netdev - [PATCH net-next 26/36] can: dev: add hardware TX timestamp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220731192029.746751-27-mkl@pengutronix.de>
Date:   Sun, 31 Jul 2022 21:20:19 +0200
From:   Marc Kleine-Budde <mkl@...gutronix.de>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, kuba@...nel.org, linux-can@...r.kernel.org,
        kernel@...gutronix.de,
        Vincent Mailhol <mailhol.vincent@...adoo.fr>,
        Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [PATCH net-next 26/36] can: dev: add hardware TX timestamp

From: Vincent Mailhol <mailhol.vincent@...adoo.fr>

Because of the loopback feature of socket CAN, hardware TX timestamps
are nothing else than the hardware RX timespamp of the corresponding
loopback packet. This patch simply reuses the hardware RX timestamp.

The rationale to clone this timestamp value is that existing tools
which rely of libpcap (such as tcpdump) expect support for both TX and
RX hardware timestamps in order to activate the feature (i.e. no
granular control to activate either of TX or RX hardware timestamps).

Signed-off-by: Vincent Mailhol <mailhol.vincent@...adoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-7-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
---
 drivers/net/can/dev/skb.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 8bb62dd864c8..07e0feac8629 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -72,6 +72,9 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 		/* save frame_len to reuse it when transmission is completed */
 		can_skb_prv(skb)->frame_len = frame_len;
 
+		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
+			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+
 		skb_tx_timestamp(skb);
 
 		/* save this skb for tx interrupt echo handling */
@@ -107,6 +110,9 @@ __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr,
 		struct can_skb_priv *can_skb_priv = can_skb_prv(skb);
 		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 
+		if (skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)
+			skb_tstamp_tx(skb, skb_hwtstamps(skb));
+
 		/* get the real payload length for netdev statistics */
 		if (cf->can_id & CAN_RTR_FLAG)
 			*len_ptr = 0;
-- 
2.35.1