[PATCH v2] Bluetooth: ISO: add socket option to report packet seqnum via CMSG

[PATCH v2] Bluetooth: ISO: add socket option to report packet seqnum via CMSG

[Pauli Virtanen]

User applications need a way to track which ISO interval a given SDU
belongs to, to properly detect packet loss. All controllers do not set
timestamps, and it's not guaranteed user application receives all packet
reports (small socket buffer, or controller doesn't send all reports
like Intel AX210 is doing).

Add socket option BT_PKT_SEQNUM that enables reporting of received
packet ISO sequence number in BT_SCM_PKT_SEQNUM CMSG.

Use BT_PKT_SEQNUM == 22 for the socket option, as 21 was used earlier
for a removed experimental feature that never got into mainline.

Signed-off-by: Pauli Virtanen <pav@iki.fi>
---

Notes:
    v2:
    - fix missing __le16_to_cpu for hdr->sn
    - change BT_PKT_SEQNUM value to 22, to avoid clashing with removed
      experimental feature (only in bluetooth-next, it was never merged in
      mainline)
    - still call seqnum "sn", as the name is used in "hdr->sn"
    
    Tests: https://lore.kernel.org/linux-bluetooth/c9a75585e3640d8a1efca0bf96158eec1ca25fdc.1752501450.git.pav@iki.fi/

 include/net/bluetooth/bluetooth.h | 11 ++++++++++-
 net/bluetooth/af_bluetooth.c      |  7 +++++++
 net/bluetooth/iso.c               | 21 ++++++++++++++++++---
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index 114299bd8b98..ada5b56a4413 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -244,6 +244,12 @@ struct bt_codecs {
 
 #define BT_ISO_BASE		20
 
+/* Socket option value 21 reserved */
+
+#define BT_PKT_SEQNUM		22
+
+#define BT_SCM_PKT_SEQNUM	0x05
+
 __printf(1, 2)
 void bt_info(const char *fmt, ...);
 __printf(1, 2)
@@ -391,7 +397,8 @@ struct bt_sock {
 enum {
 	BT_SK_DEFER_SETUP,
 	BT_SK_SUSPEND,
-	BT_SK_PKT_STATUS
+	BT_SK_PKT_STATUS,
+	BT_SK_PKT_SEQNUM,
 };
 
 struct bt_sock_list {
@@ -475,6 +482,7 @@ struct bt_skb_cb {
 	u8 pkt_type;
 	u8 force_active;
 	u16 expect;
+	u16 pkt_seqnum;
 	u8 incoming:1;
 	u8 pkt_status:2;
 	union {
@@ -488,6 +496,7 @@ struct bt_skb_cb {
 
 #define hci_skb_pkt_type(skb) bt_cb((skb))->pkt_type
 #define hci_skb_pkt_status(skb) bt_cb((skb))->pkt_status
+#define hci_skb_pkt_seqnum(skb) bt_cb((skb))->pkt_seqnum
 #define hci_skb_expect(skb) bt_cb((skb))->expect
 #define hci_skb_opcode(skb) bt_cb((skb))->hci.opcode
 #define hci_skb_event(skb) bt_cb((skb))->hci.req_event
diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 6ad2f72f53f4..44b7acb20a67 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -364,6 +364,13 @@ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 			put_cmsg(msg, SOL_BLUETOOTH, BT_SCM_PKT_STATUS,
 				 sizeof(pkt_status), &pkt_status);
 		}
+
+		if (test_bit(BT_SK_PKT_SEQNUM, &bt_sk(sk)->flags)) {
+			u16 pkt_seqnum = hci_skb_pkt_seqnum(skb);
+
+			put_cmsg(msg, SOL_BLUETOOTH, BT_SCM_PKT_SEQNUM,
+				 sizeof(pkt_seqnum), &pkt_seqnum);
+		}
 	}
 
 	skb_free_datagram(sk, skb);
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index fc22782cbeeb..d402a22c8f91 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -1687,6 +1687,17 @@ static int iso_sock_setsockopt(struct socket *sock, int level, int optname,
 			clear_bit(BT_SK_PKT_STATUS, &bt_sk(sk)->flags);
 		break;
 
+	case BT_PKT_SEQNUM:
+		err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
+		if (err)
+			break;
+
+		if (opt)
+			set_bit(BT_SK_PKT_SEQNUM, &bt_sk(sk)->flags);
+		else
+			clear_bit(BT_SK_PKT_SEQNUM, &bt_sk(sk)->flags);
+		break;
+
 	case BT_ISO_QOS:
 		if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND &&
 		    sk->sk_state != BT_CONNECT2 &&
@@ -2278,7 +2289,7 @@ static void iso_disconn_cfm(struct hci_conn *hcon, __u8 reason)
 void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 {
 	struct iso_conn *conn = hcon->iso_data;
-	__u16 pb, ts, len;
+	__u16 pb, ts, len, sn;
 
 	if (!conn)
 		goto drop;
@@ -2308,6 +2319,7 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 				goto drop;
 			}
 
+			sn = __le16_to_cpu(hdr->sn);
 			len = __le16_to_cpu(hdr->slen);
 		} else {
 			struct hci_iso_data_hdr *hdr;
@@ -2318,18 +2330,20 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 				goto drop;
 			}
 
+			sn = __le16_to_cpu(hdr->sn);
 			len = __le16_to_cpu(hdr->slen);
 		}
 
 		flags  = hci_iso_data_flags(len);
 		len    = hci_iso_data_len(len);
 
-		BT_DBG("Start: total len %d, frag len %d flags 0x%4.4x", len,
-		       skb->len, flags);
+		BT_DBG("Start: total len %d, frag len %d flags 0x%4.4x sn %d",
+		       len, skb->len, flags, sn);
 
 		if (len == skb->len) {
 			/* Complete frame received */
 			hci_skb_pkt_status(skb) = flags & 0x03;
+			hci_skb_pkt_seqnum(skb) = sn;
 			iso_recv_frame(conn, skb);
 			return;
 		}
@@ -2352,6 +2366,7 @@ void iso_recv(struct hci_conn *hcon, struct sk_buff *skb, u16 flags)
 			goto drop;
 
 		hci_skb_pkt_status(conn->rx_skb) = flags & 0x03;
+		hci_skb_pkt_seqnum(conn->rx_skb) = sn;
 		skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
 					  skb->len);
 		conn->rx_len = len - skb->len;
-- 
2.50.1

RE: [v2] Bluetooth: ISO: add socket option to report packet seqnum via CMSG

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2264 bytes --]

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=982160

---Test result---

Test Summary:
CheckPatch                    PENDING   0.26 seconds
GitLint                       PENDING   0.23 seconds
SubjectPrefix                 PASS      0.13 seconds
BuildKernel                   PASS      24.14 seconds
CheckAllWarning               PASS      26.36 seconds
CheckSparse                   WARNING   29.81 seconds
BuildKernel32                 PASS      23.98 seconds
TestRunnerSetup               PASS      467.63 seconds
TestRunner_l2cap-tester       PASS      25.08 seconds
TestRunner_iso-tester         PASS      38.25 seconds
TestRunner_bnep-tester        PASS      5.89 seconds
TestRunner_mgmt-tester        PASS      129.51 seconds
TestRunner_rfcomm-tester      PASS      9.28 seconds
TestRunner_sco-tester         PASS      14.69 seconds
TestRunner_ioctl-tester       PASS      10.05 seconds
TestRunner_mesh-tester        FAIL      11.39 seconds
TestRunner_smp-tester         PASS      8.45 seconds
TestRunner_userchan-tester    PASS      6.17 seconds
IncrementalBuild              PENDING   0.51 seconds

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

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

##############################
Test: CheckSparse - WARNING
Desc: Run sparse tool with linux kernel
Output:
net/bluetooth/af_bluetooth.c:248:25: warning: context imbalance in 'bt_accept_enqueue' - different lock contexts for basic block
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.157 seconds
Mesh - Send cancel - 2                               Timed out    1.999 seconds
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH v2] Bluetooth: ISO: add socket option to report packet seqnum via CMSG

[patchwork-bot+bluetooth]

Hello:

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

On Mon, 14 Jul 2025 19:40:37 +0300 you wrote:
> User applications need a way to track which ISO interval a given SDU
> belongs to, to properly detect packet loss. All controllers do not set
> timestamps, and it's not guaranteed user application receives all packet
> reports (small socket buffer, or controller doesn't send all reports
> like Intel AX210 is doing).
> 
> Add socket option BT_PKT_SEQNUM that enables reporting of received
> packet ISO sequence number in BT_SCM_PKT_SEQNUM CMSG.
> 
> [...]

Here is the summary with links:
  - [v2] Bluetooth: ISO: add socket option to report packet seqnum via CMSG
    https://git.kernel.org/bluetooth/bluetooth-next/c/b3a08d3efd5c

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
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