The bpq ether driver is modifying the data art of the skb by first
dropping the KISS byte (a command byte for the radio) then prepending the
length + 4 of the remaining AX.25 packet to be transmitted as a little
endian 16-bit number.  If the high byte of the length has a different
value than the dropped KISS byte users of clones of the skb may observe
this as corruption.  This was observed with by running listen(8) -a which
uses a packet socket which clones transmit packets.  The corruption will
then typically be displayed for as a KISS "TX Delay" command for AX.25
packets in the range of 252..508 bytes or any other KISS command for
yet larger packets.

Fixed by using skb_cow to create a private copy should the skb be cloned.
Using skb_cow also allows us to cleanup the old logic to ensure sufficient
headroom in the skb.

While at it, replace a return of 0 from bpq_xmit with the proper constant
NETDEV_TX_OK which is now being used everywhere else in this function.

Affected: all 2.2, 2.4 and 2.6 kernels.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Reported-by: NJann Traschewski <jann@gmx.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is the result of an automatic spatch transformation to convert
all ndo_start_xmit() return values of 0 to NETDEV_TX_OK.

Some occurences are missed by the automatic conversion, those will be
handled in a seperate patch.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix up remaining drivers returning a magic or an errno value from their
ndo_start_xmit() functions that were missed in the first pass:

- isdn_net: missed conversion
- bpqether: missed conversion: skb is freed, so return NETDEV_TX_OK
- hp100: intention appears to be to resubmit skb once resources are
  available, but due to no queue handling it is dropped for now.
- lapbether: skb is freed, so return NETDEV_TX_OK
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix up hamradio drivers that return an errno value to dev_queue_xmit(), causing
it to print a warning an free the skb.

- bpqether: skb is freed: use after free

Compile tested only.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Protocols that use packet_type can be __read_mostly section for better
locality. Elminate any unnecessary initializations of NULL.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Impact: Attribute functions with __acquires(...) resp. __releases(...).

Fix this sparse warnings:
  drivers/net/hamradio/bpqether.c:387:13: warning: context imbalance in 'bpq_seq_start' - wrong count at exit
  drivers/net/hamradio/bpqether.c:419:13: warning: context imbalance in 'bpq_seq_stop' - unexpected unlock
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Impact: Use 'static const char[]' instead of 'static char[]' and while
being at it fix an issue in 'mkiss_init_driver', where in case of an
error the status code was not passed to printk.

Fix this warnings:
  drivers/net/hamradio/6pack.c: In function 'sixpack_init_driver':
  drivers/net/hamradio/6pack.c:802: warning: format not a string literal and no format arguments
  drivers/net/hamradio/bpqether.c: In function 'bpq_init_driver':
  drivers/net/hamradio/bpqether.c:609: warning: format not a string literal and no format arguments
  drivers/net/hamradio/mkiss.c: In function 'mkiss_init_driver':
  drivers/net/hamradio/mkiss.c:988: warning: format not a string literal and no format arguments
  drivers/net/hamradio/mkiss.c:991: warning: format not a string literal and no format arguments
  drivers/net/hamradio/scc.c: In function 'scc_init_driver':
  drivers/net/hamradio/scc.c:2109: warning: format not a string literal and no format arguments
  drivers/net/hamradio/yam.c: In function 'yam_init_driver':
  drivers/net/hamradio/yam.c:1094: warning: format not a string literal and no format arguments
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Base versions handle constant folding now.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.

Drivers need not do it any more.

Some cases had to be skipped over because the drivers
were making use of the ->last_rx value themselves.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This converts pretty much everything to print_mac. There were
a few things that had conflicts which I have just dropped for
now, no harm done.

I've built an allyesconfig with this and looked at the files
that weren't built very carefully, but it's a huge patch.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The new address list lock needs to handle the same device layering
issues that the _xmit_lock one does.

This integrates work done by Patrick McHardy.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

alloc_netdev_mq() now allocates an array of netdev_queue
structures for TX, based upon the queue_count argument.

Furthermore, all accesses to the TX queues are now vectored
through the netdev_get_tx_queue() and netdev_for_each_tx_queue()
interfaces.  This makes it easy to grep the tree for all
things that want to get to a TX queue of a net device.

Problem spots which are not really multiqueue aware yet, and
only work with one queue, can easily be spotted by grepping
for all netdev_get_tx_queue() calls that pass in a zero index.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Accesses are mostly structured such that when there are multiple TX
queues the code transformations will be a little bit simpler.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

Since hardware header operations are part of the protocol class
not the device instance, make them into a separate object and
save memory.
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add inline for common usage of hardware header creation, and
fix bug in IPV6 mcast where the assumption about negative return is
an errno. Negative return from hard_header means not enough space
was available,(ie -N bytes).
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is nicer than the MAC_FMT stuff.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Every user of the network device notifiers is either a protocol
stack or a pseudo device.  If a protocol stack that does not have
support for multiple network namespaces receives an event for a
device that is not in the initial network namespace it quite possibly
can get confused and do the wrong thing.

To avoid problems until all of the protocol stacks are converted
this patch modifies all netdev event handlers to ignore events on
devices that are not in the initial network namespace.

As the rest of the code is made network namespace aware these
checks can be removed.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch modifies every packet receive function
registered with dev_add_pack() to drop packets if they
are not from the initial network namespace.

This should ensure that the various network stacks do
not receive packets in a anything but the initial network
namespace until the code has been converted and is ready
for them.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes /proc/net per network namespace.  It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.

Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The rcu_dereference() primitive needs to be applied to an l-value in order to
ensure that compiler writers don't get an opportunity to apply reordering
optimizations that could result in multiple fetches or in other misbehavior.
This patch pulls the rcu_dereference() calls in bpq_seq_next() up to the point
at which the fetched pointers are still l-values, rather than after
list_entry() has transformed them into r-values.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For the common, open coded 'skb->nh.raw = skb->data' operation, so that we can
later turn skb->nh.raw into a offset, reducing the size of struct sk_buff in
64bit land while possibly keeping it as a pointer on 32bit.

This one touches just the most simple case, next will handle the slightly more
"complex" cases.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Only the callsign but not the SSID part of an AX.25 address is ASCII
based but Linux by initializes the SSID which should be just a 4-bit
number from ASCII anyway.

Fix that and convert the code to use a shared constant for both default
addresses.  While at it, use the same style for null_ax25_address also.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bpqether is encapsulating AX.25 frames into ethernet frames.  There is a
virtual bpqether device paired with each ethernet devices, so it's normal
to pass through dev_queue_xmit twice for each frame which triggers the
locking detector.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

From Suzanne Wood <suzannew@cs.pdx.edu>:

Clarify RCU implementation in bpqether.c.

Because bpq_new_device() calls list_add_rcu() and bpq_free_device() calls
list_del_rcu(), substitute list_for_each_entry_rcu() for
list_for_each_entry() in bpq_get_ax25_dev() and in bpq_seq_start().

Add rcu dereference protection in bpq_seq_next().

The rcu_read_lock()/unlock() in bpq_device_event() are removed because
netdev event handlers are called with RTNL locking in place.

FYI: bpq_free_device() calls list_del_rcu() which, per list.h, requires
synchronize_rcu() which can block or call_rcu() or call_rcu_bh() which
cannot block.  Herbert Xu notes that synchronization is done here by
unregister_netdevice().  This calls synchronize_net() which in turn uses
synchronize_rcu().
Signed-off-by: NRalf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

Rename ax25_encapsulate to ax25_hard_header which these days more
accurately describes what the function is supposed to do.
Signed-off-by: NRalf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bonding just wants the device before the skb_bond()
decapsulation occurs, so simply pass that original
device into packet_type->func() as an argument.

It remains to be seen whether we can use this same
exact thing to get rid of skb->input_dev as well.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replacing the open coded equivalents and making ax25 look more like
a linux network protocol, i.e. more similar to inet.
Signed-off-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!