/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
{
- const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct can_priv *priv = netdev_priv(dev);
- if (skb->protocol == htons(ETH_P_CAN)) {
- if (unlikely(skb->len != CAN_MTU ||
- cfd->len > CAN_MAX_DLEN))
+ switch (ntohs(skb->protocol)) {
+ case ETH_P_CAN:
+ if (!can_is_can_skb(skb))
goto inval_skb;
- } else if (skb->protocol == htons(ETH_P_CANFD)) {
- if (unlikely(skb->len != CANFD_MTU ||
- cfd->len > CANFD_MAX_DLEN))
+ break;
+
+ case ETH_P_CANFD:
+ if (!can_is_canfd_skb(skb))
goto inval_skb;
- } else {
+ break;
+
+ default:
goto inval_skb;
}
return nskb;
}
+static inline bool can_is_can_skb(const struct sk_buff *skb)
+{
+ struct can_frame *cf = (struct can_frame *)skb->data;
+
+ /* the CAN specific type of skb is identified by its data length */
+ return (skb->len == CAN_MTU && cf->len <= CAN_MAX_DLEN);
+}
+
static inline bool can_is_canfd_skb(const struct sk_buff *skb)
{
+ struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
/* the CAN specific type of skb is identified by its data length */
- return skb->len == CANFD_MTU;
+ return (skb->len == CANFD_MTU && cfd->len <= CANFD_MAX_DLEN);
}
#endif /* !_CAN_SKB_H */
int can_send(struct sk_buff *skb, int loop)
{
struct sk_buff *newskb = NULL;
- struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
struct can_pkg_stats *pkg_stats = dev_net(skb->dev)->can.pkg_stats;
int err = -EINVAL;
- if (skb->len == CAN_MTU) {
+ if (can_is_can_skb(skb)) {
skb->protocol = htons(ETH_P_CAN);
- if (unlikely(cfd->len > CAN_MAX_DLEN))
- goto inval_skb;
- } else if (skb->len == CANFD_MTU) {
+ } else if (can_is_canfd_skb(skb)) {
skb->protocol = htons(ETH_P_CANFD);
- if (unlikely(cfd->len > CANFD_MAX_DLEN))
- goto inval_skb;
} else {
goto inval_skb;
}
- /* 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)) {
+ /* Make sure the CAN frame can pass the selected CAN netdevice. */
+ if (unlikely(skb->len > skb->dev->mtu)) {
err = -EMSGSIZE;
goto inval_skb;
}
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(dev->type != ARPHRD_CAN || skb->len != CAN_MTU)) {
+ if (unlikely(dev->type != ARPHRD_CAN || (!can_is_can_skb(skb)))) {
pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n",
dev->type, skb->len);
- goto free_skb;
- }
- /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
- if (unlikely(cfd->len > CAN_MAX_DLEN)) {
- pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d, datalen %d\n",
- dev->type, skb->len, cfd->len);
- goto free_skb;
+ kfree_skb(skb);
+ return NET_RX_DROP;
}
can_receive(skb, dev);
return NET_RX_SUCCESS;
-
-free_skb:
- 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(dev->type != ARPHRD_CAN || skb->len != CANFD_MTU)) {
+ if (unlikely(dev->type != ARPHRD_CAN || (!can_is_canfd_skb(skb)))) {
pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n",
dev->type, skb->len);
- goto free_skb;
- }
- /* This check is made separately since cfd->len would be uninitialized if skb->len = 0. */
- if (unlikely(cfd->len > CANFD_MAX_DLEN)) {
- pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d, datalen %d\n",
- dev->type, skb->len, cfd->len);
- goto free_skb;
+ kfree_skb(skb);
+ return NET_RX_DROP;
}
can_receive(skb, dev);
return NET_RX_SUCCESS;
-
-free_skb:
- kfree_skb(skb);
- return NET_RX_DROP;
}
/* af_can protocol functions */