wifi: mac80211: clean up assignments to pointer cache.

The assignment to pointer cache in function mesh_fast_tx_gc can
be made at the declaration time rather than a later assignment.
There are also 3 functions where pointer cache is being initialized
at declaration time and later re-assigned again with the same
value, these are redundant and can be removed.

Cleans up code and three clang scan build warnings:
warning: Value stored to 'cache' during its initialization is never
read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://msgid.link/20240215232151.2075483-1-colin.i.king@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: Replace ENOTSUPP with EOPNOTSUPP

ENOTSUP isn't a standard error code. EOPNOTSUPP should be used instead.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20231211085121.3841b71c867d.Idf2ad01d9dfe8d6d6c352bf02deb06e49701ad1d@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: mesh: fix some kdoc warnings

These were mostly missing or incorrectly tagged return values.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230928172905.33fea2968c62.I41d197b570370ab7cad1405518512fdd36e08717@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: fix RCU usage warning in mesh fast-xmit

In mesh_fast_tx_flush_addr() we already hold the lock, so
don't need additional hashtable RCU protection. Use the
rhashtable_lookup_fast() variant to avoid RCU protection
warnings.

Fixes: d5edb9ae8d56 ("wifi: mac80211: mesh fast xmit support")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

wifi: mac80211: mesh fast xmit support

Previously, fast xmit only worked on interface types where initially a
sta lookup is performed, and a cached header can be attached to the sta,
requiring only some fields to be updated at runtime.

This technique is not directly applicable for a mesh device type due
to the dynamic nature of the topology and protocol. There are more
addresses that need to be filled, and there is an extra header with a
dynamic length based on the addressing mode.

Change the code to cache entries contain a copy of the mesh subframe header +
bridge tunnel header, as well as an embedded struct ieee80211_fast_tx, which
contains the information for building the 802.11 header.

Add a mesh specific early fast xmit call, which looks up a cached entry and
adds only the mesh subframe header, before passing it over to the generic
fast xmit code.

To ensure the changes in network are reflected in these cached headers,
flush affected cached entries on path changes, as well as other conditions
that currently trigger a fast xmit check in other modes (key changes etc.)

This code is loosely based on a previous implementation by:
Sriram R <quic_srirrama@quicinc.com>

Cc: Sriram R <quic_srirrama@quicinc.com>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20230314095956.62085-4-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

treewide: Convert del_timer*() to timer_shutdown*()

Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown". After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed. It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

$ cat timer.cocci
@@
expression ptr, slab;
identifier timer, rfield;
@@
(
- del_timer(&ptr->timer);
+ timer_shutdown(&ptr->timer);
|
- del_timer_sync(&ptr->timer);
+ timer_shutdown_sync(&ptr->timer);
)
... when strict
when != ptr->timer
(
kfree_rcu(ptr, rfield);
|
kmem_cache_free(slab, ptr);
|
kfree(ptr);
)

$ spatch timer.cocci . > /tmp/t.patch
$ patch -p1 < /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

wifi: mac80211: Fix ack frame idr leak when mesh has no route

When trying to transmit an data frame with tx_status to a destination
that have no route in the mesh, then it is dropped without recrediting
the ack_status_frames idr.

Once it is exhausted, wpa_supplicant starts failing to do SAE with
NL80211_CMD_FRAME and logs "nl80211: Frame command failed".

Use ieee80211_free_txskb() instead of kfree_skb() to fix it.

Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
Link: https://lore.kernel.org/r/20221027140133.1504-1-nicolas.cavallari@green-communications.fr
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: embedd mesh_paths and mpp_paths into ieee80211_if_mesh

Syzbot hit NULL deref in rhashtable_free_and_destroy(). The problem was
in mesh_paths and mpp_paths being NULL.

mesh_pathtbl_init() could fail in case of memory allocation failure, but
nobody cared, since ieee80211_mesh_init_sdata() returns void. It led to
leaving 2 pointers as NULL. Syzbot has found null deref on exit path,
but it could happen anywhere else, because code assumes these pointers are
valid.

Since all ieee80211_*_setup_sdata functions are void and do not fail,
let's embedd mesh_paths and mpp_paths into parent struct to avoid
adding error handling on higher levels and follow the pattern of others
setup_sdata functions

Fixes: 60854fd94573 ("mac80211: mesh: convert path table to rhashtable")
Reported-and-tested-by: syzbot+860268315ba86ea6b96b@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20211230195547.23977-1-paskripkin@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net: mac80211: check return value of rhashtable_init

When rhashtable_init() fails, it returns -EINVAL.
However, since error return value of rhashtable_init is not checked,
it can cause use of uninitialized pointers.
So, fix unhandled errors of rhashtable_init.

Signed-off-by: MichelleJin <shjy180909@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: check return value of rhashtable_init

When rhashtable_init() fails, it returns -EINVAL.
However, since error return value of rhashtable_init is not checked,
it can cause use of uninitialized pointers.
So, fix unhandled errors of rhashtable_init.

Signed-off-by: MichelleJin <shjy180909@gmail.com>
Link: https://lore.kernel.org/r/20210927033457.1020967-4-shjy180909@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: fix some spelling mistakes

Fix some spelling mistakes in comments:
freeed ==> freed
addreses ==> addresses
containging ==> containing
capablity ==> capability
sucess ==> success
atleast ==> at least

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Link: https://lore.kernel.org/r/20210607150047.2855962-1-zhengyongjun3@huawei.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: fix mesh_pathtbl_init() error path

If tbl_mpp can not be allocated, we call mesh_table_free(tbl_path)
while tbl_path rhashtable has not yet been initialized, which causes
panics.

Simply factorize the rhashtable_init() call into mesh_table_alloc()

WARNING: CPU: 1 PID: 8474 at kernel/workqueue.c:3040 __flush_work kernel/workqueue.c:3040 [inline]
WARNING: CPU: 1 PID: 8474 at kernel/workqueue.c:3040 __cancel_work_timer+0x514/0x540 kernel/workqueue.c:3136
Modules linked in:
CPU: 1 PID: 8474 Comm: syz-executor663 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__flush_work kernel/workqueue.c:3040 [inline]
RIP: 0010:__cancel_work_timer+0x514/0x540 kernel/workqueue.c:3136
Code: 5d c3 e8 bf ae 29 00 0f 0b e9 f0 fd ff ff e8 b3 ae 29 00 0f 0b 43 80 3c 3e 00 0f 85 31 ff ff ff e9 34 ff ff ff e8 9c ae 29 00 <0f> 0b e9 dc fe ff ff 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 7d fd ff
RSP: 0018:ffffc9000165f5a0 EFLAGS: 00010293
RAX: ffffffff814b7064 RBX: 0000000000000001 RCX: ffff888021c80000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888024039ca0 R08: dffffc0000000000 R09: fffffbfff1dd3e64
R10: fffffbfff1dd3e64 R11: 0000000000000000 R12: 1ffff920002cbebd
R13: ffff888024039c88 R14: 1ffff11004807391 R15: dffffc0000000000
FS: 0000000001347880(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 000000002cc0a000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rhashtable_free_and_destroy+0x25/0x9c0 lib/rhashtable.c:1137
mesh_table_free net/mac80211/mesh_pathtbl.c:69 [inline]
mesh_pathtbl_init+0x287/0x2e0 net/mac80211/mesh_pathtbl.c:785
ieee80211_mesh_init_sdata+0x2ee/0x530 net/mac80211/mesh.c:1591
ieee80211_setup_sdata+0x733/0xc40 net/mac80211/iface.c:1569
ieee80211_if_add+0xd5c/0x1cd0 net/mac80211/iface.c:1987
ieee80211_add_iface+0x59/0x130 net/mac80211/cfg.c:125
rdev_add_virtual_intf net/wireless/rdev-ops.h:45 [inline]
nl80211_new_interface+0x563/0xb40 net/wireless/nl80211.c:3855
genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
genl_rcv_msg+0xe4e/0x1280 net/netlink/genetlink.c:800
netlink_rcv_skb+0x190/0x3a0 net/netlink/af_netlink.c:2494
genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
netlink_unicast+0x780/0x930 net/netlink/af_netlink.c:1330
netlink_sendmsg+0x9a8/0xd40 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg net/socket.c:671 [inline]
____sys_sendmsg+0x519/0x800 net/socket.c:2353
___sys_sendmsg net/socket.c:2407 [inline]
__sys_sendmsg+0x2b1/0x360 net/socket.c:2440
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 60854fd94573 ("mac80211: mesh: convert path table to rhashtable")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://lore.kernel.org/r/20201204162428.2583119-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mac80211: mesh: Free pending skb when destroying a mpath

A mpath object can hold reference on a list of skb that are waiting for
mpath resolution to be sent. When destroying a mpath this skb list
should be cleaned up in order to not leak memory.

Fixing that kind of leak:

unreferenced object 0xffff0000181c9300 (size 1088):
comm "openvpn", pid 1782, jiffies 4295071698 (age 80.416s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 f9 80 36 00 00 00 00 00 ..........6.....
02 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace:
[<000000004bc6a443>] kmem_cache_alloc+0x1a4/0x2f0
[<000000002caaef13>] sk_prot_alloc.isra.39+0x34/0x178
[<00000000ceeaa916>] sk_alloc+0x34/0x228
[<00000000ca1f1d04>] inet_create+0x198/0x518
[<0000000035626b1c>] __sock_create+0x134/0x328
[<00000000a12b3a87>] __sys_socket+0xb0/0x158
[<00000000ff859f23>] __arm64_sys_socket+0x40/0x58
[<00000000263486ec>] el0_svc_handler+0xd0/0x1a0
[<0000000005b5157d>] el0_svc+0x8/0xc
unreferenced object 0xffff000012973a40 (size 216):
comm "openvpn", pid 1782, jiffies 4295082137 (age 38.660s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 c0 06 16 00 00 ff ff 00 93 1c 18 00 00 ff ff ................
backtrace:
[<000000004bc6a443>] kmem_cache_alloc+0x1a4/0x2f0
[<0000000023c8c8f9>] __alloc_skb+0xc0/0x2b8
[<000000007ad950bb>] alloc_skb_with_frags+0x60/0x320
[<00000000ef90023a>] sock_alloc_send_pskb+0x388/0x3c0
[<00000000104fb1a3>] sock_alloc_send_skb+0x1c/0x28
[<000000006919d2dd>] __ip_append_data+0xba4/0x11f0
[<0000000083477587>] ip_make_skb+0x14c/0x1a8
[<0000000024f3d592>] udp_sendmsg+0xaf0/0xcf0
[<000000005aabe255>] inet_sendmsg+0x5c/0x80
[<000000008651ea08>] __sys_sendto+0x15c/0x218
[<000000003505c99b>] __arm64_sys_sendto+0x74/0x90
[<00000000263486ec>] el0_svc_handler+0xd0/0x1a0
[<0000000005b5157d>] el0_svc+0x8/0xc

Fixes: 2bdaf386f99c (mac80211: mesh: move path tables into if_mesh)
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Link: https://lore.kernel.org/r/20200704135419.27703-1-repk@triplefau.lt
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net: mac80211: kerneldoc fixes

Simple fixes which require no deep knowledge of the code.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mac80211: mesh: drop redundant rcu_read_lock/unlock calls

The callers of these functions are all within RCU locked sections

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: fix unaligned access in mesh table hash function

The pointer to the last four bytes of the address is not guaranteed to be
aligned, so we need to use __get_unaligned_cpu32 here

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Use rhashtable_lookup_get_insert_fast instead of racy code

The code in mesh_path_add tries to handle the case where a duplicate
entry is added to the rhashtable by doing a lookup after a failed
insertion. It also tries to handle races by repeating the insertion
should the lookup fail.

This is now unnecessary as we have rhashtable API functions that can
directly return the mathcing object.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: fix missing unlock on error in table_path_del()

spin_lock_bh() is used in table_path_del() but rcu_read_unlock()
is used for unlocking. Fix it by using spin_unlock_bh() instead
of rcu_read_unlock() in the error handling case.

Fixes: b4c3fbe63601 ("mac80211: Use linked list instead of rhashtable walk for mesh tables")
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: Free mpath object when rhashtable insertion fails

When rhashtable insertion fails the mesh table code doesn't free
the now-orphan mesh path object. This patch fixes that.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Use linked list instead of rhashtable walk for mesh tables

The mesh table code walks over hash tables for two purposes. First of
all it's used as part of a netlink dump process, but it is also used
for looking up entries to delete using criteria other than the hash
key.

The second purpose is directly contrary to the design specification
of rhashtable walks. It is only meant for use by netlink dumps.

This is because rhashtable is resizable and you cannot obtain a
stable walk over it during a resize process.

In fact mesh's use of rhashtable for dumping is bogus too. Rather
than using rhashtable walk's iterator to keep track of the current
position, it always converts the current position to an integer
which defeats the purpose of the iterator.

Therefore this patch converts all uses of rhashtable walk into a
simple linked list.

This patch also adds a new spin lock to protect the hash table
insertion/removal as well as the walk list modifications. In fact
the previous code was buggy as the removals can race with each
other, potentially resulting in a double-free.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

rhashtable: Change rhashtable_walk_start to return void

Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

ret = rhashtable_walk_start(rhiter);
if (ret && ret != -EAGAIN)
goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Use setup_timer instead of init_timer for mesh path

Use setup_timer() and setup_deferrable_timer() to set the data and
function timer fields. It makes the code cleaner and will allow for
easier change of the timer struct internals.

Signed-off-by: Ondřej Lysoněk <ondrej.lysonek@seznam.cz>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <linux-wireless@vger.kernel.org>
Cc: <netdev@vger.kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: use DECLARE_EWMA for mesh_fail_avg

As moving average is not considering fractional part, it will
get stuck at the same level after certain state. For example,
with current values, it can get stuck at 96. Fortunately the
current threshold 95%, but if it were increased to 96 or more
mesh paths would never be deactivated. Fix failure average
movement by using EWMA helpers, which does take into account
fractional parts.

Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
[johannes: pick a larger EWMA factor for more precision with
the limited range that we will feed into it, adjust to new API]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: make mpath path fixing more robust

A fixed mpath was not quite being treated as such:

1) if a PERR frame was received, a fixed mpath was
deactivated.

2) queued path discovery for fixed mpath was potentially
being considered, changing mpath state.

3) other mpath flags were potentially being inherited when
fixing the mpath. Just assign PATH_FIXED and SN_VALID.

This solves several issues when fixing a mesh path in one
direction. The reverse direction mpath should probably
also be fixed, or root announcements at least be enabled.

Signed-off-by: Thomas Pedersen <twp@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: embed gates hlist head directly

Since we have converted the mesh path tables to rhashtable, we are
no longer swapping out the entire mesh_pathtbl pointer with RCU.
As a result, we no longer need indirection to the hlist head for
the gates list and can simply embed it, saving a pair of
pointer-sized allocations.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: fix crash in mesh_path_timer

The mesh_path_reclaim() function, called from an rcu callback, cancels
the mesh_path_timer associated with a mesh path. Unfortunately, this
call can happen much later, perhaps after the hash table itself is
destroyed.

Such a situation led to the following crash in mesh_path_send_to_gates()
when dereferencing the tbl pointer:

[ 23.901661] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 23.905516] IP: [<ffffffff814c910b>] mesh_path_send_to_gates+0x2b/0x740
[ 23.908757] PGD 99ca067 PUD 99c4067 PMD 0
[ 23.910789] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 23.913485] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.5.0-rc6-wt+ #43
[ 23.916675] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
[ 23.920471] task: ffffffff81685500 ti: ffffffff81678000 task.ti: ffffffff81678000
[ 23.922619] RIP: 0010:[<ffffffff814c910b>] [<ffffffff814c910b>] mesh_path_send_to_gates+0x2b/0x740
[ 23.925237] RSP: 0018:ffff88000b403d30 EFLAGS: 00010286
[ 23.926739] RAX: 0000000000000000 RBX: ffff880009bc0d20 RCX: 0000000000000102
[ 23.928796] RDX: 000000000000002e RSI: 0000000000000001 RDI: ffff880009bc0d20
[ 23.930895] RBP: ffff88000b403e18 R08: 0000000000000001 R09: 0000000000000001
[ 23.932917] R10: 0000000000000000 R11: 0000000000000001 R12: ffff880009c20940
[ 23.936370] R13: ffff880009bc0e70 R14: ffff880009c21c40 R15: ffff880009bc0d20
[ 23.939823] FS: 0000000000000000(0000) GS:ffff88000b400000(0000) knlGS:0000000000000000
[ 23.943688] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 23.946429] CR2: 0000000000000008 CR3: 00000000099c5000 CR4: 00000000000006b0
[ 23.949861] Stack:
[ 23.950840] 000000000000002e ffff880009c20940 ffff88000b403da8 ffffffff8109e551
[ 23.954467] ffffffff82711be2 000000000000002e 0000000000000000 ffffffff8166a5f5
[ 23.958141] 0000000000685ce8 0000000000000246 ffff880009bc0d20 ffff880009c20940
[ 23.961801] Call Trace:
[ 23.962987] <IRQ>
[ 23.963963] [<ffffffff8109e551>] ? vprintk_emit+0x351/0x5e0
[ 23.966782] [<ffffffff8109e8ff>] ? vprintk_default+0x1f/0x30
[ 23.969529] [<ffffffff810ffa41>] ? printk+0x48/0x50
[ 23.971956] [<ffffffff814ceef3>] mesh_path_timer+0x133/0x160
[ 23.974707] [<ffffffff814cedc0>] ? mesh_nexthop_resolve+0x230/0x230
[ 23.977775] [<ffffffff810b04ee>] call_timer_fn+0xce/0x330
[ 23.980448] [<ffffffff810b0425>] ? call_timer_fn+0x5/0x330
[ 23.983126] [<ffffffff814cedc0>] ? mesh_nexthop_resolve+0x230/0x230
[ 23.986091] [<ffffffff810b097c>] run_timer_softirq+0x22c/0x390

Instead of cancelling in the RCU callback, set a new flag to prevent the
timer from being rearmed, and then cancel the timer synchronously when
freeing the mesh path. This leaves mesh_path_reclaim() doing nothing
but kfree, so switch to kfree_rcu().

Fixes: 3b302ada7f0a ("mac80211: mesh: move path tables into if_mesh")
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: convert path table to rhashtable

In the time since the mesh path table was implemented as an
RCU-traversable, dynamically growing hash table, a generic RCU
hashtable implementation was added to the kernel.

Switch the mesh path table over to rhashtable to remove some code
and also gain some features like automatic shrinking.

Cc: Thomas Graf <tgraf@suug.ch>
Cc: netdev@vger.kernel.org
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: embed known gates list in struct mesh_path

The mesh path table uses a struct mesh_node in its hlists in
order to support a resizable hash table: the mesh_node provides
an indirection to the actual mesh path so that two different
bucket lists can point to the same path entry.

However, for the known gates list, we don't need this indirection
because there is ever only one list. So we can just embed the
hlist_node in the mesh path itself, which simplifies things a bit
and saves a linear search whenever we need to find an item in
the list.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: factor out common mesh path allocation code

Remove duplicate code to allocate and initialize a mesh
path or mesh proxy path.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: don't hash sdata in mpath tables

Now that the sdata pointer is the same for all entries of a
path table, hashing it is pointless, so hash only the address.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: move path tables into if_mesh

The mesh path and mesh gate hashtables are global, containing
all of the mpaths for every mesh interface, but the paths are
all tied logically to a single interface. The common case is
just a single mesh interface, so optimize for that by moving
the global hashtable into the per-interface struct.

Doing so allows us to drop sdata pointer comparisons inside
the lookups and also saves a few bytes of BSS and data.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Unify mesh and mpp path removal function

mpp_path_del() and mesh_path_del() are mostly the same function.
Move common code into a new static function.

Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: let unused MPP table entries timeout

Remember the last time when a mpp table entry is used for
rx or tx and remove them after MESH_PATH_EXPIRE time.

Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Remove MPP table entries with MPath

Make the mesh_path_del() function remove all mpp table entries
that are proxied by the removed mesh path.

Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: drop constant field mean_chain_len

The mean_chain_len field in struct mesh_table is copied whenever a
new mesh table is allocated, but only ever has the value 2 and is
never otherwise updated, so just remove it and use the related
define instead.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: print MAC address instead of pointer

There's no point in printing the mpath pointer since it can't
be used for anything - print the MAC address instead (like in
the forwarding case.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh: fix call_rcu() usage

When using call_rcu(), the called function may be delayed quite
significantly, and without a matching rcu_barrier() there's no
way to be sure it has finished.
Therefore, global state that could be gone/freed/reused should
never be touched in the callback.

Fix this in mesh by moving the atomic_dec() into the caller;
that's not really a problem since we already unlinked the path
and it will be destroyed anyway.

This fixes a crash Jouni observed when running certain tests in
a certain order, in which the mesh interface was torn down, the
memory reused for a function pointer (work struct) and running
that then crashed since the pointer had been decremented by 1,
resulting in an invalid instruction byte stream.

Cc: stable@vger.kernel.org
Fixes: eb2b9311fd00 ("mac80211: mesh path table implementation")
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: implement cfg80211_ops to query mesh proxy path table

Implement get_mpp and dump_mpp cfg80211_ops to export the content of the
802.11s mesh proxy path table to userspace.

Signed-off-by: Henning Rogge <henning.rogge@fkie.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: Replace rcu_dereference() with rcu_access_pointer()

The "rcu_dereference()" calls are used directly in conditions.
Since their return values are never dereferenced it is recommended to
use "rcu_access_pointer()" instead of "rcu_dereference()".
Therefore, this patch makes the replacements.

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: Johannes Berg <johannes.berg@intel.com>

mac80211: remove BUG_ON usage

These BUG_ON statements should never trigger, but in the unlikely
event that somebody does manage don't stop everything but simply
exit the code path with an error.

Leave the one BUG_ON where changing it would result in a NULL
pointer dereference.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: use put_unaligned_le in mesh when necessary

Use put_unaligned_le16 and put_unaligned_le32 for
mesh_path_error_tx and mesh_path_sel_frame_tx.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: return new mpath from mesh_path_add()

Most times that mesh_path_add() is called, it is followed by
a lookup to get the just-added mpath. We can instead just
return the new mpath in the case that we allocated one (or the
existing one if already there), so do that. Also, reorder the
code in mesh_path_add a bit so that we don't need to allocate
in the pre-existing case.

Signed-off-by: Bob Copeland <bob@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

hlist: drop the node parameter from iterators

I'm not sure why, but the hlist for each entry iterators were conceived

list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mac80211: clean up mesh code

There's various code with strange indentation,
questionable loop and locking constructs, etc.

The bigger change is moving the "sdata" argument
to the first argument of all functions, like all
other mac80211 functions that have one.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: constify IE parsing

Make all the parsed IE pointers const, and propagate
the change to all the users etc.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: mesh power save basics

Add routines to
- maintain a PS mode for each peer and a non-peer PS mode
- indicate own PS mode in transmitted frames
- track neighbor STAs power modes
- buffer frames when neighbors are in PS mode
- add TIM and Awake Window IE to beacons
- release frames in Mesh Peer Service Periods

Add local_pm to sta_info to represent the link-specific power
mode at this station towards the remote station. When a peer
link is established, use the default power mode stored in mesh
config. Update the PS status if the peering status of a neighbor
changes.
Maintain a mesh power mode for non-peer mesh STAs. Set the
non-peer power mode to active mode during peering. Authenticated
mesh peering is currently not working when either node is
configured to be in power save mode.

Indicate the current power mode in transmitted frames. Use QoS
Nulls to indicate mesh power mode transitions.
For performance reasons, calls to the function setting the frame
flags are placed in HWMP routing routines, as there the STA
pointer is already available.

Add peer_pm to sta_info to represent the peer's link-specific
power mode towards the local station. Add nonpeer_pm to
represent the peer's power mode towards all non-peer stations.
Track power modes based on received frames.

Add the ps_data structure to ieee80211_if_mesh (for TIM map, PS
neighbor counter and group-addressed frame buffer).

Set WLAN_STA_PS flag for STA in PS mode to use the unicast frame
buffering routines in the tx path. Update num_sta_ps to buffer
and release group-addressed frames after DTIM beacons.

Announce the awake window duration in beacons if in light or
deep sleep mode towards any peer or non-peer. Create a TIM IE
similarly to AP mode and add it to mesh beacons. Parse received
Awake Window IEs and check TIM IEs for buffered frames.

Release frames towards peers in mesh Peer Service Periods. Use
the corresponding trigger frames and monitor the MPSP status.
Append a QoS Null as trigger frame if neccessary to properly end
the MPSP. Currently, in HT channels MPSPs behave imperfectly and
show large delay spikes and frame losses.

Signed-off-by: Marco Porsch <marco@cozybit.com>
Signed-off-by: Ivan Bezyazychnyy <ivan.bezyazychnyy@gmail.com>
Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: clean up mpath_move_to_queue()

Use skb_queue_walk_safe instead, and fix a few issues:

- didn't free old skbs on moving
- didn't react to failed skb alloc
- needlessly held a local pointer to the destination frame queue
- didn't check destination queue length before adding skb

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: use skb_queue_walk() in mesh_path_assign_nexthop

Since all we really want is just to iterate over all skbs, do just that
and avoid (de)queueing to a clusmy tmpq.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mac80211: use eth_broadcast_addr

Instead of memset().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net: Fix (nearly-)kernel-doc comments for various functions

Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: clean up debugging

There are a few things that make the logging and
debugging in mac80211 less useful than it should
be right now:
* a lot of messages should be pr_info, not pr_debug
* wholesale use of pr_debug makes it require *both*
Kconfig and dynamic configuration
* there are still a lot of ifdefs
* the style is very inconsistent, sometimes the
sdata->name is printed in front

Clean up everything, introducing new macros and
separating out the station MLME debugging into
a new Kconfig symbol.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net: mac80211: Convert printk(KERN_DEBUG to pr_debug

Standardize the debugging to be able to use dynamic_debug.

Coalesce formats, align arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Convert compare_ether_addr to ether_addr_equal

Use the new bool function ether_addr_equal to add
some clarity and reduce the likelihood for misuse
of compare_ether_addr for sorting.

Done via cocci script:

$ cat compare_ether_addr.cocci
@@
expression a,b;
@@
- !compare_ether_addr(a, b)
+ ether_addr_equal(a, b)

@@
expression a,b;
@@
- compare_ether_addr(a, b)
+ !ether_addr_equal(a, b)

@@
expression a,b;
@@
- !ether_addr_equal(a, b) == 0
+ ether_addr_equal(a, b)

@@
expression a,b;
@@
- !ether_addr_equal(a, b) != 0
+ !ether_addr_equal(a, b)

@@
expression a,b;
@@
- ether_addr_equal(a, b) == 0
+ !ether_addr_equal(a, b)

@@
expression a,b;
@@
- ether_addr_equal(a, b) != 0
+ ether_addr_equal(a, b)

@@
expression a,b;
@@
- !!ether_addr_equal(a, b)
+ ether_addr_equal(a, b)

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: fix the assignment of PREQ's MAC address for Proactive RANN

Record the RANN sender's address only for RANNs that meet the acceptance
criteria (per sections 13.10.12.4.2).

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
Reviewed-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix smatch lock errors in mesh

smatch was complaining:

CHECK net/mac80211/mesh_pathtbl.c
net/mac80211/mesh_pathtbl.c:562 mesh_path_add() error: double lock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:580 mesh_path_add() error: double unlock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:589 mesh_path_add() error: double unlock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:691 mpp_path_add() error: double lock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:707 mpp_path_add() error: double unlock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:716 mpp_path_add() error: double unlock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:814 mesh_path_flush_by_nexthop() error:
double lock 'bottom_half:'
net/mac80211/mesh_pathtbl.c:819 mesh_path_flush_by_nexthop() error:
double unlock 'bottom_half:'
net/mac80211/mesh_pathtbl.c:887 mesh_path_del() error: double lock
'bottom_half:'
net/mac80211/mesh_pathtbl.c:901 mesh_path_del() error: double unlock
'bottom_half:'

So don't lock / unlock with _bh() while bottom halves are already
disabled.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: use compare_ether_addr on MAC addresses instead of memcmp

Because of the constant size and guaranteed 16 bit alignment, the inline
compare_ether_addr function is much cheaper than calling memcmp.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Convert call_rcu() to kfree_rcu(), drop mesh_gate_node_reclaim()

The call_rcu() in mesh_gate_del() invokes mesh_gate_node_reclaim(),
which simply calls kfree(). So convert the call_rcu() to kfree_rcu(),
allowing mesh_gate_node_reclaim() to be eliminated.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org

mac80211: rename mesh static path_lookup()

If you want to use mesh support from mac80211 on a recent
kernel on 2.6.24 you'll run into a name clash when compiling
against include/linux/namei.h, so rename this routine.

/home/mcgrof/tmp/compat-wireless-3.2.5-1/net/mac80211/mesh_pathtbl.c: At top level:
/home/mcgrof/tmp/compat-wireless-3.2.5-1/net/mac80211/mesh_pathtbl.c:342:26: error: conflicting types for ‘path_lookup’
include/linux/namei.h:71:12: note: previous declaration of ‘path_lookup’ was here

Although this could sit as a separate patch in compat-wireless it seems
best to just merge upstream.

Cc: Javier Cardona <javier@cozybit.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@frijolero.org>
Acked-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: don't initiate path discovery when forwarding frame with unknown DA

We used to initiate a path discovery when receiving a frame for which
there is no forwarding information. To cut down on PREQ spam, just send
a (gated) PERR in response.

Also separate path discovery logic from nexthop querying. This patch
means we no longer queue frames when forwarding, so kill the PERR TX
stuff in discard_frame().

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: failed forwarded mesh frame addressing

Don't write the TA until next hop is actually known, since we might need
the original TA for sending a PERR. Previously we would send a PERR to
ourself if path resolution for a forwarded frame failed.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix RCU warnings in mesh

Sparse RCU checking reports two warnings in the mesh
path table code. These are due to questionable uses of
rcu_dereference.

To fix the first one, get rid of mesh_gate_add() and
just make mesh_path_add_gate() do the correct deref.

To fix the second one, simply remove rcu_dereference()
in mesh_gate_del() -- it already gets a proper pointer
as indicated by the prototype (no __rcu annotation)
and confirmed by the code.

Cc: Javier Cardona <javier@cozybit.com>
Cc: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: simplify mesh frame queue mapping and QoS

We only need to set the skb queue twice:

1. by the netdev, on local TX.
2. when forwarding a mesh frame.

We only need to set the qos header twice:

1. by mac80211, on local TX.
2. when putting a frame on the mpath->frame_queue

We also don't need the RA in order to set the proper queue mapping since
all mesh STAs are QoS, indicate this and do it once when the frame is
received. Also fixes an issue where the QoS header and queue mapping was not
set for unicast forwarded frames.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Mesh data frames must have the QoS header

Per sec 7.1.3.5 of draft 12.0 of 802.11s, mesh frames indicate the
presence of the mesh control header in their QoS header.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Start implementing QoS support for mesh interfaces

In order to support QoS in mesh, we need to assign queue mapping only
after the next hop has been resolved, both for forwarded and locally
originated frames. Also, now that this is fixed, remove the XXX comment
in ieee80211_select_queue().

Also, V-Shy Ho reported that the queue mapping was not being applied to
the forwarded frame (fwd_skb instead of skb). Fixed that as well.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: handle allocation failures in mesh_pathtbl_init()

The calls to kzalloc() weren't checked here and it upsets the static
checkers. Obviously they're not super likely to fail, but we might
as well add some error handling.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Consolidate mesh path duplicated functions

Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Consolidate {mesh,mpp}_path_flush into one function

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Don't iterate twice over all mpaths when once in sufficient

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Remove redundant mesh path expiration checks

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Improve mpath state locking

No need to take the mpath state lock when an mpath is removed.
Also, no need checking the lock when reading mpath flags.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Remove mesh paths when an interface is removed

When an interface is removed, the mesh paths associated with it should
also be removed.

This fixes a bug we observed when reloading a device driver module
without reloading mac80211s.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Fix RCU pointer dereference in mesh_path_discard_frame()

Reported by Pedro Larbig (ASPj)

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: refactor skb copy to failq in mesh_path_move_to_queue

This seems a bit less awkward...

Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: mesh gate fixes

Since a v1 of the mesh gate series was accidentally applied, this patch
contains the changes in v2.

These are:
- automatically make mesh gate a root node.
- use TU_TO_EXP_TIME macro.
- initialize timer instead of checking for NULL timer function.
- cleanups.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: mesh gate implementation

In this implementation, a mesh gate is a root node with a certain bit
set in its RANN flags. The mpath to this root node is marked as a path
to a gate, and added to our list of known gates for this if_mesh. Once a
path discovery process fails, we forward the unresolved frames to a
known gate. Thanks to Luis Rodriguez for refactoring and bug fix help.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix mesh path flushing

Previously, mpaths were never flushed since the mpath is not active once
we call this function.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: mesh locking fixes

mesh_queue_preq is invoked invoked from both user (work queue) and
softirq (timer) context, so the _bh version of spinlock needs to be
used. Also, the mpath->state_lock should be softirq safe as well.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix mpath timer NULL function

If we have an mpath whose timer has not been initialized, don't try to
delete it.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: improve mpath debugging

make hwmp_dbg print the relevant sdata->name by default and improve
formatting. Also add mpath_dbg macro for debugging of mesh path
operations.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: update mesh path selection frame format

Make mesh path selection frames Mesh Action category, remove outdated
Mesh Path Selection category and defines, use updated reason codes, add
mesh_action_is_path_sel for readability, and update/correct path
selection IEs.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net: cleanup some rcu_dereference_raw

RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mac80211: fix smatch complains

mlme.c
l.757 ieee80211_dynamic_ps_enable_work(11)
variable dereferenced before check 'sdata'

mesh_pathtbl.c
l.650 mesh_path_del(20) double lock 'bottom_half'
l.663 mesh_path_del(33) double unlock 'bottom_half'

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Don't sleep when growing the mesh path

After commit 1928ecab620907a0953f811316d05f367f3f4dba (mac80211: fix and
simplify mesh locking) mesh table allocation is performed with the
pathtbl_resize_lock taken. Under those conditions one should not sleep.
This patch makes the allocations GFP_ATOMIC to prevent that.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: annotate and fix RCU in mesh code

This adds proper RCU annotations to the mesh path
table code, and fixes a number of bugs in the code
that I found while checking the sparse warnings I
got as a result of the annotations.

Some things like the changes in mesh_path_add() or
mesh_pathtbl_init() only serve to shut up sparse,
but other changes like the changes surrounding the
for_each_mesh_entry() macro fix real RCU bugs in
the code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix and simplify mesh locking

The locking in mesh_{mpath,mpp}_table_grow not only
has an rcu_read_unlock() missing, it's also racy
(though really only technically since it's invoked
from a single function only) since it obtains the
new size of the table without any locking, so two
invocations of the function could attempt the same
resize.

Additionally, it uses synchronize_rcu() which is
rather expensive and can be avoided trivially here.

Modify the functions to only use the table lock
and use call_rcu() instead of synchronize_rcu().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Deactivate mesh path timers when freeing nodes

Mesh paths are deleted via mesh_path_del() which properly
deactivates the timer associated to a mesh path. But if paths were
deleted by mesh_table_free(..., true) timers would not be deactivated.
This fixes this case.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: mesh: move some code to make it static

There's no need to have table functions in one
file and all users in another, move the functions
to the right file and make them static. Also move
a static variable to the beginning of the file to
make it easier to find.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Fix locking bug on mesh path table access

The mesh and mpp path tables are accessed from softirq and workqueue
context so non-irq locking cannot be used. Or at least that's what
PROVE_RCU seems to tell us here:

[ 431.240946] =================================
[ 431.241061] [ INFO: inconsistent lock state ]
[ 431.241061] 2.6.39-rc3-wl+ #354
[ 431.241061] ---------------------------------
[ 431.241061] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
[ 431.241061] kworker/u:1/1423 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 431.241061] (&(&newtbl->hashwlock[i])->rlock){+.?...}, at:
[<c14671bf>] mesh_path_add+0x167/0x257

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Check size of a new mesh path table for changes since allocation.

Not sure if I'm chasing a ghost here, seems like the
mesh_path->size_order needs to be inside an RCU-read section to prevent
that value from changing between table allocation and copying. We have
observed crashes that might be caused by this.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Allocate new mesh path and portal tables before taking locks

It is unnecessary to hold the path table resize lock while allocating a
new table. Allocate first and take lock later. This resolves a
soft-lockup:

[ 293.385799] BUG: soft lockup - CPU#0 stuck for 61s! [kworker/u:3:744]
(...)
[ 293.386049] Call Trace:
[ 293.386049] [<c119fd04>] do_raw_read_lock+0x26/0x29
[ 293.386049] [<c14b2982>] _raw_read_lock+0x8/0xa
[ 293.386049] [<c148c178>] mesh_path_add+0xb7/0x24e
[ 293.386049] [<c148b98d>] ? mesh_path_lookup+0x1b/0xa6
[ 293.386049] [<c148ded5>] hwmp_route_info_get+0x276/0x2fd
[ 293.386049] [<c148dfb6>] mesh_rx_path_sel_frame+0x5a/0x5d9
[ 293.386049] [<c102667d>] ? update_curr+0x1cf/0x1d7
[ 293.386049] [<c148b45a>] ieee80211_mesh_rx_queued_mgmt+0x60/0x67
[ 293.386049] [<c147c374>] ieee80211_iface_work+0x1f0/0x258
(...)

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

nl80211/mac80211: define and allow configuring mesh element TTL

The TTL in path selection information elements is different from
the mesh ttl used in mesh data frames. Version 7.03 of the 11s
draft calls this ttl 'Element TTL'.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: use common work struct

IBSS, managed and mesh modes all have their
own work struct, and in the future we want
to also use it in other modes to process
frames from the now common skb queue.

This also makes the skb queue and work safe
to use from other interface types.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

mac80211: reduce reliance on netdev

For bluetooth 3, we will most likely not have
a netdev for a virtual interface (sdata), so
prepare for that by reducing the reliance on
having a netdev. This patch moves the name
and address fields into the sdata struct and
uses them from there all over. Some work is
needed to keep them sync'ed, but that's not
a lot of work and in slow paths anyway.

In doing so, this also reduces the number of
pointer dereferences in many places, because
of things like sdata->dev->dev_addr becoming
sdata->vif.addr.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

tree-wide: fix assorted typos all over the place

That is "success", "unknown", "through", "performance", "[re|un]mapping"
, "access", "default", "reasonable", "[con]currently", "temperature"
, "channel", "[un]used", "application", "example","hierarchy", "therefore"
, "[over|under]flow", "contiguous", "threshold", "enough" and others.

Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

mac80211: fix endianess on mesh_path_error_tx() calls

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: use fixed broadcast address

The netdev broadcast address cannot change from
all-ones so there's no need to use it; we can
instead hard-code it. Since we already have an
instance in tkip.c, which will be shared if it
is marked static const, doing this reduces text
size at no data/bss cost.

The real motivation for this is, of course, the
desire to get rid of almost all uses of netdevs
in mac80211 so that auditing their use becomes
easier.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: update copyrights to 2009

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Andrey Yurovsky <andrey@cozybit.com>
Tested-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: replace "destination" with "target" to follow the spec

Resulting object files have the same MD5 as before.

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Andrey Yurovsky <andrey@cozybit.com>
Tested-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: update PERR frame format

Update the PERR IE frame format according to latest draft (3.03).

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Andrey Yurovsky <andrey@cozybit.com>
Tested-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Move mpath and mpp growth to mesh workqueue.

This prevents calling rcu_synchronize from within the tx path by moving the
table growth code to the mesh workqueue.

Move mesh_table_free and mesh_table_grow from mesh.c to mesh_pathtbl.c and
declare them static.

Also, re-enable mesh in Kconfig and update the configuration description.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Tested-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

nl80211: add generation number to all dumps

In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.

This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.

The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Fix regression in mesh forwarding path.

The removal of the master netdev broke the mesh forwarding path. This patch
fixes it by using the new internal 'pending' queue.

As a result of this change, mesh forwarding no longer does the inefficient
802.11 -> 802.3 -> 802.11 conversion that was done before.

[Changes since v1]
Suggested by Johannes:
- Select queue before adding to mpath queue
- ieee80211_add_pending_skb -> ieee80211_add_pending_skbs
- Remove unnecessary header wme.h

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Assign next hop address to pending mesh frames

Assign next hop address to pending mesh frames once the path is resolved.

Regression. Frames transmitted when a mesh path was wating to be resolved were
being transmitted with an invalid Receiver Address.

[Changes since v1]

Suggested by Johannes:
- Improved frame_queue traversal
- Narower RCU scope

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: use correct address for mesh Path Error

For forwarded frames, we save the precursor address in addr1 in case it
needs to be used to send a Path Error. mesh_path_discard_frame,
however, was using addr2 instead of addr1 to send Path Error frames, so
correct that and also make the comment regarding this more clear.

Signed-off-by: Andrey Yurovsky <andrey@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: disable mesh

My kvm instance was complaining a lot about sleeping
in atomic contexts in the mesh code, and it turns out
that both mesh_path_add() and mpp_path_add() need to
be able to sleep (they even use synchronize_rcu()!).
I put in a might_sleep() to annotate that, but I see
no way, at least right now, of actually making sure
those functions are only called from process context
since they are both called during TX and RX and the
mesh code itself even calls them with rcu_read_lock()
"held".

Therefore, let's disable it completely for now.

It's possible that I'm only seeing this because the
hwsim's beaconing is broken and thus the peers aren't
discovered right away, but it is possible that this
happens even if beaconing is working, for a peer that
doesn't exist or so.

It should be possible to solve this by deferring the
freeing of the tables to call_rcu() instead of using
synchronize_rcu(), and also using atomic allocations,
but maybe it makes more sense to rework the code to
not call these from atomic contexts and defer more of
the work to the workqueue. Right now, I can't work on
either of those solutions though.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: mesh portal functionality support

Currently the mesh code doesn't support bridging mesh point interfaces
with wired ethernet or AP to construct an MPP or MAP. This patch adds
code to support the "6 address frame format packet" functionality to
mesh point interfaces. Now the mesh network can be used as backhaul
for end to end communication.

Signed-off-by: Li YanBo <dreamfly281@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: split off mesh handling entirely

This patch splits off mesh handling from the STA/IBSS.
Unfortunately it increases mesh code size a bit, but I
think it makes things clearer. The patch also reduces
per-interface run-time memory usage.

Also clean up a few places where ifdef is not required.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

replace net_device arguments with ieee80211_{local,sub_if_data} as appropriate

This patch replaces net_device arguments to mac80211 internal functions
with ieee80211_{local,sub_if_data} as appropriate.

It also does the same for many 802.11s mesh functions, and changes the
mesh path table to be indexed on sub_if_data rather than net_device.

If the mesh part needs to be a separate patch let me know, but since
mesh uses a lot of mac80211 functions which were being converted anyway,
the changes go hand-in-hand somewhat.

This patch probably does not convert all the functions which could be
converted, but it is a large chunk and followup patches will be
provided.

Signed-off-by: Jasper Bryant-Greene <jasper@amiton.co.nz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix use of skb->cb for mesh forwarding

Now we deal with mesh forwarding before the 802.11->802.3 conversion, thus
eliminating a few unnecessary steps. The next hop lookup is called from
ieee80211_master_start_xmit() instead of subif_start_xmit(). Until the next hop
is found, RA in the frame will be all zeroes for frames originating from the
device. For forwarded frames, RA will contain the TA of the received frame,
which will be necessary to send a path error if a next hop is not found.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

build algorithms into the mac80211 module

The old infrastructure was:
- the default algorithm is built into mac80211
- other algorithms get into their own modules

The implementation of this complicated scheme was horrible
(just look at net/mac80211/Makefile), and anyone adding a new
algorithm would most likely not get it right at his first attempt.

This patch therefore builds all enabled algorithms into the mac80211
module.

The user interface for the rate control algorithms changes as follows:
- first the user can choose which algorithms to enable (currently only
MAC80211_RC_PID is available)
- if more than one algorithm is enabled (currently not possible since
only one algorithm is present) the user then chooses the default one

Note:
- MAC80211_RC_PID is always enables for CONFIG_EMBEDDED=n

Technical changes:
- all selected algorithms get into the mac80211 module
- net/mac80211/Makefile can now become much less complicated
- support for rc80211_pid_algo.c being modular is no longer required
- this includes unexporting mesh_plink_broken

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Do not report false error from mesh_path_add.

In case the hash grow failed, it is not fair to return error -
the new node _was_ _actually_ added in this case.

Besides, after my previous patch, this grow is more likely
to fail on large hashes.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Fix sleeping allocation under lock in mesh_path_node_copy.

The mesh_path_node_copy() can be called like this:
mesh_path_add
`- write_lock(&pathtbl_resize_lock); /* ! */
`- mesh_table_grow
`- ->copy_node
`- mesh_path_node_copy

thus, the GFP_KERNEL is not suitable here.

The acceptable fix, I suppose, is make this allocation GPF_ATOMIC -
the mpath_node being allocated is 4 pointers, i.e. this allocation
is small enough to survive even under a moderate memory pressure.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Report allocation failure from mesh_path_node_copy.

Now - return the -ENOMEM in case kmalloc fails.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Prepare mesh_table_grow to failing copy_node callback.

The mesh_path_node_copy() performs kmalloc() and thus - may fail
(well, it does not now, but I'm fixing this right now). Its caller -
the mesh_table_grow() - isn't prepared for such a trick yet.

This preparation is just flush the new hash and make copy_node()
return an int value.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Fix one more call to synchronize_rcu in atomic context.

(This set applies OK without the previous one of 4 patches,
but with some fuzz in the 7th one)

The mesh_path_node_free() does so under hashwlock.

But, this one is called
1. from mesh_path_add() after an old hash is hidden and
synchronize_rcu() is calld
2. mesh_pathtbl_unregister(), when the module is being
unloaded and no devices exist to mess with this hash.

So, it seems to me, that simply removing the call is OK.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: Brush up error paths in mesh_path_add.

There are already tree paths, that do incremental rollbacks, so
merge them together, rename labels and format the code to look a
bit nicer.

(I do not mind dropping/delaying this patch however).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Fix potential scheduling while atomic in mesh_path_add.

Calling synchronize_rcu() under write-lock-ed pathtbl_resize_lock may
result in this warning (and other side effects).

It looks safe just dropping this lock before calling synchronize_rcu.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Fix not checked kmalloc() result.

The new_node kmallocation is not checked for success, so add
this check.

BTW, it also happens under the read_lock.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

Fix GFP_KERNEL allocation under read lock.

The mesh_path_add() read-locks the pathtbl_resize_lock and calls
kmalloc with GFP_KERNEL mask.

Fix it and move the endadd2 label lower. It should be _before_ the
if() beyond, but it makes no sense for it being there, so I move it
right after this if().

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: fix mesh_path and sta_info get_by_idx functions

Skip properly entries whose dev does not match.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: add PLINK_ prefix and kernel doc to enum plink_state

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: always force mesh_path deletions

Postponing the deletion is not really useful anymore.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: delete mesh_path timer on mesh_path removal

This avoids dereferencing a no longer existing struct mesh_path.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: don't clear next_hop in path reclaim

Luis pointed out that this path is going to be freed right
away anyway so there's no point in assigning next_hop.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: RCU-ify STA info structure access

This makes access to the STA hash table/list use RCU to protect
against freeing of items. However, it's not a true RCU, the
copy step is missing: whenever somebody changes a STA item it
is simply updated. This is an existing race condition that is
now somewhat understandable.

This patch also fixes the race key freeing vs. STA destruction
by making sure that sta_info_destroy() is always called under
RTNL and frees the key.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: export mesh_plink_broken

This needs to be exported because rate control algorithms
can be modular.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

mac80211: mesh path table implementation

The mesh path table associates destinations with the next hop to reach them. The
table is a hash of linked lists protected by rcu mechanisms. Every mesh path
contains a lock to protect the mesh path state.

Each outgoing mesh frame requires a look up into this table. Therefore, the
table it has been designed so it is not necessary to hold any lock to find the
appropriate next hop.

If the path is determined to be active within a rcu context we can safely
dereference mpath->next_hop->addr, since it holds a reference to the sta
next_hop. After a mesh path has been set active for the first time it next_hop
must always point to a valid sta. If this is not possible the mpath must be
deleted or replaced in a RCU safe fashion.

Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>