we intend for the user to be able to unload them later via kldunload(2)
instead of calling linker_load_module() and then directly adjusting the
ref count on the linker file structure. This makes the resulting
consumer code simpler and cleaner and better hides the linker internals
making it possible to sanely lock the linker.
(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
