Enable the PF_CAN infrastructure to handle CAN XL frames. A new ethernet
protocol type ETH_P_CANXL is defined to tag skbuffs containing the CAN XL
frame data structure.
As the length information is now a uint16 value for CAN XL three new
helper functions have been introduced to retrieve the data length from
all types of CAN frames.
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
---
include/linux/can/skb.h | 39 +++++++++++++++++++++++++++++++++++
include/uapi/linux/if_ether.h | 1 +
net/can/af_can.c | 32 +++++++++++++++++++++++-----
3 files changed, 67 insertions(+), 5 deletions(-)
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 182749e858b3..51481f5afe62 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -101,6 +101,45 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
{
/* the CAN specific type of skb is identified by its data length */
return skb->len == CANFD_MTU;
}
+static inline bool can_is_canxl_skb(const struct sk_buff *skb)
+{
+ const struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
+
+ if (skb->len != CANXL_MTU)
+ return false;
+
+ /* check valid CAN XL data length boundaries */
+ if (cfx->len < CANXL_MIN_DLEN || cfx->len > CANXL_MAX_DLEN)
+ return false;
+
+ return cfx->flags & CANXL_XLF;
+}
+
+/* get length element value from can[|fd|xl]_frame structure */
+static inline unsigned int can_skb_get_len_val(struct sk_buff *skb)
+{
+ const struct canxl_frame *cfx = (struct canxl_frame *)skb->data;
+ const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+ if (can_is_canxl_skb(skb))
+ return cfx->len;
+
+ return cfd->len;
+}
+
+/* get needed data length inside of CAN frame for all frame types (RTR aware) */
+static inline unsigned int can_skb_get_data_len(struct sk_buff *skb)
+{
+ unsigned int len = can_skb_get_len_val(skb);
+ const struct can_frame *cf = (struct can_frame *)skb->data;
+
+ /* RTR frames have an actual length of zero */
+ if (skb->len == CAN_MTU && cf->can_id & CAN_RTR_FLAG)
+ return 0;
+
+ return len;
+}
+
#endif /* !_CAN_SKB_H */
diff --git a/include/uapi/linux/if_ether.h b/include/uapi/linux/if_ether.h
index d370165bc621..69e0457eb200 100644
--- a/include/uapi/linux/if_ether.h
+++ b/include/uapi/linux/if_ether.h
@@ -136,10 +136,11 @@
#define ETH_P_WAN_PPP 0x0007 /* Dummy type for WAN PPP frames*/
#define ETH_P_PPP_MP 0x0008 /* Dummy type for PPP MP frames */
#define ETH_P_LOCALTALK 0x0009 /* Localtalk pseudo type */
#define ETH_P_CAN 0x000C /* CAN: Controller Area Network */
#define ETH_P_CANFD 0x000D /* CANFD: CAN flexible data rate*/
+#define ETH_P_CANXL 0x000E /* CANXL: eXtended frame Length */
#define ETH_P_PPPTALK 0x0010 /* Dummy type for Atalk over PPP*/
#define ETH_P_TR_802_2 0x0011 /* 802.2 frames */
#define ETH_P_MOBITEX 0x0015 /* Mobitex (kaz@xxxxxxxx) */
#define ETH_P_CONTROL 0x0016 /* Card specific control frames */
#define ETH_P_IRDA 0x0017 /* Linux-IrDA */
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 1fb49d51b25d..23e56e4e2457 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -209,19 +209,20 @@ int can_send(struct sk_buff *skb, int loop)
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 if (skb->len == CANXL_MTU) {
+ skb->protocol = htons(ETH_P_CANXL);
+ if (unlikely(!can_is_canxl_skb(skb)))
+ 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;
}
if (unlikely(skb->dev->type != ARPHRD_CAN)) {
@@ -725,10 +726,25 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev,
free_skb:
kfree_skb(skb);
return NET_RX_DROP;
}
+static int canxl_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ if (unlikely(dev->type != ARPHRD_CAN || (!can_is_canxl_skb(skb)))) {
+ pr_warn_once("PF_CAN: dropped non conform CAN XL skbuff: dev type %d, len %d\n",
+ dev->type, skb->len);
+
+ kfree_skb(skb);
+ return NET_RX_DROP;
+ }
+
+ can_receive(skb, dev);
+ return NET_RX_SUCCESS;
+}
+
/* af_can protocol functions */
/**
* can_proto_register - register CAN transport protocol
* @cp: pointer to CAN protocol structure
@@ -849,10 +865,15 @@ static struct packet_type can_packet __read_mostly = {
static struct packet_type canfd_packet __read_mostly = {
.type = cpu_to_be16(ETH_P_CANFD),
.func = canfd_rcv,
};
+static struct packet_type canxl_packet __read_mostly = {
+ .type = cpu_to_be16(ETH_P_CANXL),
+ .func = canxl_rcv,
+};
+
static const struct net_proto_family can_family_ops = {
.family = PF_CAN,
.create = can_create,
.owner = THIS_MODULE,
};
@@ -888,10 +909,11 @@ static __init int can_init(void)
if (err)
goto out_sock;
dev_add_pack(&can_packet);
dev_add_pack(&canfd_packet);
+ dev_add_pack(&canxl_packet);
return 0;
out_sock:
unregister_pernet_subsys(&can_pernet_ops);
--
2.30.2
