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