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@xxxxxxxxx>
---
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
