(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
stations that are associated by making ieee80211_find_txnode return
NULL when a unicast frame is to be delivered to an unassociated
station. This will be handled differently in the future but for
now putting the check here allows all drivers to immediately do
the right thing.
Reviewed by: avatar
MFC after: 1 week
now just make it clear station statistics (could read
a stat block and assign to caller can do partial changes)
Reviewed by: avatar (previous version)
MFC after: 1 week
this corrects problems with drivers that rely on the host to do
crypto (iwi, ipw, ral, ural, wi (hostap), awi)
Hard work by: luigi, mlaier
Reviewed by: luigi, mlaier
MFC after: 1 week
with methods: instead of honoring non-zero values expect drivers
to write their own values on return from ieee80211_ifattach
o add a define for the default h/w bmiss count
MFC after: 2 weeks
driver; this closes a race where a response could be processed
before the timer was started and cause a RUN->SCAN state change
when operating in station mode
Reviewed by: avatar, dyoung
MFC after: 1 week
o lock the list walk
o malloc a results buffer instead of copying out one result at a time
using an on-stack buffer
o fix definition of ieee80211req_scan_result so size of variable-length
information elements is large enough to hold all possible ie's
(still only return wpa+wme, at some point may return all)
o make rssi+noise data signed; they should've been so all along
o add a bit more padding for future additions while we're here
o define a new ioctl for new api and add compat code for old ioctl
under COMPAT_FREEBSD6 (temporarily enabled local to the file)
Reviewed by: Scott Long
MFC after: 2 weeks
to have a value that's not been used before; this fixes the problem
where the first traversal of the scan list did nothing because the
entries were initialized with the current generation number (a
separate issue)
MFC after: 1 week
particular this fixes use of wme in adhoc demo mode, it wasn't possible
to set the txop limit because the aggressive mode logic would override
Reviewed by: apatti
MFC after: 2 weeks
but broke handling of the turboG channel; since we aren't ready to revamp
the channel list just check for turboA channels for now so channel 6 is
considered in auto mode
Noticed by: gibbs
case if memory allocation failed.
- Remove fourth argument from VLAN_INPUT_TAG(), that was used
incorrectly in almost all drivers. Indicate failure with
mbuf value of NULL.
In collaboration with: yongari, ru, sam
this can happen under certain conditions when scanning. This logic
will eventually go away with the new scanning code.
While here de-inline the routine.
MFC after: 1 week
in the 802.11 layer: we send a directed probe request frame to the
current ap bmiss_max times (w/o answer) before scanning for a new ap.
MFC after: 2 weeks
o plug memory leak in adhoc mode: on rx the sender may be the
current master so simply checking against ic_bss is not enough
to identify if the packet comes from an unknown sender; must
also check the mac address
o split neighbor node creation into two routines and fillin state
of nodes faked up on xmit when a beacon or probe response frame
is later received; this ensures important state like the rate set
and advertised capabilities are correct
Obtained from: netbsd
MFC after: 1 week
that can potentially be mapped to negative ieee #'s.
NB: before operation on the latter can be supported we need to cleanup
various code that assumes ieee channel #'s are >= 0
rather than in ifindex_table[]; all (except one) accesses are
through ifp anyway. IF_LLADDR() works faster, and all (except
one) ifaddr_byindex() users were converted to use ifp->if_addr.
- Stop storing a (pointer to) Ethernet address in "struct arpcom",
and drop the IFP2ENADDR() macro; all users have been converted
to use IF_LLADDR() instead.
Having an additional MT_HEADER mbuf type is superfluous and redundant
as nothing depends on it. It only adds a layer of confusion. The
distinction between header mbuf's and data mbuf's is solely done
through the m->m_flags M_PKTHDR flag.
Non-native code is not changed in this commit. For compatibility
MT_HEADER is mapped to MT_DATA.
Sponsored by: TCP/IP Optimization Fundraise 2005
switching(ifconfig devX channel Y). This fix should make channel changing
works again in monitor mode.
Submitted by: sam
X-MFC-With: other ic_curchan changes
add support for getting the current policy setting and collecting
the list of mac addresses in the acl table.
Submitted by: Michal Mertl (original version)
MFC after: 2 weeks
use the station channel properties. Fixes assert failure/bogus
operation when an ap is operating in 11a and has associated stations
then switches to 11g.
Noticed by: Michal Mertl
Reviewed by: avatar
MFC after: 2 weeks
o add ic_curchan and use it uniformly for specifying the current
channel instead of overloading ic->ic_bss->ni_chan (or in some
drivers ic_ibss_chan)
o add ieee80211_scanparams structure to encapsulate scanning-related
state captured for rx frames
o move rx beacon+probe response frame handling into separate routines
o change beacon+probe response handling to treat the scan table
more like a scan cache--look for an existing entry before adding
a new one; this combined with ic_curchan use corrects handling of
stations that were previously found at a different channel
o move adhoc neighbor discovery by beacon+probe response frames to
a new ieee80211_add_neighbor routine
Reviewed by: avatar
Tested by: avatar, Michal Mertl
MFC after: 2 weeks
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
Crypto changes:
o change driver/net80211 key_alloc api to return tx+rx key indices; a
driver can leave the rx key index set to IEEE80211_KEYIX_NONE or set
it to be the same as the tx key index (the former disables use of
the key index in building the keyix->node mapping table and is the
default setup for naive drivers by null_key_alloc)
o add cs_max_keyid to crypto state to specify the max h/w key index a
driver will return; this is used to allocate the key index mapping
table and to bounds check table loookups
o while here introduce ieee80211_keyix (finally) for the type of a h/w
key index
o change crypto notifiers for rx failures to pass the rx key index up
as appropriate (michael failure, replay, etc.)
Node table changes:
o optionally allocate a h/w key index to node mapping table for the
station table using the max key index setting supplied by drivers
(note the scan table does not get a map)
o defer node table allocation to lateattach so the driver has a chance
to set the max key id to size the key index map
o while here also defer the aid bitmap allocation
o add new ieee80211_find_rxnode_withkey api to find a sta/node entry
on frame receive with an optional h/w key index to use in checking
mapping table; also updates the map if it does a hash lookup and the
found node has a rx key index set in the unicast key; note this work
is separated from the old ieee80211_find_rxnode call so drivers do
not need to be aware of the new mechanism
o move some node table manipulation under the node table lock to close
a race on node delete
o add ieee80211_node_delucastkey to do the dirty work of deleting
unicast key state for a node (deletes any key and handles key map
references)
Ath driver:
o nuke private sc_keyixmap mechansim in favor of net80211 support
o update key alloc api
These changes close several race conditions for the ath driver operating
in ap mode. Other drivers should see no change. Station mode operation
for ath no longer uses the key index map but performance tests show no
noticeable change and this will be fixed when the scan table is eliminated
with the new scanning support.
Tested by: Michal Mertl, avatar, others
Reviewed by: avatar, others
MFC after: 2 weeks
o separate configured beacon interval from listen interval; this
avoids potential use of one value for the other (e.g. setting
powersavesleep to 0 clobbers the beacon interval used in hostap
or ibss mode)
o bounds check the beacon interval received in probe response and
beacon frames and drop frames with bogus settings; not clear
if we should instead clamp the value as any alteration would
result in mismatched sta+ap configuration and probably be more
confusing (don't want to log to the console but perhaps ok with
rate limiting)
o while here up max beacon interval to reflect WiFi standard
Noticed by: Martin <nakal@nurfuerspam.de>
MFC after: 1 week
when operating in ap mode. Previously we allocated a node from the
station table, sent the frame (using the node), then released the
reference that "held the frame in the table". But while the frame
was in flight the node might be reclaimed which could lead to
problems. The solution is to add an ieee80211_tmp_node routine
that crafts a node that does exist in a table and so isn't ever
reclaimed; it exists only so long as the associated frame is in flight.
MFC after: 5 days
o add ic_flags_ext for eventual extention of ic_flags
o define/reserve flag+capabilities bits for superg,
bg scan, and roaming support
o refactor debug msg macros
MFC after: 3 days
we bailed if we couldn't collect the 16-bytes of data required
for an aes block cipher in 2 mbufs; now we deal with it. While
here make space accounting signed so a sanity check does the
right thing for malformed mbuf chains.
Approved by: re (scottl)
legacy parts (i.e. those that have 4 global key slots). We
blindly assign unicast keys to key slot 0. Devices that need
alternate allocation logic must override this method.
Reviewed by: avatar
Approved by: re (scottl)
don't mark the MORE_DATA bit when taking it off the ps queue, there's
no 802.11 header then; we must wait to do this at encap time so
mark the mbuf instead.
Reviewed by: avatar
Approved by: re (scottl)
Obtained from: Atheros
stations in ap mode. Track when a node's first auth frame is
received and use this to decide whether or not to bump the refcnt.
This insures we only ever bump the refcnt once.
Reviewed by: avatar
Approved by: re (scottl)
This fixes duplicative BSS entries(memory leaks as well) listed in
"ifconfig dev list scan" when a station fails to associate with an AP.
Reviewed by: sam
Approved by: re (scottl)
fixes a ref cnt leak
o make unicast key handling on delete identical to set
o change legacy wep key api to reset the 802.11 state
machine for backwards compatibility
Reviewed by: avatar
Approved by: re (scottl)
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
