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can: isotp: add SF_BROADCAST support for functional addressing

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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: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Thomas Wagner <thwa1@web.de>
Link: https://lore.kernel.org/r/20201206144731.4609-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Oliver Hartkopp 2020-12-06 15:47:31 +01:00 committed by Marc Kleine-Budde
parent a7105e3472
commit 921ca574cd
2 changed files with 30 additions and 14 deletions
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2
include/uapi/linux/can/isotp.h
View File

@ -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 */

42
net/can/isotp.c
View File

@ -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;
if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
return -EADDRNOTAVAIL;
/* do not register frame reception for functional addressing */
if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
do_rx_reg = 0;
if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &
(CAN_ERR_FLAG | CAN_RTR_FLAG))
/* 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 & (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;
can_rx_register(net, dev, addr->can_addr.tp.rx_id,
SINGLE_MASK(addr->can_addr.tp.rx_id), isotp_rcv, sk,
"isotp", sk);
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);
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);