Commit 921ca574 authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by Marc Kleine-Budde
Browse files

can: isotp: add SF_BROADCAST support for functional addressing 



When CAN_ISOTP_SF_BROADCAST is set in the CAN_ISOTP_OPTS flags the CAN_ISOTP
socket is switched into functional addressing mode, where only single frame
(SF) protocol data units can be send on the specified CAN interface and the
given tp.tx_id after bind().

In opposite to normal and extended addressing this socket does not register a
CAN-ID for reception which would be needed for a 1-to-1 ISOTP connection with a
segmented bi-directional data transfer.

Sending SFs on this socket is therefore a TX-only 'broadcast' operation.

Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarThomas Wagner <thwa1@web.de>
Link: https://lore.kernel.org/r/20201206144731.4609-1-socketcan@hartkopp.net


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent a7105e34

include/uapi/linux/can/isotp.h

+1 −1
Original line number Diff line number Diff line
@@ -135,7 +135,7 @@ struct can_isotp_ll_options { 
#define CAN_ISOTP_FORCE_RXSTMIN	0x100	/* ignore CFs depending on rx stmin */

#define CAN_ISOTP_RX_EXT_ADDR	0x200	/* different rx extended addressing */

#define CAN_ISOTP_WAIT_TX_DONE	0x400	/* wait for tx completion */



#define CAN_ISOTP_SF_BROADCAST	0x800	/* 1-to-N functional addressing */



/* default values */

net/can/isotp.c

+29 −13
Original line number Diff line number Diff line
@@ -865,6 +865,14 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 
	if (!size || size > MAX_MSG_LENGTH)

		return -EINVAL;



	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */

	off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;



	/* does the given data fit into a single frame for SF_BROADCAST? */

	if ((so->opt.flags & CAN_ISOTP_SF_BROADCAST) &&

	    (size > so->tx.ll_dl - SF_PCI_SZ4 - ae - off))

		return -EINVAL;



	err = memcpy_from_msg(so->tx.buf, msg, size);

	if (err < 0)

		return err;
@@ -891,9 +899,6 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) 
	cf = (struct canfd_frame *)skb->data;

	skb_put(skb, so->ll.mtu);



	/* take care of a potential SF_DL ESC offset for TX_DL > 8 */

	off = (so->tx.ll_dl > CAN_MAX_DLEN) ? 1 : 0;



	/* check for single frame transmission depending on TX_DL */

	if (size <= so->tx.ll_dl - SF_PCI_SZ4 - ae - off) {

		/* The message size generally fits into a SingleFrame - good.
@@ -1016,7 +1021,7 @@ static int isotp_release(struct socket *sock) 
	hrtimer_cancel(&so->rxtimer);



	/* remove current filters & unregister */

	if (so->bound) {

	if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {

		if (so->ifindex) {

			struct net_device *dev;
@@ -1052,15 +1057,25 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) 
	struct net_device *dev;

	int err = 0;

	int notify_enetdown = 0;

	int do_rx_reg = 1;



	if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp))

		return -EINVAL;



	/* do not register frame reception for functional addressing */

	if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)

		do_rx_reg = 0;



	/* do not validate rx address for functional addressing */

	if (do_rx_reg) {

		if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)

			return -EADDRNOTAVAIL;



	if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &

	    (CAN_ERR_FLAG | CAN_RTR_FLAG))

		if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))

			return -EADDRNOTAVAIL;

	}



	if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))

		return -EADDRNOTAVAIL;



	if (!addr->can_ifindex)
@@ -1093,13 +1108,14 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) 


	ifindex = dev->ifindex;



	if (do_rx_reg)

		can_rx_register(net, dev, addr->can_addr.tp.rx_id,

			SINGLE_MASK(addr->can_addr.tp.rx_id), isotp_rcv, sk,

			"isotp", sk);

				SINGLE_MASK(addr->can_addr.tp.rx_id),

				isotp_rcv, sk, "isotp", sk);



	dev_put(dev);



	if (so->bound) {

	if (so->bound && do_rx_reg) {

		/* unregister old filter */

		if (so->ifindex) {

			dev = dev_get_by_index(net, so->ifindex);
@@ -1299,7 +1315,7 @@ static int isotp_notifier(struct notifier_block *nb, unsigned long msg, 
	case NETDEV_UNREGISTER:

		lock_sock(sk);

		/* remove current filters & unregister */

		if (so->bound)

		if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))

			can_rx_unregister(dev_net(dev), dev, so->rxid,

					  SINGLE_MASK(so->rxid),

					  isotp_rcv, sk);