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From: Christoph Fritz <christoph.fritz@hexdev.de>
To: Oliver Hartkopp <socketcan@hartkopp.net>,
	Marc Kleine-Budde <mkl@pengutronix.de>,
	Vincent Mailhol <mailhol.vincent@wanadoo.fr>,
	"David S . Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Jiri Kosina <jikos@kernel.org>,
	Benjamin Tissoires <bentiss@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>
Cc: Andreas Lauser <andreas.lauser@mercedes-benz.com>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-can@vger.kernel.org, netdev@vger.kernel.org,
	devicetree@vger.kernel.org, linux-input@vger.kernel.org,
	linux-serial@vger.kernel.org
Subject: [PATCH 08/11] can: bcm: Add LIN answer offloading for responder mode
Date: Mon, 22 Apr 2024 08:51:11 +0200	[thread overview]
Message-ID: <20240422065114.3185505-9-christoph.fritz@hexdev.de> (raw)
In-Reply-To: <20240422065114.3185505-1-christoph.fritz@hexdev.de>

Enhance CAN broadcast manager with RX_LIN_SETUP and RX_LIN_DELETE
operations to setup automatic LIN frame responses in responder mode.

Additionally, the patch introduces the LIN_EVENT_FRAME flag to
setup event-triggered LIN frames.

Signed-off-by: Christoph Fritz <christoph.fritz@hexdev.de>
---
 include/uapi/linux/can/bcm.h |  5 ++-
 net/can/bcm.c                | 74 +++++++++++++++++++++++++++++++++++-
 2 files changed, 77 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/can/bcm.h b/include/uapi/linux/can/bcm.h
index f1e45f533a72c..c46268a114078 100644
--- a/include/uapi/linux/can/bcm.h
+++ b/include/uapi/linux/can/bcm.h
@@ -86,7 +86,9 @@ enum {
 	TX_EXPIRED,	/* notification on performed transmissions (count=0) */
 	RX_STATUS,	/* reply to RX_READ request */
 	RX_TIMEOUT,	/* cyclic message is absent */
-	RX_CHANGED	/* updated CAN frame (detected content change) */
+	RX_CHANGED,	/* updated CAN frame (detected content change) */
+	RX_LIN_SETUP,	/* create auto-response for LIN frame */
+	RX_LIN_DELETE,  /* remove auto-response for LIN frame */
 };
 
 #define SETTIMER            0x0001
@@ -101,5 +103,6 @@ enum {
 #define TX_RESET_MULTI_IDX  0x0200
 #define RX_RTR_FRAME        0x0400
 #define CAN_FD_FRAME        0x0800
+#define LIN_EVENT_FRAME     0x1000
 
 #endif /* !_UAPI_CAN_BCM_H */
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 27d5fcf0eac9d..a717e594234d1 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -59,6 +59,7 @@
 #include <linux/can/bcm.h>
 #include <linux/slab.h>
 #include <net/sock.h>
+#include <net/lin.h>
 #include <net/net_namespace.h>
 
 /*
@@ -1330,6 +1331,59 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
 	return cfsiz + MHSIZ;
 }
 
+static int bcm_lin_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
+			 int ifindex, struct sock *sk, int cfsiz, int is_active)
+{
+	struct lin_responder_answer answ;
+	struct net_device *dev;
+	struct sk_buff *skb;
+	struct canfd_frame cf;
+	netdevice_tracker tracker;
+	size_t sz;
+	int ret;
+
+	if (msg_head->nframes > 1)
+		return -EINVAL;
+
+	if (!(msg_head->flags & CAN_FD_FRAME))
+		return -EINVAL;
+
+	ret = memcpy_from_msg(&cf, msg, cfsiz);
+	if (ret < 0)
+		return ret;
+
+	answ.lf.lin_id = cf.can_id & LIN_ID_MASK;
+	answ.is_active = is_active;
+	answ.is_event_frame = !!(msg_head->flags & LIN_EVENT_FRAME);
+	answ.event_associated_id = msg_head->can_id;
+	answ.lf.len = min(cf.len, LIN_MAX_DLEN);
+	memcpy(answ.lf.data, cf.data, answ.lf.len);
+	sz = min(sizeof(struct lin_responder_answer), sizeof(cf.data));
+	cf.can_id |= LIN_RXOFFLOAD_DATA_FLAG;
+	memcpy(cf.data, &answ, sz);
+
+	dev = netdev_get_by_index(sock_net(sk), ifindex, &tracker, GFP_KERNEL);
+	if (!dev)
+		return -ENODEV;
+
+	skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), gfp_any());
+	if (!skb)
+		goto lin_out;
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+	skb_put_data(skb, &cf, cfsiz);
+
+	skb->dev = dev;
+	can_skb_set_owner(skb, sk);
+	ret = can_send(skb, 1); /* send with loopback */
+
+lin_out:
+	netdev_put(dev, &tracker);
+	return ret;
+}
+
 /*
  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
  */
@@ -1429,12 +1483,30 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 
 	case TX_SEND:
 		/* we need exactly one CAN frame behind the msg head */
-		if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
+		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
 			ret = -EINVAL;
 		else
 			ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
 		break;
 
+	case RX_LIN_SETUP:
+		/* we need exactly one CAN frame behind the msg head */
+		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
+			ret = -EINVAL;
+		else
+			ret = bcm_lin_setup(&msg_head, msg, ifindex, sk, cfsiz,
+					    1);
+		break;
+
+	case RX_LIN_DELETE:
+		/* we need exactly one CAN frame behind the msg head */
+		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
+			ret = -EINVAL;
+		else
+			ret = bcm_lin_setup(&msg_head, msg, ifindex, sk, cfsiz,
+					    0);
+		break;
+
 	default:
 		ret = -EINVAL;
 		break;
-- 
2.39.2


  parent reply	other threads:[~2024-04-22  7:11 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-22  6:51 [PATCH 00/11] LIN Bus support for Linux Christoph Fritz
2024-04-22  6:51 ` [PATCH 01/11] can: Add LIN bus as CAN abstraction Christoph Fritz
2024-04-22  8:16   ` Jiri Slaby
2024-04-23  9:33     ` Christoph Fritz
2024-04-24  6:15       ` Jiri Slaby
2024-04-22  6:51 ` [PATCH 02/11] HID: hexLIN: Add support for USB LIN bus adapter Christoph Fritz
2024-04-22  8:21   ` Benjamin Tissoires
2024-04-25 20:49     ` Christoph Fritz
2024-04-22  6:51 ` [PATCH 03/11] tty: serdev: Add flag buffer aware receive_buf_fp() Christoph Fritz
2024-04-22  6:51 ` [PATCH 04/11] tty: serdev: Add method to enable break flags Christoph Fritz
2024-04-22  6:51 ` [PATCH 05/11] dt-bindings: net: can: Add serdev LIN bus dt bindings Christoph Fritz
2024-04-22  7:54   ` Krzysztof Kozlowski
2024-05-02  5:26     ` Christoph Fritz
2024-04-22  8:26   ` Rob Herring
2024-04-23  6:55   ` Krzysztof Kozlowski
2024-04-22  6:51 ` [PATCH 06/11] can: Add support for serdev LIN adapters Christoph Fritz
2024-04-22  6:51 ` [PATCH 07/11] can: lin: Add special frame id for rx offload config Christoph Fritz
2024-04-22  6:51 ` Christoph Fritz [this message]
2024-04-22  6:51 ` [PATCH 09/11] can: lin: Handle rx offload config frames Christoph Fritz
2024-04-22  6:51 ` [PATCH 10/11] can: lin: Support setting LIN mode Christoph Fritz
2024-04-22  6:51 ` [PATCH 11/11] HID: hexLIN: Implement ability to update lin mode Christoph Fritz

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