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.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
include/uapi/linux/can/raw.h | 6 +++
net/can/raw.c | 97 +++++++++++++++++++++++++++++++-----
2 files changed, 90 insertions(+), 13 deletions(-)
diff --git a/include/uapi/linux/can/raw.h b/include/uapi/linux/can/raw.h
index 3386aa81fdf2..5a0e480887ff 100644
--- a/include/uapi/linux/can/raw.h
+++ b/include/uapi/linux/can/raw.h
@@ -60,8 +60,14 @@ enum {
CAN_RAW_ERR_FILTER, /* set filter for error frames */
CAN_RAW_LOOPBACK, /* local loopback (default:on) */
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) */
};
+/* CAN XL data transfer modes for CAN_RAW_XL_FRAMES sockopt */
+#define CAN_RAW_XL_ENABLE (1 << 0) /* enable CAN XL frames on this socket */
+#define CAN_RAW_XL_RX_DYN (1 << 1) /* enable truncated data[] for read() */
+#define CAN_RAW_XL_TX_DYN (1 << 2) /* enable truncated data[] for write() */
+
#endif /* !_UAPI_CAN_RAW_H */
diff --git a/net/can/raw.c b/net/can/raw.c
index d1bd9cc51ebe..48b9499d13a4 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -85,10 +85,11 @@ struct raw_sock {
int ifindex;
struct list_head notifier;
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 */
struct can_filter *filter; /* pointer to filter(s) */
can_err_mask_t err_mask;
@@ -127,12 +128,13 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
/* check the received tx sock reference */
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 ((oskb->len > CAN_MTU && !ro->fd_frames && !ro->xl_frames) ||
+ (oskb->len == CANXL_MTU && !ro->xl_frames))
return;
/* eliminate multiple filter matches for the same skb */
if (this_cpu_ptr(ro->uniq)->skb == oskb &&
this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) {
@@ -344,10 +346,11 @@ static int raw_init(struct sock *sk)
/* set default loopback behaviour */
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 */
ro->uniq = alloc_percpu(struct uniqframe);
if (unlikely(!ro->uniq))
@@ -667,10 +670,23 @@ static int raw_setsockopt(struct socket *sock, int level, int optname,
if (copy_from_sockptr(&ro->fd_frames, optval, optlen))
return -EFAULT;
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;
+
+ /* sanitize flags */
+ if (ro->xl_frames & (CAN_RAW_XL_RX_DYN | CAN_RAW_XL_TX_DYN))
+ ro->xl_frames |= CAN_RAW_XL_ENABLE;
+
+ break;
+
case CAN_RAW_JOIN_FILTERS:
if (optlen != sizeof(ro->join_filters))
return -EINVAL;
if (copy_from_sockptr(&ro->join_filters, optval, optlen))
@@ -749,10 +765,16 @@ static int raw_getsockopt(struct socket *sock, int level, int optname,
if (len > sizeof(int))
len = sizeof(int);
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);
val = &ro->join_filters;
break;
@@ -773,13 +795,18 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
struct sock *sk = sock->sk;
struct raw_sock *ro = raw_sk(sk);
struct sockcm_cookie sockc;
struct sk_buff *skb;
struct net_device *dev;
+ unsigned int skb_sz = size;
int ifindex;
int err;
+ /* valid CAN frame sizes */
+ if (size < CANXL_HDR_SZ + CANXL_MIN_DLEN || size > CANXL_MTU)
+ return -EINVAL;
+
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_can *, addr, msg->msg_name);
if (msg->msg_namelen < RAW_MIN_NAMELEN)
return -EINVAL;
@@ -794,20 +821,15 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
dev = dev_get_by_index(sock_net(sk), ifindex);
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;
- }
+ /* alloc full CAN XL space */
+ if (ro->xl_frames && dev->mtu == CANXL_MTU)
+ skb_sz = CANXL_MTU;
- skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
+ skb = sock_alloc_send_skb(sk, skb_sz + sizeof(struct can_skb_priv),
msg->msg_flags & MSG_DONTWAIT, &err);
if (!skb)
goto put_dev;
can_skb_reserve(skb);
@@ -816,10 +838,49 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
err = memcpy_from_msg(skb_put(skb, size), msg, size);
if (err < 0)
goto free_skb;
+ err = -EINVAL;
+
+ if (ro->xl_frames && dev->mtu == CANXL_MTU) {
+ struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
+
+ if (cfx->flags & CANXL_XLF) {
+ /* check for valid CAN XL frame */
+ if (cfx->len < CANXL_MIN_DLEN ||
+ cfx->len > CANXL_MAX_DLEN)
+ goto free_skb;
+
+ if (ro->xl_frames & CAN_RAW_XL_TX_DYN) {
+ /* check truncated CAN XL frame structure */
+ if (size != cfx->len + CANXL_HDR_SZ)
+ goto free_skb;
+
+ /* push skb->len to CANXL_MTU */
+ if (size < CANXL_MTU)
+ skb_put_zero(skb, CANXL_MTU - size);
+ } else {
+ /* check complete CAN XL frame structure */
+ if (size != CANXL_MTU)
+ goto free_skb;
+ }
+ } else {
+ /* check for CAN FD and Classical CAN */
+ if (unlikely(size != CANFD_MTU && size != CAN_MTU))
+ goto free_skb;
+ }
+ } else if (ro->fd_frames && dev->mtu == CANFD_MTU) {
+ /* CAN FD and Classical CAN */
+ if (unlikely(size != CANFD_MTU && size != CAN_MTU))
+ goto free_skb;
+ } else {
+ /* Classical CAN */
+ if (unlikely(size != CAN_MTU))
+ goto free_skb;
+ }
+
sockcm_init(&sockc, sk);
if (msg->msg_controllen) {
err = sock_cmsg_send(sk, msg, &sockc);
if (unlikely(err))
goto free_skb;
@@ -850,25 +911,35 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
static int raw_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int flags)
{
struct sock *sk = sock->sk;
+ struct raw_sock *ro = raw_sk(sk);
struct sk_buff *skb;
+ struct canxl_frame *cfx;
+ unsigned int rx_len;
int err = 0;
if (flags & MSG_ERRQUEUE)
return sock_recv_errqueue(sk, msg, size,
SOL_CAN_RAW, SCM_CAN_RAW_ERRQUEUE);
skb = skb_recv_datagram(sk, flags, &err);
if (!skb)
return err;
- if (size < skb->len)
+ rx_len = skb->len;
+ if (rx_len == CANXL_MTU && ro->xl_frames & CAN_RAW_XL_RX_DYN) {
+ cfx = (struct canxl_frame *)skb->data;
+ if (cfx->len >= CANXL_MIN_DLEN && cfx->len < CANXL_MAX_DLEN)
+ rx_len = CANXL_HDR_SZ + cfx->len;
+ }
+
+ if (size < rx_len)
msg->msg_flags |= MSG_TRUNC;
else
- size = skb->len;
+ size = rx_len;
err = memcpy_to_msg(msg, skb->data, size);
if (err < 0) {
skb_free_datagram(sk, skb);
return err;
--
2.30.2
