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 #include "qemu/osdep.h"
  28 #include "chardev/char.h"
  29 #include "qemu/sockets.h"
  30 #include "qapi/error.h"
  31 #include "net/can_emu.h"
  32 #include "qom/object_interfaces.h"
  33
  34 struct CanBusState {
  35     Object object;
  36
  37     QTAILQ_HEAD(, CanBusClientState) clients;
  38 };
  39
  40 static void can_bus_instance_init(Object *object)
  41 {
  42     CanBusState *bus = (CanBusState *)object;
  43
  44     QTAILQ_INIT(&bus->clients);
  45 }
  46
  47 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client)
  48 {
  49     client->bus = bus;
  50     QTAILQ_INSERT_TAIL(&bus->clients, client, next);
  51     return 0;
  52 }
  53
  54 int can_bus_remove_client(CanBusClientState *client)
  55 {
  56     CanBusState *bus = client->bus;
  57     if (bus == NULL) {
  58         return 0;
  59     }
  60
  61     QTAILQ_REMOVE(&bus->clients, client, next);
  62     client->bus = NULL;
  63     return 1;
  64 }
  65
  66 ssize_t can_bus_client_send(CanBusClientState *client,
  67              const struct qemu_can_frame *frames, size_t frames_cnt)
  68 {
  69     int ret = 0;
  70     CanBusState *bus = client->bus;
  71     CanBusClientState *peer;
  72     if (bus == NULL) {
  73         return -1;
  74     }
  75
  76     QTAILQ_FOREACH(peer, &bus->clients, next) {
  77         if (peer->info->can_receive(peer)) {
  78             if (peer == client) {
  79                 /* No loopback support for now */
  80                 continue;
  81             }
  82             if (peer->info->receive(peer, frames, frames_cnt) > 0) {
  83                 ret = 1;
  84             }
  85         }
  86     }
  87
  88     return ret;
  89 }
  90
  91 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id)
  92 {
  93     int m;
  94     if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) {
  95         return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0;
  96     }
  97     m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask);
  98     return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m;
  99 }
 100
 101 int can_bus_client_set_filters(CanBusClientState *client,
 102              const struct qemu_can_filter *filters, size_t filters_cnt)
 103 {
 104     return 0;
 105 }
 106
 107
 108 static bool can_bus_can_be_deleted(UserCreatable *uc)
 109 {
 110     return false;
 111 }
 112
 113 static void can_bus_class_init(ObjectClass *klass,
 114                                 void *class_data G_GNUC_UNUSED)
 115 {
 116     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
 117
 118     uc_klass->can_be_deleted = can_bus_can_be_deleted;
 119 }
 120
 121 static const TypeInfo can_bus_info = {
 122     .parent = TYPE_OBJECT,
 123     .name = TYPE_CAN_BUS,
 124     .instance_size = sizeof(CanBusState),
 125     .instance_init = can_bus_instance_init,
 126     .class_init = can_bus_class_init,
 127     .interfaces = (InterfaceInfo[]) {
 128         { TYPE_USER_CREATABLE },
 129         { }
 130     }
 131 };
 132
 133 static void can_bus_register_types(void)
 134 {
 135     type_register_static(&can_bus_info);
 136 }
 137
 138 type_init(can_bus_register_types);