5 files changed, 85 insertions, 17 deletions

diff --git a/include/linux/can.h b/include/linux/can.h
index 17334c09bd9..1a66cf6112a 100644
--- a/include/linux/can.h
+++ b/include/linux/can.h
@@ -46,18 +46,67 @@ typedef __u32 canid_t;
  */
 typedef __u32 can_err_mask_t;
 
+/* CAN payload length and DLC definitions according to ISO 11898-1 */
+#define CAN_MAX_DLC 8
+#define CAN_MAX_DLEN 8
+
+/* CAN FD payload length and DLC definitions according to ISO 11898-7 */
+#define CANFD_MAX_DLC 15
+#define CANFD_MAX_DLEN 64
+
 /**
  * struct can_frame - basic CAN frame structure
- * @can_id:  the CAN ID of the frame and CAN_*_FLAG flags, see above.
- * @can_dlc: the data length field of the CAN frame
- * @data:    the CAN frame payload.
+ * @can_id:  CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
+ * @can_dlc: frame payload length in byte (0 .. 8) aka data length code
+ *           N.B. the DLC field from ISO 11898-1 Chapter 8.4.2.3 has a 1:1
+ *           mapping of the 'data length code' to the real payload length
+ * @data:    CAN frame payload (up to 8 byte)
  */
 struct can_frame {
         canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
-        __u8    can_dlc; /* data length code: 0 .. 8 */
-        __u8    data[8] __attribute__((aligned(8)));
+        __u8    can_dlc; /* frame payload length in byte (0 .. CAN_MAX_DLEN) */
+        __u8    data[CAN_MAX_DLEN] __attribute__((aligned(8)));
 };
 
+/*
+ * defined bits for canfd_frame.flags
+ *
+ * As the default for CAN FD should be to support the high data rate in the
+ * payload section of the frame (HDR) and to support up to 64 byte in the
+ * data section (EDL) the bits are only set in the non-default case.
+ * Btw. as long as there's no real implementation for CAN FD network driver
+ * these bits are only preliminary.
+ *
+ * RX: NOHDR/NOEDL - info about received CAN FD frame
+ *     ESI         - bit from originating CAN controller
+ * TX: NOHDR/NOEDL - control per-frame settings if supported by CAN controller
+ *     ESI         - bit is set by local CAN controller
+ */
+#define CANFD_NOHDR 0x01 /* frame without high data rate */
+#define CANFD_NOEDL 0x02 /* frame without extended data length */
+#define CANFD_ESI   0x04 /* error state indicator */
+
+/**
+ * struct canfd_frame - CAN flexible data rate frame structure
+ * @can_id: CAN ID of the frame and CAN_*_FLAG flags, see canid_t definition
+ * @len:    frame payload length in byte (0 .. CANFD_MAX_DLEN)
+ * @flags:  additional flags for CAN FD
+ * @__res0: reserved / padding
+ * @__res1: reserved / padding
+ * @data:   CAN FD frame payload (up to CANFD_MAX_DLEN byte)
+ */
+struct canfd_frame {
+        canid_t can_id;  /* 32 bit CAN_ID + EFF/RTR/ERR flags */
+        __u8    len;     /* frame payload length in byte */
+        __u8    flags;   /* additional flags for CAN FD */
+        __u8    __res0;  /* reserved / padding */
+        __u8    __res1;  /* reserved / padding */
+        __u8    data[CANFD_MAX_DLEN] __attribute__((aligned(8)));
+};
+
+#define CAN_MTU         (sizeof(struct can_frame))
+#define CANFD_MTU       (sizeof(struct canfd_frame))
+
 /* particular protocols of the protocol family PF_CAN */
 #define CAN_RAW         1 /* RAW sockets */
 #define CAN_BCM         2 /* Broadcast Manager */
diff --git a/include/linux/can/core.h b/include/linux/can/core.h
index 0ccc1cd28b9..78c6c52073a 100644
--- a/include/linux/can/core.h
+++ b/include/linux/can/core.h
@@ -17,10 +17,10 @@
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
 
-#define CAN_VERSION "20090105"
+#define CAN_VERSION "20120528"
 
 /* increment this number each time you change some user-space interface */
-#define CAN_ABI_VERSION "8"
+#define CAN_ABI_VERSION "9"
 
 #define CAN_VERSION_STRING "rev " CAN_VERSION " abi " CAN_ABI_VERSION
 
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 5d2efe7e3f1..ee5a771fb20 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -61,23 +61,40 @@ struct can_priv {
  * To be used in the CAN netdriver receive path to ensure conformance with
  * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
  */
-#define get_can_dlc(i)  (min_t(__u8, (i), 8))
+#define get_can_dlc(i)          (min_t(__u8, (i), CAN_MAX_DLC))
+#define get_canfd_dlc(i)        (min_t(__u8, (i), CANFD_MAX_DLC))
 
 /* Drop a given socketbuffer if it does not contain a valid CAN frame. */
 static inline int can_dropped_invalid_skb(struct net_device *dev,
                                           struct sk_buff *skb)
 {
-        const struct can_frame *cf = (struct can_frame *)skb->data;
-
-        if (unlikely(skb->len != sizeof(*cf) || cf->can_dlc > 8)) {
-                kfree_skb(skb);
-                dev->stats.tx_dropped++;
-                return 1;
-        }
+        const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+        if (skb->protocol == htons(ETH_P_CAN)) {
+                if (unlikely(skb->len != CAN_MTU ||
+                             cfd->len > CAN_MAX_DLEN))
+                        goto inval_skb;
+        } else if (skb->protocol == htons(ETH_P_CANFD)) {
+                if (unlikely(skb->len != CANFD_MTU ||
+                             cfd->len > CANFD_MAX_DLEN))
+                        goto inval_skb;
+        } else
+                goto inval_skb;
 
         return 0;
+
+inval_skb:
+        kfree_skb(skb);
+        dev->stats.tx_dropped++;
+        return 1;
 }
 
+/* get data length from can_dlc with sanitized can_dlc */
+u8 can_dlc2len(u8 can_dlc);
+
+/* map the sanitized data length to an appropriate data length code */
+u8 can_len2dlc(u8 len);
+
 struct net_device *alloc_candev(int sizeof_priv, unsigned int echo_skb_max);
 void free_candev(struct net_device *dev);
 
diff --git a/include/linux/can/raw.h b/include/linux/can/raw.h
index 781f3a3701b..a814062b071 100644
--- a/include/linux/can/raw.h
+++ b/include/linux/can/raw.h
@@ -23,7 +23,8 @@ enum {
         CAN_RAW_FILTER = 1,     /* set 0 .. n can_filter(s)          */
         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_RECV_OWN_MSGS,  /* receive my own msgs (default:off) */
+        CAN_RAW_FD_FRAMES,      /* allow CAN FD frames (default:off) */
 };
 
 #endif
diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index 56d907a2c80..167ce5b363d 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -105,7 +105,8 @@
 #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          /* Controller Area Network      */
+#define ETH_P_CAN       0x000C          /* CAN: Controller Area Network */
+#define ETH_P_CANFD     0x000D          /* CANFD: CAN flexible data rate*/
 #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@cafe.net)       */