287197 |
27-Aug-2015 |
glebius |
Replay r286410. Change KPI of how device drivers that provide wireless connectivity interact with the net80211 stack.
Historical background: originally wireless devices created an interface, just like Ethernet devices do. Name of an interface matched the name of the driver that created. Later, wlan(4) layer was introduced, and the wlanX interfaces become the actual interface, leaving original ones as "a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer and a driver became a mix of methods that pass a pointer to struct ifnet as identifier and methods that pass pointer to struct ieee80211com. From user point of view, the parent interface just hangs on in the ifconfig list, and user can't do anything useful with it.
Now, the struct ifnet goes away. The struct ieee80211com is the only KPI between a device driver and net80211. Details:
- The struct ieee80211com is embedded into drivers softc. - Packets are sent via new ic_transmit method, which is very much like the previous if_transmit. - Bringing parent up/down is done via new ic_parent method, which notifies driver about any changes: number of wlan(4) interfaces, number of them in promisc or allmulti state. - Device specific ioctls (if any) are received on new ic_ioctl method. - Packets/errors accounting are done by the stack. In certain cases, when driver experiences errors and can not attribute them to any specific interface, driver updates ic_oerrors or ic_ierrors counters.
Details on interface configuration with new world order: - A sequence of commands needed to bring up wireless DOESN"T change. - /etc/rc.conf parameters DON'T change. - List of devices that can be used to create wlan(4) interfaces is now provided by net.wlan.devices sysctl.
Most drivers in this change were converted by me, except of wpi(4), that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing changes to at least 8 drivers. Thanks to pluknet@, Oliver Hartmann, Olivier Cochard, gjb@, mmoll@, op@ and lev@, who also participated in testing.
Reviewed by: adrian Sponsored by: Netflix Sponsored by: Nginx, Inc.
|
286410 |
07-Aug-2015 |
glebius |
Change KPI of how device drivers that provide wireless connectivity interact with the net80211 stack.
Historical background: originally wireless devices created an interface, just like Ethernet devices do. Name of an interface matched the name of the driver that created. Later, wlan(4) layer was introduced, and the wlanX interfaces become the actual interface, leaving original ones as "a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer and a driver became a mix of methods that pass a pointer to struct ifnet as identifier and methods that pass pointer to struct ieee80211com. From user point of view, the parent interface just hangs on in the ifconfig list, and user can't do anything useful with it.
Now, the struct ifnet goes away. The struct ieee80211com is the only KPI between a device driver and net80211. Details:
- The struct ieee80211com is embedded into drivers softc. - Packets are sent via new ic_transmit method, which is very much like the previous if_transmit. - Bringing parent up/down is done via new ic_parent method, which notifies driver about any changes: number of wlan(4) interfaces, number of them in promisc or allmulti state. - Device specific ioctls (if any) are received on new ic_ioctl method. - Packets/errors accounting are done by the stack. In certain cases, when driver experiences errors and can not attribute them to any specific interface, driver updates ic_oerrors or ic_ierrors counters.
Details on interface configuration with new world order: - A sequence of commands needed to bring up wireless DOESN"T change. - /etc/rc.conf parameters DON'T change. - List of devices that can be used to create wlan(4) interfaces is now provided by net.wlan.devices sysctl.
Most drivers in this change were converted by me, except of wpi(4), that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing changes to at least 8 drivers. Thanks to Olivier Cochard, gjb@, mmoll@, op@ and lev@, who also participated in testing. Details here:
https://wiki.freebsd.org/projects/ifnet/net80211
Still, drivers: ndis, wtap, mwl, ipw, bwn, wi, upgt, uath were not tested. Changes to mwl, ipw, bwn, wi, upgt are trivial and chances of problems are low. The wtap wasn't compilable even before this change. But the ndis driver is complex, and it is likely to be broken with this commit. Help with testing and debugging it is appreciated.
Differential Revision: D2655, D2740 Sponsored by: Nginx, Inc. Sponsored by: Netflix
|
191746 |
02-May-2009 |
thompsa |
Create a taskqueue for each wireless interface which provides a serialised sleepable context for net80211 driver callbacks. This removes the need for USB and firmware based drivers to roll their own code to defer the chip programming for state changes, scan requests, channel changes and mcast/promisc updates. When a driver callback completes the hardware state is now guaranteed to have been updated and is in sync with net80211 layer.
This nukes around 1300 lines of code from the wireless device drivers making them more readable and less race prone.
The net80211 layer has been updated as follows - all state/channel changes are serialised on the taskqueue. - ieee80211_new_state() always queues and can now be called from any context - scanning runs from a single taskq function and executes to completion. driver callbacks are synchronous so the channel, phy mode and rx filters are guaranteed to be set in hardware before probe request frames are transmitted.
Help and contributions from Sam Leffler.
Reviewed by: sam
|
190579 |
30-Mar-2009 |
sam |
Hoist 802.11 encapsulation up into net80211: o call ieee80211_encap in ieee80211_start so frames passed down to drivers are already encapsulated o remove ieee80211_encap calls in drivers o fixup wi so it recreates the 802.3 head it requires from the 802.11 header contents o move fast-frame aggregation from ath to net80211 (conditional on IEEE80211_SUPPORT_SUPERG): - aggregation is now done in ieee80211_start; it is enabled when the packets/sec exceeds ieee80211_ffppsmin (net.wlan.ffppsmin) and frames are held on a staging queue according to ieee80211_ffagemax (net.wlan.ffagemax) to wait for a frame to combine with - drivers must call back to age/flush the staging queue (ath does this on tx done, at swba, and on rx according to the state of the tx queues and/or the contents of the staging queue) - remove fast-frame-related data structures from ath - add ieee80211_ff_node_init and ieee80211_ff_node_cleanup to handle per-node fast-frames state (we reuse 11n tx ampdu state) o change ieee80211_encap calling convention to include an explicit vap so frames coming through a WDS vap are recognized w/o setting M_WDS
With these changes any device able to tx/rx 3Kbyte+ frames can use fast-frames.
Reviewed by: thompsa, rpaulo, avatar, imp, sephe
|
170530 |
11-Jun-2007 |
sam |
Update 802.11 wireless support: o major overhaul of the way channels are handled: channels are now fully enumerated and uniquely identify the operating characteristics; these changes are visible to user applications which require changes o make scanning support independent of the state machine to enable background scanning and roaming o move scanning support into loadable modules based on the operating mode to enable different policies and reduce the memory footprint on systems w/ constrained resources o add background scanning in station mode (no support for adhoc/ibss mode yet) o significantly speedup sta mode scanning with a variety of techniques o add roaming support when background scanning is supported; for now we use a simple algorithm to trigger a roam: we threshold the rssi and tx rate, if either drops too low we try to roam to a new ap o add tx fragmentation support o add first cut at 802.11n support: this code works with forthcoming drivers but is incomplete; it's included now to establish a baseline for other drivers to be developed and for user applications o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates prepending mbufs for traffic generated locally o add support for Atheros protocol extensions; mainly the fast frames encapsulation (note this can be used with any card that can tx+rx large frames correctly) o add sta support for ap's that beacon both WPA1+2 support o change all data types from bsd-style to posix-style o propagate noise floor data from drivers to net80211 and on to user apps o correct various issues in the sta mode state machine related to handling authentication and association failures o enable the addition of sta mode power save support for drivers that need net80211 support (not in this commit) o remove old WI compatibility ioctls (wicontrol is officially dead) o change the data structures returned for get sta info and get scan results so future additions will not break user apps o fixed tx rate is now maintained internally as an ieee rate and not an index into the rate set; this needs to be extended to deal with multi-mode operation o add extended channel specifications to radiotap to enable 11n sniffing
Drivers: o ath: add support for bg scanning, tx fragmentation, fast frames, dynamic turbo (lightly tested), 11n (sniffing only and needs new hal) o awi: compile tested only o ndis: lightly tested o ipw: lightly tested o iwi: add support for bg scanning (well tested but may have some rough edges) o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data o wi: lightly tested
This work is based on contributions by Atheros, kmacy, sephe, thompsa, mlaier, kevlo, and others. Much of the scanning work was supported by Atheros. The 11n work was supported by Marvell.
|
166756 |
15-Feb-2007 |
luigi |
Cleanup and document the implementation of firmware(9) based on a version that i posted earlier on the -current mailing list, and subsequent feedback received.
The core of the change is just in sys/firmware.h and kern/subr_firmware.c, while other files are just adaptation of the clients to the ABI change (const-ification of some parameters and hiding of internal info, so this is fully compatible at the binary level).
In detail: - reduce the amount of information exported to clients in struct firmware, and constify the pointer;
- internally, document and simplify the implementation of the various functions, and make sure error conditions are dealt with properly.
The diffs are large, but the code is really straightforward now (i hope).
Note also that there is a subtle issue with the implementation of firmware_register(): currently, as in the previous version, we just store a reference to the 'imagename' argument, but we should rather copy it because there is no guarantee that this is a static string. I realised this while testing this code, but i prefer to fix it in a later commit -- there is no regression with respect to the past.
Note, too, that the version in RELENG_6 has various bugs including missing locks around the module release calls, mishandling of modules loaded by /boot/loader, and so on, so an MFC is absolutely necessary there. I was just postponing it until this cleanup to avoid doing things twice.
MFC after: 1 week
|
159180 |
02-Jun-2006 |
csjp |
Fix the following bpf(4) race condition which can result in a panic:
(1) bpf peer attaches to interface netif0 (2) Packet is received by netif0 (3) ifp->if_bpf pointer is checked and handed off to bpf (4) bpf peer detaches from netif0 resulting in ifp->if_bpf being initialized to NULL. (5) ifp->if_bpf is dereferenced by bpf machinery (6) Kaboom
This race condition likely explains the various different kernel panics reported around sending SIGINT to tcpdump or dhclient processes. But really this race can result in kernel panics anywhere you have frequent bpf attach and detach operations with high packet per second load.
Summary of changes:
- Remove the bpf interface's "driverp" member - When we attach bpf interfaces, we now set the ifp->if_bpf member to the bpf interface structure. Once this is done, ifp->if_bpf should never be NULL. [1] - Introduce bpf_peers_present function, an inline operation which will do a lockless read bpf peer list associated with the interface. It should be noted that the bpf code will pickup the bpf_interface lock before adding or removing bpf peers. This should serialize the access to the bpf descriptor list, removing the race. - Expose the bpf_if structure in bpf.h so that the bpf_peers_present function can use it. This also removes the struct bpf_if; hack that was there. - Adjust all consumers of the raw if_bpf structure to use bpf_peers_present
Now what happens is:
(1) Packet is received by netif0 (2) Check to see if bpf descriptor list is empty (3) Pickup the bpf interface lock (4) Hand packet off to process
From the attach/detach side:
(1) Pickup the bpf interface lock (2) Add/remove from bpf descriptor list
Now that we are storing the bpf interface structure with the ifnet, there is is no need to walk the bpf interface list to locate the correct bpf interface. We now simply look up the interface, and initialize the pointer. This has a nice side effect of changing a bpf interface attach operation from O(N) (where N is the number of bpf interfaces), to O(1).
[1] From now on, we can no longer check ifp->if_bpf to tell us whether or not we have any bpf peers that might be interested in receiving packets.
In collaboration with: sam@ MFC after: 1 month
|
150306 |
19-Sep-2005 |
imp |
Make sure that we call if_free(ifp) after bus_teardown_intr. Since we could get an interrupt after we free the ifp, and the interrupt handler depended on the ifp being still alive, this could, in theory, cause a crash. Eliminate this possibility by moving the if_free to after the bus_teardown_intr() call.
|
148887 |
09-Aug-2005 |
rwatson |
Propagate rename of IFF_OACTIVE and IFF_RUNNING to IFF_DRV_OACTIVE and IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to ifnet.if_drv_flags. Device drivers are now responsible for synchronizing access to these flags, as they are in if_drv_flags. This helps prevent races between the network stack and device driver in maintaining the interface flags field.
Many __FreeBSD__ and __FreeBSD_version checks maintained and continued; some less so.
Reviewed by: pjd, bz MFC after: 7 days
|
147256 |
10-Jun-2005 |
brooks |
Stop embedding struct ifnet at the top of driver softcs. Instead the struct ifnet or the layer 2 common structure it was embedded in have been replaced with a struct ifnet pointer to be filled by a call to the new function, if_alloc(). The layer 2 common structure is also allocated via if_alloc() based on the interface type. It is hung off the new struct ifnet member, if_l2com.
This change removes the size of these structures from the kernel ABI and will allow us to better manage them as interfaces come and go.
Other changes of note: - Struct arpcom is no longer referenced in normal interface code. Instead the Ethernet address is accessed via the IFP2ENADDR() macro. To enforce this ac_enaddr has been renamed to _ac_enaddr. - The second argument to ether_ifattach is now always the mac address from driver private storage rather than sometimes being ac_enaddr.
Reviewed by: sobomax, sam
|