*
* Definitions for CAN network layer (socket addr / CAN frame / CAN filter)
*
- * $Id$
- *
* Authors: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
* Urs Thuermann <urs.thuermann@volkswagen.de>
* Copyright (c) 2002-2007 Volkswagen Group Electronic Research
* All rights reserved.
*
- * Send feedback to <linux-can@vger.kernel.org>
- *
*/
#ifndef CAN_H
/* special address description flags for the CAN_ID */
#define CAN_EFF_FLAG 0x80000000U /* EFF/SFF is set in the MSB */
#define CAN_RTR_FLAG 0x40000000U /* remote transmission request */
-#define CAN_ERR_FLAG 0x20000000U /* error frame */
+#define CAN_ERR_FLAG 0x20000000U /* error message frame */
/* valid bits in CAN ID for frame formats */
#define CAN_SFF_MASK 0x000007FFU /* standard frame format (SFF) */
* Controller Area Network Identifier structure
*
* bit 0-28 : CAN identifier (11/29 bit)
- * bit 29 : error frame flag (0 = data frame, 1 = error frame)
+ * bit 29 : error message frame flag (0 = data frame, 1 = error message)
* bit 30 : remote transmission request flag (1 = rtr frame)
* bit 31 : frame format flag (0 = standard 11 bit, 1 = extended 29 bit)
*/
typedef __u32 canid_t;
+#define CAN_SFF_ID_BITS 11
+#define CAN_EFF_ID_BITS 29
+
/*
- * Controller Area Network Error Frame Mask structure
+ * Controller Area Network Error Message Frame Mask structure
*
* bit 0-28 : error class mask (see include/socketcan/can/error.h)
* bit 29-31 : set to zero
*/
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
+ *
+ * The use of struct canfd_frame implies the Extended Data Length (EDL) bit to
+ * be set in the CAN frame bitstream on the wire. The EDL bit switch turns
+ * the CAN controllers bitstream processor into the CAN FD mode which creates
+ * two new options within the CAN FD frame specification:
+ *
+ * Bit Rate Switch - to indicate a second bitrate is/was used for the payload
+ * Error State Indicator - represents the error state of the transmitting node
+ *
+ * As the CANFD_ESI bit is internally generated by the transmitting CAN
+ * controller only the CANFD_BRS bit is relevant for real CAN controllers when
+ * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make
+ * sense for virtual CAN interfaces to test applications with echoed frames.
+ */
+#define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */
+#define CANFD_ESI 0x02 /* error state indicator of the transmitting node */
+
+/**
+ * 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 */
#define SOL_CAN_BASE 100
+// typedef unsigned short __kernel_sa_family_t;
+// introduced in Linux 3.2 commit 6602a4baf4d1a73cc4685a39ef859e1c5ddf654c
+
/**
* struct sockaddr_can - the sockaddr structure for CAN sockets
* @can_family: address family number AF_CAN.
*/
struct sockaddr_can {
sa_family_t can_family;
+// __kernel_sa_family_t can_family;
int can_ifindex;
union {
/* transport protocol class address information (e.g. ISOTP) */
* <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).
*/
struct can_filter {
canid_t can_id;