litmus-rt.git/include/net, branch 2011.1

Bluetooth: Fix deadlock in the ERTM logic

2010-09-30T15:19:35+00:00

The Enhanced Retransmission Mode(ERTM) is a realiable mode of operation
of the Bluetooth L2CAP layer. Think on it like a simplified version of
TCP.
The problem we were facing here was a deadlock. ERTM uses a backlog
queue to queue incomimg packets while the user is helding the lock. At
some moment the sk_sndbuf can be exceeded and we can't alloc new skbs
then the code sleep with the lock to wait for memory, that stalls the
ERTM connection once we can't read the acknowledgements packets in the
backlog queue to free memory and make the allocation of outcoming skb
successful.

This patch actually affect all users of bt_skb_send_alloc(), i.e., all
L2CAP modes and SCO.

We are safe against socket states changes or channels deletion while the
we are sleeping wait memory. Checking for the sk->sk_err and
sk->sk_shutdown make the code safe, since any action that can leave the
socket or the channel in a not usable state set one of the struct
members at least. Then we can check both of them when getting the lock
again and return with the proper error if something unexpected happens.

Signed-off-by: Gustavo F. Padovan 
Signed-off-by: Ulisses Furquim

tproxy: check for transparent flag in ip_route_newports

2010-09-27T22:03:33+00:00

as done in ip_route_connect()

Signed-off-by: Ulrich Weber 
Signed-off-by: David S. Miller

ipv6: add a missing unregister_pernet_subsys call

2010-09-27T02:09:25+00:00

Clean up a missing exit path in the ipv6 module init routines.  In
addrconf_init we call ipv6_addr_label_init which calls register_pernet_subsys
for the ipv6_addr_label_ops structure.  But if module loading fails, or if the
ipv6 module is removed, there is no corresponding unregister_pernet_subsys call,
which leaves a now-bogus address on the pernet_list, leading to oopses in
subsequent registrations.  This patch cleans up both the failed load path and
the unload path.  Tested by myself with good results.

Signed-off-by: Neil Horman 

 include/net/addrconf.h |    1 +
 net/ipv6/addrconf.c    |   11 ++++++++---
 net/ipv6/addrlabel.c   |    5 +++++
 3 files changed, 14 insertions(+), 3 deletions(-)
Signed-off-by: David S. Miller

net: reset skb queue mapping when rx'ing over tunnel

2010-09-27T01:48:40+00:00

Reset queue mapping when an skb is reentering the stack via a tunnel.
On second pass, the queue mapping from the original device is no
longer valid.

Signed-off-by: Tom Herbert 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

xfrm: Allow different selector family in temporary state

2010-09-20T18:11:38+00:00

The family parameter xfrm_state_find is used to find a state matching a
certain policy. This value is set to the template's family
(encap_family) right before xfrm_state_find is called.
The family parameter is however also used to construct a temporary state
in xfrm_state_find itself which is wrong for inter-family scenarios
because it produces a selector for the wrong family. Since this selector
is included in the xfrm_user_acquire structure, user space programs
misinterpret IPv6 addresses as IPv4 and vice versa.
This patch splits up the original init_tempsel function into a part that
initializes the selector respectively the props and id of the temporary
state, to allow for differing ip address families whithin the state.

Signed-off-by: Thomas Egerer 
Signed-off-by: Steffen Klassert 
Signed-off-by: David S. Miller

tcp: Prevent overzealous packetization by SWS logic.

2010-09-15T19:01:44+00:00

If peer uses tiny MSS (say, 75 bytes) and similarly tiny advertised
window, the SWS logic will packetize to half the MSS unnecessarily.

This causes problems with some embedded devices.

However for large MSS devices we do want to half-MSS packetize
otherwise we never get enough packets into the pipe for things
like fast retransmit and recovery to work.

Be careful also to handle the case where MSS > window, otherwise
we'll never send until the probe timer.

Reported-by: ツ Leandro Melo de Sales 
Signed-off-by: David S. Miller

udp: add rehash on connect()

2010-09-09T04:45:01+00:00

commit 30fff923 introduced in linux-2.6.33 (udp: bind() optimisation)
added a secondary hash on UDP, hashed on (local addr, local port).

Problem is that following sequence :

fd = socket(...)
connect(fd, &remote, ...)

not only selects remote end point (address and port), but also sets
local address, while UDP stack stored in secondary hash table the socket
while its local address was INADDR_ANY (or ipv6 equivalent)

Sequence is :
 - autobind() : choose a random local port, insert socket in hash tables
              [while local address is INADDR_ANY]
 - connect() : set remote address and port, change local address to IP
              given by a route lookup.

When an incoming UDP frame comes, if more than 10 sockets are found in
primary hash table, we switch to secondary table, and fail to find
socket because its local address changed.

One solution to this problem is to rehash datagram socket if needed.

We add a new rehash(struct socket *) method in "struct proto", and
implement this method for UDP v4 & v6, using a common helper.

This rehashing only takes care of secondary hash table, since primary
hash (based on local port only) is not changed.

Reported-by: Krzysztof Piotr Oledzki 
Signed-off-by: Eric Dumazet 
Tested-by: Krzysztof Piotr Oledzki 
Signed-off-by: David S. Miller

ipvs: fix active FTP

2010-09-08T17:39:57+00:00

- Do not create expectation when forwarding the PORT
  command to avoid blocking the connection. The problem is that
  nf_conntrack_ftp.c:help() tries to create the same expectation later in
  POST_ROUTING and drops the packet with "dropping packet" message after
  failure in nf_ct_expect_related.

- Change ip_vs_update_conntrack to alter the conntrack
  for related connections from real server. If we do not alter the reply in
  this direction the next packet from client sent to vport 20 comes as NEW
  connection. We alter it but may be some collision happens for both
  conntracks and the second conntrack gets destroyed immediately. The
  connection stucks too.

Signed-off-by: Julian Anastasov 
Signed-off-by: Simon Horman 
Signed-off-by: David S. Miller

cls_cgroup: Fix rcu lockdep warning

2010-09-03T16:55:24+00:00

Dave reported an rcu lockdep warning on 2.6.35.4 kernel

task->cgroups and task->cgroups->subsys[i] are protected by RCU.
So we avoid accessing invalid pointers here. This might happen,
for example, when you are deref-ing those pointers while someone
move @task from one cgroup to another.

Reported-by: Dave Jones 
Signed-off-by: Li Zefan 
Signed-off-by: David S. Miller

tcp: Combat per-cpu skew in orphan tests.

2010-08-25T09:27:49+00:00

As reported by Anton Blanchard when we use
percpu_counter_read_positive() to make our orphan socket limit checks,
the check can be off by up to num_cpus_online() * batch (which is 32
by default) which on a 128 cpu machine can be as large as the default
orphan limit itself.

Fix this by doing the full expensive sum check if the optimized check
triggers.

Reported-by: Anton Blanchard 
Signed-off-by: David S. Miller 
Acked-by: Eric Dumazet