net/can/can_core.c

   1 /*
   2  * CAN common CAN bus emulation support
   3  *
   4  * Copyright (c) 2013-2014 Jin Yang
   5  * Copyright (c) 2014-2018 Pavel Pisa
   6  *
   7  * Initial development supported by Google GSoC 2013 from RTEMS project slot
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25  * THE SOFTWARE.
  26  */
  27
  28 #include "qemu/osdep.h"
  29 #include "chardev/char.h"
  30 #include "qemu/module.h"
  31 #include "qemu/sockets.h"
  32 #include "qapi/error.h"
  33 #include "net/can_emu.h"
  34 #include "qom/object_interfaces.h"
  35
  36 /* CAN DLC to real data length conversion helpers */
  37
  38 static const uint8_t dlc2len[] = {
  39     0, 1, 2, 3, 4, 5, 6, 7,
  40     8, 12, 16, 20, 24, 32, 48, 64
  41 };
  42
  43 /* get data length from can_dlc with sanitized can_dlc */
  44 uint8_t can_dlc2len(uint8_t can_dlc)
  45 {
  46     return dlc2len[can_dlc & 0x0F];
  47 }
  48
  49 static const uint8_t len2dlc[] = {
  50     0, 1, 2, 3, 4, 5, 6, 7, 8,                              /* 0 - 8 */
  51     9, 9, 9, 9,                                             /* 9 - 12 */
  52     10, 10, 10, 10,                                         /* 13 - 16 */
  53     11, 11, 11, 11,                                         /* 17 - 20 */
  54     12, 12, 12, 12,                                         /* 21 - 24 */
  55     13, 13, 13, 13, 13, 13, 13, 13,                         /* 25 - 32 */
  56     14, 14, 14, 14, 14, 14, 14, 14,                         /* 33 - 40 */
  57     14, 14, 14, 14, 14, 14, 14, 14,                         /* 41 - 48 */
  58     15, 15, 15, 15, 15, 15, 15, 15,                         /* 49 - 56 */
  59     15, 15, 15, 15, 15, 15, 15, 15                          /* 57 - 64 */
  60 };
  61
  62 /* map the sanitized data length to an appropriate data length code */
  63 uint8_t can_len2dlc(uint8_t len)
  64 {
  65     if (unlikely(len > 64)) {
  66         return 0xF;
  67     }
  68
  69     return len2dlc[len];
  70 }
  71
  72 struct CanBusState {
  73     Object object;
  74
  75     QTAILQ_HEAD(, CanBusClientState) clients;
  76 };
  77
  78 static void can_bus_instance_init(Object *object)
  79 {
  80     CanBusState *bus = (CanBusState *)object;
  81
  82     QTAILQ_INIT(&bus->clients);
  83 }
  84
  85 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client)
  86 {
  87     client->bus = bus;
  88     QTAILQ_INSERT_TAIL(&bus->clients, client, next);
  89     return 0;
  90 }
  91
  92 int can_bus_remove_client(CanBusClientState *client)
  93 {
  94     CanBusState *bus = client->bus;
  95     if (bus == NULL) {
  96         return 0;
  97     }
  98
  99     QTAILQ_REMOVE(&bus->clients, client, next);
 100     client->bus = NULL;
 101     return 1;
 102 }
 103
 104 ssize_t can_bus_client_send(CanBusClientState *client,
 105              const struct qemu_can_frame *frames, size_t frames_cnt)
 106 {
 107     int ret = 0;
 108     CanBusState *bus = client->bus;
 109     CanBusClientState *peer;
 110     if (bus == NULL) {
 111         return -1;
 112     }
 113
 114     QTAILQ_FOREACH(peer, &bus->clients, next) {
 115         if (peer->info->can_receive(peer)) {
 116             if (peer == client) {
 117                 /* No loopback support for now */
 118                 continue;
 119             }
 120             if (peer->info->receive(peer, frames, frames_cnt) > 0) {
 121                 ret = 1;
 122             }
 123         }
 124     }
 125
 126     return ret;
 127 }
 128
 129 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id)
 130 {
 131     int m;
 132     if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) {
 133         return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0;
 134     }
 135     m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask);
 136     return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m;
 137 }
 138
 139 int can_bus_client_set_filters(CanBusClientState *client,
 140              const struct qemu_can_filter *filters, size_t filters_cnt)
 141 {
 142     return 0;
 143 }
 144
 145
 146 static bool can_bus_can_be_deleted(UserCreatable *uc)
 147 {
 148     return false;
 149 }
 150
 151 static void can_bus_class_init(ObjectClass *klass,
 152                                 void *class_data G_GNUC_UNUSED)
 153 {
 154     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
 155
 156     uc_klass->can_be_deleted = can_bus_can_be_deleted;
 157 }
 158
 159 static const TypeInfo can_bus_info = {
 160     .parent = TYPE_OBJECT,
 161     .name = TYPE_CAN_BUS,
 162     .instance_size = sizeof(CanBusState),
 163     .instance_init = can_bus_instance_init,
 164     .class_init = can_bus_class_init,
 165     .interfaces = (InterfaceInfo[]) {
 166         { TYPE_USER_CREATABLE },
 167         { }
 168     }
 169 };
 170
 171 static void can_bus_register_types(void)
 172 {
 173     type_register_static(&can_bus_info);
 174 }
 175
 176 type_init(can_bus_register_types);