Quite a while ago I started this book. The required kernel-doc
patches have since gone into the tree so it is now possible to
build the book in mainline.

The actual documentation is still rather incomplete and not all
things are linked into the book, but this enables us to edit
the documentation collaboratively, hopefully driver authors can
add documentation based on their experience with mac80211.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

When we take down an interface, we need to remove the STA info
items that belong to it because otherwise we might invoke a
sta_notify() callback in the driver when we later delete the
STA entries, but in that case the driver will already have
removed its knowledge of the interface they belonged to leading
to confusion. Also, we could invoke the set_tim() callback after
the driver removed its knowledge of the interface, which can
lead to a crash if it requests a beacon with a then-invalid vif
pointer!

A side effect of this patch is that, because it was easier, it
disallows changing the WDS peer while an interface is up. Should
that actually be necessary, it can be added back, but the WDS
peer STA entry may not be added while the interface is UP so for
now I've simplified the WDS peer's STA entry lifetime management.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch cleans up the sta_info struct and documents how
each set of variables is locked. Notably, flags locking is
completely missing. It also adds kernel-doc for some (but
not all yet) members of the struct.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

sta_info_add() has two functions: allocating a station info
structure and inserting it into the hash table/list. Splitting
these two functions allows allocating with GFP_KERNEL in many
places instead of GFP_ATOMIC which is now required by the RCU
protection. Additionally, in many places RCU protection is now
no longer needed at all because between sta_info_alloc() and
sta_info_insert() the caller owns the structure.

This fixes a few race conditions with setting initial flags
and similar, but not all (see comments in ieee80211_sta.c and
cfg.c). More documentation on the existing races will be in
a follow-up patch.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

Split it into ieee80211_tx_data and ieee80211_rx_data to clarify
usage/flag usage and remove the stupid union thing.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Three __le16s followed by an enum (int) leave a two-byte hole
of padding which we can use for two of the other fields.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Accidentally copied in a __mesh_plink_deactivate, noticed by Luis
Carlos Cobo.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Moves another ifdef into the sta_info header file in favour of
compiling more code even w/o CONFIG_MAC80211_MESH.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This needs to be exported because rate control algorithms
can be modular.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This clarifies that the mesh networking code is currently
based on Draft 1.08 of the 802.11 Mesh Networking amendment.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This inserts a missing break statement which, if hit, would cause
the code to fall-through and unlock a spinlock twice. Noticed via
sparse's "lock count wrong in basic block" warning and careful
code inspection.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently marked BROKEN because of endianness problems.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This fixes missing unlocks noticed by sparse.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Various cleanups, reducing the #ifdef mess and other things.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This completes the mesh interface handling code and a few other
bits about the mac80211 module.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This adds code to allow adding mesh interfaces and configuring
mesh peers etc. Also, it adds code for station dumping.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch contains the debugfs code for mesh statistics and configuration
parameters. Please note that generic support for r/w debugfs attributes has been
added.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This file implements the on-demand Hybrid Wireless Mesh Protocol, at this moment
using hop-count as the metric. When no mesh path exists for a given destination
or the mesh path is not active, frames addressed to that destination will be
queued and a Path Request frame will be sent. Queued frames will be sent when
the path is resolved (usually after reception of a Path Response) or discarded
if discovery times out. Path Requests will also be sent to refresh paths that
are being used and are close to expiring.

Path Errors are sent when a path discovery process triggered by the attempt to
forward a frame originated in a different mesh point times out. Path Errors are
also sent when a peer link is determined to be unreachable because of high error
rates.

Multiple destination support in Path Requests and Path Errors and precursors
have not been implemented yet.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This file implements mesh discovery and peer link establishment support using
the mesh peer link table provided in mesh_plinktbl.c.

Secure peer links have not been implemented yet.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This includes support for mesh network scanning. The ugly code in
ieee80211_sta_scan_result() is my approach to work around wext. This has been
tested with wireless tools version 29 and works as expected (the new interface
mode is just not shown).
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Includes integration in struct sta_info of mesh peer link elements, previously
on their own mesh peer link table.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This changes the TX/RX paths in mac80211 to support mesh interfaces.
This code will be cleaned up later again before being enabled.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The two important features coded in mesh.c are:

Recently Multicast Cache: in on-demand HWMP, multicast traffic is retransmitted
by every receiving node. Even though a mesh TTL counter avoids infinite loops,
it is also necessary to avoid traffic explosion by keeping a cache of multicast
mesh frame that have been received recently. With this feature, maximum number
of retransmissions of a multicast frame for the case of N nodes within the range
of each other would be N. Without it, the maximum number of retransmissions
would be in the order of N^(MESH_TTL - 1).

Code to support mesh tables.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This adds the mesh interface type.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Added support for mesh id and mesh path operation as well as
station structure dumping.
Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This introduces a new WEXT type IW_MODE_MESH for mesh networks,
used for scan results.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NLuis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Introduced by changeset 95e41e93
("[IPV6]: Make ndisc_flow_init() common for later use.")

Reported by Stephen Rothwell.

In file included from net/ipv6/netfilter/ip6_tables.c:21:
include/linux/icmpv6.h:192: warning: 'struct in6_addr' declared inside parameter list
include/linux/icmpv6.h:192: warning: its scope is only this definition or declaration, which is probably not what you want
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

COSA/SRP driver: The semaphore channel_data.rsem is used as a mutex,
convert it to the mutex API
Signed-off-by: NMatthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

(Anonymous) unions can help us to avoid ugly casts.

A common cast it the (struct rtable *)skb->dst one.

Defining an union like  :
union {
     struct dst_entry *dst;
     struct rtable *rtable;
};
permits to use skb->rtable in place.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove commented lines from netns patchset.
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Conflicts:

	net/mac80211/rc80211_pid_algo.c

This patch make the changes necessary to support network namespaces in
ICMPv6.
Signed-off-by: NBenjamin Thery <benjamin.thery@bull.net>
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The different subsystem of ipv6 are ready for namespaces, so let's
activate it for ipv6_rcv.
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NBenjamin Thery <benjamin.thery@bull.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ip6_dst_lookup receive a socket as parameter. In some part of the code
it is called with a NULL socket parameter. We want to rely on the socket
to retrieve the network namespace, so we always pass a valid socket in all
cases.
Signed-off-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NBenjamin Thery <benjamin.thery@bull.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>