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Diffstat (limited to 'net/can/af_can.c')
-rw-r--r--net/can/af_can.c126
1 files changed, 94 insertions, 32 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 0ce2ad0..821022a 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -41,6 +41,7 @@
*/
#include <linux/module.h>
+#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/slab.h>
@@ -220,30 +221,46 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
* -ENOBUFS on full driver queue (see net_xmit_errno())
* -ENOMEM when local loopback failed at calling skb_clone()
* -EPERM when trying to send on a non-CAN interface
+ * -EMSGSIZE CAN frame size is bigger than CAN interface MTU
* -EINVAL when the skb->data does not contain a valid CAN frame
*/
int can_send(struct sk_buff *skb, int loop)
{
struct sk_buff *newskb = NULL;
- struct can_frame *cf = (struct can_frame *)skb->data;
- int err;
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+ int err = -EINVAL;
+
+ if (skb->len == CAN_MTU) {
+ skb->protocol = htons(ETH_P_CAN);
+ if (unlikely(cfd->len > CAN_MAX_DLEN))
+ goto inval_skb;
+ } else if (skb->len == CANFD_MTU) {
+ skb->protocol = htons(ETH_P_CANFD);
+ if (unlikely(cfd->len > CANFD_MAX_DLEN))
+ goto inval_skb;
+ } else
+ goto inval_skb;
- if (skb->len != sizeof(struct can_frame) || cf->can_dlc > 8) {
- kfree_skb(skb);
- return -EINVAL;
+ /*
+ * Make sure the CAN frame can pass the selected CAN netdevice.
+ * As structs can_frame and canfd_frame are similar, we can provide
+ * CAN FD frames to legacy CAN drivers as long as the length is <= 8
+ */
+ if (unlikely(skb->len > skb->dev->mtu && cfd->len > CAN_MAX_DLEN)) {
+ err = -EMSGSIZE;
+ goto inval_skb;
}
- if (skb->dev->type != ARPHRD_CAN) {
- kfree_skb(skb);
- return -EPERM;
+ if (unlikely(skb->dev->type != ARPHRD_CAN)) {
+ err = -EPERM;
+ goto inval_skb;
}
- if (!(skb->dev->flags & IFF_UP)) {
- kfree_skb(skb);
- return -ENETDOWN;
+ if (unlikely(!(skb->dev->flags & IFF_UP))) {
+ err = -ENETDOWN;
+ goto inval_skb;
}
- skb->protocol = htons(ETH_P_CAN);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
@@ -300,6 +317,10 @@ int can_send(struct sk_buff *skb, int loop)
can_stats.tx_frames_delta++;
return 0;
+
+inval_skb:
+ kfree_skb(skb);
+ return err;
}
EXPORT_SYMBOL(can_send);
@@ -334,8 +355,8 @@ static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
* relevant bits for the filter.
*
* The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
- * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames
- * there is a special filterlist and a special rx path filter handling.
+ * filter for error messages (CAN_ERR_FLAG bit set in mask). For error msg
+ * frames there is a special filterlist and a special rx path filter handling.
*
* Return:
* Pointer to optimal filterlist for the given can_id/mask pair.
@@ -347,7 +368,7 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
{
canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */
- /* filter for error frames in extra filterlist */
+ /* filter for error message frames in extra filterlist */
if (*mask & CAN_ERR_FLAG) {
/* clear CAN_ERR_FLAG in filter entry */
*mask &= CAN_ERR_MASK;
@@ -408,7 +429,7 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask,
* <received_can_id> & mask == can_id & mask
*
* The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
- * filter for error frames (CAN_ERR_FLAG bit set in mask).
+ * filter for error message frames (CAN_ERR_FLAG bit set in mask).
*
* The provided pointer to the sk_buff is guaranteed to be valid as long as
* the callback function is running. The callback function must *not* free
@@ -578,7 +599,7 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
return 0;
if (can_id & CAN_ERR_FLAG) {
- /* check for error frame entries only */
+ /* check for error message frame entries only */
hlist_for_each_entry_rcu(r, n, &d->rx[RX_ERR], list) {
if (can_id & r->mask) {
deliver(skb, r);
@@ -632,24 +653,11 @@ static int can_rcv_filter(struct dev_rcv_lists *d, struct sk_buff *skb)
return matches;
}
-static int can_rcv(struct sk_buff *skb, struct net_device *dev,
- struct packet_type *pt, struct net_device *orig_dev)
+static void can_receive(struct sk_buff *skb, struct net_device *dev)
{
struct dev_rcv_lists *d;
- struct can_frame *cf = (struct can_frame *)skb->data;
int matches;
- if (!net_eq(dev_net(dev), &init_net))
- goto drop;
-
- if (WARN_ONCE(dev->type != ARPHRD_CAN ||
- skb->len != sizeof(struct can_frame) ||
- cf->can_dlc > 8,
- "PF_CAN: dropped non conform skbuf: "
- "dev type %d, len %d, can_dlc %d\n",
- dev->type, skb->len, cf->can_dlc))
- goto drop;
-
/* update statistics */
can_stats.rx_frames++;
can_stats.rx_frames_delta++;
@@ -673,7 +681,49 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev,
can_stats.matches++;
can_stats.matches_delta++;
}
+}
+static int can_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (unlikely(!net_eq(dev_net(dev), &init_net)))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != CAN_MTU ||
+ cfd->len > CAN_MAX_DLEN,
+ "PF_CAN: dropped non conform CAN skbuf: "
+ "dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len))
+ goto drop;
+
+ can_receive(skb, dev);
+ return NET_RX_SUCCESS;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (unlikely(!net_eq(dev_net(dev), &init_net)))
+ goto drop;
+
+ if (WARN_ONCE(dev->type != ARPHRD_CAN ||
+ skb->len != CANFD_MTU ||
+ cfd->len > CANFD_MAX_DLEN,
+ "PF_CAN: dropped non conform CAN FD skbuf: "
+ "dev type %d, len %d, datalen %d\n",
+ dev->type, skb->len, cfd->len))
+ goto drop;
+
+ can_receive(skb, dev);
return NET_RX_SUCCESS;
drop:
@@ -807,10 +857,14 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
static struct packet_type can_packet __read_mostly = {
.type = cpu_to_be16(ETH_P_CAN),
- .dev = NULL,
.func = can_rcv,
};
+static struct packet_type canfd_packet __read_mostly = {
+ .type = cpu_to_be16(ETH_P_CANFD),
+ .func = canfd_rcv,
+};
+
static const struct net_proto_family can_family_ops = {
.family = PF_CAN,
.create = can_create,
@@ -824,6 +878,12 @@ static struct notifier_block can_netdev_notifier __read_mostly = {
static __init int can_init(void)
{
+ /* check for correct padding to be able to use the structs similarly */
+ BUILD_BUG_ON(offsetof(struct can_frame, can_dlc) !=
+ offsetof(struct canfd_frame, len) ||
+ offsetof(struct can_frame, data) !=
+ offsetof(struct canfd_frame, data));
+
printk(banner);
memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
@@ -846,6 +906,7 @@ static __init int can_init(void)
sock_register(&can_family_ops);
register_netdevice_notifier(&can_netdev_notifier);
dev_add_pack(&can_packet);
+ dev_add_pack(&canfd_packet);
return 0;
}
@@ -860,6 +921,7 @@ static __exit void can_exit(void)
can_remove_proc();
/* protocol unregister */
+ dev_remove_pack(&canfd_packet);
dev_remove_pack(&can_packet);
unregister_netdevice_notifier(&can_netdev_notifier);
sock_unregister(PF_CAN);
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