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path: root/net/wireless/scan.c
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2014-02-06cfg80211: send scan results from work queueJohannes Berg
Due to the previous commit, when a scan finishes, it is in theory possible to hit the following sequence: 1. interface starts being removed 2. scan is cancelled by driver and cfg80211 is notified 3. scan done work is scheduled 4. interface is removed completely, rdev->scan_req is freed, event sent to userspace but scan done work remains pending 5. new scan is requested on another virtual interface 6. scan done work runs, freeing the still-running scan To fix this situation, hang on to the scan done message and block new scans while that is the case, and only send the message from the work function, regardless of whether the scan_req is already freed from interface removal. This makes step 5 above impossible and changes step 6 to be 5. scan done work runs, sending the scan done message As this can't work for wext, so we send the message immediately, but this shouldn't be an issue since we still return -EBUSY. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-01-09cfg80211: Add a function to get the number of supported channelsIlan Peer
Add a utility function to get the number of channels supported by the device, and update the places in the code that need this data. Signed-off-by: Ilan Peer <ilan.peer@intel.com> [replace another occurrence in libertas, fix kernel-doc, fix bugs] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-12-05cfg80211: don't "leak" uncompleted scansEliad Peller
___cfg80211_scan_done() can be called in some cases (e.g. on NETDEV_DOWN) before the low level driver notified scan completion (which is indicated by passing leak=true). Clearing rdev->scan_req in this case is buggy, as scan_done_wk might have already being queued/running (and can't be flushed as it takes rtnl()). If a new scan will be requested at this stage, the scan_done_wk will try freeing it (instead of the previous scan), and this will later result in a use after free. Simply remove the "leak" option, and replace it with a standard WARN_ON. An example backtrace after such crash: Unable to handle kernel paging request at virtual address fffffee5 pgd = c0004000 [fffffee5] *pgd=9fdf6821, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] SMP ARM PC is at cfg80211_scan_done+0x28/0xc4 [cfg80211] LR is at __ieee80211_scan_completed+0xe4/0x2dc [mac80211] [<bf0077b0>] (cfg80211_scan_done+0x28/0xc4 [cfg80211]) [<bf0973d4>] (__ieee80211_scan_completed+0xe4/0x2dc [mac80211]) [<bf0982cc>] (ieee80211_scan_work+0x94/0x4f0 [mac80211]) [<c005fd10>] (process_one_work+0x1b0/0x4a8) [<c0060404>] (worker_thread+0x138/0x37c) [<c0066d70>] (kthread+0xa4/0xb0) Signed-off-by: Eliad Peller <eliad@wizery.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-10-21cfg80211: fix scheduled scan pointer accessJohannes Berg
Since rdev->sched_scan_req is dereferenced outside the lock protecting it, this might be done at the wrong time, causing crashes. Move the dereference to where it should be - inside the RTNL locked section. Cc: stable@vger.kernel.org [3.8+] Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-09-04wireless: scan: Remove comment to compare_ether_addrJoe Perches
This function is being removed, so remove the reference to it. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-16nl80211: add scan width to bss and scan request structsSimon Wunderlich
To allow scanning and working with 5 MHz and 10 MHz BSS, extend the inform bss commands and add wrappers to take 5 and 10 MHz bss into account. Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de> Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
2013-06-24wireless: add comments about bss refcountingBen Greear
Should help the next person that tries to understand the bss refcounting logic. Signed-off-by: Ben Greear <greearb@candelatech.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-05-24cfg80211: vastly simplify lockingJohannes Berg
Virtually all code paths in cfg80211 already (need to) hold the RTNL. As such, there's little point in having another four mutexes for various parts of the code, they just cause lock ordering issues (and much of the time, the RTNL and a few of the others need thus be held.) Simplify all this by getting rid of the extra four mutexes and just use the RTNL throughout. Only a few code changes were needed to do this and we can get rid of a work struct for bonus points. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-05-24cfg80211: move cfg80211_get_dev_from_ifindex under wextJohannes Berg
The function is only used and needed by the wext code for scanning, so move it there. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-24cfg80211: always check for scan end on P2P deviceJohannes Berg
If a P2P device wdev is removed while it has a scan, then the scan completion might crash later as it is already freed by that time. To avoid the crash always check the scan completion when the P2P device is being removed for some reason. If the driver already canceled it, don't want and free it, otherwise warn and leak it to avoid later crashes. In order to do this, locking needs to be changed away from the rdev mutex (which can't always be guaranteed). For now, use the sched_scan_mtx instead, I'll rename it to just scan_mtx in a later patch. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-03-07cfg80211: fix potential BSS memory leak and updateJohannes Berg
In the odd case that while updating information from a beacon, a BSS was found that is part of a hidden group, we drop the new information. In this case, however, we leak the IE buffer from the update, and erroneously update the entry's timestamp so it will never time out. Fix both these issues. Cc: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-15Merge remote-tracking branch 'mac80211/master' into HEADJohannes Berg
2013-02-15nl80211/cfg80211: add radar detection command/eventSimon Wunderlich
Add new NL80211_CMD_RADAR_DETECT, which starts the Channel Availability Check (CAC). This command will also notify the usermode about events (CAC finished, CAC aborted, radar detected, NOP finished). Once radar detection has started it should continuously monitor for radars as long as the channel is active. This patch enables DFS for AP mode in nl80211/cfg80211. Based on original patch by Victor Goldenshtein <victorg@ti.com> Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de> [remove WIPHY_FLAG_HAS_RADAR_DETECT again -- my mistake] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-13cfg80211: check vendor IE length to avoid overrunLuciano Coelho
cfg80211_find_vendor_ie() was checking only that the vendor IE would fit in the remaining IEs buffer. If a corrupt includes a vendor IE that is too small, we could potentially overrun the IEs buffer. Fix this by checking that the vendor IE fits in the reported IE length field and skip it otherwise. Reported-by: Jouni Malinen <j@w1.fi> Signed-off-by: Luciano Coelho <coelho@ti.com> [change BUILD_BUG_ON to != 1 (from >= 2)] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-11cfg80211: move TSF into IEsJohannes Berg
While technically the TSF isn't an IE, it can be necessary to distinguish between the TSF from a beacon and a probe response, in particular in order to know the next DTIM TBTT, as not all APs are spec compliant wrt. TSF==0 being a DTIM TBTT and thus the DTIM count needs to be taken into account as well. To allow this, move the TSF into the IE struct so it can be known whence it came. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-11cfg80211: remove scan ies NULL checkJohannes Berg
There's no way scan BSS IEs can be NULL as even if the allocation fails the frame is discarded. Remove some code checking for this and document that it is always non-NULL. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-11cfg80211: track hidden SSID networks properlyJohannes Berg
Currently, cfg80211 will copy beacon IEs from a previously received hidden SSID beacon to a probe response entry, if that entry is created after the beacon entry. However, if it is the other way around, or if the beacon is updated, such changes aren't propagated. Fix this by tracking the relation between the probe response and beacon BSS structs in this case. In case drivers have private data stored in a BSS struct and need access to such data from a beacon entry, cfg80211 now provides the hidden_beacon_bss pointer from the probe response entry to the beacon entry. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-11cfg80211: pass wiphy to cfg80211_ref_bss/put_bssJohannes Berg
This prepares for using the spinlock instead of krefs which is needed in the next patch to track the refs of combined BSSes correctly. Acked-by: Bing Zhao <bzhao@marvell.com> [mwifiex] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: wrap BSS krefJohannes Berg
Add inline wrappers for the BSS struct krefs to be able to extend them easily later. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: remove a local variableJohannes Berg
This local variable is only used once, so remove it. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: use lockdep to assert lock is heldJohannes Berg
Instead of annotating with a comment, add a lockdep annotation which also serves as documentation. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: move locking into cfg80211_bss_ageJohannes Berg
There's no reason for it to require external locking, move it into the function. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: fix BSS IE allocation commentJohannes Berg
The comment about allocating the IEs together with the BSS struct is no longer true, remove it. Also fix a typo in the same area. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: remove unused cfg80211_get_meshJohannes Berg
As Thomas pointed out, cfg80211_get_mesh() is unused and can be removed. Cc: Thomas Pedersen <thomas@cozybit.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: simplify mesh BSS comparisonJohannes Berg
Instead of first checking if a BSS is an MBSS and then doing the comparisons, inline it all into the BSS comparison function. This avoids doing the IE searches twice and is also a lot less code. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: fix BSS list hidden SSID lookupJohannes Berg
When trying to find a hidden SSID, the lookup function is done wrong; the code is trying to combine the two lookups into one, and as a consequence doesn't always find the entry at all. To understand this, consider a case where multiple BSS entries with the same channel and BSSID exist but have different SSID length. Then comparing against the probe response SSID length is bound to cause problems since the hidden one might be either zeroed out or zero-length. To fix this we need to do two lookups for the two ways to hide SSIDs. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-02-04cfg80211: refactor hidden SSID findingJohannes Berg
Instead of duplicating the rbtree functions, pass an argument to the compare function. This removes the code duplication for the two searches. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-31cfg80211: remove free_priv BSS APIJohannes Berg
Now that mac80211 no longer uses this API, remove it completely. If anyone needs it again, we can revert this patch of course, but mac80211 was the only user right now. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2013-01-24cfg80211: off by one in ieee80211_bss()Dan Carpenter
We do a: sprintf(buf, " Last beacon: %ums ago", elapsed_jiffies_msecs(bss->ts)); elapsed_jiffies_msecs() can return a 10 digit number so "buf" needs to be 31 characters long. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-11-30cfg80211: fix BSS struct IE access racesJohannes Berg
When a BSS struct is updated, the IEs are currently overwritten or freed. This can lead to races if some other CPU is accessing the BSS struct and using the IEs concurrently. Fix this by always allocating the IEs in a new struct that holds the data and length and protecting access to this new struct with RCU. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-11-30cfg80211: fix cmp_hidden_bssJohannes Berg
The cmp_bss() comparator function uses memcmp() to compare the SSID. This means that cmp_hidden_bss() needs to similarly return a number bigger than zero (use 1) instead of -1 when ie1 is bigger than ie2, which is the case if an ie2 byte is non-zero. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-11-30cfg80211: fix whitespace in scan handlingJohannes Berg
Fix a number of indentation and similar issues. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-11-30cfg80211: don't BUG_ON BSS struct issuesJohannes Berg
There's no need to stop the machine, just leak the BSS entry if there's an issue with its hold counter when freeing. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-11-23cfg80211: use DS or HT operation IEs to determine BSS channelJohannes Berg
Currently, mac80211 checks the DS params IE if present and uses it for the (primary) BSS channel, instead of the one that the frame was received on. This is particularly useful in the 2.4 GHz band since a frame is often received on one of the adjacent channels due to overlap. Move this code to cfg80211 so other drivers also do this. Additionally, on 5 GHz, in particular with some (possibly) upcoming changes in 802.11ai and duplicate transmissions when wider channels are used, something similar happens. So if present, also use the (primary) channel information contained in the HT operation IE. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-10-18cfg80211: add cfg80211 exported function tracingBeni Lev
Also add tracing to the API functions that drivers (and mac80211) can call in cfg80211. Signed-off-by: Beni Lev <beni.lev@intel.com> Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Reviewed-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-10-18cfg80211: add wrappers for registered_device_opsHila Gonen
This will allow adding central tracing like in mac80211. Signed-off-by: Hila Gonen <hila.gonen@intel.com> Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Reviewed-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-10-18cfg80211: add support for flushing old scan resultsSam Leffler
Add an NL80211_SCAN_FLAG_FLUSH flag that causes old bss cache entries to be flushed on scan completion. This is useful for collecting guaranteed fresh scan/survey result (e.g. on resume). For normal scan, flushing only happens on successful completion of a scan; i.e. it does not happen if the scan is aborted. For scheduled scan, previous scan results are flushed everytime when we get new scan results. This feature is enabled by default. Drivers can disable it by unsetting the NL80211_FEATURE_SCAN_FLUSH flag. Signed-off-by: Sam Leffler <sleffler@chromium.org> Tested-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Bing Zhao <bzhao@marvell.com> [invert polarity of feature flag to account for old kernels] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-10-18cfg80211: code rearrangement to avoid forward declarationsAmitkumar Karwar
bss_release() and __cfg80211_unlink_bss() function definitions are moved at the begining of the file. They are used in next patch in this series. Signed-off-by: Amitkumar Karwar <akarwar@marvell.com> Signed-off-by: Bing Zhao <bzhao@marvell.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-09-05cfg80211: fix indentationHila Gonen
checkpatch pointed out an issue, fix it. Signed-off-by: Hila Gonen <hila.gonen@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-07-12nl80211: move scan API to wdevJohannes Berg
The new P2P Device will have to be able to scan for P2P search, so move scanning to use struct wireless_dev instead of struct net_device. Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-05-14Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
2012-05-10wireless: Convert compare_ether_addr to ether_addr_equalJoe Perches
Use the new bool function ether_addr_equal to add some clarity and reduce the likelihood for misuse of compare_ether_addr for sorting. I removed a conversion from scan.c/cmp_bss_core that appears to be a sorting function. Done via cocci script: $ cat compare_ether_addr.cocci @@ expression a,b; @@ - !compare_ether_addr(a, b) + ether_addr_equal(a, b) @@ expression a,b; @@ - compare_ether_addr(a, b) + !ether_addr_equal(a, b) @@ expression a,b; @@ - !ether_addr_equal(a, b) == 0 + ether_addr_equal(a, b) @@ expression a,b; @@ - !ether_addr_equal(a, b) != 0 + !ether_addr_equal(a, b) @@ expression a,b; @@ - ether_addr_equal(a, b) == 0 + !ether_addr_equal(a, b) @@ expression a,b; @@ - ether_addr_equal(a, b) != 0 + ether_addr_equal(a, b) @@ expression a,b; @@ - !!ether_addr_equal(a, b) + ether_addr_equal(a, b) Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-09cfg80211: fix BSS comparisonEmmanuel Grumbach
Since the BSS table is organized in a RB tree, the BSSs need to be comparable. This means that we must define a < and > operator to the BSS object. compare_ethr_addr isn't enough since it returns only a binary value. Since Felix's cfg80211: use compare_ether_addr on MAC addresses instead of memcmp Because of the constant size and guaranteed 16 bit alignment, the inline compare_ether_addr function is much cheaper than calling memcmp. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com> The BSS table is corrupted: rb_find_bss can't find the bss. As a result BSSes are duplicated in the BSS table, and we get stuck while probing an AP before associating (in STA mode). Change-Id: I85928756f4328028230832c1565ece7f412f3843 CC: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Acked-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-16cfg80211: increse bss expire timeRajkumar Manoharan
The background scan completion takes more time when the station is having heavy uplink traffic. The scan state machine decides to fall back to home channel on every off-channel visit when there are pending frames in tx queue. bgscan completion took ~30sec on dual band US regulatory card. scan period = (20 active channels * probe timeout) + (12 passive channels * passive probe timeout) + (32 * timeout on home channel) + (32 * flush timeout) Signed-off-by: Rajkumar Manoharan <rmanohar@qca.qualcomm.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-09cfg80211: use compare_ether_addr on MAC addresses instead of memcmpFelix Fietkau
Because of the constant size and guaranteed 16 bit alignment, the inline compare_ether_addr function is much cheaper than calling memcmp. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-03-13cfg80211: clarify timestamp in cfg80211_inform_bssJohannes Berg
This is intended to be the timestamp sent by the peer in the beacon/probe response, not any form of host timestamp. Clarify the documentation and variable names. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-02-06cfg80211: export cfg80211_ref_bssJohannes Berg
This is needed by mac80211 to keep a reference to a BSS alive for the auth process. Remove the old version of cfg80211_ref_bss() since it's not actually used. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-11cfg80211: merge in beacon ies of hidden bss.Dmitry Tarnyagin
The problem with PSM when a hidden SSID was used was originally reported by Juuso Oikarinen. - When generally scanning, the AP is getting a bss entry with a zero SSID. - When associating, a probe-req is sent to the AP with the SSID, and as a result a probe-response is received with the hidden SSID in place. As a consequence, a second bss entry is created for the AP, now with the real SSID. - After association, mac80211 executes ieee80211_recalc_ps(), but does not switch to powersave because the beacon-ies are missing. As result, the STA does not ever enter PSM. The patch merges in beacon ies of hidden bss from beacon to the probe response, creating a consistent set of ies in place. Patch is depended on "cfg80211: fix cmp_ies" made by Johannes. Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-07cfg80211: fix cmp_iesJohannes Berg
When comparing two items by IE, the sort order wasn't stable, which could lead to issues in the rbtree. Make it stable by making a missing IE sort before a present IE. Also sort by length first if it differs and then by contents. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-09-19cfg80211: add cfg80211_find_vendor_ie() functionEliad Peller
Add function to find vendor-specific ie (along with vendor-specific ie struct definition and P2P OUI values) Signed-off-by: Eliad Peller <eliad@wizery.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: John W. Linville <linville@tuxdriver.com>