Add BT_POWER socket option used to control the power characteristics of the underlying ACL link. When the remote end has put the link in sniff mode and the host stack wants to send data we need need to explicitly exit sniff mode to work well with certain devices (For example, A2DP on Plantronics Voyager 855). However, this causes problems with HID devices. Hence, moving into active mode when sending data, irrespective of who set the sniff mode has been made as a socket option. By default, we will move into active mode. HID devices can set the L2CAP socket option to prevent this from happening. Currently, this has been implemented for L2CAP sockets. This has been tested with incoming and outgoing L2CAP sockets for HID and A2DP. Based on discussions on linux-bluetooth and patches submitted by Andrei Emeltchenko. Signed-off-by: Jaikumar Ganesh <jaikumar@google.com>
The Enhanced Retransmission Mode(ERTM) is a realiable mode of operation of the Bluetooth L2CAP layer. Think on it like a simplified version of TCP. The problem we were facing here was a deadlock. ERTM uses a backlog queue to queue incomimg packets while the user is helding the lock. At some moment the sk_sndbuf can be exceeded and we can't alloc new skbs then the code sleep with the lock to wait for memory, that stalls the ERTM connection once we can't read the acknowledgements packets in the backlog queue to free memory and make the allocation of outcoming skb successful. This patch actually affect all users of bt_skb_send_alloc(), i.e., all L2CAP modes and SCO. We are safe against socket states changes or channels deletion while the we are sleeping wait memory. Checking for the sk->sk_err and sk->sk_shutdown make the code safe, since any action that can leave the socket or the channel in a not usable state set one of the struct members at least. Then we can check both of them when getting the lock again and return with the proper error if something unexpected happens. Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi> Signed-off-by: Ulisses Furquim <ulisses@profusion.mobi>
With Bluetooth 2.1 ACL packets can be flushable or non-flushable. This commit makes ACL data packets non-flushable by default on compatible chipsets, and adds the L2CAP_LM_FLUSHABLE socket option to explicitly request flushable ACL data packets for a given L2CAP socket. This is useful for A2DP data which can be safely discarded if it can not be delivered within a short time (while other ACL data should not be discarded). Note that making ACL data flushable has no effect unless the automatic flush timeout for that ACL link is changed from its default of 0 (infinite). Change-Id: Ie3d4befdeaefb8c979de7ae603ff5ec462b3483c Signed-off-by: Nick Pelly <npelly@google.com>
This reverts commit d7897fd1e9fb3a5df0740dc2dc45ec94ca0965f2. Change-Id: I3401550b6dc97b683104e9fdac30a617a2db8c8e Signed-off-by: Nick Pelly <npelly@google.com>
__u16 sco_pkt_type is introduced to struct sockaddr_sco. It allows bitwise selection of SCO/eSCO packet types. Currently those bits are: 0x0001 HV1 may be used. 0x0002 HV2 may be used. 0x0004 HV3 may be used. 0x0008 EV3 may be used. 0x0010 EV4 may be used. 0x0020 EV5 may be used. 0x0040 2-EV3 may be used. 0x0080 3-EV3 may be used. 0x0100 2-EV5 may be used. 0x0200 3-EV5 may be used. This is similar to the Packet Type parameter in the HCI Setup Synchronous Connection Command, except that we are not reversing the logic on the EDR bits. This makes the use of sco_pkt_tpye forward portable for the use case of white-listing packet types, which we expect will be the primary use case. If sco_pkt_type is zero, or userspace uses the old struct sockaddr_sco, then the default behavior is to allow all packet types. Packet type selection is just a request made to the Bluetooth chipset, and it is up to the link manager on the chipset to negiotiate and decide on the actual packet types used. Furthermore, when a SCO/eSCO connection is eventually made there is no way for the host stack to determine which packet type was used (however it is possible to get the link type of SCO or eSCO). sco_pkt_type is ignored for incoming SCO connections. It is possible to add this in the future as a parameter to the Accept Synchronous Connection Command, however its a little trickier because the kernel does not currently preserve sockaddr_sco data between userspace calls to accept(). The most common use for sco_pkt_type will be to white-list only SCO packets, which can be done with the hci.h constant SCO_ESCO_MASK. This patch is motivated by broken Bluetooth carkits such as the Motorolo HF850 (it claims to support eSCO, but will actually reject eSCO connections after 5 seconds) and the 2007/2008 Infiniti G35/37 (fails to route audio if a 2-EV5 packet type is negiotiated). With this patch userspace can maintain a list of compatible packet types to workaround remote devices such as these. Based on a patch by Marcel Holtmann. Change-Id: I304d8fda5b4145254820a3003820163bf53de5a5 Signed-off-by: Nick Pelly <npelly@google.com>
This reverts commit 9e726b17422bade75fba94e625cd35fd1353e682. Change-Id: I3bc2e4caa2a0e0c36b9c7de4a09b03276adae4e1 Signed-off-by: Nick Pelly <npelly@google.com>
With Bluetooth 2.1 ACL packets can be flushable or non-flushable. This changes makes the default ACL packet non-flushable, and allows selection of flushable packets on a per-L2CAP socket basis with L2CAP_LM_FLUSHABLE. Note the HCI Write Automatic Flush Timeout command also needs to be issued to set the flush timeout to non-zero. Need to featurize this change to Bluetooth 2.1 chipsets only before pushing upstream. Signed-off-by: Nick Pelly <npelly@google.com>
This provides userspace debugging tools access to ACL flow control state. Signed-off-by: Nick Pelly <npelly@google.com>
Legacy pairing is a bit of a problem because on the incoming end it is
impossible to know pairing has begun:
2009-09-18 18:29:24.115692 > HCI Event: Connect Request (0x04) plen 10
bdaddr 00:23:D4:04:51:7A class 0x58020c type ACL
2009-09-18 18:29:24.115966 < HCI Command: Accept Connection Request (0x01|0x0009) plen 7
bdaddr 00:23:D4:04:51:7A role 0x00
Role: Master
2009-09-18 18:29:24.117065 > HCI Event: Command Status (0x0f) plen 4
Accept Connection Request (0x01|0x0009) status 0x00 ncmd 1
2009-09-18 18:29:24.282928 > HCI Event: Role Change (0x12) plen 8
status 0x00 bdaddr 00:23:D4:04:51:7A role 0x00
Role: Master
2009-09-18 18:29:24.291534 > HCI Event: Connect Complete (0x03) plen 11
status 0x00 handle 1 bdaddr 00:23:D4:04:51:7A type ACL encrypt 0x00
2009-09-18 18:29:24.291839 < HCI Command: Read Remote Supported Features (0x01|0x001b) plen 2
handle 1
2009-09-18 18:29:24.292144 > HCI Event: Page Scan Repetition Mode Change (0x20) plen 7
bdaddr 00:23:D4:04:51:7A mode 1
2009-09-18 18:29:24.293823 > HCI Event: Command Status (0x0f) plen 4
Read Remote Supported Features (0x01|0x001b) status 0x00 ncmd 1
2009-09-18 18:29:24.303588 > HCI Event: Max Slots Change (0x1b) plen 3
handle 1 slots 5
2009-09-18 18:29:24.309448 > HCI Event: Read Remote Supported Features (0x0b) plen 11
status 0x00 handle 1
Features: 0xff 0xff 0x2d 0xfe 0x9b 0xff 0x79 0x83
2009-09-18 18:29:24.345916 < HCI Command: Remote Name Request (0x01|0x0019) plen 10
bdaddr 00:23:D4:04:51:7A mode 2 clkoffset 0x0000
2009-09-18 18:29:24.346923 > HCI Event: Command Status (0x0f) plen 4
Remote Name Request (0x01|0x0019) status 0x00 ncmd 1
2009-09-18 18:29:24.375793 > HCI Event: Remote Name Req Complete (0x07) plen 255
status 0x00 bdaddr 00:23:D4:04:51:7A name 'test'
2009-09-18 18:29:34.332190 < HCI Command: Disconnect (0x01|0x0006) plen 3
handle 1 reason 0x13
There are some mainline patches such as "Add different pairing timeout for
Legacy Pairing" but they do not address the HCI sequence above.
I think the real solution is to avoid using CreateBond(), and instead make
the profile connection immediately. This way both sides will use a longer
timeout because there is a higher level connection in progress, and we will
not end up with the useless HCI sequence above.
Signed-off-by: Nick Pelly <npelly@google.com>