nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

can: raw: add CAN XL support

Browse source 
Enable CAN_RAW sockets to read and write CAN XL frames analogue to the
CAN FD extension (new CAN_RAW_XL_FRAMES sockopt).

A CAN XL network interface is capable to handle Classical CAN, CAN FD and
CAN XL frames. When CAN_RAW_XL_FRAMES is enabled, the CAN_RAW socket checks
whether the addressed CAN network interface is capable to handle the
provided CAN frame.

In opposite to the fixed number of bytes for
- CAN frames (CAN_MTU = sizeof(struct can_frame))
- CAN FD frames (CANFD_MTU = sizeof(struct can_frame))
the number of bytes when reading/writing CAN XL frames depends on the
number of data bytes. For efficiency reasons the length of the struct
canxl_frame is truncated to the needed size for read/write operations.
This leads to a calculated size of CANXL_HDR_SIZE + canxl_frame::len which
is enforced on write() operations and guaranteed on read() operations.

NB: Valid length values are 1 .. 2048 (CANXL_MIN_DLEN .. CANXL_MAX_DLEN).

Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20220912170725.120748-8-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Oliver Hartkopp 2022-09-12 19:07:25 +02:00 committed by Marc Kleine-Budde
parent ebf87fc728
commit 626332696d
2 changed files with 44 additions and 12 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
include/uapi/linux/can/raw.h
View file

@ -62,6 +62,7 @@ enum {
CAN_RAW_RECV_OWN_MSGS, /* receive my own msgs (default:off) */
CAN_RAW_FD_FRAMES, /* allow CAN FD frames (default:off) */
CAN_RAW_JOIN_FILTERS, /* all filters must match to trigger */
CAN_RAW_XL_FRAMES, /* allow CAN XL frames (default:off) */
};
#endif /* !_UAPI_CAN_RAW_H */

55
net/can/raw.c
View file

@ -50,6 +50,7 @@
#include <linux/skbuff.h>
#include <linux/can.h>
#include <linux/can/core.h>
#include <linux/can/dev.h> /* for can_is_canxl_dev_mtu() */
#include <linux/can/skb.h>
#include <linux/can/raw.h>
#include <net/sock.h>
@ -87,6 +88,7 @@ struct raw_sock {
int loopback;
int recv_own_msgs;
int fd_frames;
int xl_frames;
int join_filters;
int count; /* number of active filters */
struct can_filter dfilter; /* default/single filter */
@ -129,8 +131,9 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
if (!ro->recv_own_msgs && oskb->sk == sk)
return;
/* do not pass non-CAN2.0 frames to a legacy socket */
if (!ro->fd_frames && oskb->len != CAN_MTU)
/* make sure to not pass oversized frames to the socket */
if ((can_is_canfd_skb(oskb) && !ro->fd_frames && !ro->xl_frames) ||
(can_is_canxl_skb(oskb) && !ro->xl_frames))
return;
/* eliminate multiple filter matches for the same skb */
@ -345,6 +348,7 @@ static int raw_init(struct sock *sk)
ro->loopback = 1;
ro->recv_own_msgs = 0;
ro->fd_frames = 0;
ro->xl_frames = 0;
ro->join_filters = 0;
/* alloc_percpu provides zero'ed memory */
@ -668,6 +672,15 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
break;
case CAN_RAW_XL_FRAMES:
if (optlen != sizeof(ro->xl_frames))
return -EINVAL;
if (copy_from_sockptr(&ro->xl_frames, optval, optlen))
return -EFAULT;
break;
case CAN_RAW_JOIN_FILTERS:
if (optlen != sizeof(ro->join_filters))
return -EINVAL;
@ -750,6 +763,12 @@ static int raw_getsockopt(struct socket *sock, int level, int optname,
val = &ro->fd_frames;
break;
case CAN_RAW_XL_FRAMES:
if (len > sizeof(int))
len = sizeof(int);
val = &ro->xl_frames;
break;
case CAN_RAW_JOIN_FILTERS:
if (len > sizeof(int))
len = sizeof(int);
@ -775,7 +794,11 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
struct sk_buff *skb;
struct net_device *dev;
int ifindex;
int err;
int err = -EINVAL;
/* check for valid CAN frame sizes */
if (size < CANXL_HDR_SIZE + CANXL_MIN_DLEN || size > CANXL_MTU)
return -EINVAL;
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
@ -795,15 +818,6 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
if (!dev)
return -ENXIO;
err = -EINVAL;
if (ro->fd_frames && dev->mtu == CANFD_MTU) {
if (unlikely(size != CANFD_MTU && size != CAN_MTU))
goto put_dev;
} else {
if (unlikely(size != CAN_MTU))
goto put_dev;
}
skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
msg->msg_flags & MSG_DONTWAIT, &err);
if (!skb)
@ -813,10 +827,27 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
can_skb_prv(skb)->ifindex = dev->ifindex;
can_skb_prv(skb)->skbcnt = 0;
/* fill the skb before testing for valid CAN frames */
err = memcpy_from_msg(skb_put(skb, size), msg, size);
if (err < 0)
goto free_skb;
err = -EINVAL;
if (ro->xl_frames && can_is_canxl_dev_mtu(dev->mtu)) {
/* CAN XL, CAN FD and Classical CAN */
if (!can_is_canxl_skb(skb) && !can_is_canfd_skb(skb) &&
!can_is_can_skb(skb))
goto free_skb;
} else if (ro->fd_frames && dev->mtu == CANFD_MTU) {
/* CAN FD and Classical CAN */
if (!can_is_canfd_skb(skb) && !can_is_can_skb(skb))
goto free_skb;
} else {
/* Classical CAN */
if (!can_is_can_skb(skb))
goto free_skb;
}
sockcm_init(&sockc, sk);
if (msg->msg_controllen) {
err = sock_cmsg_send(sk, msg, &sockc);