qemu

can_core.c (5214B)

---

 /*
  * CAN common CAN bus emulation support
  *
  * Copyright (c) 2013-2014 Jin Yang
  * Copyright (c) 2014-2018 Pavel Pisa
  *
  * Initial development supported by Google GSoC 2013 from RTEMS project slot
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 
 #include "qemu/osdep.h"
 #include "chardev/char.h"
 #include "qemu/module.h"
 #include "qemu/sockets.h"
 #include "qapi/error.h"
 #include "net/can_emu.h"
 #include "qom/object_interfaces.h"
 
 /* CAN DLC to real data length conversion helpers */
 
 static const uint8_t dlc2len[] = {
     0, 1, 2, 3, 4, 5, 6, 7,
     8, 12, 16, 20, 24, 32, 48, 64
 };
 
 /* get data length from can_dlc with sanitized can_dlc */
 uint8_t can_dlc2len(uint8_t can_dlc)
 {
     return dlc2len[can_dlc & 0x0F];
 }
 
 static const uint8_t len2dlc[] = {
     0, 1, 2, 3, 4, 5, 6, 7, 8,                              /* 0 - 8 */
     9, 9, 9, 9,                                             /* 9 - 12 */
     10, 10, 10, 10,                                         /* 13 - 16 */
     11, 11, 11, 11,                                         /* 17 - 20 */
     12, 12, 12, 12,                                         /* 21 - 24 */
     13, 13, 13, 13, 13, 13, 13, 13,                         /* 25 - 32 */
     14, 14, 14, 14, 14, 14, 14, 14,                         /* 33 - 40 */
     14, 14, 14, 14, 14, 14, 14, 14,                         /* 41 - 48 */
     15, 15, 15, 15, 15, 15, 15, 15,                         /* 49 - 56 */
     15, 15, 15, 15, 15, 15, 15, 15                          /* 57 - 64 */
 };
 
 /* map the sanitized data length to an appropriate data length code */
 uint8_t can_len2dlc(uint8_t len)
 {
     if (unlikely(len > 64)) {
         return 0xF;
     }
 
     return len2dlc[len];
 }
 
 struct CanBusState {
     Object object;
 
     QTAILQ_HEAD(, CanBusClientState) clients;
 };
 
 static void can_bus_instance_init(Object *object)
 {
     CanBusState *bus = (CanBusState *)object;
 
     QTAILQ_INIT(&bus->clients);
 }
 
 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client)
 {
     client->bus = bus;
     QTAILQ_INSERT_TAIL(&bus->clients, client, next);
     return 0;
 }
 
 int can_bus_remove_client(CanBusClientState *client)
 {
     CanBusState *bus = client->bus;
     if (bus == NULL) {
         return 0;
     }
 
     QTAILQ_REMOVE(&bus->clients, client, next);
     client->bus = NULL;
     return 1;
 }
 
 ssize_t can_bus_client_send(CanBusClientState *client,
              const struct qemu_can_frame *frames, size_t frames_cnt)
 {
     int ret = 0;
     CanBusState *bus = client->bus;
     CanBusClientState *peer;
     if (bus == NULL) {
         return -1;
     }
 
     QTAILQ_FOREACH(peer, &bus->clients, next) {
         if (peer->info->can_receive(peer)) {
             if (peer == client) {
                 /* No loopback support for now */
                 continue;
             }
             if (peer->info->receive(peer, frames, frames_cnt) > 0) {
                 ret = 1;
             }
         }
     }
 
     return ret;
 }
 
 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id)
 {
     int m;
     if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) {
         return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0;
     }
     m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask);
     return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m;
 }
 
 int can_bus_client_set_filters(CanBusClientState *client,
              const struct qemu_can_filter *filters, size_t filters_cnt)
 {
     return 0;
 }
 
 
 static bool can_bus_can_be_deleted(UserCreatable *uc)
 {
     return false;
 }
 
 static void can_bus_class_init(ObjectClass *klass,
                                 void *class_data G_GNUC_UNUSED)
 {
     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
 
     uc_klass->can_be_deleted = can_bus_can_be_deleted;
 }
 
 static const TypeInfo can_bus_info = {
     .parent = TYPE_OBJECT,
     .name = TYPE_CAN_BUS,
     .instance_size = sizeof(CanBusState),
     .instance_init = can_bus_instance_init,
     .class_init = can_bus_class_init,
     .interfaces = (InterfaceInfo[]) {
         { TYPE_USER_CREATABLE },
         { }
     }
 };
 
 static void can_bus_register_types(void)
 {
     type_register_static(&can_bus_info);
 }
 
 type_init(can_bus_register_types);