--- /dev/null
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/*
+ * linux/can/gw.h
+ *
+ * Definitions for CAN frame Gateway/Router/Bridge
+ *
+ * Author: Oliver Hartkopp <oliver.hartkopp@volkswagen.de>
+ * Copyright (c) 2011 Volkswagen Group Electronic Research
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+#ifndef _CAN_GW_H
+#define _CAN_GW_H
+
+#include <linux/types.h>
+#include <linux/can.h>
+
+struct rtcanmsg {
+ __u8 can_family;
+ __u8 gwtype;
+ __u16 flags;
+};
+
+/* 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_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_DELETED, /* number of deleted CAN frames (see max_hops param) */
+ CGW_LIM_HOPS, /* limit the number of hops of this specific rule */
+ CGW_MOD_UID, /* user defined identifier for modification updates */
+ __CGW_MAX
+};
+
+#define CGW_MAX (__CGW_MAX - 1)
+
+#define CGW_FLAGS_CAN_ECHO 0x01
+#define CGW_FLAGS_CAN_SRC_TSTAMP 0x02
+#define CGW_FLAGS_CAN_IIF_TX_OK 0x04
+
+#define CGW_MOD_FUNCS 4 /* AND OR XOR SET */
+
+/* CAN frame elements that are affected by curr. 3 CAN frame modifications */
+#define CGW_MOD_ID 0x01
+#define CGW_MOD_DLC 0x02
+#define CGW_MOD_DATA 0x04
+
+#define CGW_FRAME_MODS 3 /* ID DLC DATA */
+
+#define MAX_MODFUNCTIONS (CGW_MOD_FUNCS * CGW_FRAME_MODS)
+
+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_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
+ *
+ * CGW_MOD_(AND|OR|XOR|SET) (length 17 bytes):
+ * Specifies a modification that's done to a received CAN frame before it is
+ * send out to the destination interface.
+ *
+ * <struct can_frame> data used as operator
+ * <u8> affected CAN frame elements
+ *
+ * CGW_LIM_HOPS (length 1 byte):
+ * Limit the number of hops of this specific rule. Usually the received CAN
+ * frame can be processed as much as 'max_hops' times (which is given at module
+ * load time of the can-gw module). This value is used to reduce the number of
+ * possible hops for this gateway rule to a value smaller then max_hops.
+ *
+ * CGW_MOD_UID (length 4 bytes):
+ * Optional non-zero user defined routing job identifier to alter existing
+ * modification settings at runtime.
+ *
+ * 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 /* !_UAPI_CAN_GW_H */
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