[PATCH BlueZ v4 1/2] org.bluez.Media: add SupportedFeatures

[PATCH BlueZ v4 1/2] org.bluez.Media: add SupportedFeatures

[Pauli Virtanen]

Add SupportedFeatures property for feature information that applications
cannot find otherwise.

Add feature tx-timestamping. Applications cannot enable it on old BlueZ
versions without that feature, as it requires special handling on BlueZ
side.
---

Notes:
    v4 & v3:
    - no change
    
    v2:
    - mention user application can check tstamp types itself

 doc/org.bluez.Media.rst | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/doc/org.bluez.Media.rst b/doc/org.bluez.Media.rst
index ecd982652..ef13a56a9 100644
--- a/doc/org.bluez.Media.rst
+++ b/doc/org.bluez.Media.rst
@@ -7,7 +7,7 @@ BlueZ D-Bus Media API documentation
 -----------------------------------
 
 :Version: BlueZ
-:Date: September 2023
+:Date: April 2025
 :Manual section: 5
 :Manual group: Linux System Administration
 
@@ -131,3 +131,16 @@ array{string} SupportedUUIDs [readonly]
 
 	List of 128-bit UUIDs that represents the supported Endpoint
 	registration.
+
+array{string} SupportedFeatures [readonly]
+``````````````````````````````````````````
+
+	List of strings that represent supported special features.
+	Possible values:
+
+	:"tx-timestamping":
+
+		Bluetooth TX timestamping in media stream sockets is
+		supported by BlueZ and kernel.  Applications may check
+		kernel support for specific timestamp types via
+		SIOCETHTOOL.
-- 
2.49.0

[PATCH BlueZ v4 2/2] media: implement SupportedFeatures property

[Pauli Virtanen]

Add org.bluez.Media.SupportedFeatures. Add feature tx-timestamping.
---

Notes:
    v4:
    - add code comments
    - remove stray change in adapter.h
    
    v3:
    - fix #includes
    
    v2:
    - use SIOCETHTOOL to get kernel support

 profiles/audio/media.c | 83 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/profiles/audio/media.c b/profiles/audio/media.c
index 69c6dc671..a18ddc9fe 100644
--- a/profiles/audio/media.c
+++ b/profiles/audio/media.c
@@ -18,6 +18,17 @@
 #include <errno.h>
 #include <inttypes.h>
 
+#include <time.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <linux/errqueue.h>
+#include <linux/net_tstamp.h>
+#include <linux/ethtool.h>
+#include <linux/sockios.h>
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+
 #include <glib.h>
 
 #include "lib/bluetooth.h"
@@ -81,6 +92,7 @@ struct media_adapter {
 #ifdef HAVE_AVRCP
 	GSList			*players;	/* Players list */
 #endif
+	int			so_timestamping;
 };
 
 struct endpoint_request {
@@ -3340,8 +3352,78 @@ static gboolean supported_uuids(const GDBusPropertyTable *property,
 	return TRUE;
 }
 
+static bool probe_tx_timestamping(struct media_adapter *adapter)
+{
+	struct ifreq ifr = {};
+	struct ethtool_ts_info cmd = {};
+	int sk = -1;
+
+	/* TX timestamping requires support from BlueZ in order to not mistake
+	 * errqueue for socket errors in media stream sockets. This is always
+	 * enabled (io_glib_add_err_watch), so need only check kernel side here.
+	 */
+
+	if (adapter->so_timestamping != -1)
+		goto done;
+
+	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "hci%u",
+				btd_adapter_get_index(adapter->btd_adapter));
+	ifr.ifr_data = (void *)&cmd;
+	cmd.cmd = ETHTOOL_GET_TS_INFO;
+
+	/* Check kernel reports some support for TX timestamping for L2CAP. If
+	 * yes then kernel version is new enough to have TX timestamping
+	 * available for other socket types too.
+	 */
+	sk = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
+	if (sk < 0)
+		goto error;
+	if (ioctl(sk, SIOCETHTOOL, &ifr))
+		goto error;
+	close(sk);
+
+	adapter->so_timestamping = cmd.so_timestamping;
+
+done:
+	return adapter->so_timestamping & SOF_TIMESTAMPING_TX_SOFTWARE;
+
+error:
+	if (sk >= 0)
+		close(sk);
+	adapter->so_timestamping = 0;
+	return false;
+}
+
+static const struct {
+	const char *name;
+	bool (*probe)(struct media_adapter *adapter);
+} features[] = {
+	{ "tx-timestamping", probe_tx_timestamping },
+};
+
+static gboolean supported_features(const GDBusPropertyTable *property,
+					DBusMessageIter *iter, void *data)
+{
+	struct media_adapter *adapter = data;
+	DBusMessageIter entry;
+	size_t i;
+
+	dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY,
+				DBUS_TYPE_STRING_AS_STRING, &entry);
+
+	for (i = 0; i < ARRAY_SIZE(features); ++i)
+		if (features[i].probe(adapter))
+			dbus_message_iter_append_basic(&entry, DBUS_TYPE_STRING,
+							&features[i].name);
+
+	dbus_message_iter_close_container(iter, &entry);
+
+	return TRUE;
+}
+
 static const GDBusPropertyTable media_properties[] = {
 	{ "SupportedUUIDs", "as", supported_uuids },
+	{ "SupportedFeatures", "as", supported_features },
 	{ }
 };
 
@@ -3383,6 +3465,7 @@ int media_register(struct btd_adapter *btd_adapter)
 	adapter = g_new0(struct media_adapter, 1);
 	adapter->btd_adapter = btd_adapter_ref(btd_adapter);
 	adapter->apps = queue_new();
+	adapter->so_timestamping = -1;
 
 	if (!g_dbus_register_interface(btd_get_dbus_connection(),
 					adapter_get_path(btd_adapter),
-- 
2.49.0

RE: [BlueZ,v4,1/2] org.bluez.Media: add SupportedFeatures

[bluez.test.bot]

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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=959306

---Test result---

Test Summary:
CheckPatch                    PENDING   0.21 seconds
GitLint                       PENDING   0.21 seconds
BuildEll                      PASS      20.37 seconds
BluezMake                     PASS      2626.66 seconds
MakeCheck                     PASS      19.91 seconds
MakeDistcheck                 PASS      198.02 seconds
CheckValgrind                 PASS      279.34 seconds
CheckSmatch                   PASS      308.92 seconds
bluezmakeextell               PASS      131.38 seconds
IncrementalBuild              PENDING   0.30 seconds
ScanBuild                     PASS      913.02 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH BlueZ v4 1/2] org.bluez.Media: add SupportedFeatures

[patchwork-bot+bluetooth]

Hello:

This series was applied to bluetooth/bluez.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Sat,  3 May 2025 10:24:25 +0300 you wrote:
> Add SupportedFeatures property for feature information that applications
> cannot find otherwise.
> 
> Add feature tx-timestamping. Applications cannot enable it on old BlueZ
> versions without that feature, as it requires special handling on BlueZ
> side.
> 
> [...]

Here is the summary with links:
  - [BlueZ,v4,1/2] org.bluez.Media: add SupportedFeatures
    https://git.kernel.org/pub/scm/bluetooth/bluez.git/?id=30d2de12868d
  - [BlueZ,v4,2/2] media: implement SupportedFeatures property
    https://git.kernel.org/pub/scm/bluetooth/bluez.git/?id=9ea27141c71f

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html