[BlueZ,v2] adapter: Use regular discovery for filters which only have discoverable set

Commit Message

Hans de Goede March 31, 2023, 8:03 p.m. UTC

discovery_filter_to_mgmt_cp() does not add discovery_filter.discoverable
to the created mgmt_cp_start_service_discovery struct.

Instead update_discovery_filter() separately checks
client->discovery_filter->discoverable for all clients.

This means that for discovery-filters which only have the discoverable
flag set, to put the adapter in discoverable mode while discovering,
the created mgmt_cp_start_service_discovery struct is empty.

This empty mgmt_cp_start_service_discovery struct then gets sent
to the kernel as part of a MGMT_OP_START_SERVICE_DISCOVERY msg
by start_discovery_timeout().

This use of an empty filter with MGMT_OP_START_SERVICE_DISCOVERY
causes some bluetooth devices to not get seen with some (most?)
Broadcom bluetooth adapters. This problem has been observed with
the following Broadcom models: BCM4343A0, BCM43430A1, BCM43341B0 .

On these models the following 2 devices were not being discovered
when starting a scan with a filter with just discoverable set
in the filter (as gnome-bluetooth does):

Device 09:02:01:03:0F:87 (public)
        Name: Bluetooth 3.0 Keyboard
        Alias: Bluetooth 3.0 Keyboard
        Class: 0x00000540
        Icon: input-keyboard
        Paired: yes
        Bonded: yes
        Trusted: yes
        Blocked: no
        Connected: yes
        WakeAllowed: yes
        LegacyPairing: yes
        UUID: Service Discovery Serve.. (00001000-0000-1000-8000-00805f9b34fb)
        UUID: Human Interface Device... (00001124-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        Modalias: bluetooth:v05ACp022Cd011B

Device 00:60:D1:00:00:34 (public)
        Name: Bluetooth Mouse
        Alias: Bluetooth Mouse
        Class: 0x00002580
        Icon: input-mouse
        Paired: yes
        Bonded: yes
        Trusted: yes
        Blocked: no
        Connected: yes
        WakeAllowed: yes
        LegacyPairing: no
        UUID: Human Interface Device... (00001124-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v0103p0204d001E

Since setting the discoverable flag on a filter only is a way to
automatically put the adapter in discoverable mode itself while
it is discovering; and since this does not any device filtering
at all; modify merge_discovery_filters() to treat discovery with
such filters as regular unfiltered discovery.

This results in start_discovery_timeout() starting regular
discovery through a MGMT_OP_START_DISCOVERY message and this
fixes these 2 example devices not getting discovered by the
mentioned Broadcom BT adapter models.

Link: https://gitlab.gnome.org/GNOME/gnome-bluetooth/-/merge_requests/163
Reviewed-by: Bastien Nocera <[e-mail]>
---
Note the same argument can be made for the pattern and duplicate part of
the filters which also get handled outside of the kernel filter.
But I prefer to keep the first patch small and targetted at solving things
not working with the gnome-bluetooth filter settings.

Also I'm not familiar enough with the code to say with certainty that
filters with just a pattern or the duplicate flag set (or a combination)
should also be treated as unfiltered discovery.
---
Changes in v2:
- Fix a couple of typos / grammar errors in the commit message
- Replace hard-tabs in commit message with spaces
- Add Bastien's Reviewed-by tag
---
 src/adapter.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Comments

[e-mail] March 31, 2023, 9:17 p.m. UTC | #1

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=735968

---Test result---

Test Summary:
CheckPatch                    FAIL      0.78 seconds
GitLint                       FAIL      0.74 seconds
BuildEll                      PASS      30.08 seconds
BluezMake                     PASS      959.28 seconds
MakeCheck                     PASS      11.70 seconds
MakeDistcheck                 PASS      163.67 seconds
CheckValgrind                 PASS      265.82 seconds
CheckSmatch                   PASS      357.50 seconds
bluezmakeextell               PASS      109.16 seconds
IncrementalBuild              PASS      767.40 seconds
ScanBuild                     PASS      1090.61 seconds

Details
##############################
Test: CheckPatch - FAIL
Desc: Run checkpatch.pl script
Output:
[BlueZ,v2] adapter: Use regular discovery for filters which only have discoverable set
WARNING:COMMIT_LOG_LONG_LINE: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#100: 
        UUID: Service Discovery Serve.. (00001000-0000-1000-8000-00805f9b34fb)

/github/workspace/src/src/13196553.patch total: 0 errors, 1 warnings, 35 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

/github/workspace/src/src/13196553.patch has style problems, please review.

NOTE: Ignored message types: COMMIT_MESSAGE COMPLEX_MACRO CONST_STRUCT FILE_PATH_CHANGES MISSING_SIGN_OFF PREFER_PACKED SPDX_LICENSE_TAG SPLIT_STRING SSCANF_TO_KSTRTO

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.


##############################
Test: GitLint - FAIL
Desc: Run gitlint
Output:
[BlueZ,v2] adapter: Use regular discovery for filters which only have discoverable set

WARNING: I3 - ignore-body-lines: gitlint will be switching from using Python regex 'match' (match beginning) to 'search' (match anywhere) semantics. Please review your ignore-body-lines.regex option accordingly. To remove this warning, set general.regex-style-search=True. More details: https://jorisroovers.github.io/gitlint/configuration/#regex-style-search
1: T1 Title exceeds max length (86>80): "[BlueZ,v2] adapter: Use regular discovery for filters which only have discoverable set"


---
Regards,
Linux Bluetooth

[e-mail] March 31, 2023, 10:20 p.m. UTC | #2

Hello:

This patch was applied to bluetooth/bluez.git (master)
by Luiz Augusto von Dentz <[e-mail]>:

On Fri, 31 Mar 2023 22:03:29 +0200 you wrote:
> discovery_filter_to_mgmt_cp() does not add discovery_filter.discoverable
> to the created mgmt_cp_start_service_discovery struct.
> 
> Instead update_discovery_filter() separately checks
> client->discovery_filter->discoverable for all clients.
> 
> This means that for discovery-filters which only have the discoverable
> flag set, to put the adapter in discoverable mode while discovering,
> the created mgmt_cp_start_service_discovery struct is empty.
> 
> [...]

Here is the summary with links:
  - [BlueZ,v2] adapter: Use regular discovery for filters which only have discoverable set
    https://git.kernel.org/pub/scm/bluetooth/bluez.git/?id=de8e7cfce25b

You are awesome, thank you!

Patch

diff --git a/src/adapter.c b/src/adapter.c
index 7947160a6..cc7f891d9 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -2192,6 +2192,7 @@  static int merge_discovery_filters(struct btd_adapter *adapter, int *rssi,
 	bool empty_uuid = false;
 	bool has_regular_discovery = false;
 	bool has_filtered_discovery = false;
+	uint8_t adapter_scan_type = get_scan_type(adapter);
 
 	for (l = adapter->discovery_list; l != NULL; l = g_slist_next(l)) {
 		struct discovery_client *client = l->data;
@@ -2202,6 +2203,20 @@  static int merge_discovery_filters(struct btd_adapter *adapter, int *rssi,
 			continue;
 		}
 
+		/*
+		 * Detect empty filter with only discoverable
+		 * (which does not require a kernel filter) set.
+		 */
+		if (item->uuids == NULL &&
+		    item->pathloss == DISTANCE_VAL_INVALID &&
+		    item->rssi == DISTANCE_VAL_INVALID &&
+		    item->type == adapter_scan_type &&
+		    item->duplicate == false &&
+		    item->pattern == NULL) {
+			has_regular_discovery = true;
+			continue;
+		}
+
 		has_filtered_discovery = true;
 
 		*transport |= item->type;
@@ -2251,7 +2266,7 @@  static int merge_discovery_filters(struct btd_adapter *adapter, int *rssi,
 		 * It there is both regular and filtered scan running, then
 		 * clear whole fitler to report all devices.
 		 */
-		*transport = get_scan_type(adapter);
+		*transport = adapter_scan_type;
 		*rssi = HCI_RSSI_INVALID;
 		g_slist_free(*uuids);
 		*uuids = NULL;