replace rcu_dereference() with rcu_access_pointer()
The "rcu_dereference()" call is used directly in a condition.
Since its return value is never dereferenced it is recommended to use
"rcu_access_pointer()" instead of "rcu_dereference()".
Therefore, this patch makes the replacement.

The following Coccinelle semantic patch was used:
@@
@@

(
 if(
 (<+...
- rcu_dereference
+ rcu_access_pointer
  (...)
  ...+>)) {...}
|
 while(
 (<+...
- rcu_dereference
+ rcu_access_pointer
  (...)
  ...+>)) {...}
)

Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22 12:23:10 -07:00
Sébastien Barré
1dced6a854 ipv4: Restore accept_local behaviour in fib_validate_source()
Commit 7a9bc9b81a ("ipv4: Elide fib_validate_source() completely when possible.")
introduced a short-circuit to avoid calling fib_validate_source when not
needed. That change took rp_filter into account, but not accept_local.
This resulted in a change of behaviour: with rp_filter and accept_local
off, incoming packets with a local address in the source field should be
dropped.

Here is how to reproduce the change pre/post 7a9bc9b81a commit:
-configure the same IPv4 address on hosts A and B.
-try to send an ARP request from B to A.
-The ARP request will be dropped before that commit, but accepted and answered
after that commit.

This adds a check for ACCEPT_LOCAL, to maintain full
fib validation in case it is 0. We also leave __fib_validate_source() earlier
when possible, based on the same check as fib_validate_source(), once the
accept_local stuff is verified.

Cc: Gregory Detal <gregory.detal@uclouvain.be>
Cc: Christoph Paasch <christoph.paasch@uclouvain.be>
Cc: Hannes Frederic Sowa <hannes@redhat.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Sébastien Barré <sebastien.barre@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22 12:23:10 -07:00
Pablo Neira Ayuso
8993cf8edf netfilter: move NAT Kconfig switches out of the iptables scope
Currently, the NAT configs depend on iptables and ip6tables. However,
users should be capable of enabling NAT for nft without having to
switch on iptables.

Fix this by adding new specific IP_NF_NAT and IP6_NF_NAT config
switches for iptables and ip6tables NAT support. I have also moved
the original NF_NAT_IPV4 and NF_NAT_IPV6 configs out of the scope
of iptables to make them independent of it.

This patch also adds NETFILTER_XT_NAT which selects the xt_nat
combo that provides snat/dnat for iptables. We cannot use NF_NAT
anymore since nf_tables can select this.

Reported-by: Matteo Croce <technoboy85@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-08-18 21:55:54 +02:00
Neal Cardwell
0c9ab09223 tcp: fix ssthresh and undo for consecutive short FRTO episodes
Fix TCP FRTO logic so that it always notices when snd_una advances,
indicating that any RTO after that point will be a new and distinct
loss episode.

Previously there was a very specific sequence that could cause FRTO to
fail to notice a new loss episode had started:

(1) RTO timer fires, enter FRTO and retransmit packet 1 in write queue
(2) receiver ACKs packet 1
(3) FRTO sends 2 more packets
(4) RTO timer fires again (should start a new loss episode)

The problem was in step (3) above, where tcp_process_loss() returned
early (in the spot marked "Step 2.b"), so that it never got to the
logic to clear icsk_retransmits. Thus icsk_retransmits stayed
non-zero. Thus in step (4) tcp_enter_loss() would see the non-zero
icsk_retransmits, decide that this RTO is not a new episode, and
decide not to cut ssthresh and remember the current cwnd and ssthresh
for undo.

There were two main consequences to the bug that we have
observed. First, ssthresh was not decreased in step (4). Second, when
there was a series of such FRTO (1-4) sequences that happened to be
followed by an FRTO undo, we would restore the cwnd and ssthresh from
before the entire series started (instead of the cwnd and ssthresh
from before the most recent RTO). This could result in cwnd and
ssthresh being restored to values much bigger than the proper values.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Fixes: e33099f96d ("tcp: implement RFC5682 F-RTO")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-14 14:38:55 -07:00
Hannes Frederic Sowa
a26552afe8 tcp: don't allow syn packets without timestamps to pass tcp_tw_recycle logic
tcp_tw_recycle heavily relies on tcp timestamps to build a per-host
ordering of incoming connections and teardowns without the need to
hold state on a specific quadruple for TCP_TIMEWAIT_LEN, but only for
the last measured RTO. To do so, we keep the last seen timestamp in a
per-host indexed data structure and verify if the incoming timestamp
in a connection request is strictly greater than the saved one during
last connection teardown. Thus we can verify later on that no old data
packets will be accepted by the new connection.

During moving a socket to time-wait state we already verify if timestamps
where seen on a connection. Only if that was the case we let the
time-wait socket expire after the RTO, otherwise normal TCP_TIMEWAIT_LEN
will be used. But we don't verify this on incoming SYN packets. If a
connection teardown was less than TCP_PAWS_MSL seconds in the past we
cannot guarantee to not accept data packets from an old connection if
no timestamps are present. We should drop this SYN packet. This patch
closes this loophole.

Please note, this patch does not make tcp_tw_recycle in any way more
usable but only adds another safety check:
Sporadic drops of SYN packets because of reordering in the network or
in the socket backlog queues can happen. Users behing NAT trying to
connect to a tcp_tw_recycle enabled server can get caught in blackholes
and their connection requests may regullary get dropped because hosts
behind an address translator don't have synchronized tcp timestamp clocks.
tcp_tw_recycle cannot work if peers don't have tcp timestamps enabled.

In general, use of tcp_tw_recycle is disadvised.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-14 14:38:54 -07:00
Neal Cardwell
4fab907195 tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()
Make sure we use the correct address-family-specific function for
handling MTU reductions from within tcp_release_cb().

Previously AF_INET6 sockets were incorrectly always using the IPv6
code path when sometimes they were handling IPv4 traffic and thus had
an IPv4 dst.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Diagnosed-by: Willem de Bruijn <willemb@google.com>
Fixes: 563d34d057 ("tcp: dont drop MTU reduction indications")
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-14 14:38:54 -07:00
Andrey Vagin
9d186cac7f tcp: don't use timestamp from repaired skb-s to calculate RTT (v2)
We don't know right timestamp for repaired skb-s. Wrong RTT estimations
isn't good, because some congestion modules heavily depends on it.

This patch adds the TCPCB_REPAIRED flag, which is included in
TCPCB_RETRANS.

Thanks to Eric for the advice how to fix this issue.

This patch fixes the warning:
[  879.562947] WARNING: CPU: 0 PID: 2825 at net/ipv4/tcp_input.c:3078 tcp_ack+0x11f5/0x1380()
[  879.567253] CPU: 0 PID: 2825 Comm: socket-tcpbuf-l Not tainted 3.16.0-next-20140811 #1
[  879.567829] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  879.568177]  0000000000000000 00000000c532680c ffff880039643d00 ffffffff817aa2d2
[  879.568776]  0000000000000000 ffff880039643d38 ffffffff8109afbd ffff880039d6ba80
[  879.569386]  ffff88003a449800 000000002983d6bd 0000000000000000 000000002983d6bc
[  879.569982] Call Trace:
[  879.570264]  [<ffffffff817aa2d2>] dump_stack+0x4d/0x66
[  879.570599]  [<ffffffff8109afbd>] warn_slowpath_common+0x7d/0xa0
[  879.570935]  [<ffffffff8109b0ea>] warn_slowpath_null+0x1a/0x20
[  879.571292]  [<ffffffff816d0a05>] tcp_ack+0x11f5/0x1380
[  879.571614]  [<ffffffff816d10bd>] tcp_rcv_established+0x1ed/0x710
[  879.571958]  [<ffffffff816dc9da>] tcp_v4_do_rcv+0x10a/0x370
[  879.572315]  [<ffffffff81657459>] release_sock+0x89/0x1d0
[  879.572642]  [<ffffffff816c81a0>] do_tcp_setsockopt.isra.36+0x120/0x860
[  879.573000]  [<ffffffff8110a52e>] ? rcu_read_lock_held+0x6e/0x80
[  879.573352]  [<ffffffff816c8912>] tcp_setsockopt+0x32/0x40
[  879.573678]  [<ffffffff81654ac4>] sock_common_setsockopt+0x14/0x20
[  879.574031]  [<ffffffff816537b0>] SyS_setsockopt+0x80/0xf0
[  879.574393]  [<ffffffff817b40a9>] system_call_fastpath+0x16/0x1b
[  879.574730] ---[ end trace a17cbc38eb8c5c00 ]---

v2: moving setting of skb->when for repaired skb-s in tcp_write_xmit,
    where it's set for other skb-s.

Fixes: 431a91242d ("tcp: timestamp SYN+DATA messages")
Fixes: 740b0f1841 ("tcp: switch rtt estimations to usec resolution")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-14 14:38:54 -07:00
Willem de Bruijn
490cc7d03c net-timestamp: fix missing tcp fragmentation cases
Bytestream timestamps are correlated with a single byte in the skbuff,
recorded in skb_shinfo(skb)->tskey. When fragmenting skbuffs, ensure
that the tskey is set for the fragment in which the tskey falls
(seqno <= tskey < end_seqno).

The original implementation did not address fragmentation in
tcp_fragment or tso_fragment. Add code to inspect the sequence numbers
and move both tskey and the relevant tx_flags if necessary.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-13 20:06:06 -07:00
Willem de Bruijn
712a72213f net-timestamp: fix missing ACK timestamp
ACK timestamps are generated in tcp_clean_rtx_queue. The TSO datapath
can break out early, causing the timestamp code to be skipped. Move
the code up before the break.

Reported-by: David S. Miller <davem@davemloft.net>

Also fix a boundary condition: tp->snd_una is the next unacknowledged
byte and between tests inclusive (a <= b <= c), so generate a an ACK
timestamp if (prior_snd_una <= tskey <= tp->snd_una - 1).

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-13 20:06:06 -07:00
Niv Yehezkel
b7a71b51ee ipv4: removed redundant conditional
Since fib_lookup cannot return ESRCH no longer,
checking for this error code is no longer neccesary.

Signed-off-by: Niv Yehezkel <executerx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-08 10:22:22 -07:00
Linus Torvalds
33caee3992 Merge branch 'akpm' (patchbomb from Andrew Morton)
Merge incoming from Andrew Morton:
 - Various misc things.
 - arch/sh updates.
 - Part of ocfs2.  Review is slow.
 - Slab updates.
 - Most of -mm.
 - printk updates.
 - lib/ updates.
 - checkpatch updates.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (226 commits)
  checkpatch: update $declaration_macros, add uninitialized_var
  checkpatch: warn on missing spaces in broken up quoted
  checkpatch: fix false positives for --strict "space after cast" test
  checkpatch: fix false positive MISSING_BREAK warnings with --file
  checkpatch: add test for native c90 types in unusual order
  checkpatch: add signed generic types
  checkpatch: add short int to c variable types
  checkpatch: add for_each tests to indentation and brace tests
  checkpatch: fix brace style misuses of else and while
  checkpatch: add --fix option for a couple OPEN_BRACE misuses
  checkpatch: use the correct indentation for which()
  checkpatch: add fix_insert_line and fix_delete_line helpers
  checkpatch: add ability to insert and delete lines to patch/file
  checkpatch: add an index variable for fixed lines
  checkpatch: warn on break after goto or return with same tab indentation
  checkpatch: emit a warning on file add/move/delete
  checkpatch: add test for commit id formatting style in commit log
  checkpatch: emit fewer kmalloc_array/kcalloc conversion warnings
  checkpatch: improve "no space after cast" test
  checkpatch: allow multiple const * types
  ...
2014-08-06 21:14:42 -07:00
Ken Helias
1d023284c3 list: fix order of arguments for hlist_add_after(_rcu)
All other add functions for lists have the new item as first argument
and the position where it is added as second argument.  This was changed
for no good reason in this function and makes using it unnecessary
confusing.

The name was changed to hlist_add_behind() to cause unconverted code to
generate a compile error instead of using the wrong parameter order.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Ken Helias <kenhelias@firemail.de>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>	[intel driver bits]
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:24 -07:00
Dmitry Popov
9ea88a1530 tcp: md5: check md5 signature without socket lock
Since a8afca032 (tcp: md5: protects md5sig_info with RCU) tcp_md5_do_lookup
doesn't require socket lock, rcu_read_lock is enough. Therefore socket lock is
no longer required for tcp_v{4,6}_inbound_md5_hash too, so we can move these
calls (wrapped with rcu_read_{,un}lock) before bh_lock_sock:
from tcp_v{4,6}_do_rcv to tcp_v{4,6}_rcv.

Signed-off-by: Dmitry Popov <ixaphire@qrator.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-06 16:00:20 -07:00
Willem de Bruijn
f066e2b091 net-timestamp: cumulative tcp timestamping fixes
A set of small fixes pointed out just after the merge:
- make tcp_tx_timestamp static
- make tcp_gso_tstamp static
- use before() to compare TCP seqno, instead of cast to u64
- add tstamp to tx_flags in GSO, instead of overwrite tx_flags
- record skb_shinfo(skb)->tskey for all timestamps, also HW.
- optimization in tcp_tx_timestamp:
  call sock_tx_timestamp only if a tstamp option is set.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Fixes: 4ed2d765df ("net-timestamp: TCP timestamping")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-06 14:09:01 -07:00
Linus Torvalds
ae045e2455 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:
 "Highlights:

   1) Steady transitioning of the BPF instructure to a generic spot so
      all kernel subsystems can make use of it, from Alexei Starovoitov.

   2) SFC driver supports busy polling, from Alexandre Rames.

   3) Take advantage of hash table in UDP multicast delivery, from David
      Held.

   4) Lighten locking, in particular by getting rid of the LRU lists, in
      inet frag handling.  From Florian Westphal.

   5) Add support for various RFC6458 control messages in SCTP, from
      Geir Ola Vaagland.

   6) Allow to filter bridge forwarding database dumps by device, from
      Jamal Hadi Salim.

   7) virtio-net also now supports busy polling, from Jason Wang.

   8) Some low level optimization tweaks in pktgen from Jesper Dangaard
      Brouer.

   9) Add support for ipv6 address generation modes, so that userland
      can have some input into the process.  From Jiri Pirko.

  10) Consolidate common TCP connection request code in ipv4 and ipv6,
      from Octavian Purdila.

  11) New ARP packet logger in netfilter, from Pablo Neira Ayuso.

  12) Generic resizable RCU hash table, with intial users in netlink and
      nftables.  From Thomas Graf.

  13) Maintain a name assignment type so that userspace can see where a
      network device name came from (enumerated by kernel, assigned
      explicitly by userspace, etc.) From Tom Gundersen.

  14) Automatic flow label generation on transmit in ipv6, from Tom
      Herbert.

  15) New packet timestamping facilities from Willem de Bruijn, meant to
      assist in measuring latencies going into/out-of the packet
      scheduler, latency from TCP data transmission to ACK, etc"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1536 commits)
  cxgb4 : Disable recursive mailbox commands when enabling vi
  net: reduce USB network driver config options.
  tg3: Modify tg3_tso_bug() to handle multiple TX rings
  amd-xgbe: Perform phy connect/disconnect at dev open/stop
  amd-xgbe: Use dma_set_mask_and_coherent to set DMA mask
  net: sun4i-emac: fix memory leak on bad packet
  sctp: fix possible seqlock seadlock in sctp_packet_transmit()
  Revert "net: phy: Set the driver when registering an MDIO bus device"
  cxgb4vf: Turn off SGE RX/TX Callback Timers and interrupts in PCI shutdown routine
  team: Simplify return path of team_newlink
  bridge: Update outdated comment on promiscuous mode
  net-timestamp: ACK timestamp for bytestreams
  net-timestamp: TCP timestamping
  net-timestamp: SCHED timestamp on entering packet scheduler
  net-timestamp: add key to disambiguate concurrent datagrams
  net-timestamp: move timestamp flags out of sk_flags
  net-timestamp: extend SCM_TIMESTAMPING ancillary data struct
  cxgb4i : Move stray CPL definitions to cxgb4 driver
  tcp: reduce spurious retransmits due to transient SACK reneging
  qlcnic: Initialize dcbnl_ops before register_netdev
  ...
2014-08-06 09:38:14 -07:00
Linus Torvalds
bb2cbf5e93 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "In this release:

   - PKCS#7 parser for the key management subsystem from David Howells
   - appoint Kees Cook as seccomp maintainer
   - bugfixes and general maintenance across the subsystem"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (94 commits)
  X.509: Need to export x509_request_asymmetric_key()
  netlabel: shorter names for the NetLabel catmap funcs/structs
  netlabel: fix the catmap walking functions
  netlabel: fix the horribly broken catmap functions
  netlabel: fix a problem when setting bits below the previously lowest bit
  PKCS#7: X.509 certificate issuer and subject are mandatory fields in the ASN.1
  tpm: simplify code by using %*phN specifier
  tpm: Provide a generic means to override the chip returned timeouts
  tpm: missing tpm_chip_put in tpm_get_random()
  tpm: Properly clean sysfs entries in error path
  tpm: Add missing tpm_do_selftest to ST33 I2C driver
  PKCS#7: Use x509_request_asymmetric_key()
  Revert "selinux: fix the default socket labeling in sock_graft()"
  X.509: x509_request_asymmetric_keys() doesn't need string length arguments
  PKCS#7: fix sparse non static symbol warning
  KEYS: revert encrypted key change
  ima: add support for measuring and appraising firmware
  firmware_class: perform new LSM checks
  security: introduce kernel_fw_from_file hook
  PKCS#7: Missing inclusion of linux/err.h
  ...
2014-08-06 08:06:39 -07:00
David S. Miller
d247b6ab3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/Makefile
	net/ipv6/sysctl_net_ipv6.c

Two ipv6_table_template[] additions overlap, so the index
of the ipv6_table[x] assignments needed to be adjusted.

In the drivers/net/Makefile case, we've gotten rid of the
garbage whereby we had to list every single USB networking
driver in the top-level Makefile, there is just one
"USB_NETWORKING" that guards everything.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-05 18:46:26 -07:00
Willem de Bruijn
e1c8a607b2 net-timestamp: ACK timestamp for bytestreams
Add SOF_TIMESTAMPING_TX_ACK, a request for a tstamp when the last byte
in the send() call is acknowledged. It implements the feature for TCP.

The timestamp is generated when the TCP socket cumulative ACK is moved
beyond the tracked seqno for the first time. The feature ignores SACK
and FACK, because those acknowledge the specific byte, but not
necessarily the entire contents of the buffer up to that byte.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-05 16:35:54 -07:00
Willem de Bruijn
4ed2d765df net-timestamp: TCP timestamping
TCP timestamping extends SO_TIMESTAMPING to bytestreams.

Bytestreams do not have a 1:1 relationship between send() buffers and
network packets. The feature interprets a send call on a bytestream as
a request for a timestamp for the last byte in that send() buffer.

The choice corresponds to a request for a timestamp when all bytes in
the buffer have been sent. That assumption depends on in-order kernel
transmission. This is the common case. That said, it is possible to
construct a traffic shaping tree that would result in reordering.
The guarantee is strong, then, but not ironclad.

This implementation supports send and sendpages (splice). GSO replaces
one large packet with multiple smaller packets. This patch also copies
the option into the correct smaller packet.

This patch does not yet support timestamping on data in an initial TCP
Fast Open SYN, because that takes a very different data path.

If ID generation in ee_data is enabled, bytestream timestamps return a
byte offset, instead of the packet counter for datagrams.

The implementation supports a single timestamp per packet. It silenty
replaces requests for previous timestamps. To avoid missing tstamps,
flush the tcp queue by disabling Nagle, cork and autocork. Missing
tstamps can be detected by offset when the ee_data ID is enabled.

Implementation details:

- On GSO, the timestamping code can be included in the main loop. I
moved it into its own loop to reduce the impact on the common case
to a single branch.

- To avoid leaking the absolute seqno to userspace, the offset
returned in ee_data must always be relative. It is an offset between
an skb and sk field. The first is always set (also for GSO & ACK).
The second must also never be uninitialized. Only allow the ID
option on sockets in the ESTABLISHED state, for which the seqno
is available. Never reset it to zero (instead, move it to the
current seqno when reenabling the option).

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-05 16:35:54 -07:00
Willem de Bruijn
09c2d251b7 net-timestamp: add key to disambiguate concurrent datagrams
Datagrams timestamped on transmission can coexist in the kernel stack
and be reordered in packet scheduling. When reading looped datagrams
from the socket error queue it is not always possible to unique
correlate looped data with original send() call (for application
level retransmits). Even if possible, it may be expensive and complex,
requiring packet inspection.

Introduce a data-independent ID mechanism to associate timestamps with
send calls. Pass an ID alongside the timestamp in field ee_data of
sock_extended_err.

The ID is a simple 32 bit unsigned int that is associated with the
socket and incremented on each send() call for which software tx
timestamp generation is enabled.

The feature is enabled only if SOF_TIMESTAMPING_OPT_ID is set, to
avoid changing ee_data for existing applications that expect it 0.
The counter is reset each time the flag is reenabled. Reenabling
does not change the ID of already submitted data. It is possible
to receive out of order IDs if the timestamp stream is not quiesced
first.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-05 16:35:54 -07:00
Neal Cardwell
5ae344c949 tcp: reduce spurious retransmits due to transient SACK reneging
This commit reduces spurious retransmits due to apparent SACK reneging
by only reacting to SACK reneging that persists for a short delay.

When a sequence space hole at snd_una is filled, some TCP receivers
send a series of ACKs as they apparently scan their out-of-order queue
and cumulatively ACK all the packets that have now been consecutiveyly
received. This is essentially misbehavior B in "Misbehaviors in TCP
SACK generation" ACM SIGCOMM Computer Communication Review, April
2011, so we suspect that this is from several common OSes (Windows
2000, Windows Server 2003, Windows XP). However, this issue has also
been seen in other cases, e.g. the netdev thread "TCP being hoodwinked
into spurious retransmissions by lack of timestamps?" from March 2014,
where the receiver was thought to be a BSD box.

Since snd_una would temporarily be adjacent to a previously SACKed
range in these scenarios, this receiver behavior triggered the Linux
SACK reneging code path in the sender. This led the sender to clear
the SACK scoreboard, enter CA_Loss, and spuriously retransmit
(potentially) every packet from the entire write queue at line rate
just a few milliseconds before the ACK for each packet arrives at the
sender.

To avoid such situations, now when a sender sees apparent reneging it
does not yet retransmit, but rather adjusts the RTO timer to give the
receiver a little time (max(RTT/2, 10ms)) to send us some more ACKs
that will restore sanity to the SACK scoreboard. If the reneging
persists until this RTO then, as before, we clear the SACK scoreboard
and enter CA_Loss.

A 10ms delay tolerates a receiver sending such a stream of ACKs at
56Kbit/sec. And to allow for receivers with slower or more congested
paths, we wait for at least RTT/2.

We validated the resulting max(RTT/2, 10ms) delay formula with a mix
of North American and South American Google web server traffic, and
found that for ACKs displaying transient reneging:

 (1) 90% of inter-ACK delays were less than 10ms
 (2) 99% of inter-ACK delays were less than RTT/2

In tests on Google web servers this commit reduced reneging events by
75%-90% (as measured by the TcpExtTCPSACKReneging counter), without
any measurable impact on latency for user HTTP and SPDY requests.

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-05 16:29:33 -07:00
Dmitry Popov
64a124edcc tcp: md5: remove unneeded check in tcp_v4_parse_md5_keys
tcpm_key is an array inside struct tcp_md5sig, there is no need to check it
against NULL.

Signed-off-by: Dmitry Popov <ixaphire@qrator.net>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-04 15:09:45 -07:00
Linus Torvalds
47dfe4037e Merge branch 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo:
 "Mostly changes to get the v2 interface ready.  The core features are
  mostly ready now and I think it's reasonable to expect to drop the
  devel mask in one or two devel cycles at least for a subset of
  controllers.

   - cgroup added a controller dependency mechanism so that block cgroup
     can depend on memory cgroup.  This will be used to finally support
     IO provisioning on the writeback traffic, which is currently being
     implemented.

   - The v2 interface now uses a separate table so that the interface
     files for the new interface are explicitly declared in one place.
     Each controller will explicitly review and add the files for the
     new interface.

   - cpuset is getting ready for the hierarchical behavior which is in
     the similar style with other controllers so that an ancestor's
     configuration change doesn't change the descendants' configurations
     irreversibly and processes aren't silently migrated when a CPU or
     node goes down.

  All the changes are to the new interface and no behavior changed for
  the multiple hierarchies"

* 'for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (29 commits)
  cpuset: fix the WARN_ON() in update_nodemasks_hier()
  cgroup: initialize cgrp_dfl_root_inhibit_ss_mask from !->dfl_files test
  cgroup: make CFTYPE_ONLY_ON_DFL and CFTYPE_NO_ internal to cgroup core
  cgroup: distinguish the default and legacy hierarchies when handling cftypes
  cgroup: replace cgroup_add_cftypes() with cgroup_add_legacy_cftypes()
  cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes
  cgroup: split cgroup_base_files[] into cgroup_{dfl|legacy}_base_files[]
  cpuset: export effective masks to userspace
  cpuset: allow writing offlined masks to cpuset.cpus/mems
  cpuset: enable onlined cpu/node in effective masks
  cpuset: refactor cpuset_hotplug_update_tasks()
  cpuset: make cs->{cpus, mems}_allowed as user-configured masks
  cpuset: apply cs->effective_{cpus,mems}
  cpuset: initialize top_cpuset's configured masks at mount
  cpuset: use effective cpumask to build sched domains
  cpuset: inherit ancestor's masks if effective_{cpus, mems} becomes empty
  cpuset: update cs->effective_{cpus, mems} when config changes
  cpuset: update cpuset->effective_{cpus,mems} at hotplug
  cpuset: add cs->effective_cpus and cs->effective_mems
  cgroup: clean up sane_behavior handling
  ...
2014-08-04 10:11:28 -07:00
Nikolay Aleksandrov
d4ad4d22e7 inet: frags: use kmem_cache for inet_frag_queue
Use kmem_cache to allocate/free inet_frag_queue objects since they're
all the same size per inet_frags user and are alloced/freed in high volumes
thus making it a perfect case for kmem_cache.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-02 15:31:31 -07:00
Nikolay Aleksandrov
2e404f632f inet: frags: use INET_FRAG_EVICTED to prevent icmp messages
Now that we have INET_FRAG_EVICTED we might as well use it to stop
sending icmp messages in the "frag_expire" functions instead of
stripping INET_FRAG_FIRST_IN from their flags when evicting.
Also fix the comment style in ip6_expire_frag_queue().

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-02 15:31:31 -07:00