linux.git/Documentation/networking, branch v4.8

Documentation: networking: dsa: Remove platform device TODO

2016-08-29T03:43:06+00:00

Since commit 83c0afaec7b7 ("net: dsa: Add new binding implementation"),
the shortcomings of the dsa platform device have been addressed, remove
that TODO item.

Signed-off-by: Florian Fainelli 
Acked-by: Andrew Lunn 
Signed-off-by: David S. Miller

rxrpc: Fix races between skb free, ACK generation and replying

2016-08-06T04:08:40+00:00

Inside the kafs filesystem it is possible to occasionally have a call
processed and terminated before we've had a chance to check whether we need
to clean up the rx queue for that call because afs_send_simple_reply() ends
the call when it is done, but this is done in a workqueue item that might
happen to run to completion before afs_deliver_to_call() completes.

Further, it is possible for rxrpc_kernel_send_data() to be called to send a
reply before the last request-phase data skb is released.  The rxrpc skb
destructor is where the ACK processing is done and the call state is
advanced upon release of the last skb.  ACK generation is also deferred to
a work item because it's possible that the skb destructor is not called in
a context where kernel_sendmsg() can be invoked.

To this end, the following changes are made:

 (1) kernel_rxrpc_data_consumed() is added.  This should be called whenever
     an skb is emptied so as to crank the ACK and call states.  This does
     not release the skb, however.  kernel_rxrpc_free_skb() must now be
     called to achieve that.  These together replace
     rxrpc_kernel_data_delivered().

 (2) kernel_rxrpc_data_consumed() is wrapped by afs_data_consumed().

     This makes afs_deliver_to_call() easier to work as the skb can simply
     be discarded unconditionally here without trying to work out what the
     return value of the ->deliver() function means.

     The ->deliver() functions can, via afs_data_complete(),
     afs_transfer_reply() and afs_extract_data() mark that an skb has been
     consumed (thereby cranking the state) without the need to
     conditionally free the skb to make sure the state is correct on an
     incoming call for when the call processor tries to send the reply.

 (3) rxrpc_recvmsg() now has to call kernel_rxrpc_data_consumed() when it
     has finished with a packet and MSG_PEEK isn't set.

 (4) rxrpc_packet_destructor() no longer calls rxrpc_hard_ACK_data().

     Because of this, we no longer need to clear the destructor and put the
     call before we free the skb in cases where we don't want the ACK/call
     state to be cranked.

 (5) The ->deliver() call-type callbacks are made to return -EAGAIN rather
     than 0 if they expect more data (afs_extract_data() returns -EAGAIN to
     the delivery function already), and the caller is now responsible for
     producing an abort if that was the last packet.

 (6) There are many bits of unmarshalling code where:

 		ret = afs_extract_data(call, skb, last, ...);
		switch (ret) {
		case 0:		break;
		case -EAGAIN:	return 0;
		default:	return ret;
		}

     is to be found.  As -EAGAIN can now be passed back to the caller, we
     now just return if ret < 0:

 		ret = afs_extract_data(call, skb, last, ...);
		if (ret < 0)
			return ret;

 (7) Checks for trailing data and empty final data packets has been
     consolidated as afs_data_complete().  So:

		if (skb->len > 0)
			return -EBADMSG;
		if (!last)
			return 0;

     becomes:

		ret = afs_data_complete(call, skb, last);
		if (ret < 0)
			return ret;

 (8) afs_transfer_reply() now checks the amount of data it has against the
     amount of data desired and the amount of data in the skb and returns
     an error to induce an abort if we don't get exactly what we want.

Without these changes, the following oops can occasionally be observed,
particularly if some printks are inserted into the delivery path:

general protection fault: 0000 [#1] SMP
Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc]
CPU: 0 PID: 1305 Comm: kworker/u8:3 Tainted: G            E   4.7.0-fsdevel+ #1303
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Workqueue: kafsd afs_async_workfn [kafs]
task: ffff88040be041c0 ti: ffff88040c070000 task.ti: ffff88040c070000
RIP: 0010:[]  [] __lock_acquire+0xcf/0x15a1
RSP: 0018:ffff88040c073bc0  EFLAGS: 00010002
RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000000 RCX: ffff88040d29a710
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88040d29a710
RBP: ffff88040c073c70 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88040be041c0 R15: ffffffff814c928f
FS:  0000000000000000(0000) GS:ffff88041fa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4595f4750 CR3: 0000000001c14000 CR4: 00000000001406f0
Stack:
 0000000000000006 000000000be04930 0000000000000000 ffff880400000000
 ffff880400000000 ffffffff8108f847 ffff88040be041c0 ffffffff81050446
 ffff8803fc08a920 ffff8803fc08a958 ffff88040be041c0 ffff88040c073c38
Call Trace:
 [] ? mark_held_locks+0x5e/0x74
 [] ? __local_bh_enable_ip+0x9b/0xa1
 [] ? trace_hardirqs_on_caller+0x16d/0x189
 [] lock_acquire+0x122/0x1b6
 [] ? lock_acquire+0x122/0x1b6
 [] ? skb_dequeue+0x18/0x61
 [] _raw_spin_lock_irqsave+0x35/0x49
 [] ? skb_dequeue+0x18/0x61
 [] skb_dequeue+0x18/0x61
 [] afs_deliver_to_call+0x344/0x39d [kafs]
 [] afs_process_async_call+0x4c/0xd5 [kafs]
 [] afs_async_workfn+0xe/0x10 [kafs]
 [] process_one_work+0x29d/0x57c
 [] worker_thread+0x24a/0x385
 [] ? rescuer_thread+0x2d0/0x2d0
 [] kthread+0xf3/0xfb
 [] ret_from_fork+0x1f/0x40
 [] ? kthread_create_on_node+0x1cf/0x1cf

Signed-off-by: David Howells 
Signed-off-by: David S. Miller

Documentation: RDS: Document Multipath RDS (mprds)

2016-07-15T18:36:58+00:00

Document the design of mprds, covering a brief description
of the motivation, data-structures and modifications to the
RDS control plane.

Acked-by: Santosh Shilimkar 
Signed-off-by: Sowmini Varadhan 
Signed-off-by: David S. Miller

Documentation: RDS: updates for SO_RDS_TRANSPORT socket option

2016-07-15T18:36:58+00:00

Update the documentation to describe the changes added by
commit 8ba38460f363 ("net/rds Add getsockopt support for SO_RDS_TRANSPORT")

Acked-by: Santosh Shilimkar 
Signed-off-by: Sowmini Varadhan 
Signed-off-by: David S. Miller

net: vrf: Address comments from last documentation update

2016-07-14T01:04:17+00:00

Comments from Frank Kellerman on last doc update:
- extra whitespace in front of a neigh show command
- convert the brief link example to 'vrf red'

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: vrf: Documentation update

2016-07-13T18:36:27+00:00

Update vrf documentation for changes made to 4.4 - 4.8 kernels
and iproute2 support for vrf keyword.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next

2016-07-06T16:15:15+00:00

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for net-next,
they are:

1) Don't use userspace datatypes in bridge netfilter code, from
   Tobin Harding.

2) Iterate only once over the expectation table when removing the
   helper module, instead of once per-netns, from Florian Westphal.

3) Extra sanitization in xt_hook_ops_alloc() to return error in case
   we ever pass zero hooks, xt_hook_ops_alloc():

4) Handle NFPROTO_INET from the logging core infrastructure, from
   Liping Zhang.

5) Autoload loggers when TRACE target is used from rules, this doesn't
   change the behaviour in case the user already selected nfnetlink_log
   as preferred way to print tracing logs, also from Liping Zhang.

6) Conntrack slabs with SLAB_HWCACHE_ALIGN to allow rearranging fields
   by cache lines, increases the size of entries in 11% per entry.
   From Florian Westphal.

7) Skip zone comparison if CONFIG_NF_CONNTRACK_ZONES=n, from Florian.

8) Remove useless defensive check in nf_logger_find_get() from Shivani
   Bhardwaj.

9) Remove zone extension as place it in the conntrack object, this is
   always include in the hashing and we expect more intensive use of
   zones since containers are in place. Also from Florian Westphal.

10) Owner match now works from any namespace, from Eric Bierdeman.

11) Make sure we only reply with TCP reset to TCP traffic from
    nf_reject_ipv4, patch from Liping Zhang.

12) Introduce --nflog-size to indicate amount of network packet bytes
    that are copied to userspace via log message, from Vishwanath Pai.
    This obsoletes --nflog-range that has never worked, it was designed
    to achieve this but it has never worked.

13) Introduce generic macros for nf_tables object generation masks.

14) Use generation mask in table, chain and set objects in nf_tables.
    This allows fixes interferences with ongoing preparation phase of
    the commit protocol and object listings going on at the same time.
    This update is introduced in three patches, one per object.

15) Check if the object is active in the next generation for element
    deactivation in the rbtree implementation, given that deactivation
    happens from the commit phase path we have to observe the future
    status of the object.

16) Support for deletion of just added elements in the hash set type.

17) Allow to resize hashtable from /proc entry, not only from the
    obscure /sys entry that maps to the module parameter, from Florian
    Westphal.

18) Get rid of NFT_BASECHAIN_DISABLED, this code is not exercised
    anymore since we tear down the ruleset whenever the netdevice
    goes away.

19) Support for matching inverted set lookups, from Arturo Borrero.

20) Simplify the iptables_mangle_hook() by removing a superfluous
    extra branch.

21) Introduce ether_addr_equal_masked() and use it from the netfilter
    codebase, from Joe Perches.

22) Remove references to "Use netfilter MARK value as routing key"
    from the Netfilter Kconfig description given that this toggle
    doesn't exists already for 10 years, from Moritz Sichert.

23) Introduce generic NF_INVF() and use it from the xtables codebase,
    from Joe Perches.

24) Setting logger to NONE via /proc was not working unless explicit
    nul-termination was included in the string. This fixes seems to
    leave the former behaviour there, so we don't break backward.
====================

Signed-off-by: David S. Miller

drivers: net: stmmac: reworking the PCS code.

2016-06-28T12:54:23+00:00

The 3.xx and 4.xx synopsys gmacs have a very similar
PCS embedded module and they share almost the same registers:
for example:
  AN_Control, AN_Status, AN_Advertisement, AN_Link_Partner_Ability,
  AN_Expansion, TBI_Extended_Status.

Just the RGMII/SMII Control/Status register differs.

So This patch aims to reorganize and enhance the PCS support.
It removes the existent support from the dwmac1000/dwmac4_core.c
moving basic PCS functions inside a new file called: stmmac_pcs.h.

The patch also reviews the available APIs to be better shared among
different hardware and easily enhanced to support new features.

Signed-off-by: Giuseppe Cavallaro 
Signed-off-by: David S. Miller

netfilter: conntrack: allow increasing bucket size via sysctl too

2016-06-24T09:03:28+00:00

No need to restrict this to module parameter.

We export a copy of the real hash size -- when user alters the value we
allocate the new table, copy entries etc before we update the real size
to the requested one.

This is also needed because the real size is used by concurrent readers
and cannot be changed without synchronizing the conntrack generation
seqcnt.

We only allow changing this value from the initial net namespace.

Tested using http-client-benchmark vs. httpterm with concurrent

while true;do
 echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets
done

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

can: bcm: add documentation for CAN FD support

2016-06-17T13:39:47+00:00

Signed-off-by: Oliver Hartkopp 
Signed-off-by: Marc Kleine-Budde