upper layer(s).
This eliminates the if_snd queue from net80211. Yay!
This unfortunately has a few side effects:
* It breaks ALTQ to net80211 for now - sorry everyone, but fixing
parallelism and eliminating the if_snd queue is more important
than supporting this broken traffic scheduling model. :-)
* There's no VAP and IC flush methods just yet - I think I'll add
some NULL methods for now just as placeholders.
* It reduces throughput a little because now net80211 will drop packets
rather than buffer them if the driver doesn't do its own buffering.
This will be addressed in the future as I implement per-node software
queues.
Tested:
* ath(4) and iwn(4) in STA operation
the normal and the mesh transmit paths can use.
The API is a bit horrible because it both consumes the mbuf and frees
the node reference regardless of whether it succeeds or not.
It's a hold-over from how the code behaves; it'd be nice to have it
not free the node reference / mbuf if TX fails and let the caller
decide what to do.
* Add 802.11n 2ghz and 5ghz tables, including legacy rates and up to
MCS23 rates (3x3.)
* Populate the rate code -> rate index lookup table with MCS _and_
normal rates, but _not_ the basic rate flag. Since the basic rate flag
is the same as the MCS flag, we can only use one.
* Introduce some accessor inlines that do PLCP and rate table lookup/access
and enforce that it doesn't set the basic rate bit. They're not
designed for MCS rates, so it will panic.
* Start converting drivers that use the rate table stuff to use the
accessor inlines and strip the basic flag.
* Teach AMRR about basic 11n - it's still as crap for MCS as it is
being used by iwn, so it's not a step _backwardS_.
* Convert iwn over to accept 11n MCS rates rather than 'translate' legacy
to MCS rates. It doesn't use a lookup table any longer; instead it's a
function which takes the current node (for HT parameters) and the
rate code, and returns the hardware PLCP code to use.
Tested:
* ath - it's a no-op, and it works that way
* iwn - both 11n and non-11n
The "find node" function call will increase the node reference anyway;
so there's no reason to hold the node table lock during the MLME change.
The only reason I could think of is to stop overlapping mlme ioctls
from causing issues, but this should be fixed a different way.
This fixes a whole class of LORs that creep up when nodes are being
timed out or removed by hostapd.
Tested:
* AR5416, hostap, with nodes coming and going. No LORs or stability
issues were observed.
When creating fragment frames, the header length should honour the
DATAPAD flag.
This fixes the fragments that are queued to the ath(4) driver but it
doesn't yet fix fragment transmission. That requires further changes
to the ath(4) transmit path. Well, strictly speaking, it requires
further changes to _all_ wifi driver transmit paths, but this is at least
a start.
Tested:
* AR5416, STA mode, w/ fragthreshold set to 256.
before using said node.
The "blessed" way here is to take a node reference before referencing
anything inside the node, otherwise the node can be freed between
the time the pointer is copied/dereferenced and the time the node contents
are used.
This mirrors fixes that I've done elsewhere in the net80211/driver
stack.
PR: kern/178470
the given node.
This takes into account the per-node cap, the ic cap and the
per-channel regulatory caps.
This is designed to replace references to ni_txpower in various net80211
drivers - ni_txpower doesn't necessarily reflect the actual cap for
the given node (eg if the node has the default value of 50dBm (100) and
the administrator has manually configured a lower TX power.)
This patchset implements a new TX lock, covering both the per-VAP (and
thus per-node) TX locking and the serialisation through to the underlying
physical device.
This implements the hard requirement that frames to the underlying physical
device are scheduled to the underlying device in the same order that they
are processed at the VAP layer. This includes adding extra encapsulation
state (such as sequence numbers and CCMP IV numbers.) Any order mismatch
here will result in dropped packets at the receiver.
There are multiple transmit contexts from the upper protocol layers as well
as the "raw" interface via the management and BPF transmit paths.
All of these need to be correctly serialised or bad behaviour will result
under load.
The specifics:
* add a new TX IC lock - it will eventually just be used for serialisation
to the underlying physical device but for now it's used for both the
VAP encapsulation/serialisation and the physical device dispatch.
This lock is specifically non-recursive.
* Methodize the parent transmit, vap transmit and ic_raw_xmit function
pointers; use lock assertions in the parent/vap transmit routines.
* Add a lock assertion in ieee80211_encap() - the TX lock must be held
here to guarantee sensible behaviour.
* Refactor out the packet sending code from ieee80211_start() - now
ieee80211_start() is just a loop over the ifnet queue and it dispatches
each VAP packet send through ieee80211_start_pkt().
Yes, I will likely rename ieee80211_start_pkt() to something that
better reflects its status as a VAP packet transmit path. More on
that later.
* Add locking around the management and BAR TX sending - to ensure that
encapsulation and TX are done hand-in-hand.
* Add locking in the mesh code - again, to ensure that encapsulation
and mesh transmit are done hand-in-hand.
* Add locking around the power save queue and ageq handling, when
dispatching to the parent interface.
* Add locking around the WDS handoff.
* Add a note in the mesh dispatch code that the TX path needs to be
re-thought-out - right now it's doing a direct parent device transmit
rather than going via the vap layer. It may "work", but it's likely
incorrect (as it bypasses any possible per-node power save and
aggregation handling.)
Why not a per-VAP or per-node lock?
Because in order to ensure per-VAP ordering, we'd have to hold the
VAP lock across parent->if_transmit(). There are a few problems
with this:
* There's some state being setup during each driver transmit - specifically,
the encryption encap / CCMP IV setup. That should eventually be dragged
back into the encapsulation phase but for now it lives in the driver TX path.
This should be locked.
* Two drivers (ath, iwn) re-use the node->ni_txseqs array in order to
allocate sequence numbers when doing transmit aggregation. This should
also be locked.
* Drivers may have multiple frames queued already - so when one calls
if_transmit(), it may end up dispatching multiple frames for different
VAPs/nodes, each needing a different lock when handling that particular
end destination.
So to be "correct" locking-wise, we'd end up needing to grab a VAP or
node lock inside the driver TX path when setting up crypto / AMPDU sequence
numbers, and we may already _have_ a TX lock held - mostly for the same
destination vap/node, but sometimes it'll be for others. That could lead
to LORs and thus deadlocks.
So for now, I'm sticking with an IC TX lock. It has the advantage of
papering over the above and it also has the added advantage that I can
assert that it's being held when doing a parent device transmit.
I'll look at splitting the locks out a bit more later on.
General outstanding net80211 TX path issues / TODO:
* Look into separating out the VAP serialisation and the IC handoff.
It's going to be tricky as parent->if_transmit() doesn't give me the
opportunity to split queuing from driver dispatch. See above.
* Work with monthadar to fix up the mesh transmit path so it doesn't go via
the parent interface when retransmitting frames.
* Push the encryption handling back into the driver, if it's at all
architectually sane to do so. I know it's possible - it's what mac80211
in Linux does.
* Make ieee80211_raw_xmit() queue a frame into VAP or parent queue rather
than doing a short-cut direct into the driver. There are QoS issues
here - you do want your management frames to be encapsulated and pushed
onto the stack sooner than the (large, bursty) amount of data frames
that are queued. But there has to be a saner way to do this.
* Fragments are still broken - drivers need to be upgraded to an if_transmit()
implementation and then fragmentation handling needs to be properly fixed.
Tested:
* STA - AR5416, AR9280, Intel 5300 abgn wifi
* Hostap - AR5416, AR9160, AR9280
* Mesh - some testing by monthadar@, more to come.
* The following bit flags where incroccetly defined:
o Mesh Control Present
o Mesh Power Save Level
o RSPI
This is now corrected according to Table 8.4 as per IEEE 802.11 2012;
Approved by: adrian (mentor)
since the former is defined everywhere. This cuts off some code not
necessary on non strict aligment arches.
Reviewed by: adrian
Sponsored by: Nginx, Inc.
* Add the superg.h header to allow ieee80211_check_ff() to work
* Since the assert stuff creates assertions based on line numbers and there
was a conflict, just nudge things down a bit.
* Added hwmp_update_transmitter function that checks if the metric
to the transmitter have improved. If old FI is invalid or metric
is larger the FI to the transmitter is updated occurdingly.
This is a recommendation from the 802.11 2012 standard, table 13-9;
Approved by: adrian (mentor)
* When calling ieee80211_mesh_rt_flush_peer, the rt->rt_dest argument
should not be passed because it can get freed before invalidating
the other routes that depends on it to compare with next_hop.
Use PERR_DADDR(i) instead;
Approved by: adrian (mentor)
* The standard is unclear about what should happen in case a mesh STA (not
marked as a mesh gate) recevies a PREQ for a destination that is marked
as proxy. Solution for now is not to do intermediate reply at all, and
let the PREQ reach the mesh gate;
Approved by: adrian (mentor)
* Original PREP frame is transmitted only by the target mesh STA or the
mesh STA that is the proxy target;
* Fixed so that metric value is not over written incorrectly in
hwmp_recv_preq for when replying back with a PREP;
Approved by: adrian (mentor)
This is a code re-write. ic->raw_xmit need a pointer to ieee80211_node
for the destination node (da). I have reorganized the code so that
a pointer to the da node is searched for in the end & in one place.
* Make mesh_find_txnode public to be used by HWMP, renamed to
ieee80211_mesh_finx_txnode;
* changed the argument from ieee80211_node to ieee80211vap for all
hwmp_send_* functions;
* removed the 'sa' argument from hwmp_send_* functions as all HWMP frames
have the source address equal to vap->iv_myaddr;
* Modified hwmp_send_action so that if da is MULTCAST ni=vap->iv_bss
otherwise we called ieee80211_mesh_find_txnode. Also no need to hold
a reference in this functions if da is not MULTICAST as by finding the
node it became referenced in ieee80211_find_txnode;
Approved by: adrian (mentor)
* Modified mesh_find_txnode to be able to handle proxy marked entries by
recursively calling itself to find the txnode towards the active mesh gate;
* Mesh Gate: Added a new function that transmits data frames
similar to ieee80211_start;
* Modified ieee80211_mesh_forward_to_gates so that:
+ Frames are duplicated and sent to each valid Mesh Gate;
+ Route is marked invalid before return of function, this is
because we dont know yet which Mesh Gate is we will use;
Approved by: adrian (mentor)
* Send frames that have no path to a known valid Mesh Gate;
* Added the function ieee80211_mesh_forward_to_gates that sends the frame
to the first found Mesh Gate in the forwarding information;
* If we try to discover again while we are discovering queue frame,
the discovery callout will send the frames either to mesh gates
or discards them silently;
* Queue frame also if we try to discover to frequently;
Approved by: adrian (mentor)
* Add function ieee80211_mesh_mark_gate in ieee80211_mesh.h;
* When received a proactive PREQ or RANN with corresponding mesh gate
flag set, create a new entry in the known mesh gate list;
Approved by: adrian (mentor)
* Modified mesh_recv_action_meshgate to do following:
+ if mesh STA already knows the mesh gate of the recevied GANN frame
+ if mesh gate is know, check seq number according to 802.11 standard
+ if mesh gate is not know, add it to the list of known mesh gates
+ if forwarding is enabled and ttl >= 1 then propagate the GANN frame;
* Declare a new malloc type M_80211_MESH_GT_RT;
* Declare a struct to store GANN information, ieee80211_mesh_gate_route. And
add it as a TAILQ list to ieee80211_mesh_state;
Approved by: adrian (mentor)
A Mesh Gate should transmit a Mesh Action frame containing
ieee80211_meshgann_ie as its only information element periodically
every ieee80211_mesh_gateint ms. Unless the mesh gate is also configure
as a ROOT, then these frames should not be send.
This is according to 802.11 2012 standard;
* Introduce new SYSCTL net.wlan.mesh.gateint, with 10s default;
* Add two new functions mesh_gatemode_setup and mesh_gatemode_cb. This
is similar to how HWMP setups up a callout;
* Add two new action handlers mesh_recv_action_meshgate and
mesh_send_action_meshgate;
* Added ieee80211_add_meshgate to ieee80211_mesh.h;
* Modified mesh_send_action to look similar to hwmp_send_action. This is
because we need to send out broadcast management frames.
* Introduced a new flag for mesh state IEEE80211_MESHFLAGS_ROOT. This flag
is now set by HWMP code when a mesh STA is configured as a ROOT. This
is then checked by mesh_gatemode_cb before scheduling a new callout;
* Added to new field to ieee80211_mesh_state:
+ struct callout ms_gatetimer
+ ieee80211_mesh_seq ms_gateseq;
Approved by: adrian (mentor)
when not peered.
* Modified ieee80211_recv_action to check if neighbour is peered for
IEEE80211_ACTION_CAT_MESH frames, if not frame is discarded. This is
according to IEEE802.11 2012 standard;
* Removed duplicate checks in each hwmp_recv_* handlers because HWMP
is a subtype of mesh action;
Approved by: adrian (mentor)
* Removed meshlm_send_action and hwmp_send_action. Introduced one common
for all Mesh Action frames meshaction_send_action. According to 802.11
standard Link Metric and HWMP are all under Mesh Action category;
* Did similar changes to recv_action part;
* The size of meshaction_*_action is set to 12. This is to make room for
the rest of Mesh Action category subtypes;
Approved by: adrian (mentor)
* Change all field prefix from pann_ to gann_;
* Added IEEE80211_MESHGANN_BASE_SZ macro to be used in the length field
of a GANN frame according to 802.11 standard;
* Changed gann_seq field type to uint32_t;
* Added a Gate Announcement interval field according to
IEEE802.11 2012 standard;
* Added IEEE80211_MESHRT_FLAGS_GATE as flag bit to ieee80211_mesh_route;
* Added IEEE80211_MESHRT_FLAGS_GATE as flag bit to ieee80211req_mesh_route;
Approved by: adrian (mentor)
* An HWMP PERR should be accepted even if path is valid. Because
we check if we recevied it from a neighbour that we use as a next hop;
Approved by: adrian (mentor)
* A bug occurs while in discovery mode which leaves a path marked with
both Discover and Valid flag. This happens when receiving/sending
PREQ and PREP in a particular order. Solution is to assign the Valid bit
instead of oring it;
Approved by: adrian (mentor)
This problem happens when using ACL policy to filter mesh STA
but two nodes have different policy. Then one of them will try to
peer all the time. This can also help if for any reason one of the
peering mesh STA have problems sending/receiving peer frames.
* Modified struct ieee80211_node to include two new fields:
+ struct callout ni_mlhtimer /* link mesh backoff timer */
+ uint8_t ni_mlhcnt /* link mesh holding counter */
* Added two new sysctl (check sysctl -d for more info):
+ net.wlan.mesh.backofftimeout=5000
+ net.wlan.mesh.maxholding=2;
* When receiving a beacon and we are in IEEE80211_NODE_MESH_IDLE
check if ni_mlhcnt >= ieee80211_mesh_maxholding, if so do not do anything;
* In mesh_peer_timeout_cb when transitioning from IEEE80211_NODE_MESH_HOLDING
to IEEE80211_NODE_MESH_IDLE increment ni_mlhcnt, and eventually start
ieee80211_mesh_backofftimeout;
Approved by: adrian (mentor)
