1 | /* SPDX-License-Identifier: ((GPL-2.0-only WITH Linux-syscall-note) OR BSD-3-Clause) */ |
2 | /* |
3 | * linux/can/gw.h |
4 | * |
5 | * Definitions for CAN frame Gateway/Router/Bridge |
6 | * |
7 | * Author: Oliver Hartkopp <oliver.hartkopp@volkswagen.de> |
8 | * Copyright (c) 2011 Volkswagen Group Electronic Research |
9 | * All rights reserved. |
10 | * |
11 | * Redistribution and use in source and binary forms, with or without |
12 | * modification, are permitted provided that the following conditions |
13 | * are met: |
14 | * 1. Redistributions of source code must retain the above copyright |
15 | * notice, this list of conditions and the following disclaimer. |
16 | * 2. Redistributions in binary form must reproduce the above copyright |
17 | * notice, this list of conditions and the following disclaimer in the |
18 | * documentation and/or other materials provided with the distribution. |
19 | * 3. Neither the name of Volkswagen nor the names of its contributors |
20 | * may be used to endorse or promote products derived from this software |
21 | * without specific prior written permission. |
22 | * |
23 | * Alternatively, provided that this notice is retained in full, this |
24 | * software may be distributed under the terms of the GNU General |
25 | * Public License ("GPL") version 2, in which case the provisions of the |
26 | * GPL apply INSTEAD OF those given above. |
27 | * |
28 | * The provided data structures and external interfaces from this code |
29 | * are not restricted to be used by modules with a GPL compatible license. |
30 | * |
31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
35 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
36 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
37 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
38 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
39 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
40 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
41 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
42 | * DAMAGE. |
43 | */ |
44 | |
45 | #ifndef _UAPI_CAN_GW_H |
46 | #define _UAPI_CAN_GW_H |
47 | |
48 | #include <linux/types.h> |
49 | #include <linux/can.h> |
50 | |
51 | struct rtcanmsg { |
52 | __u8 can_family; |
53 | __u8 gwtype; |
54 | __u16 flags; |
55 | }; |
56 | |
57 | /* CAN gateway types */ |
58 | enum { |
59 | CGW_TYPE_UNSPEC, |
60 | CGW_TYPE_CAN_CAN, /* CAN->CAN routing */ |
61 | __CGW_TYPE_MAX |
62 | }; |
63 | |
64 | #define CGW_TYPE_MAX (__CGW_TYPE_MAX - 1) |
65 | |
66 | /* CAN rtnetlink attribute definitions */ |
67 | enum { |
68 | CGW_UNSPEC, |
69 | CGW_MOD_AND, /* CAN frame modification binary AND */ |
70 | CGW_MOD_OR, /* CAN frame modification binary OR */ |
71 | CGW_MOD_XOR, /* CAN frame modification binary XOR */ |
72 | CGW_MOD_SET, /* CAN frame modification set alternate values */ |
73 | CGW_CS_XOR, /* set data[] XOR checksum into data[index] */ |
74 | CGW_CS_CRC8, /* set data[] CRC8 checksum into data[index] */ |
75 | CGW_HANDLED, /* number of handled CAN frames */ |
76 | CGW_DROPPED, /* number of dropped CAN frames */ |
77 | CGW_SRC_IF, /* ifindex of source network interface */ |
78 | CGW_DST_IF, /* ifindex of destination network interface */ |
79 | CGW_FILTER, /* specify struct can_filter on source CAN device */ |
80 | CGW_DELETED, /* number of deleted CAN frames (see max_hops param) */ |
81 | CGW_LIM_HOPS, /* limit the number of hops of this specific rule */ |
82 | CGW_MOD_UID, /* user defined identifier for modification updates */ |
83 | CGW_FDMOD_AND, /* CAN FD frame modification binary AND */ |
84 | CGW_FDMOD_OR, /* CAN FD frame modification binary OR */ |
85 | CGW_FDMOD_XOR, /* CAN FD frame modification binary XOR */ |
86 | CGW_FDMOD_SET, /* CAN FD frame modification set alternate values */ |
87 | __CGW_MAX |
88 | }; |
89 | |
90 | #define CGW_MAX (__CGW_MAX - 1) |
91 | |
92 | #define CGW_FLAGS_CAN_ECHO 0x01 |
93 | #define CGW_FLAGS_CAN_SRC_TSTAMP 0x02 |
94 | #define CGW_FLAGS_CAN_IIF_TX_OK 0x04 |
95 | #define CGW_FLAGS_CAN_FD 0x08 |
96 | |
97 | #define CGW_MOD_FUNCS 4 /* AND OR XOR SET */ |
98 | |
99 | /* CAN frame elements that are affected by curr. 3 CAN frame modifications */ |
100 | #define CGW_MOD_ID 0x01 |
101 | #define CGW_MOD_DLC 0x02 /* Classical CAN data length code */ |
102 | #define CGW_MOD_LEN CGW_MOD_DLC /* CAN FD (plain) data length */ |
103 | #define CGW_MOD_DATA 0x04 |
104 | #define CGW_MOD_FLAGS 0x08 /* CAN FD flags */ |
105 | |
106 | #define CGW_FRAME_MODS 4 /* ID DLC/LEN DATA FLAGS */ |
107 | |
108 | #define MAX_MODFUNCTIONS (CGW_MOD_FUNCS * CGW_FRAME_MODS) |
109 | |
110 | struct cgw_frame_mod { |
111 | struct can_frame cf; |
112 | __u8 modtype; |
113 | } __attribute__((packed)); |
114 | |
115 | struct cgw_fdframe_mod { |
116 | struct canfd_frame cf; |
117 | __u8 modtype; |
118 | } __attribute__((packed)); |
119 | |
120 | #define CGW_MODATTR_LEN sizeof(struct cgw_frame_mod) |
121 | #define CGW_FDMODATTR_LEN sizeof(struct cgw_fdframe_mod) |
122 | |
123 | struct cgw_csum_xor { |
124 | __s8 from_idx; |
125 | __s8 to_idx; |
126 | __s8 result_idx; |
127 | __u8 init_xor_val; |
128 | } __attribute__((packed)); |
129 | |
130 | struct cgw_csum_crc8 { |
131 | __s8 from_idx; |
132 | __s8 to_idx; |
133 | __s8 result_idx; |
134 | __u8 init_crc_val; |
135 | __u8 final_xor_val; |
136 | __u8 crctab[256]; |
137 | __u8 profile; |
138 | __u8 profile_data[20]; |
139 | } __attribute__((packed)); |
140 | |
141 | /* length of checksum operation parameters. idx = index in CAN frame data[] */ |
142 | #define CGW_CS_XOR_LEN sizeof(struct cgw_csum_xor) |
143 | #define CGW_CS_CRC8_LEN sizeof(struct cgw_csum_crc8) |
144 | |
145 | /* CRC8 profiles (compute CRC for additional data elements - see below) */ |
146 | enum { |
147 | CGW_CRC8PRF_UNSPEC, |
148 | CGW_CRC8PRF_1U8, /* compute one additional u8 value */ |
149 | CGW_CRC8PRF_16U8, /* u8 value table indexed by data[1] & 0xF */ |
150 | CGW_CRC8PRF_SFFID_XOR, /* (can_id & 0xFF) ^ (can_id >> 8 & 0xFF) */ |
151 | __CGW_CRC8PRF_MAX |
152 | }; |
153 | |
154 | #define CGW_CRC8PRF_MAX (__CGW_CRC8PRF_MAX - 1) |
155 | |
156 | /* |
157 | * CAN rtnetlink attribute contents in detail |
158 | * |
159 | * CGW_XXX_IF (length 4 bytes): |
160 | * Sets an interface index for source/destination network interfaces. |
161 | * For the CAN->CAN gwtype the indices of _two_ CAN interfaces are mandatory. |
162 | * |
163 | * CGW_FILTER (length 8 bytes): |
164 | * Sets a CAN receive filter for the gateway job specified by the |
165 | * struct can_filter described in include/linux/can.h |
166 | * |
167 | * CGW_MOD_(AND|OR|XOR|SET) (length 17 bytes): |
168 | * Specifies a modification that's done to a received CAN frame before it is |
169 | * send out to the destination interface. |
170 | * |
171 | * <struct can_frame> data used as operator |
172 | * <u8> affected CAN frame elements |
173 | * |
174 | * CGW_LIM_HOPS (length 1 byte): |
175 | * Limit the number of hops of this specific rule. Usually the received CAN |
176 | * frame can be processed as much as 'max_hops' times (which is given at module |
177 | * load time of the can-gw module). This value is used to reduce the number of |
178 | * possible hops for this gateway rule to a value smaller then max_hops. |
179 | * |
180 | * CGW_MOD_UID (length 4 bytes): |
181 | * Optional non-zero user defined routing job identifier to alter existing |
182 | * modification settings at runtime. |
183 | * |
184 | * CGW_CS_XOR (length 4 bytes): |
185 | * Set a simple XOR checksum starting with an initial value into |
186 | * data[result-idx] using data[start-idx] .. data[end-idx] |
187 | * |
188 | * The XOR checksum is calculated like this: |
189 | * |
190 | * xor = init_xor_val |
191 | * |
192 | * for (i = from_idx .. to_idx) |
193 | * xor ^= can_frame.data[i] |
194 | * |
195 | * can_frame.data[ result_idx ] = xor |
196 | * |
197 | * CGW_CS_CRC8 (length 282 bytes): |
198 | * Set a CRC8 value into data[result-idx] using a given 256 byte CRC8 table, |
199 | * a given initial value and a defined input data[start-idx] .. data[end-idx]. |
200 | * Finally the result value is XOR'ed with the final_xor_val. |
201 | * |
202 | * The CRC8 checksum is calculated like this: |
203 | * |
204 | * crc = init_crc_val |
205 | * |
206 | * for (i = from_idx .. to_idx) |
207 | * crc = crctab[ crc ^ can_frame.data[i] ] |
208 | * |
209 | * can_frame.data[ result_idx ] = crc ^ final_xor_val |
210 | * |
211 | * The calculated CRC may contain additional source data elements that can be |
212 | * defined in the handling of 'checksum profiles' e.g. shown in AUTOSAR specs |
213 | * like http://www.autosar.org/download/R4.0/AUTOSAR_SWS_E2ELibrary.pdf |
214 | * E.g. the profile_data[] may contain additional u8 values (called DATA_IDs) |
215 | * that are used depending on counter values inside the CAN frame data[]. |
216 | * So far only three profiles have been implemented for illustration. |
217 | * |
218 | * Remark: In general the attribute data is a linear buffer. |
219 | * Beware of sending unpacked or aligned structs! |
220 | */ |
221 | |
222 | #endif /* !_UAPI_CAN_GW_H */ |
223 | |