Commit Graph

5901 Commits

Author SHA1 Message Date
Ying Cai
e96f2e7c43 ip_tunnel: Set network header properly for IP_ECN_decapsulate()
In ip_tunnel_rcv(), set skb->network_header to inner IP header
before IP_ECN_decapsulate().

Without the fix, IP_ECN_decapsulate() takes outer IP header as
inner IP header, possibly causing error messages or packet drops.

Note that this skb_reset_network_header() call was in this spot when
the original feature for checking consistency of ECN bits through
tunnels was added in eccc1bb8d4 ("tunnel: drop packet if ECN present
with not-ECT"). It was only removed from this spot in 3d7b46cd20
("ip_tunnel: push generic protocol handling to ip_tunnel module.").

Fixes: 3d7b46cd20 ("ip_tunnel: push generic protocol handling to ip_tunnel module.")
Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Ying Cai <ycai@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-05 16:32:17 -04:00
Liu Yu
0cda345d1b tcp_cubic: fix the range of delayed_ack
commit b9f47a3aae (tcp_cubic: limit delayed_ack ratio to prevent
divide error) try to prevent divide error, but there is still a little
chance that delayed_ack can reach zero. In case the param cnt get
negative value, then ratio+cnt would overflow and may happen to be zero.
As a result, min(ratio, ACK_RATIO_LIMIT) will calculate to be zero.

In some old kernels, such as 2.6.32, there is a bug that would
pass negative param, which then ultimately leads to this divide error.

commit 5b35e1e6e9 (tcp: fix tcp_trim_head() to adjust segment count
with skb MSS) fixed the negative param issue. However,
it's safe that we fix the range of delayed_ack as well,
to make sure we do not hit a divide by zero.

CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Liu Yu <allanyuliu@tencent.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-30 16:12:22 -04:00
Eric Dumazet
fc9f350106 tcp: increment retransmit counters in tlp and fast open
Both TLP and Fast Open call __tcp_retransmit_skb() instead of
tcp_retransmit_skb() to avoid changing tp->retrans_out.

This has the side effect of missing SNMP counters increments as well
as tcp_info tcpi_total_retrans updates.

Fix this by moving the stats increments of into __tcp_retransmit_skb()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Nandita Dukkipati <nanditad@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-30 16:12:22 -04:00
Nicolas Dichtel
8c923ce219 ip_tunnel: use the right netns in ioctl handler
Because the netdevice may be in another netns than the i/o netns, we should
use the i/o netns instead of dev_net(dev).

The variable 'tunnel' was used only to get 'itn', hence to simplify code I
remove it and use 't' instead.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-16 15:16:02 -04:00
Cong Wang
0d5edc6873 ipv4, route: pass 0 instead of LOOPBACK_IFINDEX to fib_validate_source()
In my special case, when a packet is redirected from veth0 to lo,
its skb->dev->ifindex would be LOOPBACK_IFINDEX. Meanwhile we
pass the hard-coded LOOPBACK_IFINDEX to fib_validate_source()
in ip_route_input_slow(). This would cause the following check
in fib_validate_source() fail:

            (dev->ifindex != oif || !IN_DEV_TX_REDIRECTS(idev))

when rp_filter is disabeld on loopback. As suggested by Julian,
the caller should pass 0 here so that we will not end up by
calling __fib_validate_source().

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-16 15:05:12 -04:00
Cong Wang
6a662719c9 ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif
As suggested by Julian:

	Simply, flowi4_iif must not contain 0, it does not
	look logical to ignore all ip rules with specified iif.

because in fib_rule_match() we do:

        if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
                goto out;

flowi4_iif should be LOOPBACK_IFINDEX by default.

We need to move LOOPBACK_IFINDEX to include/net/flow.h:

1) It is mostly used by flowi_iif

2) Fix the following compile error if we use it in flow.h
by the patches latter:

In file included from include/linux/netfilter.h:277:0,
                 from include/net/netns/netfilter.h:5,
                 from include/net/net_namespace.h:21,
                 from include/linux/netdevice.h:43,
                 from include/linux/icmpv6.h:12,
                 from include/linux/ipv6.h:61,
                 from include/net/ipv6.h:16,
                 from include/linux/sunrpc/clnt.h:27,
                 from include/linux/nfs_fs.h:30,
                 from init/do_mounts.c:32:
include/net/flow.h: In function ‘flowi4_init_output’:
include/net/flow.h:84:32: error: ‘LOOPBACK_IFINDEX’ undeclared (first use in this function)

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-16 15:05:11 -04:00
Eric Dumazet
aad88724c9 ipv4: add a sock pointer to dst->output() path.
In the dst->output() path for ipv4, the code assumes the skb it has to
transmit is attached to an inet socket, specifically via
ip_mc_output() : The sk_mc_loop() test triggers a WARN_ON() when the
provider of the packet is an AF_PACKET socket.

The dst->output() method gets an additional 'struct sock *sk'
parameter. This needs a cascade of changes so that this parameter can
be propagated from vxlan to final consumer.

Fixes: 8f646c922d ("vxlan: keep original skb ownership")
Reported-by: lucien xin <lucien.xin@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-15 13:47:15 -04:00
Eric Dumazet
b0270e9101 ipv4: add a sock pointer to ip_queue_xmit()
ip_queue_xmit() assumes the skb it has to transmit is attached to an
inet socket. Commit 31c70d5956 ("l2tp: keep original skb ownership")
changed l2tp to not change skb ownership and thus broke this assumption.

One fix is to add a new 'struct sock *sk' parameter to ip_queue_xmit(),
so that we do not assume skb->sk points to the socket used by l2tp
tunnel.

Fixes: 31c70d5956 ("l2tp: keep original skb ownership")
Reported-by: Zhan Jianyu <nasa4836@gmail.com>
Tested-by: Zhan Jianyu <nasa4836@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-15 12:58:34 -04:00
Julian Anastasov
91146153da ipv4: return valid RTA_IIF on ip route get
Extend commit 13378cad02
("ipv4: Change rt->rt_iif encoding.") from 3.6 to return valid
RTA_IIF on 'ip route get ... iif DEVICE' instead of rt_iif 0
which is displayed as 'iif *'.

inet_iif is not appropriate to use because skb_iif is not set.
Use the skb->dev->ifindex instead.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-13 23:23:41 -04:00
Wang, Xiaoming
b04c461902 net: ipv4: current group_info should be put after using.
Plug a group_info refcount leak in ping_init.
group_info is only needed during initialization and
the code failed to release the reference on exit.
While here move grabbing the reference to a place
where it is actually needed.

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Zhang Dongxing <dongxing.zhang@intel.com>
Signed-off-by: xiaoming wang <xiaoming.wang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-13 22:52:58 -04:00
Nicolas Dichtel
8d89dcdf80 vti: don't allow to add the same tunnel twice
Before the patch, it was possible to add two times the same tunnel:
ip l a vti1 type vti remote 10.16.0.121 local 10.16.0.249 key 41
ip l a vti2 type vti remote 10.16.0.121 local 10.16.0.249 key 41

It was possible, because ip_tunnel_newlink() calls ip_tunnel_find() with the
argument dev->type, which was set only later (when calling ndo_init handler
in register_netdevice()). Let's set this type in the setup handler, which is
called before newlink handler.

Introduced by commit b9959fd3b0 ("vti: switch to new ip tunnel code").

CC: Cong Wang <amwang@redhat.com>
CC: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-12 17:03:11 -04:00
Nicolas Dichtel
5a4552752d gre: don't allow to add the same tunnel twice
Before the patch, it was possible to add two times the same tunnel:
ip l a gre1 type gre remote 10.16.0.121 local 10.16.0.249
ip l a gre2 type gre remote 10.16.0.121 local 10.16.0.249

It was possible, because ip_tunnel_newlink() calls ip_tunnel_find() with the
argument dev->type, which was set only later (when calling ndo_init handler
in register_netdevice()). Let's set this type in the setup handler, which is
called before newlink handler.

Introduced by commit c544193214 ("GRE: Refactor GRE tunneling code.").

CC: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-12 17:03:11 -04:00
David S. Miller
676d23690f net: Fix use after free by removing length arg from sk_data_ready callbacks.
Several spots in the kernel perform a sequence like:

	skb_queue_tail(&sk->s_receive_queue, skb);
	sk->sk_data_ready(sk, skb->len);

But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up.  So this skb->len access is potentially
to freed up memory.

Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.

And finally, no actual implementation of this callback actually uses
the length argument.  And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.

So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.

Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-11 16:15:36 -04:00
Linus Torvalds
ce7613db2d Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull more networking updates from David Miller:

 1) If a VXLAN interface is created with no groups, we can crash on
    reception of packets.  Fix from Mike Rapoport.

 2) Missing includes in CPTS driver, from Alexei Starovoitov.

 3) Fix string validations in isdnloop driver, from YOSHIFUJI Hideaki
    and Dan Carpenter.

 4) Missing irq.h include in bnxw2x, enic, and qlcnic drivers.  From
    Josh Boyer.

 5) AF_PACKET transmit doesn't statistically count TX drops, from Daniel
    Borkmann.

 6) Byte-Queue-Limit enabled drivers aren't handled properly in
    AF_PACKET transmit path, also from Daniel Borkmann.

    Same problem exists in pktgen, and Daniel fixed it there too.

 7) Fix resource leaks in driver probe error paths of new sxgbe driver,
    from Francois Romieu.

 8) Truesize of SKBs can gradually get more and more corrupted in NAPI
    packet recycling path, fix from Eric Dumazet.

 9) Fix uniprocessor netfilter build, from Florian Westphal.  In the
    longer term we should perhaps try to find a way for ARRAY_SIZE() to
    work even with zero sized array elements.

10) Fix crash in netfilter conntrack extensions due to mis-estimation of
    required extension space.  From Andrey Vagin.

11) Since we commit table rule updates before trying to copy the
    counters back to userspace (it's the last action we perform), we
    really can't signal the user copy with an error as we are beyond the
    point from which we can unwind everything.  This causes all kinds of
    use after free crashes and other mysterious behavior.

    From Thomas Graf.

12) Restore previous behvaior of div/mod by zero in BPF filter
    processing.  From Daniel Borkmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (38 commits)
  net: sctp: wake up all assocs if sndbuf policy is per socket
  isdnloop: several buffer overflows
  netdev: remove potentially harmful checks
  pktgen: fix xmit test for BQL enabled devices
  net/at91_ether: avoid NULL pointer dereference
  tipc: Let tipc_release() return 0
  at86rf230: fix MAX_CSMA_RETRIES parameter
  mac802154: fix duplicate #include headers
  sxgbe: fix duplicate #include headers
  net: filter: be more defensive on div/mod by X==0
  netfilter: Can't fail and free after table replacement
  xen-netback: Trivial format string fix
  net: bcmgenet: Remove unnecessary version.h inclusion
  net: smc911x: Remove unused local variable
  bonding: Inactive slaves should keep inactive flag's value
  netfilter: nf_tables: fix wrong format in request_module()
  netfilter: nf_tables: set names cannot be larger than 15 bytes
  netfilter: nf_conntrack: reserve two bytes for nf_ct_ext->len
  netfilter: Add {ipt,ip6t}_osf aliases for xt_osf
  netfilter: x_tables: allow to use cgroup match for LOCAL_IN nf hooks
  ...
2014-04-08 12:41:23 -07:00
Christoph Lameter
3ed66e910c net: replace __this_cpu_inc in route.c with raw_cpu_inc
The RT_CACHE_STAT_INC macro triggers the new preemption checks
for __this_cpu ops.

I do not see any other synchronization that would allow the use of a
__this_cpu operation here however in commit dbd2915ce8 ("[IPV4]:
RT_CACHE_STAT_INC() warning fix") Andrew justifies the use of
raw_smp_processor_id() here because "we do not care" about races.  In
the past we agreed that the price of disabling interrupts here to get
consistent counters would be too high.  These counters may be inaccurate
due to race conditions.

The use of __this_cpu op improves the situation already from what commit
dbd2915ce8 did since the single instruction emitted on x86 does not
allow the race to occur anymore.  However, non x86 platforms could still
experience a race here.

Trace:

  __this_cpu_add operation in preemptible [00000000] code: avahi-daemon/1193
  caller is __this_cpu_preempt_check+0x38/0x60
  CPU: 1 PID: 1193 Comm: avahi-daemon Tainted: GF            3.12.0-rc4+ #187
  Call Trace:
    check_preemption_disabled+0xec/0x110
    __this_cpu_preempt_check+0x38/0x60
    __ip_route_output_key+0x575/0x8c0
    ip_route_output_flow+0x27/0x70
    udp_sendmsg+0x825/0xa20
    inet_sendmsg+0x85/0xc0
    sock_sendmsg+0x9c/0xd0
    ___sys_sendmsg+0x37c/0x390
    __sys_sendmsg+0x49/0x90
    SyS_sendmsg+0x12/0x20
    tracesys+0xe1/0xe6

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:14 -07:00
Thomas Graf
c58dd2dd44 netfilter: Can't fail and free after table replacement
All xtables variants suffer from the defect that the copy_to_user()
to copy the counters to user memory may fail after the table has
already been exchanged and thus exposed. Return an error at this
point will result in freeing the already exposed table. Any
subsequent packet processing will result in a kernel panic.

We can't copy the counters before exposing the new tables as we
want provide the counter state after the old table has been
unhooked. Therefore convert this into a silent error.

Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-04-05 17:46:22 +02:00
Linus Torvalds
32d01dc7be Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "A lot updates for cgroup:

   - The biggest one is cgroup's conversion to kernfs.  cgroup took
     after the long abandoned vfs-entangled sysfs implementation and
     made it even more convoluted over time.  cgroup's internal objects
     were fused with vfs objects which also brought in vfs locking and
     object lifetime rules.  Naturally, there are places where vfs rules
     don't fit and nasty hacks, such as credential switching or lock
     dance interleaving inode mutex and cgroup_mutex with object serial
     number comparison thrown in to decide whether the operation is
     actually necessary, needed to be employed.

     After conversion to kernfs, internal object lifetime and locking
     rules are mostly isolated from vfs interactions allowing shedding
     of several nasty hacks and overall simplification.  This will also
     allow implmentation of operations which may affect multiple cgroups
     which weren't possible before as it would have required nesting
     i_mutexes.

   - Various simplifications including dropping of module support,
     easier cgroup name/path handling, simplified cgroup file type
     handling and task_cg_lists optimization.

   - Prepatory changes for the planned unified hierarchy, which is still
     a patchset away from being actually operational.  The dummy
     hierarchy is updated to serve as the default unified hierarchy.
     Controllers which aren't claimed by other hierarchies are
     associated with it, which BTW was what the dummy hierarchy was for
     anyway.

   - Various fixes from Li and others.  This pull request includes some
     patches to add missing slab.h to various subsystems.  This was
     triggered xattr.h include removal from cgroup.h.  cgroup.h
     indirectly got included a lot of files which brought in xattr.h
     which brought in slab.h.

  There are several merge commits - one to pull in kernfs updates
  necessary for converting cgroup (already in upstream through
  driver-core), others for interfering changes in the fixes branch"

* 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (74 commits)
  cgroup: remove useless argument from cgroup_exit()
  cgroup: fix spurious lockdep warning in cgroup_exit()
  cgroup: Use RCU_INIT_POINTER(x, NULL) in cgroup.c
  cgroup: break kernfs active_ref protection in cgroup directory operations
  cgroup: fix cgroup_taskset walking order
  cgroup: implement CFTYPE_ONLY_ON_DFL
  cgroup: make cgrp_dfl_root mountable
  cgroup: drop const from @buffer of cftype->write_string()
  cgroup: rename cgroup_dummy_root and related names
  cgroup: move ->subsys_mask from cgroupfs_root to cgroup
  cgroup: treat cgroup_dummy_root as an equivalent hierarchy during rebinding
  cgroup: remove NULL checks from [pr_cont_]cgroup_{name|path}()
  cgroup: use cgroup_setup_root() to initialize cgroup_dummy_root
  cgroup: reorganize cgroup bootstrapping
  cgroup: relocate setting of CGRP_DEAD
  cpuset: use rcu_read_lock() to protect task_cs()
  cgroup_freezer: document freezer_fork() subtleties
  cgroup: update cgroup_transfer_tasks() to either succeed or fail
  cgroup: drop task_lock() protection around task->cgroups
  cgroup: update how a newly forked task gets associated with css_set
  ...
2014-04-03 13:05:42 -07:00
David S. Miller
64c27237a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/marvell/mvneta.c

The mvneta.c conflict is a case of overlapping changes,
a conversion to devm_ioremap_resource() vs. a conversion
to netdev_alloc_pcpu_stats.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-29 18:48:54 -04:00
Eric Dumazet
e2a1d3e47b tcp: fix get_timewait4_sock() delay computation on 64bit
It seems I missed one change in get_timewait4_sock() to compute
the remaining time before deletion of IPV4 timewait socket.

This could result in wrong output in /proc/net/tcp for tm->when field.

Fixes: 96f817fede ("tcp: shrink tcp6_timewait_sock by one cache line")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-28 16:43:14 -04:00
Eric Dumazet
a0b8486caf tcp: tcp_make_synack() minor changes
There is no need to allocate 15 bytes in excess for a SYNACK packet,
as it contains no data, only headers.

SYNACK are always generated in softirq context, and contain a single
segment, we can use TCP_INC_STATS_BH()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-27 15:10:10 -04:00
Peter Pan(潘卫平)
cc93fc51f3 tcp: delete unused parameter in tcp_nagle_check()
After commit d4589926d7 (tcp: refine TSO splits), tcp_nagle_check() does
not use parameter mss_now anymore.

Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-26 15:43:40 -04:00
Pravin B Shelar
fbd02dd405 ip_tunnel: Fix dst ref-count.
Commit 10ddceb22b (ip_tunnel:multicast process cause panic due
to skb->_skb_refdst NULL pointer) removed dst-drop call from
ip-tunnel-recv.

Following commit reintroduce dst-drop and fix the original bug by
checking loopback packet before releasing dst.
Original bug: https://bugzilla.kernel.org/show_bug.cgi?id=70681

CC: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-26 15:18:40 -04:00
David S. Miller
04f58c8854 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	Documentation/devicetree/bindings/net/micrel-ks8851.txt
	net/core/netpoll.c

The net/core/netpoll.c conflict is a bug fix in 'net' happening
to code which is completely removed in 'net-next'.

In micrel-ks8851.txt we simply have overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-25 20:29:20 -04:00
Li RongQing
0b8c7f6f2a ipv4: remove ip_rt_dump from route.c
ip_rt_dump do nothing after IPv4 route caches removal, so we can remove it.

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-24 12:45:01 -04:00
Li RongQing
4a4eb21fd6 ipv4: remove ipv4_ifdown_dst from route.c
ipv4_ifdown_dst does nothing after IPv4 route caches removal,
so we can remove it.

Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-24 00:18:44 -04:00
Nicolas Dichtel
65886f439a ipmr: fix mfc notification flags
Commit 8cd3ac9f9b ("ipmr: advertise new mfc entries via rtnl") reuses the
function ipmr_fill_mroute() to notify mfc events.
But this function was used only for dump and thus was always setting the
flag NLM_F_MULTI, which is wrong in case of a single notification.

Libraries like libnl will wait forever for NLMSG_DONE.

CC: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-20 16:24:28 -04:00
Daniel Baluta
e35bad5d87 net: remove empty lines from tcp_syn_flood_action
Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-20 16:17:22 -04:00
Tejun Heo
4d3bb511b5 cgroup: drop const from @buffer of cftype->write_string()
cftype->write_string() just passes on the writeable buffer from kernfs
and there's no reason to add const restriction on the buffer.  The
only thing const achieves is unnecessarily complicating parsing of the
buffer.  Drop const from @buffer.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>                                           
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2014-03-19 10:23:54 -04:00
David S. Miller
995dca4ce9 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
One patch to rename a newly introduced struct. The rest is
the rework of the IPsec virtual tunnel interface for ipv6 to
support inter address family tunneling and namespace crossing.

1) Rename the newly introduced struct xfrm_filter to avoid a
   conflict with iproute2. From Nicolas Dichtel.

2) Introduce xfrm_input_afinfo to access the address family
   dependent tunnel callback functions properly.

3) Add and use a IPsec protocol multiplexer for ipv6.

4) Remove dst_entry caching. vti can lookup multiple different
   dst entries, dependent of the configured xfrm states. Therefore
   it does not make to cache a dst_entry.

5) Remove caching of flow informations. vti6 does not use the the
   tunnel endpoint addresses to do route and xfrm lookups.

6) Update the vti6 to use its own receive hook.

7) Remove the now unused xfrm_tunnel_notifier. This was used from vti
   and is replaced by the IPsec protocol multiplexer hooks.

8) Support inter address family tunneling for vti6.

9) Check if the tunnel endpoints of the xfrm state and the vti interface
   are matching and return an error otherwise.

10) Enable namespace crossing for vti devices.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-18 14:09:07 -04:00
David S. Miller
e86e180b82 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for net-next,
most relevantly they are:

* cleanup to remove double semicolon from stephen hemminger.

* calm down sparse warning in xt_ipcomp, from Fan Du.

* nf_ct_labels support for nf_tables, from Florian Westphal.

* new macros to simplify rcu dereferences in the scope of nfnetlink
  and nf_tables, from Patrick McHardy.

* Accept queue and drop (including reason for drop) to verdict
  parsing in nf_tables, also from Patrick.

* Remove unused random seed initialization in nfnetlink_log, from
  Florian Westphal.

* Allow to attach user-specific information to nf_tables rules, useful
  to attach user comments to rule, from me.

* Return errors in ipset according to the manpage documentation, from
  Jozsef Kadlecsik.

* Fix coccinelle warnings related to incorrect bool type usage for ipset,
  from Fengguang Wu.

* Add hash:ip,mark set type to ipset, from Vytas Dauksa.

* Fix message for each spotted by ipset for each netns that is created,
  from Ilia Mirkin.

* Add forceadd option to ipset, which evicts a random entry from the set
  if it becomes full, from Josh Hunt.

* Minor IPVS cleanups and fixes from Andi Kleen and Tingwei Liu.

* Improve conntrack scalability by removing a central spinlock, original
  work from Eric Dumazet. Jesper Dangaard Brouer took them over to address
  remaining issues. Several patches to prepare this change come in first
  place.

* Rework nft_hash to resolve bugs (leaking chain, missing rcu synchronization
  on element removal, etc. from Patrick McHardy.

* Restore context in the rule deletion path, as we now release rule objects
  synchronously, from Patrick McHardy. This gets back event notification for
  anonymous sets.

* Fix NAT family validation in nft_nat, also from Patrick.

* Improve scalability of xt_connlimit by using an array of spinlocks and
  by introducing a rb-tree of hashtables for faster lookup of accounted
  objects per network. This patch was preceded by several patches and
  refactorizations to accomodate this change including the use of kmem_cache,
  from Florian Westphal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-17 15:06:24 -04:00
Eric W. Biederman
57a7744e09 net: Replace u64_stats_fetch_begin_bh to u64_stats_fetch_begin_irq
Replace the bh safe variant with the hard irq safe variant.

We need a hard irq safe variant to deal with netpoll transmitting
packets from hard irq context, and we need it in most if not all of
the places using the bh safe variant.

Except on 32bit uni-processor the code is exactly the same so don't
bother with a bh variant, just have a hard irq safe variant that
everyone can use.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-14 22:41:36 -04:00
David S. Miller
85dcce7a73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/usb/r8152.c
	drivers/net/xen-netback/netback.c

Both the r8152 and netback conflicts were simple overlapping
changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-14 22:31:55 -04:00
Steffen Klassert
2f32b51b60 xfrm: Introduce xfrm_input_afinfo to access the the callbacks properly
IPv6 can be build as a module, so we need mechanism to access
the address family dependent callback functions properly.
Therefore we introduce xfrm_input_afinfo, similar to that
what we have for the address family dependent part of
policies and states.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-03-14 07:28:07 +01:00
Eric Dumazet
c3f9b01849 tcp: tcp_release_cb() should release socket ownership
Lars Persson reported following deadlock :

-000 |M:0x0:0x802B6AF8(asm) <-- arch_spin_lock
-001 |tcp_v4_rcv(skb = 0x8BD527A0) <-- sk = 0x8BE6B2A0
-002 |ip_local_deliver_finish(skb = 0x8BD527A0)
-003 |__netif_receive_skb_core(skb = 0x8BD527A0, ?)
-004 |netif_receive_skb(skb = 0x8BD527A0)
-005 |elk_poll(napi = 0x8C770500, budget = 64)
-006 |net_rx_action(?)
-007 |__do_softirq()
-008 |do_softirq()
-009 |local_bh_enable()
-010 |tcp_rcv_established(sk = 0x8BE6B2A0, skb = 0x87D3A9E0, th = 0x814EBE14, ?)
-011 |tcp_v4_do_rcv(sk = 0x8BE6B2A0, skb = 0x87D3A9E0)
-012 |tcp_delack_timer_handler(sk = 0x8BE6B2A0)
-013 |tcp_release_cb(sk = 0x8BE6B2A0)
-014 |release_sock(sk = 0x8BE6B2A0)
-015 |tcp_sendmsg(?, sk = 0x8BE6B2A0, ?, ?)
-016 |sock_sendmsg(sock = 0x8518C4C0, msg = 0x87D8DAA8, size = 4096)
-017 |kernel_sendmsg(?, ?, ?, ?, size = 4096)
-018 |smb_send_kvec()
-019 |smb_send_rqst(server = 0x87C4D400, rqst = 0x87D8DBA0)
-020 |cifs_call_async()
-021 |cifs_async_writev(wdata = 0x87FD6580)
-022 |cifs_writepages(mapping = 0x852096E4, wbc = 0x87D8DC88)
-023 |__writeback_single_inode(inode = 0x852095D0, wbc = 0x87D8DC88)
-024 |writeback_sb_inodes(sb = 0x87D6D800, wb = 0x87E4A9C0, work = 0x87D8DD88)
-025 |__writeback_inodes_wb(wb = 0x87E4A9C0, work = 0x87D8DD88)
-026 |wb_writeback(wb = 0x87E4A9C0, work = 0x87D8DD88)
-027 |wb_do_writeback(wb = 0x87E4A9C0, force_wait = 0)
-028 |bdi_writeback_workfn(work = 0x87E4A9CC)
-029 |process_one_work(worker = 0x8B045880, work = 0x87E4A9CC)
-030 |worker_thread(__worker = 0x8B045880)
-031 |kthread(_create = 0x87CADD90)
-032 |ret_from_kernel_thread(asm)

Bug occurs because __tcp_checksum_complete_user() enables BH, assuming
it is running from softirq context.

Lars trace involved a NIC without RX checksum support but other points
are problematic as well, like the prequeue stuff.

Problem is triggered by a timer, that found socket being owned by user.

tcp_release_cb() should call tcp_write_timer_handler() or
tcp_delack_timer_handler() in the appropriate context :

BH disabled and socket lock held, but 'owned' field cleared,
as if they were running from timer handlers.

Fixes: 6f458dfb40 ("tcp: improve latencies of timer triggered events")
Reported-by: Lars Persson <lars.persson@axis.com>
Tested-by: Lars Persson <lars.persson@axis.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-11 16:45:59 -04:00
Eric Dumazet
431a91242d tcp: timestamp SYN+DATA messages
All skb in socket write queue should be properly timestamped.

In case of FastOpen, we special case the SYN+DATA 'message' as we
queue in socket wrote queue the two fallback skbs:

1) SYN message by itself.
2) DATA segment by itself.

We should make sure these skbs have proper timestamps.

Add a WARN_ON_ONCE() to eventually catch future violations.

Fixes: 740b0f1841 ("tcp: switch rtt estimations to usec resolution")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-10 16:15:54 -04:00
Eric Dumazet
2196269242 tcp: do not leak non zero tstamp in output packets
Usage of skb->tstamp should remain private to TCP stack
(only set on packets on write queue, not on cloned ones)

Otherwise, packets given to loopback interface with a non null tstamp
can confuse netif_rx() / net_timestamp_check()

Other possibility would be to clear tstamp in loopback_xmit(),
as done in skb_scrub_packet()

Fixes: 740b0f1841 ("tcp: switch rtt estimations to usec resolution")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-07 14:32:57 -05:00
Florian Westphal
e588e2f286 inet: frag: make sure forced eviction removes all frags
Quoting Alexander Aring:
  While fragmentation and unloading of 6lowpan module I got this kernel Oops
  after few seconds:

  BUG: unable to handle kernel paging request at f88bbc30
  [..]
  Modules linked in: ipv6 [last unloaded: 6lowpan]
  Call Trace:
   [<c012af4c>] ? call_timer_fn+0x54/0xb3
   [<c012aef8>] ? process_timeout+0xa/0xa
   [<c012b66b>] run_timer_softirq+0x140/0x15f

Problem is that incomplete frags are still around after unload; when
their frag expire timer fires, we get crash.

When a netns is removed (also done when unloading module), inet_frag
calls the evictor with 'force' argument to purge remaining frags.

The evictor loop terminates when accounted memory ('work') drops to 0
or the lru-list becomes empty.  However, the mem accounting is done
via percpu counters and may not be accurate, i.e. loop may terminate
prematurely.

Alter evictor to only stop once the lru list is empty when force is
requested.

Reported-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Reported-by: Alexander Aring <alex.aring@gmail.com>
Tested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06 15:28:45 -05:00
David S. Miller
f7324acd98 tcp: Use NET_ADD_STATS instead of NET_ADD_STATS_BH in tcp_event_new_data_sent()
Can be invoked from non-BH context.

Based upon a patch by Eric Dumazet.

Fixes: f19c29e3e3 ("tcp: snmp stats for Fast Open, SYN rtx, and data pkts")
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06 15:19:43 -05:00
David S. Miller
67ddc87f16 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/wireless/ath/ath9k/recv.c
	drivers/net/wireless/mwifiex/pcie.c
	net/ipv6/sit.c

The SIT driver conflict consists of a bug fix being done by hand
in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper
was created (netdev_alloc_pcpu_stats()) which takes care of this.

The two wireless conflicts were overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-05 20:32:02 -05:00
Nikolay Aleksandrov
24b9bf43e9 net: fix for a race condition in the inet frag code
I stumbled upon this very serious bug while hunting for another one,
it's a very subtle race condition between inet_frag_evictor,
inet_frag_intern and the IPv4/6 frag_queue and expire functions
(basically the users of inet_frag_kill/inet_frag_put).

What happens is that after a fragment has been added to the hash chain
but before it's been added to the lru_list (inet_frag_lru_add) in
inet_frag_intern, it may get deleted (either by an expired timer if
the system load is high or the timer sufficiently low, or by the
fraq_queue function for different reasons) before it's added to the
lru_list, then after it gets added it's a matter of time for the
evictor to get to a piece of memory which has been freed leading to a
number of different bugs depending on what's left there.

I've been able to trigger this on both IPv4 and IPv6 (which is normal
as the frag code is the same), but it's been much more difficult to
trigger on IPv4 due to the protocol differences about how fragments
are treated.

The setup I used to reproduce this is: 2 machines with 4 x 10G bonded
in a RR bond, so the same flow can be seen on multiple cards at the
same time. Then I used multiple instances of ping/ping6 to generate
fragmented packets and flood the machines with them while running
other processes to load the attacked machine.

*It is very important to have the _same flow_ coming in on multiple CPUs
concurrently. Usually the attacked machine would die in less than 30
minutes, if configured properly to have many evictor calls and timeouts
it could happen in 10 minutes or so.

An important point to make is that any caller (frag_queue or timer) of
inet_frag_kill will remove both the timer refcount and the
original/guarding refcount thus removing everything that's keeping the
frag from being freed at the next inet_frag_put.  All of this could
happen before the frag was ever added to the LRU list, then it gets
added and the evictor uses a freed fragment.

An example for IPv6 would be if a fragment is being added and is at
the stage of being inserted in the hash after the hash lock is
released, but before inet_frag_lru_add executes (or is able to obtain
the lru lock) another overlapping fragment for the same flow arrives
at a different CPU which finds it in the hash, but since it's
overlapping it drops it invoking inet_frag_kill and thus removing all
guarding refcounts, and afterwards freeing it by invoking
inet_frag_put which removes the last refcount added previously by
inet_frag_find, then inet_frag_lru_add gets executed by
inet_frag_intern and we have a freed fragment in the lru_list.

The fix is simple, just move the lru_add under the hash chain locked
region so when a removing function is called it'll have to wait for
the fragment to be added to the lru_list, and then it'll remove it (it
works because the hash chain removal is done before the lru_list one
and there's no window between the two list adds when the frag can get
dropped). With this fix applied I couldn't kill the same machine in 24
hours with the same setup.

Fixes: 3ef0eb0db4 ("net: frag, move LRU list maintenance outside of
rwlock")

CC: Florian Westphal <fw@strlen.de>
CC: Jesper Dangaard Brouer <brouer@redhat.com>
CC: David S. Miller <davem@davemloft.net>

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-05 20:31:42 -05:00
Yuchung Cheng
f19c29e3e3 tcp: snmp stats for Fast Open, SYN rtx, and data pkts
Add the following snmp stats:

TCPFastOpenActiveFail: Fast Open attempts (SYN/data) failed beacuse
the remote does not accept it or the attempts timed out.

TCPSynRetrans: number of SYN and SYN/ACK retransmits to break down
retransmissions into SYN, fast-retransmits, timeout retransmits, etc.

TCPOrigDataSent: number of outgoing packets with original data (excluding
retransmission but including data-in-SYN). This counter is different from
TcpOutSegs because TcpOutSegs also tracks pure ACKs. TCPOrigDataSent is
more useful to track the TCP retransmission rate.

Change TCPFastOpenActive to track only successful Fast Opens to be symmetric to
TCPFastOpenPassive.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Lawrence Brakmo <brakmo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-03 15:58:03 -05:00
Xin Long
10ddceb22b ip_tunnel:multicast process cause panic due to skb->_skb_refdst NULL pointer
when ip_tunnel process multicast packets, it may check if the packet is looped
back packet though 'rt_is_output_route(skb_rtable(skb))' in ip_tunnel_rcv(),
but before that , skb->_skb_refdst has been dropped in iptunnel_pull_header(),
so which leads to a panic.

fix the bug: https://bugzilla.kernel.org/show_bug.cgi?id=70681

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-03 15:56:40 -05:00
Yuchung Cheng
c84a57113f tcp: fix bogus RTT on special retransmission
RTT may be bogus with tall loss probe (TLP) when a packet
is retransmitted and latter (s)acked without TCPCB_SACKED_RETRANS flag.

For example, TLP calls __tcp_retransmit_skb() instead of
tcp_retransmit_skb(). The skb timestamps are updated but the sacked
flag is not marked with TCPCB_SACKED_RETRANS. As a result we'll
get bogus RTT in tcp_clean_rtx_queue() or in tcp_sacktag_one() on
spurious retransmission.

The fix is to apply the sticky flag TCP_EVER_RETRANS to enforce Karn's
check on RTT sampling. However this will disable F-RTO if timeout occurs
after TLP, by resetting undo_marker in tcp_enter_loss(). We relax this
check to only if any pending retransmists are still in-flight.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-03 15:33:02 -05:00
David S. Miller
8e1f40ec77 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next
Steffen Klassert says:

====================
This is the rework of the IPsec virtual tunnel interface
for ipv4 to support inter address family tunneling and
namespace crossing. The only change to the last RFC version
is a compile fix for an odd configuration where CONFIG_XFRM
is set but CONFIG_INET is not set.

1) Add and use a IPsec protocol multiplexer.

2) Add xfrm_tunnel_skb_cb to the skb common buffer
   to store a receive callback there.

3) Make vti work with i_key set by not including the i_key
   when comupting the hash for the tunnel lookup in case of
   vti tunnels.

4) Update ip_vti to use it's own receive hook.

5) Remove xfrm_tunnel_notifier, this is replaced by the IPsec
   protocol multiplexer.

6) We need to be protocol family indepenent, so use the on xfrm_lookup
   returned dst_entry instead of the ipv4 rtable in vti_tunnel_xmit().

7) Add support for inter address family tunneling.

8) Check if the tunnel endpoints of the xfrm state and the vti interface
   are matching and return an error otherwise.

8) Enable namespace crossing tor vti devices.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-27 16:31:54 -05:00
Eric Dumazet
740b0f1841 tcp: switch rtt estimations to usec resolution
Upcoming congestion controls for TCP require usec resolution for RTT
estimations. Millisecond resolution is simply not enough these days.

FQ/pacing in DC environments also require this change for finer control
and removal of bimodal behavior due to the current hack in
tcp_update_pacing_rate() for 'small rtt'

TCP_CONG_RTT_STAMP is no longer needed.

As Julian Anastasov pointed out, we need to keep user compatibility :
tcp_metrics used to export RTT and RTTVAR in msec resolution,
so we added RTT_US and RTTVAR_US. An iproute2 patch is needed
to use the new attributes if provided by the kernel.

In this example ss command displays a srtt of 32 usecs (10Gbit link)

lpk51:~# ./ss -i dst lpk52
Netid  State      Recv-Q Send-Q   Local Address:Port       Peer
Address:Port
tcp    ESTAB      0      1         10.246.11.51:42959
10.246.11.52:64614
         cubic wscale:6,6 rto:201 rtt:0.032/0.001 ato:40 mss:1448
cwnd:10 send
3620.0Mbps pacing_rate 7240.0Mbps unacked:1 rcv_rtt:993 rcv_space:29559

Updated iproute2 ip command displays :

lpk51:~# ./ip tcp_metrics | grep 10.246.11.52
10.246.11.52 age 561.914sec cwnd 10 rtt 274us rttvar 213us source
10.246.11.51

Old binary displays :

lpk51:~# ip tcp_metrics | grep 10.246.11.52
10.246.11.52 age 561.914sec cwnd 10 rtt 250us rttvar 125us source
10.246.11.51

With help from Julian Anastasov, Stephen Hemminger and Yuchung Cheng

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Larry Brakmo <brakmo@google.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-26 17:08:40 -05:00
Hannes Frederic Sowa
1b34657635 ipv4: yet another new IP_MTU_DISCOVER option IP_PMTUDISC_OMIT
IP_PMTUDISC_INTERFACE has a design error: because it does not allow the
generation of fragments if the interface mtu is exceeded, it is very
hard to make use of this option in already deployed name server software
for which I introduced this option.

This patch adds yet another new IP_MTU_DISCOVER option to not honor any
path mtu information and not accepting new icmp notifications destined for
the socket this option is enabled on. But we allow outgoing fragmentation
in case the packet size exceeds the outgoing interface mtu.

As such this new option can be used as a drop-in replacement for
IP_PMTUDISC_DONT, which is currently in use by most name server software
making the adoption of this option very smooth and easy.

The original advantage of IP_PMTUDISC_INTERFACE is still maintained:
ignoring incoming path MTU updates and not honoring discovered path MTUs
in the output path.

Fixes: 482fc6094a ("ipv4: introduce new IP_MTU_DISCOVER mode IP_PMTUDISC_INTERFACE")
Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-26 15:51:00 -05:00
Hannes Frederic Sowa
69647ce46a ipv4: use ip_skb_dst_mtu to determine mtu in ip_fragment
ip_skb_dst_mtu mostly falls back to ip_dst_mtu_maybe_forward if no socket
is attached to the skb (in case of forwarding) or determines the mtu like
we do in ip_finish_output, which actually checks if we should branch to
ip_fragment. Thus use the same function to determine the mtu here, too.

This is important for the introduction of IP_PMTUDISC_OMIT, where we
want the packets getting cut in pieces of the size of the outgoing
interface mtu. IPv6 already does this correctly.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-26 15:51:00 -05:00
Florian Westphal
8e165e2034 net: tcp: add mib counters to track zero window transitions
Three counters are added:
- one to track when we went from non-zero to zero window
- one to track the reverse
- one counter incremented when we want to announce zero window,
  but can't because we would shrink current window.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-26 15:23:30 -05:00
Eric Dumazet
9a9bfd032f net: tcp: use NET_INC_STATS()
While LINUX_MIB_TCPSPURIOUS_RTX_HOSTQUEUES can only be incremented
in tcp_transmit_skb() from softirq (incoming message or timer
activation), it is better to use NET_INC_STATS() instead of
NET_INC_STATS_BH() as tcp_transmit_skb() can be called from process
context.

This will avoid copy/paste confusion when/if we want to add
other SNMP counters in tcp_transmit_skb()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-26 15:19:47 -05:00
Hannes Frederic Sowa
91a48a2e85 ipv4: ipv6: better estimate tunnel header cut for correct ufo handling
Currently the UFO fragmentation process does not correctly handle inner
UDP frames.

(The following tcpdumps are captured on the parent interface with ufo
disabled while tunnel has ufo enabled, 2000 bytes payload, mtu 1280,
both sit device):

IPv6:
16:39:10.031613 IP (tos 0x0, ttl 64, id 3208, offset 0, flags [DF], proto IPv6 (41), length 1300)
    192.168.122.151 > 1.1.1.1: IP6 (hlim 64, next-header Fragment (44) payload length: 1240) 2001::1 > 2001::8: frag (0x00000001:0|1232) 44883 > distinct: UDP, length 2000
16:39:10.031709 IP (tos 0x0, ttl 64, id 3209, offset 0, flags [DF], proto IPv6 (41), length 844)
    192.168.122.151 > 1.1.1.1: IP6 (hlim 64, next-header Fragment (44) payload length: 784) 2001::1 > 2001::8: frag (0x00000001:0|776) 58979 > 46366: UDP, length 5471

We can see that fragmentation header offset is not correctly updated.
(fragmentation id handling is corrected by 916e4cf46d ("ipv6: reuse
ip6_frag_id from ip6_ufo_append_data")).

IPv4:
16:39:57.737761 IP (tos 0x0, ttl 64, id 3209, offset 0, flags [DF], proto IPIP (4), length 1296)
    192.168.122.151 > 1.1.1.1: IP (tos 0x0, ttl 64, id 57034, offset 0, flags [none], proto UDP (17), length 1276)
    192.168.99.1.35961 > 192.168.99.2.distinct: UDP, length 2000
16:39:57.738028 IP (tos 0x0, ttl 64, id 3210, offset 0, flags [DF], proto IPIP (4), length 792)
    192.168.122.151 > 1.1.1.1: IP (tos 0x0, ttl 64, id 57035, offset 0, flags [none], proto UDP (17), length 772)
    192.168.99.1.13531 > 192.168.99.2.20653: UDP, length 51109

In this case fragmentation id is incremented and offset is not updated.

First, I aligned inet_gso_segment and ipv6_gso_segment:
* align naming of flags
* ipv6_gso_segment: setting skb->encapsulation is unnecessary, as we
  always ensure that the state of this flag is left untouched when
  returning from upper gso segmenation function
* ipv6_gso_segment: move skb_reset_inner_headers below updating the
  fragmentation header data, we don't care for updating fragmentation
  header data
* remove currently unneeded comment indicating skb->encapsulation might
  get changed by upper gso_segment callback (gre and udp-tunnel reset
  encapsulation after segmentation on each fragment)

If we encounter an IPIP or SIT gso skb we now check for the protocol ==
IPPROTO_UDP and that we at least have already traversed another ip(6)
protocol header.

The reason why we have to special case GSO_IPIP and GSO_SIT is that
we reset skb->encapsulation to 0 while skb_mac_gso_segment the inner
protocol of GSO_UDP_TUNNEL or GSO_GRE packets.

Reported-by: Wolfgang Walter <linux@stwm.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-25 18:27:06 -05:00