/*
* socketcan/can/gw.h
*
- * Definitions for CAN frame Gateway/Router/Bridge
+ * Definitions for CAN frame Gateway/Router/Bridge
*
* $Id$
*
* Author: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
- * Copyright (c) 2002-2010 Volkswagen Group Electronic Research
+ * Copyright (c) 2011 Volkswagen Group Electronic Research
* All rights reserved.
*
* Send feedback to <socketcan-users@lists.berlios.de>
#ifndef CAN_GW_H
#define CAN_GW_H
+#include <linux/types.h>
#include <socketcan/can.h>
struct rtcanmsg {
__u8 can_family;
- __u8 can_txflags;
- __u16 pad;
- __u32 src_ifindex;
- __u32 dst_ifindex;
+ __u8 gwtype;
+ __u16 flags;
};
-#define CAN_GW_TXFLAGS_LOOPBACK 0x01
-#define CAN_GW_TXFLAGS_SRC_TSTAMP 0x02
+/* CAN gateway types */
+enum {
+ CGW_TYPE_UNSPEC,
+ CGW_TYPE_CAN_CAN, /* CAN->CAN routing */
+ __CGW_TYPE_MAX
+};
+
+#define CGW_TYPE_MAX (__CGW_TYPE_MAX - 1)
/* CAN rtnetlink attribute definitions */
enum {
CGW_UNSPEC,
- CGW_FILTER, /* specify struct can_filter on source CAN device */
CGW_MOD_AND, /* CAN frame modification binary AND */
CGW_MOD_OR, /* CAN frame modification binary OR */
CGW_MOD_XOR, /* CAN frame modification binary XOR */
CGW_MOD_SET, /* CAN frame modification set alternate values */
+ CGW_CS_XOR, /* set data[] XOR checksum into data[index] */
+ CGW_CS_CRC8, /* set data[] CRC8 checksum into data[index] */
+ CGW_HANDLED, /* number of handled CAN frames */
+ CGW_DROPPED, /* number of dropped CAN frames */
+ CGW_SRC_IF, /* ifindex of source network interface */
+ CGW_DST_IF, /* ifindex of destination network interface */
+ CGW_FILTER, /* specify struct can_filter on source CAN device */
__CGW_MAX
};
#define CGW_MAX (__CGW_MAX - 1)
+#define CGW_FLAGS_CAN_ECHO 0x01
+#define CGW_FLAGS_CAN_SRC_TSTAMP 0x02
+
#define CGW_MOD_FUNCS 4 /* AND OR XOR SET */
/* CAN frame elements that are affected by curr. 3 CAN frame modifications */
#define MAX_MODFUNCTIONS (CGW_MOD_FUNCS * CGW_FRAME_MODS)
-#define CGW_MODATTR_LEN (sizeof(struct can_frame) + 1)
+struct cgw_frame_mod {
+ struct can_frame cf;
+ __u8 modtype;
+} __attribute__((packed));
+
+#define CGW_MODATTR_LEN sizeof(struct cgw_frame_mod)
+
+struct cgw_csum_xor {
+ __s8 from_idx;
+ __s8 to_idx;
+ __s8 result_idx;
+ __u8 init_xor_val;
+} __attribute__((packed));
+
+struct cgw_csum_crc8 {
+ __s8 from_idx;
+ __s8 to_idx;
+ __s8 result_idx;
+ __u8 init_crc_val;
+ __u8 final_xor_val;
+ __u8 crctab[256];
+ __u8 profile;
+ __u8 profile_data[20];
+} __attribute__((packed));
+
+/* length of checksum operation parameters. idx = index in CAN frame data[] */
+#define CGW_CS_XOR_LEN sizeof(struct cgw_csum_xor)
+#define CGW_CS_CRC8_LEN sizeof(struct cgw_csum_crc8)
+
+/* CRC8 profiles (compute CRC for additional data elements - see below) */
+enum {
+ CGW_CRC8PRF_UNSPEC,
+ CGW_CRC8PRF_1U8, /* compute one additional u8 value */
+ CGW_CRC8PRF_16U8, /* u8 value table indexed by data[1] & 0xF */
+ CGW_CRC8PRF_SFFID_XOR, /* (can_id & 0xFF) ^ (can_id >> 8 & 0xFF) */
+ __CGW_CRC8PRF_MAX
+};
+
+#define CGW_CRC8PRF_MAX (__CGW_CRC8PRF_MAX - 1)
/*
* CAN rtnetlink attribute contents in detail
*
- * CGW_FILTER (length 32 bytes):
+ * CGW_XXX_IF (length 4 bytes):
+ * Sets an interface index for source/destination network interfaces.
+ * For the CAN->CAN gwtype the indices of _two_ CAN interfaces are mandatory.
+ *
+ * CGW_FILTER (length 8 bytes):
* Sets a CAN receive filter for the gateway job specified by the
* struct can_filter described in include/linux/can.h
*
* <struct can_frame> data used as operator
* <u8> affected CAN frame elements
*
- * Remark: The attribute data is a linear buffer. Beware of sending structs!
+ * CGW_CS_XOR (length 4 bytes):
+ * Set a simple XOR checksum starting with an initial value into
+ * data[result-idx] using data[start-idx] .. data[end-idx]
+ *
+ * The XOR checksum is calculated like this:
+ *
+ * xor = init_xor_val
+ *
+ * for (i = from_idx .. to_idx)
+ * xor ^= can_frame.data[i]
+ *
+ * can_frame.data[ result_idx ] = xor
+ *
+ * CGW_CS_CRC8 (length 282 bytes):
+ * Set a CRC8 value into data[result-idx] using a given 256 byte CRC8 table,
+ * a given initial value and a defined input data[start-idx] .. data[end-idx].
+ * Finally the result value is XOR'ed with the final_xor_val.
+ *
+ * The CRC8 checksum is calculated like this:
+ *
+ * crc = init_crc_val
+ *
+ * for (i = from_idx .. to_idx)
+ * crc = crctab[ crc ^ can_frame.data[i] ]
+ *
+ * can_frame.data[ result_idx ] = crc ^ final_xor_val
+ *
+ * The calculated CRC may contain additional source data elements that can be
+ * defined in the handling of 'checksum profiles' e.g. shown in AUTOSAR specs
+ * like http://www.autosar.org/download/R4.0/AUTOSAR_SWS_E2ELibrary.pdf
+ * E.g. the profile_data[] may contain additional u8 values (called DATA_IDs)
+ * that are used depending on counter values inside the CAN frame data[].
+ * So far only three profiles have been implemented for illustration.
+ *
+ * Remark: In general the attribute data is a linear buffer.
+ * Beware of sending unpacked or aligned structs!
*/
#endif